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f4e584dc | 1 | /* Global common subexpression elimination/Partial redundancy elimination |
7506f491 | 2 | and global constant/copy propagation for GNU compiler. |
62e5bf5d RS |
3 | Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, |
4 | 2006, 2007 Free Software Foundation, Inc. | |
7506f491 | 5 | |
1322177d | 6 | This file is part of GCC. |
7506f491 | 7 | |
1322177d LB |
8 | GCC is free software; you can redistribute it and/or modify it under |
9 | the terms of the GNU General Public License as published by the Free | |
10 | Software Foundation; either version 2, or (at your option) any later | |
11 | version. | |
7506f491 | 12 | |
1322177d LB |
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
7506f491 DE |
17 | |
18 | You should have received a copy of the GNU General Public License | |
1322177d | 19 | along with GCC; see the file COPYING. If not, write to the Free |
366ccddb KC |
20 | Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA |
21 | 02110-1301, USA. */ | |
7506f491 DE |
22 | |
23 | /* TODO | |
24 | - reordering of memory allocation and freeing to be more space efficient | |
25 | - do rough calc of how many regs are needed in each block, and a rough | |
26 | calc of how many regs are available in each class and use that to | |
27 | throttle back the code in cases where RTX_COST is minimal. | |
f4e584dc JL |
28 | - a store to the same address as a load does not kill the load if the |
29 | source of the store is also the destination of the load. Handling this | |
30 | allows more load motion, particularly out of loops. | |
7506f491 DE |
31 | - ability to realloc sbitmap vectors would allow one initial computation |
32 | of reg_set_in_block with only subsequent additions, rather than | |
33 | recomputing it for each pass | |
34 | ||
7506f491 DE |
35 | */ |
36 | ||
37 | /* References searched while implementing this. | |
7506f491 DE |
38 | |
39 | Compilers Principles, Techniques and Tools | |
40 | Aho, Sethi, Ullman | |
41 | Addison-Wesley, 1988 | |
42 | ||
43 | Global Optimization by Suppression of Partial Redundancies | |
44 | E. Morel, C. Renvoise | |
45 | communications of the acm, Vol. 22, Num. 2, Feb. 1979 | |
46 | ||
47 | A Portable Machine-Independent Global Optimizer - Design and Measurements | |
48 | Frederick Chow | |
49 | Stanford Ph.D. thesis, Dec. 1983 | |
50 | ||
7506f491 DE |
51 | A Fast Algorithm for Code Movement Optimization |
52 | D.M. Dhamdhere | |
53 | SIGPLAN Notices, Vol. 23, Num. 10, Oct. 1988 | |
54 | ||
55 | A Solution to a Problem with Morel and Renvoise's | |
56 | Global Optimization by Suppression of Partial Redundancies | |
57 | K-H Drechsler, M.P. Stadel | |
58 | ACM TOPLAS, Vol. 10, Num. 4, Oct. 1988 | |
59 | ||
60 | Practical Adaptation of the Global Optimization | |
61 | Algorithm of Morel and Renvoise | |
62 | D.M. Dhamdhere | |
63 | ACM TOPLAS, Vol. 13, Num. 2. Apr. 1991 | |
64 | ||
65 | Efficiently Computing Static Single Assignment Form and the Control | |
66 | Dependence Graph | |
67 | R. Cytron, J. Ferrante, B.K. Rosen, M.N. Wegman, and F.K. Zadeck | |
68 | ACM TOPLAS, Vol. 13, Num. 4, Oct. 1991 | |
69 | ||
7506f491 DE |
70 | Lazy Code Motion |
71 | J. Knoop, O. Ruthing, B. Steffen | |
72 | ACM SIGPLAN Notices Vol. 27, Num. 7, Jul. 1992, '92 Conference on PLDI | |
73 | ||
74 | What's In a Region? Or Computing Control Dependence Regions in Near-Linear | |
75 | Time for Reducible Flow Control | |
76 | Thomas Ball | |
77 | ACM Letters on Programming Languages and Systems, | |
78 | Vol. 2, Num. 1-4, Mar-Dec 1993 | |
79 | ||
80 | An Efficient Representation for Sparse Sets | |
81 | Preston Briggs, Linda Torczon | |
82 | ACM Letters on Programming Languages and Systems, | |
83 | Vol. 2, Num. 1-4, Mar-Dec 1993 | |
84 | ||
85 | A Variation of Knoop, Ruthing, and Steffen's Lazy Code Motion | |
86 | K-H Drechsler, M.P. Stadel | |
87 | ACM SIGPLAN Notices, Vol. 28, Num. 5, May 1993 | |
88 | ||
89 | Partial Dead Code Elimination | |
90 | J. Knoop, O. Ruthing, B. Steffen | |
91 | ACM SIGPLAN Notices, Vol. 29, Num. 6, Jun. 1994 | |
92 | ||
93 | Effective Partial Redundancy Elimination | |
94 | P. Briggs, K.D. Cooper | |
95 | ACM SIGPLAN Notices, Vol. 29, Num. 6, Jun. 1994 | |
96 | ||
97 | The Program Structure Tree: Computing Control Regions in Linear Time | |
98 | R. Johnson, D. Pearson, K. Pingali | |
99 | ACM SIGPLAN Notices, Vol. 29, Num. 6, Jun. 1994 | |
100 | ||
101 | Optimal Code Motion: Theory and Practice | |
102 | J. Knoop, O. Ruthing, B. Steffen | |
103 | ACM TOPLAS, Vol. 16, Num. 4, Jul. 1994 | |
104 | ||
105 | The power of assignment motion | |
106 | J. Knoop, O. Ruthing, B. Steffen | |
107 | ACM SIGPLAN Notices Vol. 30, Num. 6, Jun. 1995, '95 Conference on PLDI | |
108 | ||
109 | Global code motion / global value numbering | |
110 | C. Click | |
111 | ACM SIGPLAN Notices Vol. 30, Num. 6, Jun. 1995, '95 Conference on PLDI | |
112 | ||
113 | Value Driven Redundancy Elimination | |
114 | L.T. Simpson | |
115 | Rice University Ph.D. thesis, Apr. 1996 | |
116 | ||
117 | Value Numbering | |
118 | L.T. Simpson | |
119 | Massively Scalar Compiler Project, Rice University, Sep. 1996 | |
120 | ||
121 | High Performance Compilers for Parallel Computing | |
122 | Michael Wolfe | |
123 | Addison-Wesley, 1996 | |
124 | ||
f4e584dc JL |
125 | Advanced Compiler Design and Implementation |
126 | Steven Muchnick | |
127 | Morgan Kaufmann, 1997 | |
128 | ||
a42cd965 AM |
129 | Building an Optimizing Compiler |
130 | Robert Morgan | |
131 | Digital Press, 1998 | |
132 | ||
f4e584dc JL |
133 | People wishing to speed up the code here should read: |
134 | Elimination Algorithms for Data Flow Analysis | |
135 | B.G. Ryder, M.C. Paull | |
136 | ACM Computing Surveys, Vol. 18, Num. 3, Sep. 1986 | |
137 | ||
138 | How to Analyze Large Programs Efficiently and Informatively | |
139 | D.M. Dhamdhere, B.K. Rosen, F.K. Zadeck | |
140 | ACM SIGPLAN Notices Vol. 27, Num. 7, Jul. 1992, '92 Conference on PLDI | |
141 | ||
7506f491 DE |
142 | People wishing to do something different can find various possibilities |
143 | in the above papers and elsewhere. | |
144 | */ | |
145 | ||
146 | #include "config.h" | |
50b2596f | 147 | #include "system.h" |
4977bab6 ZW |
148 | #include "coretypes.h" |
149 | #include "tm.h" | |
01198c2f | 150 | #include "toplev.h" |
7506f491 DE |
151 | |
152 | #include "rtl.h" | |
b0656d8b | 153 | #include "tree.h" |
6baf1cc8 | 154 | #include "tm_p.h" |
7506f491 DE |
155 | #include "regs.h" |
156 | #include "hard-reg-set.h" | |
157 | #include "flags.h" | |
158 | #include "real.h" | |
159 | #include "insn-config.h" | |
160 | #include "recog.h" | |
161 | #include "basic-block.h" | |
50b2596f | 162 | #include "output.h" |
49ad7cfa | 163 | #include "function.h" |
589005ff | 164 | #include "expr.h" |
e7d482b9 | 165 | #include "except.h" |
fb0c0a12 | 166 | #include "ggc.h" |
f1fa37ff | 167 | #include "params.h" |
ae860ff7 | 168 | #include "cselib.h" |
d128effb | 169 | #include "intl.h" |
7506f491 | 170 | #include "obstack.h" |
27fb79ad | 171 | #include "timevar.h" |
ef330312 | 172 | #include "tree-pass.h" |
9727e468 | 173 | #include "hashtab.h" |
6fb5fa3c DB |
174 | #include "df.h" |
175 | #include "dbgcnt.h" | |
4fa31c2a | 176 | |
7506f491 DE |
177 | /* Propagate flow information through back edges and thus enable PRE's |
178 | moving loop invariant calculations out of loops. | |
179 | ||
180 | Originally this tended to create worse overall code, but several | |
181 | improvements during the development of PRE seem to have made following | |
182 | back edges generally a win. | |
183 | ||
184 | Note much of the loop invariant code motion done here would normally | |
185 | be done by loop.c, which has more heuristics for when to move invariants | |
186 | out of loops. At some point we might need to move some of those | |
187 | heuristics into gcse.c. */ | |
7506f491 | 188 | |
f4e584dc JL |
189 | /* We support GCSE via Partial Redundancy Elimination. PRE optimizations |
190 | are a superset of those done by GCSE. | |
7506f491 | 191 | |
f4e584dc | 192 | We perform the following steps: |
7506f491 DE |
193 | |
194 | 1) Compute basic block information. | |
195 | ||
196 | 2) Compute table of places where registers are set. | |
197 | ||
198 | 3) Perform copy/constant propagation. | |
199 | ||
e83f4801 SB |
200 | 4) Perform global cse using lazy code motion if not optimizing |
201 | for size, or code hoisting if we are. | |
7506f491 | 202 | |
e78d9500 | 203 | 5) Perform another pass of copy/constant propagation. |
7506f491 DE |
204 | |
205 | Two passes of copy/constant propagation are done because the first one | |
206 | enables more GCSE and the second one helps to clean up the copies that | |
207 | GCSE creates. This is needed more for PRE than for Classic because Classic | |
208 | GCSE will try to use an existing register containing the common | |
209 | subexpression rather than create a new one. This is harder to do for PRE | |
210 | because of the code motion (which Classic GCSE doesn't do). | |
211 | ||
212 | Expressions we are interested in GCSE-ing are of the form | |
213 | (set (pseudo-reg) (expression)). | |
214 | Function want_to_gcse_p says what these are. | |
215 | ||
216 | PRE handles moving invariant expressions out of loops (by treating them as | |
f4e584dc | 217 | partially redundant). |
7506f491 DE |
218 | |
219 | Eventually it would be nice to replace cse.c/gcse.c with SSA (static single | |
220 | assignment) based GVN (global value numbering). L. T. Simpson's paper | |
221 | (Rice University) on value numbering is a useful reference for this. | |
222 | ||
223 | ********************** | |
224 | ||
225 | We used to support multiple passes but there are diminishing returns in | |
226 | doing so. The first pass usually makes 90% of the changes that are doable. | |
227 | A second pass can make a few more changes made possible by the first pass. | |
228 | Experiments show any further passes don't make enough changes to justify | |
229 | the expense. | |
230 | ||
231 | A study of spec92 using an unlimited number of passes: | |
232 | [1 pass] = 1208 substitutions, [2] = 577, [3] = 202, [4] = 192, [5] = 83, | |
233 | [6] = 34, [7] = 17, [8] = 9, [9] = 4, [10] = 4, [11] = 2, | |
234 | [12] = 2, [13] = 1, [15] = 1, [16] = 2, [41] = 1 | |
235 | ||
236 | It was found doing copy propagation between each pass enables further | |
237 | substitutions. | |
238 | ||
239 | PRE is quite expensive in complicated functions because the DFA can take | |
7b1b4aed SB |
240 | a while to converge. Hence we only perform one pass. The parameter |
241 | max-gcse-passes can be modified if one wants to experiment. | |
7506f491 DE |
242 | |
243 | ********************** | |
244 | ||
245 | The steps for PRE are: | |
246 | ||
247 | 1) Build the hash table of expressions we wish to GCSE (expr_hash_table). | |
248 | ||
249 | 2) Perform the data flow analysis for PRE. | |
250 | ||
251 | 3) Delete the redundant instructions | |
252 | ||
253 | 4) Insert the required copies [if any] that make the partially | |
254 | redundant instructions fully redundant. | |
255 | ||
256 | 5) For other reaching expressions, insert an instruction to copy the value | |
257 | to a newly created pseudo that will reach the redundant instruction. | |
258 | ||
259 | The deletion is done first so that when we do insertions we | |
260 | know which pseudo reg to use. | |
261 | ||
262 | Various papers have argued that PRE DFA is expensive (O(n^2)) and others | |
263 | argue it is not. The number of iterations for the algorithm to converge | |
264 | is typically 2-4 so I don't view it as that expensive (relatively speaking). | |
265 | ||
f4e584dc | 266 | PRE GCSE depends heavily on the second CSE pass to clean up the copies |
7506f491 DE |
267 | we create. To make an expression reach the place where it's redundant, |
268 | the result of the expression is copied to a new register, and the redundant | |
269 | expression is deleted by replacing it with this new register. Classic GCSE | |
270 | doesn't have this problem as much as it computes the reaching defs of | |
a3c28ba2 KH |
271 | each register in each block and thus can try to use an existing |
272 | register. */ | |
7506f491 DE |
273 | \f |
274 | /* GCSE global vars. */ | |
275 | ||
f4e584dc JL |
276 | /* Note whether or not we should run jump optimization after gcse. We |
277 | want to do this for two cases. | |
278 | ||
279 | * If we changed any jumps via cprop. | |
280 | ||
281 | * If we added any labels via edge splitting. */ | |
f4e584dc JL |
282 | static int run_jump_opt_after_gcse; |
283 | ||
7506f491 DE |
284 | /* An obstack for our working variables. */ |
285 | static struct obstack gcse_obstack; | |
286 | ||
c4c81601 | 287 | struct reg_use {rtx reg_rtx; }; |
abd535b6 | 288 | |
7506f491 DE |
289 | /* Hash table of expressions. */ |
290 | ||
291 | struct expr | |
292 | { | |
293 | /* The expression (SET_SRC for expressions, PATTERN for assignments). */ | |
294 | rtx expr; | |
295 | /* Index in the available expression bitmaps. */ | |
296 | int bitmap_index; | |
297 | /* Next entry with the same hash. */ | |
298 | struct expr *next_same_hash; | |
299 | /* List of anticipatable occurrences in basic blocks in the function. | |
300 | An "anticipatable occurrence" is one that is the first occurrence in the | |
f4e584dc JL |
301 | basic block, the operands are not modified in the basic block prior |
302 | to the occurrence and the output is not used between the start of | |
303 | the block and the occurrence. */ | |
7506f491 DE |
304 | struct occr *antic_occr; |
305 | /* List of available occurrence in basic blocks in the function. | |
306 | An "available occurrence" is one that is the last occurrence in the | |
307 | basic block and the operands are not modified by following statements in | |
308 | the basic block [including this insn]. */ | |
309 | struct occr *avail_occr; | |
310 | /* Non-null if the computation is PRE redundant. | |
311 | The value is the newly created pseudo-reg to record a copy of the | |
312 | expression in all the places that reach the redundant copy. */ | |
313 | rtx reaching_reg; | |
314 | }; | |
315 | ||
316 | /* Occurrence of an expression. | |
317 | There is one per basic block. If a pattern appears more than once the | |
318 | last appearance is used [or first for anticipatable expressions]. */ | |
319 | ||
320 | struct occr | |
321 | { | |
322 | /* Next occurrence of this expression. */ | |
323 | struct occr *next; | |
324 | /* The insn that computes the expression. */ | |
325 | rtx insn; | |
cc2902df | 326 | /* Nonzero if this [anticipatable] occurrence has been deleted. */ |
7506f491 | 327 | char deleted_p; |
cc2902df | 328 | /* Nonzero if this [available] occurrence has been copied to |
7506f491 DE |
329 | reaching_reg. */ |
330 | /* ??? This is mutually exclusive with deleted_p, so they could share | |
331 | the same byte. */ | |
332 | char copied_p; | |
333 | }; | |
334 | ||
335 | /* Expression and copy propagation hash tables. | |
336 | Each hash table is an array of buckets. | |
337 | ??? It is known that if it were an array of entries, structure elements | |
338 | `next_same_hash' and `bitmap_index' wouldn't be necessary. However, it is | |
339 | not clear whether in the final analysis a sufficient amount of memory would | |
340 | be saved as the size of the available expression bitmaps would be larger | |
341 | [one could build a mapping table without holes afterwards though]. | |
c4c81601 | 342 | Someday I'll perform the computation and figure it out. */ |
7506f491 | 343 | |
02280659 ZD |
344 | struct hash_table |
345 | { | |
346 | /* The table itself. | |
347 | This is an array of `expr_hash_table_size' elements. */ | |
348 | struct expr **table; | |
349 | ||
350 | /* Size of the hash table, in elements. */ | |
351 | unsigned int size; | |
2e653e39 | 352 | |
02280659 ZD |
353 | /* Number of hash table elements. */ |
354 | unsigned int n_elems; | |
7506f491 | 355 | |
02280659 ZD |
356 | /* Whether the table is expression of copy propagation one. */ |
357 | int set_p; | |
358 | }; | |
c4c81601 | 359 | |
02280659 ZD |
360 | /* Expression hash table. */ |
361 | static struct hash_table expr_hash_table; | |
362 | ||
363 | /* Copy propagation hash table. */ | |
364 | static struct hash_table set_hash_table; | |
7506f491 DE |
365 | |
366 | /* Mapping of uids to cuids. | |
367 | Only real insns get cuids. */ | |
368 | static int *uid_cuid; | |
369 | ||
370 | /* Highest UID in UID_CUID. */ | |
371 | static int max_uid; | |
372 | ||
373 | /* Get the cuid of an insn. */ | |
b86db3eb | 374 | #ifdef ENABLE_CHECKING |
282899df NS |
375 | #define INSN_CUID(INSN) \ |
376 | (gcc_assert (INSN_UID (INSN) <= max_uid), uid_cuid[INSN_UID (INSN)]) | |
b86db3eb | 377 | #else |
7506f491 | 378 | #define INSN_CUID(INSN) (uid_cuid[INSN_UID (INSN)]) |
b86db3eb | 379 | #endif |
7506f491 DE |
380 | |
381 | /* Number of cuids. */ | |
382 | static int max_cuid; | |
383 | ||
384 | /* Mapping of cuids to insns. */ | |
385 | static rtx *cuid_insn; | |
386 | ||
387 | /* Get insn from cuid. */ | |
388 | #define CUID_INSN(CUID) (cuid_insn[CUID]) | |
389 | ||
390 | /* Maximum register number in function prior to doing gcse + 1. | |
391 | Registers created during this pass have regno >= max_gcse_regno. | |
392 | This is named with "gcse" to not collide with global of same name. */ | |
770ae6cc | 393 | static unsigned int max_gcse_regno; |
7506f491 | 394 | |
7506f491 | 395 | /* Table of registers that are modified. |
c4c81601 | 396 | |
7506f491 DE |
397 | For each register, each element is a list of places where the pseudo-reg |
398 | is set. | |
399 | ||
400 | For simplicity, GCSE is done on sets of pseudo-regs only. PRE GCSE only | |
401 | requires knowledge of which blocks kill which regs [and thus could use | |
f4e584dc | 402 | a bitmap instead of the lists `reg_set_table' uses]. |
7506f491 | 403 | |
c4c81601 RK |
404 | `reg_set_table' and could be turned into an array of bitmaps (num-bbs x |
405 | num-regs) [however perhaps it may be useful to keep the data as is]. One | |
406 | advantage of recording things this way is that `reg_set_table' is fairly | |
407 | sparse with respect to pseudo regs but for hard regs could be fairly dense | |
408 | [relatively speaking]. And recording sets of pseudo-regs in lists speeds | |
7506f491 DE |
409 | up functions like compute_transp since in the case of pseudo-regs we only |
410 | need to iterate over the number of times a pseudo-reg is set, not over the | |
411 | number of basic blocks [clearly there is a bit of a slow down in the cases | |
412 | where a pseudo is set more than once in a block, however it is believed | |
413 | that the net effect is to speed things up]. This isn't done for hard-regs | |
414 | because recording call-clobbered hard-regs in `reg_set_table' at each | |
c4c81601 RK |
415 | function call can consume a fair bit of memory, and iterating over |
416 | hard-regs stored this way in compute_transp will be more expensive. */ | |
7506f491 | 417 | |
c4c81601 RK |
418 | typedef struct reg_set |
419 | { | |
7506f491 DE |
420 | /* The next setting of this register. */ |
421 | struct reg_set *next; | |
ed425871 JL |
422 | /* The index of the block where it was set. */ |
423 | int bb_index; | |
7506f491 | 424 | } reg_set; |
c4c81601 | 425 | |
7506f491 | 426 | static reg_set **reg_set_table; |
c4c81601 | 427 | |
7506f491 DE |
428 | /* Size of `reg_set_table'. |
429 | The table starts out at max_gcse_regno + slop, and is enlarged as | |
430 | necessary. */ | |
431 | static int reg_set_table_size; | |
c4c81601 | 432 | |
7506f491 DE |
433 | /* Amount to grow `reg_set_table' by when it's full. */ |
434 | #define REG_SET_TABLE_SLOP 100 | |
435 | ||
a13d4ebf | 436 | /* This is a list of expressions which are MEMs and will be used by load |
589005ff | 437 | or store motion. |
a13d4ebf | 438 | Load motion tracks MEMs which aren't killed by |
454ff5cb | 439 | anything except itself. (i.e., loads and stores to a single location). |
589005ff | 440 | We can then allow movement of these MEM refs with a little special |
a13d4ebf AM |
441 | allowance. (all stores copy the same value to the reaching reg used |
442 | for the loads). This means all values used to store into memory must have | |
589005ff | 443 | no side effects so we can re-issue the setter value. |
a13d4ebf AM |
444 | Store Motion uses this structure as an expression table to track stores |
445 | which look interesting, and might be moveable towards the exit block. */ | |
446 | ||
447 | struct ls_expr | |
448 | { | |
449 | struct expr * expr; /* Gcse expression reference for LM. */ | |
450 | rtx pattern; /* Pattern of this mem. */ | |
47a3dae1 | 451 | rtx pattern_regs; /* List of registers mentioned by the mem. */ |
aaa4ca30 AJ |
452 | rtx loads; /* INSN list of loads seen. */ |
453 | rtx stores; /* INSN list of stores seen. */ | |
a13d4ebf AM |
454 | struct ls_expr * next; /* Next in the list. */ |
455 | int invalid; /* Invalid for some reason. */ | |
456 | int index; /* If it maps to a bitmap index. */ | |
b58b21d5 | 457 | unsigned int hash_index; /* Index when in a hash table. */ |
a13d4ebf AM |
458 | rtx reaching_reg; /* Register to use when re-writing. */ |
459 | }; | |
460 | ||
fbef91d8 RS |
461 | /* Array of implicit set patterns indexed by basic block index. */ |
462 | static rtx *implicit_sets; | |
463 | ||
a13d4ebf AM |
464 | /* Head of the list of load/store memory refs. */ |
465 | static struct ls_expr * pre_ldst_mems = NULL; | |
466 | ||
9727e468 RG |
467 | /* Hashtable for the load/store memory refs. */ |
468 | static htab_t pre_ldst_table = NULL; | |
469 | ||
7506f491 DE |
470 | /* Bitmap containing one bit for each register in the program. |
471 | Used when performing GCSE to track which registers have been set since | |
472 | the start of the basic block. */ | |
73991d6a | 473 | static regset reg_set_bitmap; |
7506f491 DE |
474 | |
475 | /* For each block, a bitmap of registers set in the block. | |
e83f4801 | 476 | This is used by compute_transp. |
7506f491 DE |
477 | It is computed during hash table computation and not by compute_sets |
478 | as it includes registers added since the last pass (or between cprop and | |
479 | gcse) and it's currently not easy to realloc sbitmap vectors. */ | |
480 | static sbitmap *reg_set_in_block; | |
481 | ||
a13d4ebf AM |
482 | /* Array, indexed by basic block number for a list of insns which modify |
483 | memory within that block. */ | |
484 | static rtx * modify_mem_list; | |
0516f6fe | 485 | static bitmap modify_mem_list_set; |
a13d4ebf AM |
486 | |
487 | /* This array parallels modify_mem_list, but is kept canonicalized. */ | |
488 | static rtx * canon_modify_mem_list; | |
0516f6fe | 489 | |
aa47fcfa JL |
490 | /* Bitmap indexed by block numbers to record which blocks contain |
491 | function calls. */ | |
492 | static bitmap blocks_with_calls; | |
493 | ||
7506f491 DE |
494 | /* Various variables for statistics gathering. */ |
495 | ||
496 | /* Memory used in a pass. | |
497 | This isn't intended to be absolutely precise. Its intent is only | |
498 | to keep an eye on memory usage. */ | |
499 | static int bytes_used; | |
c4c81601 | 500 | |
7506f491 DE |
501 | /* GCSE substitutions made. */ |
502 | static int gcse_subst_count; | |
503 | /* Number of copy instructions created. */ | |
504 | static int gcse_create_count; | |
27fb79ad SB |
505 | /* Number of local constants propagated. */ |
506 | static int local_const_prop_count; | |
0fa2e4df | 507 | /* Number of local copies propagated. */ |
27fb79ad SB |
508 | static int local_copy_prop_count; |
509 | /* Number of global constants propagated. */ | |
510 | static int global_const_prop_count; | |
0fa2e4df | 511 | /* Number of global copies propagated. */ |
27fb79ad | 512 | static int global_copy_prop_count; |
7506f491 | 513 | \f |
e83f4801 SB |
514 | /* For available exprs */ |
515 | static sbitmap *ae_kill, *ae_gen; | |
7506f491 | 516 | \f |
1d088dee | 517 | static void compute_can_copy (void); |
9fe15a12 KG |
518 | static void *gmalloc (size_t) ATTRIBUTE_MALLOC; |
519 | static void *gcalloc (size_t, size_t) ATTRIBUTE_MALLOC; | |
520 | static void *grealloc (void *, size_t); | |
703ad42b | 521 | static void *gcse_alloc (unsigned long); |
eb232f4e | 522 | static void alloc_gcse_mem (void); |
1d088dee AJ |
523 | static void free_gcse_mem (void); |
524 | static void alloc_reg_set_mem (int); | |
525 | static void free_reg_set_mem (void); | |
1d088dee AJ |
526 | static void record_one_set (int, rtx); |
527 | static void record_set_info (rtx, rtx, void *); | |
eb232f4e | 528 | static void compute_sets (void); |
1d088dee AJ |
529 | static void hash_scan_insn (rtx, struct hash_table *, int); |
530 | static void hash_scan_set (rtx, rtx, struct hash_table *); | |
531 | static void hash_scan_clobber (rtx, rtx, struct hash_table *); | |
532 | static void hash_scan_call (rtx, rtx, struct hash_table *); | |
533 | static int want_to_gcse_p (rtx); | |
1707bafa | 534 | static bool can_assign_to_reg_p (rtx); |
1d088dee AJ |
535 | static bool gcse_constant_p (rtx); |
536 | static int oprs_unchanged_p (rtx, rtx, int); | |
537 | static int oprs_anticipatable_p (rtx, rtx); | |
538 | static int oprs_available_p (rtx, rtx); | |
539 | static void insert_expr_in_table (rtx, enum machine_mode, rtx, int, int, | |
540 | struct hash_table *); | |
541 | static void insert_set_in_table (rtx, rtx, struct hash_table *); | |
542 | static unsigned int hash_expr (rtx, enum machine_mode, int *, int); | |
1d088dee AJ |
543 | static unsigned int hash_set (int, int); |
544 | static int expr_equiv_p (rtx, rtx); | |
545 | static void record_last_reg_set_info (rtx, int); | |
546 | static void record_last_mem_set_info (rtx); | |
547 | static void record_last_set_info (rtx, rtx, void *); | |
548 | static void compute_hash_table (struct hash_table *); | |
549 | static void alloc_hash_table (int, struct hash_table *, int); | |
550 | static void free_hash_table (struct hash_table *); | |
551 | static void compute_hash_table_work (struct hash_table *); | |
552 | static void dump_hash_table (FILE *, const char *, struct hash_table *); | |
1d088dee AJ |
553 | static struct expr *lookup_set (unsigned int, struct hash_table *); |
554 | static struct expr *next_set (unsigned int, struct expr *); | |
555 | static void reset_opr_set_tables (void); | |
556 | static int oprs_not_set_p (rtx, rtx); | |
557 | static void mark_call (rtx); | |
558 | static void mark_set (rtx, rtx); | |
559 | static void mark_clobber (rtx, rtx); | |
560 | static void mark_oprs_set (rtx); | |
561 | static void alloc_cprop_mem (int, int); | |
562 | static void free_cprop_mem (void); | |
563 | static void compute_transp (rtx, int, sbitmap *, int); | |
564 | static void compute_transpout (void); | |
565 | static void compute_local_properties (sbitmap *, sbitmap *, sbitmap *, | |
566 | struct hash_table *); | |
567 | static void compute_cprop_data (void); | |
568 | static void find_used_regs (rtx *, void *); | |
569 | static int try_replace_reg (rtx, rtx, rtx); | |
570 | static struct expr *find_avail_set (int, rtx); | |
571 | static int cprop_jump (basic_block, rtx, rtx, rtx, rtx); | |
572 | static void mems_conflict_for_gcse_p (rtx, rtx, void *); | |
573 | static int load_killed_in_block_p (basic_block, int, rtx, int); | |
574 | static void canon_list_insert (rtx, rtx, void *); | |
575 | static int cprop_insn (rtx, int); | |
576 | static int cprop (int); | |
577 | static void find_implicit_sets (void); | |
eb232f4e SB |
578 | static int one_cprop_pass (int, bool, bool); |
579 | static bool constprop_register (rtx, rtx, rtx, bool); | |
1d088dee AJ |
580 | static struct expr *find_bypass_set (int, int); |
581 | static bool reg_killed_on_edge (rtx, edge); | |
582 | static int bypass_block (basic_block, rtx, rtx); | |
583 | static int bypass_conditional_jumps (void); | |
584 | static void alloc_pre_mem (int, int); | |
585 | static void free_pre_mem (void); | |
586 | static void compute_pre_data (void); | |
587 | static int pre_expr_reaches_here_p (basic_block, struct expr *, | |
588 | basic_block); | |
6fb5fa3c | 589 | static void insert_insn_end_basic_block (struct expr *, basic_block, int); |
1d088dee AJ |
590 | static void pre_insert_copy_insn (struct expr *, rtx); |
591 | static void pre_insert_copies (void); | |
592 | static int pre_delete (void); | |
593 | static int pre_gcse (void); | |
594 | static int one_pre_gcse_pass (int); | |
595 | static void add_label_notes (rtx, rtx); | |
596 | static void alloc_code_hoist_mem (int, int); | |
597 | static void free_code_hoist_mem (void); | |
598 | static void compute_code_hoist_vbeinout (void); | |
599 | static void compute_code_hoist_data (void); | |
600 | static int hoist_expr_reaches_here_p (basic_block, int, basic_block, char *); | |
601 | static void hoist_code (void); | |
602 | static int one_code_hoisting_pass (void); | |
1d088dee AJ |
603 | static rtx process_insert_insn (struct expr *); |
604 | static int pre_edge_insert (struct edge_list *, struct expr **); | |
1d088dee AJ |
605 | static int pre_expr_reaches_here_p_work (basic_block, struct expr *, |
606 | basic_block, char *); | |
607 | static struct ls_expr * ldst_entry (rtx); | |
608 | static void free_ldst_entry (struct ls_expr *); | |
609 | static void free_ldst_mems (void); | |
610 | static void print_ldst_list (FILE *); | |
611 | static struct ls_expr * find_rtx_in_ldst (rtx); | |
612 | static int enumerate_ldsts (void); | |
613 | static inline struct ls_expr * first_ls_expr (void); | |
614 | static inline struct ls_expr * next_ls_expr (struct ls_expr *); | |
615 | static int simple_mem (rtx); | |
616 | static void invalidate_any_buried_refs (rtx); | |
617 | static void compute_ld_motion_mems (void); | |
618 | static void trim_ld_motion_mems (void); | |
619 | static void update_ld_motion_stores (struct expr *); | |
620 | static void reg_set_info (rtx, rtx, void *); | |
01c43039 | 621 | static void reg_clear_last_set (rtx, rtx, void *); |
1d088dee AJ |
622 | static bool store_ops_ok (rtx, int *); |
623 | static rtx extract_mentioned_regs (rtx); | |
624 | static rtx extract_mentioned_regs_helper (rtx, rtx); | |
625 | static void find_moveable_store (rtx, int *, int *); | |
626 | static int compute_store_table (void); | |
3b14e3af ZD |
627 | static bool load_kills_store (rtx, rtx, int); |
628 | static bool find_loads (rtx, rtx, int); | |
629 | static bool store_killed_in_insn (rtx, rtx, rtx, int); | |
1d088dee AJ |
630 | static bool store_killed_after (rtx, rtx, rtx, basic_block, int *, rtx *); |
631 | static bool store_killed_before (rtx, rtx, rtx, basic_block, int *); | |
632 | static void build_store_vectors (void); | |
6fb5fa3c | 633 | static void insert_insn_start_basic_block (rtx, basic_block); |
1d088dee | 634 | static int insert_store (struct ls_expr *, edge); |
d088acea ZD |
635 | static void remove_reachable_equiv_notes (basic_block, struct ls_expr *); |
636 | static void replace_store_insn (rtx, rtx, basic_block, struct ls_expr *); | |
1d088dee AJ |
637 | static void delete_store (struct ls_expr *, basic_block); |
638 | static void free_store_memory (void); | |
639 | static void store_motion (void); | |
640 | static void free_insn_expr_list_list (rtx *); | |
641 | static void clear_modify_mem_tables (void); | |
642 | static void free_modify_mem_tables (void); | |
643 | static rtx gcse_emit_move_after (rtx, rtx, rtx); | |
644 | static void local_cprop_find_used_regs (rtx *, void *); | |
eb232f4e | 645 | static bool do_local_cprop (rtx, rtx, bool, rtx*); |
1d088dee | 646 | static bool adjust_libcall_notes (rtx, rtx, rtx, rtx*); |
eb232f4e | 647 | static void local_cprop_pass (bool); |
d128effb | 648 | static bool is_too_expensive (const char *); |
7506f491 | 649 | \f |
d128effb | 650 | |
7506f491 | 651 | /* Entry point for global common subexpression elimination. |
b732f36f KH |
652 | F is the first instruction in the function. Return nonzero if a |
653 | change is mode. */ | |
7506f491 | 654 | |
65727068 | 655 | static int |
10d22567 | 656 | gcse_main (rtx f ATTRIBUTE_UNUSED) |
7506f491 DE |
657 | { |
658 | int changed, pass; | |
659 | /* Bytes used at start of pass. */ | |
660 | int initial_bytes_used; | |
661 | /* Maximum number of bytes used by a pass. */ | |
662 | int max_pass_bytes; | |
663 | /* Point to release obstack data from for each pass. */ | |
664 | char *gcse_obstack_bottom; | |
665 | ||
b5ce41ff JL |
666 | /* We do not construct an accurate cfg in functions which call |
667 | setjmp, so just punt to be safe. */ | |
7506f491 | 668 | if (current_function_calls_setjmp) |
e78d9500 | 669 | return 0; |
589005ff | 670 | |
b5ce41ff JL |
671 | /* Assume that we do not need to run jump optimizations after gcse. */ |
672 | run_jump_opt_after_gcse = 0; | |
673 | ||
b5ce41ff JL |
674 | /* Identify the basic block information for this function, including |
675 | successors and predecessors. */ | |
7506f491 | 676 | max_gcse_regno = max_reg_num (); |
7506f491 | 677 | |
6fb5fa3c DB |
678 | df_note_add_problem (); |
679 | df_analyze (); | |
680 | ||
10d22567 | 681 | if (dump_file) |
5b4fdb20 | 682 | dump_flow_info (dump_file, dump_flags); |
a42cd965 | 683 | |
d128effb | 684 | /* Return if there's nothing to do, or it is too expensive. */ |
ab9a1ff8 SB |
685 | if (n_basic_blocks <= NUM_FIXED_BLOCKS + 1 |
686 | || is_too_expensive (_("GCSE disabled"))) | |
a18820c6 | 687 | return 0; |
7b1b4aed | 688 | |
7506f491 | 689 | gcc_obstack_init (&gcse_obstack); |
a42cd965 | 690 | bytes_used = 0; |
7506f491 | 691 | |
a13d4ebf AM |
692 | /* We need alias. */ |
693 | init_alias_analysis (); | |
c4c81601 RK |
694 | /* Record where pseudo-registers are set. This data is kept accurate |
695 | during each pass. ??? We could also record hard-reg information here | |
696 | [since it's unchanging], however it is currently done during hash table | |
697 | computation. | |
b5ce41ff | 698 | |
c4c81601 RK |
699 | It may be tempting to compute MEM set information here too, but MEM sets |
700 | will be subject to code motion one day and thus we need to compute | |
b5ce41ff | 701 | information about memory sets when we build the hash tables. */ |
7506f491 DE |
702 | |
703 | alloc_reg_set_mem (max_gcse_regno); | |
eb232f4e | 704 | compute_sets (); |
7506f491 DE |
705 | |
706 | pass = 0; | |
707 | initial_bytes_used = bytes_used; | |
708 | max_pass_bytes = 0; | |
709 | gcse_obstack_bottom = gcse_alloc (1); | |
710 | changed = 1; | |
740f35a0 | 711 | while (changed && pass < MAX_GCSE_PASSES) |
7506f491 DE |
712 | { |
713 | changed = 0; | |
10d22567 ZD |
714 | if (dump_file) |
715 | fprintf (dump_file, "GCSE pass %d\n\n", pass + 1); | |
7506f491 DE |
716 | |
717 | /* Initialize bytes_used to the space for the pred/succ lists, | |
