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f4e584dc | 1 | /* Global common subexpression elimination/Partial redundancy elimination |
7506f491 | 2 | and global constant/copy propagation for GNU compiler. |
8e42ace1 KH |
3 | Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 |
4 | 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 LB |
19 | along with GCC; see the file COPYING. If not, write to the Free |
20 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
21 | 02111-1307, 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" |
01198c2f | 148 | #include "toplev.h" |
7506f491 DE |
149 | |
150 | #include "rtl.h" | |
6baf1cc8 | 151 | #include "tm_p.h" |
7506f491 DE |
152 | #include "regs.h" |
153 | #include "hard-reg-set.h" | |
154 | #include "flags.h" | |
155 | #include "real.h" | |
156 | #include "insn-config.h" | |
157 | #include "recog.h" | |
158 | #include "basic-block.h" | |
50b2596f | 159 | #include "output.h" |
49ad7cfa | 160 | #include "function.h" |
3cdbd1f8 | 161 | #include "expr.h" |
e7d482b9 | 162 | #include "except.h" |
fb0c0a12 | 163 | #include "ggc.h" |
f1fa37ff | 164 | #include "params.h" |
aaa4ca30 | 165 | |
7506f491 DE |
166 | #include "obstack.h" |
167 | #define obstack_chunk_alloc gmalloc | |
168 | #define obstack_chunk_free free | |
169 | ||
7506f491 DE |
170 | /* Propagate flow information through back edges and thus enable PRE's |
171 | moving loop invariant calculations out of loops. | |
172 | ||
173 | Originally this tended to create worse overall code, but several | |
174 | improvements during the development of PRE seem to have made following | |
175 | back edges generally a win. | |
176 | ||
177 | Note much of the loop invariant code motion done here would normally | |
178 | be done by loop.c, which has more heuristics for when to move invariants | |
179 | out of loops. At some point we might need to move some of those | |
180 | heuristics into gcse.c. */ | |
181 | #define FOLLOW_BACK_EDGES 1 | |
182 | ||
f4e584dc JL |
183 | /* We support GCSE via Partial Redundancy Elimination. PRE optimizations |
184 | are a superset of those done by GCSE. | |
7506f491 | 185 | |
f4e584dc | 186 | We perform the following steps: |
7506f491 DE |
187 | |
188 | 1) Compute basic block information. | |
189 | ||
190 | 2) Compute table of places where registers are set. | |
191 | ||
192 | 3) Perform copy/constant propagation. | |
193 | ||
194 | 4) Perform global cse. | |
195 | ||
e78d9500 | 196 | 5) Perform another pass of copy/constant propagation. |
7506f491 DE |
197 | |
198 | Two passes of copy/constant propagation are done because the first one | |
199 | enables more GCSE and the second one helps to clean up the copies that | |
200 | GCSE creates. This is needed more for PRE than for Classic because Classic | |
201 | GCSE will try to use an existing register containing the common | |
202 | subexpression rather than create a new one. This is harder to do for PRE | |
203 | because of the code motion (which Classic GCSE doesn't do). | |
204 | ||
205 | Expressions we are interested in GCSE-ing are of the form | |
206 | (set (pseudo-reg) (expression)). | |
207 | Function want_to_gcse_p says what these are. | |
208 | ||
209 | PRE handles moving invariant expressions out of loops (by treating them as | |
f4e584dc | 210 | partially redundant). |
7506f491 DE |
211 | |
212 | Eventually it would be nice to replace cse.c/gcse.c with SSA (static single | |
213 | assignment) based GVN (global value numbering). L. T. Simpson's paper | |
214 | (Rice University) on value numbering is a useful reference for this. | |
215 | ||
216 | ********************** | |
217 | ||
218 | We used to support multiple passes but there are diminishing returns in | |
219 | doing so. The first pass usually makes 90% of the changes that are doable. | |
220 | A second pass can make a few more changes made possible by the first pass. | |
221 | Experiments show any further passes don't make enough changes to justify | |
222 | the expense. | |
223 | ||
224 | A study of spec92 using an unlimited number of passes: | |
225 | [1 pass] = 1208 substitutions, [2] = 577, [3] = 202, [4] = 192, [5] = 83, | |
226 | [6] = 34, [7] = 17, [8] = 9, [9] = 4, [10] = 4, [11] = 2, | |
227 | [12] = 2, [13] = 1, [15] = 1, [16] = 2, [41] = 1 | |
228 | ||
229 | It was found doing copy propagation between each pass enables further | |
230 | substitutions. | |
231 | ||
232 | PRE is quite expensive in complicated functions because the DFA can take | |
740f35a0 | 233 | awhile to converge. Hence we only perform one pass. The parameter max-gcse-passes can |
7506f491 DE |
234 | be modified if one wants to experiment. |
235 | ||
236 | ********************** | |
237 | ||
238 | The steps for PRE are: | |
239 | ||
240 | 1) Build the hash table of expressions we wish to GCSE (expr_hash_table). | |
241 | ||
242 | 2) Perform the data flow analysis for PRE. | |
243 | ||
244 | 3) Delete the redundant instructions | |
245 | ||
246 | 4) Insert the required copies [if any] that make the partially | |
247 | redundant instructions fully redundant. | |
248 | ||
249 | 5) For other reaching expressions, insert an instruction to copy the value | |
250 | to a newly created pseudo that will reach the redundant instruction. | |
251 | ||
252 | The deletion is done first so that when we do insertions we | |
253 | know which pseudo reg to use. | |
254 | ||
255 | Various papers have argued that PRE DFA is expensive (O(n^2)) and others | |
256 | argue it is not. The number of iterations for the algorithm to converge | |
257 | is typically 2-4 so I don't view it as that expensive (relatively speaking). | |
258 | ||
f4e584dc | 259 | PRE GCSE depends heavily on the second CSE pass to clean up the copies |
7506f491 DE |
260 | we create. To make an expression reach the place where it's redundant, |
261 | the result of the expression is copied to a new register, and the redundant | |
262 | expression is deleted by replacing it with this new register. Classic GCSE | |
263 | doesn't have this problem as much as it computes the reaching defs of | |
264 | each register in each block and thus can try to use an existing register. | |
265 | ||
266 | ********************** | |
267 | ||
7506f491 DE |
268 | A fair bit of simplicity is created by creating small functions for simple |
269 | tasks, even when the function is only called in one place. This may | |
270 | measurably slow things down [or may not] by creating more function call | |
271 | overhead than is necessary. The source is laid out so that it's trivial | |
272 | to make the affected functions inline so that one can measure what speed | |
273 | up, if any, can be achieved, and maybe later when things settle things can | |
274 | be rearranged. | |
275 | ||
276 | Help stamp out big monolithic functions! */ | |
277 | \f | |
278 | /* GCSE global vars. */ | |
279 | ||
280 | /* -dG dump file. */ | |
281 | static FILE *gcse_file; | |
282 | ||
f4e584dc JL |
283 | /* Note whether or not we should run jump optimization after gcse. We |
284 | want to do this for two cases. | |
285 | ||
286 | * If we changed any jumps via cprop. | |
287 | ||
288 | * If we added any labels via edge splitting. */ | |
289 | ||
290 | static int run_jump_opt_after_gcse; | |
291 | ||
7506f491 DE |
292 | /* Bitmaps are normally not included in debugging dumps. |
293 | However it's useful to be able to print them from GDB. | |
294 | We could create special functions for this, but it's simpler to | |
295 | just allow passing stderr to the dump_foo fns. Since stderr can | |
296 | be a macro, we store a copy here. */ | |
297 | static FILE *debug_stderr; | |
298 | ||
299 | /* An obstack for our working variables. */ | |
300 | static struct obstack gcse_obstack; | |
301 | ||
302 | /* Non-zero for each mode that supports (set (reg) (reg)). | |
303 | This is trivially true for integer and floating point values. | |
304 | It may or may not be true for condition codes. */ | |
305 | static char can_copy_p[(int) NUM_MACHINE_MODES]; | |
306 | ||
307 | /* Non-zero if can_copy_p has been initialized. */ | |
308 | static int can_copy_init_p; | |
309 | ||
c4c81601 | 310 | struct reg_use {rtx reg_rtx; }; |
abd535b6 | 311 | |
7506f491 DE |
312 | /* Hash table of expressions. */ |
313 | ||
314 | struct expr | |
315 | { | |
316 | /* The expression (SET_SRC for expressions, PATTERN for assignments). */ | |
317 | rtx expr; | |
318 | /* Index in the available expression bitmaps. */ | |
319 | int bitmap_index; | |
320 | /* Next entry with the same hash. */ | |
321 | struct expr *next_same_hash; | |
322 | /* List of anticipatable occurrences in basic blocks in the function. | |
323 | An "anticipatable occurrence" is one that is the first occurrence in the | |
f4e584dc JL |
324 | basic block, the operands are not modified in the basic block prior |
325 | to the occurrence and the output is not used between the start of | |
326 | the block and the occurrence. */ | |
7506f491 DE |
327 | struct occr *antic_occr; |
328 | /* List of available occurrence in basic blocks in the function. | |
329 | An "available occurrence" is one that is the last occurrence in the | |
330 | basic block and the operands are not modified by following statements in | |
331 | the basic block [including this insn]. */ | |
332 | struct occr *avail_occr; | |
333 | /* Non-null if the computation is PRE redundant. | |
334 | The value is the newly created pseudo-reg to record a copy of the | |
335 | expression in all the places that reach the redundant copy. */ | |
336 | rtx reaching_reg; | |
337 | }; | |
338 | ||
339 | /* Occurrence of an expression. | |
340 | There is one per basic block. If a pattern appears more than once the | |
341 | last appearance is used [or first for anticipatable expressions]. */ | |
342 | ||
343 | struct occr | |
344 | { | |
345 | /* Next occurrence of this expression. */ | |
346 | struct occr *next; | |
347 | /* The insn that computes the expression. */ | |
348 | rtx insn; | |
349 | /* Non-zero if this [anticipatable] occurrence has been deleted. */ | |
350 | char deleted_p; | |
351 | /* Non-zero if this [available] occurrence has been copied to | |
352 | reaching_reg. */ | |
353 | /* ??? This is mutually exclusive with deleted_p, so they could share | |
354 | the same byte. */ | |
355 | char copied_p; | |
356 | }; | |
357 | ||
358 | /* Expression and copy propagation hash tables. | |
359 | Each hash table is an array of buckets. | |
360 | ??? It is known that if it were an array of entries, structure elements | |
361 | `next_same_hash' and `bitmap_index' wouldn't be necessary. However, it is | |
362 | not clear whether in the final analysis a sufficient amount of memory would | |
363 | be saved as the size of the available expression bitmaps would be larger | |
364 | [one could build a mapping table without holes afterwards though]. | |
c4c81601 | 365 | Someday I'll perform the computation and figure it out. */ |
7506f491 DE |
366 | |
367 | /* Total size of the expression hash table, in elements. */ | |
2e653e39 RK |
368 | static unsigned int expr_hash_table_size; |
369 | ||
7506f491 DE |
370 | /* The table itself. |
371 | This is an array of `expr_hash_table_size' elements. */ | |
372 | static struct expr **expr_hash_table; | |
373 | ||
374 | /* Total size of the copy propagation hash table, in elements. */ | |
ebb13e7e | 375 | static unsigned int set_hash_table_size; |
c4c81601 | 376 | |
7506f491 DE |
377 | /* The table itself. |
378 | This is an array of `set_hash_table_size' elements. */ | |
379 | static struct expr **set_hash_table; | |
380 | ||
381 | /* Mapping of uids to cuids. | |
382 | Only real insns get cuids. */ | |
383 | static int *uid_cuid; | |
384 | ||
385 | /* Highest UID in UID_CUID. */ | |
386 | static int max_uid; | |
387 | ||
388 | /* Get the cuid of an insn. */ | |
b86db3eb BS |
389 | #ifdef ENABLE_CHECKING |
390 | #define INSN_CUID(INSN) (INSN_UID (INSN) > max_uid ? (abort (), 0) : uid_cuid[INSN_UID (INSN)]) | |
391 | #else | |
7506f491 | 392 | #define INSN_CUID(INSN) (uid_cuid[INSN_UID (INSN)]) |
b86db3eb | 393 | #endif |
7506f491 DE |
394 | |
395 | /* Number of cuids. */ | |
396 | static int max_cuid; | |
397 | ||
398 | /* Mapping of cuids to insns. */ | |
399 | static rtx *cuid_insn; | |
400 | ||
401 | /* Get insn from cuid. */ | |
402 | #define CUID_INSN(CUID) (cuid_insn[CUID]) | |
403 | ||
404 | /* Maximum register number in function prior to doing gcse + 1. | |
405 | Registers created during this pass have regno >= max_gcse_regno. | |
406 | This is named with "gcse" to not collide with global of same name. */ | |
770ae6cc | 407 | static unsigned int max_gcse_regno; |
7506f491 DE |
408 | |
409 | /* Maximum number of cse-able expressions found. */ | |
410 | static int n_exprs; | |
c4c81601 | 411 | |
7506f491 DE |
412 | /* Maximum number of assignments for copy propagation found. */ |
413 | static int n_sets; | |
414 | ||
415 | /* Table of registers that are modified. | |
c4c81601 | 416 | |
7506f491 DE |
417 | For each register, each element is a list of places where the pseudo-reg |
418 | is set. | |
419 | ||
420 | For simplicity, GCSE is done on sets of pseudo-regs only. PRE GCSE only | |
421 | requires knowledge of which blocks kill which regs [and thus could use | |
f4e584dc | 422 | a bitmap instead of the lists `reg_set_table' uses]. |
7506f491 | 423 | |
c4c81601 RK |
424 | `reg_set_table' and could be turned into an array of bitmaps (num-bbs x |
425 | num-regs) [however perhaps it may be useful to keep the data as is]. One | |
426 | advantage of recording things this way is that `reg_set_table' is fairly | |
427 | sparse with respect to pseudo regs but for hard regs could be fairly dense | |
428 | [relatively speaking]. And recording sets of pseudo-regs in lists speeds | |
7506f491 DE |
429 | up functions like compute_transp since in the case of pseudo-regs we only |
430 | need to iterate over the number of times a pseudo-reg is set, not over the | |
431 | number of basic blocks [clearly there is a bit of a slow down in the cases | |
432 | where a pseudo is set more than once in a block, however it is believed | |
433 | that the net effect is to speed things up]. This isn't done for hard-regs | |
434 | because recording call-clobbered hard-regs in `reg_set_table' at each | |
c4c81601 RK |
435 | function call can consume a fair bit of memory, and iterating over |
436 | hard-regs stored this way in compute_transp will be more expensive. */ | |
7506f491 | 437 | |
c4c81601 RK |
438 | typedef struct reg_set |
439 | { | |
7506f491 DE |
440 | /* The next setting of this register. */ |
441 | struct reg_set *next; | |
442 | /* The insn where it was set. */ | |
443 | rtx insn; | |
444 | } reg_set; | |
c4c81601 | 445 | |
7506f491 | 446 | static reg_set **reg_set_table; |
c4c81601 | 447 | |
7506f491 DE |
448 | /* Size of `reg_set_table'. |
449 | The table starts out at max_gcse_regno + slop, and is enlarged as | |
450 | necessary. */ | |
451 | static int reg_set_table_size; | |
c4c81601 | 452 | |
7506f491 DE |
453 | /* Amount to grow `reg_set_table' by when it's full. */ |
454 | #define REG_SET_TABLE_SLOP 100 | |
455 | ||
a13d4ebf AM |
456 | /* This is a list of expressions which are MEMs and will be used by load |
457 | or store motion. | |
458 | Load motion tracks MEMs which aren't killed by | |
459 | anything except itself. (ie, loads and stores to a single location). | |
460 | We can then allow movement of these MEM refs with a little special | |
461 | allowance. (all stores copy the same value to the reaching reg used | |
462 | for the loads). This means all values used to store into memory must have | |
463 | no side effects so we can re-issue the setter value. | |
464 | Store Motion uses this structure as an expression table to track stores | |
465 | which look interesting, and might be moveable towards the exit block. */ | |
466 | ||
467 | struct ls_expr | |
468 | { | |
469 | struct expr * expr; /* Gcse expression reference for LM. */ | |
470 | rtx pattern; /* Pattern of this mem. */ | |
aaa4ca30 AJ |
471 | rtx loads; /* INSN list of loads seen. */ |
472 | rtx stores; /* INSN list of stores seen. */ | |
a13d4ebf AM |
473 | struct ls_expr * next; /* Next in the list. */ |
474 | int invalid; /* Invalid for some reason. */ | |
475 | int index; /* If it maps to a bitmap index. */ | |
476 | int hash_index; /* Index when in a hash table. */ | |
477 | rtx reaching_reg; /* Register to use when re-writing. */ | |
478 | }; | |
479 | ||
480 | /* Head of the list of load/store memory refs. */ | |
481 | static struct ls_expr * pre_ldst_mems = NULL; | |
482 | ||
7506f491 DE |
483 | /* Bitmap containing one bit for each register in the program. |
484 | Used when performing GCSE to track which registers have been set since | |
485 | the start of the basic block. */ | |
73991d6a | 486 | static regset reg_set_bitmap; |
7506f491 DE |
487 | |
488 | /* For each block, a bitmap of registers set in the block. | |
489 | This is used by expr_killed_p and compute_transp. | |
490 | It is computed during hash table computation and not by compute_sets | |
491 | as it includes registers added since the last pass (or between cprop and | |
492 | gcse) and it's currently not easy to realloc sbitmap vectors. */ | |
493 | static sbitmap *reg_set_in_block; | |
494 | ||
a13d4ebf AM |
495 | /* Array, indexed by basic block number for a list of insns which modify |
496 | memory within that block. */ | |
497 | static rtx * modify_mem_list; | |
73991d6a | 498 | bitmap modify_mem_list_set; |
a13d4ebf AM |
499 | |
500 | /* This array parallels modify_mem_list, but is kept canonicalized. */ | |
501 | static rtx * canon_modify_mem_list; | |
73991d6a | 502 | bitmap canon_modify_mem_list_set; |
7506f491 DE |
503 | /* Various variables for statistics gathering. */ |
504 | ||
505 | /* Memory used in a pass. | |
506 | This isn't intended to be absolutely precise. Its intent is only | |
507 | to keep an eye on memory usage. */ | |
508 | static int bytes_used; | |
c4c81601 | 509 | |
7506f491 DE |
510 | /* GCSE substitutions made. */ |
511 | static int gcse_subst_count; | |
512 | /* Number of copy instructions created. */ | |
513 | static int gcse_create_count; | |
514 | /* Number of constants propagated. */ | |
515 | static int const_prop_count; | |
516 | /* Number of copys propagated. */ | |
517 | static int copy_prop_count; | |
7506f491 DE |
518 | \f |
519 | /* These variables are used by classic GCSE. | |
520 | Normally they'd be defined a bit later, but `rd_gen' needs to | |
521 | be declared sooner. */ | |
522 | ||
7506f491 DE |
523 | /* Each block has a bitmap of each type. |
524 | The length of each blocks bitmap is: | |
525 | ||
526 | max_cuid - for reaching definitions | |
527 | n_exprs - for available expressions | |
528 | ||
529 | Thus we view the bitmaps as 2 dimensional arrays. i.e. | |
530 | rd_kill[block_num][cuid_num] | |
c4c81601 | 531 | ae_kill[block_num][expr_num] */ |
7506f491 DE |
532 | |
533 | /* For reaching defs */ | |
534 | static sbitmap *rd_kill, *rd_gen, *reaching_defs, *rd_out; | |
535 | ||
536 | /* for available exprs */ | |
537 | static sbitmap *ae_kill, *ae_gen, *ae_in, *ae_out; | |
b5ce41ff | 538 | |
0511851c MM |
539 | /* Objects of this type are passed around by the null-pointer check |
540 | removal routines. */ | |
c4c81601 RK |
541 | struct null_pointer_info |
542 | { | |
0511851c | 543 | /* The basic block being processed. */ |
e0082a72 | 544 | basic_block current_block; |
0511851c | 545 | /* The first register to be handled in this pass. */ |
770ae6cc | 546 | unsigned int min_reg; |
0511851c | 547 | /* One greater than the last register to be handled in this pass. */ |
770ae6cc | 548 | unsigned int max_reg; |
0511851c MM |
549 | sbitmap *nonnull_local; |
550 | sbitmap *nonnull_killed; | |
551 | }; | |
7506f491 | 552 | \f |
c4c81601 RK |
553 | static void compute_can_copy PARAMS ((void)); |
554 | static char *gmalloc PARAMS ((unsigned int)); | |
555 | static char *grealloc PARAMS ((char *, unsigned int)); | |
556 | static char *gcse_alloc PARAMS ((unsigned long)); | |
557 | static void alloc_gcse_mem PARAMS ((rtx)); | |
558 | static void free_gcse_mem PARAMS ((void)); | |
559 | static void alloc_reg_set_mem PARAMS ((int)); | |
560 | static void free_reg_set_mem PARAMS ((void)); | |
561 | static int get_bitmap_width PARAMS ((int, int, int)); | |
562 | static void record_one_set PARAMS ((int, rtx)); | |
563 | static void record_set_info PARAMS ((rtx, rtx, void *)); | |
564 | static void compute_sets PARAMS ((rtx)); | |
565 | static void hash_scan_insn PARAMS ((rtx, int, int)); | |
566 | static void hash_scan_set PARAMS ((rtx, rtx, int)); | |
567 | static void hash_scan_clobber PARAMS ((rtx, rtx)); | |
568 | static void hash_scan_call PARAMS ((rtx, rtx)); | |
569 | static int want_to_gcse_p PARAMS ((rtx)); | |
570 | static int oprs_unchanged_p PARAMS ((rtx, rtx, int)); | |
571 | static int oprs_anticipatable_p PARAMS ((rtx, rtx)); | |
572 | static int oprs_available_p PARAMS ((rtx, rtx)); | |
573 | static void insert_expr_in_table PARAMS ((rtx, enum machine_mode, rtx, | |
574 | int, int)); | |
575 | static void insert_set_in_table PARAMS ((rtx, rtx)); | |
576 | static unsigned int hash_expr PARAMS ((rtx, enum machine_mode, int *, int)); | |
577 | static unsigned int hash_expr_1 PARAMS ((rtx, enum machine_mode, int *)); | |
c0712acb | 578 | static unsigned int hash_string_1 PARAMS ((const char *)); |
c4c81601 RK |
579 | static unsigned int hash_set PARAMS ((int, int)); |
580 | static int expr_equiv_p PARAMS ((rtx, rtx)); | |
581 | static void record_last_reg_set_info PARAMS ((rtx, int)); | |
582 | static void record_last_mem_set_info PARAMS ((rtx)); | |
583 | static void record_last_set_info PARAMS ((rtx, rtx, void *)); | |
711d877c | 584 | static void compute_hash_table PARAMS ((int)); |
c4c81601 RK |
585 | static void alloc_set_hash_table PARAMS ((int)); |
586 | static void free_set_hash_table PARAMS ((void)); | |
587 | static void compute_set_hash_table PARAMS ((void)); | |
2e653e39 | 588 | static void alloc_expr_hash_table PARAMS ((unsigned int)); |
c4c81601 RK |
589 | static void free_expr_hash_table PARAMS ((void)); |
590 | static void compute_expr_hash_table PARAMS ((void)); | |
591 | static void dump_hash_table PARAMS ((FILE *, const char *, struct expr **, | |
592 | int, int)); | |
593 | static struct expr *lookup_expr PARAMS ((rtx)); | |
770ae6cc RK |
594 | static struct expr *lookup_set PARAMS ((unsigned int, rtx)); |
595 | static struct expr *next_set PARAMS ((unsigned int, struct expr *)); | |
c4c81601 RK |
596 | static void reset_opr_set_tables PARAMS ((void)); |
597 | static int oprs_not_set_p PARAMS ((rtx, rtx)); | |
598 | static void mark_call PARAMS ((rtx)); | |
599 | static void mark_set PARAMS ((rtx, rtx)); | |
600 | static void mark_clobber PARAMS ((rtx, rtx)); | |
601 | static void mark_oprs_set PARAMS ((rtx)); | |
602 | static void alloc_cprop_mem PARAMS ((int, int)); | |
603 | static void free_cprop_mem PARAMS ((void)); | |
604 | static void compute_transp PARAMS ((rtx, int, sbitmap *, int)); | |
605 | static void compute_transpout PARAMS ((void)); | |
606 | static void compute_local_properties PARAMS ((sbitmap *, sbitmap *, sbitmap *, | |
607 | int)); | |
711d877c | 608 | static void compute_cprop_data PARAMS ((void)); |
9e71c818 | 609 | static void find_used_regs PARAMS ((rtx *, void *)); |
c4c81601 RK |
610 | static int try_replace_reg PARAMS ((rtx, rtx, rtx)); |
611 | static struct expr *find_avail_set PARAMS ((int, rtx)); | |
0e3f0221 | 612 | static int cprop_jump PARAMS ((basic_block, rtx, rtx, rtx, rtx)); |
a13d4ebf | 613 | static void mems_conflict_for_gcse_p PARAMS ((rtx, rtx, void *)); |
e2d2ed72 | 614 | static int load_killed_in_block_p PARAMS ((basic_block, int, rtx, int)); |
a13d4ebf | 615 | static void canon_list_insert PARAMS ((rtx, rtx, void *)); |
0005550b | 616 | static int cprop_insn PARAMS ((basic_block, rtx, int)); |
c4c81601 RK |
617 | static int cprop PARAMS ((int)); |
618 | static int one_cprop_pass PARAMS ((int, int)); | |
0e3f0221 RS |
619 | static struct expr *find_bypass_set PARAMS ((int, int)); |
620 | static int bypass_block PARAMS ((basic_block, rtx, rtx)); | |
621 | static int bypass_conditional_jumps PARAMS ((void)); | |
c4c81601 RK |
622 | static void alloc_pre_mem PARAMS ((int, int)); |
623 | static void free_pre_mem PARAMS ((void)); | |
624 | static void compute_pre_data PARAMS ((void)); | |
e2d2ed72 AM |
625 | static int pre_expr_reaches_here_p PARAMS ((basic_block, struct expr *, |
626 | basic_block)); | |
627 | static void insert_insn_end_bb PARAMS ((struct expr *, basic_block, int)); | |
c4c81601 RK |
628 | static void pre_insert_copy_insn PARAMS ((struct expr *, rtx)); |
629 | static void pre_insert_copies PARAMS ((void)); | |
630 | static int pre_delete PARAMS ((void)); | |
631 | static int pre_gcse PARAMS ((void)); | |
632 | static int one_pre_gcse_pass PARAMS ((int)); | |
633 | static void add_label_notes PARAMS ((rtx, rtx)); | |
634 | static void alloc_code_hoist_mem PARAMS ((int, int)); | |
635 | static void free_code_hoist_mem PARAMS ((void)); | |
711d877c | 636 | static void compute_code_hoist_vbeinout PARAMS ((void)); |
c4c81601 | 637 | static void compute_code_hoist_data PARAMS ((void)); |
e2d2ed72 AM |
638 | static int hoist_expr_reaches_here_p PARAMS ((basic_block, int, basic_block, |
639 | char *)); | |
c4c81601 RK |
640 | static void hoist_code PARAMS ((void)); |
641 | static int one_code_hoisting_pass PARAMS ((void)); | |
642 | static void alloc_rd_mem PARAMS ((int, int)); | |
643 | static void free_rd_mem PARAMS ((void)); | |
e2d2ed72 | 644 | static void handle_rd_kill_set PARAMS ((rtx, int, basic_block)); |
c4c81601 | 645 | static void compute_kill_rd PARAMS ((void)); |
711d877c | 646 | static void compute_rd PARAMS ((void)); |
c4c81601 RK |
647 | static void alloc_avail_expr_mem PARAMS ((int, int)); |
648 | static void free_avail_expr_mem PARAMS ((void)); | |
649 | static void compute_ae_gen PARAMS ((void)); | |
e2d2ed72 | 650 | static int expr_killed_p PARAMS ((rtx, basic_block)); |
c4c81601 | 651 | static void compute_ae_kill PARAMS ((sbitmap *, sbitmap *)); |
711d877c | 652 | static int expr_reaches_here_p PARAMS ((struct occr *, struct expr *, |
e2d2ed72 | 653 | basic_block, int)); |
c4c81601 RK |
654 | static rtx computing_insn PARAMS ((struct expr *, rtx)); |
655 | static int def_reaches_here_p PARAMS ((rtx, rtx)); | |
656 | static int can_disregard_other_sets PARAMS ((struct reg_set **, rtx, int)); | |
657 | static int handle_avail_expr PARAMS ((rtx, struct expr *)); | |
658 | static int classic_gcse PARAMS ((void)); | |
659 | static int one_classic_gcse_pass PARAMS ((int)); | |
660 | static void invalidate_nonnull_info PARAMS ((rtx, rtx, void *)); | |
9cd56be1 | 661 | static void delete_null_pointer_checks_1 PARAMS ((unsigned int *, |
8e184d9c | 662 | sbitmap *, sbitmap *, |
711d877c KG |
663 | struct null_pointer_info *)); |
664 | static rtx process_insert_insn PARAMS ((struct expr *)); | |
665 | static int pre_edge_insert PARAMS ((struct edge_list *, struct expr **)); | |
c4c81601 | 666 | static int expr_reaches_here_p_work PARAMS ((struct occr *, struct expr *, |
e2d2ed72 AM |
667 | basic_block, int, char *)); |
668 | static int pre_expr_reaches_here_p_work PARAMS ((basic_block, struct expr *, | |
669 | basic_block, char *)); | |
a13d4ebf AM |
670 | static struct ls_expr * ldst_entry PARAMS ((rtx)); |
671 | static void free_ldst_entry PARAMS ((struct ls_expr *)); | |
672 | static void free_ldst_mems PARAMS ((void)); | |
673 | static void print_ldst_list PARAMS ((FILE *)); | |
674 | static struct ls_expr * find_rtx_in_ldst PARAMS ((rtx)); | |
675 | static int enumerate_ldsts PARAMS ((void)); | |
676 | static inline struct ls_expr * first_ls_expr PARAMS ((void)); | |
677 | static inline struct ls_expr * next_ls_expr PARAMS ((struct ls_expr *)); | |
678 | static int simple_mem PARAMS ((rtx)); | |
679 | static void invalidate_any_buried_refs PARAMS ((rtx)); | |
680 | static void compute_ld_motion_mems PARAMS ((void)); | |
681 | static void trim_ld_motion_mems PARAMS ((void)); | |
682 | static void update_ld_motion_stores PARAMS ((struct expr *)); | |
aaa4ca30 AJ |
683 | static void reg_set_info PARAMS ((rtx, rtx, void *)); |
684 | static int store_ops_ok PARAMS ((rtx, basic_block)); | |
a13d4ebf AM |
685 | static void find_moveable_store PARAMS ((rtx)); |
686 | static int compute_store_table PARAMS ((void)); | |
687 | static int load_kills_store PARAMS ((rtx, rtx)); | |
688 | static int find_loads PARAMS ((rtx, rtx)); | |
689 | static int store_killed_in_insn PARAMS ((rtx, rtx)); | |
aaa4ca30 | 690 | static int store_killed_after PARAMS ((rtx, rtx, basic_block)); |
e2d2ed72 | 691 | static int store_killed_before PARAMS ((rtx, rtx, basic_block)); |
a13d4ebf | 692 | static void build_store_vectors PARAMS ((void)); |
e2d2ed72 | 693 | static void insert_insn_start_bb PARAMS ((rtx, basic_block)); |
a13d4ebf | 694 | static int insert_store PARAMS ((struct ls_expr *, edge)); |
e2d2ed72 AM |
695 | static void replace_store_insn PARAMS ((rtx, rtx, basic_block)); |
696 | static void delete_store PARAMS ((struct ls_expr *, | |
697 | basic_block)); | |
a13d4ebf AM |
698 | static void free_store_memory PARAMS ((void)); |
699 | static void store_motion PARAMS ((void)); | |
0fe854a7 | 700 | static void free_insn_expr_list_list PARAMS ((rtx *)); |
73991d6a JH |
701 | static void clear_modify_mem_tables PARAMS ((void)); |
702 | static void free_modify_mem_tables PARAMS ((void)); | |
10d1bb36 | 703 | static rtx gcse_emit_move_after PARAMS ((rtx, rtx, rtx)); |
7506f491 DE |
704 | \f |
705 | /* Entry point for global common subexpression elimination. | |
706 | F is the first instruction in the function. */ | |
707 | ||
e78d9500 | 708 | int |
7506f491 DE |
709 | gcse_main (f, file) |
710 | rtx f; | |
711 | FILE *file; | |
712 | { | |
713 | int changed, pass; | |
714 | /* Bytes used at start of pass. */ | |
715 | int initial_bytes_used; | |
716 | /* Maximum number of bytes used by a pass. */ | |
717 | int max_pass_bytes; | |
718 | /* Point to release obstack data from for each pass. */ | |
719 | char *gcse_obstack_bottom; | |
720 | ||
a13d4ebf AM |
721 | /* Insertion of instructions on edges can create new basic blocks; we |
722 | need the original basic block count so that we can properly deallocate | |
723 | arrays sized on the number of basic blocks originally in the cfg. */ | |
724 | int orig_bb_count; | |
b5ce41ff JL |
725 | /* We do not construct an accurate cfg in functions which call |
726 | setjmp, so just punt to be safe. */ | |
7506f491 | 727 | if (current_function_calls_setjmp) |
e78d9500 | 728 | return 0; |
7506f491 | 729 | |
b5ce41ff JL |
730 | /* Assume that we do not need to run jump optimizations after gcse. */ |
731 | run_jump_opt_after_gcse = 0; | |
732 | ||
7506f491 DE |
733 | /* For calling dump_foo fns from gdb. */ |
734 | debug_stderr = stderr; | |
b5ce41ff | 735 | gcse_file = file; |
7506f491 | 736 | |
b5ce41ff JL |
737 | /* Identify the basic block information for this function, including |
738 | successors and predecessors. */ | |
7506f491 | 739 | max_gcse_regno = max_reg_num (); |
7506f491 | 740 | |
a42cd965 AM |
741 | if (file) |
742 | dump_flow_info (file); | |
743 | ||
0b17ab2f | 744 | orig_bb_count = n_basic_blocks; |
7506f491 | 745 | /* Return if there's nothing to do. */ |
0b17ab2f | 746 | if (n_basic_blocks <= 1) |
a18820c6 | 747 | return 0; |
7506f491 | 748 | |
55f7891b JL |
749 | /* Trying to perform global optimizations on flow graphs which have |
750 | a high connectivity will take a long time and is unlikely to be | |
751 | particularly useful. | |
752 | ||
43e72072 | 753 | In normal circumstances a cfg should have about twice as many edges |
55f7891b JL |
754 | as blocks. But we do not want to punish small functions which have |
755 | a couple switch statements. So we require a relatively large number | |
756 | of basic blocks and the ratio of edges to blocks to be high. */ | |
0b17ab2f | 757 | if (n_basic_blocks > 1000 && n_edges / n_basic_blocks >= 20) |
18424ae1 BL |
758 | { |
759 | if (warn_disabled_optimization) | |
8e42ace1 | 760 | warning ("GCSE disabled: %d > 1000 basic blocks and %d >= 20 edges/basic block", |
0b17ab2f | 761 | n_basic_blocks, n_edges / n_basic_blocks); |
18424ae1 BL |
762 | return 0; |
763 | } | |
55f7891b | 764 | |
f1fa37ff MM |
765 | /* If allocating memory for the cprop bitmap would take up too much |
766 | storage it's better just to disable the optimization. */ | |
0b17ab2f | 767 | if ((n_basic_blocks |
f1fa37ff MM |
768 | * SBITMAP_SET_SIZE (max_gcse_regno) |
769 | * sizeof (SBITMAP_ELT_TYPE)) > MAX_GCSE_MEMORY) | |
770 | { | |
771 | if (warn_disabled_optimization) | |
772 | warning ("GCSE disabled: %d basic blocks and %d registers", | |
0b17ab2f | 773 | n_basic_blocks, max_gcse_regno); |
f1fa37ff MM |
774 | |
775 | return 0; | |
776 | } | |
777 | ||
7506f491 DE |
778 | /* See what modes support reg/reg copy operations. */ |
779 | if (! can_copy_init_p) | |
780 | { | |
781 | compute_can_copy (); | |
782 | can_copy_init_p = 1; | |
783 | } | |
784 | ||
785 | gcc_obstack_init (&gcse_obstack); | |
a42cd965 | 786 | bytes_used = 0; |
7506f491 | 787 | |
a13d4ebf AM |
788 | /* We need alias. */ |
789 | init_alias_analysis (); | |
c4c81601 RK |
790 | /* Record where pseudo-registers are set. This data is kept accurate |
791 | during each pass. ??? We could also record hard-reg information here | |
792 | [since it's unchanging], however it is currently done during hash table | |
793 | computation. | |
b5ce41ff | 794 | |
c4c81601 RK |
795 | It may be tempting to compute MEM set information here too, but MEM sets |
796 | will be subject to code motion one day and thus we need to compute | |
b5ce41ff | 797 | information about memory sets when we build the hash tables. */ |
7506f491 DE |
798 | |
799 | alloc_reg_set_mem (max_gcse_regno); | |
800 | compute_sets (f); | |
801 | ||
802 | pass = 0; | |
803 | initial_bytes_used = bytes_used; | |
804 | max_pass_bytes = 0; | |
805 | gcse_obstack_bottom = gcse_alloc (1); | |
806 | changed = 1; | |
740f35a0 | 807 | while (changed && pass < MAX_GCSE_PASSES) |
7506f491 DE |
808 | { |
809 | changed = 0; | |
810 | if (file) | |
811 | fprintf (file, "GCSE pass %d\n\n", pass + 1); | |
812 | ||
813 | /* Initialize bytes_used to the space for the pred/succ lists, | |
814 | and the reg_set_table data. */ | |
815 | bytes_used = initial_bytes_used; | |
816 | ||
817 | /* Each pass may create new registers, so recalculate each time. */ | |
818 | max_gcse_regno = max_reg_num (); | |
819 | ||
820 | alloc_gcse_mem (f); | |
821 | ||
b5ce41ff JL |
822 | /* Don't allow constant propagation to modify jumps |
823 | during this pass. */ | |
824 | changed = one_cprop_pass (pass + 1, 0); | |
7506f491 DE |
825 | |
826 | if (optimize_size) | |
b5ce41ff | 827 | changed |= one_classic_gcse_pass (pass + 1); |
7506f491 | 828 | else |
a42cd965 AM |
829 | { |
