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c9e93168 | 1 | /* Tail merging for gimple. |
aeee4812 | 2 | Copyright (C) 2011-2023 Free Software Foundation, Inc. |
c9e93168 TV |
3 | Contributed by Tom de Vries (tom@codesourcery.com) |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | /* Pass overview. | |
22 | ||
23 | ||
24 | MOTIVATIONAL EXAMPLE | |
25 | ||
26 | gimple representation of gcc/testsuite/gcc.dg/pr43864.c at | |
27 | ||
28 | hprofStartupp (charD.1 * outputFileNameD.2600, charD.1 * ctxD.2601) | |
29 | { | |
30 | struct FILED.1638 * fpD.2605; | |
31 | charD.1 fileNameD.2604[1000]; | |
32 | intD.0 D.3915; | |
33 | const charD.1 * restrict outputFileName.0D.3914; | |
34 | ||
35 | # BLOCK 2 freq:10000 | |
36 | # PRED: ENTRY [100.0%] (fallthru,exec) | |
37 | # PT = nonlocal { D.3926 } (restr) | |
38 | outputFileName.0D.3914_3 | |
39 | = (const charD.1 * restrict) outputFileNameD.2600_2(D); | |
40 | # .MEMD.3923_13 = VDEF <.MEMD.3923_12(D)> | |
41 | # USE = nonlocal null { fileNameD.2604 D.3926 } (restr) | |
42 | # CLB = nonlocal null { fileNameD.2604 D.3926 } (restr) | |
43 | sprintfD.759 (&fileNameD.2604, outputFileName.0D.3914_3); | |
44 | # .MEMD.3923_14 = VDEF <.MEMD.3923_13> | |
45 | # USE = nonlocal null { fileNameD.2604 D.3926 } (restr) | |
46 | # CLB = nonlocal null { fileNameD.2604 D.3926 } (restr) | |
47 | D.3915_4 = accessD.2606 (&fileNameD.2604, 1); | |
48 | if (D.3915_4 == 0) | |
49 | goto <bb 3>; | |
50 | else | |
51 | goto <bb 4>; | |
52 | # SUCC: 3 [10.0%] (true,exec) 4 [90.0%] (false,exec) | |
53 | ||
54 | # BLOCK 3 freq:1000 | |
55 | # PRED: 2 [10.0%] (true,exec) | |
56 | # .MEMD.3923_15 = VDEF <.MEMD.3923_14> | |
57 | # USE = nonlocal null { fileNameD.2604 D.3926 } (restr) | |
58 | # CLB = nonlocal null { fileNameD.2604 D.3926 } (restr) | |
59 | freeD.898 (ctxD.2601_5(D)); | |
60 | goto <bb 7>; | |
61 | # SUCC: 7 [100.0%] (fallthru,exec) | |
62 | ||
63 | # BLOCK 4 freq:9000 | |
64 | # PRED: 2 [90.0%] (false,exec) | |
65 | # .MEMD.3923_16 = VDEF <.MEMD.3923_14> | |
66 | # PT = nonlocal escaped | |
67 | # USE = nonlocal null { fileNameD.2604 D.3926 } (restr) | |
68 | # CLB = nonlocal null { fileNameD.2604 D.3926 } (restr) | |
69 | fpD.2605_8 = fopenD.1805 (&fileNameD.2604[0], 0B); | |
70 | if (fpD.2605_8 == 0B) | |
71 | goto <bb 5>; | |
72 | else | |
73 | goto <bb 6>; | |
74 | # SUCC: 5 [1.9%] (true,exec) 6 [98.1%] (false,exec) | |
75 | ||
76 | # BLOCK 5 freq:173 | |
77 | # PRED: 4 [1.9%] (true,exec) | |
78 | # .MEMD.3923_17 = VDEF <.MEMD.3923_16> | |
79 | # USE = nonlocal null { fileNameD.2604 D.3926 } (restr) | |
80 | # CLB = nonlocal null { fileNameD.2604 D.3926 } (restr) | |
81 | freeD.898 (ctxD.2601_5(D)); | |
82 | goto <bb 7>; | |
83 | # SUCC: 7 [100.0%] (fallthru,exec) | |
84 | ||
85 | # BLOCK 6 freq:8827 | |
86 | # PRED: 4 [98.1%] (false,exec) | |
87 | # .MEMD.3923_18 = VDEF <.MEMD.3923_16> | |
88 | # USE = nonlocal null { fileNameD.2604 D.3926 } (restr) | |
89 | # CLB = nonlocal null { fileNameD.2604 D.3926 } (restr) | |
90 | fooD.2599 (outputFileNameD.2600_2(D), fpD.2605_8); | |
91 | # SUCC: 7 [100.0%] (fallthru,exec) | |
92 | ||
93 | # BLOCK 7 freq:10000 | |
94 | # PRED: 3 [100.0%] (fallthru,exec) 5 [100.0%] (fallthru,exec) | |
daf347dd | 95 | 6 [100.0%] (fallthru,exec) |
c9e93168 TV |
96 | # PT = nonlocal null |
97 | ||
