]>
Commit | Line | Data |
---|---|---|
f4e584dc | 1 | /* Global common subexpression elimination/Partial redundancy elimination |
7506f491 | 2 | and global constant/copy propagation for GNU compiler. |
a0134312 | 3 | Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003 |
8e42ace1 | 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" |
4977bab6 ZW |
148 | #include "coretypes.h" |
149 | #include "tm.h" | |
01198c2f | 150 | #include "toplev.h" |
7506f491 DE |
151 | |
152 | #include "rtl.h" | |
6baf1cc8 | 153 | #include "tm_p.h" |
7506f491 DE |
154 | #include "regs.h" |
155 | #include "hard-reg-set.h" | |
156 | #include "flags.h" | |
157 | #include "real.h" | |
158 | #include "insn-config.h" | |
159 | #include "recog.h" | |
160 | #include "basic-block.h" | |
50b2596f | 161 | #include "output.h" |
49ad7cfa | 162 | #include "function.h" |
589005ff | 163 | #include "expr.h" |
e7d482b9 | 164 | #include "except.h" |
fb0c0a12 | 165 | #include "ggc.h" |
f1fa37ff | 166 | #include "params.h" |
ae860ff7 | 167 | #include "cselib.h" |
aaa4ca30 | 168 | |
7506f491 | 169 | #include "obstack.h" |
4fa31c2a | 170 | |
7506f491 DE |
171 | /* Propagate flow information through back edges and thus enable PRE's |
172 | moving loop invariant calculations out of loops. | |
173 | ||
174 | Originally this tended to create worse overall code, but several | |
175 | improvements during the development of PRE seem to have made following | |
176 | back edges generally a win. | |
177 | ||
178 | Note much of the loop invariant code motion done here would normally | |
179 | be done by loop.c, which has more heuristics for when to move invariants | |
180 | out of loops. At some point we might need to move some of those | |
181 | heuristics into gcse.c. */ | |
7506f491 | 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 | ||
cc2902df | 302 | /* Nonzero for each mode that supports (set (reg) (reg)). |
7506f491 DE |
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 | ||
cc2902df | 307 | /* Nonzero if can_copy_p has been initialized. */ |
7506f491 DE |
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; | |
cc2902df | 349 | /* Nonzero if this [anticipatable] occurrence has been deleted. */ |
7506f491 | 350 | char deleted_p; |
cc2902df | 351 | /* Nonzero if this [available] occurrence has been copied to |
7506f491 DE |
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 | 366 | |
02280659 ZD |
367 | struct hash_table |
368 | { | |
369 | /* The table itself. | |
370 | This is an array of `expr_hash_table_size' elements. */ | |
371 | struct expr **table; | |
372 | ||
373 | /* Size of the hash table, in elements. */ | |
374 | unsigned int size; | |
2e653e39 | 375 | |
02280659 ZD |
376 | /* Number of hash table elements. */ |
377 | unsigned int n_elems; | |
7506f491 | 378 | |
02280659 ZD |
379 | /* Whether the table is expression of copy propagation one. */ |
380 | int set_p; | |
381 | }; | |
c4c81601 | 382 | |
02280659 ZD |
383 | /* Expression hash table. */ |
384 | static struct hash_table expr_hash_table; | |
385 | ||
386 | /* Copy propagation hash table. */ | |
387 | static struct hash_table set_hash_table; | |
7506f491 DE |
388 | |
389 | /* Mapping of uids to cuids. | |
390 | Only real insns get cuids. */ | |
391 | static int *uid_cuid; | |
392 | ||
393 | /* Highest UID in UID_CUID. */ | |
394 | static int max_uid; | |
395 | ||
396 | /* Get the cuid of an insn. */ | |
b86db3eb BS |
397 | #ifdef ENABLE_CHECKING |
398 | #define INSN_CUID(INSN) (INSN_UID (INSN) > max_uid ? (abort (), 0) : uid_cuid[INSN_UID (INSN)]) | |
399 | #else | |
7506f491 | 400 | #define INSN_CUID(INSN) (uid_cuid[INSN_UID (INSN)]) |
b86db3eb | 401 | #endif |
7506f491 DE |
402 | |
403 | /* Number of cuids. */ | |
404 | static int max_cuid; | |
405 | ||
406 | /* Mapping of cuids to insns. */ | |
407 | static rtx *cuid_insn; | |
408 | ||
409 | /* Get insn from cuid. */ | |
410 | #define CUID_INSN(CUID) (cuid_insn[CUID]) | |
411 | ||
412 | /* Maximum register number in function prior to doing gcse + 1. | |
413 | Registers created during this pass have regno >= max_gcse_regno. | |
414 | This is named with "gcse" to not collide with global of same name. */ | |
770ae6cc | 415 | static unsigned int max_gcse_regno; |
7506f491 | 416 | |
7506f491 | 417 | /* Table of registers that are modified. |
c4c81601 | 418 | |
7506f491 DE |
419 | For each register, each element is a list of places where the pseudo-reg |
420 | is set. | |
421 | ||
422 | For simplicity, GCSE is done on sets of pseudo-regs only. PRE GCSE only | |
423 | requires knowledge of which blocks kill which regs [and thus could use | |
f4e584dc | 424 | a bitmap instead of the lists `reg_set_table' uses]. |
7506f491 | 425 | |
c4c81601 RK |
426 | `reg_set_table' and could be turned into an array of bitmaps (num-bbs x |
427 | num-regs) [however perhaps it may be useful to keep the data as is]. One | |
428 | advantage of recording things this way is that `reg_set_table' is fairly | |
429 | sparse with respect to pseudo regs but for hard regs could be fairly dense | |
430 | [relatively speaking]. And recording sets of pseudo-regs in lists speeds | |
7506f491 DE |
431 | up functions like compute_transp since in the case of pseudo-regs we only |
432 | need to iterate over the number of times a pseudo-reg is set, not over the | |
433 | number of basic blocks [clearly there is a bit of a slow down in the cases | |
434 | where a pseudo is set more than once in a block, however it is believed | |
435 | that the net effect is to speed things up]. This isn't done for hard-regs | |
436 | because recording call-clobbered hard-regs in `reg_set_table' at each | |
c4c81601 RK |
437 | function call can consume a fair bit of memory, and iterating over |
438 | hard-regs stored this way in compute_transp will be more expensive. */ | |
7506f491 | 439 | |
c4c81601 RK |
440 | typedef struct reg_set |
441 | { | |
7506f491 DE |
442 | /* The next setting of this register. */ |
443 | struct reg_set *next; | |
444 | /* The insn where it was set. */ | |
445 | rtx insn; | |
446 | } reg_set; | |
c4c81601 | 447 | |
7506f491 | 448 | static reg_set **reg_set_table; |
c4c81601 | 449 | |
7506f491 DE |
450 | /* Size of `reg_set_table'. |
451 | The table starts out at max_gcse_regno + slop, and is enlarged as | |
452 | necessary. */ | |
453 | static int reg_set_table_size; | |
c4c81601 | 454 | |
7506f491 DE |
455 | /* Amount to grow `reg_set_table' by when it's full. */ |
456 | #define REG_SET_TABLE_SLOP 100 | |
457 | ||
a13d4ebf | 458 | /* This is a list of expressions which are MEMs and will be used by load |
589005ff | 459 | or store motion. |
a13d4ebf AM |
460 | Load motion tracks MEMs which aren't killed by |
461 | anything except itself. (ie, loads and stores to a single location). | |
589005ff | 462 | We can then allow movement of these MEM refs with a little special |
a13d4ebf AM |
463 | allowance. (all stores copy the same value to the reaching reg used |
464 | for the loads). This means all values used to store into memory must have | |
589005ff | 465 | no side effects so we can re-issue the setter value. |
a13d4ebf AM |
466 | Store Motion uses this structure as an expression table to track stores |
467 | which look interesting, and might be moveable towards the exit block. */ | |
468 | ||
469 | struct ls_expr | |
470 | { | |
471 | struct expr * expr; /* Gcse expression reference for LM. */ | |
472 | rtx pattern; /* Pattern of this mem. */ | |
47a3dae1 | 473 | rtx pattern_regs; /* List of registers mentioned by the mem. */ |
aaa4ca30 AJ |
474 | rtx loads; /* INSN list of loads seen. */ |
475 | rtx stores; /* INSN list of stores seen. */ | |
a13d4ebf AM |
476 | struct ls_expr * next; /* Next in the list. */ |
477 | int invalid; /* Invalid for some reason. */ | |
478 | int index; /* If it maps to a bitmap index. */ | |
479 | int hash_index; /* Index when in a hash table. */ | |
480 | rtx reaching_reg; /* Register to use when re-writing. */ | |
481 | }; | |
482 | ||
fbef91d8 RS |
483 | /* Array of implicit set patterns indexed by basic block index. */ |
484 | static rtx *implicit_sets; | |
485 | ||
a13d4ebf AM |
486 | /* Head of the list of load/store memory refs. */ |
487 | static struct ls_expr * pre_ldst_mems = NULL; | |
488 | ||
7506f491 DE |
489 | /* Bitmap containing one bit for each register in the program. |
490 | Used when performing GCSE to track which registers have been set since | |
491 | the start of the basic block. */ | |
73991d6a | 492 | static regset reg_set_bitmap; |
7506f491 DE |
493 | |
494 | /* For each block, a bitmap of registers set in the block. | |
495 | This is used by expr_killed_p and compute_transp. | |
496 | It is computed during hash table computation and not by compute_sets | |
497 | as it includes registers added since the last pass (or between cprop and | |
498 | gcse) and it's currently not easy to realloc sbitmap vectors. */ | |
499 | static sbitmap *reg_set_in_block; | |
500 | ||
a13d4ebf AM |
501 | /* Array, indexed by basic block number for a list of insns which modify |
502 | memory within that block. */ | |
503 | static rtx * modify_mem_list; | |
73991d6a | 504 | bitmap modify_mem_list_set; |
a13d4ebf AM |
505 | |
506 | /* This array parallels modify_mem_list, but is kept canonicalized. */ | |
507 | static rtx * canon_modify_mem_list; | |
73991d6a | 508 | bitmap canon_modify_mem_list_set; |
7506f491 DE |
509 | /* Various variables for statistics gathering. */ |
510 | ||
511 | /* Memory used in a pass. | |
512 | This isn't intended to be absolutely precise. Its intent is only | |
513 | to keep an eye on memory usage. */ | |
514 | static int bytes_used; | |
c4c81601 | 515 | |
7506f491 DE |
516 | /* GCSE substitutions made. */ |
517 | static int gcse_subst_count; | |
518 | /* Number of copy instructions created. */ | |
519 | static int gcse_create_count; | |
520 | /* Number of constants propagated. */ | |
521 | static int const_prop_count; | |
522 | /* Number of copys propagated. */ | |
523 | static int copy_prop_count; | |
7506f491 DE |
524 | \f |
525 | /* These variables are used by classic GCSE. | |
526 | Normally they'd be defined a bit later, but `rd_gen' needs to | |
527 | be declared sooner. */ | |
528 | ||
7506f491 DE |
529 | /* Each block has a bitmap of each type. |
530 | The length of each blocks bitmap is: | |
531 | ||
532 | max_cuid - for reaching definitions | |
533 | n_exprs - for available expressions | |
534 | ||
535 | Thus we view the bitmaps as 2 dimensional arrays. i.e. | |
536 | rd_kill[block_num][cuid_num] | |
c4c81601 | 537 | ae_kill[block_num][expr_num] */ |
7506f491 DE |
538 | |
539 | /* For reaching defs */ | |
540 | static sbitmap *rd_kill, *rd_gen, *reaching_defs, *rd_out; | |
541 | ||
542 | /* for available exprs */ | |
543 | static sbitmap *ae_kill, *ae_gen, *ae_in, *ae_out; | |
b5ce41ff | 544 | |
0511851c MM |
545 | /* Objects of this type are passed around by the null-pointer check |
546 | removal routines. */ | |
c4c81601 RK |
547 | struct null_pointer_info |
548 | { | |
0511851c | 549 | /* The basic block being processed. */ |
e0082a72 | 550 | basic_block current_block; |
0511851c | 551 | /* The first register to be handled in this pass. */ |
770ae6cc | 552 | unsigned int min_reg; |
0511851c | 553 | /* One greater than the last register to be handled in this pass. */ |
770ae6cc | 554 | unsigned int max_reg; |
0511851c MM |
555 | sbitmap *nonnull_local; |
556 | sbitmap *nonnull_killed; | |
557 | }; | |
7506f491 | 558 | \f |
c4c81601 RK |
559 | static void compute_can_copy PARAMS ((void)); |
560 | static char *gmalloc PARAMS ((unsigned int)); | |
561 | static char *grealloc PARAMS ((char *, unsigned int)); | |
562 | static char *gcse_alloc PARAMS ((unsigned long)); | |
563 | static void alloc_gcse_mem PARAMS ((rtx)); | |
564 | static void free_gcse_mem PARAMS ((void)); | |
565 | static void alloc_reg_set_mem PARAMS ((int)); | |
566 | static void free_reg_set_mem PARAMS ((void)); | |
567 | static int get_bitmap_width PARAMS ((int, int, int)); | |
568 | static void record_one_set PARAMS ((int, rtx)); | |
569 | static void record_set_info PARAMS ((rtx, rtx, void *)); | |
570 | static void compute_sets PARAMS ((rtx)); | |
02280659 ZD |
571 | static void hash_scan_insn PARAMS ((rtx, struct hash_table *, int)); |
572 | static void hash_scan_set PARAMS ((rtx, rtx, struct hash_table *)); | |
573 | static void hash_scan_clobber PARAMS ((rtx, rtx, struct hash_table *)); | |
574 | static void hash_scan_call PARAMS ((rtx, rtx, struct hash_table *)); | |
c4c81601 | 575 | static int want_to_gcse_p PARAMS ((rtx)); |
6b2d1c9e | 576 | static bool gcse_constant_p PARAMS ((rtx)); |
c4c81601 RK |
577 | static int oprs_unchanged_p PARAMS ((rtx, rtx, int)); |
578 | static int oprs_anticipatable_p PARAMS ((rtx, rtx)); | |
579 | static int oprs_available_p PARAMS ((rtx, rtx)); | |
580 | static void insert_expr_in_table PARAMS ((rtx, enum machine_mode, rtx, | |
02280659 ZD |
581 | int, int, struct hash_table *)); |
582 | static void insert_set_in_table PARAMS ((rtx, rtx, struct hash_table *)); | |
c4c81601 RK |
583 | static unsigned int hash_expr PARAMS ((rtx, enum machine_mode, int *, int)); |
584 | static unsigned int hash_expr_1 PARAMS ((rtx, enum machine_mode, int *)); | |
c0712acb | 585 | static unsigned int hash_string_1 PARAMS ((const char *)); |
c4c81601 RK |
586 | static unsigned int hash_set PARAMS ((int, int)); |
587 | static int expr_equiv_p PARAMS ((rtx, rtx)); | |
588 | static void record_last_reg_set_info PARAMS ((rtx, int)); | |
589 | static void record_last_mem_set_info PARAMS ((rtx)); | |
590 | static void record_last_set_info PARAMS ((rtx, rtx, void *)); | |
02280659 ZD |
591 | static void compute_hash_table PARAMS ((struct hash_table *)); |
592 | static void alloc_hash_table PARAMS ((int, struct hash_table *, int)); | |
593 | static void free_hash_table PARAMS ((struct hash_table *)); | |
594 | static void compute_hash_table_work PARAMS ((struct hash_table *)); | |
595 | static void dump_hash_table PARAMS ((FILE *, const char *, | |
596 | struct hash_table *)); | |
597 | static struct expr *lookup_expr PARAMS ((rtx, struct hash_table *)); | |
ceda50e9 | 598 | static struct expr *lookup_set PARAMS ((unsigned int, struct hash_table *)); |
770ae6cc | 599 | static struct expr *next_set PARAMS ((unsigned int, struct expr *)); |
c4c81601 RK |
600 | static void reset_opr_set_tables PARAMS ((void)); |
601 | static int oprs_not_set_p PARAMS ((rtx, rtx)); | |
602 | static void mark_call PARAMS ((rtx)); | |
603 | static void mark_set PARAMS ((rtx, rtx)); | |
604 | static void mark_clobber PARAMS ((rtx, rtx)); | |
605 | static void mark_oprs_set PARAMS ((rtx)); | |
606 | static void alloc_cprop_mem PARAMS ((int, int)); | |
607 | static void free_cprop_mem PARAMS ((void)); | |
608 | static void compute_transp PARAMS ((rtx, int, sbitmap *, int)); | |
609 | static void compute_transpout PARAMS ((void)); | |
610 | static void compute_local_properties PARAMS ((sbitmap *, sbitmap *, sbitmap *, | |
02280659 | 611 | struct hash_table *)); |
711d877c | 612 | static void compute_cprop_data PARAMS ((void)); |
9e71c818 | 613 | static void find_used_regs PARAMS ((rtx *, void *)); |
c4c81601 RK |
614 | static int try_replace_reg PARAMS ((rtx, rtx, rtx)); |
615 | static struct expr *find_avail_set PARAMS ((int, rtx)); | |
0e3f0221 | 616 | static int cprop_jump PARAMS ((basic_block, rtx, rtx, rtx, rtx)); |
a13d4ebf | 617 | static void mems_conflict_for_gcse_p PARAMS ((rtx, rtx, void *)); |
e2d2ed72 | 618 | static int load_killed_in_block_p PARAMS ((basic_block, int, rtx, int)); |
a13d4ebf | 619 | static void canon_list_insert PARAMS ((rtx, rtx, void *)); |
ae860ff7 | 620 | static int cprop_insn PARAMS ((rtx, int)); |
c4c81601 | 621 | static int cprop PARAMS ((int)); |
fbef91d8 RS |
622 | static rtx fis_get_condition PARAMS ((rtx)); |
623 | static void find_implicit_sets PARAMS ((void)); | |
a0134312 | 624 | static int one_cprop_pass PARAMS ((int, int, int)); |
ae860ff7 | 625 | static bool constprop_register PARAMS ((rtx, rtx, rtx, int)); |
0e3f0221 RS |
626 | static struct expr *find_bypass_set PARAMS ((int, int)); |
627 | static int bypass_block PARAMS ((basic_block, rtx, rtx)); | |
628 | static int bypass_conditional_jumps PARAMS ((void)); | |
c4c81601 RK |
629 | static void alloc_pre_mem PARAMS ((int, int)); |
630 | static void free_pre_mem PARAMS ((void)); | |
631 | static void compute_pre_data PARAMS ((void)); | |
589005ff | 632 | static int pre_expr_reaches_here_p PARAMS ((basic_block, struct expr *, |
e2d2ed72 AM |
633 | basic_block)); |
634 | static void insert_insn_end_bb PARAMS ((struct expr *, basic_block, int)); | |
c4c81601 RK |
635 | static void pre_insert_copy_insn PARAMS ((struct expr *, rtx)); |
636 | static void pre_insert_copies PARAMS ((void)); | |
637 | static int pre_delete PARAMS ((void)); | |
638 | static int pre_gcse PARAMS ((void)); | |
639 | static int one_pre_gcse_pass PARAMS ((int)); | |
640 | static void add_label_notes PARAMS ((rtx, rtx)); | |
641 | static void alloc_code_hoist_mem PARAMS ((int, int)); | |
642 | static void free_code_hoist_mem PARAMS ((void)); | |
711d877c | 643 | static void compute_code_hoist_vbeinout PARAMS ((void)); |
c4c81601 | 644 | static void compute_code_hoist_data PARAMS ((void)); |
589005ff | 645 | static int hoist_expr_reaches_here_p PARAMS ((basic_block, int, basic_block, |
e2d2ed72 | 646 | char *)); |
c4c81601 RK |
647 | static void hoist_code PARAMS ((void)); |
648 | static int one_code_hoisting_pass PARAMS ((void)); | |
649 | static void alloc_rd_mem PARAMS ((int, int)); | |
650 | static void free_rd_mem PARAMS ((void)); | |
e2d2ed72 | 651 | static void handle_rd_kill_set PARAMS ((rtx, int, basic_block)); |
c4c81601 | 652 | static void compute_kill_rd PARAMS ((void)); |
711d877c | 653 | static void compute_rd PARAMS ((void)); |
c4c81601 RK |
654 | static void alloc_avail_expr_mem PARAMS ((int, int)); |
655 | static void free_avail_expr_mem PARAMS ((void)); | |
02280659 | 656 | static void compute_ae_gen PARAMS ((struct hash_table *)); |
e2d2ed72 | 657 | static int expr_killed_p PARAMS ((rtx, basic_block)); |
02280659 | 658 | static void compute_ae_kill PARAMS ((sbitmap *, sbitmap *, struct hash_table *)); |
711d877c | 659 | static int expr_reaches_here_p PARAMS ((struct occr *, struct expr *, |
e2d2ed72 | 660 | basic_block, int)); |
c4c81601 RK |
661 | static rtx computing_insn PARAMS ((struct expr *, rtx)); |
662 | static int def_reaches_here_p PARAMS ((rtx, rtx)); | |
663 | static int can_disregard_other_sets PARAMS ((struct reg_set **, rtx, int)); | |
664 | static int handle_avail_expr PARAMS ((rtx, struct expr *)); | |
665 | static int classic_gcse PARAMS ((void)); | |
666 | static int one_classic_gcse_pass PARAMS ((int)); | |
667 | static void invalidate_nonnull_info PARAMS ((rtx, rtx, void *)); | |
99a15921 | 668 | static int delete_null_pointer_checks_1 PARAMS ((unsigned int *, |
8e184d9c | 669 | sbitmap *, sbitmap *, |
711d877c KG |
670 | struct null_pointer_info *)); |
671 | static rtx process_insert_insn PARAMS ((struct expr *)); | |
672 | static int pre_edge_insert PARAMS ((struct edge_list *, struct expr **)); | |
c4c81601 | 673 | static int expr_reaches_here_p_work PARAMS ((struct occr *, struct expr *, |
e2d2ed72 AM |
674 | basic_block, int, char *)); |
675 | static int pre_expr_reaches_here_p_work PARAMS ((basic_block, struct expr *, | |
676 | basic_block, char *)); | |
a13d4ebf AM |
677 | static struct ls_expr * ldst_entry PARAMS ((rtx)); |
678 | static void free_ldst_entry PARAMS ((struct ls_expr *)); | |
679 | static void free_ldst_mems PARAMS ((void)); | |
680 | static void print_ldst_list PARAMS ((FILE *)); | |
681 | static struct ls_expr * find_rtx_in_ldst PARAMS ((rtx)); | |
682 | static int enumerate_ldsts PARAMS ((void)); | |
683 | static inline struct ls_expr * first_ls_expr PARAMS ((void)); | |
684 | static inline struct ls_expr * next_ls_expr PARAMS ((struct ls_expr *)); | |
685 | static int simple_mem PARAMS ((rtx)); | |
686 | static void invalidate_any_buried_refs PARAMS ((rtx)); | |
589005ff | 687 | static void compute_ld_motion_mems PARAMS ((void)); |
a13d4ebf AM |
688 | static void trim_ld_motion_mems PARAMS ((void)); |
689 | static void update_ld_motion_stores PARAMS ((struct expr *)); | |
aaa4ca30 | 690 | static void reg_set_info PARAMS ((rtx, rtx, void *)); |
47a3dae1 ZD |
691 | static bool store_ops_ok PARAMS ((rtx, int *)); |
692 | static rtx extract_mentioned_regs PARAMS ((rtx)); | |
693 | static rtx extract_mentioned_regs_helper PARAMS ((rtx, rtx)); | |
694 | static void find_moveable_store PARAMS ((rtx, int *, int *)); | |
a13d4ebf | 695 | static int compute_store_table PARAMS ((void)); |
47a3dae1 ZD |
696 | static bool load_kills_store PARAMS ((rtx, rtx)); |
697 | static bool find_loads PARAMS ((rtx, rtx)); | |
698 | static bool store_killed_in_insn PARAMS ((rtx, rtx, rtx)); | |
699 | static bool store_killed_after PARAMS ((rtx, rtx, rtx, basic_block, | |
700 | int *, rtx *)); | |
701 | static bool store_killed_before PARAMS ((rtx, rtx, rtx, basic_block, | |
702 | int *)); | |
a13d4ebf | 703 | static void build_store_vectors PARAMS ((void)); |
e2d2ed72 | 704 | static void insert_insn_start_bb PARAMS ((rtx, basic_block)); |
a13d4ebf | 705 | static int insert_store PARAMS ((struct ls_expr *, edge)); |
e2d2ed72 | 706 | static void replace_store_insn PARAMS ((rtx, rtx, basic_block)); |
589005ff | 707 | static void delete_store PARAMS ((struct ls_expr *, |
e2d2ed72 | 708 | basic_block)); |
a13d4ebf AM |
709 | static void free_store_memory PARAMS ((void)); |
710 | static void store_motion PARAMS ((void)); | |
0fe854a7 | 711 | static void free_insn_expr_list_list PARAMS ((rtx *)); |
73991d6a JH |
712 | static void clear_modify_mem_tables PARAMS ((void)); |
713 | static void free_modify_mem_tables PARAMS ((void)); | |
10d1bb36 | 714 | static rtx gcse_emit_move_after PARAMS ((rtx, rtx, rtx)); |
710ee3ed | 715 | static void local_cprop_find_used_regs PARAMS ((rtx *, void *)); |
8ba46434 R |
716 | static bool do_local_cprop PARAMS ((rtx, rtx, int, rtx*)); |
717 | static bool adjust_libcall_notes PARAMS ((rtx, rtx, rtx, rtx*)); | |
ae860ff7 | 718 | static void local_cprop_pass PARAMS ((int)); |
7506f491 DE |
719 | \f |
720 | /* Entry point for global common subexpression elimination. | |
721 | F is the first instruction in the function. */ | |
722 | ||
e78d9500 | 723 | int |
7506f491 DE |
724 | gcse_main (f, file) |
725 | rtx f; | |
726 | FILE *file; | |
727 | { | |
728 | int changed, pass; | |
729 | /* Bytes used at start of pass. */ | |
730 | int initial_bytes_used; | |
731 | /* Maximum number of bytes used by a pass. */ | |
732 | int max_pass_bytes; | |
733 | /* Point to release obstack data from for each pass. */ | |
734 | char *gcse_obstack_bottom; | |
735 | ||
b5ce41ff JL |
736 | /* We do not construct an accurate cfg in functions which call |
737 | setjmp, so just punt to be safe. */ | |
7506f491 | 738 | if (current_function_calls_setjmp) |
e78d9500 | 739 | return 0; |
589005ff | 740 | |
b5ce41ff JL |
741 | /* Assume that we do not need to run jump optimizations after gcse. */ |
742 | run_jump_opt_after_gcse = 0; | |
743 | ||
7506f491 DE |
744 | /* For calling dump_foo fns from gdb. */ |
745 | debug_stderr = stderr; | |
b5ce41ff | 746 | gcse_file = file; |
7506f491 | 747 | |
b5ce41ff JL |
748 | /* Identify the basic block information for this function, including |
749 | successors and predecessors. */ | |
7506f491 | 750 | max_gcse_regno = max_reg_num (); |
7506f491 | 751 | |
a42cd965 AM |
752 | if (file) |
753 | dump_flow_info (file); | |
754 | ||
7506f491 | 755 | /* Return if there's nothing to do. */ |
0b17ab2f | 756 | if (n_basic_blocks <= 1) |
a18820c6 | 757 | return 0; |
7506f491 | 758 | |
55f7891b JL |
759 | /* Trying to perform global optimizations on flow graphs which have |
760 | a high connectivity will take a long time and is unlikely to be | |
761 | particularly useful. | |
762 | ||
43e72072 | 763 | In normal circumstances a cfg should have about twice as many edges |
55f7891b JL |
764 | as blocks. But we do not want to punish small functions which have |
765 | a couple switch statements. So we require a relatively large number | |
766 | of basic blocks and the ratio of edges to blocks to be high. */ | |
0b17ab2f | 767 | if (n_basic_blocks > 1000 && n_edges / n_basic_blocks >= 20) |
18424ae1 BL |
768 | { |
769 | if (warn_disabled_optimization) | |
8e42ace1 | 770 | warning ("GCSE disabled: %d > 1000 basic blocks and %d >= 20 edges/basic block", |
0b17ab2f | 771 | n_basic_blocks, n_edges / n_basic_blocks); |
18424ae1 BL |
772 | return 0; |
773 | } | |
55f7891b | 774 | |
f1fa37ff MM |
775 | /* If allocating memory for the cprop bitmap would take up too much |
776 | storage it's better just to disable the optimization. */ | |
589005ff | 777 | if ((n_basic_blocks |
f1fa37ff MM |
778 | * SBITMAP_SET_SIZE (max_gcse_regno) |
779 | * sizeof (SBITMAP_ELT_TYPE)) > MAX_GCSE_MEMORY) | |
780 | { | |
781 | if (warn_disabled_optimization) | |
782 | warning ("GCSE disabled: %d basic blocks and %d registers", | |
0b17ab2f | 783 | n_basic_blocks, max_gcse_regno); |
f1fa37ff MM |
784 | |
785 | return 0; | |
786 | } | |
787 | ||
7506f491 DE |
788 | /* See what modes support reg/reg copy operations. */ |
789 | if (! can_copy_init_p) | |
790 | { | |
791 | compute_can_copy (); | |
792 | can_copy_init_p = 1; | |
793 | } | |
794 | ||
795 | gcc_obstack_init (&gcse_obstack); | |
a42cd965 | 796 | bytes_used = 0; |
7506f491 | 797 | |
a13d4ebf AM |
798 | /* We need alias. */ |
799 | init_alias_analysis (); | |
c4c81601 RK |
800 | /* Record where pseudo-registers are set. This data is kept accurate |
801 | during each pass. ??? We could also record hard-reg information here | |
802 | [since it's unchanging], however it is currently done during hash table | |
803 | computation. | |
b5ce41ff | 804 | |
c4c81601 RK |
805 | It may be tempting to compute MEM set information here too, but MEM sets |
806 | will be subject to code motion one day and thus we need to compute | |
b5ce41ff | 807 | information about memory sets when we build the hash tables. */ |
7506f491 DE |
808 | |
809 | alloc_reg_set_mem (max_gcse_regno); | |
810 | compute_sets (f); | |
811 | ||
812 | pass = 0; | |
813 | initial_bytes_used = bytes_used; | |
814 | max_pass_bytes = 0; | |
815 | gcse_obstack_bottom = gcse_alloc (1); | |
816 | changed = 1; | |
740f35a0 | 817 | while (changed && pass < MAX_GCSE_PASSES) |
7506f491 DE |
818 | { |
819 | changed = 0; | |
820 | if (file) | |
821 | fprintf (file, "GCSE pass %d\n\n", pass + 1); | |
822 | ||
823 | /* Initialize bytes_used to the space for the pred/succ lists, | |
824 | and the reg_set_table data. */ | |
825 | bytes_used = initial_bytes_used; | |
826 | ||
827 | /* Each pass may create new registers, so recalculate each time. */ | |
828 | max_gcse_regno = max_reg_num (); | |
829 | ||
830 | alloc_gcse_mem (f); | |
831 | ||
b5ce41ff JL |
832 | /* Don't allow constant propagation to modify jumps |
833 | during this pass. */ | |
a0134312 | 834 | changed = one_cprop_pass (pass + 1, 0, 0); |
7506f491 DE |
835 | |
836 | if (optimize_size) | |
b5ce41ff | 837 | changed |= one_classic_gcse_pass (pass + 1); |
7506f491 | 838 | else |
589005ff | 839 | { |
a42cd965 | 840 | changed |= one_pre_gcse_pass (pass + 1); |
a13d4ebf AM |
841 | /* We may have just created new basic blocks. Release and |
842 | recompute various things which are sized on the number of | |
843 | basic blocks. */ | |
844 | if (changed) | |
845 | { | |
73991d6a | 846 | free_modify_mem_tables (); |
a13d4ebf | 847 | modify_mem_list |
d55bc081 | 848 | = (rtx *) gmalloc (last_basic_block * sizeof (rtx)); |
a13d4ebf | 849 | canon_modify_mem_list |
d55bc081 ZD |
850 | = (rtx *) gmalloc (last_basic_block * sizeof (rtx)); |
851 | memset ((char *) modify_mem_list, 0, last_basic_block * sizeof (rtx)); | |
852 | memset ((char *) canon_modify_mem_list, 0, last_basic_block * sizeof (rtx)); | |
a13d4ebf | 853 | } |
a42cd965 AM |
854 | free_reg_set_mem (); |
855 | alloc_reg_set_mem (max_reg_num ()); | |
856 | compute_sets (f); | |
857 | run_jump_opt_after_gcse = 1; | |
858 | } | |
7506f491 DE |
859 | |
860 | if (max_pass_bytes < bytes_used) | |
861 | max_pass_bytes = bytes_used; | |
862 | ||
bb457bd9 JL |
863 | /* Free up memory, then reallocate for code hoisting. We can |
864 | not re-use the existing allocated memory because the tables | |
865 | will not have info for the insns or registers created by | |
866 | partial redundancy elimination. */ | |
7506f491 DE |
867 | free_gcse_mem (); |
868 | ||
bb457bd9 JL |
869 | /* It does not make sense to run code hoisting unless we optimizing |
870 | for code size -- it rarely makes programs faster, and can make | |
871 | them bigger if we did partial redundancy elimination (when optimizing | |
872 | for space, we use a classic gcse algorithm instead of partial | |
873 | redundancy algorithms). */ | |
874 | if (optimize_size) | |
589005ff | 875 | { |
bb457bd9 JL |
876 | max_gcse_regno = max_reg_num (); |
877 | alloc_gcse_mem (f); | |
878 | changed |= one_code_hoisting_pass (); | |
879 | free_gcse_mem (); | |
880 | ||
881 | if (max_pass_bytes < bytes_used) | |
882 | max_pass_bytes = bytes_used; | |
589005ff | 883 | } |
bb457bd9 | 884 | |
7506f491 DE |
885 | if (file) |
886 | { | |
887 | fprintf (file, "\n"); | |
888 | fflush (file); | |
889 | } | |
c4c81601 | 890 | |
7506f491 DE |
891 | obstack_free (&gcse_obstack, gcse_obstack_bottom); |
892 | pass++; | |
893 | } | |
894 | ||
b5ce41ff JL |
895 | /* Do one last pass of copy propagation, including cprop into |
896 | conditional jumps. */ | |
897 | ||
898 | max_gcse_regno = max_reg_num (); | |
899 | alloc_gcse_mem (f); | |
900 | /* This time, go ahead and allow cprop to alter jumps. */ | |
a0134312 | 901 | one_cprop_pass (pass + 1, 1, 0); |
b5ce41ff | 902 | free_gcse_mem (); |
7506f491 DE |
903 | |
904 | if (file) | |
905 | { | |
906 | fprintf (file, "GCSE of %s: %d basic blocks, ", | |
0b17ab2f | 907 | current_function_name, n_basic_blocks); |
7506f491 DE |
908 | fprintf (file, "%d pass%s, %d bytes\n\n", |
909 | pass, pass > 1 ? "es" : "", max_pass_bytes); | |
910 | } | |
911 | ||
6496a589 | 912 | obstack_free (&gcse_obstack, NULL); |
7506f491 | 913 | free_reg_set_mem (); |
a13d4ebf AM |
914 | /* We are finished with alias. */ |
915 | end_alias_analysis (); | |
916 | allocate_reg_info (max_reg_num (), FALSE, FALSE); | |
917 | ||
47a3dae1 | 918 | if (!optimize_size && flag_gcse_sm) |
a13d4ebf | 919 | store_motion (); |
47a3dae1 | 920 | |
a13d4ebf | 921 | /* Record where pseudo-registers are set. */ |
e78d9500 | 922 | return run_jump_opt_after_gcse; |
7506f491 DE |
923 | } |
924 | \f | |
925 | /* Misc. utilities. */ | |
926 | ||
927 | /* Compute which modes support reg/reg copy operations. */ | |
928 | ||
929 | static void | |
930 | compute_can_copy () | |
931 | { | |
932 | int i; | |
50b2596f | 933 | #ifndef AVOID_CCMODE_COPIES |
8e42ace1 | 934 | rtx reg, insn; |
50b2596f | 935 | #endif |
961192e1 | 936 | memset (can_copy_p, 0, NUM_MACHINE_MODES); |
7506f491 DE |
937 | |
938 | start_sequence (); | |
939 | for (i = 0; i < NUM_MACHINE_MODES; i++) | |
c4c81601 RK |
940 | if (GET_MODE_CLASS (i) == MODE_CC) |
941 | { | |
7506f491 | 942 | #ifdef AVOID_CCMODE_COPIES |
c4c81601 | 943 | can_copy_p[i] = 0; |
7506f491 | 944 | #else |
c4c81601 RK |
945 | reg = gen_rtx_REG ((enum machine_mode) i, LAST_VIRTUAL_REGISTER + 1); |
946 | insn = emit_insn (gen_rtx_SET (VOIDmode, reg, reg)); | |
9714cf43 | 947 | if (recog (PATTERN (insn), insn, NULL) >= 0) |
c4c81601 | 948 | can_copy_p[i] = 1; |
7506f491 | 949 | #endif |
c4c81601 | 950 | } |
141b5810 AO |
951 | else |
952 | can_copy_p[i] = 1; | |
c4c81601 | 953 | |
7506f491 | 954 | end_sequence (); |
7506f491 DE |
955 | } |
956 | \f | |
957 | /* Cover function to xmalloc to record bytes allocated. */ | |
958 | ||
959 | static char * | |
960 | gmalloc (size) | |
961 | unsigned int size; | |
962 | { | |
963 | bytes_used += size; | |
964 | return xmalloc (size); | |
965 | } | |
966 | ||
967 | /* Cover function to xrealloc. | |
968 | We don't record the additional size since we don't know it. | |
969 | It won't affect memory usage stats much anyway. */ | |
970 | ||
971 | static char * | |
972 | grealloc (ptr, size) | |
973 | char *ptr; | |
974 | unsigned int size; | |
975 | { | |
976 | return xrealloc (ptr, size); | |
977 | } | |
978 | ||
77bbd421 | 979 | /* Cover function to obstack_alloc. */ |
7506f491 DE |
980 | |
981 | static char * | |
982 | gcse_alloc (size) | |
983 | unsigned long size; | |
984 | { | |
77bbd421 | 985 | bytes_used += size; |
7506f491 DE |
986 | return (char *) obstack_alloc (&gcse_obstack, size); |
987 | } | |
988 | ||
989 | /* Allocate memory for the cuid mapping array, | |
990 | and reg/memory set tracking tables. | |
991 | ||
992 | This is called at the start of each pass. */ | |
993 | ||
994 | static void | |
995 | alloc_gcse_mem (f) | |
996 | rtx f; | |
997 | { | |
8e42ace1 | 998 | int i, n; |
7506f491 DE |
999 | rtx insn; |
1000 | ||
1001 | /* Find the largest UID and create a mapping from UIDs to CUIDs. | |
1002 | CUIDs are like UIDs except they increase monotonically, have no gaps, | |
1003 | and only apply to real insns. */ | |
1004 | ||
1005 | max_uid = get_max_uid (); | |
1006 | n = (max_uid + 1) * sizeof (int); | |
1007 | uid_cuid = (int *) gmalloc (n); | |
961192e1 | 1008 | memset ((char *) uid_cuid, 0, n); |
7506f491 DE |
1009 | for (insn = f, i = 0; insn; insn = NEXT_INSN (insn)) |
1010 | { | |
2c3c49de | 1011 | if (INSN_P (insn)) |
b86db3eb | 1012 | uid_cuid[INSN_UID (insn)] = i++; |
7506f491 | 1013 | else |
b86db3eb | 1014 | uid_cuid[INSN_UID (insn)] = i; |
7506f491 DE |
1015 | } |
1016 | ||
1017 | /* Create a table mapping cuids to insns. */ | |
1018 | ||
1019 | max_cuid = i; | |
1020 | n = (max_cuid + 1) * sizeof (rtx); | |
1021 | cuid_insn = (rtx *) gmalloc (n); | |
961192e1 | 1022 | memset ((char *) cuid_insn, 0, n); |
7506f491 | 1023 | for (insn = f, i = 0; insn; insn = NEXT_INSN (insn)) |
2c3c49de | 1024 | if (INSN_P (insn)) |
c4c81601 | 1025 | CUID_INSN (i++) = insn; |
7506f491 DE |
1026 | |
1027 | /* Allocate vars to track sets of regs. */ | |
73991d6a | 1028 | reg_set_bitmap = BITMAP_XMALLOC (); |
7506f491 DE |
1029 | |
1030 | /* Allocate vars to track sets of regs, memory per block. */ | |
d55bc081 | 1031 | reg_set_in_block = (sbitmap *) sbitmap_vector_alloc (last_basic_block, |
7506f491 | 1032 | max_gcse_regno); |
a13d4ebf AM |
1033 | /* Allocate array to keep a list of insns which modify memory in each |
1034 | basic block. */ | |
d55bc081 ZD |
1035 | modify_mem_list = (rtx *) gmalloc (last_basic_block * sizeof (rtx)); |
1036 | canon_modify_mem_list = (rtx *) gmalloc (last_basic_block * sizeof (rtx)); | |
1037 | memset ((char *) modify_mem_list, 0, last_basic_block * sizeof (rtx)); | |
1038 | memset ((char *) canon_modify_mem_list, 0, last_basic_block * sizeof (rtx)); | |
73991d6a JH |
1039 | modify_mem_list_set = BITMAP_XMALLOC (); |
1040 | canon_modify_mem_list_set = BITMAP_XMALLOC (); | |
7506f491 DE |
1041 | } |
1042 | ||
1043 | /* Free memory allocated by alloc_gcse_mem. */ | |
1044 | ||
1045 | static void | |
1046 | free_gcse_mem () | |
1047 | { | |
1048 | free (uid_cuid); | |
1049 | free (cuid_insn); | |
1050 | ||
73991d6a | 1051 | BITMAP_XFREE (reg_set_bitmap); |
7506f491 | 1052 | |
5a660bff | 1053 | sbitmap_vector_free (reg_set_in_block); |
73991d6a JH |
1054 | free_modify_mem_tables (); |
1055 | BITMAP_XFREE (modify_mem_list_set); | |
1056 | BITMAP_XFREE (canon_modify_mem_list_set); | |
7506f491 DE |
1057 | } |
1058 | ||
0511851c MM |
1059 | /* Many of the global optimization algorithms work by solving dataflow |
1060 | equations for various expressions. Initially, some local value is | |
c4c81601 RK |
1061 | computed for each expression in each block. Then, the values across the |
1062 | various blocks are combined (by following flow graph edges) to arrive at | |
1063 | global values. Conceptually, each set of equations is independent. We | |
1064 | may therefore solve all the equations in parallel, solve them one at a | |
1065 | time, or pick any intermediate approach. | |
1066 | ||
1067 | When you're going to need N two-dimensional bitmaps, each X (say, the | |
1068 | number of blocks) by Y (say, the number of expressions), call this | |
1069 | function. It's not important what X and Y represent; only that Y | |
1070 | correspond to the things that can be done in parallel. This function will | |
1071 | return an appropriate chunking factor C; you should solve C sets of | |
1072 | equations in parallel. By going through this function, we can easily | |
1073 | trade space against time; by solving fewer equations in parallel we use | |
1074 | less space. */ | |
0511851c MM |
1075 | |
1076 | static int | |
1077 | get_bitmap_width (n, x, y) | |
1078 | int n; | |
1079 | int x; | |
1080 | int y; | |
1081 | { | |
1082 | /* It's not really worth figuring out *exactly* how much memory will | |
1083 | be used by a particular choice. The important thing is to get | |
1084 | something approximately right. */ | |
1085 | size_t max_bitmap_memory = 10 * 1024 * 1024; | |
1086 | ||
1087 | /* The number of bytes we'd use for a single column of minimum | |
1088 | width. */ | |
1089 | size_t column_size = n * x * sizeof (SBITMAP_ELT_TYPE); | |