830 | changed |= one_pre_gcse_pass (pass + 1); | |
a13d4ebf AM |
831 | /* We may have just created new basic blocks. Release and |
832 | recompute various things which are sized on the number of | |
833 | basic blocks. */ | |
834 | if (changed) | |
835 | { | |
73991d6a | 836 | free_modify_mem_tables (); |
a13d4ebf | 837 | modify_mem_list |
d55bc081 | 838 | = (rtx *) gmalloc (last_basic_block * sizeof (rtx)); |
a13d4ebf | 839 | canon_modify_mem_list |
d55bc081 ZD |
840 | = (rtx *) gmalloc (last_basic_block * sizeof (rtx)); |
841 | memset ((char *) modify_mem_list, 0, last_basic_block * sizeof (rtx)); | |
842 | memset ((char *) canon_modify_mem_list, 0, last_basic_block * sizeof (rtx)); | |
0b17ab2f | 843 | orig_bb_count = n_basic_blocks; |
a13d4ebf | 844 | } |
a42cd965 AM |
845 | free_reg_set_mem (); |
846 | alloc_reg_set_mem (max_reg_num ()); | |
847 | compute_sets (f); | |
848 | run_jump_opt_after_gcse = 1; | |
849 | } | |
7506f491 DE |
850 | |
851 | if (max_pass_bytes < bytes_used) | |
852 | max_pass_bytes = bytes_used; | |
853 | ||
bb457bd9 JL |
854 | /* Free up memory, then reallocate for code hoisting. We can |
855 | not re-use the existing allocated memory because the tables | |
856 | will not have info for the insns or registers created by | |
857 | partial redundancy elimination. */ | |
7506f491 DE |
858 | free_gcse_mem (); |
859 | ||
bb457bd9 JL |
860 | /* It does not make sense to run code hoisting unless we optimizing |
861 | for code size -- it rarely makes programs faster, and can make | |
862 | them bigger if we did partial redundancy elimination (when optimizing | |
863 | for space, we use a classic gcse algorithm instead of partial | |
864 | redundancy algorithms). */ | |
865 | if (optimize_size) | |
866 | { | |
867 | max_gcse_regno = max_reg_num (); | |
868 | alloc_gcse_mem (f); | |
869 | changed |= one_code_hoisting_pass (); | |
870 | free_gcse_mem (); | |
871 | ||
872 | if (max_pass_bytes < bytes_used) | |
873 | max_pass_bytes = bytes_used; | |
874 | } | |
875 | ||
7506f491 DE |
876 | if (file) |
877 | { | |
878 | fprintf (file, "\n"); | |
879 | fflush (file); | |
880 | } | |
c4c81601 | 881 | |
7506f491 DE |
882 | obstack_free (&gcse_obstack, gcse_obstack_bottom); |
883 | pass++; | |
884 | } | |
885 | ||
b5ce41ff JL |
886 | /* Do one last pass of copy propagation, including cprop into |
887 | conditional jumps. */ | |
888 | ||
889 | max_gcse_regno = max_reg_num (); | |
890 | alloc_gcse_mem (f); | |
891 | /* This time, go ahead and allow cprop to alter jumps. */ | |
892 | one_cprop_pass (pass + 1, 1); | |
893 | free_gcse_mem (); | |
7506f491 DE |
894 | |
895 | if (file) | |
896 | { | |
897 | fprintf (file, "GCSE of %s: %d basic blocks, ", | |
0b17ab2f | 898 | current_function_name, n_basic_blocks); |
7506f491 DE |
899 | fprintf (file, "%d pass%s, %d bytes\n\n", |
900 | pass, pass > 1 ? "es" : "", max_pass_bytes); | |
901 | } | |
902 | ||
6496a589 | 903 | obstack_free (&gcse_obstack, NULL); |
7506f491 | 904 | free_reg_set_mem (); |
a13d4ebf AM |
905 | /* We are finished with alias. */ |
906 | end_alias_analysis (); | |
907 | allocate_reg_info (max_reg_num (), FALSE, FALSE); | |
908 | ||
61ad9a34 JJ |
909 | /* Store motion disabled until it is fixed. */ |
910 | if (0 && !optimize_size && flag_gcse_sm) | |
a13d4ebf AM |
911 | store_motion (); |
912 | /* Record where pseudo-registers are set. */ | |
e78d9500 | 913 | return run_jump_opt_after_gcse; |
7506f491 DE |
914 | } |
915 | \f | |
916 | /* Misc. utilities. */ | |
917 | ||
918 | /* Compute which modes support reg/reg copy operations. */ | |
919 | ||
920 | static void | |
921 | compute_can_copy () | |
922 | { | |
923 | int i; | |
50b2596f | 924 | #ifndef AVOID_CCMODE_COPIES |
8e42ace1 | 925 | rtx reg, insn; |
50b2596f | 926 | #endif |
961192e1 | 927 | memset (can_copy_p, 0, NUM_MACHINE_MODES); |
7506f491 DE |
928 | |
929 | start_sequence (); | |
930 | for (i = 0; i < NUM_MACHINE_MODES; i++) | |
c4c81601 RK |
931 | if (GET_MODE_CLASS (i) == MODE_CC) |
932 | { | |
7506f491 | 933 | #ifdef AVOID_CCMODE_COPIES |
c4c81601 | 934 | can_copy_p[i] = 0; |
7506f491 | 935 | #else |
c4c81601 RK |
936 | reg = gen_rtx_REG ((enum machine_mode) i, LAST_VIRTUAL_REGISTER + 1); |
937 | insn = emit_insn (gen_rtx_SET (VOIDmode, reg, reg)); | |
9714cf43 | 938 | if (recog (PATTERN (insn), insn, NULL) >= 0) |
c4c81601 | 939 | can_copy_p[i] = 1; |
7506f491 | 940 | #endif |
c4c81601 | 941 | } |
141b5810 AO |
942 | else |
943 | can_copy_p[i] = 1; | |
c4c81601 | 944 | |
7506f491 | 945 | end_sequence (); |
7506f491 DE |
946 | } |
947 | \f | |
948 | /* Cover function to xmalloc to record bytes allocated. */ | |
949 | ||
950 | static char * | |
951 | gmalloc (size) | |
952 | unsigned int size; | |
953 | { | |
954 | bytes_used += size; | |
955 | return xmalloc (size); | |
956 | } | |
957 | ||
958 | /* Cover function to xrealloc. | |
959 | We don't record the additional size since we don't know it. | |
960 | It won't affect memory usage stats much anyway. */ | |
961 | ||
962 | static char * | |
963 | grealloc (ptr, size) | |
964 | char *ptr; | |
965 | unsigned int size; | |
966 | { | |
967 | return xrealloc (ptr, size); | |
968 | } | |
969 | ||
970 | /* Cover function to obstack_alloc. | |
971 | We don't need to record the bytes allocated here since | |
972 | obstack_chunk_alloc is set to gmalloc. */ | |
973 | ||
974 | static char * | |
975 | gcse_alloc (size) | |
976 | unsigned long size; | |
977 | { | |
978 | return (char *) obstack_alloc (&gcse_obstack, size); | |
979 | } | |
980 | ||
981 | /* Allocate memory for the cuid mapping array, | |
982 | and reg/memory set tracking tables. | |
983 | ||
984 | This is called at the start of each pass. */ | |
985 | ||
986 | static void | |
987 | alloc_gcse_mem (f) | |
988 | rtx f; | |
989 | { | |
8e42ace1 | 990 | int i, n; |
7506f491 DE |
991 | rtx insn; |
992 | ||
993 | /* Find the largest UID and create a mapping from UIDs to CUIDs. | |
994 | CUIDs are like UIDs except they increase monotonically, have no gaps, | |
995 | and only apply to real insns. */ | |
996 | ||
997 | max_uid = get_max_uid (); | |
998 | n = (max_uid + 1) * sizeof (int); | |
999 | uid_cuid = (int *) gmalloc (n); | |
961192e1 | 1000 | memset ((char *) uid_cuid, 0, n); |
7506f491 DE |
1001 | for (insn = f, i = 0; insn; insn = NEXT_INSN (insn)) |
1002 | { | |
2c3c49de | 1003 | if (INSN_P (insn)) |
b86db3eb | 1004 | uid_cuid[INSN_UID (insn)] = i++; |
7506f491 | 1005 | else |
b86db3eb | 1006 | uid_cuid[INSN_UID (insn)] = i; |
7506f491 DE |
1007 | } |
1008 | ||
1009 | /* Create a table mapping cuids to insns. */ | |
1010 | ||
1011 | max_cuid = i; | |
1012 | n = (max_cuid + 1) * sizeof (rtx); | |
1013 | cuid_insn = (rtx *) gmalloc (n); | |
961192e1 | 1014 | memset ((char *) cuid_insn, 0, n); |
7506f491 | 1015 | for (insn = f, i = 0; insn; insn = NEXT_INSN (insn)) |
2c3c49de | 1016 | if (INSN_P (insn)) |
c4c81601 | 1017 | CUID_INSN (i++) = insn; |
7506f491 DE |
1018 | |
1019 | /* Allocate vars to track sets of regs. */ | |
73991d6a | 1020 | reg_set_bitmap = BITMAP_XMALLOC (); |
7506f491 DE |
1021 | |
1022 | /* Allocate vars to track sets of regs, memory per block. */ | |
d55bc081 | 1023 | reg_set_in_block = (sbitmap *) sbitmap_vector_alloc (last_basic_block, |
7506f491 | 1024 | max_gcse_regno); |
a13d4ebf AM |
1025 | /* Allocate array to keep a list of insns which modify memory in each |
1026 | basic block. */ | |
d55bc081 ZD |
1027 | modify_mem_list = (rtx *) gmalloc (last_basic_block * sizeof (rtx)); |
1028 | canon_modify_mem_list = (rtx *) gmalloc (last_basic_block * sizeof (rtx)); | |
1029 | memset ((char *) modify_mem_list, 0, last_basic_block * sizeof (rtx)); | |
1030 | memset ((char *) canon_modify_mem_list, 0, last_basic_block * sizeof (rtx)); | |
73991d6a JH |
1031 | modify_mem_list_set = BITMAP_XMALLOC (); |
1032 | canon_modify_mem_list_set = BITMAP_XMALLOC (); | |
7506f491 DE |
1033 | } |
1034 | ||
1035 | /* Free memory allocated by alloc_gcse_mem. */ | |
1036 | ||
1037 | static void | |
1038 | free_gcse_mem () | |
1039 | { | |
1040 | free (uid_cuid); | |
1041 | free (cuid_insn); | |
1042 | ||
73991d6a | 1043 | BITMAP_XFREE (reg_set_bitmap); |
7506f491 | 1044 | |
5a660bff | 1045 | sbitmap_vector_free (reg_set_in_block); |
73991d6a JH |
1046 | free_modify_mem_tables (); |
1047 | BITMAP_XFREE (modify_mem_list_set); | |
1048 | BITMAP_XFREE (canon_modify_mem_list_set); | |
7506f491 DE |
1049 | } |
1050 | ||
0511851c MM |
1051 | /* Many of the global optimization algorithms work by solving dataflow |
1052 | equations for various expressions. Initially, some local value is | |
c4c81601 RK |
1053 | computed for each expression in each block. Then, the values across the |
1054 | various blocks are combined (by following flow graph edges) to arrive at | |
1055 | global values. Conceptually, each set of equations is independent. We | |
1056 | may therefore solve all the equations in parallel, solve them one at a | |
1057 | time, or pick any intermediate approach. | |
1058 | ||
1059 | When you're going to need N two-dimensional bitmaps, each X (say, the | |
1060 | number of blocks) by Y (say, the number of expressions), call this | |
1061 | function. It's not important what X and Y represent; only that Y | |
1062 | correspond to the things that can be done in parallel. This function will | |
1063 | return an appropriate chunking factor C; you should solve C sets of | |
1064 | equations in parallel. By going through this function, we can easily | |
1065 | trade space against time; by solving fewer equations in parallel we use | |
1066 | less space. */ | |
0511851c MM |
1067 | |
1068 | static int | |
1069 | get_bitmap_width (n, x, y) | |
1070 | int n; | |
1071 | int x; | |
1072 | int y; | |
1073 | { | |
1074 | /* It's not really worth figuring out *exactly* how much memory will | |
1075 | be used by a particular choice. The important thing is to get | |
1076 | something approximately right. */ | |
1077 | size_t max_bitmap_memory = 10 * 1024 * 1024; | |
1078 | ||
1079 | /* The number of bytes we'd use for a single column of minimum | |
1080 | width. */ | |
1081 | size_t column_size = n * x * sizeof (SBITMAP_ELT_TYPE); | |
1082 | ||
1083 | /* Often, it's reasonable just to solve all the equations in | |
1084 | parallel. */ | |
1085 | if (column_size * SBITMAP_SET_SIZE (y) <= max_bitmap_memory) | |
1086 | return y; | |
1087 | ||
1088 | /* Otherwise, pick the largest width we can, without going over the | |
1089 | limit. */ | |
1090 | return SBITMAP_ELT_BITS * ((max_bitmap_memory + column_size - 1) | |
1091 | / column_size); | |
1092 | } | |
b5ce41ff JL |
1093 | \f |
1094 | /* Compute the local properties of each recorded expression. | |
c4c81601 RK |
1095 | |
1096 | Local properties are those that are defined by the block, irrespective of | |
1097 | other blocks. | |
b5ce41ff JL |
1098 | |
1099 | An expression is transparent in a block if its operands are not modified | |
1100 | in the block. | |
1101 | ||
1102 | An expression is computed (locally available) in a block if it is computed | |
1103 | at least once and expression would contain the same value if the | |
1104 | computation was moved to the end of the block. | |
1105 | ||
1106 | An expression is locally anticipatable in a block if it is computed at | |
1107 | least once and expression would contain the same value if the computation | |
1108 | was moved to the beginning of the block. | |
1109 | ||
c4c81601 RK |
1110 | We call this routine for cprop, pre and code hoisting. They all compute |
1111 | basically the same information and thus can easily share this code. | |
7506f491 | 1112 | |
c4c81601 RK |
1113 | TRANSP, COMP, and ANTLOC are destination sbitmaps for recording local |
1114 | properties. If NULL, then it is not necessary to compute or record that | |
1115 | particular property. | |
b5ce41ff | 1116 | |
c4c81601 RK |
1117 | SETP controls which hash table to look at. If zero, this routine looks at |
1118 | the expr hash table; if nonzero this routine looks at the set hash table. | |
1119 | Additionally, TRANSP is computed as ~TRANSP, since this is really cprop's | |
1120 | ABSALTERED. */ | |
b5ce41ff JL |
1121 | |
1122 | static void | |
1123 | compute_local_properties (transp, comp, antloc, setp) | |
1124 | sbitmap *transp; | |
1125 | sbitmap *comp; | |
1126 | sbitmap *antloc; | |
1127 | int setp; | |
1128 | { | |
2e653e39 | 1129 | unsigned int i, hash_table_size; |
b5ce41ff JL |
1130 | struct expr **hash_table; |
1131 | ||
1132 | /* Initialize any bitmaps that were passed in. */ | |
1133 | if (transp) | |
695ab36a BS |
1134 | { |
1135 | if (setp) | |
d55bc081 | 1136 | sbitmap_vector_zero (transp, last_basic_block); |
695ab36a | 1137 | else |
d55bc081 | 1138 | sbitmap_vector_ones (transp, last_basic_block); |
695ab36a | 1139 | } |
c4c81601 | 1140 | |
b5ce41ff | 1141 | if (comp) |
d55bc081 | 1142 | sbitmap_vector_zero (comp, last_basic_block); |
b5ce41ff | 1143 | if (antloc) |
d55bc081 | 1144 | sbitmap_vector_zero (antloc, last_basic_block); |
b5ce41ff JL |
1145 | |
1146 | /* We use the same code for cprop, pre and hoisting. For cprop | |
1147 | we care about the set hash table, for pre and hoisting we | |
1148 | care about the expr hash table. */ | |
1149 | hash_table_size = setp ? set_hash_table_size : expr_hash_table_size; | |
1150 | hash_table = setp ? set_hash_table : expr_hash_table; | |
1151 | ||
1152 | for (i = 0; i < hash_table_size; i++) | |
7506f491 | 1153 | { |
b5ce41ff JL |
1154 | struct expr *expr; |
1155 | ||
1156 | for (expr = hash_table[i]; expr != NULL; expr = expr->next_same_hash) | |
1157 | { | |
b5ce41ff | 1158 | int indx = expr->bitmap_index; |
c4c81601 | 1159 | struct occr *occr; |
b5ce41ff JL |
1160 | |
1161 | /* The expression is transparent in this block if it is not killed. | |
1162 | We start by assuming all are transparent [none are killed], and | |
1163 | then reset the bits for those that are. */ | |
b5ce41ff JL |
1164 | if (transp) |
1165 | compute_transp (expr->expr, indx, transp, setp); | |
1166 | ||
1167 | /* The occurrences recorded in antic_occr are exactly those that | |
1168 | we want to set to non-zero in ANTLOC. */ | |
b5ce41ff | 1169 | if (antloc) |
c4c81601 RK |
1170 | for (occr = expr->antic_occr; occr != NULL; occr = occr->next) |
1171 | { | |
1172 | SET_BIT (antloc[BLOCK_NUM (occr->insn)], indx); | |
b5ce41ff | 1173 | |
c4c81601 RK |
1174 | /* While we're scanning the table, this is a good place to |
1175 | initialize this. */ | |
1176 | occr->deleted_p = 0; | |
1177 | } | |
b5ce41ff JL |
1178 | |
1179 | /* The occurrences recorded in avail_occr are exactly those that | |
1180 | we want to set to non-zero in COMP. */ | |
1181 | if (comp) | |
c4c81601 RK |
1182 | for (occr = expr->avail_occr; occr != NULL; occr = occr->next) |
1183 | { | |
1184 | SET_BIT (comp[BLOCK_NUM (occr->insn)], indx); | |
b5ce41ff | 1185 | |
c4c81601 RK |
1186 | /* While we're scanning the table, this is a good place to |
1187 | initialize this. */ | |
1188 | occr->copied_p = 0; | |
1189 | } | |
b5ce41ff JL |
1190 | |
1191 | /* While we're scanning the table, this is a good place to | |
1192 | initialize this. */ | |
1193 | expr->reaching_reg = 0; | |
1194 | } | |
7506f491 | 1195 | } |
7506f491 DE |
1196 | } |
1197 | \f | |
1198 | /* Register set information. | |
1199 | ||
1200 | `reg_set_table' records where each register is set or otherwise | |
1201 | modified. */ | |
1202 | ||
1203 | static struct obstack reg_set_obstack; | |
1204 | ||
1205 | static void | |
1206 | alloc_reg_set_mem (n_regs) | |
1207 | int n_regs; | |
1208 | { | |
c4c81601 | 1209 | unsigned int n; |
7506f491 DE |
1210 | |
1211 | reg_set_table_size = n_regs + REG_SET_TABLE_SLOP; | |
1212 | n = reg_set_table_size * sizeof (struct reg_set *); | |
1213 | reg_set_table = (struct reg_set **) gmalloc (n); | |
961192e1 | 1214 | memset ((char *) reg_set_table, 0, n); |
7506f491 DE |
1215 | |
1216 | gcc_obstack_init (®_set_obstack); | |
1217 | } | |
1218 | ||
1219 | static void | |
1220 | free_reg_set_mem () | |
1221 | { | |
1222 | free (reg_set_table); | |
6496a589 | 1223 | obstack_free (®_set_obstack, NULL); |
7506f491 DE |
1224 | } |
1225 | ||
1226 | /* Record REGNO in the reg_set table. */ | |
1227 | ||
1228 | static void | |
1229 | record_one_set (regno, insn) | |
1230 | int regno; | |
1231 | rtx insn; | |
1232 | { | |
172890a2 | 1233 | /* Allocate a new reg_set element and link it onto the list. */ |
63bc1d05 | 1234 | struct reg_set *new_reg_info; |
7506f491 DE |
1235 | |
1236 | /* If the table isn't big enough, enlarge it. */ | |
1237 | if (regno >= reg_set_table_size) | |
1238 | { | |
1239 | int new_size = regno + REG_SET_TABLE_SLOP; | |
c4c81601 RK |
1240 | |
1241 | reg_set_table | |
1242 | = (struct reg_set **) grealloc ((char *) reg_set_table, | |
1243 | new_size * sizeof (struct reg_set *)); | |
961192e1 | 1244 | memset ((char *) (reg_set_table + reg_set_table_size), 0, |
8e42ace1 | 1245 | (new_size - reg_set_table_size) * sizeof (struct reg_set *)); |
7506f491 DE |
1246 | reg_set_table_size = new_size; |
1247 | } | |
1248 | ||
1249 | new_reg_info = (struct reg_set *) obstack_alloc (®_set_obstack, | |
1250 | sizeof (struct reg_set)); | |
1251 | bytes_used += sizeof (struct reg_set); | |
1252 | new_reg_info->insn = insn; | |
274969ea MM |
1253 | new_reg_info->next = reg_set_table[regno]; |
1254 | reg_set_table[regno] = new_reg_info; | |
7506f491 DE |
1255 | } |
1256 | ||
c4c81601 RK |
1257 | /* Called from compute_sets via note_stores to handle one SET or CLOBBER in |
1258 | an insn. The DATA is really the instruction in which the SET is | |
1259 | occurring. */ | |
7506f491 DE |
1260 | |
1261 | static void | |
84832317 | 1262 | record_set_info (dest, setter, data) |
50b2596f | 1263 | rtx dest, setter ATTRIBUTE_UNUSED; |
84832317 | 1264 | void *data; |
7506f491 | 1265 | { |
84832317 MM |
1266 | rtx record_set_insn = (rtx) data; |
1267 | ||
c4c81601 RK |
1268 | if (GET_CODE (dest) == REG && REGNO (dest) >= FIRST_PSEUDO_REGISTER) |
1269 | record_one_set (REGNO (dest), record_set_insn); | |
7506f491 DE |
1270 | } |
1271 | ||
1272 | /* Scan the function and record each set of each pseudo-register. | |
1273 | ||
c4c81601 RK |
1274 | This is called once, at the start of the gcse pass. See the comments for |
1275 | `reg_set_table' for further documenation. */ | |
7506f491 DE |
1276 | |
1277 | static void | |
1278 | compute_sets (f) | |
1279 | rtx f; | |
1280 | { | |
c4c81601 | 1281 | rtx insn; |
7506f491 | 1282 | |
c4c81601 | 1283 | for (insn = f; insn != 0; insn = NEXT_INSN (insn)) |
2c3c49de | 1284 | if (INSN_P (insn)) |
c4c81601 | 1285 | note_stores (PATTERN (insn), record_set_info, insn); |
7506f491 DE |
1286 | } |
1287 | \f | |
1288 | /* Hash table support. */ | |
1289 | ||
80c29cc4 RZ |
1290 | /* For each register, the cuid of the first/last insn in the block |
1291 | that set it, or -1 if not set. */ | |
c4c81601 | 1292 | #define NEVER_SET -1 |
80c29cc4 RZ |
1293 | |
1294 | struct reg_avail_info | |
1295 | { | |
e0082a72 | 1296 | basic_block last_bb; |
80c29cc4 RZ |
1297 | int first_set; |
1298 | int last_set; | |
1299 | }; | |
1300 | ||
1301 | static struct reg_avail_info *reg_avail_info; | |
e0082a72 | 1302 | static basic_block current_bb; |
7506f491 | 1303 | |
7506f491 | 1304 | |
fb0c0a12 RK |
1305 | /* See whether X, the source of a set, is something we want to consider for |
1306 | GCSE. */ | |
7506f491 | 1307 | |
e2500fed | 1308 | static GTY(()) rtx test_insn; |
7506f491 DE |
1309 | static int |
1310 | want_to_gcse_p (x) | |
1311 | rtx x; | |
1312 | { | |
fb0c0a12 RK |
1313 | int num_clobbers = 0; |
1314 | int icode; | |
1315 | ||
c4c81601 | 1316 | switch (GET_CODE (x)) |
7506f491 DE |
1317 | { |
1318 | case REG: | |
1319 | case SUBREG: | |
1320 | case CONST_INT: | |
1321 | case CONST_DOUBLE: | |
69ef87e2 | 1322 | case CONST_VECTOR: |
7506f491 DE |
1323 | case CALL: |
1324 | return 0; | |
1325 | ||
1326 | default: | |
1327 | break; | |
1328 | } | |
1329 | ||
fb0c0a12 RK |
1330 | /* If this is a valid operand, we are OK. If it's VOIDmode, we aren't. */ |
1331 | if (general_operand (x, GET_MODE (x))) | |
1332 | return 1; | |
1333 | else if (GET_MODE (x) == VOIDmode) | |
1334 | return 0; | |
1335 | ||
1336 | /* Otherwise, check if we can make a valid insn from it. First initialize | |
1337 | our test insn if we haven't already. */ | |
1338 | if (test_insn == 0) | |
1339 | { | |
1340 | test_insn | |
1341 | = make_insn_raw (gen_rtx_SET (VOIDmode, | |
1342 | gen_rtx_REG (word_mode, | |
1343 | FIRST_PSEUDO_REGISTER * 2), | |
1344 | const0_rtx)); | |
1345 | NEXT_INSN (test_insn) = PREV_INSN (test_insn) = 0; | |
fb0c0a12 RK |
1346 | } |
1347 | ||
1348 | /* Now make an insn like the one we would make when GCSE'ing and see if | |
1349 | valid. */ | |
1350 | PUT_MODE (SET_DEST (PATTERN (test_insn)), GET_MODE (x)); | |
1351 | SET_SRC (PATTERN (test_insn)) = x; | |
1352 | return ((icode = recog (PATTERN (test_insn), test_insn, &num_clobbers)) >= 0 | |
1353 | && (num_clobbers == 0 || ! added_clobbers_hard_reg_p (icode))); | |
7506f491 DE |
1354 | } |
1355 | ||
1356 | /* Return non-zero if the operands of expression X are unchanged from the | |
1357 | start of INSN's basic block up to but not including INSN (if AVAIL_P == 0), | |
1358 | or from INSN to the end of INSN's basic block (if AVAIL_P != 0). */ | |
1359 | ||
1360 | static int | |
1361 | oprs_unchanged_p (x, insn, avail_p) | |
1362 | rtx x, insn; | |
1363 | int avail_p; | |
1364 | { | |
c4c81601 | 1365 | int i, j; |
7506f491 | 1366 | enum rtx_code code; |
6f7d635c | 1367 | const char *fmt; |
7506f491 | 1368 | |
7506f491 DE |
1369 | if (x == 0) |
1370 | return 1; | |
1371 | ||
1372 | code = GET_CODE (x); | |
1373 | switch (code) | |
1374 | { | |
1375 | case REG: | |
80c29cc4 RZ |
1376 | { |
1377 | struct reg_avail_info *info = ®_avail_info[REGNO (x)]; | |
1378 | ||
1379 | if (info->last_bb != current_bb) | |
1380 | return 1; | |
1381 | if (avail_p) | |
1382 | return info->last_set < INSN_CUID (insn); | |
1383 | else | |
1384 | return info->first_set >= INSN_CUID (insn); | |
1385 | } | |
7506f491 DE |
1386 | |
1387 | case MEM: | |
e0082a72 | 1388 | if (load_killed_in_block_p (current_bb, INSN_CUID (insn), |
a13d4ebf AM |
1389 | x, avail_p)) |
1390 | return 0; | |
7506f491 | 1391 | else |
c4c81601 | 1392 | return oprs_unchanged_p (XEXP (x, 0), insn, avail_p); |
7506f491 DE |
1393 | |
1394 | case PRE_DEC: | |
1395 | case PRE_INC: | |
1396 | case POST_DEC: | |
1397 | case POST_INC: | |
4b983fdc RH |
1398 | case PRE_MODIFY: |
1399 | case POST_MODIFY: | |
7506f491 DE |
1400 | return 0; |
1401 | ||
1402 | case PC: | |
1403 | case CC0: /*FIXME*/ | |
1404 | case CONST: | |
1405 | case CONST_INT: | |
1406 | case CONST_DOUBLE: | |
69ef87e2 | 1407 | case CONST_VECTOR: |
7506f491 DE |
1408 | case SYMBOL_REF: |
1409 | case LABEL_REF: | |
1410 | case ADDR_VEC: | |
1411 | case ADDR_DIFF_VEC: | |
1412 | return 1; | |
1413 | ||
1414 | default: | |
1415 | break; | |
1416 | } | |
1417 | ||
c4c81601 | 1418 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
1419 | { |
1420 | if (fmt[i] == 'e') | |
1421 | { | |
c4c81601 RK |
1422 | /* If we are about to do the last recursive call needed at this |
1423 | level, change it into iteration. This function is called enough | |
1424 | to be worth it. */ | |
7506f491 | 1425 | if (i == 0) |
c4c81601 RK |
1426 | return oprs_unchanged_p (XEXP (x, i), insn, avail_p); |
1427 | ||
1428 | else if (! oprs_unchanged_p (XEXP (x, i), insn, avail_p)) | |
7506f491 DE |
1429 | return 0; |
1430 | } | |
1431 | else if (fmt[i] == 'E') | |
c4c81601 RK |
1432 | for (j = 0; j < XVECLEN (x, i); j++) |
1433 | if (! oprs_unchanged_p (XVECEXP (x, i, j), insn, avail_p)) | |
1434 | return 0; | |
7506f491 DE |
1435 | } |
1436 | ||
1437 | return 1; | |
1438 | } | |
1439 | ||
a13d4ebf AM |
1440 | /* Used for communication between mems_conflict_for_gcse_p and |
1441 | load_killed_in_block_p. Nonzero if mems_conflict_for_gcse_p finds a | |
1442 | conflict between two memory references. */ | |
1443 | static int gcse_mems_conflict_p; | |
1444 | ||
1445 | /* Used for communication between mems_conflict_for_gcse_p and | |
1446 | load_killed_in_block_p. A memory reference for a load instruction, | |
1447 | mems_conflict_for_gcse_p will see if a memory store conflicts with | |
1448 | this memory load. */ | |
1449 | static rtx gcse_mem_operand; | |
1450 | ||
1451 | /* DEST is the output of an instruction. If it is a memory reference, and | |
1452 | possibly conflicts with the load found in gcse_mem_operand, then set | |
1453 | gcse_mems_conflict_p to a nonzero value. */ | |
1454 | ||
1455 | static void | |
1456 | mems_conflict_for_gcse_p (dest, setter, data) | |
1457 | rtx dest, setter ATTRIBUTE_UNUSED; | |
1458 | void *data ATTRIBUTE_UNUSED; | |
1459 | { | |
1460 | while (GET_CODE (dest) == SUBREG | |
1461 | || GET_CODE (dest) == ZERO_EXTRACT | |
1462 | || GET_CODE (dest) == SIGN_EXTRACT | |
1463 | || GET_CODE (dest) == STRICT_LOW_PART) | |
1464 | dest = XEXP (dest, 0); | |
1465 | ||
1466 | /* If DEST is not a MEM, then it will not conflict with the load. Note | |
1467 | that function calls are assumed to clobber memory, but are handled | |
1468 | elsewhere. */ | |
1469 | if (GET_CODE (dest) != MEM) | |
1470 | return; | |
aaa4ca30 | 1471 | |
a13d4ebf AM |
1472 | /* If we are setting a MEM in our list of specially recognized MEMs, |
1473 | don't mark as killed this time. */ | |
1474 | ||
1475 | if (dest == gcse_mem_operand && pre_ldst_mems != NULL) | |
1476 | { | |
1477 | if (!find_rtx_in_ldst (dest)) | |
1478 | gcse_mems_conflict_p = 1; | |
1479 | return; | |
1480 | } | |
aaa4ca30 | 1481 | |
a13d4ebf AM |
1482 | if (true_dependence (dest, GET_MODE (dest), gcse_mem_operand, |
1483 | rtx_addr_varies_p)) | |
1484 | gcse_mems_conflict_p = 1; | |
1485 | } | |
1486 | ||
1487 | /* Return nonzero if the expression in X (a memory reference) is killed | |
1488 | in block BB before or after the insn with the CUID in UID_LIMIT. | |
1489 | AVAIL_P is nonzero for kills after UID_LIMIT, and zero for kills | |
1490 | before UID_LIMIT. | |
1491 | ||
1492 | To check the entire block, set UID_LIMIT to max_uid + 1 and | |
1493 | AVAIL_P to 0. */ | |
1494 | ||
1495 | static int | |
1496 | load_killed_in_block_p (bb, uid_limit, x, avail_p) | |
e2d2ed72 | 1497 | basic_block bb; |
a13d4ebf AM |
1498 | int uid_limit; |
1499 | rtx x; | |
1500 | int avail_p; | |
1501 | { | |
0b17ab2f | 1502 | rtx list_entry = modify_mem_list[bb->index]; |
a13d4ebf AM |
1503 | while (list_entry) |
1504 | { | |
1505 | rtx setter; | |
1506 | /* Ignore entries in the list that do not apply. */ | |
1507 | if ((avail_p | |
1508 | && INSN_CUID (XEXP (list_entry, 0)) < uid_limit) | |
1509 | || (! avail_p | |
1510 | && INSN_CUID (XEXP (list_entry, 0)) > uid_limit)) | |
1511 | { | |
1512 | list_entry = XEXP (list_entry, 1); | |
1513 | continue; | |
1514 | } | |
1515 | ||
1516 | setter = XEXP (list_entry, 0); | |
1517 | ||
1518 | /* If SETTER is a call everything is clobbered. Note that calls | |
1519 | to pure functions are never put on the list, so we need not | |
1520 | worry about them. */ | |
1521 | if (GET_CODE (setter) == CALL_INSN) | |
1522 | return 1; | |
1523 | ||
1524 | /* SETTER must be an INSN of some kind that sets memory. Call | |
1525 | note_stores to examine each hunk of memory that is modified. | |
1526 | ||
1527 | The note_stores interface is pretty limited, so we have to | |
1528 | communicate via global variables. Yuk. */ | |
1529 | gcse_mem_operand = x; | |
1530 | gcse_mems_conflict_p = 0; | |
1531 | note_stores (PATTERN (setter), mems_conflict_for_gcse_p, NULL); | |
1532 | if (gcse_mems_conflict_p) | |
1533 | return 1; | |
1534 | list_entry = XEXP (list_entry, 1); | |
1535 | } | |
1536 | return 0; | |
1537 | } | |
1538 | ||
7506f491 DE |
1539 | /* Return non-zero if the operands of expression X are unchanged from |
1540 | the start of INSN's basic block up to but not including INSN. */ | |
1541 | ||
1542 | static int | |
1543 | oprs_anticipatable_p (x, insn) | |
1544 | rtx x, insn; | |
1545 | { | |
1546 | return oprs_unchanged_p (x, insn, 0); | |
1547 | } | |
1548 | ||
1549 | /* Return non-zero if the operands of expression X are unchanged from | |
1550 | INSN to the end of INSN's basic block. */ | |
1551 | ||
1552 | static int | |
1553 | oprs_available_p (x, insn) | |
1554 | rtx x, insn; | |
1555 | { | |
1556 | return oprs_unchanged_p (x, insn, 1); | |
1557 | } | |
1558 | ||
1559 | /* Hash expression X. | |
c4c81601 RK |
1560 | |
1561 | MODE is only used if X is a CONST_INT. DO_NOT_RECORD_P is a boolean | |
1562 | indicating if a volatile operand is found or if the expression contains | |
1563 | something we don't want to insert in the table. | |
7506f491 DE |
1564 | |
1565 | ??? One might want to merge this with canon_hash. Later. */ | |
1566 | ||
1567 | static unsigned int | |
1568 | hash_expr (x, mode, do_not_record_p, hash_table_size) | |
1569 | rtx x; | |
1570 | enum machine_mode mode; | |
1571 | int *do_not_record_p; | |
1572 | int hash_table_size; | |
1573 | { | |
1574 | unsigned int hash; | |
1575 | ||
1576 | *do_not_record_p = 0; | |
1577 | ||
1578 | hash = hash_expr_1 (x, mode, do_not_record_p); | |
1579 | return hash % hash_table_size; | |
1580 | } | |
172890a2 | 1581 | |
6462bb43 | 1582 | /* Hash a string. Just add its bytes up. */ |
172890a2 | 1583 | |
6462bb43 AO |
1584 | static inline unsigned |
1585 | hash_string_1 (ps) | |
1586 | const char *ps; | |
1587 | { | |
1588 | unsigned hash = 0; | |
8e42ace1 | 1589 | const unsigned char *p = (const unsigned char *) ps; |
6462bb43 AO |
1590 | |
1591 | if (p) | |
1592 | while (*p) | |
1593 | hash += *p++; | |
1594 | ||
1595 | return hash; | |
1596 | } | |
7506f491 DE |
1597 | |
1598 | /* Subroutine of hash_expr to do the actual work. */ | |
1599 | ||
1600 | static unsigned int | |
1601 | hash_expr_1 (x, mode, do_not_record_p) | |
1602 | rtx x; | |
1603 | enum machine_mode mode; | |
1604 | int *do_not_record_p; | |
1605 | { | |
1606 | int i, j; | |
1607 | unsigned hash = 0; | |
1608 | enum rtx_code code; | |
6f7d635c | 1609 | const char *fmt; |
7506f491 | 1610 | |
c4c81601 RK |
1611 | /* Used to turn recursion into iteration. We can't rely on GCC's |
1612 | tail-recursion eliminatio since we need to keep accumulating values | |
1613 | in HASH. */ | |
7506f491 DE |
1614 | |
1615 | if (x == 0) | |
1616 | return hash; | |
1617 | ||
c4c81601 | 1618 | repeat: |
7506f491 DE |
1619 | code = GET_CODE (x); |
1620 | switch (code) | |
1621 | { | |
1622 | case REG: | |
c4c81601 RK |
1623 | hash += ((unsigned int) REG << 7) + REGNO (x); |
1624 | return hash; | |
7506f491 DE |
1625 | |
1626 | case CONST_INT: | |
c4c81601 RK |
1627 | hash += (((unsigned int) CONST_INT << 7) + (unsigned int) mode |
1628 | + (unsigned int) INTVAL (x)); | |
1629 | return hash; | |
7506f491 DE |
1630 | |
1631 | case CONST_DOUBLE: | |
1632 | /* This is like the general case, except that it only counts | |
1633 | the integers representing the constant. */ | |
c4c81601 | 1634 | hash += (unsigned int) code + (unsigned int) GET_MODE (x); |
7506f491 DE |
1635 | if (GET_MODE (x) != VOIDmode) |
1636 | for (i = 2; i < GET_RTX_LENGTH (CONST_DOUBLE); i++) | |
c4c81601 | 1637 | hash += (unsigned int) XWINT (x, i); |
7506f491 | 1638 | else |
c4c81601 RK |
1639 | hash += ((unsigned int) CONST_DOUBLE_LOW (x) |
1640 | + (unsigned int) CONST_DOUBLE_HIGH (x)); | |
7506f491 DE |
1641 | return hash; |
1642 | ||
69ef87e2 AH |
1643 | case CONST_VECTOR: |
1644 | { | |
1645 | int units; | |
1646 | rtx elt; | |
1647 | ||
1648 | units = CONST_VECTOR_NUNITS (x); | |
1649 | ||
1650 | for (i = 0; i < units; ++i) | |
1651 | { | |
1652 | elt = CONST_VECTOR_ELT (x, i); | |
1653 | hash += hash_expr_1 (elt, GET_MODE (elt), do_not_record_p); | |
1654 | } | |
1655 | ||
1656 | return hash; | |
1657 | } | |
1658 | ||
7506f491 DE |
1659 | /* Assume there is only one rtx object for any given label. */ |
1660 | case LABEL_REF: | |
1661 | /* We don't hash on the address of the CODE_LABEL to avoid bootstrap | |
1662 | differences and differences between each stage's debugging dumps. */ | |
c4c81601 RK |
1663 | hash += (((unsigned int) LABEL_REF << 7) |
1664 | + CODE_LABEL_NUMBER (XEXP (x, 0))); | |
7506f491 DE |
1665 | return hash; |
1666 | ||
1667 | case SYMBOL_REF: | |
1668 | { | |
1669 | /* Don't hash on the symbol's address to avoid bootstrap differences. | |
1670 | Different hash values may cause expressions to be recorded in | |
1671 | different orders and thus different registers to be used in the | |
1672 | final assembler. This also avoids differences in the dump files | |
1673 | between various stages. */ | |
1674 | unsigned int h = 0; | |
3cce094d | 1675 | const unsigned char *p = (const unsigned char *) XSTR (x, 0); |
c4c81601 | 1676 | |
7506f491 DE |
1677 | while (*p) |
1678 | h += (h << 7) + *p++; /* ??? revisit */ | |
c4c81601 RK |
1679 | |
1680 | hash += ((unsigned int) SYMBOL_REF << 7) + h; | |
7506f491 DE |
1681 | return hash; |
1682 | } | |
1683 | ||
1684 | case MEM: | |
1685 | if (MEM_VOLATILE_P (x)) | |
1686 | { | |
1687 | *do_not_record_p = 1; | |
1688 | return 0; | |
1689 | } | |
c4c81601 RK |
1690 | |
1691 | hash += (unsigned int) MEM; | |
d51f3632 JH |
1692 | /* We used alias set for hashing, but this is not good, since the alias |
1693 | set may differ in -fprofile-arcs and -fbranch-probabilities compilation | |
1694 | causing the profiles to fail to match. */ | |
7506f491 DE |
1695 | x = XEXP (x, 0); |
1696 | goto repeat; | |
1697 | ||
1698 | case PRE_DEC: | |
1699 | case PRE_INC: | |
1700 | case POST_DEC: | |
1701 | case POST_INC: | |
1702 | case PC: | |
1703 | case CC0: | |
1704 | case CALL: | |
1705 | case UNSPEC_VOLATILE: | |
1706 | *do_not_record_p = 1; | |
1707 | return 0; | |
1708 | ||
1709 | case ASM_OPERANDS: | |
1710 | if (MEM_VOLATILE_P (x)) | |
1711 | { | |
1712 | *do_not_record_p = 1; | |
1713 | return 0; | |
1714 | } | |
6462bb43 AO |
1715 | else |
1716 | { | |
1717 | /* We don't want to take the filename and line into account. */ | |
1718 | hash += (unsigned) code + (unsigned) GET_MODE (x) | |
1719 | + hash_string_1 (ASM_OPERANDS_TEMPLATE (x)) | |
1720 | + hash_string_1 (ASM_OPERANDS_OUTPUT_CONSTRAINT (x)) | |
1721 | + (unsigned) ASM_OPERANDS_OUTPUT_IDX (x); | |
1722 | ||
1723 | if (ASM_OPERANDS_INPUT_LENGTH (x)) | |
1724 | { | |
1725 | for (i = 1; i < ASM_OPERANDS_INPUT_LENGTH (x); i++) | |
1726 | { | |
1727 | hash += (hash_expr_1 (ASM_OPERANDS_INPUT (x, i), | |
1728 | GET_MODE (ASM_OPERANDS_INPUT (x, i)), | |
1729 | do_not_record_p) | |
1730 | + hash_string_1 (ASM_OPERANDS_INPUT_CONSTRAINT | |
1731 | (x, i))); | |
1732 | } | |
1733 | ||
1734 | hash += hash_string_1 (ASM_OPERANDS_INPUT_CONSTRAINT (x, 0)); | |
1735 | x = ASM_OPERANDS_INPUT (x, 0); | |
1736 | mode = GET_MODE (x); | |
1737 | goto repeat; | |
1738 | } | |
1739 | return hash; | |
1740 | } | |
7506f491 DE |
1741 | |
1742 | default: | |
1743 | break; | |
1744 | } | |
1745 | ||
7506f491 | 1746 | hash += (unsigned) code + (unsigned) GET_MODE (x); |
