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749a2da1 | 1 | /* RTL simplification functions for GNU compiler. |
af841dbd JL |
2 | Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, |
3 | 1999, 2000 Free Software Foundation, Inc. | |
0cedb36c JL |
4 | |
5 | This file is part of GNU CC. | |
6 | ||
7 | GNU CC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GNU CC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GNU CC; see the file COPYING. If not, write to | |
19 | the Free Software Foundation, 59 Temple Place - Suite 330, | |
20 | Boston, MA 02111-1307, USA. */ | |
21 | ||
22 | ||
23 | #include "config.h" | |
0cedb36c JL |
24 | #include "system.h" |
25 | #include <setjmp.h> | |
26 | ||
27 | #include "rtl.h" | |
28 | #include "tm_p.h" | |
29 | #include "regs.h" | |
30 | #include "hard-reg-set.h" | |
31 | #include "flags.h" | |
32 | #include "real.h" | |
33 | #include "insn-config.h" | |
34 | #include "recog.h" | |
35 | #include "function.h" | |
36 | #include "expr.h" | |
37 | #include "toplev.h" | |
38 | #include "output.h" | |
eab5c70a BS |
39 | #include "ggc.h" |
40 | #include "obstack.h" | |
41 | #include "hashtab.h" | |
42 | #include "cselib.h" | |
0cedb36c JL |
43 | |
44 | /* Simplification and canonicalization of RTL. */ | |
45 | ||
46 | /* Nonzero if X has the form (PLUS frame-pointer integer). We check for | |
47 | virtual regs here because the simplify_*_operation routines are called | |
48 | by integrate.c, which is called before virtual register instantiation. | |
49 | ||
50 | ?!? FIXED_BASE_PLUS_P and NONZERO_BASE_PLUS_P need to move into | |
51 | a header file so that their definitions can be shared with the | |
52 | simplification routines in simplify-rtx.c. Until then, do not | |
53 | change these macros without also changing the copy in simplify-rtx.c. */ | |
54 | ||
55 | #define FIXED_BASE_PLUS_P(X) \ | |
56 | ((X) == frame_pointer_rtx || (X) == hard_frame_pointer_rtx \ | |
57 | || ((X) == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM])\ | |
58 | || (X) == virtual_stack_vars_rtx \ | |
59 | || (X) == virtual_incoming_args_rtx \ | |
60 | || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \ | |
61 | && (XEXP (X, 0) == frame_pointer_rtx \ | |
62 | || XEXP (X, 0) == hard_frame_pointer_rtx \ | |
63 | || ((X) == arg_pointer_rtx \ | |
64 | && fixed_regs[ARG_POINTER_REGNUM]) \ | |
65 | || XEXP (X, 0) == virtual_stack_vars_rtx \ | |
66 | || XEXP (X, 0) == virtual_incoming_args_rtx)) \ | |
67 | || GET_CODE (X) == ADDRESSOF) | |
68 | ||
69 | /* Similar, but also allows reference to the stack pointer. | |
70 | ||
71 | This used to include FIXED_BASE_PLUS_P, however, we can't assume that | |
72 | arg_pointer_rtx by itself is nonzero, because on at least one machine, | |
73 | the i960, the arg pointer is zero when it is unused. */ | |
74 | ||
75 | #define NONZERO_BASE_PLUS_P(X) \ | |
76 | ((X) == frame_pointer_rtx || (X) == hard_frame_pointer_rtx \ | |
77 | || (X) == virtual_stack_vars_rtx \ | |
78 | || (X) == virtual_incoming_args_rtx \ | |
79 | || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \ | |
80 | && (XEXP (X, 0) == frame_pointer_rtx \ | |
81 | || XEXP (X, 0) == hard_frame_pointer_rtx \ | |
82 | || ((X) == arg_pointer_rtx \ | |
83 | && fixed_regs[ARG_POINTER_REGNUM]) \ | |
84 | || XEXP (X, 0) == virtual_stack_vars_rtx \ | |
85 | || XEXP (X, 0) == virtual_incoming_args_rtx)) \ | |
86 | || (X) == stack_pointer_rtx \ | |
87 | || (X) == virtual_stack_dynamic_rtx \ | |
88 | || (X) == virtual_outgoing_args_rtx \ | |
89 | || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \ | |
90 | && (XEXP (X, 0) == stack_pointer_rtx \ | |
91 | || XEXP (X, 0) == virtual_stack_dynamic_rtx \ | |
92 | || XEXP (X, 0) == virtual_outgoing_args_rtx)) \ | |
93 | || GET_CODE (X) == ADDRESSOF) | |
94 | ||
95 | ||
749a2da1 RK |
96 | static rtx simplify_plus_minus PARAMS ((enum rtx_code, |
97 | enum machine_mode, rtx, rtx)); | |
98 | static void check_fold_consts PARAMS ((PTR)); | |
99 | static int entry_and_rtx_equal_p PARAMS ((const void *, const void *)); | |
100 | static unsigned int get_value_hash PARAMS ((const void *)); | |
101 | static struct elt_list *new_elt_list PARAMS ((struct elt_list *, | |
102 | cselib_val *)); | |
103 | static struct elt_loc_list *new_elt_loc_list PARAMS ((struct elt_loc_list *, | |
104 | rtx)); | |
105 | static void unchain_one_value PARAMS ((cselib_val *)); | |
106 | static void unchain_one_elt_list PARAMS ((struct elt_list **)); | |
107 | static void unchain_one_elt_loc_list PARAMS ((struct elt_loc_list **)); | |
108 | static void clear_table PARAMS ((void)); | |
749a2da1 RK |
109 | static int discard_useless_locs PARAMS ((void **, void *)); |
110 | static int discard_useless_values PARAMS ((void **, void *)); | |
111 | static void remove_useless_values PARAMS ((void)); | |
112 | static unsigned int hash_rtx PARAMS ((rtx, enum machine_mode, int)); | |
113 | static cselib_val *new_cselib_val PARAMS ((unsigned int, | |
114 | enum machine_mode)); | |
115 | static void add_mem_for_addr PARAMS ((cselib_val *, cselib_val *, | |
116 | rtx)); | |
117 | static cselib_val *cselib_lookup_mem PARAMS ((rtx, int)); | |
118 | static rtx cselib_subst_to_values PARAMS ((rtx)); | |
119 | static void cselib_invalidate_regno PARAMS ((unsigned int, | |
120 | enum machine_mode)); | |
121 | static int cselib_mem_conflict_p PARAMS ((rtx, rtx)); | |
122 | static int cselib_invalidate_mem_1 PARAMS ((void **, void *)); | |
123 | static void cselib_invalidate_mem PARAMS ((rtx)); | |
124 | static void cselib_invalidate_rtx PARAMS ((rtx, rtx, void *)); | |
125 | static void cselib_record_set PARAMS ((rtx, cselib_val *, | |
126 | cselib_val *)); | |
127 | static void cselib_record_sets PARAMS ((rtx)); | |
128 | ||
129 | /* There are three ways in which cselib can look up an rtx: | |
130 | - for a REG, the reg_values table (which is indexed by regno) is used | |
131 | - for a MEM, we recursively look up its address and then follow the | |
132 | addr_list of that value | |
133 | - for everything else, we compute a hash value and go through the hash | |
134 | table. Since different rtx's can still have the same hash value, | |
135 | this involves walking the table entries for a given value and comparing | |
136 | the locations of the entries with the rtx we are looking up. */ | |
137 | ||
138 | /* A table that enables us to look up elts by their value. */ | |
139 | static htab_t hash_table; | |
140 | ||
141 | /* This is a global so we don't have to pass this through every function. | |
142 | It is used in new_elt_loc_list to set SETTING_INSN. */ | |
143 | static rtx cselib_current_insn; | |
144 | ||
145 | /* Every new unknown value gets a unique number. */ | |
146 | static unsigned int next_unknown_value; | |
0cedb36c | 147 | |
749a2da1 RK |
148 | /* The number of registers we had when the varrays were last resized. */ |
149 | static unsigned int cselib_nregs; | |
150 | ||
151 | /* Count values without known locations. Whenever this grows too big, we | |
152 | remove these useless values from the table. */ | |
153 | static int n_useless_values; | |
154 | ||
155 | /* Number of useless values before we remove them from the hash table. */ | |
156 | #define MAX_USELESS_VALUES 32 | |
157 | ||
158 | /* This table maps from register number to values. It does not contain | |
159 | pointers to cselib_val structures, but rather elt_lists. The purpose is | |
160 | to be able to refer to the same register in different modes. */ | |
161 | static varray_type reg_values; | |
162 | #define REG_VALUES(I) VARRAY_ELT_LIST (reg_values, (I)) | |
163 | ||
164 | /* We pass this to cselib_invalidate_mem to invalidate all of | |
165 | memory for a non-const call instruction. */ | |
166 | static rtx callmem; | |
167 | ||
168 | /* Memory for our structures is allocated from this obstack. */ | |
169 | static struct obstack cselib_obstack; | |
170 | ||
171 | /* Used to quickly free all memory. */ | |
172 | static char *cselib_startobj; | |
173 | ||
174 | /* Caches for unused structures. */ | |
175 | static cselib_val *empty_vals; | |
176 | static struct elt_list *empty_elt_lists; | |
177 | static struct elt_loc_list *empty_elt_loc_lists; | |
178 | ||
179 | /* Set by discard_useless_locs if it deleted the last location of any | |
180 | value. */ | |
181 | static int values_became_useless; | |
182 | \f | |
0cedb36c JL |
183 | /* Make a binary operation by properly ordering the operands and |
184 | seeing if the expression folds. */ | |
185 | ||
186 | rtx | |
187 | simplify_gen_binary (code, mode, op0, op1) | |
188 | enum rtx_code code; | |
189 | enum machine_mode mode; | |
190 | rtx op0, op1; | |
191 | { | |
192 | rtx tem; | |
193 | ||
194 | /* Put complex operands first and constants second if commutative. */ | |
195 | if (GET_RTX_CLASS (code) == 'c' | |
196 | && ((CONSTANT_P (op0) && GET_CODE (op1) != CONST_INT) | |
197 | || (GET_RTX_CLASS (GET_CODE (op0)) == 'o' | |
198 | && GET_RTX_CLASS (GET_CODE (op1)) != 'o') | |
199 | || (GET_CODE (op0) == SUBREG | |
200 | && GET_RTX_CLASS (GET_CODE (SUBREG_REG (op0))) == 'o' | |
201 | && GET_RTX_CLASS (GET_CODE (op1)) != 'o'))) | |
202 | tem = op0, op0 = op1, op1 = tem; | |
203 | ||
204 | /* If this simplifies, do it. */ | |
205 | tem = simplify_binary_operation (code, mode, op0, op1); | |
206 | ||
207 | if (tem) | |
208 | return tem; | |
209 | ||
210 | /* Handle addition and subtraction of CONST_INT specially. Otherwise, | |
211 | just form the operation. */ | |
212 | ||
213 | if (code == PLUS && GET_CODE (op1) == CONST_INT | |
214 | && GET_MODE (op0) != VOIDmode) | |
215 | return plus_constant (op0, INTVAL (op1)); | |
216 | else if (code == MINUS && GET_CODE (op1) == CONST_INT | |
217 | && GET_MODE (op0) != VOIDmode) | |
218 | return plus_constant (op0, - INTVAL (op1)); | |
219 | else | |
220 | return gen_rtx_fmt_ee (code, mode, op0, op1); | |
221 | } | |
222 | \f | |
223 | /* Try to simplify a unary operation CODE whose output mode is to be | |
224 | MODE with input operand OP whose mode was originally OP_MODE. | |
225 | Return zero if no simplification can be made. */ | |
226 | ||
227 | rtx | |
228 | simplify_unary_operation (code, mode, op, op_mode) | |
229 | enum rtx_code code; | |
230 | enum machine_mode mode; | |
231 | rtx op; | |
232 | enum machine_mode op_mode; | |
233 | { | |
770ae6cc | 234 | unsigned int width = GET_MODE_BITSIZE (mode); |
0cedb36c JL |
235 | |
236 | /* The order of these tests is critical so that, for example, we don't | |
237 | check the wrong mode (input vs. output) for a conversion operation, | |
238 | such as FIX. At some point, this should be simplified. */ | |
239 | ||
240 | #if !defined(REAL_IS_NOT_DOUBLE) || defined(REAL_ARITHMETIC) | |
241 | ||
242 | if (code == FLOAT && GET_MODE (op) == VOIDmode | |
243 | && (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT)) | |
244 | { | |
245 | HOST_WIDE_INT hv, lv; | |
246 | REAL_VALUE_TYPE d; | |
247 | ||
248 | if (GET_CODE (op) == CONST_INT) | |
249 | lv = INTVAL (op), hv = INTVAL (op) < 0 ? -1 : 0; | |
250 | else | |
251 | lv = CONST_DOUBLE_LOW (op), hv = CONST_DOUBLE_HIGH (op); | |
252 | ||
253 | #ifdef REAL_ARITHMETIC | |
254 | REAL_VALUE_FROM_INT (d, lv, hv, mode); | |
255 | #else | |
256 | if (hv < 0) | |
257 | { | |
258 | d = (double) (~ hv); | |
259 | d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) | |
260 | * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))); | |
261 | d += (double) (unsigned HOST_WIDE_INT) (~ lv); | |
262 | d = (- d - 1.0); | |
263 | } | |
264 | else | |
265 | { | |
266 | d = (double) hv; | |
267 | d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) | |
268 | * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))); | |
269 | d += (double) (unsigned HOST_WIDE_INT) lv; | |
270 | } | |
271 | #endif /* REAL_ARITHMETIC */ | |
272 | d = real_value_truncate (mode, d); | |
273 | return CONST_DOUBLE_FROM_REAL_VALUE (d, mode); | |
274 | } | |
275 | else if (code == UNSIGNED_FLOAT && GET_MODE (op) == VOIDmode | |
276 | && (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT)) | |
277 | { | |
278 | HOST_WIDE_INT hv, lv; | |
279 | REAL_VALUE_TYPE d; | |
280 | ||
281 | if (GET_CODE (op) == CONST_INT) | |
282 | lv = INTVAL (op), hv = INTVAL (op) < 0 ? -1 : 0; | |
283 | else | |
284 | lv = CONST_DOUBLE_LOW (op), hv = CONST_DOUBLE_HIGH (op); | |
285 | ||
286 | if (op_mode == VOIDmode) | |
287 | { | |
288 | /* We don't know how to interpret negative-looking numbers in | |
289 | this case, so don't try to fold those. */ | |
290 | if (hv < 0) | |
291 | return 0; | |
292 | } | |
293 | else if (GET_MODE_BITSIZE (op_mode) >= HOST_BITS_PER_WIDE_INT * 2) | |
294 | ; | |
295 | else | |
296 | hv = 0, lv &= GET_MODE_MASK (op_mode); | |
297 | ||
298 | #ifdef REAL_ARITHMETIC | |
299 | REAL_VALUE_FROM_UNSIGNED_INT (d, lv, hv, mode); | |
300 | #else | |
301 | ||
302 | d = (double) (unsigned HOST_WIDE_INT) hv; | |
303 | d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) | |
304 | * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))); | |
305 | d += (double) (unsigned HOST_WIDE_INT) lv; | |
306 | #endif /* REAL_ARITHMETIC */ | |
307 | d = real_value_truncate (mode, d); | |
308 | return CONST_DOUBLE_FROM_REAL_VALUE (d, mode); | |
309 | } | |
310 | #endif | |
311 | ||
312 | if (GET_CODE (op) == CONST_INT | |
313 | && width <= HOST_BITS_PER_WIDE_INT && width > 0) | |
314 | { | |
315 | register HOST_WIDE_INT arg0 = INTVAL (op); | |
316 | register HOST_WIDE_INT val; | |
317 | ||
318 | switch (code) | |
319 | { | |
320 | case NOT: | |
321 | val = ~ arg0; | |
322 | break; | |
323 | ||
324 | case NEG: | |
325 | val = - arg0; | |
326 | break; | |
327 | ||
328 | case ABS: | |
329 | val = (arg0 >= 0 ? arg0 : - arg0); | |
330 | break; | |
331 | ||
332 | case FFS: | |
333 | /* Don't use ffs here. Instead, get low order bit and then its | |
334 | number. If arg0 is zero, this will return 0, as desired. */ | |
335 | arg0 &= GET_MODE_MASK (mode); | |
336 | val = exact_log2 (arg0 & (- arg0)) + 1; | |
337 | break; | |
338 | ||
339 | case TRUNCATE: | |
340 | val = arg0; | |
341 | break; | |
342 | ||