1090 | ||
1091 | /* Often, it's reasonable just to solve all the equations in | |
1092 | parallel. */ | |
1093 | if (column_size * SBITMAP_SET_SIZE (y) <= max_bitmap_memory) | |
1094 | return y; | |
1095 | ||
1096 | /* Otherwise, pick the largest width we can, without going over the | |
1097 | limit. */ | |
1098 | return SBITMAP_ELT_BITS * ((max_bitmap_memory + column_size - 1) | |
1099 | / column_size); | |
1100 | } | |
b5ce41ff JL |
1101 | \f |
1102 | /* Compute the local properties of each recorded expression. | |
c4c81601 RK |
1103 | |
1104 | Local properties are those that are defined by the block, irrespective of | |
1105 | other blocks. | |
b5ce41ff JL |
1106 | |
1107 | An expression is transparent in a block if its operands are not modified | |
1108 | in the block. | |
1109 | ||
1110 | An expression is computed (locally available) in a block if it is computed | |
1111 | at least once and expression would contain the same value if the | |
1112 | computation was moved to the end of the block. | |
1113 | ||
1114 | An expression is locally anticipatable in a block if it is computed at | |
1115 | least once and expression would contain the same value if the computation | |
1116 | was moved to the beginning of the block. | |
1117 | ||
c4c81601 RK |
1118 | We call this routine for cprop, pre and code hoisting. They all compute |
1119 | basically the same information and thus can easily share this code. | |
7506f491 | 1120 | |
c4c81601 RK |
1121 | TRANSP, COMP, and ANTLOC are destination sbitmaps for recording local |
1122 | properties. If NULL, then it is not necessary to compute or record that | |
1123 | particular property. | |
b5ce41ff | 1124 | |
02280659 ZD |
1125 | TABLE controls which hash table to look at. If it is set hash table, |
1126 | additionally, TRANSP is computed as ~TRANSP, since this is really cprop's | |
c4c81601 | 1127 | ABSALTERED. */ |
589005ff | 1128 | |
b5ce41ff | 1129 | static void |
02280659 | 1130 | compute_local_properties (transp, comp, antloc, table) |
b5ce41ff JL |
1131 | sbitmap *transp; |
1132 | sbitmap *comp; | |
1133 | sbitmap *antloc; | |
02280659 | 1134 | struct hash_table *table; |
b5ce41ff | 1135 | { |
02280659 | 1136 | unsigned int i; |
589005ff | 1137 | |
b5ce41ff JL |
1138 | /* Initialize any bitmaps that were passed in. */ |
1139 | if (transp) | |
695ab36a | 1140 | { |
02280659 | 1141 | if (table->set_p) |
d55bc081 | 1142 | sbitmap_vector_zero (transp, last_basic_block); |
695ab36a | 1143 | else |
d55bc081 | 1144 | sbitmap_vector_ones (transp, last_basic_block); |
695ab36a | 1145 | } |
c4c81601 | 1146 | |
b5ce41ff | 1147 | if (comp) |
d55bc081 | 1148 | sbitmap_vector_zero (comp, last_basic_block); |
b5ce41ff | 1149 | if (antloc) |
d55bc081 | 1150 | sbitmap_vector_zero (antloc, last_basic_block); |
b5ce41ff | 1151 | |
02280659 | 1152 | for (i = 0; i < table->size; i++) |
7506f491 | 1153 | { |
b5ce41ff JL |
1154 | struct expr *expr; |
1155 | ||
02280659 | 1156 | for (expr = table->table[i]; expr != NULL; expr = expr->next_same_hash) |
b5ce41ff | 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 | 1164 | if (transp) |
02280659 | 1165 | compute_transp (expr->expr, indx, transp, table->set_p); |
b5ce41ff JL |
1166 | |
1167 | /* The occurrences recorded in antic_occr are exactly those that | |
cc2902df | 1168 | we want to set to nonzero 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 | |
cc2902df | 1180 | we want to set to nonzero in COMP. */ |
b5ce41ff | 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 | 1274 | This is called once, at the start of the gcse pass. See the comments for |
fbe5a4a6 | 1275 | `reg_set_table' for further documentation. */ |
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 | struct reg_avail_info |
1291 | { | |
e0082a72 | 1292 | basic_block last_bb; |
80c29cc4 RZ |
1293 | int first_set; |
1294 | int last_set; | |
1295 | }; | |
1296 | ||
1297 | static struct reg_avail_info *reg_avail_info; | |
e0082a72 | 1298 | static basic_block current_bb; |
7506f491 | 1299 | |
7506f491 | 1300 | |
fb0c0a12 RK |
1301 | /* See whether X, the source of a set, is something we want to consider for |
1302 | GCSE. */ | |
7506f491 | 1303 | |
e2500fed | 1304 | static GTY(()) rtx test_insn; |
7506f491 DE |
1305 | static int |
1306 | want_to_gcse_p (x) | |
1307 | rtx x; | |
1308 | { | |
fb0c0a12 RK |
1309 | int num_clobbers = 0; |
1310 | int icode; | |
1311 | ||
c4c81601 | 1312 | switch (GET_CODE (x)) |
7506f491 DE |
1313 | { |
1314 | case REG: | |
1315 | case SUBREG: | |
1316 | case CONST_INT: | |
1317 | case CONST_DOUBLE: | |
69ef87e2 | 1318 | case CONST_VECTOR: |
7506f491 | 1319 | case CALL: |
34ee7f82 | 1320 | case CONSTANT_P_RTX: |
7506f491 DE |
1321 | return 0; |
1322 | ||
1323 | default: | |
1324 | break; | |
1325 | } | |
1326 | ||
fb0c0a12 RK |
1327 | /* If this is a valid operand, we are OK. If it's VOIDmode, we aren't. */ |
1328 | if (general_operand (x, GET_MODE (x))) | |
1329 | return 1; | |
1330 | else if (GET_MODE (x) == VOIDmode) | |
1331 | return 0; | |
1332 | ||
1333 | /* Otherwise, check if we can make a valid insn from it. First initialize | |
1334 | our test insn if we haven't already. */ | |
1335 | if (test_insn == 0) | |
1336 | { | |
1337 | test_insn | |
1338 | = make_insn_raw (gen_rtx_SET (VOIDmode, | |
1339 | gen_rtx_REG (word_mode, | |
1340 | FIRST_PSEUDO_REGISTER * 2), | |
1341 | const0_rtx)); | |
1342 | NEXT_INSN (test_insn) = PREV_INSN (test_insn) = 0; | |
fb0c0a12 RK |
1343 | } |
1344 | ||
1345 | /* Now make an insn like the one we would make when GCSE'ing and see if | |
1346 | valid. */ | |
1347 | PUT_MODE (SET_DEST (PATTERN (test_insn)), GET_MODE (x)); | |
1348 | SET_SRC (PATTERN (test_insn)) = x; | |
1349 | return ((icode = recog (PATTERN (test_insn), test_insn, &num_clobbers)) >= 0 | |
1350 | && (num_clobbers == 0 || ! added_clobbers_hard_reg_p (icode))); | |
7506f491 DE |
1351 | } |
1352 | ||
cc2902df | 1353 | /* Return nonzero if the operands of expression X are unchanged from the |
7506f491 DE |
1354 | start of INSN's basic block up to but not including INSN (if AVAIL_P == 0), |
1355 | or from INSN to the end of INSN's basic block (if AVAIL_P != 0). */ | |
1356 | ||
1357 | static int | |
1358 | oprs_unchanged_p (x, insn, avail_p) | |
1359 | rtx x, insn; | |
1360 | int avail_p; | |
1361 | { | |
c4c81601 | 1362 | int i, j; |
7506f491 | 1363 | enum rtx_code code; |
6f7d635c | 1364 | const char *fmt; |
7506f491 | 1365 | |
7506f491 DE |
1366 | if (x == 0) |
1367 | return 1; | |
1368 | ||
1369 | code = GET_CODE (x); | |
1370 | switch (code) | |
1371 | { | |
1372 | case REG: | |
80c29cc4 RZ |
1373 | { |
1374 | struct reg_avail_info *info = ®_avail_info[REGNO (x)]; | |
1375 | ||
1376 | if (info->last_bb != current_bb) | |
1377 | return 1; | |
589005ff | 1378 | if (avail_p) |
80c29cc4 RZ |
1379 | return info->last_set < INSN_CUID (insn); |
1380 | else | |
1381 | return info->first_set >= INSN_CUID (insn); | |
1382 | } | |
7506f491 DE |
1383 | |
1384 | case MEM: | |
e0082a72 | 1385 | if (load_killed_in_block_p (current_bb, INSN_CUID (insn), |
a13d4ebf AM |
1386 | x, avail_p)) |
1387 | return 0; | |
7506f491 | 1388 | else |
c4c81601 | 1389 | return oprs_unchanged_p (XEXP (x, 0), insn, avail_p); |
7506f491 DE |
1390 | |
1391 | case PRE_DEC: | |
1392 | case PRE_INC: | |
1393 | case POST_DEC: | |
1394 | case POST_INC: | |
4b983fdc RH |
1395 | case PRE_MODIFY: |
1396 | case POST_MODIFY: | |
7506f491 DE |
1397 | return 0; |
1398 | ||
1399 | case PC: | |
1400 | case CC0: /*FIXME*/ | |
1401 | case CONST: | |
1402 | case CONST_INT: | |
1403 | case CONST_DOUBLE: | |
69ef87e2 | 1404 | case CONST_VECTOR: |
7506f491 DE |
1405 | case SYMBOL_REF: |
1406 | case LABEL_REF: | |
1407 | case ADDR_VEC: | |
1408 | case ADDR_DIFF_VEC: | |
1409 | return 1; | |
1410 | ||
1411 | default: | |
1412 | break; | |
1413 | } | |
1414 | ||
c4c81601 | 1415 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
1416 | { |
1417 | if (fmt[i] == 'e') | |
1418 | { | |
c4c81601 RK |
1419 | /* If we are about to do the last recursive call needed at this |
1420 | level, change it into iteration. This function is called enough | |
1421 | to be worth it. */ | |
7506f491 | 1422 | if (i == 0) |
c4c81601 RK |
1423 | return oprs_unchanged_p (XEXP (x, i), insn, avail_p); |
1424 | ||
1425 | else if (! oprs_unchanged_p (XEXP (x, i), insn, avail_p)) | |
7506f491 DE |
1426 | return 0; |
1427 | } | |
1428 | else if (fmt[i] == 'E') | |
c4c81601 RK |
1429 | for (j = 0; j < XVECLEN (x, i); j++) |
1430 | if (! oprs_unchanged_p (XVECEXP (x, i, j), insn, avail_p)) | |
1431 | return 0; | |
7506f491 DE |
1432 | } |
1433 | ||
1434 | return 1; | |
1435 | } | |
1436 | ||
a13d4ebf AM |
1437 | /* Used for communication between mems_conflict_for_gcse_p and |
1438 | load_killed_in_block_p. Nonzero if mems_conflict_for_gcse_p finds a | |
1439 | conflict between two memory references. */ | |
1440 | static int gcse_mems_conflict_p; | |
1441 | ||
1442 | /* Used for communication between mems_conflict_for_gcse_p and | |
1443 | load_killed_in_block_p. A memory reference for a load instruction, | |
1444 | mems_conflict_for_gcse_p will see if a memory store conflicts with | |
1445 | this memory load. */ | |
1446 | static rtx gcse_mem_operand; | |
1447 | ||
1448 | /* DEST is the output of an instruction. If it is a memory reference, and | |
1449 | possibly conflicts with the load found in gcse_mem_operand, then set | |
1450 | gcse_mems_conflict_p to a nonzero value. */ | |
1451 | ||
1452 | static void | |
1453 | mems_conflict_for_gcse_p (dest, setter, data) | |
1454 | rtx dest, setter ATTRIBUTE_UNUSED; | |
1455 | void *data ATTRIBUTE_UNUSED; | |
1456 | { | |
1457 | while (GET_CODE (dest) == SUBREG | |
1458 | || GET_CODE (dest) == ZERO_EXTRACT | |
1459 | || GET_CODE (dest) == SIGN_EXTRACT | |
1460 | || GET_CODE (dest) == STRICT_LOW_PART) | |
1461 | dest = XEXP (dest, 0); | |
1462 | ||
1463 | /* If DEST is not a MEM, then it will not conflict with the load. Note | |
1464 | that function calls are assumed to clobber memory, but are handled | |
1465 | elsewhere. */ | |
1466 | if (GET_CODE (dest) != MEM) | |
1467 | return; | |
aaa4ca30 | 1468 | |
a13d4ebf | 1469 | /* If we are setting a MEM in our list of specially recognized MEMs, |
589005ff KH |
1470 | don't mark as killed this time. */ |
1471 | ||
47a3dae1 | 1472 | if (expr_equiv_p (dest, gcse_mem_operand) && pre_ldst_mems != NULL) |
a13d4ebf AM |
1473 | { |
1474 | if (!find_rtx_in_ldst (dest)) | |
1475 | gcse_mems_conflict_p = 1; | |
1476 | return; | |
1477 | } | |
aaa4ca30 | 1478 | |
a13d4ebf AM |
1479 | if (true_dependence (dest, GET_MODE (dest), gcse_mem_operand, |
1480 | rtx_addr_varies_p)) | |
1481 | gcse_mems_conflict_p = 1; | |
1482 | } | |
1483 | ||
1484 | /* Return nonzero if the expression in X (a memory reference) is killed | |
1485 | in block BB before or after the insn with the CUID in UID_LIMIT. | |
1486 | AVAIL_P is nonzero for kills after UID_LIMIT, and zero for kills | |
1487 | before UID_LIMIT. | |
1488 | ||
1489 | To check the entire block, set UID_LIMIT to max_uid + 1 and | |
1490 | AVAIL_P to 0. */ | |
1491 | ||
1492 | static int | |
1493 | load_killed_in_block_p (bb, uid_limit, x, avail_p) | |
e2d2ed72 | 1494 | basic_block bb; |
a13d4ebf AM |
1495 | int uid_limit; |
1496 | rtx x; | |
1497 | int avail_p; | |
1498 | { | |
0b17ab2f | 1499 | rtx list_entry = modify_mem_list[bb->index]; |
a13d4ebf AM |
1500 | while (list_entry) |
1501 | { | |
1502 | rtx setter; | |
1503 | /* Ignore entries in the list that do not apply. */ | |
1504 | if ((avail_p | |
1505 | && INSN_CUID (XEXP (list_entry, 0)) < uid_limit) | |
1506 | || (! avail_p | |
1507 | && INSN_CUID (XEXP (list_entry, 0)) > uid_limit)) | |
1508 | { | |
1509 | list_entry = XEXP (list_entry, 1); | |
1510 | continue; | |
1511 | } | |
1512 | ||
1513 | setter = XEXP (list_entry, 0); | |
1514 | ||
1515 | /* If SETTER is a call everything is clobbered. Note that calls | |
1516 | to pure functions are never put on the list, so we need not | |
1517 | worry about them. */ | |
1518 | if (GET_CODE (setter) == CALL_INSN) | |
1519 | return 1; | |
1520 | ||
1521 | /* SETTER must be an INSN of some kind that sets memory. Call | |
589005ff | 1522 | note_stores to examine each hunk of memory that is modified. |
a13d4ebf AM |
1523 | |
1524 | The note_stores interface is pretty limited, so we have to | |
1525 | communicate via global variables. Yuk. */ | |
1526 | gcse_mem_operand = x; | |
1527 | gcse_mems_conflict_p = 0; | |
1528 | note_stores (PATTERN (setter), mems_conflict_for_gcse_p, NULL); | |
1529 | if (gcse_mems_conflict_p) | |
1530 | return 1; | |
1531 | list_entry = XEXP (list_entry, 1); | |
1532 | } | |
1533 | return 0; | |
1534 | } | |
1535 | ||
cc2902df | 1536 | /* Return nonzero if the operands of expression X are unchanged from |
7506f491 DE |
1537 | the start of INSN's basic block up to but not including INSN. */ |
1538 | ||
1539 | static int | |
1540 | oprs_anticipatable_p (x, insn) | |
1541 | rtx x, insn; | |
1542 | { | |
1543 | return oprs_unchanged_p (x, insn, 0); | |
1544 | } | |
1545 | ||
cc2902df | 1546 | /* Return nonzero if the operands of expression X are unchanged from |
7506f491 DE |
1547 | INSN to the end of INSN's basic block. */ |
1548 | ||
1549 | static int | |
1550 | oprs_available_p (x, insn) | |
1551 | rtx x, insn; | |
1552 | { | |
1553 | return oprs_unchanged_p (x, insn, 1); | |
1554 | } | |
1555 | ||
1556 | /* Hash expression X. | |
c4c81601 RK |
1557 | |
1558 | MODE is only used if X is a CONST_INT. DO_NOT_RECORD_P is a boolean | |
1559 | indicating if a volatile operand is found or if the expression contains | |
1560 | something we don't want to insert in the table. | |
7506f491 DE |
1561 | |
1562 | ??? One might want to merge this with canon_hash. Later. */ | |
1563 | ||
1564 | static unsigned int | |
1565 | hash_expr (x, mode, do_not_record_p, hash_table_size) | |
1566 | rtx x; | |
1567 | enum machine_mode mode; | |
1568 | int *do_not_record_p; | |
1569 | int hash_table_size; | |
1570 | { | |
1571 | unsigned int hash; | |
1572 | ||
1573 | *do_not_record_p = 0; | |
1574 | ||
1575 | hash = hash_expr_1 (x, mode, do_not_record_p); | |
1576 | return hash % hash_table_size; | |
1577 | } | |
172890a2 | 1578 | |
6462bb43 | 1579 | /* Hash a string. Just add its bytes up. */ |
172890a2 | 1580 | |
6462bb43 AO |
1581 | static inline unsigned |
1582 | hash_string_1 (ps) | |
1583 | const char *ps; | |
1584 | { | |
1585 | unsigned hash = 0; | |
8e42ace1 | 1586 | const unsigned char *p = (const unsigned char *) ps; |
589005ff | 1587 | |
6462bb43 AO |
1588 | if (p) |
1589 | while (*p) | |
1590 | hash += *p++; | |
1591 | ||
1592 | return hash; | |
1593 | } | |
7506f491 DE |
1594 | |
1595 | /* Subroutine of hash_expr to do the actual work. */ | |
1596 | ||
1597 | static unsigned int | |
1598 | hash_expr_1 (x, mode, do_not_record_p) | |
1599 | rtx x; | |
1600 | enum machine_mode mode; | |
1601 | int *do_not_record_p; | |
1602 | { | |
1603 | int i, j; | |
1604 | unsigned hash = 0; | |
1605 | enum rtx_code code; | |
6f7d635c | 1606 | const char *fmt; |
7506f491 | 1607 | |
c4c81601 | 1608 | /* Used to turn recursion into iteration. We can't rely on GCC's |
fbe5a4a6 | 1609 | tail-recursion elimination since we need to keep accumulating values |
c4c81601 | 1610 | in HASH. */ |
7506f491 DE |
1611 | |
1612 | if (x == 0) | |
1613 | return hash; | |
1614 | ||
c4c81601 | 1615 | repeat: |
7506f491 DE |
1616 | code = GET_CODE (x); |
1617 | switch (code) | |
1618 | { | |
1619 | case REG: | |
c4c81601 RK |
1620 | hash += ((unsigned int) REG << 7) + REGNO (x); |
1621 | return hash; | |
7506f491 DE |
1622 | |
1623 | case CONST_INT: | |
c4c81601 RK |
1624 | hash += (((unsigned int) CONST_INT << 7) + (unsigned int) mode |
1625 | + (unsigned int) INTVAL (x)); | |
1626 | return hash; | |
7506f491 DE |
1627 | |
1628 | case CONST_DOUBLE: | |
1629 | /* This is like the general case, except that it only counts | |
1630 | the integers representing the constant. */ | |
c4c81601 | 1631 | hash += (unsigned int) code + (unsigned int) GET_MODE (x); |
7506f491 DE |
1632 | if (GET_MODE (x) != VOIDmode) |
1633 | for (i = 2; i < GET_RTX_LENGTH (CONST_DOUBLE); i++) | |
c4c81601 | 1634 | hash += (unsigned int) XWINT (x, i); |
7506f491 | 1635 | else |
c4c81601 RK |
1636 | hash += ((unsigned int) CONST_DOUBLE_LOW (x) |
1637 | + (unsigned int) CONST_DOUBLE_HIGH (x)); | |
7506f491 DE |
1638 | return hash; |
1639 | ||
69ef87e2 AH |
1640 | case CONST_VECTOR: |
1641 | { | |
1642 | int units; | |
1643 | rtx elt; | |
1644 | ||
1645 | units = CONST_VECTOR_NUNITS (x); | |
1646 | ||
1647 | for (i = 0; i < units; ++i) | |
1648 | { | |
1649 | elt = CONST_VECTOR_ELT (x, i); | |
1650 | hash += hash_expr_1 (elt, GET_MODE (elt), do_not_record_p); | |
1651 | } | |
1652 | ||
1653 | return hash; | |
1654 | } | |
1655 | ||
7506f491 DE |
1656 | /* Assume there is only one rtx object for any given label. */ |
1657 | case LABEL_REF: | |
1658 | /* We don't hash on the address of the CODE_LABEL to avoid bootstrap | |
1659 | differences and differences between each stage's debugging dumps. */ | |
c4c81601 RK |
1660 | hash += (((unsigned int) LABEL_REF << 7) |
1661 | + CODE_LABEL_NUMBER (XEXP (x, 0))); | |
7506f491 DE |
1662 | return hash; |
1663 | ||
1664 | case SYMBOL_REF: | |
1665 | { | |
1666 | /* Don't hash on the symbol's address to avoid bootstrap differences. | |
1667 | Different hash values may cause expressions to be recorded in | |
1668 | different orders and thus different registers to be used in the | |
1669 | final assembler. This also avoids differences in the dump files | |
1670 | between various stages. */ | |
1671 | unsigned int h = 0; | |
3cce094d | 1672 | const unsigned char *p = (const unsigned char *) XSTR (x, 0); |
c4c81601 | 1673 | |
7506f491 DE |
1674 | while (*p) |
1675 | h += (h << 7) + *p++; /* ??? revisit */ | |
c4c81601 RK |
1676 | |
1677 | hash += ((unsigned int) SYMBOL_REF << 7) + h; | |
7506f491 DE |
1678 | return hash; |
1679 | } | |
1680 | ||
1681 | case MEM: | |
1682 | if (MEM_VOLATILE_P (x)) | |
1683 | { | |
1684 | *do_not_record_p = 1; | |
1685 | return 0; | |
1686 | } | |
c4c81601 RK |
1687 | |
1688 | hash += (unsigned int) MEM; | |
d51f3632 JH |
1689 | /* We used alias set for hashing, but this is not good, since the alias |
1690 | set may differ in -fprofile-arcs and -fbranch-probabilities compilation | |
1691 | causing the profiles to fail to match. */ | |
7506f491 DE |
1692 | x = XEXP (x, 0); |
1693 | goto repeat; | |
1694 | ||
1695 | case PRE_DEC: | |
1696 | case PRE_INC: | |
1697 | case POST_DEC: | |
1698 | case POST_INC: | |
1699 | case PC: | |
1700 | case CC0: | |
1701 | case CALL: | |
1702 | case UNSPEC_VOLATILE: | |
1703 | *do_not_record_p = 1; | |
1704 | return 0; | |
1705 | ||
1706 | case ASM_OPERANDS: | |
1707 | if (MEM_VOLATILE_P (x)) | |
1708 | { | |
1709 | *do_not_record_p = 1; | |
1710 | return 0; | |
1711 | } | |
6462bb43 AO |
1712 | else |
1713 | { | |
1714 | /* We don't want to take the filename and line into account. */ | |
1715 | hash += (unsigned) code + (unsigned) GET_MODE (x) | |
1716 | + hash_string_1 (ASM_OPERANDS_TEMPLATE (x)) | |
1717 | + hash_string_1 (ASM_OPERANDS_OUTPUT_CONSTRAINT (x)) | |
1718 | + (unsigned) ASM_OPERANDS_OUTPUT_IDX (x); | |
1719 | ||
1720 | if (ASM_OPERANDS_INPUT_LENGTH (x)) | |
1721 | { | |
1722 | for (i = 1; i < ASM_OPERANDS_INPUT_LENGTH (x); i++) | |
1723 | { | |
1724 | hash += (hash_expr_1 (ASM_OPERANDS_INPUT (x, i), | |
1725 | GET_MODE (ASM_OPERANDS_INPUT (x, i)), | |
1726 | do_not_record_p) | |
1727 | + hash_string_1 (ASM_OPERANDS_INPUT_CONSTRAINT | |
1728 | (x, i))); | |
1729 | } | |
1730 | ||
1731 | hash += hash_string_1 (ASM_OPERANDS_INPUT_CONSTRAINT (x, 0)); | |
1732 | x = ASM_OPERANDS_INPUT (x, 0); | |
1733 | mode = GET_MODE (x); | |
1734 | goto repeat; | |
1735 | } | |
1736 | return hash; | |
1737 | } | |
7506f491 DE |
1738 | |
1739 | default: | |
1740 | break; | |
1741 | } | |
1742 | ||
7506f491 | 1743 | hash += (unsigned) code + (unsigned) GET_MODE (x); |
c4c81601 | 1744 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
1745 | { |
1746 | if (fmt[i] == 'e') | |
1747 | { | |
7506f491 DE |
1748 | /* If we are about to do the last recursive call |
1749 | needed at this level, change it into iteration. | |
1750 | This function is called enough to be worth it. */ | |
1751 | if (i == 0) | |
1752 | { | |
c4c81601 | 1753 | x = XEXP (x, i); |
7506f491 DE |
1754 | goto repeat; |
1755 | } | |
c4c81601 RK |
1756 | |
1757 | hash += hash_expr_1 (XEXP (x, i), 0, do_not_record_p); | |
7506f491 DE |
1758 | if (*do_not_record_p) |
1759 | return 0; | |
1760 | } | |
c4c81601 | 1761 | |
7506f491 DE |
1762 | else if (fmt[i] == 'E') |
1763 | for (j = 0; j < XVECLEN (x, i); j++) | |
1764 | { | |
1765 | hash += hash_expr_1 (XVECEXP (x, i, j), 0, do_not_record_p); | |
1766 | if (*do_not_record_p) | |
1767 | return 0; | |
1768 | } | |
c4c81601 | 1769 | |
7506f491 | 1770 | else if (fmt[i] == 's') |
6462bb43 | 1771 | hash += hash_string_1 (XSTR (x, i)); |
7506f491 | 1772 | else if (fmt[i] == 'i') |
c4c81601 | 1773 | hash += (unsigned int) XINT (x, i); |
7506f491 DE |
1774 | else |
1775 | abort (); | |
1776 | } | |
1777 | ||
1778 | return hash; | |
1779 | } | |
1780 | ||
1781 | /* Hash a set of register REGNO. | |
1782 | ||
c4c81601 RK |
1783 | Sets are hashed on the register that is set. This simplifies the PRE copy |
1784 | propagation code. | |
7506f491 DE |
1785 | |
1786 | ??? May need to make things more elaborate. Later, as necessary. */ | |
1787 | ||
1788 | static unsigned int | |
1789 | hash_set (regno, hash_table_size) | |
1790 | int regno; | |
1791 | int hash_table_size; | |
1792 | { | |
1793 | unsigned int hash; | |
1794 | ||
1795 | hash = regno; | |
1796 | return hash % hash_table_size; | |
1797 | } | |
1798 | ||
cc2902df | 1799 | /* Return nonzero if exp1 is equivalent to exp2. |
7506f491 DE |
1800 | ??? Borrowed from cse.c. Might want to remerge with cse.c. Later. */ |
1801 | ||
1802 | static int | |
1803 | expr_equiv_p (x, y) | |
1804 | rtx x, y; | |
1805 | { | |
b3694847 SS |
1806 | int i, j; |
1807 | enum rtx_code code; | |
1808 | const char *fmt; | |
7506f491 DE |
1809 | |
1810 | if (x == y) | |
1811 | return 1; | |
c4c81601 | 1812 | |
7506f491 DE |
1813 | if (x == 0 || y == 0) |
1814 | return x == y; | |
1815 | ||
1816 | code = GET_CODE (x); | |
1817 | if (code != GET_CODE (y)) | |
1818 | return 0; | |
1819 | ||
1820 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */ | |
1821 | if (GET_MODE (x) != GET_MODE (y)) | |
1822 | return 0; | |
1823 | ||
1824 | switch (code) | |
1825 | { | |
1826 | case PC: | |
1827 | case CC0: | |
1828 | return x == y; | |
1829 | ||
1830 | case CONST_INT: | |
1831 | return INTVAL (x) == INTVAL (y); | |
1832 | ||
1833 | case LABEL_REF: | |
1834 | return XEXP (x, 0) == XEXP (y, 0); | |
1835 | ||
1836 | case SYMBOL_REF: | |
1837 | return XSTR (x, 0) == XSTR (y, 0); | |
1838 | ||
1839 | case REG: | |
1840 | return REGNO (x) == REGNO (y); | |
1841 | ||
297c3335 RH |
1842 | case MEM: |
1843 | /* Can't merge two expressions in different alias sets, since we can | |
1844 | decide that the expression is transparent in a block when it isn't, | |
1845 | due to it being set with the different alias set. */ | |
1846 | if (MEM_ALIAS_SET (x) != MEM_ALIAS_SET (y)) | |
1847 | return 0; | |
1848 | break; | |
1849 | ||
7506f491 DE |
1850 | /* For commutative operations, check both orders. */ |
1851 | case PLUS: | |
1852 | case MULT: | |
1853 | case AND: | |
1854 | case IOR: | |
1855 | case XOR: | |
1856 | case NE: | |
1857 | case EQ: | |
1858 | return ((expr_equiv_p (XEXP (x, 0), XEXP (y, 0)) | |
1859 | && expr_equiv_p (XEXP (x, 1), XEXP (y, 1))) | |
1860 | || (expr_equiv_p (XEXP (x, 0), XEXP (y, 1)) | |
1861 | && expr_equiv_p (XEXP (x, 1), XEXP (y, 0)))); | |
1862 | ||
6462bb43 AO |
1863 | case ASM_OPERANDS: |
1864 | /* We don't use the generic code below because we want to | |
1865 | disregard filename and line numbers. */ | |
1866 | ||
1867 | /* A volatile asm isn't equivalent to any other. */ | |
1868 | if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y)) | |
1869 | return 0; | |
1870 | ||
1871 | if (GET_MODE (x) != GET_MODE (y) | |
1872 | || strcmp (ASM_OPERANDS_TEMPLATE (x), ASM_OPERANDS_TEMPLATE (y)) | |
1873 | || strcmp (ASM_OPERANDS_OUTPUT_CONSTRAINT (x), | |
1874 | ASM_OPERANDS_OUTPUT_CONSTRAINT (y)) | |
1875 | || ASM_OPERANDS_OUTPUT_IDX (x) != ASM_OPERANDS_OUTPUT_IDX (y) | |
1876 | || ASM_OPERANDS_INPUT_LENGTH (x) != ASM_OPERANDS_INPUT_LENGTH (y)) | |
1877 | return 0; | |
1878 | ||
1879 | if (ASM_OPERANDS_INPUT_LENGTH (x)) | |
1880 | { | |
1881 | for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--) | |
1882 | if (! expr_equiv_p (ASM_OPERANDS_INPUT (x, i), | |
1883 | ASM_OPERANDS_INPUT (y, i)) | |
1884 | || strcmp (ASM_OPERANDS_INPUT_CONSTRAINT (x, i), | |
1885 | ASM_OPERANDS_INPUT_CONSTRAINT (y, i))) | |
1886 | return 0; | |
1887 | } | |
1888 | ||
1889 | return 1; | |
1890 | ||
7506f491 DE |
1891 | default: |
1892 | break; | |
1893 | } | |
1894 | ||
1895 | /* Compare the elements. If any pair of corresponding elements | |
1896 | fail to match, return 0 for the whole thing. */ | |
1897 | ||
1898 | fmt = GET_RTX_FORMAT (code); | |
1899 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1900 | { | |
1901 | switch (fmt[i]) | |
1902 | { | |
1903 | case 'e': | |
1904 | if (! expr_equiv_p (XEXP (x, i), XEXP (y, i))) | |
1905 | return 0; | |
1906 | break; | |
1907 | ||
1908 | case 'E': | |
1909 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
1910 | return 0; | |
1911 | for (j = 0; j < XVECLEN (x, i); j++) | |
1912 | if (! expr_equiv_p (XVECEXP (x, i, j), XVECEXP (y, i, j))) | |
1913 | return 0; | |
1914 | break; | |
1915 | ||
1916 | case 's': | |
1917 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
1918 | return 0; | |
1919 | break; | |
1920 | ||
1921 | case 'i': | |
1922 | if (XINT (x, i) != XINT (y, i)) | |
1923 | return 0; | |
1924 | break; | |
1925 | ||
1926 | case 'w': | |
1927 | if (XWINT (x, i) != XWINT (y, i)) | |
1928 | return 0; | |
1929 | break; | |
1930 | ||
1931 | case '0': | |
1932 | break; | |
aaa4ca30 | 1933 | |
7506f491 DE |
1934 | default: |
1935 | abort (); | |
1936 | } | |
8e42ace1 | 1937 | } |
7506f491 DE |
1938 | |
1939 | return 1; | |
1940 | } | |
1941 | ||
02280659 | 1942 | /* Insert expression X in INSN in the hash TABLE. |
7506f491 DE |
1943 | If it is already present, record it as the last occurrence in INSN's |
1944 | basic block. | |
1945 | ||
1946 | MODE is the mode of the value X is being stored into. | |
1947 | It is only used if X is a CONST_INT. | |
1948 | ||
cc2902df KH |
1949 | ANTIC_P is nonzero if X is an anticipatable expression. |
1950 | AVAIL_P is nonzero if X is an available expression. */ | |
7506f491 DE |
1951 | |
1952 | static void | |
02280659 | 1953 | insert_expr_in_table (x, mode, insn, antic_p, avail_p, table) |
7506f491 DE |
1954 | rtx x; |
1955 | enum machine_mode mode; | |
1956 | rtx insn; | |
1957 | int antic_p, avail_p; | |
02280659 | 1958 | struct hash_table *table; |
7506f491 DE |
1959 | { |
1960 | int found, do_not_record_p; | |
1961 | unsigned int hash; | |
1962 | struct expr *cur_expr, *last_expr = NULL; | |
1963 | struct occr *antic_occr, *avail_occr; | |
1964 | struct occr *last_occr = NULL; | |
1965 | ||
02280659 | 1966 | hash = hash_expr (x, mode, &do_not_record_p, table->size); |
7506f491 DE |
1967 | |
1968 | /* Do not insert expression in table if it contains volatile operands, | |
1969 | or if hash_expr determines the expression is something we don't want | |
1970 | to or can't handle. */ | |
1971 | if (do_not_record_p) | |
1972 | return; | |
1973 | ||
02280659 | 1974 | cur_expr = table->table[hash]; |
7506f491 DE |
1975 | found = 0; |
1976 | ||
c4c81601 | 1977 | while (cur_expr && 0 == (found = expr_equiv_p (cur_expr->expr, x))) |
7506f491 DE |
1978 | { |
1979 | /* If the expression isn't found, save a pointer to the end of | |
1980 | the list. */ | |
1981 | last_expr = cur_expr; | |
1982 | cur_expr = cur_expr->next_same_hash; | |
1983 | } | |
1984 | ||
1985 | if (! found) | |
1986 | { | |
1987 | cur_expr = (struct expr *) gcse_alloc (sizeof (struct expr)); | |
1988 | bytes_used += sizeof (struct expr); | |
02280659 | 1989 | if (table->table[hash] == NULL) |
c4c81601 | 1990 | /* This is the first pattern that hashed to this index. */ |
02280659 | 1991 | table->table[hash] = cur_expr; |
7506f491 | 1992 | else |
c4c81601 RK |
1993 | /* Add EXPR to end of this hash chain. */ |
1994 | last_expr->next_same_hash = cur_expr; | |
1995 | ||
589005ff | 1996 | /* Set the fields of the expr element. */ |
7506f491 | 1997 | cur_expr->expr = x; |
02280659 | 1998 | cur_expr->bitmap_index = table->n_elems++; |
7506f491 DE |
1999 | cur_expr->next_same_hash = NULL; |
2000 | cur_expr->antic_occr = NULL; | |
2001 | cur_expr->avail_occr = NULL; | |
2002 | } | |
2003 | ||
2004 | /* Now record the occurrence(s). */ | |
7506f491 DE |
2005 | if (antic_p) |
2006 | { | |
2007 | antic_occr = cur_expr->antic_occr; | |
2008 | ||
2009 | /* Search for another occurrence in the same basic block. */ | |
2010 | while (antic_occr && BLOCK_NUM (antic_occr->insn) != BLOCK_NUM (insn)) | |
2011 | { | |
2012 | /* If an occurrence isn't found, save a pointer to the end of | |
2013 | the list. */ | |
2014 | last_occr = antic_occr; | |
2015 | antic_occr = antic_occr->next; | |
2016 | } | |
2017 | ||
2018 | if (antic_occr) | |
c4c81601 RK |
2019 | /* Found another instance of the expression in the same basic block. |
2020 | Prefer the currently recorded one. We want the first one in the | |
2021 | block and the block is scanned from start to end. */ | |
2022 | ; /* nothing to do */ | |
7506f491 DE |
2023 | else |
2024 | { | |
2025 | /* First occurrence of this expression in this basic block. */ | |
2026 | antic_occr = (struct occr *) gcse_alloc (sizeof (struct occr)); | |
2027 | bytes_used += sizeof (struct occr); | |
2028 | /* First occurrence of this expression in any block? */ | |
2029 | if (cur_expr->antic_occr == NULL) | |
2030 | cur_expr->antic_occr = antic_occr; | |
2031 | else | |
2032 | last_occr->next = antic_occr; | |
c4c81601 | 2033 | |
7506f491 DE |
2034 | antic_occr->insn = insn; |
2035 | antic_occr->next = NULL; | |
2036 | } | |
2037 | } | |
2038 | ||
2039 | if (avail_p) | |
2040 | { | |
2041 | avail_occr = cur_expr->avail_occr; | |
2042 | ||
2043 | /* Search for another occurrence in the same basic block. */ | |
2044 | while (avail_occr && BLOCK_NUM (avail_occr->insn) != BLOCK_NUM (insn)) | |
2045 | { | |
2046 | /* If an occurrence isn't found, save a pointer to the end of | |
2047 | the list. */ | |
2048 | last_occr = avail_occr; | |
2049 | avail_occr = avail_occr->next; | |
2050 | } | |
2051 | ||
2052 | if (avail_occr) | |
c4c81601 RK |
2053 | /* Found another instance of the expression in the same basic block. |
2054 | Prefer this occurrence to the currently recorded one. We want | |
2055 | the last one in the block and the block is scanned from start | |
2056 | to end. */ | |
2057 | avail_occr->insn = insn; | |
7506f491 DE |
2058 | else |
2059 | { | |
2060 | /* First occurrence of this expression in this basic block. */ | |
2061 | avail_occr = (struct occr *) gcse_alloc (sizeof (struct occr)); | |
2062 | bytes_used += sizeof (struct occr); | |
c4c81601 | 2063 | |
7506f491 DE |
2064 | /* First occurrence of this expression in any block? */ |
2065 | if (cur_expr->avail_occr == NULL) | |
2066 | cur_expr->avail_occr = avail_occr; | |
2067 | else | |
2068 | last_occr->next = avail_occr; | |
c4c81601 | 2069 | |
7506f491 DE |
2070 | avail_occr->insn = insn; |
2071 | avail_occr->next = NULL; | |
2072 | } | |
2073 | } | |
2074 | } | |
2075 | ||
2076 | /* Insert pattern X in INSN in the hash table. | |
2077 | X is a SET of a reg to either another reg or a constant. | |
2078 | If it is already present, record it as the last occurrence in INSN's | |
2079 | basic block. */ | |
2080 | ||
2081 | static void | |
02280659 | 2082 | insert_set_in_table (x, insn, table) |
7506f491 DE |
2083 | rtx x; |
2084 | rtx insn; | |
02280659 | 2085 | struct hash_table *table; |
7506f491 DE |
2086 | { |
2087 | int found; | |
2088 | unsigned int hash; | |
2089 | struct expr *cur_expr, *last_expr = NULL; | |
2090 | struct occr *cur_occr, *last_occr = NULL; | |
2091 | ||
2092 | if (GET_CODE (x) != SET | |
2093 | || GET_CODE (SET_DEST (x)) != REG) | |
2094 | abort (); | |
2095 | ||
02280659 | 2096 | hash = hash_set (REGNO (SET_DEST (x)), table->size); |
7506f491 | 2097 | |
02280659 | 2098 | cur_expr = table->table[hash]; |
7506f491 DE |
2099 | found = 0; |
2100 | ||
c4c81601 | 2101 | while (cur_expr && 0 == (found = expr_equiv_p (cur_expr->expr, x))) |
7506f491 DE |
2102 | { |
2103 | /* If the expression isn't found, save a pointer to the end of | |
2104 | the list. */ | |
2105 | last_expr = cur_expr; | |
2106 | cur_expr = cur_expr->next_same_hash; | |
2107 | } | |
2108 | ||
2109 | if (! found) | |
2110 | { | |
2111 | cur_expr = (struct expr *) gcse_alloc (sizeof (struct expr)); | |
2112 | bytes_used += sizeof (struct expr); | |
02280659 | 2113 | if (table->table[hash] == NULL) |
c4c81601 | 2114 | /* This is the first pattern that hashed to this index. */ |
02280659 | 2115 | table->table[hash] = cur_expr; |
7506f491 | 2116 | else |
c4c81601 RK |
2117 | /* Add EXPR to end of this hash chain. */ |
2118 | last_expr->next_same_hash = cur_expr; | |
2119 | ||
7506f491 DE |
2120 | /* Set the fields of the expr element. |
2121 | We must copy X because it can be modified when copy propagation is | |
2122 | performed on its operands. */ | |
7506f491 | 2123 | cur_expr->expr = copy_rtx (x); |
02280659 | 2124 | cur_expr->bitmap_index = table->n_elems++; |
7506f491 DE |
2125 | cur_expr->next_same_hash = NULL; |
2126 | cur_expr->antic_occr = NULL; | |
2127 | cur_expr->avail_occr = NULL; | |
2128 | } | |
2129 | ||
2130 | /* Now record the occurrence. */ | |
7506f491 DE |
2131 | cur_occr = cur_expr->avail_occr; |
2132 | ||
2133 | /* Search for another occurrence in the same basic block. */ | |
2134 | while (cur_occr && BLOCK_NUM (cur_occr->insn) != BLOCK_NUM (insn)) | |
2135 | { | |
2136 | /* If an occurrence isn't found, save a pointer to the end of | |
2137 | the list. */ | |
2138 | last_occr = cur_occr; | |
2139 | cur_occr = cur_occr->next; | |
2140 | } | |
2141 | ||
2142 | if (cur_occr) | |
c4c81601 RK |
2143 | /* Found another instance of the expression in the same basic block. |
2144 | Prefer this occurrence to the currently recorded one. We want the | |
2145 | last one in the block and the block is scanned from start to end. */ | |
2146 | cur_occr->insn = insn; | |
7506f491 DE |
2147 | else |
2148 | { | |
2149 | /* First occurrence of this expression in this basic block. */ | |
2150 | cur_occr = (struct occr *) gcse_alloc (sizeof (struct occr)); | |
2151 | bytes_used += sizeof (struct occr); | |
c4c81601 | 2152 | |
7506f491 DE |
2153 | /* First occurrence of this expression in any block? */ |
2154 | if (cur_expr->avail_occr == NULL) | |
2155 | cur_expr->avail_occr = cur_occr; | |
2156 | else | |
2157 | last_occr->next = cur_occr; | |
c4c81601 | 2158 | |
7506f491 DE |
2159 | cur_occr->insn = insn; |
2160 | cur_occr->next = NULL; | |
2161 | } | |
2162 | } | |
2163 | ||
6b2d1c9e RS |
2164 | /* Determine whether the rtx X should be treated as a constant for |
2165 | the purposes of GCSE's constant propagation. */ | |
2166 | ||
2167 | static bool | |
2168 | gcse_constant_p (x) | |
2169 | rtx x; | |
2170 | { | |
2171 | /* Consider a COMPARE of two integers constant. */ | |
2172 | if (GET_CODE (x) == COMPARE | |
2173 | && GET_CODE (XEXP (x, 0)) == CONST_INT | |
2174 | && GET_CODE (XEXP (x, 1)) == CONST_INT) | |
2175 | return true; | |
2176 | ||
2177 | if (GET_CODE (x) == CONSTANT_P_RTX) | |
2178 | return false; | |
2179 | ||
2180 | return CONSTANT_P (x); | |
2181 | } | |
2182 | ||
02280659 ZD |
2183 | /* Scan pattern PAT of INSN and add an entry to the hash TABLE (set or |
2184 | expression one). */ | |
7506f491 DE |
2185 | |
2186 | static void | |
02280659 | 2187 | hash_scan_set (pat, insn, table) |
7506f491 | 2188 | rtx pat, insn; |
02280659 | 2189 | struct hash_table *table; |
7506f491 DE |
2190 | { |
2191 | rtx src = SET_SRC (pat); | |
2192 | rtx dest = SET_DEST (pat); | |
172890a2 | 2193 | rtx note; |
7506f491 DE |
2194 | |
2195 | if (GET_CODE (src) == CALL) | |
02280659 | 2196 | hash_scan_call (src, insn, table); |
7506f491 | 2197 | |
172890a2 | 2198 | else if (GET_CODE (dest) == REG) |
7506f491 | 2199 | { |
172890a2 | 2200 | unsigned int regno = REGNO (dest); |
7506f491 DE |
2201 | rtx tmp; |
2202 | ||
172890a2 RK |
2203 | /* If this is a single set and we are doing constant propagation, |
2204 | see if a REG_NOTE shows this equivalent to a constant. */ | |
02280659 | 2205 | if (table->set_p && (note = find_reg_equal_equiv_note (insn)) != 0 |
6b2d1c9e | 2206 | && gcse_constant_p (XEXP (note, 0))) |
172890a2 RK |
2207 | src = XEXP (note, 0), pat = gen_rtx_SET (VOIDmode, dest, src); |
2208 | ||
7506f491 | 2209 | /* Only record sets of pseudo-regs in the hash table. */ |
02280659 | 2210 | if (! table->set_p |
7506f491 DE |
2211 | && regno >= FIRST_PSEUDO_REGISTER |
2212 | /* Don't GCSE something if we can't do a reg/reg copy. */ | |
2213 | && can_copy_p [GET_MODE (dest)] | |
068473ec JH |