98 | # ctxD.2601_1 = PHI <0B(3), 0B(5), ctxD.2601_5(D)(6)> | |
99 | # .MEMD.3923_11 = PHI <.MEMD.3923_15(3), .MEMD.3923_17(5), | |
daf347dd | 100 | .MEMD.3923_18(6)> |
c9e93168 TV |
101 | # VUSE <.MEMD.3923_11> |
102 | return ctxD.2601_1; | |
103 | # SUCC: EXIT [100.0%] | |
104 | } | |
105 | ||
106 | bb 3 and bb 5 can be merged. The blocks have different predecessors, but the | |
107 | same successors, and the same operations. | |
108 | ||
109 | ||
110 | CONTEXT | |
111 | ||
112 | A technique called tail merging (or cross jumping) can fix the example | |
113 | above. For a block, we look for common code at the end (the tail) of the | |
114 | predecessor blocks, and insert jumps from one block to the other. | |
115 | The example is a special case for tail merging, in that 2 whole blocks | |
116 | can be merged, rather than just the end parts of it. | |
117 | We currently only focus on whole block merging, so in that sense | |
118 | calling this pass tail merge is a bit of a misnomer. | |
119 | ||
120 | We distinguish 2 kinds of situations in which blocks can be merged: | |
121 | - same operations, same predecessors. The successor edges coming from one | |
122 | block are redirected to come from the other block. | |
123 | - same operations, same successors. The predecessor edges entering one block | |
124 | are redirected to enter the other block. Note that this operation might | |
125 | involve introducing phi operations. | |
126 | ||
127 | For efficient implementation, we would like to value numbers the blocks, and | |
128 | have a comparison operator that tells us whether the blocks are equal. | |
129 | Besides being runtime efficient, block value numbering should also abstract | |
130 | from irrelevant differences in order of operations, much like normal value | |
131 | numbering abstracts from irrelevant order of operations. | |
132 | ||
133 | For the first situation (same_operations, same predecessors), normal value | |
134 | numbering fits well. We can calculate a block value number based on the | |
135 | value numbers of the defs and vdefs. | |
136 | ||
137 | For the second situation (same operations, same successors), this approach | |
138 | doesn't work so well. We can illustrate this using the example. The calls | |
139 | to free use different vdefs: MEMD.3923_16 and MEMD.3923_14, and these will | |
140 | remain different in value numbering, since they represent different memory | |
141 | states. So the resulting vdefs of the frees will be different in value | |
142 | numbering, so the block value numbers will be different. | |
143 | ||
144 | The reason why we call the blocks equal is not because they define the same | |
145 | values, but because uses in the blocks use (possibly different) defs in the | |
146 | same way. To be able to detect this efficiently, we need to do some kind of | |
147 | reverse value numbering, meaning number the uses rather than the defs, and | |
148 | calculate a block value number based on the value number of the uses. | |
149 | Ideally, a block comparison operator will also indicate which phis are needed | |
150 | to merge the blocks. | |
151 | ||
152 | For the moment, we don't do block value numbering, but we do insn-by-insn | |
153 | matching, using scc value numbers to match operations with results, and | |