718 | and the reg_set_table data. */ | |
719 | bytes_used = initial_bytes_used; | |
720 | ||
721 | /* Each pass may create new registers, so recalculate each time. */ | |
722 | max_gcse_regno = max_reg_num (); | |
723 | ||
eb232f4e | 724 | alloc_gcse_mem (); |
7506f491 | 725 | |
b5ce41ff JL |
726 | /* Don't allow constant propagation to modify jumps |
727 | during this pass. */ | |
27fb79ad | 728 | timevar_push (TV_CPROP1); |
eb232f4e | 729 | changed = one_cprop_pass (pass + 1, false, false); |
27fb79ad | 730 | timevar_pop (TV_CPROP1); |
7506f491 DE |
731 | |
732 | if (optimize_size) | |
e83f4801 | 733 | /* Do nothing. */ ; |
7506f491 | 734 | else |
589005ff | 735 | { |
27fb79ad | 736 | timevar_push (TV_PRE); |
a42cd965 | 737 | changed |= one_pre_gcse_pass (pass + 1); |
a13d4ebf AM |
738 | /* We may have just created new basic blocks. Release and |
739 | recompute various things which are sized on the number of | |
740 | basic blocks. */ | |
741 | if (changed) | |
742 | { | |
73991d6a | 743 | free_modify_mem_tables (); |
9fe15a12 KG |
744 | modify_mem_list = gcalloc (last_basic_block, sizeof (rtx)); |
745 | canon_modify_mem_list = gcalloc (last_basic_block, sizeof (rtx)); | |
a13d4ebf | 746 | } |
a42cd965 AM |
747 | free_reg_set_mem (); |
748 | alloc_reg_set_mem (max_reg_num ()); | |
eb232f4e | 749 | compute_sets (); |
a42cd965 | 750 | run_jump_opt_after_gcse = 1; |
27fb79ad | 751 | timevar_pop (TV_PRE); |
a42cd965 | 752 | } |
7506f491 DE |
753 | |
754 | if (max_pass_bytes < bytes_used) | |
755 | max_pass_bytes = bytes_used; | |
756 | ||
bb457bd9 JL |
757 | /* Free up memory, then reallocate for code hoisting. We can |
758 | not re-use the existing allocated memory because the tables | |
759 | will not have info for the insns or registers created by | |
760 | partial redundancy elimination. */ | |
7506f491 DE |
761 | free_gcse_mem (); |
762 | ||
5d3cc252 | 763 | /* It does not make sense to run code hoisting unless we are optimizing |
bb457bd9 JL |
764 | for code size -- it rarely makes programs faster, and can make |
765 | them bigger if we did partial redundancy elimination (when optimizing | |
e83f4801 | 766 | for space, we don't run the partial redundancy algorithms). */ |
bb457bd9 | 767 | if (optimize_size) |
589005ff | 768 | { |
27fb79ad | 769 | timevar_push (TV_HOIST); |
bb457bd9 | 770 | max_gcse_regno = max_reg_num (); |
eb232f4e | 771 | alloc_gcse_mem (); |
bb457bd9 JL |
772 | changed |= one_code_hoisting_pass (); |
773 | free_gcse_mem (); | |
774 | ||
775 | if (max_pass_bytes < bytes_used) | |
776 | max_pass_bytes = bytes_used; | |
27fb79ad | 777 | timevar_pop (TV_HOIST); |
589005ff | 778 | } |
bb457bd9 | 779 | |
10d22567 | 780 | if (dump_file) |
7506f491 | 781 | { |
10d22567 ZD |
782 | fprintf (dump_file, "\n"); |
783 | fflush (dump_file); | |
7506f491 | 784 | } |
c4c81601 | 785 | |
7506f491 DE |
786 | obstack_free (&gcse_obstack, gcse_obstack_bottom); |
787 | pass++; | |
788 | } | |
789 | ||
b5ce41ff JL |
790 | /* Do one last pass of copy propagation, including cprop into |
791 | conditional jumps. */ | |
792 | ||
793 | max_gcse_regno = max_reg_num (); | |
eb232f4e | 794 | alloc_gcse_mem (); |
b5ce41ff | 795 | /* This time, go ahead and allow cprop to alter jumps. */ |
27fb79ad | 796 | timevar_push (TV_CPROP2); |
bae8b6b2 | 797 | one_cprop_pass (pass + 1, true, true); |
27fb79ad | 798 | timevar_pop (TV_CPROP2); |
b5ce41ff | 799 | free_gcse_mem (); |
7506f491 | 800 | |
10d22567 | 801 | if (dump_file) |
7506f491 | 802 | { |
10d22567 | 803 | fprintf (dump_file, "GCSE of %s: %d basic blocks, ", |
faed5cc3 | 804 | current_function_name (), n_basic_blocks); |
10d22567 | 805 | fprintf (dump_file, "%d pass%s, %d bytes\n\n", |
7506f491 DE |
806 | pass, pass > 1 ? "es" : "", max_pass_bytes); |
807 | } | |
808 | ||
6496a589 | 809 | obstack_free (&gcse_obstack, NULL); |
7506f491 | 810 | free_reg_set_mem (); |
7b1b4aed | 811 | |
a13d4ebf AM |
812 | /* We are finished with alias. */ |
813 | end_alias_analysis (); | |
a13d4ebf | 814 | |
47a3dae1 | 815 | if (!optimize_size && flag_gcse_sm) |
27fb79ad SB |
816 | { |
817 | timevar_push (TV_LSM); | |
818 | store_motion (); | |
819 | timevar_pop (TV_LSM); | |
820 | } | |
47a3dae1 | 821 | |
a13d4ebf | 822 | /* Record where pseudo-registers are set. */ |
e78d9500 | 823 | return run_jump_opt_after_gcse; |
7506f491 DE |
824 | } |
825 | \f | |
826 | /* Misc. utilities. */ | |
827 | ||
773eae39 EB |
828 | /* Nonzero for each mode that supports (set (reg) (reg)). |
829 | This is trivially true for integer and floating point values. | |
830 | It may or may not be true for condition codes. */ | |
831 | static char can_copy[(int) NUM_MACHINE_MODES]; | |
832 | ||
7506f491 DE |
833 | /* Compute which modes support reg/reg copy operations. */ |
834 | ||
835 | static void | |
1d088dee | 836 | compute_can_copy (void) |
7506f491 DE |
837 | { |
838 | int i; | |
50b2596f | 839 | #ifndef AVOID_CCMODE_COPIES |
8e42ace1 | 840 | rtx reg, insn; |
50b2596f | 841 | #endif |
773eae39 | 842 | memset (can_copy, 0, NUM_MACHINE_MODES); |
7506f491 DE |
843 | |
844 | start_sequence (); | |
845 | for (i = 0; i < NUM_MACHINE_MODES; i++) | |
c4c81601 RK |
846 | if (GET_MODE_CLASS (i) == MODE_CC) |
847 | { | |
7506f491 | 848 | #ifdef AVOID_CCMODE_COPIES |
773eae39 | 849 | can_copy[i] = 0; |
7506f491 | 850 | #else |
c4c81601 RK |
851 | reg = gen_rtx_REG ((enum machine_mode) i, LAST_VIRTUAL_REGISTER + 1); |
852 | insn = emit_insn (gen_rtx_SET (VOIDmode, reg, reg)); | |
9714cf43 | 853 | if (recog (PATTERN (insn), insn, NULL) >= 0) |
773eae39 | 854 | can_copy[i] = 1; |
7506f491 | 855 | #endif |
c4c81601 | 856 | } |
141b5810 | 857 | else |
773eae39 | 858 | can_copy[i] = 1; |
c4c81601 | 859 | |
7506f491 | 860 | end_sequence (); |
7506f491 | 861 | } |
773eae39 EB |
862 | |
863 | /* Returns whether the mode supports reg/reg copy operations. */ | |
864 | ||
865 | bool | |
1d088dee | 866 | can_copy_p (enum machine_mode mode) |
773eae39 EB |
867 | { |
868 | static bool can_copy_init_p = false; | |
869 | ||
870 | if (! can_copy_init_p) | |
871 | { | |
872 | compute_can_copy (); | |
873 | can_copy_init_p = true; | |
874 | } | |
875 | ||
876 | return can_copy[mode] != 0; | |
877 | } | |
7506f491 DE |
878 | \f |
879 | /* Cover function to xmalloc to record bytes allocated. */ | |
880 | ||
703ad42b | 881 | static void * |
4ac11022 | 882 | gmalloc (size_t size) |
7506f491 DE |
883 | { |
884 | bytes_used += size; | |
885 | return xmalloc (size); | |
886 | } | |
887 | ||
9fe15a12 KG |
888 | /* Cover function to xcalloc to record bytes allocated. */ |
889 | ||
890 | static void * | |
891 | gcalloc (size_t nelem, size_t elsize) | |
892 | { | |
893 | bytes_used += nelem * elsize; | |
894 | return xcalloc (nelem, elsize); | |
895 | } | |
896 | ||
7506f491 DE |
897 | /* Cover function to xrealloc. |
898 | We don't record the additional size since we don't know it. | |
899 | It won't affect memory usage stats much anyway. */ | |
900 | ||
703ad42b | 901 | static void * |
9fe15a12 | 902 | grealloc (void *ptr, size_t size) |
7506f491 DE |
903 | { |
904 | return xrealloc (ptr, size); | |
905 | } | |
906 | ||
77bbd421 | 907 | /* Cover function to obstack_alloc. */ |
7506f491 | 908 | |
703ad42b | 909 | static void * |
1d088dee | 910 | gcse_alloc (unsigned long size) |
7506f491 | 911 | { |
77bbd421 | 912 | bytes_used += size; |
703ad42b | 913 | return obstack_alloc (&gcse_obstack, size); |
7506f491 DE |
914 | } |
915 | ||
916 | /* Allocate memory for the cuid mapping array, | |
917 | and reg/memory set tracking tables. | |
918 | ||
919 | This is called at the start of each pass. */ | |
920 | ||
921 | static void | |
eb232f4e | 922 | alloc_gcse_mem (void) |
7506f491 | 923 | { |
9fe15a12 | 924 | int i; |
eb232f4e | 925 | basic_block bb; |
7506f491 DE |
926 | rtx insn; |
927 | ||
928 | /* Find the largest UID and create a mapping from UIDs to CUIDs. | |
929 | CUIDs are like UIDs except they increase monotonically, have no gaps, | |
eb232f4e SB |
930 | and only apply to real insns. |
931 | (Actually, there are gaps, for insn that are not inside a basic block. | |
932 | but we should never see those anyway, so this is OK.) */ | |
7506f491 DE |
933 | |
934 | max_uid = get_max_uid (); | |
9fe15a12 | 935 | uid_cuid = gcalloc (max_uid + 1, sizeof (int)); |
eb232f4e SB |
936 | i = 0; |
937 | FOR_EACH_BB (bb) | |
938 | FOR_BB_INSNS (bb, insn) | |
939 | { | |
940 | if (INSN_P (insn)) | |
941 | uid_cuid[INSN_UID (insn)] = i++; | |
942 | else | |
943 | uid_cuid[INSN_UID (insn)] = i; | |
944 | } | |
7506f491 DE |
945 | |
946 | /* Create a table mapping cuids to insns. */ | |
947 | ||
948 | max_cuid = i; | |
9fe15a12 | 949 | cuid_insn = gcalloc (max_cuid + 1, sizeof (rtx)); |
eb232f4e SB |
950 | i = 0; |
951 | FOR_EACH_BB (bb) | |
952 | FOR_BB_INSNS (bb, insn) | |
953 | if (INSN_P (insn)) | |
954 | CUID_INSN (i++) = insn; | |
7506f491 DE |
955 | |
956 | /* Allocate vars to track sets of regs. */ | |
8bdbfff5 | 957 | reg_set_bitmap = BITMAP_ALLOC (NULL); |
7506f491 DE |
958 | |
959 | /* Allocate vars to track sets of regs, memory per block. */ | |
703ad42b | 960 | reg_set_in_block = sbitmap_vector_alloc (last_basic_block, max_gcse_regno); |
a13d4ebf AM |
961 | /* Allocate array to keep a list of insns which modify memory in each |
962 | basic block. */ | |
9fe15a12 KG |
963 | modify_mem_list = gcalloc (last_basic_block, sizeof (rtx)); |
964 | canon_modify_mem_list = gcalloc (last_basic_block, sizeof (rtx)); | |
8bdbfff5 NS |
965 | modify_mem_list_set = BITMAP_ALLOC (NULL); |
966 | blocks_with_calls = BITMAP_ALLOC (NULL); | |
7506f491 DE |
967 | } |
968 | ||
969 | /* Free memory allocated by alloc_gcse_mem. */ | |
970 | ||
971 | static void | |
1d088dee | 972 | free_gcse_mem (void) |
7506f491 DE |
973 | { |
974 | free (uid_cuid); | |
975 | free (cuid_insn); | |
976 | ||
8bdbfff5 | 977 | BITMAP_FREE (reg_set_bitmap); |
7506f491 | 978 | |
5a660bff | 979 | sbitmap_vector_free (reg_set_in_block); |
73991d6a | 980 | free_modify_mem_tables (); |
8bdbfff5 NS |
981 | BITMAP_FREE (modify_mem_list_set); |
982 | BITMAP_FREE (blocks_with_calls); | |
7506f491 | 983 | } |
b5ce41ff JL |
984 | \f |
985 | /* Compute the local properties of each recorded expression. | |
c4c81601 RK |
986 | |
987 | Local properties are those that are defined by the block, irrespective of | |
988 | other blocks. | |
b5ce41ff JL |
989 | |
990 | An expression is transparent in a block if its operands are not modified | |
991 | in the block. | |
992 | ||
993 | An expression is computed (locally available) in a block if it is computed | |
994 | at least once and expression would contain the same value if the | |
995 | computation was moved to the end of the block. | |
996 | ||
997 | An expression is locally anticipatable in a block if it is computed at | |
998 | least once and expression would contain the same value if the computation | |
999 | was moved to the beginning of the block. | |
1000 | ||
c4c81601 RK |
1001 | We call this routine for cprop, pre and code hoisting. They all compute |
1002 | basically the same information and thus can easily share this code. | |
7506f491 | 1003 | |
c4c81601 RK |
1004 | TRANSP, COMP, and ANTLOC are destination sbitmaps for recording local |
1005 | properties. If NULL, then it is not necessary to compute or record that | |
1006 | particular property. | |
b5ce41ff | 1007 | |
02280659 ZD |
1008 | TABLE controls which hash table to look at. If it is set hash table, |
1009 | additionally, TRANSP is computed as ~TRANSP, since this is really cprop's | |
c4c81601 | 1010 | ABSALTERED. */ |
589005ff | 1011 | |
b5ce41ff | 1012 | static void |
7b1b4aed SB |
1013 | compute_local_properties (sbitmap *transp, sbitmap *comp, sbitmap *antloc, |
1014 | struct hash_table *table) | |
b5ce41ff | 1015 | { |
02280659 | 1016 | unsigned int i; |
589005ff | 1017 | |
b5ce41ff JL |
1018 | /* Initialize any bitmaps that were passed in. */ |
1019 | if (transp) | |
695ab36a | 1020 | { |
02280659 | 1021 | if (table->set_p) |
d55bc081 | 1022 | sbitmap_vector_zero (transp, last_basic_block); |
695ab36a | 1023 | else |
d55bc081 | 1024 | sbitmap_vector_ones (transp, last_basic_block); |
695ab36a | 1025 | } |
c4c81601 | 1026 | |
b5ce41ff | 1027 | if (comp) |
d55bc081 | 1028 | sbitmap_vector_zero (comp, last_basic_block); |
b5ce41ff | 1029 | if (antloc) |
d55bc081 | 1030 | sbitmap_vector_zero (antloc, last_basic_block); |
b5ce41ff | 1031 | |
02280659 | 1032 | for (i = 0; i < table->size; i++) |
7506f491 | 1033 | { |
b5ce41ff JL |
1034 | struct expr *expr; |
1035 | ||
02280659 | 1036 | for (expr = table->table[i]; expr != NULL; expr = expr->next_same_hash) |
b5ce41ff | 1037 | { |
b5ce41ff | 1038 | int indx = expr->bitmap_index; |
c4c81601 | 1039 | struct occr *occr; |
b5ce41ff JL |
1040 | |
1041 | /* The expression is transparent in this block if it is not killed. | |
1042 | We start by assuming all are transparent [none are killed], and | |
1043 | then reset the bits for those that are. */ | |
b5ce41ff | 1044 | if (transp) |
02280659 | 1045 | compute_transp (expr->expr, indx, transp, table->set_p); |
b5ce41ff JL |
1046 | |
1047 | /* The occurrences recorded in antic_occr are exactly those that | |
cc2902df | 1048 | we want to set to nonzero in ANTLOC. */ |
b5ce41ff | 1049 | if (antloc) |
c4c81601 RK |
1050 | for (occr = expr->antic_occr; occr != NULL; occr = occr->next) |
1051 | { | |
1052 | SET_BIT (antloc[BLOCK_NUM (occr->insn)], indx); | |
b5ce41ff | 1053 | |
c4c81601 RK |
1054 | /* While we're scanning the table, this is a good place to |
1055 | initialize this. */ | |
1056 | occr->deleted_p = 0; | |
1057 | } | |
b5ce41ff JL |
1058 | |
1059 | /* The occurrences recorded in avail_occr are exactly those that | |
cc2902df | 1060 | we want to set to nonzero in COMP. */ |
b5ce41ff | 1061 | if (comp) |
c4c81601 RK |
1062 | for (occr = expr->avail_occr; occr != NULL; occr = occr->next) |
1063 | { | |
1064 | SET_BIT (comp[BLOCK_NUM (occr->insn)], indx); | |
b5ce41ff | 1065 | |
c4c81601 RK |
1066 | /* While we're scanning the table, this is a good place to |
1067 | initialize this. */ | |
1068 | occr->copied_p = 0; | |
1069 | } | |
b5ce41ff JL |
1070 | |
1071 | /* While we're scanning the table, this is a good place to | |
1072 | initialize this. */ | |
1073 | expr->reaching_reg = 0; | |
1074 | } | |
7506f491 | 1075 | } |
7506f491 DE |
1076 | } |
1077 | \f | |
1078 | /* Register set information. | |
1079 | ||
1080 | `reg_set_table' records where each register is set or otherwise | |
1081 | modified. */ | |
1082 | ||
1083 | static struct obstack reg_set_obstack; | |
1084 | ||
1085 | static void | |
1d088dee | 1086 | alloc_reg_set_mem (int n_regs) |
7506f491 | 1087 | { |
7506f491 | 1088 | reg_set_table_size = n_regs + REG_SET_TABLE_SLOP; |
9fe15a12 | 1089 | reg_set_table = gcalloc (reg_set_table_size, sizeof (struct reg_set *)); |
7506f491 DE |
1090 | |
1091 | gcc_obstack_init (®_set_obstack); | |
1092 | } | |
1093 | ||
1094 | static void | |
1d088dee | 1095 | free_reg_set_mem (void) |
7506f491 DE |
1096 | { |
1097 | free (reg_set_table); | |
6496a589 | 1098 | obstack_free (®_set_obstack, NULL); |
7506f491 DE |
1099 | } |
1100 | ||
1101 | /* Record REGNO in the reg_set table. */ | |
1102 | ||
1103 | static void | |
1d088dee | 1104 | record_one_set (int regno, rtx insn) |
7506f491 | 1105 | { |
172890a2 | 1106 | /* Allocate a new reg_set element and link it onto the list. */ |
63bc1d05 | 1107 | struct reg_set *new_reg_info; |
7506f491 DE |
1108 | |
1109 | /* If the table isn't big enough, enlarge it. */ | |
1110 | if (regno >= reg_set_table_size) | |
1111 | { | |
1112 | int new_size = regno + REG_SET_TABLE_SLOP; | |
c4c81601 | 1113 | |
703ad42b KG |
1114 | reg_set_table = grealloc (reg_set_table, |
1115 | new_size * sizeof (struct reg_set *)); | |
1116 | memset (reg_set_table + reg_set_table_size, 0, | |
8e42ace1 | 1117 | (new_size - reg_set_table_size) * sizeof (struct reg_set *)); |
7506f491 DE |
1118 | reg_set_table_size = new_size; |
1119 | } | |
1120 | ||
703ad42b | 1121 | new_reg_info = obstack_alloc (®_set_obstack, sizeof (struct reg_set)); |
7506f491 | 1122 | bytes_used += sizeof (struct reg_set); |
ed425871 | 1123 | new_reg_info->bb_index = BLOCK_NUM (insn); |
274969ea MM |
1124 | new_reg_info->next = reg_set_table[regno]; |
1125 | reg_set_table[regno] = new_reg_info; | |
7506f491 DE |
1126 | } |
1127 | ||
c4c81601 RK |
1128 | /* Called from compute_sets via note_stores to handle one SET or CLOBBER in |
1129 | an insn. The DATA is really the instruction in which the SET is | |
1130 | occurring. */ | |
7506f491 DE |
1131 | |
1132 | static void | |
1d088dee | 1133 | record_set_info (rtx dest, rtx setter ATTRIBUTE_UNUSED, void *data) |
7506f491 | 1134 | { |
84832317 MM |
1135 | rtx record_set_insn = (rtx) data; |
1136 | ||
7b1b4aed | 1137 | if (REG_P (dest) && REGNO (dest) >= FIRST_PSEUDO_REGISTER) |
c4c81601 | 1138 | record_one_set (REGNO (dest), record_set_insn); |
7506f491 DE |
1139 | } |
1140 | ||
1141 | /* Scan the function and record each set of each pseudo-register. | |
1142 | ||
c4c81601 | 1143 | This is called once, at the start of the gcse pass. See the comments for |
fbe5a4a6 | 1144 | `reg_set_table' for further documentation. */ |
7506f491 DE |
1145 | |
1146 | static void | |
eb232f4e | 1147 | compute_sets (void) |
7506f491 | 1148 | { |
eb232f4e | 1149 | basic_block bb; |
c4c81601 | 1150 | rtx insn; |
7506f491 | 1151 | |
eb232f4e SB |
1152 | FOR_EACH_BB (bb) |
1153 | FOR_BB_INSNS (bb, insn) | |
1154 | if (INSN_P (insn)) | |
1155 | note_stores (PATTERN (insn), record_set_info, insn); | |
7506f491 DE |
1156 | } |
1157 | \f | |
1158 | /* Hash table support. */ | |
1159 | ||
80c29cc4 RZ |
1160 | struct reg_avail_info |
1161 | { | |
e0082a72 | 1162 | basic_block last_bb; |
80c29cc4 RZ |
1163 | int first_set; |
1164 | int last_set; | |
1165 | }; | |
1166 | ||
1167 | static struct reg_avail_info *reg_avail_info; | |
e0082a72 | 1168 | static basic_block current_bb; |
7506f491 | 1169 | |
7506f491 | 1170 | |
fb0c0a12 RK |
1171 | /* See whether X, the source of a set, is something we want to consider for |
1172 | GCSE. */ | |
7506f491 DE |
1173 | |
1174 | static int | |
1d088dee | 1175 | want_to_gcse_p (rtx x) |
7506f491 | 1176 | { |
3d8504ac RS |
1177 | #ifdef STACK_REGS |
1178 | /* On register stack architectures, don't GCSE constants from the | |
1179 | constant pool, as the benefits are often swamped by the overhead | |
1180 | of shuffling the register stack between basic blocks. */ | |
1181 | if (IS_STACK_MODE (GET_MODE (x))) | |
1182 | x = avoid_constant_pool_reference (x); | |
1183 | #endif | |
1184 | ||
c4c81601 | 1185 | switch (GET_CODE (x)) |
7506f491 DE |
1186 | { |
1187 | case REG: | |
1188 | case SUBREG: | |
1189 | case CONST_INT: | |
1190 | case CONST_DOUBLE: | |
69ef87e2 | 1191 | case CONST_VECTOR: |
7506f491 DE |
1192 | case CALL: |
1193 | return 0; | |
1194 | ||
1195 | default: | |
1707bafa | 1196 | return can_assign_to_reg_p (x); |
7506f491 | 1197 | } |
1707bafa RS |
1198 | } |
1199 | ||
1200 | /* Used internally by can_assign_to_reg_p. */ | |
1201 | ||
1202 | static GTY(()) rtx test_insn; | |
1203 | ||
1204 | /* Return true if we can assign X to a pseudo register. */ | |
1205 | ||
1206 | static bool | |
1207 | can_assign_to_reg_p (rtx x) | |
1208 | { | |
1209 | int num_clobbers = 0; | |
1210 | int icode; | |
7506f491 | 1211 | |
fb0c0a12 RK |
1212 | /* If this is a valid operand, we are OK. If it's VOIDmode, we aren't. */ |
1213 | if (general_operand (x, GET_MODE (x))) | |
1214 | return 1; | |
1215 | else if (GET_MODE (x) == VOIDmode) | |
1216 | return 0; | |
1217 | ||
1218 | /* Otherwise, check if we can make a valid insn from it. First initialize | |
1219 | our test insn if we haven't already. */ | |
1220 | if (test_insn == 0) | |
1221 | { | |
1222 | test_insn | |
1223 | = make_insn_raw (gen_rtx_SET (VOIDmode, | |
1224 | gen_rtx_REG (word_mode, | |
1225 | FIRST_PSEUDO_REGISTER * 2), | |
1226 | const0_rtx)); | |
1227 | NEXT_INSN (test_insn) = PREV_INSN (test_insn) = 0; | |
fb0c0a12 RK |
1228 | } |
1229 | ||
1230 | /* Now make an insn like the one we would make when GCSE'ing and see if | |
1231 | valid. */ | |
1232 | PUT_MODE (SET_DEST (PATTERN (test_insn)), GET_MODE (x)); | |
1233 | SET_SRC (PATTERN (test_insn)) = x; | |
1234 | return ((icode = recog (PATTERN (test_insn), test_insn, &num_clobbers)) >= 0 | |
1235 | && (num_clobbers == 0 || ! added_clobbers_hard_reg_p (icode))); | |
7506f491 DE |
1236 | } |
1237 | ||
cc2902df | 1238 | /* Return nonzero if the operands of expression X are unchanged from the |
7506f491 DE |
1239 | start of INSN's basic block up to but not including INSN (if AVAIL_P == 0), |
1240 | or from INSN to the end of INSN's basic block (if AVAIL_P != 0). */ | |
1241 | ||
1242 | static int | |
1d088dee | 1243 | oprs_unchanged_p (rtx x, rtx insn, int avail_p) |
7506f491 | 1244 | { |
c4c81601 | 1245 | int i, j; |
7506f491 | 1246 | enum rtx_code code; |
6f7d635c | 1247 | const char *fmt; |
7506f491 | 1248 | |
7506f491 DE |
1249 | if (x == 0) |
1250 | return 1; | |
1251 | ||
1252 | code = GET_CODE (x); | |
1253 | switch (code) | |
1254 | { | |
1255 | case REG: | |
80c29cc4 RZ |
1256 | { |
1257 | struct reg_avail_info *info = ®_avail_info[REGNO (x)]; | |
1258 | ||
1259 | if (info->last_bb != current_bb) | |
1260 | return 1; | |
589005ff | 1261 | if (avail_p) |
80c29cc4 RZ |
1262 | return info->last_set < INSN_CUID (insn); |
1263 | else | |
1264 | return info->first_set >= INSN_CUID (insn); | |
1265 | } | |
7506f491 DE |
1266 | |
1267 | case MEM: | |
e0082a72 | 1268 | if (load_killed_in_block_p (current_bb, INSN_CUID (insn), |
a13d4ebf AM |
1269 | x, avail_p)) |
1270 | return 0; | |
7506f491 | 1271 | else |
c4c81601 | 1272 | return oprs_unchanged_p (XEXP (x, 0), insn, avail_p); |
7506f491 DE |
1273 | |
1274 | case PRE_DEC: | |
1275 | case PRE_INC: | |
1276 | case POST_DEC: | |
1277 | case POST_INC: | |
4b983fdc RH |
1278 | case PRE_MODIFY: |
1279 | case POST_MODIFY: | |
7506f491 DE |
1280 | return 0; |
1281 | ||
1282 | case PC: | |
1283 | case CC0: /*FIXME*/ | |
1284 | case CONST: | |
1285 | case CONST_INT: | |
1286 | case CONST_DOUBLE: | |
69ef87e2 | 1287 | case CONST_VECTOR: |
7506f491 DE |
1288 | case SYMBOL_REF: |
1289 | case LABEL_REF: | |
1290 | case ADDR_VEC: | |
1291 | case ADDR_DIFF_VEC: | |
1292 | return 1; | |
1293 | ||
1294 | default: | |
1295 | break; | |
1296 | } | |
1297 | ||
c4c81601 | 1298 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
1299 | { |
1300 | if (fmt[i] == 'e') | |
1301 | { | |
c4c81601 RK |
1302 | /* If we are about to do the last recursive call needed at this |
1303 | level, change it into iteration. This function is called enough | |
1304 | to be worth it. */ | |
7506f491 | 1305 | if (i == 0) |
c4c81601 RK |
1306 | return oprs_unchanged_p (XEXP (x, i), insn, avail_p); |
1307 | ||
1308 | else if (! oprs_unchanged_p (XEXP (x, i), insn, avail_p)) | |
7506f491 DE |
1309 | return 0; |
1310 | } | |
1311 | else if (fmt[i] == 'E') | |
c4c81601 RK |
1312 | for (j = 0; j < XVECLEN (x, i); j++) |
1313 | if (! oprs_unchanged_p (XVECEXP (x, i, j), insn, avail_p)) | |
1314 | return 0; | |
7506f491 DE |
1315 | } |
1316 | ||
1317 | return 1; | |
1318 | } | |
1319 | ||
a13d4ebf AM |
1320 | /* Used for communication between mems_conflict_for_gcse_p and |
1321 | load_killed_in_block_p. Nonzero if mems_conflict_for_gcse_p finds a | |
1322 | conflict between two memory references. */ | |
1323 | static int gcse_mems_conflict_p; | |
1324 | ||
1325 | /* Used for communication between mems_conflict_for_gcse_p and | |
1326 | load_killed_in_block_p. A memory reference for a load instruction, | |
1327 | mems_conflict_for_gcse_p will see if a memory store conflicts with | |
1328 | this memory load. */ | |
1329 | static rtx gcse_mem_operand; | |
1330 | ||
1331 | /* DEST is the output of an instruction. If it is a memory reference, and | |
1332 | possibly conflicts with the load found in gcse_mem_operand, then set | |
1333 | gcse_mems_conflict_p to a nonzero value. */ | |
1334 | ||
1335 | static void | |
1d088dee AJ |
1336 | mems_conflict_for_gcse_p (rtx dest, rtx setter ATTRIBUTE_UNUSED, |
1337 | void *data ATTRIBUTE_UNUSED) | |
a13d4ebf AM |
1338 | { |
1339 | while (GET_CODE (dest) == SUBREG | |
1340 | || GET_CODE (dest) == ZERO_EXTRACT | |
a13d4ebf AM |
1341 | || GET_CODE (dest) == STRICT_LOW_PART) |
1342 | dest = XEXP (dest, 0); | |
1343 | ||
1344 | /* If DEST is not a MEM, then it will not conflict with the load. Note | |
1345 | that function calls are assumed to clobber memory, but are handled | |
1346 | elsewhere. */ | |
7b1b4aed | 1347 | if (! MEM_P (dest)) |
a13d4ebf | 1348 | return; |
aaa4ca30 | 1349 | |
a13d4ebf | 1350 | /* If we are setting a MEM in our list of specially recognized MEMs, |
589005ff KH |
1351 | don't mark as killed this time. */ |
1352 | ||
47a3dae1 | 1353 | if (expr_equiv_p (dest, gcse_mem_operand) && pre_ldst_mems != NULL) |
a13d4ebf AM |
1354 | { |
1355 | if (!find_rtx_in_ldst (dest)) | |
1356 | gcse_mems_conflict_p = 1; | |
1357 | return; | |
1358 | } | |
aaa4ca30 | 1359 | |
a13d4ebf AM |
1360 | if (true_dependence (dest, GET_MODE (dest), gcse_mem_operand, |
1361 | rtx_addr_varies_p)) | |
1362 | gcse_mems_conflict_p = 1; | |
1363 | } | |
1364 | ||
1365 | /* Return nonzero if the expression in X (a memory reference) is killed | |
1366 | in block BB before or after the insn with the CUID in UID_LIMIT. | |
1367 | AVAIL_P is nonzero for kills after UID_LIMIT, and zero for kills | |
1368 | before UID_LIMIT. | |
1369 | ||
1370 | To check the entire block, set UID_LIMIT to max_uid + 1 and | |
1371 | AVAIL_P to 0. */ | |
1372 | ||
1373 | static int | |
1d088dee | 1374 | load_killed_in_block_p (basic_block bb, int uid_limit, rtx x, int avail_p) |
a13d4ebf | 1375 | { |
0b17ab2f | 1376 | rtx list_entry = modify_mem_list[bb->index]; |
16c5b95d MH |
1377 | |
1378 | /* If this is a readonly then we aren't going to be changing it. */ | |
1379 | if (MEM_READONLY_P (x)) | |
1380 | return 0; | |
1381 | ||
a13d4ebf AM |
1382 | while (list_entry) |
1383 | { | |
1384 | rtx setter; | |
1385 | /* Ignore entries in the list that do not apply. */ | |
1386 | if ((avail_p | |
1387 | && INSN_CUID (XEXP (list_entry, 0)) < uid_limit) | |
1388 | || (! avail_p | |
1389 | && INSN_CUID (XEXP (list_entry, 0)) > uid_limit)) | |
1390 | { | |
1391 | list_entry = XEXP (list_entry, 1); | |
1392 | continue; | |
1393 | } | |
1394 | ||
1395 | setter = XEXP (list_entry, 0); | |
1396 | ||
1397 | /* If SETTER is a call everything is clobbered. Note that calls | |
1398 | to pure functions are never put on the list, so we need not | |
1399 | worry about them. */ | |
7b1b4aed | 1400 | if (CALL_P (setter)) |
a13d4ebf AM |
1401 | return 1; |
1402 | ||
1403 | /* SETTER must be an INSN of some kind that sets memory. Call | |
589005ff | 1404 | note_stores to examine each hunk of memory that is modified. |
a13d4ebf AM |
1405 | |
1406 | The note_stores interface is pretty limited, so we have to | |
1407 | communicate via global variables. Yuk. */ | |
1408 | gcse_mem_operand = x; | |
1409 | gcse_mems_conflict_p = 0; | |
1410 | note_stores (PATTERN (setter), mems_conflict_for_gcse_p, NULL); | |
1411 | if (gcse_mems_conflict_p) | |
1412 | return 1; | |
1413 | list_entry = XEXP (list_entry, 1); | |
1414 | } | |
1415 | return 0; | |
1416 | } | |
1417 | ||
cc2902df | 1418 | /* Return nonzero if the operands of expression X are unchanged from |
7506f491 DE |
1419 | the start of INSN's basic block up to but not including INSN. */ |
1420 | ||
1421 | static int | |
1d088dee | 1422 | oprs_anticipatable_p (rtx x, rtx insn) |
7506f491 DE |
1423 | { |
1424 | return oprs_unchanged_p (x, insn, 0); | |
1425 | } | |
1426 | ||
cc2902df | 1427 | /* Return nonzero if the operands of expression X are unchanged from |
7506f491 DE |
1428 | INSN to the end of INSN's basic block. */ |
1429 | ||
1430 | static int | |
1d088dee | 1431 | oprs_available_p (rtx x, rtx insn) |
7506f491 DE |
1432 | { |
1433 | return oprs_unchanged_p (x, insn, 1); | |
1434 | } | |
1435 | ||
1436 | /* Hash expression X. | |
c4c81601 RK |
1437 | |
1438 | MODE is only used if X is a CONST_INT. DO_NOT_RECORD_P is a boolean | |
1439 | indicating if a volatile operand is found or if the expression contains | |
b58b21d5 | 1440 | something we don't want to insert in the table. HASH_TABLE_SIZE is |
0516f6fe | 1441 | the current size of the hash table to be probed. */ |
7506f491 DE |
1442 | |
1443 | static unsigned int | |
b58b21d5 RS |
1444 | hash_expr (rtx x, enum machine_mode mode, int *do_not_record_p, |
1445 | int hash_table_size) | |
7506f491 DE |
1446 | { |
1447 | unsigned int hash; | |
1448 | ||
1449 | *do_not_record_p = 0; | |
1450 | ||
0516f6fe SB |
1451 | hash = hash_rtx (x, mode, do_not_record_p, |
1452 | NULL, /*have_reg_qty=*/false); | |
7506f491 DE |
1453 | return hash % hash_table_size; |
1454 | } | |
172890a2 | 1455 | |
7506f491 DE |
1456 | /* Hash a set of register REGNO. |
1457 | ||
c4c81601 RK |
1458 | Sets are hashed on the register that is set. This simplifies the PRE copy |
1459 | propagation code. | |
7506f491 DE |
1460 | |
1461 | ??? May need to make things more elaborate. Later, as necessary. */ | |
1462 | ||
1463 | static unsigned int | |
1d088dee | 1464 | hash_set (int regno, int hash_table_size) |
7506f491 DE |
1465 | { |
1466 | unsigned int hash; | |
1467 | ||
1468 | hash = regno; | |
1469 | return hash % hash_table_size; | |
1470 | } | |
1471 | ||
0516f6fe | 1472 | /* Return nonzero if exp1 is equivalent to exp2. */ |
7506f491 DE |
1473 | |
1474 | static int | |
1d088dee | 1475 | expr_equiv_p (rtx x, rtx y) |
7506f491 | 1476 | { |
0516f6fe | 1477 | return exp_equiv_p (x, y, 0, true); |
7506f491 DE |
1478 | } |
1479 | ||
02280659 | 1480 | /* Insert expression X in INSN in the hash TABLE. |
7506f491 DE |
1481 | If it is already present, record it as the last occurrence in INSN's |
1482 | basic block. | |
1483 | ||
1484 | MODE is the mode of the value X is being stored into. | |
1485 | It is only used if X is a CONST_INT. | |
1486 | ||
cc2902df KH |
1487 | ANTIC_P is nonzero if X is an anticipatable expression. |
1488 | AVAIL_P is nonzero if X is an available expression. */ | |
7506f491 DE |
1489 | |
1490 | static void | |
1d088dee AJ |
1491 | insert_expr_in_table (rtx x, enum machine_mode mode, rtx insn, int antic_p, |
1492 | int avail_p, struct hash_table *table) | |
7506f491 DE |
1493 | { |
1494 | int found, do_not_record_p; | |
1495 | unsigned int hash; | |
1496 | struct expr *cur_expr, *last_expr = NULL; | |
1497 | struct occr *antic_occr, *avail_occr; | |
7506f491 | 1498 | |
02280659 | 1499 | hash = hash_expr (x, mode, &do_not_record_p, table->size); |
7506f491 DE |
1500 | |
1501 | /* Do not insert expression in table if it contains volatile operands, | |
1502 | or if hash_expr determines the expression is something we don't want | |
1503 | to or can't handle. */ | |
1504 | if (do_not_record_p) | |
1505 | return; | |
1506 | ||
02280659 | 1507 | cur_expr = table->table[hash]; |
7506f491 DE |
1508 | found = 0; |
1509 | ||
c4c81601 | 1510 | while (cur_expr && 0 == (found = expr_equiv_p (cur_expr->expr, x))) |
7506f491 DE |
1511 | { |
1512 | /* If the expression isn't found, save a pointer to the end of | |
1513 | the list. */ | |
1514 | last_expr = cur_expr; | |
1515 | cur_expr = cur_expr->next_same_hash; | |
1516 | } | |
1517 | ||
1518 | if (! found) | |
1519 | { | |
703ad42b | 1520 | cur_expr = gcse_alloc (sizeof (struct expr)); |
7506f491 | 1521 | bytes_used += sizeof (struct expr); |
02280659 | 1522 | if (table->table[hash] == NULL) |
c4c81601 | 1523 | /* This is the first pattern that hashed to this index. */ |
02280659 | 1524 | table->table[hash] = cur_expr; |
7506f491 | 1525 | else |
c4c81601 RK |
1526 | /* Add EXPR to end of this hash chain. */ |
1527 | last_expr->next_same_hash = cur_expr; | |
1528 | ||
589005ff | 1529 | /* Set the fields of the expr element. */ |
7506f491 | 1530 | cur_expr->expr = x; |
02280659 | 1531 | cur_expr->bitmap_index = table->n_elems++; |
7506f491 DE |
1532 | cur_expr->next_same_hash = NULL; |
1533 | cur_expr->antic_occr = NULL; | |
1534 | cur_expr->avail_occr = NULL; | |
1535 | } | |
1536 | ||
1537 | /* Now record the occurrence(s). */ | |
7506f491 DE |
1538 | if (antic_p) |
1539 | { | |
1540 | antic_occr = cur_expr->antic_occr; | |
1541 | ||
b6e47ceb JL |
1542 | if (antic_occr && BLOCK_NUM (antic_occr->insn) != BLOCK_NUM (insn)) |
1543 | antic_occr = NULL; | |
7506f491 DE |
1544 | |
1545 | if (antic_occr) | |
c4c81601 RK |
1546 | /* Found another instance of the expression in the same basic block. |
1547 | Prefer the currently recorded one. We want the first one in the | |
1548 | block and the block is scanned from start to end. */ | |
1549 | ; /* nothing to do */ | |
7506f491 DE |
1550 | else |
1551 | { | |
1552 | /* First occurrence of this expression in this basic block. */ | |
703ad42b | 1553 | antic_occr = gcse_alloc (sizeof (struct occr)); |
7506f491 | 1554 | bytes_used += sizeof (struct occr); |
7506f491 | 1555 | antic_occr->insn = insn; |
b6e47ceb | 1556 | antic_occr->next = cur_expr->antic_occr; |
f9957958 | 1557 | antic_occr->deleted_p = 0; |
b6e47ceb | 1558 | cur_expr->antic_occr = antic_occr; |
7506f491 DE |
1559 | } |
1560 | } | |
1561 | ||
1562 | if (avail_p) | |
1563 | { | |
1564 | avail_occr = cur_expr->avail_occr; | |
1565 | ||
b6e47ceb | 1566 | if (avail_occr && BLOCK_NUM (avail_occr->insn) == BLOCK_NUM (insn)) |
7506f491 | 1567 | { |
b6e47ceb JL |
1568 | /* Found another instance of the expression in the same basic block. |
1569 | Prefer this occurrence to the currently recorded one. We want | |
1570 | the last one in the block and the block is scanned from start | |
1571 | to end. */ | |
1572 | avail_occr->insn = insn; | |
7506f491 | 1573 | } |
7506f491 DE |
1574 | else |
1575 | { | |
1576 | /* First occurrence of this expression in this basic block. */ | |
703ad42b | 1577 | avail_occr = gcse_alloc (sizeof (struct occr)); |
7506f491 | 1578 | bytes_used += sizeof (struct occr); |
7506f491 | 1579 | avail_occr->insn = insn; |
b6e47ceb | 1580 | avail_occr->next = cur_expr->avail_occr; |
f9957958 | 1581 | avail_occr->deleted_p = 0; |
b6e47ceb | 1582 | cur_expr->avail_occr = avail_occr; |
7506f491 DE |
1583 | } |
1584 | } | |
1585 | } | |
1586 | ||
1587 | /* Insert pattern X in INSN in the hash table. | |
1588 | X is a SET of a reg to either another reg or a constant. | |
1589 | If it is already present, record it as the last occurrence in INSN's | |
1590 | basic block. */ | |
1591 | ||
1592 | static void | |
1d088dee | 1593 | insert_set_in_table (rtx x, rtx insn, struct hash_table *table) |
7506f491 DE |
1594 | { |
1595 | int found; | |
1596 | unsigned int hash; | |
1597 | struct expr *cur_expr, *last_expr = NULL; | |
b6e47ceb | 1598 | struct occr *cur_occr; |