2214 | /* GCSE commonly inserts instruction after the insn. We can't |
2215 | do that easily for EH_REGION notes so disable GCSE on these | |
2216 | for now. */ | |
2217 | && !find_reg_note (insn, REG_EH_REGION, NULL_RTX) | |
7506f491 | 2218 | /* Is SET_SRC something we want to gcse? */ |
172890a2 RK |
2219 | && want_to_gcse_p (src) |
2220 | /* Don't CSE a nop. */ | |
43e72072 JJ |
2221 | && ! set_noop_p (pat) |
2222 | /* Don't GCSE if it has attached REG_EQUIV note. | |
2223 | At this point this only function parameters should have | |
2224 | REG_EQUIV notes and if the argument slot is used somewhere | |
a1f300c0 | 2225 | explicitly, it means address of parameter has been taken, |
43e72072 JJ |
2226 | so we should not extend the lifetime of the pseudo. */ |
2227 | && ((note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) == 0 | |
2228 | || GET_CODE (XEXP (note, 0)) != MEM)) | |
7506f491 DE |
2229 | { |
2230 | /* An expression is not anticipatable if its operands are | |
52d76e11 RK |
2231 | modified before this insn or if this is not the only SET in |
2232 | this insn. */ | |
2233 | int antic_p = oprs_anticipatable_p (src, insn) && single_set (insn); | |
7506f491 | 2234 | /* An expression is not available if its operands are |
eb296bd9 GK |
2235 | subsequently modified, including this insn. It's also not |
2236 | available if this is a branch, because we can't insert | |
2237 | a set after the branch. */ | |
2238 | int avail_p = (oprs_available_p (src, insn) | |
2239 | && ! JUMP_P (insn)); | |
c4c81601 | 2240 | |
02280659 | 2241 | insert_expr_in_table (src, GET_MODE (dest), insn, antic_p, avail_p, table); |
7506f491 | 2242 | } |
c4c81601 | 2243 | |
7506f491 | 2244 | /* Record sets for constant/copy propagation. */ |
02280659 | 2245 | else if (table->set_p |
7506f491 DE |
2246 | && regno >= FIRST_PSEUDO_REGISTER |
2247 | && ((GET_CODE (src) == REG | |
2248 | && REGNO (src) >= FIRST_PSEUDO_REGISTER | |
172890a2 RK |
2249 | && can_copy_p [GET_MODE (dest)] |
2250 | && REGNO (src) != regno) | |
6b2d1c9e | 2251 | || gcse_constant_p (src)) |
7506f491 DE |
2252 | /* A copy is not available if its src or dest is subsequently |
2253 | modified. Here we want to search from INSN+1 on, but | |
2254 | oprs_available_p searches from INSN on. */ | |
2255 | && (insn == BLOCK_END (BLOCK_NUM (insn)) | |
2256 | || ((tmp = next_nonnote_insn (insn)) != NULL_RTX | |
2257 | && oprs_available_p (pat, tmp)))) | |
02280659 | 2258 | insert_set_in_table (pat, insn, table); |
7506f491 | 2259 | } |
7506f491 DE |
2260 | } |
2261 | ||
2262 | static void | |
02280659 | 2263 | hash_scan_clobber (x, insn, table) |
50b2596f | 2264 | rtx x ATTRIBUTE_UNUSED, insn ATTRIBUTE_UNUSED; |
02280659 | 2265 | struct hash_table *table ATTRIBUTE_UNUSED; |
7506f491 DE |
2266 | { |
2267 | /* Currently nothing to do. */ | |
2268 | } | |
2269 | ||
2270 | static void | |
02280659 | 2271 | hash_scan_call (x, insn, table) |
50b2596f | 2272 | rtx x ATTRIBUTE_UNUSED, insn ATTRIBUTE_UNUSED; |
02280659 | 2273 | struct hash_table *table ATTRIBUTE_UNUSED; |
7506f491 DE |
2274 | { |
2275 | /* Currently nothing to do. */ | |
2276 | } | |
2277 | ||
2278 | /* Process INSN and add hash table entries as appropriate. | |
2279 | ||
2280 | Only available expressions that set a single pseudo-reg are recorded. | |
2281 | ||
2282 | Single sets in a PARALLEL could be handled, but it's an extra complication | |
2283 | that isn't dealt with right now. The trick is handling the CLOBBERs that | |
2284 | are also in the PARALLEL. Later. | |
2285 | ||
cc2902df | 2286 | If SET_P is nonzero, this is for the assignment hash table, |
ed79bb3d R |
2287 | otherwise it is for the expression hash table. |
2288 | If IN_LIBCALL_BLOCK nonzero, we are in a libcall block, and should | |
2289 | not record any expressions. */ | |
7506f491 DE |
2290 | |
2291 | static void | |
02280659 | 2292 | hash_scan_insn (insn, table, in_libcall_block) |
7506f491 | 2293 | rtx insn; |
02280659 | 2294 | struct hash_table *table; |
48e87cef | 2295 | int in_libcall_block; |
7506f491 DE |
2296 | { |
2297 | rtx pat = PATTERN (insn); | |
c4c81601 | 2298 | int i; |
7506f491 | 2299 | |
172890a2 RK |
2300 | if (in_libcall_block) |
2301 | return; | |
2302 | ||
7506f491 DE |
2303 | /* Pick out the sets of INSN and for other forms of instructions record |
2304 | what's been modified. */ | |
2305 | ||
172890a2 | 2306 | if (GET_CODE (pat) == SET) |
02280659 | 2307 | hash_scan_set (pat, insn, table); |
7506f491 | 2308 | else if (GET_CODE (pat) == PARALLEL) |
c4c81601 RK |
2309 | for (i = 0; i < XVECLEN (pat, 0); i++) |
2310 | { | |
2311 | rtx x = XVECEXP (pat, 0, i); | |
7506f491 | 2312 | |
c4c81601 | 2313 | if (GET_CODE (x) == SET) |
02280659 | 2314 | hash_scan_set (x, insn, table); |
c4c81601 | 2315 | else if (GET_CODE (x) == CLOBBER) |
02280659 | 2316 | hash_scan_clobber (x, insn, table); |
c4c81601 | 2317 | else if (GET_CODE (x) == CALL) |
02280659 | 2318 | hash_scan_call (x, insn, table); |
c4c81601 | 2319 | } |
7506f491 | 2320 | |
7506f491 | 2321 | else if (GET_CODE (pat) == CLOBBER) |
02280659 | 2322 | hash_scan_clobber (pat, insn, table); |
7506f491 | 2323 | else if (GET_CODE (pat) == CALL) |
02280659 | 2324 | hash_scan_call (pat, insn, table); |
7506f491 DE |
2325 | } |
2326 | ||
2327 | static void | |
02280659 | 2328 | dump_hash_table (file, name, table) |
7506f491 | 2329 | FILE *file; |
dff01034 | 2330 | const char *name; |
02280659 | 2331 | struct hash_table *table; |
7506f491 DE |
2332 | { |
2333 | int i; | |
2334 | /* Flattened out table, so it's printed in proper order. */ | |
4da896b2 MM |
2335 | struct expr **flat_table; |
2336 | unsigned int *hash_val; | |
c4c81601 | 2337 | struct expr *expr; |
4da896b2 | 2338 | |
589005ff | 2339 | flat_table |
02280659 ZD |
2340 | = (struct expr **) xcalloc (table->n_elems, sizeof (struct expr *)); |
2341 | hash_val = (unsigned int *) xmalloc (table->n_elems * sizeof (unsigned int)); | |
7506f491 | 2342 | |
02280659 ZD |
2343 | for (i = 0; i < (int) table->size; i++) |
2344 | for (expr = table->table[i]; expr != NULL; expr = expr->next_same_hash) | |
c4c81601 RK |
2345 | { |
2346 | flat_table[expr->bitmap_index] = expr; | |
2347 | hash_val[expr->bitmap_index] = i; | |
2348 | } | |
7506f491 DE |
2349 | |
2350 | fprintf (file, "%s hash table (%d buckets, %d entries)\n", | |
02280659 | 2351 | name, table->size, table->n_elems); |
7506f491 | 2352 | |
02280659 | 2353 | for (i = 0; i < (int) table->n_elems; i++) |
21318741 RK |
2354 | if (flat_table[i] != 0) |
2355 | { | |
a0ac9e5a | 2356 | expr = flat_table[i]; |
21318741 RK |
2357 | fprintf (file, "Index %d (hash value %d)\n ", |
2358 | expr->bitmap_index, hash_val[i]); | |
a0ac9e5a | 2359 | print_rtl (file, expr->expr); |
21318741 RK |
2360 | fprintf (file, "\n"); |
2361 | } | |
7506f491 DE |
2362 | |
2363 | fprintf (file, "\n"); | |
4da896b2 | 2364 | |
4da896b2 MM |
2365 | free (flat_table); |
2366 | free (hash_val); | |
7506f491 DE |
2367 | } |
2368 | ||
2369 | /* Record register first/last/block set information for REGNO in INSN. | |
c4c81601 | 2370 | |
80c29cc4 | 2371 | first_set records the first place in the block where the register |
7506f491 | 2372 | is set and is used to compute "anticipatability". |
c4c81601 | 2373 | |
80c29cc4 | 2374 | last_set records the last place in the block where the register |
7506f491 | 2375 | is set and is used to compute "availability". |
c4c81601 | 2376 | |
80c29cc4 RZ |
2377 | last_bb records the block for which first_set and last_set are |
2378 | valid, as a quick test to invalidate them. | |
2379 | ||
7506f491 DE |
2380 | reg_set_in_block records whether the register is set in the block |
2381 | and is used to compute "transparency". */ | |
2382 | ||
2383 | static void | |
2384 | record_last_reg_set_info (insn, regno) | |
2385 | rtx insn; | |
2386 | int regno; | |
2387 | { | |
80c29cc4 RZ |
2388 | struct reg_avail_info *info = ®_avail_info[regno]; |
2389 | int cuid = INSN_CUID (insn); | |
c4c81601 | 2390 | |
80c29cc4 RZ |
2391 | info->last_set = cuid; |
2392 | if (info->last_bb != current_bb) | |
2393 | { | |
2394 | info->last_bb = current_bb; | |
2395 | info->first_set = cuid; | |
e0082a72 | 2396 | SET_BIT (reg_set_in_block[current_bb->index], regno); |
80c29cc4 | 2397 | } |
7506f491 DE |
2398 | } |
2399 | ||
a13d4ebf AM |
2400 | |
2401 | /* Record all of the canonicalized MEMs of record_last_mem_set_info's insn. | |
2402 | Note we store a pair of elements in the list, so they have to be | |
2403 | taken off pairwise. */ | |
2404 | ||
589005ff | 2405 | static void |
a13d4ebf AM |
2406 | canon_list_insert (dest, unused1, v_insn) |
2407 | rtx dest ATTRIBUTE_UNUSED; | |
2408 | rtx unused1 ATTRIBUTE_UNUSED; | |
2409 | void * v_insn; | |
2410 | { | |
2411 | rtx dest_addr, insn; | |
0fe854a7 | 2412 | int bb; |
a13d4ebf AM |
2413 | |
2414 | while (GET_CODE (dest) == SUBREG | |
2415 | || GET_CODE (dest) == ZERO_EXTRACT | |
2416 | || GET_CODE (dest) == SIGN_EXTRACT | |
2417 | || GET_CODE (dest) == STRICT_LOW_PART) | |
2418 | dest = XEXP (dest, 0); | |
2419 | ||
2420 | /* If DEST is not a MEM, then it will not conflict with a load. Note | |
2421 | that function calls are assumed to clobber memory, but are handled | |
2422 | elsewhere. */ | |
2423 | ||
2424 | if (GET_CODE (dest) != MEM) | |
2425 | return; | |
2426 | ||
2427 | dest_addr = get_addr (XEXP (dest, 0)); | |
2428 | dest_addr = canon_rtx (dest_addr); | |
589005ff | 2429 | insn = (rtx) v_insn; |
0fe854a7 | 2430 | bb = BLOCK_NUM (insn); |
a13d4ebf | 2431 | |
589005ff | 2432 | canon_modify_mem_list[bb] = |
0fe854a7 | 2433 | alloc_EXPR_LIST (VOIDmode, dest_addr, canon_modify_mem_list[bb]); |
589005ff | 2434 | canon_modify_mem_list[bb] = |
0fe854a7 RH |
2435 | alloc_EXPR_LIST (VOIDmode, dest, canon_modify_mem_list[bb]); |
2436 | bitmap_set_bit (canon_modify_mem_list_set, bb); | |
a13d4ebf AM |
2437 | } |
2438 | ||
a13d4ebf AM |
2439 | /* Record memory modification information for INSN. We do not actually care |
2440 | about the memory location(s) that are set, or even how they are set (consider | |
2441 | a CALL_INSN). We merely need to record which insns modify memory. */ | |
7506f491 DE |
2442 | |
2443 | static void | |
2444 | record_last_mem_set_info (insn) | |
2445 | rtx insn; | |
2446 | { | |
0fe854a7 RH |
2447 | int bb = BLOCK_NUM (insn); |
2448 | ||
ccef9ef5 | 2449 | /* load_killed_in_block_p will handle the case of calls clobbering |
dc297297 | 2450 | everything. */ |
0fe854a7 RH |
2451 | modify_mem_list[bb] = alloc_INSN_LIST (insn, modify_mem_list[bb]); |
2452 | bitmap_set_bit (modify_mem_list_set, bb); | |
a13d4ebf AM |
2453 | |
2454 | if (GET_CODE (insn) == CALL_INSN) | |
2455 | { | |
2456 | /* Note that traversals of this loop (other than for free-ing) | |
2457 | will break after encountering a CALL_INSN. So, there's no | |
dc297297 | 2458 | need to insert a pair of items, as canon_list_insert does. */ |
589005ff KH |
2459 | canon_modify_mem_list[bb] = |
2460 | alloc_INSN_LIST (insn, canon_modify_mem_list[bb]); | |
0fe854a7 | 2461 | bitmap_set_bit (canon_modify_mem_list_set, bb); |
a13d4ebf AM |
2462 | } |
2463 | else | |
0fe854a7 | 2464 | note_stores (PATTERN (insn), canon_list_insert, (void*) insn); |
7506f491 DE |
2465 | } |
2466 | ||
7506f491 | 2467 | /* Called from compute_hash_table via note_stores to handle one |
84832317 MM |
2468 | SET or CLOBBER in an insn. DATA is really the instruction in which |
2469 | the SET is taking place. */ | |
7506f491 DE |
2470 | |
2471 | static void | |
84832317 | 2472 | record_last_set_info (dest, setter, data) |
50b2596f | 2473 | rtx dest, setter ATTRIBUTE_UNUSED; |
84832317 | 2474 | void *data; |
7506f491 | 2475 | { |
84832317 MM |
2476 | rtx last_set_insn = (rtx) data; |
2477 | ||
7506f491 DE |
2478 | if (GET_CODE (dest) == SUBREG) |
2479 | dest = SUBREG_REG (dest); | |
2480 | ||
2481 | if (GET_CODE (dest) == REG) | |
2482 | record_last_reg_set_info (last_set_insn, REGNO (dest)); | |
2483 | else if (GET_CODE (dest) == MEM | |
2484 | /* Ignore pushes, they clobber nothing. */ | |
2485 | && ! push_operand (dest, GET_MODE (dest))) | |
2486 | record_last_mem_set_info (last_set_insn); | |
2487 | } | |
2488 | ||
2489 | /* Top level function to create an expression or assignment hash table. | |
2490 | ||
2491 | Expression entries are placed in the hash table if | |
2492 | - they are of the form (set (pseudo-reg) src), | |
2493 | - src is something we want to perform GCSE on, | |
2494 | - none of the operands are subsequently modified in the block | |
2495 | ||
2496 | Assignment entries are placed in the hash table if | |
2497 | - they are of the form (set (pseudo-reg) src), | |
2498 | - src is something we want to perform const/copy propagation on, | |
2499 | - none of the operands or target are subsequently modified in the block | |
c4c81601 | 2500 | |
7506f491 DE |
2501 | Currently src must be a pseudo-reg or a const_int. |
2502 | ||
02280659 | 2503 | TABLE is the table computed. */ |
7506f491 DE |
2504 | |
2505 | static void | |
02280659 ZD |
2506 | compute_hash_table_work (table) |
2507 | struct hash_table *table; | |
7506f491 | 2508 | { |
80c29cc4 | 2509 | unsigned int i; |
7506f491 DE |
2510 | |
2511 | /* While we compute the hash table we also compute a bit array of which | |
2512 | registers are set in which blocks. | |
7506f491 DE |
2513 | ??? This isn't needed during const/copy propagation, but it's cheap to |
2514 | compute. Later. */ | |
d55bc081 | 2515 | sbitmap_vector_zero (reg_set_in_block, last_basic_block); |
7506f491 | 2516 | |
a13d4ebf | 2517 | /* re-Cache any INSN_LIST nodes we have allocated. */ |
73991d6a | 2518 | clear_modify_mem_tables (); |
7506f491 | 2519 | /* Some working arrays used to track first and last set in each block. */ |
80c29cc4 RZ |
2520 | reg_avail_info = (struct reg_avail_info*) |
2521 | gmalloc (max_gcse_regno * sizeof (struct reg_avail_info)); | |
2522 | ||
2523 | for (i = 0; i < max_gcse_regno; ++i) | |
e0082a72 | 2524 | reg_avail_info[i].last_bb = NULL; |
7506f491 | 2525 | |
e0082a72 | 2526 | FOR_EACH_BB (current_bb) |
7506f491 DE |
2527 | { |
2528 | rtx insn; | |
770ae6cc | 2529 | unsigned int regno; |
ed79bb3d | 2530 | int in_libcall_block; |
7506f491 DE |
2531 | |
2532 | /* First pass over the instructions records information used to | |
2533 | determine when registers and memory are first and last set. | |
ccef9ef5 | 2534 | ??? hard-reg reg_set_in_block computation |
7506f491 DE |
2535 | could be moved to compute_sets since they currently don't change. */ |
2536 | ||
e0082a72 ZD |
2537 | for (insn = current_bb->head; |
2538 | insn && insn != NEXT_INSN (current_bb->end); | |
7506f491 DE |
2539 | insn = NEXT_INSN (insn)) |
2540 | { | |
2c3c49de | 2541 | if (! INSN_P (insn)) |
7506f491 DE |
2542 | continue; |
2543 | ||
2544 | if (GET_CODE (insn) == CALL_INSN) | |
2545 | { | |
19652adf | 2546 | bool clobbers_all = false; |
589005ff | 2547 | #ifdef NON_SAVING_SETJMP |
19652adf ZW |
2548 | if (NON_SAVING_SETJMP |
2549 | && find_reg_note (insn, REG_SETJMP, NULL_RTX)) | |
2550 | clobbers_all = true; | |
2551 | #endif | |
2552 | ||
7506f491 | 2553 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) |
19652adf ZW |
2554 | if (clobbers_all |
2555 | || TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) | |
7506f491 | 2556 | record_last_reg_set_info (insn, regno); |
c4c81601 | 2557 | |
24a28584 | 2558 | mark_call (insn); |
7506f491 DE |
2559 | } |
2560 | ||
84832317 | 2561 | note_stores (PATTERN (insn), record_last_set_info, insn); |
7506f491 DE |
2562 | } |
2563 | ||
fbef91d8 RS |
2564 | /* Insert implicit sets in the hash table. */ |
2565 | if (table->set_p | |
2566 | && implicit_sets[current_bb->index] != NULL_RTX) | |
2567 | hash_scan_set (implicit_sets[current_bb->index], | |
2568 | current_bb->head, table); | |
2569 | ||
7506f491 DE |
2570 | /* The next pass builds the hash table. */ |
2571 | ||
e0082a72 ZD |
2572 | for (insn = current_bb->head, in_libcall_block = 0; |
2573 | insn && insn != NEXT_INSN (current_bb->end); | |
7506f491 | 2574 | insn = NEXT_INSN (insn)) |
2c3c49de | 2575 | if (INSN_P (insn)) |
c4c81601 RK |
2576 | { |
2577 | if (find_reg_note (insn, REG_LIBCALL, NULL_RTX)) | |
589005ff | 2578 | in_libcall_block = 1; |
02280659 | 2579 | else if (table->set_p && find_reg_note (insn, REG_RETVAL, NULL_RTX)) |
589005ff | 2580 | in_libcall_block = 0; |
02280659 ZD |
2581 | hash_scan_insn (insn, table, in_libcall_block); |
2582 | if (!table->set_p && find_reg_note (insn, REG_RETVAL, NULL_RTX)) | |
589005ff | 2583 | in_libcall_block = 0; |
8e42ace1 | 2584 | } |
7506f491 DE |
2585 | } |
2586 | ||
80c29cc4 RZ |
2587 | free (reg_avail_info); |
2588 | reg_avail_info = NULL; | |
7506f491 DE |
2589 | } |
2590 | ||
02280659 | 2591 | /* Allocate space for the set/expr hash TABLE. |
7506f491 | 2592 | N_INSNS is the number of instructions in the function. |
02280659 ZD |
2593 | It is used to determine the number of buckets to use. |
2594 | SET_P determines whether set or expression table will | |
2595 | be created. */ | |
7506f491 DE |
2596 | |
2597 | static void | |
02280659 | 2598 | alloc_hash_table (n_insns, table, set_p) |
7506f491 | 2599 | int n_insns; |
02280659 ZD |
2600 | struct hash_table *table; |
2601 | int set_p; | |
7506f491 DE |
2602 | { |
2603 | int n; | |
2604 | ||
02280659 ZD |
2605 | table->size = n_insns / 4; |
2606 | if (table->size < 11) | |
2607 | table->size = 11; | |
c4c81601 | 2608 | |
7506f491 DE |
2609 | /* Attempt to maintain efficient use of hash table. |
2610 | Making it an odd number is simplest for now. | |
2611 | ??? Later take some measurements. */ | |
02280659 ZD |
2612 | table->size |= 1; |
2613 | n = table->size * sizeof (struct expr *); | |
2614 | table->table = (struct expr **) gmalloc (n); | |
2615 | table->set_p = set_p; | |
7506f491 DE |
2616 | } |
2617 | ||
02280659 | 2618 | /* Free things allocated by alloc_hash_table. */ |
7506f491 DE |
2619 | |
2620 | static void | |
02280659 ZD |
2621 | free_hash_table (table) |
2622 | struct hash_table *table; | |
7506f491 | 2623 | { |
02280659 | 2624 | free (table->table); |
7506f491 DE |
2625 | } |
2626 | ||
02280659 ZD |
2627 | /* Compute the hash TABLE for doing copy/const propagation or |
2628 | expression hash table. */ | |
7506f491 DE |
2629 | |
2630 | static void | |
02280659 ZD |
2631 | compute_hash_table (table) |
2632 | struct hash_table *table; | |
7506f491 DE |
2633 | { |
2634 | /* Initialize count of number of entries in hash table. */ | |
02280659 ZD |
2635 | table->n_elems = 0; |
2636 | memset ((char *) table->table, 0, | |
2637 | table->size * sizeof (struct expr *)); | |
7506f491 | 2638 | |
02280659 | 2639 | compute_hash_table_work (table); |
7506f491 DE |
2640 | } |
2641 | \f | |
2642 | /* Expression tracking support. */ | |
2643 | ||
02280659 | 2644 | /* Lookup pattern PAT in the expression TABLE. |
7506f491 DE |
2645 | The result is a pointer to the table entry, or NULL if not found. */ |
2646 | ||
2647 | static struct expr * | |
02280659 | 2648 | lookup_expr (pat, table) |
7506f491 | 2649 | rtx pat; |
02280659 | 2650 | struct hash_table *table; |
7506f491 DE |
2651 | { |
2652 | int do_not_record_p; | |
2653 | unsigned int hash = hash_expr (pat, GET_MODE (pat), &do_not_record_p, | |
02280659 | 2654 | table->size); |
7506f491 DE |
2655 | struct expr *expr; |
2656 | ||
2657 | if (do_not_record_p) | |
2658 | return NULL; | |
2659 | ||
02280659 | 2660 | expr = table->table[hash]; |
7506f491 DE |
2661 | |
2662 | while (expr && ! expr_equiv_p (expr->expr, pat)) | |
2663 | expr = expr->next_same_hash; | |
2664 | ||
2665 | return expr; | |
2666 | } | |
2667 | ||
ceda50e9 RH |
2668 | /* Lookup REGNO in the set TABLE. The result is a pointer to the |
2669 | table entry, or NULL if not found. */ | |
7506f491 DE |
2670 | |
2671 | static struct expr * | |
ceda50e9 | 2672 | lookup_set (regno, table) |
770ae6cc | 2673 | unsigned int regno; |
02280659 | 2674 | struct hash_table *table; |
7506f491 | 2675 | { |
02280659 | 2676 | unsigned int hash = hash_set (regno, table->size); |
7506f491 DE |
2677 | struct expr *expr; |
2678 | ||
02280659 | 2679 | expr = table->table[hash]; |
7506f491 | 2680 | |
ceda50e9 RH |
2681 | while (expr && REGNO (SET_DEST (expr->expr)) != regno) |
2682 | expr = expr->next_same_hash; | |
7506f491 DE |
2683 | |
2684 | return expr; | |
2685 | } | |
2686 | ||
2687 | /* Return the next entry for REGNO in list EXPR. */ | |
2688 | ||
2689 | static struct expr * | |
2690 | next_set (regno, expr) | |
770ae6cc | 2691 | unsigned int regno; |
7506f491 DE |
2692 | struct expr *expr; |
2693 | { | |
2694 | do | |
2695 | expr = expr->next_same_hash; | |
2696 | while (expr && REGNO (SET_DEST (expr->expr)) != regno); | |
c4c81601 | 2697 | |
7506f491 DE |
2698 | return expr; |
2699 | } | |
2700 | ||
0fe854a7 RH |
2701 | /* Like free_INSN_LIST_list or free_EXPR_LIST_list, except that the node |
2702 | types may be mixed. */ | |
2703 | ||
2704 | static void | |
2705 | free_insn_expr_list_list (listp) | |
2706 | rtx *listp; | |
2707 | { | |
2708 | rtx list, next; | |
2709 | ||
2710 | for (list = *listp; list ; list = next) | |
2711 | { | |
2712 | next = XEXP (list, 1); | |
2713 | if (GET_CODE (list) == EXPR_LIST) | |
2714 | free_EXPR_LIST_node (list); | |
2715 | else | |
2716 | free_INSN_LIST_node (list); | |
2717 | } | |
2718 | ||
2719 | *listp = NULL; | |
2720 | } | |
2721 | ||
73991d6a JH |
2722 | /* Clear canon_modify_mem_list and modify_mem_list tables. */ |
2723 | static void | |
2724 | clear_modify_mem_tables () | |
2725 | { | |
2726 | int i; | |
2727 | ||
2728 | EXECUTE_IF_SET_IN_BITMAP | |
0fe854a7 RH |
2729 | (modify_mem_list_set, 0, i, free_INSN_LIST_list (modify_mem_list + i)); |
2730 | bitmap_clear (modify_mem_list_set); | |
73991d6a JH |
2731 | |
2732 | EXECUTE_IF_SET_IN_BITMAP | |
2733 | (canon_modify_mem_list_set, 0, i, | |
0fe854a7 RH |
2734 | free_insn_expr_list_list (canon_modify_mem_list + i)); |
2735 | bitmap_clear (canon_modify_mem_list_set); | |
73991d6a JH |
2736 | } |
2737 | ||
2738 | /* Release memory used by modify_mem_list_set and canon_modify_mem_list_set. */ | |
2739 | ||
2740 | static void | |
2741 | free_modify_mem_tables () | |
2742 | { | |
2743 | clear_modify_mem_tables (); | |
2744 | free (modify_mem_list); | |
2745 | free (canon_modify_mem_list); | |
2746 | modify_mem_list = 0; | |
2747 | canon_modify_mem_list = 0; | |
2748 | } | |
2749 | ||
7506f491 DE |
2750 | /* Reset tables used to keep track of what's still available [since the |
2751 | start of the block]. */ | |
2752 | ||
2753 | static void | |
2754 | reset_opr_set_tables () | |
2755 | { | |
2756 | /* Maintain a bitmap of which regs have been set since beginning of | |
2757 | the block. */ | |
73991d6a | 2758 | CLEAR_REG_SET (reg_set_bitmap); |
c4c81601 | 2759 | |
7506f491 DE |
2760 | /* Also keep a record of the last instruction to modify memory. |
2761 | For now this is very trivial, we only record whether any memory | |
2762 | location has been modified. */ | |
73991d6a | 2763 | clear_modify_mem_tables (); |
7506f491 DE |
2764 | } |
2765 | ||
cc2902df | 2766 | /* Return nonzero if the operands of X are not set before INSN in |
7506f491 DE |
2767 | INSN's basic block. */ |
2768 | ||
2769 | static int | |
2770 | oprs_not_set_p (x, insn) | |
2771 | rtx x, insn; | |
2772 | { | |
c4c81601 | 2773 | int i, j; |
7506f491 | 2774 | enum rtx_code code; |
6f7d635c | 2775 | const char *fmt; |
7506f491 | 2776 | |
7506f491 DE |
2777 | if (x == 0) |
2778 | return 1; | |
2779 | ||
2780 | code = GET_CODE (x); | |
2781 | switch (code) | |
2782 | { | |
2783 | case PC: | |
2784 | case CC0: | |
2785 | case CONST: | |
2786 | case CONST_INT: | |
2787 | case CONST_DOUBLE: | |
69ef87e2 | 2788 | case CONST_VECTOR: |
7506f491 DE |
2789 | case SYMBOL_REF: |
2790 | case LABEL_REF: | |
2791 | case ADDR_VEC: | |
2792 | case ADDR_DIFF_VEC: | |
2793 | return 1; | |
2794 | ||
2795 | case MEM: | |
589005ff | 2796 | if (load_killed_in_block_p (BLOCK_FOR_INSN (insn), |
e2d2ed72 | 2797 | INSN_CUID (insn), x, 0)) |
a13d4ebf | 2798 | return 0; |
c4c81601 RK |
2799 | else |
2800 | return oprs_not_set_p (XEXP (x, 0), insn); | |
7506f491 DE |
2801 | |
2802 | case REG: | |
73991d6a | 2803 | return ! REGNO_REG_SET_P (reg_set_bitmap, REGNO (x)); |
7506f491 DE |
2804 | |
2805 | default: | |
2806 | break; | |
2807 | } | |
2808 | ||
c4c81601 | 2809 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
2810 | { |
2811 | if (fmt[i] == 'e') | |
2812 | { | |
7506f491 DE |
2813 | /* If we are about to do the last recursive call |
2814 | needed at this level, change it into iteration. | |
2815 | This function is called enough to be worth it. */ | |
2816 | if (i == 0) | |
c4c81601 RK |
2817 | return oprs_not_set_p (XEXP (x, i), insn); |
2818 | ||
2819 | if (! oprs_not_set_p (XEXP (x, i), insn)) | |
7506f491 DE |
2820 | return 0; |
2821 | } | |
2822 | else if (fmt[i] == 'E') | |
c4c81601 RK |
2823 | for (j = 0; j < XVECLEN (x, i); j++) |
2824 | if (! oprs_not_set_p (XVECEXP (x, i, j), insn)) | |
2825 | return 0; | |
7506f491 DE |
2826 | } |
2827 | ||
2828 | return 1; | |
2829 | } | |
2830 | ||
2831 | /* Mark things set by a CALL. */ | |
2832 | ||
2833 | static void | |
b5ce41ff JL |
2834 | mark_call (insn) |
2835 | rtx insn; | |
7506f491 | 2836 | { |
24a28584 | 2837 | if (! CONST_OR_PURE_CALL_P (insn)) |
a13d4ebf | 2838 | record_last_mem_set_info (insn); |
7506f491 DE |
2839 | } |
2840 | ||
2841 | /* Mark things set by a SET. */ | |
2842 | ||
2843 | static void | |
2844 | mark_set (pat, insn) | |
2845 | rtx pat, insn; | |
2846 | { | |
2847 | rtx dest = SET_DEST (pat); | |
2848 | ||
2849 | while (GET_CODE (dest) == SUBREG | |
2850 | || GET_CODE (dest) == ZERO_EXTRACT | |
2851 | || GET_CODE (dest) == SIGN_EXTRACT | |
2852 | || GET_CODE (dest) == STRICT_LOW_PART) | |
2853 | dest = XEXP (dest, 0); | |
2854 | ||
a13d4ebf | 2855 | if (GET_CODE (dest) == REG) |
73991d6a | 2856 | SET_REGNO_REG_SET (reg_set_bitmap, REGNO (dest)); |
a13d4ebf AM |
2857 | else if (GET_CODE (dest) == MEM) |
2858 | record_last_mem_set_info (insn); | |
2859 | ||
7506f491 | 2860 | if (GET_CODE (SET_SRC (pat)) == CALL) |
b5ce41ff | 2861 | mark_call (insn); |
7506f491 DE |
2862 | } |
2863 | ||
2864 | /* Record things set by a CLOBBER. */ | |
2865 | ||
2866 | static void | |
2867 | mark_clobber (pat, insn) | |
2868 | rtx pat, insn; | |
2869 | { | |
2870 | rtx clob = XEXP (pat, 0); | |
2871 | ||
2872 | while (GET_CODE (clob) == SUBREG || GET_CODE (clob) == STRICT_LOW_PART) | |
2873 | clob = XEXP (clob, 0); | |
2874 | ||
a13d4ebf | 2875 | if (GET_CODE (clob) == REG) |
73991d6a | 2876 | SET_REGNO_REG_SET (reg_set_bitmap, REGNO (clob)); |
a13d4ebf AM |
2877 | else |
2878 | record_last_mem_set_info (insn); | |
7506f491 DE |
2879 | } |
2880 | ||
2881 | /* Record things set by INSN. | |
2882 | This data is used by oprs_not_set_p. */ | |
2883 | ||
2884 | static void | |
2885 | mark_oprs_set (insn) | |
2886 | rtx insn; | |
2887 | { | |
2888 | rtx pat = PATTERN (insn); | |
c4c81601 | 2889 | int i; |
7506f491 DE |
2890 | |
2891 | if (GET_CODE (pat) == SET) | |
2892 | mark_set (pat, insn); | |
2893 | else if (GET_CODE (pat) == PARALLEL) | |
c4c81601 RK |
2894 | for (i = 0; i < XVECLEN (pat, 0); i++) |
2895 | { | |
2896 | rtx x = XVECEXP (pat, 0, i); | |
2897 | ||
2898 | if (GET_CODE (x) == SET) | |
2899 | mark_set (x, insn); | |
2900 | else if (GET_CODE (x) == CLOBBER) | |
2901 | mark_clobber (x, insn); | |
2902 | else if (GET_CODE (x) == CALL) | |
2903 | mark_call (insn); | |
2904 | } | |
7506f491 | 2905 | |
7506f491 DE |
2906 | else if (GET_CODE (pat) == CLOBBER) |
2907 | mark_clobber (pat, insn); | |
2908 | else if (GET_CODE (pat) == CALL) | |
b5ce41ff | 2909 | mark_call (insn); |
7506f491 | 2910 | } |
b5ce41ff | 2911 | |
7506f491 DE |
2912 | \f |
2913 | /* Classic GCSE reaching definition support. */ | |
2914 | ||
2915 | /* Allocate reaching def variables. */ | |
2916 | ||
2917 | static void | |
2918 | alloc_rd_mem (n_blocks, n_insns) | |
2919 | int n_blocks, n_insns; | |
2920 | { | |
2921 | rd_kill = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_insns); | |
d55bc081 | 2922 | sbitmap_vector_zero (rd_kill, n_blocks); |
7506f491 DE |
2923 | |
2924 | rd_gen = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_insns); | |
d55bc081 | 2925 | sbitmap_vector_zero (rd_gen, n_blocks); |
7506f491 DE |
2926 | |
2927 | reaching_defs = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_insns); | |
d55bc081 | 2928 | sbitmap_vector_zero (reaching_defs, n_blocks); |
7506f491 DE |
2929 | |
2930 | rd_out = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_insns); | |
d55bc081 | 2931 | sbitmap_vector_zero (rd_out, n_blocks); |
7506f491 DE |
2932 | } |
2933 | ||
2934 | /* Free reaching def variables. */ | |
2935 | ||
2936 | static void | |
2937 | free_rd_mem () | |
2938 | { | |
5a660bff DB |
2939 | sbitmap_vector_free (rd_kill); |
2940 | sbitmap_vector_free (rd_gen); | |
2941 | sbitmap_vector_free (reaching_defs); | |
2942 | sbitmap_vector_free (rd_out); | |
7506f491 DE |
2943 | } |
2944 | ||
c4c81601 | 2945 | /* Add INSN to the kills of BB. REGNO, set in BB, is killed by INSN. */ |
7506f491 DE |
2946 | |
2947 | static void | |
2948 | handle_rd_kill_set (insn, regno, bb) | |
2949 | rtx insn; | |
e2d2ed72 AM |
2950 | int regno; |
2951 | basic_block bb; | |
7506f491 | 2952 | { |
c4c81601 | 2953 | struct reg_set *this_reg; |
7506f491 | 2954 | |
c4c81601 RK |
2955 | for (this_reg = reg_set_table[regno]; this_reg; this_reg = this_reg ->next) |
2956 | if (BLOCK_NUM (this_reg->insn) != BLOCK_NUM (insn)) | |
0b17ab2f | 2957 | SET_BIT (rd_kill[bb->index], INSN_CUID (this_reg->insn)); |
7506f491 DE |
2958 | } |
2959 | ||
7506f491 DE |
2960 | /* Compute the set of kill's for reaching definitions. */ |
2961 | ||
2962 | static void | |
2963 | compute_kill_rd () | |
2964 | { | |
e0082a72 | 2965 | int cuid; |
172890a2 RK |
2966 | unsigned int regno; |
2967 | int i; | |
e0082a72 | 2968 | basic_block bb; |
7506f491 DE |
2969 | |
2970 | /* For each block | |
2971 | For each set bit in `gen' of the block (i.e each insn which | |
ac7c5af5 JL |
2972 | generates a definition in the block) |
2973 | Call the reg set by the insn corresponding to that bit regx | |
2974 | Look at the linked list starting at reg_set_table[regx] | |
2975 | For each setting of regx in the linked list, which is not in | |
2976 | this block | |
6d2f8887 | 2977 | Set the bit in `kill' corresponding to that insn. */ |
e0082a72 | 2978 | FOR_EACH_BB (bb) |
c4c81601 | 2979 | for (cuid = 0; cuid < max_cuid; cuid++) |
e0082a72 | 2980 | if (TEST_BIT (rd_gen[bb->index], cuid)) |
7506f491 | 2981 | { |
c4c81601 RK |
2982 | rtx insn = CUID_INSN (cuid); |
2983 | rtx pat = PATTERN (insn); | |
7506f491 | 2984 | |
c4c81601 RK |
2985 | if (GET_CODE (insn) == CALL_INSN) |
2986 | { | |
2987 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) | |
4e2db584 | 2988 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) |
e0082a72 | 2989 | handle_rd_kill_set (insn, regno, bb); |
c4c81601 | 2990 | } |
7506f491 | 2991 | |
c4c81601 RK |
2992 | if (GET_CODE (pat) == PARALLEL) |
2993 | { | |
2994 | for (i = XVECLEN (pat, 0) - 1; i >= 0; i--) | |
7506f491 | 2995 | { |
c4c81601 | 2996 | enum rtx_code code = GET_CODE (XVECEXP (pat, 0, i)); |
7506f491 | 2997 | |
c4c81601 RK |
2998 | if ((code == SET || code == CLOBBER) |
2999 | && GET_CODE (XEXP (XVECEXP (pat, 0, i), 0)) == REG) | |
3000 | handle_rd_kill_set (insn, | |
3001 | REGNO (XEXP (XVECEXP (pat, 0, i), 0)), | |
e0082a72 | 3002 | bb); |
ac7c5af5 | 3003 | } |
ac7c5af5 | 3004 | } |
c4c81601 RK |
3005 | else if (GET_CODE (pat) == SET && GET_CODE (SET_DEST (pat)) == REG) |
3006 | /* Each setting of this register outside of this block | |
3007 | must be marked in the set of kills in this block. */ | |
e0082a72 | 3008 | handle_rd_kill_set (insn, REGNO (SET_DEST (pat)), bb); |
7506f491 | 3009 | } |
7506f491 DE |
3010 | } |
3011 | ||
589005ff | 3012 | /* Compute the reaching definitions as in |
7506f491 DE |
3013 | Compilers Principles, Techniques, and Tools. Aho, Sethi, Ullman, |
3014 | Chapter 10. It is the same algorithm as used for computing available | |
3015 | expressions but applied to the gens and kills of reaching definitions. */ | |
3016 | ||
3017 | static void | |
3018 | compute_rd () | |
3019 | { | |
e0082a72 ZD |
3020 | int changed, passes; |
3021 | basic_block bb; | |
7506f491 | 3022 | |
e0082a72 ZD |
3023 | FOR_EACH_BB (bb) |
3024 | sbitmap_copy (rd_out[bb->index] /*dst*/, rd_gen[bb->index] /*src*/); | |
7506f491 DE |
3025 | |
3026 | passes = 0; | |
3027 | changed = 1; | |
3028 | while (changed) | |
3029 | { | |
3030 | changed = 0; | |
e0082a72 | 3031 | FOR_EACH_BB (bb) |
ac7c5af5 | 3032 | { |
e0082a72 ZD |
3033 | sbitmap_union_of_preds (reaching_defs[bb->index], rd_out, bb->index); |
3034 | changed |= sbitmap_union_of_diff_cg (rd_out[bb->index], rd_gen[bb->index], | |
3035 | reaching_defs[bb->index], rd_kill[bb->index]); | |
ac7c5af5 | 3036 | } |
7506f491 DE |
3037 | passes++; |
3038 | } | |
3039 | ||
3040 | if (gcse_file) | |
3041 | fprintf (gcse_file, "reaching def computation: %d passes\n", passes); | |
3042 | } | |
3043 | \f | |
3044 | /* Classic GCSE available expression support. */ | |
3045 | ||
3046 | /* Allocate memory for available expression computation. */ | |
3047 | ||
3048 | static void | |
3049 | alloc_avail_expr_mem (n_blocks, n_exprs) | |
3050 | int n_blocks, n_exprs; | |
3051 | { | |
3052 | ae_kill = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_exprs); | |
d55bc081 | 3053 | sbitmap_vector_zero (ae_kill, n_blocks); |
7506f491 DE |
3054 | |
3055 | ae_gen = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_exprs); | |
d55bc081 | 3056 | sbitmap_vector_zero (ae_gen, n_blocks); |
7506f491 DE |
3057 | |
3058 | ae_in = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_exprs); | |
d55bc081 | 3059 | sbitmap_vector_zero (ae_in, n_blocks); |
7506f491 DE |
3060 | |
3061 | ae_out = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_exprs); | |
d55bc081 | 3062 | sbitmap_vector_zero (ae_out, n_blocks); |
7506f491 DE |
3063 | } |
3064 | ||
3065 | static void | |
3066 | free_avail_expr_mem () | |
3067 | { | |
5a660bff DB |
3068 | sbitmap_vector_free (ae_kill); |
3069 | sbitmap_vector_free (ae_gen); | |
3070 | sbitmap_vector_free (ae_in); | |
3071 | sbitmap_vector_free (ae_out); | |
7506f491 DE |
3072 | } |
3073 | ||
3074 | /* Compute the set of available expressions generated in each basic block. */ | |
3075 | ||
3076 | static void | |
02280659 ZD |
3077 | compute_ae_gen (expr_hash_table) |
3078 | struct hash_table *expr_hash_table; | |
7506f491 | 3079 | { |
2e653e39 | 3080 | unsigned int i; |
c4c81601 RK |
3081 | struct expr *expr; |
3082 | struct occr *occr; | |
7506f491 DE |
3083 | |
3084 | /* For each recorded occurrence of each expression, set ae_gen[bb][expr]. | |
3085 | This is all we have to do because an expression is not recorded if it | |
3086 | is not available, and the only expressions we want to work with are the | |
3087 | ones that are recorded. */ | |
02280659 ZD |
3088 | for (i = 0; i < expr_hash_table->size; i++) |
3089 | for (expr = expr_hash_table->table[i]; expr != 0; expr = expr->next_same_hash) | |
c4c81601 RK |
3090 | for (occr = expr->avail_occr; occr != 0; occr = occr->next) |
3091 | SET_BIT (ae_gen[BLOCK_NUM (occr->insn)], expr->bitmap_index); | |
7506f491 DE |
3092 | } |
3093 | ||
cc2902df | 3094 | /* Return nonzero if expression X is killed in BB. */ |
7506f491 DE |
3095 | |
3096 | static int | |
3097 | expr_killed_p (x, bb) | |
3098 | rtx x; | |
e2d2ed72 | 3099 | basic_block bb; |
7506f491 | 3100 | { |
c4c81601 | 3101 | int i, j; |
7506f491 | 3102 | enum rtx_code code; |
6f7d635c | 3103 | const char *fmt; |
7506f491 | 3104 | |
7506f491 DE |
3105 | if (x == 0) |
3106 | return 1; | |
3107 | ||
3108 | code = GET_CODE (x); | |
3109 | switch (code) | |
3110 | { | |
3111 | case REG: | |
0b17ab2f | 3112 | return TEST_BIT (reg_set_in_block[bb->index], REGNO (x)); |
7506f491 DE |
3113 | |
3114 | case MEM: | |
a13d4ebf AM |
3115 | if (load_killed_in_block_p (bb, get_max_uid () + 1, x, 0)) |
3116 | return 1; | |
c4c81601 RK |
3117 | else |
3118 | return expr_killed_p (XEXP (x, 0), bb); | |
7506f491 DE |
3119 | |
3120 | case PC: | |
3121 | case CC0: /*FIXME*/ | |
3122 | case CONST: | |
3123 | case CONST_INT: | |
3124 | case CONST_DOUBLE: | |
69ef87e2 | 3125 | case CONST_VECTOR: |
7506f491 DE |
3126 | case SYMBOL_REF: |
3127 | case LABEL_REF: | |
3128 | case ADDR_VEC: | |
3129 | case ADDR_DIFF_VEC: | |
3130 | return 0; | |
3131 | ||
3132 | default: | |
3133 | break; | |
3134 | } | |
3135 | ||
c4c81601 | 3136 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
3137 | { |
3138 | if (fmt[i] == 'e') | |
3139 | { | |
7506f491 DE |
3140 | /* If we are about to do the last recursive call |
3141 | needed at this level, change it into iteration. | |
3142 | This function is called enough to be worth it. */ | |
3143 | if (i == 0) | |
c4c81601 RK |
3144 | return expr_killed_p (XEXP (x, i), bb); |
3145 | else if (expr_killed_p (XEXP (x, i), bb)) | |
7506f491 DE |
3146 | return 1; |
3147 | } | |
3148 | else if (fmt[i] == 'E') | |
c4c81601 RK |
3149 | for (j = 0; j < XVECLEN (x, i); j++) |
3150 | if (expr_killed_p (XVECEXP (x, i, j), bb)) | |
3151 | return 1; | |
7506f491 DE |
3152 | } |
3153 | ||
3154 | return 0; | |
3155 | } | |
3156 | ||