154 | structural comparison otherwise, while ignoring vop mismatches. | |
155 | ||
156 | ||
157 | IMPLEMENTATION | |
158 | ||
159 | 1. The pass first determines all groups of blocks with the same successor | |
160 | blocks. | |
161 | 2. Within each group, it tries to determine clusters of equal basic blocks. | |
162 | 3. The clusters are applied. | |
163 | 4. The same successor groups are updated. | |
164 | 5. This process is repeated from 2 onwards, until no more changes. | |
165 | ||
166 | ||
167 | LIMITATIONS/TODO | |
168 | ||
169 | - block only | |
170 | - handles only 'same operations, same successors'. | |
171 | It handles same predecessors as a special subcase though. | |
172 | - does not implement the reverse value numbering and block value numbering. | |
173 | - improve memory allocation: use garbage collected memory, obstacks, | |
174 | allocpools where appropriate. | |
175 | - no insertion of gimple_reg phis, We only introduce vop-phis. | |
176 | - handle blocks with gimple_reg phi_nodes. | |
177 | ||
178 | ||
8dee4479 TV |
179 | PASS PLACEMENT |
180 | This 'pass' is not a stand-alone gimple pass, but runs as part of | |
181 | pass_pre, in order to share the value numbering. | |
182 | ||
183 | ||
c9e93168 TV |
184 | SWITCHES |
185 | ||
186 | - ftree-tail-merge. On at -O2. We may have to enable it only at -Os. */ | |
187 | ||
188 | #include "config.h" | |
189 | #include "system.h" | |
190 | #include "coretypes.h" | |
c7131fb2 | 191 | #include "backend.h" |
c9e93168 | 192 | #include "tree.h" |
c7131fb2 | 193 | #include "gimple.h" |
957060b5 AM |
194 | #include "cfghooks.h" |
195 | #include "tree-pass.h" | |
c7131fb2 | 196 | #include "ssa.h" |
40e23961 | 197 | #include "fold-const.h" |
d8a2d370 | 198 | #include "trans-mem.h" |
60393bbc AM |
199 | #include "cfganal.h" |
200 | #include "cfgcleanup.h" | |
5be5c238 | 201 | #include "gimple-iterator.h" |
442b4905 | 202 | #include "tree-cfg.h" |
442b4905 | 203 | #include "tree-into-ssa.h" |
c9e93168 | 204 | #include "tree-ssa-sccvn.h" |
a9e0d843 | 205 | #include "cfgloop.h" |
27947670 | 206 | #include "tree-eh.h" |
7581ce9a | 207 | #include "tree-cfgcleanup.h" |
7ee2468b | 208 | |
be086ff5 TV |
209 | const int ignore_edge_flags = EDGE_DFS_BACK | EDGE_EXECUTABLE; |
210 | ||
c9e93168 TV |
211 | /* Describes a group of bbs with the same successors. The successor bbs are |
212 | cached in succs, and the successor edge flags are cached in succ_flags. | |
f0cbb0af | 213 | If a bb has the EDGE_TRUE/FALSE_VALUE flags swapped compared to succ_flags, |
c9e93168 TV |
214 | it's marked in inverse. |
215 | Additionally, the hash value for the struct is cached in hashval, and | |
216 | in_worklist indicates whether it's currently part of worklist. */ | |
217 | ||
526ceb68 | 218 | struct same_succ : pointer_hash <same_succ> |
c9e93168 TV |
219 | { |
220 | /* The bbs that have the same successor bbs. */ | |
221 | bitmap bbs; | |
222 | /* The successor bbs. */ | |
223 | bitmap succs; | |
224 | /* Indicates whether the EDGE_TRUE/FALSE_VALUEs of succ_flags are swapped for | |
225 | bb. */ | |
226 | bitmap inverse; | |
227 | /* The edge flags for each of the successor bbs. */ | |
9771b263 | 228 | vec<int> succ_flags; |
c9e93168 TV |
229 | /* Indicates whether the struct is currently in the worklist. */ |
230 | bool in_worklist; | |
231 | /* The hash value of the struct. */ | |
