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7afe21cc | 1 | /* Common subexpression elimination for GNU compiler. |
c85f7c16 | 2 | Copyright (C) 1987, 88, 89, 92-7, 1998 Free Software Foundation, Inc. |
7afe21cc RK |
3 | |
4 | This file is part of GNU CC. | |
5 | ||
6 | GNU CC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU CC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU CC; see the file COPYING. If not, write to | |
940d9d63 RK |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, |
19 | Boston, MA 02111-1307, USA. */ | |
7afe21cc RK |
20 | |
21 | ||
22 | #include "config.h" | |
670ee920 KG |
23 | /* stdio.h must precede rtl.h for FFS. */ |
24 | #include "system.h" | |
50b2596f | 25 | #include <setjmp.h> |
9c3b4c8b | 26 | |
7afe21cc RK |
27 | #include "rtl.h" |
28 | #include "regs.h" | |
29 | #include "hard-reg-set.h" | |
30 | #include "flags.h" | |
31 | #include "real.h" | |
32 | #include "insn-config.h" | |
33 | #include "recog.h" | |
956d6950 | 34 | #include "expr.h" |
50b2596f KG |
35 | #include "toplev.h" |
36 | #include "output.h" | |
7afe21cc RK |
37 | |
38 | /* The basic idea of common subexpression elimination is to go | |
39 | through the code, keeping a record of expressions that would | |
40 | have the same value at the current scan point, and replacing | |
41 | expressions encountered with the cheapest equivalent expression. | |
42 | ||
43 | It is too complicated to keep track of the different possibilities | |
44 | when control paths merge; so, at each label, we forget all that is | |
45 | known and start fresh. This can be described as processing each | |
46 | basic block separately. Note, however, that these are not quite | |
47 | the same as the basic blocks found by a later pass and used for | |
48 | data flow analysis and register packing. We do not need to start fresh | |
49 | after a conditional jump instruction if there is no label there. | |
50 | ||
51 | We use two data structures to record the equivalent expressions: | |
52 | a hash table for most expressions, and several vectors together | |
53 | with "quantity numbers" to record equivalent (pseudo) registers. | |
54 | ||
55 | The use of the special data structure for registers is desirable | |
56 | because it is faster. It is possible because registers references | |
57 | contain a fairly small number, the register number, taken from | |
58 | a contiguously allocated series, and two register references are | |
59 | identical if they have the same number. General expressions | |
60 | do not have any such thing, so the only way to retrieve the | |
61 | information recorded on an expression other than a register | |
62 | is to keep it in a hash table. | |
63 | ||
64 | Registers and "quantity numbers": | |
65 | ||
66 | At the start of each basic block, all of the (hardware and pseudo) | |
67 | registers used in the function are given distinct quantity | |
68 | numbers to indicate their contents. During scan, when the code | |
69 | copies one register into another, we copy the quantity number. | |
70 | When a register is loaded in any other way, we allocate a new | |
71 | quantity number to describe the value generated by this operation. | |
72 | `reg_qty' records what quantity a register is currently thought | |
73 | of as containing. | |
74 | ||
75 | All real quantity numbers are greater than or equal to `max_reg'. | |
76 | If register N has not been assigned a quantity, reg_qty[N] will equal N. | |
77 | ||
78 | Quantity numbers below `max_reg' do not exist and none of the `qty_...' | |
79 | variables should be referenced with an index below `max_reg'. | |
80 | ||
81 | We also maintain a bidirectional chain of registers for each | |
82 | quantity number. `qty_first_reg', `qty_last_reg', | |
83 | `reg_next_eqv' and `reg_prev_eqv' hold these chains. | |
84 | ||
85 | The first register in a chain is the one whose lifespan is least local. | |
86 | Among equals, it is the one that was seen first. | |
87 | We replace any equivalent register with that one. | |
88 | ||
89 | If two registers have the same quantity number, it must be true that | |
90 | REG expressions with `qty_mode' must be in the hash table for both | |
91 | registers and must be in the same class. | |
92 | ||
93 | The converse is not true. Since hard registers may be referenced in | |
94 | any mode, two REG expressions might be equivalent in the hash table | |
95 | but not have the same quantity number if the quantity number of one | |
96 | of the registers is not the same mode as those expressions. | |
97 | ||
98 | Constants and quantity numbers | |
99 | ||
100 | When a quantity has a known constant value, that value is stored | |
101 | in the appropriate element of qty_const. This is in addition to | |
102 | putting the constant in the hash table as is usual for non-regs. | |
103 | ||
d45cf215 | 104 | Whether a reg or a constant is preferred is determined by the configuration |
7afe21cc RK |
105 | macro CONST_COSTS and will often depend on the constant value. In any |
106 | event, expressions containing constants can be simplified, by fold_rtx. | |
107 | ||
108 | When a quantity has a known nearly constant value (such as an address | |
109 | of a stack slot), that value is stored in the appropriate element | |
110 | of qty_const. | |
111 | ||
112 | Integer constants don't have a machine mode. However, cse | |
113 | determines the intended machine mode from the destination | |
114 | of the instruction that moves the constant. The machine mode | |
115 | is recorded in the hash table along with the actual RTL | |
116 | constant expression so that different modes are kept separate. | |
117 | ||
118 | Other expressions: | |
119 | ||
120 | To record known equivalences among expressions in general | |
121 | we use a hash table called `table'. It has a fixed number of buckets | |
122 | that contain chains of `struct table_elt' elements for expressions. | |
123 | These chains connect the elements whose expressions have the same | |
124 | hash codes. | |
125 | ||
126 | Other chains through the same elements connect the elements which | |
127 | currently have equivalent values. | |
128 | ||
129 | Register references in an expression are canonicalized before hashing | |
130 | the expression. This is done using `reg_qty' and `qty_first_reg'. | |
131 | The hash code of a register reference is computed using the quantity | |
132 | number, not the register number. | |
133 | ||
134 | When the value of an expression changes, it is necessary to remove from the | |
135 | hash table not just that expression but all expressions whose values | |
136 | could be different as a result. | |
137 | ||
138 | 1. If the value changing is in memory, except in special cases | |
139 | ANYTHING referring to memory could be changed. That is because | |
140 | nobody knows where a pointer does not point. | |
141 | The function `invalidate_memory' removes what is necessary. | |
142 | ||
143 | The special cases are when the address is constant or is | |
144 | a constant plus a fixed register such as the frame pointer | |
145 | or a static chain pointer. When such addresses are stored in, | |
146 | we can tell exactly which other such addresses must be invalidated | |
147 | due to overlap. `invalidate' does this. | |
148 | All expressions that refer to non-constant | |
149 | memory addresses are also invalidated. `invalidate_memory' does this. | |
150 | ||
151 | 2. If the value changing is a register, all expressions | |
152 | containing references to that register, and only those, | |
153 | must be removed. | |
154 | ||
155 | Because searching the entire hash table for expressions that contain | |
156 | a register is very slow, we try to figure out when it isn't necessary. | |
157 | Precisely, this is necessary only when expressions have been | |
158 | entered in the hash table using this register, and then the value has | |
159 | changed, and then another expression wants to be added to refer to | |
160 | the register's new value. This sequence of circumstances is rare | |
161 | within any one basic block. | |
162 | ||
163 | The vectors `reg_tick' and `reg_in_table' are used to detect this case. | |
164 | reg_tick[i] is incremented whenever a value is stored in register i. | |
165 | reg_in_table[i] holds -1 if no references to register i have been | |
166 | entered in the table; otherwise, it contains the value reg_tick[i] had | |
167 | when the references were entered. If we want to enter a reference | |
168 | and reg_in_table[i] != reg_tick[i], we must scan and remove old references. | |
169 | Until we want to enter a new entry, the mere fact that the two vectors | |
170 | don't match makes the entries be ignored if anyone tries to match them. | |
171 | ||
172 | Registers themselves are entered in the hash table as well as in | |
173 | the equivalent-register chains. However, the vectors `reg_tick' | |
174 | and `reg_in_table' do not apply to expressions which are simple | |
175 | register references. These expressions are removed from the table | |
176 | immediately when they become invalid, and this can be done even if | |
177 | we do not immediately search for all the expressions that refer to | |
178 | the register. | |
179 | ||
180 | A CLOBBER rtx in an instruction invalidates its operand for further | |
181 | reuse. A CLOBBER or SET rtx whose operand is a MEM:BLK | |
182 | invalidates everything that resides in memory. | |
183 | ||
184 | Related expressions: | |
185 | ||
186 | Constant expressions that differ only by an additive integer | |
187 | are called related. When a constant expression is put in | |
188 | the table, the related expression with no constant term | |
189 | is also entered. These are made to point at each other | |
190 | so that it is possible to find out if there exists any | |
191 | register equivalent to an expression related to a given expression. */ | |
192 | ||
193 | /* One plus largest register number used in this function. */ | |
194 | ||
195 | static int max_reg; | |
196 | ||
556c714b JW |
197 | /* One plus largest instruction UID used in this function at time of |
198 | cse_main call. */ | |
199 | ||
200 | static int max_insn_uid; | |
201 | ||
7afe21cc RK |
202 | /* Length of vectors indexed by quantity number. |
203 | We know in advance we will not need a quantity number this big. */ | |
204 | ||
205 | static int max_qty; | |
206 | ||
207 | /* Next quantity number to be allocated. | |
208 | This is 1 + the largest number needed so far. */ | |
209 | ||
210 | static int next_qty; | |
211 | ||
71d306d1 | 212 | /* Indexed by quantity number, gives the first (or last) register |
7afe21cc RK |
213 | in the chain of registers that currently contain this quantity. */ |
214 | ||
215 | static int *qty_first_reg; | |
216 | static int *qty_last_reg; | |
217 | ||
218 | /* Index by quantity number, gives the mode of the quantity. */ | |
219 | ||
220 | static enum machine_mode *qty_mode; | |
221 | ||
222 | /* Indexed by quantity number, gives the rtx of the constant value of the | |
223 | quantity, or zero if it does not have a known value. | |
224 | A sum of the frame pointer (or arg pointer) plus a constant | |
225 | can also be entered here. */ | |
226 | ||
227 | static rtx *qty_const; | |
228 | ||
229 | /* Indexed by qty number, gives the insn that stored the constant value | |
230 | recorded in `qty_const'. */ | |
231 | ||
232 | static rtx *qty_const_insn; | |
233 | ||
234 | /* The next three variables are used to track when a comparison between a | |
235 | quantity and some constant or register has been passed. In that case, we | |
236 | know the results of the comparison in case we see it again. These variables | |
237 | record a comparison that is known to be true. */ | |
238 | ||
239 | /* Indexed by qty number, gives the rtx code of a comparison with a known | |
240 | result involving this quantity. If none, it is UNKNOWN. */ | |
241 | static enum rtx_code *qty_comparison_code; | |
242 | ||
243 | /* Indexed by qty number, gives the constant being compared against in a | |
244 | comparison of known result. If no such comparison, it is undefined. | |
245 | If the comparison is not with a constant, it is zero. */ | |
246 | ||
247 | static rtx *qty_comparison_const; | |
248 | ||
249 | /* Indexed by qty number, gives the quantity being compared against in a | |
250 | comparison of known result. If no such comparison, if it undefined. | |
251 | If the comparison is not with a register, it is -1. */ | |
252 | ||
253 | static int *qty_comparison_qty; | |
254 | ||
255 | #ifdef HAVE_cc0 | |
256 | /* For machines that have a CC0, we do not record its value in the hash | |
257 | table since its use is guaranteed to be the insn immediately following | |
258 | its definition and any other insn is presumed to invalidate it. | |
259 | ||
260 | Instead, we store below the value last assigned to CC0. If it should | |
261 | happen to be a constant, it is stored in preference to the actual | |
262 | assigned value. In case it is a constant, we store the mode in which | |
263 | the constant should be interpreted. */ | |
264 | ||
265 | static rtx prev_insn_cc0; | |
266 | static enum machine_mode prev_insn_cc0_mode; | |
267 | #endif | |
268 | ||
269 | /* Previous actual insn. 0 if at first insn of basic block. */ | |
270 | ||
271 | static rtx prev_insn; | |
272 | ||
273 | /* Insn being scanned. */ | |
274 | ||
275 | static rtx this_insn; | |
276 | ||
71d306d1 | 277 | /* Index by register number, gives the quantity number |
7afe21cc RK |
278 | of the register's current contents. */ |
279 | ||
280 | static int *reg_qty; | |
281 | ||
71d306d1 DE |
282 | /* Index by register number, gives the number of the next (or |
283 | previous) register in the chain of registers sharing the same | |
7afe21cc RK |
284 | value. |
285 | ||
286 | Or -1 if this register is at the end of the chain. | |
287 | ||
288 | If reg_qty[N] == N, reg_next_eqv[N] is undefined. */ | |
289 | ||
290 | static int *reg_next_eqv; | |
291 | static int *reg_prev_eqv; | |
292 | ||
71d306d1 | 293 | /* Index by register number, gives the number of times |
7afe21cc RK |
294 | that register has been altered in the current basic block. */ |
295 | ||
296 | static int *reg_tick; | |
297 | ||
71d306d1 | 298 | /* Index by register number, gives the reg_tick value at which |
7afe21cc RK |
299 | rtx's containing this register are valid in the hash table. |
300 | If this does not equal the current reg_tick value, such expressions | |
301 | existing in the hash table are invalid. | |
302 | If this is -1, no expressions containing this register have been | |
303 | entered in the table. */ | |
304 | ||
305 | static int *reg_in_table; | |
306 | ||
307 | /* A HARD_REG_SET containing all the hard registers for which there is | |
308 | currently a REG expression in the hash table. Note the difference | |
309 | from the above variables, which indicate if the REG is mentioned in some | |
310 | expression in the table. */ | |
311 | ||
312 | static HARD_REG_SET hard_regs_in_table; | |
313 | ||
314 | /* A HARD_REG_SET containing all the hard registers that are invalidated | |
315 | by a CALL_INSN. */ | |
316 | ||
317 | static HARD_REG_SET regs_invalidated_by_call; | |
318 | ||
319 | /* Two vectors of ints: | |
320 | one containing max_reg -1's; the other max_reg + 500 (an approximation | |
321 | for max_qty) elements where element i contains i. | |
322 | These are used to initialize various other vectors fast. */ | |
323 | ||
324 | static int *all_minus_one; | |
325 | static int *consec_ints; | |
326 | ||
327 | /* CUID of insn that starts the basic block currently being cse-processed. */ | |
328 | ||
329 | static int cse_basic_block_start; | |
330 | ||
331 | /* CUID of insn that ends the basic block currently being cse-processed. */ | |
332 | ||
333 | static int cse_basic_block_end; | |
334 | ||
335 | /* Vector mapping INSN_UIDs to cuids. | |
d45cf215 | 336 | The cuids are like uids but increase monotonically always. |
7afe21cc RK |
337 | We use them to see whether a reg is used outside a given basic block. */ |
338 | ||
906c4e36 | 339 | static int *uid_cuid; |
7afe21cc | 340 | |
164c8956 RK |
341 | /* Highest UID in UID_CUID. */ |
342 | static int max_uid; | |
343 | ||
7afe21cc RK |
344 | /* Get the cuid of an insn. */ |
345 | ||
346 | #define INSN_CUID(INSN) (uid_cuid[INSN_UID (INSN)]) | |
347 | ||
348 | /* Nonzero if cse has altered conditional jump insns | |
349 | in such a way that jump optimization should be redone. */ | |
350 | ||
351 | static int cse_jumps_altered; | |
352 | ||
a5dfb4ee RK |
353 | /* Nonzero if we put a LABEL_REF into the hash table. Since we may have put |
354 | it into an INSN without a REG_LABEL, we have to rerun jump after CSE | |
355 | to put in the note. */ | |
356 | static int recorded_label_ref; | |
357 | ||
7afe21cc RK |
358 | /* canon_hash stores 1 in do_not_record |
359 | if it notices a reference to CC0, PC, or some other volatile | |
360 | subexpression. */ | |
361 | ||
362 | static int do_not_record; | |
363 | ||
7bac1be0 RK |
364 | #ifdef LOAD_EXTEND_OP |
365 | ||
366 | /* Scratch rtl used when looking for load-extended copy of a MEM. */ | |
367 | static rtx memory_extend_rtx; | |
368 | #endif | |
369 | ||
7afe21cc RK |
370 | /* canon_hash stores 1 in hash_arg_in_memory |
371 | if it notices a reference to memory within the expression being hashed. */ | |
372 | ||
373 | static int hash_arg_in_memory; | |
374 | ||
375 | /* canon_hash stores 1 in hash_arg_in_struct | |
376 | if it notices a reference to memory that's part of a structure. */ | |
377 | ||
378 | static int hash_arg_in_struct; | |
379 | ||
380 | /* The hash table contains buckets which are chains of `struct table_elt's, | |
381 | each recording one expression's information. | |
382 | That expression is in the `exp' field. | |
383 | ||
384 | Those elements with the same hash code are chained in both directions | |
385 | through the `next_same_hash' and `prev_same_hash' fields. | |
386 | ||
387 | Each set of expressions with equivalent values | |
388 | are on a two-way chain through the `next_same_value' | |
389 | and `prev_same_value' fields, and all point with | |
390 | the `first_same_value' field at the first element in | |
391 | that chain. The chain is in order of increasing cost. | |
392 | Each element's cost value is in its `cost' field. | |
393 | ||
394 | The `in_memory' field is nonzero for elements that | |
395 | involve any reference to memory. These elements are removed | |
396 | whenever a write is done to an unidentified location in memory. | |
397 | To be safe, we assume that a memory address is unidentified unless | |
398 | the address is either a symbol constant or a constant plus | |
399 | the frame pointer or argument pointer. | |
400 | ||
401 | The `in_struct' field is nonzero for elements that | |
402 | involve any reference to memory inside a structure or array. | |
403 | ||
404 | The `related_value' field is used to connect related expressions | |
405 | (that differ by adding an integer). | |
406 | The related expressions are chained in a circular fashion. | |
407 | `related_value' is zero for expressions for which this | |
408 | chain is not useful. | |
409 | ||
410 | The `cost' field stores the cost of this element's expression. | |
411 | ||
412 | The `is_const' flag is set if the element is a constant (including | |
413 | a fixed address). | |
414 | ||
415 | The `flag' field is used as a temporary during some search routines. | |
416 | ||
417 | The `mode' field is usually the same as GET_MODE (`exp'), but | |
418 | if `exp' is a CONST_INT and has no machine mode then the `mode' | |
419 | field is the mode it was being used as. Each constant is | |
420 | recorded separately for each mode it is used with. */ | |
421 | ||
422 | ||
423 | struct table_elt | |
424 | { | |
425 | rtx exp; | |
426 | struct table_elt *next_same_hash; | |
427 | struct table_elt *prev_same_hash; | |
428 | struct table_elt *next_same_value; | |
429 | struct table_elt *prev_same_value; | |
430 | struct table_elt *first_same_value; | |
431 | struct table_elt *related_value; | |
432 | int cost; | |
433 | enum machine_mode mode; | |
434 | char in_memory; | |
435 | char in_struct; | |
436 | char is_const; | |
437 | char flag; | |
438 | }; | |
439 | ||
7afe21cc RK |
440 | /* We don't want a lot of buckets, because we rarely have very many |
441 | things stored in the hash table, and a lot of buckets slows | |
442 | down a lot of loops that happen frequently. */ | |
443 | #define NBUCKETS 31 | |
444 | ||
445 | /* Compute hash code of X in mode M. Special-case case where X is a pseudo | |
446 | register (hard registers may require `do_not_record' to be set). */ | |
447 | ||
448 | #define HASH(X, M) \ | |
449 | (GET_CODE (X) == REG && REGNO (X) >= FIRST_PSEUDO_REGISTER \ | |
2197a88a | 450 | ? (((unsigned) REG << 7) + (unsigned) reg_qty[REGNO (X)]) % NBUCKETS \ |
7afe21cc RK |
451 | : canon_hash (X, M) % NBUCKETS) |
452 | ||
453 | /* Determine whether register number N is considered a fixed register for CSE. | |
454 | It is desirable to replace other regs with fixed regs, to reduce need for | |
455 | non-fixed hard regs. | |
456 | A reg wins if it is either the frame pointer or designated as fixed, | |
457 | but not if it is an overlapping register. */ | |
458 | #ifdef OVERLAPPING_REGNO_P | |
459 | #define FIXED_REGNO_P(N) \ | |
8bc169f2 | 460 | (((N) == FRAME_POINTER_REGNUM || (N) == HARD_FRAME_POINTER_REGNUM \ |
6ab832bc | 461 | || fixed_regs[N] || global_regs[N]) \ |
7afe21cc RK |
462 | && ! OVERLAPPING_REGNO_P ((N))) |
463 | #else | |
464 | #define FIXED_REGNO_P(N) \ | |
8bc169f2 | 465 | ((N) == FRAME_POINTER_REGNUM || (N) == HARD_FRAME_POINTER_REGNUM \ |
6ab832bc | 466 | || fixed_regs[N] || global_regs[N]) |
7afe21cc RK |
467 | #endif |
468 | ||
469 | /* Compute cost of X, as stored in the `cost' field of a table_elt. Fixed | |
ac07e066 RK |
470 | hard registers and pointers into the frame are the cheapest with a cost |
471 | of 0. Next come pseudos with a cost of one and other hard registers with | |
472 | a cost of 2. Aside from these special cases, call `rtx_cost'. */ | |
473 | ||
6ab832bc | 474 | #define CHEAP_REGNO(N) \ |
8bc169f2 DE |
475 | ((N) == FRAME_POINTER_REGNUM || (N) == HARD_FRAME_POINTER_REGNUM \ |
476 | || (N) == STACK_POINTER_REGNUM || (N) == ARG_POINTER_REGNUM \ | |
477 | || ((N) >= FIRST_VIRTUAL_REGISTER && (N) <= LAST_VIRTUAL_REGISTER) \ | |
478 | || ((N) < FIRST_PSEUDO_REGISTER \ | |
e7bb59fa | 479 | && FIXED_REGNO_P (N) && REGNO_REG_CLASS (N) != NO_REGS)) |
7afe21cc | 480 | |
6ab832bc RK |
481 | /* A register is cheap if it is a user variable assigned to the register |
482 | or if its register number always corresponds to a cheap register. */ | |
483 | ||
484 | #define CHEAP_REG(N) \ | |
485 | ((REG_USERVAR_P (N) && REGNO (N) < FIRST_PSEUDO_REGISTER) \ | |
486 | || CHEAP_REGNO (REGNO (N))) | |
487 | ||
38734e55 ILT |
488 | #define COST(X) \ |
489 | (GET_CODE (X) == REG \ | |
490 | ? (CHEAP_REG (X) ? 0 \ | |
491 | : REGNO (X) >= FIRST_PSEUDO_REGISTER ? 1 \ | |
492 | : 2) \ | |
954a5693 | 493 | : notreg_cost(X)) |
7afe21cc RK |
494 | |
495 | /* Determine if the quantity number for register X represents a valid index | |
496 | into the `qty_...' variables. */ | |
497 | ||
498 | #define REGNO_QTY_VALID_P(N) (reg_qty[N] != (N)) | |
499 | ||
2f541799 MM |
500 | #ifdef ADDRESS_COST |
501 | /* The ADDRESS_COST macro does not deal with ADDRESSOF nodes. But, | |
502 | during CSE, such nodes are present. Using an ADDRESSOF node which | |
503 | refers to the address of a REG is a good thing because we can then | |
504 | turn (MEM (ADDRESSSOF (REG))) into just plain REG. */ | |
505 | #define CSE_ADDRESS_COST(RTX) \ | |
506 | ((GET_CODE (RTX) == ADDRESSOF && REG_P (XEXP ((RTX), 0))) \ | |
507 | ? -1 : ADDRESS_COST(RTX)) | |
508 | #endif | |
509 | ||
7afe21cc RK |
510 | static struct table_elt *table[NBUCKETS]; |
511 | ||
512 | /* Chain of `struct table_elt's made so far for this function | |
513 | but currently removed from the table. */ | |
514 | ||
515 | static struct table_elt *free_element_chain; | |
516 | ||
517 | /* Number of `struct table_elt' structures made so far for this function. */ | |
518 | ||
519 | static int n_elements_made; | |
520 | ||
521 | /* Maximum value `n_elements_made' has had so far in this compilation | |
522 | for functions previously processed. */ | |
523 | ||
524 | static int max_elements_made; | |
525 | ||
526 | /* Surviving equivalence class when two equivalence classes are merged | |
527 | by recording the effects of a jump in the last insn. Zero if the | |
528 | last insn was not a conditional jump. */ | |
529 | ||
530 | static struct table_elt *last_jump_equiv_class; | |
531 | ||
532 | /* Set to the cost of a constant pool reference if one was found for a | |
533 | symbolic constant. If this was found, it means we should try to | |
534 | convert constants into constant pool entries if they don't fit in | |
535 | the insn. */ | |
536 | ||
537 | static int constant_pool_entries_cost; | |
538 | ||
6cd4575e RK |
539 | /* Define maximum length of a branch path. */ |
540 | ||
541 | #define PATHLENGTH 10 | |
542 | ||
543 | /* This data describes a block that will be processed by cse_basic_block. */ | |
544 | ||
545 | struct cse_basic_block_data { | |
546 | /* Lowest CUID value of insns in block. */ | |
547 | int low_cuid; | |
548 | /* Highest CUID value of insns in block. */ | |
549 | int high_cuid; | |
550 | /* Total number of SETs in block. */ | |
551 | int nsets; | |
552 | /* Last insn in the block. */ | |
553 | rtx last; | |
554 | /* Size of current branch path, if any. */ | |
555 | int path_size; | |
556 | /* Current branch path, indicating which branches will be taken. */ | |
557 | struct branch_path { | |
0f41302f | 558 | /* The branch insn. */ |
6cd4575e RK |
559 | rtx branch; |
560 | /* Whether it should be taken or not. AROUND is the same as taken | |
561 | except that it is used when the destination label is not preceded | |
562 | by a BARRIER. */ | |
563 | enum taken {TAKEN, NOT_TAKEN, AROUND} status; | |
564 | } path[PATHLENGTH]; | |
565 | }; | |
566 | ||
7afe21cc RK |
567 | /* Nonzero if X has the form (PLUS frame-pointer integer). We check for |
568 | virtual regs here because the simplify_*_operation routines are called | |
569 | by integrate.c, which is called before virtual register instantiation. */ | |
570 | ||
571 | #define FIXED_BASE_PLUS_P(X) \ | |
8bc169f2 DE |
572 | ((X) == frame_pointer_rtx || (X) == hard_frame_pointer_rtx \ |
573 | || (X) == arg_pointer_rtx \ | |
7afe21cc RK |
574 | || (X) == virtual_stack_vars_rtx \ |
575 | || (X) == virtual_incoming_args_rtx \ | |
576 | || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \ | |
577 | && (XEXP (X, 0) == frame_pointer_rtx \ | |
8bc169f2 | 578 | || XEXP (X, 0) == hard_frame_pointer_rtx \ |
7afe21cc RK |
579 | || XEXP (X, 0) == arg_pointer_rtx \ |
580 | || XEXP (X, 0) == virtual_stack_vars_rtx \ | |
e9a25f70 JL |
581 | || XEXP (X, 0) == virtual_incoming_args_rtx)) \ |
582 | || GET_CODE (X) == ADDRESSOF) | |
7afe21cc | 583 | |
6f90e075 JW |
584 | /* Similar, but also allows reference to the stack pointer. |
585 | ||
586 | This used to include FIXED_BASE_PLUS_P, however, we can't assume that | |
587 | arg_pointer_rtx by itself is nonzero, because on at least one machine, | |
588 | the i960, the arg pointer is zero when it is unused. */ | |
7afe21cc RK |
589 | |
590 | #define NONZERO_BASE_PLUS_P(X) \ | |
8bc169f2 | 591 | ((X) == frame_pointer_rtx || (X) == hard_frame_pointer_rtx \ |
6f90e075 JW |
592 | || (X) == virtual_stack_vars_rtx \ |
593 | || (X) == virtual_incoming_args_rtx \ | |
594 | || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \ | |
595 | && (XEXP (X, 0) == frame_pointer_rtx \ | |
8bc169f2 | 596 | || XEXP (X, 0) == hard_frame_pointer_rtx \ |
6f90e075 JW |
597 | || XEXP (X, 0) == arg_pointer_rtx \ |
598 | || XEXP (X, 0) == virtual_stack_vars_rtx \ | |
599 | || XEXP (X, 0) == virtual_incoming_args_rtx)) \ | |
7afe21cc RK |
600 | || (X) == stack_pointer_rtx \ |
601 | || (X) == virtual_stack_dynamic_rtx \ | |
602 | || (X) == virtual_outgoing_args_rtx \ | |
603 | || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \ | |
604 | && (XEXP (X, 0) == stack_pointer_rtx \ | |
605 | || XEXP (X, 0) == virtual_stack_dynamic_rtx \ | |
e9a25f70 JL |
606 | || XEXP (X, 0) == virtual_outgoing_args_rtx)) \ |
607 | || GET_CODE (X) == ADDRESSOF) | |
7afe21cc | 608 | |
954a5693 | 609 | static int notreg_cost PROTO((rtx)); |
6cd4575e RK |
610 | static void new_basic_block PROTO((void)); |
611 | static void make_new_qty PROTO((int)); | |
612 | static void make_regs_eqv PROTO((int, int)); | |
613 | static void delete_reg_equiv PROTO((int)); | |
614 | static int mention_regs PROTO((rtx)); | |
615 | static int insert_regs PROTO((rtx, struct table_elt *, int)); | |
616 | static void free_element PROTO((struct table_elt *)); | |
2197a88a | 617 | static void remove_from_table PROTO((struct table_elt *, unsigned)); |
6cd4575e | 618 | static struct table_elt *get_element PROTO((void)); |
2197a88a RK |
619 | static struct table_elt *lookup PROTO((rtx, unsigned, enum machine_mode)), |
620 | *lookup_for_remove PROTO((rtx, unsigned, enum machine_mode)); | |
6cd4575e | 621 | static rtx lookup_as_function PROTO((rtx, enum rtx_code)); |
2197a88a | 622 | static struct table_elt *insert PROTO((rtx, struct table_elt *, unsigned, |
6cd4575e RK |
623 | enum machine_mode)); |
624 | static void merge_equiv_classes PROTO((struct table_elt *, | |
625 | struct table_elt *)); | |
68c1e173 | 626 | static void invalidate PROTO((rtx, enum machine_mode)); |
9ae8ffe7 | 627 | static int cse_rtx_varies_p PROTO((rtx)); |
6cd4575e RK |
628 | static void remove_invalid_refs PROTO((int)); |
629 | static void rehash_using_reg PROTO((rtx)); | |
9ae8ffe7 | 630 | static void invalidate_memory PROTO((void)); |
6cd4575e RK |
631 | static void invalidate_for_call PROTO((void)); |
632 | static rtx use_related_value PROTO((rtx, struct table_elt *)); | |
2197a88a RK |
633 | static unsigned canon_hash PROTO((rtx, enum machine_mode)); |
634 | static unsigned safe_hash PROTO((rtx, enum machine_mode)); | |
6cd4575e | 635 | static int exp_equiv_p PROTO((rtx, rtx, int, int)); |
f451db89 | 636 | static void set_nonvarying_address_components PROTO((rtx, int, rtx *, |
6500fb43 RK |
637 | HOST_WIDE_INT *, |
638 | HOST_WIDE_INT *)); | |
6cd4575e | 639 | static int refers_to_p PROTO((rtx, rtx)); |
6cd4575e RK |
640 | static rtx canon_reg PROTO((rtx, rtx)); |
641 | static void find_best_addr PROTO((rtx, rtx *)); | |
642 | static enum rtx_code find_comparison_args PROTO((enum rtx_code, rtx *, rtx *, | |
643 | enum machine_mode *, | |
644 | enum machine_mode *)); | |
96b0e481 RK |
645 | static rtx cse_gen_binary PROTO((enum rtx_code, enum machine_mode, |
646 | rtx, rtx)); | |
647 | static rtx simplify_plus_minus PROTO((enum rtx_code, enum machine_mode, | |
648 | rtx, rtx)); | |
6cd4575e RK |
649 | static rtx fold_rtx PROTO((rtx, rtx)); |
650 | static rtx equiv_constant PROTO((rtx)); | |
651 | static void record_jump_equiv PROTO((rtx, int)); | |
652 | static void record_jump_cond PROTO((enum rtx_code, enum machine_mode, | |
653 | rtx, rtx, int)); | |
7bd8b2a8 | 654 | static void cse_insn PROTO((rtx, rtx)); |
9ae8ffe7 JL |
655 | static int note_mem_written PROTO((rtx)); |
656 | static void invalidate_from_clobbers PROTO((rtx)); | |
6cd4575e RK |
657 | static rtx cse_process_notes PROTO((rtx, rtx)); |
658 | static void cse_around_loop PROTO((rtx)); | |
659 | static void invalidate_skipped_set PROTO((rtx, rtx)); | |
660 | static void invalidate_skipped_block PROTO((rtx)); | |
661 | static void cse_check_loop_start PROTO((rtx, rtx)); | |
662 | static void cse_set_around_loop PROTO((rtx, rtx, rtx)); | |
663 | static rtx cse_basic_block PROTO((rtx, rtx, struct branch_path *, int)); | |
79644f06 | 664 | static void count_reg_usage PROTO((rtx, int *, rtx, int)); |
c407b802 RK |
665 | |
666 | extern int rtx_equal_function_value_matters; | |
7afe21cc RK |
667 | \f |
668 | /* Return an estimate of the cost of computing rtx X. | |
669 | One use is in cse, to decide which expression to keep in the hash table. | |
670 | Another is in rtl generation, to pick the cheapest way to multiply. | |
671 | Other uses like the latter are expected in the future. */ | |
672 | ||
954a5693 RK |
673 | /* Internal function, to compute cost when X is not a register; called |
674 | from COST macro to keep it simple. */ | |
675 | ||
676 | static int | |
677 | notreg_cost (x) | |
678 | rtx x; | |
679 | { | |
680 | return ((GET_CODE (x) == SUBREG | |
681 | && GET_CODE (SUBREG_REG (x)) == REG | |
682 | && GET_MODE_CLASS (GET_MODE (x)) == MODE_INT | |
683 | && GET_MODE_CLASS (GET_MODE (SUBREG_REG (x))) == MODE_INT | |
684 | && (GET_MODE_SIZE (GET_MODE (x)) | |
685 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))) | |
686 | && subreg_lowpart_p (x) | |
687 | && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (GET_MODE (x)), | |
688 | GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x))))) | |
689 | ? (CHEAP_REG (SUBREG_REG (x)) ? 0 | |
690 | : (REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER ? 1 | |
691 | : 2)) | |
692 | : rtx_cost (x, SET) * 2); | |
693 | } | |
694 | ||
7afe21cc RK |
695 | /* Return the right cost to give to an operation |
696 | to make the cost of the corresponding register-to-register instruction | |
697 | N times that of a fast register-to-register instruction. */ | |
698 | ||
699 | #define COSTS_N_INSNS(N) ((N) * 4 - 2) | |
700 | ||
701 | int | |
e5f6a288 | 702 | rtx_cost (x, outer_code) |
7afe21cc | 703 | rtx x; |
e5f6a288 | 704 | enum rtx_code outer_code; |
7afe21cc RK |
705 | { |
706 | register int i, j; | |
707 | register enum rtx_code code; | |
708 | register char *fmt; | |
709 | register int total; | |
710 | ||
711 | if (x == 0) | |
712 | return 0; | |
713 | ||
714 | /* Compute the default costs of certain things. | |
715 | Note that RTX_COSTS can override the defaults. */ | |
716 | ||
717 | code = GET_CODE (x); | |
718 | switch (code) | |
719 | { | |
720 | case MULT: | |
721 | /* Count multiplication by 2**n as a shift, | |
722 | because if we are considering it, we would output it as a shift. */ | |
723 | if (GET_CODE (XEXP (x, 1)) == CONST_INT | |
724 | && exact_log2 (INTVAL (XEXP (x, 1))) >= 0) | |
725 | total = 2; | |
726 | else | |
727 | total = COSTS_N_INSNS (5); | |
728 | break; | |
729 | case DIV: | |
730 | case UDIV: | |
731 | case MOD: | |
732 | case UMOD: | |
733 | total = COSTS_N_INSNS (7); | |
734 | break; | |
735 | case USE: | |
736 | /* Used in loop.c and combine.c as a marker. */ | |
737 | total = 0; | |
738 | break; | |
538b78e7 RS |
739 | case ASM_OPERANDS: |
740 | /* We don't want these to be used in substitutions because | |
741 | we have no way of validating the resulting insn. So assign | |
742 | anything containing an ASM_OPERANDS a very high cost. */ | |
743 | total = 1000; | |
744 | break; | |
7afe21cc RK |
745 | default: |
746 | total = 2; | |
747 | } | |
748 | ||
749 | switch (code) | |
750 | { | |
751 | case REG: | |
6ab832bc | 752 | return ! CHEAP_REG (x); |
ac07e066 | 753 | |
7afe21cc | 754 | case SUBREG: |
fc3ffe83 RK |
755 | /* If we can't tie these modes, make this expensive. The larger |
756 | the mode, the more expensive it is. */ | |
757 | if (! MODES_TIEABLE_P (GET_MODE (x), GET_MODE (SUBREG_REG (x)))) | |
758 | return COSTS_N_INSNS (2 | |
759 | + GET_MODE_SIZE (GET_MODE (x)) / UNITS_PER_WORD); | |
7afe21cc RK |
760 | return 2; |
761 | #ifdef RTX_COSTS | |
e5f6a288 | 762 | RTX_COSTS (x, code, outer_code); |
7afe21cc | 763 | #endif |
47a0b68f | 764 | #ifdef CONST_COSTS |
e5f6a288 | 765 | CONST_COSTS (x, code, outer_code); |
47a0b68f | 766 | #endif |
8625fab5 KG |
767 | |
768 | default: | |
769 | #ifdef DEFAULT_RTX_COSTS | |
770 | DEFAULT_RTX_COSTS(x, code, outer_code); | |
771 | #endif | |
772 | break; | |
7afe21cc RK |
773 | } |
774 | ||
775 | /* Sum the costs of the sub-rtx's, plus cost of this operation, | |
776 | which is already in total. */ | |
777 | ||
778 | fmt = GET_RTX_FORMAT (code); | |
779 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
780 | if (fmt[i] == 'e') | |
e5f6a288 | 781 | total += rtx_cost (XEXP (x, i), code); |
7afe21cc RK |
782 | else if (fmt[i] == 'E') |
783 | for (j = 0; j < XVECLEN (x, i); j++) | |
e5f6a288 | 784 | total += rtx_cost (XVECEXP (x, i, j), code); |
7afe21cc RK |
785 | |
786 | return total; | |
787 | } | |
788 | \f | |
789 | /* Clear the hash table and initialize each register with its own quantity, | |
790 | for a new basic block. */ | |
791 | ||
792 | static void | |
793 | new_basic_block () | |
794 | { | |
795 | register int i; | |
796 | ||
797 | next_qty = max_reg; | |
798 | ||
4c9a05bc | 799 | bzero ((char *) reg_tick, max_reg * sizeof (int)); |
7afe21cc | 800 | |
4c9a05bc RK |
801 | bcopy ((char *) all_minus_one, (char *) reg_in_table, |
802 | max_reg * sizeof (int)); | |
803 | bcopy ((char *) consec_ints, (char *) reg_qty, max_reg * sizeof (int)); | |
7afe21cc RK |
804 | CLEAR_HARD_REG_SET (hard_regs_in_table); |
805 | ||
806 | /* The per-quantity values used to be initialized here, but it is | |
807 | much faster to initialize each as it is made in `make_new_qty'. */ | |
808 | ||
809 | for (i = 0; i < NBUCKETS; i++) | |
810 | { | |
811 | register struct table_elt *this, *next; | |
812 | for (this = table[i]; this; this = next) | |
813 | { | |
814 | next = this->next_same_hash; | |
815 | free_element (this); | |
816 | } | |
817 | } | |
818 | ||
4c9a05bc | 819 | bzero ((char *) table, sizeof table); |
7afe21cc RK |
820 | |
821 | prev_insn = 0; | |
822 | ||
823 | #ifdef HAVE_cc0 | |
824 | prev_insn_cc0 = 0; | |
825 | #endif | |
826 | } | |
827 | ||
828 | /* Say that register REG contains a quantity not in any register before | |
829 | and initialize that quantity. */ | |
830 | ||
831 | static void | |
832 | make_new_qty (reg) | |
833 | register int reg; | |
834 | { | |
835 | register int q; | |
836 | ||
837 | if (next_qty >= max_qty) | |
838 | abort (); | |
839 | ||
840 | q = reg_qty[reg] = next_qty++; | |
841 | qty_first_reg[q] = reg; | |
842 | qty_last_reg[q] = reg; | |
843 | qty_const[q] = qty_const_insn[q] = 0; | |
844 | qty_comparison_code[q] = UNKNOWN; | |
845 | ||
846 | reg_next_eqv[reg] = reg_prev_eqv[reg] = -1; | |
847 | } | |
848 | ||
849 | /* Make reg NEW equivalent to reg OLD. | |
850 | OLD is not changing; NEW is. */ | |
851 | ||
852 | static void | |
853 | make_regs_eqv (new, old) | |
854 | register int new, old; | |
855 | { | |
856 | register int lastr, firstr; | |
857 | register int q = reg_qty[old]; | |
858 | ||
859 | /* Nothing should become eqv until it has a "non-invalid" qty number. */ | |
860 | if (! REGNO_QTY_VALID_P (old)) | |
861 | abort (); | |
862 | ||
863 | reg_qty[new] = q; | |
864 | firstr = qty_first_reg[q]; | |
865 | lastr = qty_last_reg[q]; | |
866 | ||
867 | /* Prefer fixed hard registers to anything. Prefer pseudo regs to other | |
868 | hard regs. Among pseudos, if NEW will live longer than any other reg | |
869 | of the same qty, and that is beyond the current basic block, | |
870 | make it the new canonical replacement for this qty. */ | |
871 | if (! (firstr < FIRST_PSEUDO_REGISTER && FIXED_REGNO_P (firstr)) | |
872 | /* Certain fixed registers might be of the class NO_REGS. This means | |
873 | that not only can they not be allocated by the compiler, but | |
830a38ee | 874 | they cannot be used in substitutions or canonicalizations |
7afe21cc RK |
875 | either. */ |
876 | && (new >= FIRST_PSEUDO_REGISTER || REGNO_REG_CLASS (new) != NO_REGS) | |
877 | && ((new < FIRST_PSEUDO_REGISTER && FIXED_REGNO_P (new)) | |
878 | || (new >= FIRST_PSEUDO_REGISTER | |
879 | && (firstr < FIRST_PSEUDO_REGISTER | |
b1f21e0a MM |
880 | || ((uid_cuid[REGNO_LAST_UID (new)] > cse_basic_block_end |
881 | || (uid_cuid[REGNO_FIRST_UID (new)] | |
7afe21cc | 882 | < cse_basic_block_start)) |
b1f21e0a MM |
883 | && (uid_cuid[REGNO_LAST_UID (new)] |
884 | > uid_cuid[REGNO_LAST_UID (firstr)])))))) | |
7afe21cc RK |
885 | { |
886 | reg_prev_eqv[firstr] = new; | |
887 | reg_next_eqv[new] = firstr; | |
888 | reg_prev_eqv[new] = -1; | |
889 | qty_first_reg[q] = new; | |
890 | } | |
891 | else | |
892 | { | |
893 | /* If NEW is a hard reg (known to be non-fixed), insert at end. | |
894 | Otherwise, insert before any non-fixed hard regs that are at the | |
895 | end. Registers of class NO_REGS cannot be used as an | |
896 | equivalent for anything. */ | |
897 | while (lastr < FIRST_PSEUDO_REGISTER && reg_prev_eqv[lastr] >= 0 | |
898 | && (REGNO_REG_CLASS (lastr) == NO_REGS || ! FIXED_REGNO_P (lastr)) | |
899 | && new >= FIRST_PSEUDO_REGISTER) | |
900 | lastr = reg_prev_eqv[lastr]; | |
901 | reg_next_eqv[new] = reg_next_eqv[lastr]; | |
902 | if (reg_next_eqv[lastr] >= 0) | |
903 | reg_prev_eqv[reg_next_eqv[lastr]] = new; | |
904 | else | |
905 | qty_last_reg[q] = new; | |
906 | reg_next_eqv[lastr] = new; | |
907 | reg_prev_eqv[new] = lastr; | |
908 | } | |
909 | } | |
910 | ||
911 | /* Remove REG from its equivalence class. */ | |
912 | ||
913 | static void | |
914 | delete_reg_equiv (reg) | |
915 | register int reg; | |
916 | { | |
7afe21cc | 917 | register int q = reg_qty[reg]; |
a4e262bc | 918 | register int p, n; |
7afe21cc | 919 | |
a4e262bc | 920 | /* If invalid, do nothing. */ |
7afe21cc RK |
921 | if (q == reg) |
922 | return; | |
923 | ||
a4e262bc RK |
924 | p = reg_prev_eqv[reg]; |
925 | n = reg_next_eqv[reg]; | |
926 | ||
7afe21cc RK |
927 | if (n != -1) |
928 | reg_prev_eqv[n] = p; | |
929 | else | |
930 | qty_last_reg[q] = p; | |
931 | if (p != -1) | |
932 | reg_next_eqv[p] = n; | |
933 | else | |
934 | qty_first_reg[q] = n; | |
935 | ||
936 | reg_qty[reg] = reg; | |
937 | } | |
938 | ||
939 | /* Remove any invalid expressions from the hash table | |
940 | that refer to any of the registers contained in expression X. | |
941 | ||
942 | Make sure that newly inserted references to those registers | |
943 | as subexpressions will be considered valid. | |
944 | ||
945 | mention_regs is not called when a register itself | |
946 | is being stored in the table. | |
947 | ||
948 | Return 1 if we have done something that may have changed the hash code | |
949 | of X. */ | |
950 | ||
951 | static int | |
952 | mention_regs (x) | |
953 | rtx x; | |
954 | { | |
955 | register enum rtx_code code; | |
956 | register int i, j; | |
957 | register char *fmt; | |
958 | register int changed = 0; | |
959 | ||
960 | if (x == 0) | |
e5f6a288 | 961 | return 0; |
7afe21cc RK |
962 | |
963 | code = GET_CODE (x); | |
964 | if (code == REG) | |
965 | { | |
966 | register int regno = REGNO (x); | |
967 | register int endregno | |
968 | = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1 | |
969 | : HARD_REGNO_NREGS (regno, GET_MODE (x))); | |
970 | int i; | |
971 | ||
972 | for (i = regno; i < endregno; i++) | |
973 | { | |
974 | if (reg_in_table[i] >= 0 && reg_in_table[i] != reg_tick[i]) | |
975 | remove_invalid_refs (i); | |
976 | ||
977 | reg_in_table[i] = reg_tick[i]; | |
978 | } | |
979 | ||
980 | return 0; | |
981 | } | |
982 | ||
983 | /* If X is a comparison or a COMPARE and either operand is a register | |
984 | that does not have a quantity, give it one. This is so that a later | |
985 | call to record_jump_equiv won't cause X to be assigned a different | |
986 | hash code and not found in the table after that call. | |
987 | ||
988 | It is not necessary to do this here, since rehash_using_reg can | |
989 | fix up the table later, but doing this here eliminates the need to | |
990 | call that expensive function in the most common case where the only | |
991 | use of the register is in the comparison. */ | |
992 | ||
993 | if (code == COMPARE || GET_RTX_CLASS (code) == '<') | |
994 | { | |
995 | if (GET_CODE (XEXP (x, 0)) == REG | |
996 | && ! REGNO_QTY_VALID_P (REGNO (XEXP (x, 0)))) | |
906c4e36 | 997 | if (insert_regs (XEXP (x, 0), NULL_PTR, 0)) |
7afe21cc RK |
998 | { |
999 | rehash_using_reg (XEXP (x, 0)); | |
1000 | changed = 1; | |
1001 | } | |
1002 | ||
1003 | if (GET_CODE (XEXP (x, 1)) == REG | |
1004 | && ! REGNO_QTY_VALID_P (REGNO (XEXP (x, 1)))) | |
906c4e36 | 1005 | if (insert_regs (XEXP (x, 1), NULL_PTR, 0)) |
7afe21cc RK |
1006 | { |
1007 | rehash_using_reg (XEXP (x, 1)); | |
1008 | changed = 1; | |
1009 | } | |
1010 | } | |
1011 | ||
1012 | fmt = GET_RTX_FORMAT (code); | |
1013 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1014 | if (fmt[i] == 'e') | |
1015 | changed |= mention_regs (XEXP (x, i)); | |
1016 | else if (fmt[i] == 'E') | |
1017 | for (j = 0; j < XVECLEN (x, i); j++) | |
1018 | changed |= mention_regs (XVECEXP (x, i, j)); | |
1019 | ||
1020 | return changed; | |
1021 | } | |
1022 | ||
1023 | /* Update the register quantities for inserting X into the hash table | |
1024 | with a value equivalent to CLASSP. | |
1025 | (If the class does not contain a REG, it is irrelevant.) | |
1026 | If MODIFIED is nonzero, X is a destination; it is being modified. | |
1027 | Note that delete_reg_equiv should be called on a register | |
1028 | before insert_regs is done on that register with MODIFIED != 0. | |
1029 | ||
1030 | Nonzero value means that elements of reg_qty have changed | |
1031 | so X's hash code may be different. */ | |
1032 | ||