c4c81601 | 1747 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
1748 | { |
1749 | if (fmt[i] == 'e') | |
1750 | { | |
7506f491 DE |
1751 | /* If we are about to do the last recursive call |
1752 | needed at this level, change it into iteration. | |
1753 | This function is called enough to be worth it. */ | |
1754 | if (i == 0) | |
1755 | { | |
c4c81601 | 1756 | x = XEXP (x, i); |
7506f491 DE |
1757 | goto repeat; |
1758 | } | |
c4c81601 RK |
1759 | |
1760 | hash += hash_expr_1 (XEXP (x, i), 0, do_not_record_p); | |
7506f491 DE |
1761 | if (*do_not_record_p) |
1762 | return 0; | |
1763 | } | |
c4c81601 | 1764 | |
7506f491 DE |
1765 | else if (fmt[i] == 'E') |
1766 | for (j = 0; j < XVECLEN (x, i); j++) | |
1767 | { | |
1768 | hash += hash_expr_1 (XVECEXP (x, i, j), 0, do_not_record_p); | |
1769 | if (*do_not_record_p) | |
1770 | return 0; | |
1771 | } | |
c4c81601 | 1772 | |
7506f491 | 1773 | else if (fmt[i] == 's') |
6462bb43 | 1774 | hash += hash_string_1 (XSTR (x, i)); |
7506f491 | 1775 | else if (fmt[i] == 'i') |
c4c81601 | 1776 | hash += (unsigned int) XINT (x, i); |
7506f491 DE |
1777 | else |
1778 | abort (); | |
1779 | } | |
1780 | ||
1781 | return hash; | |
1782 | } | |
1783 | ||
1784 | /* Hash a set of register REGNO. | |
1785 | ||
c4c81601 RK |
1786 | Sets are hashed on the register that is set. This simplifies the PRE copy |
1787 | propagation code. | |
7506f491 DE |
1788 | |
1789 | ??? May need to make things more elaborate. Later, as necessary. */ | |
1790 | ||
1791 | static unsigned int | |
1792 | hash_set (regno, hash_table_size) | |
1793 | int regno; | |
1794 | int hash_table_size; | |
1795 | { | |
1796 | unsigned int hash; | |
1797 | ||
1798 | hash = regno; | |
1799 | return hash % hash_table_size; | |
1800 | } | |
1801 | ||
1802 | /* Return non-zero if exp1 is equivalent to exp2. | |
1803 | ??? Borrowed from cse.c. Might want to remerge with cse.c. Later. */ | |
1804 | ||
1805 | static int | |
1806 | expr_equiv_p (x, y) | |
1807 | rtx x, y; | |
1808 | { | |
b3694847 SS |
1809 | int i, j; |
1810 | enum rtx_code code; | |
1811 | const char *fmt; | |
7506f491 DE |
1812 | |
1813 | if (x == y) | |
1814 | return 1; | |
c4c81601 | 1815 | |
7506f491 DE |
1816 | if (x == 0 || y == 0) |
1817 | return x == y; | |
1818 | ||
1819 | code = GET_CODE (x); | |
1820 | if (code != GET_CODE (y)) | |
1821 | return 0; | |
1822 | ||
1823 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */ | |
1824 | if (GET_MODE (x) != GET_MODE (y)) | |
1825 | return 0; | |
1826 | ||
1827 | switch (code) | |
1828 | { | |
1829 | case PC: | |
1830 | case CC0: | |
1831 | return x == y; | |
1832 | ||
1833 | case CONST_INT: | |
1834 | return INTVAL (x) == INTVAL (y); | |
1835 | ||
1836 | case LABEL_REF: | |
1837 | return XEXP (x, 0) == XEXP (y, 0); | |
1838 | ||
1839 | case SYMBOL_REF: | |
1840 | return XSTR (x, 0) == XSTR (y, 0); | |
1841 | ||
1842 | case REG: | |
1843 | return REGNO (x) == REGNO (y); | |
1844 | ||
297c3335 RH |
1845 | case MEM: |
1846 | /* Can't merge two expressions in different alias sets, since we can | |
1847 | decide that the expression is transparent in a block when it isn't, | |
1848 | due to it being set with the different alias set. */ | |
1849 | if (MEM_ALIAS_SET (x) != MEM_ALIAS_SET (y)) | |
1850 | return 0; | |
1851 | break; | |
1852 | ||
7506f491 DE |
1853 | /* For commutative operations, check both orders. */ |
1854 | case PLUS: | |
1855 | case MULT: | |
1856 | case AND: | |
1857 | case IOR: | |
1858 | case XOR: | |
1859 | case NE: | |
1860 | case EQ: | |
1861 | return ((expr_equiv_p (XEXP (x, 0), XEXP (y, 0)) | |
1862 | && expr_equiv_p (XEXP (x, 1), XEXP (y, 1))) | |
1863 | || (expr_equiv_p (XEXP (x, 0), XEXP (y, 1)) | |
1864 | && expr_equiv_p (XEXP (x, 1), XEXP (y, 0)))); | |
1865 | ||
6462bb43 AO |
1866 | case ASM_OPERANDS: |
1867 | /* We don't use the generic code below because we want to | |
1868 | disregard filename and line numbers. */ | |
1869 | ||
1870 | /* A volatile asm isn't equivalent to any other. */ | |
1871 | if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y)) | |
1872 | return 0; | |
1873 | ||
1874 | if (GET_MODE (x) != GET_MODE (y) | |
1875 | || strcmp (ASM_OPERANDS_TEMPLATE (x), ASM_OPERANDS_TEMPLATE (y)) | |
1876 | || strcmp (ASM_OPERANDS_OUTPUT_CONSTRAINT (x), | |
1877 | ASM_OPERANDS_OUTPUT_CONSTRAINT (y)) | |
1878 | || ASM_OPERANDS_OUTPUT_IDX (x) != ASM_OPERANDS_OUTPUT_IDX (y) | |
1879 | || ASM_OPERANDS_INPUT_LENGTH (x) != ASM_OPERANDS_INPUT_LENGTH (y)) | |
1880 | return 0; | |
1881 | ||
1882 | if (ASM_OPERANDS_INPUT_LENGTH (x)) | |
1883 | { | |
1884 | for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--) | |
1885 | if (! expr_equiv_p (ASM_OPERANDS_INPUT (x, i), | |
1886 | ASM_OPERANDS_INPUT (y, i)) | |
1887 | || strcmp (ASM_OPERANDS_INPUT_CONSTRAINT (x, i), | |
1888 | ASM_OPERANDS_INPUT_CONSTRAINT (y, i))) | |
1889 | return 0; | |
1890 | } | |
1891 | ||
1892 | return 1; | |
1893 | ||
7506f491 DE |
1894 | default: |
1895 | break; | |
1896 | } | |
1897 | ||
1898 | /* Compare the elements. If any pair of corresponding elements | |
1899 | fail to match, return 0 for the whole thing. */ | |
1900 | ||
1901 | fmt = GET_RTX_FORMAT (code); | |
1902 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1903 | { | |
1904 | switch (fmt[i]) | |
1905 | { | |
1906 | case 'e': | |
1907 | if (! expr_equiv_p (XEXP (x, i), XEXP (y, i))) | |
1908 | return 0; | |
1909 | break; | |
1910 | ||
1911 | case 'E': | |
1912 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
1913 | return 0; | |
1914 | for (j = 0; j < XVECLEN (x, i); j++) | |
1915 | if (! expr_equiv_p (XVECEXP (x, i, j), XVECEXP (y, i, j))) | |
1916 | return 0; | |
1917 | break; | |
1918 | ||
1919 | case 's': | |
1920 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
1921 | return 0; | |
1922 | break; | |
1923 | ||
1924 | case 'i': | |
1925 | if (XINT (x, i) != XINT (y, i)) | |
1926 | return 0; | |
1927 | break; | |
1928 | ||
1929 | case 'w': | |
1930 | if (XWINT (x, i) != XWINT (y, i)) | |
1931 | return 0; | |
1932 | break; | |
1933 | ||
1934 | case '0': | |
1935 | break; | |
aaa4ca30 | 1936 | |
7506f491 DE |
1937 | default: |
1938 | abort (); | |
1939 | } | |
8e42ace1 | 1940 | } |
7506f491 DE |
1941 | |
1942 | return 1; | |
1943 | } | |
1944 | ||
1945 | /* Insert expression X in INSN in the hash table. | |
1946 | If it is already present, record it as the last occurrence in INSN's | |
1947 | basic block. | |
1948 | ||
1949 | MODE is the mode of the value X is being stored into. | |
1950 | It is only used if X is a CONST_INT. | |
1951 | ||
1952 | ANTIC_P is non-zero if X is an anticipatable expression. | |
1953 | AVAIL_P is non-zero if X is an available expression. */ | |
1954 | ||
1955 | static void | |
1956 | insert_expr_in_table (x, mode, insn, antic_p, avail_p) | |
1957 | rtx x; | |
1958 | enum machine_mode mode; | |
1959 | rtx insn; | |
1960 | int antic_p, avail_p; | |
1961 | { | |
1962 | int found, do_not_record_p; | |
1963 | unsigned int hash; | |
1964 | struct expr *cur_expr, *last_expr = NULL; | |
1965 | struct occr *antic_occr, *avail_occr; | |
1966 | struct occr *last_occr = NULL; | |
1967 | ||
1968 | hash = hash_expr (x, mode, &do_not_record_p, expr_hash_table_size); | |
1969 | ||
1970 | /* Do not insert expression in table if it contains volatile operands, | |
1971 | or if hash_expr determines the expression is something we don't want | |
1972 | to or can't handle. */ | |
1973 | if (do_not_record_p) | |
1974 | return; | |
1975 | ||
1976 | cur_expr = expr_hash_table[hash]; | |
1977 | found = 0; | |
1978 | ||
c4c81601 | 1979 | while (cur_expr && 0 == (found = expr_equiv_p (cur_expr->expr, x))) |
7506f491 DE |
1980 | { |
1981 | /* If the expression isn't found, save a pointer to the end of | |
1982 | the list. */ | |
1983 | last_expr = cur_expr; | |
1984 | cur_expr = cur_expr->next_same_hash; | |
1985 | } | |
1986 | ||
1987 | if (! found) | |
1988 | { | |
1989 | cur_expr = (struct expr *) gcse_alloc (sizeof (struct expr)); | |
1990 | bytes_used += sizeof (struct expr); | |
1991 | if (expr_hash_table[hash] == NULL) | |
c4c81601 RK |
1992 | /* This is the first pattern that hashed to this index. */ |
1993 | expr_hash_table[hash] = cur_expr; | |
7506f491 | 1994 | else |
c4c81601 RK |
1995 | /* Add EXPR to end of this hash chain. */ |
1996 | last_expr->next_same_hash = cur_expr; | |
1997 | ||
7506f491 DE |
1998 | /* Set the fields of the expr element. */ |
1999 | cur_expr->expr = x; | |
2000 | cur_expr->bitmap_index = n_exprs++; | |
2001 | cur_expr->next_same_hash = NULL; | |
2002 | cur_expr->antic_occr = NULL; | |
2003 | cur_expr->avail_occr = NULL; | |
2004 | } | |
2005 | ||
2006 | /* Now record the occurrence(s). */ | |
7506f491 DE |
2007 | if (antic_p) |
2008 | { | |
2009 | antic_occr = cur_expr->antic_occr; | |
2010 | ||
2011 | /* Search for another occurrence in the same basic block. */ | |
2012 | while (antic_occr && BLOCK_NUM (antic_occr->insn) != BLOCK_NUM (insn)) | |
2013 | { | |
2014 | /* If an occurrence isn't found, save a pointer to the end of | |
2015 | the list. */ | |
2016 | last_occr = antic_occr; | |
2017 | antic_occr = antic_occr->next; | |
2018 | } | |
2019 | ||
2020 | if (antic_occr) | |
c4c81601 RK |
2021 | /* Found another instance of the expression in the same basic block. |
2022 | Prefer the currently recorded one. We want the first one in the | |
2023 | block and the block is scanned from start to end. */ | |
2024 | ; /* nothing to do */ | |
7506f491 DE |
2025 | else |
2026 | { | |
2027 | /* First occurrence of this expression in this basic block. */ | |
2028 | antic_occr = (struct occr *) gcse_alloc (sizeof (struct occr)); | |
2029 | bytes_used += sizeof (struct occr); | |
2030 | /* First occurrence of this expression in any block? */ | |
2031 | if (cur_expr->antic_occr == NULL) | |
2032 | cur_expr->antic_occr = antic_occr; | |
2033 | else | |
2034 | last_occr->next = antic_occr; | |
c4c81601 | 2035 | |
7506f491 DE |
2036 | antic_occr->insn = insn; |
2037 | antic_occr->next = NULL; | |
2038 | } | |
2039 | } | |
2040 | ||
2041 | if (avail_p) | |
2042 | { | |
2043 | avail_occr = cur_expr->avail_occr; | |
2044 | ||
2045 | /* Search for another occurrence in the same basic block. */ | |
2046 | while (avail_occr && BLOCK_NUM (avail_occr->insn) != BLOCK_NUM (insn)) | |
2047 | { | |
2048 | /* If an occurrence isn't found, save a pointer to the end of | |
2049 | the list. */ | |
2050 | last_occr = avail_occr; | |
2051 | avail_occr = avail_occr->next; | |
2052 | } | |
2053 | ||
2054 | if (avail_occr) | |
c4c81601 RK |
2055 | /* Found another instance of the expression in the same basic block. |
2056 | Prefer this occurrence to the currently recorded one. We want | |
2057 | the last one in the block and the block is scanned from start | |
2058 | to end. */ | |
2059 | avail_occr->insn = insn; | |
7506f491 DE |
2060 | else |
2061 | { | |
2062 | /* First occurrence of this expression in this basic block. */ | |
2063 | avail_occr = (struct occr *) gcse_alloc (sizeof (struct occr)); | |
2064 | bytes_used += sizeof (struct occr); | |
c4c81601 | 2065 | |
7506f491 DE |
2066 | /* First occurrence of this expression in any block? */ |
2067 | if (cur_expr->avail_occr == NULL) | |
2068 | cur_expr->avail_occr = avail_occr; | |
2069 | else | |
2070 | last_occr->next = avail_occr; | |
c4c81601 | 2071 | |
7506f491 DE |
2072 | avail_occr->insn = insn; |
2073 | avail_occr->next = NULL; | |
2074 | } | |
2075 | } | |
2076 | } | |
2077 | ||
2078 | /* Insert pattern X in INSN in the hash table. | |
2079 | X is a SET of a reg to either another reg or a constant. | |
2080 | If it is already present, record it as the last occurrence in INSN's | |
2081 | basic block. */ | |
2082 | ||
2083 | static void | |
2084 | insert_set_in_table (x, insn) | |
2085 | rtx x; | |
2086 | rtx insn; | |
2087 | { | |
2088 | int found; | |
2089 | unsigned int hash; | |
2090 | struct expr *cur_expr, *last_expr = NULL; | |
2091 | struct occr *cur_occr, *last_occr = NULL; | |
2092 | ||
2093 | if (GET_CODE (x) != SET | |
2094 | || GET_CODE (SET_DEST (x)) != REG) | |
2095 | abort (); | |
2096 | ||
2097 | hash = hash_set (REGNO (SET_DEST (x)), set_hash_table_size); | |
2098 | ||
2099 | cur_expr = set_hash_table[hash]; | |
2100 | found = 0; | |
2101 | ||
c4c81601 | 2102 | while (cur_expr && 0 == (found = expr_equiv_p (cur_expr->expr, x))) |
7506f491 DE |
2103 | { |
2104 | /* If the expression isn't found, save a pointer to the end of | |
2105 | the list. */ | |
2106 | last_expr = cur_expr; | |
2107 | cur_expr = cur_expr->next_same_hash; | |
2108 | } | |
2109 | ||
2110 | if (! found) | |
2111 | { | |
2112 | cur_expr = (struct expr *) gcse_alloc (sizeof (struct expr)); | |
2113 | bytes_used += sizeof (struct expr); | |
2114 | if (set_hash_table[hash] == NULL) | |
c4c81601 RK |
2115 | /* This is the first pattern that hashed to this index. */ |
2116 | set_hash_table[hash] = cur_expr; | |
7506f491 | 2117 | else |
c4c81601 RK |
2118 | /* Add EXPR to end of this hash chain. */ |
2119 | last_expr->next_same_hash = cur_expr; | |
2120 | ||
7506f491 DE |
2121 | /* Set the fields of the expr element. |
2122 | We must copy X because it can be modified when copy propagation is | |
2123 | performed on its operands. */ | |
7506f491 DE |
2124 | cur_expr->expr = copy_rtx (x); |
2125 | cur_expr->bitmap_index = n_sets++; | |
2126 | cur_expr->next_same_hash = NULL; | |
2127 | cur_expr->antic_occr = NULL; | |
2128 | cur_expr->avail_occr = NULL; | |
2129 | } | |
2130 | ||
2131 | /* Now record the occurrence. */ | |
7506f491 DE |
2132 | cur_occr = cur_expr->avail_occr; |
2133 | ||
2134 | /* Search for another occurrence in the same basic block. */ | |
2135 | while (cur_occr && BLOCK_NUM (cur_occr->insn) != BLOCK_NUM (insn)) | |
2136 | { | |
2137 | /* If an occurrence isn't found, save a pointer to the end of | |
2138 | the list. */ | |
2139 | last_occr = cur_occr; | |
2140 | cur_occr = cur_occr->next; | |
2141 | } | |
2142 | ||
2143 | if (cur_occr) | |
c4c81601 RK |
2144 | /* Found another instance of the expression in the same basic block. |
2145 | Prefer this occurrence to the currently recorded one. We want the | |
2146 | last one in the block and the block is scanned from start to end. */ | |
2147 | cur_occr->insn = insn; | |
7506f491 DE |
2148 | else |
2149 | { | |
2150 | /* First occurrence of this expression in this basic block. */ | |
2151 | cur_occr = (struct occr *) gcse_alloc (sizeof (struct occr)); | |
2152 | bytes_used += sizeof (struct occr); | |
c4c81601 | 2153 | |
7506f491 DE |
2154 | /* First occurrence of this expression in any block? */ |
2155 | if (cur_expr->avail_occr == NULL) | |
2156 | cur_expr->avail_occr = cur_occr; | |
2157 | else | |
2158 | last_occr->next = cur_occr; | |
c4c81601 | 2159 | |
7506f491 DE |
2160 | cur_occr->insn = insn; |
2161 | cur_occr->next = NULL; | |
2162 | } | |
2163 | } | |
2164 | ||
c4c81601 RK |
2165 | /* Scan pattern PAT of INSN and add an entry to the hash table. If SET_P is |
2166 | non-zero, this is for the assignment hash table, otherwise it is for the | |
2167 | expression hash table. */ | |
7506f491 DE |
2168 | |
2169 | static void | |
2170 | hash_scan_set (pat, insn, set_p) | |
2171 | rtx pat, insn; | |
2172 | int set_p; | |
2173 | { | |
2174 | rtx src = SET_SRC (pat); | |
2175 | rtx dest = SET_DEST (pat); | |
172890a2 | 2176 | rtx note; |
7506f491 DE |
2177 | |
2178 | if (GET_CODE (src) == CALL) | |
2179 | hash_scan_call (src, insn); | |
2180 | ||
172890a2 | 2181 | else if (GET_CODE (dest) == REG) |
7506f491 | 2182 | { |
172890a2 | 2183 | unsigned int regno = REGNO (dest); |
7506f491 DE |
2184 | rtx tmp; |
2185 | ||
172890a2 RK |
2186 | /* If this is a single set and we are doing constant propagation, |
2187 | see if a REG_NOTE shows this equivalent to a constant. */ | |
2188 | if (set_p && (note = find_reg_equal_equiv_note (insn)) != 0 | |
2189 | && CONSTANT_P (XEXP (note, 0))) | |
2190 | src = XEXP (note, 0), pat = gen_rtx_SET (VOIDmode, dest, src); | |
2191 | ||
7506f491 DE |
2192 | /* Only record sets of pseudo-regs in the hash table. */ |
2193 | if (! set_p | |
2194 | && regno >= FIRST_PSEUDO_REGISTER | |
2195 | /* Don't GCSE something if we can't do a reg/reg copy. */ | |
2196 | && can_copy_p [GET_MODE (dest)] | |
068473ec JH |
2197 | /* GCSE commonly inserts instruction after the insn. We can't |
2198 | do that easily for EH_REGION notes so disable GCSE on these | |
2199 | for now. */ | |
2200 | && !find_reg_note (insn, REG_EH_REGION, NULL_RTX) | |
7506f491 | 2201 | /* Is SET_SRC something we want to gcse? */ |
172890a2 RK |
2202 | && want_to_gcse_p (src) |
2203 | /* Don't CSE a nop. */ | |
43e72072 JJ |
2204 | && ! set_noop_p (pat) |
2205 | /* Don't GCSE if it has attached REG_EQUIV note. | |
2206 | At this point this only function parameters should have | |
2207 | REG_EQUIV notes and if the argument slot is used somewhere | |
a1f300c0 | 2208 | explicitly, it means address of parameter has been taken, |
43e72072 JJ |
2209 | so we should not extend the lifetime of the pseudo. */ |
2210 | && ((note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) == 0 | |
2211 | || GET_CODE (XEXP (note, 0)) != MEM)) | |
7506f491 DE |
2212 | { |
2213 | /* An expression is not anticipatable if its operands are | |
52d76e11 RK |
2214 | modified before this insn or if this is not the only SET in |
2215 | this insn. */ | |
2216 | int antic_p = oprs_anticipatable_p (src, insn) && single_set (insn); | |
7506f491 | 2217 | /* An expression is not available if its operands are |
eb296bd9 GK |
2218 | subsequently modified, including this insn. It's also not |
2219 | available if this is a branch, because we can't insert | |
2220 | a set after the branch. */ | |
2221 | int avail_p = (oprs_available_p (src, insn) | |
2222 | && ! JUMP_P (insn)); | |
c4c81601 | 2223 | |
7506f491 DE |
2224 | insert_expr_in_table (src, GET_MODE (dest), insn, antic_p, avail_p); |
2225 | } | |
c4c81601 | 2226 | |
7506f491 DE |
2227 | /* Record sets for constant/copy propagation. */ |
2228 | else if (set_p | |
2229 | && regno >= FIRST_PSEUDO_REGISTER | |
2230 | && ((GET_CODE (src) == REG | |
2231 | && REGNO (src) >= FIRST_PSEUDO_REGISTER | |
172890a2 RK |
2232 | && can_copy_p [GET_MODE (dest)] |
2233 | && REGNO (src) != regno) | |
b446e5a2 | 2234 | || CONSTANT_P (src)) |
7506f491 DE |
2235 | /* A copy is not available if its src or dest is subsequently |
2236 | modified. Here we want to search from INSN+1 on, but | |
2237 | oprs_available_p searches from INSN on. */ | |
2238 | && (insn == BLOCK_END (BLOCK_NUM (insn)) | |
2239 | || ((tmp = next_nonnote_insn (insn)) != NULL_RTX | |
2240 | && oprs_available_p (pat, tmp)))) | |
2241 | insert_set_in_table (pat, insn); | |
2242 | } | |
7506f491 DE |
2243 | } |
2244 | ||
2245 | static void | |
2246 | hash_scan_clobber (x, insn) | |
50b2596f | 2247 | rtx x ATTRIBUTE_UNUSED, insn ATTRIBUTE_UNUSED; |
7506f491 DE |
2248 | { |
2249 | /* Currently nothing to do. */ | |
2250 | } | |
2251 | ||
2252 | static void | |
2253 | hash_scan_call (x, insn) | |
50b2596f | 2254 | rtx x ATTRIBUTE_UNUSED, insn ATTRIBUTE_UNUSED; |
7506f491 DE |
2255 | { |
2256 | /* Currently nothing to do. */ | |
2257 | } | |
2258 | ||
2259 | /* Process INSN and add hash table entries as appropriate. | |
2260 | ||
2261 | Only available expressions that set a single pseudo-reg are recorded. | |
2262 | ||
2263 | Single sets in a PARALLEL could be handled, but it's an extra complication | |
2264 | that isn't dealt with right now. The trick is handling the CLOBBERs that | |
2265 | are also in the PARALLEL. Later. | |
2266 | ||
2267 | If SET_P is non-zero, this is for the assignment hash table, | |
ed79bb3d R |
2268 | otherwise it is for the expression hash table. |
2269 | If IN_LIBCALL_BLOCK nonzero, we are in a libcall block, and should | |
2270 | not record any expressions. */ | |
7506f491 DE |
2271 | |
2272 | static void | |
ed79bb3d | 2273 | hash_scan_insn (insn, set_p, in_libcall_block) |
7506f491 DE |
2274 | rtx insn; |
2275 | int set_p; | |
48e87cef | 2276 | int in_libcall_block; |
7506f491 DE |
2277 | { |
2278 | rtx pat = PATTERN (insn); | |
c4c81601 | 2279 | int i; |
7506f491 | 2280 | |
172890a2 RK |
2281 | if (in_libcall_block) |
2282 | return; | |
2283 | ||
7506f491 DE |
2284 | /* Pick out the sets of INSN and for other forms of instructions record |
2285 | what's been modified. */ | |
2286 | ||
172890a2 RK |
2287 | if (GET_CODE (pat) == SET) |
2288 | hash_scan_set (pat, insn, set_p); | |
7506f491 | 2289 | else if (GET_CODE (pat) == PARALLEL) |
c4c81601 RK |
2290 | for (i = 0; i < XVECLEN (pat, 0); i++) |
2291 | { | |
2292 | rtx x = XVECEXP (pat, 0, i); | |
7506f491 | 2293 | |
c4c81601 | 2294 | if (GET_CODE (x) == SET) |
172890a2 | 2295 | hash_scan_set (x, insn, set_p); |
c4c81601 RK |
2296 | else if (GET_CODE (x) == CLOBBER) |
2297 | hash_scan_clobber (x, insn); | |
2298 | else if (GET_CODE (x) == CALL) | |
2299 | hash_scan_call (x, insn); | |
2300 | } | |
7506f491 | 2301 | |
7506f491 DE |
2302 | else if (GET_CODE (pat) == CLOBBER) |
2303 | hash_scan_clobber (pat, insn); | |
2304 | else if (GET_CODE (pat) == CALL) | |
2305 | hash_scan_call (pat, insn); | |
2306 | } | |
2307 | ||
2308 | static void | |
2309 | dump_hash_table (file, name, table, table_size, total_size) | |
2310 | FILE *file; | |
dff01034 | 2311 | const char *name; |
7506f491 DE |
2312 | struct expr **table; |
2313 | int table_size, total_size; | |
2314 | { | |
2315 | int i; | |
2316 | /* Flattened out table, so it's printed in proper order. */ | |
4da896b2 MM |
2317 | struct expr **flat_table; |
2318 | unsigned int *hash_val; | |
c4c81601 | 2319 | struct expr *expr; |
4da896b2 MM |
2320 | |
2321 | flat_table | |
2322 | = (struct expr **) xcalloc (total_size, sizeof (struct expr *)); | |
2323 | hash_val = (unsigned int *) xmalloc (total_size * sizeof (unsigned int)); | |
7506f491 | 2324 | |
7506f491 | 2325 | for (i = 0; i < table_size; i++) |
c4c81601 RK |
2326 | for (expr = table[i]; expr != NULL; expr = expr->next_same_hash) |
2327 | { | |
2328 | flat_table[expr->bitmap_index] = expr; | |
2329 | hash_val[expr->bitmap_index] = i; | |
2330 | } | |
7506f491 DE |
2331 | |
2332 | fprintf (file, "%s hash table (%d buckets, %d entries)\n", | |
2333 | name, table_size, total_size); | |
2334 | ||
2335 | for (i = 0; i < total_size; i++) | |
21318741 RK |
2336 | if (flat_table[i] != 0) |
2337 | { | |
a0ac9e5a | 2338 | expr = flat_table[i]; |
21318741 RK |
2339 | fprintf (file, "Index %d (hash value %d)\n ", |
2340 | expr->bitmap_index, hash_val[i]); | |
a0ac9e5a | 2341 | print_rtl (file, expr->expr); |
21318741 RK |
2342 | fprintf (file, "\n"); |
2343 | } | |
7506f491 DE |
2344 | |
2345 | fprintf (file, "\n"); | |
4da896b2 | 2346 | |
4da896b2 MM |
2347 | free (flat_table); |
2348 | free (hash_val); | |
7506f491 DE |
2349 | } |
2350 | ||
2351 | /* Record register first/last/block set information for REGNO in INSN. | |
c4c81601 | 2352 | |
80c29cc4 | 2353 | first_set records the first place in the block where the register |
7506f491 | 2354 | is set and is used to compute "anticipatability". |
c4c81601 | 2355 | |
80c29cc4 | 2356 | last_set records the last place in the block where the register |
7506f491 | 2357 | is set and is used to compute "availability". |
c4c81601 | 2358 | |
80c29cc4 RZ |
2359 | last_bb records the block for which first_set and last_set are |
2360 | valid, as a quick test to invalidate them. | |
2361 | ||
7506f491 DE |
2362 | reg_set_in_block records whether the register is set in the block |
2363 | and is used to compute "transparency". */ | |
2364 | ||
2365 | static void | |
2366 | record_last_reg_set_info (insn, regno) | |
2367 | rtx insn; | |
2368 | int regno; | |
2369 | { | |
80c29cc4 RZ |
2370 | struct reg_avail_info *info = ®_avail_info[regno]; |
2371 | int cuid = INSN_CUID (insn); | |
c4c81601 | 2372 | |
80c29cc4 RZ |
2373 | info->last_set = cuid; |
2374 | if (info->last_bb != current_bb) | |
2375 | { | |
2376 | info->last_bb = current_bb; | |
2377 | info->first_set = cuid; | |
e0082a72 | 2378 | SET_BIT (reg_set_in_block[current_bb->index], regno); |
80c29cc4 | 2379 | } |
7506f491 DE |
2380 | } |
2381 | ||
a13d4ebf AM |
2382 | |
2383 | /* Record all of the canonicalized MEMs of record_last_mem_set_info's insn. | |
2384 | Note we store a pair of elements in the list, so they have to be | |
2385 | taken off pairwise. */ | |
2386 | ||
2387 | static void | |
2388 | canon_list_insert (dest, unused1, v_insn) | |
2389 | rtx dest ATTRIBUTE_UNUSED; | |
2390 | rtx unused1 ATTRIBUTE_UNUSED; | |
2391 | void * v_insn; | |
2392 | { | |
2393 | rtx dest_addr, insn; | |
0fe854a7 | 2394 | int bb; |
a13d4ebf AM |
2395 | |
2396 | while (GET_CODE (dest) == SUBREG | |
2397 | || GET_CODE (dest) == ZERO_EXTRACT | |
2398 | || GET_CODE (dest) == SIGN_EXTRACT | |
2399 | || GET_CODE (dest) == STRICT_LOW_PART) | |
2400 | dest = XEXP (dest, 0); | |
2401 | ||
2402 | /* If DEST is not a MEM, then it will not conflict with a load. Note | |
2403 | that function calls are assumed to clobber memory, but are handled | |
2404 | elsewhere. */ | |
2405 | ||
2406 | if (GET_CODE (dest) != MEM) | |
2407 | return; | |
2408 | ||
2409 | dest_addr = get_addr (XEXP (dest, 0)); | |
2410 | dest_addr = canon_rtx (dest_addr); | |
2411 | insn = (rtx) v_insn; | |
0fe854a7 | 2412 | bb = BLOCK_NUM (insn); |
a13d4ebf | 2413 | |
0fe854a7 RH |
2414 | canon_modify_mem_list[bb] = |
2415 | alloc_EXPR_LIST (VOIDmode, dest_addr, canon_modify_mem_list[bb]); | |
2416 | canon_modify_mem_list[bb] = | |
2417 | alloc_EXPR_LIST (VOIDmode, dest, canon_modify_mem_list[bb]); | |
2418 | bitmap_set_bit (canon_modify_mem_list_set, bb); | |
a13d4ebf AM |
2419 | } |
2420 | ||
a13d4ebf AM |
2421 | /* Record memory modification information for INSN. We do not actually care |
2422 | about the memory location(s) that are set, or even how they are set (consider | |
2423 | a CALL_INSN). We merely need to record which insns modify memory. */ | |
7506f491 DE |
2424 | |
2425 | static void | |
2426 | record_last_mem_set_info (insn) | |
2427 | rtx insn; | |
2428 | { | |
0fe854a7 RH |
2429 | int bb = BLOCK_NUM (insn); |
2430 | ||
ccef9ef5 | 2431 | /* load_killed_in_block_p will handle the case of calls clobbering |
dc297297 | 2432 | everything. */ |
0fe854a7 RH |
2433 | modify_mem_list[bb] = alloc_INSN_LIST (insn, modify_mem_list[bb]); |
2434 | bitmap_set_bit (modify_mem_list_set, bb); | |
a13d4ebf AM |
2435 | |
2436 | if (GET_CODE (insn) == CALL_INSN) | |
2437 | { | |
2438 | /* Note that traversals of this loop (other than for free-ing) | |
2439 | will break after encountering a CALL_INSN. So, there's no | |
dc297297 | 2440 | need to insert a pair of items, as canon_list_insert does. */ |
0fe854a7 RH |
2441 | canon_modify_mem_list[bb] = |
2442 | alloc_INSN_LIST (insn, canon_modify_mem_list[bb]); | |
2443 | bitmap_set_bit (canon_modify_mem_list_set, bb); | |
a13d4ebf AM |
2444 | } |
2445 | else | |
0fe854a7 | 2446 | note_stores (PATTERN (insn), canon_list_insert, (void*) insn); |
7506f491 DE |
2447 | } |
2448 | ||
7506f491 | 2449 | /* Called from compute_hash_table via note_stores to handle one |
84832317 MM |
2450 | SET or CLOBBER in an insn. DATA is really the instruction in which |
2451 | the SET is taking place. */ | |
7506f491 DE |
2452 | |
2453 | static void | |
84832317 | 2454 | record_last_set_info (dest, setter, data) |
50b2596f | 2455 | rtx dest, setter ATTRIBUTE_UNUSED; |
84832317 | 2456 | void *data; |
7506f491 | 2457 | { |
84832317 MM |
2458 | rtx last_set_insn = (rtx) data; |
2459 | ||
7506f491 DE |
2460 | if (GET_CODE (dest) == SUBREG) |
2461 | dest = SUBREG_REG (dest); | |
2462 | ||
2463 | if (GET_CODE (dest) == REG) | |
2464 | record_last_reg_set_info (last_set_insn, REGNO (dest)); | |
2465 | else if (GET_CODE (dest) == MEM | |
2466 | /* Ignore pushes, they clobber nothing. */ | |
2467 | && ! push_operand (dest, GET_MODE (dest))) | |
2468 | record_last_mem_set_info (last_set_insn); | |
2469 | } | |
2470 | ||
2471 | /* Top level function to create an expression or assignment hash table. | |
2472 | ||
2473 | Expression entries are placed in the hash table if | |
2474 | - they are of the form (set (pseudo-reg) src), | |
2475 | - src is something we want to perform GCSE on, | |
2476 | - none of the operands are subsequently modified in the block | |
2477 | ||
2478 | Assignment entries are placed in the hash table if | |
2479 | - they are of the form (set (pseudo-reg) src), | |
2480 | - src is something we want to perform const/copy propagation on, | |
2481 | - none of the operands or target are subsequently modified in the block | |
c4c81601 | 2482 | |
7506f491 DE |
2483 | Currently src must be a pseudo-reg or a const_int. |
2484 | ||
2485 | F is the first insn. | |
2486 | SET_P is non-zero for computing the assignment hash table. */ | |
2487 | ||
2488 | static void | |
b5ce41ff | 2489 | compute_hash_table (set_p) |
7506f491 DE |
2490 | int set_p; |
2491 | { | |
80c29cc4 | 2492 | unsigned int i; |
7506f491 DE |
2493 | |
2494 | /* While we compute the hash table we also compute a bit array of which | |
2495 | registers are set in which blocks. | |
7506f491 DE |
2496 | ??? This isn't needed during const/copy propagation, but it's cheap to |
2497 | compute. Later. */ | |
d55bc081 | 2498 | sbitmap_vector_zero (reg_set_in_block, last_basic_block); |
7506f491 | 2499 | |
a13d4ebf | 2500 | /* re-Cache any INSN_LIST nodes we have allocated. */ |
73991d6a | 2501 | clear_modify_mem_tables (); |
7506f491 | 2502 | /* Some working arrays used to track first and last set in each block. */ |
80c29cc4 RZ |
2503 | reg_avail_info = (struct reg_avail_info*) |
2504 | gmalloc (max_gcse_regno * sizeof (struct reg_avail_info)); | |
2505 | ||
2506 | for (i = 0; i < max_gcse_regno; ++i) | |
e0082a72 | 2507 | reg_avail_info[i].last_bb = NULL; |
7506f491 | 2508 | |
e0082a72 | 2509 | FOR_EACH_BB (current_bb) |
7506f491 DE |
2510 | { |
2511 | rtx insn; | |
770ae6cc | 2512 | unsigned int regno; |
ed79bb3d | 2513 | int in_libcall_block; |
7506f491 DE |
2514 | |
2515 | /* First pass over the instructions records information used to | |
2516 | determine when registers and memory are first and last set. | |
ccef9ef5 | 2517 | ??? hard-reg reg_set_in_block computation |
7506f491 DE |
2518 | could be moved to compute_sets since they currently don't change. */ |
2519 | ||
e0082a72 ZD |
2520 | for (insn = current_bb->head; |
2521 | insn && insn != NEXT_INSN (current_bb->end); | |
7506f491 DE |
2522 | insn = NEXT_INSN (insn)) |
2523 | { | |
2c3c49de | 2524 | if (! INSN_P (insn)) |
7506f491 DE |
2525 | continue; |
2526 | ||
2527 | if (GET_CODE (insn) == CALL_INSN) | |
2528 | { | |
19652adf ZW |
2529 | bool clobbers_all = false; |
2530 | #ifdef NON_SAVING_SETJMP | |
2531 | if (NON_SAVING_SETJMP | |
2532 | && find_reg_note (insn, REG_SETJMP, NULL_RTX)) | |
2533 | clobbers_all = true; | |
2534 | #endif | |
2535 | ||
7506f491 | 2536 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) |
19652adf ZW |
2537 | if (clobbers_all |
2538 | || TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) | |
7506f491 | 2539 | record_last_reg_set_info (insn, regno); |
c4c81601 | 2540 | |
24a28584 | 2541 | mark_call (insn); |
7506f491 DE |
2542 | } |
2543 | ||
84832317 | 2544 | note_stores (PATTERN (insn), record_last_set_info, insn); |
7506f491 DE |
2545 | } |
2546 | ||
2547 | /* The next pass builds the hash table. */ | |
2548 | ||
e0082a72 ZD |
2549 | for (insn = current_bb->head, in_libcall_block = 0; |
2550 | insn && insn != NEXT_INSN (current_bb->end); | |
7506f491 | 2551 | insn = NEXT_INSN (insn)) |
2c3c49de | 2552 | if (INSN_P (insn)) |
c4c81601 RK |
2553 | { |
2554 | if (find_reg_note (insn, REG_LIBCALL, NULL_RTX)) | |
c63b1ae8 AM |
2555 | in_libcall_block = 1; |
2556 | else if (set_p && find_reg_note (insn, REG_RETVAL, NULL_RTX)) | |
2557 | in_libcall_block = 0; | |
2558 | hash_scan_insn (insn, set_p, in_libcall_block); | |
2559 | if (!set_p && find_reg_note (insn, REG_RETVAL, NULL_RTX)) | |
2560 | in_libcall_block = 0; | |
8e42ace1 | 2561 | } |
7506f491 DE |
2562 | } |
2563 | ||
80c29cc4 RZ |
2564 | free (reg_avail_info); |
2565 | reg_avail_info = NULL; | |
7506f491 DE |
2566 | } |
2567 | ||
2568 | /* Allocate space for the set hash table. | |
2569 | N_INSNS is the number of instructions in the function. | |
2570 | It is used to determine the number of buckets to use. */ | |
2571 | ||
2572 | static void | |
2573 | alloc_set_hash_table (n_insns) | |
2574 | int n_insns; | |
2575 | { | |
2576 | int n; | |
2577 | ||
2578 | set_hash_table_size = n_insns / 4; | |
2579 | if (set_hash_table_size < 11) | |
2580 | set_hash_table_size = 11; | |
c4c81601 | 2581 | |
7506f491 DE |
2582 | /* Attempt to maintain efficient use of hash table. |
2583 | Making it an odd number is simplest for now. | |
2584 | ??? Later take some measurements. */ | |
2585 | set_hash_table_size |= 1; | |
2586 | n = set_hash_table_size * sizeof (struct expr *); | |
2587 | set_hash_table = (struct expr **) gmalloc (n); | |
2588 | } | |
2589 | ||
2590 | /* Free things allocated by alloc_set_hash_table. */ | |
2591 | ||
2592 | static void | |
2593 | free_set_hash_table () | |
2594 | { | |
2595 | free (set_hash_table); | |
2596 | } | |
2597 | ||
2598 | /* Compute the hash table for doing copy/const propagation. */ | |
2599 | ||
2600 | static void | |
b5ce41ff | 2601 | compute_set_hash_table () |
7506f491 DE |
2602 | { |
2603 | /* Initialize count of number of entries in hash table. */ | |
2604 | n_sets = 0; | |
961192e1 | 2605 | memset ((char *) set_hash_table, 0, |
8e42ace1 | 2606 | set_hash_table_size * sizeof (struct expr *)); |
7506f491 | 2607 | |
b5ce41ff | 2608 | compute_hash_table (1); |
7506f491 DE |
2609 | } |
2610 | ||
2611 | /* Allocate space for the expression hash table. | |
2612 | N_INSNS is the number of instructions in the function. | |
2613 | It is used to determine the number of buckets to use. */ | |
2614 | ||
2615 | static void | |
2616 | alloc_expr_hash_table (n_insns) | |
2e653e39 | 2617 | unsigned int n_insns; |
7506f491 DE |
2618 | { |
2619 | int n; | |
2620 | ||
2621 | expr_hash_table_size = n_insns / 2; | |
2622 | /* Make sure the amount is usable. */ | |
2623 | if (expr_hash_table_size < 11) | |
2624 | expr_hash_table_size = 11; | |
c4c81601 | 2625 | |
7506f491 DE |
2626 | /* Attempt to maintain efficient use of hash table. |
2627 | Making it an odd number is simplest for now. | |
2628 | ??? Later take some measurements. */ | |
2629 | expr_hash_table_size |= 1; | |
2630 | n = expr_hash_table_size * sizeof (struct expr *); | |
2631 | expr_hash_table = (struct expr **) gmalloc (n); | |
2632 | } | |
2633 | ||
2634 | /* Free things allocated by alloc_expr_hash_table. */ | |
2635 | ||
2636 | static void | |
2637 | free_expr_hash_table () | |
2638 | { | |
2639 | free (expr_hash_table); | |
2640 | } | |
2641 | ||
2642 | /* Compute the hash table for doing GCSE. */ | |
2643 | ||
2644 | static void | |
b5ce41ff | 2645 | compute_expr_hash_table () |
7506f491 DE |
2646 | { |
2647 | /* Initialize count of number of entries in hash table. */ | |