232 | hashval_t hashval; | |
5deac340 RG |
233 | |
234 | /* hash_table support. */ | |
526ceb68 TS |
235 | static inline hashval_t hash (const same_succ *); |
236 | static int equal (const same_succ *, const same_succ *); | |
237 | static void remove (same_succ *); | |
c9e93168 | 238 | }; |
c9e93168 | 239 | |
5deac340 RG |
240 | /* hash routine for hash_table support, returns hashval of E. */ |
241 | ||
242 | inline hashval_t | |
526ceb68 | 243 | same_succ::hash (const same_succ *e) |
5deac340 RG |
244 | { |
245 | return e->hashval; | |
246 | } | |
247 | ||
c9e93168 TV |
248 | /* A group of bbs where 1 bb from bbs can replace the other bbs. */ |
249 | ||
526ceb68 | 250 | struct bb_cluster |
c9e93168 TV |
251 | { |
252 | /* The bbs in the cluster. */ | |
253 | bitmap bbs; | |
254 | /* The preds of the bbs in the cluster. */ | |
255 | bitmap preds; | |
256 | /* Index in all_clusters vector. */ | |
257 | int index; | |
258 | /* The bb to replace the cluster with. */ | |
259 | basic_block rep_bb; | |
260 | }; | |
c9e93168 TV |
261 | |
262 | /* Per bb-info. */ | |
263 | ||
264 | struct aux_bb_info | |
265 | { | |
266 | /* The number of non-debug statements in the bb. */ | |
267 | int size; | |
268 | /* The same_succ that this bb is a member of. */ | |
526ceb68 | 269 | same_succ *bb_same_succ; |
c9e93168 | 270 | /* The cluster that this bb is a member of. */ |
526ceb68 | 271 | bb_cluster *cluster; |
c9e93168 TV |
272 | /* The vop state at the exit of a bb. This is shortlived data, used to |
273 | communicate data between update_block_by and update_vuses. */ | |
274 | tree vop_at_exit; | |
275 | /* The bb that either contains or is dominated by the dependencies of the | |
276 | bb. */ | |
277 | basic_block dep_bb; | |
278 | }; | |
279 | ||
280 | /* Macros to access the fields of struct aux_bb_info. */ | |
281 | ||
282 | #define BB_SIZE(bb) (((struct aux_bb_info *)bb->aux)->size) | |
283 | #define BB_SAME_SUCC(bb) (((struct aux_bb_info *)bb->aux)->bb_same_succ) | |
284 | #define BB_CLUSTER(bb) (((struct aux_bb_info *)bb->aux)->cluster) | |
285 | #define BB_VOP_AT_EXIT(bb) (((struct aux_bb_info *)bb->aux)->vop_at_exit) | |
286 | #define BB_DEP_BB(bb) (((struct aux_bb_info *)bb->aux)->dep_bb) | |
287 | ||
86c8eea6 RB |
288 | /* Valueization helper querying the VN lattice. */ |
289 | ||
290 | static tree | |
291 | tail_merge_valueize (tree name) | |
292 | { | |
293 | if (TREE_CODE (name) == SSA_NAME | |
294 | && has_VN_INFO (name)) | |
295 | { | |
296 | tree tem = VN_INFO (name)->valnum; | |
297 | if (tem != VN_TOP) | |
298 | return tem; | |
299 | } | |
300 | return name; | |
301 | } | |
302 | ||
b2b2f160 TV |
303 | /* Returns true if the only effect a statement STMT has, is to define locally |
304 | used SSA_NAMEs. */ | |
305 | ||
306 | static bool | |
355fe088 | 307 | stmt_local_def (gimple *stmt) |
b2b2f160 TV |
308 | { |
309 | basic_block bb, def_bb; | |
310 | imm_use_iterator iter; | |
311 | use_operand_p use_p; | |
312 | tree val; | |
313 | def_operand_p def_p; | |
314 | ||
12d3031b RB |
315 | if (gimple_vdef (stmt) != NULL_TREE |
316 | || gimple_has_side_effects (stmt) | |
8024d4b6 | 317 | || gimple_could_trap_p_1 (stmt, false, false) |
494e7532 | 318 | || gimple_vuse (stmt) != NULL_TREE |
e53b6e56 | 319 | /* Copied from tree-ssa-ifcombine.cc:bb_no_side_effects_p(): |
494e7532 TV |