3157 | /* Compute the set of available expressions killed in each basic block. */ | |
3158 | ||
3159 | static void | |
02280659 | 3160 | compute_ae_kill (ae_gen, ae_kill, expr_hash_table) |
a42cd965 | 3161 | sbitmap *ae_gen, *ae_kill; |
02280659 | 3162 | struct hash_table *expr_hash_table; |
7506f491 | 3163 | { |
e0082a72 | 3164 | basic_block bb; |
2e653e39 | 3165 | unsigned int i; |
c4c81601 | 3166 | struct expr *expr; |
7506f491 | 3167 | |
e0082a72 | 3168 | FOR_EACH_BB (bb) |
02280659 ZD |
3169 | for (i = 0; i < expr_hash_table->size; i++) |
3170 | for (expr = expr_hash_table->table[i]; expr; expr = expr->next_same_hash) | |
7506f491 | 3171 | { |
c4c81601 | 3172 | /* Skip EXPR if generated in this block. */ |
e0082a72 | 3173 | if (TEST_BIT (ae_gen[bb->index], expr->bitmap_index)) |
c4c81601 | 3174 | continue; |
7506f491 | 3175 | |
e0082a72 ZD |
3176 | if (expr_killed_p (expr->expr, bb)) |
3177 | SET_BIT (ae_kill[bb->index], expr->bitmap_index); | |
7506f491 | 3178 | } |
7506f491 | 3179 | } |
7506f491 DE |
3180 | \f |
3181 | /* Actually perform the Classic GCSE optimizations. */ | |
3182 | ||
cc2902df | 3183 | /* Return nonzero if occurrence OCCR of expression EXPR reaches block BB. |
7506f491 | 3184 | |
cc2902df | 3185 | CHECK_SELF_LOOP is nonzero if we should consider a block reaching itself |
7506f491 DE |
3186 | as a positive reach. We want to do this when there are two computations |
3187 | of the expression in the block. | |
3188 | ||
3189 | VISITED is a pointer to a working buffer for tracking which BB's have | |
3190 | been visited. It is NULL for the top-level call. | |
3191 | ||
3192 | We treat reaching expressions that go through blocks containing the same | |
3193 | reaching expression as "not reaching". E.g. if EXPR is generated in blocks | |
3194 | 2 and 3, INSN is in block 4, and 2->3->4, we treat the expression in block | |
3195 | 2 as not reaching. The intent is to improve the probability of finding | |
3196 | only one reaching expression and to reduce register lifetimes by picking | |
3197 | the closest such expression. */ | |
3198 | ||
3199 | static int | |
283a2545 | 3200 | expr_reaches_here_p_work (occr, expr, bb, check_self_loop, visited) |
7506f491 DE |
3201 | struct occr *occr; |
3202 | struct expr *expr; | |
e2d2ed72 | 3203 | basic_block bb; |
7506f491 DE |
3204 | int check_self_loop; |
3205 | char *visited; | |
3206 | { | |
36349f8b | 3207 | edge pred; |
7506f491 | 3208 | |
e2d2ed72 | 3209 | for (pred = bb->pred; pred != NULL; pred = pred->pred_next) |
7506f491 | 3210 | { |
e2d2ed72 | 3211 | basic_block pred_bb = pred->src; |
7506f491 | 3212 | |
0b17ab2f | 3213 | if (visited[pred_bb->index]) |
c4c81601 | 3214 | /* This predecessor has already been visited. Nothing to do. */ |
7506f491 | 3215 | ; |
7506f491 | 3216 | else if (pred_bb == bb) |
ac7c5af5 | 3217 | { |
7506f491 DE |
3218 | /* BB loops on itself. */ |
3219 | if (check_self_loop | |
0b17ab2f RH |
3220 | && TEST_BIT (ae_gen[pred_bb->index], expr->bitmap_index) |
3221 | && BLOCK_NUM (occr->insn) == pred_bb->index) | |
7506f491 | 3222 | return 1; |
c4c81601 | 3223 | |
0b17ab2f | 3224 | visited[pred_bb->index] = 1; |
ac7c5af5 | 3225 | } |
c4c81601 | 3226 | |
7506f491 | 3227 | /* Ignore this predecessor if it kills the expression. */ |
0b17ab2f RH |
3228 | else if (TEST_BIT (ae_kill[pred_bb->index], expr->bitmap_index)) |
3229 | visited[pred_bb->index] = 1; | |
c4c81601 | 3230 | |
7506f491 | 3231 | /* Does this predecessor generate this expression? */ |
0b17ab2f | 3232 | else if (TEST_BIT (ae_gen[pred_bb->index], expr->bitmap_index)) |
7506f491 DE |
3233 | { |
3234 | /* Is this the occurrence we're looking for? | |
3235 | Note that there's only one generating occurrence per block | |
3236 | so we just need to check the block number. */ | |
0b17ab2f | 3237 | if (BLOCK_NUM (occr->insn) == pred_bb->index) |
7506f491 | 3238 | return 1; |
c4c81601 | 3239 | |
0b17ab2f | 3240 | visited[pred_bb->index] = 1; |
7506f491 | 3241 | } |
c4c81601 | 3242 | |
7506f491 DE |
3243 | /* Neither gen nor kill. */ |
3244 | else | |
ac7c5af5 | 3245 | { |
0b17ab2f | 3246 | visited[pred_bb->index] = 1; |
589005ff | 3247 | if (expr_reaches_here_p_work (occr, expr, pred_bb, check_self_loop, |
283a2545 | 3248 | visited)) |
c4c81601 | 3249 | |
7506f491 | 3250 | return 1; |
ac7c5af5 | 3251 | } |
7506f491 DE |
3252 | } |
3253 | ||
3254 | /* All paths have been checked. */ | |
3255 | return 0; | |
3256 | } | |
3257 | ||
283a2545 | 3258 | /* This wrapper for expr_reaches_here_p_work() is to ensure that any |
dc297297 | 3259 | memory allocated for that function is returned. */ |
283a2545 RL |
3260 | |
3261 | static int | |
3262 | expr_reaches_here_p (occr, expr, bb, check_self_loop) | |
3263 | struct occr *occr; | |
3264 | struct expr *expr; | |
e2d2ed72 | 3265 | basic_block bb; |
283a2545 RL |
3266 | int check_self_loop; |
3267 | { | |
3268 | int rval; | |
d55bc081 | 3269 | char *visited = (char *) xcalloc (last_basic_block, 1); |
283a2545 | 3270 | |
c4c81601 | 3271 | rval = expr_reaches_here_p_work (occr, expr, bb, check_self_loop, visited); |
589005ff | 3272 | |
283a2545 | 3273 | free (visited); |
c4c81601 | 3274 | return rval; |
283a2545 RL |
3275 | } |
3276 | ||
7506f491 DE |
3277 | /* Return the instruction that computes EXPR that reaches INSN's basic block. |
3278 | If there is more than one such instruction, return NULL. | |
3279 | ||
3280 | Called only by handle_avail_expr. */ | |
3281 | ||
3282 | static rtx | |
3283 | computing_insn (expr, insn) | |
3284 | struct expr *expr; | |
3285 | rtx insn; | |
3286 | { | |
e2d2ed72 | 3287 | basic_block bb = BLOCK_FOR_INSN (insn); |
7506f491 DE |
3288 | |
3289 | if (expr->avail_occr->next == NULL) | |
589005ff | 3290 | { |
e2d2ed72 | 3291 | if (BLOCK_FOR_INSN (expr->avail_occr->insn) == bb) |
c4c81601 RK |
3292 | /* The available expression is actually itself |
3293 | (i.e. a loop in the flow graph) so do nothing. */ | |
3294 | return NULL; | |
3295 | ||
7506f491 DE |
3296 | /* (FIXME) Case that we found a pattern that was created by |
3297 | a substitution that took place. */ | |
3298 | return expr->avail_occr->insn; | |
3299 | } | |
3300 | else | |
3301 | { | |
3302 | /* Pattern is computed more than once. | |
589005ff | 3303 | Search backwards from this insn to see how many of these |
7506f491 DE |
3304 | computations actually reach this insn. */ |
3305 | struct occr *occr; | |
3306 | rtx insn_computes_expr = NULL; | |
3307 | int can_reach = 0; | |
3308 | ||
3309 | for (occr = expr->avail_occr; occr != NULL; occr = occr->next) | |
3310 | { | |
e2d2ed72 | 3311 | if (BLOCK_FOR_INSN (occr->insn) == bb) |
7506f491 DE |
3312 | { |
3313 | /* The expression is generated in this block. | |
3314 | The only time we care about this is when the expression | |
3315 | is generated later in the block [and thus there's a loop]. | |
3316 | We let the normal cse pass handle the other cases. */ | |
c4c81601 RK |
3317 | if (INSN_CUID (insn) < INSN_CUID (occr->insn) |
3318 | && expr_reaches_here_p (occr, expr, bb, 1)) | |
7506f491 DE |
3319 | { |
3320 | can_reach++; | |
3321 | if (can_reach > 1) | |
3322 | return NULL; | |
c4c81601 | 3323 | |
7506f491 DE |
3324 | insn_computes_expr = occr->insn; |
3325 | } | |
3326 | } | |
c4c81601 RK |
3327 | else if (expr_reaches_here_p (occr, expr, bb, 0)) |
3328 | { | |
3329 | can_reach++; | |
3330 | if (can_reach > 1) | |
3331 | return NULL; | |
3332 | ||
3333 | insn_computes_expr = occr->insn; | |
3334 | } | |
7506f491 DE |
3335 | } |
3336 | ||
3337 | if (insn_computes_expr == NULL) | |
3338 | abort (); | |
c4c81601 | 3339 | |
7506f491 DE |
3340 | return insn_computes_expr; |
3341 | } | |
3342 | } | |
3343 | ||
cc2902df | 3344 | /* Return nonzero if the definition in DEF_INSN can reach INSN. |
7506f491 DE |
3345 | Only called by can_disregard_other_sets. */ |
3346 | ||
3347 | static int | |
3348 | def_reaches_here_p (insn, def_insn) | |
3349 | rtx insn, def_insn; | |
3350 | { | |
3351 | rtx reg; | |
3352 | ||
3353 | if (TEST_BIT (reaching_defs[BLOCK_NUM (insn)], INSN_CUID (def_insn))) | |
3354 | return 1; | |
3355 | ||
3356 | if (BLOCK_NUM (insn) == BLOCK_NUM (def_insn)) | |
3357 | { | |
3358 | if (INSN_CUID (def_insn) < INSN_CUID (insn)) | |
ac7c5af5 | 3359 | { |
7506f491 DE |
3360 | if (GET_CODE (PATTERN (def_insn)) == PARALLEL) |
3361 | return 1; | |
c4c81601 | 3362 | else if (GET_CODE (PATTERN (def_insn)) == CLOBBER) |
7506f491 DE |
3363 | reg = XEXP (PATTERN (def_insn), 0); |
3364 | else if (GET_CODE (PATTERN (def_insn)) == SET) | |
3365 | reg = SET_DEST (PATTERN (def_insn)); | |
3366 | else | |
3367 | abort (); | |
c4c81601 | 3368 | |
7506f491 DE |
3369 | return ! reg_set_between_p (reg, NEXT_INSN (def_insn), insn); |
3370 | } | |
3371 | else | |
3372 | return 0; | |
3373 | } | |
3374 | ||
3375 | return 0; | |
3376 | } | |
3377 | ||
cc2902df | 3378 | /* Return nonzero if *ADDR_THIS_REG can only have one value at INSN. The |
c4c81601 RK |
3379 | value returned is the number of definitions that reach INSN. Returning a |
3380 | value of zero means that [maybe] more than one definition reaches INSN and | |
3381 | the caller can't perform whatever optimization it is trying. i.e. it is | |
3382 | always safe to return zero. */ | |
7506f491 DE |
3383 | |
3384 | static int | |
3385 | can_disregard_other_sets (addr_this_reg, insn, for_combine) | |
3386 | struct reg_set **addr_this_reg; | |
3387 | rtx insn; | |
3388 | int for_combine; | |
3389 | { | |
3390 | int number_of_reaching_defs = 0; | |
c4c81601 | 3391 | struct reg_set *this_reg; |
7506f491 | 3392 | |
c4c81601 RK |
3393 | for (this_reg = *addr_this_reg; this_reg != 0; this_reg = this_reg->next) |
3394 | if (def_reaches_here_p (insn, this_reg->insn)) | |
3395 | { | |
3396 | number_of_reaching_defs++; | |
3397 | /* Ignore parallels for now. */ | |
3398 | if (GET_CODE (PATTERN (this_reg->insn)) == PARALLEL) | |
3399 | return 0; | |
3400 | ||
3401 | if (!for_combine | |
3402 | && (GET_CODE (PATTERN (this_reg->insn)) == CLOBBER | |
3403 | || ! rtx_equal_p (SET_SRC (PATTERN (this_reg->insn)), | |
3404 | SET_SRC (PATTERN (insn))))) | |
3405 | /* A setting of the reg to a different value reaches INSN. */ | |
3406 | return 0; | |
3407 | ||
3408 | if (number_of_reaching_defs > 1) | |
3409 | { | |
3410 | /* If in this setting the value the register is being set to is | |
3411 | equal to the previous value the register was set to and this | |
3412 | setting reaches the insn we are trying to do the substitution | |
3413 | on then we are ok. */ | |
3414 | if (GET_CODE (PATTERN (this_reg->insn)) == CLOBBER) | |
7506f491 | 3415 | return 0; |
c4c81601 RK |
3416 | else if (! rtx_equal_p (SET_SRC (PATTERN (this_reg->insn)), |
3417 | SET_SRC (PATTERN (insn)))) | |
3418 | return 0; | |
3419 | } | |
7506f491 | 3420 | |
589005ff | 3421 | *addr_this_reg = this_reg; |
c4c81601 | 3422 | } |
7506f491 DE |
3423 | |
3424 | return number_of_reaching_defs; | |
3425 | } | |
3426 | ||
3427 | /* Expression computed by insn is available and the substitution is legal, | |
3428 | so try to perform the substitution. | |
3429 | ||
cc2902df | 3430 | The result is nonzero if any changes were made. */ |
7506f491 DE |
3431 | |
3432 | static int | |
3433 | handle_avail_expr (insn, expr) | |
3434 | rtx insn; | |
3435 | struct expr *expr; | |
3436 | { | |
0631e0bf | 3437 | rtx pat, insn_computes_expr, expr_set; |
7506f491 DE |
3438 | rtx to; |
3439 | struct reg_set *this_reg; | |
3440 | int found_setting, use_src; | |
3441 | int changed = 0; | |
3442 | ||
3443 | /* We only handle the case where one computation of the expression | |
3444 | reaches this instruction. */ | |
3445 | insn_computes_expr = computing_insn (expr, insn); | |
3446 | if (insn_computes_expr == NULL) | |
3447 | return 0; | |
0631e0bf JH |
3448 | expr_set = single_set (insn_computes_expr); |
3449 | if (!expr_set) | |
3450 | abort (); | |
7506f491 DE |
3451 | |
3452 | found_setting = 0; | |
3453 | use_src = 0; | |
3454 | ||
3455 | /* At this point we know only one computation of EXPR outside of this | |
3456 | block reaches this insn. Now try to find a register that the | |
3457 | expression is computed into. */ | |
0631e0bf | 3458 | if (GET_CODE (SET_SRC (expr_set)) == REG) |
7506f491 DE |
3459 | { |
3460 | /* This is the case when the available expression that reaches | |
3461 | here has already been handled as an available expression. */ | |
770ae6cc | 3462 | unsigned int regnum_for_replacing |
0631e0bf | 3463 | = REGNO (SET_SRC (expr_set)); |
c4c81601 | 3464 | |
7506f491 DE |
3465 | /* If the register was created by GCSE we can't use `reg_set_table', |
3466 | however we know it's set only once. */ | |
3467 | if (regnum_for_replacing >= max_gcse_regno | |
3468 | /* If the register the expression is computed into is set only once, | |
3469 | or only one set reaches this insn, we can use it. */ | |
3470 | || (((this_reg = reg_set_table[regnum_for_replacing]), | |
3471 | this_reg->next == NULL) | |
3472 | || can_disregard_other_sets (&this_reg, insn, 0))) | |
8e42ace1 KH |
3473 | { |
3474 | use_src = 1; | |
3475 | found_setting = 1; | |
3476 | } | |
7506f491 DE |
3477 | } |
3478 | ||
3479 | if (!found_setting) | |
3480 | { | |
770ae6cc | 3481 | unsigned int regnum_for_replacing |
0631e0bf | 3482 | = REGNO (SET_DEST (expr_set)); |
c4c81601 | 3483 | |
7506f491 DE |
3484 | /* This shouldn't happen. */ |
3485 | if (regnum_for_replacing >= max_gcse_regno) | |
3486 | abort (); | |
c4c81601 | 3487 | |
7506f491 | 3488 | this_reg = reg_set_table[regnum_for_replacing]; |
c4c81601 | 3489 | |
7506f491 DE |
3490 | /* If the register the expression is computed into is set only once, |
3491 | or only one set reaches this insn, use it. */ | |
3492 | if (this_reg->next == NULL | |
3493 | || can_disregard_other_sets (&this_reg, insn, 0)) | |
3494 | found_setting = 1; | |
3495 | } | |
3496 | ||
3497 | if (found_setting) | |
3498 | { | |
3499 | pat = PATTERN (insn); | |
3500 | if (use_src) | |
0631e0bf | 3501 | to = SET_SRC (expr_set); |
7506f491 | 3502 | else |
0631e0bf | 3503 | to = SET_DEST (expr_set); |
7506f491 DE |
3504 | changed = validate_change (insn, &SET_SRC (pat), to, 0); |
3505 | ||
3506 | /* We should be able to ignore the return code from validate_change but | |
3507 | to play it safe we check. */ | |
3508 | if (changed) | |
3509 | { | |
3510 | gcse_subst_count++; | |
3511 | if (gcse_file != NULL) | |
3512 | { | |
c4c81601 RK |
3513 | fprintf (gcse_file, "GCSE: Replacing the source in insn %d with", |
3514 | INSN_UID (insn)); | |
3515 | fprintf (gcse_file, " reg %d %s insn %d\n", | |
3516 | REGNO (to), use_src ? "from" : "set in", | |
7506f491 DE |
3517 | INSN_UID (insn_computes_expr)); |
3518 | } | |
7506f491 DE |
3519 | } |
3520 | } | |
c4c81601 | 3521 | |
7506f491 DE |
3522 | /* The register that the expr is computed into is set more than once. */ |
3523 | else if (1 /*expensive_op(this_pattrn->op) && do_expensive_gcse)*/) | |
3524 | { | |
3525 | /* Insert an insn after insnx that copies the reg set in insnx | |
3526 | into a new pseudo register call this new register REGN. | |
3527 | From insnb until end of basic block or until REGB is set | |
3528 | replace all uses of REGB with REGN. */ | |
3529 | rtx new_insn; | |
3530 | ||
0631e0bf | 3531 | to = gen_reg_rtx (GET_MODE (SET_DEST (expr_set))); |
7506f491 DE |
3532 | |
3533 | /* Generate the new insn. */ | |
3534 | /* ??? If the change fails, we return 0, even though we created | |
3535 | an insn. I think this is ok. */ | |
9e6a5703 JC |
3536 | new_insn |
3537 | = emit_insn_after (gen_rtx_SET (VOIDmode, to, | |
0631e0bf | 3538 | SET_DEST (expr_set)), |
c4c81601 RK |
3539 | insn_computes_expr); |
3540 | ||
7506f491 DE |
3541 | /* Keep register set table up to date. */ |
3542 | record_one_set (REGNO (to), new_insn); | |
3543 | ||
3544 | gcse_create_count++; | |
3545 | if (gcse_file != NULL) | |
ac7c5af5 | 3546 | { |
c4c81601 | 3547 | fprintf (gcse_file, "GCSE: Creating insn %d to copy value of reg %d", |
7506f491 | 3548 | INSN_UID (NEXT_INSN (insn_computes_expr)), |
c4c81601 RK |
3549 | REGNO (SET_SRC (PATTERN (NEXT_INSN (insn_computes_expr))))); |
3550 | fprintf (gcse_file, ", computed in insn %d,\n", | |
7506f491 | 3551 | INSN_UID (insn_computes_expr)); |
c4c81601 RK |
3552 | fprintf (gcse_file, " into newly allocated reg %d\n", |
3553 | REGNO (to)); | |
ac7c5af5 | 3554 | } |
7506f491 DE |
3555 | |
3556 | pat = PATTERN (insn); | |
3557 | ||
3558 | /* Do register replacement for INSN. */ | |
3559 | changed = validate_change (insn, &SET_SRC (pat), | |
c4c81601 RK |
3560 | SET_DEST (PATTERN |
3561 | (NEXT_INSN (insn_computes_expr))), | |
7506f491 DE |
3562 | 0); |
3563 | ||
3564 | /* We should be able to ignore the return code from validate_change but | |
3565 | to play it safe we check. */ | |
3566 | if (changed) | |
3567 | { | |
3568 | gcse_subst_count++; | |
3569 | if (gcse_file != NULL) | |
3570 | { | |
c4c81601 RK |
3571 | fprintf (gcse_file, |
3572 | "GCSE: Replacing the source in insn %d with reg %d ", | |
7506f491 | 3573 | INSN_UID (insn), |
c4c81601 RK |
3574 | REGNO (SET_DEST (PATTERN (NEXT_INSN |
3575 | (insn_computes_expr))))); | |
3576 | fprintf (gcse_file, "set in insn %d\n", | |
589005ff | 3577 | INSN_UID (insn_computes_expr)); |
7506f491 | 3578 | } |
7506f491 DE |
3579 | } |
3580 | } | |
3581 | ||
3582 | return changed; | |
3583 | } | |
3584 | ||
c4c81601 RK |
3585 | /* Perform classic GCSE. This is called by one_classic_gcse_pass after all |
3586 | the dataflow analysis has been done. | |
7506f491 | 3587 | |
cc2902df | 3588 | The result is nonzero if a change was made. */ |
7506f491 DE |
3589 | |
3590 | static int | |
3591 | classic_gcse () | |
3592 | { | |
e0082a72 | 3593 | int changed; |
7506f491 | 3594 | rtx insn; |
e0082a72 | 3595 | basic_block bb; |
7506f491 DE |
3596 | |
3597 | /* Note we start at block 1. */ | |
3598 | ||
e0082a72 ZD |
3599 | if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) |
3600 | return 0; | |
3601 | ||
7506f491 | 3602 | changed = 0; |
e0082a72 | 3603 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb->next_bb, EXIT_BLOCK_PTR, next_bb) |
7506f491 DE |
3604 | { |
3605 | /* Reset tables used to keep track of what's still valid [since the | |
3606 | start of the block]. */ | |
3607 | reset_opr_set_tables (); | |
3608 | ||
e0082a72 ZD |
3609 | for (insn = bb->head; |
3610 | insn != NULL && insn != NEXT_INSN (bb->end); | |
7506f491 DE |
3611 | insn = NEXT_INSN (insn)) |
3612 | { | |
3613 | /* Is insn of form (set (pseudo-reg) ...)? */ | |
7506f491 DE |
3614 | if (GET_CODE (insn) == INSN |
3615 | && GET_CODE (PATTERN (insn)) == SET | |
3616 | && GET_CODE (SET_DEST (PATTERN (insn))) == REG | |
3617 | && REGNO (SET_DEST (PATTERN (insn))) >= FIRST_PSEUDO_REGISTER) | |
3618 | { | |
3619 | rtx pat = PATTERN (insn); | |
3620 | rtx src = SET_SRC (pat); | |
3621 | struct expr *expr; | |
3622 | ||
3623 | if (want_to_gcse_p (src) | |
3624 | /* Is the expression recorded? */ | |
02280659 | 3625 | && ((expr = lookup_expr (src, &expr_hash_table)) != NULL) |
7506f491 DE |
3626 | /* Is the expression available [at the start of the |
3627 | block]? */ | |
e0082a72 | 3628 | && TEST_BIT (ae_in[bb->index], expr->bitmap_index) |
7506f491 DE |
3629 | /* Are the operands unchanged since the start of the |
3630 | block? */ | |
3631 | && oprs_not_set_p (src, insn)) | |
3632 | changed |= handle_avail_expr (insn, expr); | |
3633 | } | |
3634 | ||
3635 | /* Keep track of everything modified by this insn. */ | |
3636 | /* ??? Need to be careful w.r.t. mods done to INSN. */ | |
2c3c49de | 3637 | if (INSN_P (insn)) |
7506f491 | 3638 | mark_oprs_set (insn); |
ac7c5af5 | 3639 | } |
7506f491 DE |
3640 | } |
3641 | ||
3642 | return changed; | |
3643 | } | |
3644 | ||
3645 | /* Top level routine to perform one classic GCSE pass. | |
3646 | ||
cc2902df | 3647 | Return nonzero if a change was made. */ |
7506f491 DE |
3648 | |
3649 | static int | |
b5ce41ff | 3650 | one_classic_gcse_pass (pass) |
7506f491 DE |
3651 | int pass; |
3652 | { | |
3653 | int changed = 0; | |
3654 | ||
3655 | gcse_subst_count = 0; | |
3656 | gcse_create_count = 0; | |
3657 | ||
02280659 | 3658 | alloc_hash_table (max_cuid, &expr_hash_table, 0); |
d55bc081 | 3659 | alloc_rd_mem (last_basic_block, max_cuid); |
02280659 | 3660 | compute_hash_table (&expr_hash_table); |
7506f491 | 3661 | if (gcse_file) |
02280659 | 3662 | dump_hash_table (gcse_file, "Expression", &expr_hash_table); |
c4c81601 | 3663 | |
02280659 | 3664 | if (expr_hash_table.n_elems > 0) |
7506f491 DE |
3665 | { |
3666 | compute_kill_rd (); | |
3667 | compute_rd (); | |
02280659 ZD |
3668 | alloc_avail_expr_mem (last_basic_block, expr_hash_table.n_elems); |
3669 | compute_ae_gen (&expr_hash_table); | |
3670 | compute_ae_kill (ae_gen, ae_kill, &expr_hash_table); | |
bd0eaec2 | 3671 | compute_available (ae_gen, ae_kill, ae_out, ae_in); |
7506f491 DE |
3672 | changed = classic_gcse (); |
3673 | free_avail_expr_mem (); | |
3674 | } | |
c4c81601 | 3675 | |
7506f491 | 3676 | free_rd_mem (); |
02280659 | 3677 | free_hash_table (&expr_hash_table); |
7506f491 DE |
3678 | |
3679 | if (gcse_file) | |
3680 | { | |
3681 | fprintf (gcse_file, "\n"); | |
c4c81601 RK |
3682 | fprintf (gcse_file, "GCSE of %s, pass %d: %d bytes needed, %d substs,", |
3683 | current_function_name, pass, bytes_used, gcse_subst_count); | |
3684 | fprintf (gcse_file, "%d insns created\n", gcse_create_count); | |
7506f491 DE |
3685 | } |
3686 | ||
3687 | return changed; | |
3688 | } | |
3689 | \f | |
3690 | /* Compute copy/constant propagation working variables. */ | |
3691 | ||
3692 | /* Local properties of assignments. */ | |
7506f491 DE |
3693 | static sbitmap *cprop_pavloc; |
3694 | static sbitmap *cprop_absaltered; | |
3695 | ||
3696 | /* Global properties of assignments (computed from the local properties). */ | |
7506f491 DE |
3697 | static sbitmap *cprop_avin; |
3698 | static sbitmap *cprop_avout; | |
3699 | ||
c4c81601 RK |
3700 | /* Allocate vars used for copy/const propagation. N_BLOCKS is the number of |
3701 | basic blocks. N_SETS is the number of sets. */ | |
7506f491 DE |
3702 | |
3703 | static void | |
3704 | alloc_cprop_mem (n_blocks, n_sets) | |
3705 | int n_blocks, n_sets; | |
3706 | { | |
3707 | cprop_pavloc = sbitmap_vector_alloc (n_blocks, n_sets); | |
3708 | cprop_absaltered = sbitmap_vector_alloc (n_blocks, n_sets); | |
3709 | ||
3710 | cprop_avin = sbitmap_vector_alloc (n_blocks, n_sets); | |
3711 | cprop_avout = sbitmap_vector_alloc (n_blocks, n_sets); | |
3712 | } | |
3713 | ||
3714 | /* Free vars used by copy/const propagation. */ | |
3715 | ||
3716 | static void | |
3717 | free_cprop_mem () | |
3718 | { | |
5a660bff DB |
3719 | sbitmap_vector_free (cprop_pavloc); |
3720 | sbitmap_vector_free (cprop_absaltered); | |
3721 | sbitmap_vector_free (cprop_avin); | |
3722 | sbitmap_vector_free (cprop_avout); | |
7506f491 DE |
3723 | } |
3724 | ||
c4c81601 RK |
3725 | /* For each block, compute whether X is transparent. X is either an |
3726 | expression or an assignment [though we don't care which, for this context | |
3727 | an assignment is treated as an expression]. For each block where an | |
3728 | element of X is modified, set (SET_P == 1) or reset (SET_P == 0) the INDX | |
3729 | bit in BMAP. */ | |
7506f491 DE |
3730 | |
3731 | static void | |
3732 | compute_transp (x, indx, bmap, set_p) | |
3733 | rtx x; | |
3734 | int indx; | |
3735 | sbitmap *bmap; | |
3736 | int set_p; | |
3737 | { | |
e0082a72 ZD |
3738 | int i, j; |
3739 | basic_block bb; | |
7506f491 | 3740 | enum rtx_code code; |
c4c81601 | 3741 | reg_set *r; |
6f7d635c | 3742 | const char *fmt; |
7506f491 | 3743 | |
c4c81601 RK |
3744 | /* repeat is used to turn tail-recursion into iteration since GCC |
3745 | can't do it when there's no return value. */ | |
7506f491 DE |
3746 | repeat: |
3747 | ||
3748 | if (x == 0) | |
3749 | return; | |
3750 | ||
3751 | code = GET_CODE (x); | |
3752 | switch (code) | |
3753 | { | |
3754 | case REG: | |
c4c81601 RK |
3755 | if (set_p) |
3756 | { | |
3757 | if (REGNO (x) < FIRST_PSEUDO_REGISTER) | |
3758 | { | |
e0082a72 ZD |
3759 | FOR_EACH_BB (bb) |
3760 | if (TEST_BIT (reg_set_in_block[bb->index], REGNO (x))) | |
3761 | SET_BIT (bmap[bb->index], indx); | |
c4c81601 RK |
3762 | } |
3763 | else | |
3764 | { | |
3765 | for (r = reg_set_table[REGNO (x)]; r != NULL; r = r->next) | |
3766 | SET_BIT (bmap[BLOCK_NUM (r->insn)], indx); | |
3767 | } | |
3768 | } | |
3769 | else | |
3770 | { | |
3771 | if (REGNO (x) < FIRST_PSEUDO_REGISTER) | |
3772 | { | |
e0082a72 ZD |
3773 | FOR_EACH_BB (bb) |
3774 | if (TEST_BIT (reg_set_in_block[bb->index], REGNO (x))) | |
3775 | RESET_BIT (bmap[bb->index], indx); | |
c4c81601 RK |
3776 | } |
3777 | else | |
3778 | { | |
3779 | for (r = reg_set_table[REGNO (x)]; r != NULL; r = r->next) | |
3780 | RESET_BIT (bmap[BLOCK_NUM (r->insn)], indx); | |
3781 | } | |
3782 | } | |
7506f491 | 3783 | |
c4c81601 | 3784 | return; |
7506f491 DE |
3785 | |
3786 | case MEM: | |
e0082a72 | 3787 | FOR_EACH_BB (bb) |
a13d4ebf | 3788 | { |
e0082a72 | 3789 | rtx list_entry = canon_modify_mem_list[bb->index]; |
a13d4ebf AM |
3790 | |
3791 | while (list_entry) | |
3792 | { | |
3793 | rtx dest, dest_addr; | |
3794 | ||
3795 | if (GET_CODE (XEXP (list_entry, 0)) == CALL_INSN) | |
3796 | { | |
3797 | if (set_p) | |
e0082a72 | 3798 | SET_BIT (bmap[bb->index], indx); |
a13d4ebf | 3799 | else |
e0082a72 | 3800 | RESET_BIT (bmap[bb->index], indx); |
a13d4ebf AM |
3801 | break; |
3802 | } | |
3803 | /* LIST_ENTRY must be an INSN of some kind that sets memory. | |
3804 | Examine each hunk of memory that is modified. */ | |
3805 | ||
3806 | dest = XEXP (list_entry, 0); | |
3807 | list_entry = XEXP (list_entry, 1); | |
3808 | dest_addr = XEXP (list_entry, 0); | |
589005ff | 3809 | |
a13d4ebf AM |
3810 | if (canon_true_dependence (dest, GET_MODE (dest), dest_addr, |
3811 | x, rtx_addr_varies_p)) | |
3812 | { | |
3813 | if (set_p) | |
e0082a72 | 3814 | SET_BIT (bmap[bb->index], indx); |
a13d4ebf | 3815 | else |
e0082a72 | 3816 | RESET_BIT (bmap[bb->index], indx); |
a13d4ebf AM |
3817 | break; |
3818 | } | |
3819 | list_entry = XEXP (list_entry, 1); | |
3820 | } | |
3821 | } | |
c4c81601 | 3822 | |
7506f491 DE |
3823 | x = XEXP (x, 0); |
3824 | goto repeat; | |
3825 | ||
3826 | case PC: | |
3827 | case CC0: /*FIXME*/ | |
3828 | case CONST: | |
3829 | case CONST_INT: | |
3830 | case CONST_DOUBLE: | |
69ef87e2 | 3831 | case CONST_VECTOR: |
7506f491 DE |
3832 | case SYMBOL_REF: |
3833 | case LABEL_REF: | |
3834 | case ADDR_VEC: | |
3835 | case ADDR_DIFF_VEC: | |
3836 | return; | |
3837 | ||
3838 | default: | |
3839 | break; | |
3840 | } | |
3841 | ||
c4c81601 | 3842 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
3843 | { |
3844 | if (fmt[i] == 'e') | |
3845 | { | |
7506f491 DE |
3846 | /* If we are about to do the last recursive call |
3847 | needed at this level, change it into iteration. | |
3848 | This function is called enough to be worth it. */ | |
3849 | if (i == 0) | |
3850 | { | |
c4c81601 | 3851 | x = XEXP (x, i); |
7506f491 DE |
3852 | goto repeat; |
3853 | } | |
c4c81601 RK |
3854 | |
3855 | compute_transp (XEXP (x, i), indx, bmap, set_p); | |
7506f491 DE |
3856 | } |
3857 | else if (fmt[i] == 'E') | |
c4c81601 RK |
3858 | for (j = 0; j < XVECLEN (x, i); j++) |
3859 | compute_transp (XVECEXP (x, i, j), indx, bmap, set_p); | |
7506f491 DE |
3860 | } |
3861 | } | |
3862 | ||
7506f491 DE |
3863 | /* Top level routine to do the dataflow analysis needed by copy/const |
3864 | propagation. */ | |
3865 | ||
3866 | static void | |
3867 | compute_cprop_data () | |
3868 | { | |
02280659 | 3869 | compute_local_properties (cprop_absaltered, cprop_pavloc, NULL, &set_hash_table); |
ce724250 JL |
3870 | compute_available (cprop_pavloc, cprop_absaltered, |
3871 | cprop_avout, cprop_avin); | |
7506f491 DE |
3872 | } |
3873 | \f | |
3874 | /* Copy/constant propagation. */ | |
3875 | ||
7506f491 DE |
3876 | /* Maximum number of register uses in an insn that we handle. */ |
3877 | #define MAX_USES 8 | |
3878 | ||
3879 | /* Table of uses found in an insn. | |
3880 | Allocated statically to avoid alloc/free complexity and overhead. */ | |
3881 | static struct reg_use reg_use_table[MAX_USES]; | |
3882 | ||
3883 | /* Index into `reg_use_table' while building it. */ | |
3884 | static int reg_use_count; | |
3885 | ||
c4c81601 RK |
3886 | /* Set up a list of register numbers used in INSN. The found uses are stored |
3887 | in `reg_use_table'. `reg_use_count' is initialized to zero before entry, | |
3888 | and contains the number of uses in the table upon exit. | |
7506f491 | 3889 | |
c4c81601 RK |
3890 | ??? If a register appears multiple times we will record it multiple times. |
3891 | This doesn't hurt anything but it will slow things down. */ | |
7506f491 DE |
3892 | |
3893 | static void | |
9e71c818 JH |
3894 | find_used_regs (xptr, data) |
3895 | rtx *xptr; | |
3896 | void *data ATTRIBUTE_UNUSED; | |
7506f491 | 3897 | { |
c4c81601 | 3898 | int i, j; |
7506f491 | 3899 | enum rtx_code code; |
6f7d635c | 3900 | const char *fmt; |
9e71c818 | 3901 | rtx x = *xptr; |
7506f491 | 3902 | |
c4c81601 RK |
3903 | /* repeat is used to turn tail-recursion into iteration since GCC |
3904 | can't do it when there's no return value. */ | |
7506f491 | 3905 | repeat: |
7506f491 DE |
3906 | if (x == 0) |
3907 | return; | |
3908 | ||
3909 | code = GET_CODE (x); | |
9e71c818 | 3910 | if (REG_P (x)) |
7506f491 | 3911 | { |
7506f491 DE |
3912 | if (reg_use_count == MAX_USES) |
3913 | return; | |
c4c81601 | 3914 | |
7506f491 DE |
3915 | reg_use_table[reg_use_count].reg_rtx = x; |
3916 | reg_use_count++; | |
7506f491 DE |
3917 | } |
3918 | ||
3919 | /* Recursively scan the operands of this expression. */ | |
3920 | ||
c4c81601 | 3921 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
7506f491 DE |
3922 | { |
3923 | if (fmt[i] == 'e') | |
3924 | { | |
3925 | /* If we are about to do the last recursive call | |
3926 | needed at this level, change it into iteration. | |
3927 | This function is called enough to be worth it. */ | |
3928 | if (i == 0) | |
3929 | { | |
3930 | x = XEXP (x, 0); | |
3931 | goto repeat; | |
3932 | } | |
c4c81601 | 3933 | |
9e71c818 | 3934 | find_used_regs (&XEXP (x, i), data); |
7506f491 DE |
3935 | } |
3936 | else if (fmt[i] == 'E') | |
c4c81601 | 3937 | for (j = 0; j < XVECLEN (x, i); j++) |
9e71c818 | 3938 | find_used_regs (&XVECEXP (x, i, j), data); |
7506f491 DE |
3939 | } |
3940 | } | |
3941 | ||
3942 | /* Try to replace all non-SET_DEST occurrences of FROM in INSN with TO. | |
cc2902df | 3943 | Returns nonzero is successful. */ |
7506f491 DE |
3944 | |
3945 | static int | |
3946 | try_replace_reg (from, to, insn) | |
3947 | rtx from, to, insn; | |
3948 | { | |
172890a2 | 3949 | rtx note = find_reg_equal_equiv_note (insn); |
fb0c0a12 | 3950 | rtx src = 0; |
172890a2 RK |
3951 | int success = 0; |
3952 | rtx set = single_set (insn); | |
833fc3ad | 3953 | |
2b773ee2 JH |
3954 | validate_replace_src_group (from, to, insn); |
3955 | if (num_changes_pending () && apply_change_group ()) | |
3956 | success = 1; | |
9e71c818 | 3957 | |
f305679f | 3958 | if (!success && set && reg_mentioned_p (from, SET_SRC (set))) |
833fc3ad | 3959 | { |
f305679f JH |
3960 | /* If above failed and this is a single set, try to simplify the source of |
3961 | the set given our substitution. We could perhaps try this for multiple | |
3962 | SETs, but it probably won't buy us anything. */ | |
172890a2 RK |
3963 | src = simplify_replace_rtx (SET_SRC (set), from, to); |
3964 | ||
9e71c818 JH |
3965 | if (!rtx_equal_p (src, SET_SRC (set)) |
3966 | && validate_change (insn, &SET_SRC (set), src, 0)) | |
172890a2 | 3967 | success = 1; |
833fc3ad | 3968 | |
f305679f JH |
3969 | /* If we've failed to do replacement, have a single SET, and don't already |
3970 | have a note, add a REG_EQUAL note to not lose information. */ | |
3971 | if (!success && note == 0 && set != 0) | |
3972 | note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (src)); | |
3973 | } | |
e251e2a2 | 3974 | |
172890a2 RK |
3975 | /* If there is already a NOTE, update the expression in it with our |
3976 | replacement. */ | |
3977 | else if (note != 0) | |
3978 | XEXP (note, 0) = simplify_replace_rtx (XEXP (note, 0), from, to); | |
833fc3ad | 3979 | |
172890a2 RK |
3980 | /* REG_EQUAL may get simplified into register. |
3981 | We don't allow that. Remove that note. This code ought | |
fbe5a4a6 | 3982 | not to happen, because previous code ought to synthesize |
172890a2 RK |
3983 | reg-reg move, but be on the safe side. */ |
3984 | if (note && REG_P (XEXP (note, 0))) | |
3985 | remove_note (insn, note); | |
833fc3ad | 3986 | |
833fc3ad JH |
3987 | return success; |
3988 | } | |
c4c81601 RK |
3989 | |
3990 | /* Find a set of REGNOs that are available on entry to INSN's block. Returns | |
3991 | NULL no such set is found. */ | |
7506f491 DE |
3992 | |
3993 | static struct expr * | |
3994 | find_avail_set (regno, insn) | |
3995 | int regno; | |
3996 | rtx insn; | |
3997 | { | |
cafba495 BS |
3998 | /* SET1 contains the last set found that can be returned to the caller for |
3999 | use in a substitution. */ | |
4000 | struct expr *set1 = 0; | |
589005ff | 4001 | |
cafba495 BS |
4002 | /* Loops are not possible here. To get a loop we would need two sets |
4003 | available at the start of the block containing INSN. ie we would | |
4004 | need two sets like this available at the start of the block: | |
4005 | ||
4006 | (set (reg X) (reg Y)) | |
4007 | (set (reg Y) (reg X)) | |
4008 | ||
4009 | This can not happen since the set of (reg Y) would have killed the | |
4010 | set of (reg X) making it unavailable at the start of this block. */ | |
4011 | while (1) | |
8e42ace1 | 4012 | { |
cafba495 | 4013 | rtx src; |
ceda50e9 | 4014 | struct expr *set = lookup_set (regno, &set_hash_table); |
cafba495 BS |
4015 | |
4016 | /* Find a set that is available at the start of the block | |
4017 | which contains INSN. */ | |
4018 | while (set) | |
4019 | { | |
4020 | if (TEST_BIT (cprop_avin[BLOCK_NUM (insn)], set->bitmap_index)) | |
4021 | break; | |
4022 | set = next_set (regno, set); | |
4023 | } | |
7506f491 | 4024 | |
cafba495 BS |
4025 | /* If no available set was found we've reached the end of the |
4026 | (possibly empty) copy chain. */ | |
4027 | if (set == 0) | |
589005ff | 4028 | break; |
cafba495 BS |
4029 | |
4030 | if (GET_CODE (set->expr) != SET) | |
4031 | abort (); | |
4032 | ||
4033 | src = SET_SRC (set->expr); | |
4034 | ||
4035 | /* We know the set is available. | |
4036 | Now check that SRC is ANTLOC (i.e. none of the source operands | |
589005ff | 4037 | have changed since the start of the block). |
cafba495 BS |
4038 | |
4039 | If the source operand changed, we may still use it for the next | |
4040 | iteration of this loop, but we may not use it for substitutions. */ | |
c4c81601 | 4041 | |
6b2d1c9e | 4042 | if (gcse_constant_p (src) || oprs_not_set_p (src, insn)) |
cafba495 BS |
4043 | set1 = set; |
4044 | ||
4045 | /* If the source of the set is anything except a register, then | |
4046 | we have reached the end of the copy chain. */ | |
4047 | if (GET_CODE (src) != REG) | |
7506f491 | 4048 | break; |
7506f491 | 4049 | |
cafba495 BS |
4050 | /* Follow the copy chain, ie start another iteration of the loop |
4051 | and see if we have an available copy into SRC. */ | |
4052 | regno = REGNO (src); | |
8e42ace1 | 4053 | } |
cafba495 BS |
4054 | |
4055 | /* SET1 holds the last set that was available and anticipatable at | |
4056 | INSN. */ | |
4057 | return set1; | |
7506f491 DE |
4058 | } |
4059 | ||
abd535b6 | 4060 | /* Subroutine of cprop_insn that tries to propagate constants into |
0e3f0221 | 4061 | JUMP_INSNS. JUMP must be a conditional jump. If SETCC is non-NULL |
fbe5a4a6 | 4062 | it is the instruction that immediately precedes JUMP, and must be a |
818b6b7f | 4063 | single SET of a register. FROM is what we will try to replace, |
0e3f0221 | 4064 | SRC is the constant we will try to substitute for it. Returns nonzero |
589005ff | 4065 | if a change was made. */ |
c4c81601 | 4066 | |
abd535b6 | 4067 | static int |
0e3f0221 RS |
4068 | cprop_jump (bb, setcc, jump, from, src) |
4069 | basic_block bb; | |
4070 | rtx setcc; | |
4071 | rtx jump; | |
172890a2 | 4072 | rtx from; |
abd535b6 BS |
4073 | rtx src; |
4074 | { | |
0e3f0221 RS |
4075 | rtx new, new_set; |
4076 | rtx set = pc_set (jump); | |
4077 | ||
4078 | /* First substitute in the INSN condition as the SET_SRC of the JUMP, | |
4079 | then substitute that given values in this expanded JUMP. */ | |
48ddd46c JH |
4080 | if (setcc != NULL |
4081 | && !modified_between_p (from, setcc, jump) | |
4082 | && !modified_between_p (src, setcc, jump)) | |
b2f02503 RS |
4083 | { |
4084 | rtx setcc_set = single_set (setcc); | |
4085 | new_set = simplify_replace_rtx (SET_SRC (set), | |
4086 | SET_DEST (setcc_set), | |
9e48c409 | 4087 | SET_SRC (setcc_set)); |
b2f02503 | 4088 | } |
0e3f0221 RS |
4089 | else |
4090 | new_set = set; | |
4091 | ||
9e48c409 | 4092 | new = simplify_replace_rtx (new_set, from, src); |
abd535b6 | 4093 | |
9e48c409 KH |
4094 | /* If no simplification can be made, then try the next |
4095 | register. */ | |
4096 | if (rtx_equal_p (new, new_set) || rtx_equal_p (new, SET_SRC (set))) | |
4097 | return 0; | |
589005ff | 4098 | |