7506f491 | 1599 | |
282899df | 1600 | gcc_assert (GET_CODE (x) == SET && REG_P (SET_DEST (x))); |
7506f491 | 1601 | |
02280659 | 1602 | hash = hash_set (REGNO (SET_DEST (x)), table->size); |
7506f491 | 1603 | |
02280659 | 1604 | cur_expr = table->table[hash]; |
7506f491 DE |
1605 | found = 0; |
1606 | ||
c4c81601 | 1607 | while (cur_expr && 0 == (found = expr_equiv_p (cur_expr->expr, x))) |
7506f491 DE |
1608 | { |
1609 | /* If the expression isn't found, save a pointer to the end of | |
1610 | the list. */ | |
1611 | last_expr = cur_expr; | |
1612 | cur_expr = cur_expr->next_same_hash; | |
1613 | } | |
1614 | ||
1615 | if (! found) | |
1616 | { | |
703ad42b | 1617 | cur_expr = gcse_alloc (sizeof (struct expr)); |
7506f491 | 1618 | bytes_used += sizeof (struct expr); |
02280659 | 1619 | if (table->table[hash] == NULL) |
c4c81601 | 1620 | /* This is the first pattern that hashed to this index. */ |
02280659 | 1621 | table->table[hash] = cur_expr; |
7506f491 | 1622 | else |
c4c81601 RK |
1623 | /* Add EXPR to end of this hash chain. */ |
1624 | last_expr->next_same_hash = cur_expr; | |
1625 | ||
7506f491 DE |
1626 | /* Set the fields of the expr element. |
1627 | We must copy X because it can be modified when copy propagation is | |
1628 | performed on its operands. */ | |
7506f491 | 1629 | cur_expr->expr = copy_rtx (x); |
02280659 | 1630 | cur_expr->bitmap_index = table->n_elems++; |
7506f491 DE |
1631 | cur_expr->next_same_hash = NULL; |
1632 | cur_expr->antic_occr = NULL; | |
1633 | cur_expr->avail_occr = NULL; | |
1634 | } | |
1635 | ||
1636 | /* Now record the occurrence. */ | |
7506f491 DE |
1637 | cur_occr = cur_expr->avail_occr; |
1638 | ||
b6e47ceb | 1639 | if (cur_occr && BLOCK_NUM (cur_occr->insn) == BLOCK_NUM (insn)) |
7506f491 | 1640 | { |
b6e47ceb JL |
1641 | /* Found another instance of the expression in the same basic block. |
1642 | Prefer this occurrence to the currently recorded one. We want | |
1643 | the last one in the block and the block is scanned from start | |
1644 | to end. */ | |
1645 | cur_occr->insn = insn; | |
7506f491 | 1646 | } |
7506f491 DE |
1647 | else |
1648 | { | |
1649 | /* First occurrence of this expression in this basic block. */ | |
703ad42b | 1650 | cur_occr = gcse_alloc (sizeof (struct occr)); |
7506f491 | 1651 | bytes_used += sizeof (struct occr); |
c4c81601 | 1652 | |
b6e47ceb JL |
1653 | cur_occr->insn = insn; |
1654 | cur_occr->next = cur_expr->avail_occr; | |
1655 | cur_occr->deleted_p = 0; | |
1656 | cur_expr->avail_occr = cur_occr; | |
7506f491 DE |
1657 | } |
1658 | } | |
1659 | ||
6b2d1c9e RS |
1660 | /* Determine whether the rtx X should be treated as a constant for |
1661 | the purposes of GCSE's constant propagation. */ | |
1662 | ||
1663 | static bool | |
1d088dee | 1664 | gcse_constant_p (rtx x) |
6b2d1c9e RS |
1665 | { |
1666 | /* Consider a COMPARE of two integers constant. */ | |
1667 | if (GET_CODE (x) == COMPARE | |
1668 | && GET_CODE (XEXP (x, 0)) == CONST_INT | |
1669 | && GET_CODE (XEXP (x, 1)) == CONST_INT) | |
1670 | return true; | |
1671 | ||
db2f435b | 1672 | /* Consider a COMPARE of the same registers is a constant |
7b1b4aed | 1673 | if they are not floating point registers. */ |
db2f435b | 1674 | if (GET_CODE(x) == COMPARE |
7b1b4aed | 1675 | && REG_P (XEXP (x, 0)) && REG_P (XEXP (x, 1)) |
db2f435b AP |
1676 | && REGNO (XEXP (x, 0)) == REGNO (XEXP (x, 1)) |
1677 | && ! FLOAT_MODE_P (GET_MODE (XEXP (x, 0))) | |
1678 | && ! FLOAT_MODE_P (GET_MODE (XEXP (x, 1)))) | |
1679 | return true; | |
1680 | ||
6b2d1c9e RS |
1681 | return CONSTANT_P (x); |
1682 | } | |
1683 | ||
02280659 ZD |
1684 | /* Scan pattern PAT of INSN and add an entry to the hash TABLE (set or |
1685 | expression one). */ | |
7506f491 DE |
1686 | |
1687 | static void | |
1d088dee | 1688 | hash_scan_set (rtx pat, rtx insn, struct hash_table *table) |
7506f491 DE |
1689 | { |
1690 | rtx src = SET_SRC (pat); | |
1691 | rtx dest = SET_DEST (pat); | |
172890a2 | 1692 | rtx note; |
7506f491 | 1693 | |
6e72d1e9 | 1694 | if (GET_CODE (src) == CALL) |
02280659 | 1695 | hash_scan_call (src, insn, table); |
7506f491 | 1696 | |
7b1b4aed | 1697 | else if (REG_P (dest)) |
7506f491 | 1698 | { |
172890a2 | 1699 | unsigned int regno = REGNO (dest); |
7506f491 DE |
1700 | rtx tmp; |
1701 | ||
90631280 PB |
1702 | /* See if a REG_NOTE shows this equivalent to a simpler expression. |
1703 | This allows us to do a single GCSE pass and still eliminate | |
1704 | redundant constants, addresses or other expressions that are | |
1705 | constructed with multiple instructions. */ | |
1706 | note = find_reg_equal_equiv_note (insn); | |
1707 | if (note != 0 | |
1708 | && (table->set_p | |
1709 | ? gcse_constant_p (XEXP (note, 0)) | |
1710 | : want_to_gcse_p (XEXP (note, 0)))) | |
172890a2 RK |
1711 | src = XEXP (note, 0), pat = gen_rtx_SET (VOIDmode, dest, src); |
1712 | ||
7506f491 | 1713 | /* Only record sets of pseudo-regs in the hash table. */ |
02280659 | 1714 | if (! table->set_p |
7506f491 DE |
1715 | && regno >= FIRST_PSEUDO_REGISTER |
1716 | /* Don't GCSE something if we can't do a reg/reg copy. */ | |
773eae39 | 1717 | && can_copy_p (GET_MODE (dest)) |
068473ec JH |
1718 | /* GCSE commonly inserts instruction after the insn. We can't |
1719 | do that easily for EH_REGION notes so disable GCSE on these | |
1720 | for now. */ | |
1721 | && !find_reg_note (insn, REG_EH_REGION, NULL_RTX) | |
7506f491 | 1722 | /* Is SET_SRC something we want to gcse? */ |
172890a2 RK |
1723 | && want_to_gcse_p (src) |
1724 | /* Don't CSE a nop. */ | |
43e72072 JJ |
1725 | && ! set_noop_p (pat) |
1726 | /* Don't GCSE if it has attached REG_EQUIV note. | |
1727 | At this point this only function parameters should have | |
1728 | REG_EQUIV notes and if the argument slot is used somewhere | |
a1f300c0 | 1729 | explicitly, it means address of parameter has been taken, |
43e72072 | 1730 | so we should not extend the lifetime of the pseudo. */ |
90631280 | 1731 | && (note == NULL_RTX || ! MEM_P (XEXP (note, 0)))) |
7506f491 DE |
1732 | { |
1733 | /* An expression is not anticipatable if its operands are | |
52d76e11 | 1734 | modified before this insn or if this is not the only SET in |
6fb5fa3c DB |
1735 | this insn. The latter condition does not have to mean that |
1736 | SRC itself is not anticipatable, but we just will not be | |
1737 | able to handle code motion of insns with multiple sets. */ | |
1738 | int antic_p = oprs_anticipatable_p (src, insn) | |
1739 | && !multiple_sets (insn); | |
7506f491 | 1740 | /* An expression is not available if its operands are |
eb296bd9 GK |
1741 | subsequently modified, including this insn. It's also not |
1742 | available if this is a branch, because we can't insert | |
1743 | a set after the branch. */ | |
1744 | int avail_p = (oprs_available_p (src, insn) | |
1745 | && ! JUMP_P (insn)); | |
c4c81601 | 1746 | |
02280659 | 1747 | insert_expr_in_table (src, GET_MODE (dest), insn, antic_p, avail_p, table); |
7506f491 | 1748 | } |
c4c81601 | 1749 | |
7506f491 | 1750 | /* Record sets for constant/copy propagation. */ |
02280659 | 1751 | else if (table->set_p |
7506f491 | 1752 | && regno >= FIRST_PSEUDO_REGISTER |
7b1b4aed | 1753 | && ((REG_P (src) |
7506f491 | 1754 | && REGNO (src) >= FIRST_PSEUDO_REGISTER |
773eae39 | 1755 | && can_copy_p (GET_MODE (dest)) |
172890a2 | 1756 | && REGNO (src) != regno) |
6b2d1c9e | 1757 | || gcse_constant_p (src)) |
7506f491 DE |
1758 | /* A copy is not available if its src or dest is subsequently |
1759 | modified. Here we want to search from INSN+1 on, but | |
1760 | oprs_available_p searches from INSN on. */ | |
a813c111 | 1761 | && (insn == BB_END (BLOCK_FOR_INSN (insn)) |
7506f491 DE |
1762 | || ((tmp = next_nonnote_insn (insn)) != NULL_RTX |
1763 | && oprs_available_p (pat, tmp)))) | |
02280659 | 1764 | insert_set_in_table (pat, insn, table); |
7506f491 | 1765 | } |
d91edf86 | 1766 | /* In case of store we want to consider the memory value as available in |
f5f2e3cd MH |
1767 | the REG stored in that memory. This makes it possible to remove |
1768 | redundant loads from due to stores to the same location. */ | |
7b1b4aed | 1769 | else if (flag_gcse_las && REG_P (src) && MEM_P (dest)) |
f5f2e3cd MH |
1770 | { |
1771 | unsigned int regno = REGNO (src); | |
1772 | ||
1773 | /* Do not do this for constant/copy propagation. */ | |
1774 | if (! table->set_p | |
1775 | /* Only record sets of pseudo-regs in the hash table. */ | |
1776 | && regno >= FIRST_PSEUDO_REGISTER | |
1777 | /* Don't GCSE something if we can't do a reg/reg copy. */ | |
1778 | && can_copy_p (GET_MODE (src)) | |
1779 | /* GCSE commonly inserts instruction after the insn. We can't | |
1780 | do that easily for EH_REGION notes so disable GCSE on these | |
1781 | for now. */ | |
1782 | && ! find_reg_note (insn, REG_EH_REGION, NULL_RTX) | |
1783 | /* Is SET_DEST something we want to gcse? */ | |
1784 | && want_to_gcse_p (dest) | |
1785 | /* Don't CSE a nop. */ | |
1786 | && ! set_noop_p (pat) | |
1787 | /* Don't GCSE if it has attached REG_EQUIV note. | |
1788 | At this point this only function parameters should have | |
1789 | REG_EQUIV notes and if the argument slot is used somewhere | |
1790 | explicitly, it means address of parameter has been taken, | |
1791 | so we should not extend the lifetime of the pseudo. */ | |
1792 | && ((note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) == 0 | |
7b1b4aed | 1793 | || ! MEM_P (XEXP (note, 0)))) |
f5f2e3cd MH |
1794 | { |
1795 | /* Stores are never anticipatable. */ | |
1796 | int antic_p = 0; | |
1797 | /* An expression is not available if its operands are | |
1798 | subsequently modified, including this insn. It's also not | |
1799 | available if this is a branch, because we can't insert | |
1800 | a set after the branch. */ | |
1801 | int avail_p = oprs_available_p (dest, insn) | |
1802 | && ! JUMP_P (insn); | |
1803 | ||
1804 | /* Record the memory expression (DEST) in the hash table. */ | |
1805 | insert_expr_in_table (dest, GET_MODE (dest), insn, | |
1806 | antic_p, avail_p, table); | |
1807 | } | |
1808 | } | |
7506f491 DE |
1809 | } |
1810 | ||
1811 | static void | |
1d088dee AJ |
1812 | hash_scan_clobber (rtx x ATTRIBUTE_UNUSED, rtx insn ATTRIBUTE_UNUSED, |
1813 | struct hash_table *table ATTRIBUTE_UNUSED) | |
7506f491 DE |
1814 | { |
1815 | /* Currently nothing to do. */ | |
1816 | } | |
1817 | ||
1818 | static void | |
1d088dee AJ |
1819 | hash_scan_call (rtx x ATTRIBUTE_UNUSED, rtx insn ATTRIBUTE_UNUSED, |
1820 | struct hash_table *table ATTRIBUTE_UNUSED) | |
7506f491 DE |
1821 | { |
1822 | /* Currently nothing to do. */ | |
1823 | } | |
1824 | ||
1825 | /* Process INSN and add hash table entries as appropriate. | |
1826 | ||
1827 | Only available expressions that set a single pseudo-reg are recorded. | |
1828 | ||
1829 | Single sets in a PARALLEL could be handled, but it's an extra complication | |
1830 | that isn't dealt with right now. The trick is handling the CLOBBERs that | |
1831 | are also in the PARALLEL. Later. | |
1832 | ||
cc2902df | 1833 | If SET_P is nonzero, this is for the assignment hash table, |
ed79bb3d R |
1834 | otherwise it is for the expression hash table. |
1835 | If IN_LIBCALL_BLOCK nonzero, we are in a libcall block, and should | |
1836 | not record any expressions. */ | |
7506f491 DE |
1837 | |
1838 | static void | |
1d088dee | 1839 | hash_scan_insn (rtx insn, struct hash_table *table, int in_libcall_block) |
7506f491 DE |
1840 | { |
1841 | rtx pat = PATTERN (insn); | |
c4c81601 | 1842 | int i; |
7506f491 | 1843 | |
172890a2 RK |
1844 | if (in_libcall_block) |
1845 | return; | |
1846 | ||
7506f491 DE |
1847 | /* Pick out the sets of INSN and for other forms of instructions record |
1848 | what's been modified. */ | |
1849 | ||
172890a2 | 1850 | if (GET_CODE (pat) == SET) |
02280659 | 1851 | hash_scan_set (pat, insn, table); |
7506f491 | 1852 | else if (GET_CODE (pat) == PARALLEL) |
c4c81601 RK |
1853 | for (i = 0; i < XVECLEN (pat, 0); i++) |
1854 | { | |
1855 | rtx x = XVECEXP (pat, 0, i); | |
7506f491 | 1856 | |
c4c81601 | 1857 | if (GET_CODE (x) == SET) |
02280659 | 1858 | hash_scan_set (x, insn, table); |
c4c81601 | 1859 | else if (GET_CODE (x) == CLOBBER) |
02280659 | 1860 | hash_scan_clobber (x, insn, table); |
6e72d1e9 | 1861 | else if (GET_CODE (x) == CALL) |
02280659 | 1862 | hash_scan_call (x, insn, table); |
c4c81601 | 1863 | } |
7506f491 | 1864 | |
7506f491 | 1865 | else if (GET_CODE (pat) == CLOBBER) |
02280659 | 1866 | hash_scan_clobber (pat, insn, table); |
6e72d1e9 | 1867 | else if (GET_CODE (pat) == CALL) |
02280659 | 1868 | hash_scan_call (pat, insn, table); |
7506f491 DE |
1869 | } |
1870 | ||
1871 | static void | |
1d088dee | 1872 | dump_hash_table (FILE *file, const char *name, struct hash_table *table) |
7506f491 DE |
1873 | { |
1874 | int i; | |
1875 | /* Flattened out table, so it's printed in proper order. */ | |
4da896b2 MM |
1876 | struct expr **flat_table; |
1877 | unsigned int *hash_val; | |
c4c81601 | 1878 | struct expr *expr; |
4da896b2 | 1879 | |
703ad42b KG |
1880 | flat_table = xcalloc (table->n_elems, sizeof (struct expr *)); |
1881 | hash_val = xmalloc (table->n_elems * sizeof (unsigned int)); | |
7506f491 | 1882 | |
02280659 ZD |
1883 | for (i = 0; i < (int) table->size; i++) |
1884 | for (expr = table->table[i]; expr != NULL; expr = expr->next_same_hash) | |
c4c81601 RK |
1885 | { |
1886 | flat_table[expr->bitmap_index] = expr; | |
1887 | hash_val[expr->bitmap_index] = i; | |
1888 | } | |
7506f491 DE |
1889 | |
1890 | fprintf (file, "%s hash table (%d buckets, %d entries)\n", | |
02280659 | 1891 | name, table->size, table->n_elems); |
7506f491 | 1892 | |
02280659 | 1893 | for (i = 0; i < (int) table->n_elems; i++) |
21318741 RK |
1894 | if (flat_table[i] != 0) |
1895 | { | |
a0ac9e5a | 1896 | expr = flat_table[i]; |
21318741 RK |
1897 | fprintf (file, "Index %d (hash value %d)\n ", |
1898 | expr->bitmap_index, hash_val[i]); | |
a0ac9e5a | 1899 | print_rtl (file, expr->expr); |
21318741 RK |
1900 | fprintf (file, "\n"); |
1901 | } | |
7506f491 DE |
1902 | |
1903 | fprintf (file, "\n"); | |
4da896b2 | 1904 | |
4da896b2 MM |
1905 | free (flat_table); |
1906 | free (hash_val); | |
7506f491 DE |
1907 | } |
1908 | ||
1909 | /* Record register first/last/block set information for REGNO in INSN. | |
c4c81601 | 1910 | |
80c29cc4 | 1911 | first_set records the first place in the block where the register |
7506f491 | 1912 | is set and is used to compute "anticipatability". |
c4c81601 | 1913 | |
80c29cc4 | 1914 | last_set records the last place in the block where the register |
7506f491 | 1915 | is set and is used to compute "availability". |
c4c81601 | 1916 | |
80c29cc4 RZ |
1917 | last_bb records the block for which first_set and last_set are |
1918 | valid, as a quick test to invalidate them. | |
1919 | ||
7506f491 DE |
1920 | reg_set_in_block records whether the register is set in the block |
1921 | and is used to compute "transparency". */ | |
1922 | ||
1923 | static void | |
1d088dee | 1924 | record_last_reg_set_info (rtx insn, int regno) |
7506f491 | 1925 | { |
80c29cc4 RZ |
1926 | struct reg_avail_info *info = ®_avail_info[regno]; |
1927 | int cuid = INSN_CUID (insn); | |
c4c81601 | 1928 | |
80c29cc4 RZ |
1929 | info->last_set = cuid; |
1930 | if (info->last_bb != current_bb) | |
1931 | { | |
1932 | info->last_bb = current_bb; | |
1933 | info->first_set = cuid; | |
e0082a72 | 1934 | SET_BIT (reg_set_in_block[current_bb->index], regno); |
80c29cc4 | 1935 | } |
7506f491 DE |
1936 | } |
1937 | ||
a13d4ebf AM |
1938 | |
1939 | /* Record all of the canonicalized MEMs of record_last_mem_set_info's insn. | |
1940 | Note we store a pair of elements in the list, so they have to be | |
1941 | taken off pairwise. */ | |
1942 | ||
589005ff | 1943 | static void |
1d088dee AJ |
1944 | canon_list_insert (rtx dest ATTRIBUTE_UNUSED, rtx unused1 ATTRIBUTE_UNUSED, |
1945 | void * v_insn) | |
a13d4ebf AM |
1946 | { |
1947 | rtx dest_addr, insn; | |
0fe854a7 | 1948 | int bb; |
a13d4ebf AM |
1949 | |
1950 | while (GET_CODE (dest) == SUBREG | |
1951 | || GET_CODE (dest) == ZERO_EXTRACT | |
a13d4ebf AM |
1952 | || GET_CODE (dest) == STRICT_LOW_PART) |
1953 | dest = XEXP (dest, 0); | |
1954 | ||
1955 | /* If DEST is not a MEM, then it will not conflict with a load. Note | |
1956 | that function calls are assumed to clobber memory, but are handled | |
1957 | elsewhere. */ | |
1958 | ||
7b1b4aed | 1959 | if (! MEM_P (dest)) |
a13d4ebf AM |
1960 | return; |
1961 | ||
1962 | dest_addr = get_addr (XEXP (dest, 0)); | |
1963 | dest_addr = canon_rtx (dest_addr); | |
589005ff | 1964 | insn = (rtx) v_insn; |
0fe854a7 | 1965 | bb = BLOCK_NUM (insn); |
a13d4ebf | 1966 | |
589005ff | 1967 | canon_modify_mem_list[bb] = |
0fe854a7 | 1968 | alloc_EXPR_LIST (VOIDmode, dest_addr, canon_modify_mem_list[bb]); |
589005ff | 1969 | canon_modify_mem_list[bb] = |
0fe854a7 | 1970 | alloc_EXPR_LIST (VOIDmode, dest, canon_modify_mem_list[bb]); |
a13d4ebf AM |
1971 | } |
1972 | ||
a13d4ebf AM |
1973 | /* Record memory modification information for INSN. We do not actually care |
1974 | about the memory location(s) that are set, or even how they are set (consider | |
1975 | a CALL_INSN). We merely need to record which insns modify memory. */ | |
7506f491 DE |
1976 | |
1977 | static void | |
1d088dee | 1978 | record_last_mem_set_info (rtx insn) |
7506f491 | 1979 | { |
0fe854a7 RH |
1980 | int bb = BLOCK_NUM (insn); |
1981 | ||
ccef9ef5 | 1982 | /* load_killed_in_block_p will handle the case of calls clobbering |
dc297297 | 1983 | everything. */ |
0fe854a7 RH |
1984 | modify_mem_list[bb] = alloc_INSN_LIST (insn, modify_mem_list[bb]); |
1985 | bitmap_set_bit (modify_mem_list_set, bb); | |
a13d4ebf | 1986 | |
7b1b4aed | 1987 | if (CALL_P (insn)) |
a13d4ebf AM |
1988 | { |
1989 | /* Note that traversals of this loop (other than for free-ing) | |
1990 | will break after encountering a CALL_INSN. So, there's no | |
dc297297 | 1991 | need to insert a pair of items, as canon_list_insert does. */ |
589005ff KH |
1992 | canon_modify_mem_list[bb] = |
1993 | alloc_INSN_LIST (insn, canon_modify_mem_list[bb]); | |
aa47fcfa | 1994 | bitmap_set_bit (blocks_with_calls, bb); |
a13d4ebf AM |
1995 | } |
1996 | else | |
0fe854a7 | 1997 | note_stores (PATTERN (insn), canon_list_insert, (void*) insn); |
7506f491 DE |
1998 | } |
1999 | ||
7506f491 | 2000 | /* Called from compute_hash_table via note_stores to handle one |
84832317 MM |
2001 | SET or CLOBBER in an insn. DATA is really the instruction in which |
2002 | the SET is taking place. */ | |
7506f491 DE |
2003 | |
2004 | static void | |
1d088dee | 2005 | record_last_set_info (rtx dest, rtx setter ATTRIBUTE_UNUSED, void *data) |
7506f491 | 2006 | { |
84832317 MM |
2007 | rtx last_set_insn = (rtx) data; |
2008 | ||
7506f491 DE |
2009 | if (GET_CODE (dest) == SUBREG) |
2010 | dest = SUBREG_REG (dest); | |
2011 | ||
7b1b4aed | 2012 | if (REG_P (dest)) |
7506f491 | 2013 | record_last_reg_set_info (last_set_insn, REGNO (dest)); |
7b1b4aed | 2014 | else if (MEM_P (dest) |
7506f491 DE |
2015 | /* Ignore pushes, they clobber nothing. */ |
2016 | && ! push_operand (dest, GET_MODE (dest))) | |
2017 | record_last_mem_set_info (last_set_insn); | |
2018 | } | |
2019 | ||
2020 | /* Top level function to create an expression or assignment hash table. | |
2021 | ||
2022 | Expression entries are placed in the hash table if | |
2023 | - they are of the form (set (pseudo-reg) src), | |
2024 | - src is something we want to perform GCSE on, | |
2025 | - none of the operands are subsequently modified in the block | |
2026 | ||
2027 | Assignment entries are placed in the hash table if | |
2028 | - they are of the form (set (pseudo-reg) src), | |
2029 | - src is something we want to perform const/copy propagation on, | |
2030 | - none of the operands or target are subsequently modified in the block | |
c4c81601 | 2031 | |
7506f491 DE |
2032 | Currently src must be a pseudo-reg or a const_int. |
2033 | ||
02280659 | 2034 | TABLE is the table computed. */ |
7506f491 DE |
2035 | |
2036 | static void | |
1d088dee | 2037 | compute_hash_table_work (struct hash_table *table) |
7506f491 | 2038 | { |
80c29cc4 | 2039 | unsigned int i; |
7506f491 DE |
2040 | |
2041 | /* While we compute the hash table we also compute a bit array of which | |
2042 | registers are set in which blocks. | |
7506f491 DE |
2043 | ??? This isn't needed during const/copy propagation, but it's cheap to |
2044 | compute. Later. */ | |
d55bc081 | 2045 | sbitmap_vector_zero (reg_set_in_block, last_basic_block); |
7506f491 | 2046 | |
a13d4ebf | 2047 | /* re-Cache any INSN_LIST nodes we have allocated. */ |
73991d6a | 2048 | clear_modify_mem_tables (); |
7506f491 | 2049 | /* Some working arrays used to track first and last set in each block. */ |
703ad42b | 2050 | reg_avail_info = gmalloc (max_gcse_regno * sizeof (struct reg_avail_info)); |
80c29cc4 RZ |
2051 | |
2052 | for (i = 0; i < max_gcse_regno; ++i) | |
e0082a72 | 2053 | reg_avail_info[i].last_bb = NULL; |
7506f491 | 2054 | |
e0082a72 | 2055 | FOR_EACH_BB (current_bb) |
7506f491 DE |
2056 | { |
2057 | rtx insn; | |
770ae6cc | 2058 | unsigned int regno; |
ed79bb3d | 2059 | int in_libcall_block; |
7506f491 DE |
2060 | |
2061 | /* First pass over the instructions records information used to | |
2062 | determine when registers and memory are first and last set. | |
ccef9ef5 | 2063 | ??? hard-reg reg_set_in_block computation |
7506f491 DE |
2064 | could be moved to compute_sets since they currently don't change. */ |
2065 | ||
eb232f4e | 2066 | FOR_BB_INSNS (current_bb, insn) |
7506f491 | 2067 | { |
2c3c49de | 2068 | if (! INSN_P (insn)) |
7506f491 DE |
2069 | continue; |
2070 | ||
7b1b4aed | 2071 | if (CALL_P (insn)) |
7506f491 DE |
2072 | { |
2073 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) | |
6e14af16 | 2074 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) |
7506f491 | 2075 | record_last_reg_set_info (insn, regno); |
c4c81601 | 2076 | |
24a28584 | 2077 | mark_call (insn); |
7506f491 DE |
2078 | } |
2079 | ||
84832317 | 2080 | note_stores (PATTERN (insn), record_last_set_info, insn); |
7506f491 DE |
2081 | } |
2082 | ||
fbef91d8 RS |
2083 | /* Insert implicit sets in the hash table. */ |
2084 | if (table->set_p | |
2085 | && implicit_sets[current_bb->index] != NULL_RTX) | |
2086 | hash_scan_set (implicit_sets[current_bb->index], | |
a813c111 | 2087 | BB_HEAD (current_bb), table); |
fbef91d8 | 2088 | |
7506f491 | 2089 | /* The next pass builds the hash table. */ |
eb232f4e SB |
2090 | in_libcall_block = 0; |
2091 | FOR_BB_INSNS (current_bb, insn) | |
2c3c49de | 2092 | if (INSN_P (insn)) |
c4c81601 RK |
2093 | { |
2094 | if (find_reg_note (insn, REG_LIBCALL, NULL_RTX)) | |
589005ff | 2095 | in_libcall_block = 1; |
02280659 | 2096 | else if (table->set_p && find_reg_note (insn, REG_RETVAL, NULL_RTX)) |
589005ff | 2097 | in_libcall_block = 0; |
02280659 ZD |
2098 | hash_scan_insn (insn, table, in_libcall_block); |
2099 | if (!table->set_p && find_reg_note (insn, REG_RETVAL, NULL_RTX)) | |
589005ff | 2100 | in_libcall_block = 0; |
8e42ace1 | 2101 | } |
7506f491 DE |
2102 | } |
2103 | ||
80c29cc4 RZ |
2104 | free (reg_avail_info); |
2105 | reg_avail_info = NULL; | |
7506f491 DE |
2106 | } |
2107 | ||
02280659 | 2108 | /* Allocate space for the set/expr hash TABLE. |
7506f491 | 2109 | N_INSNS is the number of instructions in the function. |
02280659 ZD |
2110 | It is used to determine the number of buckets to use. |
2111 | SET_P determines whether set or expression table will | |
2112 | be created. */ | |
7506f491 DE |
2113 | |
2114 | static void | |
1d088dee | 2115 | alloc_hash_table (int n_insns, struct hash_table *table, int set_p) |
7506f491 DE |
2116 | { |
2117 | int n; | |
2118 | ||
02280659 ZD |
2119 | table->size = n_insns / 4; |
2120 | if (table->size < 11) | |
2121 | table->size = 11; | |
c4c81601 | 2122 | |
7506f491 DE |
2123 | /* Attempt to maintain efficient use of hash table. |
2124 | Making it an odd number is simplest for now. | |
2125 | ??? Later take some measurements. */ | |
02280659 ZD |
2126 | table->size |= 1; |
2127 | n = table->size * sizeof (struct expr *); | |
703ad42b | 2128 | table->table = gmalloc (n); |
02280659 | 2129 | table->set_p = set_p; |
7506f491 DE |
2130 | } |
2131 | ||
02280659 | 2132 | /* Free things allocated by alloc_hash_table. */ |
7506f491 DE |
2133 | |
2134 | static void | |
1d088dee | 2135 | free_hash_table (struct hash_table *table) |
7506f491 | 2136 | { |
02280659 | 2137 | free (table->table); |
7506f491 DE |
2138 | } |
2139 | ||
02280659 ZD |
2140 | /* Compute the hash TABLE for doing copy/const propagation or |
2141 | expression hash table. */ | |
7506f491 DE |
2142 | |
2143 | static void | |
1d088dee | 2144 | compute_hash_table (struct hash_table *table) |
7506f491 DE |
2145 | { |
2146 | /* Initialize count of number of entries in hash table. */ | |
02280659 | 2147 | table->n_elems = 0; |
703ad42b | 2148 | memset (table->table, 0, table->size * sizeof (struct expr *)); |
7506f491 | 2149 | |
02280659 | 2150 | compute_hash_table_work (table); |
7506f491 DE |
2151 | } |
2152 | \f | |
2153 | /* Expression tracking support. */ | |
2154 | ||
ceda50e9 RH |
2155 | /* Lookup REGNO in the set TABLE. The result is a pointer to the |
2156 | table entry, or NULL if not found. */ | |
7506f491 DE |
2157 | |
2158 | static struct expr * | |
1d088dee | 2159 | lookup_set (unsigned int regno, struct hash_table *table) |
7506f491 | 2160 | { |
02280659 | 2161 | unsigned int hash = hash_set (regno, table->size); |
7506f491 DE |
2162 | struct expr *expr; |
2163 | ||
02280659 | 2164 | expr = table->table[hash]; |
7506f491 | 2165 | |
ceda50e9 RH |
2166 | while (expr && REGNO (SET_DEST (expr->expr)) != regno) |
2167 | expr = expr->next_same_hash; | |
7506f491 DE |
2168 | |
2169 | return expr; | |
2170 | } | |
2171 | ||
2172 | /* Return the next entry for REGNO in list EXPR. */ | |
2173 | ||
2174 | static struct expr * | |
1d088dee | 2175 | next_set (unsigned int regno, struct expr *expr) |
7506f491 DE |
2176 | { |
2177 | do | |
2178 | expr = expr->next_same_hash; | |
2179 | while (expr && REGNO (SET_DEST (expr->expr)) != regno); | |
c4c81601 | 2180 | |
7506f491 DE |
2181 | return expr; |
2182 | } | |
2183 | ||
0fe854a7 RH |
2184 | /* Like free_INSN_LIST_list or free_EXPR_LIST_list, except that the node |
2185 | types may be mixed. */ | |
2186 | ||
2187 | static void | |
1d088dee | 2188 | free_insn_expr_list_list (rtx *listp) |
0fe854a7 RH |
2189 | { |
2190 | rtx list, next; | |
2191 | ||
2192 | for (list = *listp; list ; list = next) | |
2193 | { | |
2194 | next = XEXP (list, 1); | |
2195 | if (GET_CODE (list) == EXPR_LIST) | |
2196 | free_EXPR_LIST_node (list); | |
2197 | else | |
2198 | free_INSN_LIST_node (list); | |
2199 | } | |
2200 | ||
2201 | *listp = NULL; | |
2202 | } | |
2203 | ||
73991d6a JH |
2204 | /* Clear canon_modify_mem_list and modify_mem_list tables. */ |
2205 | static void | |
1d088dee | 2206 | clear_modify_mem_tables (void) |
73991d6a | 2207 | { |
3cd8c58a | 2208 | unsigned i; |
87c476a2 | 2209 | bitmap_iterator bi; |
73991d6a | 2210 | |
87c476a2 ZD |
2211 | EXECUTE_IF_SET_IN_BITMAP (modify_mem_list_set, 0, i, bi) |
2212 | { | |
2213 | free_INSN_LIST_list (modify_mem_list + i); | |
87c476a2 ZD |
2214 | free_insn_expr_list_list (canon_modify_mem_list + i); |
2215 | } | |
9a6cf911 | 2216 | bitmap_clear (modify_mem_list_set); |
aa47fcfa | 2217 | bitmap_clear (blocks_with_calls); |
73991d6a JH |
2218 | } |
2219 | ||
9a6cf911 | 2220 | /* Release memory used by modify_mem_list_set. */ |
73991d6a JH |
2221 | |
2222 | static void | |
1d088dee | 2223 | free_modify_mem_tables (void) |
73991d6a JH |
2224 | { |
2225 | clear_modify_mem_tables (); | |
2226 | free (modify_mem_list); | |
2227 | free (canon_modify_mem_list); | |
2228 | modify_mem_list = 0; | |
2229 | canon_modify_mem_list = 0; | |
2230 | } | |
2231 | ||
7506f491 DE |
2232 | /* Reset tables used to keep track of what's still available [since the |
2233 | start of the block]. */ | |
2234 | ||
2235 | static void | |
1d088dee | 2236 | reset_opr_set_tables (void) |
7506f491 DE |
2237 | { |
2238 | /* Maintain a bitmap of which regs have been set since beginning of | |
2239 | the block. */ | |
73991d6a | 2240 | CLEAR_REG_SET (reg_set_bitmap); |
c4c81601 | 2241 | |
7506f491 DE |
2242 | /* Also keep a record of the last instruction to modify memory. |
2243 | For now this is very trivial, we only record whether any memory | |
2244 | location has been modified. */ | |
73991d6a | 2245 | clear_modify_mem_tables (); |
7506f491 DE |
2246 | } |
2247 | ||
cc2902df | 2248 | /* Return nonzero if the operands of X are not set before INSN in |
7506f491 DE |
2249 | INSN's basic block. */ |
2250 | ||
2251 | static int | |
1d088dee | 2252 | oprs_not_set_p (rtx x, rtx insn) |
7506f491 | 2253 | { |
c4c81601 | 2254 | int i, j; |
7506f491 | 2255 | enum rtx_code code; |
6f7d635c | 2256 | const char *fmt; |
7506f491 | 2257 | |
7506f491 DE |
2258 | if (x == 0) |
2259 | return 1; | |
2260 | ||
2261 | code = GET_CODE (x); | |
2262 | switch (code) | |
2263 | { | |
2264 | case PC: | |
2265 | case CC0: | |
2266 | case CONST: | |
2267 | case CONST_INT: | |
2268 | case CONST_DOUBLE: | |
69ef87e2 | 2269 | case CONST_VECTOR: |
7506f491 DE |
2270 | case SYMBOL_REF: |
2271 | case LABEL_REF: | |
2272 | case ADDR_VEC: | |
2273 | case ADDR_DIFF_VEC: | |
2274 | return 1; | |
2275 | ||
2276 | case MEM: | |
589005ff | 2277 | if (load_killed_in_block_p (BLOCK_FOR_INSN (insn), |
e2d2ed72 | 2278 | INSN_CUID (insn), x, 0)) |
a13d4ebf | 2279 | return 0; |
c4c81601 RK |
2280 | else |
2281 | return oprs_not_set_p (XEXP (x, 0), insn); | |
7506f491 DE |
2282 | |
2283 | case REG: | |
73991d6a | 2284 | return ! REGNO_REG_SET_P (reg_set_bitmap, REGNO (x)); |
7506f491 DE |
2285 | |
2286 | default: | |
2287 | break; | |
2288 | } | |
2289 | ||
c4c81601 | 2290 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
2291 | { |
2292 | if (fmt[i] == 'e') | |
2293 | { | |
7506f491 DE |
2294 | /* If we are about to do the last recursive call |
2295 | needed at this level, change it into iteration. | |
2296 | This function is called enough to be worth it. */ | |
2297 | if (i == 0) | |
c4c81601 RK |
2298 | return oprs_not_set_p (XEXP (x, i), insn); |
2299 | ||
2300 | if (! oprs_not_set_p (XEXP (x, i), insn)) | |
7506f491 DE |
2301 | return 0; |
2302 | } | |
2303 | else if (fmt[i] == 'E') | |
c4c81601 RK |
2304 | for (j = 0; j < XVECLEN (x, i); j++) |
2305 | if (! oprs_not_set_p (XVECEXP (x, i, j), insn)) | |
2306 | return 0; | |
7506f491 DE |
2307 | } |
2308 | ||
2309 | return 1; | |
2310 | } | |
2311 | ||
2312 | /* Mark things set by a CALL. */ | |
2313 | ||
2314 | static void | |
1d088dee | 2315 | mark_call (rtx insn) |
7506f491 | 2316 | { |
24a28584 | 2317 | if (! CONST_OR_PURE_CALL_P (insn)) |
a13d4ebf | 2318 | record_last_mem_set_info (insn); |
7506f491 DE |
2319 | } |
2320 | ||
2321 | /* Mark things set by a SET. */ | |
2322 | ||
2323 | static void | |
1d088dee | 2324 | mark_set (rtx pat, rtx insn) |
7506f491 DE |
2325 | { |
2326 | rtx dest = SET_DEST (pat); | |
2327 | ||
2328 | while (GET_CODE (dest) == SUBREG | |
2329 | || GET_CODE (dest) == ZERO_EXTRACT | |
7506f491 DE |
2330 | || GET_CODE (dest) == STRICT_LOW_PART) |
2331 | dest = XEXP (dest, 0); | |
2332 | ||
7b1b4aed | 2333 | if (REG_P (dest)) |
73991d6a | 2334 | SET_REGNO_REG_SET (reg_set_bitmap, REGNO (dest)); |
7b1b4aed | 2335 | else if (MEM_P (dest)) |
a13d4ebf AM |
2336 | record_last_mem_set_info (insn); |
2337 | ||
6e72d1e9 | 2338 | if (GET_CODE (SET_SRC (pat)) == CALL) |
b5ce41ff | 2339 | mark_call (insn); |
7506f491 DE |
2340 | } |
2341 | ||
2342 | /* Record things set by a CLOBBER. */ | |
2343 | ||
2344 | static void | |
1d088dee | 2345 | mark_clobber (rtx pat, rtx insn) |
7506f491 DE |
2346 | { |
2347 | rtx clob = XEXP (pat, 0); | |
2348 | ||
2349 | while (GET_CODE (clob) == SUBREG || GET_CODE (clob) == STRICT_LOW_PART) | |
2350 | clob = XEXP (clob, 0); | |
2351 | ||
7b1b4aed | 2352 | if (REG_P (clob)) |
73991d6a | 2353 | SET_REGNO_REG_SET (reg_set_bitmap, REGNO (clob)); |
a13d4ebf AM |
2354 | else |
2355 | record_last_mem_set_info (insn); | |
7506f491 DE |
2356 | } |
2357 | ||
2358 | /* Record things set by INSN. | |
2359 | This data is used by oprs_not_set_p. */ | |
2360 | ||
2361 | static void | |
1d088dee | 2362 | mark_oprs_set (rtx insn) |
7506f491 DE |
2363 | { |
2364 | rtx pat = PATTERN (insn); | |
c4c81601 | 2365 | int i; |
7506f491 DE |
2366 | |
2367 | if (GET_CODE (pat) == SET) | |
2368 | mark_set (pat, insn); | |
2369 | else if (GET_CODE (pat) == PARALLEL) | |
c4c81601 RK |
2370 | for (i = 0; i < XVECLEN (pat, 0); i++) |
2371 | { | |
2372 | rtx x = XVECEXP (pat, 0, i); | |
2373 | ||
2374 | if (GET_CODE (x) == SET) | |
2375 | mark_set (x, insn); | |
2376 | else if (GET_CODE (x) == CLOBBER) | |
2377 | mark_clobber (x, insn); | |
6e72d1e9 | 2378 | else if (GET_CODE (x) == CALL) |
c4c81601 RK |
2379 | mark_call (insn); |
2380 | } | |
7506f491 | 2381 | |
7506f491 DE |
2382 | else if (GET_CODE (pat) == CLOBBER) |
2383 | mark_clobber (pat, insn); | |
6e72d1e9 | 2384 | else if (GET_CODE (pat) == CALL) |
b5ce41ff | 2385 | mark_call (insn); |
7506f491 | 2386 | } |
b5ce41ff | 2387 | |
7506f491 DE |
2388 | \f |
2389 | /* Compute copy/constant propagation working variables. */ | |
2390 | ||
2391 | /* Local properties of assignments. */ | |
7506f491 DE |
2392 | static sbitmap *cprop_pavloc; |
2393 | static sbitmap *cprop_absaltered; | |
2394 | ||
2395 | /* Global properties of assignments (computed from the local properties). */ | |
7506f491 DE |
2396 | static sbitmap *cprop_avin; |
2397 | static sbitmap *cprop_avout; | |
2398 | ||
c4c81601 RK |
2399 | /* Allocate vars used for copy/const propagation. N_BLOCKS is the number of |
2400 | basic blocks. N_SETS is the number of sets. */ | |
7506f491 DE |
2401 | |
2402 | static void | |
1d088dee | 2403 | alloc_cprop_mem (int n_blocks, int n_sets) |
7506f491 DE |
2404 | { |
2405 | cprop_pavloc = sbitmap_vector_alloc (n_blocks, n_sets); | |
2406 | cprop_absaltered = sbitmap_vector_alloc (n_blocks, n_sets); | |
2407 | ||
2408 | cprop_avin = sbitmap_vector_alloc (n_blocks, n_sets); | |
2409 | cprop_avout = sbitmap_vector_alloc (n_blocks, n_sets); | |
2410 | } | |
2411 | ||
2412 | /* Free vars used by copy/const propagation. */ | |
2413 | ||
2414 | static void | |
1d088dee | 2415 | free_cprop_mem (void) |
7506f491 | 2416 | { |
5a660bff DB |
2417 | sbitmap_vector_free (cprop_pavloc); |
2418 | sbitmap_vector_free (cprop_absaltered); | |
2419 | sbitmap_vector_free (cprop_avin); | |
2420 | sbitmap_vector_free (cprop_avout); | |
7506f491 DE |
2421 | } |
2422 | ||
c4c81601 RK |
2423 | /* For each block, compute whether X is transparent. X is either an |