320 | const calls don't match any of the above, yet they could |
321 | still have some side-effects - they could contain | |
322 | gimple_could_trap_p statements, like floating point | |
323 | exceptions or integer division by zero. See PR70586. | |
324 | FIXME: perhaps gimple_has_side_effects or gimple_could_trap_p | |
325 | should handle this. */ | |
326 | || is_gimple_call (stmt)) | |
b2b2f160 TV |
327 | return false; |
328 | ||
329 | def_p = SINGLE_SSA_DEF_OPERAND (stmt, SSA_OP_DEF); | |
330 | if (def_p == NULL) | |
331 | return false; | |
332 | ||
333 | val = DEF_FROM_PTR (def_p); | |
334 | if (val == NULL_TREE || TREE_CODE (val) != SSA_NAME) | |
335 | return false; | |
336 | ||
337 | def_bb = gimple_bb (stmt); | |
338 | ||
339 | FOR_EACH_IMM_USE_FAST (use_p, iter, val) | |
340 | { | |
341 | if (is_gimple_debug (USE_STMT (use_p))) | |
342 | continue; | |
343 | bb = gimple_bb (USE_STMT (use_p)); | |
344 | if (bb == def_bb) | |
345 | continue; | |
346 | ||
347 | if (gimple_code (USE_STMT (use_p)) == GIMPLE_PHI | |
348 | && EDGE_PRED (bb, PHI_ARG_INDEX_FROM_USE (use_p))->src == def_bb) | |
349 | continue; | |
350 | ||
351 | return false; | |
352 | } | |
353 | ||
354 | return true; | |
355 | } | |
356 | ||
357 | /* Let GSI skip forwards over local defs. */ | |
358 | ||
359 | static void | |
360 | gsi_advance_fw_nondebug_nonlocal (gimple_stmt_iterator *gsi) | |
361 | { | |
355fe088 | 362 | gimple *stmt; |
b2b2f160 TV |
363 | |
364 | while (true) | |
365 | { | |
366 | if (gsi_end_p (*gsi)) | |
367 | return; | |
368 | stmt = gsi_stmt (*gsi); | |
369 | if (!stmt_local_def (stmt)) | |
370 | return; | |
21c0a521 | 371 | gsi_next_nondebug (gsi); |
b2b2f160 TV |
372 | } |
373 | } | |
374 | ||
c9e93168 TV |
375 | /* VAL1 and VAL2 are either: |
376 | - uses in BB1 and BB2, or | |
377 | - phi alternatives for BB1 and BB2. | |
378 | Return true if the uses have the same gvn value. */ | |
379 | ||
380 | static bool | |
381 | gvn_uses_equal (tree val1, tree val2) | |
382 | { | |
383 | gcc_checking_assert (val1 != NULL_TREE && val2 != NULL_TREE); | |
384 | ||
385 | if (val1 == val2) | |
386 | return true; | |
387 | ||
86c8eea6 | 388 | if (tail_merge_valueize (val1) != tail_merge_valueize (val2)) |
c9e93168 TV |
389 | return false; |
390 | ||
391 | return ((TREE_CODE (val1) == SSA_NAME || CONSTANT_CLASS_P (val1)) | |
392 | && (TREE_CODE (val2) == SSA_NAME || CONSTANT_CLASS_P (val2))); | |
393 | } | |
394 | ||
395 | /* Prints E to FILE. */ | |
396 | ||
397 | static void | |
526ceb68 | 398 | same_succ_print (FILE *file, const same_succ *e) |
c9e93168 TV |
399 | { |
400 | unsigned int i; | |
401 | bitmap_print (file, e->bbs, "bbs:", "\n"); | |
402 | bitmap_print (file, e->succs, "succs:", "\n"); | |
403 | bitmap_print (file, e->inverse, "inverse:", "\n"); | |
404 | fprintf (file, "flags:"); | |
9771b263 DN |
405 | for (i = 0; i < e->succ_flags.length (); ++i) |
406 | fprintf (file, " %x", e->succ_flags[i]); | |
c9e93168 TV |
407 | fprintf (file, "\n"); |
408 | } | |
409 | ||
410 | /* Prints same_succ VE to VFILE. */ | |
411 | ||
0823efed | 412 | inline int |
526ceb68 | 413 | ssa_same_succ_print_traverse (same_succ **pe, FILE *file) |
c9e93168 | 414 | { |
526ceb68 | 415 | const same_succ *e = *pe; |
c9e93168 TV |
416 | same_succ_print (file, e); |
417 | return 1; | |
418 | } | |
419 | ||