343 | case ZERO_EXTEND: | |
344 | if (op_mode == VOIDmode) | |
345 | op_mode = mode; | |
346 | if (GET_MODE_BITSIZE (op_mode) == HOST_BITS_PER_WIDE_INT) | |
347 | { | |
348 | /* If we were really extending the mode, | |
349 | we would have to distinguish between zero-extension | |
350 | and sign-extension. */ | |
351 | if (width != GET_MODE_BITSIZE (op_mode)) | |
352 | abort (); | |
353 | val = arg0; | |
354 | } | |
355 | else if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT) | |
356 | val = arg0 & ~((HOST_WIDE_INT) (-1) << GET_MODE_BITSIZE (op_mode)); | |
357 | else | |
358 | return 0; | |
359 | break; | |
360 | ||
361 | case SIGN_EXTEND: | |
362 | if (op_mode == VOIDmode) | |
363 | op_mode = mode; | |
364 | if (GET_MODE_BITSIZE (op_mode) == HOST_BITS_PER_WIDE_INT) | |
365 | { | |
366 | /* If we were really extending the mode, | |
367 | we would have to distinguish between zero-extension | |
368 | and sign-extension. */ | |
369 | if (width != GET_MODE_BITSIZE (op_mode)) | |
370 | abort (); | |
371 | val = arg0; | |
372 | } | |
373 | else if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT) | |
374 | { | |
375 | val | |
376 | = arg0 & ~((HOST_WIDE_INT) (-1) << GET_MODE_BITSIZE (op_mode)); | |
377 | if (val | |
378 | & ((HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (op_mode) - 1))) | |
379 | val -= (HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (op_mode); | |
380 | } | |
381 | else | |
382 | return 0; | |
383 | break; | |
384 | ||
385 | case SQRT: | |
386 | return 0; | |
387 | ||
388 | default: | |
389 | abort (); | |
390 | } | |
391 | ||
392 | val = trunc_int_for_mode (val, mode); | |
393 | ||
394 | return GEN_INT (val); | |
395 | } | |
396 | ||
397 | /* We can do some operations on integer CONST_DOUBLEs. Also allow | |
398 | for a DImode operation on a CONST_INT. */ | |
399 | else if (GET_MODE (op) == VOIDmode && width <= HOST_BITS_PER_INT * 2 | |
400 | && (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT)) | |
401 | { | |
402 | HOST_WIDE_INT l1, h1, lv, hv; | |
403 | ||
404 | if (GET_CODE (op) == CONST_DOUBLE) | |
405 | l1 = CONST_DOUBLE_LOW (op), h1 = CONST_DOUBLE_HIGH (op); | |
406 | else | |
407 | l1 = INTVAL (op), h1 = l1 < 0 ? -1 : 0; | |
408 | ||
409 | switch (code) | |
410 | { | |
411 | case NOT: | |
412 | lv = ~ l1; | |
413 | hv = ~ h1; | |
414 | break; | |
415 | ||
416 | case NEG: | |
417 | neg_double (l1, h1, &lv, &hv); | |
418 | break; | |
419 | ||
420 | case ABS: | |
421 | if (h1 < 0) | |
422 | neg_double (l1, h1, &lv, &hv); | |
423 | else | |
424 | lv = l1, hv = h1; | |
425 | break; | |
426 | ||
427 | case FFS: | |
428 | hv = 0; | |
429 | if (l1 == 0) | |
430 | lv = HOST_BITS_PER_WIDE_INT + exact_log2 (h1 & (-h1)) + 1; | |
431 | else | |
432 | lv = exact_log2 (l1 & (-l1)) + 1; | |
433 | break; | |
434 | ||
435 | case TRUNCATE: | |
436 | /* This is just a change-of-mode, so do nothing. */ | |
437 | lv = l1, hv = h1; | |
438 | break; | |
439 | ||
440 | case ZERO_EXTEND: | |
441 | if (op_mode == VOIDmode | |
442 | || GET_MODE_BITSIZE (op_mode) > HOST_BITS_PER_WIDE_INT) | |
443 | return 0; | |
444 | ||
445 | hv = 0; | |
446 | lv = l1 & GET_MODE_MASK (op_mode); | |
447 | break; | |
448 | ||
449 | case SIGN_EXTEND: | |
450 | if (op_mode == VOIDmode | |
451 | || GET_MODE_BITSIZE (op_mode) > HOST_BITS_PER_WIDE_INT) | |
452 | return 0; | |
453 | else | |
454 | { | |
455 | lv = l1 & GET_MODE_MASK (op_mode); | |
456 | if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT | |
457 | && (lv & ((HOST_WIDE_INT) 1 | |
458 | << (GET_MODE_BITSIZE (op_mode) - 1))) != 0) | |
459 | lv -= (HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (op_mode); | |
460 | ||
461 | hv = (lv < 0) ? ~ (HOST_WIDE_INT) 0 : 0; | |
462 | } | |
463 | break; | |
464 | ||
465 | case SQRT: | |
466 | return 0; | |
467 | ||
468 | default: | |
469 | return 0; | |
470 | } | |
471 | ||
472 | return immed_double_const (lv, hv, mode); | |
473 | } | |
474 | ||
475 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
476 | else if (GET_CODE (op) == CONST_DOUBLE | |
477 | && GET_MODE_CLASS (mode) == MODE_FLOAT) | |
478 | { | |
479 | REAL_VALUE_TYPE d; | |
480 | jmp_buf handler; | |
481 | rtx x; | |
482 | ||
483 | if (setjmp (handler)) | |
484 | /* There used to be a warning here, but that is inadvisable. | |
485 | People may want to cause traps, and the natural way | |
486 | to do it should not get a warning. */ | |
487 | return 0; | |
488 | ||
489 | set_float_handler (handler); | |
490 | ||
491 | REAL_VALUE_FROM_CONST_DOUBLE (d, op); | |
492 | ||
493 | switch (code) | |
494 | { | |
495 | case NEG: | |
496 | d = REAL_VALUE_NEGATE (d); | |
497 | break; | |
498 | ||
499 | case ABS: | |
500 | if (REAL_VALUE_NEGATIVE (d)) | |
501 | d = REAL_VALUE_NEGATE (d); | |
502 | break; | |
503 | ||
504 | case FLOAT_TRUNCATE: | |
505 | d = real_value_truncate (mode, d); | |
506 | break; | |
507 | ||
508 | case FLOAT_EXTEND: | |
509 | /* All this does is change the mode. */ | |
510 | break; | |
511 | ||
512 | case FIX: | |
513 | d = REAL_VALUE_RNDZINT (d); | |
514 | break; | |
515 | ||
516 | case UNSIGNED_FIX: | |
517 | d = REAL_VALUE_UNSIGNED_RNDZINT (d); | |
518 | break; | |
519 | ||
520 | case SQRT: | |
521 | return 0; | |
522 | ||
523 | default: | |
524 | abort (); | |
525 | } | |
526 | ||
527 | x = CONST_DOUBLE_FROM_REAL_VALUE (d, mode); | |
528 | set_float_handler (NULL_PTR); | |
529 | return x; | |
530 | } | |
531 | ||
532 | else if (GET_CODE (op) == CONST_DOUBLE | |
533 | && GET_MODE_CLASS (GET_MODE (op)) == MODE_FLOAT | |
534 | && GET_MODE_CLASS (mode) == MODE_INT | |
535 | && width <= HOST_BITS_PER_WIDE_INT && width > 0) | |
536 | { | |
537 | REAL_VALUE_TYPE d; | |
538 | jmp_buf handler; | |
539 | HOST_WIDE_INT val; | |
540 | ||
541 | if (setjmp (handler)) | |
542 | return 0; | |
543 | ||
544 | set_float_handler (handler); | |
545 | ||
546 | REAL_VALUE_FROM_CONST_DOUBLE (d, op); | |
547 | ||
548 | switch (code) | |
549 | { | |
550 | case FIX: | |
551 | val = REAL_VALUE_FIX (d); | |
552 | break; | |
553 | ||
554 | case UNSIGNED_FIX: | |
555 | val = REAL_VALUE_UNSIGNED_FIX (d); | |
556 | break; | |
557 | ||
558 | default: | |
559 | abort (); | |
560 | } | |
561 | ||
562 | set_float_handler (NULL_PTR); | |
563 | ||
564 | val = trunc_int_for_mode (val, mode); | |
565 | ||
566 | return GEN_INT (val); | |
567 | } | |
568 | #endif | |
569 | /* This was formerly used only for non-IEEE float. | |
570 | eggert@twinsun.com says it is safe for IEEE also. */ | |
571 | else | |
572 | { | |
573 | /* There are some simplifications we can do even if the operands | |
574 | aren't constant. */ | |
575 | switch (code) | |
576 | { | |
577 | case NEG: | |
578 | case NOT: | |
579 | /* (not (not X)) == X, similarly for NEG. */ | |
580 | if (GET_CODE (op) == code) | |
581 | return XEXP (op, 0); | |
582 | break; | |
583 | ||
584 | case SIGN_EXTEND: | |
585 | /* (sign_extend (truncate (minus (label_ref L1) (label_ref L2)))) | |
586 | becomes just the MINUS if its mode is MODE. This allows | |
587 | folding switch statements on machines using casesi (such as | |
588 | the Vax). */ | |
589 | if (GET_CODE (op) == TRUNCATE | |
590 | && GET_MODE (XEXP (op, 0)) == mode | |
591 | && GET_CODE (XEXP (op, 0)) == MINUS | |
592 | && GET_CODE (XEXP (XEXP (op, 0), 0)) == LABEL_REF | |
593 | && GET_CODE (XEXP (XEXP (op, 0), 1)) == LABEL_REF) | |
594 | return XEXP (op, 0); | |
595 | ||
596 | #ifdef POINTERS_EXTEND_UNSIGNED | |
597 | if (! POINTERS_EXTEND_UNSIGNED | |
598 | && mode == Pmode && GET_MODE (op) == ptr_mode | |
599 | && CONSTANT_P (op)) | |
600 | return convert_memory_address (Pmode, op); | |
601 | #endif | |
602 | break; | |
603 | ||
604 | #ifdef POINTERS_EXTEND_UNSIGNED | |
605 | case ZERO_EXTEND: | |
606 | if (POINTERS_EXTEND_UNSIGNED | |
607 | && mode == Pmode && GET_MODE (op) == ptr_mode | |
608 | && CONSTANT_P (op)) | |
609 | return convert_memory_address (Pmode, op); | |
610 | break; | |
611 | #endif | |
612 | ||
613 | default: | |
614 | break; | |
615 | } | |
616 | ||
617 | return 0; | |
618 | } | |
619 | } | |
620 | \f | |
621 | /* Simplify a binary operation CODE with result mode MODE, operating on OP0 | |
622 | and OP1. Return 0 if no simplification is possible. | |
623 | ||
624 | Don't use this for relational operations such as EQ or LT. | |
625 | Use simplify_relational_operation instead. */ | |
626 | ||
627 | rtx | |
628 | simplify_binary_operation (code, mode, op0, op1) | |
629 | enum rtx_code code; | |
630 | enum machine_mode mode; | |
631 | rtx op0, op1; | |
632 | { | |
633 | register HOST_WIDE_INT arg0, arg1, arg0s, arg1s; | |
634 | HOST_WIDE_INT val; | |
770ae6cc | 635 | unsigned int width = GET_MODE_BITSIZE (mode); |
0cedb36c JL |
636 | rtx tem; |
637 | ||
638 | /* Relational operations don't work here. We must know the mode | |
639 | of the operands in order to do the comparison correctly. | |
640 | Assuming a full word can give incorrect results. | |
641 | Consider comparing 128 with -128 in QImode. */ | |
642 | ||
643 | if (GET_RTX_CLASS (code) == '<') | |
644 | abort (); | |
645 | ||
646 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
647 | if (GET_MODE_CLASS (mode) == MODE_FLOAT | |
648 | && GET_CODE (op0) == CONST_DOUBLE && GET_CODE (op1) == CONST_DOUBLE | |
649 | && mode == GET_MODE (op0) && mode == GET_MODE (op1)) | |
650 | { | |
651 | REAL_VALUE_TYPE f0, f1, value; | |
652 | jmp_buf handler; | |
653 | ||
654 | if (setjmp (handler)) | |
655 | return 0; | |
656 | ||
657 | set_float_handler (handler); | |
658 | ||
659 | REAL_VALUE_FROM_CONST_DOUBLE (f0, op0); | |
660 | REAL_VALUE_FROM_CONST_DOUBLE (f1, op1); | |
661 | f0 = real_value_truncate (mode, f0); | |
662 | f1 = real_value_truncate (mode, f1); | |
663 | ||
664 | #ifdef REAL_ARITHMETIC | |
665 | #ifndef REAL_INFINITY | |
666 | if (code == DIV && REAL_VALUES_EQUAL (f1, dconst0)) | |
667 | return 0; | |
668 | #endif | |
669 | REAL_ARITHMETIC (value, rtx_to_tree_code (code), f0, f1); | |
670 | #else | |
671 | switch (code) | |
672 | { | |
673 | case PLUS: | |
674 | value = f0 + f1; | |
675 | break; | |
676 | case MINUS: | |
677 | value = f0 - f1; | |
678 | break; | |
679 | case MULT: | |
680 | value = f0 * f1; | |
681 | break; | |
682 | case DIV: | |
683 | #ifndef REAL_INFINITY | |
684 | if (f1 == 0) | |
685 | return 0; | |
686 | #endif | |
687 | value = f0 / f1; | |
688 | break; | |
689 | case SMIN: | |
690 | value = MIN (f0, f1); | |
691 | break; | |
692 | case SMAX: | |
693 | value = MAX (f0, f1); | |
694 | break; | |
695 | default: | |
696 | abort (); | |
697 | } | |
698 | #endif | |
699 | ||
700 | value = real_value_truncate (mode, value); | |
701 | set_float_handler (NULL_PTR); | |
702 | return CONST_DOUBLE_FROM_REAL_VALUE (value, mode); | |
703 | } | |
704 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
705 | ||
706 | /* We can fold some multi-word operations. */ | |
707 | if (GET_MODE_CLASS (mode) == MODE_INT | |
708 | && width == HOST_BITS_PER_WIDE_INT * 2 | |
709 | && (GET_CODE (op0) == CONST_DOUBLE || GET_CODE (op0) == CONST_INT) | |
710 | && (GET_CODE (op1) == CONST_DOUBLE || GET_CODE (op1) == CONST_INT)) | |
711 | { | |
712 | HOST_WIDE_INT l1, l2, h1, h2, lv, hv; | |
713 | ||
714 | if (GET_CODE (op0) == CONST_DOUBLE) | |
715 | l1 = CONST_DOUBLE_LOW (op0), h1 = CONST_DOUBLE_HIGH (op0); | |
716 | else | |
717 | l1 = INTVAL (op0), h1 = l1 < 0 ? -1 : 0; | |
718 | ||
719 | if (GET_CODE (op1) == CONST_DOUBLE) | |
720 | l2 = CONST_DOUBLE_LOW (op1), h2 = CONST_DOUBLE_HIGH (op1); | |
721 | else | |
722 | l2 = INTVAL (op1), h2 = l2 < 0 ? -1 : 0; | |
723 | ||
724 | switch (code) | |
725 | { | |
726 | case MINUS: | |
727 | /* A - B == A + (-B). */ | |
728 | neg_double (l2, h2, &lv, &hv); | |
729 | l2 = lv, h2 = hv; | |
730 | ||
731 | /* .. fall through ... */ | |
732 | ||
733 | case PLUS: | |
734 | add_double (l1, h1, l2, h2, &lv, &hv); | |
735 | break; | |
736 | ||
737 | case MULT: | |
738 | mul_double (l1, h1, l2, h2, &lv, &hv); | |
739 | break; | |
740 | ||
741 | case DIV: case MOD: case UDIV: case UMOD: | |
742 | /* We'd need to include tree.h to do this and it doesn't seem worth | |
743 | it. */ | |
744 | return 0; | |
745 | ||
746 | case AND: | |
747 | lv = l1 & l2, hv = h1 & h2; | |
748 | break; | |
749 | ||
750 | case IOR: | |
751 | lv = l1 | l2, hv = h1 | h2; | |
752 | break; | |
753 | ||
754 | case XOR: | |
755 | lv = l1 ^ l2, hv = h1 ^ h2; | |
756 | break; | |
757 | ||
758 | case SMIN: | |
759 | if (h1 < h2 | |
760 | || (h1 == h2 | |
761 | && ((unsigned HOST_WIDE_INT) l1 | |
762 | < (unsigned HOST_WIDE_INT) l2))) | |
763 | lv = l1, hv = h1; | |
764 | else | |
765 | lv = l2, hv = h2; | |
766 | break; | |
767 | ||
768 | case SMAX: | |
769 | if (h1 > h2 | |
770 | || (h1 == h2 | |
771 | && ((unsigned HOST_WIDE_INT) l1 | |
772 | > (unsigned HOST_WIDE_INT) l2))) | |
773 | lv = l1, hv = h1; | |
774 | else | |
775 | lv = l2, hv = h2; | |
776 | break; | |
777 | ||
778 | case UMIN: | |
779 | if ((unsigned HOST_WIDE_INT) h1 < (unsigned HOST_WIDE_INT) h2 | |
780 | || (h1 == h2 | |
781 | && ((unsigned HOST_WIDE_INT) l1 | |
782 | < (unsigned HOST_WIDE_INT) l2))) | |
783 | lv = l1, hv = h1; | |
784 | else | |
785 | lv = l2, hv = h2; | |
786 | break; | |
787 | ||
788 | case UMAX: | |
789 | if ((unsigned HOST_WIDE_INT) h1 > (unsigned HOST_WIDE_INT) h2 | |
790 | || (h1 == h2 | |
791 | && ((unsigned HOST_WIDE_INT) l1 | |
792 | > (unsigned HOST_WIDE_INT) l2))) | |
793 | lv = l1, hv = h1; | |
794 | else | |
795 | lv = l2, hv = h2; | |
796 | break; | |
797 | ||
798 | case LSHIFTRT: case ASHIFTRT: | |
799 | case ASHIFT: | |
800 | case ROTATE: case ROTATERT: | |
801 | #ifdef SHIFT_COUNT_TRUNCATED | |
802 | if (SHIFT_COUNT_TRUNCATED) | |
803 | l2 &= (GET_MODE_BITSIZE (mode) - 1), h2 = 0; | |
804 | #endif | |
805 | ||
806 | if (h2 != 0 || l2 < 0 || l2 >= GET_MODE_BITSIZE (mode)) | |
807 | return 0; | |
808 | ||
809 | if (code == LSHIFTRT || code == ASHIFTRT) | |
810 | rshift_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv, | |
811 | code == ASHIFTRT); | |
812 | else if (code == ASHIFT) | |
813 | lshift_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv, 1); | |
814 | else if (code == ROTATE) | |