2648 | n_exprs = 0; | |
961192e1 | 2649 | memset ((char *) expr_hash_table, 0, |
8e42ace1 | 2650 | expr_hash_table_size * sizeof (struct expr *)); |
7506f491 | 2651 | |
b5ce41ff | 2652 | compute_hash_table (0); |
7506f491 DE |
2653 | } |
2654 | \f | |
2655 | /* Expression tracking support. */ | |
2656 | ||
2657 | /* Lookup pattern PAT in the expression table. | |
2658 | The result is a pointer to the table entry, or NULL if not found. */ | |
2659 | ||
2660 | static struct expr * | |
2661 | lookup_expr (pat) | |
2662 | rtx pat; | |
2663 | { | |
2664 | int do_not_record_p; | |
2665 | unsigned int hash = hash_expr (pat, GET_MODE (pat), &do_not_record_p, | |
2666 | expr_hash_table_size); | |
2667 | struct expr *expr; | |
2668 | ||
2669 | if (do_not_record_p) | |
2670 | return NULL; | |
2671 | ||
2672 | expr = expr_hash_table[hash]; | |
2673 | ||
2674 | while (expr && ! expr_equiv_p (expr->expr, pat)) | |
2675 | expr = expr->next_same_hash; | |
2676 | ||
2677 | return expr; | |
2678 | } | |
2679 | ||
c4c81601 RK |
2680 | /* Lookup REGNO in the set table. If PAT is non-NULL look for the entry that |
2681 | matches it, otherwise return the first entry for REGNO. The result is a | |
2682 | pointer to the table entry, or NULL if not found. */ | |
7506f491 DE |
2683 | |
2684 | static struct expr * | |
2685 | lookup_set (regno, pat) | |
770ae6cc | 2686 | unsigned int regno; |
7506f491 DE |
2687 | rtx pat; |
2688 | { | |
2689 | unsigned int hash = hash_set (regno, set_hash_table_size); | |
2690 | struct expr *expr; | |
2691 | ||
2692 | expr = set_hash_table[hash]; | |
2693 | ||
2694 | if (pat) | |
2695 | { | |
2696 | while (expr && ! expr_equiv_p (expr->expr, pat)) | |
2697 | expr = expr->next_same_hash; | |
2698 | } | |
2699 | else | |
2700 | { | |
2701 | while (expr && REGNO (SET_DEST (expr->expr)) != regno) | |
2702 | expr = expr->next_same_hash; | |
2703 | } | |
2704 | ||
2705 | return expr; | |
2706 | } | |
2707 | ||
2708 | /* Return the next entry for REGNO in list EXPR. */ | |
2709 | ||
2710 | static struct expr * | |
2711 | next_set (regno, expr) | |
770ae6cc | 2712 | unsigned int regno; |
7506f491 DE |
2713 | struct expr *expr; |
2714 | { | |
2715 | do | |
2716 | expr = expr->next_same_hash; | |
2717 | while (expr && REGNO (SET_DEST (expr->expr)) != regno); | |
c4c81601 | 2718 | |
7506f491 DE |
2719 | return expr; |
2720 | } | |
2721 | ||
0fe854a7 RH |
2722 | /* Like free_INSN_LIST_list or free_EXPR_LIST_list, except that the node |
2723 | types may be mixed. */ | |
2724 | ||
2725 | static void | |
2726 | free_insn_expr_list_list (listp) | |
2727 | rtx *listp; | |
2728 | { | |
2729 | rtx list, next; | |
2730 | ||
2731 | for (list = *listp; list ; list = next) | |
2732 | { | |
2733 | next = XEXP (list, 1); | |
2734 | if (GET_CODE (list) == EXPR_LIST) | |
2735 | free_EXPR_LIST_node (list); | |
2736 | else | |
2737 | free_INSN_LIST_node (list); | |
2738 | } | |
2739 | ||
2740 | *listp = NULL; | |
2741 | } | |
2742 | ||
73991d6a JH |
2743 | /* Clear canon_modify_mem_list and modify_mem_list tables. */ |
2744 | static void | |
2745 | clear_modify_mem_tables () | |
2746 | { | |
2747 | int i; | |
2748 | ||
2749 | EXECUTE_IF_SET_IN_BITMAP | |
0fe854a7 RH |
2750 | (modify_mem_list_set, 0, i, free_INSN_LIST_list (modify_mem_list + i)); |
2751 | bitmap_clear (modify_mem_list_set); | |
73991d6a JH |
2752 | |
2753 | EXECUTE_IF_SET_IN_BITMAP | |
2754 | (canon_modify_mem_list_set, 0, i, | |
0fe854a7 RH |
2755 | free_insn_expr_list_list (canon_modify_mem_list + i)); |
2756 | bitmap_clear (canon_modify_mem_list_set); | |
73991d6a JH |
2757 | } |
2758 | ||
2759 | /* Release memory used by modify_mem_list_set and canon_modify_mem_list_set. */ | |
2760 | ||
2761 | static void | |
2762 | free_modify_mem_tables () | |
2763 | { | |
2764 | clear_modify_mem_tables (); | |
2765 | free (modify_mem_list); | |
2766 | free (canon_modify_mem_list); | |
2767 | modify_mem_list = 0; | |
2768 | canon_modify_mem_list = 0; | |
2769 | } | |
2770 | ||
7506f491 DE |
2771 | /* Reset tables used to keep track of what's still available [since the |
2772 | start of the block]. */ | |
2773 | ||
2774 | static void | |
2775 | reset_opr_set_tables () | |
2776 | { | |
2777 | /* Maintain a bitmap of which regs have been set since beginning of | |
2778 | the block. */ | |
73991d6a | 2779 | CLEAR_REG_SET (reg_set_bitmap); |
c4c81601 | 2780 | |
7506f491 DE |
2781 | /* Also keep a record of the last instruction to modify memory. |
2782 | For now this is very trivial, we only record whether any memory | |
2783 | location has been modified. */ | |
73991d6a | 2784 | clear_modify_mem_tables (); |
7506f491 DE |
2785 | } |
2786 | ||
2787 | /* Return non-zero if the operands of X are not set before INSN in | |
2788 | INSN's basic block. */ | |
2789 | ||
2790 | static int | |
2791 | oprs_not_set_p (x, insn) | |
2792 | rtx x, insn; | |
2793 | { | |
c4c81601 | 2794 | int i, j; |
7506f491 | 2795 | enum rtx_code code; |
6f7d635c | 2796 | const char *fmt; |
7506f491 | 2797 | |
7506f491 DE |
2798 | if (x == 0) |
2799 | return 1; | |
2800 | ||
2801 | code = GET_CODE (x); | |
2802 | switch (code) | |
2803 | { | |
2804 | case PC: | |
2805 | case CC0: | |
2806 | case CONST: | |
2807 | case CONST_INT: | |
2808 | case CONST_DOUBLE: | |
69ef87e2 | 2809 | case CONST_VECTOR: |
7506f491 DE |
2810 | case SYMBOL_REF: |
2811 | case LABEL_REF: | |
2812 | case ADDR_VEC: | |
2813 | case ADDR_DIFF_VEC: | |
2814 | return 1; | |
2815 | ||
2816 | case MEM: | |
e2d2ed72 AM |
2817 | if (load_killed_in_block_p (BLOCK_FOR_INSN (insn), |
2818 | INSN_CUID (insn), x, 0)) | |
a13d4ebf | 2819 | return 0; |
c4c81601 RK |
2820 | else |
2821 | return oprs_not_set_p (XEXP (x, 0), insn); | |
7506f491 DE |
2822 | |
2823 | case REG: | |
73991d6a | 2824 | return ! REGNO_REG_SET_P (reg_set_bitmap, REGNO (x)); |
7506f491 DE |
2825 | |
2826 | default: | |
2827 | break; | |
2828 | } | |
2829 | ||
c4c81601 | 2830 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
2831 | { |
2832 | if (fmt[i] == 'e') | |
2833 | { | |
7506f491 DE |
2834 | /* If we are about to do the last recursive call |
2835 | needed at this level, change it into iteration. | |
2836 | This function is called enough to be worth it. */ | |
2837 | if (i == 0) | |
c4c81601 RK |
2838 | return oprs_not_set_p (XEXP (x, i), insn); |
2839 | ||
2840 | if (! oprs_not_set_p (XEXP (x, i), insn)) | |
7506f491 DE |
2841 | return 0; |
2842 | } | |
2843 | else if (fmt[i] == 'E') | |
c4c81601 RK |
2844 | for (j = 0; j < XVECLEN (x, i); j++) |
2845 | if (! oprs_not_set_p (XVECEXP (x, i, j), insn)) | |
2846 | return 0; | |
7506f491 DE |
2847 | } |
2848 | ||
2849 | return 1; | |
2850 | } | |
2851 | ||
2852 | /* Mark things set by a CALL. */ | |
2853 | ||
2854 | static void | |
b5ce41ff JL |
2855 | mark_call (insn) |
2856 | rtx insn; | |
7506f491 | 2857 | { |
24a28584 | 2858 | if (! CONST_OR_PURE_CALL_P (insn)) |
a13d4ebf | 2859 | record_last_mem_set_info (insn); |
7506f491 DE |
2860 | } |
2861 | ||
2862 | /* Mark things set by a SET. */ | |
2863 | ||
2864 | static void | |
2865 | mark_set (pat, insn) | |
2866 | rtx pat, insn; | |
2867 | { | |
2868 | rtx dest = SET_DEST (pat); | |
2869 | ||
2870 | while (GET_CODE (dest) == SUBREG | |
2871 | || GET_CODE (dest) == ZERO_EXTRACT | |
2872 | || GET_CODE (dest) == SIGN_EXTRACT | |
2873 | || GET_CODE (dest) == STRICT_LOW_PART) | |
2874 | dest = XEXP (dest, 0); | |
2875 | ||
a13d4ebf | 2876 | if (GET_CODE (dest) == REG) |
73991d6a | 2877 | SET_REGNO_REG_SET (reg_set_bitmap, REGNO (dest)); |
a13d4ebf AM |
2878 | else if (GET_CODE (dest) == MEM) |
2879 | record_last_mem_set_info (insn); | |
2880 | ||
7506f491 | 2881 | if (GET_CODE (SET_SRC (pat)) == CALL) |
b5ce41ff | 2882 | mark_call (insn); |
7506f491 DE |
2883 | } |
2884 | ||
2885 | /* Record things set by a CLOBBER. */ | |
2886 | ||
2887 | static void | |
2888 | mark_clobber (pat, insn) | |
2889 | rtx pat, insn; | |
2890 | { | |
2891 | rtx clob = XEXP (pat, 0); | |
2892 | ||
2893 | while (GET_CODE (clob) == SUBREG || GET_CODE (clob) == STRICT_LOW_PART) | |
2894 | clob = XEXP (clob, 0); | |
2895 | ||
a13d4ebf | 2896 | if (GET_CODE (clob) == REG) |
73991d6a | 2897 | SET_REGNO_REG_SET (reg_set_bitmap, REGNO (clob)); |
a13d4ebf AM |
2898 | else |
2899 | record_last_mem_set_info (insn); | |
7506f491 DE |
2900 | } |
2901 | ||
2902 | /* Record things set by INSN. | |
2903 | This data is used by oprs_not_set_p. */ | |
2904 | ||
2905 | static void | |
2906 | mark_oprs_set (insn) | |
2907 | rtx insn; | |
2908 | { | |
2909 | rtx pat = PATTERN (insn); | |
c4c81601 | 2910 | int i; |
7506f491 DE |
2911 | |
2912 | if (GET_CODE (pat) == SET) | |
2913 | mark_set (pat, insn); | |
2914 | else if (GET_CODE (pat) == PARALLEL) | |
c4c81601 RK |
2915 | for (i = 0; i < XVECLEN (pat, 0); i++) |
2916 | { | |
2917 | rtx x = XVECEXP (pat, 0, i); | |
2918 | ||
2919 | if (GET_CODE (x) == SET) | |
2920 | mark_set (x, insn); | |
2921 | else if (GET_CODE (x) == CLOBBER) | |
2922 | mark_clobber (x, insn); | |
2923 | else if (GET_CODE (x) == CALL) | |
2924 | mark_call (insn); | |
2925 | } | |
7506f491 | 2926 | |
7506f491 DE |
2927 | else if (GET_CODE (pat) == CLOBBER) |
2928 | mark_clobber (pat, insn); | |
2929 | else if (GET_CODE (pat) == CALL) | |
b5ce41ff | 2930 | mark_call (insn); |
7506f491 | 2931 | } |
b5ce41ff | 2932 | |
7506f491 DE |
2933 | \f |
2934 | /* Classic GCSE reaching definition support. */ | |
2935 | ||
2936 | /* Allocate reaching def variables. */ | |
2937 | ||
2938 | static void | |
2939 | alloc_rd_mem (n_blocks, n_insns) | |
2940 | int n_blocks, n_insns; | |
2941 | { | |
2942 | rd_kill = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_insns); | |
d55bc081 | 2943 | sbitmap_vector_zero (rd_kill, n_blocks); |
7506f491 DE |
2944 | |
2945 | rd_gen = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_insns); | |
d55bc081 | 2946 | sbitmap_vector_zero (rd_gen, n_blocks); |
7506f491 DE |
2947 | |
2948 | reaching_defs = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_insns); | |
d55bc081 | 2949 | sbitmap_vector_zero (reaching_defs, n_blocks); |
7506f491 DE |
2950 | |
2951 | rd_out = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_insns); | |
d55bc081 | 2952 | sbitmap_vector_zero (rd_out, n_blocks); |
7506f491 DE |
2953 | } |
2954 | ||
2955 | /* Free reaching def variables. */ | |
2956 | ||
2957 | static void | |
2958 | free_rd_mem () | |
2959 | { | |
5a660bff DB |
2960 | sbitmap_vector_free (rd_kill); |
2961 | sbitmap_vector_free (rd_gen); | |
2962 | sbitmap_vector_free (reaching_defs); | |
2963 | sbitmap_vector_free (rd_out); | |
7506f491 DE |
2964 | } |
2965 | ||
c4c81601 | 2966 | /* Add INSN to the kills of BB. REGNO, set in BB, is killed by INSN. */ |
7506f491 DE |
2967 | |
2968 | static void | |
2969 | handle_rd_kill_set (insn, regno, bb) | |
2970 | rtx insn; | |
e2d2ed72 AM |
2971 | int regno; |
2972 | basic_block bb; | |
7506f491 | 2973 | { |
c4c81601 | 2974 | struct reg_set *this_reg; |
7506f491 | 2975 | |
c4c81601 RK |
2976 | for (this_reg = reg_set_table[regno]; this_reg; this_reg = this_reg ->next) |
2977 | if (BLOCK_NUM (this_reg->insn) != BLOCK_NUM (insn)) | |
0b17ab2f | 2978 | SET_BIT (rd_kill[bb->index], INSN_CUID (this_reg->insn)); |
7506f491 DE |
2979 | } |
2980 | ||
7506f491 DE |
2981 | /* Compute the set of kill's for reaching definitions. */ |
2982 | ||
2983 | static void | |
2984 | compute_kill_rd () | |
2985 | { | |
e0082a72 | 2986 | int cuid; |
172890a2 RK |
2987 | unsigned int regno; |
2988 | int i; | |
e0082a72 | 2989 | basic_block bb; |
7506f491 DE |
2990 | |
2991 | /* For each block | |
2992 | For each set bit in `gen' of the block (i.e each insn which | |
ac7c5af5 JL |
2993 | generates a definition in the block) |
2994 | Call the reg set by the insn corresponding to that bit regx | |
2995 | Look at the linked list starting at reg_set_table[regx] | |
2996 | For each setting of regx in the linked list, which is not in | |
2997 | this block | |
6d2f8887 | 2998 | Set the bit in `kill' corresponding to that insn. */ |
e0082a72 | 2999 | FOR_EACH_BB (bb) |
c4c81601 | 3000 | for (cuid = 0; cuid < max_cuid; cuid++) |
e0082a72 | 3001 | if (TEST_BIT (rd_gen[bb->index], cuid)) |
7506f491 | 3002 | { |
c4c81601 RK |
3003 | rtx insn = CUID_INSN (cuid); |
3004 | rtx pat = PATTERN (insn); | |
7506f491 | 3005 | |
c4c81601 RK |
3006 | if (GET_CODE (insn) == CALL_INSN) |
3007 | { | |
3008 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) | |
4e2db584 | 3009 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) |
e0082a72 | 3010 | handle_rd_kill_set (insn, regno, bb); |
c4c81601 | 3011 | } |
7506f491 | 3012 | |
c4c81601 RK |
3013 | if (GET_CODE (pat) == PARALLEL) |
3014 | { | |
3015 | for (i = XVECLEN (pat, 0) - 1; i >= 0; i--) | |
7506f491 | 3016 | { |
c4c81601 | 3017 | enum rtx_code code = GET_CODE (XVECEXP (pat, 0, i)); |
7506f491 | 3018 | |
c4c81601 RK |
3019 | if ((code == SET || code == CLOBBER) |
3020 | && GET_CODE (XEXP (XVECEXP (pat, 0, i), 0)) == REG) | |
3021 | handle_rd_kill_set (insn, | |
3022 | REGNO (XEXP (XVECEXP (pat, 0, i), 0)), | |
e0082a72 | 3023 | bb); |
ac7c5af5 | 3024 | } |
ac7c5af5 | 3025 | } |
c4c81601 RK |
3026 | else if (GET_CODE (pat) == SET && GET_CODE (SET_DEST (pat)) == REG) |
3027 | /* Each setting of this register outside of this block | |
3028 | must be marked in the set of kills in this block. */ | |
e0082a72 | 3029 | handle_rd_kill_set (insn, REGNO (SET_DEST (pat)), bb); |
7506f491 | 3030 | } |
7506f491 DE |
3031 | } |
3032 | ||
3033 | /* Compute the reaching definitions as in | |
3034 | Compilers Principles, Techniques, and Tools. Aho, Sethi, Ullman, | |
3035 | Chapter 10. It is the same algorithm as used for computing available | |
3036 | expressions but applied to the gens and kills of reaching definitions. */ | |
3037 | ||
3038 | static void | |
3039 | compute_rd () | |
3040 | { | |
e0082a72 ZD |
3041 | int changed, passes; |
3042 | basic_block bb; | |
7506f491 | 3043 | |
e0082a72 ZD |
3044 | FOR_EACH_BB (bb) |
3045 | sbitmap_copy (rd_out[bb->index] /*dst*/, rd_gen[bb->index] /*src*/); | |
7506f491 DE |
3046 | |
3047 | passes = 0; | |
3048 | changed = 1; | |
3049 | while (changed) | |
3050 | { | |
3051 | changed = 0; | |
e0082a72 | 3052 | FOR_EACH_BB (bb) |
ac7c5af5 | 3053 | { |
e0082a72 ZD |
3054 | sbitmap_union_of_preds (reaching_defs[bb->index], rd_out, bb->index); |
3055 | changed |= sbitmap_union_of_diff_cg (rd_out[bb->index], rd_gen[bb->index], | |
3056 | reaching_defs[bb->index], rd_kill[bb->index]); | |
ac7c5af5 | 3057 | } |
7506f491 DE |
3058 | passes++; |
3059 | } | |
3060 | ||
3061 | if (gcse_file) | |
3062 | fprintf (gcse_file, "reaching def computation: %d passes\n", passes); | |
3063 | } | |
3064 | \f | |
3065 | /* Classic GCSE available expression support. */ | |
3066 | ||
3067 | /* Allocate memory for available expression computation. */ | |
3068 | ||
3069 | static void | |
3070 | alloc_avail_expr_mem (n_blocks, n_exprs) | |
3071 | int n_blocks, n_exprs; | |
3072 | { | |
3073 | ae_kill = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_exprs); | |
d55bc081 | 3074 | sbitmap_vector_zero (ae_kill, n_blocks); |
7506f491 DE |
3075 | |
3076 | ae_gen = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_exprs); | |
d55bc081 | 3077 | sbitmap_vector_zero (ae_gen, n_blocks); |
7506f491 DE |
3078 | |
3079 | ae_in = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_exprs); | |
d55bc081 | 3080 | sbitmap_vector_zero (ae_in, n_blocks); |
7506f491 DE |
3081 | |
3082 | ae_out = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_exprs); | |
d55bc081 | 3083 | sbitmap_vector_zero (ae_out, n_blocks); |
7506f491 DE |
3084 | } |
3085 | ||
3086 | static void | |
3087 | free_avail_expr_mem () | |
3088 | { | |
5a660bff DB |
3089 | sbitmap_vector_free (ae_kill); |
3090 | sbitmap_vector_free (ae_gen); | |
3091 | sbitmap_vector_free (ae_in); | |
3092 | sbitmap_vector_free (ae_out); | |
7506f491 DE |
3093 | } |
3094 | ||
3095 | /* Compute the set of available expressions generated in each basic block. */ | |
3096 | ||
3097 | static void | |
3098 | compute_ae_gen () | |
3099 | { | |
2e653e39 | 3100 | unsigned int i; |
c4c81601 RK |
3101 | struct expr *expr; |
3102 | struct occr *occr; | |
7506f491 DE |
3103 | |
3104 | /* For each recorded occurrence of each expression, set ae_gen[bb][expr]. | |
3105 | This is all we have to do because an expression is not recorded if it | |
3106 | is not available, and the only expressions we want to work with are the | |
3107 | ones that are recorded. */ | |
7506f491 | 3108 | for (i = 0; i < expr_hash_table_size; i++) |
c4c81601 RK |
3109 | for (expr = expr_hash_table[i]; expr != 0; expr = expr->next_same_hash) |
3110 | for (occr = expr->avail_occr; occr != 0; occr = occr->next) | |
3111 | SET_BIT (ae_gen[BLOCK_NUM (occr->insn)], expr->bitmap_index); | |
7506f491 DE |
3112 | } |
3113 | ||
3114 | /* Return non-zero if expression X is killed in BB. */ | |
3115 | ||
3116 | static int | |
3117 | expr_killed_p (x, bb) | |
3118 | rtx x; | |
e2d2ed72 | 3119 | basic_block bb; |
7506f491 | 3120 | { |
c4c81601 | 3121 | int i, j; |
7506f491 | 3122 | enum rtx_code code; |
6f7d635c | 3123 | const char *fmt; |
7506f491 | 3124 | |
7506f491 DE |
3125 | if (x == 0) |
3126 | return 1; | |
3127 | ||
3128 | code = GET_CODE (x); | |
3129 | switch (code) | |
3130 | { | |
3131 | case REG: | |
0b17ab2f | 3132 | return TEST_BIT (reg_set_in_block[bb->index], REGNO (x)); |
7506f491 DE |
3133 | |
3134 | case MEM: | |
a13d4ebf AM |
3135 | if (load_killed_in_block_p (bb, get_max_uid () + 1, x, 0)) |
3136 | return 1; | |
c4c81601 RK |
3137 | else |
3138 | return expr_killed_p (XEXP (x, 0), bb); | |
7506f491 DE |
3139 | |
3140 | case PC: | |
3141 | case CC0: /*FIXME*/ | |
3142 | case CONST: | |
3143 | case CONST_INT: | |
3144 | case CONST_DOUBLE: | |
69ef87e2 | 3145 | case CONST_VECTOR: |
7506f491 DE |
3146 | case SYMBOL_REF: |
3147 | case LABEL_REF: | |
3148 | case ADDR_VEC: | |
3149 | case ADDR_DIFF_VEC: | |
3150 | return 0; | |
3151 | ||
3152 | default: | |
3153 | break; | |
3154 | } | |
3155 | ||
c4c81601 | 3156 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
3157 | { |
3158 | if (fmt[i] == 'e') | |
3159 | { | |
7506f491 DE |
3160 | /* If we are about to do the last recursive call |
3161 | needed at this level, change it into iteration. | |
3162 | This function is called enough to be worth it. */ | |
3163 | if (i == 0) | |
c4c81601 RK |
3164 | return expr_killed_p (XEXP (x, i), bb); |
3165 | else if (expr_killed_p (XEXP (x, i), bb)) | |
7506f491 DE |
3166 | return 1; |
3167 | } | |
3168 | else if (fmt[i] == 'E') | |
c4c81601 RK |
3169 | for (j = 0; j < XVECLEN (x, i); j++) |
3170 | if (expr_killed_p (XVECEXP (x, i, j), bb)) | |
3171 | return 1; | |
7506f491 DE |
3172 | } |
3173 | ||
3174 | return 0; | |
3175 | } | |
3176 | ||
3177 | /* Compute the set of available expressions killed in each basic block. */ | |
3178 | ||
3179 | static void | |
a42cd965 AM |
3180 | compute_ae_kill (ae_gen, ae_kill) |
3181 | sbitmap *ae_gen, *ae_kill; | |
7506f491 | 3182 | { |
e0082a72 | 3183 | basic_block bb; |
2e653e39 | 3184 | unsigned int i; |
c4c81601 | 3185 | struct expr *expr; |
7506f491 | 3186 | |
e0082a72 | 3187 | FOR_EACH_BB (bb) |
c4c81601 RK |
3188 | for (i = 0; i < expr_hash_table_size; i++) |
3189 | for (expr = expr_hash_table[i]; expr; expr = expr->next_same_hash) | |
7506f491 | 3190 | { |
c4c81601 | 3191 | /* Skip EXPR if generated in this block. */ |
e0082a72 | 3192 | if (TEST_BIT (ae_gen[bb->index], expr->bitmap_index)) |
c4c81601 | 3193 | continue; |
7506f491 | 3194 | |
e0082a72 ZD |
3195 | if (expr_killed_p (expr->expr, bb)) |
3196 | SET_BIT (ae_kill[bb->index], expr->bitmap_index); | |
7506f491 | 3197 | } |
7506f491 | 3198 | } |
7506f491 DE |
3199 | \f |
3200 | /* Actually perform the Classic GCSE optimizations. */ | |
3201 | ||
3202 | /* Return non-zero if occurrence OCCR of expression EXPR reaches block BB. | |
3203 | ||
3204 | CHECK_SELF_LOOP is non-zero if we should consider a block reaching itself | |
3205 | as a positive reach. We want to do this when there are two computations | |
3206 | of the expression in the block. | |
3207 | ||
3208 | VISITED is a pointer to a working buffer for tracking which BB's have | |
3209 | been visited. It is NULL for the top-level call. | |
3210 | ||
3211 | We treat reaching expressions that go through blocks containing the same | |
3212 | reaching expression as "not reaching". E.g. if EXPR is generated in blocks | |
3213 | 2 and 3, INSN is in block 4, and 2->3->4, we treat the expression in block | |
3214 | 2 as not reaching. The intent is to improve the probability of finding | |
3215 | only one reaching expression and to reduce register lifetimes by picking | |
3216 | the closest such expression. */ | |
3217 | ||
3218 | static int | |
283a2545 | 3219 | expr_reaches_here_p_work (occr, expr, bb, check_self_loop, visited) |
7506f491 DE |
3220 | struct occr *occr; |
3221 | struct expr *expr; | |
e2d2ed72 | 3222 | basic_block bb; |
7506f491 DE |
3223 | int check_self_loop; |
3224 | char *visited; | |
3225 | { | |
36349f8b | 3226 | edge pred; |
7506f491 | 3227 | |
e2d2ed72 | 3228 | for (pred = bb->pred; pred != NULL; pred = pred->pred_next) |
7506f491 | 3229 | { |
e2d2ed72 | 3230 | basic_block pred_bb = pred->src; |
7506f491 | 3231 | |
0b17ab2f | 3232 | if (visited[pred_bb->index]) |
c4c81601 | 3233 | /* This predecessor has already been visited. Nothing to do. */ |
7506f491 | 3234 | ; |
7506f491 | 3235 | else if (pred_bb == bb) |
ac7c5af5 | 3236 | { |
7506f491 DE |
3237 | /* BB loops on itself. */ |
3238 | if (check_self_loop | |
0b17ab2f RH |
3239 | && TEST_BIT (ae_gen[pred_bb->index], expr->bitmap_index) |
3240 | && BLOCK_NUM (occr->insn) == pred_bb->index) | |
7506f491 | 3241 | return 1; |
c4c81601 | 3242 | |
0b17ab2f | 3243 | visited[pred_bb->index] = 1; |
ac7c5af5 | 3244 | } |
c4c81601 | 3245 | |
7506f491 | 3246 | /* Ignore this predecessor if it kills the expression. */ |
0b17ab2f RH |
3247 | else if (TEST_BIT (ae_kill[pred_bb->index], expr->bitmap_index)) |
3248 | visited[pred_bb->index] = 1; | |
c4c81601 | 3249 | |
7506f491 | 3250 | /* Does this predecessor generate this expression? */ |
0b17ab2f | 3251 | else if (TEST_BIT (ae_gen[pred_bb->index], expr->bitmap_index)) |
7506f491 DE |
3252 | { |
3253 | /* Is this the occurrence we're looking for? | |
3254 | Note that there's only one generating occurrence per block | |
3255 | so we just need to check the block number. */ | |
0b17ab2f | 3256 | if (BLOCK_NUM (occr->insn) == pred_bb->index) |
7506f491 | 3257 | return 1; |
c4c81601 | 3258 | |
0b17ab2f | 3259 | visited[pred_bb->index] = 1; |
7506f491 | 3260 | } |
c4c81601 | 3261 | |
7506f491 DE |
3262 | /* Neither gen nor kill. */ |
3263 | else | |
ac7c5af5 | 3264 | { |
0b17ab2f | 3265 | visited[pred_bb->index] = 1; |
283a2545 RL |
3266 | if (expr_reaches_here_p_work (occr, expr, pred_bb, check_self_loop, |
3267 | visited)) | |
c4c81601 | 3268 | |
7506f491 | 3269 | return 1; |
ac7c5af5 | 3270 | } |
7506f491 DE |
3271 | } |
3272 | ||
3273 | /* All paths have been checked. */ | |
3274 | return 0; | |
3275 | } | |
3276 | ||
283a2545 | 3277 | /* This wrapper for expr_reaches_here_p_work() is to ensure that any |
dc297297 | 3278 | memory allocated for that function is returned. */ |
283a2545 RL |
3279 | |
3280 | static int | |
3281 | expr_reaches_here_p (occr, expr, bb, check_self_loop) | |
3282 | struct occr *occr; | |
3283 | struct expr *expr; | |
e2d2ed72 | 3284 | basic_block bb; |
283a2545 RL |
3285 | int check_self_loop; |
3286 | { | |
3287 | int rval; | |
d55bc081 | 3288 | char *visited = (char *) xcalloc (last_basic_block, 1); |
283a2545 | 3289 | |
c4c81601 | 3290 | rval = expr_reaches_here_p_work (occr, expr, bb, check_self_loop, visited); |
283a2545 RL |
3291 | |
3292 | free (visited); | |
c4c81601 | 3293 | return rval; |
283a2545 RL |
3294 | } |
3295 | ||
7506f491 DE |
3296 | /* Return the instruction that computes EXPR that reaches INSN's basic block. |
3297 | If there is more than one such instruction, return NULL. | |
3298 | ||
3299 | Called only by handle_avail_expr. */ | |
3300 | ||
3301 | static rtx | |
3302 | computing_insn (expr, insn) | |
3303 | struct expr *expr; | |
3304 | rtx insn; | |
3305 | { | |
e2d2ed72 | 3306 | basic_block bb = BLOCK_FOR_INSN (insn); |
7506f491 DE |
3307 | |
3308 | if (expr->avail_occr->next == NULL) | |
3309 | { | |
e2d2ed72 | 3310 | if (BLOCK_FOR_INSN (expr->avail_occr->insn) == bb) |
c4c81601 RK |
3311 | /* The available expression is actually itself |
3312 | (i.e. a loop in the flow graph) so do nothing. */ | |
3313 | return NULL; | |
3314 | ||
7506f491 DE |
3315 | /* (FIXME) Case that we found a pattern that was created by |
3316 | a substitution that took place. */ | |
3317 | return expr->avail_occr->insn; | |
3318 | } | |
3319 | else | |
3320 | { | |
3321 | /* Pattern is computed more than once. | |
3322 | Search backwards from this insn to see how many of these | |
3323 | computations actually reach this insn. */ | |
3324 | struct occr *occr; | |
3325 | rtx insn_computes_expr = NULL; | |
3326 | int can_reach = 0; | |
3327 | ||
3328 | for (occr = expr->avail_occr; occr != NULL; occr = occr->next) | |
3329 | { | |
e2d2ed72 | 3330 | if (BLOCK_FOR_INSN (occr->insn) == bb) |
7506f491 DE |
3331 | { |
3332 | /* The expression is generated in this block. | |
3333 | The only time we care about this is when the expression | |
3334 | is generated later in the block [and thus there's a loop]. | |
3335 | We let the normal cse pass handle the other cases. */ | |
c4c81601 RK |
3336 | if (INSN_CUID (insn) < INSN_CUID (occr->insn) |
3337 | && expr_reaches_here_p (occr, expr, bb, 1)) | |
7506f491 DE |
3338 | { |
3339 | can_reach++; | |
3340 | if (can_reach > 1) | |
3341 | return NULL; | |
c4c81601 | 3342 | |
7506f491 DE |
3343 | insn_computes_expr = occr->insn; |
3344 | } | |
3345 | } | |
c4c81601 RK |
3346 | else if (expr_reaches_here_p (occr, expr, bb, 0)) |
3347 | { | |
3348 | can_reach++; | |
3349 | if (can_reach > 1) | |
3350 | return NULL; | |
3351 | ||
3352 | insn_computes_expr = occr->insn; | |
3353 | } | |
7506f491 DE |
3354 | } |
3355 | ||
3356 | if (insn_computes_expr == NULL) | |
3357 | abort (); | |
c4c81601 | 3358 | |
7506f491 DE |
3359 | return insn_computes_expr; |
3360 | } | |
3361 | } | |
3362 | ||
3363 | /* Return non-zero if the definition in DEF_INSN can reach INSN. | |
3364 | Only called by can_disregard_other_sets. */ | |
3365 | ||
3366 | static int | |
3367 | def_reaches_here_p (insn, def_insn) | |
3368 | rtx insn, def_insn; | |
3369 | { | |
3370 | rtx reg; | |
3371 | ||
3372 | if (TEST_BIT (reaching_defs[BLOCK_NUM (insn)], INSN_CUID (def_insn))) | |
3373 | return 1; | |
3374 | ||
3375 | if (BLOCK_NUM (insn) == BLOCK_NUM (def_insn)) | |
3376 | { | |
3377 | if (INSN_CUID (def_insn) < INSN_CUID (insn)) | |
ac7c5af5 | 3378 | { |
7506f491 DE |
3379 | if (GET_CODE (PATTERN (def_insn)) == PARALLEL) |
3380 | return 1; | |
c4c81601 | 3381 | else if (GET_CODE (PATTERN (def_insn)) == CLOBBER) |
7506f491 DE |
3382 | reg = XEXP (PATTERN (def_insn), 0); |
3383 | else if (GET_CODE (PATTERN (def_insn)) == SET) | |
3384 | reg = SET_DEST (PATTERN (def_insn)); | |
3385 | else | |
3386 | abort (); | |
c4c81601 | 3387 | |
7506f491 DE |
3388 | return ! reg_set_between_p (reg, NEXT_INSN (def_insn), insn); |
3389 | } | |
3390 | else | |
3391 | return 0; | |
3392 | } | |
3393 | ||
3394 | return 0; | |
3395 | } | |
3396 | ||
c4c81601 RK |
3397 | /* Return non-zero if *ADDR_THIS_REG can only have one value at INSN. The |
3398 | value returned is the number of definitions that reach INSN. Returning a | |
3399 | value of zero means that [maybe] more than one definition reaches INSN and | |
3400 | the caller can't perform whatever optimization it is trying. i.e. it is | |
3401 | always safe to return zero. */ | |
7506f491 DE |
3402 | |
3403 | static int | |
3404 | can_disregard_other_sets (addr_this_reg, insn, for_combine) | |
3405 | struct reg_set **addr_this_reg; | |
3406 | rtx insn; | |
3407 | int for_combine; | |
3408 | { | |
3409 | int number_of_reaching_defs = 0; | |
c4c81601 | 3410 | struct reg_set *this_reg; |
7506f491 | 3411 | |
c4c81601 RK |
3412 | for (this_reg = *addr_this_reg; this_reg != 0; this_reg = this_reg->next) |
3413 | if (def_reaches_here_p (insn, this_reg->insn)) | |
3414 | { | |
3415 | number_of_reaching_defs++; | |
3416 | /* Ignore parallels for now. */ | |
3417 | if (GET_CODE (PATTERN (this_reg->insn)) == PARALLEL) | |
3418 | return 0; | |
3419 | ||
3420 | if (!for_combine | |
3421 | && (GET_CODE (PATTERN (this_reg->insn)) == CLOBBER | |
3422 | || ! rtx_equal_p (SET_SRC (PATTERN (this_reg->insn)), | |
3423 | SET_SRC (PATTERN (insn))))) | |
3424 | /* A setting of the reg to a different value reaches INSN. */ | |
3425 | return 0; | |
3426 | ||
3427 | if (number_of_reaching_defs > 1) | |
3428 | { | |
3429 | /* If in this setting the value the register is being set to is | |
3430 | equal to the previous value the register was set to and this | |
3431 | setting reaches the insn we are trying to do the substitution | |
3432 | on then we are ok. */ | |
3433 | if (GET_CODE (PATTERN (this_reg->insn)) == CLOBBER) | |
7506f491 | 3434 | return 0; |
c4c81601 RK |
3435 | else if (! rtx_equal_p (SET_SRC (PATTERN (this_reg->insn)), |
3436 | SET_SRC (PATTERN (insn)))) | |
3437 | return 0; | |
3438 | } | |
7506f491 | 3439 | |
c4c81601 RK |
3440 | *addr_this_reg = this_reg; |
3441 | } | |
7506f491 DE |
3442 | |
3443 | return number_of_reaching_defs; | |
3444 | } | |
3445 | ||
3446 | /* Expression computed by insn is available and the substitution is legal, | |
3447 | so try to perform the substitution. | |
3448 | ||
3449 | The result is non-zero if any changes were made. */ | |
3450 | ||
3451 | static int | |
3452 | handle_avail_expr (insn, expr) | |
3453 | rtx insn; | |
3454 | struct expr *expr; | |
3455 | { | |
0631e0bf | 3456 | rtx pat, insn_computes_expr, expr_set; |
7506f491 DE |
3457 | rtx to; |
3458 | struct reg_set *this_reg; | |
3459 | int found_setting, use_src; | |
3460 | int changed = 0; | |
3461 | ||
3462 | /* We only handle the case where one computation of the expression | |
3463 | reaches this instruction. */ | |
3464 | insn_computes_expr = computing_insn (expr, insn); | |
3465 | if (insn_computes_expr == NULL) | |
3466 | return 0; | |
0631e0bf JH |
3467 | expr_set = single_set (insn_computes_expr); |
3468 | if (!expr_set) | |
3469 | abort (); | |
7506f491 DE |
3470 | |
3471 | found_setting = 0; | |
3472 | use_src = 0; | |
3473 | ||
3474 | /* At this point we know only one computation of EXPR outside of this | |
3475 | block reaches this insn. Now try to find a register that the | |
3476 | expression is computed into. */ | |
0631e0bf | 3477 | if (GET_CODE (SET_SRC (expr_set)) == REG) |
7506f491 DE |
3478 | { |
3479 | /* This is the case when the available expression that reaches | |
3480 | here has already been handled as an available expression. */ | |
770ae6cc | 3481 | unsigned int regnum_for_replacing |
0631e0bf | 3482 | = REGNO (SET_SRC (expr_set)); |
c4c81601 | 3483 | |
7506f491 DE |
3484 | /* If the register was created by GCSE we can't use `reg_set_table', |
3485 | however we know it's set only once. */ | |
3486 | if (regnum_for_replacing >= max_gcse_regno | |
3487 | /* If the register the expression is computed into is set only once, | |
3488 | or only one set reaches this insn, we can use it. */ | |
3489 | || (((this_reg = reg_set_table[regnum_for_replacing]), | |
3490 | this_reg->next == NULL) | |
3491 | || can_disregard_other_sets (&this_reg, insn, 0))) | |
8e42ace1 KH |
3492 | { |
3493 | use_src = 1; | |
3494 | found_setting = 1; | |
3495 | } | |
7506f491 DE |
3496 | } |
3497 | ||
3498 | if (!found_setting) | |
3499 | { | |
770ae6cc | 3500 | unsigned int regnum_for_replacing |
0631e0bf | 3501 | = REGNO (SET_DEST (expr_set)); |
c4c81601 | 3502 | |
7506f491 DE |
3503 | /* This shouldn't happen. */ |
3504 | if (regnum_for_replacing >= max_gcse_regno) | |
3505 | abort (); | |
c4c81601 | 3506 | |
7506f491 | 3507 | this_reg = reg_set_table[regnum_for_replacing]; |
c4c81601 | 3508 | |
7506f491 DE |
3509 | /* If the register the expression is computed into is set only once, |
3510 | or only one set reaches this insn, use it. */ | |
3511 | if (this_reg->next == NULL | |
3512 | || can_disregard_other_sets (&this_reg, insn, 0)) | |
3513 | found_setting = 1; | |
3514 | } | |
3515 | ||
3516 | if (found_setting) | |
3517 | { | |
3518 | pat = PATTERN (insn); | |
3519 | if (use_src) | |
0631e0bf | 3520 | to = SET_SRC (expr_set); |
7506f491 | 3521 | else |
0631e0bf | 3522 | to = SET_DEST (expr_set); |
7506f491 DE |
3523 | changed = validate_change (insn, &SET_SRC (pat), to, 0); |
3524 | ||
3525 | /* We should be able to ignore the return code from validate_change but | |
3526 | to play it safe we check. */ | |
3527 | if (changed) | |
3528 | { | |
3529 | gcse_subst_count++; | |
3530 | if (gcse_file != NULL) | |
3531 | { | |
c4c81601 RK |
3532 | fprintf (gcse_file, "GCSE: Replacing the source in insn %d with", |
3533 | INSN_UID (insn)); | |
3534 | fprintf (gcse_file, " reg %d %s insn %d\n", | |
3535 | REGNO (to), use_src ? "from" : "set in", | |
7506f491 DE |
3536 | INSN_UID (insn_computes_expr)); |
3537 | } | |
7506f491 DE |
3538 | } |
3539 | } | |
c4c81601 | 3540 | |
7506f491 DE |
3541 | /* The register that the expr is computed into is set more than once. */ |
3542 | else if (1 /*expensive_op(this_pattrn->op) && do_expensive_gcse)*/) | |
3543 | { | |
3544 | /* Insert an insn after insnx that copies the reg set in insnx | |
3545 | into a new pseudo register call this new register REGN. | |
3546 | From insnb until end of basic block or until REGB is set | |
3547 | replace all uses of REGB with REGN. */ | |
3548 | rtx new_insn; | |
3549 | ||
0631e0bf | 3550 | to = gen_reg_rtx (GET_MODE (SET_DEST (expr_set))); |
7506f491 DE |
3551 | |
3552 | /* Generate the new insn. */ | |
3553 | /* ??? If the change fails, we return 0, even though we created | |
3554 | an insn. I think this is ok. */ | |
9e6a5703 JC |
3555 | new_insn |
3556 | = emit_insn_after (gen_rtx_SET (VOIDmode, to, | |
0631e0bf | 3557 | SET_DEST (expr_set)), |
c4c81601 RK |
3558 | insn_computes_expr); |
3559 | ||
7506f491 DE |
3560 | /* Keep register set table up to date. */ |
3561 | record_one_set (REGNO (to), new_insn); | |
3562 | ||
3563 | gcse_create_count++; | |
3564 | if (gcse_file != NULL) | |
ac7c5af5 | 3565 | { |
c4c81601 | 3566 | fprintf (gcse_file, "GCSE: Creating insn %d to copy value of reg %d", |
7506f491 | 3567 | INSN_UID (NEXT_INSN (insn_computes_expr)), |
c4c81601 RK |
3568 | REGNO (SET_SRC (PATTERN (NEXT_INSN (insn_computes_expr))))); |
3569 | fprintf (gcse_file, ", computed in insn %d,\n", | |
7506f491 | 3570 | INSN_UID (insn_computes_expr)); |
c4c81601 RK |
3571 | fprintf (gcse_file, " into newly allocated reg %d\n", |
3572 | REGNO (to)); | |
ac7c5af5 | 3573 | } |
7506f491 DE |
3574 | |
3575 | pat = PATTERN (insn); | |
3576 | ||