7d5ab30e | 4099 | /* If this is now a no-op delete it, otherwise this must be a valid insn. */ |
172890a2 | 4100 | if (new == pc_rtx) |
0e3f0221 | 4101 | delete_insn (jump); |
7d5ab30e | 4102 | else |
abd535b6 | 4103 | { |
48ddd46c JH |
4104 | /* Ensure the value computed inside the jump insn to be equivalent |
4105 | to one computed by setcc. */ | |
4106 | if (setcc | |
4107 | && modified_in_p (new, setcc)) | |
4108 | return 0; | |
0e3f0221 | 4109 | if (! validate_change (jump, &SET_SRC (set), new, 0)) |
7d5ab30e | 4110 | return 0; |
abd535b6 | 4111 | |
7d5ab30e JH |
4112 | /* If this has turned into an unconditional jump, |
4113 | then put a barrier after it so that the unreachable | |
4114 | code will be deleted. */ | |
4115 | if (GET_CODE (SET_SRC (set)) == LABEL_REF) | |
0e3f0221 | 4116 | emit_barrier_after (jump); |
7d5ab30e | 4117 | } |
abd535b6 | 4118 | |
0e3f0221 RS |
4119 | #ifdef HAVE_cc0 |
4120 | /* Delete the cc0 setter. */ | |
818b6b7f | 4121 | if (setcc != NULL && CC0_P (SET_DEST (single_set (setcc)))) |
0e3f0221 RS |
4122 | delete_insn (setcc); |
4123 | #endif | |
4124 | ||
172890a2 | 4125 | run_jump_opt_after_gcse = 1; |
c4c81601 | 4126 | |
172890a2 RK |
4127 | const_prop_count++; |
4128 | if (gcse_file != NULL) | |
4129 | { | |
4130 | fprintf (gcse_file, | |
818b6b7f | 4131 | "CONST-PROP: Replacing reg %d in jump_insn %d with constant ", |
0e3f0221 | 4132 | REGNO (from), INSN_UID (jump)); |
172890a2 RK |
4133 | print_rtl (gcse_file, src); |
4134 | fprintf (gcse_file, "\n"); | |
abd535b6 | 4135 | } |
0005550b | 4136 | purge_dead_edges (bb); |
172890a2 RK |
4137 | |
4138 | return 1; | |
abd535b6 BS |
4139 | } |
4140 | ||
ae860ff7 JH |
4141 | static bool |
4142 | constprop_register (insn, from, to, alter_jumps) | |
4143 | rtx insn; | |
4144 | rtx from; | |
4145 | rtx to; | |
4146 | int alter_jumps; | |
4147 | { | |
4148 | rtx sset; | |
4149 | ||
4150 | /* Check for reg or cc0 setting instructions followed by | |
4151 | conditional branch instructions first. */ | |
4152 | if (alter_jumps | |
4153 | && (sset = single_set (insn)) != NULL | |
244d05fb | 4154 | && NEXT_INSN (insn) |
ae860ff7 JH |
4155 | && any_condjump_p (NEXT_INSN (insn)) && onlyjump_p (NEXT_INSN (insn))) |
4156 | { | |
4157 | rtx dest = SET_DEST (sset); | |
4158 | if ((REG_P (dest) || CC0_P (dest)) | |
4159 | && cprop_jump (BLOCK_FOR_INSN (insn), insn, NEXT_INSN (insn), from, to)) | |
4160 | return 1; | |
4161 | } | |
4162 | ||
4163 | /* Handle normal insns next. */ | |
4164 | if (GET_CODE (insn) == INSN | |
4165 | && try_replace_reg (from, to, insn)) | |
4166 | return 1; | |
4167 | ||
4168 | /* Try to propagate a CONST_INT into a conditional jump. | |
4169 | We're pretty specific about what we will handle in this | |
4170 | code, we can extend this as necessary over time. | |
4171 | ||
4172 | Right now the insn in question must look like | |
4173 | (set (pc) (if_then_else ...)) */ | |
4174 | else if (alter_jumps && any_condjump_p (insn) && onlyjump_p (insn)) | |
4175 | return cprop_jump (BLOCK_FOR_INSN (insn), NULL, insn, from, to); | |
4176 | return 0; | |
4177 | } | |
4178 | ||
7506f491 | 4179 | /* Perform constant and copy propagation on INSN. |
cc2902df | 4180 | The result is nonzero if a change was made. */ |
7506f491 DE |
4181 | |
4182 | static int | |
ae860ff7 | 4183 | cprop_insn (insn, alter_jumps) |
7506f491 | 4184 | rtx insn; |
b5ce41ff | 4185 | int alter_jumps; |
7506f491 DE |
4186 | { |
4187 | struct reg_use *reg_used; | |
4188 | int changed = 0; | |
833fc3ad | 4189 | rtx note; |
7506f491 | 4190 | |
9e71c818 | 4191 | if (!INSN_P (insn)) |
7506f491 DE |
4192 | return 0; |
4193 | ||
4194 | reg_use_count = 0; | |
9e71c818 | 4195 | note_uses (&PATTERN (insn), find_used_regs, NULL); |
589005ff | 4196 | |
172890a2 | 4197 | note = find_reg_equal_equiv_note (insn); |
833fc3ad | 4198 | |
dc297297 | 4199 | /* We may win even when propagating constants into notes. */ |
833fc3ad | 4200 | if (note) |
9e71c818 | 4201 | find_used_regs (&XEXP (note, 0), NULL); |
7506f491 | 4202 | |
c4c81601 RK |
4203 | for (reg_used = ®_use_table[0]; reg_use_count > 0; |
4204 | reg_used++, reg_use_count--) | |
7506f491 | 4205 | { |
770ae6cc | 4206 | unsigned int regno = REGNO (reg_used->reg_rtx); |
7506f491 DE |
4207 | rtx pat, src; |
4208 | struct expr *set; | |
7506f491 DE |
4209 | |
4210 | /* Ignore registers created by GCSE. | |
dc297297 | 4211 | We do this because ... */ |
7506f491 DE |
4212 | if (regno >= max_gcse_regno) |
4213 | continue; | |
4214 | ||
4215 | /* If the register has already been set in this block, there's | |
4216 | nothing we can do. */ | |
4217 | if (! oprs_not_set_p (reg_used->reg_rtx, insn)) | |
4218 | continue; | |
4219 | ||
4220 | /* Find an assignment that sets reg_used and is available | |
4221 | at the start of the block. */ | |
4222 | set = find_avail_set (regno, insn); | |
4223 | if (! set) | |
4224 | continue; | |
589005ff | 4225 | |
7506f491 DE |
4226 | pat = set->expr; |
4227 | /* ??? We might be able to handle PARALLELs. Later. */ | |
4228 | if (GET_CODE (pat) != SET) | |
4229 | abort (); | |
c4c81601 | 4230 | |
7506f491 DE |
4231 | src = SET_SRC (pat); |
4232 | ||
e78d9500 | 4233 | /* Constant propagation. */ |
6b2d1c9e | 4234 | if (gcse_constant_p (src)) |
7506f491 | 4235 | { |
ae860ff7 | 4236 | if (constprop_register (insn, reg_used->reg_rtx, src, alter_jumps)) |
7506f491 DE |
4237 | { |
4238 | changed = 1; | |
4239 | const_prop_count++; | |
4240 | if (gcse_file != NULL) | |
4241 | { | |
ae860ff7 JH |
4242 | fprintf (gcse_file, "GLOBAL CONST-PROP: Replacing reg %d in ", regno); |
4243 | fprintf (gcse_file, "insn %d with constant ", INSN_UID (insn)); | |
e78d9500 | 4244 | print_rtl (gcse_file, src); |
7506f491 DE |
4245 | fprintf (gcse_file, "\n"); |
4246 | } | |
7506f491 DE |
4247 | } |
4248 | } | |
4249 | else if (GET_CODE (src) == REG | |
4250 | && REGNO (src) >= FIRST_PSEUDO_REGISTER | |
4251 | && REGNO (src) != regno) | |
4252 | { | |
cafba495 | 4253 | if (try_replace_reg (reg_used->reg_rtx, src, insn)) |
7506f491 | 4254 | { |
cafba495 BS |
4255 | changed = 1; |
4256 | copy_prop_count++; | |
4257 | if (gcse_file != NULL) | |
7506f491 | 4258 | { |
ae860ff7 | 4259 | fprintf (gcse_file, "GLOBAL COPY-PROP: Replacing reg %d in insn %d", |
c4c81601 RK |
4260 | regno, INSN_UID (insn)); |
4261 | fprintf (gcse_file, " with reg %d\n", REGNO (src)); | |
7506f491 | 4262 | } |
cafba495 BS |
4263 | |
4264 | /* The original insn setting reg_used may or may not now be | |
4265 | deletable. We leave the deletion to flow. */ | |
4266 | /* FIXME: If it turns out that the insn isn't deletable, | |
4267 | then we may have unnecessarily extended register lifetimes | |
4268 | and made things worse. */ | |
7506f491 DE |
4269 | } |
4270 | } | |
4271 | } | |
4272 | ||
4273 | return changed; | |
4274 | } | |
4275 | ||
710ee3ed RH |
4276 | /* Like find_used_regs, but avoid recording uses that appear in |
4277 | input-output contexts such as zero_extract or pre_dec. This | |
4278 | restricts the cases we consider to those for which local cprop | |
4279 | can legitimately make replacements. */ | |
4280 | ||
4281 | static void | |
4282 | local_cprop_find_used_regs (xptr, data) | |
4283 | rtx *xptr; | |
4284 | void *data; | |
4285 | { | |
4286 | rtx x = *xptr; | |
4287 | ||
4288 | if (x == 0) | |
4289 | return; | |
4290 | ||
4291 | switch (GET_CODE (x)) | |
4292 | { | |
4293 | case ZERO_EXTRACT: | |
4294 | case SIGN_EXTRACT: | |
4295 | case STRICT_LOW_PART: | |
4296 | return; | |
4297 | ||
4298 | case PRE_DEC: | |
4299 | case PRE_INC: | |
4300 | case POST_DEC: | |
4301 | case POST_INC: | |
4302 | case PRE_MODIFY: | |
4303 | case POST_MODIFY: | |
4304 | /* Can only legitimately appear this early in the context of | |
4305 | stack pushes for function arguments, but handle all of the | |
4306 | codes nonetheless. */ | |
4307 | return; | |
4308 | ||
4309 | case SUBREG: | |
4310 | /* Setting a subreg of a register larger than word_mode leaves | |
4311 | the non-written words unchanged. */ | |
4312 | if (GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x))) > BITS_PER_WORD) | |
4313 | return; | |
4314 | break; | |
4315 | ||
4316 | default: | |
4317 | break; | |
4318 | } | |
4319 | ||
4320 | find_used_regs (xptr, data); | |
4321 | } | |
4322 | ||
8ba46434 R |
4323 | /* LIBCALL_SP is a zero-terminated array of insns at the end of a libcall; |
4324 | their REG_EQUAL notes need updating. */ | |
e197b6fc | 4325 | |
ae860ff7 | 4326 | static bool |
8ba46434 | 4327 | do_local_cprop (x, insn, alter_jumps, libcall_sp) |
ae860ff7 JH |
4328 | rtx x; |
4329 | rtx insn; | |
4330 | int alter_jumps; | |
8ba46434 | 4331 | rtx *libcall_sp; |
ae860ff7 JH |
4332 | { |
4333 | rtx newreg = NULL, newcnst = NULL; | |
4334 | ||
e197b6fc RH |
4335 | /* Rule out USE instructions and ASM statements as we don't want to |
4336 | change the hard registers mentioned. */ | |
ae860ff7 JH |
4337 | if (GET_CODE (x) == REG |
4338 | && (REGNO (x) >= FIRST_PSEUDO_REGISTER | |
e197b6fc RH |
4339 | || (GET_CODE (PATTERN (insn)) != USE |
4340 | && asm_noperands (PATTERN (insn)) < 0))) | |
ae860ff7 JH |
4341 | { |
4342 | cselib_val *val = cselib_lookup (x, GET_MODE (x), 0); | |
4343 | struct elt_loc_list *l; | |
4344 | ||
4345 | if (!val) | |
4346 | return false; | |
4347 | for (l = val->locs; l; l = l->next) | |
4348 | { | |
4349 | rtx this_rtx = l->loc; | |
46690369 JH |
4350 | rtx note; |
4351 | ||
9635cfad JH |
4352 | if (l->in_libcall) |
4353 | continue; | |
4354 | ||
6b2d1c9e | 4355 | if (gcse_constant_p (this_rtx)) |
ae860ff7 | 4356 | newcnst = this_rtx; |
46690369 JH |
4357 | if (REG_P (this_rtx) && REGNO (this_rtx) >= FIRST_PSEUDO_REGISTER |
4358 | /* Don't copy propagate if it has attached REG_EQUIV note. | |
4359 | At this point this only function parameters should have | |
4360 | REG_EQUIV notes and if the argument slot is used somewhere | |
4361 | explicitly, it means address of parameter has been taken, | |
4362 | so we should not extend the lifetime of the pseudo. */ | |
4363 | && (!(note = find_reg_note (l->setting_insn, REG_EQUIV, NULL_RTX)) | |
4364 | || GET_CODE (XEXP (note, 0)) != MEM)) | |
ae860ff7 JH |
4365 | newreg = this_rtx; |
4366 | } | |
4367 | if (newcnst && constprop_register (insn, x, newcnst, alter_jumps)) | |
4368 | { | |
8ba46434 | 4369 | /* If we find a case where we can't fix the retval REG_EQUAL notes |
fbe5a4a6 | 4370 | match the new register, we either have to abandon this replacement |
8ba46434 R |
4371 | or fix delete_trivially_dead_insns to preserve the setting insn, |
4372 | or make it delete the REG_EUAQL note, and fix up all passes that | |
4373 | require the REG_EQUAL note there. */ | |
4374 | if (!adjust_libcall_notes (x, newcnst, insn, libcall_sp)) | |
4375 | abort (); | |
ae860ff7 JH |
4376 | if (gcse_file != NULL) |
4377 | { | |
4378 | fprintf (gcse_file, "LOCAL CONST-PROP: Replacing reg %d in ", | |
4379 | REGNO (x)); | |
4380 | fprintf (gcse_file, "insn %d with constant ", | |
4381 | INSN_UID (insn)); | |
4382 | print_rtl (gcse_file, newcnst); | |
4383 | fprintf (gcse_file, "\n"); | |
4384 | } | |
4385 | const_prop_count++; | |
4386 | return true; | |
4387 | } | |
4388 | else if (newreg && newreg != x && try_replace_reg (x, newreg, insn)) | |
4389 | { | |
8ba46434 | 4390 | adjust_libcall_notes (x, newreg, insn, libcall_sp); |
ae860ff7 JH |
4391 | if (gcse_file != NULL) |
4392 | { | |
4393 | fprintf (gcse_file, | |
4394 | "LOCAL COPY-PROP: Replacing reg %d in insn %d", | |
4395 | REGNO (x), INSN_UID (insn)); | |
4396 | fprintf (gcse_file, " with reg %d\n", REGNO (newreg)); | |
4397 | } | |
4398 | copy_prop_count++; | |
4399 | return true; | |
4400 | } | |
4401 | } | |
4402 | return false; | |
4403 | } | |
4404 | ||
8ba46434 R |
4405 | /* LIBCALL_SP is a zero-terminated array of insns at the end of a libcall; |
4406 | their REG_EQUAL notes need updating to reflect that OLDREG has been | |
f4e3e618 RH |
4407 | replaced with NEWVAL in INSN. Return true if all substitutions could |
4408 | be made. */ | |
8ba46434 R |
4409 | static bool |
4410 | adjust_libcall_notes (oldreg, newval, insn, libcall_sp) | |
4411 | rtx oldreg, newval, insn, *libcall_sp; | |
4412 | { | |
f4e3e618 | 4413 | rtx end; |
8ba46434 R |
4414 | |
4415 | while ((end = *libcall_sp++)) | |
4416 | { | |
f4e3e618 | 4417 | rtx note = find_reg_equal_equiv_note (end); |
8ba46434 R |
4418 | |
4419 | if (! note) | |
4420 | continue; | |
4421 | ||
4422 | if (REG_P (newval)) | |
4423 | { | |
4424 | if (reg_set_between_p (newval, PREV_INSN (insn), end)) | |
4425 | { | |
4426 | do | |
4427 | { | |
4428 | note = find_reg_equal_equiv_note (end); | |
4429 | if (! note) | |
4430 | continue; | |
4431 | if (reg_mentioned_p (newval, XEXP (note, 0))) | |
4432 | return false; | |
4433 | } | |
4434 | while ((end = *libcall_sp++)); | |
4435 | return true; | |
4436 | } | |
4437 | } | |
4438 | XEXP (note, 0) = replace_rtx (XEXP (note, 0), oldreg, newval); | |
4439 | insn = end; | |
4440 | } | |
4441 | return true; | |
4442 | } | |
4443 | ||
4444 | #define MAX_NESTED_LIBCALLS 9 | |
4445 | ||
ae860ff7 JH |
4446 | static void |
4447 | local_cprop_pass (alter_jumps) | |
4448 | int alter_jumps; | |
4449 | { | |
4450 | rtx insn; | |
4451 | struct reg_use *reg_used; | |
8ba46434 | 4452 | rtx libcall_stack[MAX_NESTED_LIBCALLS + 1], *libcall_sp; |
1649d92f | 4453 | bool changed = false; |
ae860ff7 JH |
4454 | |
4455 | cselib_init (); | |
8ba46434 R |
4456 | libcall_sp = &libcall_stack[MAX_NESTED_LIBCALLS]; |
4457 | *libcall_sp = 0; | |
ae860ff7 JH |
4458 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) |
4459 | { | |
4460 | if (INSN_P (insn)) | |
4461 | { | |
8ba46434 | 4462 | rtx note = find_reg_note (insn, REG_LIBCALL, NULL_RTX); |
ae860ff7 | 4463 | |
8ba46434 R |
4464 | if (note) |
4465 | { | |
4466 | if (libcall_sp == libcall_stack) | |
4467 | abort (); | |
4468 | *--libcall_sp = XEXP (note, 0); | |
4469 | } | |
4470 | note = find_reg_note (insn, REG_RETVAL, NULL_RTX); | |
4471 | if (note) | |
4472 | libcall_sp++; | |
4473 | note = find_reg_equal_equiv_note (insn); | |
ae860ff7 JH |
4474 | do |
4475 | { | |
4476 | reg_use_count = 0; | |
710ee3ed | 4477 | note_uses (&PATTERN (insn), local_cprop_find_used_regs, NULL); |
ae860ff7 | 4478 | if (note) |
710ee3ed | 4479 | local_cprop_find_used_regs (&XEXP (note, 0), NULL); |
ae860ff7 JH |
4480 | |
4481 | for (reg_used = ®_use_table[0]; reg_use_count > 0; | |
4482 | reg_used++, reg_use_count--) | |
8ba46434 R |
4483 | if (do_local_cprop (reg_used->reg_rtx, insn, alter_jumps, |
4484 | libcall_sp)) | |
1649d92f JH |
4485 | { |
4486 | changed = true; | |
4487 | break; | |
4488 | } | |
ae860ff7 JH |
4489 | } |
4490 | while (reg_use_count); | |
4491 | } | |
4492 | cselib_process_insn (insn); | |
4493 | } | |
4494 | cselib_finish (); | |
1649d92f JH |
4495 | /* Global analysis may get into infinite loops for unreachable blocks. */ |
4496 | if (changed && alter_jumps) | |
5f0bea72 JH |
4497 | { |
4498 | delete_unreachable_blocks (); | |
4499 | free_reg_set_mem (); | |
4500 | alloc_reg_set_mem (max_reg_num ()); | |
4501 | compute_sets (get_insns ()); | |
4502 | } | |
ae860ff7 JH |
4503 | } |
4504 | ||
c4c81601 | 4505 | /* Forward propagate copies. This includes copies and constants. Return |
cc2902df | 4506 | nonzero if a change was made. */ |
7506f491 DE |
4507 | |
4508 | static int | |
b5ce41ff JL |
4509 | cprop (alter_jumps) |
4510 | int alter_jumps; | |
7506f491 | 4511 | { |
e0082a72 ZD |
4512 | int changed; |
4513 | basic_block bb; | |
7506f491 DE |
4514 | rtx insn; |
4515 | ||
4516 | /* Note we start at block 1. */ | |
e0082a72 ZD |
4517 | if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) |
4518 | { | |
4519 | if (gcse_file != NULL) | |
4520 | fprintf (gcse_file, "\n"); | |
4521 | return 0; | |
4522 | } | |
7506f491 DE |
4523 | |
4524 | changed = 0; | |
e0082a72 | 4525 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb->next_bb, EXIT_BLOCK_PTR, next_bb) |
7506f491 DE |
4526 | { |
4527 | /* Reset tables used to keep track of what's still valid [since the | |
4528 | start of the block]. */ | |
4529 | reset_opr_set_tables (); | |
4530 | ||
e0082a72 ZD |
4531 | for (insn = bb->head; |
4532 | insn != NULL && insn != NEXT_INSN (bb->end); | |
7506f491 | 4533 | insn = NEXT_INSN (insn)) |
172890a2 RK |
4534 | if (INSN_P (insn)) |
4535 | { | |
ae860ff7 | 4536 | changed |= cprop_insn (insn, alter_jumps); |
7506f491 | 4537 | |
172890a2 RK |
4538 | /* Keep track of everything modified by this insn. */ |
4539 | /* ??? Need to be careful w.r.t. mods done to INSN. Don't | |
4540 | call mark_oprs_set if we turned the insn into a NOTE. */ | |
4541 | if (GET_CODE (insn) != NOTE) | |
4542 | mark_oprs_set (insn); | |
8e42ace1 | 4543 | } |
7506f491 DE |
4544 | } |
4545 | ||
4546 | if (gcse_file != NULL) | |
4547 | fprintf (gcse_file, "\n"); | |
4548 | ||
4549 | return changed; | |
4550 | } | |
4551 | ||
fbef91d8 RS |
4552 | /* Similar to get_condition, only the resulting condition must be |
4553 | valid at JUMP, instead of at EARLIEST. | |
4554 | ||
4555 | This differs from noce_get_condition in ifcvt.c in that we prefer not to | |
4556 | settle for the condition variable in the jump instruction being integral. | |
4557 | We prefer to be able to record the value of a user variable, rather than | |
4558 | the value of a temporary used in a condition. This could be solved by | |
4559 | recording the value of *every* register scaned by canonicalize_condition, | |
4560 | but this would require some code reorganization. */ | |
4561 | ||
4562 | static rtx | |
4563 | fis_get_condition (jump) | |
4564 | rtx jump; | |
4565 | { | |
4566 | rtx cond, set, tmp, insn, earliest; | |
4567 | bool reverse; | |
4568 | ||
4569 | if (! any_condjump_p (jump)) | |
4570 | return NULL_RTX; | |
4571 | ||
4572 | set = pc_set (jump); | |
4573 | cond = XEXP (SET_SRC (set), 0); | |
4574 | ||
4575 | /* If this branches to JUMP_LABEL when the condition is false, | |
4576 | reverse the condition. */ | |
4577 | reverse = (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF | |
4578 | && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (jump)); | |
4579 | ||
4580 | /* Use canonicalize_condition to do the dirty work of manipulating | |
4581 | MODE_CC values and COMPARE rtx codes. */ | |
4582 | tmp = canonicalize_condition (jump, cond, reverse, &earliest, NULL_RTX); | |
4583 | if (!tmp) | |
4584 | return NULL_RTX; | |
4585 | ||
4586 | /* Verify that the given condition is valid at JUMP by virtue of not | |
4587 | having been modified since EARLIEST. */ | |
4588 | for (insn = earliest; insn != jump; insn = NEXT_INSN (insn)) | |
4589 | if (INSN_P (insn) && modified_in_p (tmp, insn)) | |
4590 | break; | |
4591 | if (insn == jump) | |
4592 | return tmp; | |
4593 | ||
4594 | /* The condition was modified. See if we can get a partial result | |
4595 | that doesn't follow all the reversals. Perhaps combine can fold | |
4596 | them together later. */ | |
4597 | tmp = XEXP (tmp, 0); | |
4598 | if (!REG_P (tmp) || GET_MODE_CLASS (GET_MODE (tmp)) != MODE_INT) | |
4599 | return NULL_RTX; | |
4600 | tmp = canonicalize_condition (jump, cond, reverse, &earliest, tmp); | |
4601 | if (!tmp) | |
4602 | return NULL_RTX; | |
4603 | ||
4604 | /* For sanity's sake, re-validate the new result. */ | |
4605 | for (insn = earliest; insn != jump; insn = NEXT_INSN (insn)) | |
4606 | if (INSN_P (insn) && modified_in_p (tmp, insn)) | |
4607 | return NULL_RTX; | |
4608 | ||
4609 | return tmp; | |
4610 | } | |
4611 | ||
4612 | /* Find the implicit sets of a function. An "implicit set" is a constraint | |
4613 | on the value of a variable, implied by a conditional jump. For example, | |
4614 | following "if (x == 2)", the then branch may be optimized as though the | |
4615 | conditional performed an "explicit set", in this example, "x = 2". This | |
4616 | function records the set patterns that are implicit at the start of each | |
4617 | basic block. */ | |
4618 | ||
4619 | static void | |
4620 | find_implicit_sets () | |
4621 | { | |
4622 | basic_block bb, dest; | |
4623 | unsigned int count; | |
4624 | rtx cond, new; | |
4625 | ||
4626 | count = 0; | |
4627 | FOR_EACH_BB (bb) | |
4628 | /* Check for more than one sucessor. */ | |
4629 | if (bb->succ && bb->succ->succ_next) | |
4630 | { | |
4631 | cond = fis_get_condition (bb->end); | |
4632 | ||
4633 | if (cond | |
4634 | && (GET_CODE (cond) == EQ || GET_CODE (cond) == NE) | |
4635 | && GET_CODE (XEXP (cond, 0)) == REG | |
4636 | && REGNO (XEXP (cond, 0)) >= FIRST_PSEUDO_REGISTER | |
6b2d1c9e | 4637 | && gcse_constant_p (XEXP (cond, 1))) |
fbef91d8 RS |
4638 | { |
4639 | dest = GET_CODE (cond) == EQ ? BRANCH_EDGE (bb)->dest | |
4640 | : FALLTHRU_EDGE (bb)->dest; | |
4641 | ||
4642 | if (dest && ! dest->pred->pred_next | |
4643 | && dest != EXIT_BLOCK_PTR) | |
4644 | { | |
4645 | new = gen_rtx_SET (VOIDmode, XEXP (cond, 0), | |
4646 | XEXP (cond, 1)); | |
4647 | implicit_sets[dest->index] = new; | |
4648 | if (gcse_file) | |
4649 | { | |
4650 | fprintf(gcse_file, "Implicit set of reg %d in ", | |
4651 | REGNO (XEXP (cond, 0))); | |
4652 | fprintf(gcse_file, "basic block %d\n", dest->index); | |
4653 | } | |
4654 | count++; | |
4655 | } | |
4656 | } | |
4657 | } | |
4658 | ||
4659 | if (gcse_file) | |
4660 | fprintf (gcse_file, "Found %d implicit sets\n", count); | |
4661 | } | |
4662 | ||
7506f491 | 4663 | /* Perform one copy/constant propagation pass. |
a0134312 RS |
4664 | PASS is the pass count. If CPROP_JUMPS is true, perform constant |
4665 | propagation into conditional jumps. If BYPASS_JUMPS is true, | |
4666 | perform conditional jump bypassing optimizations. */ | |
7506f491 DE |
4667 | |
4668 | static int | |
a0134312 | 4669 | one_cprop_pass (pass, cprop_jumps, bypass_jumps) |
7506f491 | 4670 | int pass; |
a0134312 RS |
4671 | int cprop_jumps; |
4672 | int bypass_jumps; | |
7506f491 DE |
4673 | { |
4674 | int changed = 0; | |
4675 | ||
4676 | const_prop_count = 0; | |
4677 | copy_prop_count = 0; | |
4678 | ||
a0134312 | 4679 | local_cprop_pass (cprop_jumps); |
ae860ff7 | 4680 | |
fbef91d8 RS |
4681 | /* Determine implicit sets. */ |
4682 | implicit_sets = (rtx *) xcalloc (last_basic_block, sizeof (rtx)); | |
4683 | find_implicit_sets (); | |
4684 | ||
02280659 ZD |
4685 | alloc_hash_table (max_cuid, &set_hash_table, 1); |
4686 | compute_hash_table (&set_hash_table); | |
fbef91d8 RS |
4687 | |
4688 | /* Free implicit_sets before peak usage. */ | |
4689 | free (implicit_sets); | |
4690 | implicit_sets = NULL; | |
4691 | ||
7506f491 | 4692 | if (gcse_file) |
02280659 ZD |
4693 | dump_hash_table (gcse_file, "SET", &set_hash_table); |
4694 | if (set_hash_table.n_elems > 0) | |
7506f491 | 4695 | { |
02280659 | 4696 | alloc_cprop_mem (last_basic_block, set_hash_table.n_elems); |
7506f491 | 4697 | compute_cprop_data (); |
a0134312 RS |
4698 | changed = cprop (cprop_jumps); |
4699 | if (bypass_jumps) | |
0e3f0221 | 4700 | changed |= bypass_conditional_jumps (); |
7506f491 DE |
4701 | free_cprop_mem (); |
4702 | } | |
c4c81601 | 4703 | |
02280659 | 4704 | free_hash_table (&set_hash_table); |
7506f491 DE |
4705 | |
4706 | if (gcse_file) | |
4707 | { | |
c4c81601 RK |
4708 | fprintf (gcse_file, "CPROP of %s, pass %d: %d bytes needed, ", |
4709 | current_function_name, pass, bytes_used); | |
4710 | fprintf (gcse_file, "%d const props, %d copy props\n\n", | |
4711 | const_prop_count, copy_prop_count); | |
7506f491 | 4712 | } |
1649d92f JH |
4713 | /* Global analysis may get into infinite loops for unreachable blocks. */ |
4714 | if (changed && cprop_jumps) | |
4715 | delete_unreachable_blocks (); | |
7506f491 DE |
4716 | |
4717 | return changed; | |
4718 | } | |
4719 | \f | |
0e3f0221 RS |
4720 | /* Bypass conditional jumps. */ |
4721 | ||
7821bfc7 RS |
4722 | /* The value of last_basic_block at the beginning of the jump_bypass |
4723 | pass. The use of redirect_edge_and_branch_force may introduce new | |
4724 | basic blocks, but the data flow analysis is only valid for basic | |
4725 | block indices less than bypass_last_basic_block. */ | |
4726 | ||
4727 | static int bypass_last_basic_block; | |
4728 | ||
0e3f0221 RS |
4729 | /* Find a set of REGNO to a constant that is available at the end of basic |
4730 | block BB. Returns NULL if no such set is found. Based heavily upon | |
4731 | find_avail_set. */ | |
4732 | ||
4733 | static struct expr * | |
4734 | find_bypass_set (regno, bb) | |
4735 | int regno; | |
4736 | int bb; | |
4737 | { | |
4738 | struct expr *result = 0; | |
4739 | ||
4740 | for (;;) | |
4741 | { | |
4742 | rtx src; | |
ceda50e9 | 4743 | struct expr *set = lookup_set (regno, &set_hash_table); |
0e3f0221 RS |
4744 | |
4745 | while (set) | |
4746 | { | |
4747 | if (TEST_BIT (cprop_avout[bb], set->bitmap_index)) | |
4748 | break; | |
4749 | set = next_set (regno, set); | |
4750 | } | |
4751 | ||
4752 | if (set == 0) | |
4753 | break; | |
4754 | ||
4755 | if (GET_CODE (set->expr) != SET) | |
4756 | abort (); | |
4757 | ||
4758 | src = SET_SRC (set->expr); | |
6b2d1c9e | 4759 | if (gcse_constant_p (src)) |
0e3f0221 RS |
4760 | result = set; |
4761 | ||
4762 | if (GET_CODE (src) != REG) | |
4763 | break; | |
4764 | ||
4765 | regno = REGNO (src); | |
4766 | } | |
4767 | return result; | |
4768 | } | |
4769 | ||
4770 | ||
4771 | /* Subroutine of bypass_conditional_jumps that attempts to bypass the given | |
4772 | basic block BB which has more than one predecessor. If not NULL, SETCC | |
4773 | is the first instruction of BB, which is immediately followed by JUMP_INSN | |
4774 | JUMP. Otherwise, SETCC is NULL, and JUMP is the first insn of BB. | |
4775 | Returns nonzero if a change was made. */ | |
4776 | ||
4777 | static int | |
4778 | bypass_block (bb, setcc, jump) | |
4779 | basic_block bb; | |
4780 | rtx setcc, jump; | |
4781 | { | |
4782 | rtx insn, note; | |
4783 | edge e, enext; | |
818b6b7f | 4784 | int i, change; |
72b8d451 | 4785 | int may_be_loop_header; |
0e3f0221 RS |
4786 | |
4787 | insn = (setcc != NULL) ? setcc : jump; | |
4788 | ||
4789 | /* Determine set of register uses in INSN. */ | |
4790 | reg_use_count = 0; | |
4791 | note_uses (&PATTERN (insn), find_used_regs, NULL); | |
4792 | note = find_reg_equal_equiv_note (insn); | |
4793 | if (note) | |
4794 | find_used_regs (&XEXP (note, 0), NULL); | |
4795 | ||
72b8d451 ZD |
4796 | may_be_loop_header = false; |
4797 | for (e = bb->pred; e; e = e->pred_next) | |
4798 | if (e->flags & EDGE_DFS_BACK) | |
4799 | { | |
4800 | may_be_loop_header = true; | |
4801 | break; | |
4802 | } | |
4803 | ||
0e3f0221 RS |
4804 | change = 0; |
4805 | for (e = bb->pred; e; e = enext) | |
4806 | { | |
4807 | enext = e->pred_next; | |
7821bfc7 RS |
4808 | if (e->flags & EDGE_COMPLEX) |
4809 | continue; | |
4810 | ||
4811 | /* We can't redirect edges from new basic blocks. */ | |
4812 | if (e->src->index >= bypass_last_basic_block) | |
4813 | continue; | |
4814 | ||
72b8d451 ZD |
4815 | /* The irreducible loops created by redirecting of edges entering the |
4816 | loop from outside would decrease effectivity of some of the following | |
4817 | optimalizations, so prevent this. */ | |
4818 | if (may_be_loop_header | |
4819 | && !(e->flags & EDGE_DFS_BACK)) | |
4820 | continue; | |
4821 | ||
0e3f0221 RS |
4822 | for (i = 0; i < reg_use_count; i++) |
4823 | { | |
4824 | struct reg_use *reg_used = ®_use_table[i]; | |
589005ff | 4825 | unsigned int regno = REGNO (reg_used->reg_rtx); |
818b6b7f | 4826 | basic_block dest, old_dest; |
589005ff KH |
4827 | struct expr *set; |
4828 | rtx src, new; | |
0e3f0221 | 4829 | |
589005ff KH |
4830 | if (regno >= max_gcse_regno) |
4831 | continue; | |
0e3f0221 | 4832 | |
589005ff | 4833 | set = find_bypass_set (regno, e->src->index); |
0e3f0221 RS |
4834 | |
4835 | if (! set) | |
4836 | continue; | |
4837 | ||
589005ff | 4838 | src = SET_SRC (pc_set (jump)); |
0e3f0221 RS |
4839 | |
4840 | if (setcc != NULL) | |
4841 | src = simplify_replace_rtx (src, | |
589005ff KH |
4842 | SET_DEST (PATTERN (setcc)), |
4843 | SET_SRC (PATTERN (setcc))); | |
0e3f0221 RS |
4844 | |
4845 | new = simplify_replace_rtx (src, reg_used->reg_rtx, | |
589005ff | 4846 | SET_SRC (set->expr)); |
0e3f0221 | 4847 | |
589005ff | 4848 | if (new == pc_rtx) |
0e3f0221 RS |
4849 | dest = FALLTHRU_EDGE (bb)->dest; |
4850 | else if (GET_CODE (new) == LABEL_REF) | |
9a71ece1 | 4851 | dest = BLOCK_FOR_INSN (XEXP (new, 0)); |
0e3f0221 RS |
4852 | else |
4853 | dest = NULL; | |
4854 | ||
818b6b7f | 4855 | old_dest = e->dest; |
7821bfc7 RS |
4856 | if (dest != NULL |
4857 | && dest != old_dest | |
4858 | && dest != EXIT_BLOCK_PTR) | |
4859 | { | |
4860 | redirect_edge_and_branch_force (e, dest); | |
4861 | ||
818b6b7f | 4862 | /* Copy the register setter to the redirected edge. |
0e3f0221 RS |
4863 | Don't copy CC0 setters, as CC0 is dead after jump. */ |
4864 | if (setcc) | |
4865 | { | |
4866 | rtx pat = PATTERN (setcc); | |
818b6b7f | 4867 | if (!CC0_P (SET_DEST (pat))) |
0e3f0221 RS |
4868 | insert_insn_on_edge (copy_insn (pat), e); |
4869 | } | |
4870 | ||
4871 | if (gcse_file != NULL) | |
4872 | { | |
818b6b7f RH |
4873 | fprintf (gcse_file, "JUMP-BYPASS: Proved reg %d in jump_insn %d equals constant ", |
4874 | regno, INSN_UID (jump)); | |
0e3f0221 RS |
4875 | print_rtl (gcse_file, SET_SRC (set->expr)); |
4876 | fprintf (gcse_file, "\nBypass edge from %d->%d to %d\n", | |
818b6b7f | 4877 | e->src->index, old_dest->index, dest->index); |
0e3f0221 RS |
4878 | } |
4879 | change = 1; | |
4880 | break; | |
4881 | } | |
4882 | } | |
4883 | } | |
4884 | return change; | |
4885 | } | |
4886 | ||
4887 | /* Find basic blocks with more than one predecessor that only contain a | |
4888 | single conditional jump. If the result of the comparison is known at | |
4889 | compile-time from any incoming edge, redirect that edge to the | |
9a71ece1 RH |
4890 | appropriate target. Returns nonzero if a change was made. |
4891 | ||
4892 | This function is now mis-named, because we also handle indirect jumps. */ | |
0e3f0221 RS |
4893 | |
4894 | static int | |
4895 | bypass_conditional_jumps () | |
4896 | { | |
4897 | basic_block bb; | |
4898 | int changed; | |
4899 | rtx setcc; | |
4900 | rtx insn; | |
4901 | rtx dest; | |
4902 | ||
4903 | /* Note we start at block 1. */ | |
4904 | if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) | |
4905 | return 0; | |
4906 | ||
7821bfc7 | 4907 | bypass_last_basic_block = last_basic_block; |
72b8d451 | 4908 | mark_dfs_back_edges (); |
7821bfc7 | 4909 | |
0e3f0221 RS |
4910 | changed = 0; |
4911 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb->next_bb, | |
589005ff | 4912 | EXIT_BLOCK_PTR, next_bb) |
0e3f0221 RS |
4913 | { |
4914 | /* Check for more than one predecessor. */ | |
4915 | if (bb->pred && bb->pred->pred_next) | |
4916 | { | |
4917 | setcc = NULL_RTX; | |
4918 | for (insn = bb->head; | |
4919 | insn != NULL && insn != NEXT_INSN (bb->end); | |
4920 | insn = NEXT_INSN (insn)) | |
4921 | if (GET_CODE (insn) == INSN) | |
4922 | { | |
9543a9d2 | 4923 | if (setcc) |
0e3f0221 | 4924 | break; |
ba4f7968 | 4925 | if (GET_CODE (PATTERN (insn)) != SET) |
0e3f0221 RS |
4926 | break; |
4927 | ||
ba4f7968 | 4928 | dest = SET_DEST (PATTERN (insn)); |
818b6b7f | 4929 | if (REG_P (dest) || CC0_P (dest)) |
0e3f0221 | 4930 | setcc = insn; |
0e3f0221 RS |
4931 | else |
4932 | break; | |
4933 | } | |
4934 | else if (GET_CODE (insn) == JUMP_INSN) | |
4935 | { | |
9a71ece1 RH |
4936 | if ((any_condjump_p (insn) || computed_jump_p (insn)) |
4937 | && onlyjump_p (insn)) | |
0e3f0221 RS |
4938 | changed |= bypass_block (bb, setcc, insn); |
4939 | break; | |
4940 | } | |
4941 | else if (INSN_P (insn)) | |
4942 | break; | |
4943 | } | |
4944 | } | |
4945 | ||
818b6b7f | 4946 | /* If we bypassed any register setting insns, we inserted a |
fbe5a4a6 | 4947 | copy on the redirected edge. These need to be committed. */ |
0e3f0221 RS |
4948 | if (changed) |
4949 | commit_edge_insertions(); | |
4950 | ||
4951 | return changed; | |
4952 | } | |
4953 | \f | |
a65f3558 | 4954 | /* Compute PRE+LCM working variables. */ |
7506f491 DE |
4955 | |
4956 | /* Local properties of expressions. */ | |
4957 | /* Nonzero for expressions that are transparent in the block. */ | |
a65f3558 | 4958 | static sbitmap *transp; |
7506f491 | 4959 | |
5c35539b RH |
4960 | /* Nonzero for expressions that are transparent at the end of the block. |
4961 | This is only zero for expressions killed by abnormal critical edge | |
4962 | created by a calls. */ | |
a65f3558 | 4963 | static sbitmap *transpout; |
5c35539b | 4964 | |
a65f3558 JL |
4965 | /* Nonzero for expressions that are computed (available) in the block. */ |
4966 | static sbitmap *comp; | |
7506f491 | 4967 | |
a65f3558 JL |
4968 | /* Nonzero for expressions that are locally anticipatable in the block. */ |
4969 | static sbitmap *antloc; | |
7506f491 | 4970 | |
a65f3558 JL |
4971 | /* Nonzero for expressions where this block is an optimal computation |
4972 | point. */ | |
4973 | static sbitmap *pre_optimal; | |
5c35539b | 4974 | |
a65f3558 JL |
4975 | /* Nonzero for expressions which are redundant in a particular block. */ |
4976 | static sbitmap *pre_redundant; | |
7506f491 | 4977 | |
a42cd965 AM |
4978 | /* Nonzero for expressions which should be inserted on a specific edge. */ |
4979 | static sbitmap *pre_insert_map; | |
4980 | ||
4981 | /* Nonzero for expressions which should be deleted in a specific block. */ | |
4982 | static sbitmap *pre_delete_map; | |
4983 | ||
4984 | /* Contains the edge_list returned by pre_edge_lcm. */ | |
4985 | static struct edge_list *edge_list; | |
4986 | ||
a65f3558 JL |
4987 | /* Redundant insns. */ |
4988 | static sbitmap pre_redundant_insns; | |
7506f491 | 4989 | |
a65f3558 | 4990 | /* Allocate vars used for PRE analysis. */ |
7506f491 DE |
4991 | |
4992 | static void | |
a65f3558 JL |
4993 | alloc_pre_mem (n_blocks, n_exprs) |
4994 | int n_blocks, n_exprs; | |
7506f491 | 4995 | { |
a65f3558 JL |
4996 | transp = sbitmap_vector_alloc (n_blocks, n_exprs); |
4997 | comp = sbitmap_vector_alloc (n_blocks, n_exprs); | |
4998 | antloc = sbitmap_vector_alloc (n_blocks, n_exprs); | |
5faf03ae | 4999 | |
a42cd965 AM |
5000 | pre_optimal = NULL; |
5001 | pre_redundant = NULL; | |
5002 | pre_insert_map = NULL; | |
5003 | pre_delete_map = NULL; | |
5004 | ae_in = NULL; | |
5005 | ae_out = NULL; | |
a42cd965 | 5006 | ae_kill = sbitmap_vector_alloc (n_blocks, n_exprs); |
c4c81601 | 5007 | |
a42cd965 | 5008 | /* pre_insert and pre_delete are allocated later. */ |
7506f491 DE |
5009 | } |
5010 | ||
a65f3558 | 5011 | /* Free vars used for PRE analysis. */ |
7506f491 DE |
5012 | |
5013 | static void | |
a65f3558 | 5014 | free_pre_mem () |
7506f491 | 5015 | { |
5a660bff DB |
5016 | sbitmap_vector_free (transp); |
5017 | sbitmap_vector_free (comp); | |
bd3675fc JL |
5018 | |
5019 | /* ANTLOC and AE_KILL are freed just after pre_lcm finishes. */ | |
7506f491 | 5020 | |
a42cd965 | 5021 | if (pre_optimal) |
5a660bff | 5022 | sbitmap_vector_free (pre_optimal); |
a42cd965 | 5023 | if (pre_redundant) |
5a660bff | 5024 | sbitmap_vector_free (pre_redundant); |
a42cd965 | 5025 | if (pre_insert_map) |
5a660bff | 5026 | sbitmap_vector_free (pre_insert_map); |
a42cd965 | 5027 | if (pre_delete_map) |
5a660bff | 5028 | sbitmap_vector_free (pre_delete_map); |
a42cd965 | 5029 | if (ae_in) |
5a660bff | 5030 | sbitmap_vector_free (ae_in); |
a42cd965 | 5031 | if (ae_out) |
5a660bff | 5032 | sbitmap_vector_free (ae_out); |
a42cd965 | 5033 | |
bd3675fc | 5034 | transp = comp = NULL; |
a42cd965 | 5035 | pre_optimal = pre_redundant = pre_insert_map = pre_delete_map = NULL; |
55d3f917 | 5036 | ae_in = ae_out = NULL; |
7506f491 DE |
5037 | } |
5038 | ||
5039 | /* Top level routine to do the dataflow analysis needed by PRE. */ | |
5040 | ||
5041 | static void | |
5042 | compute_pre_data () | |
5043 | { | |
b614171e | 5044 | sbitmap trapping_expr; |
e0082a72 | 5045 | basic_block bb; |
b614171e | 5046 | unsigned int ui; |
c66e8ae9 | 5047 | |
02280659 | 5048 | compute_local_properties (transp, comp, antloc, &expr_hash_table); |
d55bc081 | 5049 | sbitmap_vector_zero (ae_kill, last_basic_block); |
c66e8ae9 | 5050 | |
b614171e | 5051 | /* Collect expressions which might trap. */ |
02280659 | 5052 | trapping_expr = sbitmap_alloc (expr_hash_table.n_elems); |
b614171e | 5053 | sbitmap_zero (trapping_expr); |
02280659 | 5054 | for (ui = 0; ui < expr_hash_table.size; ui++) |
b614171e MM |
5055 | { |
5056 | struct expr *e; | |
02280659 | 5057 | for (e = expr_hash_table.table[ui]; e != NULL; e = e->next_same_hash) |
b614171e MM |
5058 | if (may_trap_p (e->expr)) |
5059 | SET_BIT (trapping_expr, e->bitmap_index); | |
5060 | } | |
5061 | ||
c66e8ae9 JL |
5062 | /* Compute ae_kill for each basic block using: |
5063 | ||
5064 | ~(TRANSP | COMP) | |
5065 | ||
a2e90653 | 5066 | This is significantly faster than compute_ae_kill. */ |
c66e8ae9 | 5067 | |
e0082a72 | 5068 | FOR_EACH_BB (bb) |
c66e8ae9 | 5069 | { |
b614171e MM |
5070 | edge e; |
5071 | ||
5072 | /* If the current block is the destination of an abnormal edge, we | |
5073 | kill all trapping expressions because we won't be able to properly | |
5074 | place the instruction on the edge. So make them neither | |
5075 | anticipatable nor transparent. This is fairly conservative. */ | |
e0082a72 | 5076 | for (e = bb->pred; e ; e = e->pred_next) |
b614171e MM |
5077 | if (e->flags & EDGE_ABNORMAL) |