815 | lrotate_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv); | |
816 | else /* code == ROTATERT */ | |
817 | rrotate_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv); | |
818 | break; | |
819 | ||
820 | default: | |
821 | return 0; | |
822 | } | |
823 | ||
824 | return immed_double_const (lv, hv, mode); | |
825 | } | |
826 | ||
827 | if (GET_CODE (op0) != CONST_INT || GET_CODE (op1) != CONST_INT | |
828 | || width > HOST_BITS_PER_WIDE_INT || width == 0) | |
829 | { | |
830 | /* Even if we can't compute a constant result, | |
831 | there are some cases worth simplifying. */ | |
832 | ||
833 | switch (code) | |
834 | { | |
835 | case PLUS: | |
836 | /* In IEEE floating point, x+0 is not the same as x. Similarly | |
837 | for the other optimizations below. */ | |
838 | if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT | |
839 | && FLOAT_MODE_P (mode) && ! flag_fast_math) | |
840 | break; | |
841 | ||
842 | if (op1 == CONST0_RTX (mode)) | |
843 | return op0; | |
844 | ||
845 | /* ((-a) + b) -> (b - a) and similarly for (a + (-b)) */ | |
846 | if (GET_CODE (op0) == NEG) | |
847 | return simplify_gen_binary (MINUS, mode, op1, XEXP (op0, 0)); | |
848 | else if (GET_CODE (op1) == NEG) | |
849 | return simplify_gen_binary (MINUS, mode, op0, XEXP (op1, 0)); | |
850 | ||
851 | /* Handle both-operands-constant cases. We can only add | |
852 | CONST_INTs to constants since the sum of relocatable symbols | |
853 | can't be handled by most assemblers. Don't add CONST_INT | |
854 | to CONST_INT since overflow won't be computed properly if wider | |
855 | than HOST_BITS_PER_WIDE_INT. */ | |
856 | ||
857 | if (CONSTANT_P (op0) && GET_MODE (op0) != VOIDmode | |
858 | && GET_CODE (op1) == CONST_INT) | |
859 | return plus_constant (op0, INTVAL (op1)); | |
860 | else if (CONSTANT_P (op1) && GET_MODE (op1) != VOIDmode | |
861 | && GET_CODE (op0) == CONST_INT) | |
862 | return plus_constant (op1, INTVAL (op0)); | |
863 | ||
864 | /* See if this is something like X * C - X or vice versa or | |
865 | if the multiplication is written as a shift. If so, we can | |
866 | distribute and make a new multiply, shift, or maybe just | |
867 | have X (if C is 2 in the example above). But don't make | |
868 | real multiply if we didn't have one before. */ | |
869 | ||
870 | if (! FLOAT_MODE_P (mode)) | |
871 | { | |
872 | HOST_WIDE_INT coeff0 = 1, coeff1 = 1; | |
873 | rtx lhs = op0, rhs = op1; | |
874 | int had_mult = 0; | |
875 | ||
876 | if (GET_CODE (lhs) == NEG) | |
877 | coeff0 = -1, lhs = XEXP (lhs, 0); | |
878 | else if (GET_CODE (lhs) == MULT | |
879 | && GET_CODE (XEXP (lhs, 1)) == CONST_INT) | |
880 | { | |
881 | coeff0 = INTVAL (XEXP (lhs, 1)), lhs = XEXP (lhs, 0); | |
882 | had_mult = 1; | |
883 | } | |
884 | else if (GET_CODE (lhs) == ASHIFT | |
885 | && GET_CODE (XEXP (lhs, 1)) == CONST_INT | |
886 | && INTVAL (XEXP (lhs, 1)) >= 0 | |
887 | && INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT) | |
888 | { | |
889 | coeff0 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1)); | |
890 | lhs = XEXP (lhs, 0); | |
891 | } | |
892 | ||
893 | if (GET_CODE (rhs) == NEG) | |
894 | coeff1 = -1, rhs = XEXP (rhs, 0); | |
895 | else if (GET_CODE (rhs) == MULT | |
896 | && GET_CODE (XEXP (rhs, 1)) == CONST_INT) | |
897 | { | |
898 | coeff1 = INTVAL (XEXP (rhs, 1)), rhs = XEXP (rhs, 0); | |
899 | had_mult = 1; | |
900 | } | |
901 | else if (GET_CODE (rhs) == ASHIFT | |
902 | && GET_CODE (XEXP (rhs, 1)) == CONST_INT | |
903 | && INTVAL (XEXP (rhs, 1)) >= 0 | |
904 | && INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT) | |
905 | { | |
906 | coeff1 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1)); | |
907 | rhs = XEXP (rhs, 0); | |
908 | } | |
909 | ||
910 | if (rtx_equal_p (lhs, rhs)) | |
911 | { | |
912 | tem = simplify_gen_binary (MULT, mode, lhs, | |
913 | GEN_INT (coeff0 + coeff1)); | |
914 | return (GET_CODE (tem) == MULT && ! had_mult) ? 0 : tem; | |
915 | } | |
916 | } | |
917 | ||
918 | /* If one of the operands is a PLUS or a MINUS, see if we can | |
919 | simplify this by the associative law. | |
920 | Don't use the associative law for floating point. | |
921 | The inaccuracy makes it nonassociative, | |
922 | and subtle programs can break if operations are associated. */ | |
923 | ||
924 | if (INTEGRAL_MODE_P (mode) | |
925 | && (GET_CODE (op0) == PLUS || GET_CODE (op0) == MINUS | |
926 | || GET_CODE (op1) == PLUS || GET_CODE (op1) == MINUS) | |
927 | && (tem = simplify_plus_minus (code, mode, op0, op1)) != 0) | |
928 | return tem; | |
929 | break; | |
930 | ||
931 | case COMPARE: | |
932 | #ifdef HAVE_cc0 | |
933 | /* Convert (compare FOO (const_int 0)) to FOO unless we aren't | |
934 | using cc0, in which case we want to leave it as a COMPARE | |
935 | so we can distinguish it from a register-register-copy. | |
936 | ||
937 | In IEEE floating point, x-0 is not the same as x. */ | |
938 | ||
939 | if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
940 | || ! FLOAT_MODE_P (mode) || flag_fast_math) | |
941 | && op1 == CONST0_RTX (mode)) | |
942 | return op0; | |
943 | #else | |
944 | /* Do nothing here. */ | |
945 | #endif | |
946 | break; | |
947 | ||
948 | case MINUS: | |
949 | /* None of these optimizations can be done for IEEE | |
950 | floating point. */ | |
951 | if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT | |
952 | && FLOAT_MODE_P (mode) && ! flag_fast_math) | |
953 | break; | |
954 | ||
955 | /* We can't assume x-x is 0 even with non-IEEE floating point, | |
956 | but since it is zero except in very strange circumstances, we | |
957 | will treat it as zero with -ffast-math. */ | |
958 | if (rtx_equal_p (op0, op1) | |
959 | && ! side_effects_p (op0) | |
960 | && (! FLOAT_MODE_P (mode) || flag_fast_math)) | |
961 | return CONST0_RTX (mode); | |
962 | ||
963 | /* Change subtraction from zero into negation. */ | |
964 | if (op0 == CONST0_RTX (mode)) | |
965 | return gen_rtx_NEG (mode, op1); | |
966 | ||
967 | /* (-1 - a) is ~a. */ | |
968 | if (op0 == constm1_rtx) | |
969 | return gen_rtx_NOT (mode, op1); | |
970 | ||
971 | /* Subtracting 0 has no effect. */ | |
972 | if (op1 == CONST0_RTX (mode)) | |
973 | return op0; | |
974 | ||
975 | /* See if this is something like X * C - X or vice versa or | |
976 | if the multiplication is written as a shift. If so, we can | |
977 | distribute and make a new multiply, shift, or maybe just | |
978 | have X (if C is 2 in the example above). But don't make | |
979 | real multiply if we didn't have one before. */ | |
980 | ||
981 | if (! FLOAT_MODE_P (mode)) | |
982 | { | |
983 | HOST_WIDE_INT coeff0 = 1, coeff1 = 1; | |
984 | rtx lhs = op0, rhs = op1; | |
985 | int had_mult = 0; | |
986 | ||
987 | if (GET_CODE (lhs) == NEG) | |
988 | coeff0 = -1, lhs = XEXP (lhs, 0); | |
989 | else if (GET_CODE (lhs) == MULT | |
990 | && GET_CODE (XEXP (lhs, 1)) == CONST_INT) | |
991 | { | |
992 | coeff0 = INTVAL (XEXP (lhs, 1)), lhs = XEXP (lhs, 0); | |
993 | had_mult = 1; | |
994 | } | |
995 | else if (GET_CODE (lhs) == ASHIFT | |
996 | && GET_CODE (XEXP (lhs, 1)) == CONST_INT | |
997 | && INTVAL (XEXP (lhs, 1)) >= 0 | |
998 | && INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT) | |
999 | { | |
1000 | coeff0 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1)); | |
1001 | lhs = XEXP (lhs, 0); | |
1002 | } | |
1003 | ||
1004 | if (GET_CODE (rhs) == NEG) | |
1005 | coeff1 = - 1, rhs = XEXP (rhs, 0); | |
1006 | else if (GET_CODE (rhs) == MULT | |
1007 | && GET_CODE (XEXP (rhs, 1)) == CONST_INT) | |
1008 | { | |
1009 | coeff1 = INTVAL (XEXP (rhs, 1)), rhs = XEXP (rhs, 0); | |
1010 | had_mult = 1; | |
1011 | } | |
1012 | else if (GET_CODE (rhs) == ASHIFT | |
1013 | && GET_CODE (XEXP (rhs, 1)) == CONST_INT | |
1014 | && INTVAL (XEXP (rhs, 1)) >= 0 | |
1015 | && INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT) | |
1016 | { | |
1017 | coeff1 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1)); | |
1018 | rhs = XEXP (rhs, 0); | |
1019 | } | |
1020 | ||
1021 | if (rtx_equal_p (lhs, rhs)) | |
1022 | { | |
1023 | tem = simplify_gen_binary (MULT, mode, lhs, | |
1024 | GEN_INT (coeff0 - coeff1)); | |
1025 | return (GET_CODE (tem) == MULT && ! had_mult) ? 0 : tem; | |
1026 | } | |
1027 | } | |
1028 | ||
1029 | /* (a - (-b)) -> (a + b). */ | |
1030 | if (GET_CODE (op1) == NEG) | |
1031 | return simplify_gen_binary (PLUS, mode, op0, XEXP (op1, 0)); | |
1032 | ||
1033 | /* If one of the operands is a PLUS or a MINUS, see if we can | |
1034 | simplify this by the associative law. | |
1035 | Don't use the associative law for floating point. | |
1036 | The inaccuracy makes it nonassociative, | |
1037 | and subtle programs can break if operations are associated. */ | |
1038 | ||
1039 | if (INTEGRAL_MODE_P (mode) | |
1040 | && (GET_CODE (op0) == PLUS || GET_CODE (op0) == MINUS | |
1041 | || GET_CODE (op1) == PLUS || GET_CODE (op1) == MINUS) | |
1042 | && (tem = simplify_plus_minus (code, mode, op0, op1)) != 0) | |
1043 | return tem; | |
1044 | ||
1045 | /* Don't let a relocatable value get a negative coeff. */ | |
1046 | if (GET_CODE (op1) == CONST_INT && GET_MODE (op0) != VOIDmode) | |
1047 | return plus_constant (op0, - INTVAL (op1)); | |
1048 | ||
1049 | /* (x - (x & y)) -> (x & ~y) */ | |
1050 | if (GET_CODE (op1) == AND) | |
1051 | { | |
1052 | if (rtx_equal_p (op0, XEXP (op1, 0))) | |
1053 | return simplify_gen_binary (AND, mode, op0, | |
1054 | gen_rtx_NOT (mode, XEXP (op1, 1))); | |
1055 | if (rtx_equal_p (op0, XEXP (op1, 1))) | |
1056 | return simplify_gen_binary (AND, mode, op0, | |
1057 | gen_rtx_NOT (mode, XEXP (op1, 0))); | |
1058 | } | |
1059 | break; | |
1060 | ||
1061 | case MULT: | |
1062 | if (op1 == constm1_rtx) | |
1063 | { | |
1064 | tem = simplify_unary_operation (NEG, mode, op0, mode); | |
1065 | ||
1066 | return tem ? tem : gen_rtx_NEG (mode, op0); | |
1067 | } | |
1068 | ||
1069 | /* In IEEE floating point, x*0 is not always 0. */ | |
1070 | if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
1071 | || ! FLOAT_MODE_P (mode) || flag_fast_math) | |
1072 | && op1 == CONST0_RTX (mode) | |
1073 | && ! side_effects_p (op0)) | |
1074 | return op1; | |
1075 | ||
1076 | /* In IEEE floating point, x*1 is not equivalent to x for nans. | |
1077 | However, ANSI says we can drop signals, | |
1078 | so we can do this anyway. */ | |
1079 | if (op1 == CONST1_RTX (mode)) | |
1080 | return op0; | |
1081 | ||
1082 | /* Convert multiply by constant power of two into shift unless | |
1083 | we are still generating RTL. This test is a kludge. */ | |
1084 | if (GET_CODE (op1) == CONST_INT | |
1085 | && (val = exact_log2 (INTVAL (op1))) >= 0 | |
1086 | /* If the mode is larger than the host word size, and the | |
1087 | uppermost bit is set, then this isn't a power of two due | |
1088 | to implicit sign extension. */ | |
1089 | && (width <= HOST_BITS_PER_WIDE_INT | |
1090 | || val != HOST_BITS_PER_WIDE_INT - 1) | |
1091 | && ! rtx_equal_function_value_matters) | |
1092 | return gen_rtx_ASHIFT (mode, op0, GEN_INT (val)); | |
1093 | ||
1094 | if (GET_CODE (op1) == CONST_DOUBLE | |
1095 | && GET_MODE_CLASS (GET_MODE (op1)) == MODE_FLOAT) | |
1096 | { | |
1097 | REAL_VALUE_TYPE d; | |
1098 | jmp_buf handler; | |
1099 | int op1is2, op1ism1; | |
1100 | ||
1101 | if (setjmp (handler)) | |
1102 | return 0; | |
1103 | ||
1104 | set_float_handler (handler); | |
1105 | REAL_VALUE_FROM_CONST_DOUBLE (d, op1); | |
1106 | op1is2 = REAL_VALUES_EQUAL (d, dconst2); | |
1107 | op1ism1 = REAL_VALUES_EQUAL (d, dconstm1); | |
1108 | set_float_handler (NULL_PTR); | |
1109 | ||
1110 | /* x*2 is x+x and x*(-1) is -x */ | |
1111 | if (op1is2 && GET_MODE (op0) == mode) | |
1112 | return gen_rtx_PLUS (mode, op0, copy_rtx (op0)); | |
1113 | ||
1114 | else if (op1ism1 && GET_MODE (op0) == mode) | |
1115 | return gen_rtx_NEG (mode, op0); | |
1116 | } | |
1117 | break; | |
1118 | ||
1119 | case IOR: | |
1120 | if (op1 == const0_rtx) | |
1121 | return op0; | |
1122 | if (GET_CODE (op1) == CONST_INT | |
1123 | && (INTVAL (op1) & GET_MODE_MASK (mode)) == GET_MODE_MASK (mode)) | |
1124 | return op1; | |
1125 | if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
1126 | return op0; | |
1127 | /* A | (~A) -> -1 */ | |
1128 | if (((GET_CODE (op0) == NOT && rtx_equal_p (XEXP (op0, 0), op1)) | |
1129 | || (GET_CODE (op1) == NOT && rtx_equal_p (XEXP (op1, 0), op0))) | |
1130 | && ! side_effects_p (op0) | |
1131 | && GET_MODE_CLASS (mode) != MODE_CC) | |
1132 | return constm1_rtx; | |
1133 | break; | |
1134 | ||
1135 | case XOR: | |
1136 | if (op1 == const0_rtx) | |
1137 | return op0; | |
1138 | if (GET_CODE (op1) == CONST_INT | |
1139 | && (INTVAL (op1) & GET_MODE_MASK (mode)) == GET_MODE_MASK (mode)) | |
1140 | return gen_rtx_NOT (mode, op0); | |
1141 | if (op0 == op1 && ! side_effects_p (op0) | |
1142 | && GET_MODE_CLASS (mode) != MODE_CC) | |
1143 | return const0_rtx; | |
1144 | break; | |
1145 | ||
1146 | case AND: | |
1147 | if (op1 == const0_rtx && ! side_effects_p (op0)) | |
1148 | return const0_rtx; | |
1149 | if (GET_CODE (op1) == CONST_INT | |
1150 | && (INTVAL (op1) & GET_MODE_MASK (mode)) == GET_MODE_MASK (mode)) | |
1151 | return op0; | |
1152 | if (op0 == op1 && ! side_effects_p (op0) | |
1153 | && GET_MODE_CLASS (mode) != MODE_CC) | |
1154 | return op0; | |
1155 | /* A & (~A) -> 0 */ | |
1156 | if (((GET_CODE (op0) == NOT && rtx_equal_p (XEXP (op0, 0), op1)) | |
1157 | || (GET_CODE (op1) == NOT && rtx_equal_p (XEXP (op1, 0), op0))) | |
1158 | && ! side_effects_p (op0) | |
1159 | && GET_MODE_CLASS (mode) != MODE_CC) | |
1160 | return const0_rtx; | |
1161 | break; | |
1162 | ||
1163 | case UDIV: | |
1164 | /* Convert divide by power of two into shift (divide by 1 handled | |
1165 | below). */ | |
1166 | if (GET_CODE (op1) == CONST_INT | |
1167 | && (arg1 = exact_log2 (INTVAL (op1))) > 0) | |
1168 | return gen_rtx_LSHIFTRT (mode, op0, GEN_INT (arg1)); | |
1169 | ||
1170 | /* ... fall through ... */ | |
1171 | ||
1172 | case DIV: | |
1173 | if (op1 == CONST1_RTX (mode)) | |
1174 | return op0; | |
1175 | ||
1176 | /* In IEEE floating point, 0/x is not always 0. */ | |