3577 | /* Do register replacement for INSN. */ | |
3578 | changed = validate_change (insn, &SET_SRC (pat), | |
c4c81601 RK |
3579 | SET_DEST (PATTERN |
3580 | (NEXT_INSN (insn_computes_expr))), | |
7506f491 DE |
3581 | 0); |
3582 | ||
3583 | /* We should be able to ignore the return code from validate_change but | |
3584 | to play it safe we check. */ | |
3585 | if (changed) | |
3586 | { | |
3587 | gcse_subst_count++; | |
3588 | if (gcse_file != NULL) | |
3589 | { | |
c4c81601 RK |
3590 | fprintf (gcse_file, |
3591 | "GCSE: Replacing the source in insn %d with reg %d ", | |
7506f491 | 3592 | INSN_UID (insn), |
c4c81601 RK |
3593 | REGNO (SET_DEST (PATTERN (NEXT_INSN |
3594 | (insn_computes_expr))))); | |
3595 | fprintf (gcse_file, "set in insn %d\n", | |
7506f491 DE |
3596 | INSN_UID (insn_computes_expr)); |
3597 | } | |
7506f491 DE |
3598 | } |
3599 | } | |
3600 | ||
3601 | return changed; | |
3602 | } | |
3603 | ||
c4c81601 RK |
3604 | /* Perform classic GCSE. This is called by one_classic_gcse_pass after all |
3605 | the dataflow analysis has been done. | |
7506f491 DE |
3606 | |
3607 | The result is non-zero if a change was made. */ | |
3608 | ||
3609 | static int | |
3610 | classic_gcse () | |
3611 | { | |
e0082a72 | 3612 | int changed; |
7506f491 | 3613 | rtx insn; |
e0082a72 | 3614 | basic_block bb; |
7506f491 DE |
3615 | |
3616 | /* Note we start at block 1. */ | |
3617 | ||
e0082a72 ZD |
3618 | if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) |
3619 | return 0; | |
3620 | ||
7506f491 | 3621 | changed = 0; |
e0082a72 | 3622 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb->next_bb, EXIT_BLOCK_PTR, next_bb) |
7506f491 DE |
3623 | { |
3624 | /* Reset tables used to keep track of what's still valid [since the | |
3625 | start of the block]. */ | |
3626 | reset_opr_set_tables (); | |
3627 | ||
e0082a72 ZD |
3628 | for (insn = bb->head; |
3629 | insn != NULL && insn != NEXT_INSN (bb->end); | |
7506f491 DE |
3630 | insn = NEXT_INSN (insn)) |
3631 | { | |
3632 | /* Is insn of form (set (pseudo-reg) ...)? */ | |
7506f491 DE |
3633 | if (GET_CODE (insn) == INSN |
3634 | && GET_CODE (PATTERN (insn)) == SET | |
3635 | && GET_CODE (SET_DEST (PATTERN (insn))) == REG | |
3636 | && REGNO (SET_DEST (PATTERN (insn))) >= FIRST_PSEUDO_REGISTER) | |
3637 | { | |
3638 | rtx pat = PATTERN (insn); | |
3639 | rtx src = SET_SRC (pat); | |
3640 | struct expr *expr; | |
3641 | ||
3642 | if (want_to_gcse_p (src) | |
3643 | /* Is the expression recorded? */ | |
3644 | && ((expr = lookup_expr (src)) != NULL) | |
3645 | /* Is the expression available [at the start of the | |
3646 | block]? */ | |
e0082a72 | 3647 | && TEST_BIT (ae_in[bb->index], expr->bitmap_index) |
7506f491 DE |
3648 | /* Are the operands unchanged since the start of the |
3649 | block? */ | |
3650 | && oprs_not_set_p (src, insn)) | |
3651 | changed |= handle_avail_expr (insn, expr); | |
3652 | } | |
3653 | ||
3654 | /* Keep track of everything modified by this insn. */ | |
3655 | /* ??? Need to be careful w.r.t. mods done to INSN. */ | |
2c3c49de | 3656 | if (INSN_P (insn)) |
7506f491 | 3657 | mark_oprs_set (insn); |
ac7c5af5 | 3658 | } |
7506f491 DE |
3659 | } |
3660 | ||
3661 | return changed; | |
3662 | } | |
3663 | ||
3664 | /* Top level routine to perform one classic GCSE pass. | |
3665 | ||
3666 | Return non-zero if a change was made. */ | |
3667 | ||
3668 | static int | |
b5ce41ff | 3669 | one_classic_gcse_pass (pass) |
7506f491 DE |
3670 | int pass; |
3671 | { | |
3672 | int changed = 0; | |
3673 | ||
3674 | gcse_subst_count = 0; | |
3675 | gcse_create_count = 0; | |
3676 | ||
3677 | alloc_expr_hash_table (max_cuid); | |
d55bc081 | 3678 | alloc_rd_mem (last_basic_block, max_cuid); |
b5ce41ff | 3679 | compute_expr_hash_table (); |
7506f491 DE |
3680 | if (gcse_file) |
3681 | dump_hash_table (gcse_file, "Expression", expr_hash_table, | |
3682 | expr_hash_table_size, n_exprs); | |
c4c81601 | 3683 | |
7506f491 DE |
3684 | if (n_exprs > 0) |
3685 | { | |
3686 | compute_kill_rd (); | |
3687 | compute_rd (); | |
d55bc081 | 3688 | alloc_avail_expr_mem (last_basic_block, n_exprs); |
7506f491 | 3689 | compute_ae_gen (); |
a42cd965 | 3690 | compute_ae_kill (ae_gen, ae_kill); |
bd0eaec2 | 3691 | compute_available (ae_gen, ae_kill, ae_out, ae_in); |
7506f491 DE |
3692 | changed = classic_gcse (); |
3693 | free_avail_expr_mem (); | |
3694 | } | |
c4c81601 | 3695 | |
7506f491 DE |
3696 | free_rd_mem (); |
3697 | free_expr_hash_table (); | |
3698 | ||
3699 | if (gcse_file) | |
3700 | { | |
3701 | fprintf (gcse_file, "\n"); | |
c4c81601 RK |
3702 | fprintf (gcse_file, "GCSE of %s, pass %d: %d bytes needed, %d substs,", |
3703 | current_function_name, pass, bytes_used, gcse_subst_count); | |
3704 | fprintf (gcse_file, "%d insns created\n", gcse_create_count); | |
7506f491 DE |
3705 | } |
3706 | ||
3707 | return changed; | |
3708 | } | |
3709 | \f | |
3710 | /* Compute copy/constant propagation working variables. */ | |
3711 | ||
3712 | /* Local properties of assignments. */ | |
7506f491 DE |
3713 | static sbitmap *cprop_pavloc; |
3714 | static sbitmap *cprop_absaltered; | |
3715 | ||
3716 | /* Global properties of assignments (computed from the local properties). */ | |
7506f491 DE |
3717 | static sbitmap *cprop_avin; |
3718 | static sbitmap *cprop_avout; | |
3719 | ||
c4c81601 RK |
3720 | /* Allocate vars used for copy/const propagation. N_BLOCKS is the number of |
3721 | basic blocks. N_SETS is the number of sets. */ | |
7506f491 DE |
3722 | |
3723 | static void | |
3724 | alloc_cprop_mem (n_blocks, n_sets) | |
3725 | int n_blocks, n_sets; | |
3726 | { | |
3727 | cprop_pavloc = sbitmap_vector_alloc (n_blocks, n_sets); | |
3728 | cprop_absaltered = sbitmap_vector_alloc (n_blocks, n_sets); | |
3729 | ||
3730 | cprop_avin = sbitmap_vector_alloc (n_blocks, n_sets); | |
3731 | cprop_avout = sbitmap_vector_alloc (n_blocks, n_sets); | |
3732 | } | |
3733 | ||
3734 | /* Free vars used by copy/const propagation. */ | |
3735 | ||
3736 | static void | |
3737 | free_cprop_mem () | |
3738 | { | |
5a660bff DB |
3739 | sbitmap_vector_free (cprop_pavloc); |
3740 | sbitmap_vector_free (cprop_absaltered); | |
3741 | sbitmap_vector_free (cprop_avin); | |
3742 | sbitmap_vector_free (cprop_avout); | |
7506f491 DE |
3743 | } |
3744 | ||
c4c81601 RK |
3745 | /* For each block, compute whether X is transparent. X is either an |
3746 | expression or an assignment [though we don't care which, for this context | |
3747 | an assignment is treated as an expression]. For each block where an | |
3748 | element of X is modified, set (SET_P == 1) or reset (SET_P == 0) the INDX | |
3749 | bit in BMAP. */ | |
7506f491 DE |
3750 | |
3751 | static void | |
3752 | compute_transp (x, indx, bmap, set_p) | |
3753 | rtx x; | |
3754 | int indx; | |
3755 | sbitmap *bmap; | |
3756 | int set_p; | |
3757 | { | |
e0082a72 ZD |
3758 | int i, j; |
3759 | basic_block bb; | |
7506f491 | 3760 | enum rtx_code code; |
c4c81601 | 3761 | reg_set *r; |
6f7d635c | 3762 | const char *fmt; |
7506f491 | 3763 | |
c4c81601 RK |
3764 | /* repeat is used to turn tail-recursion into iteration since GCC |
3765 | can't do it when there's no return value. */ | |
7506f491 DE |
3766 | repeat: |
3767 | ||
3768 | if (x == 0) | |
3769 | return; | |
3770 | ||
3771 | code = GET_CODE (x); | |
3772 | switch (code) | |
3773 | { | |
3774 | case REG: | |
c4c81601 RK |
3775 | if (set_p) |
3776 | { | |
3777 | if (REGNO (x) < FIRST_PSEUDO_REGISTER) | |
3778 | { | |
e0082a72 ZD |
3779 | FOR_EACH_BB (bb) |
3780 | if (TEST_BIT (reg_set_in_block[bb->index], REGNO (x))) | |
3781 | SET_BIT (bmap[bb->index], indx); | |
c4c81601 RK |
3782 | } |
3783 | else | |
3784 | { | |
3785 | for (r = reg_set_table[REGNO (x)]; r != NULL; r = r->next) | |
3786 | SET_BIT (bmap[BLOCK_NUM (r->insn)], indx); | |
3787 | } | |
3788 | } | |
3789 | else | |
3790 | { | |
3791 | if (REGNO (x) < FIRST_PSEUDO_REGISTER) | |
3792 | { | |
e0082a72 ZD |
3793 | FOR_EACH_BB (bb) |
3794 | if (TEST_BIT (reg_set_in_block[bb->index], REGNO (x))) | |
3795 | RESET_BIT (bmap[bb->index], indx); | |
c4c81601 RK |
3796 | } |
3797 | else | |
3798 | { | |
3799 | for (r = reg_set_table[REGNO (x)]; r != NULL; r = r->next) | |
3800 | RESET_BIT (bmap[BLOCK_NUM (r->insn)], indx); | |
3801 | } | |
3802 | } | |
7506f491 | 3803 | |
c4c81601 | 3804 | return; |
7506f491 DE |
3805 | |
3806 | case MEM: | |
e0082a72 | 3807 | FOR_EACH_BB (bb) |
a13d4ebf | 3808 | { |
e0082a72 | 3809 | rtx list_entry = canon_modify_mem_list[bb->index]; |
a13d4ebf AM |
3810 | |
3811 | while (list_entry) | |
3812 | { | |
3813 | rtx dest, dest_addr; | |
3814 | ||
3815 | if (GET_CODE (XEXP (list_entry, 0)) == CALL_INSN) | |
3816 | { | |
3817 | if (set_p) | |
e0082a72 | 3818 | SET_BIT (bmap[bb->index], indx); |
a13d4ebf | 3819 | else |
e0082a72 | 3820 | RESET_BIT (bmap[bb->index], indx); |
a13d4ebf AM |
3821 | break; |
3822 | } | |
3823 | /* LIST_ENTRY must be an INSN of some kind that sets memory. | |
3824 | Examine each hunk of memory that is modified. */ | |
3825 | ||
3826 | dest = XEXP (list_entry, 0); | |
3827 | list_entry = XEXP (list_entry, 1); | |
3828 | dest_addr = XEXP (list_entry, 0); | |
3829 | ||
3830 | if (canon_true_dependence (dest, GET_MODE (dest), dest_addr, | |
3831 | x, rtx_addr_varies_p)) | |
3832 | { | |
3833 | if (set_p) | |
e0082a72 | 3834 | SET_BIT (bmap[bb->index], indx); |
a13d4ebf | 3835 | else |
e0082a72 | 3836 | RESET_BIT (bmap[bb->index], indx); |
a13d4ebf AM |
3837 | break; |
3838 | } | |
3839 | list_entry = XEXP (list_entry, 1); | |
3840 | } | |
3841 | } | |
c4c81601 | 3842 | |
7506f491 DE |
3843 | x = XEXP (x, 0); |
3844 | goto repeat; | |
3845 | ||
3846 | case PC: | |
3847 | case CC0: /*FIXME*/ | |
3848 | case CONST: | |
3849 | case CONST_INT: | |
3850 | case CONST_DOUBLE: | |
69ef87e2 | 3851 | case CONST_VECTOR: |
7506f491 DE |
3852 | case SYMBOL_REF: |
3853 | case LABEL_REF: | |
3854 | case ADDR_VEC: | |
3855 | case ADDR_DIFF_VEC: | |
3856 | return; | |
3857 | ||
3858 | default: | |
3859 | break; | |
3860 | } | |
3861 | ||
c4c81601 | 3862 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
3863 | { |
3864 | if (fmt[i] == 'e') | |
3865 | { | |
7506f491 DE |
3866 | /* If we are about to do the last recursive call |
3867 | needed at this level, change it into iteration. | |
3868 | This function is called enough to be worth it. */ | |
3869 | if (i == 0) | |
3870 | { | |
c4c81601 | 3871 | x = XEXP (x, i); |
7506f491 DE |
3872 | goto repeat; |
3873 | } | |
c4c81601 RK |
3874 | |
3875 | compute_transp (XEXP (x, i), indx, bmap, set_p); | |
7506f491 DE |
3876 | } |
3877 | else if (fmt[i] == 'E') | |
c4c81601 RK |
3878 | for (j = 0; j < XVECLEN (x, i); j++) |
3879 | compute_transp (XVECEXP (x, i, j), indx, bmap, set_p); | |
7506f491 DE |
3880 | } |
3881 | } | |
3882 | ||
7506f491 DE |
3883 | /* Top level routine to do the dataflow analysis needed by copy/const |
3884 | propagation. */ | |
3885 | ||
3886 | static void | |
3887 | compute_cprop_data () | |
3888 | { | |
b5ce41ff | 3889 | compute_local_properties (cprop_absaltered, cprop_pavloc, NULL, 1); |
ce724250 JL |
3890 | compute_available (cprop_pavloc, cprop_absaltered, |
3891 | cprop_avout, cprop_avin); | |
7506f491 DE |
3892 | } |
3893 | \f | |
3894 | /* Copy/constant propagation. */ | |
3895 | ||
7506f491 DE |
3896 | /* Maximum number of register uses in an insn that we handle. */ |
3897 | #define MAX_USES 8 | |
3898 | ||
3899 | /* Table of uses found in an insn. | |
3900 | Allocated statically to avoid alloc/free complexity and overhead. */ | |
3901 | static struct reg_use reg_use_table[MAX_USES]; | |
3902 | ||
3903 | /* Index into `reg_use_table' while building it. */ | |
3904 | static int reg_use_count; | |
3905 | ||
c4c81601 RK |
3906 | /* Set up a list of register numbers used in INSN. The found uses are stored |
3907 | in `reg_use_table'. `reg_use_count' is initialized to zero before entry, | |
3908 | and contains the number of uses in the table upon exit. | |
7506f491 | 3909 | |
c4c81601 RK |
3910 | ??? If a register appears multiple times we will record it multiple times. |
3911 | This doesn't hurt anything but it will slow things down. */ | |
7506f491 DE |
3912 | |
3913 | static void | |
9e71c818 JH |
3914 | find_used_regs (xptr, data) |
3915 | rtx *xptr; | |
3916 | void *data ATTRIBUTE_UNUSED; | |
7506f491 | 3917 | { |
c4c81601 | 3918 | int i, j; |
7506f491 | 3919 | enum rtx_code code; |
6f7d635c | 3920 | const char *fmt; |
9e71c818 | 3921 | rtx x = *xptr; |
7506f491 | 3922 | |
c4c81601 RK |
3923 | /* repeat is used to turn tail-recursion into iteration since GCC |
3924 | can't do it when there's no return value. */ | |
7506f491 | 3925 | repeat: |
7506f491 DE |
3926 | if (x == 0) |
3927 | return; | |
3928 | ||
3929 | code = GET_CODE (x); | |
9e71c818 | 3930 | if (REG_P (x)) |
7506f491 | 3931 | { |
7506f491 DE |
3932 | if (reg_use_count == MAX_USES) |
3933 | return; | |
c4c81601 | 3934 | |
7506f491 DE |
3935 | reg_use_table[reg_use_count].reg_rtx = x; |
3936 | reg_use_count++; | |
7506f491 DE |
3937 | } |
3938 | ||
3939 | /* Recursively scan the operands of this expression. */ | |
3940 | ||
c4c81601 | 3941 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
3942 | { |
3943 | if (fmt[i] == 'e') | |
3944 | { | |
3945 | /* If we are about to do the last recursive call | |
3946 | needed at this level, change it into iteration. | |
3947 | This function is called enough to be worth it. */ | |
3948 | if (i == 0) | |
3949 | { | |
3950 | x = XEXP (x, 0); | |
3951 | goto repeat; | |
3952 | } | |
c4c81601 | 3953 | |
9e71c818 | 3954 | find_used_regs (&XEXP (x, i), data); |
7506f491 DE |
3955 | } |
3956 | else if (fmt[i] == 'E') | |
c4c81601 | 3957 | for (j = 0; j < XVECLEN (x, i); j++) |
9e71c818 | 3958 | find_used_regs (&XVECEXP (x, i, j), data); |
7506f491 DE |
3959 | } |
3960 | } | |
3961 | ||
3962 | /* Try to replace all non-SET_DEST occurrences of FROM in INSN with TO. | |
3963 | Returns non-zero is successful. */ | |
3964 | ||
3965 | static int | |
3966 | try_replace_reg (from, to, insn) | |
3967 | rtx from, to, insn; | |
3968 | { | |
172890a2 | 3969 | rtx note = find_reg_equal_equiv_note (insn); |
fb0c0a12 | 3970 | rtx src = 0; |
172890a2 RK |
3971 | int success = 0; |
3972 | rtx set = single_set (insn); | |
833fc3ad | 3973 | |
9e71c818 JH |
3974 | success = validate_replace_src (from, to, insn); |
3975 | ||
3976 | /* If above failed and this is a single set, try to simplify the source of | |
3977 | the set given our substitution. We could perhaps try this for multiple | |
3978 | SETs, but it probably won't buy us anything. */ | |
3979 | if (!success && set != 0) | |
833fc3ad | 3980 | { |
172890a2 RK |
3981 | src = simplify_replace_rtx (SET_SRC (set), from, to); |
3982 | ||
9e71c818 JH |
3983 | if (!rtx_equal_p (src, SET_SRC (set)) |
3984 | && validate_change (insn, &SET_SRC (set), src, 0)) | |
172890a2 | 3985 | success = 1; |
833fc3ad JH |
3986 | } |
3987 | ||
fb0c0a12 RK |
3988 | /* If we've failed to do replacement, have a single SET, and don't already |
3989 | have a note, add a REG_EQUAL note to not lose information. */ | |
172890a2 | 3990 | if (!success && note == 0 && set != 0) |
7fcd7218 | 3991 | note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (src)); |
e251e2a2 | 3992 | |
172890a2 RK |
3993 | /* If there is already a NOTE, update the expression in it with our |
3994 | replacement. */ | |
3995 | else if (note != 0) | |
3996 | XEXP (note, 0) = simplify_replace_rtx (XEXP (note, 0), from, to); | |
833fc3ad | 3997 | |
172890a2 RK |
3998 | /* REG_EQUAL may get simplified into register. |
3999 | We don't allow that. Remove that note. This code ought | |
4000 | not to hapen, because previous code ought to syntetize | |
4001 | reg-reg move, but be on the safe side. */ | |
4002 | if (note && REG_P (XEXP (note, 0))) | |
4003 | remove_note (insn, note); | |
833fc3ad | 4004 | |
833fc3ad JH |
4005 | return success; |
4006 | } | |
c4c81601 RK |
4007 | |
4008 | /* Find a set of REGNOs that are available on entry to INSN's block. Returns | |
4009 | NULL no such set is found. */ | |
7506f491 DE |
4010 | |
4011 | static struct expr * | |
4012 | find_avail_set (regno, insn) | |
4013 | int regno; | |
4014 | rtx insn; | |
4015 | { | |
cafba495 BS |
4016 | /* SET1 contains the last set found that can be returned to the caller for |
4017 | use in a substitution. */ | |
4018 | struct expr *set1 = 0; | |
4019 | ||
4020 | /* Loops are not possible here. To get a loop we would need two sets | |
4021 | available at the start of the block containing INSN. ie we would | |
4022 | need two sets like this available at the start of the block: | |
4023 | ||
4024 | (set (reg X) (reg Y)) | |
4025 | (set (reg Y) (reg X)) | |
4026 | ||
4027 | This can not happen since the set of (reg Y) would have killed the | |
4028 | set of (reg X) making it unavailable at the start of this block. */ | |
4029 | while (1) | |
8e42ace1 | 4030 | { |
cafba495 BS |
4031 | rtx src; |
4032 | struct expr *set = lookup_set (regno, NULL_RTX); | |
4033 | ||
4034 | /* Find a set that is available at the start of the block | |
4035 | which contains INSN. */ | |
4036 | while (set) | |
4037 | { | |
4038 | if (TEST_BIT (cprop_avin[BLOCK_NUM (insn)], set->bitmap_index)) | |
4039 | break; | |
4040 | set = next_set (regno, set); | |
4041 | } | |
7506f491 | 4042 | |
cafba495 BS |
4043 | /* If no available set was found we've reached the end of the |
4044 | (possibly empty) copy chain. */ | |
4045 | if (set == 0) | |
4046 | break; | |
4047 | ||
4048 | if (GET_CODE (set->expr) != SET) | |
4049 | abort (); | |
4050 | ||
4051 | src = SET_SRC (set->expr); | |
4052 | ||
4053 | /* We know the set is available. | |
4054 | Now check that SRC is ANTLOC (i.e. none of the source operands | |
4055 | have changed since the start of the block). | |
4056 | ||
4057 | If the source operand changed, we may still use it for the next | |
4058 | iteration of this loop, but we may not use it for substitutions. */ | |
c4c81601 | 4059 | |
cafba495 BS |
4060 | if (CONSTANT_P (src) || oprs_not_set_p (src, insn)) |
4061 | set1 = set; | |
4062 | ||
4063 | /* If the source of the set is anything except a register, then | |
4064 | we have reached the end of the copy chain. */ | |
4065 | if (GET_CODE (src) != REG) | |
7506f491 | 4066 | break; |
7506f491 | 4067 | |
cafba495 BS |
4068 | /* Follow the copy chain, ie start another iteration of the loop |
4069 | and see if we have an available copy into SRC. */ | |
4070 | regno = REGNO (src); | |
8e42ace1 | 4071 | } |
cafba495 BS |
4072 | |
4073 | /* SET1 holds the last set that was available and anticipatable at | |
4074 | INSN. */ | |
4075 | return set1; | |
7506f491 DE |
4076 | } |
4077 | ||
abd535b6 | 4078 | /* Subroutine of cprop_insn that tries to propagate constants into |
0e3f0221 RS |
4079 | JUMP_INSNS. JUMP must be a conditional jump. If SETCC is non-NULL |
4080 | it is the instruction that immediately preceeds JUMP, and must be a | |
818b6b7f | 4081 | single SET of a register. FROM is what we will try to replace, |
0e3f0221 RS |
4082 | SRC is the constant we will try to substitute for it. Returns nonzero |
4083 | if a change was made. */ | |
c4c81601 | 4084 | |
abd535b6 | 4085 | static int |
0e3f0221 RS |
4086 | cprop_jump (bb, setcc, jump, from, src) |
4087 | basic_block bb; | |
4088 | rtx setcc; | |
4089 | rtx jump; | |
172890a2 | 4090 | rtx from; |
abd535b6 BS |
4091 | rtx src; |
4092 | { | |
0e3f0221 RS |
4093 | rtx new, new_set; |
4094 | rtx set = pc_set (jump); | |
4095 | ||
4096 | /* First substitute in the INSN condition as the SET_SRC of the JUMP, | |
4097 | then substitute that given values in this expanded JUMP. */ | |
4098 | if (setcc != NULL) | |
b2f02503 RS |
4099 | { |
4100 | rtx setcc_set = single_set (setcc); | |
4101 | new_set = simplify_replace_rtx (SET_SRC (set), | |
4102 | SET_DEST (setcc_set), | |
4103 | SET_SRC (setcc_set)); | |
4104 | } | |
0e3f0221 RS |
4105 | else |
4106 | new_set = set; | |
4107 | ||
4108 | new = simplify_replace_rtx (new_set, from, src); | |
abd535b6 BS |
4109 | |
4110 | /* If no simplification can be made, then try the next | |
4111 | register. */ | |
0e3f0221 | 4112 | if (rtx_equal_p (new, new_set)) |
abd535b6 BS |
4113 | return 0; |
4114 | ||
7d5ab30e | 4115 | /* If this is now a no-op delete it, otherwise this must be a valid insn. */ |
172890a2 | 4116 | if (new == pc_rtx) |
0e3f0221 | 4117 | delete_insn (jump); |
7d5ab30e | 4118 | else |
abd535b6 | 4119 | { |
0e3f0221 | 4120 | if (! validate_change (jump, &SET_SRC (set), new, 0)) |
7d5ab30e | 4121 | return 0; |
abd535b6 | 4122 | |
7d5ab30e JH |
4123 | /* If this has turned into an unconditional jump, |
4124 | then put a barrier after it so that the unreachable | |
4125 | code will be deleted. */ | |
4126 | if (GET_CODE (SET_SRC (set)) == LABEL_REF) | |
0e3f0221 | 4127 | emit_barrier_after (jump); |
7d5ab30e | 4128 | } |
abd535b6 | 4129 | |
0e3f0221 RS |
4130 | #ifdef HAVE_cc0 |
4131 | /* Delete the cc0 setter. */ | |
818b6b7f | 4132 | if (setcc != NULL && CC0_P (SET_DEST (single_set (setcc)))) |
0e3f0221 RS |
4133 | delete_insn (setcc); |
4134 | #endif | |
4135 | ||
172890a2 | 4136 | run_jump_opt_after_gcse = 1; |
c4c81601 | 4137 | |
172890a2 RK |
4138 | const_prop_count++; |
4139 | if (gcse_file != NULL) | |
4140 | { | |
4141 | fprintf (gcse_file, | |
818b6b7f | 4142 | "CONST-PROP: Replacing reg %d in jump_insn %d with constant ", |
0e3f0221 | 4143 | REGNO (from), INSN_UID (jump)); |
172890a2 RK |
4144 | print_rtl (gcse_file, src); |
4145 | fprintf (gcse_file, "\n"); | |
abd535b6 | 4146 | } |
0005550b | 4147 | purge_dead_edges (bb); |
172890a2 RK |
4148 | |
4149 | return 1; | |
abd535b6 BS |
4150 | } |
4151 | ||
7506f491 DE |
4152 | /* Perform constant and copy propagation on INSN. |
4153 | The result is non-zero if a change was made. */ | |
4154 | ||
4155 | static int | |
0005550b JH |
4156 | cprop_insn (bb, insn, alter_jumps) |
4157 | basic_block bb; | |
7506f491 | 4158 | rtx insn; |
b5ce41ff | 4159 | int alter_jumps; |
7506f491 DE |
4160 | { |
4161 | struct reg_use *reg_used; | |
4162 | int changed = 0; | |
833fc3ad | 4163 | rtx note; |
7506f491 | 4164 | |
9e71c818 | 4165 | if (!INSN_P (insn)) |
7506f491 DE |
4166 | return 0; |
4167 | ||
4168 | reg_use_count = 0; | |
9e71c818 | 4169 | note_uses (&PATTERN (insn), find_used_regs, NULL); |
833fc3ad | 4170 | |
172890a2 | 4171 | note = find_reg_equal_equiv_note (insn); |
833fc3ad | 4172 | |
dc297297 | 4173 | /* We may win even when propagating constants into notes. */ |
833fc3ad | 4174 | if (note) |
9e71c818 | 4175 | find_used_regs (&XEXP (note, 0), NULL); |
7506f491 | 4176 | |
c4c81601 RK |
4177 | for (reg_used = ®_use_table[0]; reg_use_count > 0; |
4178 | reg_used++, reg_use_count--) | |
7506f491 | 4179 | { |
770ae6cc | 4180 | unsigned int regno = REGNO (reg_used->reg_rtx); |
7506f491 DE |
4181 | rtx pat, src; |
4182 | struct expr *set; | |
7506f491 DE |
4183 | |
4184 | /* Ignore registers created by GCSE. | |
dc297297 | 4185 | We do this because ... */ |
7506f491 DE |
4186 | if (regno >= max_gcse_regno) |
4187 | continue; | |
4188 | ||
4189 | /* If the register has already been set in this block, there's | |
4190 | nothing we can do. */ | |
4191 | if (! oprs_not_set_p (reg_used->reg_rtx, insn)) | |
4192 | continue; | |
4193 | ||
4194 | /* Find an assignment that sets reg_used and is available | |
4195 | at the start of the block. */ | |
4196 | set = find_avail_set (regno, insn); | |
4197 | if (! set) | |
4198 | continue; | |
4199 | ||
4200 | pat = set->expr; | |
4201 | /* ??? We might be able to handle PARALLELs. Later. */ | |
4202 | if (GET_CODE (pat) != SET) | |
4203 | abort (); | |
c4c81601 | 4204 | |
7506f491 DE |
4205 | src = SET_SRC (pat); |
4206 | ||
e78d9500 | 4207 | /* Constant propagation. */ |
b446e5a2 | 4208 | if (CONSTANT_P (src)) |
7506f491 | 4209 | { |
818b6b7f RH |
4210 | rtx sset; |
4211 | ||
4212 | /* Check for reg or cc0 setting instructions followed by | |
0e3f0221 RS |
4213 | conditional branch instructions first. */ |
4214 | if (alter_jumps | |
818b6b7f | 4215 | && (sset = single_set (insn)) != NULL |
0e3f0221 RS |
4216 | && any_condjump_p (NEXT_INSN (insn)) |
4217 | && onlyjump_p (NEXT_INSN (insn))) | |
4218 | { | |
818b6b7f RH |
4219 | rtx dest = SET_DEST (sset); |
4220 | if ((REG_P (dest) || CC0_P (dest)) | |
4221 | && cprop_jump (bb, insn, NEXT_INSN (insn), | |
4222 | reg_used->reg_rtx, src)) | |
0e3f0221 RS |
4223 | { |
4224 | changed = 1; | |
4225 | break; | |
4226 | } | |
4227 | } | |
4228 | ||
4229 | /* Handle normal insns next. */ | |
e78d9500 JL |
4230 | if (GET_CODE (insn) == INSN |
4231 | && try_replace_reg (reg_used->reg_rtx, src, insn)) | |
7506f491 DE |
4232 | { |
4233 | changed = 1; | |
4234 | const_prop_count++; | |
4235 | if (gcse_file != NULL) | |
4236 | { | |
c4c81601 RK |
4237 | fprintf (gcse_file, "CONST-PROP: Replacing reg %d in ", |
4238 | regno); | |
4239 | fprintf (gcse_file, "insn %d with constant ", | |
4240 | INSN_UID (insn)); | |
e78d9500 | 4241 | print_rtl (gcse_file, src); |
7506f491 DE |
4242 | fprintf (gcse_file, "\n"); |
4243 | } | |
4244 | ||
4245 | /* The original insn setting reg_used may or may not now be | |
4246 | deletable. We leave the deletion to flow. */ | |
4247 | } | |
e78d9500 JL |
4248 | |
4249 | /* Try to propagate a CONST_INT into a conditional jump. | |
4250 | We're pretty specific about what we will handle in this | |
4251 | code, we can extend this as necessary over time. | |
4252 | ||
4253 | Right now the insn in question must look like | |
abd535b6 | 4254 | (set (pc) (if_then_else ...)) */ |
b5ce41ff | 4255 | else if (alter_jumps |
0e3f0221 RS |
4256 | && any_condjump_p (insn) |
4257 | && onlyjump_p (insn)) | |
4258 | changed |= cprop_jump (bb, NULL, insn, reg_used->reg_rtx, src); | |
172890a2 | 4259 | |
7506f491 DE |
4260 | } |
4261 | else if (GET_CODE (src) == REG | |
4262 | && REGNO (src) >= FIRST_PSEUDO_REGISTER | |
4263 | && REGNO (src) != regno) | |
4264 | { | |
cafba495 | 4265 | if (try_replace_reg (reg_used->reg_rtx, src, insn)) |
7506f491 | 4266 | { |
cafba495 BS |
4267 | changed = 1; |
4268 | copy_prop_count++; | |
4269 | if (gcse_file != NULL) | |
7506f491 | 4270 | { |
c4c81601 RK |
4271 | fprintf (gcse_file, "COPY-PROP: Replacing reg %d in insn %d", |
4272 | regno, INSN_UID (insn)); | |
4273 | fprintf (gcse_file, " with reg %d\n", REGNO (src)); | |
7506f491 | 4274 | } |
cafba495 BS |
4275 | |
4276 | /* The original insn setting reg_used may or may not now be | |
4277 | deletable. We leave the deletion to flow. */ | |
4278 | /* FIXME: If it turns out that the insn isn't deletable, | |
4279 | then we may have unnecessarily extended register lifetimes | |
4280 | and made things worse. */ | |
7506f491 DE |
4281 | } |
4282 | } | |
4283 | } | |
4284 | ||
4285 | return changed; | |
4286 | } | |
4287 | ||
c4c81601 RK |
4288 | /* Forward propagate copies. This includes copies and constants. Return |
4289 | non-zero if a change was made. */ | |
7506f491 DE |
4290 | |
4291 | static int | |
b5ce41ff JL |
4292 | cprop (alter_jumps) |
4293 | int alter_jumps; | |
7506f491 | 4294 | { |
e0082a72 ZD |
4295 | int changed; |
4296 | basic_block bb; | |
7506f491 DE |
4297 | rtx insn; |
4298 | ||
4299 | /* Note we start at block 1. */ | |
e0082a72 ZD |
4300 | if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) |
4301 | { | |
4302 | if (gcse_file != NULL) | |
4303 | fprintf (gcse_file, "\n"); | |
4304 | return 0; | |
4305 | } | |
7506f491 DE |
4306 | |
4307 | changed = 0; | |
e0082a72 | 4308 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb->next_bb, EXIT_BLOCK_PTR, next_bb) |
7506f491 DE |
4309 | { |
4310 | /* Reset tables used to keep track of what's still valid [since the | |
4311 | start of the block]. */ | |
4312 | reset_opr_set_tables (); | |
4313 | ||
e0082a72 ZD |
4314 | for (insn = bb->head; |
4315 | insn != NULL && insn != NEXT_INSN (bb->end); | |
7506f491 | 4316 | insn = NEXT_INSN (insn)) |
172890a2 RK |
4317 | if (INSN_P (insn)) |
4318 | { | |
e0082a72 | 4319 | changed |= cprop_insn (bb, insn, alter_jumps); |
7506f491 | 4320 | |
172890a2 RK |
4321 | /* Keep track of everything modified by this insn. */ |
4322 | /* ??? Need to be careful w.r.t. mods done to INSN. Don't | |
4323 | call mark_oprs_set if we turned the insn into a NOTE. */ | |
4324 | if (GET_CODE (insn) != NOTE) | |
4325 | mark_oprs_set (insn); | |
8e42ace1 | 4326 | } |
7506f491 DE |
4327 | } |
4328 | ||
4329 | if (gcse_file != NULL) | |
4330 | fprintf (gcse_file, "\n"); | |
4331 | ||
4332 | return changed; | |
4333 | } | |
4334 | ||
4335 | /* Perform one copy/constant propagation pass. | |
4336 | F is the first insn in the function. | |
4337 | PASS is the pass count. */ | |
4338 | ||
4339 | static int | |
b5ce41ff | 4340 | one_cprop_pass (pass, alter_jumps) |
7506f491 | 4341 | int pass; |
b5ce41ff | 4342 | int alter_jumps; |
7506f491 DE |
4343 | { |
4344 | int changed = 0; | |
4345 | ||
4346 | const_prop_count = 0; | |
4347 | copy_prop_count = 0; | |
4348 | ||
4349 | alloc_set_hash_table (max_cuid); | |
b5ce41ff | 4350 | compute_set_hash_table (); |
7506f491 DE |
4351 | if (gcse_file) |
4352 | dump_hash_table (gcse_file, "SET", set_hash_table, set_hash_table_size, | |
4353 | n_sets); | |
4354 | if (n_sets > 0) | |
4355 | { | |
d55bc081 | 4356 | alloc_cprop_mem (last_basic_block, n_sets); |
7506f491 | 4357 | compute_cprop_data (); |
b5ce41ff | 4358 | changed = cprop (alter_jumps); |
0e3f0221 RS |
4359 | if (alter_jumps) |
4360 | changed |= bypass_conditional_jumps (); | |
7506f491 DE |
4361 | free_cprop_mem (); |
4362 | } | |
c4c81601 | 4363 | |
7506f491 DE |
4364 | free_set_hash_table (); |
4365 | ||
4366 | if (gcse_file) | |
4367 | { | |
c4c81601 RK |
4368 | fprintf (gcse_file, "CPROP of %s, pass %d: %d bytes needed, ", |
4369 | current_function_name, pass, bytes_used); | |
4370 | fprintf (gcse_file, "%d const props, %d copy props\n\n", | |
4371 | const_prop_count, copy_prop_count); | |
7506f491 DE |
4372 | } |
4373 | ||
4374 | return changed; | |
4375 | } | |
4376 | \f | |
0e3f0221 RS |
4377 | /* Bypass conditional jumps. */ |
4378 | ||
4379 | /* Find a set of REGNO to a constant that is available at the end of basic | |
4380 | block BB. Returns NULL if no such set is found. Based heavily upon | |
4381 | find_avail_set. */ | |
4382 | ||
4383 | static struct expr * | |
4384 | find_bypass_set (regno, bb) | |
4385 | int regno; | |
4386 | int bb; | |
4387 | { | |
4388 | struct expr *result = 0; | |
4389 | ||
4390 | for (;;) | |
4391 | { | |
4392 | rtx src; | |
4393 | struct expr *set = lookup_set (regno, NULL_RTX); | |
4394 | ||
4395 | while (set) | |
4396 | { | |
4397 | if (TEST_BIT (cprop_avout[bb], set->bitmap_index)) | |
4398 | break; | |
4399 | set = next_set (regno, set); | |
4400 | } | |
4401 | ||
4402 | if (set == 0) | |
4403 | break; | |
4404 | ||
4405 | if (GET_CODE (set->expr) != SET) | |
4406 | abort (); | |
4407 | ||
4408 | src = SET_SRC (set->expr); | |
4409 | if (CONSTANT_P (src)) | |
4410 | result = set; | |
4411 | ||
4412 | if (GET_CODE (src) != REG) | |
4413 | break; | |
4414 | ||
4415 | regno = REGNO (src); | |
4416 | } | |
4417 | return result; | |
4418 | } | |
4419 | ||
4420 | ||
4421 | /* Subroutine of bypass_conditional_jumps that attempts to bypass the given | |
4422 | basic block BB which has more than one predecessor. If not NULL, SETCC | |
4423 | is the first instruction of BB, which is immediately followed by JUMP_INSN | |
4424 | JUMP. Otherwise, SETCC is NULL, and JUMP is the first insn of BB. | |
4425 | Returns nonzero if a change was made. */ | |
4426 | ||
4427 | static int | |
4428 | bypass_block (bb, setcc, jump) | |
4429 | basic_block bb; | |
4430 | rtx setcc, jump; | |
4431 | { | |
4432 | rtx insn, note; | |
4433 | edge e, enext; | |
818b6b7f | 4434 | int i, change; |
0e3f0221 RS |
4435 | |
4436 | insn = (setcc != NULL) ? setcc : jump; | |
4437 | ||
4438 | /* Determine set of register uses in INSN. */ | |
4439 | reg_use_count = 0; | |
4440 | note_uses (&PATTERN (insn), find_used_regs, NULL); | |
4441 | note = find_reg_equal_equiv_note (insn); | |
4442 | if (note) | |
4443 | find_used_regs (&XEXP (note, 0), NULL); | |
4444 | ||
4445 | change = 0; | |
4446 | for (e = bb->pred; e; e = enext) | |
4447 | { | |
4448 | enext = e->pred_next; | |
4449 | for (i = 0; i < reg_use_count; i++) | |
4450 | { | |
4451 | struct reg_use *reg_used = ®_use_table[i]; | |
4452 | unsigned int regno = REGNO (reg_used->reg_rtx); | |
818b6b7f | 4453 | basic_block dest, old_dest; |
0e3f0221 RS |
4454 | struct expr *set; |
4455 | rtx src, new; | |
4456 | ||
4457 | if (regno >= max_gcse_regno) | |
4458 | continue; | |
4459 | ||
4460 | set = find_bypass_set (regno, e->src->index); | |
4461 | ||
4462 | if (! set) | |
4463 | continue; | |
4464 | ||
4465 | src = SET_SRC (pc_set (jump)); | |
4466 | ||
4467 | if (setcc != NULL) | |
4468 | src = simplify_replace_rtx (src, | |
4469 | SET_DEST (PATTERN (setcc)), | |
4470 | SET_SRC (PATTERN (setcc))); | |
4471 | ||
4472 | new = simplify_replace_rtx (src, reg_used->reg_rtx, | |
4473 | SET_SRC (set->expr)); | |
4474 | ||
4475 | if (new == pc_rtx) | |
4476 | dest = FALLTHRU_EDGE (bb)->dest; | |
4477 | else if (GET_CODE (new) == LABEL_REF) | |
4478 | dest = BRANCH_EDGE (bb)->dest; | |
4479 | else | |
4480 | dest = NULL; | |
4481 | ||
4482 | /* Once basic block indices are stable, we should be able | |
4483 | to use redirect_edge_and_branch_force instead. */ | |
818b6b7f RH |
4484 | old_dest = e->dest; |
4485 | if (dest != NULL && dest != old_dest | |
0e3f0221 RS |
4486 | && redirect_edge_and_branch (e, dest)) |
4487 | { | |
818b6b7f | 4488 | /* Copy the register setter to the redirected edge. |
0e3f0221 RS |
4489 | Don't copy CC0 setters, as CC0 is dead after jump. */ |
4490 | if (setcc) | |
4491 | { | |
4492 | rtx pat = PATTERN (setcc); | |
818b6b7f | 4493 | if (!CC0_P (SET_DEST (pat))) |
0e3f0221 RS |
4494 | insert_insn_on_edge (copy_insn (pat), e); |
4495 | } | |
4496 | ||
4497 | if (gcse_file != NULL) | |
4498 | { | |
818b6b7f RH |
4499 | fprintf (gcse_file, "JUMP-BYPASS: Proved reg %d in jump_insn %d equals constant ", |
4500 | regno, INSN_UID (jump)); | |
0e3f0221 RS |
4501 | print_rtl (gcse_file, SET_SRC (set->expr)); |
4502 | fprintf (gcse_file, "\nBypass edge from %d->%d to %d\n", | |
818b6b7f | 4503 | e->src->index, old_dest->index, dest->index); |
0e3f0221 RS |
4504 | } |
4505 | change = 1; | |
4506 | break; | |
4507 | } | |
4508 | } | |
4509 | } | |
4510 | return change; | |
4511 | } | |
4512 | ||
4513 | /* Find basic blocks with more than one predecessor that only contain a | |
4514 | single conditional jump. If the result of the comparison is known at | |
4515 | compile-time from any incoming edge, redirect that edge to the | |
4516 | appropriate target. Returns nonzero if a change was made. */ | |
4517 | ||
4518 | static int | |
4519 | bypass_conditional_jumps () | |
4520 | { | |
4521 | basic_block bb; | |
4522 | int changed; | |
4523 | rtx setcc; | |
4524 | rtx insn; | |
4525 | rtx dest; | |
4526 | ||
4527 | /* Note we start at block 1. */ | |