5078 | { | |
e0082a72 ZD |
5079 | sbitmap_difference (antloc[bb->index], antloc[bb->index], trapping_expr); |
5080 | sbitmap_difference (transp[bb->index], transp[bb->index], trapping_expr); | |
b614171e MM |
5081 | break; |
5082 | } | |
5083 | ||
e0082a72 ZD |
5084 | sbitmap_a_or_b (ae_kill[bb->index], transp[bb->index], comp[bb->index]); |
5085 | sbitmap_not (ae_kill[bb->index], ae_kill[bb->index]); | |
c66e8ae9 JL |
5086 | } |
5087 | ||
02280659 | 5088 | edge_list = pre_edge_lcm (gcse_file, expr_hash_table.n_elems, transp, comp, antloc, |
a42cd965 | 5089 | ae_kill, &pre_insert_map, &pre_delete_map); |
5a660bff | 5090 | sbitmap_vector_free (antloc); |
bd3675fc | 5091 | antloc = NULL; |
5a660bff | 5092 | sbitmap_vector_free (ae_kill); |
589005ff | 5093 | ae_kill = NULL; |
76ac938b | 5094 | sbitmap_free (trapping_expr); |
7506f491 DE |
5095 | } |
5096 | \f | |
5097 | /* PRE utilities */ | |
5098 | ||
cc2902df | 5099 | /* Return nonzero if an occurrence of expression EXPR in OCCR_BB would reach |
a65f3558 | 5100 | block BB. |
7506f491 DE |
5101 | |
5102 | VISITED is a pointer to a working buffer for tracking which BB's have | |
5103 | been visited. It is NULL for the top-level call. | |
5104 | ||
5105 | We treat reaching expressions that go through blocks containing the same | |
5106 | reaching expression as "not reaching". E.g. if EXPR is generated in blocks | |
5107 | 2 and 3, INSN is in block 4, and 2->3->4, we treat the expression in block | |
5108 | 2 as not reaching. The intent is to improve the probability of finding | |
5109 | only one reaching expression and to reduce register lifetimes by picking | |
5110 | the closest such expression. */ | |
5111 | ||
5112 | static int | |
89e606c9 | 5113 | pre_expr_reaches_here_p_work (occr_bb, expr, bb, visited) |
e2d2ed72 | 5114 | basic_block occr_bb; |
7506f491 | 5115 | struct expr *expr; |
e2d2ed72 | 5116 | basic_block bb; |
7506f491 DE |
5117 | char *visited; |
5118 | { | |
36349f8b | 5119 | edge pred; |
7506f491 | 5120 | |
e2d2ed72 | 5121 | for (pred = bb->pred; pred != NULL; pred = pred->pred_next) |
7506f491 | 5122 | { |
e2d2ed72 | 5123 | basic_block pred_bb = pred->src; |
7506f491 | 5124 | |
36349f8b | 5125 | if (pred->src == ENTRY_BLOCK_PTR |
7506f491 | 5126 | /* Has predecessor has already been visited? */ |
0b17ab2f | 5127 | || visited[pred_bb->index]) |
c4c81601 RK |
5128 | ;/* Nothing to do. */ |
5129 | ||
7506f491 | 5130 | /* Does this predecessor generate this expression? */ |
0b17ab2f | 5131 | else if (TEST_BIT (comp[pred_bb->index], expr->bitmap_index)) |
7506f491 DE |
5132 | { |
5133 | /* Is this the occurrence we're looking for? | |
5134 | Note that there's only one generating occurrence per block | |
5135 | so we just need to check the block number. */ | |
a65f3558 | 5136 | if (occr_bb == pred_bb) |
7506f491 | 5137 | return 1; |
c4c81601 | 5138 | |
0b17ab2f | 5139 | visited[pred_bb->index] = 1; |
7506f491 DE |
5140 | } |
5141 | /* Ignore this predecessor if it kills the expression. */ | |
0b17ab2f RH |
5142 | else if (! TEST_BIT (transp[pred_bb->index], expr->bitmap_index)) |
5143 | visited[pred_bb->index] = 1; | |
c4c81601 | 5144 | |
7506f491 DE |
5145 | /* Neither gen nor kill. */ |
5146 | else | |
ac7c5af5 | 5147 | { |
0b17ab2f | 5148 | visited[pred_bb->index] = 1; |
89e606c9 | 5149 | if (pre_expr_reaches_here_p_work (occr_bb, expr, pred_bb, visited)) |
7506f491 | 5150 | return 1; |
ac7c5af5 | 5151 | } |
7506f491 DE |
5152 | } |
5153 | ||
5154 | /* All paths have been checked. */ | |
5155 | return 0; | |
5156 | } | |
283a2545 RL |
5157 | |
5158 | /* The wrapper for pre_expr_reaches_here_work that ensures that any | |
dc297297 | 5159 | memory allocated for that function is returned. */ |
283a2545 RL |
5160 | |
5161 | static int | |
89e606c9 | 5162 | pre_expr_reaches_here_p (occr_bb, expr, bb) |
e2d2ed72 | 5163 | basic_block occr_bb; |
283a2545 | 5164 | struct expr *expr; |
e2d2ed72 | 5165 | basic_block bb; |
283a2545 RL |
5166 | { |
5167 | int rval; | |
d55bc081 | 5168 | char *visited = (char *) xcalloc (last_basic_block, 1); |
283a2545 | 5169 | |
8e42ace1 | 5170 | rval = pre_expr_reaches_here_p_work (occr_bb, expr, bb, visited); |
283a2545 RL |
5171 | |
5172 | free (visited); | |
c4c81601 | 5173 | return rval; |
283a2545 | 5174 | } |
7506f491 | 5175 | \f |
a42cd965 AM |
5176 | |
5177 | /* Given an expr, generate RTL which we can insert at the end of a BB, | |
589005ff | 5178 | or on an edge. Set the block number of any insns generated to |
a42cd965 AM |
5179 | the value of BB. */ |
5180 | ||
5181 | static rtx | |
5182 | process_insert_insn (expr) | |
5183 | struct expr *expr; | |
5184 | { | |
5185 | rtx reg = expr->reaching_reg; | |
fb0c0a12 RK |
5186 | rtx exp = copy_rtx (expr->expr); |
5187 | rtx pat; | |
a42cd965 AM |
5188 | |
5189 | start_sequence (); | |
fb0c0a12 RK |
5190 | |
5191 | /* If the expression is something that's an operand, like a constant, | |
5192 | just copy it to a register. */ | |
5193 | if (general_operand (exp, GET_MODE (reg))) | |
5194 | emit_move_insn (reg, exp); | |
5195 | ||
5196 | /* Otherwise, make a new insn to compute this expression and make sure the | |
5197 | insn will be recognized (this also adds any needed CLOBBERs). Copy the | |
5198 | expression to make sure we don't have any sharing issues. */ | |
8d444206 | 5199 | else if (insn_invalid_p (emit_insn (gen_rtx_SET (VOIDmode, reg, exp)))) |
fb0c0a12 | 5200 | abort (); |
589005ff | 5201 | |
2f937369 | 5202 | pat = get_insns (); |
a42cd965 AM |
5203 | end_sequence (); |
5204 | ||
5205 | return pat; | |
5206 | } | |
589005ff | 5207 | |
a65f3558 JL |
5208 | /* Add EXPR to the end of basic block BB. |
5209 | ||
5210 | This is used by both the PRE and code hoisting. | |
5211 | ||
5212 | For PRE, we want to verify that the expr is either transparent | |
5213 | or locally anticipatable in the target block. This check makes | |
5214 | no sense for code hoisting. */ | |
7506f491 DE |
5215 | |
5216 | static void | |
a65f3558 | 5217 | insert_insn_end_bb (expr, bb, pre) |
7506f491 | 5218 | struct expr *expr; |
e2d2ed72 | 5219 | basic_block bb; |
a65f3558 | 5220 | int pre; |
7506f491 | 5221 | { |
e2d2ed72 | 5222 | rtx insn = bb->end; |
7506f491 DE |
5223 | rtx new_insn; |
5224 | rtx reg = expr->reaching_reg; | |
5225 | int regno = REGNO (reg); | |
2f937369 | 5226 | rtx pat, pat_end; |
7506f491 | 5227 | |
a42cd965 | 5228 | pat = process_insert_insn (expr); |
2f937369 DM |
5229 | if (pat == NULL_RTX || ! INSN_P (pat)) |
5230 | abort (); | |
5231 | ||
5232 | pat_end = pat; | |
5233 | while (NEXT_INSN (pat_end) != NULL_RTX) | |
5234 | pat_end = NEXT_INSN (pat_end); | |
7506f491 DE |
5235 | |
5236 | /* If the last insn is a jump, insert EXPR in front [taking care to | |
068473ec JH |
5237 | handle cc0, etc. properly]. Similary we need to care trapping |
5238 | instructions in presence of non-call exceptions. */ | |
7506f491 | 5239 | |
068473ec JH |
5240 | if (GET_CODE (insn) == JUMP_INSN |
5241 | || (GET_CODE (insn) == INSN | |
5242 | && (bb->succ->succ_next || (bb->succ->flags & EDGE_ABNORMAL)))) | |
7506f491 | 5243 | { |
50b2596f | 5244 | #ifdef HAVE_cc0 |
7506f491 | 5245 | rtx note; |
50b2596f | 5246 | #endif |
068473ec JH |
5247 | /* It should always be the case that we can put these instructions |
5248 | anywhere in the basic block with performing PRE optimizations. | |
5249 | Check this. */ | |
3b25fbfe | 5250 | if (GET_CODE (insn) == INSN && pre |
0b17ab2f | 5251 | && !TEST_BIT (antloc[bb->index], expr->bitmap_index) |
589005ff | 5252 | && !TEST_BIT (transp[bb->index], expr->bitmap_index)) |
068473ec | 5253 | abort (); |
7506f491 DE |
5254 | |
5255 | /* If this is a jump table, then we can't insert stuff here. Since | |
5256 | we know the previous real insn must be the tablejump, we insert | |
5257 | the new instruction just before the tablejump. */ | |
5258 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
5259 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
5260 | insn = prev_real_insn (insn); | |
5261 | ||
5262 | #ifdef HAVE_cc0 | |
5263 | /* FIXME: 'twould be nice to call prev_cc0_setter here but it aborts | |
5264 | if cc0 isn't set. */ | |
5265 | note = find_reg_note (insn, REG_CC_SETTER, NULL_RTX); | |
5266 | if (note) | |
5267 | insn = XEXP (note, 0); | |
5268 | else | |
5269 | { | |
5270 | rtx maybe_cc0_setter = prev_nonnote_insn (insn); | |
5271 | if (maybe_cc0_setter | |
2c3c49de | 5272 | && INSN_P (maybe_cc0_setter) |
7506f491 DE |
5273 | && sets_cc0_p (PATTERN (maybe_cc0_setter))) |
5274 | insn = maybe_cc0_setter; | |
5275 | } | |
5276 | #endif | |
5277 | /* FIXME: What if something in cc0/jump uses value set in new insn? */ | |
3c030e88 | 5278 | new_insn = emit_insn_before (pat, insn); |
3947e2f9 | 5279 | } |
c4c81601 | 5280 | |
3947e2f9 RH |
5281 | /* Likewise if the last insn is a call, as will happen in the presence |
5282 | of exception handling. */ | |
068473ec JH |
5283 | else if (GET_CODE (insn) == CALL_INSN |
5284 | && (bb->succ->succ_next || (bb->succ->flags & EDGE_ABNORMAL))) | |
3947e2f9 | 5285 | { |
3947e2f9 RH |
5286 | /* Keeping in mind SMALL_REGISTER_CLASSES and parameters in registers, |
5287 | we search backward and place the instructions before the first | |
5288 | parameter is loaded. Do this for everyone for consistency and a | |
fbe5a4a6 | 5289 | presumption that we'll get better code elsewhere as well. |
3947e2f9 | 5290 | |
c4c81601 | 5291 | It should always be the case that we can put these instructions |
a65f3558 JL |
5292 | anywhere in the basic block with performing PRE optimizations. |
5293 | Check this. */ | |
c4c81601 | 5294 | |
a65f3558 | 5295 | if (pre |
0b17ab2f | 5296 | && !TEST_BIT (antloc[bb->index], expr->bitmap_index) |
589005ff | 5297 | && !TEST_BIT (transp[bb->index], expr->bitmap_index)) |
3947e2f9 RH |
5298 | abort (); |
5299 | ||
5300 | /* Since different machines initialize their parameter registers | |
5301 | in different orders, assume nothing. Collect the set of all | |
5302 | parameter registers. */ | |
833366d6 | 5303 | insn = find_first_parameter_load (insn, bb->head); |
3947e2f9 | 5304 | |
b1d26727 JL |
5305 | /* If we found all the parameter loads, then we want to insert |
5306 | before the first parameter load. | |
5307 | ||
5308 | If we did not find all the parameter loads, then we might have | |
5309 | stopped on the head of the block, which could be a CODE_LABEL. | |
5310 | If we inserted before the CODE_LABEL, then we would be putting | |
5311 | the insn in the wrong basic block. In that case, put the insn | |
b5229628 | 5312 | after the CODE_LABEL. Also, respect NOTE_INSN_BASIC_BLOCK. */ |
0a377997 | 5313 | while (GET_CODE (insn) == CODE_LABEL |
589ca5cb | 5314 | || NOTE_INSN_BASIC_BLOCK_P (insn)) |
b5229628 | 5315 | insn = NEXT_INSN (insn); |
c4c81601 | 5316 | |
3c030e88 | 5317 | new_insn = emit_insn_before (pat, insn); |
7506f491 DE |
5318 | } |
5319 | else | |
3c030e88 | 5320 | new_insn = emit_insn_after (pat, insn); |
7506f491 | 5321 | |
2f937369 | 5322 | while (1) |
a65f3558 | 5323 | { |
2f937369 | 5324 | if (INSN_P (pat)) |
a65f3558 | 5325 | { |
2f937369 DM |
5326 | add_label_notes (PATTERN (pat), new_insn); |
5327 | note_stores (PATTERN (pat), record_set_info, pat); | |
a65f3558 | 5328 | } |
2f937369 DM |
5329 | if (pat == pat_end) |
5330 | break; | |
5331 | pat = NEXT_INSN (pat); | |
a65f3558 | 5332 | } |
3947e2f9 | 5333 | |
7506f491 DE |
5334 | gcse_create_count++; |
5335 | ||
5336 | if (gcse_file) | |
5337 | { | |
c4c81601 | 5338 | fprintf (gcse_file, "PRE/HOIST: end of bb %d, insn %d, ", |
0b17ab2f | 5339 | bb->index, INSN_UID (new_insn)); |
c4c81601 RK |
5340 | fprintf (gcse_file, "copying expression %d to reg %d\n", |
5341 | expr->bitmap_index, regno); | |
7506f491 DE |
5342 | } |
5343 | } | |
5344 | ||
a42cd965 AM |
5345 | /* Insert partially redundant expressions on edges in the CFG to make |
5346 | the expressions fully redundant. */ | |
7506f491 | 5347 | |
a42cd965 AM |
5348 | static int |
5349 | pre_edge_insert (edge_list, index_map) | |
5350 | struct edge_list *edge_list; | |
7506f491 DE |
5351 | struct expr **index_map; |
5352 | { | |
c4c81601 | 5353 | int e, i, j, num_edges, set_size, did_insert = 0; |
a65f3558 JL |
5354 | sbitmap *inserted; |
5355 | ||
a42cd965 AM |
5356 | /* Where PRE_INSERT_MAP is nonzero, we add the expression on that edge |
5357 | if it reaches any of the deleted expressions. */ | |
7506f491 | 5358 | |
a42cd965 AM |
5359 | set_size = pre_insert_map[0]->size; |
5360 | num_edges = NUM_EDGES (edge_list); | |
02280659 | 5361 | inserted = sbitmap_vector_alloc (num_edges, expr_hash_table.n_elems); |
a42cd965 | 5362 | sbitmap_vector_zero (inserted, num_edges); |
7506f491 | 5363 | |
a42cd965 | 5364 | for (e = 0; e < num_edges; e++) |
7506f491 DE |
5365 | { |
5366 | int indx; | |
e2d2ed72 | 5367 | basic_block bb = INDEX_EDGE_PRED_BB (edge_list, e); |
a65f3558 | 5368 | |
a65f3558 | 5369 | for (i = indx = 0; i < set_size; i++, indx += SBITMAP_ELT_BITS) |
7506f491 | 5370 | { |
a42cd965 | 5371 | SBITMAP_ELT_TYPE insert = pre_insert_map[e]->elms[i]; |
7506f491 | 5372 | |
02280659 | 5373 | for (j = indx; insert && j < (int) expr_hash_table.n_elems; j++, insert >>= 1) |
c4c81601 RK |
5374 | if ((insert & 1) != 0 && index_map[j]->reaching_reg != NULL_RTX) |
5375 | { | |
5376 | struct expr *expr = index_map[j]; | |
5377 | struct occr *occr; | |
a65f3558 | 5378 | |
ff7cc307 | 5379 | /* Now look at each deleted occurrence of this expression. */ |
c4c81601 RK |
5380 | for (occr = expr->antic_occr; occr != NULL; occr = occr->next) |
5381 | { | |
5382 | if (! occr->deleted_p) | |
5383 | continue; | |
5384 | ||
5385 | /* Insert this expression on this edge if if it would | |
ff7cc307 | 5386 | reach the deleted occurrence in BB. */ |
c4c81601 RK |
5387 | if (!TEST_BIT (inserted[e], j)) |
5388 | { | |
5389 | rtx insn; | |
5390 | edge eg = INDEX_EDGE (edge_list, e); | |
5391 | ||
5392 | /* We can't insert anything on an abnormal and | |
5393 | critical edge, so we insert the insn at the end of | |
5394 | the previous block. There are several alternatives | |
5395 | detailed in Morgans book P277 (sec 10.5) for | |
5396 | handling this situation. This one is easiest for | |
5397 | now. */ | |
5398 | ||
5399 | if ((eg->flags & EDGE_ABNORMAL) == EDGE_ABNORMAL) | |
5400 | insert_insn_end_bb (index_map[j], bb, 0); | |
5401 | else | |
5402 | { | |
5403 | insn = process_insert_insn (index_map[j]); | |
5404 | insert_insn_on_edge (insn, eg); | |
5405 | } | |
5406 | ||
5407 | if (gcse_file) | |
5408 | { | |
5409 | fprintf (gcse_file, "PRE/HOIST: edge (%d,%d), ", | |
0b17ab2f RH |
5410 | bb->index, |
5411 | INDEX_EDGE_SUCC_BB (edge_list, e)->index); | |
c4c81601 RK |
5412 | fprintf (gcse_file, "copy expression %d\n", |
5413 | expr->bitmap_index); | |
5414 | } | |
5415 | ||
a13d4ebf | 5416 | update_ld_motion_stores (expr); |
c4c81601 RK |
5417 | SET_BIT (inserted[e], j); |
5418 | did_insert = 1; | |
5419 | gcse_create_count++; | |
5420 | } | |
5421 | } | |
5422 | } | |
7506f491 DE |
5423 | } |
5424 | } | |
5faf03ae | 5425 | |
5a660bff | 5426 | sbitmap_vector_free (inserted); |
a42cd965 | 5427 | return did_insert; |
7506f491 DE |
5428 | } |
5429 | ||
c4c81601 | 5430 | /* Copy the result of INSN to REG. INDX is the expression number. */ |
7506f491 DE |
5431 | |
5432 | static void | |
5433 | pre_insert_copy_insn (expr, insn) | |
5434 | struct expr *expr; | |
5435 | rtx insn; | |
5436 | { | |
5437 | rtx reg = expr->reaching_reg; | |
5438 | int regno = REGNO (reg); | |
5439 | int indx = expr->bitmap_index; | |
5440 | rtx set = single_set (insn); | |
5441 | rtx new_insn; | |
5442 | ||
5443 | if (!set) | |
5444 | abort (); | |
c4c81601 | 5445 | |
47a3dae1 | 5446 | new_insn = emit_insn_after (gen_move_insn (reg, copy_rtx (SET_DEST (set))), insn); |
c4c81601 | 5447 | |
7506f491 DE |
5448 | /* Keep register set table up to date. */ |
5449 | record_one_set (regno, new_insn); | |
5450 | ||
5451 | gcse_create_count++; | |
5452 | ||
5453 | if (gcse_file) | |
a42cd965 AM |
5454 | fprintf (gcse_file, |
5455 | "PRE: bb %d, insn %d, copy expression %d in insn %d to reg %d\n", | |
5456 | BLOCK_NUM (insn), INSN_UID (new_insn), indx, | |
5457 | INSN_UID (insn), regno); | |
222f7ba9 | 5458 | update_ld_motion_stores (expr); |
7506f491 DE |
5459 | } |
5460 | ||
5461 | /* Copy available expressions that reach the redundant expression | |
5462 | to `reaching_reg'. */ | |
5463 | ||
5464 | static void | |
5465 | pre_insert_copies () | |
5466 | { | |
2e653e39 | 5467 | unsigned int i; |
c4c81601 RK |
5468 | struct expr *expr; |
5469 | struct occr *occr; | |
5470 | struct occr *avail; | |
a65f3558 | 5471 | |
7506f491 DE |
5472 | /* For each available expression in the table, copy the result to |
5473 | `reaching_reg' if the expression reaches a deleted one. | |
5474 | ||
5475 | ??? The current algorithm is rather brute force. | |
5476 | Need to do some profiling. */ | |
5477 | ||
02280659 ZD |
5478 | for (i = 0; i < expr_hash_table.size; i++) |
5479 | for (expr = expr_hash_table.table[i]; expr != NULL; expr = expr->next_same_hash) | |
c4c81601 RK |
5480 | { |
5481 | /* If the basic block isn't reachable, PPOUT will be TRUE. However, | |
5482 | we don't want to insert a copy here because the expression may not | |
5483 | really be redundant. So only insert an insn if the expression was | |
5484 | deleted. This test also avoids further processing if the | |
5485 | expression wasn't deleted anywhere. */ | |
5486 | if (expr->reaching_reg == NULL) | |
5487 | continue; | |
5488 | ||
5489 | for (occr = expr->antic_occr; occr != NULL; occr = occr->next) | |
5490 | { | |
5491 | if (! occr->deleted_p) | |
5492 | continue; | |
7506f491 | 5493 | |
c4c81601 RK |
5494 | for (avail = expr->avail_occr; avail != NULL; avail = avail->next) |
5495 | { | |
5496 | rtx insn = avail->insn; | |
7506f491 | 5497 | |
c4c81601 RK |
5498 | /* No need to handle this one if handled already. */ |
5499 | if (avail->copied_p) | |
5500 | continue; | |
7506f491 | 5501 | |
c4c81601 RK |
5502 | /* Don't handle this one if it's a redundant one. */ |
5503 | if (TEST_BIT (pre_redundant_insns, INSN_CUID (insn))) | |
5504 | continue; | |
7506f491 | 5505 | |
c4c81601 | 5506 | /* Or if the expression doesn't reach the deleted one. */ |
589005ff | 5507 | if (! pre_expr_reaches_here_p (BLOCK_FOR_INSN (avail->insn), |
e2d2ed72 AM |
5508 | expr, |
5509 | BLOCK_FOR_INSN (occr->insn))) | |
c4c81601 | 5510 | continue; |
7506f491 | 5511 | |
c4c81601 RK |
5512 | /* Copy the result of avail to reaching_reg. */ |
5513 | pre_insert_copy_insn (expr, insn); | |
5514 | avail->copied_p = 1; | |
5515 | } | |
5516 | } | |
5517 | } | |
7506f491 DE |
5518 | } |
5519 | ||
10d1bb36 JH |
5520 | /* Emit move from SRC to DEST noting the equivalence with expression computed |
5521 | in INSN. */ | |
5522 | static rtx | |
5523 | gcse_emit_move_after (src, dest, insn) | |
5524 | rtx src, dest, insn; | |
5525 | { | |
5526 | rtx new; | |
6bdb8dd6 | 5527 | rtx set = single_set (insn), set2; |
10d1bb36 JH |
5528 | rtx note; |
5529 | rtx eqv; | |
5530 | ||
5531 | /* This should never fail since we're creating a reg->reg copy | |
5532 | we've verified to be valid. */ | |
5533 | ||
6bdb8dd6 | 5534 | new = emit_insn_after (gen_move_insn (dest, src), insn); |
285464d0 | 5535 | |
10d1bb36 | 5536 | /* Note the equivalence for local CSE pass. */ |
6bdb8dd6 JH |
5537 | set2 = single_set (new); |
5538 | if (!set2 || !rtx_equal_p (SET_DEST (set2), dest)) | |
5539 | return new; | |
10d1bb36 JH |
5540 | if ((note = find_reg_equal_equiv_note (insn))) |
5541 | eqv = XEXP (note, 0); | |
5542 | else | |
5543 | eqv = SET_SRC (set); | |
5544 | ||
a500466b | 5545 | set_unique_reg_note (new, REG_EQUAL, copy_insn_1 (eqv)); |
10d1bb36 JH |
5546 | |
5547 | return new; | |
5548 | } | |
5549 | ||
7506f491 | 5550 | /* Delete redundant computations. |
7506f491 DE |
5551 | Deletion is done by changing the insn to copy the `reaching_reg' of |
5552 | the expression into the result of the SET. It is left to later passes | |
5553 | (cprop, cse2, flow, combine, regmove) to propagate the copy or eliminate it. | |
5554 | ||
cc2902df | 5555 | Returns nonzero if a change is made. */ |
7506f491 DE |
5556 | |
5557 | static int | |
5558 | pre_delete () | |
5559 | { | |
2e653e39 | 5560 | unsigned int i; |
63bc1d05 | 5561 | int changed; |
c4c81601 RK |
5562 | struct expr *expr; |
5563 | struct occr *occr; | |
a65f3558 | 5564 | |
7506f491 | 5565 | changed = 0; |
02280659 ZD |
5566 | for (i = 0; i < expr_hash_table.size; i++) |
5567 | for (expr = expr_hash_table.table[i]; expr != NULL; expr = expr->next_same_hash) | |
c4c81601 RK |
5568 | { |
5569 | int indx = expr->bitmap_index; | |
7506f491 | 5570 | |
c4c81601 RK |
5571 | /* We only need to search antic_occr since we require |
5572 | ANTLOC != 0. */ | |
7506f491 | 5573 | |
c4c81601 RK |
5574 | for (occr = expr->antic_occr; occr != NULL; occr = occr->next) |
5575 | { | |
5576 | rtx insn = occr->insn; | |
5577 | rtx set; | |
e2d2ed72 | 5578 | basic_block bb = BLOCK_FOR_INSN (insn); |
7506f491 | 5579 | |
0b17ab2f | 5580 | if (TEST_BIT (pre_delete_map[bb->index], indx)) |
c4c81601 RK |
5581 | { |
5582 | set = single_set (insn); | |
5583 | if (! set) | |
5584 | abort (); | |
5585 | ||
5586 | /* Create a pseudo-reg to store the result of reaching | |
5587 | expressions into. Get the mode for the new pseudo from | |
5588 | the mode of the original destination pseudo. */ | |
5589 | if (expr->reaching_reg == NULL) | |
5590 | expr->reaching_reg | |
5591 | = gen_reg_rtx (GET_MODE (SET_DEST (set))); | |
5592 | ||
10d1bb36 JH |
5593 | gcse_emit_move_after (expr->reaching_reg, SET_DEST (set), insn); |
5594 | delete_insn (insn); | |
5595 | occr->deleted_p = 1; | |
5596 | SET_BIT (pre_redundant_insns, INSN_CUID (insn)); | |
5597 | changed = 1; | |
5598 | gcse_subst_count++; | |
7506f491 | 5599 | |
c4c81601 RK |
5600 | if (gcse_file) |
5601 | { | |
5602 | fprintf (gcse_file, | |
5603 | "PRE: redundant insn %d (expression %d) in ", | |
5604 | INSN_UID (insn), indx); | |
5605 | fprintf (gcse_file, "bb %d, reaching reg is %d\n", | |
0b17ab2f | 5606 | bb->index, REGNO (expr->reaching_reg)); |
c4c81601 RK |
5607 | } |
5608 | } | |
5609 | } | |
5610 | } | |
7506f491 DE |
5611 | |
5612 | return changed; | |
5613 | } | |
5614 | ||
5615 | /* Perform GCSE optimizations using PRE. | |
5616 | This is called by one_pre_gcse_pass after all the dataflow analysis | |
5617 | has been done. | |
5618 | ||
c4c81601 RK |
5619 | This is based on the original Morel-Renvoise paper Fred Chow's thesis, and |
5620 | lazy code motion from Knoop, Ruthing and Steffen as described in Advanced | |
5621 | Compiler Design and Implementation. | |
7506f491 | 5622 | |
c4c81601 RK |
5623 | ??? A new pseudo reg is created to hold the reaching expression. The nice |
5624 | thing about the classical approach is that it would try to use an existing | |
5625 | reg. If the register can't be adequately optimized [i.e. we introduce | |
5626 | reload problems], one could add a pass here to propagate the new register | |
5627 | through the block. | |
7506f491 | 5628 | |
c4c81601 RK |
5629 | ??? We don't handle single sets in PARALLELs because we're [currently] not |
5630 | able to copy the rest of the parallel when we insert copies to create full | |
5631 | redundancies from partial redundancies. However, there's no reason why we | |
5632 | can't handle PARALLELs in the cases where there are no partial | |
7506f491 DE |
5633 | redundancies. */ |
5634 | ||
5635 | static int | |
5636 | pre_gcse () | |
5637 | { | |
2e653e39 RK |
5638 | unsigned int i; |
5639 | int did_insert, changed; | |
7506f491 | 5640 | struct expr **index_map; |
c4c81601 | 5641 | struct expr *expr; |
7506f491 DE |
5642 | |
5643 | /* Compute a mapping from expression number (`bitmap_index') to | |
5644 | hash table entry. */ | |
5645 | ||
02280659 ZD |
5646 | index_map = (struct expr **) xcalloc (expr_hash_table.n_elems, sizeof (struct expr *)); |
5647 | for (i = 0; i < expr_hash_table.size; i++) | |
5648 | for (expr = expr_hash_table.table[i]; expr != NULL; expr = expr->next_same_hash) | |
c4c81601 | 5649 | index_map[expr->bitmap_index] = expr; |
7506f491 DE |
5650 | |
5651 | /* Reset bitmap used to track which insns are redundant. */ | |
a65f3558 JL |
5652 | pre_redundant_insns = sbitmap_alloc (max_cuid); |
5653 | sbitmap_zero (pre_redundant_insns); | |
7506f491 DE |
5654 | |
5655 | /* Delete the redundant insns first so that | |
5656 | - we know what register to use for the new insns and for the other | |
5657 | ones with reaching expressions | |
5658 | - we know which insns are redundant when we go to create copies */ | |
c4c81601 | 5659 | |
7506f491 DE |
5660 | changed = pre_delete (); |
5661 | ||
a42cd965 | 5662 | did_insert = pre_edge_insert (edge_list, index_map); |
c4c81601 | 5663 | |
7506f491 | 5664 | /* In other places with reaching expressions, copy the expression to the |
a42cd965 | 5665 | specially allocated pseudo-reg that reaches the redundant expr. */ |
7506f491 | 5666 | pre_insert_copies (); |
a42cd965 AM |
5667 | if (did_insert) |
5668 | { | |
5669 | commit_edge_insertions (); | |
5670 | changed = 1; | |
5671 | } | |
7506f491 | 5672 | |
283a2545 | 5673 | free (index_map); |
76ac938b | 5674 | sbitmap_free (pre_redundant_insns); |
7506f491 DE |
5675 | return changed; |
5676 | } | |
5677 | ||
5678 | /* Top level routine to perform one PRE GCSE pass. | |
5679 | ||
cc2902df | 5680 | Return nonzero if a change was made. */ |
7506f491 DE |
5681 | |
5682 | static int | |
b5ce41ff | 5683 | one_pre_gcse_pass (pass) |
7506f491 DE |
5684 | int pass; |
5685 | { | |
5686 | int changed = 0; | |
5687 | ||
5688 | gcse_subst_count = 0; | |
5689 | gcse_create_count = 0; | |
5690 | ||
02280659 | 5691 | alloc_hash_table (max_cuid, &expr_hash_table, 0); |
a42cd965 | 5692 | add_noreturn_fake_exit_edges (); |
a13d4ebf AM |
5693 | if (flag_gcse_lm) |
5694 | compute_ld_motion_mems (); | |
5695 | ||
02280659 | 5696 | compute_hash_table (&expr_hash_table); |
a13d4ebf | 5697 | trim_ld_motion_mems (); |
7506f491 | 5698 | if (gcse_file) |
02280659 | 5699 | dump_hash_table (gcse_file, "Expression", &expr_hash_table); |
c4c81601 | 5700 | |
02280659 | 5701 | if (expr_hash_table.n_elems > 0) |
7506f491 | 5702 | { |
02280659 | 5703 | alloc_pre_mem (last_basic_block, expr_hash_table.n_elems); |
7506f491 DE |
5704 | compute_pre_data (); |
5705 | changed |= pre_gcse (); | |
a42cd965 | 5706 | free_edge_list (edge_list); |
7506f491 DE |
5707 | free_pre_mem (); |
5708 | } | |
c4c81601 | 5709 | |
a13d4ebf | 5710 | free_ldst_mems (); |
a42cd965 | 5711 | remove_fake_edges (); |
02280659 | 5712 | free_hash_table (&expr_hash_table); |
7506f491 DE |
5713 | |
5714 | if (gcse_file) | |
5715 | { | |
c4c81601 RK |
5716 | fprintf (gcse_file, "\nPRE GCSE of %s, pass %d: %d bytes needed, ", |
5717 | current_function_name, pass, bytes_used); | |
5718 | fprintf (gcse_file, "%d substs, %d insns created\n", | |
5719 | gcse_subst_count, gcse_create_count); | |
7506f491 DE |
5720 | } |
5721 | ||
5722 | return changed; | |
5723 | } | |
aeb2f500 JW |
5724 | \f |
5725 | /* If X contains any LABEL_REF's, add REG_LABEL notes for them to INSN. | |
5b1ef594 JDA |
5726 | If notes are added to an insn which references a CODE_LABEL, the |
5727 | LABEL_NUSES count is incremented. We have to add REG_LABEL notes, | |
5728 | because the following loop optimization pass requires them. */ | |
aeb2f500 JW |
5729 | |
5730 | /* ??? This is very similar to the loop.c add_label_notes function. We | |
5731 | could probably share code here. */ | |
5732 | ||
5733 | /* ??? If there was a jump optimization pass after gcse and before loop, | |
5734 | then we would not need to do this here, because jump would add the | |
5735 | necessary REG_LABEL notes. */ | |
5736 | ||
5737 | static void | |
5738 | add_label_notes (x, insn) | |
5739 | rtx x; | |
5740 | rtx insn; | |
5741 | { | |
5742 | enum rtx_code code = GET_CODE (x); | |
5743 | int i, j; | |
6f7d635c | 5744 | const char *fmt; |
aeb2f500 JW |
5745 | |
5746 | if (code == LABEL_REF && !LABEL_REF_NONLOCAL_P (x)) | |
5747 | { | |
6b3603c2 | 5748 | /* This code used to ignore labels that referred to dispatch tables to |
ac7c5af5 | 5749 | avoid flow generating (slighly) worse code. |
6b3603c2 | 5750 | |
ac7c5af5 JL |
5751 | We no longer ignore such label references (see LABEL_REF handling in |
5752 | mark_jump_label for additional information). */ | |
c4c81601 | 5753 | |
6b8c9327 | 5754 | REG_NOTES (insn) = gen_rtx_INSN_LIST (REG_LABEL, XEXP (x, 0), |
6b3603c2 | 5755 | REG_NOTES (insn)); |
5b1ef594 | 5756 | if (LABEL_P (XEXP (x, 0))) |
589005ff | 5757 | LABEL_NUSES (XEXP (x, 0))++; |
aeb2f500 JW |
5758 | return; |
5759 | } | |
5760 | ||
c4c81601 | 5761 | for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--) |
aeb2f500 JW |
5762 | { |
5763 | if (fmt[i] == 'e') | |
5764 | add_label_notes (XEXP (x, i), insn); | |
5765 | else if (fmt[i] == 'E') | |
5766 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
5767 | add_label_notes (XVECEXP (x, i, j), insn); | |
5768 | } | |
5769 | } | |
a65f3558 JL |
5770 | |
5771 | /* Compute transparent outgoing information for each block. | |
5772 | ||
5773 | An expression is transparent to an edge unless it is killed by | |
5774 | the edge itself. This can only happen with abnormal control flow, | |
5775 | when the edge is traversed through a call. This happens with | |
5776 | non-local labels and exceptions. | |
5777 | ||
5778 | This would not be necessary if we split the edge. While this is | |
5779 | normally impossible for abnormal critical edges, with some effort | |
5780 | it should be possible with exception handling, since we still have | |
5781 | control over which handler should be invoked. But due to increased | |
5782 | EH table sizes, this may not be worthwhile. */ | |
5783 | ||
5784 | static void | |
5785 | compute_transpout () | |
5786 | { | |
e0082a72 | 5787 | basic_block bb; |
2e653e39 | 5788 | unsigned int i; |
c4c81601 | 5789 | struct expr *expr; |
a65f3558 | 5790 | |
d55bc081 | 5791 | sbitmap_vector_ones (transpout, last_basic_block); |
a65f3558 | 5792 | |
e0082a72 | 5793 | FOR_EACH_BB (bb) |
a65f3558 | 5794 | { |
a65f3558 JL |
5795 | /* Note that flow inserted a nop a the end of basic blocks that |
5796 | end in call instructions for reasons other than abnormal | |
5797 | control flow. */ | |
e0082a72 | 5798 | if (GET_CODE (bb->end) != CALL_INSN) |
a65f3558 JL |
5799 | continue; |
5800 | ||
02280659 ZD |
5801 | for (i = 0; i < expr_hash_table.size; i++) |
5802 | for (expr = expr_hash_table.table[i]; expr ; expr = expr->next_same_hash) | |
c4c81601 RK |
5803 | if (GET_CODE (expr->expr) == MEM) |
5804 | { | |
5805 | if (GET_CODE (XEXP (expr->expr, 0)) == SYMBOL_REF | |
5806 | && CONSTANT_POOL_ADDRESS_P (XEXP (expr->expr, 0))) | |
5807 | continue; | |
589005ff | 5808 | |
c4c81601 RK |
5809 | /* ??? Optimally, we would use interprocedural alias |
5810 | analysis to determine if this mem is actually killed | |
5811 | by this call. */ | |
e0082a72 | 5812 | RESET_BIT (transpout[bb->index], expr->bitmap_index); |
c4c81601 | 5813 | } |
a65f3558 JL |
5814 | } |
5815 | } | |
dfdb644f JL |
5816 | |
5817 | /* Removal of useless null pointer checks */ | |
5818 | ||
dfdb644f | 5819 | /* Called via note_stores. X is set by SETTER. If X is a register we must |
0511851c MM |
5820 | invalidate nonnull_local and set nonnull_killed. DATA is really a |
5821 | `null_pointer_info *'. | |
dfdb644f JL |
5822 | |
5823 | We ignore hard registers. */ | |
c4c81601 | 5824 | |
dfdb644f | 5825 | static void |
84832317 | 5826 | invalidate_nonnull_info (x, setter, data) |
dfdb644f JL |
5827 | rtx x; |
5828 | rtx setter ATTRIBUTE_UNUSED; | |
0511851c | 5829 | void *data; |
dfdb644f | 5830 | { |
770ae6cc RK |
5831 | unsigned int regno; |
5832 | struct null_pointer_info *npi = (struct null_pointer_info *) data; | |
c4c81601 | 5833 | |
dfdb644f JL |
5834 | while (GET_CODE (x) == SUBREG) |
5835 | x = SUBREG_REG (x); | |
5836 | ||
5837 | /* Ignore anything that is not a register or is a hard register. */ | |
5838 | if (GET_CODE (x) != REG | |
0511851c MM |
5839 | || REGNO (x) < npi->min_reg |
5840 | || REGNO (x) >= npi->max_reg) | |
dfdb644f JL |
5841 | return; |
5842 | ||
0511851c | 5843 | regno = REGNO (x) - npi->min_reg; |
dfdb644f | 5844 | |
e0082a72 ZD |
5845 | RESET_BIT (npi->nonnull_local[npi->current_block->index], regno); |
5846 | SET_BIT (npi->nonnull_killed[npi->current_block->index], regno); | |
dfdb644f JL |
5847 | } |
5848 | ||
0511851c MM |
5849 | /* Do null-pointer check elimination for the registers indicated in |
5850 | NPI. NONNULL_AVIN and NONNULL_AVOUT are pre-allocated sbitmaps; | |
5851 | they are not our responsibility to free. */ | |
dfdb644f | 5852 | |
99a15921 | 5853 | static int |
9cd56be1 | 5854 | delete_null_pointer_checks_1 (block_reg, nonnull_avin, |
8e184d9c | 5855 | nonnull_avout, npi) |
770ae6cc | 5856 | unsigned int *block_reg; |
0511851c MM |
5857 | sbitmap *nonnull_avin; |
5858 | sbitmap *nonnull_avout; | |
5859 | struct null_pointer_info *npi; | |
dfdb644f | 5860 | { |
e0082a72 | 5861 | basic_block bb, current_block; |
0511851c MM |
5862 | sbitmap *nonnull_local = npi->nonnull_local; |
5863 | sbitmap *nonnull_killed = npi->nonnull_killed; | |
99a15921 | 5864 | int something_changed = 0; |
589005ff | 5865 | |
dfdb644f JL |
5866 | /* Compute local properties, nonnull and killed. A register will have |
5867 | the nonnull property if at the end of the current block its value is | |
5868 | known to be nonnull. The killed property indicates that somewhere in | |
5869 | the block any information we had about the register is killed. | |
5870 | ||
5871 | Note that a register can have both properties in a single block. That | |
5872 | indicates that it's killed, then later in the block a new value is | |
5873 | computed. */ | |
d55bc081 ZD |
5874 | sbitmap_vector_zero (nonnull_local, last_basic_block); |
5875 | sbitmap_vector_zero (nonnull_killed, last_basic_block); | |
c4c81601 | 5876 | |
e0082a72 | 5877 | FOR_EACH_BB (current_block) |
dfdb644f JL |
5878 | { |
5879 | rtx insn, stop_insn; | |
5880 | ||
0511851c MM |
5881 | /* Set the current block for invalidate_nonnull_info. */ |
5882 | npi->current_block = current_block; | |
5883 | ||
dfdb644f JL |
5884 | /* Scan each insn in the basic block looking for memory references and |
5885 | register sets. */ | |
e0082a72 ZD |
5886 | stop_insn = NEXT_INSN (current_block->end); |
5887 | for (insn = current_block->head; | |
dfdb644f JL |
5888 | insn != stop_insn; |
5889 | insn = NEXT_INSN (insn)) | |
5890 | { | |
5891 | rtx set; | |
0511851c | 5892 | rtx reg; |
dfdb644f JL |
5893 | |
5894 | /* Ignore anything that is not a normal insn. */ | |
2c3c49de | 5895 | if (! INSN_P (insn)) |
dfdb644f JL |
5896 | continue; |
5897 | ||
5898 | /* Basically ignore anything that is not a simple SET. We do have | |
5899 | to make sure to invalidate nonnull_local and set nonnull_killed | |
5900 | for such insns though. */ | |
5901 | set = single_set (insn); | |
5902 | if (!set) | |
5903 | { | |
0511851c | 5904 | note_stores (PATTERN (insn), invalidate_nonnull_info, npi); |
dfdb644f JL |
5905 | continue; |
5906 | } | |
5907 | ||
f63d1bf7 | 5908 | /* See if we've got a usable memory load. We handle it first |
dfdb644f JL |
5909 | in case it uses its address register as a dest (which kills |
5910 | the nonnull property). */ | |
5911 | if (GET_CODE (SET_SRC (set)) == MEM | |
0511851c MM |
5912 | && GET_CODE ((reg = XEXP (SET_SRC (set), 0))) == REG |
5913 | && REGNO (reg) >= npi->min_reg | |
5914 | && REGNO (reg) < npi->max_reg) | |
e0082a72 | 5915 | SET_BIT (nonnull_local[current_block->index], |
0511851c | 5916 | REGNO (reg) - npi->min_reg); |
dfdb644f JL |
5917 | |
5918 | /* Now invalidate stuff clobbered by this insn. */ | |
0511851c | 5919 | note_stores (PATTERN (insn), invalidate_nonnull_info, npi); |
dfdb644f JL |
5920 | |
5921 | /* And handle stores, we do these last since any sets in INSN can | |
5922 | not kill the nonnull property if it is derived from a MEM | |
5923 | appearing in a SET_DEST. */ | |
5924 | if (GET_CODE (SET_DEST (set)) == MEM | |
0511851c MM |
5925 | && GET_CODE ((reg = XEXP (SET_DEST (set), 0))) == REG |
5926 | && REGNO (reg) >= npi->min_reg | |
5927 | && REGNO (reg) < npi->max_reg) | |
e0082a72 | 5928 | SET_BIT (nonnull_local[current_block->index], |
0511851c | 5929 | REGNO (reg) - npi->min_reg); |
dfdb644f JL |
5930 | } |
5931 | } | |
5932 | ||
5933 | /* Now compute global properties based on the local properties. This | |
fbe5a4a6 | 5934 | is a classic global availability algorithm. */ |
ce724250 JL |
5935 | compute_available (nonnull_local, nonnull_killed, |
5936 | nonnull_avout, nonnull_avin); | |
dfdb644f JL |
5937 | |
5938 | /* Now look at each bb and see if it ends with a compare of a value | |
5939 | against zero. */ | |
e0082a72 | 5940 | FOR_EACH_BB (bb) |
dfdb644f | 5941 | { |
e0082a72 | 5942 | rtx last_insn = bb->end; |
0511851c | 5943 | rtx condition, earliest; |
dfdb644f JL |
5944 | int compare_and_branch; |
5945 | ||
0511851c MM |
5946 | /* Since MIN_REG is always at least FIRST_PSEUDO_REGISTER, and |
5947 | since BLOCK_REG[BB] is zero if this block did not end with a | |
5948 | comparison against zero, this condition works. */ | |
e0082a72 ZD |