1033 | static int | |
1034 | insert_regs (x, classp, modified) | |
1035 | rtx x; | |
1036 | struct table_elt *classp; | |
1037 | int modified; | |
1038 | { | |
1039 | if (GET_CODE (x) == REG) | |
1040 | { | |
1041 | register int regno = REGNO (x); | |
1042 | ||
1ff0c00d RK |
1043 | /* If REGNO is in the equivalence table already but is of the |
1044 | wrong mode for that equivalence, don't do anything here. */ | |
1045 | ||
1046 | if (REGNO_QTY_VALID_P (regno) | |
1047 | && qty_mode[reg_qty[regno]] != GET_MODE (x)) | |
1048 | return 0; | |
1049 | ||
1050 | if (modified || ! REGNO_QTY_VALID_P (regno)) | |
7afe21cc RK |
1051 | { |
1052 | if (classp) | |
1053 | for (classp = classp->first_same_value; | |
1054 | classp != 0; | |
1055 | classp = classp->next_same_value) | |
1056 | if (GET_CODE (classp->exp) == REG | |
1057 | && GET_MODE (classp->exp) == GET_MODE (x)) | |
1058 | { | |
1059 | make_regs_eqv (regno, REGNO (classp->exp)); | |
1060 | return 1; | |
1061 | } | |
1062 | ||
1063 | make_new_qty (regno); | |
1064 | qty_mode[reg_qty[regno]] = GET_MODE (x); | |
1065 | return 1; | |
1066 | } | |
cdf4112f TG |
1067 | |
1068 | return 0; | |
7afe21cc | 1069 | } |
c610adec RK |
1070 | |
1071 | /* If X is a SUBREG, we will likely be inserting the inner register in the | |
1072 | table. If that register doesn't have an assigned quantity number at | |
1073 | this point but does later, the insertion that we will be doing now will | |
1074 | not be accessible because its hash code will have changed. So assign | |
1075 | a quantity number now. */ | |
1076 | ||
1077 | else if (GET_CODE (x) == SUBREG && GET_CODE (SUBREG_REG (x)) == REG | |
1078 | && ! REGNO_QTY_VALID_P (REGNO (SUBREG_REG (x)))) | |
1079 | { | |
906c4e36 | 1080 | insert_regs (SUBREG_REG (x), NULL_PTR, 0); |
c610adec RK |
1081 | mention_regs (SUBREG_REG (x)); |
1082 | return 1; | |
1083 | } | |
7afe21cc RK |
1084 | else |
1085 | return mention_regs (x); | |
1086 | } | |
1087 | \f | |
1088 | /* Look in or update the hash table. */ | |
1089 | ||
1090 | /* Put the element ELT on the list of free elements. */ | |
1091 | ||
1092 | static void | |
1093 | free_element (elt) | |
1094 | struct table_elt *elt; | |
1095 | { | |
1096 | elt->next_same_hash = free_element_chain; | |
1097 | free_element_chain = elt; | |
1098 | } | |
1099 | ||
1100 | /* Return an element that is free for use. */ | |
1101 | ||
1102 | static struct table_elt * | |
1103 | get_element () | |
1104 | { | |
1105 | struct table_elt *elt = free_element_chain; | |
1106 | if (elt) | |
1107 | { | |
1108 | free_element_chain = elt->next_same_hash; | |
1109 | return elt; | |
1110 | } | |
1111 | n_elements_made++; | |
1112 | return (struct table_elt *) oballoc (sizeof (struct table_elt)); | |
1113 | } | |
1114 | ||
1115 | /* Remove table element ELT from use in the table. | |
1116 | HASH is its hash code, made using the HASH macro. | |
1117 | It's an argument because often that is known in advance | |
1118 | and we save much time not recomputing it. */ | |
1119 | ||
1120 | static void | |
1121 | remove_from_table (elt, hash) | |
1122 | register struct table_elt *elt; | |
2197a88a | 1123 | unsigned hash; |
7afe21cc RK |
1124 | { |
1125 | if (elt == 0) | |
1126 | return; | |
1127 | ||
1128 | /* Mark this element as removed. See cse_insn. */ | |
1129 | elt->first_same_value = 0; | |
1130 | ||
1131 | /* Remove the table element from its equivalence class. */ | |
1132 | ||
1133 | { | |
1134 | register struct table_elt *prev = elt->prev_same_value; | |
1135 | register struct table_elt *next = elt->next_same_value; | |
1136 | ||
1137 | if (next) next->prev_same_value = prev; | |
1138 | ||
1139 | if (prev) | |
1140 | prev->next_same_value = next; | |
1141 | else | |
1142 | { | |
1143 | register struct table_elt *newfirst = next; | |
1144 | while (next) | |
1145 | { | |
1146 | next->first_same_value = newfirst; | |
1147 | next = next->next_same_value; | |
1148 | } | |
1149 | } | |
1150 | } | |
1151 | ||
1152 | /* Remove the table element from its hash bucket. */ | |
1153 | ||
1154 | { | |
1155 | register struct table_elt *prev = elt->prev_same_hash; | |
1156 | register struct table_elt *next = elt->next_same_hash; | |
1157 | ||
1158 | if (next) next->prev_same_hash = prev; | |
1159 | ||
1160 | if (prev) | |
1161 | prev->next_same_hash = next; | |
1162 | else if (table[hash] == elt) | |
1163 | table[hash] = next; | |
1164 | else | |
1165 | { | |
1166 | /* This entry is not in the proper hash bucket. This can happen | |
1167 | when two classes were merged by `merge_equiv_classes'. Search | |
1168 | for the hash bucket that it heads. This happens only very | |
1169 | rarely, so the cost is acceptable. */ | |
1170 | for (hash = 0; hash < NBUCKETS; hash++) | |
1171 | if (table[hash] == elt) | |
1172 | table[hash] = next; | |
1173 | } | |
1174 | } | |
1175 | ||
1176 | /* Remove the table element from its related-value circular chain. */ | |
1177 | ||
1178 | if (elt->related_value != 0 && elt->related_value != elt) | |
1179 | { | |
1180 | register struct table_elt *p = elt->related_value; | |
1181 | while (p->related_value != elt) | |
1182 | p = p->related_value; | |
1183 | p->related_value = elt->related_value; | |
1184 | if (p->related_value == p) | |
1185 | p->related_value = 0; | |
1186 | } | |
1187 | ||
1188 | free_element (elt); | |
1189 | } | |
1190 | ||
1191 | /* Look up X in the hash table and return its table element, | |
1192 | or 0 if X is not in the table. | |
1193 | ||
1194 | MODE is the machine-mode of X, or if X is an integer constant | |
1195 | with VOIDmode then MODE is the mode with which X will be used. | |
1196 | ||
1197 | Here we are satisfied to find an expression whose tree structure | |
1198 | looks like X. */ | |
1199 | ||
1200 | static struct table_elt * | |
1201 | lookup (x, hash, mode) | |
1202 | rtx x; | |
2197a88a | 1203 | unsigned hash; |
7afe21cc RK |
1204 | enum machine_mode mode; |
1205 | { | |
1206 | register struct table_elt *p; | |
1207 | ||
1208 | for (p = table[hash]; p; p = p->next_same_hash) | |
1209 | if (mode == p->mode && ((x == p->exp && GET_CODE (x) == REG) | |
1210 | || exp_equiv_p (x, p->exp, GET_CODE (x) != REG, 0))) | |
1211 | return p; | |
1212 | ||
1213 | return 0; | |
1214 | } | |
1215 | ||
1216 | /* Like `lookup' but don't care whether the table element uses invalid regs. | |
1217 | Also ignore discrepancies in the machine mode of a register. */ | |
1218 | ||
1219 | static struct table_elt * | |
1220 | lookup_for_remove (x, hash, mode) | |
1221 | rtx x; | |
2197a88a | 1222 | unsigned hash; |
7afe21cc RK |
1223 | enum machine_mode mode; |
1224 | { | |
1225 | register struct table_elt *p; | |
1226 | ||
1227 | if (GET_CODE (x) == REG) | |
1228 | { | |
1229 | int regno = REGNO (x); | |
1230 | /* Don't check the machine mode when comparing registers; | |
1231 | invalidating (REG:SI 0) also invalidates (REG:DF 0). */ | |
1232 | for (p = table[hash]; p; p = p->next_same_hash) | |
1233 | if (GET_CODE (p->exp) == REG | |
1234 | && REGNO (p->exp) == regno) | |
1235 | return p; | |
1236 | } | |
1237 | else | |
1238 | { | |
1239 | for (p = table[hash]; p; p = p->next_same_hash) | |
1240 | if (mode == p->mode && (x == p->exp || exp_equiv_p (x, p->exp, 0, 0))) | |
1241 | return p; | |
1242 | } | |
1243 | ||
1244 | return 0; | |
1245 | } | |
1246 | ||
1247 | /* Look for an expression equivalent to X and with code CODE. | |
1248 | If one is found, return that expression. */ | |
1249 | ||
1250 | static rtx | |
1251 | lookup_as_function (x, code) | |
1252 | rtx x; | |
1253 | enum rtx_code code; | |
1254 | { | |
1255 | register struct table_elt *p = lookup (x, safe_hash (x, VOIDmode) % NBUCKETS, | |
1256 | GET_MODE (x)); | |
1257 | if (p == 0) | |
1258 | return 0; | |
1259 | ||
1260 | for (p = p->first_same_value; p; p = p->next_same_value) | |
1261 | { | |
1262 | if (GET_CODE (p->exp) == code | |
1263 | /* Make sure this is a valid entry in the table. */ | |
1264 | && exp_equiv_p (p->exp, p->exp, 1, 0)) | |
1265 | return p->exp; | |
1266 | } | |
1267 | ||
1268 | return 0; | |
1269 | } | |
1270 | ||
1271 | /* Insert X in the hash table, assuming HASH is its hash code | |
1272 | and CLASSP is an element of the class it should go in | |
1273 | (or 0 if a new class should be made). | |
1274 | It is inserted at the proper position to keep the class in | |
1275 | the order cheapest first. | |
1276 | ||
1277 | MODE is the machine-mode of X, or if X is an integer constant | |
1278 | with VOIDmode then MODE is the mode with which X will be used. | |
1279 | ||
1280 | For elements of equal cheapness, the most recent one | |
1281 | goes in front, except that the first element in the list | |
1282 | remains first unless a cheaper element is added. The order of | |
1283 | pseudo-registers does not matter, as canon_reg will be called to | |
830a38ee | 1284 | find the cheapest when a register is retrieved from the table. |
7afe21cc RK |
1285 | |
1286 | The in_memory field in the hash table element is set to 0. | |
1287 | The caller must set it nonzero if appropriate. | |
1288 | ||
1289 | You should call insert_regs (X, CLASSP, MODIFY) before calling here, | |
1290 | and if insert_regs returns a nonzero value | |
1291 | you must then recompute its hash code before calling here. | |
1292 | ||
1293 | If necessary, update table showing constant values of quantities. */ | |
1294 | ||
1295 | #define CHEAPER(X,Y) ((X)->cost < (Y)->cost) | |
1296 | ||
1297 | static struct table_elt * | |
1298 | insert (x, classp, hash, mode) | |
1299 | register rtx x; | |
1300 | register struct table_elt *classp; | |
2197a88a | 1301 | unsigned hash; |
7afe21cc RK |
1302 | enum machine_mode mode; |
1303 | { | |
1304 | register struct table_elt *elt; | |
1305 | ||
1306 | /* If X is a register and we haven't made a quantity for it, | |
1307 | something is wrong. */ | |
1308 | if (GET_CODE (x) == REG && ! REGNO_QTY_VALID_P (REGNO (x))) | |
1309 | abort (); | |
1310 | ||
1311 | /* If X is a hard register, show it is being put in the table. */ | |
1312 | if (GET_CODE (x) == REG && REGNO (x) < FIRST_PSEUDO_REGISTER) | |
1313 | { | |
1314 | int regno = REGNO (x); | |
1315 | int endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
1316 | int i; | |
1317 | ||
1318 | for (i = regno; i < endregno; i++) | |
1319 | SET_HARD_REG_BIT (hard_regs_in_table, i); | |
1320 | } | |
1321 | ||
a5dfb4ee | 1322 | /* If X is a label, show we recorded it. */ |
970c9ace RK |
1323 | if (GET_CODE (x) == LABEL_REF |
1324 | || (GET_CODE (x) == CONST && GET_CODE (XEXP (x, 0)) == PLUS | |
1325 | && GET_CODE (XEXP (XEXP (x, 0), 0)) == LABEL_REF)) | |
a5dfb4ee | 1326 | recorded_label_ref = 1; |
7afe21cc RK |
1327 | |
1328 | /* Put an element for X into the right hash bucket. */ | |
1329 | ||
1330 | elt = get_element (); | |
1331 | elt->exp = x; | |
1332 | elt->cost = COST (x); | |
1333 | elt->next_same_value = 0; | |
1334 | elt->prev_same_value = 0; | |
1335 | elt->next_same_hash = table[hash]; | |
1336 | elt->prev_same_hash = 0; | |
1337 | elt->related_value = 0; | |
1338 | elt->in_memory = 0; | |
1339 | elt->mode = mode; | |
1340 | elt->is_const = (CONSTANT_P (x) | |
1341 | /* GNU C++ takes advantage of this for `this' | |
1342 | (and other const values). */ | |
1343 | || (RTX_UNCHANGING_P (x) | |
1344 | && GET_CODE (x) == REG | |
1345 | && REGNO (x) >= FIRST_PSEUDO_REGISTER) | |
1346 | || FIXED_BASE_PLUS_P (x)); | |
1347 | ||
1348 | if (table[hash]) | |
1349 | table[hash]->prev_same_hash = elt; | |
1350 | table[hash] = elt; | |
1351 | ||
1352 | /* Put it into the proper value-class. */ | |
1353 | if (classp) | |
1354 | { | |
1355 | classp = classp->first_same_value; | |
1356 | if (CHEAPER (elt, classp)) | |
1357 | /* Insert at the head of the class */ | |
1358 | { | |
1359 | register struct table_elt *p; | |
1360 | elt->next_same_value = classp; | |
1361 | classp->prev_same_value = elt; | |
1362 | elt->first_same_value = elt; | |
1363 | ||
1364 | for (p = classp; p; p = p->next_same_value) | |
1365 | p->first_same_value = elt; | |
1366 | } | |
1367 | else | |
1368 | { | |
1369 | /* Insert not at head of the class. */ | |
1370 | /* Put it after the last element cheaper than X. */ | |
1371 | register struct table_elt *p, *next; | |
1372 | for (p = classp; (next = p->next_same_value) && CHEAPER (next, elt); | |
1373 | p = next); | |
1374 | /* Put it after P and before NEXT. */ | |
1375 | elt->next_same_value = next; | |
1376 | if (next) | |
1377 | next->prev_same_value = elt; | |
1378 | elt->prev_same_value = p; | |
1379 | p->next_same_value = elt; | |
1380 | elt->first_same_value = classp; | |
1381 | } | |
1382 | } | |
1383 | else | |
1384 | elt->first_same_value = elt; | |
1385 | ||
1386 | /* If this is a constant being set equivalent to a register or a register | |
1387 | being set equivalent to a constant, note the constant equivalence. | |
1388 | ||
1389 | If this is a constant, it cannot be equivalent to a different constant, | |
1390 | and a constant is the only thing that can be cheaper than a register. So | |
1391 | we know the register is the head of the class (before the constant was | |
1392 | inserted). | |
1393 | ||
1394 | If this is a register that is not already known equivalent to a | |
1395 | constant, we must check the entire class. | |
1396 | ||
1397 | If this is a register that is already known equivalent to an insn, | |
1398 | update `qty_const_insn' to show that `this_insn' is the latest | |
1399 | insn making that quantity equivalent to the constant. */ | |
1400 | ||
f353588a RK |
1401 | if (elt->is_const && classp && GET_CODE (classp->exp) == REG |
1402 | && GET_CODE (x) != REG) | |
7afe21cc RK |
1403 | { |
1404 | qty_const[reg_qty[REGNO (classp->exp)]] | |
1405 | = gen_lowpart_if_possible (qty_mode[reg_qty[REGNO (classp->exp)]], x); | |
1406 | qty_const_insn[reg_qty[REGNO (classp->exp)]] = this_insn; | |
1407 | } | |
1408 | ||
f353588a RK |
1409 | else if (GET_CODE (x) == REG && classp && ! qty_const[reg_qty[REGNO (x)]] |
1410 | && ! elt->is_const) | |
7afe21cc RK |
1411 | { |
1412 | register struct table_elt *p; | |
1413 | ||
1414 | for (p = classp; p != 0; p = p->next_same_value) | |
1415 | { | |
f353588a | 1416 | if (p->is_const && GET_CODE (p->exp) != REG) |
7afe21cc RK |
1417 | { |
1418 | qty_const[reg_qty[REGNO (x)]] | |
1419 | = gen_lowpart_if_possible (GET_MODE (x), p->exp); | |
1420 | qty_const_insn[reg_qty[REGNO (x)]] = this_insn; | |
1421 | break; | |
1422 | } | |
1423 | } | |
1424 | } | |
1425 | ||
1426 | else if (GET_CODE (x) == REG && qty_const[reg_qty[REGNO (x)]] | |
1427 | && GET_MODE (x) == qty_mode[reg_qty[REGNO (x)]]) | |
1428 | qty_const_insn[reg_qty[REGNO (x)]] = this_insn; | |
1429 | ||
1430 | /* If this is a constant with symbolic value, | |
1431 | and it has a term with an explicit integer value, | |
1432 | link it up with related expressions. */ | |
1433 | if (GET_CODE (x) == CONST) | |
1434 | { | |
1435 | rtx subexp = get_related_value (x); | |
2197a88a | 1436 | unsigned subhash; |
7afe21cc RK |
1437 | struct table_elt *subelt, *subelt_prev; |
1438 | ||
1439 | if (subexp != 0) | |
1440 | { | |
1441 | /* Get the integer-free subexpression in the hash table. */ | |
1442 | subhash = safe_hash (subexp, mode) % NBUCKETS; | |
1443 | subelt = lookup (subexp, subhash, mode); | |
1444 | if (subelt == 0) | |
906c4e36 | 1445 | subelt = insert (subexp, NULL_PTR, subhash, mode); |
7afe21cc RK |
1446 | /* Initialize SUBELT's circular chain if it has none. */ |
1447 | if (subelt->related_value == 0) | |
1448 | subelt->related_value = subelt; | |
1449 | /* Find the element in the circular chain that precedes SUBELT. */ | |
1450 | subelt_prev = subelt; | |
1451 | while (subelt_prev->related_value != subelt) | |
1452 | subelt_prev = subelt_prev->related_value; | |
1453 | /* Put new ELT into SUBELT's circular chain just before SUBELT. | |
1454 | This way the element that follows SUBELT is the oldest one. */ | |
1455 | elt->related_value = subelt_prev->related_value; | |
1456 | subelt_prev->related_value = elt; | |
1457 | } | |
1458 | } | |
1459 | ||
1460 | return elt; | |
1461 | } | |
1462 | \f | |
1463 | /* Given two equivalence classes, CLASS1 and CLASS2, put all the entries from | |
1464 | CLASS2 into CLASS1. This is done when we have reached an insn which makes | |
1465 | the two classes equivalent. | |
1466 | ||
1467 | CLASS1 will be the surviving class; CLASS2 should not be used after this | |
1468 | call. | |
1469 | ||
1470 | Any invalid entries in CLASS2 will not be copied. */ | |
1471 | ||
1472 | static void | |
1473 | merge_equiv_classes (class1, class2) | |
1474 | struct table_elt *class1, *class2; | |
1475 | { | |
1476 | struct table_elt *elt, *next, *new; | |
1477 | ||
1478 | /* Ensure we start with the head of the classes. */ | |
1479 | class1 = class1->first_same_value; | |
1480 | class2 = class2->first_same_value; | |
1481 | ||
1482 | /* If they were already equal, forget it. */ | |
1483 | if (class1 == class2) | |
1484 | return; | |
1485 | ||
1486 | for (elt = class2; elt; elt = next) | |
1487 | { | |
2197a88a | 1488 | unsigned hash; |
7afe21cc RK |
1489 | rtx exp = elt->exp; |
1490 | enum machine_mode mode = elt->mode; | |
1491 | ||
1492 | next = elt->next_same_value; | |
1493 | ||
1494 | /* Remove old entry, make a new one in CLASS1's class. | |
1495 | Don't do this for invalid entries as we cannot find their | |
0f41302f | 1496 | hash code (it also isn't necessary). */ |
7afe21cc RK |
1497 | if (GET_CODE (exp) == REG || exp_equiv_p (exp, exp, 1, 0)) |
1498 | { | |
1499 | hash_arg_in_memory = 0; | |
1500 | hash_arg_in_struct = 0; | |
1501 | hash = HASH (exp, mode); | |
1502 | ||
1503 | if (GET_CODE (exp) == REG) | |
1504 | delete_reg_equiv (REGNO (exp)); | |
1505 | ||
1506 | remove_from_table (elt, hash); | |
1507 | ||
1508 | if (insert_regs (exp, class1, 0)) | |
8ae2b8f6 JW |
1509 | { |
1510 | rehash_using_reg (exp); | |
1511 | hash = HASH (exp, mode); | |
1512 | } | |
7afe21cc RK |
1513 | new = insert (exp, class1, hash, mode); |
1514 | new->in_memory = hash_arg_in_memory; | |
1515 | new->in_struct = hash_arg_in_struct; | |
1516 | } | |
1517 | } | |
1518 | } | |
1519 | \f | |
1520 | /* Remove from the hash table, or mark as invalid, | |
1521 | all expressions whose values could be altered by storing in X. | |
1522 | X is a register, a subreg, or a memory reference with nonvarying address | |
1523 | (because, when a memory reference with a varying address is stored in, | |
1524 | all memory references are removed by invalidate_memory | |
1525 | so specific invalidation is superfluous). | |
bb4034b3 JW |
1526 | FULL_MODE, if not VOIDmode, indicates that this much should be invalidated |
1527 | instead of just the amount indicated by the mode of X. This is only used | |
1528 | for bitfield stores into memory. | |
7afe21cc RK |
1529 | |
1530 | A nonvarying address may be just a register or just | |
1531 | a symbol reference, or it may be either of those plus | |
1532 | a numeric offset. */ | |
1533 | ||
1534 | static void | |
bb4034b3 | 1535 | invalidate (x, full_mode) |
7afe21cc | 1536 | rtx x; |
bb4034b3 | 1537 | enum machine_mode full_mode; |
7afe21cc RK |
1538 | { |
1539 | register int i; | |
1540 | register struct table_elt *p; | |
7afe21cc RK |
1541 | |
1542 | /* If X is a register, dependencies on its contents | |
1543 | are recorded through the qty number mechanism. | |
1544 | Just change the qty number of the register, | |
1545 | mark it as invalid for expressions that refer to it, | |
1546 | and remove it itself. */ | |
1547 | ||
1548 | if (GET_CODE (x) == REG) | |
1549 | { | |
1550 | register int regno = REGNO (x); | |
2197a88a | 1551 | register unsigned hash = HASH (x, GET_MODE (x)); |
7afe21cc RK |
1552 | |
1553 | /* Remove REGNO from any quantity list it might be on and indicate | |
9ec36da5 | 1554 | that its value might have changed. If it is a pseudo, remove its |
7afe21cc RK |
1555 | entry from the hash table. |
1556 | ||
1557 | For a hard register, we do the first two actions above for any | |
1558 | additional hard registers corresponding to X. Then, if any of these | |
1559 | registers are in the table, we must remove any REG entries that | |
1560 | overlap these registers. */ | |
1561 | ||
1562 | delete_reg_equiv (regno); | |
1563 | reg_tick[regno]++; | |
1564 | ||
1565 | if (regno >= FIRST_PSEUDO_REGISTER) | |
85e4d983 RK |
1566 | { |
1567 | /* Because a register can be referenced in more than one mode, | |
1568 | we might have to remove more than one table entry. */ | |
1569 | ||
1570 | struct table_elt *elt; | |
1571 | ||
2d8b0f3a | 1572 | while ((elt = lookup_for_remove (x, hash, GET_MODE (x)))) |
85e4d983 RK |
1573 | remove_from_table (elt, hash); |
1574 | } | |
7afe21cc RK |
1575 | else |
1576 | { | |
54b1de55 RK |
1577 | HOST_WIDE_INT in_table |
1578 | = TEST_HARD_REG_BIT (hard_regs_in_table, regno); | |
7afe21cc RK |
1579 | int endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (x)); |
1580 | int tregno, tendregno; | |
1581 | register struct table_elt *p, *next; | |
1582 | ||
1583 | CLEAR_HARD_REG_BIT (hard_regs_in_table, regno); | |
1584 | ||
1585 | for (i = regno + 1; i < endregno; i++) | |
1586 | { | |
1587 | in_table |= TEST_HARD_REG_BIT (hard_regs_in_table, i); | |
1588 | CLEAR_HARD_REG_BIT (hard_regs_in_table, i); | |
1589 | delete_reg_equiv (i); | |
1590 | reg_tick[i]++; | |
1591 | } | |
1592 | ||
1593 | if (in_table) | |
1594 | for (hash = 0; hash < NBUCKETS; hash++) | |
1595 | for (p = table[hash]; p; p = next) | |
1596 | { | |
1597 | next = p->next_same_hash; | |
1598 | ||
1599 | if (GET_CODE (p->exp) != REG | |
1600 | || REGNO (p->exp) >= FIRST_PSEUDO_REGISTER) | |
1601 | continue; | |
1602 | ||
1603 | tregno = REGNO (p->exp); | |
1604 | tendregno | |
1605 | = tregno + HARD_REGNO_NREGS (tregno, GET_MODE (p->exp)); | |
1606 | if (tendregno > regno && tregno < endregno) | |
1607 | remove_from_table (p, hash); | |
1608 | } | |
1609 | } | |
1610 | ||
1611 | return; | |
1612 | } | |
1613 | ||
1614 | if (GET_CODE (x) == SUBREG) | |
1615 | { | |
1616 | if (GET_CODE (SUBREG_REG (x)) != REG) | |
1617 | abort (); | |
bb4034b3 | 1618 | invalidate (SUBREG_REG (x), VOIDmode); |
7afe21cc RK |
1619 | return; |
1620 | } | |
1621 | ||
aac5cc16 RH |
1622 | /* If X is a parallel, invalidate all of its elements. */ |
1623 | ||
1624 | if (GET_CODE (x) == PARALLEL) | |
1625 | { | |
1626 | for (i = XVECLEN (x, 0) - 1; i >= 0 ; --i) | |
1627 | invalidate (XVECEXP (x, 0, i), VOIDmode); | |
1628 | return; | |
1629 | } | |
1630 | ||
1631 | /* If X is an expr_list, this is part of a disjoint return value; | |
1632 | extract the location in question ignoring the offset. */ | |
1633 | ||
1634 | if (GET_CODE (x) == EXPR_LIST) | |
1635 | { | |
1636 | invalidate (XEXP (x, 0), VOIDmode); | |
1637 | return; | |
1638 | } | |
1639 | ||
7afe21cc RK |
1640 | /* X is not a register; it must be a memory reference with |
1641 | a nonvarying address. Remove all hash table elements | |
1642 | that refer to overlapping pieces of memory. */ | |
1643 | ||
1644 | if (GET_CODE (x) != MEM) | |
1645 | abort (); | |
7afe21cc | 1646 | |
bb4034b3 JW |
1647 | if (full_mode == VOIDmode) |
1648 | full_mode = GET_MODE (x); | |
1649 | ||
7afe21cc RK |
1650 | for (i = 0; i < NBUCKETS; i++) |
1651 | { | |
1652 | register struct table_elt *next; | |
1653 | for (p = table[i]; p; p = next) | |
1654 | { | |
1655 | next = p->next_same_hash; | |
9ae8ffe7 JL |
1656 | /* Invalidate ASM_OPERANDS which reference memory (this is easier |
1657 | than checking all the aliases). */ | |
1658 | if (p->in_memory | |
1659 | && (GET_CODE (p->exp) != MEM | |
1660 | || true_dependence (x, full_mode, p->exp, cse_rtx_varies_p))) | |
7afe21cc RK |
1661 | remove_from_table (p, i); |
1662 | } | |
1663 | } | |
1664 | } | |
1665 | ||
1666 | /* Remove all expressions that refer to register REGNO, | |
1667 | since they are already invalid, and we are about to | |
1668 | mark that register valid again and don't want the old | |
1669 | expressions to reappear as valid. */ | |
1670 | ||
1671 | static void | |
1672 | remove_invalid_refs (regno) | |
1673 | int regno; | |
1674 | { | |
1675 | register int i; | |
1676 | register struct table_elt *p, *next; | |
1677 | ||
1678 | for (i = 0; i < NBUCKETS; i++) | |
1679 | for (p = table[i]; p; p = next) | |
1680 | { | |
1681 | next = p->next_same_hash; | |
1682 | if (GET_CODE (p->exp) != REG | |
906c4e36 | 1683 | && refers_to_regno_p (regno, regno + 1, p->exp, NULL_PTR)) |
7afe21cc RK |
1684 | remove_from_table (p, i); |
1685 | } | |
1686 | } | |
1687 | \f | |
1688 | /* Recompute the hash codes of any valid entries in the hash table that | |
1689 | reference X, if X is a register, or SUBREG_REG (X) if X is a SUBREG. | |
1690 | ||
1691 | This is called when we make a jump equivalence. */ | |
1692 | ||
1693 | static void | |
1694 | rehash_using_reg (x) | |
1695 | rtx x; | |
1696 | { | |
1697 | int i; | |
1698 | struct table_elt *p, *next; | |
2197a88a | 1699 | unsigned hash; |
7afe21cc RK |
1700 | |
1701 | if (GET_CODE (x) == SUBREG) | |
1702 | x = SUBREG_REG (x); | |
1703 | ||
1704 | /* If X is not a register or if the register is known not to be in any | |
1705 | valid entries in the table, we have no work to do. */ | |
1706 | ||
1707 | if (GET_CODE (x) != REG | |
1708 | || reg_in_table[REGNO (x)] < 0 | |
1709 | || reg_in_table[REGNO (x)] != reg_tick[REGNO (x)]) | |
1710 | return; | |
1711 | ||
1712 | /* Scan all hash chains looking for valid entries that mention X. | |
1713 | If we find one and it is in the wrong hash chain, move it. We can skip | |
1714 | objects that are registers, since they are handled specially. */ | |
1715 | ||
1716 | for (i = 0; i < NBUCKETS; i++) | |
1717 | for (p = table[i]; p; p = next) | |
1718 | { | |
1719 | next = p->next_same_hash; | |
1720 | if (GET_CODE (p->exp) != REG && reg_mentioned_p (x, p->exp) | |
538b78e7 | 1721 | && exp_equiv_p (p->exp, p->exp, 1, 0) |
7afe21cc RK |
1722 | && i != (hash = safe_hash (p->exp, p->mode) % NBUCKETS)) |
1723 | { | |
1724 | if (p->next_same_hash) | |
1725 | p->next_same_hash->prev_same_hash = p->prev_same_hash; | |
1726 | ||
1727 | if (p->prev_same_hash) | |
1728 | p->prev_same_hash->next_same_hash = p->next_same_hash; | |
1729 | else | |
1730 | table[i] = p->next_same_hash; | |
1731 | ||
1732 | p->next_same_hash = table[hash]; | |
1733 | p->prev_same_hash = 0; | |
1734 | if (table[hash]) | |
1735 | table[hash]->prev_same_hash = p; | |
1736 | table[hash] = p; | |
1737 | } | |
1738 | } | |
1739 | } | |
1740 | \f | |
7afe21cc RK |
1741 | /* Remove from the hash table any expression that is a call-clobbered |
1742 | register. Also update their TICK values. */ | |
1743 | ||
1744 | static void | |
1745 | invalidate_for_call () | |
1746 | { | |
1747 | int regno, endregno; | |
1748 | int i; | |
2197a88a | 1749 | unsigned hash; |
7afe21cc RK |
1750 | struct table_elt *p, *next; |
1751 | int in_table = 0; | |
1752 | ||
1753 | /* Go through all the hard registers. For each that is clobbered in | |
1754 | a CALL_INSN, remove the register from quantity chains and update | |
1755 | reg_tick if defined. Also see if any of these registers is currently | |
1756 | in the table. */ | |
1757 | ||
1758 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) | |
1759 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) | |
1760 | { | |
1761 | delete_reg_equiv (regno); | |
1762 | if (reg_tick[regno] >= 0) | |
1763 | reg_tick[regno]++; | |
1764 | ||
0e227018 | 1765 | in_table |= (TEST_HARD_REG_BIT (hard_regs_in_table, regno) != 0); |
7afe21cc RK |
1766 | } |
1767 | ||
1768 | /* In the case where we have no call-clobbered hard registers in the | |
1769 | table, we are done. Otherwise, scan the table and remove any | |
1770 | entry that overlaps a call-clobbered register. */ | |
1771 | ||
1772 | if (in_table) | |
1773 | for (hash = 0; hash < NBUCKETS; hash++) | |
1774 | for (p = table[hash]; p; p = next) | |
1775 | { | |
1776 | next = p->next_same_hash; | |
1777 | ||
9ae8ffe7 JL |
1778 | if (p->in_memory) |
1779 | { | |
1780 | remove_from_table (p, hash); | |
1781 | continue; | |
1782 | } | |
1783 | ||
7afe21cc RK |
1784 | if (GET_CODE (p->exp) != REG |
1785 | || REGNO (p->exp) >= FIRST_PSEUDO_REGISTER) | |
1786 | continue; | |
1787 | ||
1788 | regno = REGNO (p->exp); | |
1789 | endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (p->exp)); | |
1790 | ||
1791 | for (i = regno; i < endregno; i++) | |
1792 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i)) | |
1793 | { | |
1794 | remove_from_table (p, hash); | |
1795 | break; | |
1796 | } | |
1797 | } | |
1798 | } | |
1799 | \f | |
1800 | /* Given an expression X of type CONST, | |
1801 | and ELT which is its table entry (or 0 if it | |
1802 | is not in the hash table), | |
1803 | return an alternate expression for X as a register plus integer. | |
1804 | If none can be found, return 0. */ | |
1805 | ||
1806 | static rtx | |
1807 | use_related_value (x, elt) | |
1808 | rtx x; | |
1809 | struct table_elt *elt; | |
1810 | { | |
1811 | register struct table_elt *relt = 0; | |
1812 | register struct table_elt *p, *q; | |
906c4e36 | 1813 | HOST_WIDE_INT offset; |
7afe21cc RK |
1814 | |
1815 | /* First, is there anything related known? | |
1816 | If we have a table element, we can tell from that. | |
1817 | Otherwise, must look it up. */ | |
1818 | ||
1819 | if (elt != 0 && elt->related_value != 0) | |
1820 | relt = elt; | |
1821 | else if (elt == 0 && GET_CODE (x) == CONST) | |
1822 | { | |
1823 | rtx subexp = get_related_value (x); | |
1824 | if (subexp != 0) | |
1825 | relt = lookup (subexp, | |
1826 | safe_hash (subexp, GET_MODE (subexp)) % NBUCKETS, | |
1827 | GET_MODE (subexp)); | |
1828 | } | |
1829 | ||
1830 | if (relt == 0) | |
1831 | return 0; | |
1832 | ||
1833 | /* Search all related table entries for one that has an | |
1834 | equivalent register. */ | |
1835 | ||
1836 | p = relt; | |
1837 | while (1) | |
1838 | { | |
1839 | /* This loop is strange in that it is executed in two different cases. | |
1840 | The first is when X is already in the table. Then it is searching | |
1841 | the RELATED_VALUE list of X's class (RELT). The second case is when | |
1842 | X is not in the table. Then RELT points to a class for the related | |
1843 | value. | |
1844 | ||
1845 | Ensure that, whatever case we are in, that we ignore classes that have | |
1846 | the same value as X. */ | |
1847 | ||
1848 | if (rtx_equal_p (x, p->exp)) | |
1849 | q = 0; | |
1850 | else | |
1851 | for (q = p->first_same_value; q; q = q->next_same_value) | |
1852 | if (GET_CODE (q->exp) == REG) | |
1853 | break; | |
1854 | ||
1855 | if (q) | |
1856 | break; | |
1857 | ||
1858 | p = p->related_value; | |
1859 | ||
1860 | /* We went all the way around, so there is nothing to be found. | |
1861 | Alternatively, perhaps RELT was in the table for some other reason | |
1862 | and it has no related values recorded. */ | |
1863 | if (p == relt || p == 0) | |
1864 | break; | |
1865 | } | |
1866 | ||
1867 | if (q == 0) | |
1868 | return 0; | |
1869 | ||
1870 | offset = (get_integer_term (x) - get_integer_term (p->exp)); | |
1871 | /* Note: OFFSET may be 0 if P->xexp and X are related by commutativity. */ | |
1872 | return plus_constant (q->exp, offset); | |
1873 | } | |
1874 | \f | |
1875 | /* Hash an rtx. We are careful to make sure the value is never negative. | |
1876 | Equivalent registers hash identically. | |
1877 | MODE is used in hashing for CONST_INTs only; | |
1878 | otherwise the mode of X is used. | |
1879 | ||
1880 | Store 1 in do_not_record if any subexpression is volatile. | |
1881 | ||
1882 | Store 1 in hash_arg_in_memory if X contains a MEM rtx | |
1883 | which does not have the RTX_UNCHANGING_P bit set. | |
1884 | In this case, also store 1 in hash_arg_in_struct | |
1885 | if there is a MEM rtx which has the MEM_IN_STRUCT_P bit set. | |
1886 | ||
1887 | Note that cse_insn knows that the hash code of a MEM expression | |
1888 | is just (int) MEM plus the hash code of the address. */ | |
1889 | ||
2197a88a | 1890 | static unsigned |
7afe21cc RK |
1891 | canon_hash (x, mode) |
1892 | rtx x; | |
1893 | enum machine_mode mode; | |
1894 | { | |
1895 | register int i, j; | |
2197a88a | 1896 | register unsigned hash = 0; |
7afe21cc RK |
1897 | register enum rtx_code code; |
1898 | register char *fmt; | |
1899 | ||
1900 | /* repeat is used to turn tail-recursion into iteration. */ | |
1901 | repeat: | |
1902 | if (x == 0) | |
1903 | return hash; | |
1904 | ||
1905 | code = GET_CODE (x); | |
1906 | switch (code) | |
1907 | { | |
1908 | case REG: | |
1909 | { | |
1910 | register int regno = REGNO (x); | |
1911 | ||
1912 | /* On some machines, we can't record any non-fixed hard register, | |
1913 | because extending its life will cause reload problems. We | |
1914 | consider ap, fp, and sp to be fixed for this purpose. | |
0f41302f | 1915 | On all machines, we can't record any global registers. */ |
7afe21cc RK |
1916 | |
1917 | if (regno < FIRST_PSEUDO_REGISTER | |
1918 | && (global_regs[regno] | |
f95182a4 ILT |
1919 | || (SMALL_REGISTER_CLASSES |
1920 | && ! fixed_regs[regno] | |
7afe21cc | 1921 | && regno != FRAME_POINTER_REGNUM |
8bc169f2 | 1922 | && regno != HARD_FRAME_POINTER_REGNUM |
7afe21cc | 1923 | && regno != ARG_POINTER_REGNUM |
e9a25f70 | 1924 | && regno != STACK_POINTER_REGNUM))) |
7afe21cc RK |
1925 | { |
1926 | do_not_record = 1; | |
1927 | return 0; | |
1928 | } | |
2197a88a RK |
1929 | hash += ((unsigned) REG << 7) + (unsigned) reg_qty[regno]; |
1930 | return hash; | |
7afe21cc RK |
1931 | } |
1932 | ||
1933 | case CONST_INT: | |
2197a88a RK |
1934 | { |
1935 | unsigned HOST_WIDE_INT tem = INTVAL (x); | |
1936 | hash += ((unsigned) CONST_INT << 7) + (unsigned) mode + tem; | |
1937 | return hash; | |
1938 | } | |
7afe21cc RK |
1939 | |
1940 | case CONST_DOUBLE: | |
1941 | /* This is like the general case, except that it only counts | |
1942 | the integers representing the constant. */ | |
2197a88a | 1943 | hash += (unsigned) code + (unsigned) GET_MODE (x); |
969c8517 RK |
1944 | if (GET_MODE (x) != VOIDmode) |
1945 | for (i = 2; i < GET_RTX_LENGTH (CONST_DOUBLE); i++) | |
1946 | { | |
1947 | unsigned tem = XINT (x, i); | |
1948 | hash += tem; | |
1949 | } | |
1950 | else | |
1951 | hash += ((unsigned) CONST_DOUBLE_LOW (x) | |
1952 | + (unsigned) CONST_DOUBLE_HIGH (x)); | |
7afe21cc RK |
1953 | return hash; |
1954 | ||
1955 | /* Assume there is only one rtx object for any given label. */ | |
1956 | case LABEL_REF: | |
3c543775 | 1957 | hash |
7bcac048 | 1958 | += ((unsigned) LABEL_REF << 7) + (unsigned long) XEXP (x, 0); |
2197a88a | 1959 | return hash; |
7afe21cc RK |
1960 | |
1961 | case SYMBOL_REF: | |
3c543775 | 1962 | hash |
7bcac048 | 1963 | += ((unsigned) SYMBOL_REF << 7) + (unsigned long) XSTR (x, 0); |
2197a88a | 1964 | return hash; |
7afe21cc RK |
1965 | |
1966 | case MEM: | |
1967 | if (MEM_VOLATILE_P (x)) | |
1968 | { | |
1969 | do_not_record = 1; | |
1970 | return 0; | |
1971 | } | |
9ad91d71 | 1972 | if (! RTX_UNCHANGING_P (x) || FIXED_BASE_PLUS_P (XEXP (x, 0))) |
7afe21cc RK |
1973 | { |
1974 | hash_arg_in_memory = 1; | |
1975 | if (MEM_IN_STRUCT_P (x)) hash_arg_in_struct = 1; | |
1976 | } | |
1977 | /* Now that we have already found this special case, | |
1978 | might as well speed it up as much as possible. */ | |
2197a88a | 1979 | hash += (unsigned) MEM; |
7afe21cc RK |
1980 | x = XEXP (x, 0); |
1981 | goto repeat; | |
1982 | ||
1983 | case PRE_DEC: | |
1984 | case PRE_INC: | |
1985 | case POST_DEC: | |
1986 | case POST_INC: | |
1987 | case PC: | |
1988 | case CC0: | |
1989 | case CALL: | |
1990 | case UNSPEC_VOLATILE: | |
1991 | do_not_record = 1; | |
1992 | return 0; | |
1993 | ||
1994 | case ASM_OPERANDS: | |
1995 | if (MEM_VOLATILE_P (x)) | |
1996 | { | |
1997 | do_not_record = 1; | |
1998 | return 0; | |
1999 | } | |
e9a25f70 JL |
2000 | break; |
2001 | ||
2002 | default: | |
2003 | break; | |
7afe21cc RK |
2004 | } |
2005 | ||
2006 | i = GET_RTX_LENGTH (code) - 1; | |
2197a88a | 2007 | hash += (unsigned) code + (unsigned) GET_MODE (x); |
7afe21cc RK |
2008 | fmt = GET_RTX_FORMAT (code); |
2009 | for (; i >= 0; i--) | |
2010 | { | |
2011 | if (fmt[i] == 'e') | |
2012 | { | |
2013 | rtx tem = XEXP (x, i); | |
7afe21cc RK |
2014 | |
2015 | /* If we are about to do the last recursive call | |
2016 | needed at this level, change it into iteration. | |
2017 | This function is called enough to be worth it. */ | |
2018 | if (i == 0) | |
2019 | { | |
2020 | x = tem; | |
2021 | goto repeat; | |
2022 | } | |
2023 | hash += canon_hash (tem, 0); | |
2024 | } | |
2025 | else if (fmt[i] == 'E') | |
2026 | for (j = 0; j < XVECLEN (x, i); j++) | |
2027 | hash += canon_hash (XVECEXP (x, i, j), 0); | |
2028 | else if (fmt[i] == 's') | |
2029 | { | |
2197a88a | 2030 | register unsigned char *p = (unsigned char *) XSTR (x, i); |
7afe21cc RK |
2031 | if (p) |
2032 | while (*p) | |
2197a88a | 2033 | hash += *p++; |
7afe21cc RK |
2034 | } |
2035 | else if (fmt[i] == 'i') | |
2036 | { | |
2197a88a RK |
2037 | register unsigned tem = XINT (x, i); |
2038 | hash += tem; | |
7afe21cc | 2039 | } |
e9a25f70 JL |
2040 | else if (fmt[i] == '0') |
2041 | /* unused */; | |
7afe21cc RK |
2042 | else |
2043 | abort (); | |
2044 | } | |
2045 | return hash; | |
2046 | } | |
2047 | ||
2048 | /* Like canon_hash but with no side effects. */ | |
2049 | ||
2197a88a | 2050 | static unsigned |
7afe21cc RK |
2051 | safe_hash (x, mode) |
2052 | rtx x; | |
2053 | enum machine_mode mode; | |
2054 | { | |
2055 | int save_do_not_record = do_not_record; | |
2056 | int save_hash_arg_in_memory = hash_arg_in_memory; | |
2057 | int save_hash_arg_in_struct = hash_arg_in_struct; | |
2197a88a | 2058 | unsigned hash = canon_hash (x, mode); |
7afe21cc RK |
2059 | hash_arg_in_memory = save_hash_arg_in_memory; |
2060 | hash_arg_in_struct = save_hash_arg_in_struct; | |
2061 | do_not_record = save_do_not_record; | |
2062 | return hash; | |
2063 | } | |
2064 | \f | |
2065 | /* Return 1 iff X and Y would canonicalize into the same thing, | |
2066 | without actually constructing the canonicalization of either one. | |
2067 | If VALIDATE is nonzero, | |
2068 | we assume X is an expression being processed from the rtl | |
2069 | and Y was found in the hash table. We check register refs | |
2070 | in Y for being marked as valid. | |
2071 | ||
2072 | If EQUAL_VALUES is nonzero, we allow a register to match a constant value | |
2073 | that is known to be in the register. Ordinarily, we don't allow them | |
2074 | to match, because letting them match would cause unpredictable results | |
2075 | in all the places that search a hash table chain for an equivalent | |
2076 | for a given value. A possible equivalent that has different structure | |
2077 | has its hash code computed from different data. Whether the hash code | |
38e01259 | 2078 | is the same as that of the given value is pure luck. */ |
7afe21cc RK |
2079 | |
2080 | static int | |
2081 | exp_equiv_p (x, y, validate, equal_values) | |
2082 | rtx x, y; | |
2083 | int validate; | |
2084 | int equal_values; | |
2085 | { | |
906c4e36 | 2086 | register int i, j; |
7afe21cc RK |
2087 | register enum rtx_code code; |
2088 | register char *fmt; | |
2089 | ||
2090 | /* Note: it is incorrect to assume an expression is equivalent to itself | |
2091 | if VALIDATE is nonzero. */ | |
2092 | if (x == y && !validate) | |
2093 | return 1; | |
2094 | if (x == 0 || y == 0) | |
2095 | return x == y; | |
2096 | ||
2097 | code = GET_CODE (x); | |
2098 | if (code != GET_CODE (y)) | |
2099 | { | |
2100 | if (!equal_values) | |
2101 | return 0; | |
2102 | ||
2103 | /* If X is a constant and Y is a register or vice versa, they may be | |
2104 | equivalent. We only have to validate if Y is a register. */ | |
2105 | if (CONSTANT_P (x) && GET_CODE (y) == REG | |
2106 | && REGNO_QTY_VALID_P (REGNO (y)) | |
2107 | && GET_MODE (y) == qty_mode[reg_qty[REGNO (y)]] | |
2108 | && rtx_equal_p (x, qty_const[reg_qty[REGNO (y)]]) | |
2109 | && (! validate || reg_in_table[REGNO (y)] == reg_tick[REGNO (y)])) | |
2110 | return 1; | |
2111 | ||
2112 | if (CONSTANT_P (y) && code == REG | |
2113 | && REGNO_QTY_VALID_P (REGNO (x)) | |
2114 | && GET_MODE (x) == qty_mode[reg_qty[REGNO (x)]] | |
2115 | && rtx_equal_p (y, qty_const[reg_qty[REGNO (x)]])) | |
2116 | return 1; | |
2117 | ||
2118 | return 0; | |
2119 | } | |
2120 | ||
2121 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */ | |
2122 | if (GET_MODE (x) != GET_MODE (y)) | |
2123 | return 0; | |
2124 | ||
2125 | switch (code) | |
2126 | { | |
2127 | case PC: | |
2128 | case CC0: | |
2129 | return x == y; | |
2130 | ||
2131 | case CONST_INT: | |
58c8c593 | 2132 | return INTVAL (x) == INTVAL (y); |
7afe21cc RK |
2133 | |
2134 | case LABEL_REF: | |
7afe21cc RK |
2135 | return XEXP (x, 0) == XEXP (y, 0); |
2136 | ||
f54d4924 RK |
2137 | case SYMBOL_REF: |
2138 | return XSTR (x, 0) == XSTR (y, 0); | |
2139 | ||
7afe21cc RK |
2140 | case REG: |
2141 | { | |
2142 | int regno = REGNO (y); | |
2143 | int endregno | |
2144 | = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1 | |
2145 | : HARD_REGNO_NREGS (regno, GET_MODE (y))); | |
2146 | int i; | |
2147 | ||
2148 | /* If the quantities are not the same, the expressions are not | |
2149 | equivalent. If there are and we are not to validate, they | |
2150 | are equivalent. Otherwise, ensure all regs are up-to-date. */ | |
2151 | ||
2152 | if (reg_qty[REGNO (x)] != reg_qty[regno]) | |
2153 | return 0; | |
2154 | ||
2155 | if (! validate) | |
2156 | return 1; | |
2157 | ||
2158 | for (i = regno; i < endregno; i++) | |
2159 | if (reg_in_table[i] != reg_tick[i]) | |
2160 | return 0; | |
2161 | ||
2162 | return 1; | |
2163 | } | |
2164 | ||
2165 | /* For commutative operations, check both orders. */ | |
2166 | case PLUS: | |
2167 | case MULT: | |
2168 | case AND: | |
2169 | case IOR: | |
2170 | case XOR: | |
2171 | case NE: | |
2172 | case EQ: | |
2173 | return ((exp_equiv_p (XEXP (x, 0), XEXP (y, 0), validate, equal_values) | |
2174 | && exp_equiv_p (XEXP (x, 1), XEXP (y, 1), | |
2175 | validate, equal_values)) | |
2176 | || (exp_equiv_p (XEXP (x, 0), XEXP (y, 1), | |
2177 | validate, equal_values) | |
2178 | && exp_equiv_p (XEXP (x, 1), XEXP (y, 0), | |
2179 | validate, equal_values))); | |
e9a25f70 JL |
2180 | |
2181 | default: | |
2182 | break; | |
7afe21cc RK |
2183 | } |
2184 | ||
2185 | /* Compare the elements. If any pair of corresponding elements | |
2186 | fail to match, return 0 for the whole things. */ | |
2187 | ||
2188 | fmt = GET_RTX_FORMAT (code); | |
2189 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2190 | { | |
906c4e36 | 2191 | switch (fmt[i]) |
7afe21cc | 2192 | { |
906c4e36 | 2193 | case 'e': |
7afe21cc RK |
2194 | if (! exp_equiv_p (XEXP (x, i), XEXP (y, i), validate, equal_values)) |
2195 | return 0; | |
906c4e36 RK |
2196 | break; |
2197 | ||
2198 | case 'E': | |
7afe21cc RK |
2199 | if (XVECLEN (x, i) != XVECLEN (y, i)) |
2200 | return 0; | |
2201 | for (j = 0; j < XVECLEN (x, i); j++) | |
2202 | if (! exp_equiv_p (XVECEXP (x, i, j), XVECEXP (y, i, j), | |
2203 | validate, equal_values)) | |
2204 | return 0; | |
906c4e36 RK |
2205 | break; |
2206 | ||
2207 | case 's': | |
7afe21cc RK |
2208 | if (strcmp (XSTR (x, i), XSTR (y, i))) |
2209 | return 0; | |
906c4e36 RK |
2210 | break; |
2211 | ||
2212 | case 'i': | |
7afe21cc RK |
2213 | if (XINT (x, i) != XINT (y, i)) |
2214 | return 0; | |
906c4e36 RK |
2215 | break; |
2216 | ||
2217 | case 'w': | |
2218 | if (XWINT (x, i) != XWINT (y, i)) | |
2219 | return 0; | |
2220 | break; | |
2221 | ||
2222 | case '0': | |
2223 | break; | |
2224 | ||
2225 | default: | |
2226 | abort (); | |
7afe21cc | 2227 | } |
906c4e36 RK |
2228 | } |
2229 | ||
7afe21cc RK |
2230 | return 1; |
2231 | } | |
2232 | \f | |
2233 | /* Return 1 iff any subexpression of X matches Y. | |
2234 | Here we do not require that X or Y be valid (for registers referred to) | |
2235 | for being in the hash table. */ | |
2236 | ||
6cd4575e | 2237 | static int |
7afe21cc RK |
2238 | refers_to_p (x, y) |
2239 | rtx x, y; | |
2240 | { | |
2241 | register int i; | |
2242 | register enum rtx_code code; | |
2243 | register char *fmt; | |
2244 | ||
2245 | repeat: | |
2246 | if (x == y) | |
2247 | return 1; | |
2248 | if (x == 0 || y == 0) | |
2249 | return 0; | |
2250 | ||
2251 | code = GET_CODE (x); | |
2252 | /* If X as a whole has the same code as Y, they may match. | |
2253 | If so, return 1. */ | |
2254 | if (code == GET_CODE (y)) | |
2255 | { | |
2256 | if (exp_equiv_p (x, y, 0, 1)) | |
2257 | return 1; | |
2258 | } | |
2259 | ||
2260 | /* X does not match, so try its subexpressions. */ | |
2261 | ||
2262 | fmt = GET_RTX_FORMAT (code); | |
2263 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2264 | if (fmt[i] == 'e') | |
2265 | { | |
2266 | if (i == 0) | |
2267 | { | |
2268 | x = XEXP (x, 0); | |
2269 | goto repeat; | |
2270 | } | |
2271 | else | |
2272 | if (refers_to_p (XEXP (x, i), y)) | |
2273 | return 1; | |
2274 | } | |
2275 | else if (fmt[i] == 'E') | |
2276 | { | |
2277 | int j; | |
2278 | for (j = 0; j < XVECLEN (x, i); j++) | |
2279 | if (refers_to_p (XVECEXP (x, i, j), y)) | |
2280 | return 1; | |
2281 | } | |
2282 | ||
2283 | return 0; | |
2284 | } | |
2285 | \f | |
f451db89 JL |
2286 | /* Given ADDR and SIZE (a memory address, and the size of the memory reference), |