1177 | if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
1178 | || ! FLOAT_MODE_P (mode) || flag_fast_math) | |
1179 | && op0 == CONST0_RTX (mode) | |
1180 | && ! side_effects_p (op1)) | |
1181 | return op0; | |
1182 | ||
1183 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
1184 | /* Change division by a constant into multiplication. Only do | |
1185 | this with -ffast-math until an expert says it is safe in | |
1186 | general. */ | |
1187 | else if (GET_CODE (op1) == CONST_DOUBLE | |
1188 | && GET_MODE_CLASS (GET_MODE (op1)) == MODE_FLOAT | |
1189 | && op1 != CONST0_RTX (mode) | |
1190 | && flag_fast_math) | |
1191 | { | |
1192 | REAL_VALUE_TYPE d; | |
1193 | REAL_VALUE_FROM_CONST_DOUBLE (d, op1); | |
1194 | ||
1195 | if (! REAL_VALUES_EQUAL (d, dconst0)) | |
1196 | { | |
1197 | #if defined (REAL_ARITHMETIC) | |
1198 | REAL_ARITHMETIC (d, rtx_to_tree_code (DIV), dconst1, d); | |
1199 | return gen_rtx_MULT (mode, op0, | |
1200 | CONST_DOUBLE_FROM_REAL_VALUE (d, mode)); | |
1201 | #else | |
1202 | return | |
1203 | gen_rtx_MULT (mode, op0, | |
1204 | CONST_DOUBLE_FROM_REAL_VALUE (1./d, mode)); | |
1205 | #endif | |
1206 | } | |
1207 | } | |
1208 | #endif | |
1209 | break; | |
1210 | ||
1211 | case UMOD: | |
1212 | /* Handle modulus by power of two (mod with 1 handled below). */ | |
1213 | if (GET_CODE (op1) == CONST_INT | |
1214 | && exact_log2 (INTVAL (op1)) > 0) | |
1215 | return gen_rtx_AND (mode, op0, GEN_INT (INTVAL (op1) - 1)); | |
1216 | ||
1217 | /* ... fall through ... */ | |
1218 | ||
1219 | case MOD: | |
1220 | if ((op0 == const0_rtx || op1 == const1_rtx) | |
1221 | && ! side_effects_p (op0) && ! side_effects_p (op1)) | |
1222 | return const0_rtx; | |
1223 | break; | |
1224 | ||
1225 | case ROTATERT: | |
1226 | case ROTATE: | |
1227 | /* Rotating ~0 always results in ~0. */ | |
1228 | if (GET_CODE (op0) == CONST_INT && width <= HOST_BITS_PER_WIDE_INT | |
1229 | && (unsigned HOST_WIDE_INT) INTVAL (op0) == GET_MODE_MASK (mode) | |
1230 | && ! side_effects_p (op1)) | |
1231 | return op0; | |
1232 | ||
1233 | /* ... fall through ... */ | |
1234 | ||
1235 | case ASHIFT: | |
1236 | case ASHIFTRT: | |
1237 | case LSHIFTRT: | |
1238 | if (op1 == const0_rtx) | |
1239 | return op0; | |
1240 | if (op0 == const0_rtx && ! side_effects_p (op1)) | |
1241 | return op0; | |
1242 | break; | |
1243 | ||
1244 | case SMIN: | |
1245 | if (width <= HOST_BITS_PER_WIDE_INT && GET_CODE (op1) == CONST_INT | |
1246 | && INTVAL (op1) == (HOST_WIDE_INT) 1 << (width -1) | |
1247 | && ! side_effects_p (op0)) | |
1248 | return op1; | |
1249 | else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
1250 | return op0; | |
1251 | break; | |
1252 | ||
1253 | case SMAX: | |
1254 | if (width <= HOST_BITS_PER_WIDE_INT && GET_CODE (op1) == CONST_INT | |
1255 | && ((unsigned HOST_WIDE_INT) INTVAL (op1) | |
1256 | == (unsigned HOST_WIDE_INT) GET_MODE_MASK (mode) >> 1) | |
1257 | && ! side_effects_p (op0)) | |
1258 | return op1; | |
1259 | else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
1260 | return op0; | |
1261 | break; | |
1262 | ||
1263 | case UMIN: | |
1264 | if (op1 == const0_rtx && ! side_effects_p (op0)) | |
1265 | return op1; | |
1266 | else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
1267 | return op0; | |
1268 | break; | |
1269 | ||
1270 | case UMAX: | |
1271 | if (op1 == constm1_rtx && ! side_effects_p (op0)) | |
1272 | return op1; | |
1273 | else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
1274 | return op0; | |
1275 | break; | |
1276 | ||
1277 | default: | |
1278 | abort (); | |
1279 | } | |
1280 | ||
1281 | return 0; | |
1282 | } | |
1283 | ||
1284 | /* Get the integer argument values in two forms: | |
1285 | zero-extended in ARG0, ARG1 and sign-extended in ARG0S, ARG1S. */ | |
1286 | ||
1287 | arg0 = INTVAL (op0); | |
1288 | arg1 = INTVAL (op1); | |
1289 | ||
1290 | if (width < HOST_BITS_PER_WIDE_INT) | |
1291 | { | |
1292 | arg0 &= ((HOST_WIDE_INT) 1 << width) - 1; | |
1293 | arg1 &= ((HOST_WIDE_INT) 1 << width) - 1; | |
1294 | ||
1295 | arg0s = arg0; | |
1296 | if (arg0s & ((HOST_WIDE_INT) 1 << (width - 1))) | |
1297 | arg0s |= ((HOST_WIDE_INT) (-1) << width); | |
1298 | ||
1299 | arg1s = arg1; | |
1300 | if (arg1s & ((HOST_WIDE_INT) 1 << (width - 1))) | |
1301 | arg1s |= ((HOST_WIDE_INT) (-1) << width); | |
1302 | } | |
1303 | else | |
1304 | { | |
1305 | arg0s = arg0; | |
1306 | arg1s = arg1; | |
1307 | } | |
1308 | ||
1309 | /* Compute the value of the arithmetic. */ | |
1310 | ||
1311 | switch (code) | |
1312 | { | |
1313 | case PLUS: | |
1314 | val = arg0s + arg1s; | |
1315 | break; | |
1316 | ||
1317 | case MINUS: | |
1318 | val = arg0s - arg1s; | |
1319 | break; | |
1320 | ||
1321 | case MULT: | |
1322 | val = arg0s * arg1s; | |
1323 | break; | |
1324 | ||
1325 | case DIV: | |
1326 | if (arg1s == 0) | |
1327 | return 0; | |
1328 | val = arg0s / arg1s; | |
1329 | break; | |
1330 | ||
1331 | case MOD: | |
1332 | if (arg1s == 0) | |
1333 | return 0; | |
1334 | val = arg0s % arg1s; | |
1335 | break; | |
1336 | ||
1337 | case UDIV: | |
1338 | if (arg1 == 0) | |
1339 | return 0; | |
1340 | val = (unsigned HOST_WIDE_INT) arg0 / arg1; | |
1341 | break; | |
1342 | ||
1343 | case UMOD: | |
1344 | if (arg1 == 0) | |
1345 | return 0; | |
1346 | val = (unsigned HOST_WIDE_INT) arg0 % arg1; | |
1347 | break; | |
1348 | ||
1349 | case AND: | |
1350 | val = arg0 & arg1; | |
1351 | break; | |
1352 | ||
1353 | case IOR: | |
1354 | val = arg0 | arg1; | |
1355 | break; | |
1356 | ||
1357 | case XOR: | |
1358 | val = arg0 ^ arg1; | |
1359 | break; | |
1360 | ||
1361 | case LSHIFTRT: | |
1362 | /* If shift count is undefined, don't fold it; let the machine do | |
1363 | what it wants. But truncate it if the machine will do that. */ | |
1364 | if (arg1 < 0) | |
1365 | return 0; | |
1366 | ||
1367 | #ifdef SHIFT_COUNT_TRUNCATED | |
1368 | if (SHIFT_COUNT_TRUNCATED) | |
1369 | arg1 %= width; | |
1370 | #endif | |
1371 | ||
1372 | val = ((unsigned HOST_WIDE_INT) arg0) >> arg1; | |
1373 | break; | |
1374 | ||
1375 | case ASHIFT: | |
1376 | if (arg1 < 0) | |
1377 | return 0; | |
1378 | ||
1379 | #ifdef SHIFT_COUNT_TRUNCATED | |
1380 | if (SHIFT_COUNT_TRUNCATED) | |
1381 | arg1 %= width; | |
1382 | #endif | |
1383 | ||
1384 | val = ((unsigned HOST_WIDE_INT) arg0) << arg1; | |
1385 | break; | |
1386 | ||
1387 | case ASHIFTRT: | |
1388 | if (arg1 < 0) | |
1389 | return 0; | |
1390 | ||
1391 | #ifdef SHIFT_COUNT_TRUNCATED | |
1392 | if (SHIFT_COUNT_TRUNCATED) | |
1393 | arg1 %= width; | |
1394 | #endif | |
1395 | ||
1396 | val = arg0s >> arg1; | |
1397 | ||
1398 | /* Bootstrap compiler may not have sign extended the right shift. | |
1399 | Manually extend the sign to insure bootstrap cc matches gcc. */ | |
1400 | if (arg0s < 0 && arg1 > 0) | |
1401 | val |= ((HOST_WIDE_INT) -1) << (HOST_BITS_PER_WIDE_INT - arg1); | |
1402 | ||
1403 | break; | |
1404 | ||
1405 | case ROTATERT: | |
1406 | if (arg1 < 0) | |
1407 | return 0; | |
1408 | ||
1409 | arg1 %= width; | |
1410 | val = ((((unsigned HOST_WIDE_INT) arg0) << (width - arg1)) | |
1411 | | (((unsigned HOST_WIDE_INT) arg0) >> arg1)); | |
1412 | break; | |
1413 | ||
1414 | case ROTATE: | |
1415 | if (arg1 < 0) | |
1416 | return 0; | |
1417 | ||
1418 | arg1 %= width; | |
1419 | val = ((((unsigned HOST_WIDE_INT) arg0) << arg1) | |
1420 | | (((unsigned HOST_WIDE_INT) arg0) >> (width - arg1))); | |
1421 | break; | |
1422 | ||
1423 | case COMPARE: | |
1424 | /* Do nothing here. */ | |
1425 | return 0; | |
1426 | ||
1427 | case SMIN: | |
1428 | val = arg0s <= arg1s ? arg0s : arg1s; | |
1429 | break; | |
1430 | ||
1431 | case UMIN: | |
1432 | val = ((unsigned HOST_WIDE_INT) arg0 | |
1433 | <= (unsigned HOST_WIDE_INT) arg1 ? arg0 : arg1); | |
1434 | break; | |
1435 | ||
1436 | case SMAX: | |
1437 | val = arg0s > arg1s ? arg0s : arg1s; | |
1438 | break; | |
1439 | ||
1440 | case UMAX: | |
1441 | val = ((unsigned HOST_WIDE_INT) arg0 | |
1442 | > (unsigned HOST_WIDE_INT) arg1 ? arg0 : arg1); | |
1443 | break; | |
1444 | ||
1445 | default: | |
1446 | abort (); | |
1447 | } | |
1448 | ||
1449 | val = trunc_int_for_mode (val, mode); | |
1450 | ||
1451 | return GEN_INT (val); | |
1452 | } | |
1453 | \f | |
1454 | /* Simplify a PLUS or MINUS, at least one of whose operands may be another | |
1455 | PLUS or MINUS. | |
1456 | ||
1457 | Rather than test for specific case, we do this by a brute-force method | |
1458 | and do all possible simplifications until no more changes occur. Then | |
1459 | we rebuild the operation. */ | |
1460 | ||
1461 | static rtx | |
1462 | simplify_plus_minus (code, mode, op0, op1) | |
1463 | enum rtx_code code; | |
1464 | enum machine_mode mode; | |
1465 | rtx op0, op1; | |
1466 | { | |
1467 | rtx ops[8]; | |
1468 | int negs[8]; | |
1469 | rtx result, tem; | |
1470 | int n_ops = 2, input_ops = 2, input_consts = 0, n_consts = 0; | |
1471 | int first = 1, negate = 0, changed; | |
1472 | int i, j; | |
1473 | ||
1474 | bzero ((char *) ops, sizeof ops); | |
1475 | ||
1476 | /* Set up the two operands and then expand them until nothing has been | |
1477 | changed. If we run out of room in our array, give up; this should | |
1478 | almost never happen. */ | |
1479 | ||
1480 | ops[0] = op0, ops[1] = op1, negs[0] = 0, negs[1] = (code == MINUS); | |
1481 | ||
1482 | changed = 1; | |
1483 | while (changed) | |
1484 | { | |
1485 | changed = 0; | |
1486 | ||
1487 | for (i = 0; i < n_ops; i++) | |
1488 | switch (GET_CODE (ops[i])) | |
1489 | { | |
1490 | case PLUS: | |
1491 | case MINUS: | |
1492 | if (n_ops == 7) | |
1493 | return 0; | |
1494 | ||
1495 | ops[n_ops] = XEXP (ops[i], 1); | |
1496 | negs[n_ops++] = GET_CODE (ops[i]) == MINUS ? !negs[i] : negs[i]; | |
1497 | ops[i] = XEXP (ops[i], 0); | |
1498 | input_ops++; | |
1499 | changed = 1; | |
1500 | break; | |
1501 | ||
1502 | case NEG: | |
1503 | ops[i] = XEXP (ops[i], 0); | |
1504 | negs[i] = ! negs[i]; | |
1505 | changed = 1; | |
1506 | break; | |
1507 | ||
1508 | case CONST: | |
1509 | ops[i] = XEXP (ops[i], 0); | |
1510 | input_consts++; | |
1511 | changed = 1; | |
1512 | break; | |
1513 | ||
1514 | case NOT: | |
1515 | /* ~a -> (-a - 1) */ | |
1516 | if (n_ops != 7) | |
1517 | { | |
1518 | ops[n_ops] = constm1_rtx; | |
1519 | negs[n_ops++] = negs[i]; | |
1520 | ops[i] = XEXP (ops[i], 0); | |
1521 | negs[i] = ! negs[i]; | |
1522 | changed = 1; | |
1523 | } | |
1524 | break; | |
1525 | ||
1526 | case CONST_INT: | |
1527 | if (negs[i]) | |
1528 | ops[i] = GEN_INT (- INTVAL (ops[i])), negs[i] = 0, changed = 1; | |
1529 | break; | |
1530 | ||
1531 | default: | |
1532 | break; | |
1533 | } | |
1534 | } | |
1535 | ||
1536 | /* If we only have two operands, we can't do anything. */ | |
1537 | if (n_ops <= 2) | |
1538 | return 0; | |
1539 | ||
1540 | /* Now simplify each pair of operands until nothing changes. The first | |
1541 | time through just simplify constants against each other. */ | |
1542 | ||
1543 | changed = 1; | |
1544 | while (changed) | |
1545 | { | |
1546 | changed = first; | |
1547 | ||
1548 | for (i = 0; i < n_ops - 1; i++) | |
1549 | for (j = i + 1; j < n_ops; j++) | |
1550 | if (ops[i] != 0 && ops[j] != 0 | |
1551 | && (! first || (CONSTANT_P (ops[i]) && CONSTANT_P (ops[j])))) | |
1552 | { | |
1553 | rtx lhs = ops[i], rhs = ops[j]; | |
1554 | enum rtx_code ncode = PLUS; | |
1555 | ||
1556 | if (negs[i] && ! negs[j]) | |
1557 | lhs = ops[j], rhs = ops[i], ncode = MINUS; | |
1558 | else if (! negs[i] && negs[j]) | |
1559 | ncode = MINUS; | |
1560 | ||
1561 | tem = simplify_binary_operation (ncode, mode, lhs, rhs); | |
1562 | if (tem) | |
1563 | { | |
1564 | ops[i] = tem, ops[j] = 0; | |
1565 | negs[i] = negs[i] && negs[j]; | |
1566 | if (GET_CODE (tem) == NEG) | |
1567 | ops[i] = XEXP (tem, 0), negs[i] = ! negs[i]; | |
1568 | ||
1569 | if (GET_CODE (ops[i]) == CONST_INT && negs[i]) | |
1570 | ops[i] = GEN_INT (- INTVAL (ops[i])), negs[i] = 0; | |
1571 | changed = 1; | |
1572 | } | |
1573 | } | |
1574 | ||
1575 | first = 0; | |
1576 | } | |
1577 | ||
1578 | /* Pack all the operands to the lower-numbered entries and give up if | |
1579 | we didn't reduce the number of operands we had. Make sure we | |
1580 | count a CONST as two operands. If we have the same number of | |
1581 | operands, but have made more CONSTs than we had, this is also | |
1582 | an improvement, so accept it. */ | |
1583 | ||
1584 | for (i = 0, j = 0; j < n_ops; j++) | |
1585 | if (ops[j] != 0) | |
1586 | { | |
1587 | ops[i] = ops[j], negs[i++] = negs[j]; | |
1588 | if (GET_CODE (ops[j]) == CONST) | |
1589 | n_consts++; | |
1590 | } | |
1591 | ||
1592 | if (i + n_consts > input_ops | |
1593 | || (i + n_consts == input_ops && n_consts <= input_consts)) | |
1594 | return 0; | |
1595 | ||
1596 | n_ops = i; | |
1597 | ||
1598 | /* If we have a CONST_INT, put it last. */ | |
1599 | for (i = 0; i < n_ops - 1; i++) | |
1600 | if (GET_CODE (ops[i]) == CONST_INT) | |
1601 | { | |
1602 | tem = ops[n_ops - 1], ops[n_ops - 1] = ops[i] , ops[i] = tem; | |
1603 | j = negs[n_ops - 1], negs[n_ops - 1] = negs[i], negs[i] = j; | |
1604 | } | |
1605 | ||
1606 | /* Put a non-negated operand first. If there aren't any, make all | |
1607 | operands positive and negate the whole thing later. */ | |
1608 | for (i = 0; i < n_ops && negs[i]; i++) | |
1609 | ; | |
1610 | ||
1611 | if (i == n_ops) | |
1612 | { | |
1613 | for (i = 0; i < n_ops; i++) | |
1614 | negs[i] = 0; | |
1615 | negate = 1; | |
1616 | } | |
1617 | else if (i != 0) | |
1618 | { | |
1619 | tem = ops[0], ops[0] = ops[i], ops[i] = tem; | |
1620 | j = negs[0], negs[0] = negs[i], negs[i] = j; | |
1621 | } | |
1622 | ||
1623 | /* Now make the result by performing the requested operations. */ | |
1624 | result = ops[0]; | |
1625 | for (i = 1; i < n_ops; i++) | |
1626 | result = simplify_gen_binary (negs[i] ? MINUS : PLUS, mode, result, ops[i]); | |
1627 | ||
1628 | return negate ? gen_rtx_NEG (mode, result) : result; | |
1629 | } | |
1630 | ||
1631 | struct cfc_args | |
1632 | { | |
14a774a9 RK |
1633 | rtx op0, op1; /* Input */ |
1634 | int equal, op0lt, op1lt; /* Output */ | |
0cedb36c JL |
1635 | }; |