4528 | if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) | |
4529 | return 0; | |
4530 | ||
4531 | changed = 0; | |
4532 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb->next_bb, | |
4533 | EXIT_BLOCK_PTR, next_bb) | |
4534 | { | |
4535 | /* Check for more than one predecessor. */ | |
4536 | if (bb->pred && bb->pred->pred_next) | |
4537 | { | |
4538 | setcc = NULL_RTX; | |
4539 | for (insn = bb->head; | |
4540 | insn != NULL && insn != NEXT_INSN (bb->end); | |
4541 | insn = NEXT_INSN (insn)) | |
4542 | if (GET_CODE (insn) == INSN) | |
4543 | { | |
ada8d98a | 4544 | if (!setcc) |
0e3f0221 | 4545 | break; |
ba4f7968 | 4546 | if (GET_CODE (PATTERN (insn)) != SET) |
0e3f0221 RS |
4547 | break; |
4548 | ||
ba4f7968 | 4549 | dest = SET_DEST (PATTERN (insn)); |
818b6b7f | 4550 | if (REG_P (dest) || CC0_P (dest)) |
0e3f0221 | 4551 | setcc = insn; |
0e3f0221 RS |
4552 | else |
4553 | break; | |
4554 | } | |
4555 | else if (GET_CODE (insn) == JUMP_INSN) | |
4556 | { | |
4557 | if (any_condjump_p (insn) && onlyjump_p (insn)) | |
4558 | changed |= bypass_block (bb, setcc, insn); | |
4559 | break; | |
4560 | } | |
4561 | else if (INSN_P (insn)) | |
4562 | break; | |
4563 | } | |
4564 | } | |
4565 | ||
818b6b7f | 4566 | /* If we bypassed any register setting insns, we inserted a |
0e3f0221 RS |
4567 | copy on the redirected edge. These need to be commited. */ |
4568 | if (changed) | |
4569 | commit_edge_insertions(); | |
4570 | ||
4571 | return changed; | |
4572 | } | |
4573 | \f | |
a65f3558 | 4574 | /* Compute PRE+LCM working variables. */ |
7506f491 DE |
4575 | |
4576 | /* Local properties of expressions. */ | |
4577 | /* Nonzero for expressions that are transparent in the block. */ | |
a65f3558 | 4578 | static sbitmap *transp; |
7506f491 | 4579 | |
5c35539b RH |
4580 | /* Nonzero for expressions that are transparent at the end of the block. |
4581 | This is only zero for expressions killed by abnormal critical edge | |
4582 | created by a calls. */ | |
a65f3558 | 4583 | static sbitmap *transpout; |
5c35539b | 4584 | |
a65f3558 JL |
4585 | /* Nonzero for expressions that are computed (available) in the block. */ |
4586 | static sbitmap *comp; | |
7506f491 | 4587 | |
a65f3558 JL |
4588 | /* Nonzero for expressions that are locally anticipatable in the block. */ |
4589 | static sbitmap *antloc; | |
7506f491 | 4590 | |
a65f3558 JL |
4591 | /* Nonzero for expressions where this block is an optimal computation |
4592 | point. */ | |
4593 | static sbitmap *pre_optimal; | |
5c35539b | 4594 | |
a65f3558 JL |
4595 | /* Nonzero for expressions which are redundant in a particular block. */ |
4596 | static sbitmap *pre_redundant; | |
7506f491 | 4597 | |
a42cd965 AM |
4598 | /* Nonzero for expressions which should be inserted on a specific edge. */ |
4599 | static sbitmap *pre_insert_map; | |
4600 | ||
4601 | /* Nonzero for expressions which should be deleted in a specific block. */ | |
4602 | static sbitmap *pre_delete_map; | |
4603 | ||
4604 | /* Contains the edge_list returned by pre_edge_lcm. */ | |
4605 | static struct edge_list *edge_list; | |
4606 | ||
a65f3558 JL |
4607 | /* Redundant insns. */ |
4608 | static sbitmap pre_redundant_insns; | |
7506f491 | 4609 | |
a65f3558 | 4610 | /* Allocate vars used for PRE analysis. */ |
7506f491 DE |
4611 | |
4612 | static void | |
a65f3558 JL |
4613 | alloc_pre_mem (n_blocks, n_exprs) |
4614 | int n_blocks, n_exprs; | |
7506f491 | 4615 | { |
a65f3558 JL |
4616 | transp = sbitmap_vector_alloc (n_blocks, n_exprs); |
4617 | comp = sbitmap_vector_alloc (n_blocks, n_exprs); | |
4618 | antloc = sbitmap_vector_alloc (n_blocks, n_exprs); | |
5faf03ae | 4619 | |
a42cd965 AM |
4620 | pre_optimal = NULL; |
4621 | pre_redundant = NULL; | |
4622 | pre_insert_map = NULL; | |
4623 | pre_delete_map = NULL; | |
4624 | ae_in = NULL; | |
4625 | ae_out = NULL; | |
a42cd965 | 4626 | ae_kill = sbitmap_vector_alloc (n_blocks, n_exprs); |
c4c81601 | 4627 | |
a42cd965 | 4628 | /* pre_insert and pre_delete are allocated later. */ |
7506f491 DE |
4629 | } |
4630 | ||
a65f3558 | 4631 | /* Free vars used for PRE analysis. */ |
7506f491 DE |
4632 | |
4633 | static void | |
a65f3558 | 4634 | free_pre_mem () |
7506f491 | 4635 | { |
5a660bff DB |
4636 | sbitmap_vector_free (transp); |
4637 | sbitmap_vector_free (comp); | |
bd3675fc JL |
4638 | |
4639 | /* ANTLOC and AE_KILL are freed just after pre_lcm finishes. */ | |
7506f491 | 4640 | |
a42cd965 | 4641 | if (pre_optimal) |
5a660bff | 4642 | sbitmap_vector_free (pre_optimal); |
a42cd965 | 4643 | if (pre_redundant) |
5a660bff | 4644 | sbitmap_vector_free (pre_redundant); |
a42cd965 | 4645 | if (pre_insert_map) |
5a660bff | 4646 | sbitmap_vector_free (pre_insert_map); |
a42cd965 | 4647 | if (pre_delete_map) |
5a660bff | 4648 | sbitmap_vector_free (pre_delete_map); |
a42cd965 | 4649 | if (ae_in) |
5a660bff | 4650 | sbitmap_vector_free (ae_in); |
a42cd965 | 4651 | if (ae_out) |
5a660bff | 4652 | sbitmap_vector_free (ae_out); |
a42cd965 | 4653 | |
bd3675fc | 4654 | transp = comp = NULL; |
a42cd965 | 4655 | pre_optimal = pre_redundant = pre_insert_map = pre_delete_map = NULL; |
55d3f917 | 4656 | ae_in = ae_out = NULL; |
7506f491 DE |
4657 | } |
4658 | ||
4659 | /* Top level routine to do the dataflow analysis needed by PRE. */ | |
4660 | ||
4661 | static void | |
4662 | compute_pre_data () | |
4663 | { | |
b614171e | 4664 | sbitmap trapping_expr; |
e0082a72 | 4665 | basic_block bb; |
b614171e | 4666 | unsigned int ui; |
c66e8ae9 | 4667 | |
a65f3558 | 4668 | compute_local_properties (transp, comp, antloc, 0); |
d55bc081 | 4669 | sbitmap_vector_zero (ae_kill, last_basic_block); |
c66e8ae9 | 4670 | |
b614171e MM |
4671 | /* Collect expressions which might trap. */ |
4672 | trapping_expr = sbitmap_alloc (n_exprs); | |
4673 | sbitmap_zero (trapping_expr); | |
4674 | for (ui = 0; ui < expr_hash_table_size; ui++) | |
4675 | { | |
4676 | struct expr *e; | |
4677 | for (e = expr_hash_table[ui]; e != NULL; e = e->next_same_hash) | |
4678 | if (may_trap_p (e->expr)) | |
4679 | SET_BIT (trapping_expr, e->bitmap_index); | |
4680 | } | |
4681 | ||
c66e8ae9 JL |
4682 | /* Compute ae_kill for each basic block using: |
4683 | ||
4684 | ~(TRANSP | COMP) | |
4685 | ||
a2e90653 | 4686 | This is significantly faster than compute_ae_kill. */ |
c66e8ae9 | 4687 | |
e0082a72 | 4688 | FOR_EACH_BB (bb) |
c66e8ae9 | 4689 | { |
b614171e MM |
4690 | edge e; |
4691 | ||
4692 | /* If the current block is the destination of an abnormal edge, we | |
4693 | kill all trapping expressions because we won't be able to properly | |
4694 | place the instruction on the edge. So make them neither | |
4695 | anticipatable nor transparent. This is fairly conservative. */ | |
e0082a72 | 4696 | for (e = bb->pred; e ; e = e->pred_next) |
b614171e MM |
4697 | if (e->flags & EDGE_ABNORMAL) |
4698 | { | |
e0082a72 ZD |
4699 | sbitmap_difference (antloc[bb->index], antloc[bb->index], trapping_expr); |
4700 | sbitmap_difference (transp[bb->index], transp[bb->index], trapping_expr); | |
b614171e MM |
4701 | break; |
4702 | } | |
4703 | ||
e0082a72 ZD |
4704 | sbitmap_a_or_b (ae_kill[bb->index], transp[bb->index], comp[bb->index]); |
4705 | sbitmap_not (ae_kill[bb->index], ae_kill[bb->index]); | |
c66e8ae9 JL |
4706 | } |
4707 | ||
a42cd965 AM |
4708 | edge_list = pre_edge_lcm (gcse_file, n_exprs, transp, comp, antloc, |
4709 | ae_kill, &pre_insert_map, &pre_delete_map); | |
5a660bff | 4710 | sbitmap_vector_free (antloc); |
bd3675fc | 4711 | antloc = NULL; |
5a660bff | 4712 | sbitmap_vector_free (ae_kill); |
bd3675fc | 4713 | ae_kill = NULL; |
76ac938b | 4714 | sbitmap_free (trapping_expr); |
7506f491 DE |
4715 | } |
4716 | \f | |
4717 | /* PRE utilities */ | |
4718 | ||
a65f3558 JL |
4719 | /* Return non-zero if an occurrence of expression EXPR in OCCR_BB would reach |
4720 | block BB. | |
7506f491 DE |
4721 | |
4722 | VISITED is a pointer to a working buffer for tracking which BB's have | |
4723 | been visited. It is NULL for the top-level call. | |
4724 | ||
4725 | We treat reaching expressions that go through blocks containing the same | |
4726 | reaching expression as "not reaching". E.g. if EXPR is generated in blocks | |
4727 | 2 and 3, INSN is in block 4, and 2->3->4, we treat the expression in block | |
4728 | 2 as not reaching. The intent is to improve the probability of finding | |
4729 | only one reaching expression and to reduce register lifetimes by picking | |
4730 | the closest such expression. */ | |
4731 | ||
4732 | static int | |
89e606c9 | 4733 | pre_expr_reaches_here_p_work (occr_bb, expr, bb, visited) |
e2d2ed72 | 4734 | basic_block occr_bb; |
7506f491 | 4735 | struct expr *expr; |
e2d2ed72 | 4736 | basic_block bb; |
7506f491 DE |
4737 | char *visited; |
4738 | { | |
36349f8b | 4739 | edge pred; |
7506f491 | 4740 | |
e2d2ed72 | 4741 | for (pred = bb->pred; pred != NULL; pred = pred->pred_next) |
7506f491 | 4742 | { |
e2d2ed72 | 4743 | basic_block pred_bb = pred->src; |
7506f491 | 4744 | |
36349f8b | 4745 | if (pred->src == ENTRY_BLOCK_PTR |
7506f491 | 4746 | /* Has predecessor has already been visited? */ |
0b17ab2f | 4747 | || visited[pred_bb->index]) |
c4c81601 RK |
4748 | ;/* Nothing to do. */ |
4749 | ||
7506f491 | 4750 | /* Does this predecessor generate this expression? */ |
0b17ab2f | 4751 | else if (TEST_BIT (comp[pred_bb->index], expr->bitmap_index)) |
7506f491 DE |
4752 | { |
4753 | /* Is this the occurrence we're looking for? | |
4754 | Note that there's only one generating occurrence per block | |
4755 | so we just need to check the block number. */ | |
a65f3558 | 4756 | if (occr_bb == pred_bb) |
7506f491 | 4757 | return 1; |
c4c81601 | 4758 | |
0b17ab2f | 4759 | visited[pred_bb->index] = 1; |
7506f491 DE |
4760 | } |
4761 | /* Ignore this predecessor if it kills the expression. */ | |
0b17ab2f RH |
4762 | else if (! TEST_BIT (transp[pred_bb->index], expr->bitmap_index)) |
4763 | visited[pred_bb->index] = 1; | |
c4c81601 | 4764 | |
7506f491 DE |
4765 | /* Neither gen nor kill. */ |
4766 | else | |
ac7c5af5 | 4767 | { |
0b17ab2f | 4768 | visited[pred_bb->index] = 1; |
89e606c9 | 4769 | if (pre_expr_reaches_here_p_work (occr_bb, expr, pred_bb, visited)) |
7506f491 | 4770 | return 1; |
ac7c5af5 | 4771 | } |
7506f491 DE |
4772 | } |
4773 | ||
4774 | /* All paths have been checked. */ | |
4775 | return 0; | |
4776 | } | |
283a2545 RL |
4777 | |
4778 | /* The wrapper for pre_expr_reaches_here_work that ensures that any | |
dc297297 | 4779 | memory allocated for that function is returned. */ |
283a2545 RL |
4780 | |
4781 | static int | |
89e606c9 | 4782 | pre_expr_reaches_here_p (occr_bb, expr, bb) |
e2d2ed72 | 4783 | basic_block occr_bb; |
283a2545 | 4784 | struct expr *expr; |
e2d2ed72 | 4785 | basic_block bb; |
283a2545 RL |
4786 | { |
4787 | int rval; | |
d55bc081 | 4788 | char *visited = (char *) xcalloc (last_basic_block, 1); |
283a2545 | 4789 | |
8e42ace1 | 4790 | rval = pre_expr_reaches_here_p_work (occr_bb, expr, bb, visited); |
283a2545 RL |
4791 | |
4792 | free (visited); | |
c4c81601 | 4793 | return rval; |
283a2545 | 4794 | } |
7506f491 | 4795 | \f |
a42cd965 AM |
4796 | |
4797 | /* Given an expr, generate RTL which we can insert at the end of a BB, | |
4798 | or on an edge. Set the block number of any insns generated to | |
4799 | the value of BB. */ | |
4800 | ||
4801 | static rtx | |
4802 | process_insert_insn (expr) | |
4803 | struct expr *expr; | |
4804 | { | |
4805 | rtx reg = expr->reaching_reg; | |
fb0c0a12 RK |
4806 | rtx exp = copy_rtx (expr->expr); |
4807 | rtx pat; | |
a42cd965 AM |
4808 | |
4809 | start_sequence (); | |
fb0c0a12 RK |
4810 | |
4811 | /* If the expression is something that's an operand, like a constant, | |
4812 | just copy it to a register. */ | |
4813 | if (general_operand (exp, GET_MODE (reg))) | |
4814 | emit_move_insn (reg, exp); | |
4815 | ||
4816 | /* Otherwise, make a new insn to compute this expression and make sure the | |
4817 | insn will be recognized (this also adds any needed CLOBBERs). Copy the | |
4818 | expression to make sure we don't have any sharing issues. */ | |
8d444206 | 4819 | else if (insn_invalid_p (emit_insn (gen_rtx_SET (VOIDmode, reg, exp)))) |
fb0c0a12 RK |
4820 | abort (); |
4821 | ||
a42cd965 AM |
4822 | pat = gen_sequence (); |
4823 | end_sequence (); | |
4824 | ||
4825 | return pat; | |
4826 | } | |
4827 | ||
a65f3558 JL |
4828 | /* Add EXPR to the end of basic block BB. |
4829 | ||
4830 | This is used by both the PRE and code hoisting. | |
4831 | ||
4832 | For PRE, we want to verify that the expr is either transparent | |
4833 | or locally anticipatable in the target block. This check makes | |
4834 | no sense for code hoisting. */ | |
7506f491 DE |
4835 | |
4836 | static void | |
a65f3558 | 4837 | insert_insn_end_bb (expr, bb, pre) |
7506f491 | 4838 | struct expr *expr; |
e2d2ed72 | 4839 | basic_block bb; |
a65f3558 | 4840 | int pre; |
7506f491 | 4841 | { |
e2d2ed72 | 4842 | rtx insn = bb->end; |
7506f491 DE |
4843 | rtx new_insn; |
4844 | rtx reg = expr->reaching_reg; | |
4845 | int regno = REGNO (reg); | |
a42cd965 | 4846 | rtx pat; |
c4c81601 | 4847 | int i; |
7506f491 | 4848 | |
a42cd965 | 4849 | pat = process_insert_insn (expr); |
7506f491 DE |
4850 | |
4851 | /* If the last insn is a jump, insert EXPR in front [taking care to | |
068473ec JH |
4852 | handle cc0, etc. properly]. Similary we need to care trapping |
4853 | instructions in presence of non-call exceptions. */ | |
7506f491 | 4854 | |
068473ec JH |
4855 | if (GET_CODE (insn) == JUMP_INSN |
4856 | || (GET_CODE (insn) == INSN | |
4857 | && (bb->succ->succ_next || (bb->succ->flags & EDGE_ABNORMAL)))) | |
7506f491 | 4858 | { |
50b2596f | 4859 | #ifdef HAVE_cc0 |
7506f491 | 4860 | rtx note; |
50b2596f | 4861 | #endif |
068473ec JH |
4862 | /* It should always be the case that we can put these instructions |
4863 | anywhere in the basic block with performing PRE optimizations. | |
4864 | Check this. */ | |
3b25fbfe | 4865 | if (GET_CODE (insn) == INSN && pre |
0b17ab2f RH |
4866 | && !TEST_BIT (antloc[bb->index], expr->bitmap_index) |
4867 | && !TEST_BIT (transp[bb->index], expr->bitmap_index)) | |
068473ec | 4868 | abort (); |
7506f491 DE |
4869 | |
4870 | /* If this is a jump table, then we can't insert stuff here. Since | |
4871 | we know the previous real insn must be the tablejump, we insert | |
4872 | the new instruction just before the tablejump. */ | |
4873 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
4874 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
4875 | insn = prev_real_insn (insn); | |
4876 | ||
4877 | #ifdef HAVE_cc0 | |
4878 | /* FIXME: 'twould be nice to call prev_cc0_setter here but it aborts | |
4879 | if cc0 isn't set. */ | |
4880 | note = find_reg_note (insn, REG_CC_SETTER, NULL_RTX); | |
4881 | if (note) | |
4882 | insn = XEXP (note, 0); | |
4883 | else | |
4884 | { | |
4885 | rtx maybe_cc0_setter = prev_nonnote_insn (insn); | |
4886 | if (maybe_cc0_setter | |
2c3c49de | 4887 | && INSN_P (maybe_cc0_setter) |
7506f491 DE |
4888 | && sets_cc0_p (PATTERN (maybe_cc0_setter))) |
4889 | insn = maybe_cc0_setter; | |
4890 | } | |
4891 | #endif | |
4892 | /* FIXME: What if something in cc0/jump uses value set in new insn? */ | |
3c030e88 | 4893 | new_insn = emit_insn_before (pat, insn); |
3947e2f9 | 4894 | } |
c4c81601 | 4895 | |
3947e2f9 RH |
4896 | /* Likewise if the last insn is a call, as will happen in the presence |
4897 | of exception handling. */ | |
068473ec JH |
4898 | else if (GET_CODE (insn) == CALL_INSN |
4899 | && (bb->succ->succ_next || (bb->succ->flags & EDGE_ABNORMAL))) | |
3947e2f9 | 4900 | { |
3947e2f9 RH |
4901 | /* Keeping in mind SMALL_REGISTER_CLASSES and parameters in registers, |
4902 | we search backward and place the instructions before the first | |
4903 | parameter is loaded. Do this for everyone for consistency and a | |
c4c81601 | 4904 | presumtion that we'll get better code elsewhere as well. |
3947e2f9 | 4905 | |
c4c81601 | 4906 | It should always be the case that we can put these instructions |
a65f3558 JL |
4907 | anywhere in the basic block with performing PRE optimizations. |
4908 | Check this. */ | |
c4c81601 | 4909 | |
a65f3558 | 4910 | if (pre |
0b17ab2f RH |
4911 | && !TEST_BIT (antloc[bb->index], expr->bitmap_index) |
4912 | && !TEST_BIT (transp[bb->index], expr->bitmap_index)) | |
3947e2f9 RH |
4913 | abort (); |
4914 | ||
4915 | /* Since different machines initialize their parameter registers | |
4916 | in different orders, assume nothing. Collect the set of all | |
4917 | parameter registers. */ | |
833366d6 | 4918 | insn = find_first_parameter_load (insn, bb->head); |
3947e2f9 | 4919 | |
b1d26727 JL |
4920 | /* If we found all the parameter loads, then we want to insert |
4921 | before the first parameter load. | |
4922 | ||
4923 | If we did not find all the parameter loads, then we might have | |
4924 | stopped on the head of the block, which could be a CODE_LABEL. | |
4925 | If we inserted before the CODE_LABEL, then we would be putting | |
4926 | the insn in the wrong basic block. In that case, put the insn | |
b5229628 | 4927 | after the CODE_LABEL. Also, respect NOTE_INSN_BASIC_BLOCK. */ |
0a377997 | 4928 | while (GET_CODE (insn) == CODE_LABEL |
589ca5cb | 4929 | || NOTE_INSN_BASIC_BLOCK_P (insn)) |
b5229628 | 4930 | insn = NEXT_INSN (insn); |
c4c81601 | 4931 | |
3c030e88 | 4932 | new_insn = emit_insn_before (pat, insn); |
7506f491 DE |
4933 | } |
4934 | else | |
3c030e88 | 4935 | new_insn = emit_insn_after (pat, insn); |
7506f491 | 4936 | |
a65f3558 JL |
4937 | /* Keep block number table up to date. |
4938 | Note, PAT could be a multiple insn sequence, we have to make | |
4939 | sure that each insn in the sequence is handled. */ | |
4940 | if (GET_CODE (pat) == SEQUENCE) | |
4941 | { | |
a65f3558 JL |
4942 | for (i = 0; i < XVECLEN (pat, 0); i++) |
4943 | { | |
4944 | rtx insn = XVECEXP (pat, 0, i); | |
2c3c49de | 4945 | if (INSN_P (insn)) |
a65f3558 | 4946 | add_label_notes (PATTERN (insn), new_insn); |
c4c81601 | 4947 | |
84832317 | 4948 | note_stores (PATTERN (insn), record_set_info, insn); |
a65f3558 JL |
4949 | } |
4950 | } | |
4951 | else | |
4952 | { | |
157bd2bb | 4953 | add_label_notes (pat, new_insn); |
c4c81601 | 4954 | |
a65f3558 JL |
4955 | /* Keep register set table up to date. */ |
4956 | record_one_set (regno, new_insn); | |
4957 | } | |
3947e2f9 | 4958 | |
7506f491 DE |
4959 | gcse_create_count++; |
4960 | ||
4961 | if (gcse_file) | |
4962 | { | |
c4c81601 | 4963 | fprintf (gcse_file, "PRE/HOIST: end of bb %d, insn %d, ", |
0b17ab2f | 4964 | bb->index, INSN_UID (new_insn)); |
c4c81601 RK |
4965 | fprintf (gcse_file, "copying expression %d to reg %d\n", |
4966 | expr->bitmap_index, regno); | |
7506f491 DE |
4967 | } |
4968 | } | |
4969 | ||
a42cd965 AM |
4970 | /* Insert partially redundant expressions on edges in the CFG to make |
4971 | the expressions fully redundant. */ | |
7506f491 | 4972 | |
a42cd965 AM |
4973 | static int |
4974 | pre_edge_insert (edge_list, index_map) | |
4975 | struct edge_list *edge_list; | |
7506f491 DE |
4976 | struct expr **index_map; |
4977 | { | |
c4c81601 | 4978 | int e, i, j, num_edges, set_size, did_insert = 0; |
a65f3558 JL |
4979 | sbitmap *inserted; |
4980 | ||
a42cd965 AM |
4981 | /* Where PRE_INSERT_MAP is nonzero, we add the expression on that edge |
4982 | if it reaches any of the deleted expressions. */ | |
7506f491 | 4983 | |
a42cd965 AM |
4984 | set_size = pre_insert_map[0]->size; |
4985 | num_edges = NUM_EDGES (edge_list); | |
4986 | inserted = sbitmap_vector_alloc (num_edges, n_exprs); | |
4987 | sbitmap_vector_zero (inserted, num_edges); | |
7506f491 | 4988 | |
a42cd965 | 4989 | for (e = 0; e < num_edges; e++) |
7506f491 DE |
4990 | { |
4991 | int indx; | |
e2d2ed72 | 4992 | basic_block bb = INDEX_EDGE_PRED_BB (edge_list, e); |
a65f3558 | 4993 | |
a65f3558 | 4994 | for (i = indx = 0; i < set_size; i++, indx += SBITMAP_ELT_BITS) |
7506f491 | 4995 | { |
a42cd965 | 4996 | SBITMAP_ELT_TYPE insert = pre_insert_map[e]->elms[i]; |
7506f491 | 4997 | |
a65f3558 | 4998 | for (j = indx; insert && j < n_exprs; j++, insert >>= 1) |
c4c81601 RK |
4999 | if ((insert & 1) != 0 && index_map[j]->reaching_reg != NULL_RTX) |
5000 | { | |
5001 | struct expr *expr = index_map[j]; | |
5002 | struct occr *occr; | |
a65f3558 | 5003 | |
ff7cc307 | 5004 | /* Now look at each deleted occurrence of this expression. */ |
c4c81601 RK |
5005 | for (occr = expr->antic_occr; occr != NULL; occr = occr->next) |
5006 | { | |
5007 | if (! occr->deleted_p) | |
5008 | continue; | |
5009 | ||
5010 | /* Insert this expression on this edge if if it would | |
ff7cc307 | 5011 | reach the deleted occurrence in BB. */ |
c4c81601 RK |
5012 | if (!TEST_BIT (inserted[e], j)) |
5013 | { | |
5014 | rtx insn; | |
5015 | edge eg = INDEX_EDGE (edge_list, e); | |
5016 | ||
5017 | /* We can't insert anything on an abnormal and | |
5018 | critical edge, so we insert the insn at the end of | |
5019 | the previous block. There are several alternatives | |
5020 | detailed in Morgans book P277 (sec 10.5) for | |
5021 | handling this situation. This one is easiest for | |
5022 | now. */ | |
5023 | ||
5024 | if ((eg->flags & EDGE_ABNORMAL) == EDGE_ABNORMAL) | |
5025 | insert_insn_end_bb (index_map[j], bb, 0); | |
5026 | else | |
5027 | { | |
5028 | insn = process_insert_insn (index_map[j]); | |
5029 | insert_insn_on_edge (insn, eg); | |
5030 | } | |
5031 | ||
5032 | if (gcse_file) | |
5033 | { | |
5034 | fprintf (gcse_file, "PRE/HOIST: edge (%d,%d), ", | |
0b17ab2f RH |
5035 | bb->index, |
5036 | INDEX_EDGE_SUCC_BB (edge_list, e)->index); | |
c4c81601 RK |
5037 | fprintf (gcse_file, "copy expression %d\n", |
5038 | expr->bitmap_index); | |
5039 | } | |
5040 | ||
a13d4ebf | 5041 | update_ld_motion_stores (expr); |
c4c81601 RK |
5042 | SET_BIT (inserted[e], j); |
5043 | did_insert = 1; | |
5044 | gcse_create_count++; | |
5045 | } | |
5046 | } | |
5047 | } | |
7506f491 DE |
5048 | } |
5049 | } | |
5faf03ae | 5050 | |
5a660bff | 5051 | sbitmap_vector_free (inserted); |
a42cd965 | 5052 | return did_insert; |
7506f491 DE |
5053 | } |
5054 | ||
c4c81601 | 5055 | /* Copy the result of INSN to REG. INDX is the expression number. */ |
7506f491 DE |
5056 | |
5057 | static void | |
5058 | pre_insert_copy_insn (expr, insn) | |
5059 | struct expr *expr; | |
5060 | rtx insn; | |
5061 | { | |
5062 | rtx reg = expr->reaching_reg; | |
5063 | int regno = REGNO (reg); | |
5064 | int indx = expr->bitmap_index; | |
5065 | rtx set = single_set (insn); | |
5066 | rtx new_insn; | |
5067 | ||
5068 | if (!set) | |
5069 | abort (); | |
c4c81601 | 5070 | |
cccf0ae8 | 5071 | new_insn = emit_insn_after (gen_move_insn (reg, SET_DEST (set)), insn); |
c4c81601 | 5072 | |
7506f491 DE |
5073 | /* Keep register set table up to date. */ |
5074 | record_one_set (regno, new_insn); | |
5075 | ||
5076 | gcse_create_count++; | |
5077 | ||
5078 | if (gcse_file) | |
a42cd965 AM |
5079 | fprintf (gcse_file, |
5080 | "PRE: bb %d, insn %d, copy expression %d in insn %d to reg %d\n", | |
5081 | BLOCK_NUM (insn), INSN_UID (new_insn), indx, | |
5082 | INSN_UID (insn), regno); | |
222f7ba9 | 5083 | update_ld_motion_stores (expr); |
7506f491 DE |
5084 | } |
5085 | ||
5086 | /* Copy available expressions that reach the redundant expression | |
5087 | to `reaching_reg'. */ | |
5088 | ||
5089 | static void | |
5090 | pre_insert_copies () | |
5091 | { | |
2e653e39 | 5092 | unsigned int i; |
c4c81601 RK |
5093 | struct expr *expr; |
5094 | struct occr *occr; | |
5095 | struct occr *avail; | |
a65f3558 | 5096 | |
7506f491 DE |
5097 | /* For each available expression in the table, copy the result to |
5098 | `reaching_reg' if the expression reaches a deleted one. | |
5099 | ||
5100 | ??? The current algorithm is rather brute force. | |
5101 | Need to do some profiling. */ | |
5102 | ||
5103 | for (i = 0; i < expr_hash_table_size; i++) | |
c4c81601 RK |
5104 | for (expr = expr_hash_table[i]; expr != NULL; expr = expr->next_same_hash) |
5105 | { | |
5106 | /* If the basic block isn't reachable, PPOUT will be TRUE. However, | |
5107 | we don't want to insert a copy here because the expression may not | |
5108 | really be redundant. So only insert an insn if the expression was | |
5109 | deleted. This test also avoids further processing if the | |
5110 | expression wasn't deleted anywhere. */ | |
5111 | if (expr->reaching_reg == NULL) | |
5112 | continue; | |
5113 | ||
5114 | for (occr = expr->antic_occr; occr != NULL; occr = occr->next) | |
5115 | { | |
5116 | if (! occr->deleted_p) | |
5117 | continue; | |
7506f491 | 5118 | |
c4c81601 RK |
5119 | for (avail = expr->avail_occr; avail != NULL; avail = avail->next) |
5120 | { | |
5121 | rtx insn = avail->insn; | |
7506f491 | 5122 | |
c4c81601 RK |
5123 | /* No need to handle this one if handled already. */ |
5124 | if (avail->copied_p) | |
5125 | continue; | |
7506f491 | 5126 | |
c4c81601 RK |
5127 | /* Don't handle this one if it's a redundant one. */ |
5128 | if (TEST_BIT (pre_redundant_insns, INSN_CUID (insn))) | |
5129 | continue; | |
7506f491 | 5130 | |
c4c81601 | 5131 | /* Or if the expression doesn't reach the deleted one. */ |
e2d2ed72 AM |
5132 | if (! pre_expr_reaches_here_p (BLOCK_FOR_INSN (avail->insn), |
5133 | expr, | |
5134 | BLOCK_FOR_INSN (occr->insn))) | |
c4c81601 | 5135 | continue; |
7506f491 | 5136 | |
c4c81601 RK |
5137 | /* Copy the result of avail to reaching_reg. */ |
5138 | pre_insert_copy_insn (expr, insn); | |
5139 | avail->copied_p = 1; | |
5140 | } | |
5141 | } | |
5142 | } | |
7506f491 DE |
5143 | } |
5144 | ||
10d1bb36 JH |
5145 | /* Emit move from SRC to DEST noting the equivalence with expression computed |
5146 | in INSN. */ | |
5147 | static rtx | |
5148 | gcse_emit_move_after (src, dest, insn) | |
5149 | rtx src, dest, insn; | |
5150 | { | |
5151 | rtx new; | |
5152 | rtx set = single_set (insn); | |
5153 | rtx note; | |
5154 | rtx eqv; | |
5155 | ||
5156 | /* This should never fail since we're creating a reg->reg copy | |
5157 | we've verified to be valid. */ | |
5158 | ||
5159 | new = emit_insn_after (gen_rtx_SET (VOIDmode, dest, src), insn); | |
5160 | ||
5161 | /* Note the equivalence for local CSE pass. */ | |
5162 | if ((note = find_reg_equal_equiv_note (insn))) | |
5163 | eqv = XEXP (note, 0); | |
5164 | else | |
5165 | eqv = SET_SRC (set); | |
5166 | ||
5167 | set_unique_reg_note (new, REG_EQUAL, copy_insn_1 (src)); | |
5168 | ||
5169 | return new; | |
5170 | } | |
5171 | ||
7506f491 | 5172 | /* Delete redundant computations. |
7506f491 DE |
5173 | Deletion is done by changing the insn to copy the `reaching_reg' of |
5174 | the expression into the result of the SET. It is left to later passes | |
5175 | (cprop, cse2, flow, combine, regmove) to propagate the copy or eliminate it. | |
5176 | ||
5177 | Returns non-zero if a change is made. */ | |
5178 | ||
5179 | static int | |
5180 | pre_delete () | |
5181 | { | |
2e653e39 | 5182 | unsigned int i; |
63bc1d05 | 5183 | int changed; |
c4c81601 RK |
5184 | struct expr *expr; |
5185 | struct occr *occr; | |
a65f3558 | 5186 | |
7506f491 DE |
5187 | changed = 0; |
5188 | for (i = 0; i < expr_hash_table_size; i++) | |
c4c81601 RK |
5189 | for (expr = expr_hash_table[i]; expr != NULL; expr = expr->next_same_hash) |
5190 | { | |
5191 | int indx = expr->bitmap_index; | |
7506f491 | 5192 | |
c4c81601 RK |
5193 | /* We only need to search antic_occr since we require |
5194 | ANTLOC != 0. */ | |
7506f491 | 5195 | |
c4c81601 RK |
5196 | for (occr = expr->antic_occr; occr != NULL; occr = occr->next) |
5197 | { | |
5198 | rtx insn = occr->insn; | |
5199 | rtx set; | |
e2d2ed72 | 5200 | basic_block bb = BLOCK_FOR_INSN (insn); |
7506f491 | 5201 | |
0b17ab2f | 5202 | if (TEST_BIT (pre_delete_map[bb->index], indx)) |
c4c81601 RK |
5203 | { |
5204 | set = single_set (insn); | |
5205 | if (! set) | |
5206 | abort (); | |
5207 | ||
5208 | /* Create a pseudo-reg to store the result of reaching | |
5209 | expressions into. Get the mode for the new pseudo from | |
5210 | the mode of the original destination pseudo. */ | |
5211 | if (expr->reaching_reg == NULL) | |
5212 | expr->reaching_reg | |
5213 | = gen_reg_rtx (GET_MODE (SET_DEST (set))); | |
5214 | ||
10d1bb36 JH |
5215 | gcse_emit_move_after (expr->reaching_reg, SET_DEST (set), insn); |
5216 | delete_insn (insn); | |
5217 | occr->deleted_p = 1; | |
5218 | SET_BIT (pre_redundant_insns, INSN_CUID (insn)); | |
5219 | changed = 1; | |
5220 | gcse_subst_count++; | |
7506f491 | 5221 | |
c4c81601 RK |
5222 | if (gcse_file) |
5223 | { | |
5224 | fprintf (gcse_file, | |
5225 | "PRE: redundant insn %d (expression %d) in ", | |
5226 | INSN_UID (insn), indx); | |
5227 | fprintf (gcse_file, "bb %d, reaching reg is %d\n", | |
0b17ab2f | 5228 | bb->index, REGNO (expr->reaching_reg)); |
c4c81601 RK |
5229 | } |
5230 | } | |
5231 | } | |
5232 | } | |
7506f491 DE |
5233 | |
5234 | return changed; | |
5235 | } | |
5236 | ||
5237 | /* Perform GCSE optimizations using PRE. | |
5238 | This is called by one_pre_gcse_pass after all the dataflow analysis | |
5239 | has been done. | |
5240 | ||
c4c81601 RK |
5241 | This is based on the original Morel-Renvoise paper Fred Chow's thesis, and |
5242 | lazy code motion from Knoop, Ruthing and Steffen as described in Advanced | |
5243 | Compiler Design and Implementation. | |
7506f491 | 5244 | |
c4c81601 RK |
5245 | ??? A new pseudo reg is created to hold the reaching expression. The nice |
5246 | thing about the classical approach is that it would try to use an existing | |
5247 | reg. If the register can't be adequately optimized [i.e. we introduce | |
5248 | reload problems], one could add a pass here to propagate the new register | |
5249 | through the block. | |
7506f491 | 5250 | |
c4c81601 RK |
5251 | ??? We don't handle single sets in PARALLELs because we're [currently] not |
5252 | able to copy the rest of the parallel when we insert copies to create full | |
5253 | redundancies from partial redundancies. However, there's no reason why we | |
5254 | can't handle PARALLELs in the cases where there are no partial | |
7506f491 DE |
5255 | redundancies. */ |
5256 | ||
5257 | static int | |
5258 | pre_gcse () | |
5259 | { | |
2e653e39 RK |
5260 | unsigned int i; |
5261 | int did_insert, changed; | |
7506f491 | 5262 | struct expr **index_map; |
c4c81601 | 5263 | struct expr *expr; |
7506f491 DE |
5264 | |
5265 | /* Compute a mapping from expression number (`bitmap_index') to | |
5266 | hash table entry. */ | |
5267 | ||
dd1bd863 | 5268 | index_map = (struct expr **) xcalloc (n_exprs, sizeof (struct expr *)); |
7506f491 | 5269 | for (i = 0; i < expr_hash_table_size; i++) |
c4c81601 RK |
5270 | for (expr = expr_hash_table[i]; expr != NULL; expr = expr->next_same_hash) |
5271 | index_map[expr->bitmap_index] = expr; | |
7506f491 DE |
5272 | |
5273 | /* Reset bitmap used to track which insns are redundant. */ | |
a65f3558 JL |
5274 | pre_redundant_insns = sbitmap_alloc (max_cuid); |
5275 | sbitmap_zero (pre_redundant_insns); | |
7506f491 DE |
5276 | |
5277 | /* Delete the redundant insns first so that | |
5278 | - we know what register to use for the new insns and for the other | |
5279 | ones with reaching expressions | |
5280 | - we know which insns are redundant when we go to create copies */ | |
c4c81601 | 5281 | |
7506f491 DE |
5282 | changed = pre_delete (); |
5283 | ||
a42cd965 | 5284 | did_insert = pre_edge_insert (edge_list, index_map); |
c4c81601 | 5285 | |
7506f491 | 5286 | /* In other places with reaching expressions, copy the expression to the |
a42cd965 | 5287 | specially allocated pseudo-reg that reaches the redundant expr. */ |
7506f491 | 5288 | pre_insert_copies (); |
a42cd965 AM |
5289 | if (did_insert) |
5290 | { | |
5291 | commit_edge_insertions (); | |
5292 | changed = 1; | |
5293 | } | |
7506f491 | 5294 | |
283a2545 | 5295 | free (index_map); |
76ac938b | 5296 | sbitmap_free (pre_redundant_insns); |
7506f491 DE |
5297 | return changed; |
5298 | } | |
5299 | ||
5300 | /* Top level routine to perform one PRE GCSE pass. | |
5301 | ||
5302 | Return non-zero if a change was made. */ | |
5303 | ||
5304 | static int | |
b5ce41ff | 5305 | one_pre_gcse_pass (pass) |
7506f491 DE |
5306 | int pass; |
5307 | { | |
5308 | int changed = 0; | |
5309 | ||
5310 | gcse_subst_count = 0; | |
5311 | gcse_create_count = 0; | |
5312 | ||
5313 | alloc_expr_hash_table (max_cuid); | |
a42cd965 | 5314 | add_noreturn_fake_exit_edges (); |
a13d4ebf AM |
5315 | if (flag_gcse_lm) |
5316 | compute_ld_motion_mems (); | |
5317 | ||
b5ce41ff | 5318 | compute_expr_hash_table (); |
a13d4ebf | 5319 | trim_ld_motion_mems (); |
7506f491 DE |
5320 | if (gcse_file) |
5321 | dump_hash_table (gcse_file, "Expression", expr_hash_table, | |
5322 | expr_hash_table_size, n_exprs); | |
c4c81601 | 5323 | |
7506f491 DE |
5324 | if (n_exprs > 0) |
5325 | { | |
d55bc081 | 5326 | alloc_pre_mem (last_basic_block, n_exprs); |
7506f491 DE |
5327 | compute_pre_data (); |
5328 | changed |= pre_gcse (); | |
a42cd965 | 5329 | free_edge_list (edge_list); |
7506f491 DE |
5330 | free_pre_mem (); |
5331 | } | |
c4c81601 | 5332 | |
a13d4ebf | 5333 | free_ldst_mems (); |
a42cd965 | 5334 | remove_fake_edges (); |
7506f491 DE |
5335 | free_expr_hash_table (); |
5336 | ||
5337 | if (gcse_file) | |
5338 | { | |
c4c81601 RK |
5339 | fprintf (gcse_file, "\nPRE GCSE of %s, pass %d: %d bytes needed, ", |
5340 | current_function_name, pass, bytes_used); | |
5341 | fprintf (gcse_file, "%d substs, %d insns created\n", | |
5342 | gcse_subst_count, gcse_create_count); | |
7506f491 DE |
5343 | } |
5344 | ||
5345 | return changed; | |
5346 | } | |
aeb2f500 JW |
5347 | \f |
5348 | /* If X contains any LABEL_REF's, add REG_LABEL notes for them to INSN. | |
5b1ef594 JDA |
5349 | If notes are added to an insn which references a CODE_LABEL, the |
5350 | LABEL_NUSES count is incremented. We have to add REG_LABEL notes, | |
5351 | because the following loop optimization pass requires them. */ | |
aeb2f500 JW |
5352 | |
5353 | /* ??? This is very similar to the loop.c add_label_notes function. We | |
5354 | could probably share code here. */ | |
5355 | ||
5356 | /* ??? If there was a jump optimization pass after gcse and before loop, | |
5357 | then we would not need to do this here, because jump would add the | |
5358 | necessary REG_LABEL notes. */ | |
5359 | ||
5360 | static void | |
5361 | add_label_notes (x, insn) | |
5362 | rtx x; | |
5363 | rtx insn; | |
5364 | { | |
5365 | enum rtx_code code = GET_CODE (x); | |
5366 | int i, j; | |
6f7d635c | 5367 | const char *fmt; |
aeb2f500 JW |
5368 | |
5369 | if (code == LABEL_REF && !LABEL_REF_NONLOCAL_P (x)) | |
5370 | { | |
6b3603c2 | 5371 | /* This code used to ignore labels that referred to dispatch tables to |
ac7c5af5 | 5372 | avoid flow generating (slighly) worse code. |
6b3603c2 | 5373 | |
ac7c5af5 JL |
5374 | We no longer ignore such label references (see LABEL_REF handling in |
5375 | mark_jump_label for additional information). */ | |
c4c81601 | 5376 | |