2287 | set PBASE, PSTART, and PEND which correspond to the base of the address, | |
2288 | the starting offset, and ending offset respectively. | |
2289 | ||
bb4034b3 | 2290 | ADDR is known to be a nonvarying address. */ |
f451db89 | 2291 | |
bb4034b3 JW |
2292 | /* ??? Despite what the comments say, this function is in fact frequently |
2293 | passed varying addresses. This does not appear to cause any problems. */ | |
f451db89 JL |
2294 | |
2295 | static void | |
2296 | set_nonvarying_address_components (addr, size, pbase, pstart, pend) | |
2297 | rtx addr; | |
2298 | int size; | |
2299 | rtx *pbase; | |
6500fb43 | 2300 | HOST_WIDE_INT *pstart, *pend; |
f451db89 JL |
2301 | { |
2302 | rtx base; | |
c85663b1 | 2303 | HOST_WIDE_INT start, end; |
f451db89 JL |
2304 | |
2305 | base = addr; | |
2306 | start = 0; | |
2307 | end = 0; | |
2308 | ||
e5e809f4 JL |
2309 | if (flag_pic && GET_CODE (base) == PLUS |
2310 | && XEXP (base, 0) == pic_offset_table_rtx) | |
2311 | base = XEXP (base, 1); | |
2312 | ||
f451db89 JL |
2313 | /* Registers with nonvarying addresses usually have constant equivalents; |
2314 | but the frame pointer register is also possible. */ | |
2315 | if (GET_CODE (base) == REG | |
2316 | && qty_const != 0 | |
2317 | && REGNO_QTY_VALID_P (REGNO (base)) | |
2318 | && qty_mode[reg_qty[REGNO (base)]] == GET_MODE (base) | |
2319 | && qty_const[reg_qty[REGNO (base)]] != 0) | |
2320 | base = qty_const[reg_qty[REGNO (base)]]; | |
2321 | else if (GET_CODE (base) == PLUS | |
2322 | && GET_CODE (XEXP (base, 1)) == CONST_INT | |
2323 | && GET_CODE (XEXP (base, 0)) == REG | |
2324 | && qty_const != 0 | |
2325 | && REGNO_QTY_VALID_P (REGNO (XEXP (base, 0))) | |
2326 | && (qty_mode[reg_qty[REGNO (XEXP (base, 0))]] | |
2327 | == GET_MODE (XEXP (base, 0))) | |
2328 | && qty_const[reg_qty[REGNO (XEXP (base, 0))]]) | |
2329 | { | |
2330 | start = INTVAL (XEXP (base, 1)); | |
2331 | base = qty_const[reg_qty[REGNO (XEXP (base, 0))]]; | |
2332 | } | |
9c6b0bae | 2333 | /* This can happen as the result of virtual register instantiation, |
abc95ed3 | 2334 | if the initial offset is too large to be a valid address. */ |
9c6b0bae RK |
2335 | else if (GET_CODE (base) == PLUS |
2336 | && GET_CODE (XEXP (base, 0)) == REG | |
2337 | && GET_CODE (XEXP (base, 1)) == REG | |
2338 | && qty_const != 0 | |
2339 | && REGNO_QTY_VALID_P (REGNO (XEXP (base, 0))) | |
2340 | && (qty_mode[reg_qty[REGNO (XEXP (base, 0))]] | |
2341 | == GET_MODE (XEXP (base, 0))) | |
2342 | && qty_const[reg_qty[REGNO (XEXP (base, 0))]] | |
2343 | && REGNO_QTY_VALID_P (REGNO (XEXP (base, 1))) | |
2344 | && (qty_mode[reg_qty[REGNO (XEXP (base, 1))]] | |
2345 | == GET_MODE (XEXP (base, 1))) | |
2346 | && qty_const[reg_qty[REGNO (XEXP (base, 1))]]) | |
2347 | { | |
2348 | rtx tem = qty_const[reg_qty[REGNO (XEXP (base, 1))]]; | |
2349 | base = qty_const[reg_qty[REGNO (XEXP (base, 0))]]; | |
2350 | ||
2351 | /* One of the two values must be a constant. */ | |
2352 | if (GET_CODE (base) != CONST_INT) | |
2353 | { | |
2354 | if (GET_CODE (tem) != CONST_INT) | |
2355 | abort (); | |
2356 | start = INTVAL (tem); | |
2357 | } | |
2358 | else | |
2359 | { | |
2360 | start = INTVAL (base); | |
2361 | base = tem; | |
2362 | } | |
2363 | } | |
f451db89 | 2364 | |
c85663b1 RK |
2365 | /* Handle everything that we can find inside an address that has been |
2366 | viewed as constant. */ | |
f451db89 | 2367 | |
c85663b1 | 2368 | while (1) |
f451db89 | 2369 | { |
c85663b1 RK |
2370 | /* If no part of this switch does a "continue", the code outside |
2371 | will exit this loop. */ | |
2372 | ||
2373 | switch (GET_CODE (base)) | |
2374 | { | |
2375 | case LO_SUM: | |
2376 | /* By definition, operand1 of a LO_SUM is the associated constant | |
2377 | address. Use the associated constant address as the base | |
2378 | instead. */ | |
2379 | base = XEXP (base, 1); | |
2380 | continue; | |
2381 | ||
2382 | case CONST: | |
2383 | /* Strip off CONST. */ | |
2384 | base = XEXP (base, 0); | |
2385 | continue; | |
2386 | ||
2387 | case PLUS: | |
2388 | if (GET_CODE (XEXP (base, 1)) == CONST_INT) | |
2389 | { | |
2390 | start += INTVAL (XEXP (base, 1)); | |
2391 | base = XEXP (base, 0); | |
2392 | continue; | |
2393 | } | |
2394 | break; | |
2395 | ||
2396 | case AND: | |
2397 | /* Handle the case of an AND which is the negative of a power of | |
2398 | two. This is used to represent unaligned memory operations. */ | |
2399 | if (GET_CODE (XEXP (base, 1)) == CONST_INT | |
2400 | && exact_log2 (- INTVAL (XEXP (base, 1))) > 0) | |
2401 | { | |
2402 | set_nonvarying_address_components (XEXP (base, 0), size, | |
2403 | pbase, pstart, pend); | |
2404 | ||
2405 | /* Assume the worst misalignment. START is affected, but not | |
2406 | END, so compensate but adjusting SIZE. Don't lose any | |
2407 | constant we already had. */ | |
2408 | ||
2409 | size = *pend - *pstart - INTVAL (XEXP (base, 1)) - 1; | |
89046535 RK |
2410 | start += *pstart + INTVAL (XEXP (base, 1)) + 1; |
2411 | end += *pend; | |
c85663b1 RK |
2412 | base = *pbase; |
2413 | } | |
2414 | break; | |
e9a25f70 JL |
2415 | |
2416 | default: | |
2417 | break; | |
c85663b1 RK |
2418 | } |
2419 | ||
2420 | break; | |
f451db89 JL |
2421 | } |
2422 | ||
336d6f0a RK |
2423 | if (GET_CODE (base) == CONST_INT) |
2424 | { | |
2425 | start += INTVAL (base); | |
2426 | base = const0_rtx; | |
2427 | } | |
2428 | ||
f451db89 JL |
2429 | end = start + size; |
2430 | ||
2431 | /* Set the return values. */ | |
2432 | *pbase = base; | |
2433 | *pstart = start; | |
2434 | *pend = end; | |
2435 | } | |
2436 | ||
9ae8ffe7 JL |
2437 | /* Return 1 if X has a value that can vary even between two |
2438 | executions of the program. 0 means X can be compared reliably | |
2439 | against certain constants or near-constants. */ | |
7afe21cc RK |
2440 | |
2441 | static int | |
9ae8ffe7 JL |
2442 | cse_rtx_varies_p (x) |
2443 | register rtx x; | |
7afe21cc RK |
2444 | { |
2445 | /* We need not check for X and the equivalence class being of the same | |
2446 | mode because if X is equivalent to a constant in some mode, it | |
2447 | doesn't vary in any mode. */ | |
2448 | ||
9ae8ffe7 JL |
2449 | if (GET_CODE (x) == REG |
2450 | && REGNO_QTY_VALID_P (REGNO (x)) | |
2451 | && GET_MODE (x) == qty_mode[reg_qty[REGNO (x)]] | |
2452 | && qty_const[reg_qty[REGNO (x)]] != 0) | |
7afe21cc RK |
2453 | return 0; |
2454 | ||
9ae8ffe7 JL |
2455 | if (GET_CODE (x) == PLUS |
2456 | && GET_CODE (XEXP (x, 1)) == CONST_INT | |
2457 | && GET_CODE (XEXP (x, 0)) == REG | |
2458 | && REGNO_QTY_VALID_P (REGNO (XEXP (x, 0))) | |
2459 | && (GET_MODE (XEXP (x, 0)) | |
2460 | == qty_mode[reg_qty[REGNO (XEXP (x, 0))]]) | |
2461 | && qty_const[reg_qty[REGNO (XEXP (x, 0))]]) | |
7afe21cc RK |
2462 | return 0; |
2463 | ||
9c6b0bae RK |
2464 | /* This can happen as the result of virtual register instantiation, if |
2465 | the initial constant is too large to be a valid address. This gives | |
2466 | us a three instruction sequence, load large offset into a register, | |
2467 | load fp minus a constant into a register, then a MEM which is the | |
2468 | sum of the two `constant' registers. */ | |
9ae8ffe7 JL |
2469 | if (GET_CODE (x) == PLUS |
2470 | && GET_CODE (XEXP (x, 0)) == REG | |
2471 | && GET_CODE (XEXP (x, 1)) == REG | |
2472 | && REGNO_QTY_VALID_P (REGNO (XEXP (x, 0))) | |
2473 | && (GET_MODE (XEXP (x, 0)) | |
2474 | == qty_mode[reg_qty[REGNO (XEXP (x, 0))]]) | |
2475 | && qty_const[reg_qty[REGNO (XEXP (x, 0))]] | |
2476 | && REGNO_QTY_VALID_P (REGNO (XEXP (x, 1))) | |
2477 | && (GET_MODE (XEXP (x, 1)) | |
2478 | == qty_mode[reg_qty[REGNO (XEXP (x, 1))]]) | |
2479 | && qty_const[reg_qty[REGNO (XEXP (x, 1))]]) | |
9c6b0bae RK |
2480 | return 0; |
2481 | ||
9ae8ffe7 | 2482 | return rtx_varies_p (x); |
7afe21cc RK |
2483 | } |
2484 | \f | |
2485 | /* Canonicalize an expression: | |
2486 | replace each register reference inside it | |
2487 | with the "oldest" equivalent register. | |
2488 | ||
2489 | If INSN is non-zero and we are replacing a pseudo with a hard register | |
7722328e RK |
2490 | or vice versa, validate_change is used to ensure that INSN remains valid |
2491 | after we make our substitution. The calls are made with IN_GROUP non-zero | |
2492 | so apply_change_group must be called upon the outermost return from this | |
2493 | function (unless INSN is zero). The result of apply_change_group can | |
2494 | generally be discarded since the changes we are making are optional. */ | |
7afe21cc RK |
2495 | |
2496 | static rtx | |
2497 | canon_reg (x, insn) | |
2498 | rtx x; | |
2499 | rtx insn; | |
2500 | { | |
2501 | register int i; | |
2502 | register enum rtx_code code; | |
2503 | register char *fmt; | |
2504 | ||
2505 | if (x == 0) | |
2506 | return x; | |
2507 | ||
2508 | code = GET_CODE (x); | |
2509 | switch (code) | |
2510 | { | |
2511 | case PC: | |
2512 | case CC0: | |
2513 | case CONST: | |
2514 | case CONST_INT: | |
2515 | case CONST_DOUBLE: | |
2516 | case SYMBOL_REF: | |
2517 | case LABEL_REF: | |
2518 | case ADDR_VEC: | |
2519 | case ADDR_DIFF_VEC: | |
2520 | return x; | |
2521 | ||
2522 | case REG: | |
2523 | { | |
2524 | register int first; | |
2525 | ||
2526 | /* Never replace a hard reg, because hard regs can appear | |
2527 | in more than one machine mode, and we must preserve the mode | |
2528 | of each occurrence. Also, some hard regs appear in | |
2529 | MEMs that are shared and mustn't be altered. Don't try to | |
2530 | replace any reg that maps to a reg of class NO_REGS. */ | |
2531 | if (REGNO (x) < FIRST_PSEUDO_REGISTER | |
2532 | || ! REGNO_QTY_VALID_P (REGNO (x))) | |
2533 | return x; | |
2534 | ||
2535 | first = qty_first_reg[reg_qty[REGNO (x)]]; | |
2536 | return (first >= FIRST_PSEUDO_REGISTER ? regno_reg_rtx[first] | |
2537 | : REGNO_REG_CLASS (first) == NO_REGS ? x | |
38a448ca | 2538 | : gen_rtx_REG (qty_mode[reg_qty[REGNO (x)]], first)); |
7afe21cc | 2539 | } |
e9a25f70 JL |
2540 | |
2541 | default: | |
2542 | break; | |
7afe21cc RK |
2543 | } |
2544 | ||
2545 | fmt = GET_RTX_FORMAT (code); | |
2546 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2547 | { | |
2548 | register int j; | |
2549 | ||
2550 | if (fmt[i] == 'e') | |
2551 | { | |
2552 | rtx new = canon_reg (XEXP (x, i), insn); | |
58873255 | 2553 | int insn_code; |
7afe21cc RK |
2554 | |
2555 | /* If replacing pseudo with hard reg or vice versa, ensure the | |
178c39f6 | 2556 | insn remains valid. Likewise if the insn has MATCH_DUPs. */ |
aee9dc31 RS |
2557 | if (insn != 0 && new != 0 |
2558 | && GET_CODE (new) == REG && GET_CODE (XEXP (x, i)) == REG | |
178c39f6 RK |
2559 | && (((REGNO (new) < FIRST_PSEUDO_REGISTER) |
2560 | != (REGNO (XEXP (x, i)) < FIRST_PSEUDO_REGISTER)) | |
58873255 RK |
2561 | || (insn_code = recog_memoized (insn)) < 0 |
2562 | || insn_n_dups[insn_code] > 0)) | |
77fa0940 | 2563 | validate_change (insn, &XEXP (x, i), new, 1); |
7afe21cc RK |
2564 | else |
2565 | XEXP (x, i) = new; | |
2566 | } | |
2567 | else if (fmt[i] == 'E') | |
2568 | for (j = 0; j < XVECLEN (x, i); j++) | |
2569 | XVECEXP (x, i, j) = canon_reg (XVECEXP (x, i, j), insn); | |
2570 | } | |
2571 | ||
2572 | return x; | |
2573 | } | |
2574 | \f | |
a2cabb29 | 2575 | /* LOC is a location within INSN that is an operand address (the contents of |
7afe21cc RK |
2576 | a MEM). Find the best equivalent address to use that is valid for this |
2577 | insn. | |
2578 | ||
2579 | On most CISC machines, complicated address modes are costly, and rtx_cost | |
2580 | is a good approximation for that cost. However, most RISC machines have | |
2581 | only a few (usually only one) memory reference formats. If an address is | |
2582 | valid at all, it is often just as cheap as any other address. Hence, for | |
2583 | RISC machines, we use the configuration macro `ADDRESS_COST' to compare the | |
2584 | costs of various addresses. For two addresses of equal cost, choose the one | |
2585 | with the highest `rtx_cost' value as that has the potential of eliminating | |
2586 | the most insns. For equal costs, we choose the first in the equivalence | |
2587 | class. Note that we ignore the fact that pseudo registers are cheaper | |
2588 | than hard registers here because we would also prefer the pseudo registers. | |
2589 | */ | |
2590 | ||
6cd4575e | 2591 | static void |
7afe21cc RK |
2592 | find_best_addr (insn, loc) |
2593 | rtx insn; | |
2594 | rtx *loc; | |
2595 | { | |
7a87758d | 2596 | struct table_elt *elt; |
7afe21cc | 2597 | rtx addr = *loc; |
7a87758d AS |
2598 | #ifdef ADDRESS_COST |
2599 | struct table_elt *p; | |
7afe21cc | 2600 | int found_better = 1; |
7a87758d | 2601 | #endif |
7afe21cc RK |
2602 | int save_do_not_record = do_not_record; |
2603 | int save_hash_arg_in_memory = hash_arg_in_memory; | |
2604 | int save_hash_arg_in_struct = hash_arg_in_struct; | |
7afe21cc RK |
2605 | int addr_volatile; |
2606 | int regno; | |
2197a88a | 2607 | unsigned hash; |
7afe21cc RK |
2608 | |
2609 | /* Do not try to replace constant addresses or addresses of local and | |
2610 | argument slots. These MEM expressions are made only once and inserted | |
2611 | in many instructions, as well as being used to control symbol table | |
2612 | output. It is not safe to clobber them. | |
2613 | ||
2614 | There are some uncommon cases where the address is already in a register | |
2615 | for some reason, but we cannot take advantage of that because we have | |
2616 | no easy way to unshare the MEM. In addition, looking up all stack | |
2617 | addresses is costly. */ | |
2618 | if ((GET_CODE (addr) == PLUS | |
2619 | && GET_CODE (XEXP (addr, 0)) == REG | |
2620 | && GET_CODE (XEXP (addr, 1)) == CONST_INT | |
2621 | && (regno = REGNO (XEXP (addr, 0)), | |
8bc169f2 DE |
2622 | regno == FRAME_POINTER_REGNUM || regno == HARD_FRAME_POINTER_REGNUM |
2623 | || regno == ARG_POINTER_REGNUM)) | |
7afe21cc | 2624 | || (GET_CODE (addr) == REG |
8bc169f2 DE |
2625 | && (regno = REGNO (addr), regno == FRAME_POINTER_REGNUM |
2626 | || regno == HARD_FRAME_POINTER_REGNUM | |
2627 | || regno == ARG_POINTER_REGNUM)) | |
e9a25f70 | 2628 | || GET_CODE (addr) == ADDRESSOF |
7afe21cc RK |
2629 | || CONSTANT_ADDRESS_P (addr)) |
2630 | return; | |
2631 | ||
2632 | /* If this address is not simply a register, try to fold it. This will | |
2633 | sometimes simplify the expression. Many simplifications | |
2634 | will not be valid, but some, usually applying the associative rule, will | |
2635 | be valid and produce better code. */ | |
8c87f107 RK |
2636 | if (GET_CODE (addr) != REG) |
2637 | { | |
2638 | rtx folded = fold_rtx (copy_rtx (addr), NULL_RTX); | |
2639 | ||
2640 | if (1 | |
2641 | #ifdef ADDRESS_COST | |
2f541799 MM |
2642 | && (CSE_ADDRESS_COST (folded) < CSE_ADDRESS_COST (addr) |
2643 | || (CSE_ADDRESS_COST (folded) == CSE_ADDRESS_COST (addr) | |
9a252d29 | 2644 | && rtx_cost (folded, MEM) > rtx_cost (addr, MEM))) |
8c87f107 | 2645 | #else |
9a252d29 | 2646 | && rtx_cost (folded, MEM) < rtx_cost (addr, MEM) |
8c87f107 RK |
2647 | #endif |
2648 | && validate_change (insn, loc, folded, 0)) | |
2649 | addr = folded; | |
2650 | } | |
7afe21cc | 2651 | |
42495ca0 RK |
2652 | /* If this address is not in the hash table, we can't look for equivalences |
2653 | of the whole address. Also, ignore if volatile. */ | |
2654 | ||
7afe21cc | 2655 | do_not_record = 0; |
2197a88a | 2656 | hash = HASH (addr, Pmode); |
7afe21cc RK |
2657 | addr_volatile = do_not_record; |
2658 | do_not_record = save_do_not_record; | |
2659 | hash_arg_in_memory = save_hash_arg_in_memory; | |
2660 | hash_arg_in_struct = save_hash_arg_in_struct; | |
2661 | ||
2662 | if (addr_volatile) | |
2663 | return; | |
2664 | ||
2197a88a | 2665 | elt = lookup (addr, hash, Pmode); |
7afe21cc | 2666 | |
7afe21cc | 2667 | #ifndef ADDRESS_COST |
42495ca0 RK |
2668 | if (elt) |
2669 | { | |
2d8b0f3a | 2670 | int our_cost = elt->cost; |
42495ca0 RK |
2671 | |
2672 | /* Find the lowest cost below ours that works. */ | |
2673 | for (elt = elt->first_same_value; elt; elt = elt->next_same_value) | |
2674 | if (elt->cost < our_cost | |
2675 | && (GET_CODE (elt->exp) == REG | |
2676 | || exp_equiv_p (elt->exp, elt->exp, 1, 0)) | |
2677 | && validate_change (insn, loc, | |
906c4e36 | 2678 | canon_reg (copy_rtx (elt->exp), NULL_RTX), 0)) |
42495ca0 RK |
2679 | return; |
2680 | } | |
2681 | #else | |
7afe21cc | 2682 | |
42495ca0 RK |
2683 | if (elt) |
2684 | { | |
2685 | /* We need to find the best (under the criteria documented above) entry | |
2686 | in the class that is valid. We use the `flag' field to indicate | |
2687 | choices that were invalid and iterate until we can't find a better | |
2688 | one that hasn't already been tried. */ | |
7afe21cc | 2689 | |
42495ca0 RK |
2690 | for (p = elt->first_same_value; p; p = p->next_same_value) |
2691 | p->flag = 0; | |
7afe21cc | 2692 | |
42495ca0 RK |
2693 | while (found_better) |
2694 | { | |
2f541799 | 2695 | int best_addr_cost = CSE_ADDRESS_COST (*loc); |
42495ca0 RK |
2696 | int best_rtx_cost = (elt->cost + 1) >> 1; |
2697 | struct table_elt *best_elt = elt; | |
2698 | ||
2699 | found_better = 0; | |
2700 | for (p = elt->first_same_value; p; p = p->next_same_value) | |
2f541799 | 2701 | if (! p->flag) |
42495ca0 | 2702 | { |
2f541799 MM |
2703 | if ((GET_CODE (p->exp) == REG |
2704 | || exp_equiv_p (p->exp, p->exp, 1, 0)) | |
2705 | && (CSE_ADDRESS_COST (p->exp) < best_addr_cost | |
2706 | || (CSE_ADDRESS_COST (p->exp) == best_addr_cost | |
2707 | && (p->cost + 1) >> 1 > best_rtx_cost))) | |
2708 | { | |
2709 | found_better = 1; | |
2710 | best_addr_cost = CSE_ADDRESS_COST (p->exp); | |
2711 | best_rtx_cost = (p->cost + 1) >> 1; | |
2712 | best_elt = p; | |
2713 | } | |
42495ca0 | 2714 | } |
7afe21cc | 2715 | |
42495ca0 RK |
2716 | if (found_better) |
2717 | { | |
2718 | if (validate_change (insn, loc, | |
906c4e36 RK |
2719 | canon_reg (copy_rtx (best_elt->exp), |
2720 | NULL_RTX), 0)) | |
42495ca0 RK |
2721 | return; |
2722 | else | |
2723 | best_elt->flag = 1; | |
2724 | } | |
2725 | } | |
2726 | } | |
7afe21cc | 2727 | |
42495ca0 RK |
2728 | /* If the address is a binary operation with the first operand a register |
2729 | and the second a constant, do the same as above, but looking for | |
2730 | equivalences of the register. Then try to simplify before checking for | |
2731 | the best address to use. This catches a few cases: First is when we | |
2732 | have REG+const and the register is another REG+const. We can often merge | |
2733 | the constants and eliminate one insn and one register. It may also be | |
2734 | that a machine has a cheap REG+REG+const. Finally, this improves the | |
2735 | code on the Alpha for unaligned byte stores. */ | |
2736 | ||
2737 | if (flag_expensive_optimizations | |
2738 | && (GET_RTX_CLASS (GET_CODE (*loc)) == '2' | |
2739 | || GET_RTX_CLASS (GET_CODE (*loc)) == 'c') | |
2740 | && GET_CODE (XEXP (*loc, 0)) == REG | |
2741 | && GET_CODE (XEXP (*loc, 1)) == CONST_INT) | |
7afe21cc | 2742 | { |
42495ca0 RK |
2743 | rtx c = XEXP (*loc, 1); |
2744 | ||
2745 | do_not_record = 0; | |
2197a88a | 2746 | hash = HASH (XEXP (*loc, 0), Pmode); |
42495ca0 RK |
2747 | do_not_record = save_do_not_record; |
2748 | hash_arg_in_memory = save_hash_arg_in_memory; | |
2749 | hash_arg_in_struct = save_hash_arg_in_struct; | |
2750 | ||
2197a88a | 2751 | elt = lookup (XEXP (*loc, 0), hash, Pmode); |
42495ca0 RK |
2752 | if (elt == 0) |
2753 | return; | |
2754 | ||
2755 | /* We need to find the best (under the criteria documented above) entry | |
2756 | in the class that is valid. We use the `flag' field to indicate | |
2757 | choices that were invalid and iterate until we can't find a better | |
2758 | one that hasn't already been tried. */ | |
7afe21cc | 2759 | |
7afe21cc | 2760 | for (p = elt->first_same_value; p; p = p->next_same_value) |
42495ca0 | 2761 | p->flag = 0; |
7afe21cc | 2762 | |
42495ca0 | 2763 | while (found_better) |
7afe21cc | 2764 | { |
2f541799 | 2765 | int best_addr_cost = CSE_ADDRESS_COST (*loc); |
42495ca0 RK |
2766 | int best_rtx_cost = (COST (*loc) + 1) >> 1; |
2767 | struct table_elt *best_elt = elt; | |
2768 | rtx best_rtx = *loc; | |
f6516aee JW |
2769 | int count; |
2770 | ||
2771 | /* This is at worst case an O(n^2) algorithm, so limit our search | |
2772 | to the first 32 elements on the list. This avoids trouble | |
2773 | compiling code with very long basic blocks that can easily | |
2774 | call cse_gen_binary so many times that we run out of memory. */ | |
42495ca0 RK |
2775 | |
2776 | found_better = 0; | |
f6516aee JW |
2777 | for (p = elt->first_same_value, count = 0; |
2778 | p && count < 32; | |
2779 | p = p->next_same_value, count++) | |
42495ca0 RK |
2780 | if (! p->flag |
2781 | && (GET_CODE (p->exp) == REG | |
2782 | || exp_equiv_p (p->exp, p->exp, 1, 0))) | |
2783 | { | |
96b0e481 | 2784 | rtx new = cse_gen_binary (GET_CODE (*loc), Pmode, p->exp, c); |
42495ca0 | 2785 | |
2f541799 MM |
2786 | if ((CSE_ADDRESS_COST (new) < best_addr_cost |
2787 | || (CSE_ADDRESS_COST (new) == best_addr_cost | |
42495ca0 RK |
2788 | && (COST (new) + 1) >> 1 > best_rtx_cost))) |
2789 | { | |
2790 | found_better = 1; | |
2f541799 | 2791 | best_addr_cost = CSE_ADDRESS_COST (new); |
42495ca0 RK |
2792 | best_rtx_cost = (COST (new) + 1) >> 1; |
2793 | best_elt = p; | |
2794 | best_rtx = new; | |
2795 | } | |
2796 | } | |
2797 | ||
2798 | if (found_better) | |
2799 | { | |
2800 | if (validate_change (insn, loc, | |
906c4e36 RK |
2801 | canon_reg (copy_rtx (best_rtx), |
2802 | NULL_RTX), 0)) | |
42495ca0 RK |
2803 | return; |
2804 | else | |
2805 | best_elt->flag = 1; | |
2806 | } | |
7afe21cc RK |
2807 | } |
2808 | } | |
2809 | #endif | |
2810 | } | |
2811 | \f | |
2812 | /* Given an operation (CODE, *PARG1, *PARG2), where code is a comparison | |
2813 | operation (EQ, NE, GT, etc.), follow it back through the hash table and | |
2814 | what values are being compared. | |
2815 | ||
2816 | *PARG1 and *PARG2 are updated to contain the rtx representing the values | |
2817 | actually being compared. For example, if *PARG1 was (cc0) and *PARG2 | |
2818 | was (const_int 0), *PARG1 and *PARG2 will be set to the objects that were | |
2819 | compared to produce cc0. | |
2820 | ||
2821 | The return value is the comparison operator and is either the code of | |
2822 | A or the code corresponding to the inverse of the comparison. */ | |
2823 | ||
2824 | static enum rtx_code | |
13c9910f | 2825 | find_comparison_args (code, parg1, parg2, pmode1, pmode2) |
7afe21cc RK |
2826 | enum rtx_code code; |
2827 | rtx *parg1, *parg2; | |
13c9910f | 2828 | enum machine_mode *pmode1, *pmode2; |
7afe21cc RK |
2829 | { |
2830 | rtx arg1, arg2; | |
2831 | ||
2832 | arg1 = *parg1, arg2 = *parg2; | |
2833 | ||
2834 | /* If ARG2 is const0_rtx, see what ARG1 is equivalent to. */ | |
2835 | ||
b2796a4b | 2836 | while (arg2 == CONST0_RTX (GET_MODE (arg1))) |
7afe21cc RK |
2837 | { |
2838 | /* Set non-zero when we find something of interest. */ | |
2839 | rtx x = 0; | |
2840 | int reverse_code = 0; | |
2841 | struct table_elt *p = 0; | |
2842 | ||
2843 | /* If arg1 is a COMPARE, extract the comparison arguments from it. | |
2844 | On machines with CC0, this is the only case that can occur, since | |
2845 | fold_rtx will return the COMPARE or item being compared with zero | |
2846 | when given CC0. */ | |
2847 | ||
2848 | if (GET_CODE (arg1) == COMPARE && arg2 == const0_rtx) | |
2849 | x = arg1; | |
2850 | ||
2851 | /* If ARG1 is a comparison operator and CODE is testing for | |
2852 | STORE_FLAG_VALUE, get the inner arguments. */ | |
2853 | ||
2854 | else if (GET_RTX_CLASS (GET_CODE (arg1)) == '<') | |
2855 | { | |
c610adec RK |
2856 | if (code == NE |
2857 | || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT | |
2858 | && code == LT && STORE_FLAG_VALUE == -1) | |
2859 | #ifdef FLOAT_STORE_FLAG_VALUE | |
2860 | || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_FLOAT | |
2861 | && FLOAT_STORE_FLAG_VALUE < 0) | |
2862 | #endif | |
2863 | ) | |
7afe21cc | 2864 | x = arg1; |
c610adec RK |
2865 | else if (code == EQ |
2866 | || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT | |
2867 | && code == GE && STORE_FLAG_VALUE == -1) | |
2868 | #ifdef FLOAT_STORE_FLAG_VALUE | |
2869 | || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_FLOAT | |
2870 | && FLOAT_STORE_FLAG_VALUE < 0) | |
2871 | #endif | |
2872 | ) | |
7afe21cc RK |
2873 | x = arg1, reverse_code = 1; |
2874 | } | |
2875 | ||
2876 | /* ??? We could also check for | |
2877 | ||
2878 | (ne (and (eq (...) (const_int 1))) (const_int 0)) | |
2879 | ||
2880 | and related forms, but let's wait until we see them occurring. */ | |
2881 | ||
2882 | if (x == 0) | |
2883 | /* Look up ARG1 in the hash table and see if it has an equivalence | |
2884 | that lets us see what is being compared. */ | |
2885 | p = lookup (arg1, safe_hash (arg1, GET_MODE (arg1)) % NBUCKETS, | |
2886 | GET_MODE (arg1)); | |
2887 | if (p) p = p->first_same_value; | |
2888 | ||
2889 | for (; p; p = p->next_same_value) | |
2890 | { | |
2891 | enum machine_mode inner_mode = GET_MODE (p->exp); | |
2892 | ||
2893 | /* If the entry isn't valid, skip it. */ | |
2894 | if (! exp_equiv_p (p->exp, p->exp, 1, 0)) | |
2895 | continue; | |
2896 | ||
2897 | if (GET_CODE (p->exp) == COMPARE | |
2898 | /* Another possibility is that this machine has a compare insn | |
2899 | that includes the comparison code. In that case, ARG1 would | |
2900 | be equivalent to a comparison operation that would set ARG1 to | |
2901 | either STORE_FLAG_VALUE or zero. If this is an NE operation, | |
2902 | ORIG_CODE is the actual comparison being done; if it is an EQ, | |
2903 | we must reverse ORIG_CODE. On machine with a negative value | |
2904 | for STORE_FLAG_VALUE, also look at LT and GE operations. */ | |
2905 | || ((code == NE | |
2906 | || (code == LT | |
c610adec | 2907 | && GET_MODE_CLASS (inner_mode) == MODE_INT |
906c4e36 RK |
2908 | && (GET_MODE_BITSIZE (inner_mode) |
2909 | <= HOST_BITS_PER_WIDE_INT) | |
7afe21cc | 2910 | && (STORE_FLAG_VALUE |
906c4e36 RK |
2911 | & ((HOST_WIDE_INT) 1 |
2912 | << (GET_MODE_BITSIZE (inner_mode) - 1)))) | |
c610adec RK |
2913 | #ifdef FLOAT_STORE_FLAG_VALUE |
2914 | || (code == LT | |
2915 | && GET_MODE_CLASS (inner_mode) == MODE_FLOAT | |
2916 | && FLOAT_STORE_FLAG_VALUE < 0) | |
2917 | #endif | |
2918 | ) | |
7afe21cc RK |
2919 | && GET_RTX_CLASS (GET_CODE (p->exp)) == '<')) |
2920 | { | |
2921 | x = p->exp; | |
2922 | break; | |
2923 | } | |
2924 | else if ((code == EQ | |
2925 | || (code == GE | |
c610adec | 2926 | && GET_MODE_CLASS (inner_mode) == MODE_INT |
906c4e36 RK |
2927 | && (GET_MODE_BITSIZE (inner_mode) |
2928 | <= HOST_BITS_PER_WIDE_INT) | |
7afe21cc | 2929 | && (STORE_FLAG_VALUE |
906c4e36 RK |
2930 | & ((HOST_WIDE_INT) 1 |
2931 | << (GET_MODE_BITSIZE (inner_mode) - 1)))) | |
c610adec RK |
2932 | #ifdef FLOAT_STORE_FLAG_VALUE |
2933 | || (code == GE | |
2934 | && GET_MODE_CLASS (inner_mode) == MODE_FLOAT | |
2935 | && FLOAT_STORE_FLAG_VALUE < 0) | |
2936 | #endif | |
2937 | ) | |
7afe21cc RK |
2938 | && GET_RTX_CLASS (GET_CODE (p->exp)) == '<') |
2939 | { | |
2940 | reverse_code = 1; | |
2941 | x = p->exp; | |
2942 | break; | |
2943 | } | |
2944 | ||
2945 | /* If this is fp + constant, the equivalent is a better operand since | |
2946 | it may let us predict the value of the comparison. */ | |
2947 | else if (NONZERO_BASE_PLUS_P (p->exp)) | |
2948 | { | |
2949 | arg1 = p->exp; | |
2950 | continue; | |
2951 | } | |
2952 | } | |
2953 | ||
2954 | /* If we didn't find a useful equivalence for ARG1, we are done. | |
2955 | Otherwise, set up for the next iteration. */ | |
2956 | if (x == 0) | |
2957 | break; | |
2958 | ||
2959 | arg1 = XEXP (x, 0), arg2 = XEXP (x, 1); | |
2960 | if (GET_RTX_CLASS (GET_CODE (x)) == '<') | |
2961 | code = GET_CODE (x); | |
2962 | ||
2963 | if (reverse_code) | |
2964 | code = reverse_condition (code); | |
2965 | } | |
2966 | ||
13c9910f RS |
2967 | /* Return our results. Return the modes from before fold_rtx |
2968 | because fold_rtx might produce const_int, and then it's too late. */ | |
2969 | *pmode1 = GET_MODE (arg1), *pmode2 = GET_MODE (arg2); | |
7afe21cc RK |
2970 | *parg1 = fold_rtx (arg1, 0), *parg2 = fold_rtx (arg2, 0); |
2971 | ||
2972 | return code; | |
2973 | } | |
2974 | \f | |
2975 | /* Try to simplify a unary operation CODE whose output mode is to be | |
2976 | MODE with input operand OP whose mode was originally OP_MODE. | |
2977 | Return zero if no simplification can be made. */ | |
2978 | ||
2979 | rtx | |
2980 | simplify_unary_operation (code, mode, op, op_mode) | |
2981 | enum rtx_code code; | |
2982 | enum machine_mode mode; | |
2983 | rtx op; | |
2984 | enum machine_mode op_mode; | |
2985 | { | |
2986 | register int width = GET_MODE_BITSIZE (mode); | |
2987 | ||
2988 | /* The order of these tests is critical so that, for example, we don't | |
2989 | check the wrong mode (input vs. output) for a conversion operation, | |
2990 | such as FIX. At some point, this should be simplified. */ | |
2991 | ||
62c0ea12 | 2992 | #if !defined(REAL_IS_NOT_DOUBLE) || defined(REAL_ARITHMETIC) |
7afe21cc | 2993 | |
62c0ea12 RK |
2994 | if (code == FLOAT && GET_MODE (op) == VOIDmode |
2995 | && (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT)) | |
7afe21cc | 2996 | { |
62c0ea12 | 2997 | HOST_WIDE_INT hv, lv; |
7afe21cc RK |
2998 | REAL_VALUE_TYPE d; |
2999 | ||
62c0ea12 RK |
3000 | if (GET_CODE (op) == CONST_INT) |
3001 | lv = INTVAL (op), hv = INTVAL (op) < 0 ? -1 : 0; | |
3002 | else | |
7ac4a266 | 3003 | lv = CONST_DOUBLE_LOW (op), hv = CONST_DOUBLE_HIGH (op); |
7afe21cc RK |
3004 | |
3005 | #ifdef REAL_ARITHMETIC | |
2ebcccf3 | 3006 | REAL_VALUE_FROM_INT (d, lv, hv, mode); |
7afe21cc | 3007 | #else |
62c0ea12 | 3008 | if (hv < 0) |
7afe21cc | 3009 | { |
62c0ea12 | 3010 | d = (double) (~ hv); |
906c4e36 RK |
3011 | d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) |
3012 | * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))); | |
62c0ea12 | 3013 | d += (double) (unsigned HOST_WIDE_INT) (~ lv); |
7afe21cc RK |
3014 | d = (- d - 1.0); |
3015 | } | |
3016 | else | |
3017 | { | |
62c0ea12 | 3018 | d = (double) hv; |
906c4e36 RK |
3019 | d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) |
3020 | * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))); | |
62c0ea12 | 3021 | d += (double) (unsigned HOST_WIDE_INT) lv; |
7afe21cc RK |
3022 | } |
3023 | #endif /* REAL_ARITHMETIC */ | |
940fd0b5 | 3024 | d = real_value_truncate (mode, d); |
7afe21cc RK |
3025 | return CONST_DOUBLE_FROM_REAL_VALUE (d, mode); |
3026 | } | |
62c0ea12 RK |
3027 | else if (code == UNSIGNED_FLOAT && GET_MODE (op) == VOIDmode |
3028 | && (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT)) | |
7afe21cc | 3029 | { |
62c0ea12 | 3030 | HOST_WIDE_INT hv, lv; |
7afe21cc RK |
3031 | REAL_VALUE_TYPE d; |
3032 | ||
62c0ea12 RK |
3033 | if (GET_CODE (op) == CONST_INT) |
3034 | lv = INTVAL (op), hv = INTVAL (op) < 0 ? -1 : 0; | |
3035 | else | |
7ac4a266 | 3036 | lv = CONST_DOUBLE_LOW (op), hv = CONST_DOUBLE_HIGH (op); |
62c0ea12 | 3037 | |
a9c6464d RK |
3038 | if (op_mode == VOIDmode) |
3039 | { | |
3040 | /* We don't know how to interpret negative-looking numbers in | |
3041 | this case, so don't try to fold those. */ | |
3042 | if (hv < 0) | |
3043 | return 0; | |
3044 | } | |
3045 | else if (GET_MODE_BITSIZE (op_mode) >= HOST_BITS_PER_WIDE_INT * 2) | |
62c0ea12 RK |
3046 | ; |
3047 | else | |
3048 | hv = 0, lv &= GET_MODE_MASK (op_mode); | |
3049 | ||
7afe21cc | 3050 | #ifdef REAL_ARITHMETIC |
2ebcccf3 | 3051 | REAL_VALUE_FROM_UNSIGNED_INT (d, lv, hv, mode); |
7afe21cc | 3052 | #else |
62c0ea12 | 3053 | |
138cec59 | 3054 | d = (double) (unsigned HOST_WIDE_INT) hv; |
906c4e36 RK |
3055 | d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) |
3056 | * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))); | |
62c0ea12 | 3057 | d += (double) (unsigned HOST_WIDE_INT) lv; |
7afe21cc | 3058 | #endif /* REAL_ARITHMETIC */ |
940fd0b5 | 3059 | d = real_value_truncate (mode, d); |
7afe21cc RK |
3060 | return CONST_DOUBLE_FROM_REAL_VALUE (d, mode); |
3061 | } | |
3062 | #endif | |
3063 | ||
f89e32e9 RK |
3064 | if (GET_CODE (op) == CONST_INT |
3065 | && width <= HOST_BITS_PER_WIDE_INT && width > 0) | |
7afe21cc | 3066 | { |
906c4e36 RK |
3067 | register HOST_WIDE_INT arg0 = INTVAL (op); |
3068 | register HOST_WIDE_INT val; | |
7afe21cc RK |
3069 | |
3070 | switch (code) | |
3071 | { | |
3072 | case NOT: | |
3073 | val = ~ arg0; | |
3074 | break; | |
3075 | ||
3076 | case NEG: | |
3077 | val = - arg0; | |
3078 | break; | |
3079 | ||
3080 | case ABS: | |
3081 | val = (arg0 >= 0 ? arg0 : - arg0); | |
3082 | break; | |
3083 | ||
3084 | case FFS: | |
3085 | /* Don't use ffs here. Instead, get low order bit and then its | |
3086 | number. If arg0 is zero, this will return 0, as desired. */ | |
3087 | arg0 &= GET_MODE_MASK (mode); | |
3088 | val = exact_log2 (arg0 & (- arg0)) + 1; | |
3089 | break; | |
3090 | ||
3091 | case TRUNCATE: | |
3092 | val = arg0; | |
3093 | break; | |
3094 | ||
3095 | case ZERO_EXTEND: | |
3096 | if (op_mode == VOIDmode) | |
3097 | op_mode = mode; | |
82a5e898 | 3098 | if (GET_MODE_BITSIZE (op_mode) == HOST_BITS_PER_WIDE_INT) |
d80e9fd7 RS |
3099 | { |
3100 | /* If we were really extending the mode, | |
3101 | we would have to distinguish between zero-extension | |
3102 | and sign-extension. */ | |
3103 | if (width != GET_MODE_BITSIZE (op_mode)) | |
3104 | abort (); | |
3105 | val = arg0; | |
3106 | } | |
82a5e898 CH |
3107 | else if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT) |
3108 | val = arg0 & ~((HOST_WIDE_INT) (-1) << GET_MODE_BITSIZE (op_mode)); | |
7afe21cc RK |
3109 | else |
3110 | return 0; | |
3111 | break; | |
3112 | ||
3113 | case SIGN_EXTEND: | |
3114 | if (op_mode == VOIDmode) | |
3115 | op_mode = mode; | |
82a5e898 | 3116 | if (GET_MODE_BITSIZE (op_mode) == HOST_BITS_PER_WIDE_INT) |
d80e9fd7 RS |
3117 | { |
3118 | /* If we were really extending the mode, | |
3119 | we would have to distinguish between zero-extension | |
3120 | and sign-extension. */ | |
3121 | if (width != GET_MODE_BITSIZE (op_mode)) | |
3122 | abort (); | |
3123 | val = arg0; | |
3124 | } | |
f12564b4 | 3125 | else if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT) |
7afe21cc | 3126 | { |
82a5e898 CH |
3127 | val |
3128 | = arg0 & ~((HOST_WIDE_INT) (-1) << GET_MODE_BITSIZE (op_mode)); | |
3129 | if (val | |
3130 | & ((HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (op_mode) - 1))) | |
3131 | val -= (HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (op_mode); | |
7afe21cc RK |
3132 | } |
3133 | else | |
3134 | return 0; | |
3135 | break; | |
3136 | ||
d45cf215 RS |
3137 | case SQRT: |
3138 | return 0; | |
3139 | ||
7afe21cc RK |
3140 | default: |
3141 | abort (); | |
3142 | } | |
3143 | ||
3144 | /* Clear the bits that don't belong in our mode, | |
3145 | unless they and our sign bit are all one. | |
3146 | So we get either a reasonable negative value or a reasonable | |
3147 | unsigned value for this mode. */ | |
906c4e36 RK |
3148 | if (width < HOST_BITS_PER_WIDE_INT |
3149 | && ((val & ((HOST_WIDE_INT) (-1) << (width - 1))) | |
3150 | != ((HOST_WIDE_INT) (-1) << (width - 1)))) | |
4879acf6 | 3151 | val &= ((HOST_WIDE_INT) 1 << width) - 1; |
7afe21cc | 3152 | |
906c4e36 | 3153 | return GEN_INT (val); |
7afe21cc RK |
3154 | } |
3155 | ||
3156 | /* We can do some operations on integer CONST_DOUBLEs. Also allow | |
0f41302f | 3157 | for a DImode operation on a CONST_INT. */ |
8e0ac43b | 3158 | else if (GET_MODE (op) == VOIDmode && width <= HOST_BITS_PER_INT * 2 |
7afe21cc RK |
3159 | && (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT)) |
3160 | { | |
906c4e36 | 3161 | HOST_WIDE_INT l1, h1, lv, hv; |
7afe21cc RK |
3162 | |
3163 | if (GET_CODE (op) == CONST_DOUBLE) | |
3164 | l1 = CONST_DOUBLE_LOW (op), h1 = CONST_DOUBLE_HIGH (op); | |
3165 | else | |
3166 | l1 = INTVAL (op), h1 = l1 < 0 ? -1 : 0; | |
3167 | ||
3168 | switch (code) | |
3169 | { | |
3170 | case NOT: | |
3171 | lv = ~ l1; | |
3172 | hv = ~ h1; | |
3173 | break; | |
3174 | ||
3175 | case NEG: | |
3176 | neg_double (l1, h1, &lv, &hv); | |
3177 | break; | |
3178 | ||
3179 | case ABS: | |
3180 | if (h1 < 0) | |
3181 | neg_double (l1, h1, &lv, &hv); | |
3182 | else | |
3183 | lv = l1, hv = h1; | |
3184 | break; | |
3185 | ||
3186 | case FFS: | |
3187 | hv = 0; | |
3188 | if (l1 == 0) | |
906c4e36 | 3189 | lv = HOST_BITS_PER_WIDE_INT + exact_log2 (h1 & (-h1)) + 1; |
7afe21cc RK |
3190 | else |
3191 | lv = exact_log2 (l1 & (-l1)) + 1; | |
3192 | break; | |
3193 | ||
3194 | case TRUNCATE: | |
8e0ac43b | 3195 | /* This is just a change-of-mode, so do nothing. */ |
d50d63c0 | 3196 | lv = l1, hv = h1; |
7afe21cc RK |
3197 | break; |
3198 | ||
f72aed24 RS |
3199 | case ZERO_EXTEND: |
3200 | if (op_mode == VOIDmode | |
906c4e36 | 3201 | || GET_MODE_BITSIZE (op_mode) > HOST_BITS_PER_WIDE_INT) |
f72aed24 RS |
3202 | return 0; |
3203 | ||
3204 | hv = 0; | |
3205 | lv = l1 & GET_MODE_MASK (op_mode); | |
3206 | break; | |
3207 | ||
3208 | case SIGN_EXTEND: | |
3209 | if (op_mode == VOIDmode | |
906c4e36 | 3210 | || GET_MODE_BITSIZE (op_mode) > HOST_BITS_PER_WIDE_INT) |
f72aed24 RS |
3211 | return 0; |
3212 | else | |
3213 | { | |
3214 | lv = l1 & GET_MODE_MASK (op_mode); | |
906c4e36 RK |
3215 | if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT |
3216 | && (lv & ((HOST_WIDE_INT) 1 | |
3217 | << (GET_MODE_BITSIZE (op_mode) - 1))) != 0) | |
3218 | lv -= (HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (op_mode); | |
f72aed24 | 3219 | |
906c4e36 | 3220 | hv = (lv < 0) ? ~ (HOST_WIDE_INT) 0 : 0; |
f72aed24 RS |
3221 | } |
3222 | break; | |
3223 | ||
d45cf215 RS |
3224 | case SQRT: |
3225 | return 0; | |
3226 | ||
7afe21cc RK |
3227 | default: |
3228 | return 0; | |
3229 | } | |
3230 | ||
3231 | return immed_double_const (lv, hv, mode); | |
3232 | } | |
3233 | ||
3234 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
3235 | else if (GET_CODE (op) == CONST_DOUBLE | |
3236 | && GET_MODE_CLASS (mode) == MODE_FLOAT) | |
3237 | { | |
3238 | REAL_VALUE_TYPE d; | |
3239 | jmp_buf handler; | |
3240 | rtx x; | |
3241 | ||
3242 | if (setjmp (handler)) | |
3243 | /* There used to be a warning here, but that is inadvisable. | |
3244 | People may want to cause traps, and the natural way | |
3245 | to do it should not get a warning. */ | |
3246 | return 0; | |
3247 | ||
3248 | set_float_handler (handler); | |
3249 | ||
3250 | REAL_VALUE_FROM_CONST_DOUBLE (d, op); | |
3251 | ||
3252 | switch (code) | |
3253 | { | |
3254 | case NEG: | |
3255 | d = REAL_VALUE_NEGATE (d); | |
3256 | break; | |
3257 | ||
3258 | case ABS: | |
8b3686ed | 3259 | if (REAL_VALUE_NEGATIVE (d)) |
7afe21cc RK |
3260 | d = REAL_VALUE_NEGATE (d); |
3261 | break; | |
3262 | ||
3263 | case FLOAT_TRUNCATE: | |
d3159aee | 3264 | d = real_value_truncate (mode, d); |
7afe21cc RK |
3265 | break; |
3266 | ||
3267 | case FLOAT_EXTEND: | |
3268 | /* All this does is change the mode. */ | |
3269 | break; | |
3270 | ||
3271 | case FIX: | |
d3159aee | 3272 | d = REAL_VALUE_RNDZINT (d); |
7afe21cc RK |
3273 | break; |
3274 | ||
3275 | case UNSIGNED_FIX: | |
d3159aee | 3276 | d = REAL_VALUE_UNSIGNED_RNDZINT (d); |
7afe21cc RK |
3277 | break; |
3278 | ||
d45cf215 RS |
3279 | case SQRT: |
3280 | return 0; | |
3281 | ||
7afe21cc RK |
3282 | default: |
3283 | abort (); | |
3284 | } | |
3285 | ||
560c94a2 | 3286 | x = CONST_DOUBLE_FROM_REAL_VALUE (d, mode); |
906c4e36 | 3287 | set_float_handler (NULL_PTR); |
7afe21cc RK |
3288 | return x; |
3289 | } | |
8e0ac43b RK |
3290 | |
3291 | else if (GET_CODE (op) == CONST_DOUBLE | |
3292 | && GET_MODE_CLASS (GET_MODE (op)) == MODE_FLOAT | |
3293 | && GET_MODE_CLASS (mode) == MODE_INT | |
906c4e36 | 3294 | && width <= HOST_BITS_PER_WIDE_INT && width > 0) |
7afe21cc RK |
3295 | { |
3296 | REAL_VALUE_TYPE d; | |
3297 | jmp_buf handler; | |
906c4e36 | 3298 | HOST_WIDE_INT val; |
7afe21cc RK |
3299 | |
3300 | if (setjmp (handler)) | |
3301 | return 0; | |
3302 | ||
3303 | set_float_handler (handler); | |
3304 | ||
3305 | REAL_VALUE_FROM_CONST_DOUBLE (d, op); | |
3306 | ||
3307 | switch (code) | |
3308 | { | |
3309 | case FIX: | |
3310 | val = REAL_VALUE_FIX (d); | |
3311 | break; | |
3312 | ||
3313 | case UNSIGNED_FIX: | |
3314 | val = REAL_VALUE_UNSIGNED_FIX (d); | |
3315 | break; | |
3316 | ||
3317 | default: | |
3318 | abort (); | |
3319 | } | |
3320 | ||
906c4e36 | 3321 | set_float_handler (NULL_PTR); |
7afe21cc RK |
3322 | |
3323 | /* Clear the bits that don't belong in our mode, | |
3324 | unless they and our sign bit are all one. | |
3325 | So we get either a reasonable negative value or a reasonable | |
3326 | unsigned value for this mode. */ | |
906c4e36 RK |
3327 | if (width < HOST_BITS_PER_WIDE_INT |
3328 | && ((val & ((HOST_WIDE_INT) (-1) << (width - 1))) | |
3329 | != ((HOST_WIDE_INT) (-1) << (width - 1)))) | |
3330 | val &= ((HOST_WIDE_INT) 1 << width) - 1; | |
7afe21cc | 3331 | |
ad89d6f6 TG |
3332 | /* If this would be an entire word for the target, but is not for |
3333 | the host, then sign-extend on the host so that the number will look | |
3334 | the same way on the host that it would on the target. | |
3335 | ||
3336 | For example, when building a 64 bit alpha hosted 32 bit sparc | |
3337 | targeted compiler, then we want the 32 bit unsigned value -1 to be | |
3338 | represented as a 64 bit value -1, and not as 0x00000000ffffffff. | |
3339 | The later confuses the sparc backend. */ | |
3340 | ||
3341 | if (BITS_PER_WORD < HOST_BITS_PER_WIDE_INT && BITS_PER_WORD == width | |
3342 | && (val & ((HOST_WIDE_INT) 1 << (width - 1)))) | |
3343 | val |= ((HOST_WIDE_INT) (-1) << width); | |
3344 | ||
906c4e36 | 3345 | return GEN_INT (val); |
7afe21cc RK |
3346 | } |
3347 | #endif | |
a6acbe15 RS |
3348 | /* This was formerly used only for non-IEEE float. |
3349 | eggert@twinsun.com says it is safe for IEEE also. */ | |
3350 | else | |
7afe21cc RK |
3351 | { |
3352 | /* There are some simplifications we can do even if the operands | |
a6acbe15 | 3353 | aren't constant. */ |
7afe21cc RK |
3354 | switch (code) |
3355 | { | |
3356 | case NEG: | |
3357 | case NOT: | |
3358 | /* (not (not X)) == X, similarly for NEG. */ | |
3359 | if (GET_CODE (op) == code) | |
3360 | return XEXP (op, 0); | |
3361 | break; | |
3362 | ||
3363 | case SIGN_EXTEND: | |
3364 | /* (sign_extend (truncate (minus (label_ref L1) (label_ref L2)))) | |
3365 | becomes just the MINUS if its mode is MODE. This allows | |
3366 | folding switch statements on machines using casesi (such as | |
3367 | the Vax). */ | |
3368 | if (GET_CODE (op) == TRUNCATE | |
3369 | && GET_MODE (XEXP (op, 0)) == mode | |
3370 | && GET_CODE (XEXP (op, 0)) == MINUS | |
3371 | && GET_CODE (XEXP (XEXP (op, 0), 0)) == LABEL_REF | |
3372 | && GET_CODE (XEXP (XEXP (op, 0), 1)) == LABEL_REF) | |
3373 | return XEXP (op, 0); | |
cceb347c RK |
3374 | |
3375 | #ifdef POINTERS_EXTEND_UNSIGNED | |
3376 | if (! POINTERS_EXTEND_UNSIGNED | |
3377 | && mode == Pmode && GET_MODE (op) == ptr_mode | |
3378 | && CONSTANT_P (op)) | |
3379 | return convert_memory_address (Pmode, op); | |
3380 | #endif | |
3381 | break; | |
3382 | ||
3383 | #ifdef POINTERS_EXTEND_UNSIGNED | |
3384 | case ZERO_EXTEND: | |
3385 | if (POINTERS_EXTEND_UNSIGNED | |
3386 | && mode == Pmode && GET_MODE (op) == ptr_mode | |
3387 | && CONSTANT_P (op)) | |
3388 | return convert_memory_address (Pmode, op); | |
7afe21cc | 3389 | break; |
cceb347c | 3390 | #endif |
e9a25f70 JL |
3391 | |
3392 | default: | |
3393 | break; | |
7afe21cc RK |
3394 | } |
3395 | ||
3396 | return 0; | |
3397 | } | |
7afe21cc RK |
3398 | } |
3399 | \f | |
3400 | /* Simplify a binary operation CODE with result mode MODE, operating on OP0 | |
3401 | and OP1. Return 0 if no simplification is possible. | |
3402 | ||
3403 | Don't use this for relational operations such as EQ or LT. | |
3404 | Use simplify_relational_operation instead. */ | |
3405 | ||
3406 | rtx | |
3407 | simplify_binary_operation (code, mode, op0, op1) | |
3408 | enum rtx_code code; | |
3409 | enum machine_mode mode; | |
3410 | rtx op0, op1; | |
3411 | { | |
906c4e36 RK |
3412 | register HOST_WIDE_INT arg0, arg1, arg0s, arg1s; |
3413 | HOST_WIDE_INT val; | |
7afe21cc | 3414 | int width = GET_MODE_BITSIZE (mode); |
96b0e481 | 3415 | rtx tem; |
7afe21cc RK |
3416 | |
3417 | /* Relational operations don't work here. We must know the mode | |
3418 | of the operands in order to do the comparison correctly. | |
3419 | Assuming a full word can give incorrect results. | |
3420 | Consider comparing 128 with -128 in QImode. */ | |
3421 | ||
3422 | if (GET_RTX_CLASS (code) == '<') | |
3423 | abort (); | |
3424 | ||
3425 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
3426 | if (GET_MODE_CLASS (mode) == MODE_FLOAT | |
3427 | && GET_CODE (op0) == CONST_DOUBLE && GET_CODE (op1) == CONST_DOUBLE | |
3428 | && mode == GET_MODE (op0) && mode == GET_MODE (op1)) | |
3429 | { | |
3430 | REAL_VALUE_TYPE f0, f1, value; | |
3431 | jmp_buf handler; | |
3432 | ||
3433 | if (setjmp (handler)) | |
3434 | return 0; | |
3435 | ||
3436 | set_float_handler (handler); | |
3437 | ||
3438 | REAL_VALUE_FROM_CONST_DOUBLE (f0, op0); | |
3439 | REAL_VALUE_FROM_CONST_DOUBLE (f1, op1); | |
5352b11a RS |
3440 | f0 = real_value_truncate (mode, f0); |