1636 | ||
1637 | static void | |
1638 | check_fold_consts (data) | |
1639 | PTR data; | |
1640 | { | |
14a774a9 | 1641 | struct cfc_args *args = (struct cfc_args *) data; |
0cedb36c JL |
1642 | REAL_VALUE_TYPE d0, d1; |
1643 | ||
1644 | REAL_VALUE_FROM_CONST_DOUBLE (d0, args->op0); | |
1645 | REAL_VALUE_FROM_CONST_DOUBLE (d1, args->op1); | |
1646 | args->equal = REAL_VALUES_EQUAL (d0, d1); | |
1647 | args->op0lt = REAL_VALUES_LESS (d0, d1); | |
1648 | args->op1lt = REAL_VALUES_LESS (d1, d0); | |
1649 | } | |
1650 | ||
1651 | /* Like simplify_binary_operation except used for relational operators. | |
1652 | MODE is the mode of the operands, not that of the result. If MODE | |
1653 | is VOIDmode, both operands must also be VOIDmode and we compare the | |
1654 | operands in "infinite precision". | |
1655 | ||
1656 | If no simplification is possible, this function returns zero. Otherwise, | |
1657 | it returns either const_true_rtx or const0_rtx. */ | |
1658 | ||
1659 | rtx | |
1660 | simplify_relational_operation (code, mode, op0, op1) | |
1661 | enum rtx_code code; | |
1662 | enum machine_mode mode; | |
1663 | rtx op0, op1; | |
1664 | { | |
1665 | int equal, op0lt, op0ltu, op1lt, op1ltu; | |
1666 | rtx tem; | |
1667 | ||
1668 | /* If op0 is a compare, extract the comparison arguments from it. */ | |
1669 | if (GET_CODE (op0) == COMPARE && op1 == const0_rtx) | |
1670 | op1 = XEXP (op0, 1), op0 = XEXP (op0, 0); | |
1671 | ||
1672 | /* We can't simplify MODE_CC values since we don't know what the | |
1673 | actual comparison is. */ | |
1674 | if (GET_MODE_CLASS (GET_MODE (op0)) == MODE_CC | |
1675 | #ifdef HAVE_cc0 | |
1676 | || op0 == cc0_rtx | |
1677 | #endif | |
1678 | ) | |
1679 | return 0; | |
1680 | ||
52a75c3c RH |
1681 | /* Make sure the constant is second. */ |
1682 | if ((CONSTANT_P (op0) && ! CONSTANT_P (op1)) | |
1683 | || (GET_CODE (op0) == CONST_INT && GET_CODE (op1) != CONST_INT)) | |
1684 | { | |
1685 | tem = op0, op0 = op1, op1 = tem; | |
1686 | code = swap_condition (code); | |
1687 | } | |
1688 | ||
0cedb36c JL |
1689 | /* For integer comparisons of A and B maybe we can simplify A - B and can |
1690 | then simplify a comparison of that with zero. If A and B are both either | |
1691 | a register or a CONST_INT, this can't help; testing for these cases will | |
1692 | prevent infinite recursion here and speed things up. | |
1693 | ||
1694 | If CODE is an unsigned comparison, then we can never do this optimization, | |
1695 | because it gives an incorrect result if the subtraction wraps around zero. | |
1696 | ANSI C defines unsigned operations such that they never overflow, and | |
1697 | thus such cases can not be ignored. */ | |
1698 | ||
1699 | if (INTEGRAL_MODE_P (mode) && op1 != const0_rtx | |
1700 | && ! ((GET_CODE (op0) == REG || GET_CODE (op0) == CONST_INT) | |
1701 | && (GET_CODE (op1) == REG || GET_CODE (op1) == CONST_INT)) | |
1702 | && 0 != (tem = simplify_binary_operation (MINUS, mode, op0, op1)) | |
1703 | && code != GTU && code != GEU && code != LTU && code != LEU) | |
1704 | return simplify_relational_operation (signed_condition (code), | |
1705 | mode, tem, const0_rtx); | |
1706 | ||
1707 | /* For non-IEEE floating-point, if the two operands are equal, we know the | |
1708 | result. */ | |
1709 | if (rtx_equal_p (op0, op1) | |
1710 | && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
1711 | || ! FLOAT_MODE_P (GET_MODE (op0)) || flag_fast_math)) | |
1712 | equal = 1, op0lt = 0, op0ltu = 0, op1lt = 0, op1ltu = 0; | |
1713 | ||
1714 | /* If the operands are floating-point constants, see if we can fold | |
1715 | the result. */ | |
1716 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
1717 | else if (GET_CODE (op0) == CONST_DOUBLE && GET_CODE (op1) == CONST_DOUBLE | |
1718 | && GET_MODE_CLASS (GET_MODE (op0)) == MODE_FLOAT) | |
1719 | { | |
1720 | struct cfc_args args; | |
1721 | ||
1722 | /* Setup input for check_fold_consts() */ | |
1723 | args.op0 = op0; | |
1724 | args.op1 = op1; | |
1725 | ||
1726 | if (do_float_handler(check_fold_consts, (PTR) &args) == 0) | |
1727 | /* We got an exception from check_fold_consts() */ | |
1728 | return 0; | |
1729 | ||
1730 | /* Receive output from check_fold_consts() */ | |
1731 | equal = args.equal; | |
1732 | op0lt = op0ltu = args.op0lt; | |
1733 | op1lt = op1ltu = args.op1lt; | |
1734 | } | |
1735 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
1736 | ||
1737 | /* Otherwise, see if the operands are both integers. */ | |
1738 | else if ((GET_MODE_CLASS (mode) == MODE_INT || mode == VOIDmode) | |
1739 | && (GET_CODE (op0) == CONST_DOUBLE || GET_CODE (op0) == CONST_INT) | |
1740 | && (GET_CODE (op1) == CONST_DOUBLE || GET_CODE (op1) == CONST_INT)) | |
1741 | { | |
1742 | int width = GET_MODE_BITSIZE (mode); | |
1743 | HOST_WIDE_INT l0s, h0s, l1s, h1s; | |
1744 | unsigned HOST_WIDE_INT l0u, h0u, l1u, h1u; | |
1745 | ||
1746 | /* Get the two words comprising each integer constant. */ | |
1747 | if (GET_CODE (op0) == CONST_DOUBLE) | |
1748 | { | |
1749 | l0u = l0s = CONST_DOUBLE_LOW (op0); | |
1750 | h0u = h0s = CONST_DOUBLE_HIGH (op0); | |
1751 | } | |
1752 | else | |
1753 | { | |
1754 | l0u = l0s = INTVAL (op0); | |
1755 | h0u = h0s = l0s < 0 ? -1 : 0; | |
1756 | } | |
1757 | ||
1758 | if (GET_CODE (op1) == CONST_DOUBLE) | |
1759 | { | |
1760 | l1u = l1s = CONST_DOUBLE_LOW (op1); | |
1761 | h1u = h1s = CONST_DOUBLE_HIGH (op1); | |
1762 | } | |
1763 | else | |
1764 | { | |
1765 | l1u = l1s = INTVAL (op1); | |
1766 | h1u = h1s = l1s < 0 ? -1 : 0; | |
1767 | } | |
1768 | ||
1769 | /* If WIDTH is nonzero and smaller than HOST_BITS_PER_WIDE_INT, | |
1770 | we have to sign or zero-extend the values. */ | |
1771 | if (width != 0 && width <= HOST_BITS_PER_WIDE_INT) | |
1772 | h0u = h1u = 0, h0s = l0s < 0 ? -1 : 0, h1s = l1s < 0 ? -1 : 0; | |
1773 | ||
1774 | if (width != 0 && width < HOST_BITS_PER_WIDE_INT) | |
1775 | { | |
1776 | l0u &= ((HOST_WIDE_INT) 1 << width) - 1; | |
1777 | l1u &= ((HOST_WIDE_INT) 1 << width) - 1; | |
1778 | ||
1779 | if (l0s & ((HOST_WIDE_INT) 1 << (width - 1))) | |
1780 | l0s |= ((HOST_WIDE_INT) (-1) << width); | |
1781 | ||
1782 | if (l1s & ((HOST_WIDE_INT) 1 << (width - 1))) | |
1783 | l1s |= ((HOST_WIDE_INT) (-1) << width); | |
1784 | } | |
1785 | ||
1786 | equal = (h0u == h1u && l0u == l1u); | |
1787 | op0lt = (h0s < h1s || (h0s == h1s && l0s < l1s)); | |
1788 | op1lt = (h1s < h0s || (h1s == h0s && l1s < l0s)); | |
1789 | op0ltu = (h0u < h1u || (h0u == h1u && l0u < l1u)); | |
1790 | op1ltu = (h1u < h0u || (h1u == h0u && l1u < l0u)); | |
1791 | } | |
1792 | ||
1793 | /* Otherwise, there are some code-specific tests we can make. */ | |
1794 | else | |
1795 | { | |
1796 | switch (code) | |
1797 | { | |
1798 | case EQ: | |
1799 | /* References to the frame plus a constant or labels cannot | |
1800 | be zero, but a SYMBOL_REF can due to #pragma weak. */ | |
1801 | if (((NONZERO_BASE_PLUS_P (op0) && op1 == const0_rtx) | |
1802 | || GET_CODE (op0) == LABEL_REF) | |
1803 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM | |
1804 | /* On some machines, the ap reg can be 0 sometimes. */ | |
1805 | && op0 != arg_pointer_rtx | |
1806 | #endif | |
1807 | ) | |
1808 | return const0_rtx; | |
1809 | break; | |
1810 | ||
1811 | case NE: | |
1812 | if (((NONZERO_BASE_PLUS_P (op0) && op1 == const0_rtx) | |
1813 | || GET_CODE (op0) == LABEL_REF) | |
1814 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM | |
1815 | && op0 != arg_pointer_rtx | |
1816 | #endif | |
1817 | ) | |
1818 | return const_true_rtx; | |
1819 | break; | |
1820 | ||
1821 | case GEU: | |
1822 | /* Unsigned values are never negative. */ | |
1823 | if (op1 == const0_rtx) | |
1824 | return const_true_rtx; | |
1825 | break; | |
1826 | ||
1827 | case LTU: | |
1828 | if (op1 == const0_rtx) | |
1829 | return const0_rtx; | |
1830 | break; | |
1831 | ||
1832 | case LEU: | |
1833 | /* Unsigned values are never greater than the largest | |
1834 | unsigned value. */ | |
1835 | if (GET_CODE (op1) == CONST_INT | |
1836 | && (unsigned HOST_WIDE_INT) INTVAL (op1) == GET_MODE_MASK (mode) | |
1837 | && INTEGRAL_MODE_P (mode)) | |
1838 | return const_true_rtx; | |
1839 | break; | |
1840 | ||
1841 | case GTU: | |
1842 | if (GET_CODE (op1) == CONST_INT | |
1843 | && (unsigned HOST_WIDE_INT) INTVAL (op1) == GET_MODE_MASK (mode) | |
1844 | && INTEGRAL_MODE_P (mode)) | |
1845 | return const0_rtx; | |
1846 | break; | |
1847 | ||
1848 | default: | |
1849 | break; | |
1850 | } | |
1851 | ||
1852 | return 0; | |
1853 | } | |
1854 | ||
1855 | /* If we reach here, EQUAL, OP0LT, OP0LTU, OP1LT, and OP1LTU are set | |
1856 | as appropriate. */ | |
1857 | switch (code) | |
1858 | { | |
1859 | case EQ: | |
1860 | return equal ? const_true_rtx : const0_rtx; | |
1861 | case NE: | |
1862 | return ! equal ? const_true_rtx : const0_rtx; | |
1863 | case LT: | |
1864 | return op0lt ? const_true_rtx : const0_rtx; | |
1865 | case GT: | |
1866 | return op1lt ? const_true_rtx : const0_rtx; | |
1867 | case LTU: | |
1868 | return op0ltu ? const_true_rtx : const0_rtx; | |
1869 | case GTU: | |
1870 | return op1ltu ? const_true_rtx : const0_rtx; | |
1871 | case LE: | |
1872 | return equal || op0lt ? const_true_rtx : const0_rtx; | |
1873 | case GE: | |
1874 | return equal || op1lt ? const_true_rtx : const0_rtx; | |
1875 | case LEU: | |
1876 | return equal || op0ltu ? const_true_rtx : const0_rtx; | |
1877 | case GEU: | |
1878 | return equal || op1ltu ? const_true_rtx : const0_rtx; | |
1879 | default: | |
1880 | abort (); | |
1881 | } | |
1882 | } | |
1883 | \f | |
1884 | /* Simplify CODE, an operation with result mode MODE and three operands, | |
1885 | OP0, OP1, and OP2. OP0_MODE was the mode of OP0 before it became | |
1886 | a constant. Return 0 if no simplifications is possible. */ | |
1887 | ||
1888 | rtx | |
1889 | simplify_ternary_operation (code, mode, op0_mode, op0, op1, op2) | |
1890 | enum rtx_code code; | |
1891 | enum machine_mode mode, op0_mode; | |
1892 | rtx op0, op1, op2; | |
1893 | { | |
749a2da1 | 1894 | unsigned int width = GET_MODE_BITSIZE (mode); |
0cedb36c JL |
1895 | |
1896 | /* VOIDmode means "infinite" precision. */ | |
1897 | if (width == 0) | |
1898 | width = HOST_BITS_PER_WIDE_INT; | |
1899 | ||
1900 | switch (code) | |
1901 | { | |
1902 | case SIGN_EXTRACT: | |
1903 | case ZERO_EXTRACT: | |
1904 | if (GET_CODE (op0) == CONST_INT | |
1905 | && GET_CODE (op1) == CONST_INT | |
1906 | && GET_CODE (op2) == CONST_INT | |
1907 | && INTVAL (op1) + INTVAL (op2) <= GET_MODE_BITSIZE (op0_mode) | |
1908 | && width <= HOST_BITS_PER_WIDE_INT) | |
1909 | { | |
1910 | /* Extracting a bit-field from a constant */ | |
1911 | HOST_WIDE_INT val = INTVAL (op0); | |
1912 | ||
1913 | if (BITS_BIG_ENDIAN) | |
1914 | val >>= (GET_MODE_BITSIZE (op0_mode) | |
1915 | - INTVAL (op2) - INTVAL (op1)); | |
1916 | else | |
1917 | val >>= INTVAL (op2); | |
1918 | ||
1919 | if (HOST_BITS_PER_WIDE_INT != INTVAL (op1)) | |
1920 | { | |
1921 | /* First zero-extend. */ | |
1922 | val &= ((HOST_WIDE_INT) 1 << INTVAL (op1)) - 1; | |
1923 | /* If desired, propagate sign bit. */ | |
1924 | if (code == SIGN_EXTRACT | |
1925 | && (val & ((HOST_WIDE_INT) 1 << (INTVAL (op1) - 1)))) | |
1926 | val |= ~ (((HOST_WIDE_INT) 1 << INTVAL (op1)) - 1); | |
1927 | } | |
1928 | ||
1929 | /* Clear the bits that don't belong in our mode, | |
1930 | unless they and our sign bit are all one. | |
1931 | So we get either a reasonable negative value or a reasonable | |
1932 | unsigned value for this mode. */ | |
1933 | if (width < HOST_BITS_PER_WIDE_INT | |
1934 | && ((val & ((HOST_WIDE_INT) (-1) << (width - 1))) | |
1935 | != ((HOST_WIDE_INT) (-1) << (width - 1)))) | |
1936 | val &= ((HOST_WIDE_INT) 1 << width) - 1; | |
1937 | ||
1938 | return GEN_INT (val); | |
1939 | } | |
1940 | break; | |
1941 | ||
1942 | case IF_THEN_ELSE: | |
1943 | if (GET_CODE (op0) == CONST_INT) | |
1944 | return op0 != const0_rtx ? op1 : op2; | |
1945 | ||
1946 | /* Convert a == b ? b : a to "a". */ | |
1947 | if (GET_CODE (op0) == NE && ! side_effects_p (op0) | |
1948 | && rtx_equal_p (XEXP (op0, 0), op1) | |
1949 | && rtx_equal_p (XEXP (op0, 1), op2)) | |
1950 | return op1; | |
1951 | else if (GET_CODE (op0) == EQ && ! side_effects_p (op0) | |
1952 | && rtx_equal_p (XEXP (op0, 1), op1) | |
1953 | && rtx_equal_p (XEXP (op0, 0), op2)) | |
1954 | return op2; | |
1955 | else if (GET_RTX_CLASS (GET_CODE (op0)) == '<' && ! side_effects_p (op0)) | |
1956 | { | |
749a2da1 RK |
1957 | rtx temp |
1958 | = simplify_relational_operation (GET_CODE (op0), op0_mode, | |
1959 | XEXP (op0, 0), XEXP (op0, 1)); | |
1960 | ||
0cedb36c JL |
1961 | /* See if any simplifications were possible. */ |
1962 | if (temp == const0_rtx) | |
1963 | return op2; | |
1964 | else if (temp == const1_rtx) | |
1965 | return op1; | |
1966 | } | |
1967 | break; | |
1968 | ||
1969 | default: | |
1970 | abort (); | |
1971 | } | |
1972 | ||
1973 | return 0; | |
1974 | } | |
1975 | ||
1976 | /* Simplify X, an rtx expression. | |
1977 | ||
1978 | Return the simplified expression or NULL if no simplifications | |
1979 | were possible. | |
1980 | ||
1981 | This is the preferred entry point into the simplification routines; | |
1982 | however, we still allow passes to call the more specific routines. | |
1983 | ||
1984 | Right now GCC has three (yes, three) major bodies of RTL simplficiation | |
1985 | code that need to be unified. | |
1986 | ||
1987 | 1. fold_rtx in cse.c. This code uses various CSE specific | |
1988 | information to aid in RTL simplification. | |
1989 | ||
1990 | 2. simplify_rtx in combine.c. Similar to fold_rtx, except that | |
1991 | it uses combine specific information to aid in RTL | |
1992 | simplification. | |
1993 | ||
1994 | 3. The routines in this file. | |
1995 | ||
1996 | ||
1997 | Long term we want to only have one body of simplification code; to | |
1998 | get to that state I recommend the following steps: | |
1999 | ||
2000 | 1. Pour over fold_rtx & simplify_rtx and move any simplifications | |
2001 | which are not pass dependent state into these routines. | |
2002 | ||