5949 | if (block_reg[bb->index] < npi->min_reg |
5950 | || block_reg[bb->index] >= npi->max_reg) | |
dfdb644f JL |
5951 | continue; |
5952 | ||
5953 | /* LAST_INSN is a conditional jump. Get its condition. */ | |
5954 | condition = get_condition (last_insn, &earliest); | |
5955 | ||
40d7a3fe NB |
5956 | /* If we can't determine the condition then skip. */ |
5957 | if (! condition) | |
5958 | continue; | |
5959 | ||
dfdb644f | 5960 | /* Is the register known to have a nonzero value? */ |
e0082a72 | 5961 | if (!TEST_BIT (nonnull_avout[bb->index], block_reg[bb->index] - npi->min_reg)) |
dfdb644f JL |
5962 | continue; |
5963 | ||
5964 | /* Try to compute whether the compare/branch at the loop end is one or | |
5965 | two instructions. */ | |
5966 | if (earliest == last_insn) | |
5967 | compare_and_branch = 1; | |
5968 | else if (earliest == prev_nonnote_insn (last_insn)) | |
5969 | compare_and_branch = 2; | |
5970 | else | |
5971 | continue; | |
5972 | ||
5973 | /* We know the register in this comparison is nonnull at exit from | |
5974 | this block. We can optimize this comparison. */ | |
5975 | if (GET_CODE (condition) == NE) | |
5976 | { | |
5977 | rtx new_jump; | |
5978 | ||
38c1593d JH |
5979 | new_jump = emit_jump_insn_after (gen_jump (JUMP_LABEL (last_insn)), |
5980 | last_insn); | |
dfdb644f JL |
5981 | JUMP_LABEL (new_jump) = JUMP_LABEL (last_insn); |
5982 | LABEL_NUSES (JUMP_LABEL (new_jump))++; | |
5983 | emit_barrier_after (new_jump); | |
5984 | } | |
8e184d9c | 5985 | |
99a15921 | 5986 | something_changed = 1; |
9cd56be1 | 5987 | delete_insn (last_insn); |
dfdb644f | 5988 | if (compare_and_branch == 2) |
589005ff | 5989 | delete_insn (earliest); |
e0082a72 | 5990 | purge_dead_edges (bb); |
0511851c MM |
5991 | |
5992 | /* Don't check this block again. (Note that BLOCK_END is | |
589005ff | 5993 | invalid here; we deleted the last instruction in the |
0511851c | 5994 | block.) */ |
e0082a72 | 5995 | block_reg[bb->index] = 0; |
0511851c | 5996 | } |
99a15921 JL |
5997 | |
5998 | return something_changed; | |
0511851c MM |
5999 | } |
6000 | ||
6001 | /* Find EQ/NE comparisons against zero which can be (indirectly) evaluated | |
6002 | at compile time. | |
6003 | ||
6004 | This is conceptually similar to global constant/copy propagation and | |
6005 | classic global CSE (it even uses the same dataflow equations as cprop). | |
6006 | ||
6007 | If a register is used as memory address with the form (mem (reg)), then we | |
6008 | know that REG can not be zero at that point in the program. Any instruction | |
6009 | which sets REG "kills" this property. | |
6010 | ||
6011 | So, if every path leading to a conditional branch has an available memory | |
6012 | reference of that form, then we know the register can not have the value | |
589005ff | 6013 | zero at the conditional branch. |
0511851c | 6014 | |
fbe5a4a6 | 6015 | So we merely need to compute the local properties and propagate that data |
0511851c MM |
6016 | around the cfg, then optimize where possible. |
6017 | ||
6018 | We run this pass two times. Once before CSE, then again after CSE. This | |
6019 | has proven to be the most profitable approach. It is rare for new | |
6020 | optimization opportunities of this nature to appear after the first CSE | |
6021 | pass. | |
6022 | ||
6023 | This could probably be integrated with global cprop with a little work. */ | |
6024 | ||
99a15921 | 6025 | int |
0511851c | 6026 | delete_null_pointer_checks (f) |
2e653e39 | 6027 | rtx f ATTRIBUTE_UNUSED; |
0511851c | 6028 | { |
0511851c | 6029 | sbitmap *nonnull_avin, *nonnull_avout; |
770ae6cc | 6030 | unsigned int *block_reg; |
e0082a72 | 6031 | basic_block bb; |
0511851c MM |
6032 | int reg; |
6033 | int regs_per_pass; | |
6034 | int max_reg; | |
6035 | struct null_pointer_info npi; | |
99a15921 | 6036 | int something_changed = 0; |
0511851c | 6037 | |
0511851c | 6038 | /* If we have only a single block, then there's nothing to do. */ |
0b17ab2f | 6039 | if (n_basic_blocks <= 1) |
99a15921 | 6040 | return 0; |
0511851c MM |
6041 | |
6042 | /* Trying to perform global optimizations on flow graphs which have | |
6043 | a high connectivity will take a long time and is unlikely to be | |
6044 | particularly useful. | |
6045 | ||
43e72072 | 6046 | In normal circumstances a cfg should have about twice as many edges |
0511851c MM |
6047 | as blocks. But we do not want to punish small functions which have |
6048 | a couple switch statements. So we require a relatively large number | |
6049 | of basic blocks and the ratio of edges to blocks to be high. */ | |
0b17ab2f | 6050 | if (n_basic_blocks > 1000 && n_edges / n_basic_blocks >= 20) |
99a15921 | 6051 | return 0; |
0511851c | 6052 | |
0511851c MM |
6053 | /* We need four bitmaps, each with a bit for each register in each |
6054 | basic block. */ | |
6055 | max_reg = max_reg_num (); | |
d55bc081 | 6056 | regs_per_pass = get_bitmap_width (4, last_basic_block, max_reg); |
0511851c MM |
6057 | |
6058 | /* Allocate bitmaps to hold local and global properties. */ | |
d55bc081 ZD |
6059 | npi.nonnull_local = sbitmap_vector_alloc (last_basic_block, regs_per_pass); |
6060 | npi.nonnull_killed = sbitmap_vector_alloc (last_basic_block, regs_per_pass); | |
6061 | nonnull_avin = sbitmap_vector_alloc (last_basic_block, regs_per_pass); | |
6062 | nonnull_avout = sbitmap_vector_alloc (last_basic_block, regs_per_pass); | |
0511851c MM |
6063 | |
6064 | /* Go through the basic blocks, seeing whether or not each block | |
6065 | ends with a conditional branch whose condition is a comparison | |
6066 | against zero. Record the register compared in BLOCK_REG. */ | |
d55bc081 | 6067 | block_reg = (unsigned int *) xcalloc (last_basic_block, sizeof (int)); |
e0082a72 | 6068 | FOR_EACH_BB (bb) |
0511851c | 6069 | { |
e0082a72 | 6070 | rtx last_insn = bb->end; |
0511851c MM |
6071 | rtx condition, earliest, reg; |
6072 | ||
6073 | /* We only want conditional branches. */ | |
6074 | if (GET_CODE (last_insn) != JUMP_INSN | |
7f1c097d JH |
6075 | || !any_condjump_p (last_insn) |
6076 | || !onlyjump_p (last_insn)) | |
0511851c MM |
6077 | continue; |
6078 | ||
6079 | /* LAST_INSN is a conditional jump. Get its condition. */ | |
6080 | condition = get_condition (last_insn, &earliest); | |
6081 | ||
4fe9b91c | 6082 | /* If we were unable to get the condition, or it is not an equality |
0511851c MM |
6083 | comparison against zero then there's nothing we can do. */ |
6084 | if (!condition | |
6085 | || (GET_CODE (condition) != NE && GET_CODE (condition) != EQ) | |
6086 | || GET_CODE (XEXP (condition, 1)) != CONST_INT | |
589005ff | 6087 | || (XEXP (condition, 1) |
0511851c MM |
6088 | != CONST0_RTX (GET_MODE (XEXP (condition, 0))))) |
6089 | continue; | |
6090 | ||
6091 | /* We must be checking a register against zero. */ | |
6092 | reg = XEXP (condition, 0); | |
6093 | if (GET_CODE (reg) != REG) | |
6094 | continue; | |
6095 | ||
e0082a72 | 6096 | block_reg[bb->index] = REGNO (reg); |
0511851c MM |
6097 | } |
6098 | ||
6099 | /* Go through the algorithm for each block of registers. */ | |
6100 | for (reg = FIRST_PSEUDO_REGISTER; reg < max_reg; reg += regs_per_pass) | |
6101 | { | |
6102 | npi.min_reg = reg; | |
6103 | npi.max_reg = MIN (reg + regs_per_pass, max_reg); | |
99a15921 JL |
6104 | something_changed |= delete_null_pointer_checks_1 (block_reg, |
6105 | nonnull_avin, | |
6106 | nonnull_avout, | |
6107 | &npi); | |
dfdb644f JL |
6108 | } |
6109 | ||
0511851c MM |
6110 | /* Free the table of registers compared at the end of every block. */ |
6111 | free (block_reg); | |
6112 | ||
dfdb644f | 6113 | /* Free bitmaps. */ |
5a660bff DB |
6114 | sbitmap_vector_free (npi.nonnull_local); |
6115 | sbitmap_vector_free (npi.nonnull_killed); | |
6116 | sbitmap_vector_free (nonnull_avin); | |
6117 | sbitmap_vector_free (nonnull_avout); | |
99a15921 JL |
6118 | |
6119 | return something_changed; | |
dfdb644f | 6120 | } |
bb457bd9 JL |
6121 | |
6122 | /* Code Hoisting variables and subroutines. */ | |
6123 | ||
6124 | /* Very busy expressions. */ | |
6125 | static sbitmap *hoist_vbein; | |
6126 | static sbitmap *hoist_vbeout; | |
6127 | ||
6128 | /* Hoistable expressions. */ | |
6129 | static sbitmap *hoist_exprs; | |
6130 | ||
6131 | /* Dominator bitmaps. */ | |
355be0dc | 6132 | dominance_info dominators; |
bb457bd9 JL |
6133 | |
6134 | /* ??? We could compute post dominators and run this algorithm in | |
68e82b83 | 6135 | reverse to perform tail merging, doing so would probably be |
bb457bd9 JL |
6136 | more effective than the tail merging code in jump.c. |
6137 | ||
6138 | It's unclear if tail merging could be run in parallel with | |
6139 | code hoisting. It would be nice. */ | |
6140 | ||
6141 | /* Allocate vars used for code hoisting analysis. */ | |
6142 | ||
6143 | static void | |
6144 | alloc_code_hoist_mem (n_blocks, n_exprs) | |
6145 | int n_blocks, n_exprs; | |
6146 | { | |
6147 | antloc = sbitmap_vector_alloc (n_blocks, n_exprs); | |
6148 | transp = sbitmap_vector_alloc (n_blocks, n_exprs); | |
6149 | comp = sbitmap_vector_alloc (n_blocks, n_exprs); | |
6150 | ||
6151 | hoist_vbein = sbitmap_vector_alloc (n_blocks, n_exprs); | |
6152 | hoist_vbeout = sbitmap_vector_alloc (n_blocks, n_exprs); | |
6153 | hoist_exprs = sbitmap_vector_alloc (n_blocks, n_exprs); | |
6154 | transpout = sbitmap_vector_alloc (n_blocks, n_exprs); | |
bb457bd9 JL |
6155 | } |
6156 | ||
6157 | /* Free vars used for code hoisting analysis. */ | |
6158 | ||
6159 | static void | |
6160 | free_code_hoist_mem () | |
6161 | { | |
5a660bff DB |
6162 | sbitmap_vector_free (antloc); |
6163 | sbitmap_vector_free (transp); | |
6164 | sbitmap_vector_free (comp); | |
bb457bd9 | 6165 | |
5a660bff DB |
6166 | sbitmap_vector_free (hoist_vbein); |
6167 | sbitmap_vector_free (hoist_vbeout); | |
6168 | sbitmap_vector_free (hoist_exprs); | |
6169 | sbitmap_vector_free (transpout); | |
bb457bd9 | 6170 | |
355be0dc | 6171 | free_dominance_info (dominators); |
bb457bd9 JL |
6172 | } |
6173 | ||
6174 | /* Compute the very busy expressions at entry/exit from each block. | |
6175 | ||
6176 | An expression is very busy if all paths from a given point | |
6177 | compute the expression. */ | |
6178 | ||
6179 | static void | |
6180 | compute_code_hoist_vbeinout () | |
6181 | { | |
e0082a72 ZD |
6182 | int changed, passes; |
6183 | basic_block bb; | |
bb457bd9 | 6184 | |
d55bc081 ZD |
6185 | sbitmap_vector_zero (hoist_vbeout, last_basic_block); |
6186 | sbitmap_vector_zero (hoist_vbein, last_basic_block); | |
bb457bd9 JL |
6187 | |
6188 | passes = 0; | |
6189 | changed = 1; | |
c4c81601 | 6190 | |
bb457bd9 JL |
6191 | while (changed) |
6192 | { | |
6193 | changed = 0; | |
c4c81601 | 6194 | |
bb457bd9 JL |
6195 | /* We scan the blocks in the reverse order to speed up |
6196 | the convergence. */ | |
e0082a72 | 6197 | FOR_EACH_BB_REVERSE (bb) |
bb457bd9 | 6198 | { |
e0082a72 ZD |
6199 | changed |= sbitmap_a_or_b_and_c_cg (hoist_vbein[bb->index], antloc[bb->index], |
6200 | hoist_vbeout[bb->index], transp[bb->index]); | |
6201 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
6202 | sbitmap_intersection_of_succs (hoist_vbeout[bb->index], hoist_vbein, bb->index); | |
bb457bd9 | 6203 | } |
c4c81601 | 6204 | |
bb457bd9 JL |
6205 | passes++; |
6206 | } | |
6207 | ||
6208 | if (gcse_file) | |
6209 | fprintf (gcse_file, "hoisting vbeinout computation: %d passes\n", passes); | |
6210 | } | |
6211 | ||
6212 | /* Top level routine to do the dataflow analysis needed by code hoisting. */ | |
6213 | ||
6214 | static void | |
6215 | compute_code_hoist_data () | |
6216 | { | |
02280659 | 6217 | compute_local_properties (transp, comp, antloc, &expr_hash_table); |
bb457bd9 JL |
6218 | compute_transpout (); |
6219 | compute_code_hoist_vbeinout (); | |
355be0dc | 6220 | dominators = calculate_dominance_info (CDI_DOMINATORS); |
bb457bd9 JL |
6221 | if (gcse_file) |
6222 | fprintf (gcse_file, "\n"); | |
6223 | } | |
6224 | ||
6225 | /* Determine if the expression identified by EXPR_INDEX would | |
6226 | reach BB unimpared if it was placed at the end of EXPR_BB. | |
6227 | ||
6228 | It's unclear exactly what Muchnick meant by "unimpared". It seems | |
6229 | to me that the expression must either be computed or transparent in | |
6230 | *every* block in the path(s) from EXPR_BB to BB. Any other definition | |
6231 | would allow the expression to be hoisted out of loops, even if | |
6232 | the expression wasn't a loop invariant. | |
6233 | ||
6234 | Contrast this to reachability for PRE where an expression is | |
6235 | considered reachable if *any* path reaches instead of *all* | |
6236 | paths. */ | |
6237 | ||
6238 | static int | |
6239 | hoist_expr_reaches_here_p (expr_bb, expr_index, bb, visited) | |
e2d2ed72 | 6240 | basic_block expr_bb; |
bb457bd9 | 6241 | int expr_index; |
e2d2ed72 | 6242 | basic_block bb; |
bb457bd9 JL |
6243 | char *visited; |
6244 | { | |
6245 | edge pred; | |
283a2545 | 6246 | int visited_allocated_locally = 0; |
589005ff | 6247 | |
bb457bd9 JL |
6248 | |
6249 | if (visited == NULL) | |
6250 | { | |
8e42ace1 | 6251 | visited_allocated_locally = 1; |
d55bc081 | 6252 | visited = xcalloc (last_basic_block, 1); |
bb457bd9 JL |
6253 | } |
6254 | ||
e2d2ed72 | 6255 | for (pred = bb->pred; pred != NULL; pred = pred->pred_next) |
bb457bd9 | 6256 | { |
e2d2ed72 | 6257 | basic_block pred_bb = pred->src; |
bb457bd9 JL |
6258 | |
6259 | if (pred->src == ENTRY_BLOCK_PTR) | |
6260 | break; | |
f305679f JH |
6261 | else if (pred_bb == expr_bb) |
6262 | continue; | |
0b17ab2f | 6263 | else if (visited[pred_bb->index]) |
bb457bd9 | 6264 | continue; |
c4c81601 | 6265 | |
bb457bd9 | 6266 | /* Does this predecessor generate this expression? */ |
0b17ab2f | 6267 | else if (TEST_BIT (comp[pred_bb->index], expr_index)) |
bb457bd9 | 6268 | break; |
0b17ab2f | 6269 | else if (! TEST_BIT (transp[pred_bb->index], expr_index)) |
bb457bd9 | 6270 | break; |
c4c81601 | 6271 | |
bb457bd9 JL |
6272 | /* Not killed. */ |
6273 | else | |
6274 | { | |
0b17ab2f | 6275 | visited[pred_bb->index] = 1; |
bb457bd9 JL |
6276 | if (! hoist_expr_reaches_here_p (expr_bb, expr_index, |
6277 | pred_bb, visited)) | |
6278 | break; | |
6279 | } | |
6280 | } | |
589005ff | 6281 | if (visited_allocated_locally) |
283a2545 | 6282 | free (visited); |
c4c81601 | 6283 | |
bb457bd9 JL |
6284 | return (pred == NULL); |
6285 | } | |
6286 | \f | |
6287 | /* Actually perform code hoisting. */ | |
c4c81601 | 6288 | |
bb457bd9 JL |
6289 | static void |
6290 | hoist_code () | |
6291 | { | |
e0082a72 | 6292 | basic_block bb, dominated; |
c635a1ec DB |
6293 | basic_block *domby; |
6294 | unsigned int domby_len; | |
6295 | unsigned int i,j; | |
bb457bd9 | 6296 | struct expr **index_map; |
c4c81601 | 6297 | struct expr *expr; |
bb457bd9 | 6298 | |
d55bc081 | 6299 | sbitmap_vector_zero (hoist_exprs, last_basic_block); |
bb457bd9 JL |
6300 | |
6301 | /* Compute a mapping from expression number (`bitmap_index') to | |
6302 | hash table entry. */ | |
6303 | ||
02280659 ZD |
6304 | index_map = (struct expr **) xcalloc (expr_hash_table.n_elems, sizeof (struct expr *)); |
6305 | for (i = 0; i < expr_hash_table.size; i++) | |
6306 | for (expr = expr_hash_table.table[i]; expr != NULL; expr = expr->next_same_hash) | |
c4c81601 | 6307 | index_map[expr->bitmap_index] = expr; |
bb457bd9 JL |
6308 | |
6309 | /* Walk over each basic block looking for potentially hoistable | |
6310 | expressions, nothing gets hoisted from the entry block. */ | |
e0082a72 | 6311 | FOR_EACH_BB (bb) |
bb457bd9 JL |
6312 | { |
6313 | int found = 0; | |
6314 | int insn_inserted_p; | |
6315 | ||
c635a1ec | 6316 | domby_len = get_dominated_by (dominators, bb, &domby); |
bb457bd9 JL |
6317 | /* Examine each expression that is very busy at the exit of this |
6318 | block. These are the potentially hoistable expressions. */ | |
e0082a72 | 6319 | for (i = 0; i < hoist_vbeout[bb->index]->n_bits; i++) |
bb457bd9 JL |
6320 | { |
6321 | int hoistable = 0; | |
c4c81601 | 6322 | |
c635a1ec DB |
6323 | if (TEST_BIT (hoist_vbeout[bb->index], i) |
6324 | && TEST_BIT (transpout[bb->index], i)) | |
bb457bd9 JL |
6325 | { |
6326 | /* We've found a potentially hoistable expression, now | |
6327 | we look at every block BB dominates to see if it | |
6328 | computes the expression. */ | |
c635a1ec | 6329 | for (j = 0; j < domby_len; j++) |
bb457bd9 | 6330 | { |
c635a1ec | 6331 | dominated = domby[j]; |
bb457bd9 | 6332 | /* Ignore self dominance. */ |
c635a1ec | 6333 | if (bb == dominated) |
bb457bd9 | 6334 | continue; |
bb457bd9 JL |
6335 | /* We've found a dominated block, now see if it computes |
6336 | the busy expression and whether or not moving that | |
6337 | expression to the "beginning" of that block is safe. */ | |
e0082a72 | 6338 | if (!TEST_BIT (antloc[dominated->index], i)) |
bb457bd9 JL |
6339 | continue; |
6340 | ||
6341 | /* Note if the expression would reach the dominated block | |
589005ff | 6342 | unimpared if it was placed at the end of BB. |
bb457bd9 JL |
6343 | |
6344 | Keep track of how many times this expression is hoistable | |
6345 | from a dominated block into BB. */ | |
e0082a72 | 6346 | if (hoist_expr_reaches_here_p (bb, i, dominated, NULL)) |
bb457bd9 JL |
6347 | hoistable++; |
6348 | } | |
6349 | ||
ff7cc307 | 6350 | /* If we found more than one hoistable occurrence of this |
bb457bd9 JL |
6351 | expression, then note it in the bitmap of expressions to |
6352 | hoist. It makes no sense to hoist things which are computed | |
6353 | in only one BB, and doing so tends to pessimize register | |
6354 | allocation. One could increase this value to try harder | |
6355 | to avoid any possible code expansion due to register | |
6356 | allocation issues; however experiments have shown that | |
6357 | the vast majority of hoistable expressions are only movable | |
6358 | from two successors, so raising this threshhold is likely | |
6359 | to nullify any benefit we get from code hoisting. */ | |
6360 | if (hoistable > 1) | |
6361 | { | |
e0082a72 | 6362 | SET_BIT (hoist_exprs[bb->index], i); |
bb457bd9 JL |
6363 | found = 1; |
6364 | } | |
6365 | } | |
6366 | } | |
bb457bd9 JL |
6367 | /* If we found nothing to hoist, then quit now. */ |
6368 | if (! found) | |
c635a1ec DB |
6369 | { |
6370 | free (domby); | |
bb457bd9 | 6371 | continue; |
c635a1ec | 6372 | } |
bb457bd9 JL |
6373 | |
6374 | /* Loop over all the hoistable expressions. */ | |
e0082a72 | 6375 | for (i = 0; i < hoist_exprs[bb->index]->n_bits; i++) |
bb457bd9 JL |
6376 | { |
6377 | /* We want to insert the expression into BB only once, so | |
6378 | note when we've inserted it. */ | |
6379 | insn_inserted_p = 0; | |
6380 | ||
6381 | /* These tests should be the same as the tests above. */ | |
e0082a72 | 6382 | if (TEST_BIT (hoist_vbeout[bb->index], i)) |
bb457bd9 JL |
6383 | { |
6384 | /* We've found a potentially hoistable expression, now | |
6385 | we look at every block BB dominates to see if it | |
6386 | computes the expression. */ | |
c635a1ec | 6387 | for (j = 0; j < domby_len; j++) |
bb457bd9 | 6388 | { |
c635a1ec | 6389 | dominated = domby[j]; |
bb457bd9 | 6390 | /* Ignore self dominance. */ |
c635a1ec | 6391 | if (bb == dominated) |
bb457bd9 JL |
6392 | continue; |
6393 | ||
6394 | /* We've found a dominated block, now see if it computes | |
6395 | the busy expression and whether or not moving that | |
6396 | expression to the "beginning" of that block is safe. */ | |
e0082a72 | 6397 | if (!TEST_BIT (antloc[dominated->index], i)) |
bb457bd9 JL |
6398 | continue; |
6399 | ||
6400 | /* The expression is computed in the dominated block and | |
6401 | it would be safe to compute it at the start of the | |
6402 | dominated block. Now we have to determine if the | |
ff7cc307 | 6403 | expression would reach the dominated block if it was |
bb457bd9 | 6404 | placed at the end of BB. */ |
e0082a72 | 6405 | if (hoist_expr_reaches_here_p (bb, i, dominated, NULL)) |
bb457bd9 JL |
6406 | { |
6407 | struct expr *expr = index_map[i]; | |
6408 | struct occr *occr = expr->antic_occr; | |
6409 | rtx insn; | |
6410 | rtx set; | |
6411 | ||
ff7cc307 | 6412 | /* Find the right occurrence of this expression. */ |
e0082a72 | 6413 | while (BLOCK_FOR_INSN (occr->insn) != dominated && occr) |
bb457bd9 JL |
6414 | occr = occr->next; |
6415 | ||
6416 | /* Should never happen. */ | |
6417 | if (!occr) | |
6418 | abort (); | |
6419 | ||
6420 | insn = occr->insn; | |
589005ff | 6421 | |
bb457bd9 JL |
6422 | set = single_set (insn); |
6423 | if (! set) | |
6424 | abort (); | |
6425 | ||
6426 | /* Create a pseudo-reg to store the result of reaching | |
6427 | expressions into. Get the mode for the new pseudo | |
6428 | from the mode of the original destination pseudo. */ | |
6429 | if (expr->reaching_reg == NULL) | |
6430 | expr->reaching_reg | |
6431 | = gen_reg_rtx (GET_MODE (SET_DEST (set))); | |
6432 | ||
10d1bb36 JH |
6433 | gcse_emit_move_after (expr->reaching_reg, SET_DEST (set), insn); |
6434 | delete_insn (insn); | |
6435 | occr->deleted_p = 1; | |
6436 | if (!insn_inserted_p) | |
bb457bd9 | 6437 | { |
10d1bb36 JH |
6438 | insert_insn_end_bb (index_map[i], bb, 0); |
6439 | insn_inserted_p = 1; | |
bb457bd9 JL |
6440 | } |
6441 | } | |
6442 | } | |
6443 | } | |
6444 | } | |
c635a1ec | 6445 | free (domby); |
bb457bd9 | 6446 | } |
c4c81601 | 6447 | |
8e42ace1 | 6448 | free (index_map); |
bb457bd9 JL |
6449 | } |
6450 | ||
6451 | /* Top level routine to perform one code hoisting (aka unification) pass | |
6452 | ||
cc2902df | 6453 | Return nonzero if a change was made. */ |
bb457bd9 JL |
6454 | |
6455 | static int | |
6456 | one_code_hoisting_pass () | |
6457 | { | |
6458 | int changed = 0; | |
6459 | ||
02280659 ZD |
6460 | alloc_hash_table (max_cuid, &expr_hash_table, 0); |
6461 | compute_hash_table (&expr_hash_table); | |
bb457bd9 | 6462 | if (gcse_file) |
02280659 | 6463 | dump_hash_table (gcse_file, "Code Hosting Expressions", &expr_hash_table); |
c4c81601 | 6464 | |
02280659 | 6465 | if (expr_hash_table.n_elems > 0) |
bb457bd9 | 6466 | { |
02280659 | 6467 | alloc_code_hoist_mem (last_basic_block, expr_hash_table.n_elems); |
bb457bd9 JL |
6468 | compute_code_hoist_data (); |
6469 | hoist_code (); | |
6470 | free_code_hoist_mem (); | |
6471 | } | |
c4c81601 | 6472 | |
02280659 | 6473 | free_hash_table (&expr_hash_table); |
bb457bd9 JL |
6474 | |
6475 | return changed; | |
6476 | } | |
a13d4ebf AM |
6477 | \f |
6478 | /* Here we provide the things required to do store motion towards | |
6479 | the exit. In order for this to be effective, gcse also needed to | |
6480 | be taught how to move a load when it is kill only by a store to itself. | |
6481 | ||
6482 | int i; | |
6483 | float a[10]; | |
6484 | ||
6485 | void foo(float scale) | |
6486 | { | |
6487 | for (i=0; i<10; i++) | |
6488 | a[i] *= scale; | |
6489 | } | |
6490 | ||
6491 | 'i' is both loaded and stored to in the loop. Normally, gcse cannot move | |
589005ff KH |
6492 | the load out since its live around the loop, and stored at the bottom |
6493 | of the loop. | |
a13d4ebf | 6494 | |
589005ff | 6495 | The 'Load Motion' referred to and implemented in this file is |
a13d4ebf AM |
6496 | an enhancement to gcse which when using edge based lcm, recognizes |
6497 | this situation and allows gcse to move the load out of the loop. | |
6498 | ||
6499 | Once gcse has hoisted the load, store motion can then push this | |
6500 | load towards the exit, and we end up with no loads or stores of 'i' | |
6501 | in the loop. */ | |
6502 | ||
ff7cc307 | 6503 | /* This will search the ldst list for a matching expression. If it |
a13d4ebf AM |
6504 | doesn't find one, we create one and initialize it. */ |
6505 | ||
6506 | static struct ls_expr * | |
6507 | ldst_entry (x) | |
6508 | rtx x; | |
6509 | { | |
6510 | struct ls_expr * ptr; | |
6511 | ||
6512 | for (ptr = first_ls_expr(); ptr != NULL; ptr = next_ls_expr (ptr)) | |
6513 | if (expr_equiv_p (ptr->pattern, x)) | |
6514 | break; | |
6515 | ||
6516 | if (!ptr) | |
6517 | { | |
6518 | ptr = (struct ls_expr *) xmalloc (sizeof (struct ls_expr)); | |
6519 | ||
6520 | ptr->next = pre_ldst_mems; | |
6521 | ptr->expr = NULL; | |
6522 | ptr->pattern = x; | |
47a3dae1 | 6523 | ptr->pattern_regs = NULL_RTX; |
a13d4ebf AM |
6524 | ptr->loads = NULL_RTX; |
6525 | ptr->stores = NULL_RTX; | |
6526 | ptr->reaching_reg = NULL_RTX; | |
6527 | ptr->invalid = 0; | |
6528 | ptr->index = 0; | |
6529 | ptr->hash_index = 0; | |
6530 | pre_ldst_mems = ptr; | |
6531 | } | |
589005ff | 6532 | |
a13d4ebf AM |
6533 | return ptr; |
6534 | } | |
6535 | ||
6536 | /* Free up an individual ldst entry. */ | |
6537 | ||
589005ff | 6538 | static void |
a13d4ebf AM |
6539 | free_ldst_entry (ptr) |
6540 | struct ls_expr * ptr; | |
6541 | { | |
aaa4ca30 AJ |
6542 | free_INSN_LIST_list (& ptr->loads); |
6543 | free_INSN_LIST_list (& ptr->stores); | |
a13d4ebf AM |
6544 | |
6545 | free (ptr); | |
6546 | } | |
6547 | ||
6548 | /* Free up all memory associated with the ldst list. */ | |
6549 | ||
6550 | static void | |
6551 | free_ldst_mems () | |
6552 | { | |
589005ff | 6553 | while (pre_ldst_mems) |
a13d4ebf AM |
6554 | { |
6555 | struct ls_expr * tmp = pre_ldst_mems; | |
6556 | ||
6557 | pre_ldst_mems = pre_ldst_mems->next; | |
6558 | ||
6559 | free_ldst_entry (tmp); | |
6560 | } | |
6561 | ||
6562 | pre_ldst_mems = NULL; | |
6563 | } | |
6564 | ||
6565 | /* Dump debugging info about the ldst list. */ | |
6566 | ||
6567 | static void | |
6568 | print_ldst_list (file) | |
6569 | FILE * file; | |
6570 | { | |
6571 | struct ls_expr * ptr; | |
6572 | ||
6573 | fprintf (file, "LDST list: \n"); | |
6574 | ||
6575 | for (ptr = first_ls_expr(); ptr != NULL; ptr = next_ls_expr (ptr)) | |
6576 | { | |
6577 | fprintf (file, " Pattern (%3d): ", ptr->index); | |
6578 | ||
6579 | print_rtl (file, ptr->pattern); | |
6580 | ||
6581 | fprintf (file, "\n Loads : "); | |
6582 | ||
6583 | if (ptr->loads) | |
6584 | print_rtl (file, ptr->loads); | |
6585 | else | |
6586 | fprintf (file, "(nil)"); | |
6587 | ||
6588 | fprintf (file, "\n Stores : "); | |
6589 | ||
6590 | if (ptr->stores) | |
6591 | print_rtl (file, ptr->stores); | |
6592 | else | |
6593 | fprintf (file, "(nil)"); | |
6594 | ||
6595 | fprintf (file, "\n\n"); | |
6596 | } | |
6597 | ||
6598 | fprintf (file, "\n"); | |
6599 | } | |
6600 | ||
6601 | /* Returns 1 if X is in the list of ldst only expressions. */ | |
6602 | ||
6603 | static struct ls_expr * | |
6604 | find_rtx_in_ldst (x) | |
6605 | rtx x; | |
6606 | { | |
6607 | struct ls_expr * ptr; | |
589005ff | 6608 | |
a13d4ebf AM |
6609 | for (ptr = pre_ldst_mems; ptr != NULL; ptr = ptr->next) |
6610 | if (expr_equiv_p (ptr->pattern, x) && ! ptr->invalid) | |
6611 | return ptr; | |
6612 | ||
6613 | return NULL; | |
6614 | } | |
6615 | ||
6616 | /* Assign each element of the list of mems a monotonically increasing value. */ | |
6617 | ||
6618 | static int | |
6619 | enumerate_ldsts () | |
6620 | { | |
6621 | struct ls_expr * ptr; | |
6622 | int n = 0; | |
6623 | ||
6624 | for (ptr = pre_ldst_mems; ptr != NULL; ptr = ptr->next) | |
6625 | ptr->index = n++; | |
6626 | ||
6627 | return n; | |
6628 | } | |
6629 | ||
6630 | /* Return first item in the list. */ | |
6631 | ||
6632 | static inline struct ls_expr * | |
6633 | first_ls_expr () | |
6634 | { | |
6635 | return pre_ldst_mems; | |
6636 | } | |
6637 | ||
6638 | /* Return the next item in ther list after the specified one. */ | |
6639 | ||
6640 | static inline struct ls_expr * | |
6641 | next_ls_expr (ptr) | |
6642 | struct ls_expr * ptr; | |
6643 | { | |
6644 | return ptr->next; | |
6645 | } | |
6646 | \f | |
6647 | /* Load Motion for loads which only kill themselves. */ | |
6648 | ||
6649 | /* Return true if x is a simple MEM operation, with no registers or | |
6650 | side effects. These are the types of loads we consider for the | |
6651 | ld_motion list, otherwise we let the usual aliasing take care of it. */ | |
6652 | ||
589005ff | 6653 | static int |
a13d4ebf AM |
6654 | simple_mem (x) |
6655 | rtx x; | |
6656 | { | |
6657 | if (GET_CODE (x) != MEM) | |
6658 | return 0; | |
589005ff | 6659 | |
a13d4ebf AM |
6660 | if (MEM_VOLATILE_P (x)) |
6661 | return 0; | |
589005ff | 6662 | |
a13d4ebf AM |
6663 | if (GET_MODE (x) == BLKmode) |
6664 | return 0; | |
aaa4ca30 | 6665 | |
47a3dae1 ZD |
6666 | /* If we are handling exceptions, we must be careful with memory references |
6667 | that may trap. If we are not, the behavior is undefined, so we may just | |
6668 | continue. */ | |
6669 | if (flag_non_call_exceptions && may_trap_p (x)) | |
98d3d336 RS |
6670 | return 0; |
6671 | ||
47a3dae1 ZD |
6672 | if (side_effects_p (x)) |
6673 | return 0; | |
589005ff | 6674 | |
47a3dae1 ZD |
6675 | /* Do not consider function arguments passed on stack. */ |
6676 | if (reg_mentioned_p (stack_pointer_rtx, x)) | |
6677 | return 0; | |
6678 | ||
6679 | if (flag_float_store && FLOAT_MODE_P (GET_MODE (x))) | |
6680 | return 0; | |
6681 | ||
6682 | return 1; | |
a13d4ebf AM |
6683 | } |
6684 | ||
589005ff KH |
6685 | /* Make sure there isn't a buried reference in this pattern anywhere. |
6686 | If there is, invalidate the entry for it since we're not capable | |
6687 | of fixing it up just yet.. We have to be sure we know about ALL | |
a13d4ebf AM |
6688 | loads since the aliasing code will allow all entries in the |
6689 | ld_motion list to not-alias itself. If we miss a load, we will get | |
589005ff | 6690 | the wrong value since gcse might common it and we won't know to |
a13d4ebf AM |
6691 | fix it up. */ |
6692 | ||
6693 | static void | |
6694 | invalidate_any_buried_refs (x) | |
6695 | rtx x; | |
6696 | { | |
6697 | const char * fmt; | |
8e42ace1 | 6698 | int i, j; |
a13d4ebf AM |
6699 | struct ls_expr * ptr; |
6700 | ||
6701 | /* Invalidate it in the list. */ | |
6702 | if (GET_CODE (x) == MEM && simple_mem (x)) | |
6703 | { | |
6704 | ptr = ldst_entry (x); | |
6705 | ptr->invalid = 1; | |
6706 | } | |
6707 | ||
6708 | /* Recursively process the insn. */ | |
6709 | fmt = GET_RTX_FORMAT (GET_CODE (x)); | |
589005ff | 6710 | |
a13d4ebf AM |
6711 | for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--) |
6712 | { | |
6713 | if (fmt[i] == 'e') | |
6714 | invalidate_any_buried_refs (XEXP (x, i)); | |
6715 | else if (fmt[i] == 'E') | |
6716 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
6717 | invalidate_any_buried_refs (XVECEXP (x, i, j)); | |
6718 | } | |
6719 | } | |
6720 | ||
6721 | /* Find all the 'simple' MEMs which are used in LOADs and STORES. Simple | |
6722 | being defined as MEM loads and stores to symbols, with no | |
589005ff | 6723 | side effects and no registers in the expression. If there are any |
f63d1bf7 | 6724 | uses/defs which don't match this criteria, it is invalidated and |
a13d4ebf AM |
6725 | trimmed out later. */ |
6726 | ||
589005ff | 6727 | static void |
a13d4ebf AM |
6728 | compute_ld_motion_mems () |
6729 | { | |
6730 | struct ls_expr * ptr; | |
e0082a72 | 6731 | basic_block bb; |
a13d4ebf | 6732 | rtx insn; |
589005ff | 6733 | |
a13d4ebf AM |
6734 | pre_ldst_mems = NULL; |
6735 | ||
e0082a72 | 6736 | FOR_EACH_BB (bb) |
a13d4ebf | 6737 | { |
e0082a72 ZD |
6738 | for (insn = bb->head; |
6739 | insn && insn != NEXT_INSN (bb->end); | |
a13d4ebf AM |
6740 | insn = NEXT_INSN (insn)) |
6741 | { | |
6742 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
6743 | { | |
6744 | if (GET_CODE (PATTERN (insn)) == SET) | |
6745 | { | |
6746 | rtx src = SET_SRC (PATTERN (insn)); | |
6747 | rtx dest = SET_DEST (PATTERN (insn)); | |
6748 | ||
6749 | /* Check for a simple LOAD... */ | |
6750 | if (GET_CODE (src) == MEM && simple_mem (src)) | |
6751 | { | |
6752 | ptr = ldst_entry (src); | |
6753 | if (GET_CODE (dest) == REG) | |
6754 | ptr->loads = alloc_INSN_LIST (insn, ptr->loads); | |
6755 | else | |
6756 | ptr->invalid = 1; | |
6757 | } | |
6758 | else | |
6759 | { | |
6760 | /* Make sure there isn't a buried load somewhere. */ | |
6761 | invalidate_any_buried_refs (src); | |
6762 | } | |
589005ff | 6763 | |
a13d4ebf AM |
6764 | /* Check for stores. Don't worry about aliased ones, they |
6765 | will block any movement we might do later. We only care | |
6766 | about this exact pattern since those are the only | |
6767 | circumstance that we will ignore the aliasing info. */ | |
6768 | if (GET_CODE (dest) == MEM && simple_mem (dest)) | |
6769 | { | |
6770 | ptr = ldst_entry (dest); | |
589005ff | 6771 | |
f54104df AO |
6772 | if (GET_CODE (src) != MEM |
6773 | && GET_CODE (src) != ASM_OPERANDS) | |
a13d4ebf AM |
6774 | ptr->stores = alloc_INSN_LIST (insn, ptr->stores); |
6775 | else | |
6776 | ptr->invalid = 1; | |
6777 | } | |
6778 | } | |
6779 | else | |
6780 | invalidate_any_buried_refs (PATTERN (insn)); | |
6781 | } | |
6782 | } | |
6783 | } | |
6784 | } | |
6785 | ||
589005ff | 6786 | /* Remove any references that have been either invalidated or are not in the |
a13d4ebf AM |
6787 | expression list for pre gcse. */ |
6788 | ||
6789 | static void | |
6790 | trim_ld_motion_mems () | |
6791 | { | |
6792 | struct ls_expr * last = NULL; | |
6793 | struct ls_expr * ptr = first_ls_expr (); | |
6794 | ||
6795 | while (ptr != NULL) | |
6796 | { | |
6797 | int del = ptr->invalid; | |
6798 | struct expr * expr = NULL; | |
589005ff | 6799 | |
a13d4ebf | 6800 | /* Delete if entry has been made invalid. */ |
589005ff | 6801 | if (!del) |
a13d4ebf AM |
6802 | { |
6803 | unsigned int i; | |
589005ff | 6804 | |
a13d4ebf AM |
6805 | del = 1; |
6806 | /* Delete if we cannot find this mem in the expression list. */ | |
02280659 | 6807 | for (i = 0; i < expr_hash_table.size && del; i++) |
a13d4ebf | 6808 | { |
02280659 | 6809 | for (expr = expr_hash_table.table[i]; |
589005ff | 6810 | expr != NULL; |
a13d4ebf AM |
6811 | expr = expr->next_same_hash) |
6812 | if (expr_equiv_p (expr->expr, ptr->pattern)) | |
6813 | { | |
6814 | del = 0; | |
6815 | break; | |
6816 | } | |
6817 | } | |
6818 | } | |
589005ff | 6819 | |
a13d4ebf AM |
6820 | if (del) |
6821 | { | |
6822 | if (last != NULL) | |
6823 | { | |
6824 | last->next = ptr->next; | |
6825 | free_ldst_entry (ptr); | |
6826 | ptr = last->next; | |
6827 | } | |
6828 | else | |
6829 | { | |
6830 | pre_ldst_mems = pre_ldst_mems->next; | |
6831 | free_ldst_entry (ptr); | |
6832 | ptr = pre_ldst_mems; | |
6833 | } | |
6834 | } | |
6835 | else | |
6836 | { | |
6837 | /* Set the expression field if we are keeping it. */ | |
6838 | last = ptr; | |
6839 | ptr->expr = expr; | |
6840 | ptr = ptr->next; | |
6841 | } | |
6842 | } | |
6843 | ||
6844 | /* Show the world what we've found. */ | |
6845 | if (gcse_file && pre_ldst_mems != NULL) | |
6846 | print_ldst_list (gcse_file); | |
6847 | } | |
6848 | ||
6849 | /* This routine will take an expression which we are replacing with | |
6850 | a reaching register, and update any stores that are needed if | |
6851 | that expression is in the ld_motion list. Stores are updated by | |
6852 | copying their SRC to the reaching register, and then storeing | |
6853 | the reaching register into the store location. These keeps the | |
6854 | correct value in the reaching register for the loads. */ | |
6855 | ||
6856 | static void | |
6857 | update_ld_motion_stores (expr) | |
6858 | struct expr * expr; | |
6859 | { | |
6860 | struct ls_expr * mem_ptr; | |
6861 | ||
6862 | if ((mem_ptr = find_rtx_in_ldst (expr->expr))) | |
6863 | { | |
589005ff KH |
6864 | /* We can try to find just the REACHED stores, but is shouldn't |
6865 | matter to set the reaching reg everywhere... some might be | |
a13d4ebf AM |
6866 | dead and should be eliminated later. */ |
6867 | ||
6868 | /* We replace SET mem = expr with | |
6869 | SET reg = expr | |
589005ff | 6870 | SET mem = reg , where reg is the |
a13d4ebf AM |
6871 | reaching reg used in the load. */ |
6872 | rtx list = mem_ptr->stores; | |
589005ff | 6873 | |
a13d4ebf AM |
6874 | for ( ; list != NULL_RTX; list = XEXP (list, 1)) |
6875 | { | |
6876 | rtx insn = XEXP (list, 0); | |
6877 | rtx pat = PATTERN (insn); | |
6878 | rtx src = SET_SRC (pat); | |
6879 | rtx reg = expr->reaching_reg; | |
c57718d3 | 6880 | rtx copy, new; |
a13d4ebf AM |
6881 | |
6882 | /* If we've already copied it, continue. */ | |
6883 | if (expr->reaching_reg == src) | |
6884 | continue; | |
589005ff | 6885 | |
a13d4ebf AM |
6886 | if (gcse_file) |
6887 | { | |
6888 | fprintf (gcse_file, "PRE: store updated with reaching reg "); | |
6889 | print_rtl (gcse_file, expr->reaching_reg); | |
6890 | fprintf (gcse_file, ":\n "); | |
6891 | print_inline_rtx (gcse_file, insn, 8); | |
6892 | fprintf (gcse_file, "\n"); | |
6893 | } | |
589005ff | 6894 | |
47a3dae1 | 6895 | copy = gen_move_insn ( reg, copy_rtx (SET_SRC (pat))); |
c57718d3 RK |
6896 | new = emit_insn_before (copy, insn); |
6897 | record_one_set (REGNO (reg), new); | |
a13d4ebf AM |
6898 | SET_SRC (pat) = reg; |
6899 | ||
6900 | /* un-recognize this pattern since it's probably different now. */ | |
6901 | INSN_CODE (insn) = -1; | |
6902 | gcse_create_count++; | |
6903 | } | |
6904 | } | |
6905 | } | |
6906 | \f | |
6907 | /* Store motion code. */ | |
6908 | ||
47a3dae1 ZD |
6909 | #define ANTIC_STORE_LIST(x) ((x)->loads) |
6910 | #define AVAIL_STORE_LIST(x) ((x)->stores) | |
6911 | #define LAST_AVAIL_CHECK_FAILURE(x) ((x)->reaching_reg) | |
6912 | ||
589005ff | 6913 | /* This is used to communicate the target bitvector we want to use in the |