2424 | expression or an assignment [though we don't care which, for this context | |
2425 | an assignment is treated as an expression]. For each block where an | |
2426 | element of X is modified, set (SET_P == 1) or reset (SET_P == 0) the INDX | |
2427 | bit in BMAP. */ | |
7506f491 DE |
2428 | |
2429 | static void | |
1d088dee | 2430 | compute_transp (rtx x, int indx, sbitmap *bmap, int set_p) |
7506f491 | 2431 | { |
e0082a72 ZD |
2432 | int i, j; |
2433 | basic_block bb; | |
7506f491 | 2434 | enum rtx_code code; |
c4c81601 | 2435 | reg_set *r; |
6f7d635c | 2436 | const char *fmt; |
7506f491 | 2437 | |
c4c81601 RK |
2438 | /* repeat is used to turn tail-recursion into iteration since GCC |
2439 | can't do it when there's no return value. */ | |
7506f491 DE |
2440 | repeat: |
2441 | ||
2442 | if (x == 0) | |
2443 | return; | |
2444 | ||
2445 | code = GET_CODE (x); | |
2446 | switch (code) | |
2447 | { | |
2448 | case REG: | |
c4c81601 RK |
2449 | if (set_p) |
2450 | { | |
2451 | if (REGNO (x) < FIRST_PSEUDO_REGISTER) | |
2452 | { | |
e0082a72 ZD |
2453 | FOR_EACH_BB (bb) |
2454 | if (TEST_BIT (reg_set_in_block[bb->index], REGNO (x))) | |
2455 | SET_BIT (bmap[bb->index], indx); | |
c4c81601 RK |
2456 | } |
2457 | else | |
2458 | { | |
2459 | for (r = reg_set_table[REGNO (x)]; r != NULL; r = r->next) | |
ed425871 | 2460 | SET_BIT (bmap[r->bb_index], indx); |
c4c81601 RK |
2461 | } |
2462 | } | |
2463 | else | |
2464 | { | |
2465 | if (REGNO (x) < FIRST_PSEUDO_REGISTER) | |
2466 | { | |
e0082a72 ZD |
2467 | FOR_EACH_BB (bb) |
2468 | if (TEST_BIT (reg_set_in_block[bb->index], REGNO (x))) | |
2469 | RESET_BIT (bmap[bb->index], indx); | |
c4c81601 RK |
2470 | } |
2471 | else | |
2472 | { | |
2473 | for (r = reg_set_table[REGNO (x)]; r != NULL; r = r->next) | |
ed425871 | 2474 | RESET_BIT (bmap[r->bb_index], indx); |
c4c81601 RK |
2475 | } |
2476 | } | |
7506f491 | 2477 | |
c4c81601 | 2478 | return; |
7506f491 DE |
2479 | |
2480 | case MEM: | |
16c5b95d MH |
2481 | if (! MEM_READONLY_P (x)) |
2482 | { | |
2483 | bitmap_iterator bi; | |
2484 | unsigned bb_index; | |
aa47fcfa | 2485 | |
16c5b95d MH |
2486 | /* First handle all the blocks with calls. We don't need to |
2487 | do any list walking for them. */ | |
2488 | EXECUTE_IF_SET_IN_BITMAP (blocks_with_calls, 0, bb_index, bi) | |
2489 | { | |
2490 | if (set_p) | |
2491 | SET_BIT (bmap[bb_index], indx); | |
2492 | else | |
2493 | RESET_BIT (bmap[bb_index], indx); | |
2494 | } | |
aa47fcfa | 2495 | |
16c5b95d MH |
2496 | /* Now iterate over the blocks which have memory modifications |
2497 | but which do not have any calls. */ | |
2498 | EXECUTE_IF_AND_COMPL_IN_BITMAP (modify_mem_list_set, | |
2499 | blocks_with_calls, | |
2500 | 0, bb_index, bi) | |
aa47fcfa | 2501 | { |
16c5b95d | 2502 | rtx list_entry = canon_modify_mem_list[bb_index]; |
aa47fcfa | 2503 | |
16c5b95d | 2504 | while (list_entry) |
aa47fcfa | 2505 | { |
16c5b95d MH |
2506 | rtx dest, dest_addr; |
2507 | ||
2508 | /* LIST_ENTRY must be an INSN of some kind that sets memory. | |
2509 | Examine each hunk of memory that is modified. */ | |
2510 | ||
2511 | dest = XEXP (list_entry, 0); | |
2512 | list_entry = XEXP (list_entry, 1); | |
2513 | dest_addr = XEXP (list_entry, 0); | |
2514 | ||
2515 | if (canon_true_dependence (dest, GET_MODE (dest), dest_addr, | |
2516 | x, rtx_addr_varies_p)) | |
2517 | { | |
2518 | if (set_p) | |
2519 | SET_BIT (bmap[bb_index], indx); | |
2520 | else | |
2521 | RESET_BIT (bmap[bb_index], indx); | |
2522 | break; | |
2523 | } | |
2524 | list_entry = XEXP (list_entry, 1); | |
2525 | } | |
aa47fcfa | 2526 | } |
16c5b95d | 2527 | } |
c4c81601 | 2528 | |
7506f491 DE |
2529 | x = XEXP (x, 0); |
2530 | goto repeat; | |
2531 | ||
2532 | case PC: | |
2533 | case CC0: /*FIXME*/ | |
2534 | case CONST: | |
2535 | case CONST_INT: | |
2536 | case CONST_DOUBLE: | |
69ef87e2 | 2537 | case CONST_VECTOR: |
7506f491 DE |
2538 | case SYMBOL_REF: |
2539 | case LABEL_REF: | |
2540 | case ADDR_VEC: | |
2541 | case ADDR_DIFF_VEC: | |
2542 | return; | |
2543 | ||
2544 | default: | |
2545 | break; | |
2546 | } | |
2547 | ||
c4c81601 | 2548 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
2549 | { |
2550 | if (fmt[i] == 'e') | |
2551 | { | |
7506f491 DE |
2552 | /* If we are about to do the last recursive call |
2553 | needed at this level, change it into iteration. | |
2554 | This function is called enough to be worth it. */ | |
2555 | if (i == 0) | |
2556 | { | |
c4c81601 | 2557 | x = XEXP (x, i); |
7506f491 DE |
2558 | goto repeat; |
2559 | } | |
c4c81601 RK |
2560 | |
2561 | compute_transp (XEXP (x, i), indx, bmap, set_p); | |
7506f491 DE |
2562 | } |
2563 | else if (fmt[i] == 'E') | |
c4c81601 RK |
2564 | for (j = 0; j < XVECLEN (x, i); j++) |
2565 | compute_transp (XVECEXP (x, i, j), indx, bmap, set_p); | |
7506f491 DE |
2566 | } |
2567 | } | |
2568 | ||
7506f491 DE |
2569 | /* Top level routine to do the dataflow analysis needed by copy/const |
2570 | propagation. */ | |
2571 | ||
2572 | static void | |
1d088dee | 2573 | compute_cprop_data (void) |
7506f491 | 2574 | { |
02280659 | 2575 | compute_local_properties (cprop_absaltered, cprop_pavloc, NULL, &set_hash_table); |
ce724250 JL |
2576 | compute_available (cprop_pavloc, cprop_absaltered, |
2577 | cprop_avout, cprop_avin); | |
7506f491 DE |
2578 | } |
2579 | \f | |
2580 | /* Copy/constant propagation. */ | |
2581 | ||
7506f491 DE |
2582 | /* Maximum number of register uses in an insn that we handle. */ |
2583 | #define MAX_USES 8 | |
2584 | ||
2585 | /* Table of uses found in an insn. | |
2586 | Allocated statically to avoid alloc/free complexity and overhead. */ | |
2587 | static struct reg_use reg_use_table[MAX_USES]; | |
2588 | ||
2589 | /* Index into `reg_use_table' while building it. */ | |
2590 | static int reg_use_count; | |
2591 | ||
c4c81601 RK |
2592 | /* Set up a list of register numbers used in INSN. The found uses are stored |
2593 | in `reg_use_table'. `reg_use_count' is initialized to zero before entry, | |
2594 | and contains the number of uses in the table upon exit. | |
7506f491 | 2595 | |
c4c81601 RK |
2596 | ??? If a register appears multiple times we will record it multiple times. |
2597 | This doesn't hurt anything but it will slow things down. */ | |
7506f491 DE |
2598 | |
2599 | static void | |
1d088dee | 2600 | find_used_regs (rtx *xptr, void *data ATTRIBUTE_UNUSED) |
7506f491 | 2601 | { |
c4c81601 | 2602 | int i, j; |
7506f491 | 2603 | enum rtx_code code; |
6f7d635c | 2604 | const char *fmt; |
9e71c818 | 2605 | rtx x = *xptr; |
7506f491 | 2606 | |
c4c81601 RK |
2607 | /* repeat is used to turn tail-recursion into iteration since GCC |
2608 | can't do it when there's no return value. */ | |
7506f491 | 2609 | repeat: |
7506f491 DE |
2610 | if (x == 0) |
2611 | return; | |
2612 | ||
2613 | code = GET_CODE (x); | |
9e71c818 | 2614 | if (REG_P (x)) |
7506f491 | 2615 | { |
7506f491 DE |
2616 | if (reg_use_count == MAX_USES) |
2617 | return; | |
c4c81601 | 2618 | |
7506f491 DE |
2619 | reg_use_table[reg_use_count].reg_rtx = x; |
2620 | reg_use_count++; | |
7506f491 DE |
2621 | } |
2622 | ||
2623 | /* Recursively scan the operands of this expression. */ | |
2624 | ||
c4c81601 | 2625 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
2626 | { |
2627 | if (fmt[i] == 'e') | |
2628 | { | |
2629 | /* If we are about to do the last recursive call | |
2630 | needed at this level, change it into iteration. | |
2631 | This function is called enough to be worth it. */ | |
2632 | if (i == 0) | |
2633 | { | |
2634 | x = XEXP (x, 0); | |
2635 | goto repeat; | |
2636 | } | |
c4c81601 | 2637 | |
9e71c818 | 2638 | find_used_regs (&XEXP (x, i), data); |
7506f491 DE |
2639 | } |
2640 | else if (fmt[i] == 'E') | |
c4c81601 | 2641 | for (j = 0; j < XVECLEN (x, i); j++) |
9e71c818 | 2642 | find_used_regs (&XVECEXP (x, i, j), data); |
7506f491 DE |
2643 | } |
2644 | } | |
2645 | ||
2646 | /* Try to replace all non-SET_DEST occurrences of FROM in INSN with TO. | |
cc2902df | 2647 | Returns nonzero is successful. */ |
7506f491 DE |
2648 | |
2649 | static int | |
1d088dee | 2650 | try_replace_reg (rtx from, rtx to, rtx insn) |
7506f491 | 2651 | { |
205eb6e7 | 2652 | rtx note = find_reg_equal_equiv_note (insn); |
fb0c0a12 | 2653 | rtx src = 0; |
172890a2 RK |
2654 | int success = 0; |
2655 | rtx set = single_set (insn); | |
833fc3ad | 2656 | |
3e916873 JH |
2657 | /* Usually we substitute easy stuff, so we won't copy everything. |
2658 | We however need to take care to not duplicate non-trivial CONST | |
2659 | expressions. */ | |
2660 | to = copy_rtx (to); | |
2661 | ||
2b773ee2 JH |
2662 | validate_replace_src_group (from, to, insn); |
2663 | if (num_changes_pending () && apply_change_group ()) | |
2664 | success = 1; | |
9e71c818 | 2665 | |
9feff114 JDA |
2666 | /* Try to simplify SET_SRC if we have substituted a constant. */ |
2667 | if (success && set && CONSTANT_P (to)) | |
2668 | { | |
2669 | src = simplify_rtx (SET_SRC (set)); | |
2670 | ||
2671 | if (src) | |
2672 | validate_change (insn, &SET_SRC (set), src, 0); | |
2673 | } | |
2674 | ||
205eb6e7 RS |
2675 | /* If there is already a REG_EQUAL note, update the expression in it |
2676 | with our replacement. */ | |
2677 | if (note != 0 && REG_NOTE_KIND (note) == REG_EQUAL) | |
a31830a7 SB |
2678 | set_unique_reg_note (insn, REG_EQUAL, |
2679 | simplify_replace_rtx (XEXP (note, 0), from, to)); | |
f305679f | 2680 | if (!success && set && reg_mentioned_p (from, SET_SRC (set))) |
833fc3ad | 2681 | { |
f305679f JH |
2682 | /* If above failed and this is a single set, try to simplify the source of |
2683 | the set given our substitution. We could perhaps try this for multiple | |
2684 | SETs, but it probably won't buy us anything. */ | |
172890a2 RK |
2685 | src = simplify_replace_rtx (SET_SRC (set), from, to); |
2686 | ||
9e71c818 JH |
2687 | if (!rtx_equal_p (src, SET_SRC (set)) |
2688 | && validate_change (insn, &SET_SRC (set), src, 0)) | |
172890a2 | 2689 | success = 1; |
833fc3ad | 2690 | |
bbd288a4 FS |
2691 | /* If we've failed to do replacement, have a single SET, don't already |
2692 | have a note, and have no special SET, add a REG_EQUAL note to not | |
2693 | lose information. */ | |
2694 | if (!success && note == 0 && set != 0 | |
70a640af AK |
2695 | && GET_CODE (SET_DEST (set)) != ZERO_EXTRACT |
2696 | && GET_CODE (SET_DEST (set)) != STRICT_LOW_PART) | |
f305679f JH |
2697 | note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (src)); |
2698 | } | |
e251e2a2 | 2699 | |
172890a2 RK |
2700 | /* REG_EQUAL may get simplified into register. |
2701 | We don't allow that. Remove that note. This code ought | |
fbe5a4a6 | 2702 | not to happen, because previous code ought to synthesize |
172890a2 | 2703 | reg-reg move, but be on the safe side. */ |
205eb6e7 | 2704 | if (note && REG_NOTE_KIND (note) == REG_EQUAL && REG_P (XEXP (note, 0))) |
172890a2 | 2705 | remove_note (insn, note); |
833fc3ad | 2706 | |
833fc3ad JH |
2707 | return success; |
2708 | } | |
c4c81601 RK |
2709 | |
2710 | /* Find a set of REGNOs that are available on entry to INSN's block. Returns | |
2711 | NULL no such set is found. */ | |
7506f491 DE |
2712 | |
2713 | static struct expr * | |
1d088dee | 2714 | find_avail_set (int regno, rtx insn) |
7506f491 | 2715 | { |
cafba495 BS |
2716 | /* SET1 contains the last set found that can be returned to the caller for |
2717 | use in a substitution. */ | |
2718 | struct expr *set1 = 0; | |
589005ff | 2719 | |
cafba495 | 2720 | /* Loops are not possible here. To get a loop we would need two sets |
454ff5cb | 2721 | available at the start of the block containing INSN. i.e. we would |
cafba495 BS |
2722 | need two sets like this available at the start of the block: |
2723 | ||
2724 | (set (reg X) (reg Y)) | |
2725 | (set (reg Y) (reg X)) | |
2726 | ||
2727 | This can not happen since the set of (reg Y) would have killed the | |
2728 | set of (reg X) making it unavailable at the start of this block. */ | |
2729 | while (1) | |
8e42ace1 | 2730 | { |
cafba495 | 2731 | rtx src; |
ceda50e9 | 2732 | struct expr *set = lookup_set (regno, &set_hash_table); |
cafba495 BS |
2733 | |
2734 | /* Find a set that is available at the start of the block | |
2735 | which contains INSN. */ | |
2736 | while (set) | |
2737 | { | |
2738 | if (TEST_BIT (cprop_avin[BLOCK_NUM (insn)], set->bitmap_index)) | |
2739 | break; | |
2740 | set = next_set (regno, set); | |
2741 | } | |
7506f491 | 2742 | |
cafba495 BS |
2743 | /* If no available set was found we've reached the end of the |
2744 | (possibly empty) copy chain. */ | |
2745 | if (set == 0) | |
589005ff | 2746 | break; |
cafba495 | 2747 | |
282899df | 2748 | gcc_assert (GET_CODE (set->expr) == SET); |
cafba495 BS |
2749 | |
2750 | src = SET_SRC (set->expr); | |
2751 | ||
2752 | /* We know the set is available. | |
2753 | Now check that SRC is ANTLOC (i.e. none of the source operands | |
589005ff | 2754 | have changed since the start of the block). |
cafba495 BS |
2755 | |
2756 | If the source operand changed, we may still use it for the next | |
2757 | iteration of this loop, but we may not use it for substitutions. */ | |
c4c81601 | 2758 | |
6b2d1c9e | 2759 | if (gcse_constant_p (src) || oprs_not_set_p (src, insn)) |
cafba495 BS |
2760 | set1 = set; |
2761 | ||
2762 | /* If the source of the set is anything except a register, then | |
2763 | we have reached the end of the copy chain. */ | |
7b1b4aed | 2764 | if (! REG_P (src)) |
7506f491 | 2765 | break; |
7506f491 | 2766 | |
454ff5cb | 2767 | /* Follow the copy chain, i.e. start another iteration of the loop |
cafba495 BS |
2768 | and see if we have an available copy into SRC. */ |
2769 | regno = REGNO (src); | |
8e42ace1 | 2770 | } |
cafba495 BS |
2771 | |
2772 | /* SET1 holds the last set that was available and anticipatable at | |
2773 | INSN. */ | |
2774 | return set1; | |
7506f491 DE |
2775 | } |
2776 | ||
abd535b6 | 2777 | /* Subroutine of cprop_insn that tries to propagate constants into |
0e3f0221 | 2778 | JUMP_INSNS. JUMP must be a conditional jump. If SETCC is non-NULL |
fbe5a4a6 | 2779 | it is the instruction that immediately precedes JUMP, and must be a |
818b6b7f | 2780 | single SET of a register. FROM is what we will try to replace, |
0e3f0221 | 2781 | SRC is the constant we will try to substitute for it. Returns nonzero |
589005ff | 2782 | if a change was made. */ |
c4c81601 | 2783 | |
abd535b6 | 2784 | static int |
1d088dee | 2785 | cprop_jump (basic_block bb, rtx setcc, rtx jump, rtx from, rtx src) |
abd535b6 | 2786 | { |
bc6688b4 | 2787 | rtx new, set_src, note_src; |
0e3f0221 | 2788 | rtx set = pc_set (jump); |
bc6688b4 | 2789 | rtx note = find_reg_equal_equiv_note (jump); |
0e3f0221 | 2790 | |
bc6688b4 RS |
2791 | if (note) |
2792 | { | |
2793 | note_src = XEXP (note, 0); | |
2794 | if (GET_CODE (note_src) == EXPR_LIST) | |
2795 | note_src = NULL_RTX; | |
2796 | } | |
2797 | else note_src = NULL_RTX; | |
2798 | ||
2799 | /* Prefer REG_EQUAL notes except those containing EXPR_LISTs. */ | |
2800 | set_src = note_src ? note_src : SET_SRC (set); | |
2801 | ||
2802 | /* First substitute the SETCC condition into the JUMP instruction, | |
2803 | then substitute that given values into this expanded JUMP. */ | |
2804 | if (setcc != NULL_RTX | |
48ddd46c JH |
2805 | && !modified_between_p (from, setcc, jump) |
2806 | && !modified_between_p (src, setcc, jump)) | |
b2f02503 | 2807 | { |
bc6688b4 | 2808 | rtx setcc_src; |
b2f02503 | 2809 | rtx setcc_set = single_set (setcc); |
bc6688b4 RS |
2810 | rtx setcc_note = find_reg_equal_equiv_note (setcc); |
2811 | setcc_src = (setcc_note && GET_CODE (XEXP (setcc_note, 0)) != EXPR_LIST) | |
2812 | ? XEXP (setcc_note, 0) : SET_SRC (setcc_set); | |
2813 | set_src = simplify_replace_rtx (set_src, SET_DEST (setcc_set), | |
2814 | setcc_src); | |
b2f02503 | 2815 | } |
0e3f0221 | 2816 | else |
bc6688b4 | 2817 | setcc = NULL_RTX; |
0e3f0221 | 2818 | |
bc6688b4 | 2819 | new = simplify_replace_rtx (set_src, from, src); |
abd535b6 | 2820 | |
bc6688b4 RS |
2821 | /* If no simplification can be made, then try the next register. */ |
2822 | if (rtx_equal_p (new, SET_SRC (set))) | |
9e48c409 | 2823 | return 0; |
589005ff | 2824 | |
7d5ab30e | 2825 | /* If this is now a no-op delete it, otherwise this must be a valid insn. */ |
172890a2 | 2826 | if (new == pc_rtx) |
0e3f0221 | 2827 | delete_insn (jump); |
7d5ab30e | 2828 | else |
abd535b6 | 2829 | { |
48ddd46c JH |
2830 | /* Ensure the value computed inside the jump insn to be equivalent |
2831 | to one computed by setcc. */ | |
bc6688b4 | 2832 | if (setcc && modified_in_p (new, setcc)) |
48ddd46c | 2833 | return 0; |
0e3f0221 | 2834 | if (! validate_change (jump, &SET_SRC (set), new, 0)) |
bc6688b4 RS |
2835 | { |
2836 | /* When (some) constants are not valid in a comparison, and there | |
2837 | are two registers to be replaced by constants before the entire | |
2838 | comparison can be folded into a constant, we need to keep | |
2839 | intermediate information in REG_EQUAL notes. For targets with | |
2840 | separate compare insns, such notes are added by try_replace_reg. | |
2841 | When we have a combined compare-and-branch instruction, however, | |
2842 | we need to attach a note to the branch itself to make this | |
2843 | optimization work. */ | |
2844 | ||
2845 | if (!rtx_equal_p (new, note_src)) | |
2846 | set_unique_reg_note (jump, REG_EQUAL, copy_rtx (new)); | |
2847 | return 0; | |
2848 | } | |
2849 | ||
2850 | /* Remove REG_EQUAL note after simplification. */ | |
2851 | if (note_src) | |
2852 | remove_note (jump, note); | |
7d5ab30e | 2853 | } |
abd535b6 | 2854 | |
0e3f0221 RS |
2855 | #ifdef HAVE_cc0 |
2856 | /* Delete the cc0 setter. */ | |
818b6b7f | 2857 | if (setcc != NULL && CC0_P (SET_DEST (single_set (setcc)))) |
0e3f0221 RS |
2858 | delete_insn (setcc); |
2859 | #endif | |
2860 | ||
172890a2 | 2861 | run_jump_opt_after_gcse = 1; |
c4c81601 | 2862 | |
27fb79ad | 2863 | global_const_prop_count++; |
10d22567 | 2864 | if (dump_file != NULL) |
172890a2 | 2865 | { |
10d22567 | 2866 | fprintf (dump_file, |
27fb79ad | 2867 | "GLOBAL CONST-PROP: Replacing reg %d in jump_insn %d with constant ", |
0e3f0221 | 2868 | REGNO (from), INSN_UID (jump)); |
10d22567 ZD |
2869 | print_rtl (dump_file, src); |
2870 | fprintf (dump_file, "\n"); | |
abd535b6 | 2871 | } |
0005550b | 2872 | purge_dead_edges (bb); |
172890a2 RK |
2873 | |
2874 | return 1; | |
abd535b6 BS |
2875 | } |
2876 | ||
ae860ff7 | 2877 | static bool |
eb232f4e | 2878 | constprop_register (rtx insn, rtx from, rtx to, bool alter_jumps) |
ae860ff7 JH |
2879 | { |
2880 | rtx sset; | |
2881 | ||
2882 | /* Check for reg or cc0 setting instructions followed by | |
2883 | conditional branch instructions first. */ | |
2884 | if (alter_jumps | |
2885 | && (sset = single_set (insn)) != NULL | |
244d05fb | 2886 | && NEXT_INSN (insn) |
ae860ff7 JH |
2887 | && any_condjump_p (NEXT_INSN (insn)) && onlyjump_p (NEXT_INSN (insn))) |
2888 | { | |
2889 | rtx dest = SET_DEST (sset); | |
2890 | if ((REG_P (dest) || CC0_P (dest)) | |
2891 | && cprop_jump (BLOCK_FOR_INSN (insn), insn, NEXT_INSN (insn), from, to)) | |
2892 | return 1; | |
2893 | } | |
2894 | ||
2895 | /* Handle normal insns next. */ | |
4b4bf941 | 2896 | if (NONJUMP_INSN_P (insn) |
ae860ff7 JH |
2897 | && try_replace_reg (from, to, insn)) |
2898 | return 1; | |
2899 | ||
2900 | /* Try to propagate a CONST_INT into a conditional jump. | |
2901 | We're pretty specific about what we will handle in this | |
2902 | code, we can extend this as necessary over time. | |
2903 | ||
2904 | Right now the insn in question must look like | |
2905 | (set (pc) (if_then_else ...)) */ | |
2906 | else if (alter_jumps && any_condjump_p (insn) && onlyjump_p (insn)) | |
2907 | return cprop_jump (BLOCK_FOR_INSN (insn), NULL, insn, from, to); | |
2908 | return 0; | |
2909 | } | |
2910 | ||
7506f491 | 2911 | /* Perform constant and copy propagation on INSN. |
cc2902df | 2912 | The result is nonzero if a change was made. */ |
7506f491 DE |
2913 | |
2914 | static int | |
1d088dee | 2915 | cprop_insn (rtx insn, int alter_jumps) |
7506f491 DE |
2916 | { |
2917 | struct reg_use *reg_used; | |
2918 | int changed = 0; | |
833fc3ad | 2919 | rtx note; |
7506f491 | 2920 | |
9e71c818 | 2921 | if (!INSN_P (insn)) |
7506f491 DE |
2922 | return 0; |
2923 | ||
2924 | reg_use_count = 0; | |
9e71c818 | 2925 | note_uses (&PATTERN (insn), find_used_regs, NULL); |
589005ff | 2926 | |
172890a2 | 2927 | note = find_reg_equal_equiv_note (insn); |
833fc3ad | 2928 | |
dc297297 | 2929 | /* We may win even when propagating constants into notes. */ |
833fc3ad | 2930 | if (note) |
9e71c818 | 2931 | find_used_regs (&XEXP (note, 0), NULL); |
7506f491 | 2932 | |
c4c81601 RK |
2933 | for (reg_used = ®_use_table[0]; reg_use_count > 0; |
2934 | reg_used++, reg_use_count--) | |
7506f491 | 2935 | { |
770ae6cc | 2936 | unsigned int regno = REGNO (reg_used->reg_rtx); |
7506f491 DE |
2937 | rtx pat, src; |
2938 | struct expr *set; | |
7506f491 DE |
2939 | |
2940 | /* Ignore registers created by GCSE. | |
dc297297 | 2941 | We do this because ... */ |
7506f491 DE |
2942 | if (regno >= max_gcse_regno) |
2943 | continue; | |
2944 | ||
2945 | /* If the register has already been set in this block, there's | |
2946 | nothing we can do. */ | |
2947 | if (! oprs_not_set_p (reg_used->reg_rtx, insn)) | |
2948 | continue; | |
2949 | ||
2950 | /* Find an assignment that sets reg_used and is available | |
2951 | at the start of the block. */ | |
2952 | set = find_avail_set (regno, insn); | |
2953 | if (! set) | |
2954 | continue; | |
589005ff | 2955 | |
7506f491 DE |
2956 | pat = set->expr; |
2957 | /* ??? We might be able to handle PARALLELs. Later. */ | |
282899df | 2958 | gcc_assert (GET_CODE (pat) == SET); |
c4c81601 | 2959 | |
7506f491 DE |
2960 | src = SET_SRC (pat); |
2961 | ||
e78d9500 | 2962 | /* Constant propagation. */ |
6b2d1c9e | 2963 | if (gcse_constant_p (src)) |
7506f491 | 2964 | { |
ae860ff7 | 2965 | if (constprop_register (insn, reg_used->reg_rtx, src, alter_jumps)) |
7506f491 DE |
2966 | { |
2967 | changed = 1; | |
27fb79ad | 2968 | global_const_prop_count++; |
10d22567 | 2969 | if (dump_file != NULL) |
7506f491 | 2970 | { |
10d22567 ZD |
2971 | fprintf (dump_file, "GLOBAL CONST-PROP: Replacing reg %d in ", regno); |
2972 | fprintf (dump_file, "insn %d with constant ", INSN_UID (insn)); | |
2973 | print_rtl (dump_file, src); | |
2974 | fprintf (dump_file, "\n"); | |
7506f491 | 2975 | } |
bc6688b4 RS |
2976 | if (INSN_DELETED_P (insn)) |
2977 | return 1; | |
7506f491 DE |
2978 | } |
2979 | } | |
7b1b4aed | 2980 | else if (REG_P (src) |
7506f491 DE |
2981 | && REGNO (src) >= FIRST_PSEUDO_REGISTER |
2982 | && REGNO (src) != regno) | |
2983 | { | |
cafba495 | 2984 | if (try_replace_reg (reg_used->reg_rtx, src, insn)) |
7506f491 | 2985 | { |
cafba495 | 2986 | changed = 1; |
27fb79ad | 2987 | global_copy_prop_count++; |
10d22567 | 2988 | if (dump_file != NULL) |
7506f491 | 2989 | { |
10d22567 | 2990 | fprintf (dump_file, "GLOBAL COPY-PROP: Replacing reg %d in insn %d", |
c4c81601 | 2991 | regno, INSN_UID (insn)); |
10d22567 | 2992 | fprintf (dump_file, " with reg %d\n", REGNO (src)); |
7506f491 | 2993 | } |
cafba495 BS |
2994 | |
2995 | /* The original insn setting reg_used may or may not now be | |
2996 | deletable. We leave the deletion to flow. */ | |
2997 | /* FIXME: If it turns out that the insn isn't deletable, | |
2998 | then we may have unnecessarily extended register lifetimes | |
2999 | and made things worse. */ | |
7506f491 DE |
3000 | } |
3001 | } | |
3002 | } | |
3003 | ||
3004 | return changed; | |
3005 | } | |
3006 | ||
710ee3ed RH |
3007 | /* Like find_used_regs, but avoid recording uses that appear in |
3008 | input-output contexts such as zero_extract or pre_dec. This | |
3009 | restricts the cases we consider to those for which local cprop | |
3010 | can legitimately make replacements. */ | |
3011 | ||
3012 | static void | |
1d088dee | 3013 | local_cprop_find_used_regs (rtx *xptr, void *data) |
710ee3ed RH |
3014 | { |
3015 | rtx x = *xptr; | |
3016 | ||
3017 | if (x == 0) | |
3018 | return; | |
3019 | ||
3020 | switch (GET_CODE (x)) | |
3021 | { | |
3022 | case ZERO_EXTRACT: | |
3023 | case SIGN_EXTRACT: | |
3024 | case STRICT_LOW_PART: | |
3025 | return; | |
3026 | ||
3027 | case PRE_DEC: | |
3028 | case PRE_INC: | |
3029 | case POST_DEC: | |
3030 | case POST_INC: | |
3031 | case PRE_MODIFY: | |
3032 | case POST_MODIFY: | |
3033 | /* Can only legitimately appear this early in the context of | |
3034 | stack pushes for function arguments, but handle all of the | |
3035 | codes nonetheless. */ | |
3036 | return; | |
3037 | ||
3038 | case SUBREG: | |
3039 | /* Setting a subreg of a register larger than word_mode leaves | |
3040 | the non-written words unchanged. */ | |
3041 | if (GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x))) > BITS_PER_WORD) | |
3042 | return; | |
3043 | break; | |
3044 | ||
3045 | default: | |
3046 | break; | |
3047 | } | |
3048 | ||
3049 | find_used_regs (xptr, data); | |
3050 | } | |
1d088dee | 3051 | |
8ba46434 R |
3052 | /* LIBCALL_SP is a zero-terminated array of insns at the end of a libcall; |
3053 | their REG_EQUAL notes need updating. */ | |
e197b6fc | 3054 | |
ae860ff7 | 3055 | static bool |
eb232f4e | 3056 | do_local_cprop (rtx x, rtx insn, bool alter_jumps, rtx *libcall_sp) |
ae860ff7 JH |
3057 | { |
3058 | rtx newreg = NULL, newcnst = NULL; | |
3059 | ||
e197b6fc RH |
3060 | /* Rule out USE instructions and ASM statements as we don't want to |
3061 | change the hard registers mentioned. */ | |
7b1b4aed | 3062 | if (REG_P (x) |
ae860ff7 | 3063 | && (REGNO (x) >= FIRST_PSEUDO_REGISTER |
e197b6fc RH |
3064 | || (GET_CODE (PATTERN (insn)) != USE |
3065 | && asm_noperands (PATTERN (insn)) < 0))) | |
ae860ff7 JH |
3066 | { |
3067 | cselib_val *val = cselib_lookup (x, GET_MODE (x), 0); | |
3068 | struct elt_loc_list *l; | |
3069 | ||
3070 | if (!val) | |
3071 | return false; | |
3072 | for (l = val->locs; l; l = l->next) | |
3073 | { | |
3074 | rtx this_rtx = l->loc; | |
46690369 JH |
3075 | rtx note; |
3076 | ||
5976e643 RS |
3077 | /* Don't CSE non-constant values out of libcall blocks. */ |
3078 | if (l->in_libcall && ! CONSTANT_P (this_rtx)) | |
9635cfad JH |
3079 | continue; |
3080 | ||
6b2d1c9e | 3081 | if (gcse_constant_p (this_rtx)) |
ae860ff7 | 3082 | newcnst = this_rtx; |
46690369 JH |
3083 | if (REG_P (this_rtx) && REGNO (this_rtx) >= FIRST_PSEUDO_REGISTER |
3084 | /* Don't copy propagate if it has attached REG_EQUIV note. | |
3085 | At this point this only function parameters should have | |
3086 | REG_EQUIV notes and if the argument slot is used somewhere | |
3087 | explicitly, it means address of parameter has been taken, | |
3088 | so we should not extend the lifetime of the pseudo. */ | |
3089 | && (!(note = find_reg_note (l->setting_insn, REG_EQUIV, NULL_RTX)) | |
7b1b4aed | 3090 | || ! MEM_P (XEXP (note, 0)))) |
ae860ff7 JH |
3091 | newreg = this_rtx; |
3092 | } | |
3093 | if (newcnst && constprop_register (insn, x, newcnst, alter_jumps)) | |
3094 | { | |
8ba46434 | 3095 | /* If we find a case where we can't fix the retval REG_EQUAL notes |
fbe5a4a6 | 3096 | match the new register, we either have to abandon this replacement |
8ba46434 | 3097 | or fix delete_trivially_dead_insns to preserve the setting insn, |
6fb5fa3c | 3098 | or make it delete the REG_EQUAL note, and fix up all passes that |
8ba46434 | 3099 | require the REG_EQUAL note there. */ |
282899df NS |
3100 | bool adjusted; |
3101 | ||
3102 | adjusted = adjust_libcall_notes (x, newcnst, insn, libcall_sp); | |
3103 | gcc_assert (adjusted); | |
3104 | ||
10d22567 | 3105 | if (dump_file != NULL) |
ae860ff7 | 3106 | { |
10d22567 | 3107 | fprintf (dump_file, "LOCAL CONST-PROP: Replacing reg %d in ", |
ae860ff7 | 3108 | REGNO (x)); |
10d22567 | 3109 | fprintf (dump_file, "insn %d with constant ", |
ae860ff7 | 3110 | INSN_UID (insn)); |
10d22567 ZD |
3111 | print_rtl (dump_file, newcnst); |
3112 | fprintf (dump_file, "\n"); | |
ae860ff7 | 3113 | } |
27fb79ad | 3114 | local_const_prop_count++; |
ae860ff7 JH |
3115 | return true; |
3116 | } | |
3117 | else if (newreg && newreg != x && try_replace_reg (x, newreg, insn)) | |
3118 | { | |
8ba46434 | 3119 | adjust_libcall_notes (x, newreg, insn, libcall_sp); |
10d22567 | 3120 | if (dump_file != NULL) |
ae860ff7 | 3121 | { |
10d22567 | 3122 | fprintf (dump_file, |
ae860ff7 JH |
3123 | "LOCAL COPY-PROP: Replacing reg %d in insn %d", |
3124 | REGNO (x), INSN_UID (insn)); | |
10d22567 | 3125 | fprintf (dump_file, " with reg %d\n", REGNO (newreg)); |
ae860ff7 | 3126 | } |
27fb79ad | 3127 | local_copy_prop_count++; |
ae860ff7 JH |
3128 | return true; |
3129 | } | |
3130 | } | |
3131 | return false; | |
3132 | } | |
3133 | ||
8ba46434 R |
3134 | /* LIBCALL_SP is a zero-terminated array of insns at the end of a libcall; |
3135 | their REG_EQUAL notes need updating to reflect that OLDREG has been | |
f4e3e618 RH |
3136 | replaced with NEWVAL in INSN. Return true if all substitutions could |
3137 | be made. */ | |
8ba46434 | 3138 | static bool |
1d088dee | 3139 | adjust_libcall_notes (rtx oldreg, rtx newval, rtx insn, rtx *libcall_sp) |
8ba46434 | 3140 | { |
f4e3e618 | 3141 | rtx end; |
8ba46434 R |
3142 | |
3143 | while ((end = *libcall_sp++)) | |
3144 | { | |
f4e3e618 | 3145 | rtx note = find_reg_equal_equiv_note (end); |
8ba46434 R |
3146 | |
3147 | if (! note) | |
3148 | continue; | |
3149 | ||
3150 | if (REG_P (newval)) | |
3151 | { | |
3152 | if (reg_set_between_p (newval, PREV_INSN (insn), end)) | |
3153 | { | |
3154 | do | |
3155 | { | |
3156 | note = find_reg_equal_equiv_note (end); | |
3157 | if (! note) | |
3158 | continue; | |
3159 | if (reg_mentioned_p (newval, XEXP (note, 0))) | |
3160 | return false; | |
3161 | } | |
3162 | while ((end = *libcall_sp++)); | |
3163 | return true; | |
3164 | } | |
3165 | } | |
5976e643 | 3166 | XEXP (note, 0) = simplify_replace_rtx (XEXP (note, 0), oldreg, newval); |
6fb5fa3c | 3167 | df_notes_rescan (end); |
8ba46434 R |
3168 | insn = end; |
3169 | } | |
3170 | return true; | |
3171 | } | |
3172 | ||
3173 | #define MAX_NESTED_LIBCALLS 9 | |
3174 | ||
eb232f4e SB |
3175 | /* Do local const/copy propagation (i.e. within each basic block). |
3176 | If ALTER_JUMPS is true, allow propagating into jump insns, which | |
3177 | could modify the CFG. */ | |
3178 | ||
ae860ff7 | 3179 | static void |
eb232f4e | 3180 | local_cprop_pass (bool alter_jumps) |
ae860ff7 | 3181 | { |
eb232f4e | 3182 | basic_block bb; |
ae860ff7 JH |
3183 | rtx insn; |
3184 | struct reg_use *reg_used; | |
8ba46434 | 3185 | rtx libcall_stack[MAX_NESTED_LIBCALLS + 1], *libcall_sp; |
1649d92f | 3186 | bool changed = false; |
ae860ff7 | 3187 | |
463301c3 | 3188 | cselib_init (false); |
8ba46434 R |
3189 | libcall_sp = &libcall_stack[MAX_NESTED_LIBCALLS]; |
3190 | *libcall_sp = 0; | |
eb232f4e | 3191 | FOR_EACH_BB (bb) |
ae860ff7 | 3192 | { |
eb232f4e | 3193 | FOR_BB_INSNS (bb, insn) |
ae860ff7 | 3194 | { |
eb232f4e | 3195 | if (INSN_P (insn)) |
ae860ff7 | 3196 | { |
eb232f4e | 3197 | rtx note = find_reg_note (insn, REG_LIBCALL, NULL_RTX); |
ae860ff7 | 3198 | |
eb232f4e SB |
3199 | if (note) |
3200 | { | |
3201 | gcc_assert (libcall_sp != libcall_stack); | |
3202 | *--libcall_sp = XEXP (note, 0); | |
3203 | } | |
3204 | note = find_reg_note (insn, REG_RETVAL, NULL_RTX); | |
3205 | if (note) | |
3206 | libcall_sp++; | |
3207 | note = find_reg_equal_equiv_note (insn); | |
3208 | do | |
3209 | { | |
3210 | reg_use_count = 0; | |
3211 | note_uses (&PATTERN (insn), local_cprop_find_used_regs, | |
3212 | NULL); | |
3213 | if (note) | |
3214 | local_cprop_find_used_regs (&XEXP (note, 0), NULL); | |
3215 | ||
3216 | for (reg_used = ®_use_table[0]; reg_use_count > 0; | |
3217 | reg_used++, reg_use_count--) | |
6fb5fa3c DB |
3218 | { |
3219 | if (do_local_cprop (reg_used->reg_rtx, insn, alter_jumps, | |
3220 | libcall_sp)) | |
3221 | { | |
3222 | changed = true; | |
3223 | break; | |
3224 | } | |
3225 | } | |
eb232f4e | 3226 | if (INSN_DELETED_P (insn)) |
1649d92f | 3227 | break; |
eb232f4e SB |
3228 | } |
3229 | while (reg_use_count); | |
ae860ff7 | 3230 | } |
eb232f4e | 3231 | cselib_process_insn (insn); |
ae860ff7 | 3232 | } |
eb232f4e SB |
3233 | |
3234 | /* Forget everything at the end of a basic block. Make sure we are | |
3235 | not inside a libcall, they should never cross basic blocks. */ | |
3236 | cselib_clear_table (); | |
3237 | gcc_assert (libcall_sp == &libcall_stack[MAX_NESTED_LIBCALLS]); | |
ae860ff7 | 3238 | } |
eb232f4e | 3239 | |
ae860ff7 | 3240 | cselib_finish (); |
eb232f4e | 3241 | |
1649d92f JH |
3242 | /* Global analysis may get into infinite loops for unreachable blocks. */ |
3243 | if (changed && alter_jumps) | |
5f0bea72 JH |
3244 | { |
3245 | delete_unreachable_blocks (); | |
3246 | free_reg_set_mem (); | |
3247 | alloc_reg_set_mem (max_reg_num ()); | |
eb232f4e | 3248 | compute_sets (); |
5f0bea72 | 3249 | } |
ae860ff7 JH |
3250 | } |
3251 | ||
c4c81601 | 3252 | /* Forward propagate copies. This includes copies and constants. Return |
cc2902df | 3253 | nonzero if a change was made. */ |
7506f491 DE |
3254 | |
3255 | static int | |
1d088dee | 3256 | cprop (int alter_jumps) |
7506f491 | 3257 | { |
e0082a72 ZD |
3258 | int changed; |
3259 | basic_block bb; | |
7506f491 DE |
3260 | rtx insn; |
3261 | ||
3262 | /* Note we start at block 1. */ | |
e0082a72 ZD |
3263 | if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) |
3264 | { | |
10d22567 ZD |
3265 | if (dump_file != NULL) |
3266 | fprintf (dump_file, "\n"); | |
e0082a72 ZD |
3267 | return 0; |
3268 | } | |
7506f491 DE |
3269 | |
3270 | changed = 0; | |
e0082a72 | 3271 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb->next_bb, EXIT_BLOCK_PTR, next_bb) |
7506f491 DE |
3272 | { |
3273 | /* Reset tables used to keep track of what's still valid [since the | |
3274 | start of the block]. */ | |
3275 | reset_opr_set_tables (); | |
3276 | ||
eb232f4e | 3277 | FOR_BB_INSNS (bb, insn) |
172890a2 RK |
3278 | if (INSN_P (insn)) |
3279 | { | |
ae860ff7 | 3280 | changed |= cprop_insn (insn, alter_jumps); |
7506f491 | 3281 | |
172890a2 RK |
3282 | /* Keep track of everything modified by this insn. */ |
3283 | /* ??? Need to be careful w.r.t. mods done to INSN. Don't | |
3284 | call mark_oprs_set if we turned the insn into a NOTE. */ | |
7b1b4aed | 3285 | if (! NOTE_P (insn)) |
172890a2 | 3286 | mark_oprs_set (insn); |
8e42ace1 | 3287 | } |
7506f491 DE |
3288 | } |
3289 | ||
10d22567 ZD |
3290 | if (dump_file != NULL) |
3291 | fprintf (dump_file, "\n"); | |
7506f491 DE |
3292 | |
3293 | return changed; | |
3294 | } | |
3295 | ||
fbef91d8 RS |
3296 | /* Similar to get_condition, only the resulting condition must be |
3297 | valid at JUMP, instead of at EARLIEST. | |