3441 | f1 = real_value_truncate (mode, f1); | |
7afe21cc RK |
3442 | |
3443 | #ifdef REAL_ARITHMETIC | |
956d6950 JL |
3444 | #ifndef REAL_INFINITY |
3445 | if (code == DIV && REAL_VALUES_EQUAL (f1, dconst0)) | |
3446 | return 0; | |
3447 | #endif | |
d3159aee | 3448 | REAL_ARITHMETIC (value, rtx_to_tree_code (code), f0, f1); |
7afe21cc RK |
3449 | #else |
3450 | switch (code) | |
3451 | { | |
3452 | case PLUS: | |
3453 | value = f0 + f1; | |
3454 | break; | |
3455 | case MINUS: | |
3456 | value = f0 - f1; | |
3457 | break; | |
3458 | case MULT: | |
3459 | value = f0 * f1; | |
3460 | break; | |
3461 | case DIV: | |
3462 | #ifndef REAL_INFINITY | |
3463 | if (f1 == 0) | |
21d12b80 | 3464 | return 0; |
7afe21cc RK |
3465 | #endif |
3466 | value = f0 / f1; | |
3467 | break; | |
3468 | case SMIN: | |
3469 | value = MIN (f0, f1); | |
3470 | break; | |
3471 | case SMAX: | |
3472 | value = MAX (f0, f1); | |
3473 | break; | |
3474 | default: | |
3475 | abort (); | |
3476 | } | |
3477 | #endif | |
3478 | ||
5352b11a | 3479 | value = real_value_truncate (mode, value); |
831522a4 | 3480 | set_float_handler (NULL_PTR); |
560c94a2 | 3481 | return CONST_DOUBLE_FROM_REAL_VALUE (value, mode); |
7afe21cc | 3482 | } |
6076248a | 3483 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ |
7afe21cc RK |
3484 | |
3485 | /* We can fold some multi-word operations. */ | |
6076248a | 3486 | if (GET_MODE_CLASS (mode) == MODE_INT |
33085906 | 3487 | && width == HOST_BITS_PER_WIDE_INT * 2 |
fe873240 | 3488 | && (GET_CODE (op0) == CONST_DOUBLE || GET_CODE (op0) == CONST_INT) |
6076248a | 3489 | && (GET_CODE (op1) == CONST_DOUBLE || GET_CODE (op1) == CONST_INT)) |
7afe21cc | 3490 | { |
906c4e36 | 3491 | HOST_WIDE_INT l1, l2, h1, h2, lv, hv; |
7afe21cc | 3492 | |
fe873240 RK |
3493 | if (GET_CODE (op0) == CONST_DOUBLE) |
3494 | l1 = CONST_DOUBLE_LOW (op0), h1 = CONST_DOUBLE_HIGH (op0); | |
3495 | else | |
3496 | l1 = INTVAL (op0), h1 = l1 < 0 ? -1 : 0; | |
7afe21cc RK |
3497 | |
3498 | if (GET_CODE (op1) == CONST_DOUBLE) | |
3499 | l2 = CONST_DOUBLE_LOW (op1), h2 = CONST_DOUBLE_HIGH (op1); | |
3500 | else | |
3501 | l2 = INTVAL (op1), h2 = l2 < 0 ? -1 : 0; | |
3502 | ||
3503 | switch (code) | |
3504 | { | |
3505 | case MINUS: | |
3506 | /* A - B == A + (-B). */ | |
3507 | neg_double (l2, h2, &lv, &hv); | |
3508 | l2 = lv, h2 = hv; | |
3509 | ||
0f41302f | 3510 | /* .. fall through ... */ |
7afe21cc RK |
3511 | |
3512 | case PLUS: | |
3513 | add_double (l1, h1, l2, h2, &lv, &hv); | |
3514 | break; | |
3515 | ||
3516 | case MULT: | |
3517 | mul_double (l1, h1, l2, h2, &lv, &hv); | |
3518 | break; | |
3519 | ||
3520 | case DIV: case MOD: case UDIV: case UMOD: | |
3521 | /* We'd need to include tree.h to do this and it doesn't seem worth | |
3522 | it. */ | |
3523 | return 0; | |
3524 | ||
3525 | case AND: | |
3526 | lv = l1 & l2, hv = h1 & h2; | |
3527 | break; | |
3528 | ||
3529 | case IOR: | |
3530 | lv = l1 | l2, hv = h1 | h2; | |
3531 | break; | |
3532 | ||
3533 | case XOR: | |
3534 | lv = l1 ^ l2, hv = h1 ^ h2; | |
3535 | break; | |
3536 | ||
3537 | case SMIN: | |
906c4e36 RK |
3538 | if (h1 < h2 |
3539 | || (h1 == h2 | |
3540 | && ((unsigned HOST_WIDE_INT) l1 | |
3541 | < (unsigned HOST_WIDE_INT) l2))) | |
7afe21cc RK |
3542 | lv = l1, hv = h1; |
3543 | else | |
3544 | lv = l2, hv = h2; | |
3545 | break; | |
3546 | ||
3547 | case SMAX: | |
906c4e36 RK |
3548 | if (h1 > h2 |
3549 | || (h1 == h2 | |
3550 | && ((unsigned HOST_WIDE_INT) l1 | |
3551 | > (unsigned HOST_WIDE_INT) l2))) | |
7afe21cc RK |
3552 | lv = l1, hv = h1; |
3553 | else | |
3554 | lv = l2, hv = h2; | |
3555 | break; | |
3556 | ||
3557 | case UMIN: | |
906c4e36 RK |
3558 | if ((unsigned HOST_WIDE_INT) h1 < (unsigned HOST_WIDE_INT) h2 |
3559 | || (h1 == h2 | |
3560 | && ((unsigned HOST_WIDE_INT) l1 | |
3561 | < (unsigned HOST_WIDE_INT) l2))) | |
7afe21cc RK |
3562 | lv = l1, hv = h1; |
3563 | else | |
3564 | lv = l2, hv = h2; | |
3565 | break; | |
3566 | ||
3567 | case UMAX: | |
906c4e36 RK |
3568 | if ((unsigned HOST_WIDE_INT) h1 > (unsigned HOST_WIDE_INT) h2 |
3569 | || (h1 == h2 | |
3570 | && ((unsigned HOST_WIDE_INT) l1 | |
3571 | > (unsigned HOST_WIDE_INT) l2))) | |
7afe21cc RK |
3572 | lv = l1, hv = h1; |
3573 | else | |
3574 | lv = l2, hv = h2; | |
3575 | break; | |
3576 | ||
3577 | case LSHIFTRT: case ASHIFTRT: | |
45620ed4 | 3578 | case ASHIFT: |
7afe21cc RK |
3579 | case ROTATE: case ROTATERT: |
3580 | #ifdef SHIFT_COUNT_TRUNCATED | |
85c0a556 RK |
3581 | if (SHIFT_COUNT_TRUNCATED) |
3582 | l2 &= (GET_MODE_BITSIZE (mode) - 1), h2 = 0; | |
7afe21cc RK |
3583 | #endif |
3584 | ||
3585 | if (h2 != 0 || l2 < 0 || l2 >= GET_MODE_BITSIZE (mode)) | |
3586 | return 0; | |
3587 | ||
3588 | if (code == LSHIFTRT || code == ASHIFTRT) | |
3589 | rshift_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv, | |
3590 | code == ASHIFTRT); | |
45620ed4 RK |
3591 | else if (code == ASHIFT) |
3592 | lshift_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv, 1); | |
7afe21cc RK |
3593 | else if (code == ROTATE) |
3594 | lrotate_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv); | |
3595 | else /* code == ROTATERT */ | |
3596 | rrotate_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv); | |
3597 | break; | |
3598 | ||
3599 | default: | |
3600 | return 0; | |
3601 | } | |
3602 | ||
3603 | return immed_double_const (lv, hv, mode); | |
3604 | } | |
7afe21cc RK |
3605 | |
3606 | if (GET_CODE (op0) != CONST_INT || GET_CODE (op1) != CONST_INT | |
906c4e36 | 3607 | || width > HOST_BITS_PER_WIDE_INT || width == 0) |
7afe21cc RK |
3608 | { |
3609 | /* Even if we can't compute a constant result, | |
3610 | there are some cases worth simplifying. */ | |
3611 | ||
3612 | switch (code) | |
3613 | { | |
3614 | case PLUS: | |
3615 | /* In IEEE floating point, x+0 is not the same as x. Similarly | |
3616 | for the other optimizations below. */ | |
3617 | if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT | |
a83afb65 | 3618 | && FLOAT_MODE_P (mode) && ! flag_fast_math) |
7afe21cc RK |
3619 | break; |
3620 | ||
3621 | if (op1 == CONST0_RTX (mode)) | |
3622 | return op0; | |
3623 | ||
7afe21cc RK |
3624 | /* ((-a) + b) -> (b - a) and similarly for (a + (-b)) */ |
3625 | if (GET_CODE (op0) == NEG) | |
96b0e481 | 3626 | return cse_gen_binary (MINUS, mode, op1, XEXP (op0, 0)); |
7afe21cc | 3627 | else if (GET_CODE (op1) == NEG) |
96b0e481 | 3628 | return cse_gen_binary (MINUS, mode, op0, XEXP (op1, 0)); |
7afe21cc | 3629 | |
96b0e481 RK |
3630 | /* Handle both-operands-constant cases. We can only add |
3631 | CONST_INTs to constants since the sum of relocatable symbols | |
fe873240 RK |
3632 | can't be handled by most assemblers. Don't add CONST_INT |
3633 | to CONST_INT since overflow won't be computed properly if wider | |
3634 | than HOST_BITS_PER_WIDE_INT. */ | |
7afe21cc | 3635 | |
fe873240 RK |
3636 | if (CONSTANT_P (op0) && GET_MODE (op0) != VOIDmode |
3637 | && GET_CODE (op1) == CONST_INT) | |
96b0e481 | 3638 | return plus_constant (op0, INTVAL (op1)); |
fe873240 RK |
3639 | else if (CONSTANT_P (op1) && GET_MODE (op1) != VOIDmode |
3640 | && GET_CODE (op0) == CONST_INT) | |
96b0e481 | 3641 | return plus_constant (op1, INTVAL (op0)); |
7afe21cc | 3642 | |
30d69925 RK |
3643 | /* See if this is something like X * C - X or vice versa or |
3644 | if the multiplication is written as a shift. If so, we can | |
3645 | distribute and make a new multiply, shift, or maybe just | |
3646 | have X (if C is 2 in the example above). But don't make | |
3647 | real multiply if we didn't have one before. */ | |
3648 | ||
3649 | if (! FLOAT_MODE_P (mode)) | |
3650 | { | |
3651 | HOST_WIDE_INT coeff0 = 1, coeff1 = 1; | |
3652 | rtx lhs = op0, rhs = op1; | |
3653 | int had_mult = 0; | |
3654 | ||
3655 | if (GET_CODE (lhs) == NEG) | |
3656 | coeff0 = -1, lhs = XEXP (lhs, 0); | |
3657 | else if (GET_CODE (lhs) == MULT | |
3658 | && GET_CODE (XEXP (lhs, 1)) == CONST_INT) | |
3659 | { | |
3660 | coeff0 = INTVAL (XEXP (lhs, 1)), lhs = XEXP (lhs, 0); | |
3661 | had_mult = 1; | |
3662 | } | |
3663 | else if (GET_CODE (lhs) == ASHIFT | |
3664 | && GET_CODE (XEXP (lhs, 1)) == CONST_INT | |
3665 | && INTVAL (XEXP (lhs, 1)) >= 0 | |
3666 | && INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT) | |
3667 | { | |
3668 | coeff0 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1)); | |
3669 | lhs = XEXP (lhs, 0); | |
3670 | } | |
3671 | ||
3672 | if (GET_CODE (rhs) == NEG) | |
3673 | coeff1 = -1, rhs = XEXP (rhs, 0); | |
3674 | else if (GET_CODE (rhs) == MULT | |
3675 | && GET_CODE (XEXP (rhs, 1)) == CONST_INT) | |
3676 | { | |
3677 | coeff1 = INTVAL (XEXP (rhs, 1)), rhs = XEXP (rhs, 0); | |
3678 | had_mult = 1; | |
3679 | } | |
3680 | else if (GET_CODE (rhs) == ASHIFT | |
3681 | && GET_CODE (XEXP (rhs, 1)) == CONST_INT | |
3682 | && INTVAL (XEXP (rhs, 1)) >= 0 | |
3683 | && INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT) | |
3684 | { | |
3685 | coeff1 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1)); | |
3686 | rhs = XEXP (rhs, 0); | |
3687 | } | |
3688 | ||
3689 | if (rtx_equal_p (lhs, rhs)) | |
3690 | { | |
3691 | tem = cse_gen_binary (MULT, mode, lhs, | |
3692 | GEN_INT (coeff0 + coeff1)); | |
3693 | return (GET_CODE (tem) == MULT && ! had_mult) ? 0 : tem; | |
3694 | } | |
3695 | } | |
3696 | ||
96b0e481 RK |
3697 | /* If one of the operands is a PLUS or a MINUS, see if we can |
3698 | simplify this by the associative law. | |
3699 | Don't use the associative law for floating point. | |
3700 | The inaccuracy makes it nonassociative, | |
3701 | and subtle programs can break if operations are associated. */ | |
7afe21cc | 3702 | |
cbf6a543 | 3703 | if (INTEGRAL_MODE_P (mode) |
96b0e481 RK |
3704 | && (GET_CODE (op0) == PLUS || GET_CODE (op0) == MINUS |
3705 | || GET_CODE (op1) == PLUS || GET_CODE (op1) == MINUS) | |
3706 | && (tem = simplify_plus_minus (code, mode, op0, op1)) != 0) | |
3707 | return tem; | |
7afe21cc RK |
3708 | break; |
3709 | ||
3710 | case COMPARE: | |
3711 | #ifdef HAVE_cc0 | |
3712 | /* Convert (compare FOO (const_int 0)) to FOO unless we aren't | |
3713 | using cc0, in which case we want to leave it as a COMPARE | |
3714 | so we can distinguish it from a register-register-copy. | |
3715 | ||
3716 | In IEEE floating point, x-0 is not the same as x. */ | |
3717 | ||
3718 | if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
a83afb65 | 3719 | || ! FLOAT_MODE_P (mode) || flag_fast_math) |
7afe21cc RK |
3720 | && op1 == CONST0_RTX (mode)) |
3721 | return op0; | |
3722 | #else | |
3723 | /* Do nothing here. */ | |
3724 | #endif | |
3725 | break; | |
3726 | ||
3727 | case MINUS: | |
21648b45 RK |
3728 | /* None of these optimizations can be done for IEEE |
3729 | floating point. */ | |
3730 | if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT | |
a83afb65 | 3731 | && FLOAT_MODE_P (mode) && ! flag_fast_math) |
21648b45 RK |
3732 | break; |
3733 | ||
a83afb65 RK |
3734 | /* We can't assume x-x is 0 even with non-IEEE floating point, |
3735 | but since it is zero except in very strange circumstances, we | |
3736 | will treat it as zero with -ffast-math. */ | |
7afe21cc RK |
3737 | if (rtx_equal_p (op0, op1) |
3738 | && ! side_effects_p (op0) | |
a83afb65 RK |
3739 | && (! FLOAT_MODE_P (mode) || flag_fast_math)) |
3740 | return CONST0_RTX (mode); | |
7afe21cc RK |
3741 | |
3742 | /* Change subtraction from zero into negation. */ | |
3743 | if (op0 == CONST0_RTX (mode)) | |
38a448ca | 3744 | return gen_rtx_NEG (mode, op1); |
7afe21cc | 3745 | |
96b0e481 RK |
3746 | /* (-1 - a) is ~a. */ |
3747 | if (op0 == constm1_rtx) | |
38a448ca | 3748 | return gen_rtx_NOT (mode, op1); |
96b0e481 | 3749 | |
7afe21cc RK |
3750 | /* Subtracting 0 has no effect. */ |
3751 | if (op1 == CONST0_RTX (mode)) | |
3752 | return op0; | |
3753 | ||
30d69925 RK |
3754 | /* See if this is something like X * C - X or vice versa or |
3755 | if the multiplication is written as a shift. If so, we can | |
3756 | distribute and make a new multiply, shift, or maybe just | |
3757 | have X (if C is 2 in the example above). But don't make | |
3758 | real multiply if we didn't have one before. */ | |
3759 | ||
3760 | if (! FLOAT_MODE_P (mode)) | |
3761 | { | |
3762 | HOST_WIDE_INT coeff0 = 1, coeff1 = 1; | |
3763 | rtx lhs = op0, rhs = op1; | |
3764 | int had_mult = 0; | |
3765 | ||
3766 | if (GET_CODE (lhs) == NEG) | |
3767 | coeff0 = -1, lhs = XEXP (lhs, 0); | |
3768 | else if (GET_CODE (lhs) == MULT | |
3769 | && GET_CODE (XEXP (lhs, 1)) == CONST_INT) | |
3770 | { | |
3771 | coeff0 = INTVAL (XEXP (lhs, 1)), lhs = XEXP (lhs, 0); | |
3772 | had_mult = 1; | |
3773 | } | |
3774 | else if (GET_CODE (lhs) == ASHIFT | |
3775 | && GET_CODE (XEXP (lhs, 1)) == CONST_INT | |
3776 | && INTVAL (XEXP (lhs, 1)) >= 0 | |
3777 | && INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT) | |
3778 | { | |
3779 | coeff0 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1)); | |
3780 | lhs = XEXP (lhs, 0); | |
3781 | } | |
3782 | ||
3783 | if (GET_CODE (rhs) == NEG) | |
3784 | coeff1 = - 1, rhs = XEXP (rhs, 0); | |
3785 | else if (GET_CODE (rhs) == MULT | |
3786 | && GET_CODE (XEXP (rhs, 1)) == CONST_INT) | |
3787 | { | |
3788 | coeff1 = INTVAL (XEXP (rhs, 1)), rhs = XEXP (rhs, 0); | |
3789 | had_mult = 1; | |
3790 | } | |
3791 | else if (GET_CODE (rhs) == ASHIFT | |
3792 | && GET_CODE (XEXP (rhs, 1)) == CONST_INT | |
3793 | && INTVAL (XEXP (rhs, 1)) >= 0 | |
3794 | && INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT) | |
3795 | { | |
3796 | coeff1 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1)); | |
3797 | rhs = XEXP (rhs, 0); | |
3798 | } | |
3799 | ||
3800 | if (rtx_equal_p (lhs, rhs)) | |
3801 | { | |
3802 | tem = cse_gen_binary (MULT, mode, lhs, | |
3803 | GEN_INT (coeff0 - coeff1)); | |
3804 | return (GET_CODE (tem) == MULT && ! had_mult) ? 0 : tem; | |
3805 | } | |
3806 | } | |
3807 | ||
7afe21cc RK |
3808 | /* (a - (-b)) -> (a + b). */ |
3809 | if (GET_CODE (op1) == NEG) | |
96b0e481 | 3810 | return cse_gen_binary (PLUS, mode, op0, XEXP (op1, 0)); |
7afe21cc | 3811 | |
96b0e481 RK |
3812 | /* If one of the operands is a PLUS or a MINUS, see if we can |
3813 | simplify this by the associative law. | |
3814 | Don't use the associative law for floating point. | |
7afe21cc RK |
3815 | The inaccuracy makes it nonassociative, |
3816 | and subtle programs can break if operations are associated. */ | |
7afe21cc | 3817 | |
cbf6a543 | 3818 | if (INTEGRAL_MODE_P (mode) |
96b0e481 RK |
3819 | && (GET_CODE (op0) == PLUS || GET_CODE (op0) == MINUS |
3820 | || GET_CODE (op1) == PLUS || GET_CODE (op1) == MINUS) | |
3821 | && (tem = simplify_plus_minus (code, mode, op0, op1)) != 0) | |
3822 | return tem; | |
7afe21cc RK |
3823 | |
3824 | /* Don't let a relocatable value get a negative coeff. */ | |
b5a09c41 | 3825 | if (GET_CODE (op1) == CONST_INT && GET_MODE (op0) != VOIDmode) |
7afe21cc | 3826 | return plus_constant (op0, - INTVAL (op1)); |
29d72c4b TG |
3827 | |
3828 | /* (x - (x & y)) -> (x & ~y) */ | |
3829 | if (GET_CODE (op1) == AND) | |
3830 | { | |
3831 | if (rtx_equal_p (op0, XEXP (op1, 0))) | |
38a448ca | 3832 | return cse_gen_binary (AND, mode, op0, gen_rtx_NOT (mode, XEXP (op1, 1))); |
29d72c4b | 3833 | if (rtx_equal_p (op0, XEXP (op1, 1))) |
38a448ca | 3834 | return cse_gen_binary (AND, mode, op0, gen_rtx_NOT (mode, XEXP (op1, 0))); |
29d72c4b | 3835 | } |
7afe21cc RK |
3836 | break; |
3837 | ||
3838 | case MULT: | |
3839 | if (op1 == constm1_rtx) | |
3840 | { | |
96b0e481 | 3841 | tem = simplify_unary_operation (NEG, mode, op0, mode); |
7afe21cc | 3842 | |
38a448ca | 3843 | return tem ? tem : gen_rtx_NEG (mode, op0); |
7afe21cc RK |
3844 | } |
3845 | ||
3846 | /* In IEEE floating point, x*0 is not always 0. */ | |
3847 | if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
a83afb65 | 3848 | || ! FLOAT_MODE_P (mode) || flag_fast_math) |
7afe21cc RK |
3849 | && op1 == CONST0_RTX (mode) |
3850 | && ! side_effects_p (op0)) | |
3851 | return op1; | |
3852 | ||
3853 | /* In IEEE floating point, x*1 is not equivalent to x for nans. | |
3854 | However, ANSI says we can drop signals, | |
3855 | so we can do this anyway. */ | |
3856 | if (op1 == CONST1_RTX (mode)) | |
3857 | return op0; | |
3858 | ||
c407b802 RK |
3859 | /* Convert multiply by constant power of two into shift unless |
3860 | we are still generating RTL. This test is a kludge. */ | |
7afe21cc | 3861 | if (GET_CODE (op1) == CONST_INT |
c407b802 | 3862 | && (val = exact_log2 (INTVAL (op1))) >= 0 |
2d917903 JW |
3863 | /* If the mode is larger than the host word size, and the |
3864 | uppermost bit is set, then this isn't a power of two due | |
3865 | to implicit sign extension. */ | |
3866 | && (width <= HOST_BITS_PER_WIDE_INT | |
3867 | || val != HOST_BITS_PER_WIDE_INT - 1) | |
c407b802 | 3868 | && ! rtx_equal_function_value_matters) |
38a448ca | 3869 | return gen_rtx_ASHIFT (mode, op0, GEN_INT (val)); |
7afe21cc RK |
3870 | |
3871 | if (GET_CODE (op1) == CONST_DOUBLE | |
3872 | && GET_MODE_CLASS (GET_MODE (op1)) == MODE_FLOAT) | |
3873 | { | |
3874 | REAL_VALUE_TYPE d; | |
5a3d4bef RK |
3875 | jmp_buf handler; |
3876 | int op1is2, op1ism1; | |
3877 | ||
3878 | if (setjmp (handler)) | |
3879 | return 0; | |
3880 | ||
3881 | set_float_handler (handler); | |
7afe21cc | 3882 | REAL_VALUE_FROM_CONST_DOUBLE (d, op1); |
5a3d4bef RK |
3883 | op1is2 = REAL_VALUES_EQUAL (d, dconst2); |
3884 | op1ism1 = REAL_VALUES_EQUAL (d, dconstm1); | |
3885 | set_float_handler (NULL_PTR); | |
7afe21cc RK |
3886 | |
3887 | /* x*2 is x+x and x*(-1) is -x */ | |
5a3d4bef | 3888 | if (op1is2 && GET_MODE (op0) == mode) |
38a448ca | 3889 | return gen_rtx_PLUS (mode, op0, copy_rtx (op0)); |
7afe21cc | 3890 | |
5a3d4bef | 3891 | else if (op1ism1 && GET_MODE (op0) == mode) |
38a448ca | 3892 | return gen_rtx_NEG (mode, op0); |
7afe21cc RK |
3893 | } |
3894 | break; | |
3895 | ||
3896 | case IOR: | |
3897 | if (op1 == const0_rtx) | |
3898 | return op0; | |
3899 | if (GET_CODE (op1) == CONST_INT | |
3900 | && (INTVAL (op1) & GET_MODE_MASK (mode)) == GET_MODE_MASK (mode)) | |
3901 | return op1; | |
3902 | if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
3903 | return op0; | |
3904 | /* A | (~A) -> -1 */ | |
3905 | if (((GET_CODE (op0) == NOT && rtx_equal_p (XEXP (op0, 0), op1)) | |
3906 | || (GET_CODE (op1) == NOT && rtx_equal_p (XEXP (op1, 0), op0))) | |
31dcf83f | 3907 | && ! side_effects_p (op0) |
8e7e5365 | 3908 | && GET_MODE_CLASS (mode) != MODE_CC) |
7afe21cc RK |
3909 | return constm1_rtx; |
3910 | break; | |
3911 | ||
3912 | case XOR: | |
3913 | if (op1 == const0_rtx) | |
3914 | return op0; | |
3915 | if (GET_CODE (op1) == CONST_INT | |
3916 | && (INTVAL (op1) & GET_MODE_MASK (mode)) == GET_MODE_MASK (mode)) | |
38a448ca | 3917 | return gen_rtx_NOT (mode, op0); |
31dcf83f | 3918 | if (op0 == op1 && ! side_effects_p (op0) |
8e7e5365 | 3919 | && GET_MODE_CLASS (mode) != MODE_CC) |
7afe21cc RK |
3920 | return const0_rtx; |
3921 | break; | |
3922 | ||
3923 | case AND: | |
3924 | if (op1 == const0_rtx && ! side_effects_p (op0)) | |
3925 | return const0_rtx; | |
3926 | if (GET_CODE (op1) == CONST_INT | |
3927 | && (INTVAL (op1) & GET_MODE_MASK (mode)) == GET_MODE_MASK (mode)) | |
3928 | return op0; | |
31dcf83f | 3929 | if (op0 == op1 && ! side_effects_p (op0) |
8e7e5365 | 3930 | && GET_MODE_CLASS (mode) != MODE_CC) |
7afe21cc RK |
3931 | return op0; |
3932 | /* A & (~A) -> 0 */ | |
3933 | if (((GET_CODE (op0) == NOT && rtx_equal_p (XEXP (op0, 0), op1)) | |
3934 | || (GET_CODE (op1) == NOT && rtx_equal_p (XEXP (op1, 0), op0))) | |
709ab4fc | 3935 | && ! side_effects_p (op0) |
8e7e5365 | 3936 | && GET_MODE_CLASS (mode) != MODE_CC) |
7afe21cc RK |
3937 | return const0_rtx; |
3938 | break; | |
3939 | ||
3940 | case UDIV: | |
3941 | /* Convert divide by power of two into shift (divide by 1 handled | |
3942 | below). */ | |
3943 | if (GET_CODE (op1) == CONST_INT | |
3944 | && (arg1 = exact_log2 (INTVAL (op1))) > 0) | |
38a448ca | 3945 | return gen_rtx_LSHIFTRT (mode, op0, GEN_INT (arg1)); |
7afe21cc | 3946 | |
0f41302f | 3947 | /* ... fall through ... */ |
7afe21cc RK |
3948 | |
3949 | case DIV: | |
3950 | if (op1 == CONST1_RTX (mode)) | |
3951 | return op0; | |
e7a522ba RS |
3952 | |
3953 | /* In IEEE floating point, 0/x is not always 0. */ | |
3954 | if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
a83afb65 | 3955 | || ! FLOAT_MODE_P (mode) || flag_fast_math) |
e7a522ba RS |
3956 | && op0 == CONST0_RTX (mode) |
3957 | && ! side_effects_p (op1)) | |
7afe21cc | 3958 | return op0; |
e7a522ba | 3959 | |
7afe21cc | 3960 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) |
a83afb65 RK |
3961 | /* Change division by a constant into multiplication. Only do |
3962 | this with -ffast-math until an expert says it is safe in | |
3963 | general. */ | |
7afe21cc RK |
3964 | else if (GET_CODE (op1) == CONST_DOUBLE |
3965 | && GET_MODE_CLASS (GET_MODE (op1)) == MODE_FLOAT | |
a83afb65 RK |
3966 | && op1 != CONST0_RTX (mode) |
3967 | && flag_fast_math) | |
7afe21cc RK |
3968 | { |
3969 | REAL_VALUE_TYPE d; | |
3970 | REAL_VALUE_FROM_CONST_DOUBLE (d, op1); | |
a83afb65 RK |
3971 | |
3972 | if (! REAL_VALUES_EQUAL (d, dconst0)) | |
3973 | { | |
7afe21cc | 3974 | #if defined (REAL_ARITHMETIC) |
a83afb65 | 3975 | REAL_ARITHMETIC (d, rtx_to_tree_code (DIV), dconst1, d); |
38a448ca RH |
3976 | return gen_rtx_MULT (mode, op0, |
3977 | CONST_DOUBLE_FROM_REAL_VALUE (d, mode)); | |
7afe21cc | 3978 | #else |
38a448ca RH |
3979 | return gen_rtx_MULT (mode, op0, |
3980 | CONST_DOUBLE_FROM_REAL_VALUE (1./d, mode)); | |
7afe21cc | 3981 | #endif |
a83afb65 RK |
3982 | } |
3983 | } | |
7afe21cc RK |
3984 | #endif |
3985 | break; | |
3986 | ||
3987 | case UMOD: | |
3988 | /* Handle modulus by power of two (mod with 1 handled below). */ | |
3989 | if (GET_CODE (op1) == CONST_INT | |
3990 | && exact_log2 (INTVAL (op1)) > 0) | |
38a448ca | 3991 | return gen_rtx_AND (mode, op0, GEN_INT (INTVAL (op1) - 1)); |
7afe21cc | 3992 | |
0f41302f | 3993 | /* ... fall through ... */ |
7afe21cc RK |
3994 | |
3995 | case MOD: | |
3996 | if ((op0 == const0_rtx || op1 == const1_rtx) | |
3997 | && ! side_effects_p (op0) && ! side_effects_p (op1)) | |
3998 | return const0_rtx; | |
3999 | break; | |
4000 | ||
4001 | case ROTATERT: | |
4002 | case ROTATE: | |
4003 | /* Rotating ~0 always results in ~0. */ | |
906c4e36 | 4004 | if (GET_CODE (op0) == CONST_INT && width <= HOST_BITS_PER_WIDE_INT |
7afe21cc RK |
4005 | && INTVAL (op0) == GET_MODE_MASK (mode) |
4006 | && ! side_effects_p (op1)) | |
4007 | return op0; | |
4008 | ||
0f41302f | 4009 | /* ... fall through ... */ |
7afe21cc | 4010 | |
7afe21cc RK |
4011 | case ASHIFT: |
4012 | case ASHIFTRT: | |
4013 | case LSHIFTRT: | |
4014 | if (op1 == const0_rtx) | |
4015 | return op0; | |
4016 | if (op0 == const0_rtx && ! side_effects_p (op1)) | |
4017 | return op0; | |
4018 | break; | |
4019 | ||
4020 | case SMIN: | |
906c4e36 RK |
4021 | if (width <= HOST_BITS_PER_WIDE_INT && GET_CODE (op1) == CONST_INT |
4022 | && INTVAL (op1) == (HOST_WIDE_INT) 1 << (width -1) | |
7afe21cc RK |
4023 | && ! side_effects_p (op0)) |
4024 | return op1; | |
4025 | else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
4026 | return op0; | |
4027 | break; | |
4028 | ||
4029 | case SMAX: | |
906c4e36 | 4030 | if (width <= HOST_BITS_PER_WIDE_INT && GET_CODE (op1) == CONST_INT |
dbbe6445 RK |
4031 | && (INTVAL (op1) |
4032 | == (unsigned HOST_WIDE_INT) GET_MODE_MASK (mode) >> 1) | |
7afe21cc RK |
4033 | && ! side_effects_p (op0)) |
4034 | return op1; | |
4035 | else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
4036 | return op0; | |
4037 | break; | |
4038 | ||
4039 | case UMIN: | |
4040 | if (op1 == const0_rtx && ! side_effects_p (op0)) | |
4041 | return op1; | |
4042 | else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
4043 | return op0; | |
4044 | break; | |
4045 | ||
4046 | case UMAX: | |
4047 | if (op1 == constm1_rtx && ! side_effects_p (op0)) | |
4048 | return op1; | |
4049 | else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
4050 | return op0; | |
4051 | break; | |
4052 | ||
4053 | default: | |
4054 | abort (); | |
4055 | } | |
4056 | ||
4057 | return 0; | |
4058 | } | |
4059 | ||
4060 | /* Get the integer argument values in two forms: | |
4061 | zero-extended in ARG0, ARG1 and sign-extended in ARG0S, ARG1S. */ | |
4062 | ||
4063 | arg0 = INTVAL (op0); | |
4064 | arg1 = INTVAL (op1); | |
4065 | ||
906c4e36 | 4066 | if (width < HOST_BITS_PER_WIDE_INT) |
7afe21cc | 4067 | { |
906c4e36 RK |
4068 | arg0 &= ((HOST_WIDE_INT) 1 << width) - 1; |
4069 | arg1 &= ((HOST_WIDE_INT) 1 << width) - 1; | |
7afe21cc RK |
4070 | |
4071 | arg0s = arg0; | |
906c4e36 RK |
4072 | if (arg0s & ((HOST_WIDE_INT) 1 << (width - 1))) |
4073 | arg0s |= ((HOST_WIDE_INT) (-1) << width); | |
7afe21cc RK |
4074 | |
4075 | arg1s = arg1; | |
906c4e36 RK |
4076 | if (arg1s & ((HOST_WIDE_INT) 1 << (width - 1))) |
4077 | arg1s |= ((HOST_WIDE_INT) (-1) << width); | |
7afe21cc RK |
4078 | } |
4079 | else | |
4080 | { | |
4081 | arg0s = arg0; | |
4082 | arg1s = arg1; | |
4083 | } | |
4084 | ||
4085 | /* Compute the value of the arithmetic. */ | |
4086 | ||
4087 | switch (code) | |
4088 | { | |
4089 | case PLUS: | |
538b78e7 | 4090 | val = arg0s + arg1s; |
7afe21cc RK |
4091 | break; |
4092 | ||
4093 | case MINUS: | |
538b78e7 | 4094 | val = arg0s - arg1s; |
7afe21cc RK |
4095 | break; |
4096 | ||
4097 | case MULT: | |
4098 | val = arg0s * arg1s; | |
4099 | break; | |
4100 | ||
4101 | case DIV: | |
4102 | if (arg1s == 0) | |
4103 | return 0; | |
4104 | val = arg0s / arg1s; | |
4105 | break; | |
4106 | ||
4107 | case MOD: | |
4108 | if (arg1s == 0) | |
4109 | return 0; | |
4110 | val = arg0s % arg1s; | |
4111 | break; | |
4112 | ||
4113 | case UDIV: | |
4114 | if (arg1 == 0) | |
4115 | return 0; | |
906c4e36 | 4116 | val = (unsigned HOST_WIDE_INT) arg0 / arg1; |
7afe21cc RK |
4117 | break; |
4118 | ||
4119 | case UMOD: | |
4120 | if (arg1 == 0) | |
4121 | return 0; | |
906c4e36 | 4122 | val = (unsigned HOST_WIDE_INT) arg0 % arg1; |
7afe21cc RK |
4123 | break; |
4124 | ||
4125 | case AND: | |
4126 | val = arg0 & arg1; | |
4127 | break; | |
4128 | ||
4129 | case IOR: | |
4130 | val = arg0 | arg1; | |
4131 | break; | |
4132 | ||
4133 | case XOR: | |
4134 | val = arg0 ^ arg1; | |
4135 | break; | |
4136 | ||
4137 | case LSHIFTRT: | |
4138 | /* If shift count is undefined, don't fold it; let the machine do | |
4139 | what it wants. But truncate it if the machine will do that. */ | |
4140 | if (arg1 < 0) | |
4141 | return 0; | |
4142 | ||
4143 | #ifdef SHIFT_COUNT_TRUNCATED | |
85c0a556 | 4144 | if (SHIFT_COUNT_TRUNCATED) |
4d61f8c5 | 4145 | arg1 %= width; |
7afe21cc RK |
4146 | #endif |
4147 | ||
906c4e36 | 4148 | val = ((unsigned HOST_WIDE_INT) arg0) >> arg1; |
7afe21cc RK |
4149 | break; |
4150 | ||
4151 | case ASHIFT: | |
7afe21cc RK |
4152 | if (arg1 < 0) |
4153 | return 0; | |
4154 | ||
4155 | #ifdef SHIFT_COUNT_TRUNCATED | |
85c0a556 | 4156 | if (SHIFT_COUNT_TRUNCATED) |
4d61f8c5 | 4157 | arg1 %= width; |
7afe21cc RK |
4158 | #endif |
4159 | ||
906c4e36 | 4160 | val = ((unsigned HOST_WIDE_INT) arg0) << arg1; |
7afe21cc RK |
4161 | break; |
4162 | ||
4163 | case ASHIFTRT: | |
4164 | if (arg1 < 0) | |
4165 | return 0; | |
4166 | ||
4167 | #ifdef SHIFT_COUNT_TRUNCATED | |
85c0a556 | 4168 | if (SHIFT_COUNT_TRUNCATED) |
4d61f8c5 | 4169 | arg1 %= width; |
7afe21cc RK |
4170 | #endif |
4171 | ||
7afe21cc | 4172 | val = arg0s >> arg1; |
2166571b RS |
4173 | |
4174 | /* Bootstrap compiler may not have sign extended the right shift. | |
4175 | Manually extend the sign to insure bootstrap cc matches gcc. */ | |
4176 | if (arg0s < 0 && arg1 > 0) | |
4177 | val |= ((HOST_WIDE_INT) -1) << (HOST_BITS_PER_WIDE_INT - arg1); | |
4178 | ||
7afe21cc RK |
4179 | break; |
4180 | ||
4181 | case ROTATERT: | |
4182 | if (arg1 < 0) | |
4183 | return 0; | |
4184 | ||
4185 | arg1 %= width; | |
906c4e36 RK |
4186 | val = ((((unsigned HOST_WIDE_INT) arg0) << (width - arg1)) |
4187 | | (((unsigned HOST_WIDE_INT) arg0) >> arg1)); | |
7afe21cc RK |
4188 | break; |
4189 | ||
4190 | case ROTATE: | |
4191 | if (arg1 < 0) | |
4192 | return 0; | |
4193 | ||
4194 | arg1 %= width; | |
906c4e36 RK |
4195 | val = ((((unsigned HOST_WIDE_INT) arg0) << arg1) |
4196 | | (((unsigned HOST_WIDE_INT) arg0) >> (width - arg1))); | |
7afe21cc RK |
4197 | break; |
4198 | ||
4199 | case COMPARE: | |
4200 | /* Do nothing here. */ | |
4201 | return 0; | |
4202 | ||
830a38ee RS |
4203 | case SMIN: |
4204 | val = arg0s <= arg1s ? arg0s : arg1s; | |
4205 | break; | |
4206 | ||
4207 | case UMIN: | |
906c4e36 RK |
4208 | val = ((unsigned HOST_WIDE_INT) arg0 |
4209 | <= (unsigned HOST_WIDE_INT) arg1 ? arg0 : arg1); | |
830a38ee RS |
4210 | break; |
4211 | ||
4212 | case SMAX: | |
4213 | val = arg0s > arg1s ? arg0s : arg1s; | |
4214 | break; | |
4215 | ||
4216 | case UMAX: | |
906c4e36 RK |
4217 | val = ((unsigned HOST_WIDE_INT) arg0 |
4218 | > (unsigned HOST_WIDE_INT) arg1 ? arg0 : arg1); | |
830a38ee RS |
4219 | break; |
4220 | ||
7afe21cc RK |
4221 | default: |
4222 | abort (); | |
4223 | } | |
4224 | ||
4225 | /* Clear the bits that don't belong in our mode, unless they and our sign | |
4226 | bit are all one. So we get either a reasonable negative value or a | |
4227 | reasonable unsigned value for this mode. */ | |
906c4e36 RK |
4228 | if (width < HOST_BITS_PER_WIDE_INT |
4229 | && ((val & ((HOST_WIDE_INT) (-1) << (width - 1))) | |
4230 | != ((HOST_WIDE_INT) (-1) << (width - 1)))) | |
4231 | val &= ((HOST_WIDE_INT) 1 << width) - 1; | |
4232 | ||
ad89d6f6 TG |
4233 | /* If this would be an entire word for the target, but is not for |
4234 | the host, then sign-extend on the host so that the number will look | |
4235 | the same way on the host that it would on the target. | |
4236 | ||
4237 | For example, when building a 64 bit alpha hosted 32 bit sparc | |
4238 | targeted compiler, then we want the 32 bit unsigned value -1 to be | |
4239 | represented as a 64 bit value -1, and not as 0x00000000ffffffff. | |
4240 | The later confuses the sparc backend. */ | |
4241 | ||
4242 | if (BITS_PER_WORD < HOST_BITS_PER_WIDE_INT && BITS_PER_WORD == width | |
4243 | && (val & ((HOST_WIDE_INT) 1 << (width - 1)))) | |
4244 | val |= ((HOST_WIDE_INT) (-1) << width); | |
4245 | ||
906c4e36 | 4246 | return GEN_INT (val); |
7afe21cc RK |
4247 | } |
4248 | \f | |
96b0e481 RK |
4249 | /* Simplify a PLUS or MINUS, at least one of whose operands may be another |
4250 | PLUS or MINUS. | |
4251 | ||
4252 | Rather than test for specific case, we do this by a brute-force method | |
4253 | and do all possible simplifications until no more changes occur. Then | |
4254 | we rebuild the operation. */ | |
4255 | ||
4256 | static rtx | |
4257 | simplify_plus_minus (code, mode, op0, op1) | |
4258 | enum rtx_code code; | |
4259 | enum machine_mode mode; | |
4260 | rtx op0, op1; | |
4261 | { | |
4262 | rtx ops[8]; | |
4263 | int negs[8]; | |
4264 | rtx result, tem; | |
fb5c8ce6 | 4265 | int n_ops = 2, input_ops = 2, input_consts = 0, n_consts = 0; |
96b0e481 | 4266 | int first = 1, negate = 0, changed; |
fb5c8ce6 | 4267 | int i, j; |
96b0e481 | 4268 | |
4c9a05bc | 4269 | bzero ((char *) ops, sizeof ops); |
96b0e481 RK |
4270 | |
4271 | /* Set up the two operands and then expand them until nothing has been | |
4272 | changed. If we run out of room in our array, give up; this should | |
4273 | almost never happen. */ | |
4274 | ||
4275 | ops[0] = op0, ops[1] = op1, negs[0] = 0, negs[1] = (code == MINUS); | |
4276 | ||
4277 | changed = 1; | |
4278 | while (changed) | |
4279 | { | |
4280 | changed = 0; | |
4281 | ||
4282 | for (i = 0; i < n_ops; i++) | |
4283 | switch (GET_CODE (ops[i])) | |
4284 | { | |
4285 | case PLUS: | |
4286 | case MINUS: | |
4287 | if (n_ops == 7) | |
4288 | return 0; | |
4289 | ||
4290 | ops[n_ops] = XEXP (ops[i], 1); | |
4291 | negs[n_ops++] = GET_CODE (ops[i]) == MINUS ? !negs[i] : negs[i]; | |
4292 | ops[i] = XEXP (ops[i], 0); | |
b7d9299b | 4293 | input_ops++; |
96b0e481 RK |
4294 | changed = 1; |
4295 | break; | |
4296 | ||
4297 | case NEG: | |
4298 | ops[i] = XEXP (ops[i], 0); | |
4299 | negs[i] = ! negs[i]; | |
4300 | changed = 1; | |
4301 | break; | |
4302 | ||
4303 | case CONST: | |
4304 | ops[i] = XEXP (ops[i], 0); | |
fb5c8ce6 | 4305 | input_consts++; |
96b0e481 RK |
4306 | changed = 1; |
4307 | break; | |
4308 | ||
4309 | case NOT: | |
4310 | /* ~a -> (-a - 1) */ | |
4311 | if (n_ops != 7) | |
4312 | { | |
4313 | ops[n_ops] = constm1_rtx; | |
5931019b | 4314 | negs[n_ops++] = negs[i]; |
96b0e481 RK |
4315 | ops[i] = XEXP (ops[i], 0); |
4316 | negs[i] = ! negs[i]; | |
4317 | changed = 1; | |
4318 | } | |
4319 | break; | |
4320 | ||
4321 | case CONST_INT: | |
4322 | if (negs[i]) | |
4323 | ops[i] = GEN_INT (- INTVAL (ops[i])), negs[i] = 0, changed = 1; | |
4324 | break; | |
e9a25f70 JL |
4325 | |
4326 | default: | |
4327 | break; | |
96b0e481 RK |
4328 | } |
4329 | } | |
4330 | ||
4331 | /* If we only have two operands, we can't do anything. */ | |
4332 | if (n_ops <= 2) | |
4333 | return 0; | |
4334 | ||
4335 | /* Now simplify each pair of operands until nothing changes. The first | |
4336 | time through just simplify constants against each other. */ | |
4337 | ||
4338 | changed = 1; | |
4339 | while (changed) | |
4340 | { | |
4341 | changed = first; | |
4342 | ||
4343 | for (i = 0; i < n_ops - 1; i++) | |
4344 | for (j = i + 1; j < n_ops; j++) | |
4345 | if (ops[i] != 0 && ops[j] != 0 | |
4346 | && (! first || (CONSTANT_P (ops[i]) && CONSTANT_P (ops[j])))) | |
4347 | { | |
4348 | rtx lhs = ops[i], rhs = ops[j]; | |
4349 | enum rtx_code ncode = PLUS; | |
4350 | ||
4351 | if (negs[i] && ! negs[j]) | |
4352 | lhs = ops[j], rhs = ops[i], ncode = MINUS; | |
4353 | else if (! negs[i] && negs[j]) | |
4354 | ncode = MINUS; | |
4355 | ||
4356 | tem = simplify_binary_operation (ncode, mode, lhs, rhs); | |
b7d9299b | 4357 | if (tem) |
96b0e481 RK |
4358 | { |
4359 | ops[i] = tem, ops[j] = 0; | |
4360 | negs[i] = negs[i] && negs[j]; | |
4361 | if (GET_CODE (tem) == NEG) | |
4362 | ops[i] = XEXP (tem, 0), negs[i] = ! negs[i]; | |
4363 | ||
4364 | if (GET_CODE (ops[i]) == CONST_INT && negs[i]) | |
4365 | ops[i] = GEN_INT (- INTVAL (ops[i])), negs[i] = 0; | |
4366 | changed = 1; | |
4367 | } | |
4368 | } | |
4369 | ||
4370 | first = 0; | |
4371 | } | |
4372 | ||
4373 | /* Pack all the operands to the lower-numbered entries and give up if | |
91a60f37 | 4374 | we didn't reduce the number of operands we had. Make sure we |
fb5c8ce6 RK |
4375 | count a CONST as two operands. If we have the same number of |
4376 | operands, but have made more CONSTs than we had, this is also | |
4377 | an improvement, so accept it. */ | |
91a60f37 | 4378 | |
fb5c8ce6 | 4379 | for (i = 0, j = 0; j < n_ops; j++) |
96b0e481 | 4380 | if (ops[j] != 0) |
91a60f37 RK |
4381 | { |
4382 | ops[i] = ops[j], negs[i++] = negs[j]; | |
4383 | if (GET_CODE (ops[j]) == CONST) | |
fb5c8ce6 | 4384 | n_consts++; |
91a60f37 | 4385 | } |
96b0e481 | 4386 | |
fb5c8ce6 RK |
4387 | if (i + n_consts > input_ops |
4388 | || (i + n_consts == input_ops && n_consts <= input_consts)) | |
96b0e481 RK |
4389 | return 0; |
4390 | ||
4391 | n_ops = i; | |
4392 | ||
4393 | /* If we have a CONST_INT, put it last. */ | |
4394 | for (i = 0; i < n_ops - 1; i++) | |
4395 | if (GET_CODE (ops[i]) == CONST_INT) | |
4396 | { | |
4397 | tem = ops[n_ops - 1], ops[n_ops - 1] = ops[i] , ops[i] = tem; | |
4398 | j = negs[n_ops - 1], negs[n_ops - 1] = negs[i], negs[i] = j; | |
4399 | } | |
4400 | ||
4401 | /* Put a non-negated operand first. If there aren't any, make all | |
4402 | operands positive and negate the whole thing later. */ | |
4403 | for (i = 0; i < n_ops && negs[i]; i++) | |
4404 | ; | |
4405 | ||
4406 | if (i == n_ops) | |
4407 | { | |
4408 | for (i = 0; i < n_ops; i++) | |
4409 | negs[i] = 0; | |
4410 | negate = 1; | |
4411 | } | |
4412 | else if (i != 0) | |
4413 | { | |
4414 | tem = ops[0], ops[0] = ops[i], ops[i] = tem; | |
4415 | j = negs[0], negs[0] = negs[i], negs[i] = j; | |
4416 | } | |
4417 | ||
4418 | /* Now make the result by performing the requested operations. */ | |
4419 | result = ops[0]; | |
4420 | for (i = 1; i < n_ops; i++) | |
4421 | result = cse_gen_binary (negs[i] ? MINUS : PLUS, mode, result, ops[i]); | |
4422 | ||
38a448ca | 4423 | return negate ? gen_rtx_NEG (mode, result) : result; |
96b0e481 RK |
4424 | } |
4425 | \f | |
4426 | /* Make a binary operation by properly ordering the operands and | |
4427 | seeing if the expression folds. */ | |
4428 | ||
4429 | static rtx | |
4430 | cse_gen_binary (code, mode, op0, op1) | |
4431 | enum rtx_code code; | |
4432 | enum machine_mode mode; | |
4433 | rtx op0, op1; | |
4434 | { | |
4435 | rtx tem; | |
4436 | ||
4437 | /* Put complex operands first and constants second if commutative. */ | |
4438 | if (GET_RTX_CLASS (code) == 'c' | |
4439 | && ((CONSTANT_P (op0) && GET_CODE (op1) != CONST_INT) | |
4440 | || (GET_RTX_CLASS (GET_CODE (op0)) == 'o' | |
4441 | && GET_RTX_CLASS (GET_CODE (op1)) != 'o') | |
4442 | || (GET_CODE (op0) == SUBREG | |
4443 | && GET_RTX_CLASS (GET_CODE (SUBREG_REG (op0))) == 'o' | |
4444 | && GET_RTX_CLASS (GET_CODE (op1)) != 'o'))) | |
4445 | tem = op0, op0 = op1, op1 = tem; | |
4446 | ||
4447 | /* If this simplifies, do it. */ | |
4448 | tem = simplify_binary_operation (code, mode, op0, op1); | |
4449 | ||
4450 | if (tem) | |
4451 | return tem; | |
4452 | ||
4453 | /* Handle addition and subtraction of CONST_INT specially. Otherwise, | |
4454 | just form the operation. */ | |
4455 | ||
4456 | if (code == PLUS && GET_CODE (op1) == CONST_INT | |
4457 | && GET_MODE (op0) != VOIDmode) | |
4458 | return plus_constant (op0, INTVAL (op1)); | |
4459 | else if (code == MINUS && GET_CODE (op1) == CONST_INT | |
4460 | && GET_MODE (op0) != VOIDmode) | |
4461 | return plus_constant (op0, - INTVAL (op1)); | |
4462 | else | |
38a448ca | 4463 | return gen_rtx_fmt_ee (code, mode, op0, op1); |
96b0e481 RK |
4464 | } |
4465 | \f | |
7afe21cc | 4466 | /* Like simplify_binary_operation except used for relational operators. |
a432f20d RK |
4467 | MODE is the mode of the operands, not that of the result. If MODE |
4468 | is VOIDmode, both operands must also be VOIDmode and we compare the | |
4469 | operands in "infinite precision". | |
4470 | ||
4471 | If no simplification is possible, this function returns zero. Otherwise, | |
4472 | it returns either const_true_rtx or const0_rtx. */ | |
7afe21cc RK |
4473 | |
4474 | rtx | |
4475 | simplify_relational_operation (code, mode, op0, op1) | |
4476 | enum rtx_code code; | |
4477 | enum machine_mode mode; | |
4478 | rtx op0, op1; | |
4479 | { | |
a432f20d RK |
4480 | int equal, op0lt, op0ltu, op1lt, op1ltu; |
4481 | rtx tem; | |
7afe21cc RK |
4482 | |
4483 | /* If op0 is a compare, extract the comparison arguments from it. */ | |
4484 | if (GET_CODE (op0) == COMPARE && op1 == const0_rtx) | |
4485 | op1 = XEXP (op0, 1), op0 = XEXP (op0, 0); | |
4486 | ||
28bad1cb RK |
4487 | /* We can't simplify MODE_CC values since we don't know what the |
4488 | actual comparison is. */ | |
4489 | if (GET_MODE_CLASS (GET_MODE (op0)) == MODE_CC | |
4490 | #ifdef HAVE_cc0 | |
4491 | || op0 == cc0_rtx | |
4492 | #endif | |
4493 | ) | |
31dcf83f RS |
4494 | return 0; |
4495 | ||
a432f20d RK |
4496 | /* For integer comparisons of A and B maybe we can simplify A - B and can |
4497 | then simplify a comparison of that with zero. If A and B are both either | |
4498 | a register or a CONST_INT, this can't help; testing for these cases will | |
4499 | prevent infinite recursion here and speed things up. | |
4500 | ||
c27b5c62 JW |
4501 | If CODE is an unsigned comparison, then we can never do this optimization, |
4502 | because it gives an incorrect result if the subtraction wraps around zero. | |
4503 | ANSI C defines unsigned operations such that they never overflow, and | |
4504 | thus such cases can not be ignored. */ | |
a432f20d RK |
4505 | |
4506 | if (INTEGRAL_MODE_P (mode) && op1 != const0_rtx | |
4507 | && ! ((GET_CODE (op0) == REG || GET_CODE (op0) == CONST_INT) | |
4508 | && (GET_CODE (op1) == REG || GET_CODE (op1) == CONST_INT)) | |
4509 | && 0 != (tem = simplify_binary_operation (MINUS, mode, op0, op1)) | |
c27b5c62 | 4510 | && code != GTU && code != GEU && code != LTU && code != LEU) |
a432f20d RK |
4511 | return simplify_relational_operation (signed_condition (code), |
4512 | mode, tem, const0_rtx); | |
4513 | ||
4514 | /* For non-IEEE floating-point, if the two operands are equal, we know the | |
4515 | result. */ | |
4516 | if (rtx_equal_p (op0, op1) | |
4517 | && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
4518 | || ! FLOAT_MODE_P (GET_MODE (op0)) || flag_fast_math)) | |
4519 | equal = 1, op0lt = 0, op0ltu = 0, op1lt = 0, op1ltu = 0; | |
4520 | ||
4521 | /* If the operands are floating-point constants, see if we can fold | |
4522 | the result. */ | |
6076248a | 4523 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) |
a432f20d RK |
4524 | else if (GET_CODE (op0) == CONST_DOUBLE && GET_CODE (op1) == CONST_DOUBLE |
4525 | && GET_MODE_CLASS (GET_MODE (op0)) == MODE_FLOAT) | |
4526 | { | |
4527 | REAL_VALUE_TYPE d0, d1; | |
4528 | jmp_buf handler; | |
4529 | ||
4530 | if (setjmp (handler)) | |
4531 | return 0; | |
7afe21cc | 4532 | |
a432f20d RK |
4533 | set_float_handler (handler); |
4534 | REAL_VALUE_FROM_CONST_DOUBLE (d0, op0); | |
4535 | REAL_VALUE_FROM_CONST_DOUBLE (d1, op1); | |
4536 | equal = REAL_VALUES_EQUAL (d0, d1); | |
4537 | op0lt = op0ltu = REAL_VALUES_LESS (d0, d1); | |
4538 | op1lt = op1ltu = REAL_VALUES_LESS (d1, d0); | |
4539 | set_float_handler (NULL_PTR); | |
4540 | } | |
4541 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
7afe21cc | 4542 | |
a432f20d RK |
4543 | /* Otherwise, see if the operands are both integers. */ |
4544 | else if ((GET_MODE_CLASS (mode) == MODE_INT || mode == VOIDmode) | |
4545 | && (GET_CODE (op0) == CONST_DOUBLE || GET_CODE (op0) == CONST_INT) | |
4546 | && (GET_CODE (op1) == CONST_DOUBLE || GET_CODE (op1) == CONST_INT)) | |
4547 | { | |
4548 | int width = GET_MODE_BITSIZE (mode); | |
64812ded RK |
4549 | HOST_WIDE_INT l0s, h0s, l1s, h1s; |
4550 | unsigned HOST_WIDE_INT l0u, h0u, l1u, h1u; | |
7afe21cc | 4551 | |
a432f20d RK |
4552 | /* Get the two words comprising each integer constant. */ |
4553 | if (GET_CODE (op0) == CONST_DOUBLE) | |
4554 | { | |
4555 | l0u = l0s = CONST_DOUBLE_LOW (op0); | |
4556 | h0u = h0s = CONST_DOUBLE_HIGH (op0); | |
7afe21cc | 4557 | } |
a432f20d | 4558 | else |
6076248a | 4559 | { |
a432f20d | 4560 | l0u = l0s = INTVAL (op0); |
cb3bb2a7 | 4561 | h0u = h0s = l0s < 0 ? -1 : 0; |
a432f20d | 4562 | } |
6076248a | 4563 | |
a432f20d RK |
4564 | if (GET_CODE (op1) == CONST_DOUBLE) |
4565 | { | |
4566 | l1u = l1s = CONST_DOUBLE_LOW (op1); | |
4567 | h1u = h1s = CONST_DOUBLE_HIGH (op1); | |
4568 | } | |
4569 | else | |
4570 | { | |
4571 | l1u = l1s = INTVAL (op1); | |
cb3bb2a7 | 4572 | h1u = h1s = l1s < 0 ? -1 : 0; |
a432f20d RK |
4573 | } |
4574 | ||
4575 | /* If WIDTH is nonzero and smaller than HOST_BITS_PER_WIDE_INT, | |
4576 | we have to sign or zero-extend the values. */ | |
4577 | if (width != 0 && width <= HOST_BITS_PER_WIDE_INT) | |
4578 | h0u = h1u = 0, h0s = l0s < 0 ? -1 : 0, h1s = l1s < 0 ? -1 : 0; | |
6076248a | 4579 | |
a432f20d RK |
4580 | if (width != 0 && width < HOST_BITS_PER_WIDE_INT) |
4581 | { | |
4582 | l0u &= ((HOST_WIDE_INT) 1 << width) - 1; | |
4583 | l1u &= ((HOST_WIDE_INT) 1 << width) - 1; | |
6076248a | 4584 | |
a432f20d RK |
4585 | if (l0s & ((HOST_WIDE_INT) 1 << (width - 1))) |
4586 | l0s |= ((HOST_WIDE_INT) (-1) << width); | |
6076248a | 4587 | |
a432f20d RK |
4588 | if (l1s & ((HOST_WIDE_INT) 1 << (width - 1))) |
4589 | l1s |= ((HOST_WIDE_INT) (-1) << width); | |
6076248a RK |
4590 | } |
4591 | ||
a432f20d RK |
4592 | equal = (h0u == h1u && l0u == l1u); |
4593 | op0lt = (h0s < h1s || (h0s == h1s && l0s < l1s)); | |
4594 | op1lt = (h1s < h0s || (h1s == h0s && l1s < l0s)); | |
4595 | op0ltu = (h0u < h1u || (h0u == h1u && l0u < l1u)); | |
4596 | op1ltu = (h1u < h0u || (h1u == h0u && l1u < l0u)); | |
4597 | } | |
4598 | ||
4599 | /* Otherwise, there are some code-specific tests we can make. */ | |
4600 | else | |
4601 | { | |
7afe21cc RK |
4602 | switch (code) |
4603 | { | |
4604 | case EQ: | |
a432f20d RK |
4605 | /* References to the frame plus a constant or labels cannot |
4606 | be zero, but a SYMBOL_REF can due to #pragma weak. */ | |
4607 | if (((NONZERO_BASE_PLUS_P (op0) && op1 == const0_rtx) | |
4608 | || GET_CODE (op0) == LABEL_REF) | |
1a7c818b | 4609 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
a432f20d RK |
4610 | /* On some machines, the ap reg can be 0 sometimes. */ |
4611 | && op0 != arg_pointer_rtx | |
7afe21cc | 4612 | #endif |
a432f20d RK |
4613 | ) |
4614 | return const0_rtx; | |
4615 | break; | |
7afe21cc RK |
4616 | |
4617 | case NE: | |
a432f20d RK |
4618 | if (((NONZERO_BASE_PLUS_P (op0) && op1 == const0_rtx) |
4619 | || GET_CODE (op0) == LABEL_REF) | |
1a7c818b | 4620 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
a432f20d | 4621 | && op0 != arg_pointer_rtx |
7afe21cc | 4622 | #endif |
a432f20d | 4623 | ) |
7afe21cc RK |
4624 | return const_true_rtx; |
4625 | break; | |
4626 | ||
4627 | case GEU: | |
a432f20d RK |