420 | /* Update BB_DEP_BB (USE_BB), given a use of VAL in USE_BB. */ | |
421 | ||
422 | static void | |
423 | update_dep_bb (basic_block use_bb, tree val) | |
424 | { | |
425 | basic_block dep_bb; | |
426 | ||
427 | /* Not a dep. */ | |
428 | if (TREE_CODE (val) != SSA_NAME) | |
429 | return; | |
430 | ||
431 | /* Skip use of global def. */ | |
432 | if (SSA_NAME_IS_DEFAULT_DEF (val)) | |
433 | return; | |
434 | ||
435 | /* Skip use of local def. */ | |
436 | dep_bb = gimple_bb (SSA_NAME_DEF_STMT (val)); | |
437 | if (dep_bb == use_bb) | |
438 | return; | |
439 | ||
440 | if (BB_DEP_BB (use_bb) == NULL | |
441 | || dominated_by_p (CDI_DOMINATORS, dep_bb, BB_DEP_BB (use_bb))) | |
442 | BB_DEP_BB (use_bb) = dep_bb; | |
443 | } | |
444 | ||
445 | /* Update BB_DEP_BB, given the dependencies in STMT. */ | |
446 | ||
447 | static void | |
355fe088 | 448 | stmt_update_dep_bb (gimple *stmt) |
c9e93168 TV |
449 | { |
450 | ssa_op_iter iter; | |
451 | use_operand_p use; | |
452 | ||
453 | FOR_EACH_SSA_USE_OPERAND (use, stmt, iter, SSA_OP_USE) | |
454 | update_dep_bb (gimple_bb (stmt), USE_FROM_PTR (use)); | |
455 | } | |
456 | ||
c9e93168 TV |
457 | /* Calculates hash value for same_succ VE. */ |
458 | ||
5deac340 | 459 | static hashval_t |
526ceb68 | 460 | same_succ_hash (const same_succ *e) |
c9e93168 | 461 | { |
bb7e83fc | 462 | inchash::hash hstate (bitmap_hash (e->succs)); |
c9e93168 TV |
463 | int flags; |
464 | unsigned int i; | |
465 | unsigned int first = bitmap_first_set_bit (e->bbs); | |
06e28de2 | 466 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, first); |
c9e93168 | 467 | int size = 0; |
355fe088 | 468 | gimple *stmt; |
c9e93168 TV |
469 | tree arg; |
470 | unsigned int s; | |
471 | bitmap_iterator bs; | |
472 | ||
538dd0b7 | 473 | for (gimple_stmt_iterator gsi = gsi_start_nondebug_bb (bb); |
c9e93168 TV |
474 | !gsi_end_p (gsi); gsi_next_nondebug (&gsi)) |
475 | { | |
476 | stmt = gsi_stmt (gsi); | |
477 | stmt_update_dep_bb (stmt); | |
b2b2f160 | 478 | if (stmt_local_def (stmt)) |
c9e93168 TV |
479 | continue; |
480 | size++; | |
481 | ||
bb7e83fc | 482 | hstate.add_int (gimple_code (stmt)); |
c9e93168 | 483 | if (is_gimple_assign (stmt)) |
bb7e83fc | 484 | hstate.add_int (gimple_assign_rhs_code (stmt)); |
c9e93168 TV |
485 | if (!is_gimple_call (stmt)) |
486 | continue; | |
487 | if (gimple_call_internal_p (stmt)) | |
daf347dd | 488 | hstate.add_int (gimple_call_internal_fn (stmt)); |
c9e93168 | 489 | else |
51d2abeb | 490 | { |
bb7e83fc | 491 | inchash::add_expr (gimple_call_fn (stmt), hstate); |
51d2abeb | 492 | if (gimple_call_chain (stmt)) |
bb7e83fc | 493 | inchash::add_expr (gimple_call_chain (stmt), hstate); |
51d2abeb | 494 | } |
c9e93168 TV |
495 | for (i = 0; i < gimple_call_num_args (stmt); i++) |
496 | { | |
497 | arg = gimple_call_arg (stmt, i); | |
86c8eea6 | 498 | arg = tail_merge_valueize (arg); |
bb7e83fc | 499 | inchash::add_expr (arg, hstate); |
c9e93168 TV |
500 | } |
501 | } | |
502 | ||
bb7e83fc | 503 | hstate.add_int (size); |
c9e93168 TV |
504 | BB_SIZE (bb) = size; |
505 | ||
4752be46 TV |
506 | hstate.add_int (bb->loop_father->num); |
507 | ||
9771b263 | 508 | for (i = 0; i < e->succ_flags.length (); ++i) |
c9e93168 | 509 | { |
9771b263 | 510 | flags = e->succ_flags[i]; |
c9e93168 | 511 | flags = flags & ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); |