6b8c9327 | 5377 | REG_NOTES (insn) = gen_rtx_INSN_LIST (REG_LABEL, XEXP (x, 0), |
6b3603c2 | 5378 | REG_NOTES (insn)); |
5b1ef594 JDA |
5379 | if (LABEL_P (XEXP (x, 0))) |
5380 | LABEL_NUSES (XEXP (x, 0))++; | |
aeb2f500 JW |
5381 | return; |
5382 | } | |
5383 | ||
c4c81601 | 5384 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
aeb2f500 JW |
5385 | { |
5386 | if (fmt[i] == 'e') | |
5387 | add_label_notes (XEXP (x, i), insn); | |
5388 | else if (fmt[i] == 'E') | |
5389 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
5390 | add_label_notes (XVECEXP (x, i, j), insn); | |
5391 | } | |
5392 | } | |
a65f3558 JL |
5393 | |
5394 | /* Compute transparent outgoing information for each block. | |
5395 | ||
5396 | An expression is transparent to an edge unless it is killed by | |
5397 | the edge itself. This can only happen with abnormal control flow, | |
5398 | when the edge is traversed through a call. This happens with | |
5399 | non-local labels and exceptions. | |
5400 | ||
5401 | This would not be necessary if we split the edge. While this is | |
5402 | normally impossible for abnormal critical edges, with some effort | |
5403 | it should be possible with exception handling, since we still have | |
5404 | control over which handler should be invoked. But due to increased | |
5405 | EH table sizes, this may not be worthwhile. */ | |
5406 | ||
5407 | static void | |
5408 | compute_transpout () | |
5409 | { | |
e0082a72 | 5410 | basic_block bb; |
2e653e39 | 5411 | unsigned int i; |
c4c81601 | 5412 | struct expr *expr; |
a65f3558 | 5413 | |
d55bc081 | 5414 | sbitmap_vector_ones (transpout, last_basic_block); |
a65f3558 | 5415 | |
e0082a72 | 5416 | FOR_EACH_BB (bb) |
a65f3558 | 5417 | { |
a65f3558 JL |
5418 | /* Note that flow inserted a nop a the end of basic blocks that |
5419 | end in call instructions for reasons other than abnormal | |
5420 | control flow. */ | |
e0082a72 | 5421 | if (GET_CODE (bb->end) != CALL_INSN) |
a65f3558 JL |
5422 | continue; |
5423 | ||
5424 | for (i = 0; i < expr_hash_table_size; i++) | |
c4c81601 RK |
5425 | for (expr = expr_hash_table[i]; expr ; expr = expr->next_same_hash) |
5426 | if (GET_CODE (expr->expr) == MEM) | |
5427 | { | |
5428 | if (GET_CODE (XEXP (expr->expr, 0)) == SYMBOL_REF | |
5429 | && CONSTANT_POOL_ADDRESS_P (XEXP (expr->expr, 0))) | |
5430 | continue; | |
a65f3558 | 5431 | |
c4c81601 RK |
5432 | /* ??? Optimally, we would use interprocedural alias |
5433 | analysis to determine if this mem is actually killed | |
5434 | by this call. */ | |
e0082a72 | 5435 | RESET_BIT (transpout[bb->index], expr->bitmap_index); |
c4c81601 | 5436 | } |
a65f3558 JL |
5437 | } |
5438 | } | |
dfdb644f JL |
5439 | |
5440 | /* Removal of useless null pointer checks */ | |
5441 | ||
dfdb644f | 5442 | /* Called via note_stores. X is set by SETTER. If X is a register we must |
0511851c MM |
5443 | invalidate nonnull_local and set nonnull_killed. DATA is really a |
5444 | `null_pointer_info *'. | |
dfdb644f JL |
5445 | |
5446 | We ignore hard registers. */ | |
c4c81601 | 5447 | |
dfdb644f | 5448 | static void |
84832317 | 5449 | invalidate_nonnull_info (x, setter, data) |
dfdb644f JL |
5450 | rtx x; |
5451 | rtx setter ATTRIBUTE_UNUSED; | |
0511851c | 5452 | void *data; |
dfdb644f | 5453 | { |
770ae6cc RK |
5454 | unsigned int regno; |
5455 | struct null_pointer_info *npi = (struct null_pointer_info *) data; | |
c4c81601 | 5456 | |
dfdb644f JL |
5457 | while (GET_CODE (x) == SUBREG) |
5458 | x = SUBREG_REG (x); | |
5459 | ||
5460 | /* Ignore anything that is not a register or is a hard register. */ | |
5461 | if (GET_CODE (x) != REG | |
0511851c MM |
5462 | || REGNO (x) < npi->min_reg |
5463 | || REGNO (x) >= npi->max_reg) | |
dfdb644f JL |
5464 | return; |
5465 | ||
0511851c | 5466 | regno = REGNO (x) - npi->min_reg; |
dfdb644f | 5467 | |
e0082a72 ZD |
5468 | RESET_BIT (npi->nonnull_local[npi->current_block->index], regno); |
5469 | SET_BIT (npi->nonnull_killed[npi->current_block->index], regno); | |
dfdb644f JL |
5470 | } |
5471 | ||
0511851c MM |
5472 | /* Do null-pointer check elimination for the registers indicated in |
5473 | NPI. NONNULL_AVIN and NONNULL_AVOUT are pre-allocated sbitmaps; | |
5474 | they are not our responsibility to free. */ | |
dfdb644f | 5475 | |
0511851c | 5476 | static void |
9cd56be1 | 5477 | delete_null_pointer_checks_1 (block_reg, nonnull_avin, |
8e184d9c | 5478 | nonnull_avout, npi) |
770ae6cc | 5479 | unsigned int *block_reg; |
0511851c MM |
5480 | sbitmap *nonnull_avin; |
5481 | sbitmap *nonnull_avout; | |
5482 | struct null_pointer_info *npi; | |
dfdb644f | 5483 | { |
e0082a72 | 5484 | basic_block bb, current_block; |
0511851c MM |
5485 | sbitmap *nonnull_local = npi->nonnull_local; |
5486 | sbitmap *nonnull_killed = npi->nonnull_killed; | |
dfdb644f | 5487 | |
dfdb644f JL |
5488 | /* Compute local properties, nonnull and killed. A register will have |
5489 | the nonnull property if at the end of the current block its value is | |
5490 | known to be nonnull. The killed property indicates that somewhere in | |
5491 | the block any information we had about the register is killed. | |
5492 | ||
5493 | Note that a register can have both properties in a single block. That | |
5494 | indicates that it's killed, then later in the block a new value is | |
5495 | computed. */ | |
d55bc081 ZD |
5496 | sbitmap_vector_zero (nonnull_local, last_basic_block); |
5497 | sbitmap_vector_zero (nonnull_killed, last_basic_block); | |
c4c81601 | 5498 | |
e0082a72 | 5499 | FOR_EACH_BB (current_block) |
dfdb644f JL |
5500 | { |
5501 | rtx insn, stop_insn; | |
5502 | ||
0511851c MM |
5503 | /* Set the current block for invalidate_nonnull_info. */ |
5504 | npi->current_block = current_block; | |
5505 | ||
dfdb644f JL |
5506 | /* Scan each insn in the basic block looking for memory references and |
5507 | register sets. */ | |
e0082a72 ZD |
5508 | stop_insn = NEXT_INSN (current_block->end); |
5509 | for (insn = current_block->head; | |
dfdb644f JL |
5510 | insn != stop_insn; |
5511 | insn = NEXT_INSN (insn)) | |
5512 | { | |
5513 | rtx set; | |
0511851c | 5514 | rtx reg; |
dfdb644f JL |
5515 | |
5516 | /* Ignore anything that is not a normal insn. */ | |
2c3c49de | 5517 | if (! INSN_P (insn)) |
dfdb644f JL |
5518 | continue; |
5519 | ||
5520 | /* Basically ignore anything that is not a simple SET. We do have | |
5521 | to make sure to invalidate nonnull_local and set nonnull_killed | |
5522 | for such insns though. */ | |
5523 | set = single_set (insn); | |
5524 | if (!set) | |
5525 | { | |
0511851c | 5526 | note_stores (PATTERN (insn), invalidate_nonnull_info, npi); |
dfdb644f JL |
5527 | continue; |
5528 | } | |
5529 | ||
f63d1bf7 | 5530 | /* See if we've got a usable memory load. We handle it first |
dfdb644f JL |
5531 | in case it uses its address register as a dest (which kills |
5532 | the nonnull property). */ | |
5533 | if (GET_CODE (SET_SRC (set)) == MEM | |
0511851c MM |
5534 | && GET_CODE ((reg = XEXP (SET_SRC (set), 0))) == REG |
5535 | && REGNO (reg) >= npi->min_reg | |
5536 | && REGNO (reg) < npi->max_reg) | |
e0082a72 | 5537 | SET_BIT (nonnull_local[current_block->index], |
0511851c | 5538 | REGNO (reg) - npi->min_reg); |
dfdb644f JL |
5539 | |
5540 | /* Now invalidate stuff clobbered by this insn. */ | |
0511851c | 5541 | note_stores (PATTERN (insn), invalidate_nonnull_info, npi); |
dfdb644f JL |
5542 | |
5543 | /* And handle stores, we do these last since any sets in INSN can | |
5544 | not kill the nonnull property if it is derived from a MEM | |
5545 | appearing in a SET_DEST. */ | |
5546 | if (GET_CODE (SET_DEST (set)) == MEM | |
0511851c MM |
5547 | && GET_CODE ((reg = XEXP (SET_DEST (set), 0))) == REG |
5548 | && REGNO (reg) >= npi->min_reg | |
5549 | && REGNO (reg) < npi->max_reg) | |
e0082a72 | 5550 | SET_BIT (nonnull_local[current_block->index], |
0511851c | 5551 | REGNO (reg) - npi->min_reg); |
dfdb644f JL |
5552 | } |
5553 | } | |
5554 | ||
5555 | /* Now compute global properties based on the local properties. This | |
5556 | is a classic global availablity algorithm. */ | |
ce724250 JL |
5557 | compute_available (nonnull_local, nonnull_killed, |
5558 | nonnull_avout, nonnull_avin); | |
dfdb644f JL |
5559 | |
5560 | /* Now look at each bb and see if it ends with a compare of a value | |
5561 | against zero. */ | |
e0082a72 | 5562 | FOR_EACH_BB (bb) |
dfdb644f | 5563 | { |
e0082a72 | 5564 | rtx last_insn = bb->end; |
0511851c | 5565 | rtx condition, earliest; |
dfdb644f JL |
5566 | int compare_and_branch; |
5567 | ||
0511851c MM |
5568 | /* Since MIN_REG is always at least FIRST_PSEUDO_REGISTER, and |
5569 | since BLOCK_REG[BB] is zero if this block did not end with a | |
5570 | comparison against zero, this condition works. */ | |
e0082a72 ZD |
5571 | if (block_reg[bb->index] < npi->min_reg |
5572 | || block_reg[bb->index] >= npi->max_reg) | |
dfdb644f JL |
5573 | continue; |
5574 | ||
5575 | /* LAST_INSN is a conditional jump. Get its condition. */ | |
5576 | condition = get_condition (last_insn, &earliest); | |
5577 | ||
40d7a3fe NB |
5578 | /* If we can't determine the condition then skip. */ |
5579 | if (! condition) | |
5580 | continue; | |
5581 | ||
dfdb644f | 5582 | /* Is the register known to have a nonzero value? */ |
e0082a72 | 5583 | if (!TEST_BIT (nonnull_avout[bb->index], block_reg[bb->index] - npi->min_reg)) |
dfdb644f JL |
5584 | continue; |
5585 | ||
5586 | /* Try to compute whether the compare/branch at the loop end is one or | |
5587 | two instructions. */ | |
5588 | if (earliest == last_insn) | |
5589 | compare_and_branch = 1; | |
5590 | else if (earliest == prev_nonnote_insn (last_insn)) | |
5591 | compare_and_branch = 2; | |
5592 | else | |
5593 | continue; | |
5594 | ||
5595 | /* We know the register in this comparison is nonnull at exit from | |
5596 | this block. We can optimize this comparison. */ | |
5597 | if (GET_CODE (condition) == NE) | |
5598 | { | |
5599 | rtx new_jump; | |
5600 | ||
38c1593d JH |
5601 | new_jump = emit_jump_insn_after (gen_jump (JUMP_LABEL (last_insn)), |
5602 | last_insn); | |
dfdb644f JL |
5603 | JUMP_LABEL (new_jump) = JUMP_LABEL (last_insn); |
5604 | LABEL_NUSES (JUMP_LABEL (new_jump))++; | |
5605 | emit_barrier_after (new_jump); | |
5606 | } | |
8e184d9c | 5607 | |
9cd56be1 | 5608 | delete_insn (last_insn); |
dfdb644f | 5609 | if (compare_and_branch == 2) |
9cd56be1 | 5610 | delete_insn (earliest); |
e0082a72 | 5611 | purge_dead_edges (bb); |
0511851c MM |
5612 | |
5613 | /* Don't check this block again. (Note that BLOCK_END is | |
5614 | invalid here; we deleted the last instruction in the | |
5615 | block.) */ | |
e0082a72 | 5616 | block_reg[bb->index] = 0; |
0511851c MM |
5617 | } |
5618 | } | |
5619 | ||
5620 | /* Find EQ/NE comparisons against zero which can be (indirectly) evaluated | |
5621 | at compile time. | |
5622 | ||
5623 | This is conceptually similar to global constant/copy propagation and | |
5624 | classic global CSE (it even uses the same dataflow equations as cprop). | |
5625 | ||
5626 | If a register is used as memory address with the form (mem (reg)), then we | |
5627 | know that REG can not be zero at that point in the program. Any instruction | |
5628 | which sets REG "kills" this property. | |
5629 | ||
5630 | So, if every path leading to a conditional branch has an available memory | |
5631 | reference of that form, then we know the register can not have the value | |
5632 | zero at the conditional branch. | |
5633 | ||
5634 | So we merely need to compute the local properies and propagate that data | |
5635 | around the cfg, then optimize where possible. | |
5636 | ||
5637 | We run this pass two times. Once before CSE, then again after CSE. This | |
5638 | has proven to be the most profitable approach. It is rare for new | |
5639 | optimization opportunities of this nature to appear after the first CSE | |
5640 | pass. | |
5641 | ||
5642 | This could probably be integrated with global cprop with a little work. */ | |
5643 | ||
5644 | void | |
5645 | delete_null_pointer_checks (f) | |
2e653e39 | 5646 | rtx f ATTRIBUTE_UNUSED; |
0511851c | 5647 | { |
0511851c | 5648 | sbitmap *nonnull_avin, *nonnull_avout; |
770ae6cc | 5649 | unsigned int *block_reg; |
e0082a72 | 5650 | basic_block bb; |
0511851c MM |
5651 | int reg; |
5652 | int regs_per_pass; | |
5653 | int max_reg; | |
5654 | struct null_pointer_info npi; | |
5655 | ||
0511851c | 5656 | /* If we have only a single block, then there's nothing to do. */ |
0b17ab2f | 5657 | if (n_basic_blocks <= 1) |
a18820c6 | 5658 | return; |
0511851c MM |
5659 | |
5660 | /* Trying to perform global optimizations on flow graphs which have | |
5661 | a high connectivity will take a long time and is unlikely to be | |
5662 | particularly useful. | |
5663 | ||
43e72072 | 5664 | In normal circumstances a cfg should have about twice as many edges |
0511851c MM |
5665 | as blocks. But we do not want to punish small functions which have |
5666 | a couple switch statements. So we require a relatively large number | |
5667 | of basic blocks and the ratio of edges to blocks to be high. */ | |
0b17ab2f | 5668 | if (n_basic_blocks > 1000 && n_edges / n_basic_blocks >= 20) |
a18820c6 | 5669 | return; |
0511851c | 5670 | |
0511851c MM |
5671 | /* We need four bitmaps, each with a bit for each register in each |
5672 | basic block. */ | |
5673 | max_reg = max_reg_num (); | |
d55bc081 | 5674 | regs_per_pass = get_bitmap_width (4, last_basic_block, max_reg); |
0511851c MM |
5675 | |
5676 | /* Allocate bitmaps to hold local and global properties. */ | |
d55bc081 ZD |
5677 | npi.nonnull_local = sbitmap_vector_alloc (last_basic_block, regs_per_pass); |
5678 | npi.nonnull_killed = sbitmap_vector_alloc (last_basic_block, regs_per_pass); | |
5679 | nonnull_avin = sbitmap_vector_alloc (last_basic_block, regs_per_pass); | |
5680 | nonnull_avout = sbitmap_vector_alloc (last_basic_block, regs_per_pass); | |
0511851c MM |
5681 | |
5682 | /* Go through the basic blocks, seeing whether or not each block | |
5683 | ends with a conditional branch whose condition is a comparison | |
5684 | against zero. Record the register compared in BLOCK_REG. */ | |
d55bc081 | 5685 | block_reg = (unsigned int *) xcalloc (last_basic_block, sizeof (int)); |
e0082a72 | 5686 | FOR_EACH_BB (bb) |
0511851c | 5687 | { |
e0082a72 | 5688 | rtx last_insn = bb->end; |
0511851c MM |
5689 | rtx condition, earliest, reg; |
5690 | ||
5691 | /* We only want conditional branches. */ | |
5692 | if (GET_CODE (last_insn) != JUMP_INSN | |
7f1c097d JH |
5693 | || !any_condjump_p (last_insn) |
5694 | || !onlyjump_p (last_insn)) | |
0511851c MM |
5695 | continue; |
5696 | ||
5697 | /* LAST_INSN is a conditional jump. Get its condition. */ | |
5698 | condition = get_condition (last_insn, &earliest); | |
5699 | ||
4fe9b91c | 5700 | /* If we were unable to get the condition, or it is not an equality |
0511851c MM |
5701 | comparison against zero then there's nothing we can do. */ |
5702 | if (!condition | |
5703 | || (GET_CODE (condition) != NE && GET_CODE (condition) != EQ) | |
5704 | || GET_CODE (XEXP (condition, 1)) != CONST_INT | |
5705 | || (XEXP (condition, 1) | |
5706 | != CONST0_RTX (GET_MODE (XEXP (condition, 0))))) | |
5707 | continue; | |
5708 | ||
5709 | /* We must be checking a register against zero. */ | |
5710 | reg = XEXP (condition, 0); | |
5711 | if (GET_CODE (reg) != REG) | |
5712 | continue; | |
5713 | ||
e0082a72 | 5714 | block_reg[bb->index] = REGNO (reg); |
0511851c MM |
5715 | } |
5716 | ||
5717 | /* Go through the algorithm for each block of registers. */ | |
5718 | for (reg = FIRST_PSEUDO_REGISTER; reg < max_reg; reg += regs_per_pass) | |
5719 | { | |
5720 | npi.min_reg = reg; | |
5721 | npi.max_reg = MIN (reg + regs_per_pass, max_reg); | |
9cd56be1 | 5722 | delete_null_pointer_checks_1 (block_reg, nonnull_avin, |
0511851c | 5723 | nonnull_avout, &npi); |
dfdb644f JL |
5724 | } |
5725 | ||
0511851c MM |
5726 | /* Free the table of registers compared at the end of every block. */ |
5727 | free (block_reg); | |
5728 | ||
dfdb644f | 5729 | /* Free bitmaps. */ |
5a660bff DB |
5730 | sbitmap_vector_free (npi.nonnull_local); |
5731 | sbitmap_vector_free (npi.nonnull_killed); | |
5732 | sbitmap_vector_free (nonnull_avin); | |
5733 | sbitmap_vector_free (nonnull_avout); | |
dfdb644f | 5734 | } |
bb457bd9 JL |
5735 | |
5736 | /* Code Hoisting variables and subroutines. */ | |
5737 | ||
5738 | /* Very busy expressions. */ | |
5739 | static sbitmap *hoist_vbein; | |
5740 | static sbitmap *hoist_vbeout; | |
5741 | ||
5742 | /* Hoistable expressions. */ | |
5743 | static sbitmap *hoist_exprs; | |
5744 | ||
5745 | /* Dominator bitmaps. */ | |
5746 | static sbitmap *dominators; | |
bb457bd9 JL |
5747 | |
5748 | /* ??? We could compute post dominators and run this algorithm in | |
5749 | reverse to to perform tail merging, doing so would probably be | |
5750 | more effective than the tail merging code in jump.c. | |
5751 | ||
5752 | It's unclear if tail merging could be run in parallel with | |
5753 | code hoisting. It would be nice. */ | |
5754 | ||
5755 | /* Allocate vars used for code hoisting analysis. */ | |
5756 | ||
5757 | static void | |
5758 | alloc_code_hoist_mem (n_blocks, n_exprs) | |
5759 | int n_blocks, n_exprs; | |
5760 | { | |
5761 | antloc = sbitmap_vector_alloc (n_blocks, n_exprs); | |
5762 | transp = sbitmap_vector_alloc (n_blocks, n_exprs); | |
5763 | comp = sbitmap_vector_alloc (n_blocks, n_exprs); | |
5764 | ||
5765 | hoist_vbein = sbitmap_vector_alloc (n_blocks, n_exprs); | |
5766 | hoist_vbeout = sbitmap_vector_alloc (n_blocks, n_exprs); | |
5767 | hoist_exprs = sbitmap_vector_alloc (n_blocks, n_exprs); | |
5768 | transpout = sbitmap_vector_alloc (n_blocks, n_exprs); | |
5769 | ||
5770 | dominators = sbitmap_vector_alloc (n_blocks, n_blocks); | |
bb457bd9 JL |
5771 | } |
5772 | ||
5773 | /* Free vars used for code hoisting analysis. */ | |
5774 | ||
5775 | static void | |
5776 | free_code_hoist_mem () | |
5777 | { | |
5a660bff DB |
5778 | sbitmap_vector_free (antloc); |
5779 | sbitmap_vector_free (transp); | |
5780 | sbitmap_vector_free (comp); | |
bb457bd9 | 5781 | |
5a660bff DB |
5782 | sbitmap_vector_free (hoist_vbein); |
5783 | sbitmap_vector_free (hoist_vbeout); | |
5784 | sbitmap_vector_free (hoist_exprs); | |
5785 | sbitmap_vector_free (transpout); | |
bb457bd9 | 5786 | |
5a660bff | 5787 | sbitmap_vector_free (dominators); |
bb457bd9 JL |
5788 | } |
5789 | ||
5790 | /* Compute the very busy expressions at entry/exit from each block. | |
5791 | ||
5792 | An expression is very busy if all paths from a given point | |
5793 | compute the expression. */ | |
5794 | ||
5795 | static void | |
5796 | compute_code_hoist_vbeinout () | |
5797 | { | |
e0082a72 ZD |
5798 | int changed, passes; |
5799 | basic_block bb; | |
bb457bd9 | 5800 | |
d55bc081 ZD |
5801 | sbitmap_vector_zero (hoist_vbeout, last_basic_block); |
5802 | sbitmap_vector_zero (hoist_vbein, last_basic_block); | |
bb457bd9 JL |
5803 | |
5804 | passes = 0; | |
5805 | changed = 1; | |
c4c81601 | 5806 | |
bb457bd9 JL |
5807 | while (changed) |
5808 | { | |
5809 | changed = 0; | |
c4c81601 | 5810 | |
bb457bd9 JL |
5811 | /* We scan the blocks in the reverse order to speed up |
5812 | the convergence. */ | |
e0082a72 | 5813 | FOR_EACH_BB_REVERSE (bb) |
bb457bd9 | 5814 | { |
e0082a72 ZD |
5815 | changed |= sbitmap_a_or_b_and_c_cg (hoist_vbein[bb->index], antloc[bb->index], |
5816 | hoist_vbeout[bb->index], transp[bb->index]); | |
5817 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
5818 | sbitmap_intersection_of_succs (hoist_vbeout[bb->index], hoist_vbein, bb->index); | |
bb457bd9 | 5819 | } |
c4c81601 | 5820 | |
bb457bd9 JL |
5821 | passes++; |
5822 | } | |
5823 | ||
5824 | if (gcse_file) | |
5825 | fprintf (gcse_file, "hoisting vbeinout computation: %d passes\n", passes); | |
5826 | } | |
5827 | ||
5828 | /* Top level routine to do the dataflow analysis needed by code hoisting. */ | |
5829 | ||
5830 | static void | |
5831 | compute_code_hoist_data () | |
5832 | { | |
5833 | compute_local_properties (transp, comp, antloc, 0); | |
5834 | compute_transpout (); | |
5835 | compute_code_hoist_vbeinout (); | |
f8032688 | 5836 | calculate_dominance_info (NULL, dominators, CDI_DOMINATORS); |
bb457bd9 JL |
5837 | if (gcse_file) |
5838 | fprintf (gcse_file, "\n"); | |
5839 | } | |
5840 | ||
5841 | /* Determine if the expression identified by EXPR_INDEX would | |
5842 | reach BB unimpared if it was placed at the end of EXPR_BB. | |
5843 | ||
5844 | It's unclear exactly what Muchnick meant by "unimpared". It seems | |
5845 | to me that the expression must either be computed or transparent in | |
5846 | *every* block in the path(s) from EXPR_BB to BB. Any other definition | |
5847 | would allow the expression to be hoisted out of loops, even if | |
5848 | the expression wasn't a loop invariant. | |
5849 | ||
5850 | Contrast this to reachability for PRE where an expression is | |
5851 | considered reachable if *any* path reaches instead of *all* | |
5852 | paths. */ | |
5853 | ||
5854 | static int | |
5855 | hoist_expr_reaches_here_p (expr_bb, expr_index, bb, visited) | |
e2d2ed72 | 5856 | basic_block expr_bb; |
bb457bd9 | 5857 | int expr_index; |
e2d2ed72 | 5858 | basic_block bb; |
bb457bd9 JL |
5859 | char *visited; |
5860 | { | |
5861 | edge pred; | |
283a2545 RL |
5862 | int visited_allocated_locally = 0; |
5863 | ||
bb457bd9 JL |
5864 | |
5865 | if (visited == NULL) | |
5866 | { | |
8e42ace1 | 5867 | visited_allocated_locally = 1; |
d55bc081 | 5868 | visited = xcalloc (last_basic_block, 1); |
bb457bd9 JL |
5869 | } |
5870 | ||
e2d2ed72 | 5871 | for (pred = bb->pred; pred != NULL; pred = pred->pred_next) |
bb457bd9 | 5872 | { |
e2d2ed72 | 5873 | basic_block pred_bb = pred->src; |
bb457bd9 JL |
5874 | |
5875 | if (pred->src == ENTRY_BLOCK_PTR) | |
5876 | break; | |
0b17ab2f | 5877 | else if (visited[pred_bb->index]) |
bb457bd9 | 5878 | continue; |
c4c81601 | 5879 | |
bb457bd9 | 5880 | /* Does this predecessor generate this expression? */ |
0b17ab2f | 5881 | else if (TEST_BIT (comp[pred_bb->index], expr_index)) |
bb457bd9 | 5882 | break; |
0b17ab2f | 5883 | else if (! TEST_BIT (transp[pred_bb->index], expr_index)) |
bb457bd9 | 5884 | break; |
c4c81601 | 5885 | |
bb457bd9 JL |
5886 | /* Not killed. */ |
5887 | else | |
5888 | { | |
0b17ab2f | 5889 | visited[pred_bb->index] = 1; |
bb457bd9 JL |
5890 | if (! hoist_expr_reaches_here_p (expr_bb, expr_index, |
5891 | pred_bb, visited)) | |
5892 | break; | |
5893 | } | |
5894 | } | |
283a2545 RL |
5895 | if (visited_allocated_locally) |
5896 | free (visited); | |
c4c81601 | 5897 | |
bb457bd9 JL |
5898 | return (pred == NULL); |
5899 | } | |
5900 | \f | |
5901 | /* Actually perform code hoisting. */ | |
c4c81601 | 5902 | |
bb457bd9 JL |
5903 | static void |
5904 | hoist_code () | |
5905 | { | |
e0082a72 | 5906 | basic_block bb, dominated; |
2e653e39 | 5907 | unsigned int i; |
bb457bd9 | 5908 | struct expr **index_map; |
c4c81601 | 5909 | struct expr *expr; |
bb457bd9 | 5910 | |
d55bc081 | 5911 | sbitmap_vector_zero (hoist_exprs, last_basic_block); |
bb457bd9 JL |
5912 | |
5913 | /* Compute a mapping from expression number (`bitmap_index') to | |
5914 | hash table entry. */ | |
5915 | ||
dd1bd863 | 5916 | index_map = (struct expr **) xcalloc (n_exprs, sizeof (struct expr *)); |
bb457bd9 | 5917 | for (i = 0; i < expr_hash_table_size; i++) |
c4c81601 RK |
5918 | for (expr = expr_hash_table[i]; expr != NULL; expr = expr->next_same_hash) |
5919 | index_map[expr->bitmap_index] = expr; | |
bb457bd9 JL |
5920 | |
5921 | /* Walk over each basic block looking for potentially hoistable | |
5922 | expressions, nothing gets hoisted from the entry block. */ | |
e0082a72 | 5923 | FOR_EACH_BB (bb) |
bb457bd9 JL |
5924 | { |
5925 | int found = 0; | |
5926 | int insn_inserted_p; | |
5927 | ||
5928 | /* Examine each expression that is very busy at the exit of this | |
5929 | block. These are the potentially hoistable expressions. */ | |
e0082a72 | 5930 | for (i = 0; i < hoist_vbeout[bb->index]->n_bits; i++) |
bb457bd9 JL |
5931 | { |
5932 | int hoistable = 0; | |
c4c81601 | 5933 | |
e0082a72 | 5934 | if (TEST_BIT (hoist_vbeout[bb->index], i) && TEST_BIT (transpout[bb->index], i)) |
bb457bd9 JL |
5935 | { |
5936 | /* We've found a potentially hoistable expression, now | |
5937 | we look at every block BB dominates to see if it | |
5938 | computes the expression. */ | |
e0082a72 | 5939 | FOR_EACH_BB (dominated) |
bb457bd9 JL |
5940 | { |
5941 | /* Ignore self dominance. */ | |
5942 | if (bb == dominated | |
e0082a72 | 5943 | || ! TEST_BIT (dominators[dominated->index], bb->index)) |
bb457bd9 JL |
5944 | continue; |
5945 | ||
5946 | /* We've found a dominated block, now see if it computes | |
5947 | the busy expression and whether or not moving that | |
5948 | expression to the "beginning" of that block is safe. */ | |
e0082a72 | 5949 | if (!TEST_BIT (antloc[dominated->index], i)) |
bb457bd9 JL |
5950 | continue; |
5951 | ||
5952 | /* Note if the expression would reach the dominated block | |
5953 | unimpared if it was placed at the end of BB. | |
5954 | ||
5955 | Keep track of how many times this expression is hoistable | |
5956 | from a dominated block into BB. */ | |
e0082a72 | 5957 | if (hoist_expr_reaches_here_p (bb, i, dominated, NULL)) |
bb457bd9 JL |
5958 | hoistable++; |
5959 | } | |
5960 | ||
ff7cc307 | 5961 | /* If we found more than one hoistable occurrence of this |
bb457bd9 JL |
5962 | expression, then note it in the bitmap of expressions to |
5963 | hoist. It makes no sense to hoist things which are computed | |
5964 | in only one BB, and doing so tends to pessimize register | |
5965 | allocation. One could increase this value to try harder | |
5966 | to avoid any possible code expansion due to register | |
5967 | allocation issues; however experiments have shown that | |
5968 | the vast majority of hoistable expressions are only movable | |
5969 | from two successors, so raising this threshhold is likely | |
5970 | to nullify any benefit we get from code hoisting. */ | |
5971 | if (hoistable > 1) | |
5972 | { | |
e0082a72 | 5973 | SET_BIT (hoist_exprs[bb->index], i); |
bb457bd9 JL |
5974 | found = 1; |
5975 | } | |
5976 | } | |
5977 | } | |
5978 | ||
5979 | /* If we found nothing to hoist, then quit now. */ | |
5980 | if (! found) | |
5981 | continue; | |
5982 | ||
5983 | /* Loop over all the hoistable expressions. */ | |
e0082a72 | 5984 | for (i = 0; i < hoist_exprs[bb->index]->n_bits; i++) |
bb457bd9 JL |
5985 | { |
5986 | /* We want to insert the expression into BB only once, so | |
5987 | note when we've inserted it. */ | |
5988 | insn_inserted_p = 0; | |
5989 | ||
5990 | /* These tests should be the same as the tests above. */ | |
e0082a72 | 5991 | if (TEST_BIT (hoist_vbeout[bb->index], i)) |
bb457bd9 JL |
5992 | { |
5993 | /* We've found a potentially hoistable expression, now | |
5994 | we look at every block BB dominates to see if it | |
5995 | computes the expression. */ | |
e0082a72 | 5996 | FOR_EACH_BB (dominated) |
bb457bd9 JL |
5997 | { |
5998 | /* Ignore self dominance. */ | |
5999 | if (bb == dominated | |
e0082a72 | 6000 | || ! TEST_BIT (dominators[dominated->index], bb->index)) |
bb457bd9 JL |
6001 | continue; |
6002 | ||
6003 | /* We've found a dominated block, now see if it computes | |
6004 | the busy expression and whether or not moving that | |
6005 | expression to the "beginning" of that block is safe. */ | |
e0082a72 | 6006 | if (!TEST_BIT (antloc[dominated->index], i)) |
bb457bd9 JL |
6007 | continue; |
6008 | ||
6009 | /* The expression is computed in the dominated block and | |
6010 | it would be safe to compute it at the start of the | |
6011 | dominated block. Now we have to determine if the | |
ff7cc307 | 6012 | expression would reach the dominated block if it was |
bb457bd9 | 6013 | placed at the end of BB. */ |
e0082a72 | 6014 | if (hoist_expr_reaches_here_p (bb, i, dominated, NULL)) |
bb457bd9 JL |
6015 | { |
6016 | struct expr *expr = index_map[i]; | |
6017 | struct occr *occr = expr->antic_occr; | |
6018 | rtx insn; | |
6019 | rtx set; | |
6020 | ||
ff7cc307 | 6021 | /* Find the right occurrence of this expression. */ |
e0082a72 | 6022 | while (BLOCK_FOR_INSN (occr->insn) != dominated && occr) |
bb457bd9 JL |
6023 | occr = occr->next; |
6024 | ||
6025 | /* Should never happen. */ | |
6026 | if (!occr) | |
6027 | abort (); | |
6028 | ||
6029 | insn = occr->insn; | |
6030 | ||
6031 | set = single_set (insn); | |
6032 | if (! set) | |
6033 | abort (); | |
6034 | ||
6035 | /* Create a pseudo-reg to store the result of reaching | |
6036 | expressions into. Get the mode for the new pseudo | |
6037 | from the mode of the original destination pseudo. */ | |
6038 | if (expr->reaching_reg == NULL) | |
6039 | expr->reaching_reg | |
6040 | = gen_reg_rtx (GET_MODE (SET_DEST (set))); | |
6041 | ||
10d1bb36 JH |
6042 | gcse_emit_move_after (expr->reaching_reg, SET_DEST (set), insn); |
6043 | delete_insn (insn); | |
6044 | occr->deleted_p = 1; | |
6045 | if (!insn_inserted_p) | |
bb457bd9 | 6046 | { |
10d1bb36 JH |
6047 | insert_insn_end_bb (index_map[i], bb, 0); |
6048 | insn_inserted_p = 1; | |
bb457bd9 JL |
6049 | } |
6050 | } | |
6051 | } | |
6052 | } | |
6053 | } | |
6054 | } | |
c4c81601 | 6055 | |
8e42ace1 | 6056 | free (index_map); |
bb457bd9 JL |
6057 | } |
6058 | ||
6059 | /* Top level routine to perform one code hoisting (aka unification) pass | |
6060 | ||
6061 | Return non-zero if a change was made. */ | |
6062 | ||
6063 | static int | |
6064 | one_code_hoisting_pass () | |
6065 | { | |
6066 | int changed = 0; | |
6067 | ||
6068 | alloc_expr_hash_table (max_cuid); | |
6069 | compute_expr_hash_table (); | |
6070 | if (gcse_file) | |
6071 | dump_hash_table (gcse_file, "Code Hosting Expressions", expr_hash_table, | |
6072 | expr_hash_table_size, n_exprs); | |
c4c81601 | 6073 | |
bb457bd9 JL |
6074 | if (n_exprs > 0) |
6075 | { | |
d55bc081 | 6076 | alloc_code_hoist_mem (last_basic_block, n_exprs); |
bb457bd9 JL |
6077 | compute_code_hoist_data (); |
6078 | hoist_code (); | |
6079 | free_code_hoist_mem (); | |
6080 | } | |
c4c81601 | 6081 | |
bb457bd9 JL |
6082 | free_expr_hash_table (); |
6083 | ||
6084 | return changed; | |
6085 | } | |
a13d4ebf AM |
6086 | \f |
6087 | /* Here we provide the things required to do store motion towards | |
6088 | the exit. In order for this to be effective, gcse also needed to | |
6089 | be taught how to move a load when it is kill only by a store to itself. | |
6090 | ||
6091 | int i; | |
6092 | float a[10]; | |
6093 | ||
6094 | void foo(float scale) | |
6095 | { | |
6096 | for (i=0; i<10; i++) | |
6097 | a[i] *= scale; | |
6098 | } | |
6099 | ||
6100 | 'i' is both loaded and stored to in the loop. Normally, gcse cannot move | |
6101 | the load out since its live around the loop, and stored at the bottom | |
6102 | of the loop. | |
6103 | ||
6104 | The 'Load Motion' referred to and implemented in this file is | |
6105 | an enhancement to gcse which when using edge based lcm, recognizes | |
6106 | this situation and allows gcse to move the load out of the loop. | |
6107 | ||
6108 | Once gcse has hoisted the load, store motion can then push this | |
6109 | load towards the exit, and we end up with no loads or stores of 'i' | |
6110 | in the loop. */ | |
6111 | ||
ff7cc307 | 6112 | /* This will search the ldst list for a matching expression. If it |
a13d4ebf AM |
6113 | doesn't find one, we create one and initialize it. */ |
6114 | ||
6115 | static struct ls_expr * | |
6116 | ldst_entry (x) | |
6117 | rtx x; | |
6118 | { | |
6119 | struct ls_expr * ptr; | |
6120 | ||
6121 | for (ptr = first_ls_expr(); ptr != NULL; ptr = next_ls_expr (ptr)) | |
6122 | if (expr_equiv_p (ptr->pattern, x)) | |
6123 | break; | |
6124 | ||
6125 | if (!ptr) | |
6126 | { | |
6127 | ptr = (struct ls_expr *) xmalloc (sizeof (struct ls_expr)); | |
6128 | ||
6129 | ptr->next = pre_ldst_mems; | |
6130 | ptr->expr = NULL; | |
6131 | ptr->pattern = x; | |
6132 | ptr->loads = NULL_RTX; | |
6133 | ptr->stores = NULL_RTX; | |
6134 | ptr->reaching_reg = NULL_RTX; | |
6135 | ptr->invalid = 0; | |
6136 | ptr->index = 0; | |
6137 | ptr->hash_index = 0; | |
6138 | pre_ldst_mems = ptr; | |
6139 | } | |
6140 | ||
6141 | return ptr; | |
6142 | } | |
6143 | ||
6144 | /* Free up an individual ldst entry. */ | |
6145 | ||
6146 | static void | |
6147 | free_ldst_entry (ptr) | |
6148 | struct ls_expr * ptr; | |
6149 | { | |
aaa4ca30 AJ |
6150 | free_INSN_LIST_list (& ptr->loads); |
6151 | free_INSN_LIST_list (& ptr->stores); | |
a13d4ebf AM |
6152 | |
6153 | free (ptr); | |
6154 | } | |
6155 | ||
6156 | /* Free up all memory associated with the ldst list. */ | |
6157 | ||
6158 | static void | |
6159 | free_ldst_mems () | |
6160 | { | |
6161 | while (pre_ldst_mems) | |
6162 | { | |
6163 | struct ls_expr * tmp = pre_ldst_mems; | |
6164 | ||
6165 | pre_ldst_mems = pre_ldst_mems->next; | |
6166 | ||
6167 | free_ldst_entry (tmp); | |
6168 | } | |
6169 | ||
6170 | pre_ldst_mems = NULL; | |
6171 | } | |
6172 | ||
6173 | /* Dump debugging info about the ldst list. */ | |
6174 | ||
6175 | static void | |
6176 | print_ldst_list (file) | |
6177 | FILE * file; | |
6178 | { | |
6179 | struct ls_expr * ptr; | |
6180 | ||
6181 | fprintf (file, "LDST list: \n"); | |
6182 | ||
6183 | for (ptr = first_ls_expr(); ptr != NULL; ptr = next_ls_expr (ptr)) | |
6184 | { | |
6185 | fprintf (file, " Pattern (%3d): ", ptr->index); | |
6186 | ||
6187 | print_rtl (file, ptr->pattern); | |
6188 | ||
6189 | fprintf (file, "\n Loads : "); | |
6190 | ||
6191 | if (ptr->loads) | |
6192 | print_rtl (file, ptr->loads); | |
6193 | else | |
6194 | fprintf (file, "(nil)"); | |
6195 | ||
6196 | fprintf (file, "\n Stores : "); | |
6197 | ||
6198 | if (ptr->stores) | |
6199 | print_rtl (file, ptr->stores); | |
6200 | else | |
6201 | fprintf (file, "(nil)"); | |
6202 | ||
6203 | fprintf (file, "\n\n"); | |
6204 | } | |
6205 | ||
6206 | fprintf (file, "\n"); | |
6207 | } | |
6208 | ||
6209 | /* Returns 1 if X is in the list of ldst only expressions. */ | |
6210 | ||
6211 | static struct ls_expr * | |
6212 | find_rtx_in_ldst (x) | |
6213 | rtx x; | |
6214 | { | |
6215 | struct ls_expr * ptr; | |
6216 | ||
6217 | for (ptr = pre_ldst_mems; ptr != NULL; ptr = ptr->next) | |
6218 | if (expr_equiv_p (ptr->pattern, x) && ! ptr->invalid) | |
6219 | return ptr; | |
6220 | ||
6221 | return NULL; | |
6222 | } | |
6223 | ||
6224 | /* Assign each element of the list of mems a monotonically increasing value. */ | |
6225 | ||
6226 | static int | |
6227 | enumerate_ldsts () | |
6228 | { | |
6229 | struct ls_expr * ptr; | |
6230 | int n = 0; | |
6231 | ||
6232 | for (ptr = pre_ldst_mems; ptr != NULL; ptr = ptr->next) | |
6233 | ptr->index = n++; | |
6234 | ||
6235 | return n; | |
6236 | } | |
6237 | ||
6238 | /* Return first item in the list. */ | |
6239 | ||
6240 | static inline struct ls_expr * | |
6241 | first_ls_expr () | |
6242 | { | |