4628 | /* Unsigned values are never negative. */ |
4629 | if (op1 == const0_rtx) | |
7afe21cc RK |
4630 | return const_true_rtx; |
4631 | break; | |
4632 | ||
4633 | case LTU: | |
a432f20d | 4634 | if (op1 == const0_rtx) |
7afe21cc RK |
4635 | return const0_rtx; |
4636 | break; | |
4637 | ||
4638 | case LEU: | |
4639 | /* Unsigned values are never greater than the largest | |
4640 | unsigned value. */ | |
4641 | if (GET_CODE (op1) == CONST_INT | |
4642 | && INTVAL (op1) == GET_MODE_MASK (mode) | |
a432f20d RK |
4643 | && INTEGRAL_MODE_P (mode)) |
4644 | return const_true_rtx; | |
7afe21cc RK |
4645 | break; |
4646 | ||
4647 | case GTU: | |
4648 | if (GET_CODE (op1) == CONST_INT | |
4649 | && INTVAL (op1) == GET_MODE_MASK (mode) | |
cbf6a543 | 4650 | && INTEGRAL_MODE_P (mode)) |
7afe21cc RK |
4651 | return const0_rtx; |
4652 | break; | |
e9a25f70 JL |
4653 | |
4654 | default: | |
4655 | break; | |
7afe21cc RK |
4656 | } |
4657 | ||
4658 | return 0; | |
4659 | } | |
4660 | ||
a432f20d RK |
4661 | /* If we reach here, EQUAL, OP0LT, OP0LTU, OP1LT, and OP1LTU are set |
4662 | as appropriate. */ | |
7afe21cc RK |
4663 | switch (code) |
4664 | { | |
7afe21cc | 4665 | case EQ: |
a432f20d RK |
4666 | return equal ? const_true_rtx : const0_rtx; |
4667 | case NE: | |
4668 | return ! equal ? const_true_rtx : const0_rtx; | |
7afe21cc | 4669 | case LT: |
a432f20d | 4670 | return op0lt ? const_true_rtx : const0_rtx; |
7afe21cc | 4671 | case GT: |
a432f20d | 4672 | return op1lt ? const_true_rtx : const0_rtx; |
7afe21cc | 4673 | case LTU: |
a432f20d | 4674 | return op0ltu ? const_true_rtx : const0_rtx; |
7afe21cc | 4675 | case GTU: |
a432f20d RK |
4676 | return op1ltu ? const_true_rtx : const0_rtx; |
4677 | case LE: | |
4678 | return equal || op0lt ? const_true_rtx : const0_rtx; | |
4679 | case GE: | |
4680 | return equal || op1lt ? const_true_rtx : const0_rtx; | |
4681 | case LEU: | |
4682 | return equal || op0ltu ? const_true_rtx : const0_rtx; | |
4683 | case GEU: | |
4684 | return equal || op1ltu ? const_true_rtx : const0_rtx; | |
e9a25f70 JL |
4685 | default: |
4686 | abort (); | |
7afe21cc | 4687 | } |
7afe21cc RK |
4688 | } |
4689 | \f | |
4690 | /* Simplify CODE, an operation with result mode MODE and three operands, | |
4691 | OP0, OP1, and OP2. OP0_MODE was the mode of OP0 before it became | |
4692 | a constant. Return 0 if no simplifications is possible. */ | |
4693 | ||
4694 | rtx | |
4695 | simplify_ternary_operation (code, mode, op0_mode, op0, op1, op2) | |
4696 | enum rtx_code code; | |
4697 | enum machine_mode mode, op0_mode; | |
4698 | rtx op0, op1, op2; | |
4699 | { | |
4700 | int width = GET_MODE_BITSIZE (mode); | |
4701 | ||
4702 | /* VOIDmode means "infinite" precision. */ | |
4703 | if (width == 0) | |
906c4e36 | 4704 | width = HOST_BITS_PER_WIDE_INT; |
7afe21cc RK |
4705 | |
4706 | switch (code) | |
4707 | { | |
4708 | case SIGN_EXTRACT: | |
4709 | case ZERO_EXTRACT: | |
4710 | if (GET_CODE (op0) == CONST_INT | |
4711 | && GET_CODE (op1) == CONST_INT | |
4712 | && GET_CODE (op2) == CONST_INT | |
4713 | && INTVAL (op1) + INTVAL (op2) <= GET_MODE_BITSIZE (op0_mode) | |
906c4e36 | 4714 | && width <= HOST_BITS_PER_WIDE_INT) |
7afe21cc RK |
4715 | { |
4716 | /* Extracting a bit-field from a constant */ | |
906c4e36 | 4717 | HOST_WIDE_INT val = INTVAL (op0); |
7afe21cc | 4718 | |
f76b9db2 ILT |
4719 | if (BITS_BIG_ENDIAN) |
4720 | val >>= (GET_MODE_BITSIZE (op0_mode) | |
4721 | - INTVAL (op2) - INTVAL (op1)); | |
4722 | else | |
4723 | val >>= INTVAL (op2); | |
4724 | ||
906c4e36 | 4725 | if (HOST_BITS_PER_WIDE_INT != INTVAL (op1)) |
7afe21cc RK |
4726 | { |
4727 | /* First zero-extend. */ | |
906c4e36 | 4728 | val &= ((HOST_WIDE_INT) 1 << INTVAL (op1)) - 1; |
7afe21cc | 4729 | /* If desired, propagate sign bit. */ |
906c4e36 RK |
4730 | if (code == SIGN_EXTRACT |
4731 | && (val & ((HOST_WIDE_INT) 1 << (INTVAL (op1) - 1)))) | |
4732 | val |= ~ (((HOST_WIDE_INT) 1 << INTVAL (op1)) - 1); | |
7afe21cc RK |
4733 | } |
4734 | ||
4735 | /* Clear the bits that don't belong in our mode, | |
4736 | unless they and our sign bit are all one. | |
4737 | So we get either a reasonable negative value or a reasonable | |
4738 | unsigned value for this mode. */ | |
906c4e36 RK |
4739 | if (width < HOST_BITS_PER_WIDE_INT |
4740 | && ((val & ((HOST_WIDE_INT) (-1) << (width - 1))) | |
4741 | != ((HOST_WIDE_INT) (-1) << (width - 1)))) | |
4742 | val &= ((HOST_WIDE_INT) 1 << width) - 1; | |
7afe21cc | 4743 | |
906c4e36 | 4744 | return GEN_INT (val); |
7afe21cc RK |
4745 | } |
4746 | break; | |
4747 | ||
4748 | case IF_THEN_ELSE: | |
4749 | if (GET_CODE (op0) == CONST_INT) | |
4750 | return op0 != const0_rtx ? op1 : op2; | |
3bf1b082 JW |
4751 | |
4752 | /* Convert a == b ? b : a to "a". */ | |
4753 | if (GET_CODE (op0) == NE && ! side_effects_p (op0) | |
4754 | && rtx_equal_p (XEXP (op0, 0), op1) | |
4755 | && rtx_equal_p (XEXP (op0, 1), op2)) | |
4756 | return op1; | |
4757 | else if (GET_CODE (op0) == EQ && ! side_effects_p (op0) | |
4758 | && rtx_equal_p (XEXP (op0, 1), op1) | |
4759 | && rtx_equal_p (XEXP (op0, 0), op2)) | |
4760 | return op2; | |
e82ad93d | 4761 | else if (GET_RTX_CLASS (GET_CODE (op0)) == '<' && ! side_effects_p (op0)) |
ed1ecb19 JL |
4762 | { |
4763 | rtx temp; | |
4764 | temp = simplify_relational_operation (GET_CODE (op0), op0_mode, | |
4765 | XEXP (op0, 0), XEXP (op0, 1)); | |
4766 | /* See if any simplifications were possible. */ | |
4767 | if (temp == const0_rtx) | |
4768 | return op2; | |
4769 | else if (temp == const1_rtx) | |
4770 | return op1; | |
4771 | } | |
7afe21cc RK |
4772 | break; |
4773 | ||
4774 | default: | |
4775 | abort (); | |
4776 | } | |
4777 | ||
4778 | return 0; | |
4779 | } | |
4780 | \f | |
4781 | /* If X is a nontrivial arithmetic operation on an argument | |
4782 | for which a constant value can be determined, return | |
4783 | the result of operating on that value, as a constant. | |
4784 | Otherwise, return X, possibly with one or more operands | |
4785 | modified by recursive calls to this function. | |
4786 | ||
e7bb59fa RK |
4787 | If X is a register whose contents are known, we do NOT |
4788 | return those contents here. equiv_constant is called to | |
4789 | perform that task. | |
7afe21cc RK |
4790 | |
4791 | INSN is the insn that we may be modifying. If it is 0, make a copy | |
4792 | of X before modifying it. */ | |
4793 | ||
4794 | static rtx | |
4795 | fold_rtx (x, insn) | |
4796 | rtx x; | |
4797 | rtx insn; | |
4798 | { | |
4799 | register enum rtx_code code; | |
4800 | register enum machine_mode mode; | |
4801 | register char *fmt; | |
906c4e36 | 4802 | register int i; |
7afe21cc RK |
4803 | rtx new = 0; |
4804 | int copied = 0; | |
4805 | int must_swap = 0; | |
4806 | ||
4807 | /* Folded equivalents of first two operands of X. */ | |
4808 | rtx folded_arg0; | |
4809 | rtx folded_arg1; | |
4810 | ||
4811 | /* Constant equivalents of first three operands of X; | |
4812 | 0 when no such equivalent is known. */ | |
4813 | rtx const_arg0; | |
4814 | rtx const_arg1; | |
4815 | rtx const_arg2; | |
4816 | ||
4817 | /* The mode of the first operand of X. We need this for sign and zero | |
4818 | extends. */ | |
4819 | enum machine_mode mode_arg0; | |
4820 | ||
4821 | if (x == 0) | |
4822 | return x; | |
4823 | ||
4824 | mode = GET_MODE (x); | |
4825 | code = GET_CODE (x); | |
4826 | switch (code) | |
4827 | { | |
4828 | case CONST: | |
4829 | case CONST_INT: | |
4830 | case CONST_DOUBLE: | |
4831 | case SYMBOL_REF: | |
4832 | case LABEL_REF: | |
4833 | case REG: | |
4834 | /* No use simplifying an EXPR_LIST | |
4835 | since they are used only for lists of args | |
4836 | in a function call's REG_EQUAL note. */ | |
4837 | case EXPR_LIST: | |
956d6950 JL |
4838 | /* Changing anything inside an ADDRESSOF is incorrect; we don't |
4839 | want to (e.g.,) make (addressof (const_int 0)) just because | |
4840 | the location is known to be zero. */ | |
4841 | case ADDRESSOF: | |
7afe21cc RK |
4842 | return x; |
4843 | ||
4844 | #ifdef HAVE_cc0 | |
4845 | case CC0: | |
4846 | return prev_insn_cc0; | |
4847 | #endif | |
4848 | ||
4849 | case PC: | |
4850 | /* If the next insn is a CODE_LABEL followed by a jump table, | |
4851 | PC's value is a LABEL_REF pointing to that label. That | |
4852 | lets us fold switch statements on the Vax. */ | |
4853 | if (insn && GET_CODE (insn) == JUMP_INSN) | |
4854 | { | |
4855 | rtx next = next_nonnote_insn (insn); | |
4856 | ||
4857 | if (next && GET_CODE (next) == CODE_LABEL | |
4858 | && NEXT_INSN (next) != 0 | |
4859 | && GET_CODE (NEXT_INSN (next)) == JUMP_INSN | |
4860 | && (GET_CODE (PATTERN (NEXT_INSN (next))) == ADDR_VEC | |
4861 | || GET_CODE (PATTERN (NEXT_INSN (next))) == ADDR_DIFF_VEC)) | |
38a448ca | 4862 | return gen_rtx_LABEL_REF (Pmode, next); |
7afe21cc RK |
4863 | } |
4864 | break; | |
4865 | ||
4866 | case SUBREG: | |
c610adec RK |
4867 | /* See if we previously assigned a constant value to this SUBREG. */ |
4868 | if ((new = lookup_as_function (x, CONST_INT)) != 0 | |
4869 | || (new = lookup_as_function (x, CONST_DOUBLE)) != 0) | |
7afe21cc RK |
4870 | return new; |
4871 | ||
4b980e20 RK |
4872 | /* If this is a paradoxical SUBREG, we have no idea what value the |
4873 | extra bits would have. However, if the operand is equivalent | |
4874 | to a SUBREG whose operand is the same as our mode, and all the | |
4875 | modes are within a word, we can just use the inner operand | |
31c85c78 RK |
4876 | because these SUBREGs just say how to treat the register. |
4877 | ||
4878 | Similarly if we find an integer constant. */ | |
4b980e20 | 4879 | |
e5f6a288 | 4880 | if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))) |
4b980e20 RK |
4881 | { |
4882 | enum machine_mode imode = GET_MODE (SUBREG_REG (x)); | |
4883 | struct table_elt *elt; | |
4884 | ||
4885 | if (GET_MODE_SIZE (mode) <= UNITS_PER_WORD | |
4886 | && GET_MODE_SIZE (imode) <= UNITS_PER_WORD | |
4887 | && (elt = lookup (SUBREG_REG (x), HASH (SUBREG_REG (x), imode), | |
4888 | imode)) != 0) | |
31c85c78 RK |
4889 | for (elt = elt->first_same_value; |
4890 | elt; elt = elt->next_same_value) | |
4891 | { | |
4892 | if (CONSTANT_P (elt->exp) | |
4893 | && GET_MODE (elt->exp) == VOIDmode) | |
4894 | return elt->exp; | |
4895 | ||
4b980e20 RK |
4896 | if (GET_CODE (elt->exp) == SUBREG |
4897 | && GET_MODE (SUBREG_REG (elt->exp)) == mode | |
906c4e36 | 4898 | && exp_equiv_p (elt->exp, elt->exp, 1, 0)) |
4b980e20 RK |
4899 | return copy_rtx (SUBREG_REG (elt->exp)); |
4900 | } | |
4901 | ||
4902 | return x; | |
4903 | } | |
e5f6a288 | 4904 | |
7afe21cc RK |
4905 | /* Fold SUBREG_REG. If it changed, see if we can simplify the SUBREG. |
4906 | We might be able to if the SUBREG is extracting a single word in an | |
4907 | integral mode or extracting the low part. */ | |
4908 | ||
4909 | folded_arg0 = fold_rtx (SUBREG_REG (x), insn); | |
4910 | const_arg0 = equiv_constant (folded_arg0); | |
4911 | if (const_arg0) | |
4912 | folded_arg0 = const_arg0; | |
4913 | ||
4914 | if (folded_arg0 != SUBREG_REG (x)) | |
4915 | { | |
4916 | new = 0; | |
4917 | ||
4918 | if (GET_MODE_CLASS (mode) == MODE_INT | |
4919 | && GET_MODE_SIZE (mode) == UNITS_PER_WORD | |
4920 | && GET_MODE (SUBREG_REG (x)) != VOIDmode) | |
4921 | new = operand_subword (folded_arg0, SUBREG_WORD (x), 0, | |
4922 | GET_MODE (SUBREG_REG (x))); | |
4923 | if (new == 0 && subreg_lowpart_p (x)) | |
4924 | new = gen_lowpart_if_possible (mode, folded_arg0); | |
4925 | if (new) | |
4926 | return new; | |
4927 | } | |
e5f6a288 RK |
4928 | |
4929 | /* If this is a narrowing SUBREG and our operand is a REG, see if | |
858a47b1 | 4930 | we can find an equivalence for REG that is an arithmetic operation |
e5f6a288 RK |
4931 | in a wider mode where both operands are paradoxical SUBREGs |
4932 | from objects of our result mode. In that case, we couldn't report | |
4933 | an equivalent value for that operation, since we don't know what the | |
4934 | extra bits will be. But we can find an equivalence for this SUBREG | |
4935 | by folding that operation is the narrow mode. This allows us to | |
4936 | fold arithmetic in narrow modes when the machine only supports | |
4b980e20 RK |
4937 | word-sized arithmetic. |
4938 | ||
4939 | Also look for a case where we have a SUBREG whose operand is the | |
4940 | same as our result. If both modes are smaller than a word, we | |
4941 | are simply interpreting a register in different modes and we | |
4942 | can use the inner value. */ | |
e5f6a288 RK |
4943 | |
4944 | if (GET_CODE (folded_arg0) == REG | |
e8d76a39 RS |
4945 | && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (folded_arg0)) |
4946 | && subreg_lowpart_p (x)) | |
e5f6a288 RK |
4947 | { |
4948 | struct table_elt *elt; | |
4949 | ||
4950 | /* We can use HASH here since we know that canon_hash won't be | |
4951 | called. */ | |
4952 | elt = lookup (folded_arg0, | |
4953 | HASH (folded_arg0, GET_MODE (folded_arg0)), | |
4954 | GET_MODE (folded_arg0)); | |
4955 | ||
4956 | if (elt) | |
4957 | elt = elt->first_same_value; | |
4958 | ||
4959 | for (; elt; elt = elt->next_same_value) | |
4960 | { | |
e8d76a39 RS |
4961 | enum rtx_code eltcode = GET_CODE (elt->exp); |
4962 | ||
e5f6a288 RK |
4963 | /* Just check for unary and binary operations. */ |
4964 | if (GET_RTX_CLASS (GET_CODE (elt->exp)) == '1' | |
4965 | && GET_CODE (elt->exp) != SIGN_EXTEND | |
4966 | && GET_CODE (elt->exp) != ZERO_EXTEND | |
4967 | && GET_CODE (XEXP (elt->exp, 0)) == SUBREG | |
4968 | && GET_MODE (SUBREG_REG (XEXP (elt->exp, 0))) == mode) | |
4969 | { | |
4970 | rtx op0 = SUBREG_REG (XEXP (elt->exp, 0)); | |
4971 | ||
4972 | if (GET_CODE (op0) != REG && ! CONSTANT_P (op0)) | |
906c4e36 | 4973 | op0 = fold_rtx (op0, NULL_RTX); |
e5f6a288 RK |
4974 | |
4975 | op0 = equiv_constant (op0); | |
4976 | if (op0) | |
4977 | new = simplify_unary_operation (GET_CODE (elt->exp), mode, | |
4978 | op0, mode); | |
4979 | } | |
4980 | else if ((GET_RTX_CLASS (GET_CODE (elt->exp)) == '2' | |
4981 | || GET_RTX_CLASS (GET_CODE (elt->exp)) == 'c') | |
e8d76a39 RS |
4982 | && eltcode != DIV && eltcode != MOD |
4983 | && eltcode != UDIV && eltcode != UMOD | |
4984 | && eltcode != ASHIFTRT && eltcode != LSHIFTRT | |
4985 | && eltcode != ROTATE && eltcode != ROTATERT | |
e5f6a288 RK |
4986 | && ((GET_CODE (XEXP (elt->exp, 0)) == SUBREG |
4987 | && (GET_MODE (SUBREG_REG (XEXP (elt->exp, 0))) | |
4988 | == mode)) | |
4989 | || CONSTANT_P (XEXP (elt->exp, 0))) | |
4990 | && ((GET_CODE (XEXP (elt->exp, 1)) == SUBREG | |
4991 | && (GET_MODE (SUBREG_REG (XEXP (elt->exp, 1))) | |
4992 | == mode)) | |
4993 | || CONSTANT_P (XEXP (elt->exp, 1)))) | |
4994 | { | |
4995 | rtx op0 = gen_lowpart_common (mode, XEXP (elt->exp, 0)); | |
4996 | rtx op1 = gen_lowpart_common (mode, XEXP (elt->exp, 1)); | |
4997 | ||
4998 | if (op0 && GET_CODE (op0) != REG && ! CONSTANT_P (op0)) | |
906c4e36 | 4999 | op0 = fold_rtx (op0, NULL_RTX); |
e5f6a288 RK |
5000 | |
5001 | if (op0) | |
5002 | op0 = equiv_constant (op0); | |
5003 | ||
5004 | if (op1 && GET_CODE (op1) != REG && ! CONSTANT_P (op1)) | |
906c4e36 | 5005 | op1 = fold_rtx (op1, NULL_RTX); |
e5f6a288 RK |
5006 | |
5007 | if (op1) | |
5008 | op1 = equiv_constant (op1); | |
5009 | ||
76fb0b60 RS |
5010 | /* If we are looking for the low SImode part of |
5011 | (ashift:DI c (const_int 32)), it doesn't work | |
5012 | to compute that in SImode, because a 32-bit shift | |
5013 | in SImode is unpredictable. We know the value is 0. */ | |
5014 | if (op0 && op1 | |
45620ed4 | 5015 | && GET_CODE (elt->exp) == ASHIFT |
76fb0b60 RS |
5016 | && GET_CODE (op1) == CONST_INT |
5017 | && INTVAL (op1) >= GET_MODE_BITSIZE (mode)) | |
5018 | { | |
5019 | if (INTVAL (op1) < GET_MODE_BITSIZE (GET_MODE (elt->exp))) | |
5020 | ||
5021 | /* If the count fits in the inner mode's width, | |
5022 | but exceeds the outer mode's width, | |
5023 | the value will get truncated to 0 | |
5024 | by the subreg. */ | |
5025 | new = const0_rtx; | |
5026 | else | |
5027 | /* If the count exceeds even the inner mode's width, | |
5028 | don't fold this expression. */ | |
5029 | new = 0; | |
5030 | } | |
5031 | else if (op0 && op1) | |
e5f6a288 RK |
5032 | new = simplify_binary_operation (GET_CODE (elt->exp), mode, |
5033 | op0, op1); | |
5034 | } | |
5035 | ||
4b980e20 RK |
5036 | else if (GET_CODE (elt->exp) == SUBREG |
5037 | && GET_MODE (SUBREG_REG (elt->exp)) == mode | |
5038 | && (GET_MODE_SIZE (GET_MODE (folded_arg0)) | |
5039 | <= UNITS_PER_WORD) | |
906c4e36 | 5040 | && exp_equiv_p (elt->exp, elt->exp, 1, 0)) |
4b980e20 RK |
5041 | new = copy_rtx (SUBREG_REG (elt->exp)); |
5042 | ||
e5f6a288 RK |
5043 | if (new) |
5044 | return new; | |
5045 | } | |
5046 | } | |
5047 | ||
7afe21cc RK |
5048 | return x; |
5049 | ||
5050 | case NOT: | |
5051 | case NEG: | |
5052 | /* If we have (NOT Y), see if Y is known to be (NOT Z). | |
5053 | If so, (NOT Y) simplifies to Z. Similarly for NEG. */ | |
5054 | new = lookup_as_function (XEXP (x, 0), code); | |
5055 | if (new) | |
5056 | return fold_rtx (copy_rtx (XEXP (new, 0)), insn); | |
5057 | break; | |
13c9910f | 5058 | |
7afe21cc RK |
5059 | case MEM: |
5060 | /* If we are not actually processing an insn, don't try to find the | |
5061 | best address. Not only don't we care, but we could modify the | |
5062 | MEM in an invalid way since we have no insn to validate against. */ | |
5063 | if (insn != 0) | |
5064 | find_best_addr (insn, &XEXP (x, 0)); | |
5065 | ||
5066 | { | |
5067 | /* Even if we don't fold in the insn itself, | |
5068 | we can safely do so here, in hopes of getting a constant. */ | |
906c4e36 | 5069 | rtx addr = fold_rtx (XEXP (x, 0), NULL_RTX); |
7afe21cc | 5070 | rtx base = 0; |
906c4e36 | 5071 | HOST_WIDE_INT offset = 0; |
7afe21cc RK |
5072 | |
5073 | if (GET_CODE (addr) == REG | |
5074 | && REGNO_QTY_VALID_P (REGNO (addr)) | |
5075 | && GET_MODE (addr) == qty_mode[reg_qty[REGNO (addr)]] | |
5076 | && qty_const[reg_qty[REGNO (addr)]] != 0) | |
5077 | addr = qty_const[reg_qty[REGNO (addr)]]; | |
5078 | ||
5079 | /* If address is constant, split it into a base and integer offset. */ | |
5080 | if (GET_CODE (addr) == SYMBOL_REF || GET_CODE (addr) == LABEL_REF) | |
5081 | base = addr; | |
5082 | else if (GET_CODE (addr) == CONST && GET_CODE (XEXP (addr, 0)) == PLUS | |
5083 | && GET_CODE (XEXP (XEXP (addr, 0), 1)) == CONST_INT) | |
5084 | { | |
5085 | base = XEXP (XEXP (addr, 0), 0); | |
5086 | offset = INTVAL (XEXP (XEXP (addr, 0), 1)); | |
5087 | } | |
5088 | else if (GET_CODE (addr) == LO_SUM | |
5089 | && GET_CODE (XEXP (addr, 1)) == SYMBOL_REF) | |
5090 | base = XEXP (addr, 1); | |
e9a25f70 | 5091 | else if (GET_CODE (addr) == ADDRESSOF) |
956d6950 | 5092 | return change_address (x, VOIDmode, addr); |
7afe21cc RK |
5093 | |
5094 | /* If this is a constant pool reference, we can fold it into its | |
5095 | constant to allow better value tracking. */ | |
5096 | if (base && GET_CODE (base) == SYMBOL_REF | |
5097 | && CONSTANT_POOL_ADDRESS_P (base)) | |
5098 | { | |
5099 | rtx constant = get_pool_constant (base); | |
5100 | enum machine_mode const_mode = get_pool_mode (base); | |
5101 | rtx new; | |
5102 | ||
5103 | if (CONSTANT_P (constant) && GET_CODE (constant) != CONST_INT) | |
5104 | constant_pool_entries_cost = COST (constant); | |
5105 | ||
5106 | /* If we are loading the full constant, we have an equivalence. */ | |
5107 | if (offset == 0 && mode == const_mode) | |
5108 | return constant; | |
5109 | ||
9faa82d8 | 5110 | /* If this actually isn't a constant (weird!), we can't do |
7afe21cc RK |
5111 | anything. Otherwise, handle the two most common cases: |
5112 | extracting a word from a multi-word constant, and extracting | |
5113 | the low-order bits. Other cases don't seem common enough to | |
5114 | worry about. */ | |
5115 | if (! CONSTANT_P (constant)) | |
5116 | return x; | |
5117 | ||
5118 | if (GET_MODE_CLASS (mode) == MODE_INT | |
5119 | && GET_MODE_SIZE (mode) == UNITS_PER_WORD | |
5120 | && offset % UNITS_PER_WORD == 0 | |
5121 | && (new = operand_subword (constant, | |
5122 | offset / UNITS_PER_WORD, | |
5123 | 0, const_mode)) != 0) | |
5124 | return new; | |
5125 | ||
5126 | if (((BYTES_BIG_ENDIAN | |
5127 | && offset == GET_MODE_SIZE (GET_MODE (constant)) - 1) | |
5128 | || (! BYTES_BIG_ENDIAN && offset == 0)) | |
5129 | && (new = gen_lowpart_if_possible (mode, constant)) != 0) | |
5130 | return new; | |
5131 | } | |
5132 | ||
5133 | /* If this is a reference to a label at a known position in a jump | |
5134 | table, we also know its value. */ | |
5135 | if (base && GET_CODE (base) == LABEL_REF) | |
5136 | { | |
5137 | rtx label = XEXP (base, 0); | |
5138 | rtx table_insn = NEXT_INSN (label); | |
5139 | ||
5140 | if (table_insn && GET_CODE (table_insn) == JUMP_INSN | |
5141 | && GET_CODE (PATTERN (table_insn)) == ADDR_VEC) | |
5142 | { | |
5143 | rtx table = PATTERN (table_insn); | |
5144 | ||
5145 | if (offset >= 0 | |
5146 | && (offset / GET_MODE_SIZE (GET_MODE (table)) | |
5147 | < XVECLEN (table, 0))) | |
5148 | return XVECEXP (table, 0, | |
5149 | offset / GET_MODE_SIZE (GET_MODE (table))); | |
5150 | } | |
5151 | if (table_insn && GET_CODE (table_insn) == JUMP_INSN | |
5152 | && GET_CODE (PATTERN (table_insn)) == ADDR_DIFF_VEC) | |
5153 | { | |
5154 | rtx table = PATTERN (table_insn); | |
5155 | ||
5156 | if (offset >= 0 | |
5157 | && (offset / GET_MODE_SIZE (GET_MODE (table)) | |
5158 | < XVECLEN (table, 1))) | |
5159 | { | |
5160 | offset /= GET_MODE_SIZE (GET_MODE (table)); | |
38a448ca RH |
5161 | new = gen_rtx_MINUS (Pmode, XVECEXP (table, 1, offset), |
5162 | XEXP (table, 0)); | |
7afe21cc RK |
5163 | |
5164 | if (GET_MODE (table) != Pmode) | |
38a448ca | 5165 | new = gen_rtx_TRUNCATE (GET_MODE (table), new); |
7afe21cc | 5166 | |
67a37737 RK |
5167 | /* Indicate this is a constant. This isn't a |
5168 | valid form of CONST, but it will only be used | |
5169 | to fold the next insns and then discarded, so | |
5170 | it should be safe. */ | |
38a448ca | 5171 | return gen_rtx_CONST (GET_MODE (new), new); |
7afe21cc RK |
5172 | } |
5173 | } | |
5174 | } | |
5175 | ||
5176 | return x; | |
5177 | } | |
9255709c RK |
5178 | |
5179 | case ASM_OPERANDS: | |
5180 | for (i = XVECLEN (x, 3) - 1; i >= 0; i--) | |
5181 | validate_change (insn, &XVECEXP (x, 3, i), | |
5182 | fold_rtx (XVECEXP (x, 3, i), insn), 0); | |
5183 | break; | |
e9a25f70 JL |
5184 | |
5185 | default: | |
5186 | break; | |
7afe21cc RK |
5187 | } |
5188 | ||
5189 | const_arg0 = 0; | |
5190 | const_arg1 = 0; | |
5191 | const_arg2 = 0; | |
5192 | mode_arg0 = VOIDmode; | |
5193 | ||
5194 | /* Try folding our operands. | |
5195 | Then see which ones have constant values known. */ | |
5196 | ||
5197 | fmt = GET_RTX_FORMAT (code); | |
5198 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
5199 | if (fmt[i] == 'e') | |
5200 | { | |
5201 | rtx arg = XEXP (x, i); | |
5202 | rtx folded_arg = arg, const_arg = 0; | |
5203 | enum machine_mode mode_arg = GET_MODE (arg); | |
5204 | rtx cheap_arg, expensive_arg; | |
5205 | rtx replacements[2]; | |
5206 | int j; | |
5207 | ||
5208 | /* Most arguments are cheap, so handle them specially. */ | |
5209 | switch (GET_CODE (arg)) | |
5210 | { | |
5211 | case REG: | |
5212 | /* This is the same as calling equiv_constant; it is duplicated | |
5213 | here for speed. */ | |
5214 | if (REGNO_QTY_VALID_P (REGNO (arg)) | |
5215 | && qty_const[reg_qty[REGNO (arg)]] != 0 | |
5216 | && GET_CODE (qty_const[reg_qty[REGNO (arg)]]) != REG | |
5217 | && GET_CODE (qty_const[reg_qty[REGNO (arg)]]) != PLUS) | |
5218 | const_arg | |
5219 | = gen_lowpart_if_possible (GET_MODE (arg), | |
5220 | qty_const[reg_qty[REGNO (arg)]]); | |
5221 | break; | |
5222 | ||
5223 | case CONST: | |
5224 | case CONST_INT: | |
5225 | case SYMBOL_REF: | |
5226 | case LABEL_REF: | |
5227 | case CONST_DOUBLE: | |
5228 | const_arg = arg; | |
5229 | break; | |
5230 | ||
5231 | #ifdef HAVE_cc0 | |
5232 | case CC0: | |
5233 | folded_arg = prev_insn_cc0; | |
5234 | mode_arg = prev_insn_cc0_mode; | |
5235 | const_arg = equiv_constant (folded_arg); | |
5236 | break; | |
5237 | #endif | |
5238 | ||
5239 | default: | |
5240 | folded_arg = fold_rtx (arg, insn); | |
5241 | const_arg = equiv_constant (folded_arg); | |
5242 | } | |
5243 | ||
5244 | /* For the first three operands, see if the operand | |
5245 | is constant or equivalent to a constant. */ | |
5246 | switch (i) | |
5247 | { | |
5248 | case 0: | |
5249 | folded_arg0 = folded_arg; | |
5250 | const_arg0 = const_arg; | |
5251 | mode_arg0 = mode_arg; | |
5252 | break; | |
5253 | case 1: | |
5254 | folded_arg1 = folded_arg; | |
5255 | const_arg1 = const_arg; | |
5256 | break; | |
5257 | case 2: | |
5258 | const_arg2 = const_arg; | |
5259 | break; | |
5260 | } | |
5261 | ||
5262 | /* Pick the least expensive of the folded argument and an | |
5263 | equivalent constant argument. */ | |
5264 | if (const_arg == 0 || const_arg == folded_arg | |
5265 | || COST (const_arg) > COST (folded_arg)) | |
5266 | cheap_arg = folded_arg, expensive_arg = const_arg; | |
5267 | else | |
5268 | cheap_arg = const_arg, expensive_arg = folded_arg; | |
5269 | ||
5270 | /* Try to replace the operand with the cheapest of the two | |
5271 | possibilities. If it doesn't work and this is either of the first | |
5272 | two operands of a commutative operation, try swapping them. | |
5273 | If THAT fails, try the more expensive, provided it is cheaper | |
5274 | than what is already there. */ | |
5275 | ||
5276 | if (cheap_arg == XEXP (x, i)) | |
5277 | continue; | |
5278 | ||
5279 | if (insn == 0 && ! copied) | |
5280 | { | |
5281 | x = copy_rtx (x); | |
5282 | copied = 1; | |
5283 | } | |
5284 | ||
5285 | replacements[0] = cheap_arg, replacements[1] = expensive_arg; | |
5286 | for (j = 0; | |
5287 | j < 2 && replacements[j] | |
5288 | && COST (replacements[j]) < COST (XEXP (x, i)); | |
5289 | j++) | |
5290 | { | |
5291 | if (validate_change (insn, &XEXP (x, i), replacements[j], 0)) | |
5292 | break; | |
5293 | ||
5294 | if (code == NE || code == EQ || GET_RTX_CLASS (code) == 'c') | |
5295 | { | |
5296 | validate_change (insn, &XEXP (x, i), XEXP (x, 1 - i), 1); | |
5297 | validate_change (insn, &XEXP (x, 1 - i), replacements[j], 1); | |
5298 | ||
5299 | if (apply_change_group ()) | |
5300 | { | |
5301 | /* Swap them back to be invalid so that this loop can | |
5302 | continue and flag them to be swapped back later. */ | |
5303 | rtx tem; | |
5304 | ||
5305 | tem = XEXP (x, 0); XEXP (x, 0) = XEXP (x, 1); | |
5306 | XEXP (x, 1) = tem; | |
5307 | must_swap = 1; | |
5308 | break; | |
5309 | } | |
5310 | } | |
5311 | } | |
5312 | } | |
5313 | ||
2d8b0f3a JL |
5314 | else |
5315 | { | |
5316 | if (fmt[i] == 'E') | |
5317 | /* Don't try to fold inside of a vector of expressions. | |
5318 | Doing nothing is harmless. */ | |
5319 | {;} | |
5320 | } | |
7afe21cc RK |
5321 | |
5322 | /* If a commutative operation, place a constant integer as the second | |
5323 | operand unless the first operand is also a constant integer. Otherwise, | |
5324 | place any constant second unless the first operand is also a constant. */ | |
5325 | ||
5326 | if (code == EQ || code == NE || GET_RTX_CLASS (code) == 'c') | |
5327 | { | |
5328 | if (must_swap || (const_arg0 | |
5329 | && (const_arg1 == 0 | |
5330 | || (GET_CODE (const_arg0) == CONST_INT | |
5331 | && GET_CODE (const_arg1) != CONST_INT)))) | |
5332 | { | |
5333 | register rtx tem = XEXP (x, 0); | |
5334 | ||
5335 | if (insn == 0 && ! copied) | |
5336 | { | |
5337 | x = copy_rtx (x); | |
5338 | copied = 1; | |
5339 | } | |
5340 | ||
5341 | validate_change (insn, &XEXP (x, 0), XEXP (x, 1), 1); | |
5342 | validate_change (insn, &XEXP (x, 1), tem, 1); | |
5343 | if (apply_change_group ()) | |
5344 | { | |
5345 | tem = const_arg0, const_arg0 = const_arg1, const_arg1 = tem; | |
5346 | tem = folded_arg0, folded_arg0 = folded_arg1, folded_arg1 = tem; | |
5347 | } | |
5348 | } | |
5349 | } | |
5350 | ||
5351 | /* If X is an arithmetic operation, see if we can simplify it. */ | |
5352 | ||
5353 | switch (GET_RTX_CLASS (code)) | |
5354 | { | |
5355 | case '1': | |
67a37737 RK |
5356 | { |
5357 | int is_const = 0; | |
5358 | ||
5359 | /* We can't simplify extension ops unless we know the | |
5360 | original mode. */ | |
5361 | if ((code == ZERO_EXTEND || code == SIGN_EXTEND) | |
5362 | && mode_arg0 == VOIDmode) | |
5363 | break; | |
5364 | ||
5365 | /* If we had a CONST, strip it off and put it back later if we | |
5366 | fold. */ | |
5367 | if (const_arg0 != 0 && GET_CODE (const_arg0) == CONST) | |
5368 | is_const = 1, const_arg0 = XEXP (const_arg0, 0); | |
5369 | ||
5370 | new = simplify_unary_operation (code, mode, | |
5371 | const_arg0 ? const_arg0 : folded_arg0, | |
5372 | mode_arg0); | |
5373 | if (new != 0 && is_const) | |
38a448ca | 5374 | new = gen_rtx_CONST (mode, new); |
67a37737 | 5375 | } |
7afe21cc RK |
5376 | break; |
5377 | ||
5378 | case '<': | |
5379 | /* See what items are actually being compared and set FOLDED_ARG[01] | |
5380 | to those values and CODE to the actual comparison code. If any are | |
5381 | constant, set CONST_ARG0 and CONST_ARG1 appropriately. We needn't | |
5382 | do anything if both operands are already known to be constant. */ | |
5383 | ||
5384 | if (const_arg0 == 0 || const_arg1 == 0) | |
5385 | { | |
5386 | struct table_elt *p0, *p1; | |
c610adec | 5387 | rtx true = const_true_rtx, false = const0_rtx; |
13c9910f | 5388 | enum machine_mode mode_arg1; |
c610adec RK |
5389 | |
5390 | #ifdef FLOAT_STORE_FLAG_VALUE | |
c7c955ee | 5391 | if (GET_MODE_CLASS (mode) == MODE_FLOAT) |
c610adec | 5392 | { |
560c94a2 RK |
5393 | true = CONST_DOUBLE_FROM_REAL_VALUE (FLOAT_STORE_FLAG_VALUE, |
5394 | mode); | |
c610adec RK |
5395 | false = CONST0_RTX (mode); |
5396 | } | |
5397 | #endif | |
7afe21cc | 5398 | |
13c9910f RS |
5399 | code = find_comparison_args (code, &folded_arg0, &folded_arg1, |
5400 | &mode_arg0, &mode_arg1); | |
7afe21cc RK |
5401 | const_arg0 = equiv_constant (folded_arg0); |
5402 | const_arg1 = equiv_constant (folded_arg1); | |
5403 | ||
13c9910f RS |
5404 | /* If the mode is VOIDmode or a MODE_CC mode, we don't know |
5405 | what kinds of things are being compared, so we can't do | |
5406 | anything with this comparison. */ | |
7afe21cc RK |
5407 | |
5408 | if (mode_arg0 == VOIDmode || GET_MODE_CLASS (mode_arg0) == MODE_CC) | |
5409 | break; | |
5410 | ||
0f41302f MS |
5411 | /* If we do not now have two constants being compared, see |
5412 | if we can nevertheless deduce some things about the | |
5413 | comparison. */ | |
7afe21cc RK |
5414 | if (const_arg0 == 0 || const_arg1 == 0) |
5415 | { | |
0f41302f MS |
5416 | /* Is FOLDED_ARG0 frame-pointer plus a constant? Or |
5417 | non-explicit constant? These aren't zero, but we | |
5418 | don't know their sign. */ | |
7afe21cc RK |
5419 | if (const_arg1 == const0_rtx |
5420 | && (NONZERO_BASE_PLUS_P (folded_arg0) | |
5421 | #if 0 /* Sad to say, on sysvr4, #pragma weak can make a symbol address | |
5422 | come out as 0. */ | |
5423 | || GET_CODE (folded_arg0) == SYMBOL_REF | |
5424 | #endif | |
5425 | || GET_CODE (folded_arg0) == LABEL_REF | |
5426 | || GET_CODE (folded_arg0) == CONST)) | |
5427 | { | |
5428 | if (code == EQ) | |
c610adec | 5429 | return false; |
7afe21cc | 5430 | else if (code == NE) |
c610adec | 5431 | return true; |
7afe21cc RK |
5432 | } |
5433 | ||
5434 | /* See if the two operands are the same. We don't do this | |
5435 | for IEEE floating-point since we can't assume x == x | |
5436 | since x might be a NaN. */ | |
5437 | ||
5438 | if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
a83afb65 | 5439 | || ! FLOAT_MODE_P (mode_arg0) || flag_fast_math) |
7afe21cc RK |
5440 | && (folded_arg0 == folded_arg1 |
5441 | || (GET_CODE (folded_arg0) == REG | |
5442 | && GET_CODE (folded_arg1) == REG | |
5443 | && (reg_qty[REGNO (folded_arg0)] | |
5444 | == reg_qty[REGNO (folded_arg1)])) | |
5445 | || ((p0 = lookup (folded_arg0, | |
5446 | (safe_hash (folded_arg0, mode_arg0) | |
5447 | % NBUCKETS), mode_arg0)) | |
5448 | && (p1 = lookup (folded_arg1, | |
5449 | (safe_hash (folded_arg1, mode_arg0) | |
5450 | % NBUCKETS), mode_arg0)) | |
5451 | && p0->first_same_value == p1->first_same_value))) | |
5452 | return ((code == EQ || code == LE || code == GE | |
5453 | || code == LEU || code == GEU) | |
c610adec | 5454 | ? true : false); |
7afe21cc RK |
5455 | |
5456 | /* If FOLDED_ARG0 is a register, see if the comparison we are | |
5457 | doing now is either the same as we did before or the reverse | |
5458 | (we only check the reverse if not floating-point). */ | |
5459 | else if (GET_CODE (folded_arg0) == REG) | |
5460 | { | |
5461 | int qty = reg_qty[REGNO (folded_arg0)]; | |
5462 | ||
5463 | if (REGNO_QTY_VALID_P (REGNO (folded_arg0)) | |
5464 | && (comparison_dominates_p (qty_comparison_code[qty], code) | |
5465 | || (comparison_dominates_p (qty_comparison_code[qty], | |
5466 | reverse_condition (code)) | |
cbf6a543 | 5467 | && ! FLOAT_MODE_P (mode_arg0))) |
7afe21cc RK |
5468 | && (rtx_equal_p (qty_comparison_const[qty], folded_arg1) |
5469 | || (const_arg1 | |
5470 | && rtx_equal_p (qty_comparison_const[qty], | |
5471 | const_arg1)) | |
5472 | || (GET_CODE (folded_arg1) == REG | |
5473 | && (reg_qty[REGNO (folded_arg1)] | |
5474 | == qty_comparison_qty[qty])))) | |
5475 | return (comparison_dominates_p (qty_comparison_code[qty], | |
5476 | code) | |
c610adec | 5477 | ? true : false); |
7afe21cc RK |
5478 | } |
5479 | } | |
5480 | } | |
5481 | ||
5482 | /* If we are comparing against zero, see if the first operand is | |
5483 | equivalent to an IOR with a constant. If so, we may be able to | |
5484 | determine the result of this comparison. */ | |
5485 | ||
5486 | if (const_arg1 == const0_rtx) | |
5487 | { | |
5488 | rtx y = lookup_as_function (folded_arg0, IOR); | |
5489 | rtx inner_const; | |
5490 | ||
5491 | if (y != 0 | |
5492 | && (inner_const = equiv_constant (XEXP (y, 1))) != 0 | |
5493 | && GET_CODE (inner_const) == CONST_INT | |
5494 | && INTVAL (inner_const) != 0) | |
5495 | { | |
5496 | int sign_bitnum = GET_MODE_BITSIZE (mode_arg0) - 1; | |
906c4e36 RK |
5497 | int has_sign = (HOST_BITS_PER_WIDE_INT >= sign_bitnum |
5498 | && (INTVAL (inner_const) | |
5499 | & ((HOST_WIDE_INT) 1 << sign_bitnum))); | |
c610adec RK |
5500 | rtx true = const_true_rtx, false = const0_rtx; |
5501 | ||
5502 | #ifdef FLOAT_STORE_FLAG_VALUE | |
c7c955ee | 5503 | if (GET_MODE_CLASS (mode) == MODE_FLOAT) |
c610adec | 5504 | { |
560c94a2 RK |
5505 | true = CONST_DOUBLE_FROM_REAL_VALUE (FLOAT_STORE_FLAG_VALUE, |
5506 | mode); | |
c610adec RK |
5507 | false = CONST0_RTX (mode); |
5508 | } | |
5509 | #endif | |
7afe21cc RK |
5510 | |
5511 | switch (code) | |
5512 | { | |
5513 | case EQ: | |
c610adec | 5514 | return false; |
7afe21cc | 5515 | case NE: |
c610adec | 5516 | return true; |
7afe21cc RK |
5517 | case LT: case LE: |
5518 | if (has_sign) | |
c610adec | 5519 | return true; |
7afe21cc RK |
5520 | break; |
5521 | case GT: case GE: | |
5522 | if (has_sign) | |
c610adec | 5523 | return false; |
7afe21cc | 5524 | break; |
e9a25f70 JL |
5525 | default: |
5526 | break; | |
7afe21cc RK |
5527 | } |
5528 | } | |
5529 | } | |
5530 | ||
5531 | new = simplify_relational_operation (code, mode_arg0, | |
5532 | const_arg0 ? const_arg0 : folded_arg0, | |
5533 | const_arg1 ? const_arg1 : folded_arg1); | |
c610adec RK |
5534 | #ifdef FLOAT_STORE_FLAG_VALUE |
5535 | if (new != 0 && GET_MODE_CLASS (mode) == MODE_FLOAT) | |
5536 | new = ((new == const0_rtx) ? CONST0_RTX (mode) | |
560c94a2 | 5537 | : CONST_DOUBLE_FROM_REAL_VALUE (FLOAT_STORE_FLAG_VALUE, mode)); |
c610adec | 5538 | #endif |
7afe21cc RK |
5539 | break; |
5540 | ||
5541 | case '2': | |
5542 | case 'c': | |
5543 | switch (code) | |
5544 | { | |
5545 | case PLUS: | |
5546 | /* If the second operand is a LABEL_REF, see if the first is a MINUS | |
5547 | with that LABEL_REF as its second operand. If so, the result is | |
5548 | the first operand of that MINUS. This handles switches with an | |
5549 | ADDR_DIFF_VEC table. */ | |
5550 | if (const_arg1 && GET_CODE (const_arg1) == LABEL_REF) | |
5551 | { | |
e650cbda RK |
5552 | rtx y |
5553 | = GET_CODE (folded_arg0) == MINUS ? folded_arg0 | |
5554 | : lookup_as_function (folded_arg0, MINUS); | |
7afe21cc RK |
5555 | |
5556 | if (y != 0 && GET_CODE (XEXP (y, 1)) == LABEL_REF | |
5557 | && XEXP (XEXP (y, 1), 0) == XEXP (const_arg1, 0)) | |
5558 | return XEXP (y, 0); | |
67a37737 RK |
5559 | |
5560 | /* Now try for a CONST of a MINUS like the above. */ | |
e650cbda RK |
5561 | if ((y = (GET_CODE (folded_arg0) == CONST ? folded_arg0 |
5562 | : lookup_as_function (folded_arg0, CONST))) != 0 | |
67a37737 RK |
5563 | && GET_CODE (XEXP (y, 0)) == MINUS |
5564 | && GET_CODE (XEXP (XEXP (y, 0), 1)) == LABEL_REF | |
5565 | && XEXP (XEXP (XEXP (y, 0),1), 0) == XEXP (const_arg1, 0)) | |
5566 | return XEXP (XEXP (y, 0), 0); | |
7afe21cc | 5567 | } |
c2cc0778 | 5568 | |
e650cbda RK |
5569 | /* Likewise if the operands are in the other order. */ |
5570 | if (const_arg0 && GET_CODE (const_arg0) == LABEL_REF) | |
5571 | { | |
5572 | rtx y | |
5573 | = GET_CODE (folded_arg1) == MINUS ? folded_arg1 | |
5574 | : lookup_as_function (folded_arg1, MINUS); | |
5575 | ||
5576 | if (y != 0 && GET_CODE (XEXP (y, 1)) == LABEL_REF | |
5577 | && XEXP (XEXP (y, 1), 0) == XEXP (const_arg0, 0)) | |
5578 | return XEXP (y, 0); | |
5579 | ||
5580 | /* Now try for a CONST of a MINUS like the above. */ | |
5581 | if ((y = (GET_CODE (folded_arg1) == CONST ? folded_arg1 | |
5582 | : lookup_as_function (folded_arg1, CONST))) != 0 | |
5583 | && GET_CODE (XEXP (y, 0)) == MINUS | |
5584 | && GET_CODE (XEXP (XEXP (y, 0), 1)) == LABEL_REF | |
5585 | && XEXP (XEXP (XEXP (y, 0),1), 0) == XEXP (const_arg0, 0)) | |
5586 | return XEXP (XEXP (y, 0), 0); | |
5587 | } | |
5588 | ||
c2cc0778 RK |
5589 | /* If second operand is a register equivalent to a negative |
5590 | CONST_INT, see if we can find a register equivalent to the | |
5591 | positive constant. Make a MINUS if so. Don't do this for | |
5d595063 | 5592 | a non-negative constant since we might then alternate between |
c2cc0778 | 5593 | chosing positive and negative constants. Having the positive |
5d595063 RK |
5594 | constant previously-used is the more common case. Be sure |
5595 | the resulting constant is non-negative; if const_arg1 were | |
5596 | the smallest negative number this would overflow: depending | |
5597 | on the mode, this would either just be the same value (and | |
5598 | hence not save anything) or be incorrect. */ | |
5599 | if (const_arg1 != 0 && GET_CODE (const_arg1) == CONST_INT | |
5600 | && INTVAL (const_arg1) < 0 | |
5601 | && - INTVAL (const_arg1) >= 0 | |
5602 | && GET_CODE (folded_arg1) == REG) | |
c2cc0778 RK |
5603 | { |
5604 | rtx new_const = GEN_INT (- INTVAL (const_arg1)); | |
5605 | struct table_elt *p | |
5606 | = lookup (new_const, safe_hash (new_const, mode) % NBUCKETS, | |
5607 | mode); | |
5608 | ||
5609 | if (p) | |
5610 | for (p = p->first_same_value; p; p = p->next_same_value) | |
5611 | if (GET_CODE (p->exp) == REG) | |
5612 | return cse_gen_binary (MINUS, mode, folded_arg0, | |
5613 | canon_reg (p->exp, NULL_RTX)); | |
5614 | } | |
13c9910f RS |
5615 | goto from_plus; |
5616 | ||
5617 | case MINUS: | |
5618 | /* If we have (MINUS Y C), see if Y is known to be (PLUS Z C2). | |
5619 | If so, produce (PLUS Z C2-C). */ | |
5620 | if (const_arg1 != 0 && GET_CODE (const_arg1) == CONST_INT) | |
5621 | { | |
5622 | rtx y = lookup_as_function (XEXP (x, 0), PLUS); | |
5623 | if (y && GET_CODE (XEXP (y, 1)) == CONST_INT) | |
f3becefd RK |
5624 | return fold_rtx (plus_constant (copy_rtx (y), |
5625 | -INTVAL (const_arg1)), | |
a3b5c94a | 5626 | NULL_RTX); |
13c9910f | 5627 | } |
7afe21cc | 5628 | |
0f41302f | 5629 | /* ... fall through ... */ |
7afe21cc | 5630 | |
13c9910f | 5631 | from_plus: |
7afe21cc RK |
5632 | case SMIN: case SMAX: case UMIN: case UMAX: |
5633 | case IOR: case AND: case XOR: | |
5634 | case MULT: case DIV: case UDIV: | |
5635 | case ASHIFT: case LSHIFTRT: case ASHIFTRT: | |
5636 | /* If we have (<op> <reg> <const_int>) for an associative OP and REG | |
5637 | is known to be of similar form, we may be able to replace the | |
5638 | operation with a combined operation. This may eliminate the | |
5639 | intermediate operation if every use is simplified in this way. | |
5640 | Note that the similar optimization done by combine.c only works | |
5641 | if the intermediate operation's result has only one reference. */ | |
5642 | ||
5643 | if (GET_CODE (folded_arg0) == REG | |
5644 | && const_arg1 && GET_CODE (const_arg1) == CONST_INT) | |
5645 | { | |
5646 | int is_shift | |
5647 | = (code == ASHIFT || code == ASHIFTRT || code == LSHIFTRT); | |
5648 | rtx y = lookup_as_function (folded_arg0, code); | |
5649 | rtx inner_const; | |
5650 | enum rtx_code associate_code; | |
5651 | rtx new_const; | |
5652 | ||
5653 | if (y == 0 | |
5654 | || 0 == (inner_const | |
5655 | = equiv_constant (fold_rtx (XEXP (y, 1), 0))) | |
5656 | || GET_CODE (inner_const) != CONST_INT | |
5657 | /* If we have compiled a statement like | |
5658 | "if (x == (x & mask1))", and now are looking at | |
5659 | "x & mask2", we will have a case where the first operand | |
5660 | of Y is the same as our first operand. Unless we detect | |
5661 | this case, an infinite loop will result. */ | |
5662 | || XEXP (y, 0) == folded_arg0) | |
5663 | break; | |
5664 | ||
5665 | /* Don't associate these operations if they are a PLUS with the | |
5666 | same constant and it is a power of two. These might be doable | |
5667 | with a pre- or post-increment. Similarly for two subtracts of | |
5668 | identical powers of two with post decrement. */ | |
5669 | ||
5670 | if (code == PLUS && INTVAL (const_arg1) == INTVAL (inner_const) | |
5671 | && (0 | |
5672 | #if defined(HAVE_PRE_INCREMENT) || defined(HAVE_POST_INCREMENT) | |
5673 | || exact_log2 (INTVAL (const_arg1)) >= 0 | |
5674 | #endif | |
5675 | #if defined(HAVE_PRE_DECREMENT) || defined(HAVE_POST_DECREMENT) | |
5676 | || exact_log2 (- INTVAL (const_arg1)) >= 0 | |
5677 | #endif | |
5678 | )) | |
5679 | break; | |
5680 | ||
5681 | /* Compute the code used to compose the constants. For example, | |
5682 | A/C1/C2 is A/(C1 * C2), so if CODE == DIV, we want MULT. */ | |
5683 | ||
5684 | associate_code | |
5685 | = (code == MULT || code == DIV || code == UDIV ? MULT | |
5686 | : is_shift || code == PLUS || code == MINUS ? PLUS : code); | |
5687 | ||
5688 | new_const = simplify_binary_operation (associate_code, mode, | |
5689 | const_arg1, inner_const); | |
5690 | ||
5691 | if (new_const == 0) | |
5692 | break; | |
5693 | ||
5694 | /* If we are associating shift operations, don't let this | |
4908e508 RS |
5695 | produce a shift of the size of the object or larger. |
5696 | This could occur when we follow a sign-extend by a right | |
5697 | shift on a machine that does a sign-extend as a pair | |
5698 | of shifts. */ | |
7afe21cc RK |
5699 | |
5700 | if (is_shift && GET_CODE (new_const) == CONST_INT | |
4908e508 RS |
5701 | && INTVAL (new_const) >= GET_MODE_BITSIZE (mode)) |
5702 | { | |
5703 | /* As an exception, we can turn an ASHIFTRT of this | |
5704 | form into a shift of the number of bits - 1. */ | |
5705 | if (code == ASHIFTRT) | |
5706 | new_const = GEN_INT (GET_MODE_BITSIZE (mode) - 1); | |
5707 | else | |
5708 | break; | |
5709 | } | |
7afe21cc RK |
5710 | |
5711 | y = copy_rtx (XEXP (y, 0)); | |
5712 | ||
5713 | /* If Y contains our first operand (the most common way this | |
5714 | can happen is if Y is a MEM), we would do into an infinite | |
5715 | loop if we tried to fold it. So don't in that case. */ | |
5716 | ||
5717 | if (! reg_mentioned_p (folded_arg0, y)) | |
5718 | y = fold_rtx (y, insn); | |
5719 | ||
96b0e481 | 5720 | return cse_gen_binary (code, mode, y, new_const); |
7afe21cc | 5721 | } |
e9a25f70 JL |
5722 | break; |
5723 | ||
5724 | default: | |
5725 | break; | |
7afe21cc RK |
5726 | } |
5727 | ||
5728 | new = simplify_binary_operation (code, mode, | |
5729 | const_arg0 ? const_arg0 : folded_arg0, | |
5730 | const_arg1 ? const_arg1 : folded_arg1); | |
5731 | break; | |
5732 | ||
5733 | case 'o': | |
5734 | /* (lo_sum (high X) X) is simply X. */ | |
5735 | if (code == LO_SUM && const_arg0 != 0 | |
5736 | && GET_CODE (const_arg0) == HIGH | |
5737 | && rtx_equal_p (XEXP (const_arg0, 0), const_arg1)) | |
5738 | return const_arg1; | |
5739 | break; | |
5740 | ||
5741 | case '3': | |
5742 | case 'b': | |
5743 | new = simplify_ternary_operation (code, mode, mode_arg0, | |
5744 | const_arg0 ? const_arg0 : folded_arg0, | |
5745 | const_arg1 ? const_arg1 : folded_arg1, | |
5746 | const_arg2 ? const_arg2 : XEXP (x, 2)); | |
5747 | break; | |
cff48d8f RH |
5748 | |
5749 | case 'x': | |
5750 | /* Always eliminate CONSTANT_P_RTX at this stage. */ | |
5751 | if (code == CONSTANT_P_RTX) | |
5752 | return (const_arg0 ? const1_rtx : const0_rtx); | |
5753 | break; | |
7afe21cc RK |
5754 | } |
5755 | ||
5756 | return new ? new : x; | |
5757 | } | |
5758 | \f | |
5759 | /* Return a constant value currently equivalent to X. | |
5760 | Return 0 if we don't know one. */ | |
5761 | ||
5762 | static rtx | |
5763 | equiv_constant (x) | |
5764 | rtx x; | |
5765 | { | |
5766 | if (GET_CODE (x) == REG | |
5767 | && REGNO_QTY_VALID_P (REGNO (x)) | |