bb7e83fc | 512 | hstate.add_int (flags); |
c9e93168 TV |
513 | } |
514 | ||
515 | EXECUTE_IF_SET_IN_BITMAP (e->succs, 0, s, bs) | |
516 | { | |
06e28de2 | 517 | int n = find_edge (bb, BASIC_BLOCK_FOR_FN (cfun, s))->dest_idx; |
538dd0b7 DM |
518 | for (gphi_iterator gsi = gsi_start_phis (BASIC_BLOCK_FOR_FN (cfun, s)); |
519 | !gsi_end_p (gsi); | |
c9e93168 TV |
520 | gsi_next (&gsi)) |
521 | { | |
538dd0b7 | 522 | gphi *phi = gsi.phi (); |
c9e93168 TV |
523 | tree lhs = gimple_phi_result (phi); |
524 | tree val = gimple_phi_arg_def (phi, n); | |
525 | ||
ea057359 | 526 | if (virtual_operand_p (lhs)) |
c9e93168 TV |
527 | continue; |
528 | update_dep_bb (bb, val); | |
529 | } | |
530 | } | |
531 | ||
bb7e83fc | 532 | return hstate.end (); |
c9e93168 TV |
533 | } |
534 | ||
535 | /* Returns true if E1 and E2 have 2 successors, and if the successor flags | |
536 | are inverse for the EDGE_TRUE_VALUE and EDGE_FALSE_VALUE flags, and equal for | |
537 | the other edge flags. */ | |
538 | ||
539 | static bool | |
526ceb68 | 540 | inverse_flags (const same_succ *e1, const same_succ *e2) |
c9e93168 TV |
541 | { |
542 | int f1a, f1b, f2a, f2b; | |
543 | int mask = ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); | |
544 | ||
9771b263 | 545 | if (e1->succ_flags.length () != 2) |
c9e93168 TV |
546 | return false; |
547 | ||
9771b263 DN |
548 | f1a = e1->succ_flags[0]; |
549 | f1b = e1->succ_flags[1]; | |
550 | f2a = e2->succ_flags[0]; | |
551 | f2b = e2->succ_flags[1]; | |
c9e93168 TV |
552 | |
553 | if (f1a == f2a && f1b == f2b) | |
554 | return false; | |
555 | ||
556 | return (f1a & mask) == (f2a & mask) && (f1b & mask) == (f2b & mask); | |
557 | } | |
558 | ||
5deac340 | 559 | /* Compares SAME_SUCCs E1 and E2. */ |
c9e93168 | 560 | |
0823efed | 561 | int |
526ceb68 | 562 | same_succ::equal (const same_succ *e1, const same_succ *e2) |
c9e93168 | 563 | { |
c9e93168 TV |
564 | unsigned int i, first1, first2; |
565 | gimple_stmt_iterator gsi1, gsi2; | |
355fe088 | 566 | gimple *s1, *s2; |
c9e93168 TV |
567 | basic_block bb1, bb2; |
568 | ||
3433ee35 NS |
569 | if (e1 == e2) |
570 | return 1; | |
571 | ||
c9e93168 TV |
572 | if (e1->hashval != e2->hashval) |
573 | return 0; | |
574 | ||
9771b263 | 575 | if (e1->succ_flags.length () != e2->succ_flags.length ()) |
c9e93168 TV |
576 | return 0; |
577 | ||
578 | if (!bitmap_equal_p (e1->succs, e2->succs)) | |
579 | return 0; | |
580 | ||
581 | if (!inverse_flags (e1, e2)) | |
582 | { | |
9771b263 | 583 | for (i = 0; i < e1->succ_flags.length (); ++i) |
707550e4 | 584 | if (e1->succ_flags[i] != e2->succ_flags[i]) |
c9e93168 TV |
585 | return 0; |
586 | } | |
587 | ||
588 | first1 = bitmap_first_set_bit (e1->bbs); | |
589 | first2 = bitmap_first_set_bit (e2->bbs); | |
590 | ||
06e28de2 DM |
591 | bb1 = BASIC_BLOCK_FOR_FN (cfun, first1); |
592 | bb2 = BASIC_BLOCK_FOR_FN (cfun, first2); | |
c9e93168 TV |
593 | |
594 | if (BB_SIZE (bb1) != BB_SIZE (bb2)) | |
595 | return 0; | |
596 | ||
4752be46 TV |
597 | if (bb1->loop_father != bb2->loop_father) |
598 | return 0; | |
599 | ||
c9e93168 TV |
600 | gsi1 = gsi_start_nondebug_bb (bb1); |
601 | gsi2 = gsi_start_nondebug_bb (bb2); | |
b2b2f160 TV |
602 | gsi_advance_fw_nondebug_nonlocal (&gsi1); |
603 | gsi_advance_fw_nondebug_nonlocal (&gsi2); | |
c9e93168 TV |