3298 | ||
3299 | This differs from noce_get_condition in ifcvt.c in that we prefer not to | |
3300 | settle for the condition variable in the jump instruction being integral. | |
3301 | We prefer to be able to record the value of a user variable, rather than | |
3302 | the value of a temporary used in a condition. This could be solved by | |
aabcd309 | 3303 | recording the value of *every* register scanned by canonicalize_condition, |
fbef91d8 RS |
3304 | but this would require some code reorganization. */ |
3305 | ||
2fa4a849 | 3306 | rtx |
1d088dee | 3307 | fis_get_condition (rtx jump) |
fbef91d8 | 3308 | { |
45d09c02 | 3309 | return get_condition (jump, NULL, false, true); |
fbef91d8 RS |
3310 | } |
3311 | ||
b0656d8b JW |
3312 | /* Check the comparison COND to see if we can safely form an implicit set from |
3313 | it. COND is either an EQ or NE comparison. */ | |
3314 | ||
3315 | static bool | |
3316 | implicit_set_cond_p (rtx cond) | |
3317 | { | |
3318 | enum machine_mode mode = GET_MODE (XEXP (cond, 0)); | |
3319 | rtx cst = XEXP (cond, 1); | |
3320 | ||
3321 | /* We can't perform this optimization if either operand might be or might | |
3322 | contain a signed zero. */ | |
3323 | if (HONOR_SIGNED_ZEROS (mode)) | |
3324 | { | |
3325 | /* It is sufficient to check if CST is or contains a zero. We must | |
3326 | handle float, complex, and vector. If any subpart is a zero, then | |
3327 | the optimization can't be performed. */ | |
3328 | /* ??? The complex and vector checks are not implemented yet. We just | |
3329 | always return zero for them. */ | |
3330 | if (GET_CODE (cst) == CONST_DOUBLE) | |
3331 | { | |
3332 | REAL_VALUE_TYPE d; | |
3333 | REAL_VALUE_FROM_CONST_DOUBLE (d, cst); | |
3334 | if (REAL_VALUES_EQUAL (d, dconst0)) | |
3335 | return 0; | |
3336 | } | |
3337 | else | |
3338 | return 0; | |
3339 | } | |
3340 | ||
3341 | return gcse_constant_p (cst); | |
3342 | } | |
3343 | ||
fbef91d8 RS |
3344 | /* Find the implicit sets of a function. An "implicit set" is a constraint |
3345 | on the value of a variable, implied by a conditional jump. For example, | |
3346 | following "if (x == 2)", the then branch may be optimized as though the | |
3347 | conditional performed an "explicit set", in this example, "x = 2". This | |
3348 | function records the set patterns that are implicit at the start of each | |
3349 | basic block. */ | |
3350 | ||
3351 | static void | |
1d088dee | 3352 | find_implicit_sets (void) |
fbef91d8 RS |
3353 | { |
3354 | basic_block bb, dest; | |
3355 | unsigned int count; | |
3356 | rtx cond, new; | |
3357 | ||
3358 | count = 0; | |
3359 | FOR_EACH_BB (bb) | |
a98ebe2e | 3360 | /* Check for more than one successor. */ |
628f6a4e | 3361 | if (EDGE_COUNT (bb->succs) > 1) |
fbef91d8 | 3362 | { |
a813c111 | 3363 | cond = fis_get_condition (BB_END (bb)); |
fbef91d8 RS |
3364 | |
3365 | if (cond | |
3366 | && (GET_CODE (cond) == EQ || GET_CODE (cond) == NE) | |
7b1b4aed | 3367 | && REG_P (XEXP (cond, 0)) |
fbef91d8 | 3368 | && REGNO (XEXP (cond, 0)) >= FIRST_PSEUDO_REGISTER |
b0656d8b | 3369 | && implicit_set_cond_p (cond)) |
fbef91d8 RS |
3370 | { |
3371 | dest = GET_CODE (cond) == EQ ? BRANCH_EDGE (bb)->dest | |
3372 | : FALLTHRU_EDGE (bb)->dest; | |
3373 | ||
c5cbcccf | 3374 | if (dest && single_pred_p (dest) |
fbef91d8 RS |
3375 | && dest != EXIT_BLOCK_PTR) |
3376 | { | |
3377 | new = gen_rtx_SET (VOIDmode, XEXP (cond, 0), | |
3378 | XEXP (cond, 1)); | |
3379 | implicit_sets[dest->index] = new; | |
10d22567 | 3380 | if (dump_file) |
fbef91d8 | 3381 | { |
10d22567 | 3382 | fprintf(dump_file, "Implicit set of reg %d in ", |
fbef91d8 | 3383 | REGNO (XEXP (cond, 0))); |
10d22567 | 3384 | fprintf(dump_file, "basic block %d\n", dest->index); |
fbef91d8 RS |
3385 | } |
3386 | count++; | |
3387 | } | |
3388 | } | |
3389 | } | |
3390 | ||
10d22567 ZD |
3391 | if (dump_file) |
3392 | fprintf (dump_file, "Found %d implicit sets\n", count); | |
fbef91d8 RS |
3393 | } |
3394 | ||
7506f491 | 3395 | /* Perform one copy/constant propagation pass. |
a0134312 RS |
3396 | PASS is the pass count. If CPROP_JUMPS is true, perform constant |
3397 | propagation into conditional jumps. If BYPASS_JUMPS is true, | |
3398 | perform conditional jump bypassing optimizations. */ | |
7506f491 DE |
3399 | |
3400 | static int | |
eb232f4e | 3401 | one_cprop_pass (int pass, bool cprop_jumps, bool bypass_jumps) |
7506f491 DE |
3402 | { |
3403 | int changed = 0; | |
3404 | ||
27fb79ad SB |
3405 | global_const_prop_count = local_const_prop_count = 0; |
3406 | global_copy_prop_count = local_copy_prop_count = 0; | |
7506f491 | 3407 | |
a52b023a PB |
3408 | if (cprop_jumps) |
3409 | local_cprop_pass (cprop_jumps); | |
ae860ff7 | 3410 | |
fbef91d8 | 3411 | /* Determine implicit sets. */ |
5ed6ace5 | 3412 | implicit_sets = XCNEWVEC (rtx, last_basic_block); |
fbef91d8 RS |
3413 | find_implicit_sets (); |
3414 | ||
02280659 ZD |
3415 | alloc_hash_table (max_cuid, &set_hash_table, 1); |
3416 | compute_hash_table (&set_hash_table); | |
fbef91d8 RS |
3417 | |
3418 | /* Free implicit_sets before peak usage. */ | |
3419 | free (implicit_sets); | |
3420 | implicit_sets = NULL; | |
3421 | ||
10d22567 ZD |
3422 | if (dump_file) |
3423 | dump_hash_table (dump_file, "SET", &set_hash_table); | |
02280659 | 3424 | if (set_hash_table.n_elems > 0) |
7506f491 | 3425 | { |
02280659 | 3426 | alloc_cprop_mem (last_basic_block, set_hash_table.n_elems); |
7506f491 | 3427 | compute_cprop_data (); |
a0134312 RS |
3428 | changed = cprop (cprop_jumps); |
3429 | if (bypass_jumps) | |
0e3f0221 | 3430 | changed |= bypass_conditional_jumps (); |
7506f491 DE |
3431 | free_cprop_mem (); |
3432 | } | |
c4c81601 | 3433 | |
02280659 | 3434 | free_hash_table (&set_hash_table); |
7506f491 | 3435 | |
10d22567 | 3436 | if (dump_file) |
7506f491 | 3437 | { |
10d22567 | 3438 | fprintf (dump_file, "CPROP of %s, pass %d: %d bytes needed, ", |
faed5cc3 | 3439 | current_function_name (), pass, bytes_used); |
10d22567 | 3440 | fprintf (dump_file, "%d local const props, %d local copy props, ", |
27fb79ad | 3441 | local_const_prop_count, local_copy_prop_count); |
10d22567 | 3442 | fprintf (dump_file, "%d global const props, %d global copy props\n\n", |
27fb79ad | 3443 | global_const_prop_count, global_copy_prop_count); |
7506f491 | 3444 | } |
1649d92f JH |
3445 | /* Global analysis may get into infinite loops for unreachable blocks. */ |
3446 | if (changed && cprop_jumps) | |
3447 | delete_unreachable_blocks (); | |
7506f491 DE |
3448 | |
3449 | return changed; | |
3450 | } | |
3451 | \f | |
0e3f0221 RS |
3452 | /* Bypass conditional jumps. */ |
3453 | ||
7821bfc7 RS |
3454 | /* The value of last_basic_block at the beginning of the jump_bypass |
3455 | pass. The use of redirect_edge_and_branch_force may introduce new | |
3456 | basic blocks, but the data flow analysis is only valid for basic | |
3457 | block indices less than bypass_last_basic_block. */ | |
3458 | ||
3459 | static int bypass_last_basic_block; | |
3460 | ||
0e3f0221 RS |
3461 | /* Find a set of REGNO to a constant that is available at the end of basic |
3462 | block BB. Returns NULL if no such set is found. Based heavily upon | |
3463 | find_avail_set. */ | |
3464 | ||
3465 | static struct expr * | |
1d088dee | 3466 | find_bypass_set (int regno, int bb) |
0e3f0221 RS |
3467 | { |
3468 | struct expr *result = 0; | |
3469 | ||
3470 | for (;;) | |
3471 | { | |
3472 | rtx src; | |
ceda50e9 | 3473 | struct expr *set = lookup_set (regno, &set_hash_table); |
0e3f0221 RS |
3474 | |
3475 | while (set) | |
3476 | { | |
3477 | if (TEST_BIT (cprop_avout[bb], set->bitmap_index)) | |
3478 | break; | |
3479 | set = next_set (regno, set); | |
3480 | } | |
3481 | ||
3482 | if (set == 0) | |
3483 | break; | |
3484 | ||
282899df | 3485 | gcc_assert (GET_CODE (set->expr) == SET); |
0e3f0221 RS |
3486 | |
3487 | src = SET_SRC (set->expr); | |
6b2d1c9e | 3488 | if (gcse_constant_p (src)) |
0e3f0221 RS |
3489 | result = set; |
3490 | ||
7b1b4aed | 3491 | if (! REG_P (src)) |
0e3f0221 RS |
3492 | break; |
3493 | ||
3494 | regno = REGNO (src); | |
3495 | } | |
3496 | return result; | |
3497 | } | |
3498 | ||
3499 | ||
e129b3f9 RS |
3500 | /* Subroutine of bypass_block that checks whether a pseudo is killed by |
3501 | any of the instructions inserted on an edge. Jump bypassing places | |
3502 | condition code setters on CFG edges using insert_insn_on_edge. This | |
3503 | function is required to check that our data flow analysis is still | |
3504 | valid prior to commit_edge_insertions. */ | |
3505 | ||
3506 | static bool | |
1d088dee | 3507 | reg_killed_on_edge (rtx reg, edge e) |
e129b3f9 RS |
3508 | { |
3509 | rtx insn; | |
3510 | ||
6de9cd9a | 3511 | for (insn = e->insns.r; insn; insn = NEXT_INSN (insn)) |
e129b3f9 RS |
3512 | if (INSN_P (insn) && reg_set_p (reg, insn)) |
3513 | return true; | |
3514 | ||
3515 | return false; | |
3516 | } | |
3517 | ||
0e3f0221 RS |
3518 | /* Subroutine of bypass_conditional_jumps that attempts to bypass the given |
3519 | basic block BB which has more than one predecessor. If not NULL, SETCC | |
3520 | is the first instruction of BB, which is immediately followed by JUMP_INSN | |
3521 | JUMP. Otherwise, SETCC is NULL, and JUMP is the first insn of BB. | |
e129b3f9 RS |
3522 | Returns nonzero if a change was made. |
3523 | ||
e0bb17a8 | 3524 | During the jump bypassing pass, we may place copies of SETCC instructions |
e129b3f9 RS |
3525 | on CFG edges. The following routine must be careful to pay attention to |
3526 | these inserted insns when performing its transformations. */ | |
0e3f0221 RS |
3527 | |
3528 | static int | |
1d088dee | 3529 | bypass_block (basic_block bb, rtx setcc, rtx jump) |
0e3f0221 RS |
3530 | { |
3531 | rtx insn, note; | |
628f6a4e | 3532 | edge e, edest; |
818b6b7f | 3533 | int i, change; |
72b8d451 | 3534 | int may_be_loop_header; |
628f6a4e BE |
3535 | unsigned removed_p; |
3536 | edge_iterator ei; | |
0e3f0221 RS |
3537 | |
3538 | insn = (setcc != NULL) ? setcc : jump; | |
3539 | ||
3540 | /* Determine set of register uses in INSN. */ | |
3541 | reg_use_count = 0; | |
3542 | note_uses (&PATTERN (insn), find_used_regs, NULL); | |
3543 | note = find_reg_equal_equiv_note (insn); | |
3544 | if (note) | |
3545 | find_used_regs (&XEXP (note, 0), NULL); | |
3546 | ||
72b8d451 | 3547 | may_be_loop_header = false; |
628f6a4e | 3548 | FOR_EACH_EDGE (e, ei, bb->preds) |
72b8d451 ZD |
3549 | if (e->flags & EDGE_DFS_BACK) |
3550 | { | |
3551 | may_be_loop_header = true; | |
3552 | break; | |
3553 | } | |
3554 | ||
0e3f0221 | 3555 | change = 0; |
628f6a4e | 3556 | for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); ) |
0e3f0221 | 3557 | { |
628f6a4e BE |
3558 | removed_p = 0; |
3559 | ||
7821bfc7 | 3560 | if (e->flags & EDGE_COMPLEX) |
628f6a4e BE |
3561 | { |
3562 | ei_next (&ei); | |
3563 | continue; | |
3564 | } | |
7821bfc7 RS |
3565 | |
3566 | /* We can't redirect edges from new basic blocks. */ | |
3567 | if (e->src->index >= bypass_last_basic_block) | |
628f6a4e BE |
3568 | { |
3569 | ei_next (&ei); | |
3570 | continue; | |
3571 | } | |
7821bfc7 | 3572 | |
72b8d451 | 3573 | /* The irreducible loops created by redirecting of edges entering the |
e0bb17a8 KH |
3574 | loop from outside would decrease effectiveness of some of the following |
3575 | optimizations, so prevent this. */ | |
72b8d451 ZD |
3576 | if (may_be_loop_header |
3577 | && !(e->flags & EDGE_DFS_BACK)) | |
628f6a4e BE |
3578 | { |
3579 | ei_next (&ei); | |
3580 | continue; | |
3581 | } | |
72b8d451 | 3582 | |
0e3f0221 RS |
3583 | for (i = 0; i < reg_use_count; i++) |
3584 | { | |
3585 | struct reg_use *reg_used = ®_use_table[i]; | |
589005ff | 3586 | unsigned int regno = REGNO (reg_used->reg_rtx); |
818b6b7f | 3587 | basic_block dest, old_dest; |
589005ff KH |
3588 | struct expr *set; |
3589 | rtx src, new; | |
0e3f0221 | 3590 | |
589005ff KH |
3591 | if (regno >= max_gcse_regno) |
3592 | continue; | |
0e3f0221 | 3593 | |
589005ff | 3594 | set = find_bypass_set (regno, e->src->index); |
0e3f0221 RS |
3595 | |
3596 | if (! set) | |
3597 | continue; | |
3598 | ||
e129b3f9 | 3599 | /* Check the data flow is valid after edge insertions. */ |
6de9cd9a | 3600 | if (e->insns.r && reg_killed_on_edge (reg_used->reg_rtx, e)) |
e129b3f9 RS |
3601 | continue; |
3602 | ||
589005ff | 3603 | src = SET_SRC (pc_set (jump)); |
0e3f0221 RS |
3604 | |
3605 | if (setcc != NULL) | |
3606 | src = simplify_replace_rtx (src, | |
589005ff KH |
3607 | SET_DEST (PATTERN (setcc)), |
3608 | SET_SRC (PATTERN (setcc))); | |
0e3f0221 RS |
3609 | |
3610 | new = simplify_replace_rtx (src, reg_used->reg_rtx, | |
589005ff | 3611 | SET_SRC (set->expr)); |
0e3f0221 | 3612 | |
1d088dee | 3613 | /* Jump bypassing may have already placed instructions on |
e129b3f9 RS |
3614 | edges of the CFG. We can't bypass an outgoing edge that |
3615 | has instructions associated with it, as these insns won't | |
3616 | get executed if the incoming edge is redirected. */ | |
3617 | ||
589005ff | 3618 | if (new == pc_rtx) |
e129b3f9 RS |
3619 | { |
3620 | edest = FALLTHRU_EDGE (bb); | |
6de9cd9a | 3621 | dest = edest->insns.r ? NULL : edest->dest; |
e129b3f9 | 3622 | } |
0e3f0221 | 3623 | else if (GET_CODE (new) == LABEL_REF) |
e129b3f9 RS |
3624 | { |
3625 | dest = BLOCK_FOR_INSN (XEXP (new, 0)); | |
3626 | /* Don't bypass edges containing instructions. */ | |
c7d1b449 KH |
3627 | edest = find_edge (bb, dest); |
3628 | if (edest && edest->insns.r) | |
3629 | dest = NULL; | |
e129b3f9 | 3630 | } |
0e3f0221 RS |
3631 | else |
3632 | dest = NULL; | |
3633 | ||
a544524a JH |
3634 | /* Avoid unification of the edge with other edges from original |
3635 | branch. We would end up emitting the instruction on "both" | |
3636 | edges. */ | |
7b1b4aed | 3637 | |
c7d1b449 KH |
3638 | if (dest && setcc && !CC0_P (SET_DEST (PATTERN (setcc))) |
3639 | && find_edge (e->src, dest)) | |
3640 | dest = NULL; | |
a544524a | 3641 | |
818b6b7f | 3642 | old_dest = e->dest; |
7821bfc7 RS |
3643 | if (dest != NULL |
3644 | && dest != old_dest | |
3645 | && dest != EXIT_BLOCK_PTR) | |
3646 | { | |
3647 | redirect_edge_and_branch_force (e, dest); | |
3648 | ||
818b6b7f | 3649 | /* Copy the register setter to the redirected edge. |
0e3f0221 RS |
3650 | Don't copy CC0 setters, as CC0 is dead after jump. */ |
3651 | if (setcc) | |
3652 | { | |
3653 | rtx pat = PATTERN (setcc); | |
818b6b7f | 3654 | if (!CC0_P (SET_DEST (pat))) |
0e3f0221 RS |
3655 | insert_insn_on_edge (copy_insn (pat), e); |
3656 | } | |
3657 | ||
10d22567 | 3658 | if (dump_file != NULL) |
0e3f0221 | 3659 | { |
10d22567 | 3660 | fprintf (dump_file, "JUMP-BYPASS: Proved reg %d " |
27fb79ad | 3661 | "in jump_insn %d equals constant ", |
818b6b7f | 3662 | regno, INSN_UID (jump)); |
10d22567 ZD |
3663 | print_rtl (dump_file, SET_SRC (set->expr)); |
3664 | fprintf (dump_file, "\nBypass edge from %d->%d to %d\n", | |
818b6b7f | 3665 | e->src->index, old_dest->index, dest->index); |
0e3f0221 RS |
3666 | } |
3667 | change = 1; | |
628f6a4e | 3668 | removed_p = 1; |
0e3f0221 RS |
3669 | break; |
3670 | } | |
3671 | } | |
628f6a4e BE |
3672 | if (!removed_p) |
3673 | ei_next (&ei); | |
0e3f0221 RS |
3674 | } |
3675 | return change; | |
3676 | } | |
3677 | ||
3678 | /* Find basic blocks with more than one predecessor that only contain a | |
3679 | single conditional jump. If the result of the comparison is known at | |
3680 | compile-time from any incoming edge, redirect that edge to the | |
9a71ece1 RH |
3681 | appropriate target. Returns nonzero if a change was made. |
3682 | ||
3683 | This function is now mis-named, because we also handle indirect jumps. */ | |
0e3f0221 RS |
3684 | |
3685 | static int | |
1d088dee | 3686 | bypass_conditional_jumps (void) |
0e3f0221 RS |
3687 | { |
3688 | basic_block bb; | |
3689 | int changed; | |
3690 | rtx setcc; | |
3691 | rtx insn; | |
3692 | rtx dest; | |
3693 | ||
3694 | /* Note we start at block 1. */ | |
3695 | if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) | |
3696 | return 0; | |
3697 | ||
7821bfc7 | 3698 | bypass_last_basic_block = last_basic_block; |
72b8d451 | 3699 | mark_dfs_back_edges (); |
7821bfc7 | 3700 | |
0e3f0221 RS |
3701 | changed = 0; |
3702 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb->next_bb, | |
589005ff | 3703 | EXIT_BLOCK_PTR, next_bb) |
0e3f0221 RS |
3704 | { |
3705 | /* Check for more than one predecessor. */ | |
c5cbcccf | 3706 | if (!single_pred_p (bb)) |
0e3f0221 RS |
3707 | { |
3708 | setcc = NULL_RTX; | |
eb232f4e | 3709 | FOR_BB_INSNS (bb, insn) |
4b4bf941 | 3710 | if (NONJUMP_INSN_P (insn)) |
0e3f0221 | 3711 | { |
9543a9d2 | 3712 | if (setcc) |
0e3f0221 | 3713 | break; |
ba4f7968 | 3714 | if (GET_CODE (PATTERN (insn)) != SET) |
0e3f0221 RS |
3715 | break; |
3716 | ||
ba4f7968 | 3717 | dest = SET_DEST (PATTERN (insn)); |
818b6b7f | 3718 | if (REG_P (dest) || CC0_P (dest)) |
0e3f0221 | 3719 | setcc = insn; |
0e3f0221 RS |
3720 | else |
3721 | break; | |
3722 | } | |
7b1b4aed | 3723 | else if (JUMP_P (insn)) |
0e3f0221 | 3724 | { |
9a71ece1 RH |
3725 | if ((any_condjump_p (insn) || computed_jump_p (insn)) |
3726 | && onlyjump_p (insn)) | |
0e3f0221 RS |
3727 | changed |= bypass_block (bb, setcc, insn); |
3728 | break; | |
3729 | } | |
3730 | else if (INSN_P (insn)) | |
3731 | break; | |
3732 | } | |
3733 | } | |
3734 | ||
818b6b7f | 3735 | /* If we bypassed any register setting insns, we inserted a |
fbe5a4a6 | 3736 | copy on the redirected edge. These need to be committed. */ |
0e3f0221 | 3737 | if (changed) |
62e5bf5d | 3738 | commit_edge_insertions (); |
0e3f0221 RS |
3739 | |
3740 | return changed; | |
3741 | } | |
3742 | \f | |
a65f3558 | 3743 | /* Compute PRE+LCM working variables. */ |
7506f491 DE |
3744 | |
3745 | /* Local properties of expressions. */ | |
3746 | /* Nonzero for expressions that are transparent in the block. */ | |
a65f3558 | 3747 | static sbitmap *transp; |
7506f491 | 3748 | |
5c35539b RH |
3749 | /* Nonzero for expressions that are transparent at the end of the block. |
3750 | This is only zero for expressions killed by abnormal critical edge | |
3751 | created by a calls. */ | |
a65f3558 | 3752 | static sbitmap *transpout; |
5c35539b | 3753 | |
a65f3558 JL |
3754 | /* Nonzero for expressions that are computed (available) in the block. */ |
3755 | static sbitmap *comp; | |
7506f491 | 3756 | |
a65f3558 JL |
3757 | /* Nonzero for expressions that are locally anticipatable in the block. */ |
3758 | static sbitmap *antloc; | |
7506f491 | 3759 | |
a65f3558 JL |
3760 | /* Nonzero for expressions where this block is an optimal computation |
3761 | point. */ | |
3762 | static sbitmap *pre_optimal; | |
5c35539b | 3763 | |
a65f3558 JL |
3764 | /* Nonzero for expressions which are redundant in a particular block. */ |
3765 | static sbitmap *pre_redundant; | |
7506f491 | 3766 | |
a42cd965 AM |
3767 | /* Nonzero for expressions which should be inserted on a specific edge. */ |
3768 | static sbitmap *pre_insert_map; | |
3769 | ||
3770 | /* Nonzero for expressions which should be deleted in a specific block. */ | |
3771 | static sbitmap *pre_delete_map; | |
3772 | ||
3773 | /* Contains the edge_list returned by pre_edge_lcm. */ | |
3774 | static struct edge_list *edge_list; | |
3775 | ||
a65f3558 JL |
3776 | /* Redundant insns. */ |
3777 | static sbitmap pre_redundant_insns; | |
7506f491 | 3778 | |
a65f3558 | 3779 | /* Allocate vars used for PRE analysis. */ |
7506f491 DE |
3780 | |
3781 | static void | |
1d088dee | 3782 | alloc_pre_mem (int n_blocks, int n_exprs) |
7506f491 | 3783 | { |
a65f3558 JL |
3784 | transp = sbitmap_vector_alloc (n_blocks, n_exprs); |
3785 | comp = sbitmap_vector_alloc (n_blocks, n_exprs); | |
3786 | antloc = sbitmap_vector_alloc (n_blocks, n_exprs); | |
5faf03ae | 3787 | |
a42cd965 AM |
3788 | pre_optimal = NULL; |
3789 | pre_redundant = NULL; | |
3790 | pre_insert_map = NULL; | |
3791 | pre_delete_map = NULL; | |
a42cd965 | 3792 | ae_kill = sbitmap_vector_alloc (n_blocks, n_exprs); |
c4c81601 | 3793 | |
a42cd965 | 3794 | /* pre_insert and pre_delete are allocated later. */ |
7506f491 DE |
3795 | } |
3796 | ||
a65f3558 | 3797 | /* Free vars used for PRE analysis. */ |
7506f491 DE |
3798 | |
3799 | static void | |
1d088dee | 3800 | free_pre_mem (void) |
7506f491 | 3801 | { |
5a660bff DB |
3802 | sbitmap_vector_free (transp); |
3803 | sbitmap_vector_free (comp); | |
bd3675fc JL |
3804 | |
3805 | /* ANTLOC and AE_KILL are freed just after pre_lcm finishes. */ | |
7506f491 | 3806 | |
a42cd965 | 3807 | if (pre_optimal) |
5a660bff | 3808 | sbitmap_vector_free (pre_optimal); |
a42cd965 | 3809 | if (pre_redundant) |
5a660bff | 3810 | sbitmap_vector_free (pre_redundant); |
a42cd965 | 3811 | if (pre_insert_map) |
5a660bff | 3812 | sbitmap_vector_free (pre_insert_map); |
a42cd965 | 3813 | if (pre_delete_map) |
5a660bff | 3814 | sbitmap_vector_free (pre_delete_map); |
a42cd965 | 3815 | |
bd3675fc | 3816 | transp = comp = NULL; |
a42cd965 | 3817 | pre_optimal = pre_redundant = pre_insert_map = pre_delete_map = NULL; |
7506f491 DE |
3818 | } |
3819 | ||
3820 | /* Top level routine to do the dataflow analysis needed by PRE. */ | |
3821 | ||
3822 | static void | |
1d088dee | 3823 | compute_pre_data (void) |
7506f491 | 3824 | { |
b614171e | 3825 | sbitmap trapping_expr; |
e0082a72 | 3826 | basic_block bb; |
b614171e | 3827 | unsigned int ui; |
c66e8ae9 | 3828 | |
02280659 | 3829 | compute_local_properties (transp, comp, antloc, &expr_hash_table); |
d55bc081 | 3830 | sbitmap_vector_zero (ae_kill, last_basic_block); |
c66e8ae9 | 3831 | |
b614171e | 3832 | /* Collect expressions which might trap. */ |
02280659 | 3833 | trapping_expr = sbitmap_alloc (expr_hash_table.n_elems); |
b614171e | 3834 | sbitmap_zero (trapping_expr); |
02280659 | 3835 | for (ui = 0; ui < expr_hash_table.size; ui++) |
b614171e MM |
3836 | { |
3837 | struct expr *e; | |
02280659 | 3838 | for (e = expr_hash_table.table[ui]; e != NULL; e = e->next_same_hash) |
b614171e MM |
3839 | if (may_trap_p (e->expr)) |
3840 | SET_BIT (trapping_expr, e->bitmap_index); | |
3841 | } | |
3842 | ||
c66e8ae9 JL |
3843 | /* Compute ae_kill for each basic block using: |
3844 | ||
3845 | ~(TRANSP | COMP) | |
e83f4801 | 3846 | */ |
c66e8ae9 | 3847 | |
e0082a72 | 3848 | FOR_EACH_BB (bb) |
c66e8ae9 | 3849 | { |
b614171e | 3850 | edge e; |
628f6a4e | 3851 | edge_iterator ei; |
b614171e MM |
3852 | |
3853 | /* If the current block is the destination of an abnormal edge, we | |
3854 | kill all trapping expressions because we won't be able to properly | |
3855 | place the instruction on the edge. So make them neither | |
3856 | anticipatable nor transparent. This is fairly conservative. */ | |
628f6a4e | 3857 | FOR_EACH_EDGE (e, ei, bb->preds) |
b614171e MM |
3858 | if (e->flags & EDGE_ABNORMAL) |
3859 | { | |
e0082a72 ZD |
3860 | sbitmap_difference (antloc[bb->index], antloc[bb->index], trapping_expr); |
3861 | sbitmap_difference (transp[bb->index], transp[bb->index], trapping_expr); | |
b614171e MM |
3862 | break; |
3863 | } | |
3864 | ||
e0082a72 ZD |
3865 | sbitmap_a_or_b (ae_kill[bb->index], transp[bb->index], comp[bb->index]); |
3866 | sbitmap_not (ae_kill[bb->index], ae_kill[bb->index]); | |
c66e8ae9 JL |
3867 | } |
3868 | ||
10d22567 | 3869 | edge_list = pre_edge_lcm (expr_hash_table.n_elems, transp, comp, antloc, |
a42cd965 | 3870 | ae_kill, &pre_insert_map, &pre_delete_map); |
5a660bff | 3871 | sbitmap_vector_free (antloc); |
bd3675fc | 3872 | antloc = NULL; |
5a660bff | 3873 | sbitmap_vector_free (ae_kill); |
589005ff | 3874 | ae_kill = NULL; |
76ac938b | 3875 | sbitmap_free (trapping_expr); |
7506f491 DE |
3876 | } |
3877 | \f | |
3878 | /* PRE utilities */ | |
3879 | ||
cc2902df | 3880 | /* Return nonzero if an occurrence of expression EXPR in OCCR_BB would reach |
a65f3558 | 3881 | block BB. |
7506f491 DE |
3882 | |
3883 | VISITED is a pointer to a working buffer for tracking which BB's have | |
3884 | been visited. It is NULL for the top-level call. | |
3885 | ||
3886 | We treat reaching expressions that go through blocks containing the same | |
3887 | reaching expression as "not reaching". E.g. if EXPR is generated in blocks | |
3888 | 2 and 3, INSN is in block 4, and 2->3->4, we treat the expression in block | |
3889 | 2 as not reaching. The intent is to improve the probability of finding | |
3890 | only one reaching expression and to reduce register lifetimes by picking | |
3891 | the closest such expression. */ | |
3892 | ||
3893 | static int | |
1d088dee | 3894 | pre_expr_reaches_here_p_work (basic_block occr_bb, struct expr *expr, basic_block bb, char *visited) |
7506f491 | 3895 | { |
36349f8b | 3896 | edge pred; |
628f6a4e BE |
3897 | edge_iterator ei; |
3898 | ||
3899 | FOR_EACH_EDGE (pred, ei, bb->preds) | |
7506f491 | 3900 | { |
e2d2ed72 | 3901 | basic_block pred_bb = pred->src; |
7506f491 | 3902 | |
36349f8b | 3903 | if (pred->src == ENTRY_BLOCK_PTR |
7506f491 | 3904 | /* Has predecessor has already been visited? */ |
0b17ab2f | 3905 | || visited[pred_bb->index]) |
c4c81601 RK |
3906 | ;/* Nothing to do. */ |
3907 | ||
7506f491 | 3908 | /* Does this predecessor generate this expression? */ |
0b17ab2f | 3909 | else if (TEST_BIT (comp[pred_bb->index], expr->bitmap_index)) |
7506f491 DE |
3910 | { |
3911 | /* Is this the occurrence we're looking for? | |
3912 | Note that there's only one generating occurrence per block | |
3913 | so we just need to check the block number. */ | |
a65f3558 | 3914 | if (occr_bb == pred_bb) |
7506f491 | 3915 | return 1; |
c4c81601 | 3916 | |
0b17ab2f | 3917 | visited[pred_bb->index] = 1; |
7506f491 DE |
3918 | } |
3919 | /* Ignore this predecessor if it kills the expression. */ | |
0b17ab2f RH |
3920 | else if (! TEST_BIT (transp[pred_bb->index], expr->bitmap_index)) |
3921 | visited[pred_bb->index] = 1; | |
c4c81601 | 3922 | |
7506f491 DE |
3923 | /* Neither gen nor kill. */ |
3924 | else | |
ac7c5af5 | 3925 | { |
0b17ab2f | 3926 | visited[pred_bb->index] = 1; |
89e606c9 | 3927 | if (pre_expr_reaches_here_p_work (occr_bb, expr, pred_bb, visited)) |
7506f491 | 3928 | return 1; |
ac7c5af5 | 3929 | } |
7506f491 DE |
3930 | } |
3931 | ||
3932 | /* All paths have been checked. */ | |
3933 | return 0; | |
3934 | } | |
283a2545 RL |
3935 | |
3936 | /* The wrapper for pre_expr_reaches_here_work that ensures that any | |
dc297297 | 3937 | memory allocated for that function is returned. */ |
283a2545 RL |
3938 | |
3939 | static int | |
1d088dee | 3940 | pre_expr_reaches_here_p (basic_block occr_bb, struct expr *expr, basic_block bb) |
283a2545 RL |
3941 | { |
3942 | int rval; | |
5ed6ace5 | 3943 | char *visited = XCNEWVEC (char, last_basic_block); |
283a2545 | 3944 | |
8e42ace1 | 3945 | rval = pre_expr_reaches_here_p_work (occr_bb, expr, bb, visited); |
283a2545 RL |
3946 | |
3947 | free (visited); | |
c4c81601 | 3948 | return rval; |
283a2545 | 3949 | } |
7506f491 | 3950 | \f |
a42cd965 AM |
3951 | |
3952 | /* Given an expr, generate RTL which we can insert at the end of a BB, | |
589005ff | 3953 | or on an edge. Set the block number of any insns generated to |
a42cd965 AM |
3954 | the value of BB. */ |
3955 | ||
3956 | static rtx | |
1d088dee | 3957 | process_insert_insn (struct expr *expr) |
a42cd965 AM |
3958 | { |
3959 | rtx reg = expr->reaching_reg; | |
fb0c0a12 RK |
3960 | rtx exp = copy_rtx (expr->expr); |
3961 | rtx pat; | |
a42cd965 AM |
3962 | |
3963 | start_sequence (); | |
fb0c0a12 RK |
3964 | |
3965 | /* If the expression is something that's an operand, like a constant, | |
3966 | just copy it to a register. */ | |
3967 | if (general_operand (exp, GET_MODE (reg))) | |
3968 | emit_move_insn (reg, exp); | |
3969 | ||
3970 | /* Otherwise, make a new insn to compute this expression and make sure the | |
3971 | insn will be recognized (this also adds any needed CLOBBERs). Copy the | |
3972 | expression to make sure we don't have any sharing issues. */ | |
282899df NS |
3973 | else |
3974 | { | |
3975 | rtx insn = emit_insn (gen_rtx_SET (VOIDmode, reg, exp)); | |
3976 | ||
2f021b67 AP |
3977 | if (insn_invalid_p (insn)) |
3978 | gcc_unreachable (); | |
282899df NS |
3979 | } |
3980 | ||
589005ff | 3981 | |
2f937369 | 3982 | pat = get_insns (); |
a42cd965 AM |
3983 | end_sequence (); |
3984 | ||
3985 | return pat; | |
3986 | } | |
589005ff | 3987 | |
a65f3558 JL |
3988 | /* Add EXPR to the end of basic block BB. |
3989 | ||
3990 | This is used by both the PRE and code hoisting. | |
3991 | ||
3992 | For PRE, we want to verify that the expr is either transparent | |
3993 | or locally anticipatable in the target block. This check makes | |
3994 | no sense for code hoisting. */ | |
7506f491 DE |
3995 | |
3996 | static void | |
6fb5fa3c | 3997 | insert_insn_end_basic_block (struct expr *expr, basic_block bb, int pre) |
7506f491 | 3998 | { |
a813c111 | 3999 | rtx insn = BB_END (bb); |
7506f491 DE |
4000 | rtx new_insn; |
4001 | rtx reg = expr->reaching_reg; | |
4002 | int regno = REGNO (reg); | |
2f937369 | 4003 | rtx pat, pat_end; |
7506f491 | 4004 | |
a42cd965 | 4005 | pat = process_insert_insn (expr); |
282899df | 4006 | gcc_assert (pat && INSN_P (pat)); |
2f937369 DM |
4007 | |
4008 | pat_end = pat; | |
4009 | while (NEXT_INSN (pat_end) != NULL_RTX) | |
4010 | pat_end = NEXT_INSN (pat_end); | |
7506f491 DE |
4011 | |
4012 | /* If the last insn is a jump, insert EXPR in front [taking care to | |
4d6922ee | 4013 | handle cc0, etc. properly]. Similarly we need to care trapping |
068473ec | 4014 | instructions in presence of non-call exceptions. */ |
7506f491 | 4015 | |
7b1b4aed | 4016 | if (JUMP_P (insn) |
4b4bf941 | 4017 | || (NONJUMP_INSN_P (insn) |
c5cbcccf ZD |
4018 | && (!single_succ_p (bb) |
4019 | || single_succ_edge (bb)->flags & EDGE_ABNORMAL))) | |
7506f491 | 4020 | { |
50b2596f | 4021 | #ifdef HAVE_cc0 |
7506f491 | 4022 | rtx note; |
50b2596f | 4023 | #endif |
068473ec JH |
4024 | /* It should always be the case that we can put these instructions |
4025 | anywhere in the basic block with performing PRE optimizations. | |
4026 | Check this. */ | |
282899df NS |
4027 | gcc_assert (!NONJUMP_INSN_P (insn) || !pre |
4028 | || TEST_BIT (antloc[bb->index], expr->bitmap_index) | |
4029 | || TEST_BIT (transp[bb->index], expr->bitmap_index)); | |
7506f491 DE |
4030 | |
4031 | /* If this is a jump table, then we can't insert stuff here. Since | |
4032 | we know the previous real insn must be the tablejump, we insert | |
4033 | the new instruction just before the tablejump. */ | |
4034 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
4035 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
4036 | insn = prev_real_insn (insn); | |
4037 | ||
4038 | #ifdef HAVE_cc0 | |
4039 | /* FIXME: 'twould be nice to call prev_cc0_setter here but it aborts | |
4040 | if cc0 isn't set. */ | |
4041 | note = find_reg_note (insn, REG_CC_SETTER, NULL_RTX); | |
4042 | if (note) | |
4043 | insn = XEXP (note, 0); | |
4044 | else | |
4045 | { | |
4046 | rtx maybe_cc0_setter = prev_nonnote_insn (insn); | |
4047 | if (maybe_cc0_setter | |
2c3c49de | 4048 | && INSN_P (maybe_cc0_setter) |
7506f491 DE |
4049 | && sets_cc0_p (PATTERN (maybe_cc0_setter))) |
4050 | insn = maybe_cc0_setter; | |
4051 | } | |
4052 | #endif | |
4053 | /* FIXME: What if something in cc0/jump uses value set in new insn? */ | |
6fb5fa3c | 4054 | new_insn = emit_insn_before_noloc (pat, insn, bb); |
3947e2f9 | 4055 | } |
c4c81601 | 4056 | |
3947e2f9 RH |
4057 | /* Likewise if the last insn is a call, as will happen in the presence |
4058 | of exception handling. */ | |
7b1b4aed | 4059 | else if (CALL_P (insn) |
c5cbcccf ZD |
4060 | && (!single_succ_p (bb) |
4061 | || single_succ_edge (bb)->flags & EDGE_ABNORMAL)) | |
3947e2f9 | 4062 | { |
3947e2f9 RH |
4063 | /* Keeping in mind SMALL_REGISTER_CLASSES and parameters in registers, |
4064 | we search backward and place the instructions before the first | |
4065 | parameter is loaded. Do this for everyone for consistency and a | |
fbe5a4a6 | 4066 | presumption that we'll get better code elsewhere as well. |
3947e2f9 | 4067 | |
c4c81601 | 4068 | It should always be the case that we can put these instructions |
a65f3558 JL |
4069 | anywhere in the basic block with performing PRE optimizations. |
4070 | Check this. */ | |
c4c81601 | 4071 | |
282899df NS |
4072 | gcc_assert (!pre |
4073 | || TEST_BIT (antloc[bb->index], expr->bitmap_index) | |
4074 | || TEST_BIT (transp[bb->index], expr->bitmap_index)); | |
3947e2f9 RH |
4075 | |
4076 | /* Since different machines initialize their parameter registers | |
4077 | in different orders, assume nothing. Collect the set of all | |
4078 | parameter registers. */ | |
a813c111 | 4079 | insn = find_first_parameter_load (insn, BB_HEAD (bb)); |
3947e2f9 | 4080 | |
b1d26727 JL |
4081 | /* If we found all the parameter loads, then we want to insert |
4082 | before the first parameter load. | |
4083 | ||
4084 | If we did not find all the parameter loads, then we might have | |
4085 | stopped on the head of the block, which could be a CODE_LABEL. | |
4086 | If we inserted before the CODE_LABEL, then we would be putting | |
4087 | the insn in the wrong basic block. In that case, put the insn | |
b5229628 | 4088 | after the CODE_LABEL. Also, respect NOTE_INSN_BASIC_BLOCK. */ |
7b1b4aed | 4089 | while (LABEL_P (insn) |
589ca5cb | 4090 | || NOTE_INSN_BASIC_BLOCK_P (insn)) |
b5229628 | 4091 | insn = NEXT_INSN (insn); |
c4c81601 | 4092 | |
6fb5fa3c | 4093 | new_insn = emit_insn_before_noloc (pat, insn, bb); |
7506f491 DE |
4094 | } |
4095 | else | |
6fb5fa3c | 4096 | new_insn = emit_insn_after_noloc (pat, insn, bb); |
7506f491 | 4097 | |
2f937369 | 4098 | while (1) |
a65f3558 | 4099 | { |
2f937369 | 4100 | if (INSN_P (pat)) |
a65f3558 | 4101 | { |
2f937369 DM |
4102 | add_label_notes (PATTERN (pat), new_insn); |
4103 | note_stores (PATTERN (pat), record_set_info, pat); | |
a65f3558 | 4104 | } |
2f937369 DM |
4105 | if (pat == pat_end) |
4106 | break; | |
4107 | pat = NEXT_INSN (pat); | |
a65f3558 | 4108 | } |
3947e2f9 | 4109 | |
7506f491 DE |
4110 | gcse_create_count++; |
4111 | ||
10d22567 | 4112 | if (dump_file) |
7506f491 | 4113 | { |
10d22567 | 4114 | fprintf (dump_file, "PRE/HOIST: end of bb %d, insn %d, ", |
0b17ab2f | 4115 | bb->index, INSN_UID (new_insn)); |
10d22567 | 4116 | fprintf (dump_file, "copying expression %d to reg %d\n", |
c4c81601 | 4117 | expr->bitmap_index, regno); |
7506f491 DE |
4118 | } |
4119 | } | |
4120 | ||
a42cd965 AM |
4121 | /* Insert partially redundant expressions on edges in the CFG to make |
4122 | the expressions fully redundant. */ | |
7506f491 | 4123 | |
a42cd965 | 4124 | static int |
1d088dee | 4125 | pre_edge_insert (struct edge_list *edge_list, struct expr **index_map) |
7506f491 | 4126 | { |
c4c81601 | 4127 | int e, i, j, num_edges, set_size, did_insert = 0; |