5768 | && qty_const[reg_qty[REGNO (x)]]) | |
5769 | x = gen_lowpart_if_possible (GET_MODE (x), qty_const[reg_qty[REGNO (x)]]); | |
5770 | ||
5771 | if (x != 0 && CONSTANT_P (x)) | |
5772 | return x; | |
5773 | ||
fc3ffe83 RK |
5774 | /* If X is a MEM, try to fold it outside the context of any insn to see if |
5775 | it might be equivalent to a constant. That handles the case where it | |
5776 | is a constant-pool reference. Then try to look it up in the hash table | |
5777 | in case it is something whose value we have seen before. */ | |
5778 | ||
5779 | if (GET_CODE (x) == MEM) | |
5780 | { | |
5781 | struct table_elt *elt; | |
5782 | ||
906c4e36 | 5783 | x = fold_rtx (x, NULL_RTX); |
fc3ffe83 RK |
5784 | if (CONSTANT_P (x)) |
5785 | return x; | |
5786 | ||
5787 | elt = lookup (x, safe_hash (x, GET_MODE (x)) % NBUCKETS, GET_MODE (x)); | |
5788 | if (elt == 0) | |
5789 | return 0; | |
5790 | ||
5791 | for (elt = elt->first_same_value; elt; elt = elt->next_same_value) | |
5792 | if (elt->is_const && CONSTANT_P (elt->exp)) | |
5793 | return elt->exp; | |
5794 | } | |
5795 | ||
7afe21cc RK |
5796 | return 0; |
5797 | } | |
5798 | \f | |
5799 | /* Assuming that X is an rtx (e.g., MEM, REG or SUBREG) for a fixed-point | |
5800 | number, return an rtx (MEM, SUBREG, or CONST_INT) that refers to the | |
5801 | least-significant part of X. | |
5802 | MODE specifies how big a part of X to return. | |
5803 | ||
5804 | If the requested operation cannot be done, 0 is returned. | |
5805 | ||
5806 | This is similar to gen_lowpart in emit-rtl.c. */ | |
5807 | ||
5808 | rtx | |
5809 | gen_lowpart_if_possible (mode, x) | |
5810 | enum machine_mode mode; | |
5811 | register rtx x; | |
5812 | { | |
5813 | rtx result = gen_lowpart_common (mode, x); | |
5814 | ||
5815 | if (result) | |
5816 | return result; | |
5817 | else if (GET_CODE (x) == MEM) | |
5818 | { | |
5819 | /* This is the only other case we handle. */ | |
5820 | register int offset = 0; | |
5821 | rtx new; | |
5822 | ||
f76b9db2 ILT |
5823 | if (WORDS_BIG_ENDIAN) |
5824 | offset = (MAX (GET_MODE_SIZE (GET_MODE (x)), UNITS_PER_WORD) | |
5825 | - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD)); | |
5826 | if (BYTES_BIG_ENDIAN) | |
5827 | /* Adjust the address so that the address-after-the-data is | |
5828 | unchanged. */ | |
5829 | offset -= (MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode)) | |
5830 | - MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (x)))); | |
38a448ca | 5831 | new = gen_rtx_MEM (mode, plus_constant (XEXP (x, 0), offset)); |
7afe21cc RK |
5832 | if (! memory_address_p (mode, XEXP (new, 0))) |
5833 | return 0; | |
5834 | MEM_VOLATILE_P (new) = MEM_VOLATILE_P (x); | |
5835 | RTX_UNCHANGING_P (new) = RTX_UNCHANGING_P (x); | |
5836 | MEM_IN_STRUCT_P (new) = MEM_IN_STRUCT_P (x); | |
5837 | return new; | |
5838 | } | |
5839 | else | |
5840 | return 0; | |
5841 | } | |
5842 | \f | |
5843 | /* Given INSN, a jump insn, TAKEN indicates if we are following the "taken" | |
5844 | branch. It will be zero if not. | |
5845 | ||
5846 | In certain cases, this can cause us to add an equivalence. For example, | |
5847 | if we are following the taken case of | |
5848 | if (i == 2) | |
5849 | we can add the fact that `i' and '2' are now equivalent. | |
5850 | ||
5851 | In any case, we can record that this comparison was passed. If the same | |
5852 | comparison is seen later, we will know its value. */ | |
5853 | ||
5854 | static void | |
5855 | record_jump_equiv (insn, taken) | |
5856 | rtx insn; | |
5857 | int taken; | |
5858 | { | |
5859 | int cond_known_true; | |
5860 | rtx op0, op1; | |
13c9910f | 5861 | enum machine_mode mode, mode0, mode1; |
7afe21cc RK |
5862 | int reversed_nonequality = 0; |
5863 | enum rtx_code code; | |
5864 | ||
5865 | /* Ensure this is the right kind of insn. */ | |
5866 | if (! condjump_p (insn) || simplejump_p (insn)) | |
5867 | return; | |
5868 | ||
5869 | /* See if this jump condition is known true or false. */ | |
5870 | if (taken) | |
5871 | cond_known_true = (XEXP (SET_SRC (PATTERN (insn)), 2) == pc_rtx); | |
5872 | else | |
5873 | cond_known_true = (XEXP (SET_SRC (PATTERN (insn)), 1) == pc_rtx); | |
5874 | ||
5875 | /* Get the type of comparison being done and the operands being compared. | |
5876 | If we had to reverse a non-equality condition, record that fact so we | |
5877 | know that it isn't valid for floating-point. */ | |
5878 | code = GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 0)); | |
5879 | op0 = fold_rtx (XEXP (XEXP (SET_SRC (PATTERN (insn)), 0), 0), insn); | |
5880 | op1 = fold_rtx (XEXP (XEXP (SET_SRC (PATTERN (insn)), 0), 1), insn); | |
5881 | ||
13c9910f | 5882 | code = find_comparison_args (code, &op0, &op1, &mode0, &mode1); |
7afe21cc RK |
5883 | if (! cond_known_true) |
5884 | { | |
5885 | reversed_nonequality = (code != EQ && code != NE); | |
5886 | code = reverse_condition (code); | |
5887 | } | |
5888 | ||
5889 | /* The mode is the mode of the non-constant. */ | |
13c9910f RS |
5890 | mode = mode0; |
5891 | if (mode1 != VOIDmode) | |
5892 | mode = mode1; | |
7afe21cc RK |
5893 | |
5894 | record_jump_cond (code, mode, op0, op1, reversed_nonequality); | |
5895 | } | |
5896 | ||
5897 | /* We know that comparison CODE applied to OP0 and OP1 in MODE is true. | |
5898 | REVERSED_NONEQUALITY is nonzero if CODE had to be swapped. | |
5899 | Make any useful entries we can with that information. Called from | |
5900 | above function and called recursively. */ | |
5901 | ||
5902 | static void | |
5903 | record_jump_cond (code, mode, op0, op1, reversed_nonequality) | |
5904 | enum rtx_code code; | |
5905 | enum machine_mode mode; | |
5906 | rtx op0, op1; | |
5907 | int reversed_nonequality; | |
5908 | { | |
2197a88a | 5909 | unsigned op0_hash, op1_hash; |
7afe21cc RK |
5910 | int op0_in_memory, op0_in_struct, op1_in_memory, op1_in_struct; |
5911 | struct table_elt *op0_elt, *op1_elt; | |
5912 | ||
5913 | /* If OP0 and OP1 are known equal, and either is a paradoxical SUBREG, | |
5914 | we know that they are also equal in the smaller mode (this is also | |
5915 | true for all smaller modes whether or not there is a SUBREG, but | |
5916 | is not worth testing for with no SUBREG. */ | |
5917 | ||
2e794ee8 | 5918 | /* Note that GET_MODE (op0) may not equal MODE. */ |
7afe21cc | 5919 | if (code == EQ && GET_CODE (op0) == SUBREG |
2e794ee8 RS |
5920 | && (GET_MODE_SIZE (GET_MODE (op0)) |
5921 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0))))) | |
7afe21cc RK |
5922 | { |
5923 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0)); | |
5924 | rtx tem = gen_lowpart_if_possible (inner_mode, op1); | |
5925 | ||
5926 | record_jump_cond (code, mode, SUBREG_REG (op0), | |
38a448ca | 5927 | tem ? tem : gen_rtx_SUBREG (inner_mode, op1, 0), |
7afe21cc RK |
5928 | reversed_nonequality); |
5929 | } | |
5930 | ||
5931 | if (code == EQ && GET_CODE (op1) == SUBREG | |
2e794ee8 RS |
5932 | && (GET_MODE_SIZE (GET_MODE (op1)) |
5933 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1))))) | |
7afe21cc RK |
5934 | { |
5935 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1)); | |
5936 | rtx tem = gen_lowpart_if_possible (inner_mode, op0); | |
5937 | ||
5938 | record_jump_cond (code, mode, SUBREG_REG (op1), | |
38a448ca | 5939 | tem ? tem : gen_rtx_SUBREG (inner_mode, op0, 0), |
7afe21cc RK |
5940 | reversed_nonequality); |
5941 | } | |
5942 | ||
5943 | /* Similarly, if this is an NE comparison, and either is a SUBREG | |
5944 | making a smaller mode, we know the whole thing is also NE. */ | |
5945 | ||
2e794ee8 RS |
5946 | /* Note that GET_MODE (op0) may not equal MODE; |
5947 | if we test MODE instead, we can get an infinite recursion | |
5948 | alternating between two modes each wider than MODE. */ | |
5949 | ||
7afe21cc RK |
5950 | if (code == NE && GET_CODE (op0) == SUBREG |
5951 | && subreg_lowpart_p (op0) | |
2e794ee8 RS |
5952 | && (GET_MODE_SIZE (GET_MODE (op0)) |
5953 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0))))) | |
7afe21cc RK |
5954 | { |
5955 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0)); | |
5956 | rtx tem = gen_lowpart_if_possible (inner_mode, op1); | |
5957 | ||
5958 | record_jump_cond (code, mode, SUBREG_REG (op0), | |
38a448ca | 5959 | tem ? tem : gen_rtx_SUBREG (inner_mode, op1, 0), |
7afe21cc RK |
5960 | reversed_nonequality); |
5961 | } | |
5962 | ||
5963 | if (code == NE && GET_CODE (op1) == SUBREG | |
5964 | && subreg_lowpart_p (op1) | |
2e794ee8 RS |
5965 | && (GET_MODE_SIZE (GET_MODE (op1)) |
5966 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1))))) | |
7afe21cc RK |
5967 | { |
5968 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1)); | |
5969 | rtx tem = gen_lowpart_if_possible (inner_mode, op0); | |
5970 | ||
5971 | record_jump_cond (code, mode, SUBREG_REG (op1), | |
38a448ca | 5972 | tem ? tem : gen_rtx_SUBREG (inner_mode, op0, 0), |
7afe21cc RK |
5973 | reversed_nonequality); |
5974 | } | |
5975 | ||
5976 | /* Hash both operands. */ | |
5977 | ||
5978 | do_not_record = 0; | |
5979 | hash_arg_in_memory = 0; | |
5980 | hash_arg_in_struct = 0; | |
2197a88a | 5981 | op0_hash = HASH (op0, mode); |
7afe21cc RK |
5982 | op0_in_memory = hash_arg_in_memory; |
5983 | op0_in_struct = hash_arg_in_struct; | |
5984 | ||
5985 | if (do_not_record) | |
5986 | return; | |
5987 | ||
5988 | do_not_record = 0; | |
5989 | hash_arg_in_memory = 0; | |
5990 | hash_arg_in_struct = 0; | |
2197a88a | 5991 | op1_hash = HASH (op1, mode); |
7afe21cc RK |
5992 | op1_in_memory = hash_arg_in_memory; |
5993 | op1_in_struct = hash_arg_in_struct; | |
5994 | ||
5995 | if (do_not_record) | |
5996 | return; | |
5997 | ||
5998 | /* Look up both operands. */ | |
2197a88a RK |
5999 | op0_elt = lookup (op0, op0_hash, mode); |
6000 | op1_elt = lookup (op1, op1_hash, mode); | |
7afe21cc | 6001 | |
af3869c1 RK |
6002 | /* If both operands are already equivalent or if they are not in the |
6003 | table but are identical, do nothing. */ | |
6004 | if ((op0_elt != 0 && op1_elt != 0 | |
6005 | && op0_elt->first_same_value == op1_elt->first_same_value) | |
6006 | || op0 == op1 || rtx_equal_p (op0, op1)) | |
6007 | return; | |
6008 | ||
7afe21cc | 6009 | /* If we aren't setting two things equal all we can do is save this |
b2796a4b RK |
6010 | comparison. Similarly if this is floating-point. In the latter |
6011 | case, OP1 might be zero and both -0.0 and 0.0 are equal to it. | |
6012 | If we record the equality, we might inadvertently delete code | |
6013 | whose intent was to change -0 to +0. */ | |
6014 | ||
cbf6a543 | 6015 | if (code != EQ || FLOAT_MODE_P (GET_MODE (op0))) |
7afe21cc RK |
6016 | { |
6017 | /* If we reversed a floating-point comparison, if OP0 is not a | |
6018 | register, or if OP1 is neither a register or constant, we can't | |
6019 | do anything. */ | |
6020 | ||
6021 | if (GET_CODE (op1) != REG) | |
6022 | op1 = equiv_constant (op1); | |
6023 | ||
cbf6a543 | 6024 | if ((reversed_nonequality && FLOAT_MODE_P (mode)) |
7afe21cc RK |
6025 | || GET_CODE (op0) != REG || op1 == 0) |
6026 | return; | |
6027 | ||
6028 | /* Put OP0 in the hash table if it isn't already. This gives it a | |
6029 | new quantity number. */ | |
6030 | if (op0_elt == 0) | |
6031 | { | |
906c4e36 | 6032 | if (insert_regs (op0, NULL_PTR, 0)) |
7afe21cc RK |
6033 | { |
6034 | rehash_using_reg (op0); | |
2197a88a | 6035 | op0_hash = HASH (op0, mode); |
2bb81c86 RK |
6036 | |
6037 | /* If OP0 is contained in OP1, this changes its hash code | |
6038 | as well. Faster to rehash than to check, except | |
6039 | for the simple case of a constant. */ | |
6040 | if (! CONSTANT_P (op1)) | |
2197a88a | 6041 | op1_hash = HASH (op1,mode); |
7afe21cc RK |
6042 | } |
6043 | ||
2197a88a | 6044 | op0_elt = insert (op0, NULL_PTR, op0_hash, mode); |
7afe21cc RK |
6045 | op0_elt->in_memory = op0_in_memory; |
6046 | op0_elt->in_struct = op0_in_struct; | |
6047 | } | |
6048 | ||
6049 | qty_comparison_code[reg_qty[REGNO (op0)]] = code; | |
6050 | if (GET_CODE (op1) == REG) | |
6051 | { | |
5d5ea909 | 6052 | /* Look it up again--in case op0 and op1 are the same. */ |
2197a88a | 6053 | op1_elt = lookup (op1, op1_hash, mode); |
5d5ea909 | 6054 | |
7afe21cc RK |
6055 | /* Put OP1 in the hash table so it gets a new quantity number. */ |
6056 | if (op1_elt == 0) | |
6057 | { | |
906c4e36 | 6058 | if (insert_regs (op1, NULL_PTR, 0)) |
7afe21cc RK |
6059 | { |
6060 | rehash_using_reg (op1); | |
2197a88a | 6061 | op1_hash = HASH (op1, mode); |
7afe21cc RK |
6062 | } |
6063 | ||
2197a88a | 6064 | op1_elt = insert (op1, NULL_PTR, op1_hash, mode); |
7afe21cc RK |
6065 | op1_elt->in_memory = op1_in_memory; |
6066 | op1_elt->in_struct = op1_in_struct; | |
6067 | } | |
6068 | ||
6069 | qty_comparison_qty[reg_qty[REGNO (op0)]] = reg_qty[REGNO (op1)]; | |
6070 | qty_comparison_const[reg_qty[REGNO (op0)]] = 0; | |
6071 | } | |
6072 | else | |
6073 | { | |
6074 | qty_comparison_qty[reg_qty[REGNO (op0)]] = -1; | |
6075 | qty_comparison_const[reg_qty[REGNO (op0)]] = op1; | |
6076 | } | |
6077 | ||
6078 | return; | |
6079 | } | |
6080 | ||
eb5ad42a RS |
6081 | /* If either side is still missing an equivalence, make it now, |
6082 | then merge the equivalences. */ | |
7afe21cc | 6083 | |
7afe21cc RK |
6084 | if (op0_elt == 0) |
6085 | { | |
eb5ad42a | 6086 | if (insert_regs (op0, NULL_PTR, 0)) |
7afe21cc RK |
6087 | { |
6088 | rehash_using_reg (op0); | |
2197a88a | 6089 | op0_hash = HASH (op0, mode); |
7afe21cc RK |
6090 | } |
6091 | ||
2197a88a | 6092 | op0_elt = insert (op0, NULL_PTR, op0_hash, mode); |
7afe21cc RK |
6093 | op0_elt->in_memory = op0_in_memory; |
6094 | op0_elt->in_struct = op0_in_struct; | |
7afe21cc RK |
6095 | } |
6096 | ||
6097 | if (op1_elt == 0) | |
6098 | { | |
eb5ad42a | 6099 | if (insert_regs (op1, NULL_PTR, 0)) |
7afe21cc RK |
6100 | { |
6101 | rehash_using_reg (op1); | |
2197a88a | 6102 | op1_hash = HASH (op1, mode); |
7afe21cc RK |
6103 | } |
6104 | ||
2197a88a | 6105 | op1_elt = insert (op1, NULL_PTR, op1_hash, mode); |
7afe21cc RK |
6106 | op1_elt->in_memory = op1_in_memory; |
6107 | op1_elt->in_struct = op1_in_struct; | |
7afe21cc | 6108 | } |
eb5ad42a RS |
6109 | |
6110 | merge_equiv_classes (op0_elt, op1_elt); | |
6111 | last_jump_equiv_class = op0_elt; | |
7afe21cc RK |
6112 | } |
6113 | \f | |
6114 | /* CSE processing for one instruction. | |
6115 | First simplify sources and addresses of all assignments | |
6116 | in the instruction, using previously-computed equivalents values. | |
6117 | Then install the new sources and destinations in the table | |
6118 | of available values. | |
6119 | ||
6120 | If IN_LIBCALL_BLOCK is nonzero, don't record any equivalence made in | |
6121 | the insn. */ | |
6122 | ||
6123 | /* Data on one SET contained in the instruction. */ | |
6124 | ||
6125 | struct set | |
6126 | { | |
6127 | /* The SET rtx itself. */ | |
6128 | rtx rtl; | |
6129 | /* The SET_SRC of the rtx (the original value, if it is changing). */ | |
6130 | rtx src; | |
6131 | /* The hash-table element for the SET_SRC of the SET. */ | |
6132 | struct table_elt *src_elt; | |
2197a88a RK |
6133 | /* Hash value for the SET_SRC. */ |
6134 | unsigned src_hash; | |
6135 | /* Hash value for the SET_DEST. */ | |
6136 | unsigned dest_hash; | |
7afe21cc RK |
6137 | /* The SET_DEST, with SUBREG, etc., stripped. */ |
6138 | rtx inner_dest; | |
6139 | /* Place where the pointer to the INNER_DEST was found. */ | |
6140 | rtx *inner_dest_loc; | |
6141 | /* Nonzero if the SET_SRC is in memory. */ | |
6142 | char src_in_memory; | |
6143 | /* Nonzero if the SET_SRC is in a structure. */ | |
6144 | char src_in_struct; | |
6145 | /* Nonzero if the SET_SRC contains something | |
6146 | whose value cannot be predicted and understood. */ | |
6147 | char src_volatile; | |
6148 | /* Original machine mode, in case it becomes a CONST_INT. */ | |
6149 | enum machine_mode mode; | |
6150 | /* A constant equivalent for SET_SRC, if any. */ | |
6151 | rtx src_const; | |
2197a88a RK |
6152 | /* Hash value of constant equivalent for SET_SRC. */ |
6153 | unsigned src_const_hash; | |
7afe21cc RK |
6154 | /* Table entry for constant equivalent for SET_SRC, if any. */ |
6155 | struct table_elt *src_const_elt; | |
6156 | }; | |
6157 | ||
6158 | static void | |
7bd8b2a8 | 6159 | cse_insn (insn, libcall_insn) |
7afe21cc | 6160 | rtx insn; |
7bd8b2a8 | 6161 | rtx libcall_insn; |
7afe21cc RK |
6162 | { |
6163 | register rtx x = PATTERN (insn); | |
7afe21cc | 6164 | register int i; |
92f9aa51 | 6165 | rtx tem; |
7afe21cc RK |
6166 | register int n_sets = 0; |
6167 | ||
2d8b0f3a | 6168 | #ifdef HAVE_cc0 |
7afe21cc RK |
6169 | /* Records what this insn does to set CC0. */ |
6170 | rtx this_insn_cc0 = 0; | |
135d84b8 | 6171 | enum machine_mode this_insn_cc0_mode = VOIDmode; |
2d8b0f3a | 6172 | #endif |
7afe21cc RK |
6173 | |
6174 | rtx src_eqv = 0; | |
6175 | struct table_elt *src_eqv_elt = 0; | |
6176 | int src_eqv_volatile; | |
6177 | int src_eqv_in_memory; | |
6178 | int src_eqv_in_struct; | |
2197a88a | 6179 | unsigned src_eqv_hash; |
7afe21cc RK |
6180 | |
6181 | struct set *sets; | |
6182 | ||
6183 | this_insn = insn; | |
7afe21cc RK |
6184 | |
6185 | /* Find all the SETs and CLOBBERs in this instruction. | |
6186 | Record all the SETs in the array `set' and count them. | |
6187 | Also determine whether there is a CLOBBER that invalidates | |
6188 | all memory references, or all references at varying addresses. */ | |
6189 | ||
f1e7c95f RK |
6190 | if (GET_CODE (insn) == CALL_INSN) |
6191 | { | |
6192 | for (tem = CALL_INSN_FUNCTION_USAGE (insn); tem; tem = XEXP (tem, 1)) | |
6193 | if (GET_CODE (XEXP (tem, 0)) == CLOBBER) | |
bb4034b3 | 6194 | invalidate (SET_DEST (XEXP (tem, 0)), VOIDmode); |
f1e7c95f RK |
6195 | } |
6196 | ||
7afe21cc RK |
6197 | if (GET_CODE (x) == SET) |
6198 | { | |
6199 | sets = (struct set *) alloca (sizeof (struct set)); | |
6200 | sets[0].rtl = x; | |
6201 | ||
6202 | /* Ignore SETs that are unconditional jumps. | |
6203 | They never need cse processing, so this does not hurt. | |
6204 | The reason is not efficiency but rather | |
6205 | so that we can test at the end for instructions | |
6206 | that have been simplified to unconditional jumps | |
6207 | and not be misled by unchanged instructions | |
6208 | that were unconditional jumps to begin with. */ | |
6209 | if (SET_DEST (x) == pc_rtx | |
6210 | && GET_CODE (SET_SRC (x)) == LABEL_REF) | |
6211 | ; | |
6212 | ||
6213 | /* Don't count call-insns, (set (reg 0) (call ...)), as a set. | |
6214 | The hard function value register is used only once, to copy to | |
6215 | someplace else, so it isn't worth cse'ing (and on 80386 is unsafe)! | |
6216 | Ensure we invalidate the destination register. On the 80386 no | |
7722328e | 6217 | other code would invalidate it since it is a fixed_reg. |
0f41302f | 6218 | We need not check the return of apply_change_group; see canon_reg. */ |
7afe21cc RK |
6219 | |
6220 | else if (GET_CODE (SET_SRC (x)) == CALL) | |
6221 | { | |
6222 | canon_reg (SET_SRC (x), insn); | |
77fa0940 | 6223 | apply_change_group (); |
7afe21cc | 6224 | fold_rtx (SET_SRC (x), insn); |
bb4034b3 | 6225 | invalidate (SET_DEST (x), VOIDmode); |
7afe21cc RK |
6226 | } |
6227 | else | |
6228 | n_sets = 1; | |
6229 | } | |
6230 | else if (GET_CODE (x) == PARALLEL) | |
6231 | { | |
6232 | register int lim = XVECLEN (x, 0); | |
6233 | ||
6234 | sets = (struct set *) alloca (lim * sizeof (struct set)); | |
6235 | ||
6236 | /* Find all regs explicitly clobbered in this insn, | |
6237 | and ensure they are not replaced with any other regs | |
6238 | elsewhere in this insn. | |
6239 | When a reg that is clobbered is also used for input, | |
6240 | we should presume that that is for a reason, | |
6241 | and we should not substitute some other register | |
6242 | which is not supposed to be clobbered. | |
6243 | Therefore, this loop cannot be merged into the one below | |
830a38ee | 6244 | because a CALL may precede a CLOBBER and refer to the |
7afe21cc RK |
6245 | value clobbered. We must not let a canonicalization do |
6246 | anything in that case. */ | |
6247 | for (i = 0; i < lim; i++) | |
6248 | { | |
6249 | register rtx y = XVECEXP (x, 0, i); | |
2708da92 RS |
6250 | if (GET_CODE (y) == CLOBBER) |
6251 | { | |
6252 | rtx clobbered = XEXP (y, 0); | |
6253 | ||
6254 | if (GET_CODE (clobbered) == REG | |
6255 | || GET_CODE (clobbered) == SUBREG) | |
bb4034b3 | 6256 | invalidate (clobbered, VOIDmode); |
2708da92 RS |
6257 | else if (GET_CODE (clobbered) == STRICT_LOW_PART |
6258 | || GET_CODE (clobbered) == ZERO_EXTRACT) | |
bb4034b3 | 6259 | invalidate (XEXP (clobbered, 0), GET_MODE (clobbered)); |
2708da92 | 6260 | } |
7afe21cc RK |
6261 | } |
6262 | ||
6263 | for (i = 0; i < lim; i++) | |
6264 | { | |
6265 | register rtx y = XVECEXP (x, 0, i); | |
6266 | if (GET_CODE (y) == SET) | |
6267 | { | |
7722328e RK |
6268 | /* As above, we ignore unconditional jumps and call-insns and |
6269 | ignore the result of apply_change_group. */ | |
7afe21cc RK |
6270 | if (GET_CODE (SET_SRC (y)) == CALL) |
6271 | { | |
6272 | canon_reg (SET_SRC (y), insn); | |
77fa0940 | 6273 | apply_change_group (); |
7afe21cc | 6274 | fold_rtx (SET_SRC (y), insn); |
bb4034b3 | 6275 | invalidate (SET_DEST (y), VOIDmode); |
7afe21cc RK |
6276 | } |
6277 | else if (SET_DEST (y) == pc_rtx | |
6278 | && GET_CODE (SET_SRC (y)) == LABEL_REF) | |
6279 | ; | |
6280 | else | |
6281 | sets[n_sets++].rtl = y; | |
6282 | } | |
6283 | else if (GET_CODE (y) == CLOBBER) | |
6284 | { | |
9ae8ffe7 | 6285 | /* If we clobber memory, canon the address. |
7afe21cc RK |
6286 | This does nothing when a register is clobbered |
6287 | because we have already invalidated the reg. */ | |
6288 | if (GET_CODE (XEXP (y, 0)) == MEM) | |
9ae8ffe7 | 6289 | canon_reg (XEXP (y, 0), NULL_RTX); |
7afe21cc RK |
6290 | } |
6291 | else if (GET_CODE (y) == USE | |
6292 | && ! (GET_CODE (XEXP (y, 0)) == REG | |
6293 | && REGNO (XEXP (y, 0)) < FIRST_PSEUDO_REGISTER)) | |
906c4e36 | 6294 | canon_reg (y, NULL_RTX); |
7afe21cc RK |
6295 | else if (GET_CODE (y) == CALL) |
6296 | { | |
7722328e RK |
6297 | /* The result of apply_change_group can be ignored; see |
6298 | canon_reg. */ | |
7afe21cc | 6299 | canon_reg (y, insn); |
77fa0940 | 6300 | apply_change_group (); |
7afe21cc RK |
6301 | fold_rtx (y, insn); |
6302 | } | |
6303 | } | |
6304 | } | |
6305 | else if (GET_CODE (x) == CLOBBER) | |
6306 | { | |
6307 | if (GET_CODE (XEXP (x, 0)) == MEM) | |
9ae8ffe7 | 6308 | canon_reg (XEXP (x, 0), NULL_RTX); |
7afe21cc RK |
6309 | } |
6310 | ||
6311 | /* Canonicalize a USE of a pseudo register or memory location. */ | |
6312 | else if (GET_CODE (x) == USE | |
6313 | && ! (GET_CODE (XEXP (x, 0)) == REG | |
6314 | && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER)) | |
906c4e36 | 6315 | canon_reg (XEXP (x, 0), NULL_RTX); |
7afe21cc RK |
6316 | else if (GET_CODE (x) == CALL) |
6317 | { | |
7722328e | 6318 | /* The result of apply_change_group can be ignored; see canon_reg. */ |
7afe21cc | 6319 | canon_reg (x, insn); |
77fa0940 | 6320 | apply_change_group (); |
7afe21cc RK |
6321 | fold_rtx (x, insn); |
6322 | } | |
6323 | ||
7b3ab05e JW |
6324 | /* Store the equivalent value in SRC_EQV, if different, or if the DEST |
6325 | is a STRICT_LOW_PART. The latter condition is necessary because SRC_EQV | |
6326 | is handled specially for this case, and if it isn't set, then there will | |
9faa82d8 | 6327 | be no equivalence for the destination. */ |
92f9aa51 RK |
6328 | if (n_sets == 1 && REG_NOTES (insn) != 0 |
6329 | && (tem = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0 | |
7b3ab05e JW |
6330 | && (! rtx_equal_p (XEXP (tem, 0), SET_SRC (sets[0].rtl)) |
6331 | || GET_CODE (SET_DEST (sets[0].rtl)) == STRICT_LOW_PART)) | |
92f9aa51 | 6332 | src_eqv = canon_reg (XEXP (tem, 0), NULL_RTX); |
7afe21cc RK |
6333 | |
6334 | /* Canonicalize sources and addresses of destinations. | |
6335 | We do this in a separate pass to avoid problems when a MATCH_DUP is | |
6336 | present in the insn pattern. In that case, we want to ensure that | |
6337 | we don't break the duplicate nature of the pattern. So we will replace | |
6338 | both operands at the same time. Otherwise, we would fail to find an | |
6339 | equivalent substitution in the loop calling validate_change below. | |
7afe21cc RK |
6340 | |
6341 | We used to suppress canonicalization of DEST if it appears in SRC, | |
77fa0940 | 6342 | but we don't do this any more. */ |
7afe21cc RK |
6343 | |
6344 | for (i = 0; i < n_sets; i++) | |
6345 | { | |
6346 | rtx dest = SET_DEST (sets[i].rtl); | |
6347 | rtx src = SET_SRC (sets[i].rtl); | |
6348 | rtx new = canon_reg (src, insn); | |
58873255 | 6349 | int insn_code; |
7afe21cc | 6350 | |
77fa0940 RK |
6351 | if ((GET_CODE (new) == REG && GET_CODE (src) == REG |
6352 | && ((REGNO (new) < FIRST_PSEUDO_REGISTER) | |
6353 | != (REGNO (src) < FIRST_PSEUDO_REGISTER))) | |
58873255 RK |
6354 | || (insn_code = recog_memoized (insn)) < 0 |
6355 | || insn_n_dups[insn_code] > 0) | |
77fa0940 | 6356 | validate_change (insn, &SET_SRC (sets[i].rtl), new, 1); |
7afe21cc RK |
6357 | else |
6358 | SET_SRC (sets[i].rtl) = new; | |
6359 | ||
6360 | if (GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SIGN_EXTRACT) | |
6361 | { | |
6362 | validate_change (insn, &XEXP (dest, 1), | |
77fa0940 | 6363 | canon_reg (XEXP (dest, 1), insn), 1); |
7afe21cc | 6364 | validate_change (insn, &XEXP (dest, 2), |
77fa0940 | 6365 | canon_reg (XEXP (dest, 2), insn), 1); |
7afe21cc RK |
6366 | } |
6367 | ||
6368 | while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART | |
6369 | || GET_CODE (dest) == ZERO_EXTRACT | |
6370 | || GET_CODE (dest) == SIGN_EXTRACT) | |
6371 | dest = XEXP (dest, 0); | |
6372 | ||
6373 | if (GET_CODE (dest) == MEM) | |
6374 | canon_reg (dest, insn); | |
6375 | } | |
6376 | ||
77fa0940 RK |
6377 | /* Now that we have done all the replacements, we can apply the change |
6378 | group and see if they all work. Note that this will cause some | |
6379 | canonicalizations that would have worked individually not to be applied | |
6380 | because some other canonicalization didn't work, but this should not | |
7722328e RK |
6381 | occur often. |
6382 | ||
6383 | The result of apply_change_group can be ignored; see canon_reg. */ | |
77fa0940 RK |
6384 | |
6385 | apply_change_group (); | |
6386 | ||
7afe21cc RK |
6387 | /* Set sets[i].src_elt to the class each source belongs to. |
6388 | Detect assignments from or to volatile things | |
6389 | and set set[i] to zero so they will be ignored | |
6390 | in the rest of this function. | |
6391 | ||
6392 | Nothing in this loop changes the hash table or the register chains. */ | |
6393 | ||
6394 | for (i = 0; i < n_sets; i++) | |
6395 | { | |
6396 | register rtx src, dest; | |
6397 | register rtx src_folded; | |
6398 | register struct table_elt *elt = 0, *p; | |
6399 | enum machine_mode mode; | |
6400 | rtx src_eqv_here; | |
6401 | rtx src_const = 0; | |
6402 | rtx src_related = 0; | |
6403 | struct table_elt *src_const_elt = 0; | |
6404 | int src_cost = 10000, src_eqv_cost = 10000, src_folded_cost = 10000; | |
6405 | int src_related_cost = 10000, src_elt_cost = 10000; | |
6406 | /* Set non-zero if we need to call force_const_mem on with the | |
6407 | contents of src_folded before using it. */ | |
6408 | int src_folded_force_flag = 0; | |
6409 | ||
6410 | dest = SET_DEST (sets[i].rtl); | |
6411 | src = SET_SRC (sets[i].rtl); | |
6412 | ||
6413 | /* If SRC is a constant that has no machine mode, | |
6414 | hash it with the destination's machine mode. | |
6415 | This way we can keep different modes separate. */ | |
6416 | ||
6417 | mode = GET_MODE (src) == VOIDmode ? GET_MODE (dest) : GET_MODE (src); | |
6418 | sets[i].mode = mode; | |
6419 | ||
6420 | if (src_eqv) | |
6421 | { | |
6422 | enum machine_mode eqvmode = mode; | |
6423 | if (GET_CODE (dest) == STRICT_LOW_PART) | |
6424 | eqvmode = GET_MODE (SUBREG_REG (XEXP (dest, 0))); | |
6425 | do_not_record = 0; | |
6426 | hash_arg_in_memory = 0; | |
6427 | hash_arg_in_struct = 0; | |
6428 | src_eqv = fold_rtx (src_eqv, insn); | |
2197a88a | 6429 | src_eqv_hash = HASH (src_eqv, eqvmode); |
7afe21cc RK |
6430 | |
6431 | /* Find the equivalence class for the equivalent expression. */ | |
6432 | ||
6433 | if (!do_not_record) | |
2197a88a | 6434 | src_eqv_elt = lookup (src_eqv, src_eqv_hash, eqvmode); |
7afe21cc RK |
6435 | |
6436 | src_eqv_volatile = do_not_record; | |
6437 | src_eqv_in_memory = hash_arg_in_memory; | |
6438 | src_eqv_in_struct = hash_arg_in_struct; | |
6439 | } | |
6440 | ||
6441 | /* If this is a STRICT_LOW_PART assignment, src_eqv corresponds to the | |
6442 | value of the INNER register, not the destination. So it is not | |
3826a3da | 6443 | a valid substitution for the source. But save it for later. */ |
7afe21cc RK |
6444 | if (GET_CODE (dest) == STRICT_LOW_PART) |
6445 | src_eqv_here = 0; | |
6446 | else | |
6447 | src_eqv_here = src_eqv; | |
6448 | ||
6449 | /* Simplify and foldable subexpressions in SRC. Then get the fully- | |
6450 | simplified result, which may not necessarily be valid. */ | |
6451 | src_folded = fold_rtx (src, insn); | |
6452 | ||
e6a125a0 RK |
6453 | #if 0 |
6454 | /* ??? This caused bad code to be generated for the m68k port with -O2. | |
6455 | Suppose src is (CONST_INT -1), and that after truncation src_folded | |
6456 | is (CONST_INT 3). Suppose src_folded is then used for src_const. | |
6457 | At the end we will add src and src_const to the same equivalence | |
6458 | class. We now have 3 and -1 on the same equivalence class. This | |
6459 | causes later instructions to be mis-optimized. */ | |
7afe21cc RK |
6460 | /* If storing a constant in a bitfield, pre-truncate the constant |
6461 | so we will be able to record it later. */ | |
6462 | if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT | |
6463 | || GET_CODE (SET_DEST (sets[i].rtl)) == SIGN_EXTRACT) | |
6464 | { | |
6465 | rtx width = XEXP (SET_DEST (sets[i].rtl), 1); | |
6466 | ||
6467 | if (GET_CODE (src) == CONST_INT | |
6468 | && GET_CODE (width) == CONST_INT | |
906c4e36 RK |
6469 | && INTVAL (width) < HOST_BITS_PER_WIDE_INT |
6470 | && (INTVAL (src) & ((HOST_WIDE_INT) (-1) << INTVAL (width)))) | |
6471 | src_folded | |
6472 | = GEN_INT (INTVAL (src) & (((HOST_WIDE_INT) 1 | |
6473 | << INTVAL (width)) - 1)); | |
7afe21cc | 6474 | } |
e6a125a0 | 6475 | #endif |
7afe21cc RK |
6476 | |
6477 | /* Compute SRC's hash code, and also notice if it | |
6478 | should not be recorded at all. In that case, | |
6479 | prevent any further processing of this assignment. */ | |
6480 | do_not_record = 0; | |
6481 | hash_arg_in_memory = 0; | |
6482 | hash_arg_in_struct = 0; | |
6483 | ||
6484 | sets[i].src = src; | |
2197a88a | 6485 | sets[i].src_hash = HASH (src, mode); |
7afe21cc RK |
6486 | sets[i].src_volatile = do_not_record; |
6487 | sets[i].src_in_memory = hash_arg_in_memory; | |
6488 | sets[i].src_in_struct = hash_arg_in_struct; | |
6489 | ||
50196afa RK |
6490 | /* If SRC is a MEM, there is a REG_EQUIV note for SRC, and DEST is |
6491 | a pseudo that is set more than once, do not record SRC. Using | |
6492 | SRC as a replacement for anything else will be incorrect in that | |
6493 | situation. Note that this usually occurs only for stack slots, | |
956d6950 | 6494 | in which case all the RTL would be referring to SRC, so we don't |
50196afa RK |
6495 | lose any optimization opportunities by not having SRC in the |
6496 | hash table. */ | |
6497 | ||
6498 | if (GET_CODE (src) == MEM | |
6499 | && find_reg_note (insn, REG_EQUIV, src) != 0 | |
6500 | && GET_CODE (dest) == REG | |
6501 | && REGNO (dest) >= FIRST_PSEUDO_REGISTER | |
b1f21e0a | 6502 | && REG_N_SETS (REGNO (dest)) != 1) |
50196afa RK |
6503 | sets[i].src_volatile = 1; |
6504 | ||
0dadecf6 RK |
6505 | #if 0 |
6506 | /* It is no longer clear why we used to do this, but it doesn't | |
6507 | appear to still be needed. So let's try without it since this | |
6508 | code hurts cse'ing widened ops. */ | |
7afe21cc RK |
6509 | /* If source is a perverse subreg (such as QI treated as an SI), |
6510 | treat it as volatile. It may do the work of an SI in one context | |
6511 | where the extra bits are not being used, but cannot replace an SI | |
6512 | in general. */ | |
6513 | if (GET_CODE (src) == SUBREG | |
6514 | && (GET_MODE_SIZE (GET_MODE (src)) | |
6515 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))))) | |
6516 | sets[i].src_volatile = 1; | |
0dadecf6 | 6517 | #endif |
7afe21cc RK |
6518 | |
6519 | /* Locate all possible equivalent forms for SRC. Try to replace | |
6520 | SRC in the insn with each cheaper equivalent. | |
6521 | ||
6522 | We have the following types of equivalents: SRC itself, a folded | |
6523 | version, a value given in a REG_EQUAL note, or a value related | |
6524 | to a constant. | |
6525 | ||
6526 | Each of these equivalents may be part of an additional class | |
6527 | of equivalents (if more than one is in the table, they must be in | |
6528 | the same class; we check for this). | |
6529 | ||
6530 | If the source is volatile, we don't do any table lookups. | |
6531 | ||
6532 | We note any constant equivalent for possible later use in a | |
6533 | REG_NOTE. */ | |
6534 | ||
6535 | if (!sets[i].src_volatile) | |
2197a88a | 6536 | elt = lookup (src, sets[i].src_hash, mode); |
7afe21cc RK |
6537 | |
6538 | sets[i].src_elt = elt; | |
6539 | ||
6540 | if (elt && src_eqv_here && src_eqv_elt) | |
6541 | { | |
6542 | if (elt->first_same_value != src_eqv_elt->first_same_value) | |
6543 | { | |
6544 | /* The REG_EQUAL is indicating that two formerly distinct | |
6545 | classes are now equivalent. So merge them. */ | |
6546 | merge_equiv_classes (elt, src_eqv_elt); | |
2197a88a RK |
6547 | src_eqv_hash = HASH (src_eqv, elt->mode); |
6548 | src_eqv_elt = lookup (src_eqv, src_eqv_hash, elt->mode); | |
7afe21cc RK |
6549 | } |
6550 | ||
6551 | src_eqv_here = 0; | |
6552 | } | |
6553 | ||
6554 | else if (src_eqv_elt) | |
6555 | elt = src_eqv_elt; | |
6556 | ||
6557 | /* Try to find a constant somewhere and record it in `src_const'. | |
6558 | Record its table element, if any, in `src_const_elt'. Look in | |
6559 | any known equivalences first. (If the constant is not in the | |
2197a88a | 6560 | table, also set `sets[i].src_const_hash'). */ |
7afe21cc RK |
6561 | if (elt) |
6562 | for (p = elt->first_same_value; p; p = p->next_same_value) | |
6563 | if (p->is_const) | |
6564 | { | |
6565 | src_const = p->exp; | |
6566 | src_const_elt = elt; | |
6567 | break; | |
6568 | } | |
6569 | ||
6570 | if (src_const == 0 | |
6571 | && (CONSTANT_P (src_folded) | |
6572 | /* Consider (minus (label_ref L1) (label_ref L2)) as | |
6573 | "constant" here so we will record it. This allows us | |
6574 | to fold switch statements when an ADDR_DIFF_VEC is used. */ | |
6575 | || (GET_CODE (src_folded) == MINUS | |
6576 | && GET_CODE (XEXP (src_folded, 0)) == LABEL_REF | |
6577 | && GET_CODE (XEXP (src_folded, 1)) == LABEL_REF))) | |
6578 | src_const = src_folded, src_const_elt = elt; | |
6579 | else if (src_const == 0 && src_eqv_here && CONSTANT_P (src_eqv_here)) | |
6580 | src_const = src_eqv_here, src_const_elt = src_eqv_elt; | |
6581 | ||
6582 | /* If we don't know if the constant is in the table, get its | |
6583 | hash code and look it up. */ | |
6584 | if (src_const && src_const_elt == 0) | |
6585 | { | |
2197a88a RK |
6586 | sets[i].src_const_hash = HASH (src_const, mode); |
6587 | src_const_elt = lookup (src_const, sets[i].src_const_hash, mode); | |
7afe21cc RK |
6588 | } |
6589 | ||
6590 | sets[i].src_const = src_const; | |
6591 | sets[i].src_const_elt = src_const_elt; | |
6592 | ||
6593 | /* If the constant and our source are both in the table, mark them as | |
6594 | equivalent. Otherwise, if a constant is in the table but the source | |
6595 | isn't, set ELT to it. */ | |
6596 | if (src_const_elt && elt | |
6597 | && src_const_elt->first_same_value != elt->first_same_value) | |
6598 | merge_equiv_classes (elt, src_const_elt); | |
6599 | else if (src_const_elt && elt == 0) | |
6600 | elt = src_const_elt; | |
6601 | ||
6602 | /* See if there is a register linearly related to a constant | |
6603 | equivalent of SRC. */ | |
6604 | if (src_const | |
6605 | && (GET_CODE (src_const) == CONST | |
6606 | || (src_const_elt && src_const_elt->related_value != 0))) | |
6607 | { | |
6608 | src_related = use_related_value (src_const, src_const_elt); | |
6609 | if (src_related) | |
6610 | { | |
6611 | struct table_elt *src_related_elt | |
6612 | = lookup (src_related, HASH (src_related, mode), mode); | |
6613 | if (src_related_elt && elt) | |
6614 | { | |
6615 | if (elt->first_same_value | |
6616 | != src_related_elt->first_same_value) | |
6617 | /* This can occur when we previously saw a CONST | |
6618 | involving a SYMBOL_REF and then see the SYMBOL_REF | |
6619 | twice. Merge the involved classes. */ | |
6620 | merge_equiv_classes (elt, src_related_elt); | |
6621 | ||
6622 | src_related = 0; | |
6623 | src_related_elt = 0; | |
6624 | } | |
6625 | else if (src_related_elt && elt == 0) | |
6626 | elt = src_related_elt; | |
6627 | } | |
6628 | } | |
6629 | ||
e4600702 RK |
6630 | /* See if we have a CONST_INT that is already in a register in a |
6631 | wider mode. */ | |
6632 | ||
6633 | if (src_const && src_related == 0 && GET_CODE (src_const) == CONST_INT | |
6634 | && GET_MODE_CLASS (mode) == MODE_INT | |
6635 | && GET_MODE_BITSIZE (mode) < BITS_PER_WORD) | |
6636 | { | |
6637 | enum machine_mode wider_mode; | |
6638 | ||
6639 | for (wider_mode = GET_MODE_WIDER_MODE (mode); | |
6640 | GET_MODE_BITSIZE (wider_mode) <= BITS_PER_WORD | |
6641 | && src_related == 0; | |
6642 | wider_mode = GET_MODE_WIDER_MODE (wider_mode)) | |
6643 | { | |
6644 | struct table_elt *const_elt | |
6645 | = lookup (src_const, HASH (src_const, wider_mode), wider_mode); | |
6646 | ||
6647 | if (const_elt == 0) | |
6648 | continue; | |
6649 | ||
6650 | for (const_elt = const_elt->first_same_value; | |
6651 | const_elt; const_elt = const_elt->next_same_value) | |
6652 | if (GET_CODE (const_elt->exp) == REG) | |
6653 | { | |
6654 | src_related = gen_lowpart_if_possible (mode, | |
6655 | const_elt->exp); | |
6656 | break; | |
6657 | } | |
6658 | } | |
6659 | } | |
6660 | ||
d45cf215 RS |
6661 | /* Another possibility is that we have an AND with a constant in |
6662 | a mode narrower than a word. If so, it might have been generated | |
6663 | as part of an "if" which would narrow the AND. If we already | |
6664 | have done the AND in a wider mode, we can use a SUBREG of that | |
6665 | value. */ | |
6666 | ||
6667 | if (flag_expensive_optimizations && ! src_related | |
6668 | && GET_CODE (src) == AND && GET_CODE (XEXP (src, 1)) == CONST_INT | |
6669 | && GET_MODE_SIZE (mode) < UNITS_PER_WORD) | |
6670 | { | |
6671 | enum machine_mode tmode; | |
38a448ca | 6672 | rtx new_and = gen_rtx_AND (VOIDmode, NULL_RTX, XEXP (src, 1)); |
d45cf215 RS |
6673 | |
6674 | for (tmode = GET_MODE_WIDER_MODE (mode); | |
6675 | GET_MODE_SIZE (tmode) <= UNITS_PER_WORD; | |
6676 | tmode = GET_MODE_WIDER_MODE (tmode)) | |
6677 | { | |
6678 | rtx inner = gen_lowpart_if_possible (tmode, XEXP (src, 0)); | |
6679 | struct table_elt *larger_elt; | |
6680 | ||
6681 | if (inner) | |
6682 | { | |
6683 | PUT_MODE (new_and, tmode); | |
6684 | XEXP (new_and, 0) = inner; | |
6685 | larger_elt = lookup (new_and, HASH (new_and, tmode), tmode); | |
6686 | if (larger_elt == 0) | |
6687 | continue; | |
6688 | ||
6689 | for (larger_elt = larger_elt->first_same_value; | |
6690 | larger_elt; larger_elt = larger_elt->next_same_value) | |
6691 | if (GET_CODE (larger_elt->exp) == REG) | |
6692 | { | |
6693 | src_related | |
6694 | = gen_lowpart_if_possible (mode, larger_elt->exp); | |
6695 | break; | |
6696 | } | |
6697 | ||
6698 | if (src_related) | |
6699 | break; | |
6700 | } | |
6701 | } | |
6702 | } | |
7bac1be0 RK |
6703 | |
6704 | #ifdef LOAD_EXTEND_OP | |
6705 | /* See if a MEM has already been loaded with a widening operation; | |
6706 | if it has, we can use a subreg of that. Many CISC machines | |
6707 | also have such operations, but this is only likely to be | |
6708 | beneficial these machines. */ | |
6709 | ||
6710 | if (flag_expensive_optimizations && src_related == 0 | |
6711 | && (GET_MODE_SIZE (mode) < UNITS_PER_WORD) | |
6712 | && GET_MODE_CLASS (mode) == MODE_INT | |
6713 | && GET_CODE (src) == MEM && ! do_not_record | |
6714 | && LOAD_EXTEND_OP (mode) != NIL) | |
6715 | { | |
6716 | enum machine_mode tmode; | |
6717 | ||
6718 | /* Set what we are trying to extend and the operation it might | |
6719 | have been extended with. */ | |
6720 | PUT_CODE (memory_extend_rtx, LOAD_EXTEND_OP (mode)); | |
6721 | XEXP (memory_extend_rtx, 0) = src; | |
6722 | ||
6723 | for (tmode = GET_MODE_WIDER_MODE (mode); | |
6724 | GET_MODE_SIZE (tmode) <= UNITS_PER_WORD; | |
6725 | tmode = GET_MODE_WIDER_MODE (tmode)) | |
6726 | { | |
6727 | struct table_elt *larger_elt; | |
6728 | ||
6729 | PUT_MODE (memory_extend_rtx, tmode); | |
6730 | larger_elt = lookup (memory_extend_rtx, | |
6731 | HASH (memory_extend_rtx, tmode), tmode); | |
6732 | if (larger_elt == 0) | |
6733 | continue; | |
6734 | ||
6735 | for (larger_elt = larger_elt->first_same_value; | |
6736 | larger_elt; larger_elt = larger_elt->next_same_value) | |
6737 | if (GET_CODE (larger_elt->exp) == REG) | |
6738 | { | |
6739 | src_related = gen_lowpart_if_possible (mode, | |
6740 | larger_elt->exp); | |
6741 | break; | |
6742 | } | |
6743 | ||
6744 | if (src_related) | |
6745 | break; | |
6746 | } | |
6747 | } | |
6748 | #endif /* LOAD_EXTEND_OP */ | |
6749 | ||
7afe21cc RK |
6750 | if (src == src_folded) |
6751 | src_folded = 0; | |
6752 | ||
6753 | /* At this point, ELT, if non-zero, points to a class of expressions | |
6754 | equivalent to the source of this SET and SRC, SRC_EQV, SRC_FOLDED, | |
6755 | and SRC_RELATED, if non-zero, each contain additional equivalent | |
6756 | expressions. Prune these latter expressions by deleting expressions | |
6757 | already in the equivalence class. | |
6758 | ||
6759 | Check for an equivalent identical to the destination. If found, | |
6760 | this is the preferred equivalent since it will likely lead to | |
6761 | elimination of the insn. Indicate this by placing it in | |
6762 | `src_related'. */ | |
6763 | ||
6764 | if (elt) elt = elt->first_same_value; | |
6765 | for (p = elt; p; p = p->next_same_value) | |
6766 | { | |
6767 | enum rtx_code code = GET_CODE (p->exp); | |
6768 | ||
6769 | /* If the expression is not valid, ignore it. Then we do not | |
6770 | have to check for validity below. In most cases, we can use | |
6771 | `rtx_equal_p', since canonicalization has already been done. */ | |
6772 | if (code != REG && ! exp_equiv_p (p->exp, p->exp, 1, 0)) | |
6773 | continue; | |
6774 | ||
5a03c8c4 RK |
6775 | /* Also skip paradoxical subregs, unless that's what we're |
6776 | looking for. */ | |
6777 | if (code == SUBREG | |
6778 | && (GET_MODE_SIZE (GET_MODE (p->exp)) | |
6779 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (p->exp)))) | |
6780 | && ! (src != 0 | |
6781 | && GET_CODE (src) == SUBREG | |
6782 | && GET_MODE (src) == GET_MODE (p->exp) | |
6783 | && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))) | |
6784 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (p->exp)))))) | |
6785 | continue; | |
6786 | ||
7afe21cc RK |
6787 | if (src && GET_CODE (src) == code && rtx_equal_p (src, p->exp)) |
6788 | src = 0; | |
6789 | else if (src_folded && GET_CODE (src_folded) == code | |
6790 | && rtx_equal_p (src_folded, p->exp)) | |
6791 | src_folded = 0; | |
6792 | else if (src_eqv_here && GET_CODE (src_eqv_here) == code | |
6793 | && rtx_equal_p (src_eqv_here, p->exp)) | |
6794 | src_eqv_here = 0; | |
6795 | else if (src_related && GET_CODE (src_related) == code | |
6796 | && rtx_equal_p (src_related, p->exp)) | |
6797 | src_related = 0; | |
6798 | ||
6799 | /* This is the same as the destination of the insns, we want | |
6800 | to prefer it. Copy it to src_related. The code below will | |
6801 | then give it a negative cost. */ | |
6802 | if (GET_CODE (dest) == code && rtx_equal_p (p->exp, dest)) | |
6803 | src_related = dest; | |
6804 | ||
6805 | } | |
6806 | ||
6807 | /* Find the cheapest valid equivalent, trying all the available | |
6808 | possibilities. Prefer items not in the hash table to ones | |
6809 | that are when they are equal cost. Note that we can never | |
6810 | worsen an insn as the current contents will also succeed. | |
05c33dd8 | 6811 | If we find an equivalent identical to the destination, use it as best, |
0f41302f | 6812 | since this insn will probably be eliminated in that case. */ |
7afe21cc RK |
6813 | if (src) |
6814 | { | |
6815 | if (rtx_equal_p (src, dest)) | |
6816 | src_cost = -1; | |
6817 | else | |
6818 | src_cost = COST (src); | |
6819 | } | |
6820 | ||
6821 | if (src_eqv_here) | |
6822 | { | |
6823 | if (rtx_equal_p (src_eqv_here, dest)) | |
6824 | src_eqv_cost = -1; | |
6825 | else | |
6826 | src_eqv_cost = COST (src_eqv_here); | |
6827 | } | |
6828 | ||
6829 | if (src_folded) | |
6830 | { | |
6831 | if (rtx_equal_p (src_folded, dest)) | |
6832 | src_folded_cost = -1; | |
6833 | else | |
6834 | src_folded_cost = COST (src_folded); | |
6835 | } | |
6836 | ||
6837 | if (src_related) | |
6838 | { | |