aaa4ca30 | 6914 | reg_set_info routine when called via the note_stores mechanism. */ |
47a3dae1 ZD |
6915 | static int * regvec; |
6916 | ||
6917 | /* And current insn, for the same routine. */ | |
6918 | static rtx compute_store_table_current_insn; | |
aaa4ca30 | 6919 | |
a13d4ebf AM |
6920 | /* Used in computing the reverse edge graph bit vectors. */ |
6921 | static sbitmap * st_antloc; | |
6922 | ||
6923 | /* Global holding the number of store expressions we are dealing with. */ | |
6924 | static int num_stores; | |
6925 | ||
aaa4ca30 | 6926 | /* Checks to set if we need to mark a register set. Called from note_stores. */ |
a13d4ebf | 6927 | |
aaa4ca30 AJ |
6928 | static void |
6929 | reg_set_info (dest, setter, data) | |
6930 | rtx dest, setter ATTRIBUTE_UNUSED; | |
6931 | void * data ATTRIBUTE_UNUSED; | |
a13d4ebf | 6932 | { |
aaa4ca30 AJ |
6933 | if (GET_CODE (dest) == SUBREG) |
6934 | dest = SUBREG_REG (dest); | |
adfcce61 | 6935 | |
aaa4ca30 | 6936 | if (GET_CODE (dest) == REG) |
47a3dae1 | 6937 | regvec[REGNO (dest)] = INSN_UID (compute_store_table_current_insn); |
a13d4ebf AM |
6938 | } |
6939 | ||
47a3dae1 ZD |
6940 | /* Return zero if some of the registers in list X are killed |
6941 | due to set of registers in bitmap REGS_SET. */ | |
6942 | ||
6943 | static bool | |
6944 | store_ops_ok (x, regs_set) | |
6945 | rtx x; | |
6946 | int *regs_set; | |
6947 | { | |
6948 | rtx reg; | |
6949 | ||
6950 | for (; x; x = XEXP (x, 1)) | |
6951 | { | |
6952 | reg = XEXP (x, 0); | |
6953 | if (regs_set[REGNO(reg)]) | |
6954 | return false; | |
6955 | } | |
a13d4ebf | 6956 | |
47a3dae1 ZD |
6957 | return true; |
6958 | } | |
6959 | ||
6960 | /* Returns a list of registers mentioned in X. */ | |
6961 | static rtx | |
6962 | extract_mentioned_regs (x) | |
a13d4ebf | 6963 | rtx x; |
47a3dae1 ZD |
6964 | { |
6965 | return extract_mentioned_regs_helper (x, NULL_RTX); | |
6966 | } | |
6967 | ||
6968 | /* Helper for extract_mentioned_regs; ACCUM is used to accumulate used | |
6969 | registers. */ | |
6970 | static rtx | |
6971 | extract_mentioned_regs_helper (x, accum) | |
6972 | rtx x; | |
6973 | rtx accum; | |
a13d4ebf AM |
6974 | { |
6975 | int i; | |
6976 | enum rtx_code code; | |
6977 | const char * fmt; | |
6978 | ||
6979 | /* Repeat is used to turn tail-recursion into iteration. */ | |
6980 | repeat: | |
6981 | ||
6982 | if (x == 0) | |
47a3dae1 | 6983 | return accum; |
a13d4ebf AM |
6984 | |
6985 | code = GET_CODE (x); | |
6986 | switch (code) | |
6987 | { | |
6988 | case REG: | |
47a3dae1 | 6989 | return alloc_EXPR_LIST (0, x, accum); |
a13d4ebf AM |
6990 | |
6991 | case MEM: | |
6992 | x = XEXP (x, 0); | |
6993 | goto repeat; | |
6994 | ||
6995 | case PRE_DEC: | |
6996 | case PRE_INC: | |
6997 | case POST_DEC: | |
6998 | case POST_INC: | |
47a3dae1 ZD |
6999 | /* We do not run this function with arguments having side effects. */ |
7000 | abort (); | |
a13d4ebf AM |
7001 | |
7002 | case PC: | |
7003 | case CC0: /*FIXME*/ | |
7004 | case CONST: | |
7005 | case CONST_INT: | |
7006 | case CONST_DOUBLE: | |
69ef87e2 | 7007 | case CONST_VECTOR: |
a13d4ebf AM |
7008 | case SYMBOL_REF: |
7009 | case LABEL_REF: | |
7010 | case ADDR_VEC: | |
7011 | case ADDR_DIFF_VEC: | |
47a3dae1 | 7012 | return accum; |
a13d4ebf AM |
7013 | |
7014 | default: | |
7015 | break; | |
7016 | } | |
7017 | ||
7018 | i = GET_RTX_LENGTH (code) - 1; | |
7019 | fmt = GET_RTX_FORMAT (code); | |
589005ff | 7020 | |
a13d4ebf AM |
7021 | for (; i >= 0; i--) |
7022 | { | |
7023 | if (fmt[i] == 'e') | |
7024 | { | |
7025 | rtx tem = XEXP (x, i); | |
7026 | ||
7027 | /* If we are about to do the last recursive call | |
47a3dae1 | 7028 | needed at this level, change it into iteration. */ |
a13d4ebf AM |
7029 | if (i == 0) |
7030 | { | |
7031 | x = tem; | |
7032 | goto repeat; | |
7033 | } | |
589005ff | 7034 | |
47a3dae1 | 7035 | accum = extract_mentioned_regs_helper (tem, accum); |
a13d4ebf AM |
7036 | } |
7037 | else if (fmt[i] == 'E') | |
7038 | { | |
7039 | int j; | |
589005ff | 7040 | |
a13d4ebf | 7041 | for (j = 0; j < XVECLEN (x, i); j++) |
47a3dae1 | 7042 | accum = extract_mentioned_regs_helper (XVECEXP (x, i, j), accum); |
a13d4ebf AM |
7043 | } |
7044 | } | |
7045 | ||
47a3dae1 | 7046 | return accum; |
a13d4ebf AM |
7047 | } |
7048 | ||
47a3dae1 ZD |
7049 | /* Determine whether INSN is MEM store pattern that we will consider moving. |
7050 | REGS_SET_BEFORE is bitmap of registers set before (and including) the | |
7051 | current insn, REGS_SET_AFTER is bitmap of registers set after (and | |
7052 | including) the insn in this basic block. We must be passing through BB from | |
7053 | head to end, as we are using this fact to speed things up. | |
7054 | ||
7055 | The results are stored this way: | |
7056 | ||
7057 | -- the first anticipatable expression is added into ANTIC_STORE_LIST | |
7058 | -- if the processed expression is not anticipatable, NULL_RTX is added | |
7059 | there instead, so that we can use it as indicator that no further | |
7060 | expression of this type may be anticipatable | |
7061 | -- if the expression is available, it is added as head of AVAIL_STORE_LIST; | |
7062 | consequently, all of them but this head are dead and may be deleted. | |
7063 | -- if the expression is not available, the insn due to that it fails to be | |
7064 | available is stored in reaching_reg. | |
7065 | ||
7066 | The things are complicated a bit by fact that there already may be stores | |
7067 | to the same MEM from other blocks; also caller must take care of the | |
7068 | neccessary cleanup of the temporary markers after end of the basic block. | |
7069 | */ | |
a13d4ebf AM |
7070 | |
7071 | static void | |
47a3dae1 | 7072 | find_moveable_store (insn, regs_set_before, regs_set_after) |
a13d4ebf | 7073 | rtx insn; |
47a3dae1 ZD |
7074 | int *regs_set_before; |
7075 | int *regs_set_after; | |
a13d4ebf AM |
7076 | { |
7077 | struct ls_expr * ptr; | |
47a3dae1 ZD |
7078 | rtx dest, set, tmp; |
7079 | int check_anticipatable, check_available; | |
7080 | basic_block bb = BLOCK_FOR_INSN (insn); | |
a13d4ebf | 7081 | |
47a3dae1 ZD |
7082 | set = single_set (insn); |
7083 | if (!set) | |
a13d4ebf AM |
7084 | return; |
7085 | ||
47a3dae1 | 7086 | dest = SET_DEST (set); |
589005ff | 7087 | |
a13d4ebf AM |
7088 | if (GET_CODE (dest) != MEM || MEM_VOLATILE_P (dest) |
7089 | || GET_MODE (dest) == BLKmode) | |
aaa4ca30 AJ |
7090 | return; |
7091 | ||
47a3dae1 ZD |
7092 | if (side_effects_p (dest)) |
7093 | return; | |
aaa4ca30 | 7094 | |
47a3dae1 ZD |
7095 | /* If we are handling exceptions, we must be careful with memory references |
7096 | that may trap. If we are not, the behavior is undefined, so we may just | |
7097 | continue. */ | |
7098 | if (flag_exceptions && may_trap_p (dest)) | |
7099 | return; | |
7100 | ||
7101 | /* Do not consider MEMs that mention stack pointer; in the following | |
7102 | we rely on that constant functions do not read memory, which of course | |
7103 | does not include their arguments if passed on stack. | |
7104 | ||
7105 | Note that this is not quite correct -- we may use other registers | |
7106 | to address stack. See store_killed_in_insn for handling of this | |
7107 | case. */ | |
7108 | if (reg_mentioned_p (stack_pointer_rtx, dest)) | |
a13d4ebf | 7109 | return; |
aaa4ca30 | 7110 | |
a13d4ebf | 7111 | ptr = ldst_entry (dest); |
47a3dae1 ZD |
7112 | if (!ptr->pattern_regs) |
7113 | ptr->pattern_regs = extract_mentioned_regs (dest); | |
7114 | ||
7115 | /* Do not check for anticipatability if we either found one anticipatable | |
7116 | store already, or tested for one and found out that it was killed. */ | |
7117 | check_anticipatable = 0; | |
7118 | if (!ANTIC_STORE_LIST (ptr)) | |
7119 | check_anticipatable = 1; | |
7120 | else | |
7121 | { | |
7122 | tmp = XEXP (ANTIC_STORE_LIST (ptr), 0); | |
7123 | if (tmp != NULL_RTX | |
7124 | && BLOCK_FOR_INSN (tmp) != bb) | |
7125 | check_anticipatable = 1; | |
7126 | } | |
7127 | if (check_anticipatable) | |
7128 | { | |
7129 | if (store_killed_before (dest, ptr->pattern_regs, insn, bb, regs_set_before)) | |
7130 | tmp = NULL_RTX; | |
7131 | else | |
7132 | tmp = insn; | |
7133 | ANTIC_STORE_LIST (ptr) = alloc_INSN_LIST (tmp, | |
7134 | ANTIC_STORE_LIST (ptr)); | |
7135 | } | |
a13d4ebf | 7136 | |
47a3dae1 ZD |
7137 | /* It is not neccessary to check whether store is available if we did |
7138 | it successfully before; if we failed before, do not bother to check | |
7139 | until we reach the insn that caused us to fail. */ | |
7140 | check_available = 0; | |
7141 | if (!AVAIL_STORE_LIST (ptr)) | |
7142 | check_available = 1; | |
7143 | else | |
7144 | { | |
7145 | tmp = XEXP (AVAIL_STORE_LIST (ptr), 0); | |
7146 | if (BLOCK_FOR_INSN (tmp) != bb) | |
7147 | check_available = 1; | |
7148 | } | |
7149 | if (check_available) | |
7150 | { | |
7151 | /* Check that we have already reached the insn at that the check | |
7152 | failed last time. */ | |
7153 | if (LAST_AVAIL_CHECK_FAILURE (ptr)) | |
7154 | { | |
7155 | for (tmp = bb->end; | |
7156 | tmp != insn && tmp != LAST_AVAIL_CHECK_FAILURE (ptr); | |
7157 | tmp = PREV_INSN (tmp)) | |
7158 | continue; | |
7159 | if (tmp == insn) | |
7160 | check_available = 0; | |
7161 | } | |
7162 | else | |
7163 | check_available = store_killed_after (dest, ptr->pattern_regs, insn, | |
7164 | bb, regs_set_after, | |
7165 | &LAST_AVAIL_CHECK_FAILURE (ptr)); | |
7166 | } | |
7167 | if (!check_available) | |
7168 | AVAIL_STORE_LIST (ptr) = alloc_INSN_LIST (insn, AVAIL_STORE_LIST (ptr)); | |
7169 | } | |
7170 | ||
7171 | /* Find available and anticipatable stores. */ | |
a13d4ebf AM |
7172 | |
7173 | static int | |
7174 | compute_store_table () | |
7175 | { | |
e0082a72 ZD |
7176 | int ret; |
7177 | basic_block bb; | |
aaa4ca30 | 7178 | unsigned regno; |
47a3dae1 ZD |
7179 | rtx insn, pat, tmp; |
7180 | int *last_set_in, *already_set; | |
7181 | struct ls_expr * ptr, **prev_next_ptr_ptr; | |
aaa4ca30 | 7182 | |
a13d4ebf AM |
7183 | max_gcse_regno = max_reg_num (); |
7184 | ||
d55bc081 | 7185 | reg_set_in_block = (sbitmap *) sbitmap_vector_alloc (last_basic_block, |
aaa4ca30 | 7186 | max_gcse_regno); |
d55bc081 | 7187 | sbitmap_vector_zero (reg_set_in_block, last_basic_block); |
a13d4ebf | 7188 | pre_ldst_mems = 0; |
47a3dae1 ZD |
7189 | last_set_in = xmalloc (sizeof (int) * max_gcse_regno); |
7190 | already_set = xmalloc (sizeof (int) * max_gcse_regno); | |
aaa4ca30 | 7191 | |
a13d4ebf | 7192 | /* Find all the stores we care about. */ |
e0082a72 | 7193 | FOR_EACH_BB (bb) |
a13d4ebf | 7194 | { |
47a3dae1 ZD |
7195 | /* First compute the registers set in this block. */ |
7196 | memset (last_set_in, 0, sizeof (int) * max_gcse_regno); | |
7197 | regvec = last_set_in; | |
7198 | ||
7199 | for (insn = bb->head; | |
7200 | insn != NEXT_INSN (bb->end); | |
7201 | insn = NEXT_INSN (insn)) | |
7202 | { | |
7203 | if (! INSN_P (insn)) | |
7204 | continue; | |
7205 | ||
7206 | if (GET_CODE (insn) == CALL_INSN) | |
7207 | { | |
7208 | bool clobbers_all = false; | |
7209 | #ifdef NON_SAVING_SETJMP | |
7210 | if (NON_SAVING_SETJMP | |
7211 | && find_reg_note (insn, REG_SETJMP, NULL_RTX)) | |
7212 | clobbers_all = true; | |
7213 | #endif | |
7214 | ||
7215 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) | |
7216 | if (clobbers_all | |
7217 | || TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) | |
7218 | last_set_in[regno] = INSN_UID (insn); | |
7219 | } | |
7220 | ||
7221 | pat = PATTERN (insn); | |
7222 | compute_store_table_current_insn = insn; | |
7223 | note_stores (pat, reg_set_info, NULL); | |
7224 | } | |
7225 | ||
7226 | /* Record the set registers. */ | |
7227 | for (regno = 0; regno < max_gcse_regno; regno++) | |
7228 | if (last_set_in[regno]) | |
7229 | SET_BIT (reg_set_in_block[bb->index], regno); | |
7230 | ||
7231 | /* Now find the stores. */ | |
7232 | memset (already_set, 0, sizeof (int) * max_gcse_regno); | |
7233 | regvec = already_set; | |
7234 | for (insn = bb->head; | |
7235 | insn != NEXT_INSN (bb->end); | |
7236 | insn = NEXT_INSN (insn)) | |
a13d4ebf | 7237 | { |
19652adf | 7238 | if (! INSN_P (insn)) |
a13d4ebf AM |
7239 | continue; |
7240 | ||
aaa4ca30 AJ |
7241 | if (GET_CODE (insn) == CALL_INSN) |
7242 | { | |
19652adf | 7243 | bool clobbers_all = false; |
589005ff | 7244 | #ifdef NON_SAVING_SETJMP |
19652adf ZW |
7245 | if (NON_SAVING_SETJMP |
7246 | && find_reg_note (insn, REG_SETJMP, NULL_RTX)) | |
7247 | clobbers_all = true; | |
7248 | #endif | |
7249 | ||
aaa4ca30 | 7250 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) |
19652adf ZW |
7251 | if (clobbers_all |
7252 | || TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) | |
47a3dae1 | 7253 | already_set[regno] = 1; |
aaa4ca30 | 7254 | } |
589005ff | 7255 | |
a13d4ebf | 7256 | pat = PATTERN (insn); |
aaa4ca30 | 7257 | note_stores (pat, reg_set_info, NULL); |
589005ff | 7258 | |
a13d4ebf | 7259 | /* Now that we've marked regs, look for stores. */ |
47a3dae1 ZD |
7260 | find_moveable_store (insn, already_set, last_set_in); |
7261 | ||
7262 | /* Unmark regs that are no longer set. */ | |
7263 | for (regno = 0; regno < max_gcse_regno; regno++) | |
7264 | if (last_set_in[regno] == INSN_UID (insn)) | |
7265 | last_set_in[regno] = 0; | |
7266 | } | |
7267 | ||
7268 | /* Clear temporary marks. */ | |
7269 | for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr)) | |
7270 | { | |
7271 | LAST_AVAIL_CHECK_FAILURE(ptr) = NULL_RTX; | |
7272 | if (ANTIC_STORE_LIST (ptr) | |
7273 | && (tmp = XEXP (ANTIC_STORE_LIST (ptr), 0)) == NULL_RTX) | |
7274 | ANTIC_STORE_LIST (ptr) = XEXP (ANTIC_STORE_LIST (ptr), 1); | |
7275 | } | |
7276 | } | |
7277 | ||
7278 | /* Remove the stores that are not available anywhere, as there will | |
7279 | be no opportunity to optimize them. */ | |
7280 | for (ptr = pre_ldst_mems, prev_next_ptr_ptr = &pre_ldst_mems; | |
7281 | ptr != NULL; | |
7282 | ptr = *prev_next_ptr_ptr) | |
7283 | { | |
7284 | if (!AVAIL_STORE_LIST (ptr)) | |
7285 | { | |
7286 | *prev_next_ptr_ptr = ptr->next; | |
7287 | free_ldst_entry (ptr); | |
a13d4ebf | 7288 | } |
47a3dae1 ZD |
7289 | else |
7290 | prev_next_ptr_ptr = &ptr->next; | |
a13d4ebf AM |
7291 | } |
7292 | ||
7293 | ret = enumerate_ldsts (); | |
589005ff | 7294 | |
a13d4ebf AM |
7295 | if (gcse_file) |
7296 | { | |
47a3dae1 | 7297 | fprintf (gcse_file, "ST_avail and ST_antic (shown under loads..)\n"); |
a13d4ebf AM |
7298 | print_ldst_list (gcse_file); |
7299 | } | |
589005ff | 7300 | |
47a3dae1 ZD |
7301 | free (last_set_in); |
7302 | free (already_set); | |
a13d4ebf AM |
7303 | return ret; |
7304 | } | |
7305 | ||
aaa4ca30 | 7306 | /* Check to see if the load X is aliased with STORE_PATTERN. */ |
a13d4ebf | 7307 | |
47a3dae1 | 7308 | static bool |
a13d4ebf AM |
7309 | load_kills_store (x, store_pattern) |
7310 | rtx x, store_pattern; | |
7311 | { | |
7312 | if (true_dependence (x, GET_MODE (x), store_pattern, rtx_addr_varies_p)) | |
47a3dae1 ZD |
7313 | return true; |
7314 | return false; | |
a13d4ebf AM |
7315 | } |
7316 | ||
589005ff | 7317 | /* Go through the entire insn X, looking for any loads which might alias |
47a3dae1 | 7318 | STORE_PATTERN. Return true if found. */ |
a13d4ebf | 7319 | |
47a3dae1 | 7320 | static bool |
a13d4ebf AM |
7321 | find_loads (x, store_pattern) |
7322 | rtx x, store_pattern; | |
7323 | { | |
7324 | const char * fmt; | |
8e42ace1 | 7325 | int i, j; |
47a3dae1 | 7326 | int ret = false; |
a13d4ebf | 7327 | |
24a28584 | 7328 | if (!x) |
47a3dae1 | 7329 | return false; |
24a28584 | 7330 | |
589005ff | 7331 | if (GET_CODE (x) == SET) |
a13d4ebf AM |
7332 | x = SET_SRC (x); |
7333 | ||
7334 | if (GET_CODE (x) == MEM) | |
7335 | { | |
7336 | if (load_kills_store (x, store_pattern)) | |
47a3dae1 | 7337 | return true; |
a13d4ebf AM |
7338 | } |
7339 | ||
7340 | /* Recursively process the insn. */ | |
7341 | fmt = GET_RTX_FORMAT (GET_CODE (x)); | |
589005ff | 7342 | |
a13d4ebf AM |
7343 | for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0 && !ret; i--) |
7344 | { | |
7345 | if (fmt[i] == 'e') | |
7346 | ret |= find_loads (XEXP (x, i), store_pattern); | |
7347 | else if (fmt[i] == 'E') | |
7348 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
7349 | ret |= find_loads (XVECEXP (x, i, j), store_pattern); | |
7350 | } | |
7351 | return ret; | |
7352 | } | |
7353 | ||
589005ff | 7354 | /* Check if INSN kills the store pattern X (is aliased with it). |
47a3dae1 | 7355 | Return true if it it does. */ |
a13d4ebf | 7356 | |
47a3dae1 ZD |
7357 | static bool |
7358 | store_killed_in_insn (x, x_regs, insn) | |
7359 | rtx x, x_regs, insn; | |
a13d4ebf AM |
7360 | { |
7361 | if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') | |
47a3dae1 | 7362 | return false; |
589005ff | 7363 | |
a13d4ebf AM |
7364 | if (GET_CODE (insn) == CALL_INSN) |
7365 | { | |
1218665b JJ |
7366 | /* A normal or pure call might read from pattern, |
7367 | but a const call will not. */ | |
47a3dae1 ZD |
7368 | if (! CONST_OR_PURE_CALL_P (insn) || pure_call_p (insn)) |
7369 | return true; | |
7370 | ||
7371 | /* But even a const call reads its parameters. It is not trivial | |
7372 | check that base of the mem is not related to stack pointer, | |
7373 | so unless it contains no registers, just assume it may. */ | |
7374 | if (x_regs) | |
7375 | return true; | |
7376 | ||
7377 | return false; | |
a13d4ebf | 7378 | } |
589005ff | 7379 | |
a13d4ebf AM |
7380 | if (GET_CODE (PATTERN (insn)) == SET) |
7381 | { | |
7382 | rtx pat = PATTERN (insn); | |
7383 | /* Check for memory stores to aliased objects. */ | |
7384 | if (GET_CODE (SET_DEST (pat)) == MEM && !expr_equiv_p (SET_DEST (pat), x)) | |
aaa4ca30 | 7385 | /* pretend its a load and check for aliasing. */ |
a13d4ebf | 7386 | if (find_loads (SET_DEST (pat), x)) |
47a3dae1 | 7387 | return true; |
a13d4ebf AM |
7388 | return find_loads (SET_SRC (pat), x); |
7389 | } | |
7390 | else | |
7391 | return find_loads (PATTERN (insn), x); | |
7392 | } | |
7393 | ||
47a3dae1 ZD |
7394 | /* Returns true if the expression X is loaded or clobbered on or after INSN |
7395 | within basic block BB. REGS_SET_AFTER is bitmap of registers set in | |
7396 | or after the insn. X_REGS is list of registers mentioned in X. If the store | |
7397 | is killed, return the last insn in that it occurs in FAIL_INSN. */ | |
a13d4ebf | 7398 | |
47a3dae1 ZD |
7399 | static bool |
7400 | store_killed_after (x, x_regs, insn, bb, regs_set_after, fail_insn) | |
7401 | rtx x, x_regs, insn; | |
e2d2ed72 | 7402 | basic_block bb; |
47a3dae1 ZD |
7403 | int *regs_set_after; |
7404 | rtx *fail_insn; | |
a13d4ebf | 7405 | { |
47a3dae1 | 7406 | rtx last = bb->end, act; |
aaa4ca30 | 7407 | |
47a3dae1 ZD |
7408 | if (!store_ops_ok (x_regs, regs_set_after)) |
7409 | { | |
7410 | /* We do not know where it will happen. */ | |
7411 | if (fail_insn) | |
7412 | *fail_insn = NULL_RTX; | |
7413 | return true; | |
7414 | } | |
a13d4ebf | 7415 | |
47a3dae1 ZD |
7416 | /* Scan from the end, so that fail_insn is determined correctly. */ |
7417 | for (act = last; act != PREV_INSN (insn); act = PREV_INSN (act)) | |
7418 | if (store_killed_in_insn (x, x_regs, act)) | |
7419 | { | |
7420 | if (fail_insn) | |
7421 | *fail_insn = act; | |
7422 | return true; | |
7423 | } | |
589005ff | 7424 | |
47a3dae1 | 7425 | return false; |
a13d4ebf | 7426 | } |
47a3dae1 ZD |
7427 | |
7428 | /* Returns true if the expression X is loaded or clobbered on or before INSN | |
7429 | within basic block BB. X_REGS is list of registers mentioned in X. | |
7430 | REGS_SET_BEFORE is bitmap of registers set before or in this insn. */ | |
7431 | static bool | |
7432 | store_killed_before (x, x_regs, insn, bb, regs_set_before) | |
7433 | rtx x, x_regs, insn; | |
e2d2ed72 | 7434 | basic_block bb; |
47a3dae1 | 7435 | int *regs_set_before; |
a13d4ebf | 7436 | { |
8e42ace1 | 7437 | rtx first = bb->head; |
a13d4ebf | 7438 | |
47a3dae1 ZD |
7439 | if (!store_ops_ok (x_regs, regs_set_before)) |
7440 | return true; | |
a13d4ebf | 7441 | |
47a3dae1 ZD |
7442 | for ( ; insn != PREV_INSN (first); insn = PREV_INSN (insn)) |
7443 | if (store_killed_in_insn (x, x_regs, insn)) | |
7444 | return true; | |
589005ff | 7445 | |
47a3dae1 | 7446 | return false; |
a13d4ebf | 7447 | } |
47a3dae1 ZD |
7448 | |
7449 | /* Fill in available, anticipatable, transparent and kill vectors in | |
7450 | STORE_DATA, based on lists of available and anticipatable stores. */ | |
a13d4ebf | 7451 | static void |
589005ff | 7452 | build_store_vectors () |
a13d4ebf | 7453 | { |
47a3dae1 ZD |
7454 | basic_block bb; |
7455 | int *regs_set_in_block; | |
a13d4ebf AM |
7456 | rtx insn, st; |
7457 | struct ls_expr * ptr; | |
47a3dae1 | 7458 | unsigned regno; |
a13d4ebf AM |
7459 | |
7460 | /* Build the gen_vector. This is any store in the table which is not killed | |
7461 | by aliasing later in its block. */ | |
d55bc081 ZD |
7462 | ae_gen = (sbitmap *) sbitmap_vector_alloc (last_basic_block, num_stores); |
7463 | sbitmap_vector_zero (ae_gen, last_basic_block); | |
a13d4ebf | 7464 | |
d55bc081 ZD |
7465 | st_antloc = (sbitmap *) sbitmap_vector_alloc (last_basic_block, num_stores); |
7466 | sbitmap_vector_zero (st_antloc, last_basic_block); | |
aaa4ca30 | 7467 | |
a13d4ebf | 7468 | for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr)) |
589005ff | 7469 | { |
47a3dae1 | 7470 | for (st = AVAIL_STORE_LIST (ptr); st != NULL; st = XEXP (st, 1)) |
a13d4ebf AM |
7471 | { |
7472 | insn = XEXP (st, 0); | |
e2d2ed72 | 7473 | bb = BLOCK_FOR_INSN (insn); |
589005ff | 7474 | |
47a3dae1 ZD |
7475 | /* If we've already seen an available expression in this block, |
7476 | we can delete this one (It occurs earlier in the block). We'll | |
7477 | copy the SRC expression to an unused register in case there | |
7478 | are any side effects. */ | |
7479 | if (TEST_BIT (ae_gen[bb->index], ptr->index)) | |
a13d4ebf | 7480 | { |
47a3dae1 ZD |
7481 | rtx r = gen_reg_rtx (GET_MODE (ptr->pattern)); |
7482 | if (gcse_file) | |
7483 | fprintf (gcse_file, "Removing redundant store:\n"); | |
7484 | replace_store_insn (r, XEXP (st, 0), bb); | |
7485 | continue; | |
a13d4ebf | 7486 | } |
47a3dae1 | 7487 | SET_BIT (ae_gen[bb->index], ptr->index); |
a13d4ebf | 7488 | } |
589005ff | 7489 | |
47a3dae1 ZD |
7490 | for (st = ANTIC_STORE_LIST (ptr); st != NULL; st = XEXP (st, 1)) |
7491 | { | |
7492 | insn = XEXP (st, 0); | |
7493 | bb = BLOCK_FOR_INSN (insn); | |
7494 | SET_BIT (st_antloc[bb->index], ptr->index); | |
7495 | } | |
a13d4ebf | 7496 | } |
589005ff | 7497 | |
d55bc081 ZD |
7498 | ae_kill = (sbitmap *) sbitmap_vector_alloc (last_basic_block, num_stores); |
7499 | sbitmap_vector_zero (ae_kill, last_basic_block); | |
a13d4ebf | 7500 | |
d55bc081 ZD |
7501 | transp = (sbitmap *) sbitmap_vector_alloc (last_basic_block, num_stores); |
7502 | sbitmap_vector_zero (transp, last_basic_block); | |
47a3dae1 | 7503 | regs_set_in_block = xmalloc (sizeof (int) * max_gcse_regno); |
a13d4ebf | 7504 | |
47a3dae1 ZD |
7505 | FOR_EACH_BB (bb) |
7506 | { | |
7507 | for (regno = 0; regno < max_gcse_regno; regno++) | |
7508 | regs_set_in_block[regno] = TEST_BIT (reg_set_in_block[bb->index], regno); | |
7509 | ||
7510 | for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr)) | |
7511 | { | |
7512 | if (store_killed_after (ptr->pattern, ptr->pattern_regs, bb->head, | |
7513 | bb, regs_set_in_block, NULL)) | |
7514 | { | |
7515 | /* It should not be neccessary to consider the expression | |
7516 | killed if it is both anticipatable and available. */ | |
7517 | if (!TEST_BIT (st_antloc[bb->index], ptr->index) | |
7518 | || !TEST_BIT (ae_gen[bb->index], ptr->index)) | |
7519 | SET_BIT (ae_kill[bb->index], ptr->index); | |
7520 | } | |
7521 | else | |
7522 | SET_BIT (transp[bb->index], ptr->index); | |
7523 | } | |
7524 | } | |
7525 | ||
7526 | free (regs_set_in_block); | |
aaa4ca30 | 7527 | |
589005ff | 7528 | if (gcse_file) |
aaa4ca30 | 7529 | { |
d55bc081 ZD |
7530 | dump_sbitmap_vector (gcse_file, "st_antloc", "", st_antloc, last_basic_block); |
7531 | dump_sbitmap_vector (gcse_file, "st_kill", "", ae_kill, last_basic_block); | |
7532 | dump_sbitmap_vector (gcse_file, "Transpt", "", transp, last_basic_block); | |
7533 | dump_sbitmap_vector (gcse_file, "st_avloc", "", ae_gen, last_basic_block); | |
a13d4ebf AM |
7534 | } |
7535 | } | |
7536 | ||
fbe5a4a6 | 7537 | /* Insert an instruction at the beginning of a basic block, and update |
a13d4ebf AM |
7538 | the BLOCK_HEAD if needed. */ |
7539 | ||
589005ff | 7540 | static void |
a13d4ebf AM |
7541 | insert_insn_start_bb (insn, bb) |
7542 | rtx insn; | |
e2d2ed72 | 7543 | basic_block bb; |
a13d4ebf AM |
7544 | { |
7545 | /* Insert at start of successor block. */ | |
e2d2ed72 AM |
7546 | rtx prev = PREV_INSN (bb->head); |
7547 | rtx before = bb->head; | |
a13d4ebf AM |
7548 | while (before != 0) |
7549 | { | |
7550 | if (GET_CODE (before) != CODE_LABEL | |
7551 | && (GET_CODE (before) != NOTE | |
7552 | || NOTE_LINE_NUMBER (before) != NOTE_INSN_BASIC_BLOCK)) | |
7553 | break; | |
7554 | prev = before; | |
e2d2ed72 | 7555 | if (prev == bb->end) |
a13d4ebf AM |
7556 | break; |
7557 | before = NEXT_INSN (before); | |
7558 | } | |
7559 | ||
7560 | insn = emit_insn_after (insn, prev); | |
7561 | ||
a13d4ebf AM |
7562 | if (gcse_file) |
7563 | { | |
7564 | fprintf (gcse_file, "STORE_MOTION insert store at start of BB %d:\n", | |
0b17ab2f | 7565 | bb->index); |
a13d4ebf AM |
7566 | print_inline_rtx (gcse_file, insn, 6); |
7567 | fprintf (gcse_file, "\n"); | |
7568 | } | |
7569 | } | |
7570 | ||
7571 | /* This routine will insert a store on an edge. EXPR is the ldst entry for | |
cc2902df | 7572 | the memory reference, and E is the edge to insert it on. Returns nonzero |
a13d4ebf AM |
7573 | if an edge insertion was performed. */ |
7574 | ||
7575 | static int | |
7576 | insert_store (expr, e) | |
7577 | struct ls_expr * expr; | |
7578 | edge e; | |
7579 | { | |
7580 | rtx reg, insn; | |
e2d2ed72 | 7581 | basic_block bb; |
a13d4ebf AM |
7582 | edge tmp; |
7583 | ||
7584 | /* We did all the deleted before this insert, so if we didn't delete a | |
7585 | store, then we haven't set the reaching reg yet either. */ | |
7586 | if (expr->reaching_reg == NULL_RTX) | |
7587 | return 0; | |
7588 | ||
7589 | reg = expr->reaching_reg; | |
47a3dae1 | 7590 | insn = gen_move_insn (copy_rtx (expr->pattern), reg); |
589005ff | 7591 | |
a13d4ebf AM |
7592 | /* If we are inserting this expression on ALL predecessor edges of a BB, |
7593 | insert it at the start of the BB, and reset the insert bits on the other | |
ff7cc307 | 7594 | edges so we don't try to insert it on the other edges. */ |
e2d2ed72 | 7595 | bb = e->dest; |
a13d4ebf AM |
7596 | for (tmp = e->dest->pred; tmp ; tmp = tmp->pred_next) |
7597 | { | |
7598 | int index = EDGE_INDEX (edge_list, tmp->src, tmp->dest); | |
7599 | if (index == EDGE_INDEX_NO_EDGE) | |
7600 | abort (); | |
7601 | if (! TEST_BIT (pre_insert_map[index], expr->index)) | |
7602 | break; | |
7603 | } | |
7604 | ||
7605 | /* If tmp is NULL, we found an insertion on every edge, blank the | |
7606 | insertion vector for these edges, and insert at the start of the BB. */ | |
e2d2ed72 | 7607 | if (!tmp && bb != EXIT_BLOCK_PTR) |
a13d4ebf AM |
7608 | { |
7609 | for (tmp = e->dest->pred; tmp ; tmp = tmp->pred_next) | |
7610 | { | |
7611 | int index = EDGE_INDEX (edge_list, tmp->src, tmp->dest); | |
7612 | RESET_BIT (pre_insert_map[index], expr->index); | |
7613 | } | |
7614 | insert_insn_start_bb (insn, bb); | |
7615 | return 0; | |
7616 | } | |
589005ff | 7617 | |
a13d4ebf AM |
7618 | /* We can't insert on this edge, so we'll insert at the head of the |
7619 | successors block. See Morgan, sec 10.5. */ | |
7620 | if ((e->flags & EDGE_ABNORMAL) == EDGE_ABNORMAL) | |
7621 | { | |
7622 | insert_insn_start_bb (insn, bb); | |
7623 | return 0; | |
7624 | } | |
7625 | ||
7626 | insert_insn_on_edge (insn, e); | |
589005ff | 7627 | |
a13d4ebf AM |
7628 | if (gcse_file) |
7629 | { | |
7630 | fprintf (gcse_file, "STORE_MOTION insert insn on edge (%d, %d):\n", | |
0b17ab2f | 7631 | e->src->index, e->dest->index); |
a13d4ebf AM |
7632 | print_inline_rtx (gcse_file, insn, 6); |
7633 | fprintf (gcse_file, "\n"); | |
7634 | } | |
589005ff | 7635 | |
a13d4ebf AM |
7636 | return 1; |
7637 | } | |
7638 | ||
7639 | /* This routine will replace a store with a SET to a specified register. */ | |
7640 | ||
7641 | static void | |
7642 | replace_store_insn (reg, del, bb) | |
7643 | rtx reg, del; | |
e2d2ed72 | 7644 | basic_block bb; |
a13d4ebf AM |
7645 | { |
7646 | rtx insn; | |
589005ff | 7647 | |
a13d4ebf AM |
7648 | insn = gen_move_insn (reg, SET_SRC (PATTERN (del))); |
7649 | insn = emit_insn_after (insn, del); | |
589005ff | 7650 | |
a13d4ebf AM |
7651 | if (gcse_file) |
7652 | { | |
589005ff | 7653 | fprintf (gcse_file, |
0b17ab2f | 7654 | "STORE_MOTION delete insn in BB %d:\n ", bb->index); |
a13d4ebf | 7655 | print_inline_rtx (gcse_file, del, 6); |
8e42ace1 | 7656 | fprintf (gcse_file, "\nSTORE MOTION replaced with insn:\n "); |
a13d4ebf | 7657 | print_inline_rtx (gcse_file, insn, 6); |
8e42ace1 | 7658 | fprintf (gcse_file, "\n"); |
a13d4ebf | 7659 | } |
589005ff | 7660 | |
49ce134f | 7661 | delete_insn (del); |
a13d4ebf AM |
7662 | } |
7663 | ||
7664 | ||
7665 | /* Delete a store, but copy the value that would have been stored into | |
7666 | the reaching_reg for later storing. */ | |
7667 | ||
7668 | static void | |
7669 | delete_store (expr, bb) | |
7670 | struct ls_expr * expr; | |
e2d2ed72 | 7671 | basic_block bb; |
a13d4ebf AM |
7672 | { |
7673 | rtx reg, i, del; | |
7674 | ||
7675 | if (expr->reaching_reg == NULL_RTX) | |
7676 | expr->reaching_reg = gen_reg_rtx (GET_MODE (expr->pattern)); | |
a13d4ebf | 7677 | |
a13d4ebf | 7678 | reg = expr->reaching_reg; |
589005ff | 7679 | |
a13d4ebf AM |
7680 | for (i = AVAIL_STORE_LIST (expr); i; i = XEXP (i, 1)) |
7681 | { | |
7682 | del = XEXP (i, 0); | |
e2d2ed72 | 7683 | if (BLOCK_FOR_INSN (del) == bb) |
a13d4ebf | 7684 | { |
589005ff | 7685 | /* We know there is only one since we deleted redundant |
a13d4ebf AM |
7686 | ones during the available computation. */ |
7687 | replace_store_insn (reg, del, bb); | |
7688 | break; | |
7689 | } | |
7690 | } | |
7691 | } | |
7692 | ||
7693 | /* Free memory used by store motion. */ | |
7694 | ||
589005ff | 7695 | static void |
a13d4ebf AM |
7696 | free_store_memory () |
7697 | { | |
7698 | free_ldst_mems (); | |
589005ff | 7699 | |
a13d4ebf | 7700 | if (ae_gen) |
5a660bff | 7701 | sbitmap_vector_free (ae_gen); |
a13d4ebf | 7702 | if (ae_kill) |
5a660bff | 7703 | sbitmap_vector_free (ae_kill); |
a13d4ebf | 7704 | if (transp) |
5a660bff | 7705 | sbitmap_vector_free (transp); |
a13d4ebf | 7706 | if (st_antloc) |
5a660bff | 7707 | sbitmap_vector_free (st_antloc); |
a13d4ebf | 7708 | if (pre_insert_map) |
5a660bff | 7709 | sbitmap_vector_free (pre_insert_map); |
a13d4ebf | 7710 | if (pre_delete_map) |
5a660bff | 7711 | sbitmap_vector_free (pre_delete_map); |
aaa4ca30 AJ |
7712 | if (reg_set_in_block) |
7713 | sbitmap_vector_free (reg_set_in_block); | |
589005ff | 7714 | |
a13d4ebf AM |
7715 | ae_gen = ae_kill = transp = st_antloc = NULL; |
7716 | pre_insert_map = pre_delete_map = reg_set_in_block = NULL; | |
7717 | } | |
7718 | ||
7719 | /* Perform store motion. Much like gcse, except we move expressions the | |
7720 | other way by looking at the flowgraph in reverse. */ | |
7721 | ||
7722 | static void | |
7723 | store_motion () | |
7724 | { | |
e0082a72 | 7725 | basic_block bb; |
0b17ab2f | 7726 | int x; |
a13d4ebf | 7727 | struct ls_expr * ptr; |
adfcce61 | 7728 | int update_flow = 0; |
aaa4ca30 | 7729 | |
a13d4ebf AM |
7730 | if (gcse_file) |
7731 | { | |
7732 | fprintf (gcse_file, "before store motion\n"); | |
7733 | print_rtl (gcse_file, get_insns ()); | |
7734 | } | |
7735 | ||
7736 | ||
7737 | init_alias_analysis (); | |
aaa4ca30 | 7738 | |
47a3dae1 | 7739 | /* Find all the available and anticipatable stores. */ |
a13d4ebf AM |
7740 | num_stores = compute_store_table (); |
7741 | if (num_stores == 0) | |
7742 | { | |
aaa4ca30 | 7743 | sbitmap_vector_free (reg_set_in_block); |
a13d4ebf AM |
7744 | end_alias_analysis (); |
7745 | return; | |
7746 | } | |
7747 | ||
47a3dae1 | 7748 | /* Now compute kill & transp vectors. */ |
a13d4ebf | 7749 | build_store_vectors (); |
47a3dae1 | 7750 | add_noreturn_fake_exit_edges (); |
a13d4ebf | 7751 | |
589005ff KH |
7752 | edge_list = pre_edge_rev_lcm (gcse_file, num_stores, transp, ae_gen, |
7753 | st_antloc, ae_kill, &pre_insert_map, | |
a13d4ebf AM |
7754 | &pre_delete_map); |
7755 | ||
7756 | /* Now we want to insert the new stores which are going to be needed. */ | |
7757 | for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr)) | |
7758 | { | |
e0082a72 ZD |
7759 | FOR_EACH_BB (bb) |
7760 | if (TEST_BIT (pre_delete_map[bb->index], ptr->index)) | |
7761 | delete_store (ptr, bb); | |
a13d4ebf | 7762 | |
0b17ab2f RH |
7763 | for (x = 0; x < NUM_EDGES (edge_list); x++) |
7764 | if (TEST_BIT (pre_insert_map[x], ptr->index)) | |
7765 | update_flow |= insert_store (ptr, INDEX_EDGE (edge_list, x)); | |
a13d4ebf AM |
7766 | } |
7767 | ||
7768 | if (update_flow) | |
7769 | commit_edge_insertions (); | |
aaa4ca30 | 7770 | |
a13d4ebf AM |
7771 | free_store_memory (); |
7772 | free_edge_list (edge_list); | |
7773 | remove_fake_edges (); | |
7774 | end_alias_analysis (); | |
7775 | } | |
e2500fed | 7776 | |
a0134312 RS |
7777 | \f |
7778 | /* Entry point for jump bypassing optimization pass. */ | |
7779 | ||
7780 | int | |
7781 | bypass_jumps (file) | |
7782 | FILE *file; | |
7783 | { | |
7784 | int changed; | |
7785 | ||
7786 | /* We do not construct an accurate cfg in functions which call | |
7787 | setjmp, so just punt to be safe. */ | |
7788 | if (current_function_calls_setjmp) | |
7789 | return 0; | |
7790 | ||
7791 | /* For calling dump_foo fns from gdb. */ | |
7792 | debug_stderr = stderr; | |
7793 | gcse_file = file; | |
7794 | ||
7795 | /* Identify the basic block information for this function, including | |
7796 | successors and predecessors. */ | |
7797 | max_gcse_regno = max_reg_num (); | |
7798 | ||
7799 | if (file) | |
7800 | dump_flow_info (file); | |
7801 | ||
7802 | /* Return if there's nothing to do. */ | |
7803 | if (n_basic_blocks <= 1) | |
7804 | return 0; | |
7805 | ||
7806 | /* Trying to perform global optimizations on flow graphs which have | |
7807 | a high connectivity will take a long time and is unlikely to be | |
7808 | particularly useful. | |
7809 | ||
7810 | In normal circumstances a cfg should have about twice as many edges | |
7811 | as blocks. But we do not want to punish small functions which have | |
7812 | a couple switch statements. So we require a relatively large number | |
7813 | of basic blocks and the ratio of edges to blocks to be high. */ | |
7814 | if (n_basic_blocks > 1000 && n_edges / n_basic_blocks >= 20) | |
7815 | { | |
7816 | if (warn_disabled_optimization) | |
7817 | warning ("BYPASS disabled: %d > 1000 basic blocks and %d >= 20 edges/basic block", | |
7818 | n_basic_blocks, n_edges / n_basic_blocks); | |
7819 | return 0; | |
7820 | } | |
7821 | ||
7822 | /* If allocating memory for the cprop bitmap would take up too much | |
7823 | storage it's better just to disable the optimization. */ | |
7824 | if ((n_basic_blocks | |
7825 | * SBITMAP_SET_SIZE (max_gcse_regno) | |
7826 | * sizeof (SBITMAP_ELT_TYPE)) > MAX_GCSE_MEMORY) | |
7827 | { | |
7828 | if (warn_disabled_optimization) | |
7829 | warning ("GCSE disabled: %d basic blocks and %d registers", | |
7830 | n_basic_blocks, max_gcse_regno); | |
7831 | ||
7832 | return 0; | |
7833 | } | |
7834 | ||
7835 | /* See what modes support reg/reg copy operations. */ | |
7836 | if (! can_copy_init_p) | |
7837 | { | |
7838 | compute_can_copy (); | |
7839 | can_copy_init_p = 1; | |
7840 | } | |
7841 | ||
7842 | gcc_obstack_init (&gcse_obstack); | |
7843 | bytes_used = 0; | |
7844 | ||
7845 | /* We need alias. */ | |
7846 | init_alias_analysis (); | |
7847 | ||
7848 | /* Record where pseudo-registers are set. This data is kept accurate | |
7849 | during each pass. ??? We could also record hard-reg information here | |
7850 | [since it's unchanging], however it is currently done during hash table | |
7851 | computation. | |
7852 | ||
7853 | It may be tempting to compute MEM set information here too, but MEM sets | |
7854 | will be subject to code motion one day and thus we need to compute | |
7855 | information about memory sets when we build the hash tables. */ | |
7856 | ||
7857 | alloc_reg_set_mem (max_gcse_regno); | |
7858 | compute_sets (get_insns ()); | |
7859 | ||
7860 | max_gcse_regno = max_reg_num (); | |
7861 | alloc_gcse_mem (get_insns ()); | |
7862 | changed = one_cprop_pass (1, 1, 1); | |
7863 | free_gcse_mem (); | |
7864 | ||
7865 | if (file) | |
7866 | { | |
7867 | fprintf (file, "BYPASS of %s: %d basic blocks, ", | |
7868 | current_function_name, n_basic_blocks); | |
7869 | fprintf (file, "%d bytes\n\n", bytes_used); | |
7870 | } | |
7871 | ||
7872 | obstack_free (&gcse_obstack, NULL); | |
7873 | free_reg_set_mem (); | |
7874 | ||
7875 | /* We are finished with alias. */ | |
7876 | end_alias_analysis (); | |
7877 | allocate_reg_info (max_reg_num (), FALSE, FALSE); | |
7878 | ||
7879 | return changed; | |
7880 | } | |
7881 | ||
e2500fed | 7882 | #include "gt-gcse.h" |