2003 | 2. As code is moved by #1, change fold_rtx & simplify_rtx to | |
2004 | use this routine whenever possible. | |
2005 | ||
2006 | 3. Allow for pass dependent state to be provided to these | |
2007 | routines and add simplifications based on the pass dependent | |
2008 | state. Remove code from cse.c & combine.c that becomes | |
2009 | redundant/dead. | |
2010 | ||
2011 | It will take time, but ultimately the compiler will be easier to | |
2012 | maintain and improve. It's totally silly that when we add a | |
2013 | simplification that it needs to be added to 4 places (3 for RTL | |
2014 | simplification and 1 for tree simplification. */ | |
2015 | ||
2016 | rtx | |
2017 | simplify_rtx (x) | |
2018 | rtx x; | |
2019 | { | |
2020 | enum rtx_code code; | |
2021 | enum machine_mode mode; | |
0cedb36c JL |
2022 | |
2023 | mode = GET_MODE (x); | |
2024 | code = GET_CODE (x); | |
2025 | ||
2026 | switch (GET_RTX_CLASS (code)) | |
2027 | { | |
2028 | case '1': | |
2029 | return simplify_unary_operation (code, mode, | |
2030 | XEXP (x, 0), GET_MODE (XEXP (x, 0))); | |
2031 | case '2': | |
2032 | case 'c': | |
2033 | return simplify_binary_operation (code, mode, XEXP (x, 0), XEXP (x, 1)); | |
2034 | ||
2035 | case '3': | |
2036 | case 'b': | |
2037 | return simplify_ternary_operation (code, mode, GET_MODE (XEXP (x, 0)), | |
2038 | XEXP (x, 0), XEXP (x, 1), XEXP (x, 2)); | |
2039 | ||
2040 | case '<': | |
2041 | return simplify_relational_operation (code, GET_MODE (XEXP (x, 0)), | |
2042 | XEXP (x, 0), XEXP (x, 1)); | |
2043 | default: | |
2044 | return NULL; | |
2045 | } | |
2046 | } | |
eab5c70a | 2047 | \f |
eab5c70a BS |
2048 | |
2049 | /* Allocate a struct elt_list and fill in its two elements with the | |
2050 | arguments. */ | |
749a2da1 | 2051 | |
eab5c70a BS |
2052 | static struct elt_list * |
2053 | new_elt_list (next, elt) | |
2054 | struct elt_list *next; | |
2055 | cselib_val *elt; | |
2056 | { | |
2057 | struct elt_list *el = empty_elt_lists; | |
749a2da1 | 2058 | |
eab5c70a BS |
2059 | if (el) |
2060 | empty_elt_lists = el->next; | |
2061 | else | |
2062 | el = (struct elt_list *) obstack_alloc (&cselib_obstack, | |
2063 | sizeof (struct elt_list)); | |
2064 | el->next = next; | |
2065 | el->elt = elt; | |
2066 | return el; | |
2067 | } | |
2068 | ||
2069 | /* Allocate a struct elt_loc_list and fill in its two elements with the | |
2070 | arguments. */ | |
749a2da1 | 2071 | |
eab5c70a BS |
2072 | static struct elt_loc_list * |
2073 | new_elt_loc_list (next, loc) | |
2074 | struct elt_loc_list *next; | |
2075 | rtx loc; | |
2076 | { | |
2077 | struct elt_loc_list *el = empty_elt_loc_lists; | |
749a2da1 | 2078 | |
eab5c70a BS |
2079 | if (el) |
2080 | empty_elt_loc_lists = el->next; | |
2081 | else | |
2082 | el = (struct elt_loc_list *) obstack_alloc (&cselib_obstack, | |
2083 | sizeof (struct elt_loc_list)); | |
2084 | el->next = next; | |
2085 | el->loc = loc; | |
2086 | el->setting_insn = cselib_current_insn; | |
2087 | return el; | |
2088 | } | |
2089 | ||
2090 | /* The elt_list at *PL is no longer needed. Unchain it and free its | |
2091 | storage. */ | |
749a2da1 | 2092 | |
eab5c70a BS |
2093 | static void |
2094 | unchain_one_elt_list (pl) | |
2095 | struct elt_list **pl; | |
2096 | { | |
2097 | struct elt_list *l = *pl; | |
749a2da1 | 2098 | |
eab5c70a BS |
2099 | *pl = l->next; |
2100 | l->next = empty_elt_lists; | |
2101 | empty_elt_lists = l; | |
2102 | } | |
2103 | ||
2104 | /* Likewise for elt_loc_lists. */ | |
749a2da1 | 2105 | |
eab5c70a BS |
2106 | static void |
2107 | unchain_one_elt_loc_list (pl) | |
2108 | struct elt_loc_list **pl; | |
2109 | { | |
2110 | struct elt_loc_list *l = *pl; | |
749a2da1 | 2111 | |
eab5c70a BS |
2112 | *pl = l->next; |
2113 | l->next = empty_elt_loc_lists; | |
2114 | empty_elt_loc_lists = l; | |
2115 | } | |
2116 | ||
2117 | /* Likewise for cselib_vals. This also frees the addr_list associated with | |
2118 | V. */ | |
749a2da1 | 2119 | |
eab5c70a BS |
2120 | static void |
2121 | unchain_one_value (v) | |
2122 | cselib_val *v; | |
2123 | { | |
2124 | while (v->addr_list) | |
2125 | unchain_one_elt_list (&v->addr_list); | |
2126 | ||
2127 | v->u.next_free = empty_vals; | |
2128 | empty_vals = v; | |
2129 | } | |
2130 | ||
2131 | /* Remove all entries from the hash table. Also used during | |
2132 | initialization. */ | |
749a2da1 | 2133 | |
eab5c70a BS |
2134 | static void |
2135 | clear_table () | |
2136 | { | |
749a2da1 RK |
2137 | unsigned int i; |
2138 | ||
eab5c70a BS |
2139 | for (i = 0; i < cselib_nregs; i++) |
2140 | REG_VALUES (i) = 0; | |
2141 | ||
2142 | htab_empty (hash_table); | |
2143 | obstack_free (&cselib_obstack, cselib_startobj); | |
2144 | ||
2145 | empty_vals = 0; | |
2146 | empty_elt_lists = 0; | |
2147 | empty_elt_loc_lists = 0; | |
2148 | n_useless_values = 0; | |
2149 | ||
2150 | next_unknown_value = 0; | |
2151 | } | |
2152 | ||
2153 | /* The equality test for our hash table. The first argument ENTRY is a table | |
2154 | element (i.e. a cselib_val), while the second arg X is an rtx. */ | |
749a2da1 | 2155 | |
eab5c70a BS |
2156 | static int |
2157 | entry_and_rtx_equal_p (entry, x_arg) | |
2158 | const void *entry, *x_arg; | |
2159 | { | |
2160 | struct elt_loc_list *l; | |
749a2da1 RK |
2161 | const cselib_val *v = (const cselib_val *) entry; |
2162 | rtx x = (rtx) x_arg; | |
eab5c70a BS |
2163 | |
2164 | /* We don't guarantee that distinct rtx's have different hash values, | |
2165 | so we need to do a comparison. */ | |
2166 | for (l = v->locs; l; l = l->next) | |
2167 | if (rtx_equal_for_cselib_p (l->loc, x)) | |
2168 | return 1; | |
749a2da1 | 2169 | |
eab5c70a BS |
2170 | return 0; |
2171 | } | |
2172 | ||
2173 | /* The hash function for our hash table. The value is always computed with | |
2174 | hash_rtx when adding an element; this function just extracts the hash | |
2175 | value from a cselib_val structure. */ | |
749a2da1 | 2176 | |
eab5c70a BS |
2177 | static unsigned int |
2178 | get_value_hash (entry) | |
2179 | const void *entry; | |
2180 | { | |
e77d72cb | 2181 | const cselib_val *v = (const cselib_val *) entry; |
eab5c70a BS |
2182 | return v->value; |
2183 | } | |
2184 | ||
eab5c70a BS |
2185 | /* Return true if X contains a VALUE rtx. If ONLY_USELESS is set, we |
2186 | only return true for values which point to a cselib_val whose value | |
2187 | element has been set to zero, which implies the cselib_val will be | |
2188 | removed. */ | |
749a2da1 | 2189 | |
eab5c70a BS |
2190 | int |
2191 | references_value_p (x, only_useless) | |
2192 | rtx x; | |
2193 | int only_useless; | |
2194 | { | |
2195 | enum rtx_code code = GET_CODE (x); | |
2196 | const char *fmt = GET_RTX_FORMAT (code); | |
749a2da1 | 2197 | int i, j; |
eab5c70a BS |
2198 | |
2199 | if (GET_CODE (x) == VALUE | |
4d0482f6 | 2200 | && (! only_useless || CSELIB_VAL_PTR (x)->locs == 0)) |
eab5c70a BS |
2201 | return 1; |
2202 | ||
2203 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2204 | { | |
749a2da1 RK |
2205 | if (fmt[i] == 'e' && references_value_p (XEXP (x, i), only_useless)) |
2206 | return 1; | |
eab5c70a | 2207 | else if (fmt[i] == 'E') |
749a2da1 RK |
2208 | for (j = 0; j < XVECLEN (x, i); j++) |
2209 | if (references_value_p (XVECEXP (x, i, j), only_useless)) | |
2210 | return 1; | |
eab5c70a BS |
2211 | } |
2212 | ||
2213 | return 0; | |
2214 | } | |
2215 | ||
eab5c70a BS |
2216 | /* For all locations found in X, delete locations that reference useless |
2217 | values (i.e. values without any location). Called through | |
2218 | htab_traverse. */ | |
749a2da1 | 2219 | |
eab5c70a BS |
2220 | static int |
2221 | discard_useless_locs (x, info) | |
2222 | void **x; | |
2223 | void *info ATTRIBUTE_UNUSED; | |
2224 | { | |
2225 | cselib_val *v = (cselib_val *)*x; | |
2226 | struct elt_loc_list **p = &v->locs; | |
4d0482f6 | 2227 | int had_locs = v->locs != 0; |
eab5c70a BS |
2228 | |
2229 | while (*p) | |
2230 | { | |
2231 | if (references_value_p ((*p)->loc, 1)) | |
2232 | unchain_one_elt_loc_list (p); | |
2233 | else | |
2234 | p = &(*p)->next; | |
2235 | } | |
749a2da1 | 2236 | |
4d0482f6 BS |
2237 | if (had_locs && v->locs == 0) |
2238 | { | |
2239 | n_useless_values++; | |
2240 | values_became_useless = 1; | |
2241 | } | |
eab5c70a BS |
2242 | return 1; |
2243 | } | |
2244 | ||
2245 | /* If X is a value with no locations, remove it from the hashtable. */ | |
2246 | ||
2247 | static int | |
2248 | discard_useless_values (x, info) | |
2249 | void **x; | |
2250 | void *info ATTRIBUTE_UNUSED; | |
2251 | { | |
2252 | cselib_val *v = (cselib_val *)*x; | |
2253 | ||
4d0482f6 | 2254 | if (v->locs == 0) |
eab5c70a BS |
2255 | { |
2256 | htab_clear_slot (hash_table, x); | |
2257 | unchain_one_value (v); | |
2258 | n_useless_values--; | |
2259 | } | |
749a2da1 | 2260 | |
eab5c70a BS |
2261 | return 1; |
2262 | } | |
2263 | ||
2264 | /* Clean out useless values (i.e. those which no longer have locations | |
2265 | associated with them) from the hash table. */ | |
749a2da1 | 2266 | |
eab5c70a BS |
2267 | static void |
2268 | remove_useless_values () | |
2269 | { | |
2270 | /* First pass: eliminate locations that reference the value. That in | |
2271 | turn can make more values useless. */ | |
2272 | do | |
2273 | { | |
2274 | values_became_useless = 0; | |
2275 | htab_traverse (hash_table, discard_useless_locs, 0); | |
2276 | } | |
2277 | while (values_became_useless); | |
2278 | ||
2279 | /* Second pass: actually remove the values. */ | |
2280 | htab_traverse (hash_table, discard_useless_values, 0); | |
2281 | ||
2282 | if (n_useless_values != 0) | |
2283 | abort (); | |
2284 | } | |
2285 | ||
2286 | /* Return nonzero if we can prove that X and Y contain the same value, taking | |
2287 | our gathered information into account. */ | |
749a2da1 | 2288 | |
eab5c70a BS |
2289 | int |
2290 | rtx_equal_for_cselib_p (x, y) | |
2291 | rtx x, y; | |
2292 | { | |
2293 | enum rtx_code code; | |
2294 | const char *fmt; | |
2295 | int i; | |
2296 | ||
2297 | if (GET_CODE (x) == REG || GET_CODE (x) == MEM) | |
2298 | { | |
2299 | cselib_val *e = cselib_lookup (x, VOIDmode, 0); | |
749a2da1 | 2300 | |
eab5c70a BS |
2301 | if (e) |
2302 | x = e->u.val_rtx; | |
2303 | } | |
749a2da1 | 2304 | |
eab5c70a BS |
2305 | if (GET_CODE (y) == REG || GET_CODE (y) == MEM) |
2306 | { | |
2307 | cselib_val *e = cselib_lookup (y, VOIDmode, 0); | |
749a2da1 | 2308 | |
eab5c70a BS |
2309 | if (e) |
2310 | y = e->u.val_rtx; | |
2311 | } | |
2312 | ||
2313 | if (x == y) | |
2314 | return 1; | |
2315 | ||
2316 | if (GET_CODE (x) == VALUE && GET_CODE (y) == VALUE) | |
2317 | return CSELIB_VAL_PTR (x) == CSELIB_VAL_PTR (y); | |
2318 | ||
2319 | if (GET_CODE (x) == VALUE) | |
2320 | { | |
2321 | cselib_val *e = CSELIB_VAL_PTR (x); | |
2322 | struct elt_loc_list *l; | |
2323 | ||
2324 | for (l = e->locs; l; l = l->next) | |
2325 | { | |
2326 | rtx t = l->loc; | |
2327 | ||
2328 | /* Avoid infinite recursion. */ | |
2329 | if (GET_CODE (t) == REG || GET_CODE (t) == MEM) | |
2330 | continue; | |
749a2da1 | 2331 | else if (rtx_equal_for_cselib_p (t, y)) |
eab5c70a BS |
2332 | return 1; |
2333 | } | |
2334 | ||
2335 | return 0; | |
2336 | } | |
2337 | ||
2338 | if (GET_CODE (y) == VALUE) | |
2339 | { | |
2340 | cselib_val *e = CSELIB_VAL_PTR (y); | |
2341 | struct elt_loc_list *l; | |
2342 | ||
2343 | for (l = e->locs; l; l = l->next) | |
2344 | { | |
2345 | rtx t = l->loc; | |
2346 | ||
2347 | if (GET_CODE (t) == REG || GET_CODE (t) == MEM) | |
2348 | continue; | |
749a2da1 | 2349 | else if (rtx_equal_for_cselib_p (x, t)) |
eab5c70a BS |
2350 | return 1; |
2351 | } | |
2352 | ||
2353 | return 0; | |
2354 | } | |
2355 | ||
749a2da1 | 2356 | if (GET_CODE (x) != GET_CODE (y) || GET_MODE (x) != GET_MODE (y)) |
eab5c70a BS |
2357 | return 0; |
2358 | ||
2359 | /* This won't be handled correctly by the code below. */ | |
2360 | if (GET_CODE (x) == LABEL_REF) | |
2361 | return XEXP (x, 0) == XEXP (y, 0); | |
2362 | ||
2363 | code = GET_CODE (x); | |
2364 | fmt = GET_RTX_FORMAT (code); | |
2365 | ||
2366 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2367 | { | |
2368 | int j; | |
749a2da1 | 2369 | |
eab5c70a BS |
2370 | switch (fmt[i]) |
2371 | { | |
2372 | case 'w': | |
2373 | if (XWINT (x, i) != XWINT (y, i)) | |
2374 | return 0; | |
2375 | break; | |
2376 | ||
2377 | case 'n': | |
2378 | case 'i': | |
2379 | if (XINT (x, i) != XINT (y, i)) | |
2380 | return 0; | |
2381 | break; | |
2382 | ||
2383 | case 'V': | |
2384 | case 'E': | |
2385 | /* Two vectors must have the same length. */ | |
2386 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
2387 | return 0; | |
2388 | ||
2389 | /* And the corresponding elements must match. */ | |
2390 | for (j = 0; j < XVECLEN (x, i); j++) | |
2391 | if (! rtx_equal_for_cselib_p (XVECEXP (x, i, j), | |
2392 | XVECEXP (y, i, j))) | |
2393 | return 0; | |
2394 | break; | |
2395 | ||
2396 | case 'e': | |
2397 | if (! rtx_equal_for_cselib_p (XEXP (x, i), XEXP (y, i))) | |
2398 | return 0; | |
2399 | break; | |
2400 | ||
2401 | case 'S': | |
2402 | case 's': | |
2403 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
2404 | return 0; | |
2405 | break; | |
2406 | ||
2407 | case 'u': | |
2408 | /* These are just backpointers, so they don't matter. */ | |
2409 | break; | |
2410 | ||
2411 | case '0': | |
2412 | case 't': | |
2413 | break; | |
2414 | ||
2415 | /* It is believed that rtx's at this level will never | |
2416 | contain anything but integers and other rtx's, | |
2417 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
2418 | default: | |
2419 | abort (); | |
2420 | } | |
2421 | } | |
2422 | return 1; | |
2423 | } | |
2424 | ||
2425 | /* Hash an rtx. Return 0 if we couldn't hash the rtx. | |
2426 | For registers and memory locations, we look up their cselib_val structure | |
2427 | and return its VALUE element. | |
2428 | Possible reasons for return 0 are: the object is volatile, or we couldn't | |
2429 | find a register or memory location in the table and CREATE is zero. If | |
2430 | CREATE is nonzero, table elts are created for regs and mem. | |
2431 | MODE is used in hashing for CONST_INTs only; | |