a65f3558 JL |
4128 | sbitmap *inserted; |
4129 | ||
a42cd965 AM |
4130 | /* Where PRE_INSERT_MAP is nonzero, we add the expression on that edge |
4131 | if it reaches any of the deleted expressions. */ | |
7506f491 | 4132 | |
a42cd965 AM |
4133 | set_size = pre_insert_map[0]->size; |
4134 | num_edges = NUM_EDGES (edge_list); | |
02280659 | 4135 | inserted = sbitmap_vector_alloc (num_edges, expr_hash_table.n_elems); |
a42cd965 | 4136 | sbitmap_vector_zero (inserted, num_edges); |
7506f491 | 4137 | |
a42cd965 | 4138 | for (e = 0; e < num_edges; e++) |
7506f491 DE |
4139 | { |
4140 | int indx; | |
e2d2ed72 | 4141 | basic_block bb = INDEX_EDGE_PRED_BB (edge_list, e); |
a65f3558 | 4142 | |
a65f3558 | 4143 | for (i = indx = 0; i < set_size; i++, indx += SBITMAP_ELT_BITS) |
7506f491 | 4144 | { |
a42cd965 | 4145 | SBITMAP_ELT_TYPE insert = pre_insert_map[e]->elms[i]; |
7506f491 | 4146 | |
02280659 | 4147 | for (j = indx; insert && j < (int) expr_hash_table.n_elems; j++, insert >>= 1) |
c4c81601 RK |
4148 | if ((insert & 1) != 0 && index_map[j]->reaching_reg != NULL_RTX) |
4149 | { | |
4150 | struct expr *expr = index_map[j]; | |
4151 | struct occr *occr; | |
a65f3558 | 4152 | |
ff7cc307 | 4153 | /* Now look at each deleted occurrence of this expression. */ |
c4c81601 RK |
4154 | for (occr = expr->antic_occr; occr != NULL; occr = occr->next) |
4155 | { | |
4156 | if (! occr->deleted_p) | |
4157 | continue; | |
4158 | ||
3f117656 | 4159 | /* Insert this expression on this edge if it would |
ff7cc307 | 4160 | reach the deleted occurrence in BB. */ |
c4c81601 RK |
4161 | if (!TEST_BIT (inserted[e], j)) |
4162 | { | |
4163 | rtx insn; | |
4164 | edge eg = INDEX_EDGE (edge_list, e); | |
4165 | ||
4166 | /* We can't insert anything on an abnormal and | |
4167 | critical edge, so we insert the insn at the end of | |
4168 | the previous block. There are several alternatives | |
4169 | detailed in Morgans book P277 (sec 10.5) for | |
4170 | handling this situation. This one is easiest for | |
4171 | now. */ | |
4172 | ||
b16aa8a5 | 4173 | if (eg->flags & EDGE_ABNORMAL) |
6fb5fa3c | 4174 | insert_insn_end_basic_block (index_map[j], bb, 0); |
c4c81601 RK |
4175 | else |
4176 | { | |
4177 | insn = process_insert_insn (index_map[j]); | |
4178 | insert_insn_on_edge (insn, eg); | |
4179 | } | |
4180 | ||
10d22567 | 4181 | if (dump_file) |
c4c81601 | 4182 | { |
10d22567 | 4183 | fprintf (dump_file, "PRE/HOIST: edge (%d,%d), ", |
0b17ab2f RH |
4184 | bb->index, |
4185 | INDEX_EDGE_SUCC_BB (edge_list, e)->index); | |
10d22567 | 4186 | fprintf (dump_file, "copy expression %d\n", |
c4c81601 RK |
4187 | expr->bitmap_index); |
4188 | } | |
4189 | ||
a13d4ebf | 4190 | update_ld_motion_stores (expr); |
c4c81601 RK |
4191 | SET_BIT (inserted[e], j); |
4192 | did_insert = 1; | |
4193 | gcse_create_count++; | |
4194 | } | |
4195 | } | |
4196 | } | |
7506f491 DE |
4197 | } |
4198 | } | |
5faf03ae | 4199 | |
5a660bff | 4200 | sbitmap_vector_free (inserted); |
a42cd965 | 4201 | return did_insert; |
7506f491 DE |
4202 | } |
4203 | ||
073089a7 | 4204 | /* Copy the result of EXPR->EXPR generated by INSN to EXPR->REACHING_REG. |
b885908b MH |
4205 | Given "old_reg <- expr" (INSN), instead of adding after it |
4206 | reaching_reg <- old_reg | |
4207 | it's better to do the following: | |
4208 | reaching_reg <- expr | |
4209 | old_reg <- reaching_reg | |
4210 | because this way copy propagation can discover additional PRE | |
f5f2e3cd MH |
4211 | opportunities. But if this fails, we try the old way. |
4212 | When "expr" is a store, i.e. | |
4213 | given "MEM <- old_reg", instead of adding after it | |
4214 | reaching_reg <- old_reg | |
4215 | it's better to add it before as follows: | |
4216 | reaching_reg <- old_reg | |
4217 | MEM <- reaching_reg. */ | |
7506f491 DE |
4218 | |
4219 | static void | |
1d088dee | 4220 | pre_insert_copy_insn (struct expr *expr, rtx insn) |
7506f491 DE |
4221 | { |
4222 | rtx reg = expr->reaching_reg; | |
4223 | int regno = REGNO (reg); | |
4224 | int indx = expr->bitmap_index; | |
073089a7 | 4225 | rtx pat = PATTERN (insn); |
64068ca2 | 4226 | rtx set, first_set, new_insn; |
b885908b | 4227 | rtx old_reg; |
073089a7 | 4228 | int i; |
7506f491 | 4229 | |
073089a7 | 4230 | /* This block matches the logic in hash_scan_insn. */ |
282899df | 4231 | switch (GET_CODE (pat)) |
073089a7 | 4232 | { |
282899df NS |
4233 | case SET: |
4234 | set = pat; | |
4235 | break; | |
4236 | ||
4237 | case PARALLEL: | |
073089a7 RS |
4238 | /* Search through the parallel looking for the set whose |
4239 | source was the expression that we're interested in. */ | |
64068ca2 | 4240 | first_set = NULL_RTX; |
073089a7 RS |
4241 | set = NULL_RTX; |
4242 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
4243 | { | |
4244 | rtx x = XVECEXP (pat, 0, i); | |
64068ca2 | 4245 | if (GET_CODE (x) == SET) |
073089a7 | 4246 | { |
64068ca2 RS |
4247 | /* If the source was a REG_EQUAL or REG_EQUIV note, we |
4248 | may not find an equivalent expression, but in this | |
4249 | case the PARALLEL will have a single set. */ | |
4250 | if (first_set == NULL_RTX) | |
4251 | first_set = x; | |
4252 | if (expr_equiv_p (SET_SRC (x), expr->expr)) | |
4253 | { | |
4254 | set = x; | |
4255 | break; | |
4256 | } | |
073089a7 RS |
4257 | } |
4258 | } | |
64068ca2 RS |
4259 | |
4260 | gcc_assert (first_set); | |
4261 | if (set == NULL_RTX) | |
4262 | set = first_set; | |
282899df NS |
4263 | break; |
4264 | ||
4265 | default: | |
4266 | gcc_unreachable (); | |
073089a7 | 4267 | } |
c4c81601 | 4268 | |
7b1b4aed | 4269 | if (REG_P (SET_DEST (set))) |
073089a7 | 4270 | { |
f5f2e3cd MH |
4271 | old_reg = SET_DEST (set); |
4272 | /* Check if we can modify the set destination in the original insn. */ | |
4273 | if (validate_change (insn, &SET_DEST (set), reg, 0)) | |
4274 | { | |
4275 | new_insn = gen_move_insn (old_reg, reg); | |
4276 | new_insn = emit_insn_after (new_insn, insn); | |
4277 | ||
4278 | /* Keep register set table up to date. */ | |
f5f2e3cd MH |
4279 | record_one_set (regno, insn); |
4280 | } | |
4281 | else | |
4282 | { | |
4283 | new_insn = gen_move_insn (reg, old_reg); | |
4284 | new_insn = emit_insn_after (new_insn, insn); | |
073089a7 | 4285 | |
f5f2e3cd MH |
4286 | /* Keep register set table up to date. */ |
4287 | record_one_set (regno, new_insn); | |
4288 | } | |
073089a7 | 4289 | } |
f5f2e3cd | 4290 | else /* This is possible only in case of a store to memory. */ |
073089a7 | 4291 | { |
f5f2e3cd | 4292 | old_reg = SET_SRC (set); |
073089a7 | 4293 | new_insn = gen_move_insn (reg, old_reg); |
f5f2e3cd MH |
4294 | |
4295 | /* Check if we can modify the set source in the original insn. */ | |
4296 | if (validate_change (insn, &SET_SRC (set), reg, 0)) | |
4297 | new_insn = emit_insn_before (new_insn, insn); | |
4298 | else | |
4299 | new_insn = emit_insn_after (new_insn, insn); | |
c4c81601 | 4300 | |
073089a7 RS |
4301 | /* Keep register set table up to date. */ |
4302 | record_one_set (regno, new_insn); | |
4303 | } | |
7506f491 DE |
4304 | |
4305 | gcse_create_count++; | |
4306 | ||
10d22567 ZD |
4307 | if (dump_file) |
4308 | fprintf (dump_file, | |
a42cd965 AM |
4309 | "PRE: bb %d, insn %d, copy expression %d in insn %d to reg %d\n", |
4310 | BLOCK_NUM (insn), INSN_UID (new_insn), indx, | |
4311 | INSN_UID (insn), regno); | |
7506f491 DE |
4312 | } |
4313 | ||
4314 | /* Copy available expressions that reach the redundant expression | |
4315 | to `reaching_reg'. */ | |
4316 | ||
4317 | static void | |
1d088dee | 4318 | pre_insert_copies (void) |
7506f491 | 4319 | { |
f5f2e3cd | 4320 | unsigned int i, added_copy; |
c4c81601 RK |
4321 | struct expr *expr; |
4322 | struct occr *occr; | |
4323 | struct occr *avail; | |
a65f3558 | 4324 | |
7506f491 DE |
4325 | /* For each available expression in the table, copy the result to |
4326 | `reaching_reg' if the expression reaches a deleted one. | |
4327 | ||
4328 | ??? The current algorithm is rather brute force. | |
4329 | Need to do some profiling. */ | |
4330 | ||
02280659 ZD |
4331 | for (i = 0; i < expr_hash_table.size; i++) |
4332 | for (expr = expr_hash_table.table[i]; expr != NULL; expr = expr->next_same_hash) | |
c4c81601 RK |
4333 | { |
4334 | /* If the basic block isn't reachable, PPOUT will be TRUE. However, | |
4335 | we don't want to insert a copy here because the expression may not | |
4336 | really be redundant. So only insert an insn if the expression was | |
4337 | deleted. This test also avoids further processing if the | |
4338 | expression wasn't deleted anywhere. */ | |
4339 | if (expr->reaching_reg == NULL) | |
4340 | continue; | |
7b1b4aed | 4341 | |
f5f2e3cd | 4342 | /* Set when we add a copy for that expression. */ |
7b1b4aed | 4343 | added_copy = 0; |
c4c81601 RK |
4344 | |
4345 | for (occr = expr->antic_occr; occr != NULL; occr = occr->next) | |
4346 | { | |
4347 | if (! occr->deleted_p) | |
4348 | continue; | |
7506f491 | 4349 | |
c4c81601 RK |
4350 | for (avail = expr->avail_occr; avail != NULL; avail = avail->next) |
4351 | { | |
4352 | rtx insn = avail->insn; | |
7506f491 | 4353 | |
c4c81601 RK |
4354 | /* No need to handle this one if handled already. */ |
4355 | if (avail->copied_p) | |
4356 | continue; | |
7506f491 | 4357 | |
c4c81601 RK |
4358 | /* Don't handle this one if it's a redundant one. */ |
4359 | if (TEST_BIT (pre_redundant_insns, INSN_CUID (insn))) | |
4360 | continue; | |
7506f491 | 4361 | |
c4c81601 | 4362 | /* Or if the expression doesn't reach the deleted one. */ |
589005ff | 4363 | if (! pre_expr_reaches_here_p (BLOCK_FOR_INSN (avail->insn), |
e2d2ed72 AM |
4364 | expr, |
4365 | BLOCK_FOR_INSN (occr->insn))) | |
c4c81601 | 4366 | continue; |
7506f491 | 4367 | |
f5f2e3cd MH |
4368 | added_copy = 1; |
4369 | ||
c4c81601 RK |
4370 | /* Copy the result of avail to reaching_reg. */ |
4371 | pre_insert_copy_insn (expr, insn); | |
4372 | avail->copied_p = 1; | |
4373 | } | |
4374 | } | |
f5f2e3cd | 4375 | |
7b1b4aed | 4376 | if (added_copy) |
f5f2e3cd | 4377 | update_ld_motion_stores (expr); |
c4c81601 | 4378 | } |
7506f491 DE |
4379 | } |
4380 | ||
10d1bb36 JH |
4381 | /* Emit move from SRC to DEST noting the equivalence with expression computed |
4382 | in INSN. */ | |
4383 | static rtx | |
1d088dee | 4384 | gcse_emit_move_after (rtx src, rtx dest, rtx insn) |
10d1bb36 JH |
4385 | { |
4386 | rtx new; | |
6bdb8dd6 | 4387 | rtx set = single_set (insn), set2; |
10d1bb36 JH |
4388 | rtx note; |
4389 | rtx eqv; | |
4390 | ||
4391 | /* This should never fail since we're creating a reg->reg copy | |
4392 | we've verified to be valid. */ | |
4393 | ||
6bdb8dd6 | 4394 | new = emit_insn_after (gen_move_insn (dest, src), insn); |
285464d0 | 4395 | |
10d1bb36 | 4396 | /* Note the equivalence for local CSE pass. */ |
6bdb8dd6 JH |
4397 | set2 = single_set (new); |
4398 | if (!set2 || !rtx_equal_p (SET_DEST (set2), dest)) | |
4399 | return new; | |
10d1bb36 JH |
4400 | if ((note = find_reg_equal_equiv_note (insn))) |
4401 | eqv = XEXP (note, 0); | |
4402 | else | |
4403 | eqv = SET_SRC (set); | |
4404 | ||
a500466b | 4405 | set_unique_reg_note (new, REG_EQUAL, copy_insn_1 (eqv)); |
10d1bb36 JH |
4406 | |
4407 | return new; | |
4408 | } | |
4409 | ||
7506f491 | 4410 | /* Delete redundant computations. |
7506f491 DE |
4411 | Deletion is done by changing the insn to copy the `reaching_reg' of |
4412 | the expression into the result of the SET. It is left to later passes | |
4413 | (cprop, cse2, flow, combine, regmove) to propagate the copy or eliminate it. | |
4414 | ||
cc2902df | 4415 | Returns nonzero if a change is made. */ |
7506f491 DE |
4416 | |
4417 | static int | |
1d088dee | 4418 | pre_delete (void) |
7506f491 | 4419 | { |
2e653e39 | 4420 | unsigned int i; |
63bc1d05 | 4421 | int changed; |
c4c81601 RK |
4422 | struct expr *expr; |
4423 | struct occr *occr; | |
a65f3558 | 4424 | |
7506f491 | 4425 | changed = 0; |
02280659 | 4426 | for (i = 0; i < expr_hash_table.size; i++) |
073089a7 RS |
4427 | for (expr = expr_hash_table.table[i]; |
4428 | expr != NULL; | |
4429 | expr = expr->next_same_hash) | |
c4c81601 RK |
4430 | { |
4431 | int indx = expr->bitmap_index; | |
7506f491 | 4432 | |
c4c81601 RK |
4433 | /* We only need to search antic_occr since we require |
4434 | ANTLOC != 0. */ | |
7506f491 | 4435 | |
c4c81601 RK |
4436 | for (occr = expr->antic_occr; occr != NULL; occr = occr->next) |
4437 | { | |
4438 | rtx insn = occr->insn; | |
4439 | rtx set; | |
e2d2ed72 | 4440 | basic_block bb = BLOCK_FOR_INSN (insn); |
7506f491 | 4441 | |
073089a7 RS |
4442 | /* We only delete insns that have a single_set. */ |
4443 | if (TEST_BIT (pre_delete_map[bb->index], indx) | |
6fb5fa3c DB |
4444 | && (set = single_set (insn)) != 0 |
4445 | && dbg_cnt (pre_insn)) | |
c4c81601 | 4446 | { |
c4c81601 RK |
4447 | /* Create a pseudo-reg to store the result of reaching |
4448 | expressions into. Get the mode for the new pseudo from | |
4449 | the mode of the original destination pseudo. */ | |
4450 | if (expr->reaching_reg == NULL) | |
4451 | expr->reaching_reg | |
4452 | = gen_reg_rtx (GET_MODE (SET_DEST (set))); | |
4453 | ||
9b76aa3b | 4454 | gcse_emit_move_after (expr->reaching_reg, SET_DEST (set), insn); |
10d1bb36 JH |
4455 | delete_insn (insn); |
4456 | occr->deleted_p = 1; | |
4457 | SET_BIT (pre_redundant_insns, INSN_CUID (insn)); | |
4458 | changed = 1; | |
4459 | gcse_subst_count++; | |
7506f491 | 4460 | |
10d22567 | 4461 | if (dump_file) |
c4c81601 | 4462 | { |
10d22567 | 4463 | fprintf (dump_file, |
c4c81601 RK |
4464 | "PRE: redundant insn %d (expression %d) in ", |
4465 | INSN_UID (insn), indx); | |
10d22567 | 4466 | fprintf (dump_file, "bb %d, reaching reg is %d\n", |
0b17ab2f | 4467 | bb->index, REGNO (expr->reaching_reg)); |
c4c81601 RK |
4468 | } |
4469 | } | |
4470 | } | |
4471 | } | |
7506f491 DE |
4472 | |
4473 | return changed; | |
4474 | } | |
4475 | ||
4476 | /* Perform GCSE optimizations using PRE. | |
4477 | This is called by one_pre_gcse_pass after all the dataflow analysis | |
4478 | has been done. | |
4479 | ||
c4c81601 RK |
4480 | This is based on the original Morel-Renvoise paper Fred Chow's thesis, and |
4481 | lazy code motion from Knoop, Ruthing and Steffen as described in Advanced | |
4482 | Compiler Design and Implementation. | |
7506f491 | 4483 | |
c4c81601 RK |
4484 | ??? A new pseudo reg is created to hold the reaching expression. The nice |
4485 | thing about the classical approach is that it would try to use an existing | |
4486 | reg. If the register can't be adequately optimized [i.e. we introduce | |
4487 | reload problems], one could add a pass here to propagate the new register | |
4488 | through the block. | |
7506f491 | 4489 | |
c4c81601 RK |
4490 | ??? We don't handle single sets in PARALLELs because we're [currently] not |
4491 | able to copy the rest of the parallel when we insert copies to create full | |
4492 | redundancies from partial redundancies. However, there's no reason why we | |
4493 | can't handle PARALLELs in the cases where there are no partial | |
7506f491 DE |
4494 | redundancies. */ |
4495 | ||
4496 | static int | |
1d088dee | 4497 | pre_gcse (void) |
7506f491 | 4498 | { |
2e653e39 RK |
4499 | unsigned int i; |
4500 | int did_insert, changed; | |
7506f491 | 4501 | struct expr **index_map; |
c4c81601 | 4502 | struct expr *expr; |
7506f491 DE |
4503 | |
4504 | /* Compute a mapping from expression number (`bitmap_index') to | |
4505 | hash table entry. */ | |
4506 | ||
5ed6ace5 | 4507 | index_map = XCNEWVEC (struct expr *, expr_hash_table.n_elems); |
02280659 ZD |
4508 | for (i = 0; i < expr_hash_table.size; i++) |
4509 | for (expr = expr_hash_table.table[i]; expr != NULL; expr = expr->next_same_hash) | |
c4c81601 | 4510 | index_map[expr->bitmap_index] = expr; |
7506f491 DE |
4511 | |
4512 | /* Reset bitmap used to track which insns are redundant. */ | |
a65f3558 JL |
4513 | pre_redundant_insns = sbitmap_alloc (max_cuid); |
4514 | sbitmap_zero (pre_redundant_insns); | |
7506f491 DE |
4515 | |
4516 | /* Delete the redundant insns first so that | |
4517 | - we know what register to use for the new insns and for the other | |
4518 | ones with reaching expressions | |
4519 | - we know which insns are redundant when we go to create copies */ | |
c4c81601 | 4520 | |
7506f491 | 4521 | changed = pre_delete (); |
a42cd965 | 4522 | did_insert = pre_edge_insert (edge_list, index_map); |
c4c81601 | 4523 | |
7506f491 | 4524 | /* In other places with reaching expressions, copy the expression to the |
a42cd965 | 4525 | specially allocated pseudo-reg that reaches the redundant expr. */ |
7506f491 | 4526 | pre_insert_copies (); |
a42cd965 AM |
4527 | if (did_insert) |
4528 | { | |
4529 | commit_edge_insertions (); | |
4530 | changed = 1; | |
4531 | } | |
7506f491 | 4532 | |
283a2545 | 4533 | free (index_map); |
76ac938b | 4534 | sbitmap_free (pre_redundant_insns); |
7506f491 DE |
4535 | return changed; |
4536 | } | |
4537 | ||
4538 | /* Top level routine to perform one PRE GCSE pass. | |
4539 | ||
cc2902df | 4540 | Return nonzero if a change was made. */ |
7506f491 DE |
4541 | |
4542 | static int | |
1d088dee | 4543 | one_pre_gcse_pass (int pass) |
7506f491 DE |
4544 | { |
4545 | int changed = 0; | |
4546 | ||
4547 | gcse_subst_count = 0; | |
4548 | gcse_create_count = 0; | |
4549 | ||
02280659 | 4550 | alloc_hash_table (max_cuid, &expr_hash_table, 0); |
a42cd965 | 4551 | add_noreturn_fake_exit_edges (); |
a13d4ebf AM |
4552 | if (flag_gcse_lm) |
4553 | compute_ld_motion_mems (); | |
4554 | ||
02280659 | 4555 | compute_hash_table (&expr_hash_table); |
a13d4ebf | 4556 | trim_ld_motion_mems (); |
10d22567 ZD |
4557 | if (dump_file) |
4558 | dump_hash_table (dump_file, "Expression", &expr_hash_table); | |
c4c81601 | 4559 | |
02280659 | 4560 | if (expr_hash_table.n_elems > 0) |
7506f491 | 4561 | { |
02280659 | 4562 | alloc_pre_mem (last_basic_block, expr_hash_table.n_elems); |
7506f491 DE |
4563 | compute_pre_data (); |
4564 | changed |= pre_gcse (); | |
a42cd965 | 4565 | free_edge_list (edge_list); |
7506f491 DE |
4566 | free_pre_mem (); |
4567 | } | |
c4c81601 | 4568 | |
a13d4ebf | 4569 | free_ldst_mems (); |
6809cbf9 | 4570 | remove_fake_exit_edges (); |
02280659 | 4571 | free_hash_table (&expr_hash_table); |
7506f491 | 4572 | |
10d22567 | 4573 | if (dump_file) |
7506f491 | 4574 | { |
10d22567 | 4575 | fprintf (dump_file, "\nPRE GCSE of %s, pass %d: %d bytes needed, ", |
faed5cc3 | 4576 | current_function_name (), pass, bytes_used); |
10d22567 | 4577 | fprintf (dump_file, "%d substs, %d insns created\n", |
c4c81601 | 4578 | gcse_subst_count, gcse_create_count); |
7506f491 DE |
4579 | } |
4580 | ||
4581 | return changed; | |
4582 | } | |
aeb2f500 JW |
4583 | \f |
4584 | /* If X contains any LABEL_REF's, add REG_LABEL notes for them to INSN. | |
5b1ef594 JDA |
4585 | If notes are added to an insn which references a CODE_LABEL, the |
4586 | LABEL_NUSES count is incremented. We have to add REG_LABEL notes, | |
4587 | because the following loop optimization pass requires them. */ | |
aeb2f500 | 4588 | |
aeb2f500 JW |
4589 | /* ??? If there was a jump optimization pass after gcse and before loop, |
4590 | then we would not need to do this here, because jump would add the | |
4591 | necessary REG_LABEL notes. */ | |
4592 | ||
4593 | static void | |
1d088dee | 4594 | add_label_notes (rtx x, rtx insn) |
aeb2f500 JW |
4595 | { |
4596 | enum rtx_code code = GET_CODE (x); | |
4597 | int i, j; | |
6f7d635c | 4598 | const char *fmt; |
aeb2f500 JW |
4599 | |
4600 | if (code == LABEL_REF && !LABEL_REF_NONLOCAL_P (x)) | |
4601 | { | |
6b3603c2 | 4602 | /* This code used to ignore labels that referred to dispatch tables to |
e0bb17a8 | 4603 | avoid flow generating (slightly) worse code. |
6b3603c2 | 4604 | |
ac7c5af5 JL |
4605 | We no longer ignore such label references (see LABEL_REF handling in |
4606 | mark_jump_label for additional information). */ | |
c4c81601 | 4607 | |
6b8c9327 | 4608 | REG_NOTES (insn) = gen_rtx_INSN_LIST (REG_LABEL, XEXP (x, 0), |
6b3603c2 | 4609 | REG_NOTES (insn)); |
5b1ef594 | 4610 | if (LABEL_P (XEXP (x, 0))) |
589005ff | 4611 | LABEL_NUSES (XEXP (x, 0))++; |
aeb2f500 JW |
4612 | return; |
4613 | } | |
4614 | ||
c4c81601 | 4615 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
aeb2f500 JW |
4616 | { |
4617 | if (fmt[i] == 'e') | |
4618 | add_label_notes (XEXP (x, i), insn); | |
4619 | else if (fmt[i] == 'E') | |
4620 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
4621 | add_label_notes (XVECEXP (x, i, j), insn); | |
4622 | } | |
4623 | } | |
a65f3558 JL |
4624 | |
4625 | /* Compute transparent outgoing information for each block. | |
4626 | ||
4627 | An expression is transparent to an edge unless it is killed by | |
4628 | the edge itself. This can only happen with abnormal control flow, | |
4629 | when the edge is traversed through a call. This happens with | |
4630 | non-local labels and exceptions. | |
4631 | ||
4632 | This would not be necessary if we split the edge. While this is | |
4633 | normally impossible for abnormal critical edges, with some effort | |
4634 | it should be possible with exception handling, since we still have | |
4635 | control over which handler should be invoked. But due to increased | |
4636 | EH table sizes, this may not be worthwhile. */ | |
4637 | ||
4638 | static void | |
1d088dee | 4639 | compute_transpout (void) |
a65f3558 | 4640 | { |
e0082a72 | 4641 | basic_block bb; |
2e653e39 | 4642 | unsigned int i; |
c4c81601 | 4643 | struct expr *expr; |
a65f3558 | 4644 | |
d55bc081 | 4645 | sbitmap_vector_ones (transpout, last_basic_block); |
a65f3558 | 4646 | |
e0082a72 | 4647 | FOR_EACH_BB (bb) |
a65f3558 | 4648 | { |
a65f3558 JL |
4649 | /* Note that flow inserted a nop a the end of basic blocks that |
4650 | end in call instructions for reasons other than abnormal | |
4651 | control flow. */ | |
7b1b4aed | 4652 | if (! CALL_P (BB_END (bb))) |
a65f3558 JL |
4653 | continue; |
4654 | ||
02280659 ZD |
4655 | for (i = 0; i < expr_hash_table.size; i++) |
4656 | for (expr = expr_hash_table.table[i]; expr ; expr = expr->next_same_hash) | |
7b1b4aed | 4657 | if (MEM_P (expr->expr)) |
c4c81601 RK |
4658 | { |
4659 | if (GET_CODE (XEXP (expr->expr, 0)) == SYMBOL_REF | |
4660 | && CONSTANT_POOL_ADDRESS_P (XEXP (expr->expr, 0))) | |
4661 | continue; | |
589005ff | 4662 | |
c4c81601 RK |
4663 | /* ??? Optimally, we would use interprocedural alias |
4664 | analysis to determine if this mem is actually killed | |
4665 | by this call. */ | |
e0082a72 | 4666 | RESET_BIT (transpout[bb->index], expr->bitmap_index); |
c4c81601 | 4667 | } |
a65f3558 JL |
4668 | } |
4669 | } | |
dfdb644f | 4670 | |
bb457bd9 JL |
4671 | /* Code Hoisting variables and subroutines. */ |
4672 | ||
4673 | /* Very busy expressions. */ | |
4674 | static sbitmap *hoist_vbein; | |
4675 | static sbitmap *hoist_vbeout; | |
4676 | ||
4677 | /* Hoistable expressions. */ | |
4678 | static sbitmap *hoist_exprs; | |
4679 | ||
bb457bd9 | 4680 | /* ??? We could compute post dominators and run this algorithm in |
68e82b83 | 4681 | reverse to perform tail merging, doing so would probably be |
bb457bd9 JL |
4682 | more effective than the tail merging code in jump.c. |
4683 | ||
4684 | It's unclear if tail merging could be run in parallel with | |
4685 | code hoisting. It would be nice. */ | |
4686 | ||
4687 | /* Allocate vars used for code hoisting analysis. */ | |
4688 | ||
4689 | static void | |
1d088dee | 4690 | alloc_code_hoist_mem (int n_blocks, int n_exprs) |
bb457bd9 JL |
4691 | { |
4692 | antloc = sbitmap_vector_alloc (n_blocks, n_exprs); | |
4693 | transp = sbitmap_vector_alloc (n_blocks, n_exprs); | |
4694 | comp = sbitmap_vector_alloc (n_blocks, n_exprs); | |
4695 | ||
4696 | hoist_vbein = sbitmap_vector_alloc (n_blocks, n_exprs); | |
4697 | hoist_vbeout = sbitmap_vector_alloc (n_blocks, n_exprs); | |
4698 | hoist_exprs = sbitmap_vector_alloc (n_blocks, n_exprs); | |
4699 | transpout = sbitmap_vector_alloc (n_blocks, n_exprs); | |
bb457bd9 JL |
4700 | } |
4701 | ||
4702 | /* Free vars used for code hoisting analysis. */ | |
4703 | ||
4704 | static void | |
1d088dee | 4705 | free_code_hoist_mem (void) |
bb457bd9 | 4706 | { |
5a660bff DB |
4707 | sbitmap_vector_free (antloc); |
4708 | sbitmap_vector_free (transp); | |
4709 | sbitmap_vector_free (comp); | |
bb457bd9 | 4710 | |
5a660bff DB |
4711 | sbitmap_vector_free (hoist_vbein); |
4712 | sbitmap_vector_free (hoist_vbeout); | |
4713 | sbitmap_vector_free (hoist_exprs); | |
4714 | sbitmap_vector_free (transpout); | |
bb457bd9 | 4715 | |
d47cc544 | 4716 | free_dominance_info (CDI_DOMINATORS); |
bb457bd9 JL |
4717 | } |
4718 | ||
4719 | /* Compute the very busy expressions at entry/exit from each block. | |
4720 | ||
4721 | An expression is very busy if all paths from a given point | |
4722 | compute the expression. */ | |
4723 | ||
4724 | static void | |
1d088dee | 4725 | compute_code_hoist_vbeinout (void) |
bb457bd9 | 4726 | { |
e0082a72 ZD |
4727 | int changed, passes; |
4728 | basic_block bb; | |
bb457bd9 | 4729 | |
d55bc081 ZD |
4730 | sbitmap_vector_zero (hoist_vbeout, last_basic_block); |
4731 | sbitmap_vector_zero (hoist_vbein, last_basic_block); | |
bb457bd9 JL |
4732 | |
4733 | passes = 0; | |
4734 | changed = 1; | |
c4c81601 | 4735 | |
bb457bd9 JL |
4736 | while (changed) |
4737 | { | |
4738 | changed = 0; | |
c4c81601 | 4739 | |
bb457bd9 JL |
4740 | /* We scan the blocks in the reverse order to speed up |
4741 | the convergence. */ | |
e0082a72 | 4742 | FOR_EACH_BB_REVERSE (bb) |
bb457bd9 | 4743 | { |
e0082a72 ZD |
4744 | changed |= sbitmap_a_or_b_and_c_cg (hoist_vbein[bb->index], antloc[bb->index], |
4745 | hoist_vbeout[bb->index], transp[bb->index]); | |
4746 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
4747 | sbitmap_intersection_of_succs (hoist_vbeout[bb->index], hoist_vbein, bb->index); | |
bb457bd9 | 4748 | } |
c4c81601 | 4749 | |
bb457bd9 JL |
4750 | passes++; |
4751 | } | |
4752 | ||
10d22567 ZD |
4753 | if (dump_file) |
4754 | fprintf (dump_file, "hoisting vbeinout computation: %d passes\n", passes); | |
bb457bd9 JL |
4755 | } |
4756 | ||
4757 | /* Top level routine to do the dataflow analysis needed by code hoisting. */ | |
4758 | ||
4759 | static void | |
1d088dee | 4760 | compute_code_hoist_data (void) |
bb457bd9 | 4761 | { |
02280659 | 4762 | compute_local_properties (transp, comp, antloc, &expr_hash_table); |
bb457bd9 JL |
4763 | compute_transpout (); |
4764 | compute_code_hoist_vbeinout (); | |
d47cc544 | 4765 | calculate_dominance_info (CDI_DOMINATORS); |
10d22567 ZD |
4766 | if (dump_file) |
4767 | fprintf (dump_file, "\n"); | |
bb457bd9 JL |
4768 | } |
4769 | ||
4770 | /* Determine if the expression identified by EXPR_INDEX would | |
4771 | reach BB unimpared if it was placed at the end of EXPR_BB. | |
4772 | ||
4773 | It's unclear exactly what Muchnick meant by "unimpared". It seems | |
4774 | to me that the expression must either be computed or transparent in | |
4775 | *every* block in the path(s) from EXPR_BB to BB. Any other definition | |
4776 | would allow the expression to be hoisted out of loops, even if | |
4777 | the expression wasn't a loop invariant. | |
4778 | ||
4779 | Contrast this to reachability for PRE where an expression is | |
4780 | considered reachable if *any* path reaches instead of *all* | |
4781 | paths. */ | |
4782 | ||
4783 | static int | |
1d088dee | 4784 | hoist_expr_reaches_here_p (basic_block expr_bb, int expr_index, basic_block bb, char *visited) |
bb457bd9 JL |
4785 | { |
4786 | edge pred; | |
628f6a4e | 4787 | edge_iterator ei; |
283a2545 | 4788 | int visited_allocated_locally = 0; |
589005ff | 4789 | |
bb457bd9 JL |
4790 | |
4791 | if (visited == NULL) | |
4792 | { | |
8e42ace1 | 4793 | visited_allocated_locally = 1; |
5ed6ace5 | 4794 | visited = XCNEWVEC (char, last_basic_block); |
bb457bd9 JL |
4795 | } |
4796 | ||
628f6a4e | 4797 | FOR_EACH_EDGE (pred, ei, bb->preds) |
bb457bd9 | 4798 | { |
e2d2ed72 | 4799 | basic_block pred_bb = pred->src; |
bb457bd9 JL |
4800 | |
4801 | if (pred->src == ENTRY_BLOCK_PTR) | |
4802 | break; | |
f305679f JH |
4803 | else if (pred_bb == expr_bb) |
4804 | continue; | |
0b17ab2f | 4805 | else if (visited[pred_bb->index]) |
bb457bd9 | 4806 | continue; |
c4c81601 | 4807 | |
bb457bd9 | 4808 | /* Does this predecessor generate this expression? */ |
0b17ab2f | 4809 | else if (TEST_BIT (comp[pred_bb->index], expr_index)) |
bb457bd9 | 4810 | break; |
0b17ab2f | 4811 | else if (! TEST_BIT (transp[pred_bb->index], expr_index)) |
bb457bd9 | 4812 | break; |
c4c81601 | 4813 | |
bb457bd9 JL |
4814 | /* Not killed. */ |
4815 | else | |
4816 | { | |
0b17ab2f | 4817 | visited[pred_bb->index] = 1; |
bb457bd9 JL |
4818 | if (! hoist_expr_reaches_here_p (expr_bb, expr_index, |
4819 | pred_bb, visited)) | |
4820 | break; | |
4821 | } | |
4822 | } | |
589005ff | 4823 | if (visited_allocated_locally) |
283a2545 | 4824 | free (visited); |
c4c81601 | 4825 | |
bb457bd9 JL |
4826 | return (pred == NULL); |
4827 | } | |
4828 | \f | |
4829 | /* Actually perform code hoisting. */ | |
c4c81601 | 4830 | |
bb457bd9 | 4831 | static void |
1d088dee | 4832 | hoist_code (void) |
bb457bd9 | 4833 | { |
e0082a72 | 4834 | basic_block bb, dominated; |
66f97d31 | 4835 | VEC (basic_block, heap) *domby; |
c635a1ec | 4836 | unsigned int i,j; |
bb457bd9 | 4837 | struct expr **index_map; |
c4c81601 | 4838 | struct expr *expr; |
bb457bd9 | 4839 | |
d55bc081 | 4840 | sbitmap_vector_zero (hoist_exprs, last_basic_block); |
bb457bd9 JL |
4841 | |
4842 | /* Compute a mapping from expression number (`bitmap_index') to | |
4843 | hash table entry. */ | |
4844 | ||
5ed6ace5 | 4845 | index_map = XCNEWVEC (struct expr *, expr_hash_table.n_elems); |
02280659 ZD |
4846 | for (i = 0; i < expr_hash_table.size; i++) |
4847 | for (expr = expr_hash_table.table[i]; expr != NULL; expr = expr->next_same_hash) | |
c4c81601 | 4848 | index_map[expr->bitmap_index] = expr; |
bb457bd9 JL |
4849 | |
4850 | /* Walk over each basic block looking for potentially hoistable | |
4851 | expressions, nothing gets hoisted from the entry block. */ | |
e0082a72 | 4852 | FOR_EACH_BB (bb) |
bb457bd9 JL |
4853 | { |
4854 | int found = 0; | |
4855 | int insn_inserted_p; | |
4856 | ||
66f97d31 | 4857 | domby = get_dominated_by (CDI_DOMINATORS, bb); |
bb457bd9 JL |
4858 | /* Examine each expression that is very busy at the exit of this |
4859 | block. These are the potentially hoistable expressions. */ | |
e0082a72 | 4860 | for (i = 0; i < hoist_vbeout[bb->index]->n_bits; i++) |
bb457bd9 JL |
4861 | { |
4862 | int hoistable = 0; | |
c4c81601 | 4863 | |
c635a1ec DB |
4864 | if (TEST_BIT (hoist_vbeout[bb->index], i) |
4865 | && TEST_BIT (transpout[bb->index], i)) | |
bb457bd9 JL |
4866 | { |
4867 | /* We've found a potentially hoistable expression, now | |
4868 | we look at every block BB dominates to see if it | |
4869 | computes the expression. */ | |
66f97d31 | 4870 | for (j = 0; VEC_iterate (basic_block, domby, j, dominated); j++) |
bb457bd9 JL |
4871 | { |
4872 | /* Ignore self dominance. */ | |
c635a1ec | 4873 | if (bb == dominated) |
bb457bd9 | 4874 | continue; |
bb457bd9 JL |
4875 | /* We've found a dominated block, now see if it computes |
4876 | the busy expression and whether or not moving that | |
4877 | expression to the "beginning" of that block is safe. */ | |
e0082a72 | 4878 | if (!TEST_BIT (antloc[dominated->index], i)) |
bb457bd9 JL |
4879 | continue; |
4880 | ||
4881 | /* Note if the expression would reach the dominated block | |
589005ff | 4882 | unimpared if it was placed at the end of BB. |
bb457bd9 JL |
4883 | |
4884 | Keep track of how many times this expression is hoistable | |
4885 | from a dominated block into BB. */ | |
e0082a72 | 4886 | if (hoist_expr_reaches_here_p (bb, i, dominated, NULL)) |
bb457bd9 JL |
4887 | hoistable++; |
4888 | } | |
4889 | ||
ff7cc307 | 4890 | /* If we found more than one hoistable occurrence of this |
bb457bd9 JL |
4891 | expression, then note it in the bitmap of expressions to |
4892 | hoist. It makes no sense to hoist things which are computed | |
4893 | in only one BB, and doing so tends to pessimize register | |
4894 | allocation. One could increase this value to try harder | |
4895 | to avoid any possible code expansion due to register | |
4896 | allocation issues; however experiments have shown that | |
4897 | the vast majority of hoistable expressions are only movable | |
e0bb17a8 | 4898 | from two successors, so raising this threshold is likely |
bb457bd9 JL |
4899 | to nullify any benefit we get from code hoisting. */ |
4900 | if (hoistable > 1) | |
4901 | { | |
e0082a72 | 4902 | SET_BIT (hoist_exprs[bb->index], i); |
bb457bd9 JL |
4903 | found = 1; |
4904 | } | |
4905 | } | |
4906 | } | |
bb457bd9 JL |
4907 | /* If we found nothing to hoist, then quit now. */ |
4908 | if (! found) | |
c635a1ec | 4909 | { |
66f97d31 ZD |
4910 | VEC_free (basic_block, heap, domby); |
4911 | continue; | |
c635a1ec | 4912 | } |
bb457bd9 JL |
4913 | |
4914 | /* Loop over all the hoistable expressions. */ | |
e0082a72 | 4915 | for (i = 0; i < hoist_exprs[bb->index]->n_bits; i++) |
bb457bd9 JL |
4916 | { |
4917 | /* We want to insert the expression into BB only once, so | |
4918 | note when we've inserted it. */ | |
4919 | insn_inserted_p = 0; | |
4920 | ||
4921 | /* These tests should be the same as the tests above. */ | |
cb83c2ec | 4922 | if (TEST_BIT (hoist_exprs[bb->index], i)) |
bb457bd9 JL |
4923 | { |
4924 | /* We've found a potentially hoistable expression, now | |
4925 | we look at every block BB dominates to see if it | |
4926 | computes the expression. */ | |
66f97d31 | 4927 | for (j = 0; VEC_iterate (basic_block, domby, j, dominated); j++) |
bb457bd9 JL |
4928 | { |
4929 | /* Ignore self dominance. */ | |
c635a1ec | 4930 | if (bb == dominated) |
bb457bd9 JL |
4931 | continue; |
4932 | ||
4933 | /* We've found a dominated block, now see if it computes | |
4934 | the busy expression and whether or not moving that | |
4935 | expression to the "beginning" of that block is safe. */ | |
e0082a72 | 4936 | if (!TEST_BIT (antloc[dominated->index], i)) |
bb457bd9 JL |
4937 | continue; |
4938 | ||
4939 | /* The expression is computed in the dominated block and | |
4940 | it would be safe to compute it at the start of the | |
4941 | dominated block. Now we have to determine if the | |
ff7cc307 | 4942 | expression would reach the dominated block if it was |
bb457bd9 | 4943 | placed at the end of BB. */ |
e0082a72 | 4944 | if (hoist_expr_reaches_here_p (bb, i, dominated, NULL)) |
bb457bd9 JL |
4945 | { |
4946 | struct expr *expr = index_map[i]; | |
4947 | struct occr *occr = expr->antic_occr; | |
4948 | rtx insn; | |
4949 | rtx set; | |
4950 | ||
ff7cc307 | 4951 | /* Find the right occurrence of this expression. */ |