6839 | if (rtx_equal_p (src_related, dest)) | |
6840 | src_related_cost = -1; | |
6841 | else | |
6842 | src_related_cost = COST (src_related); | |
6843 | } | |
6844 | ||
6845 | /* If this was an indirect jump insn, a known label will really be | |
6846 | cheaper even though it looks more expensive. */ | |
6847 | if (dest == pc_rtx && src_const && GET_CODE (src_const) == LABEL_REF) | |
6848 | src_folded = src_const, src_folded_cost = -1; | |
6849 | ||
6850 | /* Terminate loop when replacement made. This must terminate since | |
6851 | the current contents will be tested and will always be valid. */ | |
6852 | while (1) | |
6853 | { | |
7bd8b2a8 | 6854 | rtx trial, old_src; |
7afe21cc RK |
6855 | |
6856 | /* Skip invalid entries. */ | |
6857 | while (elt && GET_CODE (elt->exp) != REG | |
6858 | && ! exp_equiv_p (elt->exp, elt->exp, 1, 0)) | |
6859 | elt = elt->next_same_value; | |
5a03c8c4 RK |
6860 | |
6861 | /* A paradoxical subreg would be bad here: it'll be the right | |
6862 | size, but later may be adjusted so that the upper bits aren't | |
6863 | what we want. So reject it. */ | |
6864 | if (elt != 0 | |
6865 | && GET_CODE (elt->exp) == SUBREG | |
6866 | && (GET_MODE_SIZE (GET_MODE (elt->exp)) | |
6867 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (elt->exp)))) | |
6868 | /* It is okay, though, if the rtx we're trying to match | |
6869 | will ignore any of the bits we can't predict. */ | |
6870 | && ! (src != 0 | |
6871 | && GET_CODE (src) == SUBREG | |
6872 | && GET_MODE (src) == GET_MODE (elt->exp) | |
6873 | && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))) | |
6874 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (elt->exp)))))) | |
6875 | { | |
6876 | elt = elt->next_same_value; | |
6877 | continue; | |
6878 | } | |
7afe21cc RK |
6879 | |
6880 | if (elt) src_elt_cost = elt->cost; | |
6881 | ||
6882 | /* Find cheapest and skip it for the next time. For items | |
6883 | of equal cost, use this order: | |
6884 | src_folded, src, src_eqv, src_related and hash table entry. */ | |
6885 | if (src_folded_cost <= src_cost | |
6886 | && src_folded_cost <= src_eqv_cost | |
6887 | && src_folded_cost <= src_related_cost | |
6888 | && src_folded_cost <= src_elt_cost) | |
6889 | { | |
6890 | trial = src_folded, src_folded_cost = 10000; | |
6891 | if (src_folded_force_flag) | |
6892 | trial = force_const_mem (mode, trial); | |
6893 | } | |
6894 | else if (src_cost <= src_eqv_cost | |
6895 | && src_cost <= src_related_cost | |
6896 | && src_cost <= src_elt_cost) | |
6897 | trial = src, src_cost = 10000; | |
6898 | else if (src_eqv_cost <= src_related_cost | |
6899 | && src_eqv_cost <= src_elt_cost) | |
0af62b41 | 6900 | trial = copy_rtx (src_eqv_here), src_eqv_cost = 10000; |
7afe21cc | 6901 | else if (src_related_cost <= src_elt_cost) |
0af62b41 | 6902 | trial = copy_rtx (src_related), src_related_cost = 10000; |
7afe21cc RK |
6903 | else |
6904 | { | |
05c33dd8 | 6905 | trial = copy_rtx (elt->exp); |
7afe21cc RK |
6906 | elt = elt->next_same_value; |
6907 | src_elt_cost = 10000; | |
6908 | } | |
6909 | ||
6910 | /* We don't normally have an insn matching (set (pc) (pc)), so | |
6911 | check for this separately here. We will delete such an | |
6912 | insn below. | |
6913 | ||
6914 | Tablejump insns contain a USE of the table, so simply replacing | |
6915 | the operand with the constant won't match. This is simply an | |
6916 | unconditional branch, however, and is therefore valid. Just | |
6917 | insert the substitution here and we will delete and re-emit | |
6918 | the insn later. */ | |
6919 | ||
7bd8b2a8 JL |
6920 | /* Keep track of the original SET_SRC so that we can fix notes |
6921 | on libcall instructions. */ | |
6922 | old_src = SET_SRC (sets[i].rtl); | |
6923 | ||
7afe21cc RK |
6924 | if (n_sets == 1 && dest == pc_rtx |
6925 | && (trial == pc_rtx | |
6926 | || (GET_CODE (trial) == LABEL_REF | |
6927 | && ! condjump_p (insn)))) | |
6928 | { | |
6929 | /* If TRIAL is a label in front of a jump table, we are | |
6930 | really falling through the switch (this is how casesi | |
6931 | insns work), so we must branch around the table. */ | |
6932 | if (GET_CODE (trial) == CODE_LABEL | |
6933 | && NEXT_INSN (trial) != 0 | |
6934 | && GET_CODE (NEXT_INSN (trial)) == JUMP_INSN | |
6935 | && (GET_CODE (PATTERN (NEXT_INSN (trial))) == ADDR_DIFF_VEC | |
6936 | || GET_CODE (PATTERN (NEXT_INSN (trial))) == ADDR_VEC)) | |
6937 | ||
38a448ca | 6938 | trial = gen_rtx_LABEL_REF (Pmode, get_label_after (trial)); |
7afe21cc RK |
6939 | |
6940 | SET_SRC (sets[i].rtl) = trial; | |
44333223 | 6941 | cse_jumps_altered = 1; |
7afe21cc RK |
6942 | break; |
6943 | } | |
6944 | ||
6945 | /* Look for a substitution that makes a valid insn. */ | |
6946 | else if (validate_change (insn, &SET_SRC (sets[i].rtl), trial, 0)) | |
05c33dd8 | 6947 | { |
7bd8b2a8 JL |
6948 | /* If we just made a substitution inside a libcall, then we |
6949 | need to make the same substitution in any notes attached | |
6950 | to the RETVAL insn. */ | |
6951 | if (libcall_insn) | |
6952 | replace_rtx (REG_NOTES (libcall_insn), old_src, | |
6953 | canon_reg (SET_SRC (sets[i].rtl), insn)); | |
6954 | ||
7722328e RK |
6955 | /* The result of apply_change_group can be ignored; see |
6956 | canon_reg. */ | |
6957 | ||
6958 | validate_change (insn, &SET_SRC (sets[i].rtl), | |
6959 | canon_reg (SET_SRC (sets[i].rtl), insn), | |
6960 | 1); | |
6702af89 | 6961 | apply_change_group (); |
05c33dd8 RK |
6962 | break; |
6963 | } | |
7afe21cc RK |
6964 | |
6965 | /* If we previously found constant pool entries for | |
6966 | constants and this is a constant, try making a | |
6967 | pool entry. Put it in src_folded unless we already have done | |
6968 | this since that is where it likely came from. */ | |
6969 | ||
6970 | else if (constant_pool_entries_cost | |
6971 | && CONSTANT_P (trial) | |
1bbd065b RK |
6972 | && ! (GET_CODE (trial) == CONST |
6973 | && GET_CODE (XEXP (trial, 0)) == TRUNCATE) | |
6974 | && (src_folded == 0 | |
6975 | || (GET_CODE (src_folded) != MEM | |
6976 | && ! src_folded_force_flag)) | |
9ae8ffe7 JL |
6977 | && GET_MODE_CLASS (mode) != MODE_CC |
6978 | && mode != VOIDmode) | |
7afe21cc RK |
6979 | { |
6980 | src_folded_force_flag = 1; | |
6981 | src_folded = trial; | |
6982 | src_folded_cost = constant_pool_entries_cost; | |
6983 | } | |
6984 | } | |
6985 | ||
6986 | src = SET_SRC (sets[i].rtl); | |
6987 | ||
6988 | /* In general, it is good to have a SET with SET_SRC == SET_DEST. | |
6989 | However, there is an important exception: If both are registers | |
6990 | that are not the head of their equivalence class, replace SET_SRC | |
6991 | with the head of the class. If we do not do this, we will have | |
6992 | both registers live over a portion of the basic block. This way, | |
6993 | their lifetimes will likely abut instead of overlapping. */ | |
6994 | if (GET_CODE (dest) == REG | |
6995 | && REGNO_QTY_VALID_P (REGNO (dest)) | |
6996 | && qty_mode[reg_qty[REGNO (dest)]] == GET_MODE (dest) | |
6997 | && qty_first_reg[reg_qty[REGNO (dest)]] != REGNO (dest) | |
6998 | && GET_CODE (src) == REG && REGNO (src) == REGNO (dest) | |
6999 | /* Don't do this if the original insn had a hard reg as | |
7000 | SET_SRC. */ | |
7001 | && (GET_CODE (sets[i].src) != REG | |
7002 | || REGNO (sets[i].src) >= FIRST_PSEUDO_REGISTER)) | |
7003 | /* We can't call canon_reg here because it won't do anything if | |
7004 | SRC is a hard register. */ | |
7005 | { | |
7006 | int first = qty_first_reg[reg_qty[REGNO (src)]]; | |
759bd8b7 R |
7007 | rtx new_src |
7008 | = (first >= FIRST_PSEUDO_REGISTER | |
7009 | ? regno_reg_rtx[first] : gen_rtx_REG (GET_MODE (src), first)); | |
7010 | ||
7011 | /* We must use validate-change even for this, because this | |
7012 | might be a special no-op instruction, suitable only to | |
7013 | tag notes onto. */ | |
7014 | if (validate_change (insn, &SET_SRC (sets[i].rtl), new_src, 0)) | |
7015 | { | |
7016 | src = new_src; | |
7017 | /* If we had a constant that is cheaper than what we are now | |
7018 | setting SRC to, use that constant. We ignored it when we | |
7019 | thought we could make this into a no-op. */ | |
7020 | if (src_const && COST (src_const) < COST (src) | |
7021 | && validate_change (insn, &SET_SRC (sets[i].rtl), src_const, | |
7022 | 0)) | |
7023 | src = src_const; | |
7024 | } | |
7afe21cc RK |
7025 | } |
7026 | ||
7027 | /* If we made a change, recompute SRC values. */ | |
7028 | if (src != sets[i].src) | |
7029 | { | |
7030 | do_not_record = 0; | |
7031 | hash_arg_in_memory = 0; | |
7032 | hash_arg_in_struct = 0; | |
7033 | sets[i].src = src; | |
2197a88a | 7034 | sets[i].src_hash = HASH (src, mode); |
7afe21cc RK |
7035 | sets[i].src_volatile = do_not_record; |
7036 | sets[i].src_in_memory = hash_arg_in_memory; | |
7037 | sets[i].src_in_struct = hash_arg_in_struct; | |
2197a88a | 7038 | sets[i].src_elt = lookup (src, sets[i].src_hash, mode); |
7afe21cc RK |
7039 | } |
7040 | ||
7041 | /* If this is a single SET, we are setting a register, and we have an | |
7042 | equivalent constant, we want to add a REG_NOTE. We don't want | |
7043 | to write a REG_EQUAL note for a constant pseudo since verifying that | |
d45cf215 | 7044 | that pseudo hasn't been eliminated is a pain. Such a note also |
7afe21cc RK |
7045 | won't help anything. */ |
7046 | if (n_sets == 1 && src_const && GET_CODE (dest) == REG | |
7047 | && GET_CODE (src_const) != REG) | |
7048 | { | |
92f9aa51 | 7049 | tem = find_reg_note (insn, REG_EQUAL, NULL_RTX); |
7afe21cc RK |
7050 | |
7051 | /* Record the actual constant value in a REG_EQUAL note, making | |
7052 | a new one if one does not already exist. */ | |
7053 | if (tem) | |
7054 | XEXP (tem, 0) = src_const; | |
7055 | else | |
38a448ca RH |
7056 | REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUAL, |
7057 | src_const, REG_NOTES (insn)); | |
7afe21cc RK |
7058 | |
7059 | /* If storing a constant value in a register that | |
7060 | previously held the constant value 0, | |
7061 | record this fact with a REG_WAS_0 note on this insn. | |
7062 | ||
7063 | Note that the *register* is required to have previously held 0, | |
7064 | not just any register in the quantity and we must point to the | |
7065 | insn that set that register to zero. | |
7066 | ||
7067 | Rather than track each register individually, we just see if | |
7068 | the last set for this quantity was for this register. */ | |
7069 | ||
7070 | if (REGNO_QTY_VALID_P (REGNO (dest)) | |
7071 | && qty_const[reg_qty[REGNO (dest)]] == const0_rtx) | |
7072 | { | |
7073 | /* See if we previously had a REG_WAS_0 note. */ | |
906c4e36 | 7074 | rtx note = find_reg_note (insn, REG_WAS_0, NULL_RTX); |
7afe21cc RK |
7075 | rtx const_insn = qty_const_insn[reg_qty[REGNO (dest)]]; |
7076 | ||
7077 | if ((tem = single_set (const_insn)) != 0 | |
7078 | && rtx_equal_p (SET_DEST (tem), dest)) | |
7079 | { | |
7080 | if (note) | |
7081 | XEXP (note, 0) = const_insn; | |
7082 | else | |
38a448ca RH |
7083 | REG_NOTES (insn) = gen_rtx_INSN_LIST (REG_WAS_0, |
7084 | const_insn, | |
7085 | REG_NOTES (insn)); | |
7afe21cc RK |
7086 | } |
7087 | } | |
7088 | } | |
7089 | ||
7090 | /* Now deal with the destination. */ | |
7091 | do_not_record = 0; | |
7092 | sets[i].inner_dest_loc = &SET_DEST (sets[0].rtl); | |
7093 | ||
7094 | /* Look within any SIGN_EXTRACT or ZERO_EXTRACT | |
7095 | to the MEM or REG within it. */ | |
7096 | while (GET_CODE (dest) == SIGN_EXTRACT | |
7097 | || GET_CODE (dest) == ZERO_EXTRACT | |
7098 | || GET_CODE (dest) == SUBREG | |
7099 | || GET_CODE (dest) == STRICT_LOW_PART) | |
7100 | { | |
7101 | sets[i].inner_dest_loc = &XEXP (dest, 0); | |
7102 | dest = XEXP (dest, 0); | |
7103 | } | |
7104 | ||
7105 | sets[i].inner_dest = dest; | |
7106 | ||
7107 | if (GET_CODE (dest) == MEM) | |
7108 | { | |
9ae8ffe7 JL |
7109 | #ifdef PUSH_ROUNDING |
7110 | /* Stack pushes invalidate the stack pointer. */ | |
7111 | rtx addr = XEXP (dest, 0); | |
7112 | if ((GET_CODE (addr) == PRE_DEC || GET_CODE (addr) == PRE_INC | |
7113 | || GET_CODE (addr) == POST_DEC || GET_CODE (addr) == POST_INC) | |
7114 | && XEXP (addr, 0) == stack_pointer_rtx) | |
7115 | invalidate (stack_pointer_rtx, Pmode); | |
7116 | #endif | |
7afe21cc | 7117 | dest = fold_rtx (dest, insn); |
7afe21cc RK |
7118 | } |
7119 | ||
7120 | /* Compute the hash code of the destination now, | |
7121 | before the effects of this instruction are recorded, | |
7122 | since the register values used in the address computation | |
7123 | are those before this instruction. */ | |
2197a88a | 7124 | sets[i].dest_hash = HASH (dest, mode); |
7afe21cc RK |
7125 | |
7126 | /* Don't enter a bit-field in the hash table | |
7127 | because the value in it after the store | |
7128 | may not equal what was stored, due to truncation. */ | |
7129 | ||
7130 | if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT | |
7131 | || GET_CODE (SET_DEST (sets[i].rtl)) == SIGN_EXTRACT) | |
7132 | { | |
7133 | rtx width = XEXP (SET_DEST (sets[i].rtl), 1); | |
7134 | ||
7135 | if (src_const != 0 && GET_CODE (src_const) == CONST_INT | |
7136 | && GET_CODE (width) == CONST_INT | |
906c4e36 RK |
7137 | && INTVAL (width) < HOST_BITS_PER_WIDE_INT |
7138 | && ! (INTVAL (src_const) | |
7139 | & ((HOST_WIDE_INT) (-1) << INTVAL (width)))) | |
7afe21cc RK |
7140 | /* Exception: if the value is constant, |
7141 | and it won't be truncated, record it. */ | |
7142 | ; | |
7143 | else | |
7144 | { | |
7145 | /* This is chosen so that the destination will be invalidated | |
7146 | but no new value will be recorded. | |
7147 | We must invalidate because sometimes constant | |
7148 | values can be recorded for bitfields. */ | |
7149 | sets[i].src_elt = 0; | |
7150 | sets[i].src_volatile = 1; | |
7151 | src_eqv = 0; | |
7152 | src_eqv_elt = 0; | |
7153 | } | |
7154 | } | |
7155 | ||
7156 | /* If only one set in a JUMP_INSN and it is now a no-op, we can delete | |
7157 | the insn. */ | |
7158 | else if (n_sets == 1 && dest == pc_rtx && src == pc_rtx) | |
7159 | { | |
7160 | PUT_CODE (insn, NOTE); | |
7161 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
7162 | NOTE_SOURCE_FILE (insn) = 0; | |
7163 | cse_jumps_altered = 1; | |
7164 | /* One less use of the label this insn used to jump to. */ | |
85c3ba60 JL |
7165 | if (JUMP_LABEL (insn) != 0) |
7166 | --LABEL_NUSES (JUMP_LABEL (insn)); | |
7afe21cc RK |
7167 | /* No more processing for this set. */ |
7168 | sets[i].rtl = 0; | |
7169 | } | |
7170 | ||
7171 | /* If this SET is now setting PC to a label, we know it used to | |
7172 | be a conditional or computed branch. So we see if we can follow | |
7173 | it. If it was a computed branch, delete it and re-emit. */ | |
7174 | else if (dest == pc_rtx && GET_CODE (src) == LABEL_REF) | |
7175 | { | |
7176 | rtx p; | |
7177 | ||
7178 | /* If this is not in the format for a simple branch and | |
7179 | we are the only SET in it, re-emit it. */ | |
7180 | if (! simplejump_p (insn) && n_sets == 1) | |
7181 | { | |
7182 | rtx new = emit_jump_insn_before (gen_jump (XEXP (src, 0)), insn); | |
7183 | JUMP_LABEL (new) = XEXP (src, 0); | |
7184 | LABEL_NUSES (XEXP (src, 0))++; | |
7185 | delete_insn (insn); | |
7186 | insn = new; | |
7187 | } | |
31dcf83f RS |
7188 | else |
7189 | /* Otherwise, force rerecognition, since it probably had | |
7190 | a different pattern before. | |
7191 | This shouldn't really be necessary, since whatever | |
7192 | changed the source value above should have done this. | |
7193 | Until the right place is found, might as well do this here. */ | |
7194 | INSN_CODE (insn) = -1; | |
7afe21cc RK |
7195 | |
7196 | /* Now that we've converted this jump to an unconditional jump, | |
7197 | there is dead code after it. Delete the dead code until we | |
7198 | reach a BARRIER, the end of the function, or a label. Do | |
7199 | not delete NOTEs except for NOTE_INSN_DELETED since later | |
7200 | phases assume these notes are retained. */ | |
7201 | ||
7202 | p = insn; | |
7203 | ||
7204 | while (NEXT_INSN (p) != 0 | |
7205 | && GET_CODE (NEXT_INSN (p)) != BARRIER | |
7206 | && GET_CODE (NEXT_INSN (p)) != CODE_LABEL) | |
7207 | { | |
7208 | if (GET_CODE (NEXT_INSN (p)) != NOTE | |
7209 | || NOTE_LINE_NUMBER (NEXT_INSN (p)) == NOTE_INSN_DELETED) | |
7210 | delete_insn (NEXT_INSN (p)); | |
7211 | else | |
7212 | p = NEXT_INSN (p); | |
7213 | } | |
7214 | ||
7215 | /* If we don't have a BARRIER immediately after INSN, put one there. | |
7216 | Much code assumes that there are no NOTEs between a JUMP_INSN and | |
7217 | BARRIER. */ | |
7218 | ||
7219 | if (NEXT_INSN (insn) == 0 | |
7220 | || GET_CODE (NEXT_INSN (insn)) != BARRIER) | |
783e5bca | 7221 | emit_barrier_before (NEXT_INSN (insn)); |
7afe21cc RK |
7222 | |
7223 | /* We might have two BARRIERs separated by notes. Delete the second | |
7224 | one if so. */ | |
7225 | ||
538b78e7 RS |
7226 | if (p != insn && NEXT_INSN (p) != 0 |
7227 | && GET_CODE (NEXT_INSN (p)) == BARRIER) | |
7afe21cc RK |
7228 | delete_insn (NEXT_INSN (p)); |
7229 | ||
7230 | cse_jumps_altered = 1; | |
7231 | sets[i].rtl = 0; | |
7232 | } | |
7233 | ||
c2a47e48 RK |
7234 | /* If destination is volatile, invalidate it and then do no further |
7235 | processing for this assignment. */ | |
7afe21cc RK |
7236 | |
7237 | else if (do_not_record) | |
c2a47e48 RK |
7238 | { |
7239 | if (GET_CODE (dest) == REG || GET_CODE (dest) == SUBREG | |
7240 | || GET_CODE (dest) == MEM) | |
bb4034b3 | 7241 | invalidate (dest, VOIDmode); |
2708da92 RS |
7242 | else if (GET_CODE (dest) == STRICT_LOW_PART |
7243 | || GET_CODE (dest) == ZERO_EXTRACT) | |
bb4034b3 | 7244 | invalidate (XEXP (dest, 0), GET_MODE (dest)); |
c2a47e48 RK |
7245 | sets[i].rtl = 0; |
7246 | } | |
7afe21cc RK |
7247 | |
7248 | if (sets[i].rtl != 0 && dest != SET_DEST (sets[i].rtl)) | |
2197a88a | 7249 | sets[i].dest_hash = HASH (SET_DEST (sets[i].rtl), mode); |
7afe21cc RK |
7250 | |
7251 | #ifdef HAVE_cc0 | |
7252 | /* If setting CC0, record what it was set to, or a constant, if it | |
7253 | is equivalent to a constant. If it is being set to a floating-point | |
7254 | value, make a COMPARE with the appropriate constant of 0. If we | |
7255 | don't do this, later code can interpret this as a test against | |
7256 | const0_rtx, which can cause problems if we try to put it into an | |
7257 | insn as a floating-point operand. */ | |
7258 | if (dest == cc0_rtx) | |
7259 | { | |
7260 | this_insn_cc0 = src_const && mode != VOIDmode ? src_const : src; | |
7261 | this_insn_cc0_mode = mode; | |
cbf6a543 | 7262 | if (FLOAT_MODE_P (mode)) |
38a448ca RH |
7263 | this_insn_cc0 = gen_rtx_COMPARE (VOIDmode, this_insn_cc0, |
7264 | CONST0_RTX (mode)); | |
7afe21cc RK |
7265 | } |
7266 | #endif | |
7267 | } | |
7268 | ||
7269 | /* Now enter all non-volatile source expressions in the hash table | |
7270 | if they are not already present. | |
7271 | Record their equivalence classes in src_elt. | |
7272 | This way we can insert the corresponding destinations into | |
7273 | the same classes even if the actual sources are no longer in them | |
7274 | (having been invalidated). */ | |
7275 | ||
7276 | if (src_eqv && src_eqv_elt == 0 && sets[0].rtl != 0 && ! src_eqv_volatile | |
7277 | && ! rtx_equal_p (src_eqv, SET_DEST (sets[0].rtl))) | |
7278 | { | |
7279 | register struct table_elt *elt; | |
7280 | register struct table_elt *classp = sets[0].src_elt; | |
7281 | rtx dest = SET_DEST (sets[0].rtl); | |
7282 | enum machine_mode eqvmode = GET_MODE (dest); | |
7283 | ||
7284 | if (GET_CODE (dest) == STRICT_LOW_PART) | |
7285 | { | |
7286 | eqvmode = GET_MODE (SUBREG_REG (XEXP (dest, 0))); | |
7287 | classp = 0; | |
7288 | } | |
7289 | if (insert_regs (src_eqv, classp, 0)) | |
8ae2b8f6 JW |
7290 | { |
7291 | rehash_using_reg (src_eqv); | |
7292 | src_eqv_hash = HASH (src_eqv, eqvmode); | |
7293 | } | |
2197a88a | 7294 | elt = insert (src_eqv, classp, src_eqv_hash, eqvmode); |
7afe21cc RK |
7295 | elt->in_memory = src_eqv_in_memory; |
7296 | elt->in_struct = src_eqv_in_struct; | |
7297 | src_eqv_elt = elt; | |
f7911249 JW |
7298 | |
7299 | /* Check to see if src_eqv_elt is the same as a set source which | |
7300 | does not yet have an elt, and if so set the elt of the set source | |
7301 | to src_eqv_elt. */ | |
7302 | for (i = 0; i < n_sets; i++) | |
7303 | if (sets[i].rtl && sets[i].src_elt == 0 | |
7304 | && rtx_equal_p (SET_SRC (sets[i].rtl), src_eqv)) | |
7305 | sets[i].src_elt = src_eqv_elt; | |
7afe21cc RK |
7306 | } |
7307 | ||
7308 | for (i = 0; i < n_sets; i++) | |
7309 | if (sets[i].rtl && ! sets[i].src_volatile | |
7310 | && ! rtx_equal_p (SET_SRC (sets[i].rtl), SET_DEST (sets[i].rtl))) | |
7311 | { | |
7312 | if (GET_CODE (SET_DEST (sets[i].rtl)) == STRICT_LOW_PART) | |
7313 | { | |
7314 | /* REG_EQUAL in setting a STRICT_LOW_PART | |
7315 | gives an equivalent for the entire destination register, | |
7316 | not just for the subreg being stored in now. | |
7317 | This is a more interesting equivalence, so we arrange later | |
7318 | to treat the entire reg as the destination. */ | |
7319 | sets[i].src_elt = src_eqv_elt; | |
2197a88a | 7320 | sets[i].src_hash = src_eqv_hash; |
7afe21cc RK |
7321 | } |
7322 | else | |
7323 | { | |
7324 | /* Insert source and constant equivalent into hash table, if not | |
7325 | already present. */ | |
7326 | register struct table_elt *classp = src_eqv_elt; | |
7327 | register rtx src = sets[i].src; | |
7328 | register rtx dest = SET_DEST (sets[i].rtl); | |
7329 | enum machine_mode mode | |
7330 | = GET_MODE (src) == VOIDmode ? GET_MODE (dest) : GET_MODE (src); | |
7331 | ||
7332 | if (sets[i].src_elt == 0) | |
7333 | { | |
7334 | register struct table_elt *elt; | |
7335 | ||
7336 | /* Note that these insert_regs calls cannot remove | |
7337 | any of the src_elt's, because they would have failed to | |
7338 | match if not still valid. */ | |
7339 | if (insert_regs (src, classp, 0)) | |
8ae2b8f6 JW |
7340 | { |
7341 | rehash_using_reg (src); | |
7342 | sets[i].src_hash = HASH (src, mode); | |
7343 | } | |
2197a88a | 7344 | elt = insert (src, classp, sets[i].src_hash, mode); |
7afe21cc RK |
7345 | elt->in_memory = sets[i].src_in_memory; |
7346 | elt->in_struct = sets[i].src_in_struct; | |
7347 | sets[i].src_elt = classp = elt; | |
7348 | } | |
7349 | ||
7350 | if (sets[i].src_const && sets[i].src_const_elt == 0 | |
7351 | && src != sets[i].src_const | |
7352 | && ! rtx_equal_p (sets[i].src_const, src)) | |
7353 | sets[i].src_elt = insert (sets[i].src_const, classp, | |
2197a88a | 7354 | sets[i].src_const_hash, mode); |
7afe21cc RK |
7355 | } |
7356 | } | |
7357 | else if (sets[i].src_elt == 0) | |
7358 | /* If we did not insert the source into the hash table (e.g., it was | |
7359 | volatile), note the equivalence class for the REG_EQUAL value, if any, | |
7360 | so that the destination goes into that class. */ | |
7361 | sets[i].src_elt = src_eqv_elt; | |
7362 | ||
9ae8ffe7 | 7363 | invalidate_from_clobbers (x); |
77fa0940 RK |
7364 | |
7365 | /* Some registers are invalidated by subroutine calls. Memory is | |
7366 | invalidated by non-constant calls. */ | |
7367 | ||
7afe21cc RK |
7368 | if (GET_CODE (insn) == CALL_INSN) |
7369 | { | |
77fa0940 | 7370 | if (! CONST_CALL_P (insn)) |
9ae8ffe7 | 7371 | invalidate_memory (); |
7afe21cc RK |
7372 | invalidate_for_call (); |
7373 | } | |
7374 | ||
7375 | /* Now invalidate everything set by this instruction. | |
7376 | If a SUBREG or other funny destination is being set, | |
7377 | sets[i].rtl is still nonzero, so here we invalidate the reg | |
7378 | a part of which is being set. */ | |
7379 | ||
7380 | for (i = 0; i < n_sets; i++) | |
7381 | if (sets[i].rtl) | |
7382 | { | |
bb4034b3 JW |
7383 | /* We can't use the inner dest, because the mode associated with |
7384 | a ZERO_EXTRACT is significant. */ | |
7385 | register rtx dest = SET_DEST (sets[i].rtl); | |
7afe21cc RK |
7386 | |
7387 | /* Needed for registers to remove the register from its | |
7388 | previous quantity's chain. | |
7389 | Needed for memory if this is a nonvarying address, unless | |
7390 | we have just done an invalidate_memory that covers even those. */ | |
7391 | if (GET_CODE (dest) == REG || GET_CODE (dest) == SUBREG | |
9ae8ffe7 | 7392 | || GET_CODE (dest) == MEM) |
bb4034b3 | 7393 | invalidate (dest, VOIDmode); |
2708da92 RS |
7394 | else if (GET_CODE (dest) == STRICT_LOW_PART |
7395 | || GET_CODE (dest) == ZERO_EXTRACT) | |
bb4034b3 | 7396 | invalidate (XEXP (dest, 0), GET_MODE (dest)); |
7afe21cc RK |
7397 | } |
7398 | ||
7399 | /* Make sure registers mentioned in destinations | |
7400 | are safe for use in an expression to be inserted. | |
7401 | This removes from the hash table | |
7402 | any invalid entry that refers to one of these registers. | |
7403 | ||
7404 | We don't care about the return value from mention_regs because | |
7405 | we are going to hash the SET_DEST values unconditionally. */ | |
7406 | ||
7407 | for (i = 0; i < n_sets; i++) | |
7408 | if (sets[i].rtl && GET_CODE (SET_DEST (sets[i].rtl)) != REG) | |
7409 | mention_regs (SET_DEST (sets[i].rtl)); | |
7410 | ||
7411 | /* We may have just removed some of the src_elt's from the hash table. | |
7412 | So replace each one with the current head of the same class. */ | |
7413 | ||
7414 | for (i = 0; i < n_sets; i++) | |
7415 | if (sets[i].rtl) | |
7416 | { | |
7417 | if (sets[i].src_elt && sets[i].src_elt->first_same_value == 0) | |
7418 | /* If elt was removed, find current head of same class, | |
7419 | or 0 if nothing remains of that class. */ | |
7420 | { | |
7421 | register struct table_elt *elt = sets[i].src_elt; | |
7422 | ||
7423 | while (elt && elt->prev_same_value) | |
7424 | elt = elt->prev_same_value; | |
7425 | ||
7426 | while (elt && elt->first_same_value == 0) | |
7427 | elt = elt->next_same_value; | |
7428 | sets[i].src_elt = elt ? elt->first_same_value : 0; | |
7429 | } | |
7430 | } | |
7431 | ||
7432 | /* Now insert the destinations into their equivalence classes. */ | |
7433 | ||
7434 | for (i = 0; i < n_sets; i++) | |
7435 | if (sets[i].rtl) | |
7436 | { | |
7437 | register rtx dest = SET_DEST (sets[i].rtl); | |
9de2c71a | 7438 | rtx inner_dest = sets[i].inner_dest; |
7afe21cc RK |
7439 | register struct table_elt *elt; |
7440 | ||
7441 | /* Don't record value if we are not supposed to risk allocating | |
7442 | floating-point values in registers that might be wider than | |
7443 | memory. */ | |
7444 | if ((flag_float_store | |
7445 | && GET_CODE (dest) == MEM | |
cbf6a543 | 7446 | && FLOAT_MODE_P (GET_MODE (dest))) |
bc4ddc77 JW |
7447 | /* Don't record BLKmode values, because we don't know the |
7448 | size of it, and can't be sure that other BLKmode values | |
7449 | have the same or smaller size. */ | |
7450 | || GET_MODE (dest) == BLKmode | |
7afe21cc RK |
7451 | /* Don't record values of destinations set inside a libcall block |
7452 | since we might delete the libcall. Things should have been set | |
7453 | up so we won't want to reuse such a value, but we play it safe | |
7454 | here. */ | |
7bd8b2a8 | 7455 | || libcall_insn |
7afe21cc RK |
7456 | /* If we didn't put a REG_EQUAL value or a source into the hash |
7457 | table, there is no point is recording DEST. */ | |
1a8e9a8e RK |
7458 | || sets[i].src_elt == 0 |
7459 | /* If DEST is a paradoxical SUBREG and SRC is a ZERO_EXTEND | |
7460 | or SIGN_EXTEND, don't record DEST since it can cause | |
7461 | some tracking to be wrong. | |
7462 | ||
7463 | ??? Think about this more later. */ | |
7464 | || (GET_CODE (dest) == SUBREG | |
7465 | && (GET_MODE_SIZE (GET_MODE (dest)) | |
7466 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))) | |
7467 | && (GET_CODE (sets[i].src) == SIGN_EXTEND | |
7468 | || GET_CODE (sets[i].src) == ZERO_EXTEND))) | |
7afe21cc RK |
7469 | continue; |
7470 | ||
7471 | /* STRICT_LOW_PART isn't part of the value BEING set, | |
7472 | and neither is the SUBREG inside it. | |
7473 | Note that in this case SETS[I].SRC_ELT is really SRC_EQV_ELT. */ | |
7474 | if (GET_CODE (dest) == STRICT_LOW_PART) | |
7475 | dest = SUBREG_REG (XEXP (dest, 0)); | |
7476 | ||
c610adec | 7477 | if (GET_CODE (dest) == REG || GET_CODE (dest) == SUBREG) |
7afe21cc RK |
7478 | /* Registers must also be inserted into chains for quantities. */ |
7479 | if (insert_regs (dest, sets[i].src_elt, 1)) | |
8ae2b8f6 JW |
7480 | { |
7481 | /* If `insert_regs' changes something, the hash code must be | |
7482 | recalculated. */ | |
7483 | rehash_using_reg (dest); | |
7484 | sets[i].dest_hash = HASH (dest, GET_MODE (dest)); | |
7485 | } | |
7afe21cc | 7486 | |
9de2c71a MM |
7487 | if (GET_CODE (inner_dest) == MEM |
7488 | && GET_CODE (XEXP (inner_dest, 0)) == ADDRESSOF) | |
7489 | /* Given (SET (MEM (ADDRESSOF (X))) Y) we don't want to say | |
7490 | that (MEM (ADDRESSOF (X))) is equivalent to Y. | |
7491 | Consider the case in which the address of the MEM is | |
7492 | passed to a function, which alters the MEM. Then, if we | |
7493 | later use Y instead of the MEM we'll miss the update. */ | |
7494 | elt = insert (dest, 0, sets[i].dest_hash, GET_MODE (dest)); | |
7495 | else | |
7496 | elt = insert (dest, sets[i].src_elt, | |
7497 | sets[i].dest_hash, GET_MODE (dest)); | |
7498 | ||
c256df0b | 7499 | elt->in_memory = (GET_CODE (sets[i].inner_dest) == MEM |
9ad91d71 RK |
7500 | && (! RTX_UNCHANGING_P (sets[i].inner_dest) |
7501 | || FIXED_BASE_PLUS_P (XEXP (sets[i].inner_dest, | |
7502 | 0)))); | |
c256df0b | 7503 | |
7afe21cc RK |
7504 | if (elt->in_memory) |
7505 | { | |
7506 | /* This implicitly assumes a whole struct | |
7507 | need not have MEM_IN_STRUCT_P. | |
7508 | But a whole struct is *supposed* to have MEM_IN_STRUCT_P. */ | |
7509 | elt->in_struct = (MEM_IN_STRUCT_P (sets[i].inner_dest) | |
7510 | || sets[i].inner_dest != SET_DEST (sets[i].rtl)); | |
7511 | } | |
7512 | ||
fc3ffe83 RK |
7513 | /* If we have (set (subreg:m1 (reg:m2 foo) 0) (bar:m1)), M1 is no |
7514 | narrower than M2, and both M1 and M2 are the same number of words, | |
7515 | we are also doing (set (reg:m2 foo) (subreg:m2 (bar:m1) 0)) so | |
7516 | make that equivalence as well. | |
7afe21cc RK |
7517 | |
7518 | However, BAR may have equivalences for which gen_lowpart_if_possible | |
7519 | will produce a simpler value than gen_lowpart_if_possible applied to | |
7520 | BAR (e.g., if BAR was ZERO_EXTENDed from M2), so we will scan all | |
7521 | BAR's equivalences. If we don't get a simplified form, make | |
7522 | the SUBREG. It will not be used in an equivalence, but will | |
7523 | cause two similar assignments to be detected. | |
7524 | ||
7525 | Note the loop below will find SUBREG_REG (DEST) since we have | |
7526 | already entered SRC and DEST of the SET in the table. */ | |
7527 | ||
7528 | if (GET_CODE (dest) == SUBREG | |
6cdbaec4 RK |
7529 | && (((GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))) - 1) |
7530 | / UNITS_PER_WORD) | |
7531 | == (GET_MODE_SIZE (GET_MODE (dest)) - 1)/ UNITS_PER_WORD) | |
7afe21cc RK |
7532 | && (GET_MODE_SIZE (GET_MODE (dest)) |
7533 | >= GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))) | |
7534 | && sets[i].src_elt != 0) | |
7535 | { | |
7536 | enum machine_mode new_mode = GET_MODE (SUBREG_REG (dest)); | |
7537 | struct table_elt *elt, *classp = 0; | |
7538 | ||
7539 | for (elt = sets[i].src_elt->first_same_value; elt; | |
7540 | elt = elt->next_same_value) | |
7541 | { | |
7542 | rtx new_src = 0; | |
2197a88a | 7543 | unsigned src_hash; |
7afe21cc RK |
7544 | struct table_elt *src_elt; |
7545 | ||
7546 | /* Ignore invalid entries. */ | |
7547 | if (GET_CODE (elt->exp) != REG | |
7548 | && ! exp_equiv_p (elt->exp, elt->exp, 1, 0)) | |
7549 | continue; | |
7550 | ||
7551 | new_src = gen_lowpart_if_possible (new_mode, elt->exp); | |
7552 | if (new_src == 0) | |
38a448ca | 7553 | new_src = gen_rtx_SUBREG (new_mode, elt->exp, 0); |
7afe21cc RK |
7554 | |
7555 | src_hash = HASH (new_src, new_mode); | |
7556 | src_elt = lookup (new_src, src_hash, new_mode); | |
7557 | ||
7558 | /* Put the new source in the hash table is if isn't | |
7559 | already. */ | |
7560 | if (src_elt == 0) | |
7561 | { | |
7562 | if (insert_regs (new_src, classp, 0)) | |
8ae2b8f6 JW |
7563 | { |
7564 | rehash_using_reg (new_src); | |
7565 | src_hash = HASH (new_src, new_mode); | |
7566 | } | |
7afe21cc RK |
7567 | src_elt = insert (new_src, classp, src_hash, new_mode); |
7568 | src_elt->in_memory = elt->in_memory; | |
7569 | src_elt->in_struct = elt->in_struct; | |
7570 | } | |
7571 | else if (classp && classp != src_elt->first_same_value) | |
7572 | /* Show that two things that we've seen before are | |
7573 | actually the same. */ | |
7574 | merge_equiv_classes (src_elt, classp); | |
7575 | ||
7576 | classp = src_elt->first_same_value; | |
da932f04 JL |
7577 | /* Ignore invalid entries. */ |
7578 | while (classp | |
7579 | && GET_CODE (classp->exp) != REG | |
7580 | && ! exp_equiv_p (classp->exp, classp->exp, 1, 0)) | |
7581 | classp = classp->next_same_value; | |
7afe21cc RK |
7582 | } |
7583 | } | |
7584 | } | |
7585 | ||
7586 | /* Special handling for (set REG0 REG1) | |
7587 | where REG0 is the "cheapest", cheaper than REG1. | |
7588 | After cse, REG1 will probably not be used in the sequel, | |
7589 | so (if easily done) change this insn to (set REG1 REG0) and | |
7590 | replace REG1 with REG0 in the previous insn that computed their value. | |
7591 | Then REG1 will become a dead store and won't cloud the situation | |
7592 | for later optimizations. | |
7593 | ||
7594 | Do not make this change if REG1 is a hard register, because it will | |
7595 | then be used in the sequel and we may be changing a two-operand insn | |
7596 | into a three-operand insn. | |
7597 | ||
7598 | Also do not do this if we are operating on a copy of INSN. */ | |
7599 | ||
7600 | if (n_sets == 1 && sets[0].rtl && GET_CODE (SET_DEST (sets[0].rtl)) == REG | |
7601 | && NEXT_INSN (PREV_INSN (insn)) == insn | |
7602 | && GET_CODE (SET_SRC (sets[0].rtl)) == REG | |
7603 | && REGNO (SET_SRC (sets[0].rtl)) >= FIRST_PSEUDO_REGISTER | |
7604 | && REGNO_QTY_VALID_P (REGNO (SET_SRC (sets[0].rtl))) | |
7605 | && (qty_first_reg[reg_qty[REGNO (SET_SRC (sets[0].rtl))]] | |
7606 | == REGNO (SET_DEST (sets[0].rtl)))) | |
7607 | { | |
7608 | rtx prev = PREV_INSN (insn); | |
7609 | while (prev && GET_CODE (prev) == NOTE) | |
7610 | prev = PREV_INSN (prev); | |
7611 | ||
7612 | if (prev && GET_CODE (prev) == INSN && GET_CODE (PATTERN (prev)) == SET | |
7613 | && SET_DEST (PATTERN (prev)) == SET_SRC (sets[0].rtl)) | |
7614 | { | |
7615 | rtx dest = SET_DEST (sets[0].rtl); | |
906c4e36 | 7616 | rtx note = find_reg_note (prev, REG_EQUIV, NULL_RTX); |
7afe21cc RK |
7617 | |
7618 | validate_change (prev, & SET_DEST (PATTERN (prev)), dest, 1); | |
7619 | validate_change (insn, & SET_DEST (sets[0].rtl), | |
7620 | SET_SRC (sets[0].rtl), 1); | |
7621 | validate_change (insn, & SET_SRC (sets[0].rtl), dest, 1); | |
7622 | apply_change_group (); | |
7623 | ||
7624 | /* If REG1 was equivalent to a constant, REG0 is not. */ | |
7625 | if (note) | |
7626 | PUT_REG_NOTE_KIND (note, REG_EQUAL); | |
7627 | ||
7628 | /* If there was a REG_WAS_0 note on PREV, remove it. Move | |
7629 | any REG_WAS_0 note on INSN to PREV. */ | |
906c4e36 | 7630 | note = find_reg_note (prev, REG_WAS_0, NULL_RTX); |
7afe21cc RK |
7631 | if (note) |
7632 | remove_note (prev, note); | |
7633 | ||
906c4e36 | 7634 | note = find_reg_note (insn, REG_WAS_0, NULL_RTX); |
7afe21cc RK |
7635 | if (note) |
7636 | { | |
7637 | remove_note (insn, note); | |
7638 | XEXP (note, 1) = REG_NOTES (prev); | |
7639 | REG_NOTES (prev) = note; | |
7640 | } | |
98369a0f RK |
7641 | |
7642 | /* If INSN has a REG_EQUAL note, and this note mentions REG0, | |
7643 | then we must delete it, because the value in REG0 has changed. */ | |
7644 | note = find_reg_note (insn, REG_EQUAL, NULL_RTX); | |
7645 | if (note && reg_mentioned_p (dest, XEXP (note, 0))) | |
7646 | remove_note (insn, note); | |
7afe21cc RK |
7647 | } |
7648 | } | |
7649 | ||
7650 | /* If this is a conditional jump insn, record any known equivalences due to | |
7651 | the condition being tested. */ | |
7652 | ||
7653 | last_jump_equiv_class = 0; | |
7654 | if (GET_CODE (insn) == JUMP_INSN | |
7655 | && n_sets == 1 && GET_CODE (x) == SET | |
7656 | && GET_CODE (SET_SRC (x)) == IF_THEN_ELSE) | |
7657 | record_jump_equiv (insn, 0); | |
7658 | ||
7659 | #ifdef HAVE_cc0 | |
7660 | /* If the previous insn set CC0 and this insn no longer references CC0, | |
7661 | delete the previous insn. Here we use the fact that nothing expects CC0 | |
7662 | to be valid over an insn, which is true until the final pass. */ | |
7663 | if (prev_insn && GET_CODE (prev_insn) == INSN | |
7664 | && (tem = single_set (prev_insn)) != 0 | |
7665 | && SET_DEST (tem) == cc0_rtx | |
7666 | && ! reg_mentioned_p (cc0_rtx, x)) | |
7667 | { | |
7668 | PUT_CODE (prev_insn, NOTE); | |
7669 | NOTE_LINE_NUMBER (prev_insn) = NOTE_INSN_DELETED; | |
7670 | NOTE_SOURCE_FILE (prev_insn) = 0; | |
7671 | } | |
7672 | ||
7673 | prev_insn_cc0 = this_insn_cc0; | |
7674 | prev_insn_cc0_mode = this_insn_cc0_mode; | |
7675 | #endif | |
7676 | ||
7677 | prev_insn = insn; | |
7678 | } | |
7679 | \f | |
9ae8ffe7 | 7680 | /* Remove from the ahsh table all expressions that reference memory. */ |
7afe21cc | 7681 | static void |
9ae8ffe7 | 7682 | invalidate_memory () |
7afe21cc | 7683 | { |
9ae8ffe7 JL |
7684 | register int i; |
7685 | register struct table_elt *p, *next; | |
7afe21cc | 7686 | |
9ae8ffe7 JL |
7687 | for (i = 0; i < NBUCKETS; i++) |
7688 | for (p = table[i]; p; p = next) | |
7689 | { | |
7690 | next = p->next_same_hash; | |
7691 | if (p->in_memory) | |
7692 | remove_from_table (p, i); | |
7693 | } | |
7694 | } | |
7695 | ||
7696 | /* XXX ??? The name of this function bears little resemblance to | |
7697 | what this function actually does. FIXME. */ | |
7698 | static int | |
7699 | note_mem_written (addr) | |
7700 | register rtx addr; | |
7701 | { | |
7702 | /* Pushing or popping the stack invalidates just the stack pointer. */ | |
7703 | if ((GET_CODE (addr) == PRE_DEC || GET_CODE (addr) == PRE_INC | |
7704 | || GET_CODE (addr) == POST_DEC || GET_CODE (addr) == POST_INC) | |
7705 | && GET_CODE (XEXP (addr, 0)) == REG | |
7706 | && REGNO (XEXP (addr, 0)) == STACK_POINTER_REGNUM) | |
7afe21cc | 7707 | { |
9ae8ffe7 JL |
7708 | if (reg_tick[STACK_POINTER_REGNUM] >= 0) |
7709 | reg_tick[STACK_POINTER_REGNUM]++; | |
7710 | ||
7711 | /* This should be *very* rare. */ | |
7712 | if (TEST_HARD_REG_BIT (hard_regs_in_table, STACK_POINTER_REGNUM)) | |
7713 | invalidate (stack_pointer_rtx, VOIDmode); | |
7714 | return 1; | |
7afe21cc | 7715 | } |
9ae8ffe7 | 7716 | return 0; |
7afe21cc RK |
7717 | } |
7718 | ||
7719 | /* Perform invalidation on the basis of everything about an insn | |
7720 | except for invalidating the actual places that are SET in it. | |
7721 | This includes the places CLOBBERed, and anything that might | |
7722 | alias with something that is SET or CLOBBERed. | |
7723 | ||
7afe21cc RK |
7724 | X is the pattern of the insn. */ |
7725 | ||
7726 | static void | |
9ae8ffe7 | 7727 | invalidate_from_clobbers (x) |
7afe21cc RK |
7728 | rtx x; |
7729 | { | |
7afe21cc RK |
7730 | if (GET_CODE (x) == CLOBBER) |
7731 | { | |
7732 | rtx ref = XEXP (x, 0); | |
9ae8ffe7 JL |
7733 | if (ref) |
7734 | { | |
7735 | if (GET_CODE (ref) == REG || GET_CODE (ref) == SUBREG | |
7736 | || GET_CODE (ref) == MEM) | |
7737 | invalidate (ref, VOIDmode); | |
7738 | else if (GET_CODE (ref) == STRICT_LOW_PART | |
7739 | || GET_CODE (ref) == ZERO_EXTRACT) | |
7740 | invalidate (XEXP (ref, 0), GET_MODE (ref)); | |
7741 | } | |
7afe21cc RK |
7742 | } |
7743 | else if (GET_CODE (x) == PARALLEL) | |
7744 | { | |
7745 | register int i; | |
7746 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
7747 | { | |
7748 | register rtx y = XVECEXP (x, 0, i); | |
7749 | if (GET_CODE (y) == CLOBBER) | |
7750 | { | |
7751 | rtx ref = XEXP (y, 0); | |
9ae8ffe7 JL |
7752 | if (GET_CODE (ref) == REG || GET_CODE (ref) == SUBREG |
7753 | || GET_CODE (ref) == MEM) | |
7754 | invalidate (ref, VOIDmode); | |
7755 | else if (GET_CODE (ref) == STRICT_LOW_PART | |
7756 | || GET_CODE (ref) == ZERO_EXTRACT) | |
7757 | invalidate (XEXP (ref, 0), GET_MODE (ref)); | |
7afe21cc RK |
7758 | } |
7759 | } | |
7760 | } | |
7761 | } | |
7762 | \f | |
7763 | /* Process X, part of the REG_NOTES of an insn. Look at any REG_EQUAL notes | |
7764 | and replace any registers in them with either an equivalent constant | |
7765 | or the canonical form of the register. If we are inside an address, | |
7766 | only do this if the address remains valid. | |
7767 | ||
7768 | OBJECT is 0 except when within a MEM in which case it is the MEM. | |
7769 | ||
7770 | Return the replacement for X. */ | |
7771 | ||
7772 | static rtx | |
7773 | cse_process_notes (x, object) | |
7774 | rtx x; | |
7775 | rtx object; | |
7776 | { | |
7777 | enum rtx_code code = GET_CODE (x); | |
7778 | char *fmt = GET_RTX_FORMAT (code); | |
7afe21cc RK |
7779 | int i; |
7780 | ||
7781 | switch (code) | |
7782 | { | |
7783 | case CONST_INT: | |
7784 | case CONST: | |
7785 | case SYMBOL_REF: | |
7786 | case LABEL_REF: | |
7787 | case CONST_DOUBLE: | |
7788 | case PC: | |
7789 | case CC0: | |
7790 | case LO_SUM: | |
7791 | return x; | |
7792 | ||
7793 | case MEM: | |
7794 | XEXP (x, 0) = cse_process_notes (XEXP (x, 0), x); | |
7795 | return x; | |
7796 | ||
7797 | case EXPR_LIST: | |
7798 | case INSN_LIST: | |
7799 | if (REG_NOTE_KIND (x) == REG_EQUAL) | |
906c4e36 | 7800 | XEXP (x, 0) = cse_process_notes (XEXP (x, 0), NULL_RTX); |
7afe21cc | 7801 | if (XEXP (x, 1)) |
906c4e36 | 7802 | XEXP (x, 1) = cse_process_notes (XEXP (x, 1), NULL_RTX); |
7afe21cc RK |
7803 | return x; |
7804 | ||
e4890d45 RS |
7805 | case SIGN_EXTEND: |
7806 | case ZERO_EXTEND: | |
0b0ee36c | 7807 | case SUBREG: |
e4890d45 RS |
7808 | { |
7809 | rtx new = cse_process_notes (XEXP (x, 0), object); | |
7810 | /* We don't substitute VOIDmode constants into these rtx, | |
7811 | since they would impede folding. */ | |
7812 | if (GET_MODE (new) != VOIDmode) | |
7813 | validate_change (object, &XEXP (x, 0), new, 0); | |
7814 | return x; | |
7815 | } | |
7816 | ||
7afe21cc RK |
7817 | case REG: |
7818 | i = reg_qty[REGNO (x)]; | |
7819 | ||
7820 | /* Return a constant or a constant register. */ | |
7821 | if (REGNO_QTY_VALID_P (REGNO (x)) | |
7822 | && qty_const[i] != 0 | |
7823 | && (CONSTANT_P (qty_const[i]) | |
7824 | || GET_CODE (qty_const[i]) == REG)) | |
7825 | { | |
7826 | rtx new = gen_lowpart_if_possible (GET_MODE (x), qty_const[i]); | |
7827 | if (new) | |
7828 | return new; | |
7829 | } | |
7830 | ||
7831 | /* Otherwise, canonicalize this register. */ | |
906c4e36 | 7832 | return canon_reg (x, NULL_RTX); |
e9a25f70 JL |
7833 | |
7834 | default: | |
7835 | break; | |
7afe21cc RK |
7836 | } |
7837 | ||
7838 | for (i = 0; i < GET_RTX_LENGTH (code); i++) | |
7839 | if (fmt[i] == 'e') | |
7840 | validate_change (object, &XEXP (x, i), | |
7fe34fdf | 7841 | cse_process_notes (XEXP (x, i), object), 0); |
7afe21cc RK |
7842 | |
7843 | return x; | |
7844 | } | |
7845 | \f | |
7846 | /* Find common subexpressions between the end test of a loop and the beginning | |
7847 | of the loop. LOOP_START is the CODE_LABEL at the start of a loop. | |
7848 | ||
7849 | Often we have a loop where an expression in the exit test is used | |
7850 | in the body of the loop. For example "while (*p) *q++ = *p++;". | |
7851 | Because of the way we duplicate the loop exit test in front of the loop, | |
7852 | however, we don't detect that common subexpression. This will be caught | |
7853 | when global cse is implemented, but this is a quite common case. | |
7854 | ||
7855 | This function handles the most common cases of these common expressions. | |
7856 | It is called after we have processed the basic block ending with the | |
7857 | NOTE_INSN_LOOP_END note that ends a loop and the previous JUMP_INSN | |
7858 | jumps to a label used only once. */ | |
7859 | ||
7860 | static void | |
7861 | cse_around_loop (loop_start) | |
7862 | rtx loop_start; | |
7863 | { | |
7864 | rtx insn; | |
7865 | int i; | |
7866 | struct table_elt *p; | |
7867 | ||
7868 | /* If the jump at the end of the loop doesn't go to the start, we don't | |
7869 | do anything. */ | |
7870 | for (insn = PREV_INSN (loop_start); | |
7871 | insn && (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) >= 0); | |
7872 | insn = PREV_INSN (insn)) | |
7873 | ; | |
7874 | ||
7875 | if (insn == 0 | |
7876 | || GET_CODE (insn) != NOTE | |
7877 | || NOTE_LINE_NUMBER (insn) != NOTE_INSN_LOOP_BEG) | |
7878 | return; | |
7879 | ||
7880 | /* If the last insn of the loop (the end test) was an NE comparison, | |
7881 | we will interpret it as an EQ comparison, since we fell through | |
f72aed24 | 7882 | the loop. Any equivalences resulting from that comparison are |
7afe21cc RK |
7883 | therefore not valid and must be invalidated. */ |
7884 | if (last_jump_equiv_class) | |
7885 | for (p = last_jump_equiv_class->first_same_value; p; | |
7886 | p = p->next_same_value) | |
51723711 KG |
7887 | { |
7888 | if (GET_CODE (p->exp) == MEM || GET_CODE (p->exp) == REG | |
7889 | || (GET_CODE (p->exp) == SUBREG | |
7890 | && GET_CODE (SUBREG_REG (p->exp)) == REG)) | |
7891 | invalidate (p->exp, VOIDmode); | |