2432 | otherwise the mode of X is used. */ | |
749a2da1 | 2433 | |
eab5c70a BS |
2434 | static unsigned int |
2435 | hash_rtx (x, mode, create) | |
2436 | rtx x; | |
2437 | enum machine_mode mode; | |
2438 | int create; | |
2439 | { | |
2440 | cselib_val *e; | |
2441 | int i, j; | |
22eb7dfa BS |
2442 | enum rtx_code code; |
2443 | const char *fmt; | |
eab5c70a | 2444 | unsigned int hash = 0; |
eab5c70a BS |
2445 | |
2446 | /* repeat is used to turn tail-recursion into iteration. */ | |
2447 | repeat: | |
eab5c70a | 2448 | code = GET_CODE (x); |
22eb7dfa BS |
2449 | hash += (unsigned) code + (unsigned) GET_MODE (x); |
2450 | ||
eab5c70a BS |
2451 | switch (code) |
2452 | { | |
2453 | case MEM: | |
2454 | case REG: | |
2455 | e = cselib_lookup (x, GET_MODE (x), create); | |
2456 | if (! e) | |
2457 | return 0; | |
749a2da1 | 2458 | |
22eb7dfa BS |
2459 | hash += e->value; |
2460 | return hash; | |
eab5c70a BS |
2461 | |
2462 | case CONST_INT: | |
749a2da1 RK |
2463 | hash += ((unsigned) CONST_INT << 7) + (unsigned) mode + INTVAL (x); |
2464 | return hash ? hash : CONST_INT; | |
eab5c70a BS |
2465 | |
2466 | case CONST_DOUBLE: | |
2467 | /* This is like the general case, except that it only counts | |
2468 | the integers representing the constant. */ | |
2469 | hash += (unsigned) code + (unsigned) GET_MODE (x); | |
2470 | if (GET_MODE (x) != VOIDmode) | |
2471 | for (i = 2; i < GET_RTX_LENGTH (CONST_DOUBLE); i++) | |
749a2da1 | 2472 | hash += XWINT (x, i); |
eab5c70a BS |
2473 | else |
2474 | hash += ((unsigned) CONST_DOUBLE_LOW (x) | |
2475 | + (unsigned) CONST_DOUBLE_HIGH (x)); | |
2476 | return hash ? hash : CONST_DOUBLE; | |
2477 | ||
2478 | /* Assume there is only one rtx object for any given label. */ | |
2479 | case LABEL_REF: | |
2480 | hash | |
2481 | += ((unsigned) LABEL_REF << 7) + (unsigned long) XEXP (x, 0); | |
2482 | return hash ? hash : LABEL_REF; | |
2483 | ||
2484 | case SYMBOL_REF: | |
2485 | hash | |
2486 | += ((unsigned) SYMBOL_REF << 7) + (unsigned long) XSTR (x, 0); | |
2487 | return hash ? hash : SYMBOL_REF; | |
2488 | ||
2489 | case PRE_DEC: | |
2490 | case PRE_INC: | |
2491 | case POST_DEC: | |
2492 | case POST_INC: | |
2493 | case PC: | |
2494 | case CC0: | |
2495 | case CALL: | |
2496 | case UNSPEC_VOLATILE: | |
2497 | return 0; | |
2498 | ||
2499 | case ASM_OPERANDS: | |
2500 | if (MEM_VOLATILE_P (x)) | |
2501 | return 0; | |
2502 | ||
2503 | break; | |
2504 | ||
2505 | default: | |
2506 | break; | |
2507 | } | |
2508 | ||
2509 | i = GET_RTX_LENGTH (code) - 1; | |
eab5c70a BS |
2510 | fmt = GET_RTX_FORMAT (code); |
2511 | for (; i >= 0; i--) | |
2512 | { | |
2513 | if (fmt[i] == 'e') | |
2514 | { | |
eab5c70a | 2515 | rtx tem = XEXP (x, i); |
749a2da1 | 2516 | unsigned int tem_hash; |
eab5c70a BS |
2517 | |
2518 | /* If we are about to do the last recursive call | |
2519 | needed at this level, change it into iteration. | |
2520 | This function is called enough to be worth it. */ | |
2521 | if (i == 0) | |
2522 | { | |
2523 | x = tem; | |
2524 | goto repeat; | |
2525 | } | |
749a2da1 | 2526 | |
eab5c70a BS |
2527 | tem_hash = hash_rtx (tem, 0, create); |
2528 | if (tem_hash == 0) | |
2529 | return 0; | |
749a2da1 | 2530 | |
eab5c70a BS |
2531 | hash += tem_hash; |
2532 | } | |
2533 | else if (fmt[i] == 'E') | |
2534 | for (j = 0; j < XVECLEN (x, i); j++) | |
2535 | { | |
2536 | unsigned int tem_hash = hash_rtx (XVECEXP (x, i, j), 0, create); | |
749a2da1 | 2537 | |
eab5c70a BS |
2538 | if (tem_hash == 0) |
2539 | return 0; | |
749a2da1 | 2540 | |
eab5c70a BS |
2541 | hash += tem_hash; |
2542 | } | |
2543 | else if (fmt[i] == 's') | |
2544 | { | |
e77d72cb | 2545 | const unsigned char *p = (const unsigned char *) XSTR (x, i); |
749a2da1 | 2546 | |
eab5c70a BS |
2547 | if (p) |
2548 | while (*p) | |
2549 | hash += *p++; | |
2550 | } | |
2551 | else if (fmt[i] == 'i') | |
749a2da1 | 2552 | hash += XINT (x, i); |
eab5c70a BS |
2553 | else if (fmt[i] == '0' || fmt[i] == 't') |
2554 | /* unused */; | |
2555 | else | |
2556 | abort (); | |
2557 | } | |
749a2da1 | 2558 | |
eab5c70a BS |
2559 | return hash ? hash : 1 + GET_CODE (x); |
2560 | } | |
2561 | ||
2562 | /* Create a new value structure for VALUE and initialize it. The mode of the | |
2563 | value is MODE. */ | |
749a2da1 | 2564 | |
eab5c70a BS |
2565 | static cselib_val * |
2566 | new_cselib_val (value, mode) | |
2567 | unsigned int value; | |
2568 | enum machine_mode mode; | |
2569 | { | |
2570 | cselib_val *e = empty_vals; | |
749a2da1 | 2571 | |
eab5c70a BS |
2572 | if (e) |
2573 | empty_vals = e->u.next_free; | |
2574 | else | |
2575 | e = (cselib_val *) obstack_alloc (&cselib_obstack, sizeof (cselib_val)); | |
749a2da1 | 2576 | |
eab5c70a BS |
2577 | if (value == 0) |
2578 | abort (); | |
749a2da1 | 2579 | |
eab5c70a BS |
2580 | e->value = value; |
2581 | e->u.val_rtx = gen_rtx_VALUE (mode); | |
2582 | CSELIB_VAL_PTR (e->u.val_rtx) = e; | |
eab5c70a BS |
2583 | e->addr_list = 0; |
2584 | e->locs = 0; | |
2585 | return e; | |
2586 | } | |
2587 | ||
2588 | /* ADDR_ELT is a value that is used as address. MEM_ELT is the value that | |
2589 | contains the data at this address. X is a MEM that represents the | |
2590 | value. Update the two value structures to represent this situation. */ | |
749a2da1 | 2591 | |
eab5c70a BS |
2592 | static void |
2593 | add_mem_for_addr (addr_elt, mem_elt, x) | |
2594 | cselib_val *addr_elt, *mem_elt; | |
2595 | rtx x; | |
2596 | { | |
2597 | rtx new; | |
2598 | struct elt_loc_list *l; | |
2599 | ||
2600 | /* Avoid duplicates. */ | |
2601 | for (l = mem_elt->locs; l; l = l->next) | |
2602 | if (GET_CODE (l->loc) == MEM | |
2603 | && CSELIB_VAL_PTR (XEXP (l->loc, 0)) == addr_elt) | |
2604 | return; | |
2605 | ||
2606 | new = gen_rtx_MEM (GET_MODE (x), addr_elt->u.val_rtx); | |
eab5c70a BS |
2607 | MEM_COPY_ATTRIBUTES (new, x); |
2608 | ||
bf49b139 | 2609 | addr_elt->addr_list = new_elt_list (addr_elt->addr_list, mem_elt); |
eab5c70a BS |
2610 | mem_elt->locs = new_elt_loc_list (mem_elt->locs, new); |
2611 | } | |
2612 | ||
2613 | /* Subroutine of cselib_lookup. Return a value for X, which is a MEM rtx. | |
2614 | If CREATE, make a new one if we haven't seen it before. */ | |
749a2da1 | 2615 | |
eab5c70a BS |
2616 | static cselib_val * |
2617 | cselib_lookup_mem (x, create) | |
2618 | rtx x; | |
2619 | int create; | |
2620 | { | |
2621 | void **slot; | |
2622 | cselib_val *addr; | |
2623 | cselib_val *mem_elt; | |
2624 | struct elt_list *l; | |
2625 | ||
749a2da1 RK |
2626 | if (MEM_VOLATILE_P (x) || GET_MODE (x) == BLKmode |
2627 | || (FLOAT_MODE_P (GET_MODE (x)) && flag_float_store)) | |
eab5c70a BS |
2628 | return 0; |
2629 | ||
2630 | /* Look up the value for the address. */ | |
2631 | addr = cselib_lookup (XEXP (x, 0), GET_MODE (x), create); | |
2632 | if (! addr) | |
2633 | return 0; | |
2634 | ||
2635 | /* Find a value that describes a value of our mode at that address. */ | |
2636 | for (l = addr->addr_list; l; l = l->next) | |
2637 | if (GET_MODE (l->elt->u.val_rtx) == GET_MODE (x)) | |
2638 | return l->elt; | |
749a2da1 | 2639 | |
eab5c70a BS |
2640 | if (! create) |
2641 | return 0; | |
749a2da1 | 2642 | |
eab5c70a BS |
2643 | mem_elt = new_cselib_val (++next_unknown_value, GET_MODE (x)); |
2644 | add_mem_for_addr (addr, mem_elt, x); | |
e38992e8 | 2645 | slot = htab_find_slot_with_hash (hash_table, x, mem_elt->value, INSERT); |
eab5c70a BS |
2646 | *slot = mem_elt; |
2647 | return mem_elt; | |
2648 | } | |
2649 | ||
2650 | /* Walk rtx X and replace all occurrences of REG and MEM subexpressions | |
2651 | with VALUE expressions. This way, it becomes independent of changes | |
2652 | to registers and memory. | |
2653 | X isn't actually modified; if modifications are needed, new rtl is | |
2654 | allocated. However, the return value can share rtl with X. */ | |
749a2da1 | 2655 | |
eab5c70a BS |
2656 | static rtx |
2657 | cselib_subst_to_values (x) | |
2658 | rtx x; | |
2659 | { | |
2660 | enum rtx_code code = GET_CODE (x); | |
2661 | const char *fmt = GET_RTX_FORMAT (code); | |
2662 | cselib_val *e; | |
2663 | struct elt_list *l; | |
2664 | rtx copy = x; | |
2665 | int i; | |
2666 | ||
2667 | switch (code) | |
2668 | { | |
2669 | case REG: | |
749a2da1 | 2670 | for (l = REG_VALUES (REGNO (x)); l; l = l->next) |
eab5c70a BS |
2671 | if (GET_MODE (l->elt->u.val_rtx) == GET_MODE (x)) |
2672 | return l->elt->u.val_rtx; | |
749a2da1 | 2673 | |
eab5c70a BS |
2674 | abort (); |
2675 | ||
2676 | case MEM: | |
2677 | e = cselib_lookup_mem (x, 0); | |
2678 | if (! e) | |
2679 | abort (); | |
2680 | return e->u.val_rtx; | |
2681 | ||
2682 | /* CONST_DOUBLEs must be special-cased here so that we won't try to | |
2683 | look up the CONST_DOUBLE_MEM inside. */ | |
2684 | case CONST_DOUBLE: | |
2685 | case CONST_INT: | |
2686 | return x; | |
2687 | ||
2688 | default: | |
2689 | break; | |
2690 | } | |
2691 | ||
2692 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2693 | { | |
2694 | if (fmt[i] == 'e') | |
2695 | { | |
2696 | rtx t = cselib_subst_to_values (XEXP (x, i)); | |
749a2da1 | 2697 | |
eab5c70a BS |
2698 | if (t != XEXP (x, i) && x == copy) |
2699 | copy = shallow_copy_rtx (x); | |
749a2da1 | 2700 | |
eab5c70a BS |
2701 | XEXP (copy, i) = t; |
2702 | } | |
2703 | else if (fmt[i] == 'E') | |
2704 | { | |
2705 | int j, k; | |
2706 | ||
2707 | for (j = 0; j < XVECLEN (x, i); j++) | |
2708 | { | |
2709 | rtx t = cselib_subst_to_values (XVECEXP (x, i, j)); | |
749a2da1 | 2710 | |
eab5c70a BS |
2711 | if (t != XVECEXP (x, i, j) && XVEC (x, i) == XVEC (copy, i)) |
2712 | { | |
2713 | if (x == copy) | |
2714 | copy = shallow_copy_rtx (x); | |
749a2da1 | 2715 | |
eab5c70a BS |
2716 | XVEC (copy, i) = rtvec_alloc (XVECLEN (x, i)); |
2717 | for (k = 0; k < j; k++) | |
2718 | XVECEXP (copy, i, k) = XVECEXP (x, i, k); | |
2719 | } | |
749a2da1 | 2720 | |
eab5c70a BS |
2721 | XVECEXP (copy, i, j) = t; |
2722 | } | |
2723 | } | |
2724 | } | |
749a2da1 | 2725 | |
eab5c70a BS |
2726 | return copy; |
2727 | } | |
2728 | ||
2729 | /* Look up the rtl expression X in our tables and return the value it has. | |
2730 | If CREATE is zero, we return NULL if we don't know the value. Otherwise, | |
2731 | we create a new one if possible, using mode MODE if X doesn't have a mode | |
2732 | (i.e. because it's a constant). */ | |
749a2da1 | 2733 | |
eab5c70a BS |
2734 | cselib_val * |
2735 | cselib_lookup (x, mode, create) | |
2736 | rtx x; | |
2737 | enum machine_mode mode; | |
2738 | int create; | |
2739 | { | |
2740 | void **slot; | |
2741 | cselib_val *e; | |
2742 | unsigned int hashval; | |
2743 | ||
2744 | if (GET_MODE (x) != VOIDmode) | |
2745 | mode = GET_MODE (x); | |
2746 | ||
2747 | if (GET_CODE (x) == VALUE) | |
2748 | return CSELIB_VAL_PTR (x); | |
2749 | ||
2750 | if (GET_CODE (x) == REG) | |
2751 | { | |
2752 | struct elt_list *l; | |
749a2da1 RK |
2753 | unsigned int i = REGNO (x); |
2754 | ||
eab5c70a BS |
2755 | for (l = REG_VALUES (i); l; l = l->next) |
2756 | if (mode == GET_MODE (l->elt->u.val_rtx)) | |
2757 | return l->elt; | |
749a2da1 | 2758 | |
eab5c70a BS |
2759 | if (! create) |
2760 | return 0; | |
749a2da1 | 2761 | |
eab5c70a BS |
2762 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); |
2763 | e->locs = new_elt_loc_list (e->locs, x); | |
2764 | REG_VALUES (i) = new_elt_list (REG_VALUES (i), e); | |
e38992e8 | 2765 | slot = htab_find_slot_with_hash (hash_table, x, e->value, INSERT); |
eab5c70a BS |
2766 | *slot = e; |
2767 | return e; | |
2768 | } | |
2769 | ||
2770 | if (GET_CODE (x) == MEM) | |
2771 | return cselib_lookup_mem (x, create); | |
2772 | ||
2773 | hashval = hash_rtx (x, mode, create); | |
2774 | /* Can't even create if hashing is not possible. */ | |
2775 | if (! hashval) | |
2776 | return 0; | |
2777 | ||
e38992e8 RK |
2778 | slot = htab_find_slot_with_hash (hash_table, x, hashval, |
2779 | create ? INSERT : NO_INSERT); | |
eab5c70a BS |
2780 | if (slot == 0) |
2781 | return 0; | |
749a2da1 | 2782 | |
eab5c70a BS |
2783 | e = (cselib_val *) *slot; |
2784 | if (e) | |
2785 | return e; | |
2786 | ||
2787 | e = new_cselib_val (hashval, mode); | |
749a2da1 | 2788 | |
22eb7dfa BS |
2789 | /* We have to fill the slot before calling cselib_subst_to_values: |
2790 | the hash table is inconsistent until we do so, and | |
2791 | cselib_subst_to_values will need to do lookups. */ | |
eab5c70a | 2792 | *slot = (void *) e; |
22eb7dfa | 2793 | e->locs = new_elt_loc_list (e->locs, cselib_subst_to_values (x)); |
eab5c70a BS |
2794 | return e; |
2795 | } | |
2796 | ||
2797 | /* Invalidate any entries in reg_values that overlap REGNO. This is called | |
2798 | if REGNO is changing. MODE is the mode of the assignment to REGNO, which | |
2799 | is used to determine how many hard registers are being changed. If MODE | |
2800 | is VOIDmode, then only REGNO is being changed; this is used when | |
2801 | invalidating call clobbered registers across a call. */ | |
770ae6cc | 2802 | |
eab5c70a BS |
2803 | static void |
2804 | cselib_invalidate_regno (regno, mode) | |
770ae6cc | 2805 | unsigned int regno; |
eab5c70a BS |
2806 | enum machine_mode mode; |
2807 | { | |
770ae6cc RK |
2808 | unsigned int endregno; |
2809 | unsigned int i; | |
eab5c70a BS |
2810 | |
2811 | /* If we see pseudos after reload, something is _wrong_. */ | |
2812 | if (reload_completed && regno >= FIRST_PSEUDO_REGISTER | |
2813 | && reg_renumber[regno] >= 0) | |
2814 | abort (); | |
2815 | ||
2816 | /* Determine the range of registers that must be invalidated. For | |
2817 | pseudos, only REGNO is affected. For hard regs, we must take MODE | |
2818 | into account, and we must also invalidate lower register numbers | |
2819 | if they contain values that overlap REGNO. */ | |
2820 | endregno = regno + 1; | |
2821 | if (regno < FIRST_PSEUDO_REGISTER && mode != VOIDmode) | |
2822 | endregno = regno + HARD_REGNO_NREGS (regno, mode); | |
2823 | ||
2824 | for (i = 0; i < endregno; i++) | |
2825 | { | |
2826 | struct elt_list **l = ®_VALUES (i); | |
2827 | ||
2828 | /* Go through all known values for this reg; if it overlaps the range | |