e0082a72 | 4952 | while (BLOCK_FOR_INSN (occr->insn) != dominated && occr) |
bb457bd9 JL |
4953 | occr = occr->next; |
4954 | ||
282899df | 4955 | gcc_assert (occr); |
bb457bd9 | 4956 | insn = occr->insn; |
bb457bd9 | 4957 | set = single_set (insn); |
282899df | 4958 | gcc_assert (set); |
bb457bd9 JL |
4959 | |
4960 | /* Create a pseudo-reg to store the result of reaching | |
4961 | expressions into. Get the mode for the new pseudo | |
4962 | from the mode of the original destination pseudo. */ | |
4963 | if (expr->reaching_reg == NULL) | |
4964 | expr->reaching_reg | |
4965 | = gen_reg_rtx (GET_MODE (SET_DEST (set))); | |
4966 | ||
10d1bb36 JH |
4967 | gcse_emit_move_after (expr->reaching_reg, SET_DEST (set), insn); |
4968 | delete_insn (insn); | |
4969 | occr->deleted_p = 1; | |
4970 | if (!insn_inserted_p) | |
bb457bd9 | 4971 | { |
6fb5fa3c | 4972 | insert_insn_end_basic_block (index_map[i], bb, 0); |
10d1bb36 | 4973 | insn_inserted_p = 1; |
bb457bd9 JL |
4974 | } |
4975 | } | |
4976 | } | |
4977 | } | |
4978 | } | |
66f97d31 | 4979 | VEC_free (basic_block, heap, domby); |
bb457bd9 | 4980 | } |
c4c81601 | 4981 | |
8e42ace1 | 4982 | free (index_map); |
bb457bd9 JL |
4983 | } |
4984 | ||
4985 | /* Top level routine to perform one code hoisting (aka unification) pass | |
4986 | ||
cc2902df | 4987 | Return nonzero if a change was made. */ |
bb457bd9 JL |
4988 | |
4989 | static int | |
1d088dee | 4990 | one_code_hoisting_pass (void) |
bb457bd9 JL |
4991 | { |
4992 | int changed = 0; | |
4993 | ||
02280659 ZD |
4994 | alloc_hash_table (max_cuid, &expr_hash_table, 0); |
4995 | compute_hash_table (&expr_hash_table); | |
10d22567 ZD |
4996 | if (dump_file) |
4997 | dump_hash_table (dump_file, "Code Hosting Expressions", &expr_hash_table); | |
c4c81601 | 4998 | |
02280659 | 4999 | if (expr_hash_table.n_elems > 0) |
bb457bd9 | 5000 | { |
02280659 | 5001 | alloc_code_hoist_mem (last_basic_block, expr_hash_table.n_elems); |
bb457bd9 JL |
5002 | compute_code_hoist_data (); |
5003 | hoist_code (); | |
5004 | free_code_hoist_mem (); | |
5005 | } | |
c4c81601 | 5006 | |
02280659 | 5007 | free_hash_table (&expr_hash_table); |
bb457bd9 JL |
5008 | |
5009 | return changed; | |
5010 | } | |
a13d4ebf AM |
5011 | \f |
5012 | /* Here we provide the things required to do store motion towards | |
5013 | the exit. In order for this to be effective, gcse also needed to | |
5014 | be taught how to move a load when it is kill only by a store to itself. | |
5015 | ||
5016 | int i; | |
5017 | float a[10]; | |
5018 | ||
5019 | void foo(float scale) | |
5020 | { | |
5021 | for (i=0; i<10; i++) | |
5022 | a[i] *= scale; | |
5023 | } | |
5024 | ||
5025 | 'i' is both loaded and stored to in the loop. Normally, gcse cannot move | |
589005ff KH |
5026 | the load out since its live around the loop, and stored at the bottom |
5027 | of the loop. | |
a13d4ebf | 5028 | |
589005ff | 5029 | The 'Load Motion' referred to and implemented in this file is |
a13d4ebf AM |
5030 | an enhancement to gcse which when using edge based lcm, recognizes |
5031 | this situation and allows gcse to move the load out of the loop. | |
5032 | ||
5033 | Once gcse has hoisted the load, store motion can then push this | |
5034 | load towards the exit, and we end up with no loads or stores of 'i' | |
5035 | in the loop. */ | |
5036 | ||
9727e468 RG |
5037 | static hashval_t |
5038 | pre_ldst_expr_hash (const void *p) | |
5039 | { | |
5040 | int do_not_record_p = 0; | |
5041 | const struct ls_expr *x = p; | |
5042 | return hash_rtx (x->pattern, GET_MODE (x->pattern), &do_not_record_p, NULL, false); | |
5043 | } | |
5044 | ||
5045 | static int | |
5046 | pre_ldst_expr_eq (const void *p1, const void *p2) | |
5047 | { | |
5048 | const struct ls_expr *ptr1 = p1, *ptr2 = p2; | |
5049 | return expr_equiv_p (ptr1->pattern, ptr2->pattern); | |
5050 | } | |
5051 | ||
ff7cc307 | 5052 | /* This will search the ldst list for a matching expression. If it |
a13d4ebf AM |
5053 | doesn't find one, we create one and initialize it. */ |
5054 | ||
5055 | static struct ls_expr * | |
1d088dee | 5056 | ldst_entry (rtx x) |
a13d4ebf | 5057 | { |
b58b21d5 | 5058 | int do_not_record_p = 0; |
a13d4ebf | 5059 | struct ls_expr * ptr; |
b58b21d5 | 5060 | unsigned int hash; |
9727e468 RG |
5061 | void **slot; |
5062 | struct ls_expr e; | |
a13d4ebf | 5063 | |
0516f6fe SB |
5064 | hash = hash_rtx (x, GET_MODE (x), &do_not_record_p, |
5065 | NULL, /*have_reg_qty=*/false); | |
a13d4ebf | 5066 | |
9727e468 RG |
5067 | e.pattern = x; |
5068 | slot = htab_find_slot_with_hash (pre_ldst_table, &e, hash, INSERT); | |
5069 | if (*slot) | |
5070 | return (struct ls_expr *)*slot; | |
b58b21d5 | 5071 | |
5ed6ace5 | 5072 | ptr = XNEW (struct ls_expr); |
b58b21d5 RS |
5073 | |
5074 | ptr->next = pre_ldst_mems; | |
5075 | ptr->expr = NULL; | |
5076 | ptr->pattern = x; | |
5077 | ptr->pattern_regs = NULL_RTX; | |
5078 | ptr->loads = NULL_RTX; | |
5079 | ptr->stores = NULL_RTX; | |
5080 | ptr->reaching_reg = NULL_RTX; | |
5081 | ptr->invalid = 0; | |
5082 | ptr->index = 0; | |
5083 | ptr->hash_index = hash; | |
5084 | pre_ldst_mems = ptr; | |
9727e468 | 5085 | *slot = ptr; |
589005ff | 5086 | |
a13d4ebf AM |
5087 | return ptr; |
5088 | } | |
5089 | ||
5090 | /* Free up an individual ldst entry. */ | |
5091 | ||
589005ff | 5092 | static void |
1d088dee | 5093 | free_ldst_entry (struct ls_expr * ptr) |
a13d4ebf | 5094 | { |
aaa4ca30 AJ |
5095 | free_INSN_LIST_list (& ptr->loads); |
5096 | free_INSN_LIST_list (& ptr->stores); | |
a13d4ebf AM |
5097 | |
5098 | free (ptr); | |
5099 | } | |
5100 | ||
5101 | /* Free up all memory associated with the ldst list. */ | |
5102 | ||
5103 | static void | |
1d088dee | 5104 | free_ldst_mems (void) |
a13d4ebf | 5105 | { |
35b5442a RG |
5106 | if (pre_ldst_table) |
5107 | htab_delete (pre_ldst_table); | |
9727e468 RG |
5108 | pre_ldst_table = NULL; |
5109 | ||
589005ff | 5110 | while (pre_ldst_mems) |
a13d4ebf AM |
5111 | { |
5112 | struct ls_expr * tmp = pre_ldst_mems; | |
5113 | ||
5114 | pre_ldst_mems = pre_ldst_mems->next; | |
5115 | ||
5116 | free_ldst_entry (tmp); | |
5117 | } | |
5118 | ||
5119 | pre_ldst_mems = NULL; | |
5120 | } | |
5121 | ||
5122 | /* Dump debugging info about the ldst list. */ | |
5123 | ||
5124 | static void | |
1d088dee | 5125 | print_ldst_list (FILE * file) |
a13d4ebf AM |
5126 | { |
5127 | struct ls_expr * ptr; | |
5128 | ||
5129 | fprintf (file, "LDST list: \n"); | |
5130 | ||
62e5bf5d | 5131 | for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr)) |
a13d4ebf AM |
5132 | { |
5133 | fprintf (file, " Pattern (%3d): ", ptr->index); | |
5134 | ||
5135 | print_rtl (file, ptr->pattern); | |
5136 | ||
5137 | fprintf (file, "\n Loads : "); | |
5138 | ||
5139 | if (ptr->loads) | |
5140 | print_rtl (file, ptr->loads); | |
5141 | else | |
5142 | fprintf (file, "(nil)"); | |
5143 | ||
5144 | fprintf (file, "\n Stores : "); | |
5145 | ||
5146 | if (ptr->stores) | |
5147 | print_rtl (file, ptr->stores); | |
5148 | else | |
5149 | fprintf (file, "(nil)"); | |
5150 | ||
5151 | fprintf (file, "\n\n"); | |
5152 | } | |
5153 | ||
5154 | fprintf (file, "\n"); | |
5155 | } | |
5156 | ||
5157 | /* Returns 1 if X is in the list of ldst only expressions. */ | |
5158 | ||
5159 | static struct ls_expr * | |
1d088dee | 5160 | find_rtx_in_ldst (rtx x) |
a13d4ebf | 5161 | { |
9727e468 RG |
5162 | struct ls_expr e; |
5163 | void **slot; | |
6375779a RG |
5164 | if (!pre_ldst_table) |
5165 | return NULL; | |
9727e468 RG |
5166 | e.pattern = x; |
5167 | slot = htab_find_slot (pre_ldst_table, &e, NO_INSERT); | |
5168 | if (!slot || ((struct ls_expr *)*slot)->invalid) | |
5169 | return NULL; | |
5170 | return *slot; | |
a13d4ebf AM |
5171 | } |
5172 | ||
5173 | /* Assign each element of the list of mems a monotonically increasing value. */ | |
5174 | ||
5175 | static int | |
1d088dee | 5176 | enumerate_ldsts (void) |
a13d4ebf AM |
5177 | { |
5178 | struct ls_expr * ptr; | |
5179 | int n = 0; | |
5180 | ||
5181 | for (ptr = pre_ldst_mems; ptr != NULL; ptr = ptr->next) | |
5182 | ptr->index = n++; | |
5183 | ||
5184 | return n; | |
5185 | } | |
5186 | ||
5187 | /* Return first item in the list. */ | |
5188 | ||
5189 | static inline struct ls_expr * | |
1d088dee | 5190 | first_ls_expr (void) |
a13d4ebf AM |
5191 | { |
5192 | return pre_ldst_mems; | |
5193 | } | |
5194 | ||
0e8a66de | 5195 | /* Return the next item in the list after the specified one. */ |
a13d4ebf AM |
5196 | |
5197 | static inline struct ls_expr * | |
1d088dee | 5198 | next_ls_expr (struct ls_expr * ptr) |
a13d4ebf AM |
5199 | { |
5200 | return ptr->next; | |
5201 | } | |
5202 | \f | |
5203 | /* Load Motion for loads which only kill themselves. */ | |
5204 | ||
5205 | /* Return true if x is a simple MEM operation, with no registers or | |
5206 | side effects. These are the types of loads we consider for the | |
5207 | ld_motion list, otherwise we let the usual aliasing take care of it. */ | |
5208 | ||
589005ff | 5209 | static int |
1d088dee | 5210 | simple_mem (rtx x) |
a13d4ebf | 5211 | { |
7b1b4aed | 5212 | if (! MEM_P (x)) |
a13d4ebf | 5213 | return 0; |
589005ff | 5214 | |
a13d4ebf AM |
5215 | if (MEM_VOLATILE_P (x)) |
5216 | return 0; | |
589005ff | 5217 | |
a13d4ebf AM |
5218 | if (GET_MODE (x) == BLKmode) |
5219 | return 0; | |
aaa4ca30 | 5220 | |
47a3dae1 ZD |
5221 | /* If we are handling exceptions, we must be careful with memory references |
5222 | that may trap. If we are not, the behavior is undefined, so we may just | |
5223 | continue. */ | |
5224 | if (flag_non_call_exceptions && may_trap_p (x)) | |
98d3d336 RS |
5225 | return 0; |
5226 | ||
47a3dae1 ZD |
5227 | if (side_effects_p (x)) |
5228 | return 0; | |
589005ff | 5229 | |
47a3dae1 ZD |
5230 | /* Do not consider function arguments passed on stack. */ |
5231 | if (reg_mentioned_p (stack_pointer_rtx, x)) | |
5232 | return 0; | |
5233 | ||
5234 | if (flag_float_store && FLOAT_MODE_P (GET_MODE (x))) | |
5235 | return 0; | |
5236 | ||
5237 | return 1; | |
a13d4ebf AM |
5238 | } |
5239 | ||
589005ff KH |
5240 | /* Make sure there isn't a buried reference in this pattern anywhere. |
5241 | If there is, invalidate the entry for it since we're not capable | |
5242 | of fixing it up just yet.. We have to be sure we know about ALL | |
a13d4ebf AM |
5243 | loads since the aliasing code will allow all entries in the |
5244 | ld_motion list to not-alias itself. If we miss a load, we will get | |
589005ff | 5245 | the wrong value since gcse might common it and we won't know to |
a13d4ebf AM |
5246 | fix it up. */ |
5247 | ||
5248 | static void | |
1d088dee | 5249 | invalidate_any_buried_refs (rtx x) |
a13d4ebf AM |
5250 | { |
5251 | const char * fmt; | |
8e42ace1 | 5252 | int i, j; |
a13d4ebf AM |
5253 | struct ls_expr * ptr; |
5254 | ||
5255 | /* Invalidate it in the list. */ | |
7b1b4aed | 5256 | if (MEM_P (x) && simple_mem (x)) |
a13d4ebf AM |
5257 | { |
5258 | ptr = ldst_entry (x); | |
5259 | ptr->invalid = 1; | |
5260 | } | |
5261 | ||
5262 | /* Recursively process the insn. */ | |
5263 | fmt = GET_RTX_FORMAT (GET_CODE (x)); | |
589005ff | 5264 | |
a13d4ebf AM |
5265 | for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--) |
5266 | { | |
5267 | if (fmt[i] == 'e') | |
5268 | invalidate_any_buried_refs (XEXP (x, i)); | |
5269 | else if (fmt[i] == 'E') | |
5270 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
5271 | invalidate_any_buried_refs (XVECEXP (x, i, j)); | |
5272 | } | |
5273 | } | |
5274 | ||
4d3eb89a HPN |
5275 | /* Find all the 'simple' MEMs which are used in LOADs and STORES. Simple |
5276 | being defined as MEM loads and stores to symbols, with no side effects | |
5277 | and no registers in the expression. For a MEM destination, we also | |
5278 | check that the insn is still valid if we replace the destination with a | |
5279 | REG, as is done in update_ld_motion_stores. If there are any uses/defs | |
5280 | which don't match this criteria, they are invalidated and trimmed out | |
5281 | later. */ | |
a13d4ebf | 5282 | |
589005ff | 5283 | static void |
1d088dee | 5284 | compute_ld_motion_mems (void) |
a13d4ebf AM |
5285 | { |
5286 | struct ls_expr * ptr; | |
e0082a72 | 5287 | basic_block bb; |
a13d4ebf | 5288 | rtx insn; |
589005ff | 5289 | |
a13d4ebf | 5290 | pre_ldst_mems = NULL; |
9727e468 RG |
5291 | pre_ldst_table = htab_create (13, pre_ldst_expr_hash, |
5292 | pre_ldst_expr_eq, NULL); | |
a13d4ebf | 5293 | |
e0082a72 | 5294 | FOR_EACH_BB (bb) |
a13d4ebf | 5295 | { |
eb232f4e | 5296 | FOR_BB_INSNS (bb, insn) |
a13d4ebf | 5297 | { |
735e8085 | 5298 | if (INSN_P (insn)) |
a13d4ebf AM |
5299 | { |
5300 | if (GET_CODE (PATTERN (insn)) == SET) | |
5301 | { | |
5302 | rtx src = SET_SRC (PATTERN (insn)); | |
5303 | rtx dest = SET_DEST (PATTERN (insn)); | |
5304 | ||
5305 | /* Check for a simple LOAD... */ | |
7b1b4aed | 5306 | if (MEM_P (src) && simple_mem (src)) |
a13d4ebf AM |
5307 | { |
5308 | ptr = ldst_entry (src); | |
7b1b4aed | 5309 | if (REG_P (dest)) |
a13d4ebf AM |
5310 | ptr->loads = alloc_INSN_LIST (insn, ptr->loads); |
5311 | else | |
5312 | ptr->invalid = 1; | |
5313 | } | |
5314 | else | |
5315 | { | |
5316 | /* Make sure there isn't a buried load somewhere. */ | |
5317 | invalidate_any_buried_refs (src); | |
5318 | } | |
589005ff | 5319 | |
a13d4ebf AM |
5320 | /* Check for stores. Don't worry about aliased ones, they |
5321 | will block any movement we might do later. We only care | |
5322 | about this exact pattern since those are the only | |
5323 | circumstance that we will ignore the aliasing info. */ | |
7b1b4aed | 5324 | if (MEM_P (dest) && simple_mem (dest)) |
a13d4ebf AM |
5325 | { |
5326 | ptr = ldst_entry (dest); | |
589005ff | 5327 | |
7b1b4aed | 5328 | if (! MEM_P (src) |
4d3eb89a HPN |
5329 | && GET_CODE (src) != ASM_OPERANDS |
5330 | /* Check for REG manually since want_to_gcse_p | |
5331 | returns 0 for all REGs. */ | |
1707bafa | 5332 | && can_assign_to_reg_p (src)) |
a13d4ebf AM |
5333 | ptr->stores = alloc_INSN_LIST (insn, ptr->stores); |
5334 | else | |
5335 | ptr->invalid = 1; | |
5336 | } | |
5337 | } | |
5338 | else | |
5339 | invalidate_any_buried_refs (PATTERN (insn)); | |
5340 | } | |
5341 | } | |
5342 | } | |
5343 | } | |
5344 | ||
589005ff | 5345 | /* Remove any references that have been either invalidated or are not in the |
a13d4ebf AM |
5346 | expression list for pre gcse. */ |
5347 | ||
5348 | static void | |
1d088dee | 5349 | trim_ld_motion_mems (void) |
a13d4ebf | 5350 | { |
b58b21d5 RS |
5351 | struct ls_expr * * last = & pre_ldst_mems; |
5352 | struct ls_expr * ptr = pre_ldst_mems; | |
a13d4ebf AM |
5353 | |
5354 | while (ptr != NULL) | |
5355 | { | |
b58b21d5 | 5356 | struct expr * expr; |
589005ff | 5357 | |
a13d4ebf | 5358 | /* Delete if entry has been made invalid. */ |
b58b21d5 | 5359 | if (! ptr->invalid) |
a13d4ebf | 5360 | { |
a13d4ebf | 5361 | /* Delete if we cannot find this mem in the expression list. */ |
b58b21d5 | 5362 | unsigned int hash = ptr->hash_index % expr_hash_table.size; |
589005ff | 5363 | |
b58b21d5 RS |
5364 | for (expr = expr_hash_table.table[hash]; |
5365 | expr != NULL; | |
5366 | expr = expr->next_same_hash) | |
5367 | if (expr_equiv_p (expr->expr, ptr->pattern)) | |
5368 | break; | |
a13d4ebf AM |
5369 | } |
5370 | else | |
b58b21d5 RS |
5371 | expr = (struct expr *) 0; |
5372 | ||
5373 | if (expr) | |
a13d4ebf AM |
5374 | { |
5375 | /* Set the expression field if we are keeping it. */ | |
a13d4ebf | 5376 | ptr->expr = expr; |
b58b21d5 | 5377 | last = & ptr->next; |
a13d4ebf AM |
5378 | ptr = ptr->next; |
5379 | } | |
b58b21d5 RS |
5380 | else |
5381 | { | |
5382 | *last = ptr->next; | |
9727e468 | 5383 | htab_remove_elt_with_hash (pre_ldst_table, ptr, ptr->hash_index); |
b58b21d5 RS |
5384 | free_ldst_entry (ptr); |
5385 | ptr = * last; | |
5386 | } | |
a13d4ebf AM |
5387 | } |
5388 | ||
5389 | /* Show the world what we've found. */ | |
10d22567 ZD |
5390 | if (dump_file && pre_ldst_mems != NULL) |
5391 | print_ldst_list (dump_file); | |
a13d4ebf AM |
5392 | } |
5393 | ||
5394 | /* This routine will take an expression which we are replacing with | |
5395 | a reaching register, and update any stores that are needed if | |
5396 | that expression is in the ld_motion list. Stores are updated by | |
a98ebe2e | 5397 | copying their SRC to the reaching register, and then storing |
a13d4ebf AM |
5398 | the reaching register into the store location. These keeps the |
5399 | correct value in the reaching register for the loads. */ | |
5400 | ||
5401 | static void | |
1d088dee | 5402 | update_ld_motion_stores (struct expr * expr) |
a13d4ebf AM |
5403 | { |
5404 | struct ls_expr * mem_ptr; | |
5405 | ||
5406 | if ((mem_ptr = find_rtx_in_ldst (expr->expr))) | |
5407 | { | |
589005ff KH |
5408 | /* We can try to find just the REACHED stores, but is shouldn't |
5409 | matter to set the reaching reg everywhere... some might be | |
a13d4ebf AM |
5410 | dead and should be eliminated later. */ |
5411 | ||
4d3eb89a HPN |
5412 | /* We replace (set mem expr) with (set reg expr) (set mem reg) |
5413 | where reg is the reaching reg used in the load. We checked in | |
5414 | compute_ld_motion_mems that we can replace (set mem expr) with | |
5415 | (set reg expr) in that insn. */ | |
a13d4ebf | 5416 | rtx list = mem_ptr->stores; |
589005ff | 5417 | |
a13d4ebf AM |
5418 | for ( ; list != NULL_RTX; list = XEXP (list, 1)) |
5419 | { | |
5420 | rtx insn = XEXP (list, 0); | |
5421 | rtx pat = PATTERN (insn); | |
5422 | rtx src = SET_SRC (pat); | |
5423 | rtx reg = expr->reaching_reg; | |
c57718d3 | 5424 | rtx copy, new; |
a13d4ebf AM |
5425 | |
5426 | /* If we've already copied it, continue. */ | |
5427 | if (expr->reaching_reg == src) | |
5428 | continue; | |
589005ff | 5429 | |
10d22567 | 5430 | if (dump_file) |
a13d4ebf | 5431 | { |
10d22567 ZD |
5432 | fprintf (dump_file, "PRE: store updated with reaching reg "); |
5433 | print_rtl (dump_file, expr->reaching_reg); | |
5434 | fprintf (dump_file, ":\n "); | |
5435 | print_inline_rtx (dump_file, insn, 8); | |
5436 | fprintf (dump_file, "\n"); | |
a13d4ebf | 5437 | } |
589005ff | 5438 | |
47a3dae1 | 5439 | copy = gen_move_insn ( reg, copy_rtx (SET_SRC (pat))); |
c57718d3 RK |
5440 | new = emit_insn_before (copy, insn); |
5441 | record_one_set (REGNO (reg), new); | |
a13d4ebf | 5442 | SET_SRC (pat) = reg; |
6fb5fa3c | 5443 | df_insn_rescan (insn); |
a13d4ebf AM |
5444 | |
5445 | /* un-recognize this pattern since it's probably different now. */ | |
5446 | INSN_CODE (insn) = -1; | |
5447 | gcse_create_count++; | |
5448 | } | |
5449 | } | |
5450 | } | |
5451 | \f | |
5452 | /* Store motion code. */ | |
5453 | ||
47a3dae1 ZD |
5454 | #define ANTIC_STORE_LIST(x) ((x)->loads) |
5455 | #define AVAIL_STORE_LIST(x) ((x)->stores) | |
5456 | #define LAST_AVAIL_CHECK_FAILURE(x) ((x)->reaching_reg) | |
5457 | ||
589005ff | 5458 | /* This is used to communicate the target bitvector we want to use in the |
aaa4ca30 | 5459 | reg_set_info routine when called via the note_stores mechanism. */ |
47a3dae1 ZD |
5460 | static int * regvec; |
5461 | ||
5462 | /* And current insn, for the same routine. */ | |
5463 | static rtx compute_store_table_current_insn; | |
aaa4ca30 | 5464 | |
a13d4ebf AM |
5465 | /* Used in computing the reverse edge graph bit vectors. */ |
5466 | static sbitmap * st_antloc; | |
5467 | ||
5468 | /* Global holding the number of store expressions we are dealing with. */ | |
5469 | static int num_stores; | |
5470 | ||
01c43039 RE |
5471 | /* Checks to set if we need to mark a register set. Called from |
5472 | note_stores. */ | |
a13d4ebf | 5473 | |
aaa4ca30 | 5474 | static void |
1d088dee | 5475 | reg_set_info (rtx dest, rtx setter ATTRIBUTE_UNUSED, |
01c43039 | 5476 | void *data) |
a13d4ebf | 5477 | { |
01c43039 RE |
5478 | sbitmap bb_reg = data; |
5479 | ||
aaa4ca30 AJ |
5480 | if (GET_CODE (dest) == SUBREG) |
5481 | dest = SUBREG_REG (dest); | |
adfcce61 | 5482 | |
7b1b4aed | 5483 | if (REG_P (dest)) |
01c43039 RE |
5484 | { |
5485 | regvec[REGNO (dest)] = INSN_UID (compute_store_table_current_insn); | |
5486 | if (bb_reg) | |
5487 | SET_BIT (bb_reg, REGNO (dest)); | |
5488 | } | |
5489 | } | |
5490 | ||
5491 | /* Clear any mark that says that this insn sets dest. Called from | |
5492 | note_stores. */ | |
5493 | ||
5494 | static void | |
5495 | reg_clear_last_set (rtx dest, rtx setter ATTRIBUTE_UNUSED, | |
5496 | void *data) | |
5497 | { | |
5498 | int *dead_vec = data; | |
5499 | ||
5500 | if (GET_CODE (dest) == SUBREG) | |
5501 | dest = SUBREG_REG (dest); | |
5502 | ||
7b1b4aed | 5503 | if (REG_P (dest) && |
01c43039 RE |
5504 | dead_vec[REGNO (dest)] == INSN_UID (compute_store_table_current_insn)) |
5505 | dead_vec[REGNO (dest)] = 0; | |
a13d4ebf AM |
5506 | } |
5507 | ||
47a3dae1 ZD |
5508 | /* Return zero if some of the registers in list X are killed |
5509 | due to set of registers in bitmap REGS_SET. */ | |
1d088dee | 5510 | |
47a3dae1 | 5511 | static bool |
1d088dee | 5512 | store_ops_ok (rtx x, int *regs_set) |
47a3dae1 ZD |
5513 | { |
5514 | rtx reg; | |
5515 | ||
5516 | for (; x; x = XEXP (x, 1)) | |
5517 | { | |
5518 | reg = XEXP (x, 0); | |
5519 | if (regs_set[REGNO(reg)]) | |
1d088dee | 5520 | return false; |
47a3dae1 | 5521 | } |
a13d4ebf | 5522 | |
47a3dae1 ZD |
5523 | return true; |
5524 | } | |
5525 | ||
5526 | /* Returns a list of registers mentioned in X. */ | |
5527 | static rtx | |
1d088dee | 5528 | extract_mentioned_regs (rtx x) |
47a3dae1 ZD |
5529 | { |
5530 | return extract_mentioned_regs_helper (x, NULL_RTX); | |
5531 | } | |
5532 | ||
5533 | /* Helper for extract_mentioned_regs; ACCUM is used to accumulate used | |
5534 | registers. */ | |
5535 | static rtx | |
1d088dee | 5536 | extract_mentioned_regs_helper (rtx x, rtx accum) |
a13d4ebf AM |
5537 | { |
5538 | int i; | |
5539 | enum rtx_code code; | |
5540 | const char * fmt; | |
5541 | ||
5542 | /* Repeat is used to turn tail-recursion into iteration. */ | |
5543 | repeat: | |
5544 | ||
5545 | if (x == 0) | |
47a3dae1 | 5546 | return accum; |
a13d4ebf AM |
5547 | |
5548 | code = GET_CODE (x); | |
5549 | switch (code) | |
5550 | { | |
5551 | case REG: | |
47a3dae1 | 5552 | return alloc_EXPR_LIST (0, x, accum); |
a13d4ebf AM |
5553 | |
5554 | case MEM: | |
5555 | x = XEXP (x, 0); | |
5556 | goto repeat; | |
5557 | ||
5558 | case PRE_DEC: | |
5559 | case PRE_INC: | |
6fb5fa3c | 5560 | case PRE_MODIFY: |
a13d4ebf AM |
5561 | case POST_DEC: |
5562 | case POST_INC: | |
6fb5fa3c | 5563 | case POST_MODIFY: |
47a3dae1 | 5564 | /* We do not run this function with arguments having side effects. */ |
282899df | 5565 | gcc_unreachable (); |
a13d4ebf AM |
5566 | |
5567 | case PC: | |
5568 | case CC0: /*FIXME*/ | |
5569 | case CONST: | |
5570 | case CONST_INT: | |
5571 | case CONST_DOUBLE: | |
69ef87e2 | 5572 | case CONST_VECTOR: |
a13d4ebf AM |
5573 | case SYMBOL_REF: |
5574 | case LABEL_REF: | |
5575 | case ADDR_VEC: | |
5576 | case ADDR_DIFF_VEC: | |
47a3dae1 | 5577 | return accum; |
a13d4ebf AM |
5578 | |
5579 | default: | |
5580 | break; | |
5581 | } | |
5582 | ||
5583 | i = GET_RTX_LENGTH (code) - 1; | |
5584 | fmt = GET_RTX_FORMAT (code); | |
589005ff | 5585 | |
a13d4ebf AM |
5586 | for (; i >= 0; i--) |
5587 | { | |
5588 | if (fmt[i] == 'e') | |
5589 | { | |
5590 | rtx tem = XEXP (x, i); | |
5591 | ||
5592 | /* If we are about to do the last recursive call | |
47a3dae1 | 5593 | needed at this level, change it into iteration. */ |
a13d4ebf AM |
5594 | if (i == 0) |
5595 | { | |
5596 | x = tem; | |
5597 | goto repeat; | |
5598 | } | |
589005ff | 5599 | |
47a3dae1 | 5600 | accum = extract_mentioned_regs_helper (tem, accum); |
a13d4ebf AM |
5601 | } |
5602 | else if (fmt[i] == 'E') | |
5603 | { | |
5604 | int j; | |
589005ff | 5605 | |
a13d4ebf | 5606 | for (j = 0; j < XVECLEN (x, i); j++) |
47a3dae1 | 5607 | accum = extract_mentioned_regs_helper (XVECEXP (x, i, j), accum); |
a13d4ebf AM |
5608 | } |
5609 | } | |
5610 | ||
47a3dae1 | 5611 | return accum; |
a13d4ebf AM |
5612 | } |
5613 | ||
47a3dae1 ZD |
5614 | /* Determine whether INSN is MEM store pattern that we will consider moving. |
5615 | REGS_SET_BEFORE is bitmap of registers set before (and including) the | |
5616 | current insn, REGS_SET_AFTER is bitmap of registers set after (and | |
5617 | including) the insn in this basic block. We must be passing through BB from | |
5618 | head to end, as we are using this fact to speed things up. | |
1d088dee | 5619 | |
47a3dae1 ZD |
5620 | The results are stored this way: |
5621 | ||
5622 | -- the first anticipatable expression is added into ANTIC_STORE_LIST | |
5623 | -- if the processed expression is not anticipatable, NULL_RTX is added | |
5624 | there instead, so that we can use it as indicator that no further | |
5625 | expression of this type may be anticipatable | |
5626 | -- if the expression is available, it is added as head of AVAIL_STORE_LIST; | |
5627 | consequently, all of them but this head are dead and may be deleted. | |
5628 | -- if the expression is not available, the insn due to that it fails to be | |
5629 | available is stored in reaching_reg. | |
5630 | ||
5631 | The things are complicated a bit by fact that there already may be stores | |
5632 | to the same MEM from other blocks; also caller must take care of the | |
e0bb17a8 | 5633 | necessary cleanup of the temporary markers after end of the basic block. |
47a3dae1 | 5634 | */ |
a13d4ebf AM |
5635 | |
5636 | static void | |
1d088dee | 5637 | find_moveable_store (rtx insn, int *regs_set_before, int *regs_set_after) |
a13d4ebf AM |
5638 | { |
5639 | struct ls_expr * ptr; | |
47a3dae1 ZD |
5640 | rtx dest, set, tmp; |
5641 | int check_anticipatable, check_available; | |
5642 | basic_block bb = BLOCK_FOR_INSN (insn); | |
a13d4ebf | 5643 | |
47a3dae1 ZD |
5644 | set = single_set (insn); |
5645 | if (!set) | |
a13d4ebf AM |
5646 | return; |
5647 | ||
47a3dae1 | 5648 | dest = SET_DEST (set); |
589005ff | 5649 | |
7b1b4aed | 5650 | if (! MEM_P (dest) || MEM_VOLATILE_P (dest) |
a13d4ebf | 5651 | || GET_MODE (dest) == BLKmode) |
aaa4ca30 AJ |
5652 | return; |
5653 | ||
47a3dae1 ZD |
5654 | if (side_effects_p (dest)) |
5655 | return; | |
aaa4ca30 | 5656 | |
47a3dae1 ZD |
5657 | /* If we are handling exceptions, we must be careful with memory references |
5658 | that may trap. If we are not, the behavior is undefined, so we may just | |
5659 | continue. */ | |
94f24ddc | 5660 | if (flag_non_call_exceptions && may_trap_p (dest)) |
47a3dae1 | 5661 | return; |
1d088dee | 5662 | |
c2e2375e UW |
5663 | /* Even if the destination cannot trap, the source may. In this case we'd |
5664 | need to handle updating the REG_EH_REGION note. */ | |
5665 | if (find_reg_note (insn, REG_EH_REGION, NULL_RTX)) | |
5666 | return; | |
5667 | ||
26fb114d SB |
5668 | /* Make sure that the SET_SRC of this store insns can be assigned to |
5669 | a register, or we will fail later on in replace_store_insn, which | |
5670 | assumes that we can do this. But sometimes the target machine has | |
5671 | oddities like MEM read-modify-write instruction. See for example | |
5672 | PR24257. */ | |
5673 | if (!can_assign_to_reg_p (SET_SRC (set))) | |
5674 | return; | |
5675 | ||
a13d4ebf | 5676 | ptr = ldst_entry (dest); |
47a3dae1 ZD |
5677 | if (!ptr->pattern_regs) |
5678 | ptr->pattern_regs = extract_mentioned_regs (dest); | |
5679 | ||
5680 | /* Do not check for anticipatability if we either found one anticipatable | |
5681 | store already, or tested for one and found out that it was killed. */ | |
5682 | check_anticipatable = 0; | |
5683 | if (!ANTIC_STORE_LIST (ptr)) | |
5684 | check_anticipatable = 1; | |
5685 | else | |
5686 | { | |
5687 | tmp = XEXP (ANTIC_STORE_LIST (ptr), 0); | |
5688 | if (tmp != NULL_RTX | |
5689 | && BLOCK_FOR_INSN (tmp) != bb) | |
5690 | check_anticipatable = 1; | |
5691 | } | |
5692 | if (check_anticipatable) | |
5693 | { | |
5694 | if (store_killed_before (dest, ptr->pattern_regs, insn, bb, regs_set_before)) | |
5695 | tmp = NULL_RTX; | |
5696 | else | |
5697 | tmp = insn; | |
5698 | ANTIC_STORE_LIST (ptr) = alloc_INSN_LIST (tmp, | |
5699 | ANTIC_STORE_LIST (ptr)); | |
5700 | } | |
a13d4ebf | 5701 | |
e0bb17a8 | 5702 | /* It is not necessary to check whether store is available if we did |
47a3dae1 ZD |
5703 | it successfully before; if we failed before, do not bother to check |
5704 | until we reach the insn that caused us to fail. */ | |
5705 | check_available = 0; | |
5706 | if (!AVAIL_STORE_LIST (ptr)) | |
5707 | check_available = 1; | |
5708 | else | |
5709 | { | |
5710 | tmp = XEXP (AVAIL_STORE_LIST (ptr), 0); | |
5711 | if (BLOCK_FOR_INSN (tmp) != bb) | |
5712 | check_available = 1; | |
5713 | } | |
5714 | if (check_available) | |
5715 | { | |
5716 | /* Check that we have already reached the insn at that the check | |
5717 | failed last time. */ | |
5718 | if (LAST_AVAIL_CHECK_FAILURE (ptr)) | |
5719 | { | |
a813c111 | 5720 | for (tmp = BB_END (bb); |
47a3dae1 ZD |
5721 | tmp != insn && tmp != LAST_AVAIL_CHECK_FAILURE (ptr); |
5722 | tmp = PREV_INSN (tmp)) | |
5723 | continue; | |
5724 | if (tmp == insn) | |
5725 | check_available = 0; | |
5726 | } | |
5727 | else | |
5728 | check_available = store_killed_after (dest, ptr->pattern_regs, insn, | |
5729 | bb, regs_set_after, | |
5730 | &LAST_AVAIL_CHECK_FAILURE (ptr)); | |
5731 | } | |
5732 | if (!check_available) | |
5733 | AVAIL_STORE_LIST (ptr) = alloc_INSN_LIST (insn, AVAIL_STORE_LIST (ptr)); | |
5734 | } | |
1d088dee | 5735 | |
47a3dae1 | 5736 | /* Find available and anticipatable stores. */ |
a13d4ebf AM |
5737 | |
5738 | static int | |
1d088dee | 5739 | compute_store_table (void) |
a13d4ebf | 5740 | { |
e0082a72 ZD |
5741 | int ret; |
5742 | basic_block bb; | |
aaa4ca30 | 5743 | unsigned regno; |
47a3dae1 ZD |
5744 | rtx insn, pat, tmp; |
5745 | int *last_set_in, *already_set; | |
5746 | struct ls_expr * ptr, **prev_next_ptr_ptr; | |
aaa4ca30 | 5747 | |
a13d4ebf AM |
5748 | max_gcse_regno = max_reg_num (); |
5749 | ||
703ad42b | 5750 | reg_set_in_block = sbitmap_vector_alloc (last_basic_block, |
aaa4ca30 | 5751 | max_gcse_regno); |
d55bc081 | 5752 | sbitmap_vector_zero (reg_set_in_block, last_basic_block); |
a13d4ebf | 5753 | pre_ldst_mems = 0; |
9727e468 RG |
5754 | pre_ldst_table = htab_create (13, pre_ldst_expr_hash, |
5755 | pre_ldst_expr_eq, NULL); | |
5ed6ace5 MD |
5756 | last_set_in = XCNEWVEC (int, max_gcse_regno); |
5757 | already_set = XNEWVEC (int, max_gcse_regno); | |
aaa4ca30 | 5758 | |
a13d4ebf | 5759 | /* Find all the stores we care about. */ |
e0082a72 | 5760 | FOR_EACH_BB (bb) |
a13d4ebf | 5761 | { |
47a3dae1 | 5762 | /* First compute the registers set in this block. */ |
47a3dae1 ZD |
5763 | regvec = last_set_in; |
5764 | ||
eb232f4e | 5765 | FOR_BB_INSNS (bb, insn) |
47a3dae1 ZD |
5766 | { |
5767 | if (! INSN_P (insn)) | |
5768 | continue; | |
5769 | ||
7b1b4aed | 5770 | if (CALL_P (insn)) |
47a3dae1 | 5771 | { |
47a3dae1 | 5772 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) |
6e14af16 | 5773 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) |
01c43039 RE |
5774 | { |
5775 | last_set_in[regno] = INSN_UID (insn); | |
5776 | SET_BIT (reg_set_in_block[bb->index], regno); | |
5777 | } | |
47a3dae1 ZD |
5778 | } |
5779 | ||
5780 | pat = PATTERN (insn); | |
5781 | compute_store_table_current_insn = insn; | |
01c43039 | 5782 | note_stores (pat, reg_set_info, reg_set_in_block[bb->index]); |
47a3dae1 ZD |
5783 | } |
5784 | ||
47a3dae1 ZD |
5785 | /* Now find the stores. */ |
5786 | memset (already_set, 0, sizeof (int) * max_gcse_regno); | |
5787 | regvec = already_set; | |
eb232f4e | 5788 | FOR_BB_INSNS (bb, insn) |
a13d4ebf | 5789 | { |
19652adf | 5790 | if (! INSN_P (insn)) |
a13d4ebf AM |
5791 | continue; |
5792 | ||
7b1b4aed | 5793 | if (CALL_P (insn)) |
aaa4ca30 AJ |
5794 | { |
5795 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) | |
6e14af16 | 5796 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) |
47a3dae1 | 5797 | already_set[regno] = 1; |
aaa4ca30 | 5798 | } |
589005ff | 5799 | |
a13d4ebf | 5800 | pat = PATTERN (insn); |
aaa4ca30 | 5801 | note_stores (pat, reg_set_info, NULL); |
589005ff | 5802 | |
a13d4ebf | 5803 | /* Now that we've marked regs, look for stores. */ |
47a3dae1 ZD |
5804 | find_moveable_store (insn, already_set, last_set_in); |
5805 | ||
5806 | /* Unmark regs that are no longer set. */ | |
01c43039 RE |
5807 | compute_store_table_current_insn = insn; |
5808 | note_stores (pat, reg_clear_last_set, last_set_in); | |
7b1b4aed | 5809 | if (CALL_P (insn)) |
01c43039 | 5810 | { |
01c43039 | 5811 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) |
6e14af16 | 5812 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, regno) |
01c43039 RE |
5813 | && last_set_in[regno] == INSN_UID (insn)) |
5814 | last_set_in[regno] = 0; | |
5815 | } | |
47a3dae1 ZD |
5816 | } |
5817 | ||
01c43039 RE |
5818 | #ifdef ENABLE_CHECKING |
5819 | /* last_set_in should now be all-zero. */ | |
5820 | for (regno = 0; regno < max_gcse_regno; regno++) | |
282899df | 5821 | gcc_assert (!last_set_in[regno]); |
01c43039 RE |
5822 | #endif |
5823 | ||
47a3dae1 ZD |
5824 | /* Clear temporary marks. */ |
5825 | for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr)) | |
5826 | { | |
5827 | LAST_AVAIL_CHECK_FAILURE(ptr) = NULL_RTX; | |
5828 | if (ANTIC_STORE_LIST (ptr) | |
5829 | && (tmp = XEXP (ANTIC_STORE_LIST (ptr), 0)) == NULL_RTX) | |
5830 | ANTIC_STORE_LIST (ptr) = XEXP (ANTIC_STORE_LIST (ptr), 1); | |
5831 | } | |
5832 | } | |
5833 | ||
5834 | /* Remove the stores that are not available anywhere, as there will | |
5835 | be no opportunity to optimize them. */ | |
5836 | for (ptr = pre_ldst_mems, prev_next_ptr_ptr = &pre_ldst_mems; | |
5837 | ptr != NULL; | |
5838 | ptr = *prev_next_ptr_ptr) | |
5839 | { | |
5840 | if (!AVAIL_STORE_LIST (ptr)) | |
5841 | { | |
5842 | *prev_next_ptr_ptr = ptr->next; | |
9727e468 | 5843 | htab_remove_elt_with_hash (pre_ldst_table, ptr, ptr->hash_index); |
47a3dae1 | 5844 | free_ldst_entry (ptr); |
a13d4ebf | 5845 | } |
47a3dae1 ZD |
5846 | else |
5847 | prev_next_ptr_ptr = &ptr->next; | |
a13d4ebf AM |
5848 | } |
5849 | ||
5850 | ret = enumerate_ldsts (); | |
589005ff | 5851 | |
10d22567 | 5852 | if (dump_file) |
a13d4ebf | 5853 | { |
10d22567 ZD |
5854 | fprintf (dump_file, "ST_avail and ST_antic (shown under loads..)\n"); |
5855 | print_ldst_list (dump_file); | |
a13d4ebf | 5856 | } |
589005ff | 5857 | |
47a3dae1 ZD |
5858 | free (last_set_in); |
5859 | free (already_set); | |
a13d4ebf AM |
5860 | return ret; |
5861 | } | |
5862 | ||
3b14e3af ZD |
5863 | /* Check to see if the load X is aliased with STORE_PATTERN. |
5864 | AFTER is true if we are checking the case when STORE_PATTERN occurs | |
5865 | after the X. */ | |
a13d4ebf | 5866 | |
47a3dae1 | 5867 | static bool |
3b14e3af | 5868 | load_kills_store (rtx x, rtx store_pattern, int after) |