6243 | return pre_ldst_mems; | |
6244 | } | |
6245 | ||
6246 | /* Return the next item in ther list after the specified one. */ | |
6247 | ||
6248 | static inline struct ls_expr * | |
6249 | next_ls_expr (ptr) | |
6250 | struct ls_expr * ptr; | |
6251 | { | |
6252 | return ptr->next; | |
6253 | } | |
6254 | \f | |
6255 | /* Load Motion for loads which only kill themselves. */ | |
6256 | ||
6257 | /* Return true if x is a simple MEM operation, with no registers or | |
6258 | side effects. These are the types of loads we consider for the | |
6259 | ld_motion list, otherwise we let the usual aliasing take care of it. */ | |
6260 | ||
6261 | static int | |
6262 | simple_mem (x) | |
6263 | rtx x; | |
6264 | { | |
6265 | if (GET_CODE (x) != MEM) | |
6266 | return 0; | |
6267 | ||
6268 | if (MEM_VOLATILE_P (x)) | |
6269 | return 0; | |
6270 | ||
6271 | if (GET_MODE (x) == BLKmode) | |
6272 | return 0; | |
aaa4ca30 AJ |
6273 | |
6274 | if (!rtx_varies_p (XEXP (x, 0), 0)) | |
a13d4ebf | 6275 | return 1; |
aaa4ca30 | 6276 | |
a13d4ebf AM |
6277 | return 0; |
6278 | } | |
6279 | ||
6280 | /* Make sure there isn't a buried reference in this pattern anywhere. | |
6281 | If there is, invalidate the entry for it since we're not capable | |
6282 | of fixing it up just yet.. We have to be sure we know about ALL | |
6283 | loads since the aliasing code will allow all entries in the | |
6284 | ld_motion list to not-alias itself. If we miss a load, we will get | |
6285 | the wrong value since gcse might common it and we won't know to | |
6286 | fix it up. */ | |
6287 | ||
6288 | static void | |
6289 | invalidate_any_buried_refs (x) | |
6290 | rtx x; | |
6291 | { | |
6292 | const char * fmt; | |
8e42ace1 | 6293 | int i, j; |
a13d4ebf AM |
6294 | struct ls_expr * ptr; |
6295 | ||
6296 | /* Invalidate it in the list. */ | |
6297 | if (GET_CODE (x) == MEM && simple_mem (x)) | |
6298 | { | |
6299 | ptr = ldst_entry (x); | |
6300 | ptr->invalid = 1; | |
6301 | } | |
6302 | ||
6303 | /* Recursively process the insn. */ | |
6304 | fmt = GET_RTX_FORMAT (GET_CODE (x)); | |
6305 | ||
6306 | for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--) | |
6307 | { | |
6308 | if (fmt[i] == 'e') | |
6309 | invalidate_any_buried_refs (XEXP (x, i)); | |
6310 | else if (fmt[i] == 'E') | |
6311 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
6312 | invalidate_any_buried_refs (XVECEXP (x, i, j)); | |
6313 | } | |
6314 | } | |
6315 | ||
6316 | /* Find all the 'simple' MEMs which are used in LOADs and STORES. Simple | |
6317 | being defined as MEM loads and stores to symbols, with no | |
6318 | side effects and no registers in the expression. If there are any | |
f63d1bf7 | 6319 | uses/defs which don't match this criteria, it is invalidated and |
a13d4ebf AM |
6320 | trimmed out later. */ |
6321 | ||
6322 | static void | |
6323 | compute_ld_motion_mems () | |
6324 | { | |
6325 | struct ls_expr * ptr; | |
e0082a72 | 6326 | basic_block bb; |
a13d4ebf AM |
6327 | rtx insn; |
6328 | ||
6329 | pre_ldst_mems = NULL; | |
6330 | ||
e0082a72 | 6331 | FOR_EACH_BB (bb) |
a13d4ebf | 6332 | { |
e0082a72 ZD |
6333 | for (insn = bb->head; |
6334 | insn && insn != NEXT_INSN (bb->end); | |
a13d4ebf AM |
6335 | insn = NEXT_INSN (insn)) |
6336 | { | |
6337 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
6338 | { | |
6339 | if (GET_CODE (PATTERN (insn)) == SET) | |
6340 | { | |
6341 | rtx src = SET_SRC (PATTERN (insn)); | |
6342 | rtx dest = SET_DEST (PATTERN (insn)); | |
6343 | ||
6344 | /* Check for a simple LOAD... */ | |
6345 | if (GET_CODE (src) == MEM && simple_mem (src)) | |
6346 | { | |
6347 | ptr = ldst_entry (src); | |
6348 | if (GET_CODE (dest) == REG) | |
6349 | ptr->loads = alloc_INSN_LIST (insn, ptr->loads); | |
6350 | else | |
6351 | ptr->invalid = 1; | |
6352 | } | |
6353 | else | |
6354 | { | |
6355 | /* Make sure there isn't a buried load somewhere. */ | |
6356 | invalidate_any_buried_refs (src); | |
6357 | } | |
aaa4ca30 | 6358 | |
a13d4ebf AM |
6359 | /* Check for stores. Don't worry about aliased ones, they |
6360 | will block any movement we might do later. We only care | |
6361 | about this exact pattern since those are the only | |
6362 | circumstance that we will ignore the aliasing info. */ | |
6363 | if (GET_CODE (dest) == MEM && simple_mem (dest)) | |
6364 | { | |
6365 | ptr = ldst_entry (dest); | |
6366 | ||
f54104df AO |
6367 | if (GET_CODE (src) != MEM |
6368 | && GET_CODE (src) != ASM_OPERANDS) | |
a13d4ebf AM |
6369 | ptr->stores = alloc_INSN_LIST (insn, ptr->stores); |
6370 | else | |
6371 | ptr->invalid = 1; | |
6372 | } | |
6373 | } | |
6374 | else | |
6375 | invalidate_any_buried_refs (PATTERN (insn)); | |
6376 | } | |
6377 | } | |
6378 | } | |
6379 | } | |
6380 | ||
6381 | /* Remove any references that have been either invalidated or are not in the | |
6382 | expression list for pre gcse. */ | |
6383 | ||
6384 | static void | |
6385 | trim_ld_motion_mems () | |
6386 | { | |
6387 | struct ls_expr * last = NULL; | |
6388 | struct ls_expr * ptr = first_ls_expr (); | |
6389 | ||
6390 | while (ptr != NULL) | |
6391 | { | |
6392 | int del = ptr->invalid; | |
6393 | struct expr * expr = NULL; | |
6394 | ||
6395 | /* Delete if entry has been made invalid. */ | |
6396 | if (!del) | |
6397 | { | |
6398 | unsigned int i; | |
6399 | ||
6400 | del = 1; | |
6401 | /* Delete if we cannot find this mem in the expression list. */ | |
6402 | for (i = 0; i < expr_hash_table_size && del; i++) | |
6403 | { | |
6404 | for (expr = expr_hash_table[i]; | |
6405 | expr != NULL; | |
6406 | expr = expr->next_same_hash) | |
6407 | if (expr_equiv_p (expr->expr, ptr->pattern)) | |
6408 | { | |
6409 | del = 0; | |
6410 | break; | |
6411 | } | |
6412 | } | |
6413 | } | |
6414 | ||
6415 | if (del) | |
6416 | { | |
6417 | if (last != NULL) | |
6418 | { | |
6419 | last->next = ptr->next; | |
6420 | free_ldst_entry (ptr); | |
6421 | ptr = last->next; | |
6422 | } | |
6423 | else | |
6424 | { | |
6425 | pre_ldst_mems = pre_ldst_mems->next; | |
6426 | free_ldst_entry (ptr); | |
6427 | ptr = pre_ldst_mems; | |
6428 | } | |
6429 | } | |
6430 | else | |
6431 | { | |
6432 | /* Set the expression field if we are keeping it. */ | |
6433 | last = ptr; | |
6434 | ptr->expr = expr; | |
6435 | ptr = ptr->next; | |
6436 | } | |
6437 | } | |
6438 | ||
6439 | /* Show the world what we've found. */ | |
6440 | if (gcse_file && pre_ldst_mems != NULL) | |
6441 | print_ldst_list (gcse_file); | |
6442 | } | |
6443 | ||
6444 | /* This routine will take an expression which we are replacing with | |
6445 | a reaching register, and update any stores that are needed if | |
6446 | that expression is in the ld_motion list. Stores are updated by | |
6447 | copying their SRC to the reaching register, and then storeing | |
6448 | the reaching register into the store location. These keeps the | |
6449 | correct value in the reaching register for the loads. */ | |
6450 | ||
6451 | static void | |
6452 | update_ld_motion_stores (expr) | |
6453 | struct expr * expr; | |
6454 | { | |
6455 | struct ls_expr * mem_ptr; | |
6456 | ||
6457 | if ((mem_ptr = find_rtx_in_ldst (expr->expr))) | |
6458 | { | |
6459 | /* We can try to find just the REACHED stores, but is shouldn't | |
6460 | matter to set the reaching reg everywhere... some might be | |
6461 | dead and should be eliminated later. */ | |
6462 | ||
6463 | /* We replace SET mem = expr with | |
6464 | SET reg = expr | |
6465 | SET mem = reg , where reg is the | |
6466 | reaching reg used in the load. */ | |
6467 | rtx list = mem_ptr->stores; | |
6468 | ||
6469 | for ( ; list != NULL_RTX; list = XEXP (list, 1)) | |
6470 | { | |
6471 | rtx insn = XEXP (list, 0); | |
6472 | rtx pat = PATTERN (insn); | |
6473 | rtx src = SET_SRC (pat); | |
6474 | rtx reg = expr->reaching_reg; | |
c57718d3 | 6475 | rtx copy, new; |
a13d4ebf AM |
6476 | |
6477 | /* If we've already copied it, continue. */ | |
6478 | if (expr->reaching_reg == src) | |
6479 | continue; | |
6480 | ||
6481 | if (gcse_file) | |
6482 | { | |
6483 | fprintf (gcse_file, "PRE: store updated with reaching reg "); | |
6484 | print_rtl (gcse_file, expr->reaching_reg); | |
6485 | fprintf (gcse_file, ":\n "); | |
6486 | print_inline_rtx (gcse_file, insn, 8); | |
6487 | fprintf (gcse_file, "\n"); | |
6488 | } | |
6489 | ||
6490 | copy = gen_move_insn ( reg, SET_SRC (pat)); | |
c57718d3 RK |
6491 | new = emit_insn_before (copy, insn); |
6492 | record_one_set (REGNO (reg), new); | |
a13d4ebf AM |
6493 | SET_SRC (pat) = reg; |
6494 | ||
6495 | /* un-recognize this pattern since it's probably different now. */ | |
6496 | INSN_CODE (insn) = -1; | |
6497 | gcse_create_count++; | |
6498 | } | |
6499 | } | |
6500 | } | |
6501 | \f | |
6502 | /* Store motion code. */ | |
6503 | ||
aaa4ca30 AJ |
6504 | /* This is used to communicate the target bitvector we want to use in the |
6505 | reg_set_info routine when called via the note_stores mechanism. */ | |
6506 | static sbitmap * regvec; | |
6507 | ||
a13d4ebf AM |
6508 | /* Used in computing the reverse edge graph bit vectors. */ |
6509 | static sbitmap * st_antloc; | |
6510 | ||
6511 | /* Global holding the number of store expressions we are dealing with. */ | |
6512 | static int num_stores; | |
6513 | ||
aaa4ca30 | 6514 | /* Checks to set if we need to mark a register set. Called from note_stores. */ |
a13d4ebf | 6515 | |
aaa4ca30 AJ |
6516 | static void |
6517 | reg_set_info (dest, setter, data) | |
6518 | rtx dest, setter ATTRIBUTE_UNUSED; | |
6519 | void * data ATTRIBUTE_UNUSED; | |
a13d4ebf | 6520 | { |
aaa4ca30 AJ |
6521 | if (GET_CODE (dest) == SUBREG) |
6522 | dest = SUBREG_REG (dest); | |
adfcce61 | 6523 | |
aaa4ca30 AJ |
6524 | if (GET_CODE (dest) == REG) |
6525 | SET_BIT (*regvec, REGNO (dest)); | |
a13d4ebf AM |
6526 | } |
6527 | ||
6528 | /* Return non-zero if the register operands of expression X are killed | |
aaa4ca30 | 6529 | anywhere in basic block BB. */ |
a13d4ebf AM |
6530 | |
6531 | static int | |
aaa4ca30 | 6532 | store_ops_ok (x, bb) |
a13d4ebf | 6533 | rtx x; |
e2d2ed72 | 6534 | basic_block bb; |
a13d4ebf AM |
6535 | { |
6536 | int i; | |
6537 | enum rtx_code code; | |
6538 | const char * fmt; | |
6539 | ||
6540 | /* Repeat is used to turn tail-recursion into iteration. */ | |
6541 | repeat: | |
6542 | ||
6543 | if (x == 0) | |
6544 | return 1; | |
6545 | ||
6546 | code = GET_CODE (x); | |
6547 | switch (code) | |
6548 | { | |
6549 | case REG: | |
aaa4ca30 AJ |
6550 | /* If a reg has changed after us in this |
6551 | block, the operand has been killed. */ | |
0b17ab2f | 6552 | return TEST_BIT (reg_set_in_block[bb->index], REGNO (x)); |
a13d4ebf AM |
6553 | |
6554 | case MEM: | |
6555 | x = XEXP (x, 0); | |
6556 | goto repeat; | |
6557 | ||
6558 | case PRE_DEC: | |
6559 | case PRE_INC: | |
6560 | case POST_DEC: | |
6561 | case POST_INC: | |
6562 | return 0; | |
6563 | ||
6564 | case PC: | |
6565 | case CC0: /*FIXME*/ | |
6566 | case CONST: | |
6567 | case CONST_INT: | |
6568 | case CONST_DOUBLE: | |
69ef87e2 | 6569 | case CONST_VECTOR: |
a13d4ebf AM |
6570 | case SYMBOL_REF: |
6571 | case LABEL_REF: | |
6572 | case ADDR_VEC: | |
6573 | case ADDR_DIFF_VEC: | |
6574 | return 1; | |
6575 | ||
6576 | default: | |
6577 | break; | |
6578 | } | |
6579 | ||
6580 | i = GET_RTX_LENGTH (code) - 1; | |
6581 | fmt = GET_RTX_FORMAT (code); | |
6582 | ||
6583 | for (; i >= 0; i--) | |
6584 | { | |
6585 | if (fmt[i] == 'e') | |
6586 | { | |
6587 | rtx tem = XEXP (x, i); | |
6588 | ||
6589 | /* If we are about to do the last recursive call | |
6590 | needed at this level, change it into iteration. | |
6591 | This function is called enough to be worth it. */ | |
6592 | if (i == 0) | |
6593 | { | |
6594 | x = tem; | |
6595 | goto repeat; | |
6596 | } | |
6597 | ||
aaa4ca30 | 6598 | if (! store_ops_ok (tem, bb)) |
a13d4ebf AM |
6599 | return 0; |
6600 | } | |
6601 | else if (fmt[i] == 'E') | |
6602 | { | |
6603 | int j; | |
6604 | ||
6605 | for (j = 0; j < XVECLEN (x, i); j++) | |
6606 | { | |
aaa4ca30 | 6607 | if (! store_ops_ok (XVECEXP (x, i, j), bb)) |
a13d4ebf AM |
6608 | return 0; |
6609 | } | |
6610 | } | |
6611 | } | |
6612 | ||
6613 | return 1; | |
6614 | } | |
6615 | ||
aaa4ca30 | 6616 | /* Determine whether insn is MEM store pattern that we will consider moving. */ |
a13d4ebf AM |
6617 | |
6618 | static void | |
6619 | find_moveable_store (insn) | |
6620 | rtx insn; | |
6621 | { | |
6622 | struct ls_expr * ptr; | |
6623 | rtx dest = PATTERN (insn); | |
6624 | ||
f54104df AO |
6625 | if (GET_CODE (dest) != SET |
6626 | || GET_CODE (SET_SRC (dest)) == ASM_OPERANDS) | |
a13d4ebf AM |
6627 | return; |
6628 | ||
6629 | dest = SET_DEST (dest); | |
6630 | ||
6631 | if (GET_CODE (dest) != MEM || MEM_VOLATILE_P (dest) | |
6632 | || GET_MODE (dest) == BLKmode) | |
aaa4ca30 AJ |
6633 | return; |
6634 | ||
6635 | if (GET_CODE (XEXP (dest, 0)) != SYMBOL_REF) | |
a13d4ebf | 6636 | return; |
aaa4ca30 AJ |
6637 | |
6638 | if (rtx_varies_p (XEXP (dest, 0), 0)) | |
a13d4ebf | 6639 | return; |
aaa4ca30 | 6640 | |
a13d4ebf AM |
6641 | ptr = ldst_entry (dest); |
6642 | ptr->stores = alloc_INSN_LIST (insn, ptr->stores); | |
6643 | } | |
6644 | ||
aaa4ca30 AJ |
6645 | /* Perform store motion. Much like gcse, except we move expressions the |
6646 | other way by looking at the flowgraph in reverse. */ | |
a13d4ebf AM |
6647 | |
6648 | static int | |
6649 | compute_store_table () | |
6650 | { | |
e0082a72 ZD |
6651 | int ret; |
6652 | basic_block bb; | |
aaa4ca30 | 6653 | unsigned regno; |
a13d4ebf | 6654 | rtx insn, pat; |
aaa4ca30 | 6655 | |
a13d4ebf AM |
6656 | max_gcse_regno = max_reg_num (); |
6657 | ||
d55bc081 | 6658 | reg_set_in_block = (sbitmap *) sbitmap_vector_alloc (last_basic_block, |
aaa4ca30 | 6659 | max_gcse_regno); |
d55bc081 | 6660 | sbitmap_vector_zero (reg_set_in_block, last_basic_block); |
a13d4ebf | 6661 | pre_ldst_mems = 0; |
aaa4ca30 | 6662 | |
a13d4ebf | 6663 | /* Find all the stores we care about. */ |
e0082a72 | 6664 | FOR_EACH_BB (bb) |
a13d4ebf | 6665 | { |
e0082a72 ZD |
6666 | regvec = & (reg_set_in_block[bb->index]); |
6667 | for (insn = bb->end; | |
6668 | insn && insn != PREV_INSN (bb->end); | |
a13d4ebf AM |
6669 | insn = PREV_INSN (insn)) |
6670 | { | |
19652adf ZW |
6671 | /* Ignore anything that is not a normal insn. */ |
6672 | if (! INSN_P (insn)) | |
a13d4ebf AM |
6673 | continue; |
6674 | ||
aaa4ca30 AJ |
6675 | if (GET_CODE (insn) == CALL_INSN) |
6676 | { | |
19652adf ZW |
6677 | bool clobbers_all = false; |
6678 | #ifdef NON_SAVING_SETJMP | |
6679 | if (NON_SAVING_SETJMP | |
6680 | && find_reg_note (insn, REG_SETJMP, NULL_RTX)) | |
6681 | clobbers_all = true; | |
6682 | #endif | |
6683 | ||
aaa4ca30 | 6684 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) |
19652adf ZW |
6685 | if (clobbers_all |
6686 | || TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) | |
e0082a72 | 6687 | SET_BIT (reg_set_in_block[bb->index], regno); |
aaa4ca30 AJ |
6688 | } |
6689 | ||
a13d4ebf | 6690 | pat = PATTERN (insn); |
aaa4ca30 AJ |
6691 | note_stores (pat, reg_set_info, NULL); |
6692 | ||
a13d4ebf AM |
6693 | /* Now that we've marked regs, look for stores. */ |
6694 | if (GET_CODE (pat) == SET) | |
6695 | find_moveable_store (insn); | |
6696 | } | |
6697 | } | |
6698 | ||
6699 | ret = enumerate_ldsts (); | |
6700 | ||
6701 | if (gcse_file) | |
6702 | { | |
6703 | fprintf (gcse_file, "Store Motion Expressions.\n"); | |
6704 | print_ldst_list (gcse_file); | |
6705 | } | |
6706 | ||
6707 | return ret; | |
6708 | } | |
6709 | ||
aaa4ca30 | 6710 | /* Check to see if the load X is aliased with STORE_PATTERN. */ |
a13d4ebf AM |
6711 | |
6712 | static int | |
6713 | load_kills_store (x, store_pattern) | |
6714 | rtx x, store_pattern; | |
6715 | { | |
6716 | if (true_dependence (x, GET_MODE (x), store_pattern, rtx_addr_varies_p)) | |
6717 | return 1; | |
6718 | return 0; | |
6719 | } | |
6720 | ||
aaa4ca30 AJ |
6721 | /* Go through the entire insn X, looking for any loads which might alias |
6722 | STORE_PATTERN. Return 1 if found. */ | |
a13d4ebf AM |
6723 | |
6724 | static int | |
6725 | find_loads (x, store_pattern) | |
6726 | rtx x, store_pattern; | |
6727 | { | |
6728 | const char * fmt; | |
8e42ace1 | 6729 | int i, j; |
a13d4ebf AM |
6730 | int ret = 0; |
6731 | ||
24a28584 JH |
6732 | if (!x) |
6733 | return 0; | |
6734 | ||
a13d4ebf AM |
6735 | if (GET_CODE (x) == SET) |
6736 | x = SET_SRC (x); | |
6737 | ||
6738 | if (GET_CODE (x) == MEM) | |
6739 | { | |
6740 | if (load_kills_store (x, store_pattern)) | |
6741 | return 1; | |
6742 | } | |
6743 | ||
6744 | /* Recursively process the insn. */ | |
6745 | fmt = GET_RTX_FORMAT (GET_CODE (x)); | |
6746 | ||
6747 | for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0 && !ret; i--) | |
6748 | { | |
6749 | if (fmt[i] == 'e') | |
6750 | ret |= find_loads (XEXP (x, i), store_pattern); | |
6751 | else if (fmt[i] == 'E') | |
6752 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
6753 | ret |= find_loads (XVECEXP (x, i, j), store_pattern); | |
6754 | } | |
6755 | return ret; | |
6756 | } | |
6757 | ||
6758 | /* Check if INSN kills the store pattern X (is aliased with it). | |
6759 | Return 1 if it it does. */ | |
6760 | ||
6761 | static int | |
6762 | store_killed_in_insn (x, insn) | |
6763 | rtx x, insn; | |
6764 | { | |
6765 | if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') | |
6766 | return 0; | |
6767 | ||
6768 | if (GET_CODE (insn) == CALL_INSN) | |
6769 | { | |
1218665b JJ |
6770 | /* A normal or pure call might read from pattern, |
6771 | but a const call will not. */ | |
a6a063b8 | 6772 | return ! CONST_OR_PURE_CALL_P (insn) || pure_call_p (insn); |
a13d4ebf AM |
6773 | } |
6774 | ||
6775 | if (GET_CODE (PATTERN (insn)) == SET) | |
6776 | { | |
6777 | rtx pat = PATTERN (insn); | |
6778 | /* Check for memory stores to aliased objects. */ | |
6779 | if (GET_CODE (SET_DEST (pat)) == MEM && !expr_equiv_p (SET_DEST (pat), x)) | |
aaa4ca30 | 6780 | /* pretend its a load and check for aliasing. */ |
a13d4ebf AM |
6781 | if (find_loads (SET_DEST (pat), x)) |
6782 | return 1; | |
6783 | return find_loads (SET_SRC (pat), x); | |
6784 | } | |
6785 | else | |
6786 | return find_loads (PATTERN (insn), x); | |
6787 | } | |
6788 | ||
6789 | /* Returns 1 if the expression X is loaded or clobbered on or after INSN | |
6790 | within basic block BB. */ | |
6791 | ||
6792 | static int | |
aaa4ca30 | 6793 | store_killed_after (x, insn, bb) |
a13d4ebf | 6794 | rtx x, insn; |
e2d2ed72 | 6795 | basic_block bb; |
a13d4ebf | 6796 | { |
8e42ace1 | 6797 | rtx last = bb->end; |
a13d4ebf | 6798 | |
8e42ace1 KH |
6799 | if (insn == last) |
6800 | return 0; | |
aaa4ca30 AJ |
6801 | |
6802 | /* Check if the register operands of the store are OK in this block. | |
6803 | Note that if registers are changed ANYWHERE in the block, we'll | |
6804 | decide we can't move it, regardless of whether it changed above | |
6805 | or below the store. This could be improved by checking the register | |
6806 | operands while lookinng for aliasing in each insn. */ | |
6807 | if (!store_ops_ok (XEXP (x, 0), bb)) | |
a13d4ebf AM |
6808 | return 1; |
6809 | ||
8e42ace1 KH |
6810 | for ( ; insn && insn != NEXT_INSN (last); insn = NEXT_INSN (insn)) |
6811 | if (store_killed_in_insn (x, insn)) | |
6812 | return 1; | |
a13d4ebf AM |
6813 | |
6814 | return 0; | |
6815 | } | |
6816 | ||
aaa4ca30 | 6817 | /* Returns 1 if the expression X is loaded or clobbered on or before INSN |
a13d4ebf AM |
6818 | within basic block BB. */ |
6819 | static int | |
6820 | store_killed_before (x, insn, bb) | |
6821 | rtx x, insn; | |
e2d2ed72 | 6822 | basic_block bb; |
a13d4ebf | 6823 | { |
8e42ace1 | 6824 | rtx first = bb->head; |
a13d4ebf | 6825 | |
8e42ace1 KH |
6826 | if (insn == first) |
6827 | return store_killed_in_insn (x, insn); | |
aaa4ca30 AJ |
6828 | |
6829 | /* Check if the register operands of the store are OK in this block. | |
6830 | Note that if registers are changed ANYWHERE in the block, we'll | |
6831 | decide we can't move it, regardless of whether it changed above | |
6832 | or below the store. This could be improved by checking the register | |
6833 | operands while lookinng for aliasing in each insn. */ | |
6834 | if (!store_ops_ok (XEXP (x, 0), bb)) | |
a13d4ebf AM |
6835 | return 1; |
6836 | ||
8e42ace1 KH |
6837 | for ( ; insn && insn != PREV_INSN (first); insn = PREV_INSN (insn)) |
6838 | if (store_killed_in_insn (x, insn)) | |
6839 | return 1; | |
a13d4ebf | 6840 | |
8e42ace1 | 6841 | return 0; |
a13d4ebf AM |
6842 | } |
6843 | ||
6844 | #define ANTIC_STORE_LIST(x) ((x)->loads) | |
6845 | #define AVAIL_STORE_LIST(x) ((x)->stores) | |
6846 | ||
6847 | /* Given the table of available store insns at the end of blocks, | |
6848 | determine which ones are not killed by aliasing, and generate | |
6849 | the appropriate vectors for gen and killed. */ | |
6850 | static void | |
6851 | build_store_vectors () | |
6852 | { | |
e0082a72 | 6853 | basic_block bb, b; |
a13d4ebf AM |
6854 | rtx insn, st; |
6855 | struct ls_expr * ptr; | |
6856 | ||
6857 | /* Build the gen_vector. This is any store in the table which is not killed | |
6858 | by aliasing later in its block. */ | |
d55bc081 ZD |
6859 | ae_gen = (sbitmap *) sbitmap_vector_alloc (last_basic_block, num_stores); |
6860 | sbitmap_vector_zero (ae_gen, last_basic_block); | |
a13d4ebf | 6861 | |
d55bc081 ZD |
6862 | st_antloc = (sbitmap *) sbitmap_vector_alloc (last_basic_block, num_stores); |
6863 | sbitmap_vector_zero (st_antloc, last_basic_block); | |
aaa4ca30 | 6864 | |
a13d4ebf AM |
6865 | for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr)) |
6866 | { | |
6867 | /* Put all the stores into either the antic list, or the avail list, | |
6868 | or both. */ | |
6869 | rtx store_list = ptr->stores; | |
6870 | ptr->stores = NULL_RTX; | |
6871 | ||
6872 | for (st = store_list; st != NULL; st = XEXP (st, 1)) | |
6873 | { | |
6874 | insn = XEXP (st, 0); | |
e2d2ed72 | 6875 | bb = BLOCK_FOR_INSN (insn); |
aaa4ca30 AJ |
6876 | |
6877 | if (!store_killed_after (ptr->pattern, insn, bb)) | |
a13d4ebf AM |
6878 | { |
6879 | /* If we've already seen an availale expression in this block, | |
6880 | we can delete the one we saw already (It occurs earlier in | |
6881 | the block), and replace it with this one). We'll copy the | |
6882 | old SRC expression to an unused register in case there | |
6883 | are any side effects. */ | |
0b17ab2f | 6884 | if (TEST_BIT (ae_gen[bb->index], ptr->index)) |
a13d4ebf AM |
6885 | { |
6886 | /* Find previous store. */ | |
6887 | rtx st; | |
6888 | for (st = AVAIL_STORE_LIST (ptr); st ; st = XEXP (st, 1)) | |
e2d2ed72 | 6889 | if (BLOCK_FOR_INSN (XEXP (st, 0)) == bb) |
a13d4ebf AM |
6890 | break; |
6891 | if (st) | |
6892 | { | |
6893 | rtx r = gen_reg_rtx (GET_MODE (ptr->pattern)); | |
6894 | if (gcse_file) | |
8e42ace1 | 6895 | fprintf (gcse_file, "Removing redundant store:\n"); |
a13d4ebf AM |
6896 | replace_store_insn (r, XEXP (st, 0), bb); |
6897 | XEXP (st, 0) = insn; | |
6898 | continue; | |
6899 | } | |
6900 | } | |
0b17ab2f | 6901 | SET_BIT (ae_gen[bb->index], ptr->index); |
a13d4ebf AM |
6902 | AVAIL_STORE_LIST (ptr) = alloc_INSN_LIST (insn, |
6903 | AVAIL_STORE_LIST (ptr)); | |
6904 | } | |
6905 | ||
6906 | if (!store_killed_before (ptr->pattern, insn, bb)) | |
6907 | { | |
6908 | SET_BIT (st_antloc[BLOCK_NUM (insn)], ptr->index); | |
6909 | ANTIC_STORE_LIST (ptr) = alloc_INSN_LIST (insn, | |
6910 | ANTIC_STORE_LIST (ptr)); | |
6911 | } | |
6912 | } | |
6913 | ||
6914 | /* Free the original list of store insns. */ | |
6915 | free_INSN_LIST_list (&store_list); | |
6916 | } | |
6917 | ||
d55bc081 ZD |
6918 | ae_kill = (sbitmap *) sbitmap_vector_alloc (last_basic_block, num_stores); |
6919 | sbitmap_vector_zero (ae_kill, last_basic_block); | |
a13d4ebf | 6920 | |
d55bc081 ZD |
6921 | transp = (sbitmap *) sbitmap_vector_alloc (last_basic_block, num_stores); |
6922 | sbitmap_vector_zero (transp, last_basic_block); | |
a13d4ebf AM |
6923 | |
6924 | for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr)) | |
e0082a72 | 6925 | FOR_EACH_BB (b) |
a13d4ebf | 6926 | { |
e0082a72 | 6927 | if (store_killed_after (ptr->pattern, b->head, b)) |
a13d4ebf | 6928 | { |
dc297297 | 6929 | /* The anticipatable expression is not killed if it's gen'd. */ |
aaa4ca30 AJ |
6930 | /* |
6931 | We leave this check out for now. If we have a code sequence | |
6932 | in a block which looks like: | |
6933 | ST MEMa = x | |
6934 | L y = MEMa | |
6935 | ST MEMa = z | |
6936 | We should flag this as having an ANTIC expression, NOT | |
6937 | transparent, NOT killed, and AVAIL. | |
6938 | Unfortunately, since we haven't re-written all loads to | |
6939 | use the reaching reg, we'll end up doing an incorrect | |
6940 | Load in the middle here if we push the store down. It happens in | |
6941 | gcc.c-torture/execute/960311-1.c with -O3 | |
6942 | If we always kill it in this case, we'll sometimes do | |
6943 | uneccessary work, but it shouldn't actually hurt anything. | |
6944 | if (!TEST_BIT (ae_gen[b], ptr->index)). */ | |
e0082a72 | 6945 | SET_BIT (ae_kill[b->index], ptr->index); |
aaa4ca30 AJ |
6946 | } |
6947 | else | |
e0082a72 | 6948 | SET_BIT (transp[b->index], ptr->index); |
aaa4ca30 AJ |
6949 | } |
6950 | ||
6951 | /* Any block with no exits calls some non-returning function, so | |
6952 | we better mark the store killed here, or we might not store to | |
6953 | it at all. If we knew it was abort, we wouldn't have to store, | |
6954 | but we don't know that for sure. */ | |
6955 | if (gcse_file) | |
6956 | { | |
6957 | fprintf (gcse_file, "ST_avail and ST_antic (shown under loads..)\n"); | |
6958 | print_ldst_list (gcse_file); | |
d55bc081 ZD |
6959 | dump_sbitmap_vector (gcse_file, "st_antloc", "", st_antloc, last_basic_block); |
6960 | dump_sbitmap_vector (gcse_file, "st_kill", "", ae_kill, last_basic_block); | |
6961 | dump_sbitmap_vector (gcse_file, "Transpt", "", transp, last_basic_block); | |
6962 | dump_sbitmap_vector (gcse_file, "st_avloc", "", ae_gen, last_basic_block); | |
a13d4ebf AM |
6963 | } |
6964 | } | |
6965 | ||
6966 | /* Insert an instruction at the begining of a basic block, and update | |
6967 | the BLOCK_HEAD if needed. */ | |
6968 | ||
6969 | static void | |
6970 | insert_insn_start_bb (insn, bb) | |
6971 | rtx insn; | |
e2d2ed72 | 6972 | basic_block bb; |
a13d4ebf AM |
6973 | { |
6974 | /* Insert at start of successor block. */ | |
e2d2ed72 AM |
6975 | rtx prev = PREV_INSN (bb->head); |
6976 | rtx before = bb->head; | |
a13d4ebf AM |
6977 | while (before != 0) |
6978 | { | |
6979 | if (GET_CODE (before) != CODE_LABEL | |
6980 | && (GET_CODE (before) != NOTE | |
6981 | || NOTE_LINE_NUMBER (before) != NOTE_INSN_BASIC_BLOCK)) | |
6982 | break; | |
6983 | prev = before; | |
e2d2ed72 | 6984 | if (prev == bb->end) |
a13d4ebf AM |
6985 | break; |
6986 | before = NEXT_INSN (before); | |
6987 | } | |
6988 | ||
6989 | insn = emit_insn_after (insn, prev); | |
6990 | ||
a13d4ebf AM |
6991 | if (gcse_file) |
6992 | { | |
6993 | fprintf (gcse_file, "STORE_MOTION insert store at start of BB %d:\n", | |
0b17ab2f | 6994 | bb->index); |
a13d4ebf AM |
6995 | print_inline_rtx (gcse_file, insn, 6); |
6996 | fprintf (gcse_file, "\n"); | |
6997 | } | |
6998 | } | |
6999 | ||
7000 | /* This routine will insert a store on an edge. EXPR is the ldst entry for | |
7001 | the memory reference, and E is the edge to insert it on. Returns non-zero | |
7002 | if an edge insertion was performed. */ | |
7003 | ||
7004 | static int | |
7005 | insert_store (expr, e) | |
7006 | struct ls_expr * expr; | |
7007 | edge e; | |
7008 | { | |
7009 | rtx reg, insn; | |
e2d2ed72 | 7010 | basic_block bb; |
a13d4ebf AM |
7011 | edge tmp; |
7012 | ||
7013 | /* We did all the deleted before this insert, so if we didn't delete a | |
7014 | store, then we haven't set the reaching reg yet either. */ | |
7015 | if (expr->reaching_reg == NULL_RTX) | |
7016 | return 0; | |
7017 | ||
7018 | reg = expr->reaching_reg; | |
7019 | insn = gen_move_insn (expr->pattern, reg); | |
7020 | ||
7021 | /* If we are inserting this expression on ALL predecessor edges of a BB, | |
7022 | insert it at the start of the BB, and reset the insert bits on the other | |
ff7cc307 | 7023 | edges so we don't try to insert it on the other edges. */ |
e2d2ed72 | 7024 | bb = e->dest; |
a13d4ebf AM |
7025 | for (tmp = e->dest->pred; tmp ; tmp = tmp->pred_next) |
7026 | { | |
7027 | int index = EDGE_INDEX (edge_list, tmp->src, tmp->dest); | |
7028 | if (index == EDGE_INDEX_NO_EDGE) | |
7029 | abort (); | |
7030 | if (! TEST_BIT (pre_insert_map[index], expr->index)) | |
7031 | break; | |
7032 | } | |
7033 | ||
7034 | /* If tmp is NULL, we found an insertion on every edge, blank the | |
7035 | insertion vector for these edges, and insert at the start of the BB. */ | |
e2d2ed72 | 7036 | if (!tmp && bb != EXIT_BLOCK_PTR) |
a13d4ebf AM |
7037 | { |
7038 | for (tmp = e->dest->pred; tmp ; tmp = tmp->pred_next) | |
7039 | { | |
7040 | int index = EDGE_INDEX (edge_list, tmp->src, tmp->dest); | |
7041 | RESET_BIT (pre_insert_map[index], expr->index); | |
7042 | } | |
7043 | insert_insn_start_bb (insn, bb); | |
7044 | return 0; | |
7045 | } | |
7046 | ||
7047 | /* We can't insert on this edge, so we'll insert at the head of the | |
7048 | successors block. See Morgan, sec 10.5. */ | |
7049 | if ((e->flags & EDGE_ABNORMAL) == EDGE_ABNORMAL) | |
7050 | { | |
7051 | insert_insn_start_bb (insn, bb); | |
7052 | return 0; | |
7053 | } | |
7054 | ||
7055 | insert_insn_on_edge (insn, e); | |
7056 | ||
7057 | if (gcse_file) | |
7058 | { | |
7059 | fprintf (gcse_file, "STORE_MOTION insert insn on edge (%d, %d):\n", | |
0b17ab2f | 7060 | e->src->index, e->dest->index); |
a13d4ebf AM |
7061 | print_inline_rtx (gcse_file, insn, 6); |
7062 | fprintf (gcse_file, "\n"); | |
7063 | } | |
7064 | ||
7065 | return 1; | |
7066 | } | |
7067 | ||
7068 | /* This routine will replace a store with a SET to a specified register. */ | |
7069 | ||
7070 | static void | |
7071 | replace_store_insn (reg, del, bb) | |
7072 | rtx reg, del; | |
e2d2ed72 | 7073 | basic_block bb; |
a13d4ebf AM |
7074 | { |
7075 | rtx insn; | |
7076 | ||
7077 | insn = gen_move_insn (reg, SET_SRC (PATTERN (del))); | |
7078 | insn = emit_insn_after (insn, del); | |
a13d4ebf AM |
7079 | |
7080 | if (gcse_file) | |
7081 | { | |
7082 | fprintf (gcse_file, | |
0b17ab2f | 7083 | "STORE_MOTION delete insn in BB %d:\n ", bb->index); |
a13d4ebf | 7084 | print_inline_rtx (gcse_file, del, 6); |
8e42ace1 | 7085 | fprintf (gcse_file, "\nSTORE MOTION replaced with insn:\n "); |
a13d4ebf | 7086 | print_inline_rtx (gcse_file, insn, 6); |
8e42ace1 | 7087 | fprintf (gcse_file, "\n"); |
a13d4ebf AM |
7088 | } |
7089 | ||
49ce134f | 7090 | delete_insn (del); |
a13d4ebf AM |
7091 | } |
7092 | ||
7093 | ||
7094 | /* Delete a store, but copy the value that would have been stored into | |
7095 | the reaching_reg for later storing. */ | |
7096 | ||
7097 | static void | |
7098 | delete_store (expr, bb) | |
7099 | struct ls_expr * expr; | |
e2d2ed72 | 7100 | basic_block bb; |
a13d4ebf AM |
7101 | { |
7102 | rtx reg, i, del; | |
7103 | ||
7104 | if (expr->reaching_reg == NULL_RTX) | |
7105 | expr->reaching_reg = gen_reg_rtx (GET_MODE (expr->pattern)); | |
7106 | ||
7107 | ||
7108 | /* If there is more than 1 store, the earlier ones will be dead, | |
7109 | but it doesn't hurt to replace them here. */ | |
7110 | reg = expr->reaching_reg; | |
7111 | ||
7112 | for (i = AVAIL_STORE_LIST (expr); i; i = XEXP (i, 1)) | |
7113 | { | |
7114 | del = XEXP (i, 0); | |
e2d2ed72 | 7115 | if (BLOCK_FOR_INSN (del) == bb) |
a13d4ebf AM |
7116 | { |
7117 | /* We know there is only one since we deleted redundant | |
7118 | ones during the available computation. */ | |
7119 | replace_store_insn (reg, del, bb); | |
7120 | break; | |
7121 | } | |
7122 | } | |
7123 | } | |
7124 | ||
7125 | /* Free memory used by store motion. */ | |
7126 | ||
7127 | static void | |
7128 | free_store_memory () | |
7129 | { | |
7130 | free_ldst_mems (); | |
aaa4ca30 | 7131 | |
a13d4ebf | 7132 | if (ae_gen) |
5a660bff | 7133 | sbitmap_vector_free (ae_gen); |
a13d4ebf | 7134 | if (ae_kill) |
5a660bff | 7135 | sbitmap_vector_free (ae_kill); |
a13d4ebf | 7136 | if (transp) |
5a660bff | 7137 | sbitmap_vector_free (transp); |
a13d4ebf | 7138 | if (st_antloc) |
5a660bff | 7139 | sbitmap_vector_free (st_antloc); |
a13d4ebf | 7140 | if (pre_insert_map) |
5a660bff | 7141 | sbitmap_vector_free (pre_insert_map); |
a13d4ebf | 7142 | if (pre_delete_map) |
5a660bff | 7143 | sbitmap_vector_free (pre_delete_map); |
aaa4ca30 AJ |
7144 | if (reg_set_in_block) |
7145 | sbitmap_vector_free (reg_set_in_block); | |
a13d4ebf AM |
7146 | |
7147 | ae_gen = ae_kill = transp = st_antloc = NULL; | |
7148 | pre_insert_map = pre_delete_map = reg_set_in_block = NULL; | |
7149 | } | |
7150 | ||
7151 | /* Perform store motion. Much like gcse, except we move expressions the | |
7152 | other way by looking at the flowgraph in reverse. */ | |
7153 | ||
7154 | static void | |
7155 | store_motion () | |
7156 | { | |
e0082a72 | 7157 | basic_block bb; |
0b17ab2f | 7158 | int x; |
a13d4ebf | 7159 | struct ls_expr * ptr; |
adfcce61 | 7160 | int update_flow = 0; |
aaa4ca30 | 7161 | |
a13d4ebf AM |
7162 | if (gcse_file) |
7163 | { | |
7164 | fprintf (gcse_file, "before store motion\n"); | |
7165 | print_rtl (gcse_file, get_insns ()); | |
7166 | } | |
7167 | ||
7168 | ||
7169 | init_alias_analysis (); | |
aaa4ca30 | 7170 | |
a13d4ebf AM |
7171 | /* Find all the stores that are live to the end of their block. */ |
7172 | num_stores = compute_store_table (); | |
7173 | if (num_stores == 0) | |
7174 | { | |
aaa4ca30 | 7175 | sbitmap_vector_free (reg_set_in_block); |
a13d4ebf AM |
7176 | end_alias_analysis (); |
7177 | return; | |
7178 | } | |
7179 | ||
7180 | /* Now compute whats actually available to move. */ | |
7181 | add_noreturn_fake_exit_edges (); | |
7182 | build_store_vectors (); | |
7183 | ||
7184 | edge_list = pre_edge_rev_lcm (gcse_file, num_stores, transp, ae_gen, | |
7185 | st_antloc, ae_kill, &pre_insert_map, | |
7186 | &pre_delete_map); | |
7187 | ||
7188 | /* Now we want to insert the new stores which are going to be needed. */ | |
7189 | for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr)) | |
7190 | { | |
e0082a72 ZD |
7191 | FOR_EACH_BB (bb) |
7192 | if (TEST_BIT (pre_delete_map[bb->index], ptr->index)) | |
7193 | delete_store (ptr, bb); | |
a13d4ebf | 7194 | |
0b17ab2f RH |
7195 | for (x = 0; x < NUM_EDGES (edge_list); x++) |
7196 | if (TEST_BIT (pre_insert_map[x], ptr->index)) | |
7197 | update_flow |= insert_store (ptr, INDEX_EDGE (edge_list, x)); | |
a13d4ebf AM |
7198 | } |
7199 | ||
7200 | if (update_flow) | |
7201 | commit_edge_insertions (); | |
aaa4ca30 | 7202 | |
a13d4ebf AM |
7203 | free_store_memory (); |
7204 | free_edge_list (edge_list); | |
7205 | remove_fake_edges (); | |
7206 | end_alias_analysis (); | |
7207 | } | |
e2500fed GK |
7208 | |
7209 | #include "gt-gcse.h" |