2829 | we're invalidating, remove the value. */ | |
2830 | while (*l) | |
2831 | { | |
2832 | cselib_val *v = (*l)->elt; | |
2833 | struct elt_loc_list **p; | |
770ae6cc | 2834 | unsigned int this_last = i; |
eab5c70a BS |
2835 | |
2836 | if (i < FIRST_PSEUDO_REGISTER) | |
2837 | this_last += HARD_REGNO_NREGS (i, GET_MODE (v->u.val_rtx)) - 1; | |
770ae6cc | 2838 | |
eab5c70a BS |
2839 | if (this_last < regno) |
2840 | { | |
2841 | l = &(*l)->next; | |
2842 | continue; | |
2843 | } | |
770ae6cc | 2844 | |
eab5c70a BS |
2845 | /* We have an overlap. */ |
2846 | unchain_one_elt_list (l); | |
2847 | ||
2848 | /* Now, we clear the mapping from value to reg. It must exist, so | |
2849 | this code will crash intentionally if it doesn't. */ | |
2850 | for (p = &v->locs; ; p = &(*p)->next) | |
2851 | { | |
2852 | rtx x = (*p)->loc; | |
770ae6cc | 2853 | |
eab5c70a BS |
2854 | if (GET_CODE (x) == REG && REGNO (x) == i) |
2855 | { | |
2856 | unchain_one_elt_loc_list (p); | |
2857 | break; | |
2858 | } | |
2859 | } | |
4d0482f6 BS |
2860 | if (v->locs == 0) |
2861 | n_useless_values++; | |
eab5c70a BS |
2862 | } |
2863 | } | |
2864 | } | |
2865 | ||
2866 | /* The memory at address MEM_BASE is being changed. | |
2867 | Return whether this change will invalidate VAL. */ | |
749a2da1 | 2868 | |
eab5c70a BS |
2869 | static int |
2870 | cselib_mem_conflict_p (mem_base, val) | |
2871 | rtx mem_base; | |
2872 | rtx val; | |
2873 | { | |
2874 | enum rtx_code code; | |
2875 | const char *fmt; | |
749a2da1 | 2876 | int i, j; |
eab5c70a BS |
2877 | |
2878 | code = GET_CODE (val); | |
2879 | switch (code) | |
2880 | { | |
2881 | /* Get rid of a few simple cases quickly. */ | |
2882 | case REG: | |
2883 | case PC: | |
2884 | case CC0: | |
2885 | case SCRATCH: | |
2886 | case CONST: | |
2887 | case CONST_INT: | |
2888 | case CONST_DOUBLE: | |
2889 | case SYMBOL_REF: | |
2890 | case LABEL_REF: | |
2891 | return 0; | |
2892 | ||
2893 | case MEM: | |
2894 | if (GET_MODE (mem_base) == BLKmode | |
749a2da1 RK |
2895 | || GET_MODE (val) == BLKmode |
2896 | || anti_dependence (val, mem_base)) | |
eab5c70a | 2897 | return 1; |
749a2da1 | 2898 | |
eab5c70a BS |
2899 | /* The address may contain nested MEMs. */ |
2900 | break; | |
2901 | ||
2902 | default: | |
2903 | break; | |
2904 | } | |
2905 | ||
2906 | fmt = GET_RTX_FORMAT (code); | |
eab5c70a BS |
2907 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) |
2908 | { | |
2909 | if (fmt[i] == 'e') | |
2910 | { | |
2911 | if (cselib_mem_conflict_p (mem_base, XEXP (val, i))) | |
2912 | return 1; | |
2913 | } | |
2914 | else if (fmt[i] == 'E') | |
749a2da1 RK |
2915 | for (j = 0; j < XVECLEN (val, i); j++) |
2916 | if (cselib_mem_conflict_p (mem_base, XVECEXP (val, i, j))) | |
2917 | return 1; | |
eab5c70a BS |
2918 | } |
2919 | ||
2920 | return 0; | |
2921 | } | |
2922 | ||
2923 | /* For the value found in SLOT, walk its locations to determine if any overlap | |
2924 | INFO (which is a MEM rtx). */ | |
749a2da1 | 2925 | |
eab5c70a BS |
2926 | static int |
2927 | cselib_invalidate_mem_1 (slot, info) | |
2928 | void **slot; | |
2929 | void *info; | |
2930 | { | |
2931 | cselib_val *v = (cselib_val *) *slot; | |
2932 | rtx mem_rtx = (rtx) info; | |
2933 | struct elt_loc_list **p = &v->locs; | |
4d0482f6 | 2934 | int had_locs = v->locs != 0; |
eab5c70a BS |
2935 | |
2936 | while (*p) | |
2937 | { | |
749a2da1 | 2938 | rtx x = (*p)->loc; |
eab5c70a BS |
2939 | cselib_val *addr; |
2940 | struct elt_list **mem_chain; | |
eab5c70a BS |
2941 | |
2942 | /* MEMs may occur in locations only at the top level; below | |
2943 | that every MEM or REG is substituted by its VALUE. */ | |
2944 | if (GET_CODE (x) != MEM | |
2945 | || ! cselib_mem_conflict_p (mem_rtx, x)) | |
2946 | { | |
2947 | p = &(*p)->next; | |
2948 | continue; | |
2949 | } | |
2950 | ||
2951 | /* This one overlaps. */ | |
2952 | /* We must have a mapping from this MEM's address to the | |
2953 | value (E). Remove that, too. */ | |
2954 | addr = cselib_lookup (XEXP (x, 0), VOIDmode, 0); | |
2955 | mem_chain = &addr->addr_list; | |
2956 | for (;;) | |
2957 | { | |
2958 | if ((*mem_chain)->elt == v) | |
2959 | { | |
2960 | unchain_one_elt_list (mem_chain); | |
2961 | break; | |
2962 | } | |
749a2da1 | 2963 | |
eab5c70a BS |
2964 | mem_chain = &(*mem_chain)->next; |
2965 | } | |
749a2da1 | 2966 | |
eab5c70a BS |
2967 | unchain_one_elt_loc_list (p); |
2968 | } | |
749a2da1 | 2969 | |
4d0482f6 BS |
2970 | if (had_locs && v->locs == 0) |
2971 | n_useless_values++; | |
2972 | ||
eab5c70a BS |
2973 | return 1; |
2974 | } | |
2975 | ||
2976 | /* Invalidate any locations in the table which are changed because of a | |
2977 | store to MEM_RTX. If this is called because of a non-const call | |
2978 | instruction, MEM_RTX is (mem:BLK const0_rtx). */ | |
749a2da1 | 2979 | |
eab5c70a BS |
2980 | static void |
2981 | cselib_invalidate_mem (mem_rtx) | |
2982 | rtx mem_rtx; | |
2983 | { | |
2984 | htab_traverse (hash_table, cselib_invalidate_mem_1, mem_rtx); | |
2985 | } | |
2986 | ||
2987 | /* Invalidate DEST, which is being assigned to or clobbered. The second and | |
2988 | the third parameter exist so that this function can be passed to | |
2989 | note_stores; they are ignored. */ | |
749a2da1 | 2990 | |
eab5c70a BS |
2991 | static void |
2992 | cselib_invalidate_rtx (dest, ignore, data) | |
2993 | rtx dest; | |
2994 | rtx ignore ATTRIBUTE_UNUSED; | |
2995 | void *data ATTRIBUTE_UNUSED; | |
2996 | { | |
749a2da1 RK |
2997 | while (GET_CODE (dest) == STRICT_LOW_PART || GET_CODE (dest) == SIGN_EXTRACT |
2998 | || GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SUBREG) | |
eab5c70a BS |
2999 | dest = XEXP (dest, 0); |
3000 | ||
3001 | if (GET_CODE (dest) == REG) | |
3002 | cselib_invalidate_regno (REGNO (dest), GET_MODE (dest)); | |
3003 | else if (GET_CODE (dest) == MEM) | |
3004 | cselib_invalidate_mem (dest); | |
3005 | ||
3006 | /* Some machines don't define AUTO_INC_DEC, but they still use push | |
3007 | instructions. We need to catch that case here in order to | |
3008 | invalidate the stack pointer correctly. Note that invalidating | |
3009 | the stack pointer is different from invalidating DEST. */ | |
3010 | if (push_operand (dest, GET_MODE (dest))) | |
3011 | cselib_invalidate_rtx (stack_pointer_rtx, NULL_RTX, NULL); | |
3012 | } | |
3013 | ||
3014 | /* Record the result of a SET instruction. DEST is being set; the source | |
3015 | contains the value described by SRC_ELT. If DEST is a MEM, DEST_ADDR_ELT | |
3016 | describes its address. */ | |
770ae6cc | 3017 | |
eab5c70a BS |
3018 | static void |
3019 | cselib_record_set (dest, src_elt, dest_addr_elt) | |
3020 | rtx dest; | |
3021 | cselib_val *src_elt, *dest_addr_elt; | |
3022 | { | |
770ae6cc | 3023 | int dreg = GET_CODE (dest) == REG ? (int) REGNO (dest) : -1; |
eab5c70a BS |
3024 | |
3025 | if (src_elt == 0 || side_effects_p (dest)) | |
3026 | return; | |
3027 | ||
3028 | if (dreg >= 0) | |
3029 | { | |
3030 | REG_VALUES (dreg) = new_elt_list (REG_VALUES (dreg), src_elt); | |
4d0482f6 BS |
3031 | if (src_elt->locs == 0) |
3032 | n_useless_values--; | |
eab5c70a BS |
3033 | src_elt->locs = new_elt_loc_list (src_elt->locs, dest); |
3034 | } | |
3035 | else if (GET_CODE (dest) == MEM && dest_addr_elt != 0) | |
4d0482f6 BS |
3036 | { |
3037 | if (src_elt->locs == 0) | |
3038 | n_useless_values--; | |
3039 | add_mem_for_addr (dest_addr_elt, src_elt, dest); | |
3040 | } | |
eab5c70a BS |
3041 | } |
3042 | ||
3043 | /* Describe a single set that is part of an insn. */ | |
3044 | struct set | |
3045 | { | |
3046 | rtx src; | |
3047 | rtx dest; | |
3048 | cselib_val *src_elt; | |
3049 | cselib_val *dest_addr_elt; | |
3050 | }; | |
3051 | ||
3052 | /* There is no good way to determine how many elements there can be | |
3053 | in a PARALLEL. Since it's fairly cheap, use a really large number. */ | |
3054 | #define MAX_SETS (FIRST_PSEUDO_REGISTER * 2) | |
3055 | ||
3056 | /* Record the effects of any sets in INSN. */ | |
3057 | static void | |
3058 | cselib_record_sets (insn) | |
3059 | rtx insn; | |
3060 | { | |
3061 | int n_sets = 0; | |
3062 | int i; | |
3063 | struct set sets[MAX_SETS]; | |
3064 | rtx body = PATTERN (insn); | |
3065 | ||
3066 | body = PATTERN (insn); | |
3067 | /* Find all sets. */ | |
3068 | if (GET_CODE (body) == SET) | |
3069 | { | |
3070 | sets[0].src = SET_SRC (body); | |
3071 | sets[0].dest = SET_DEST (body); | |
3072 | n_sets = 1; | |
3073 | } | |
3074 | else if (GET_CODE (body) == PARALLEL) | |
3075 | { | |
3076 | /* Look through the PARALLEL and record the values being | |
3077 | set, if possible. Also handle any CLOBBERs. */ | |
3078 | for (i = XVECLEN (body, 0) - 1; i >= 0; --i) | |
3079 | { | |
3080 | rtx x = XVECEXP (body, 0, i); | |
3081 | ||
3082 | if (GET_CODE (x) == SET) | |
3083 | { | |
3084 | sets[n_sets].src = SET_SRC (x); | |
3085 | sets[n_sets].dest = SET_DEST (x); | |
3086 | n_sets++; | |
3087 | } | |
3088 | } | |
3089 | } | |
3090 | ||
3091 | /* Look up the values that are read. Do this before invalidating the | |
3092 | locations that are written. */ | |
3093 | for (i = 0; i < n_sets; i++) | |
3094 | { | |
3095 | sets[i].src_elt = cselib_lookup (sets[i].src, GET_MODE (sets[i].dest), | |
3096 | 1); | |
3097 | if (GET_CODE (sets[i].dest) == MEM) | |
3098 | sets[i].dest_addr_elt = cselib_lookup (XEXP (sets[i].dest, 0), Pmode, | |
3099 | 1); | |
3100 | else | |
3101 | sets[i].dest_addr_elt = 0; | |
3102 | } | |
3103 | ||
3104 | /* Invalidate all locations written by this insn. Note that the elts we | |
3105 | looked up in the previous loop aren't affected, just some of their | |
3106 | locations may go away. */ | |
3107 | note_stores (body, cselib_invalidate_rtx, NULL); | |
3108 | ||
3109 | /* Now enter the equivalences in our tables. */ | |
3110 | for (i = 0; i < n_sets; i++) | |
3111 | cselib_record_set (sets[i].dest, sets[i].src_elt, sets[i].dest_addr_elt); | |
3112 | } | |
3113 | ||
3114 | /* Record the effects of INSN. */ | |
749a2da1 | 3115 | |
eab5c70a BS |
3116 | void |
3117 | cselib_process_insn (insn) | |
3118 | rtx insn; | |
3119 | { | |
3120 | int i; | |
749a2da1 | 3121 | rtx x; |
eab5c70a BS |
3122 | |
3123 | cselib_current_insn = insn; | |
3124 | ||
3125 | /* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp. */ | |
3126 | if (GET_CODE (insn) == CODE_LABEL | |
3127 | || (GET_CODE (insn) == NOTE | |
3128 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP) | |
3129 | || (GET_CODE (insn) == INSN | |
3130 | && GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
3131 | && MEM_VOLATILE_P (PATTERN (insn)))) | |
3132 | { | |
3133 | clear_table (); | |
3134 | return; | |
3135 | } | |
3136 | ||
3137 | if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') | |
3138 | { | |
3139 | cselib_current_insn = 0; | |
3140 | return; | |
3141 | } | |
749a2da1 | 3142 | |
eab5c70a BS |
3143 | /* If this is a call instruction, forget anything stored in a |
3144 | call clobbered register, or, if this is not a const call, in | |
3145 | memory. */ | |
3146 | if (GET_CODE (insn) == CALL_INSN) | |
3147 | { | |
3148 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3149 | if (call_used_regs[i]) | |
3150 | cselib_invalidate_regno (i, VOIDmode); | |
3151 | ||
3152 | if (! CONST_CALL_P (insn)) | |
3153 | cselib_invalidate_mem (callmem); | |
3154 | } | |
3155 | ||
3156 | cselib_record_sets (insn); | |
3157 | ||
3158 | #ifdef AUTO_INC_DEC | |
3159 | /* Clobber any registers which appear in REG_INC notes. We | |
3160 | could keep track of the changes to their values, but it is | |
3161 | unlikely to help. */ | |
749a2da1 RK |
3162 | for (x = REG_NOTES (insn); x; x = XEXP (x, 1)) |
3163 | if (REG_NOTE_KIND (x) == REG_INC) | |
3164 | cselib_invalidate_rtx (XEXP (x, 0), NULL_RTX, NULL); | |
eab5c70a BS |
3165 | #endif |
3166 | ||
3167 | /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only | |
3168 | after we have processed the insn. */ | |
3169 | if (GET_CODE (insn) == CALL_INSN) | |
749a2da1 RK |
3170 | for (x = CALL_INSN_FUNCTION_USAGE (insn); x; x = XEXP (x, 1)) |
3171 | if (GET_CODE (XEXP (x, 0)) == CLOBBER) | |
3172 | cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0), NULL_RTX, NULL); | |
eab5c70a BS |
3173 | |
3174 | cselib_current_insn = 0; | |
3175 | ||
3176 | if (n_useless_values > MAX_USELESS_VALUES) | |
3177 | remove_useless_values (); | |
3178 | } | |
3179 | ||
3180 | /* Make sure our varrays are big enough. Not called from any cselib routines; | |
3181 | it must be called by the user if it allocated new registers. */ | |
749a2da1 | 3182 | |
eab5c70a BS |
3183 | void |
3184 | cselib_update_varray_sizes () | |
3185 | { | |
749a2da1 RK |
3186 | unsigned int nregs = max_reg_num (); |
3187 | ||
eab5c70a BS |
3188 | if (nregs == cselib_nregs) |
3189 | return; | |
749a2da1 | 3190 | |
eab5c70a BS |
3191 | cselib_nregs = nregs; |
3192 | VARRAY_GROW (reg_values, nregs); | |
3193 | } | |
3194 | ||
3195 | /* Initialize cselib for one pass. The caller must also call | |
3196 | init_alias_analysis. */ | |
749a2da1 | 3197 | |
eab5c70a BS |
3198 | void |
3199 | cselib_init () | |
3200 | { | |
3201 | /* These are only created once. */ | |
3202 | if (! callmem) | |
3203 | { | |
3204 | extern struct obstack permanent_obstack; | |
749a2da1 | 3205 | |
eab5c70a BS |
3206 | gcc_obstack_init (&cselib_obstack); |
3207 | cselib_startobj = obstack_alloc (&cselib_obstack, 0); | |
3208 | ||
3209 | push_obstacks (&permanent_obstack, &permanent_obstack); | |
3210 | callmem = gen_rtx_MEM (BLKmode, const0_rtx); | |
3211 | pop_obstacks (); | |
3212 | ggc_add_rtx_root (&callmem, 1); | |
3213 | } | |
3214 | ||
3215 | cselib_nregs = max_reg_num (); | |
3216 | VARRAY_ELT_LIST_INIT (reg_values, cselib_nregs, "reg_values"); | |
3217 | hash_table = htab_create (31, get_value_hash, entry_and_rtx_equal_p, NULL); | |
3218 | clear_table (); | |
3219 | } | |
3220 | ||
3221 | /* Called when the current user is done with cselib. */ | |
749a2da1 | 3222 | |
eab5c70a BS |
3223 | void |
3224 | cselib_finish () | |
3225 | { | |
3226 | clear_table (); | |
3227 | htab_delete (hash_table); | |
3228 | } |