7892 | else if (GET_CODE (p->exp) == STRICT_LOW_PART | |
7893 | || GET_CODE (p->exp) == ZERO_EXTRACT) | |
7894 | invalidate (XEXP (p->exp, 0), GET_MODE (p->exp)); | |
7895 | } | |
7afe21cc RK |
7896 | |
7897 | /* Process insns starting after LOOP_START until we hit a CALL_INSN or | |
7898 | a CODE_LABEL (we could handle a CALL_INSN, but it isn't worth it). | |
7899 | ||
7900 | The only thing we do with SET_DEST is invalidate entries, so we | |
7901 | can safely process each SET in order. It is slightly less efficient | |
556c714b JW |
7902 | to do so, but we only want to handle the most common cases. |
7903 | ||
7904 | The gen_move_insn call in cse_set_around_loop may create new pseudos. | |
7905 | These pseudos won't have valid entries in any of the tables indexed | |
7906 | by register number, such as reg_qty. We avoid out-of-range array | |
7907 | accesses by not processing any instructions created after cse started. */ | |
7afe21cc RK |
7908 | |
7909 | for (insn = NEXT_INSN (loop_start); | |
7910 | GET_CODE (insn) != CALL_INSN && GET_CODE (insn) != CODE_LABEL | |
556c714b | 7911 | && INSN_UID (insn) < max_insn_uid |
7afe21cc RK |
7912 | && ! (GET_CODE (insn) == NOTE |
7913 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END); | |
7914 | insn = NEXT_INSN (insn)) | |
7915 | { | |
7916 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
7917 | && (GET_CODE (PATTERN (insn)) == SET | |
7918 | || GET_CODE (PATTERN (insn)) == CLOBBER)) | |
7919 | cse_set_around_loop (PATTERN (insn), insn, loop_start); | |
7920 | else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
7921 | && GET_CODE (PATTERN (insn)) == PARALLEL) | |
7922 | for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--) | |
7923 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET | |
7924 | || GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == CLOBBER) | |
7925 | cse_set_around_loop (XVECEXP (PATTERN (insn), 0, i), insn, | |
7926 | loop_start); | |
7927 | } | |
7928 | } | |
7929 | \f | |
8b3686ed RK |
7930 | /* Process one SET of an insn that was skipped. We ignore CLOBBERs |
7931 | since they are done elsewhere. This function is called via note_stores. */ | |
7932 | ||
7933 | static void | |
7934 | invalidate_skipped_set (dest, set) | |
7935 | rtx set; | |
7936 | rtx dest; | |
7937 | { | |
9ae8ffe7 JL |
7938 | enum rtx_code code = GET_CODE (dest); |
7939 | ||
7940 | if (code == MEM | |
7941 | && ! note_mem_written (dest) /* If this is not a stack push ... */ | |
7942 | /* There are times when an address can appear varying and be a PLUS | |
7943 | during this scan when it would be a fixed address were we to know | |
7944 | the proper equivalences. So invalidate all memory if there is | |
7945 | a BLKmode or nonscalar memory reference or a reference to a | |
7946 | variable address. */ | |
7947 | && (MEM_IN_STRUCT_P (dest) || GET_MODE (dest) == BLKmode | |
7948 | || cse_rtx_varies_p (XEXP (dest, 0)))) | |
7949 | { | |
7950 | invalidate_memory (); | |
7951 | return; | |
7952 | } | |
ffcf6393 | 7953 | |
f47c02fa RK |
7954 | if (GET_CODE (set) == CLOBBER |
7955 | #ifdef HAVE_cc0 | |
7956 | || dest == cc0_rtx | |
7957 | #endif | |
7958 | || dest == pc_rtx) | |
7959 | return; | |
7960 | ||
9ae8ffe7 | 7961 | if (code == STRICT_LOW_PART || code == ZERO_EXTRACT) |
bb4034b3 | 7962 | invalidate (XEXP (dest, 0), GET_MODE (dest)); |
9ae8ffe7 JL |
7963 | else if (code == REG || code == SUBREG || code == MEM) |
7964 | invalidate (dest, VOIDmode); | |
8b3686ed RK |
7965 | } |
7966 | ||
7967 | /* Invalidate all insns from START up to the end of the function or the | |
7968 | next label. This called when we wish to CSE around a block that is | |
7969 | conditionally executed. */ | |
7970 | ||
7971 | static void | |
7972 | invalidate_skipped_block (start) | |
7973 | rtx start; | |
7974 | { | |
7975 | rtx insn; | |
8b3686ed RK |
7976 | |
7977 | for (insn = start; insn && GET_CODE (insn) != CODE_LABEL; | |
7978 | insn = NEXT_INSN (insn)) | |
7979 | { | |
7980 | if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') | |
7981 | continue; | |
7982 | ||
8b3686ed RK |
7983 | if (GET_CODE (insn) == CALL_INSN) |
7984 | { | |
9ae8ffe7 JL |
7985 | if (! CONST_CALL_P (insn)) |
7986 | invalidate_memory (); | |
8b3686ed | 7987 | invalidate_for_call (); |
8b3686ed RK |
7988 | } |
7989 | ||
7990 | note_stores (PATTERN (insn), invalidate_skipped_set); | |
8b3686ed RK |
7991 | } |
7992 | } | |
7993 | \f | |
7afe21cc RK |
7994 | /* Used for communication between the following two routines; contains a |
7995 | value to be checked for modification. */ | |
7996 | ||
7997 | static rtx cse_check_loop_start_value; | |
7998 | ||
7999 | /* If modifying X will modify the value in CSE_CHECK_LOOP_START_VALUE, | |
8000 | indicate that fact by setting CSE_CHECK_LOOP_START_VALUE to 0. */ | |
8001 | ||
8002 | static void | |
8003 | cse_check_loop_start (x, set) | |
8004 | rtx x; | |
d6f4ec51 | 8005 | rtx set ATTRIBUTE_UNUSED; |
7afe21cc RK |
8006 | { |
8007 | if (cse_check_loop_start_value == 0 | |
8008 | || GET_CODE (x) == CC0 || GET_CODE (x) == PC) | |
8009 | return; | |
8010 | ||
8011 | if ((GET_CODE (x) == MEM && GET_CODE (cse_check_loop_start_value) == MEM) | |
8012 | || reg_overlap_mentioned_p (x, cse_check_loop_start_value)) | |
8013 | cse_check_loop_start_value = 0; | |
8014 | } | |
8015 | ||
8016 | /* X is a SET or CLOBBER contained in INSN that was found near the start of | |
8017 | a loop that starts with the label at LOOP_START. | |
8018 | ||
8019 | If X is a SET, we see if its SET_SRC is currently in our hash table. | |
8020 | If so, we see if it has a value equal to some register used only in the | |
8021 | loop exit code (as marked by jump.c). | |
8022 | ||
8023 | If those two conditions are true, we search backwards from the start of | |
8024 | the loop to see if that same value was loaded into a register that still | |
8025 | retains its value at the start of the loop. | |
8026 | ||
8027 | If so, we insert an insn after the load to copy the destination of that | |
8028 | load into the equivalent register and (try to) replace our SET_SRC with that | |
8029 | register. | |
8030 | ||
8031 | In any event, we invalidate whatever this SET or CLOBBER modifies. */ | |
8032 | ||
8033 | static void | |
8034 | cse_set_around_loop (x, insn, loop_start) | |
8035 | rtx x; | |
8036 | rtx insn; | |
8037 | rtx loop_start; | |
8038 | { | |
7afe21cc | 8039 | struct table_elt *src_elt; |
7afe21cc RK |
8040 | |
8041 | /* If this is a SET, see if we can replace SET_SRC, but ignore SETs that | |
8042 | are setting PC or CC0 or whose SET_SRC is already a register. */ | |
8043 | if (GET_CODE (x) == SET | |
8044 | && GET_CODE (SET_DEST (x)) != PC && GET_CODE (SET_DEST (x)) != CC0 | |
8045 | && GET_CODE (SET_SRC (x)) != REG) | |
8046 | { | |
8047 | src_elt = lookup (SET_SRC (x), | |
8048 | HASH (SET_SRC (x), GET_MODE (SET_DEST (x))), | |
8049 | GET_MODE (SET_DEST (x))); | |
8050 | ||
8051 | if (src_elt) | |
8052 | for (src_elt = src_elt->first_same_value; src_elt; | |
8053 | src_elt = src_elt->next_same_value) | |
8054 | if (GET_CODE (src_elt->exp) == REG && REG_LOOP_TEST_P (src_elt->exp) | |
8055 | && COST (src_elt->exp) < COST (SET_SRC (x))) | |
8056 | { | |
8057 | rtx p, set; | |
8058 | ||
8059 | /* Look for an insn in front of LOOP_START that sets | |
8060 | something in the desired mode to SET_SRC (x) before we hit | |
8061 | a label or CALL_INSN. */ | |
8062 | ||
8063 | for (p = prev_nonnote_insn (loop_start); | |
8064 | p && GET_CODE (p) != CALL_INSN | |
8065 | && GET_CODE (p) != CODE_LABEL; | |
8066 | p = prev_nonnote_insn (p)) | |
8067 | if ((set = single_set (p)) != 0 | |
8068 | && GET_CODE (SET_DEST (set)) == REG | |
8069 | && GET_MODE (SET_DEST (set)) == src_elt->mode | |
8070 | && rtx_equal_p (SET_SRC (set), SET_SRC (x))) | |
8071 | { | |
8072 | /* We now have to ensure that nothing between P | |
8073 | and LOOP_START modified anything referenced in | |
8074 | SET_SRC (x). We know that nothing within the loop | |
8075 | can modify it, or we would have invalidated it in | |
8076 | the hash table. */ | |
8077 | rtx q; | |
8078 | ||
8079 | cse_check_loop_start_value = SET_SRC (x); | |
8080 | for (q = p; q != loop_start; q = NEXT_INSN (q)) | |
8081 | if (GET_RTX_CLASS (GET_CODE (q)) == 'i') | |
8082 | note_stores (PATTERN (q), cse_check_loop_start); | |
8083 | ||
8084 | /* If nothing was changed and we can replace our | |
8085 | SET_SRC, add an insn after P to copy its destination | |
8086 | to what we will be replacing SET_SRC with. */ | |
8087 | if (cse_check_loop_start_value | |
8088 | && validate_change (insn, &SET_SRC (x), | |
8089 | src_elt->exp, 0)) | |
e89d3e6f R |
8090 | { |
8091 | /* If this creates new pseudos, this is unsafe, | |
8092 | because the regno of new pseudo is unsuitable | |
8093 | to index into reg_qty when cse_insn processes | |
8094 | the new insn. Therefore, if a new pseudo was | |
8095 | created, discard this optimization. */ | |
8096 | int nregs = max_reg_num (); | |
8097 | rtx move | |
8098 | = gen_move_insn (src_elt->exp, SET_DEST (set)); | |
8099 | if (nregs != max_reg_num ()) | |
8100 | { | |
8101 | if (! validate_change (insn, &SET_SRC (x), | |
8102 | SET_SRC (set), 0)) | |
8103 | abort (); | |
8104 | } | |
8105 | else | |
8106 | emit_insn_after (move, p); | |
8107 | } | |
7afe21cc RK |
8108 | break; |
8109 | } | |
8110 | } | |
8111 | } | |
8112 | ||
8113 | /* Now invalidate anything modified by X. */ | |
9ae8ffe7 | 8114 | note_mem_written (SET_DEST (x)); |
7afe21cc | 8115 | |
9ae8ffe7 | 8116 | /* See comment on similar code in cse_insn for explanation of these tests. */ |
7afe21cc | 8117 | if (GET_CODE (SET_DEST (x)) == REG || GET_CODE (SET_DEST (x)) == SUBREG |
9ae8ffe7 | 8118 | || GET_CODE (SET_DEST (x)) == MEM) |
bb4034b3 | 8119 | invalidate (SET_DEST (x), VOIDmode); |
2708da92 RS |
8120 | else if (GET_CODE (SET_DEST (x)) == STRICT_LOW_PART |
8121 | || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT) | |
bb4034b3 | 8122 | invalidate (XEXP (SET_DEST (x), 0), GET_MODE (SET_DEST (x))); |
7afe21cc RK |
8123 | } |
8124 | \f | |
8125 | /* Find the end of INSN's basic block and return its range, | |
8126 | the total number of SETs in all the insns of the block, the last insn of the | |
8127 | block, and the branch path. | |
8128 | ||
8129 | The branch path indicates which branches should be followed. If a non-zero | |
8130 | path size is specified, the block should be rescanned and a different set | |
8131 | of branches will be taken. The branch path is only used if | |
8b3686ed | 8132 | FLAG_CSE_FOLLOW_JUMPS or FLAG_CSE_SKIP_BLOCKS is non-zero. |
7afe21cc RK |
8133 | |
8134 | DATA is a pointer to a struct cse_basic_block_data, defined below, that is | |
8135 | used to describe the block. It is filled in with the information about | |
8136 | the current block. The incoming structure's branch path, if any, is used | |
8137 | to construct the output branch path. */ | |
8138 | ||
7afe21cc | 8139 | void |
8b3686ed | 8140 | cse_end_of_basic_block (insn, data, follow_jumps, after_loop, skip_blocks) |
7afe21cc RK |
8141 | rtx insn; |
8142 | struct cse_basic_block_data *data; | |
8143 | int follow_jumps; | |
8144 | int after_loop; | |
8b3686ed | 8145 | int skip_blocks; |
7afe21cc RK |
8146 | { |
8147 | rtx p = insn, q; | |
8148 | int nsets = 0; | |
8149 | int low_cuid = INSN_CUID (insn), high_cuid = INSN_CUID (insn); | |
fc3ffe83 | 8150 | rtx next = GET_RTX_CLASS (GET_CODE (insn)) == 'i' ? insn : next_real_insn (insn); |
7afe21cc RK |
8151 | int path_size = data->path_size; |
8152 | int path_entry = 0; | |
8153 | int i; | |
8154 | ||
8155 | /* Update the previous branch path, if any. If the last branch was | |
8156 | previously TAKEN, mark it NOT_TAKEN. If it was previously NOT_TAKEN, | |
8157 | shorten the path by one and look at the previous branch. We know that | |
8158 | at least one branch must have been taken if PATH_SIZE is non-zero. */ | |
8159 | while (path_size > 0) | |
8160 | { | |
8b3686ed | 8161 | if (data->path[path_size - 1].status != NOT_TAKEN) |
7afe21cc RK |
8162 | { |
8163 | data->path[path_size - 1].status = NOT_TAKEN; | |
8164 | break; | |
8165 | } | |
8166 | else | |
8167 | path_size--; | |
8168 | } | |
8169 | ||
8170 | /* Scan to end of this basic block. */ | |
8171 | while (p && GET_CODE (p) != CODE_LABEL) | |
8172 | { | |
8173 | /* Don't cse out the end of a loop. This makes a difference | |
8174 | only for the unusual loops that always execute at least once; | |
8175 | all other loops have labels there so we will stop in any case. | |
8176 | Cse'ing out the end of the loop is dangerous because it | |
8177 | might cause an invariant expression inside the loop | |
8178 | to be reused after the end of the loop. This would make it | |
8179 | hard to move the expression out of the loop in loop.c, | |
8180 | especially if it is one of several equivalent expressions | |
8181 | and loop.c would like to eliminate it. | |
8182 | ||
8183 | If we are running after loop.c has finished, we can ignore | |
8184 | the NOTE_INSN_LOOP_END. */ | |
8185 | ||
8186 | if (! after_loop && GET_CODE (p) == NOTE | |
8187 | && NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END) | |
8188 | break; | |
8189 | ||
8190 | /* Don't cse over a call to setjmp; on some machines (eg vax) | |
8191 | the regs restored by the longjmp come from | |
8192 | a later time than the setjmp. */ | |
8193 | if (GET_CODE (p) == NOTE | |
8194 | && NOTE_LINE_NUMBER (p) == NOTE_INSN_SETJMP) | |
8195 | break; | |
8196 | ||
8197 | /* A PARALLEL can have lots of SETs in it, | |
8198 | especially if it is really an ASM_OPERANDS. */ | |
8199 | if (GET_RTX_CLASS (GET_CODE (p)) == 'i' | |
8200 | && GET_CODE (PATTERN (p)) == PARALLEL) | |
8201 | nsets += XVECLEN (PATTERN (p), 0); | |
8202 | else if (GET_CODE (p) != NOTE) | |
8203 | nsets += 1; | |
8204 | ||
164c8956 RK |
8205 | /* Ignore insns made by CSE; they cannot affect the boundaries of |
8206 | the basic block. */ | |
8207 | ||
8208 | if (INSN_UID (p) <= max_uid && INSN_CUID (p) > high_cuid) | |
8b3686ed | 8209 | high_cuid = INSN_CUID (p); |
164c8956 RK |
8210 | if (INSN_UID (p) <= max_uid && INSN_CUID (p) < low_cuid) |
8211 | low_cuid = INSN_CUID (p); | |
7afe21cc RK |
8212 | |
8213 | /* See if this insn is in our branch path. If it is and we are to | |
8214 | take it, do so. */ | |
8215 | if (path_entry < path_size && data->path[path_entry].branch == p) | |
8216 | { | |
8b3686ed | 8217 | if (data->path[path_entry].status != NOT_TAKEN) |
7afe21cc RK |
8218 | p = JUMP_LABEL (p); |
8219 | ||
8220 | /* Point to next entry in path, if any. */ | |
8221 | path_entry++; | |
8222 | } | |
8223 | ||
8224 | /* If this is a conditional jump, we can follow it if -fcse-follow-jumps | |
8225 | was specified, we haven't reached our maximum path length, there are | |
8226 | insns following the target of the jump, this is the only use of the | |
8b3686ed RK |
8227 | jump label, and the target label is preceded by a BARRIER. |
8228 | ||
8229 | Alternatively, we can follow the jump if it branches around a | |
8230 | block of code and there are no other branches into the block. | |
8231 | In this case invalidate_skipped_block will be called to invalidate any | |
8232 | registers set in the block when following the jump. */ | |
8233 | ||
8234 | else if ((follow_jumps || skip_blocks) && path_size < PATHLENGTH - 1 | |
7afe21cc RK |
8235 | && GET_CODE (p) == JUMP_INSN |
8236 | && GET_CODE (PATTERN (p)) == SET | |
8237 | && GET_CODE (SET_SRC (PATTERN (p))) == IF_THEN_ELSE | |
85c3ba60 | 8238 | && JUMP_LABEL (p) != 0 |
7afe21cc RK |
8239 | && LABEL_NUSES (JUMP_LABEL (p)) == 1 |
8240 | && NEXT_INSN (JUMP_LABEL (p)) != 0) | |
8241 | { | |
8242 | for (q = PREV_INSN (JUMP_LABEL (p)); q; q = PREV_INSN (q)) | |
8243 | if ((GET_CODE (q) != NOTE | |
8244 | || NOTE_LINE_NUMBER (q) == NOTE_INSN_LOOP_END | |
8245 | || NOTE_LINE_NUMBER (q) == NOTE_INSN_SETJMP) | |
8246 | && (GET_CODE (q) != CODE_LABEL || LABEL_NUSES (q) != 0)) | |
8247 | break; | |
8248 | ||
8249 | /* If we ran into a BARRIER, this code is an extension of the | |
8250 | basic block when the branch is taken. */ | |
8b3686ed | 8251 | if (follow_jumps && q != 0 && GET_CODE (q) == BARRIER) |
7afe21cc RK |
8252 | { |
8253 | /* Don't allow ourself to keep walking around an | |
8254 | always-executed loop. */ | |
fc3ffe83 RK |
8255 | if (next_real_insn (q) == next) |
8256 | { | |
8257 | p = NEXT_INSN (p); | |
8258 | continue; | |
8259 | } | |
7afe21cc RK |
8260 | |
8261 | /* Similarly, don't put a branch in our path more than once. */ | |
8262 | for (i = 0; i < path_entry; i++) | |
8263 | if (data->path[i].branch == p) | |
8264 | break; | |
8265 | ||
8266 | if (i != path_entry) | |
8267 | break; | |
8268 | ||
8269 | data->path[path_entry].branch = p; | |
8270 | data->path[path_entry++].status = TAKEN; | |
8271 | ||
8272 | /* This branch now ends our path. It was possible that we | |
8273 | didn't see this branch the last time around (when the | |
8274 | insn in front of the target was a JUMP_INSN that was | |
8275 | turned into a no-op). */ | |
8276 | path_size = path_entry; | |
8277 | ||
8278 | p = JUMP_LABEL (p); | |
8279 | /* Mark block so we won't scan it again later. */ | |
8280 | PUT_MODE (NEXT_INSN (p), QImode); | |
8281 | } | |
8b3686ed RK |
8282 | /* Detect a branch around a block of code. */ |
8283 | else if (skip_blocks && q != 0 && GET_CODE (q) != CODE_LABEL) | |
8284 | { | |
8285 | register rtx tmp; | |
8286 | ||
fc3ffe83 RK |
8287 | if (next_real_insn (q) == next) |
8288 | { | |
8289 | p = NEXT_INSN (p); | |
8290 | continue; | |
8291 | } | |
8b3686ed RK |
8292 | |
8293 | for (i = 0; i < path_entry; i++) | |
8294 | if (data->path[i].branch == p) | |
8295 | break; | |
8296 | ||
8297 | if (i != path_entry) | |
8298 | break; | |
8299 | ||
8300 | /* This is no_labels_between_p (p, q) with an added check for | |
8301 | reaching the end of a function (in case Q precedes P). */ | |
8302 | for (tmp = NEXT_INSN (p); tmp && tmp != q; tmp = NEXT_INSN (tmp)) | |
8303 | if (GET_CODE (tmp) == CODE_LABEL) | |
8304 | break; | |
8305 | ||
8306 | if (tmp == q) | |
8307 | { | |
8308 | data->path[path_entry].branch = p; | |
8309 | data->path[path_entry++].status = AROUND; | |
8310 | ||
8311 | path_size = path_entry; | |
8312 | ||
8313 | p = JUMP_LABEL (p); | |
8314 | /* Mark block so we won't scan it again later. */ | |
8315 | PUT_MODE (NEXT_INSN (p), QImode); | |
8316 | } | |
8317 | } | |
7afe21cc | 8318 | } |
7afe21cc RK |
8319 | p = NEXT_INSN (p); |
8320 | } | |
8321 | ||
8322 | data->low_cuid = low_cuid; | |
8323 | data->high_cuid = high_cuid; | |
8324 | data->nsets = nsets; | |
8325 | data->last = p; | |
8326 | ||
8327 | /* If all jumps in the path are not taken, set our path length to zero | |
8328 | so a rescan won't be done. */ | |
8329 | for (i = path_size - 1; i >= 0; i--) | |
8b3686ed | 8330 | if (data->path[i].status != NOT_TAKEN) |
7afe21cc RK |
8331 | break; |
8332 | ||
8333 | if (i == -1) | |
8334 | data->path_size = 0; | |
8335 | else | |
8336 | data->path_size = path_size; | |
8337 | ||
8338 | /* End the current branch path. */ | |
8339 | data->path[path_size].branch = 0; | |
8340 | } | |
8341 | \f | |
7afe21cc RK |
8342 | /* Perform cse on the instructions of a function. |
8343 | F is the first instruction. | |
8344 | NREGS is one plus the highest pseudo-reg number used in the instruction. | |
8345 | ||
8346 | AFTER_LOOP is 1 if this is the cse call done after loop optimization | |
8347 | (only if -frerun-cse-after-loop). | |
8348 | ||
8349 | Returns 1 if jump_optimize should be redone due to simplifications | |
8350 | in conditional jump instructions. */ | |
8351 | ||
8352 | int | |
8353 | cse_main (f, nregs, after_loop, file) | |
8354 | rtx f; | |
8355 | int nregs; | |
8356 | int after_loop; | |
8357 | FILE *file; | |
8358 | { | |
8359 | struct cse_basic_block_data val; | |
8360 | register rtx insn = f; | |
8361 | register int i; | |
8362 | ||
8363 | cse_jumps_altered = 0; | |
a5dfb4ee | 8364 | recorded_label_ref = 0; |
7afe21cc RK |
8365 | constant_pool_entries_cost = 0; |
8366 | val.path_size = 0; | |
8367 | ||
8368 | init_recog (); | |
9ae8ffe7 | 8369 | init_alias_analysis (); |
7afe21cc RK |
8370 | |
8371 | max_reg = nregs; | |
8372 | ||
556c714b JW |
8373 | max_insn_uid = get_max_uid (); |
8374 | ||
7afe21cc RK |
8375 | all_minus_one = (int *) alloca (nregs * sizeof (int)); |
8376 | consec_ints = (int *) alloca (nregs * sizeof (int)); | |
8377 | ||
8378 | for (i = 0; i < nregs; i++) | |
8379 | { | |
8380 | all_minus_one[i] = -1; | |
8381 | consec_ints[i] = i; | |
8382 | } | |
8383 | ||
8384 | reg_next_eqv = (int *) alloca (nregs * sizeof (int)); | |
8385 | reg_prev_eqv = (int *) alloca (nregs * sizeof (int)); | |
8386 | reg_qty = (int *) alloca (nregs * sizeof (int)); | |
8387 | reg_in_table = (int *) alloca (nregs * sizeof (int)); | |
8388 | reg_tick = (int *) alloca (nregs * sizeof (int)); | |
8389 | ||
7bac1be0 RK |
8390 | #ifdef LOAD_EXTEND_OP |
8391 | ||
8392 | /* Allocate scratch rtl here. cse_insn will fill in the memory reference | |
8393 | and change the code and mode as appropriate. */ | |
38a448ca | 8394 | memory_extend_rtx = gen_rtx_ZERO_EXTEND (VOIDmode, NULL_RTX); |
7bac1be0 RK |
8395 | #endif |
8396 | ||
7afe21cc RK |
8397 | /* Discard all the free elements of the previous function |
8398 | since they are allocated in the temporarily obstack. */ | |
4c9a05bc | 8399 | bzero ((char *) table, sizeof table); |
7afe21cc RK |
8400 | free_element_chain = 0; |
8401 | n_elements_made = 0; | |
8402 | ||
8403 | /* Find the largest uid. */ | |
8404 | ||
164c8956 RK |
8405 | max_uid = get_max_uid (); |
8406 | uid_cuid = (int *) alloca ((max_uid + 1) * sizeof (int)); | |
4c9a05bc | 8407 | bzero ((char *) uid_cuid, (max_uid + 1) * sizeof (int)); |
7afe21cc RK |
8408 | |
8409 | /* Compute the mapping from uids to cuids. | |
8410 | CUIDs are numbers assigned to insns, like uids, | |
8411 | except that cuids increase monotonically through the code. | |
8412 | Don't assign cuids to line-number NOTEs, so that the distance in cuids | |
8413 | between two insns is not affected by -g. */ | |
8414 | ||
8415 | for (insn = f, i = 0; insn; insn = NEXT_INSN (insn)) | |
8416 | { | |
8417 | if (GET_CODE (insn) != NOTE | |
8418 | || NOTE_LINE_NUMBER (insn) < 0) | |
8419 | INSN_CUID (insn) = ++i; | |
8420 | else | |
8421 | /* Give a line number note the same cuid as preceding insn. */ | |
8422 | INSN_CUID (insn) = i; | |
8423 | } | |
8424 | ||
8425 | /* Initialize which registers are clobbered by calls. */ | |
8426 | ||
8427 | CLEAR_HARD_REG_SET (regs_invalidated_by_call); | |
8428 | ||
8429 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
8430 | if ((call_used_regs[i] | |
8431 | /* Used to check !fixed_regs[i] here, but that isn't safe; | |
8432 | fixed regs are still call-clobbered, and sched can get | |
8433 | confused if they can "live across calls". | |
8434 | ||
8435 | The frame pointer is always preserved across calls. The arg | |
8436 | pointer is if it is fixed. The stack pointer usually is, unless | |
8437 | RETURN_POPS_ARGS, in which case an explicit CLOBBER | |
8438 | will be present. If we are generating PIC code, the PIC offset | |
8439 | table register is preserved across calls. */ | |
8440 | ||
8441 | && i != STACK_POINTER_REGNUM | |
8442 | && i != FRAME_POINTER_REGNUM | |
8bc169f2 DE |
8443 | #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM |
8444 | && i != HARD_FRAME_POINTER_REGNUM | |
8445 | #endif | |
7afe21cc RK |
8446 | #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM |
8447 | && ! (i == ARG_POINTER_REGNUM && fixed_regs[i]) | |
8448 | #endif | |
be8fe470 | 8449 | #if defined (PIC_OFFSET_TABLE_REGNUM) && !defined (PIC_OFFSET_TABLE_REG_CALL_CLOBBERED) |
7afe21cc RK |
8450 | && ! (i == PIC_OFFSET_TABLE_REGNUM && flag_pic) |
8451 | #endif | |
8452 | ) | |
8453 | || global_regs[i]) | |
8454 | SET_HARD_REG_BIT (regs_invalidated_by_call, i); | |
8455 | ||
8456 | /* Loop over basic blocks. | |
8457 | Compute the maximum number of qty's needed for each basic block | |
8458 | (which is 2 for each SET). */ | |
8459 | insn = f; | |
8460 | while (insn) | |
8461 | { | |
8b3686ed RK |
8462 | cse_end_of_basic_block (insn, &val, flag_cse_follow_jumps, after_loop, |
8463 | flag_cse_skip_blocks); | |
7afe21cc RK |
8464 | |
8465 | /* If this basic block was already processed or has no sets, skip it. */ | |
8466 | if (val.nsets == 0 || GET_MODE (insn) == QImode) | |
8467 | { | |
8468 | PUT_MODE (insn, VOIDmode); | |
8469 | insn = (val.last ? NEXT_INSN (val.last) : 0); | |
8470 | val.path_size = 0; | |
8471 | continue; | |
8472 | } | |
8473 | ||
8474 | cse_basic_block_start = val.low_cuid; | |
8475 | cse_basic_block_end = val.high_cuid; | |
8476 | max_qty = val.nsets * 2; | |
8477 | ||
8478 | if (file) | |
8479 | fprintf (file, ";; Processing block from %d to %d, %d sets.\n", | |
8480 | INSN_UID (insn), val.last ? INSN_UID (val.last) : 0, | |
8481 | val.nsets); | |
8482 | ||
8483 | /* Make MAX_QTY bigger to give us room to optimize | |
8484 | past the end of this basic block, if that should prove useful. */ | |
8485 | if (max_qty < 500) | |
8486 | max_qty = 500; | |
8487 | ||
8488 | max_qty += max_reg; | |
8489 | ||
8490 | /* If this basic block is being extended by following certain jumps, | |
8491 | (see `cse_end_of_basic_block'), we reprocess the code from the start. | |
8492 | Otherwise, we start after this basic block. */ | |
8493 | if (val.path_size > 0) | |
8494 | cse_basic_block (insn, val.last, val.path, 0); | |
8495 | else | |
8496 | { | |
8497 | int old_cse_jumps_altered = cse_jumps_altered; | |
8498 | rtx temp; | |
8499 | ||
8500 | /* When cse changes a conditional jump to an unconditional | |
8501 | jump, we want to reprocess the block, since it will give | |
8502 | us a new branch path to investigate. */ | |
8503 | cse_jumps_altered = 0; | |
8504 | temp = cse_basic_block (insn, val.last, val.path, ! after_loop); | |
8b3686ed RK |
8505 | if (cse_jumps_altered == 0 |
8506 | || (flag_cse_follow_jumps == 0 && flag_cse_skip_blocks == 0)) | |
7afe21cc RK |
8507 | insn = temp; |
8508 | ||
8509 | cse_jumps_altered |= old_cse_jumps_altered; | |
8510 | } | |
8511 | ||
8512 | #ifdef USE_C_ALLOCA | |
8513 | alloca (0); | |
8514 | #endif | |
8515 | } | |
8516 | ||
8517 | /* Tell refers_to_mem_p that qty_const info is not available. */ | |
8518 | qty_const = 0; | |
8519 | ||
8520 | if (max_elements_made < n_elements_made) | |
8521 | max_elements_made = n_elements_made; | |
8522 | ||
a5dfb4ee | 8523 | return cse_jumps_altered || recorded_label_ref; |
7afe21cc RK |
8524 | } |
8525 | ||
8526 | /* Process a single basic block. FROM and TO and the limits of the basic | |
8527 | block. NEXT_BRANCH points to the branch path when following jumps or | |
8528 | a null path when not following jumps. | |
8529 | ||
8530 | AROUND_LOOP is non-zero if we are to try to cse around to the start of a | |
8531 | loop. This is true when we are being called for the last time on a | |
8532 | block and this CSE pass is before loop.c. */ | |
8533 | ||
8534 | static rtx | |
8535 | cse_basic_block (from, to, next_branch, around_loop) | |
8536 | register rtx from, to; | |
8537 | struct branch_path *next_branch; | |
8538 | int around_loop; | |
8539 | { | |
8540 | register rtx insn; | |
8541 | int to_usage = 0; | |
7bd8b2a8 | 8542 | rtx libcall_insn = NULL_RTX; |
e9a25f70 | 8543 | int num_insns = 0; |
7afe21cc RK |
8544 | |
8545 | /* Each of these arrays is undefined before max_reg, so only allocate | |
8546 | the space actually needed and adjust the start below. */ | |
8547 | ||
8548 | qty_first_reg = (int *) alloca ((max_qty - max_reg) * sizeof (int)); | |
8549 | qty_last_reg = (int *) alloca ((max_qty - max_reg) * sizeof (int)); | |
8550 | qty_mode= (enum machine_mode *) alloca ((max_qty - max_reg) * sizeof (enum machine_mode)); | |
8551 | qty_const = (rtx *) alloca ((max_qty - max_reg) * sizeof (rtx)); | |
8552 | qty_const_insn = (rtx *) alloca ((max_qty - max_reg) * sizeof (rtx)); | |
8553 | qty_comparison_code | |
8554 | = (enum rtx_code *) alloca ((max_qty - max_reg) * sizeof (enum rtx_code)); | |
8555 | qty_comparison_qty = (int *) alloca ((max_qty - max_reg) * sizeof (int)); | |
8556 | qty_comparison_const = (rtx *) alloca ((max_qty - max_reg) * sizeof (rtx)); | |
8557 | ||
8558 | qty_first_reg -= max_reg; | |
8559 | qty_last_reg -= max_reg; | |
8560 | qty_mode -= max_reg; | |
8561 | qty_const -= max_reg; | |
8562 | qty_const_insn -= max_reg; | |
8563 | qty_comparison_code -= max_reg; | |
8564 | qty_comparison_qty -= max_reg; | |
8565 | qty_comparison_const -= max_reg; | |
8566 | ||
8567 | new_basic_block (); | |
8568 | ||
8569 | /* TO might be a label. If so, protect it from being deleted. */ | |
8570 | if (to != 0 && GET_CODE (to) == CODE_LABEL) | |
8571 | ++LABEL_NUSES (to); | |
8572 | ||
8573 | for (insn = from; insn != to; insn = NEXT_INSN (insn)) | |
8574 | { | |
1d22a2c1 | 8575 | register enum rtx_code code = GET_CODE (insn); |
e9a25f70 JL |
8576 | int i; |
8577 | struct table_elt *p, *next; | |
8578 | ||
1d22a2c1 MM |
8579 | /* If we have processed 1,000 insns, flush the hash table to |
8580 | avoid extreme quadratic behavior. We must not include NOTEs | |
8581 | in the count since there may be more or them when generating | |
8582 | debugging information. If we clear the table at different | |
8583 | times, code generated with -g -O might be different than code | |
8584 | generated with -O but not -g. | |
e9a25f70 JL |
8585 | |
8586 | ??? This is a real kludge and needs to be done some other way. | |
8587 | Perhaps for 2.9. */ | |
1d22a2c1 | 8588 | if (code != NOTE && num_insns++ > 1000) |
e9a25f70 JL |
8589 | { |
8590 | for (i = 0; i < NBUCKETS; i++) | |
8591 | for (p = table[i]; p; p = next) | |
8592 | { | |
8593 | next = p->next_same_hash; | |
8594 | ||
8595 | if (GET_CODE (p->exp) == REG) | |
8596 | invalidate (p->exp, p->mode); | |
8597 | else | |
8598 | remove_from_table (p, i); | |
8599 | } | |
8600 | ||
8601 | num_insns = 0; | |
8602 | } | |
7afe21cc RK |
8603 | |
8604 | /* See if this is a branch that is part of the path. If so, and it is | |
8605 | to be taken, do so. */ | |
8606 | if (next_branch->branch == insn) | |
8607 | { | |
8b3686ed RK |
8608 | enum taken status = next_branch++->status; |
8609 | if (status != NOT_TAKEN) | |
7afe21cc | 8610 | { |
8b3686ed RK |
8611 | if (status == TAKEN) |
8612 | record_jump_equiv (insn, 1); | |
8613 | else | |
8614 | invalidate_skipped_block (NEXT_INSN (insn)); | |
8615 | ||
7afe21cc RK |
8616 | /* Set the last insn as the jump insn; it doesn't affect cc0. |
8617 | Then follow this branch. */ | |
8618 | #ifdef HAVE_cc0 | |
8619 | prev_insn_cc0 = 0; | |
8620 | #endif | |
8621 | prev_insn = insn; | |
8622 | insn = JUMP_LABEL (insn); | |
8623 | continue; | |
8624 | } | |
8625 | } | |
8626 | ||
7afe21cc RK |
8627 | if (GET_MODE (insn) == QImode) |
8628 | PUT_MODE (insn, VOIDmode); | |
8629 | ||
8630 | if (GET_RTX_CLASS (code) == 'i') | |
8631 | { | |
7bd8b2a8 JL |
8632 | rtx p; |
8633 | ||
7afe21cc RK |
8634 | /* Process notes first so we have all notes in canonical forms when |
8635 | looking for duplicate operations. */ | |
8636 | ||
8637 | if (REG_NOTES (insn)) | |
906c4e36 | 8638 | REG_NOTES (insn) = cse_process_notes (REG_NOTES (insn), NULL_RTX); |
7afe21cc RK |
8639 | |
8640 | /* Track when we are inside in LIBCALL block. Inside such a block, | |
8641 | we do not want to record destinations. The last insn of a | |
8642 | LIBCALL block is not considered to be part of the block, since | |
830a38ee | 8643 | its destination is the result of the block and hence should be |
7afe21cc RK |
8644 | recorded. */ |
8645 | ||
7bd8b2a8 JL |
8646 | if (p = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) |
8647 | libcall_insn = XEXP (p, 0); | |
906c4e36 | 8648 | else if (find_reg_note (insn, REG_RETVAL, NULL_RTX)) |
7bd8b2a8 | 8649 | libcall_insn = NULL_RTX; |
7afe21cc | 8650 | |
7bd8b2a8 | 8651 | cse_insn (insn, libcall_insn); |
7afe21cc RK |
8652 | } |
8653 | ||
8654 | /* If INSN is now an unconditional jump, skip to the end of our | |
8655 | basic block by pretending that we just did the last insn in the | |
8656 | basic block. If we are jumping to the end of our block, show | |
8657 | that we can have one usage of TO. */ | |
8658 | ||
8659 | if (simplejump_p (insn)) | |
8660 | { | |
8661 | if (to == 0) | |
8662 | return 0; | |
8663 | ||
8664 | if (JUMP_LABEL (insn) == to) | |
8665 | to_usage = 1; | |
8666 | ||
6a5293dc RS |
8667 | /* Maybe TO was deleted because the jump is unconditional. |
8668 | If so, there is nothing left in this basic block. */ | |
8669 | /* ??? Perhaps it would be smarter to set TO | |
8670 | to whatever follows this insn, | |
8671 | and pretend the basic block had always ended here. */ | |
8672 | if (INSN_DELETED_P (to)) | |
8673 | break; | |
8674 | ||
7afe21cc RK |
8675 | insn = PREV_INSN (to); |
8676 | } | |
8677 | ||
8678 | /* See if it is ok to keep on going past the label | |
8679 | which used to end our basic block. Remember that we incremented | |
d45cf215 | 8680 | the count of that label, so we decrement it here. If we made |
7afe21cc RK |
8681 | a jump unconditional, TO_USAGE will be one; in that case, we don't |
8682 | want to count the use in that jump. */ | |
8683 | ||
8684 | if (to != 0 && NEXT_INSN (insn) == to | |
8685 | && GET_CODE (to) == CODE_LABEL && --LABEL_NUSES (to) == to_usage) | |
8686 | { | |
8687 | struct cse_basic_block_data val; | |
146135d6 | 8688 | rtx prev; |
7afe21cc RK |
8689 | |
8690 | insn = NEXT_INSN (to); | |
8691 | ||
8692 | if (LABEL_NUSES (to) == 0) | |
146135d6 | 8693 | insn = delete_insn (to); |
7afe21cc | 8694 | |
146135d6 RK |
8695 | /* If TO was the last insn in the function, we are done. */ |
8696 | if (insn == 0) | |
7afe21cc RK |
8697 | return 0; |
8698 | ||
146135d6 RK |
8699 | /* If TO was preceded by a BARRIER we are done with this block |
8700 | because it has no continuation. */ | |
8701 | prev = prev_nonnote_insn (to); | |
8702 | if (prev && GET_CODE (prev) == BARRIER) | |
8703 | return insn; | |
8704 | ||
8705 | /* Find the end of the following block. Note that we won't be | |
8706 | following branches in this case. */ | |
7afe21cc RK |
8707 | to_usage = 0; |
8708 | val.path_size = 0; | |
8b3686ed | 8709 | cse_end_of_basic_block (insn, &val, 0, 0, 0); |
7afe21cc RK |
8710 | |
8711 | /* If the tables we allocated have enough space left | |
8712 | to handle all the SETs in the next basic block, | |
8713 | continue through it. Otherwise, return, | |
8714 | and that block will be scanned individually. */ | |
8715 | if (val.nsets * 2 + next_qty > max_qty) | |
8716 | break; | |
8717 | ||
8718 | cse_basic_block_start = val.low_cuid; | |
8719 | cse_basic_block_end = val.high_cuid; | |
8720 | to = val.last; | |
8721 | ||
8722 | /* Prevent TO from being deleted if it is a label. */ | |
8723 | if (to != 0 && GET_CODE (to) == CODE_LABEL) | |
8724 | ++LABEL_NUSES (to); | |
8725 | ||
8726 | /* Back up so we process the first insn in the extension. */ | |
8727 | insn = PREV_INSN (insn); | |
8728 | } | |
8729 | } | |
8730 | ||
8731 | if (next_qty > max_qty) | |
8732 | abort (); | |
8733 | ||
8734 | /* If we are running before loop.c, we stopped on a NOTE_INSN_LOOP_END, and | |
8735 | the previous insn is the only insn that branches to the head of a loop, | |
8736 | we can cse into the loop. Don't do this if we changed the jump | |
8737 | structure of a loop unless we aren't going to be following jumps. */ | |
8738 | ||
8b3686ed RK |
8739 | if ((cse_jumps_altered == 0 |
8740 | || (flag_cse_follow_jumps == 0 && flag_cse_skip_blocks == 0)) | |
7afe21cc RK |
8741 | && around_loop && to != 0 |
8742 | && GET_CODE (to) == NOTE && NOTE_LINE_NUMBER (to) == NOTE_INSN_LOOP_END | |
8743 | && GET_CODE (PREV_INSN (to)) == JUMP_INSN | |
8744 | && JUMP_LABEL (PREV_INSN (to)) != 0 | |
8745 | && LABEL_NUSES (JUMP_LABEL (PREV_INSN (to))) == 1) | |
8746 | cse_around_loop (JUMP_LABEL (PREV_INSN (to))); | |
8747 | ||
8748 | return to ? NEXT_INSN (to) : 0; | |
8749 | } | |
8750 | \f | |
8751 | /* Count the number of times registers are used (not set) in X. | |
8752 | COUNTS is an array in which we accumulate the count, INCR is how much | |
79644f06 RK |
8753 | we count each register usage. |
8754 | ||
8755 | Don't count a usage of DEST, which is the SET_DEST of a SET which | |
8756 | contains X in its SET_SRC. This is because such a SET does not | |
8757 | modify the liveness of DEST. */ | |
7afe21cc RK |
8758 | |
8759 | static void | |
79644f06 | 8760 | count_reg_usage (x, counts, dest, incr) |
7afe21cc RK |
8761 | rtx x; |
8762 | int *counts; | |
79644f06 | 8763 | rtx dest; |
7afe21cc RK |
8764 | int incr; |
8765 | { | |
f1e7c95f | 8766 | enum rtx_code code; |
7afe21cc RK |
8767 | char *fmt; |
8768 | int i, j; | |
8769 | ||
f1e7c95f RK |
8770 | if (x == 0) |
8771 | return; | |
8772 | ||
8773 | switch (code = GET_CODE (x)) | |
7afe21cc RK |
8774 | { |
8775 | case REG: | |
79644f06 RK |
8776 | if (x != dest) |
8777 | counts[REGNO (x)] += incr; | |
7afe21cc RK |
8778 | return; |
8779 | ||
8780 | case PC: | |
8781 | case CC0: | |
8782 | case CONST: | |
8783 | case CONST_INT: | |
8784 | case CONST_DOUBLE: | |
8785 | case SYMBOL_REF: | |
8786 | case LABEL_REF: | |
02e39abc JL |
8787 | return; |
8788 | ||
8789 | case CLOBBER: | |
8790 | /* If we are clobbering a MEM, mark any registers inside the address | |
8791 | as being used. */ | |
8792 | if (GET_CODE (XEXP (x, 0)) == MEM) | |
8793 | count_reg_usage (XEXP (XEXP (x, 0), 0), counts, NULL_RTX, incr); | |
7afe21cc RK |
8794 | return; |
8795 | ||
8796 | case SET: | |
8797 | /* Unless we are setting a REG, count everything in SET_DEST. */ | |
8798 | if (GET_CODE (SET_DEST (x)) != REG) | |
79644f06 | 8799 | count_reg_usage (SET_DEST (x), counts, NULL_RTX, incr); |
9ff08f70 RK |
8800 | |
8801 | /* If SRC has side-effects, then we can't delete this insn, so the | |
8802 | usage of SET_DEST inside SRC counts. | |
8803 | ||
8804 | ??? Strictly-speaking, we might be preserving this insn | |
8805 | because some other SET has side-effects, but that's hard | |
8806 | to do and can't happen now. */ | |
8807 | count_reg_usage (SET_SRC (x), counts, | |
8808 | side_effects_p (SET_SRC (x)) ? NULL_RTX : SET_DEST (x), | |
8809 | incr); | |
7afe21cc RK |
8810 | return; |
8811 | ||
f1e7c95f RK |
8812 | case CALL_INSN: |
8813 | count_reg_usage (CALL_INSN_FUNCTION_USAGE (x), counts, NULL_RTX, incr); | |
8814 | ||
8815 | /* ... falls through ... */ | |
7afe21cc RK |
8816 | case INSN: |
8817 | case JUMP_INSN: | |
79644f06 | 8818 | count_reg_usage (PATTERN (x), counts, NULL_RTX, incr); |
7afe21cc RK |
8819 | |
8820 | /* Things used in a REG_EQUAL note aren't dead since loop may try to | |
8821 | use them. */ | |
8822 | ||
f1e7c95f | 8823 | count_reg_usage (REG_NOTES (x), counts, NULL_RTX, incr); |
7afe21cc RK |
8824 | return; |
8825 | ||
8826 | case EXPR_LIST: | |
8827 | case INSN_LIST: | |
f1e7c95f | 8828 | if (REG_NOTE_KIND (x) == REG_EQUAL |
c6a26dc4 | 8829 | || (REG_NOTE_KIND (x) != REG_NONNEG && GET_CODE (XEXP (x,0)) == USE)) |
79644f06 | 8830 | count_reg_usage (XEXP (x, 0), counts, NULL_RTX, incr); |
f1e7c95f | 8831 | count_reg_usage (XEXP (x, 1), counts, NULL_RTX, incr); |
7afe21cc | 8832 | return; |
e9a25f70 JL |
8833 | |
8834 | default: | |
8835 | break; | |
7afe21cc RK |
8836 | } |
8837 | ||
8838 | fmt = GET_RTX_FORMAT (code); | |
8839 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
8840 | { | |
8841 | if (fmt[i] == 'e') | |
79644f06 | 8842 | count_reg_usage (XEXP (x, i), counts, dest, incr); |
7afe21cc RK |
8843 | else if (fmt[i] == 'E') |
8844 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
79644f06 | 8845 | count_reg_usage (XVECEXP (x, i, j), counts, dest, incr); |
7afe21cc RK |
8846 | } |
8847 | } | |
8848 | \f | |
8849 | /* Scan all the insns and delete any that are dead; i.e., they store a register | |
8850 | that is never used or they copy a register to itself. | |
8851 | ||
c6a26dc4 JL |
8852 | This is used to remove insns made obviously dead by cse, loop or other |
8853 | optimizations. It improves the heuristics in loop since it won't try to | |
8854 | move dead invariants out of loops or make givs for dead quantities. The | |
8855 | remaining passes of the compilation are also sped up. */ | |
7afe21cc RK |
8856 | |
8857 | void | |
c6a26dc4 | 8858 | delete_trivially_dead_insns (insns, nreg) |
7afe21cc RK |
8859 | rtx insns; |
8860 | int nreg; | |
8861 | { | |
8862 | int *counts = (int *) alloca (nreg * sizeof (int)); | |
77fa0940 | 8863 | rtx insn, prev; |
51723711 | 8864 | #ifdef HAVE_cc0 |
d45cf215 | 8865 | rtx tem; |
51723711 | 8866 | #endif |
7afe21cc | 8867 | int i; |
614bb5d4 | 8868 | int in_libcall = 0, dead_libcall = 0; |
7afe21cc RK |
8869 | |
8870 | /* First count the number of times each register is used. */ | |
4c9a05bc | 8871 | bzero ((char *) counts, sizeof (int) * nreg); |
7afe21cc | 8872 | for (insn = next_real_insn (insns); insn; insn = next_real_insn (insn)) |
79644f06 | 8873 | count_reg_usage (insn, counts, NULL_RTX, 1); |
7afe21cc RK |
8874 | |
8875 | /* Go from the last insn to the first and delete insns that only set unused | |
8876 | registers or copy a register to itself. As we delete an insn, remove | |
8877 | usage counts for registers it uses. */ | |
77fa0940 | 8878 | for (insn = prev_real_insn (get_last_insn ()); insn; insn = prev) |
7afe21cc RK |
8879 | { |
8880 | int live_insn = 0; | |
614bb5d4 | 8881 | rtx note; |
7afe21cc | 8882 | |
77fa0940 RK |
8883 | prev = prev_real_insn (insn); |
8884 | ||
614bb5d4 JL |
8885 | /* Don't delete any insns that are part of a libcall block unless |
8886 | we can delete the whole libcall block. | |
8887 | ||
77fa0940 RK |
8888 | Flow or loop might get confused if we did that. Remember |
8889 | that we are scanning backwards. */ | |
906c4e36 | 8890 | if (find_reg_note (insn, REG_RETVAL, NULL_RTX)) |
614bb5d4 JL |
8891 | { |
8892 | in_libcall = 1; | |
8893 | live_insn = 1; | |
8894 | dead_libcall = 0; | |
e4890d45 | 8895 | |
614bb5d4 JL |
8896 | /* See if there's a REG_EQUAL note on this insn and try to |
8897 | replace the source with the REG_EQUAL expression. | |
8898 | ||
8899 | We assume that insns with REG_RETVALs can only be reg->reg | |
8900 | copies at this point. */ | |
8901 | note = find_reg_note (insn, REG_EQUAL, NULL_RTX); | |
8902 | if (note) | |
8903 | { | |
8904 | rtx set = single_set (insn); | |
8905 | if (set | |
8906 | && validate_change (insn, &SET_SRC (set), XEXP (note, 0), 0)) | |
8907 | { | |
8908 | remove_note (insn, | |
8909 | find_reg_note (insn, REG_RETVAL, NULL_RTX)); | |
8910 | dead_libcall = 1; | |
8911 | } | |
8912 | } | |
8913 | } | |
8914 | else if (in_libcall) | |
8915 | live_insn = ! dead_libcall; | |
e4890d45 | 8916 | else if (GET_CODE (PATTERN (insn)) == SET) |
7afe21cc RK |
8917 | { |
8918 | if (GET_CODE (SET_DEST (PATTERN (insn))) == REG | |
8919 | && SET_DEST (PATTERN (insn)) == SET_SRC (PATTERN (insn))) | |
8920 | ; | |
8921 | ||
d45cf215 RS |
8922 | #ifdef HAVE_cc0 |
8923 | else if (GET_CODE (SET_DEST (PATTERN (insn))) == CC0 | |
8924 | && ! side_effects_p (SET_SRC (PATTERN (insn))) | |
8925 | && ((tem = next_nonnote_insn (insn)) == 0 | |
8926 | || GET_RTX_CLASS (GET_CODE (tem)) != 'i' | |
8927 | || ! reg_referenced_p (cc0_rtx, PATTERN (tem)))) | |
8928 | ; | |
8929 | #endif | |
7afe21cc RK |
8930 | else if (GET_CODE (SET_DEST (PATTERN (insn))) != REG |
8931 | || REGNO (SET_DEST (PATTERN (insn))) < FIRST_PSEUDO_REGISTER | |
8932 | || counts[REGNO (SET_DEST (PATTERN (insn)))] != 0 | |
8933 | || side_effects_p (SET_SRC (PATTERN (insn)))) | |
8934 | live_insn = 1; | |
8935 | } | |
8936 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
8937 | for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--) | |
8938 | { | |
8939 | rtx elt = XVECEXP (PATTERN (insn), 0, i); | |
8940 | ||
8941 | if (GET_CODE (elt) == SET) | |
8942 | { | |
8943 | if (GET_CODE (SET_DEST (elt)) == REG | |
8944 | && SET_DEST (elt) == SET_SRC (elt)) | |
8945 | ; | |
8946 | ||
d45cf215 RS |
8947 | #ifdef HAVE_cc0 |
8948 | else if (GET_CODE (SET_DEST (elt)) == CC0 | |
8949 | && ! side_effects_p (SET_SRC (elt)) | |
8950 | && ((tem = next_nonnote_insn (insn)) == 0 | |
8951 | || GET_RTX_CLASS (GET_CODE (tem)) != 'i' | |
8952 | || ! reg_referenced_p (cc0_rtx, PATTERN (tem)))) | |
8953 | ; | |
8954 | #endif | |
7afe21cc RK |
8955 | else if (GET_CODE (SET_DEST (elt)) != REG |
8956 | || REGNO (SET_DEST (elt)) < FIRST_PSEUDO_REGISTER | |
8957 | || counts[REGNO (SET_DEST (elt))] != 0 | |
8958 | || side_effects_p (SET_SRC (elt))) | |
8959 | live_insn = 1; | |
8960 | } | |
8961 | else if (GET_CODE (elt) != CLOBBER && GET_CODE (elt) != USE) | |
8962 | live_insn = 1; | |
8963 | } | |
8964 | else | |
8965 | live_insn = 1; | |
8966 | ||
8967 | /* If this is a dead insn, delete it and show registers in it aren't | |
e4890d45 | 8968 | being used. */ |
7afe21cc | 8969 | |
e4890d45 | 8970 | if (! live_insn) |
7afe21cc | 8971 | { |
79644f06 | 8972 | count_reg_usage (insn, counts, NULL_RTX, -1); |
77fa0940 | 8973 | delete_insn (insn); |
7afe21cc | 8974 | } |
e4890d45 | 8975 | |
906c4e36 | 8976 | if (find_reg_note (insn, REG_LIBCALL, NULL_RTX)) |
614bb5d4 JL |
8977 | { |
8978 | in_libcall = 0; | |
8979 | dead_libcall = 0; | |
8980 | } | |
7afe21cc RK |
8981 | } |
8982 | } |