a13d4ebf | 5869 | { |
3b14e3af ZD |
5870 | if (after) |
5871 | return anti_dependence (x, store_pattern); | |
5872 | else | |
5873 | return true_dependence (store_pattern, GET_MODE (store_pattern), x, | |
5874 | rtx_addr_varies_p); | |
a13d4ebf AM |
5875 | } |
5876 | ||
589005ff | 5877 | /* Go through the entire insn X, looking for any loads which might alias |
3b14e3af ZD |
5878 | STORE_PATTERN. Return true if found. |
5879 | AFTER is true if we are checking the case when STORE_PATTERN occurs | |
5880 | after the insn X. */ | |
a13d4ebf | 5881 | |
47a3dae1 | 5882 | static bool |
3b14e3af | 5883 | find_loads (rtx x, rtx store_pattern, int after) |
a13d4ebf AM |
5884 | { |
5885 | const char * fmt; | |
8e42ace1 | 5886 | int i, j; |
47a3dae1 | 5887 | int ret = false; |
a13d4ebf | 5888 | |
24a28584 | 5889 | if (!x) |
47a3dae1 | 5890 | return false; |
24a28584 | 5891 | |
589005ff | 5892 | if (GET_CODE (x) == SET) |
a13d4ebf AM |
5893 | x = SET_SRC (x); |
5894 | ||
7b1b4aed | 5895 | if (MEM_P (x)) |
a13d4ebf | 5896 | { |
3b14e3af | 5897 | if (load_kills_store (x, store_pattern, after)) |
47a3dae1 | 5898 | return true; |
a13d4ebf AM |
5899 | } |
5900 | ||
5901 | /* Recursively process the insn. */ | |
5902 | fmt = GET_RTX_FORMAT (GET_CODE (x)); | |
589005ff | 5903 | |
a13d4ebf AM |
5904 | for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0 && !ret; i--) |
5905 | { | |
5906 | if (fmt[i] == 'e') | |
3b14e3af | 5907 | ret |= find_loads (XEXP (x, i), store_pattern, after); |
a13d4ebf AM |
5908 | else if (fmt[i] == 'E') |
5909 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
3b14e3af | 5910 | ret |= find_loads (XVECEXP (x, i, j), store_pattern, after); |
a13d4ebf AM |
5911 | } |
5912 | return ret; | |
5913 | } | |
5914 | ||
1071bcbd AO |
5915 | static inline bool |
5916 | store_killed_in_pat (rtx x, rtx pat, int after) | |
5917 | { | |
5918 | if (GET_CODE (pat) == SET) | |
5919 | { | |
5920 | rtx dest = SET_DEST (pat); | |
5921 | ||
5922 | if (GET_CODE (dest) == ZERO_EXTRACT) | |
5923 | dest = XEXP (dest, 0); | |
5924 | ||
5925 | /* Check for memory stores to aliased objects. */ | |
5926 | if (MEM_P (dest) | |
5927 | && !expr_equiv_p (dest, x)) | |
5928 | { | |
5929 | if (after) | |
5930 | { | |
5931 | if (output_dependence (dest, x)) | |
5932 | return true; | |
5933 | } | |
5934 | else | |
5935 | { | |
5936 | if (output_dependence (x, dest)) | |
5937 | return true; | |
5938 | } | |
5939 | } | |
5940 | } | |
5941 | ||
5942 | if (find_loads (pat, x, after)) | |
5943 | return true; | |
5944 | ||
5945 | return false; | |
5946 | } | |
5947 | ||
589005ff | 5948 | /* Check if INSN kills the store pattern X (is aliased with it). |
3b14e3af | 5949 | AFTER is true if we are checking the case when store X occurs |
3f117656 | 5950 | after the insn. Return true if it does. */ |
a13d4ebf | 5951 | |
47a3dae1 | 5952 | static bool |
3b14e3af | 5953 | store_killed_in_insn (rtx x, rtx x_regs, rtx insn, int after) |
a13d4ebf | 5954 | { |
1071bcbd | 5955 | rtx reg, base, note, pat; |
94f24ddc | 5956 | |
735e8085 | 5957 | if (!INSN_P (insn)) |
47a3dae1 | 5958 | return false; |
589005ff | 5959 | |
7b1b4aed | 5960 | if (CALL_P (insn)) |
a13d4ebf | 5961 | { |
1218665b JJ |
5962 | /* A normal or pure call might read from pattern, |
5963 | but a const call will not. */ | |
47a3dae1 ZD |
5964 | if (! CONST_OR_PURE_CALL_P (insn) || pure_call_p (insn)) |
5965 | return true; | |
5966 | ||
94f24ddc ZD |
5967 | /* But even a const call reads its parameters. Check whether the |
5968 | base of some of registers used in mem is stack pointer. */ | |
5969 | for (reg = x_regs; reg; reg = XEXP (reg, 1)) | |
5970 | { | |
bc083e18 | 5971 | base = find_base_term (XEXP (reg, 0)); |
94f24ddc ZD |
5972 | if (!base |
5973 | || (GET_CODE (base) == ADDRESS | |
5974 | && GET_MODE (base) == Pmode | |
5975 | && XEXP (base, 0) == stack_pointer_rtx)) | |
5976 | return true; | |
5977 | } | |
47a3dae1 ZD |
5978 | |
5979 | return false; | |
a13d4ebf | 5980 | } |
589005ff | 5981 | |
1071bcbd AO |
5982 | pat = PATTERN (insn); |
5983 | if (GET_CODE (pat) == SET) | |
a13d4ebf | 5984 | { |
1071bcbd | 5985 | if (store_killed_in_pat (x, pat, after)) |
d088acea | 5986 | return true; |
a13d4ebf | 5987 | } |
1071bcbd AO |
5988 | else if (GET_CODE (pat) == PARALLEL) |
5989 | { | |
5990 | int i; | |
5991 | ||
5992 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
5993 | if (store_killed_in_pat (x, XVECEXP (pat, 0, i), after)) | |
5994 | return true; | |
5995 | } | |
d088acea ZD |
5996 | else if (find_loads (PATTERN (insn), x, after)) |
5997 | return true; | |
5998 | ||
5999 | /* If this insn has a REG_EQUAL or REG_EQUIV note referencing a memory | |
6000 | location aliased with X, then this insn kills X. */ | |
6001 | note = find_reg_equal_equiv_note (insn); | |
6002 | if (! note) | |
6003 | return false; | |
6004 | note = XEXP (note, 0); | |
6005 | ||
6006 | /* However, if the note represents a must alias rather than a may | |
6007 | alias relationship, then it does not kill X. */ | |
6008 | if (expr_equiv_p (note, x)) | |
6009 | return false; | |
6010 | ||
6011 | /* See if there are any aliased loads in the note. */ | |
6012 | return find_loads (note, x, after); | |
a13d4ebf AM |
6013 | } |
6014 | ||
47a3dae1 ZD |
6015 | /* Returns true if the expression X is loaded or clobbered on or after INSN |
6016 | within basic block BB. REGS_SET_AFTER is bitmap of registers set in | |
6017 | or after the insn. X_REGS is list of registers mentioned in X. If the store | |
6018 | is killed, return the last insn in that it occurs in FAIL_INSN. */ | |
a13d4ebf | 6019 | |
47a3dae1 | 6020 | static bool |
1d088dee AJ |
6021 | store_killed_after (rtx x, rtx x_regs, rtx insn, basic_block bb, |
6022 | int *regs_set_after, rtx *fail_insn) | |
a13d4ebf | 6023 | { |
a813c111 | 6024 | rtx last = BB_END (bb), act; |
aaa4ca30 | 6025 | |
47a3dae1 | 6026 | if (!store_ops_ok (x_regs, regs_set_after)) |
1d088dee | 6027 | { |
47a3dae1 ZD |
6028 | /* We do not know where it will happen. */ |
6029 | if (fail_insn) | |
6030 | *fail_insn = NULL_RTX; | |
6031 | return true; | |
6032 | } | |
a13d4ebf | 6033 | |
47a3dae1 ZD |
6034 | /* Scan from the end, so that fail_insn is determined correctly. */ |
6035 | for (act = last; act != PREV_INSN (insn); act = PREV_INSN (act)) | |
3b14e3af | 6036 | if (store_killed_in_insn (x, x_regs, act, false)) |
47a3dae1 ZD |
6037 | { |
6038 | if (fail_insn) | |
6039 | *fail_insn = act; | |
6040 | return true; | |
6041 | } | |
589005ff | 6042 | |
47a3dae1 | 6043 | return false; |
a13d4ebf | 6044 | } |
1d088dee | 6045 | |
47a3dae1 ZD |
6046 | /* Returns true if the expression X is loaded or clobbered on or before INSN |
6047 | within basic block BB. X_REGS is list of registers mentioned in X. | |
6048 | REGS_SET_BEFORE is bitmap of registers set before or in this insn. */ | |
6049 | static bool | |
1d088dee AJ |
6050 | store_killed_before (rtx x, rtx x_regs, rtx insn, basic_block bb, |
6051 | int *regs_set_before) | |
a13d4ebf | 6052 | { |
a813c111 | 6053 | rtx first = BB_HEAD (bb); |
a13d4ebf | 6054 | |
47a3dae1 ZD |
6055 | if (!store_ops_ok (x_regs, regs_set_before)) |
6056 | return true; | |
a13d4ebf | 6057 | |
47a3dae1 | 6058 | for ( ; insn != PREV_INSN (first); insn = PREV_INSN (insn)) |
3b14e3af | 6059 | if (store_killed_in_insn (x, x_regs, insn, true)) |
47a3dae1 | 6060 | return true; |
589005ff | 6061 | |
47a3dae1 | 6062 | return false; |
a13d4ebf | 6063 | } |
1d088dee | 6064 | |
47a3dae1 ZD |
6065 | /* Fill in available, anticipatable, transparent and kill vectors in |
6066 | STORE_DATA, based on lists of available and anticipatable stores. */ | |
a13d4ebf | 6067 | static void |
1d088dee | 6068 | build_store_vectors (void) |
a13d4ebf | 6069 | { |
47a3dae1 ZD |
6070 | basic_block bb; |
6071 | int *regs_set_in_block; | |
a13d4ebf AM |
6072 | rtx insn, st; |
6073 | struct ls_expr * ptr; | |
47a3dae1 | 6074 | unsigned regno; |
a13d4ebf AM |
6075 | |
6076 | /* Build the gen_vector. This is any store in the table which is not killed | |
6077 | by aliasing later in its block. */ | |
703ad42b | 6078 | ae_gen = sbitmap_vector_alloc (last_basic_block, num_stores); |
d55bc081 | 6079 | sbitmap_vector_zero (ae_gen, last_basic_block); |
a13d4ebf | 6080 | |
703ad42b | 6081 | st_antloc = sbitmap_vector_alloc (last_basic_block, num_stores); |
d55bc081 | 6082 | sbitmap_vector_zero (st_antloc, last_basic_block); |
aaa4ca30 | 6083 | |
a13d4ebf | 6084 | for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr)) |
589005ff | 6085 | { |
47a3dae1 | 6086 | for (st = AVAIL_STORE_LIST (ptr); st != NULL; st = XEXP (st, 1)) |
a13d4ebf AM |
6087 | { |
6088 | insn = XEXP (st, 0); | |
e2d2ed72 | 6089 | bb = BLOCK_FOR_INSN (insn); |
589005ff | 6090 | |
47a3dae1 ZD |
6091 | /* If we've already seen an available expression in this block, |
6092 | we can delete this one (It occurs earlier in the block). We'll | |
6093 | copy the SRC expression to an unused register in case there | |
6094 | are any side effects. */ | |
6095 | if (TEST_BIT (ae_gen[bb->index], ptr->index)) | |
a13d4ebf | 6096 | { |
47a3dae1 | 6097 | rtx r = gen_reg_rtx (GET_MODE (ptr->pattern)); |
10d22567 ZD |
6098 | if (dump_file) |
6099 | fprintf (dump_file, "Removing redundant store:\n"); | |
d088acea | 6100 | replace_store_insn (r, XEXP (st, 0), bb, ptr); |
47a3dae1 | 6101 | continue; |
a13d4ebf | 6102 | } |
47a3dae1 | 6103 | SET_BIT (ae_gen[bb->index], ptr->index); |
a13d4ebf | 6104 | } |
589005ff | 6105 | |
47a3dae1 ZD |
6106 | for (st = ANTIC_STORE_LIST (ptr); st != NULL; st = XEXP (st, 1)) |
6107 | { | |
6108 | insn = XEXP (st, 0); | |
6109 | bb = BLOCK_FOR_INSN (insn); | |
6110 | SET_BIT (st_antloc[bb->index], ptr->index); | |
6111 | } | |
a13d4ebf | 6112 | } |
589005ff | 6113 | |
703ad42b | 6114 | ae_kill = sbitmap_vector_alloc (last_basic_block, num_stores); |
d55bc081 | 6115 | sbitmap_vector_zero (ae_kill, last_basic_block); |
a13d4ebf | 6116 | |
703ad42b | 6117 | transp = sbitmap_vector_alloc (last_basic_block, num_stores); |
d55bc081 | 6118 | sbitmap_vector_zero (transp, last_basic_block); |
5ed6ace5 | 6119 | regs_set_in_block = XNEWVEC (int, max_gcse_regno); |
a13d4ebf | 6120 | |
47a3dae1 ZD |
6121 | FOR_EACH_BB (bb) |
6122 | { | |
6123 | for (regno = 0; regno < max_gcse_regno; regno++) | |
6124 | regs_set_in_block[regno] = TEST_BIT (reg_set_in_block[bb->index], regno); | |
6125 | ||
6126 | for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr)) | |
6127 | { | |
a813c111 | 6128 | if (store_killed_after (ptr->pattern, ptr->pattern_regs, BB_HEAD (bb), |
47a3dae1 ZD |
6129 | bb, regs_set_in_block, NULL)) |
6130 | { | |
e0bb17a8 | 6131 | /* It should not be necessary to consider the expression |
47a3dae1 ZD |
6132 | killed if it is both anticipatable and available. */ |
6133 | if (!TEST_BIT (st_antloc[bb->index], ptr->index) | |
6134 | || !TEST_BIT (ae_gen[bb->index], ptr->index)) | |
6135 | SET_BIT (ae_kill[bb->index], ptr->index); | |
1d088dee AJ |
6136 | } |
6137 | else | |
6138 | SET_BIT (transp[bb->index], ptr->index); | |
6139 | } | |
47a3dae1 ZD |
6140 | } |
6141 | ||
6142 | free (regs_set_in_block); | |
aaa4ca30 | 6143 | |
10d22567 | 6144 | if (dump_file) |
aaa4ca30 | 6145 | { |
10d22567 ZD |
6146 | dump_sbitmap_vector (dump_file, "st_antloc", "", st_antloc, last_basic_block); |
6147 | dump_sbitmap_vector (dump_file, "st_kill", "", ae_kill, last_basic_block); | |
6148 | dump_sbitmap_vector (dump_file, "Transpt", "", transp, last_basic_block); | |
6149 | dump_sbitmap_vector (dump_file, "st_avloc", "", ae_gen, last_basic_block); | |
a13d4ebf AM |
6150 | } |
6151 | } | |
6152 | ||
fbe5a4a6 | 6153 | /* Insert an instruction at the beginning of a basic block, and update |
a813c111 | 6154 | the BB_HEAD if needed. */ |
a13d4ebf | 6155 | |
589005ff | 6156 | static void |
6fb5fa3c | 6157 | insert_insn_start_basic_block (rtx insn, basic_block bb) |
a13d4ebf AM |
6158 | { |
6159 | /* Insert at start of successor block. */ | |
a813c111 SB |
6160 | rtx prev = PREV_INSN (BB_HEAD (bb)); |
6161 | rtx before = BB_HEAD (bb); | |
a13d4ebf AM |
6162 | while (before != 0) |
6163 | { | |
7b1b4aed | 6164 | if (! LABEL_P (before) |
a38e7aa5 | 6165 | && !NOTE_INSN_BASIC_BLOCK_P (before)) |
a13d4ebf AM |
6166 | break; |
6167 | prev = before; | |
a813c111 | 6168 | if (prev == BB_END (bb)) |
a13d4ebf AM |
6169 | break; |
6170 | before = NEXT_INSN (before); | |
6171 | } | |
6172 | ||
6fb5fa3c | 6173 | insn = emit_insn_after_noloc (insn, prev, bb); |
a13d4ebf | 6174 | |
10d22567 | 6175 | if (dump_file) |
a13d4ebf | 6176 | { |
10d22567 | 6177 | fprintf (dump_file, "STORE_MOTION insert store at start of BB %d:\n", |
0b17ab2f | 6178 | bb->index); |
10d22567 ZD |
6179 | print_inline_rtx (dump_file, insn, 6); |
6180 | fprintf (dump_file, "\n"); | |
a13d4ebf AM |
6181 | } |
6182 | } | |
6183 | ||
6184 | /* This routine will insert a store on an edge. EXPR is the ldst entry for | |
cc2902df | 6185 | the memory reference, and E is the edge to insert it on. Returns nonzero |
a13d4ebf AM |
6186 | if an edge insertion was performed. */ |
6187 | ||
6188 | static int | |
1d088dee | 6189 | insert_store (struct ls_expr * expr, edge e) |
a13d4ebf AM |
6190 | { |
6191 | rtx reg, insn; | |
e2d2ed72 | 6192 | basic_block bb; |
a13d4ebf | 6193 | edge tmp; |
628f6a4e | 6194 | edge_iterator ei; |
a13d4ebf AM |
6195 | |
6196 | /* We did all the deleted before this insert, so if we didn't delete a | |
6197 | store, then we haven't set the reaching reg yet either. */ | |
6198 | if (expr->reaching_reg == NULL_RTX) | |
6199 | return 0; | |
6200 | ||
a0c8285b JH |
6201 | if (e->flags & EDGE_FAKE) |
6202 | return 0; | |
6203 | ||
a13d4ebf | 6204 | reg = expr->reaching_reg; |
47a3dae1 | 6205 | insn = gen_move_insn (copy_rtx (expr->pattern), reg); |
589005ff | 6206 | |
a13d4ebf AM |
6207 | /* If we are inserting this expression on ALL predecessor edges of a BB, |
6208 | insert it at the start of the BB, and reset the insert bits on the other | |
ff7cc307 | 6209 | edges so we don't try to insert it on the other edges. */ |
e2d2ed72 | 6210 | bb = e->dest; |
628f6a4e | 6211 | FOR_EACH_EDGE (tmp, ei, e->dest->preds) |
3f2eae23 | 6212 | if (!(tmp->flags & EDGE_FAKE)) |
a0c8285b JH |
6213 | { |
6214 | int index = EDGE_INDEX (edge_list, tmp->src, tmp->dest); | |
282899df NS |
6215 | |
6216 | gcc_assert (index != EDGE_INDEX_NO_EDGE); | |
a0c8285b JH |
6217 | if (! TEST_BIT (pre_insert_map[index], expr->index)) |
6218 | break; | |
6219 | } | |
a13d4ebf AM |
6220 | |
6221 | /* If tmp is NULL, we found an insertion on every edge, blank the | |
6222 | insertion vector for these edges, and insert at the start of the BB. */ | |
e2d2ed72 | 6223 | if (!tmp && bb != EXIT_BLOCK_PTR) |
a13d4ebf | 6224 | { |
628f6a4e | 6225 | FOR_EACH_EDGE (tmp, ei, e->dest->preds) |
a13d4ebf AM |
6226 | { |
6227 | int index = EDGE_INDEX (edge_list, tmp->src, tmp->dest); | |
6228 | RESET_BIT (pre_insert_map[index], expr->index); | |
6229 | } | |
6fb5fa3c | 6230 | insert_insn_start_basic_block (insn, bb); |
a13d4ebf AM |
6231 | return 0; |
6232 | } | |
589005ff | 6233 | |
b16aa8a5 RK |
6234 | /* We can't put stores in the front of blocks pointed to by abnormal |
6235 | edges since that may put a store where one didn't used to be. */ | |
6236 | gcc_assert (!(e->flags & EDGE_ABNORMAL)); | |
a13d4ebf AM |
6237 | |
6238 | insert_insn_on_edge (insn, e); | |
589005ff | 6239 | |
10d22567 | 6240 | if (dump_file) |
a13d4ebf | 6241 | { |
10d22567 | 6242 | fprintf (dump_file, "STORE_MOTION insert insn on edge (%d, %d):\n", |
0b17ab2f | 6243 | e->src->index, e->dest->index); |
10d22567 ZD |
6244 | print_inline_rtx (dump_file, insn, 6); |
6245 | fprintf (dump_file, "\n"); | |
a13d4ebf | 6246 | } |
589005ff | 6247 | |
a13d4ebf AM |
6248 | return 1; |
6249 | } | |
6250 | ||
d088acea ZD |
6251 | /* Remove any REG_EQUAL or REG_EQUIV notes containing a reference to the |
6252 | memory location in SMEXPR set in basic block BB. | |
6253 | ||
6254 | This could be rather expensive. */ | |
6255 | ||
6256 | static void | |
6257 | remove_reachable_equiv_notes (basic_block bb, struct ls_expr *smexpr) | |
6258 | { | |
628f6a4e BE |
6259 | edge_iterator *stack, ei; |
6260 | int sp; | |
6261 | edge act; | |
d088acea | 6262 | sbitmap visited = sbitmap_alloc (last_basic_block); |
d088acea ZD |
6263 | rtx last, insn, note; |
6264 | rtx mem = smexpr->pattern; | |
6265 | ||
5ed6ace5 | 6266 | stack = XNEWVEC (edge_iterator, n_basic_blocks); |
628f6a4e BE |
6267 | sp = 0; |
6268 | ei = ei_start (bb->succs); | |
6269 | ||
d088acea | 6270 | sbitmap_zero (visited); |
d088acea | 6271 | |
f76ccf60 | 6272 | act = (EDGE_COUNT (ei_container (ei)) > 0 ? EDGE_I (ei_container (ei), 0) : NULL); |
d088acea ZD |
6273 | while (1) |
6274 | { | |
6275 | if (!act) | |
6276 | { | |
628f6a4e | 6277 | if (!sp) |
d088acea ZD |
6278 | { |
6279 | free (stack); | |
6280 | sbitmap_free (visited); | |
6281 | return; | |
6282 | } | |
628f6a4e | 6283 | act = ei_edge (stack[--sp]); |
d088acea ZD |
6284 | } |
6285 | bb = act->dest; | |
7b1b4aed | 6286 | |
d088acea | 6287 | if (bb == EXIT_BLOCK_PTR |
d1c6a401 | 6288 | || TEST_BIT (visited, bb->index)) |
d088acea | 6289 | { |
628f6a4e BE |
6290 | if (!ei_end_p (ei)) |
6291 | ei_next (&ei); | |
6292 | act = (! ei_end_p (ei)) ? ei_edge (ei) : NULL; | |
d088acea ZD |
6293 | continue; |
6294 | } | |
6295 | SET_BIT (visited, bb->index); | |
6296 | ||
6297 | if (TEST_BIT (st_antloc[bb->index], smexpr->index)) | |
6298 | { | |
6299 | for (last = ANTIC_STORE_LIST (smexpr); | |
6300 | BLOCK_FOR_INSN (XEXP (last, 0)) != bb; | |
6301 | last = XEXP (last, 1)) | |
6302 | continue; | |
6303 | last = XEXP (last, 0); | |
6304 | } | |
6305 | else | |
a813c111 | 6306 | last = NEXT_INSN (BB_END (bb)); |
7b1b4aed | 6307 | |
a813c111 | 6308 | for (insn = BB_HEAD (bb); insn != last; insn = NEXT_INSN (insn)) |
d088acea ZD |
6309 | if (INSN_P (insn)) |
6310 | { | |
6311 | note = find_reg_equal_equiv_note (insn); | |
6312 | if (!note || !expr_equiv_p (XEXP (note, 0), mem)) | |
6313 | continue; | |
6314 | ||
10d22567 ZD |
6315 | if (dump_file) |
6316 | fprintf (dump_file, "STORE_MOTION drop REG_EQUAL note at insn %d:\n", | |
d088acea ZD |
6317 | INSN_UID (insn)); |
6318 | remove_note (insn, note); | |
6319 | } | |
628f6a4e BE |
6320 | |
6321 | if (!ei_end_p (ei)) | |
6322 | ei_next (&ei); | |
6323 | act = (! ei_end_p (ei)) ? ei_edge (ei) : NULL; | |
6324 | ||
6325 | if (EDGE_COUNT (bb->succs) > 0) | |
d088acea ZD |
6326 | { |
6327 | if (act) | |
628f6a4e BE |
6328 | stack[sp++] = ei; |
6329 | ei = ei_start (bb->succs); | |
f76ccf60 | 6330 | act = (EDGE_COUNT (ei_container (ei)) > 0 ? EDGE_I (ei_container (ei), 0) : NULL); |
d088acea ZD |
6331 | } |
6332 | } | |
6333 | } | |
6334 | ||
a13d4ebf AM |
6335 | /* This routine will replace a store with a SET to a specified register. */ |
6336 | ||
6337 | static void | |
d088acea | 6338 | replace_store_insn (rtx reg, rtx del, basic_block bb, struct ls_expr *smexpr) |
a13d4ebf | 6339 | { |
d7fe1183 | 6340 | rtx insn, mem, note, set, ptr, pair; |
589005ff | 6341 | |
d088acea | 6342 | mem = smexpr->pattern; |
9a318d30 | 6343 | insn = gen_move_insn (reg, SET_SRC (single_set (del))); |
589005ff | 6344 | |
d088acea ZD |
6345 | for (ptr = ANTIC_STORE_LIST (smexpr); ptr; ptr = XEXP (ptr, 1)) |
6346 | if (XEXP (ptr, 0) == del) | |
6347 | { | |
6348 | XEXP (ptr, 0) = insn; | |
6349 | break; | |
6350 | } | |
d7fe1183 ZD |
6351 | |
6352 | /* Move the notes from the deleted insn to its replacement, and patch | |
6353 | up the LIBCALL notes. */ | |
6354 | REG_NOTES (insn) = REG_NOTES (del); | |
6355 | ||
6356 | note = find_reg_note (insn, REG_RETVAL, NULL_RTX); | |
6357 | if (note) | |
6358 | { | |
6359 | pair = XEXP (note, 0); | |
6360 | note = find_reg_note (pair, REG_LIBCALL, NULL_RTX); | |
6361 | XEXP (note, 0) = insn; | |
6362 | } | |
6363 | note = find_reg_note (insn, REG_LIBCALL, NULL_RTX); | |
6364 | if (note) | |
6365 | { | |
6366 | pair = XEXP (note, 0); | |
6367 | note = find_reg_note (pair, REG_RETVAL, NULL_RTX); | |
6368 | XEXP (note, 0) = insn; | |
6369 | } | |
6370 | ||
bfff9190 SP |
6371 | /* Emit the insn AFTER all the notes are transferred. |
6372 | This is cheaper since we avoid df rescanning for the note change. */ | |
6373 | insn = emit_insn_after (insn, del); | |
6374 | ||
6375 | if (dump_file) | |
6376 | { | |
6377 | fprintf (dump_file, | |
6378 | "STORE_MOTION delete insn in BB %d:\n ", bb->index); | |
6379 | print_inline_rtx (dump_file, del, 6); | |
6380 | fprintf (dump_file, "\nSTORE MOTION replaced with insn:\n "); | |
6381 | print_inline_rtx (dump_file, insn, 6); | |
6382 | fprintf (dump_file, "\n"); | |
6383 | } | |
6384 | ||
49ce134f | 6385 | delete_insn (del); |
d088acea ZD |
6386 | |
6387 | /* Now we must handle REG_EQUAL notes whose contents is equal to the mem; | |
6388 | they are no longer accurate provided that they are reached by this | |
6389 | definition, so drop them. */ | |
a813c111 | 6390 | for (; insn != NEXT_INSN (BB_END (bb)); insn = NEXT_INSN (insn)) |
d088acea ZD |
6391 | if (INSN_P (insn)) |
6392 | { | |
6393 | set = single_set (insn); | |
6394 | if (!set) | |
6395 | continue; | |
6396 | if (expr_equiv_p (SET_DEST (set), mem)) | |
6397 | return; | |
6398 | note = find_reg_equal_equiv_note (insn); | |
6399 | if (!note || !expr_equiv_p (XEXP (note, 0), mem)) | |
6400 | continue; | |
6401 | ||
10d22567 ZD |
6402 | if (dump_file) |
6403 | fprintf (dump_file, "STORE_MOTION drop REG_EQUAL note at insn %d:\n", | |
d088acea ZD |
6404 | INSN_UID (insn)); |
6405 | remove_note (insn, note); | |
6406 | } | |
6407 | remove_reachable_equiv_notes (bb, smexpr); | |
a13d4ebf AM |
6408 | } |
6409 | ||
6410 | ||
6411 | /* Delete a store, but copy the value that would have been stored into | |
6412 | the reaching_reg for later storing. */ | |
6413 | ||
6414 | static void | |
1d088dee | 6415 | delete_store (struct ls_expr * expr, basic_block bb) |
a13d4ebf AM |
6416 | { |
6417 | rtx reg, i, del; | |
6418 | ||
6419 | if (expr->reaching_reg == NULL_RTX) | |
6420 | expr->reaching_reg = gen_reg_rtx (GET_MODE (expr->pattern)); | |
a13d4ebf | 6421 | |
a13d4ebf | 6422 | reg = expr->reaching_reg; |
589005ff | 6423 | |
a13d4ebf AM |
6424 | for (i = AVAIL_STORE_LIST (expr); i; i = XEXP (i, 1)) |
6425 | { | |
6426 | del = XEXP (i, 0); | |
e2d2ed72 | 6427 | if (BLOCK_FOR_INSN (del) == bb) |
a13d4ebf | 6428 | { |
589005ff | 6429 | /* We know there is only one since we deleted redundant |
a13d4ebf | 6430 | ones during the available computation. */ |
d088acea | 6431 | replace_store_insn (reg, del, bb, expr); |
a13d4ebf AM |
6432 | break; |
6433 | } | |
6434 | } | |
6435 | } | |
6436 | ||
6437 | /* Free memory used by store motion. */ | |
6438 | ||
589005ff | 6439 | static void |
1d088dee | 6440 | free_store_memory (void) |
a13d4ebf AM |
6441 | { |
6442 | free_ldst_mems (); | |
589005ff | 6443 | |
a13d4ebf | 6444 | if (ae_gen) |
5a660bff | 6445 | sbitmap_vector_free (ae_gen); |
a13d4ebf | 6446 | if (ae_kill) |
5a660bff | 6447 | sbitmap_vector_free (ae_kill); |
a13d4ebf | 6448 | if (transp) |
5a660bff | 6449 | sbitmap_vector_free (transp); |
a13d4ebf | 6450 | if (st_antloc) |
5a660bff | 6451 | sbitmap_vector_free (st_antloc); |
a13d4ebf | 6452 | if (pre_insert_map) |
5a660bff | 6453 | sbitmap_vector_free (pre_insert_map); |
a13d4ebf | 6454 | if (pre_delete_map) |
5a660bff | 6455 | sbitmap_vector_free (pre_delete_map); |
aaa4ca30 AJ |
6456 | if (reg_set_in_block) |
6457 | sbitmap_vector_free (reg_set_in_block); | |
589005ff | 6458 | |
a13d4ebf AM |
6459 | ae_gen = ae_kill = transp = st_antloc = NULL; |
6460 | pre_insert_map = pre_delete_map = reg_set_in_block = NULL; | |
6461 | } | |
6462 | ||
6463 | /* Perform store motion. Much like gcse, except we move expressions the | |
6464 | other way by looking at the flowgraph in reverse. */ | |
6465 | ||
6466 | static void | |
1d088dee | 6467 | store_motion (void) |
a13d4ebf | 6468 | { |
e0082a72 | 6469 | basic_block bb; |
0b17ab2f | 6470 | int x; |
a13d4ebf | 6471 | struct ls_expr * ptr; |
adfcce61 | 6472 | int update_flow = 0; |
aaa4ca30 | 6473 | |
10d22567 | 6474 | if (dump_file) |
a13d4ebf | 6475 | { |
10d22567 ZD |
6476 | fprintf (dump_file, "before store motion\n"); |
6477 | print_rtl (dump_file, get_insns ()); | |
a13d4ebf AM |
6478 | } |
6479 | ||
a13d4ebf | 6480 | init_alias_analysis (); |
aaa4ca30 | 6481 | |
47a3dae1 | 6482 | /* Find all the available and anticipatable stores. */ |
a13d4ebf AM |
6483 | num_stores = compute_store_table (); |
6484 | if (num_stores == 0) | |
6485 | { | |
9727e468 RG |
6486 | htab_delete (pre_ldst_table); |
6487 | pre_ldst_table = NULL; | |
aaa4ca30 | 6488 | sbitmap_vector_free (reg_set_in_block); |
a13d4ebf AM |
6489 | end_alias_analysis (); |
6490 | return; | |
6491 | } | |
6492 | ||
47a3dae1 | 6493 | /* Now compute kill & transp vectors. */ |
a13d4ebf | 6494 | build_store_vectors (); |
47a3dae1 | 6495 | add_noreturn_fake_exit_edges (); |
2a868ea4 | 6496 | connect_infinite_loops_to_exit (); |
a13d4ebf | 6497 | |
10d22567 | 6498 | edge_list = pre_edge_rev_lcm (num_stores, transp, ae_gen, |
589005ff | 6499 | st_antloc, ae_kill, &pre_insert_map, |
a13d4ebf AM |
6500 | &pre_delete_map); |
6501 | ||
6502 | /* Now we want to insert the new stores which are going to be needed. */ | |
6503 | for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr)) | |
6504 | { | |
b16aa8a5 RK |
6505 | /* If any of the edges we have above are abnormal, we can't move this |
6506 | store. */ | |
6507 | for (x = NUM_EDGES (edge_list) - 1; x >= 0; x--) | |
6508 | if (TEST_BIT (pre_insert_map[x], ptr->index) | |
6509 | && (INDEX_EDGE (edge_list, x)->flags & EDGE_ABNORMAL)) | |
6510 | break; | |
6511 | ||
6512 | if (x >= 0) | |
6513 | { | |
10d22567 ZD |
6514 | if (dump_file != NULL) |
6515 | fprintf (dump_file, | |
b16aa8a5 RK |
6516 | "Can't replace store %d: abnormal edge from %d to %d\n", |
6517 | ptr->index, INDEX_EDGE (edge_list, x)->src->index, | |
6518 | INDEX_EDGE (edge_list, x)->dest->index); | |
6519 | continue; | |
6520 | } | |
6521 | ||
6522 | /* Now we want to insert the new stores which are going to be needed. */ | |
6523 | ||
e0082a72 ZD |
6524 | FOR_EACH_BB (bb) |
6525 | if (TEST_BIT (pre_delete_map[bb->index], ptr->index)) | |
6526 | delete_store (ptr, bb); | |
a13d4ebf | 6527 | |
0b17ab2f RH |
6528 | for (x = 0; x < NUM_EDGES (edge_list); x++) |
6529 | if (TEST_BIT (pre_insert_map[x], ptr->index)) | |
6530 | update_flow |= insert_store (ptr, INDEX_EDGE (edge_list, x)); | |
a13d4ebf AM |
6531 | } |
6532 | ||
6533 | if (update_flow) | |
6534 | commit_edge_insertions (); | |
aaa4ca30 | 6535 | |
a13d4ebf AM |
6536 | free_store_memory (); |
6537 | free_edge_list (edge_list); | |
6809cbf9 | 6538 | remove_fake_exit_edges (); |
a13d4ebf AM |
6539 | end_alias_analysis (); |
6540 | } | |
e2500fed | 6541 | |
a0134312 RS |
6542 | \f |
6543 | /* Entry point for jump bypassing optimization pass. */ | |
6544 | ||
65727068 | 6545 | static int |
10d22567 | 6546 | bypass_jumps (void) |
a0134312 RS |
6547 | { |
6548 | int changed; | |
6549 | ||
6550 | /* We do not construct an accurate cfg in functions which call | |
6551 | setjmp, so just punt to be safe. */ | |
6552 | if (current_function_calls_setjmp) | |
6553 | return 0; | |
6554 | ||
a0134312 RS |
6555 | /* Identify the basic block information for this function, including |
6556 | successors and predecessors. */ | |
6557 | max_gcse_regno = max_reg_num (); | |
6558 | ||
10d22567 | 6559 | if (dump_file) |
5b4fdb20 | 6560 | dump_flow_info (dump_file, dump_flags); |
a0134312 | 6561 | |
6614fd40 | 6562 | /* Return if there's nothing to do, or it is too expensive. */ |
ab9a1ff8 SB |
6563 | if (n_basic_blocks <= NUM_FIXED_BLOCKS + 1 |
6564 | || is_too_expensive (_ ("jump bypassing disabled"))) | |
a0134312 RS |
6565 | return 0; |
6566 | ||
a0134312 RS |
6567 | gcc_obstack_init (&gcse_obstack); |
6568 | bytes_used = 0; | |
6569 | ||
6570 | /* We need alias. */ | |
6571 | init_alias_analysis (); | |
6572 | ||
6573 | /* Record where pseudo-registers are set. This data is kept accurate | |
6574 | during each pass. ??? We could also record hard-reg information here | |
6575 | [since it's unchanging], however it is currently done during hash table | |
6576 | computation. | |
6577 | ||
6578 | It may be tempting to compute MEM set information here too, but MEM sets | |
6579 | will be subject to code motion one day and thus we need to compute | |
6580 | information about memory sets when we build the hash tables. */ | |
6581 | ||
6582 | alloc_reg_set_mem (max_gcse_regno); | |
eb232f4e | 6583 | compute_sets (); |
a0134312 RS |
6584 | |
6585 | max_gcse_regno = max_reg_num (); | |
eb232f4e SB |
6586 | alloc_gcse_mem (); |
6587 | changed = one_cprop_pass (MAX_GCSE_PASSES + 2, true, true); | |
a0134312 RS |
6588 | free_gcse_mem (); |
6589 | ||
10d22567 | 6590 | if (dump_file) |
a0134312 | 6591 | { |
10d22567 | 6592 | fprintf (dump_file, "BYPASS of %s: %d basic blocks, ", |
faed5cc3 | 6593 | current_function_name (), n_basic_blocks); |
10d22567 | 6594 | fprintf (dump_file, "%d bytes\n\n", bytes_used); |
a0134312 RS |
6595 | } |
6596 | ||
6597 | obstack_free (&gcse_obstack, NULL); | |
6598 | free_reg_set_mem (); | |
6599 | ||
6600 | /* We are finished with alias. */ | |
6601 | end_alias_analysis (); | |
a0134312 RS |
6602 | |
6603 | return changed; | |
6604 | } | |
6605 | ||
d128effb NS |
6606 | /* Return true if the graph is too expensive to optimize. PASS is the |
6607 | optimization about to be performed. */ | |
6608 | ||
6609 | static bool | |
6610 | is_too_expensive (const char *pass) | |
6611 | { | |
6612 | /* Trying to perform global optimizations on flow graphs which have | |
6613 | a high connectivity will take a long time and is unlikely to be | |
6614 | particularly useful. | |
7b1b4aed | 6615 | |
d128effb NS |
6616 | In normal circumstances a cfg should have about twice as many |
6617 | edges as blocks. But we do not want to punish small functions | |
6618 | which have a couple switch statements. Rather than simply | |
6619 | threshold the number of blocks, uses something with a more | |
6620 | graceful degradation. */ | |
6621 | if (n_edges > 20000 + n_basic_blocks * 4) | |
6622 | { | |
44c21c7f DD |
6623 | warning (OPT_Wdisabled_optimization, |
6624 | "%s: %d basic blocks and %d edges/basic block", | |
6625 | pass, n_basic_blocks, n_edges / n_basic_blocks); | |
7b1b4aed | 6626 | |
d128effb NS |
6627 | return true; |
6628 | } | |
6629 | ||
6630 | /* If allocating memory for the cprop bitmap would take up too much | |
6631 | storage it's better just to disable the optimization. */ | |
6632 | if ((n_basic_blocks | |
6633 | * SBITMAP_SET_SIZE (max_reg_num ()) | |
6634 | * sizeof (SBITMAP_ELT_TYPE)) > MAX_GCSE_MEMORY) | |
6635 | { | |
44c21c7f DD |
6636 | warning (OPT_Wdisabled_optimization, |
6637 | "%s: %d basic blocks and %d registers", | |
6638 | pass, n_basic_blocks, max_reg_num ()); | |
d128effb NS |
6639 | |
6640 | return true; | |
6641 | } | |
6642 | ||
6643 | return false; | |
6644 | } | |
ef330312 PB |
6645 | \f |
6646 | static bool | |
6647 | gate_handle_jump_bypass (void) | |
6648 | { | |
6649 | return optimize > 0 && flag_gcse; | |
6650 | } | |
6651 | ||
6652 | /* Perform jump bypassing and control flow optimizations. */ | |
c2924966 | 6653 | static unsigned int |
ef330312 PB |
6654 | rest_of_handle_jump_bypass (void) |
6655 | { | |
6fb5fa3c | 6656 | delete_unreachable_blocks (); |
10d22567 | 6657 | if (bypass_jumps ()) |
ef330312 | 6658 | { |
ef330312 | 6659 | delete_trivially_dead_insns (get_insns (), max_reg_num ()); |
6fb5fa3c DB |
6660 | rebuild_jump_labels (get_insns ()); |
6661 | cleanup_cfg (0); | |
ef330312 | 6662 | } |
c2924966 | 6663 | return 0; |
ef330312 PB |
6664 | } |
6665 | ||
6666 | struct tree_opt_pass pass_jump_bypass = | |
6667 | { | |
6668 | "bypass", /* name */ | |
6669 | gate_handle_jump_bypass, /* gate */ | |
6670 | rest_of_handle_jump_bypass, /* execute */ | |
6671 | NULL, /* sub */ | |
6672 | NULL, /* next */ | |
6673 | 0, /* static_pass_number */ | |
6674 | TV_BYPASS, /* tv_id */ | |
6675 | 0, /* properties_required */ | |
6676 | 0, /* properties_provided */ | |
6677 | 0, /* properties_destroyed */ | |
6678 | 0, /* todo_flags_start */ | |
6679 | TODO_dump_func | | |
6680 | TODO_ggc_collect | TODO_verify_flow, /* todo_flags_finish */ | |
6681 | 'G' /* letter */ | |
6682 | }; | |
6683 | ||
6684 | ||
6685 | static bool | |
6686 | gate_handle_gcse (void) | |
6687 | { | |
6688 | return optimize > 0 && flag_gcse; | |
6689 | } | |
6690 | ||
6691 | ||
c2924966 | 6692 | static unsigned int |
ef330312 PB |
6693 | rest_of_handle_gcse (void) |
6694 | { | |
6695 | int save_csb, save_cfj; | |
6696 | int tem2 = 0, tem; | |
10d22567 | 6697 | tem = gcse_main (get_insns ()); |
ef330312 | 6698 | delete_trivially_dead_insns (get_insns (), max_reg_num ()); |
6fb5fa3c | 6699 | rebuild_jump_labels (get_insns ()); |
ef330312 PB |
6700 | save_csb = flag_cse_skip_blocks; |
6701 | save_cfj = flag_cse_follow_jumps; | |
6702 | flag_cse_skip_blocks = flag_cse_follow_jumps = 0; | |
6703 | ||
6704 | /* If -fexpensive-optimizations, re-run CSE to clean up things done | |
6705 | by gcse. */ | |
6706 | if (flag_expensive_optimizations) | |
6707 | { | |
6708 | timevar_push (TV_CSE); | |
10d22567 | 6709 | tem2 = cse_main (get_insns (), max_reg_num ()); |
8b9d606b | 6710 | df_finish_pass (); |
ef330312 PB |
6711 | purge_all_dead_edges (); |
6712 | delete_trivially_dead_insns (get_insns (), max_reg_num ()); | |
6713 | timevar_pop (TV_CSE); | |
6714 | cse_not_expected = !flag_rerun_cse_after_loop; | |
6715 | } | |
6716 | ||
6717 | /* If gcse or cse altered any jumps, rerun jump optimizations to clean | |
6718 | things up. */ | |
6719 | if (tem || tem2) | |
6720 | { | |
6721 | timevar_push (TV_JUMP); | |
6722 | rebuild_jump_labels (get_insns ()); | |
6fb5fa3c | 6723 | cleanup_cfg (0); |
ef330312 PB |
6724 | timevar_pop (TV_JUMP); |
6725 | } | |
6726 | ||
6727 | flag_cse_skip_blocks = save_csb; | |
6728 | flag_cse_follow_jumps = save_cfj; | |
c2924966 | 6729 | return 0; |
ef330312 PB |
6730 | } |
6731 | ||
6732 | struct tree_opt_pass pass_gcse = | |
6733 | { | |
6734 | "gcse1", /* name */ | |
6735 | gate_handle_gcse, /* gate */ | |
6736 | rest_of_handle_gcse, /* execute */ | |
6737 | NULL, /* sub */ | |
6738 | NULL, /* next */ | |
6739 | 0, /* static_pass_number */ | |
6740 | TV_GCSE, /* tv_id */ | |
6741 | 0, /* properties_required */ | |
6742 | 0, /* properties_provided */ | |
6743 | 0, /* properties_destroyed */ | |
6744 | 0, /* todo_flags_start */ | |
6fb5fa3c | 6745 | TODO_df_finish | |
ef330312 PB |
6746 | TODO_dump_func | |
6747 | TODO_verify_flow | TODO_ggc_collect, /* todo_flags_finish */ | |
6748 | 'G' /* letter */ | |
6749 | }; | |
6750 | ||
d128effb | 6751 | |
e2500fed | 6752 | #include "gt-gcse.h" |