604 | while (!(gsi_end_p (gsi1) || gsi_end_p (gsi2))) |
605 | { | |
606 | s1 = gsi_stmt (gsi1); | |
607 | s2 = gsi_stmt (gsi2); | |
608 | if (gimple_code (s1) != gimple_code (s2)) | |
609 | return 0; | |
610 | if (is_gimple_call (s1) && !gimple_call_same_target_p (s1, s2)) | |
611 | return 0; | |
612 | gsi_next_nondebug (&gsi1); | |
613 | gsi_next_nondebug (&gsi2); | |
b2b2f160 TV |
614 | gsi_advance_fw_nondebug_nonlocal (&gsi1); |
615 | gsi_advance_fw_nondebug_nonlocal (&gsi2); | |
c9e93168 TV |
616 | } |
617 | ||
618 | return 1; | |
619 | } | |
620 | ||
621 | /* Alloc and init a new SAME_SUCC. */ | |
622 | ||
526ceb68 | 623 | static same_succ * |
c9e93168 TV |
624 | same_succ_alloc (void) |
625 | { | |
526ceb68 | 626 | same_succ *same = XNEW (struct same_succ); |
c9e93168 TV |
627 | |
628 | same->bbs = BITMAP_ALLOC (NULL); | |
629 | same->succs = BITMAP_ALLOC (NULL); | |
630 | same->inverse = BITMAP_ALLOC (NULL); | |
9771b263 | 631 | same->succ_flags.create (10); |
c9e93168 TV |
632 | same->in_worklist = false; |
633 | ||
634 | return same; | |
635 | } | |
636 | ||
5deac340 | 637 | /* Delete same_succ E. */ |
c9e93168 | 638 | |
5deac340 | 639 | void |
526ceb68 | 640 | same_succ::remove (same_succ *e) |
c9e93168 | 641 | { |
c9e93168 TV |
642 | BITMAP_FREE (e->bbs); |
643 | BITMAP_FREE (e->succs); | |
644 | BITMAP_FREE (e->inverse); | |
9771b263 | 645 | e->succ_flags.release (); |
c9e93168 | 646 | |
0823efed | 647 | XDELETE (e); |
c9e93168 TV |
648 | } |
649 | ||
650 | /* Reset same_succ SAME. */ | |
651 | ||
652 | static void | |
526ceb68 | 653 | same_succ_reset (same_succ *same) |
c9e93168 TV |
654 | { |
655 | bitmap_clear (same->bbs); | |
656 | bitmap_clear (same->succs); | |
657 | bitmap_clear (same->inverse); | |
9771b263 | 658 | same->succ_flags.truncate (0); |
c9e93168 TV |
659 | } |
660 | ||
526ceb68 | 661 | static hash_table<same_succ> *same_succ_htab; |
c9e93168 TV |
662 | |
663 | /* Array that is used to store the edge flags for a successor. */ | |
664 | ||
665 | static int *same_succ_edge_flags; | |
666 | ||
667 | /* Bitmap that is used to mark bbs that are recently deleted. */ | |
668 | ||
669 | static bitmap deleted_bbs; | |
670 | ||
671 | /* Bitmap that is used to mark predecessors of bbs that are | |
672 | deleted. */ | |
673 | ||
674 | static bitmap deleted_bb_preds; | |
675 | ||
676 | /* Prints same_succ_htab to stderr. */ | |
677 | ||
678 | extern void debug_same_succ (void); | |
679 | DEBUG_FUNCTION void | |
680 | debug_same_succ ( void) | |
681 | { | |
c203e8a7 | 682 | same_succ_htab->traverse <FILE *, ssa_same_succ_print_traverse> (stderr); |
c9e93168 TV |
683 | } |
684 | ||
c9e93168 TV |
685 | |
686 | /* Vector of bbs to process. */ | |
687 | ||
526ceb68 | 688 | static vec<same_succ *> worklist; |
c9e93168 TV |
689 | |
690 | /* Prints worklist to FILE. */ | |
691 | ||
692 | static void | |
693 | print_worklist (FILE *file) | |
694 | { | |
695 | unsigned int i; | |
9771b263 DN |
696 | for (i = 0; i < worklist.length (); ++i) |
697 | same_succ_print (file, worklist[i]); | |
c9e93168 TV |
698 | } |
699 | ||
700 | /* Adds SAME to worklist. */ | |
701 | ||
702 | static void | |
526ceb68 | 703 | add_to_worklist (same_succ *same) |
c9e93168 TV |
704 | { |
705 | if (same->in_worklist) | |
706 | return; | |
707 | ||
708 | if (bitmap_count_bits (same->bbs) < 2) | |
709 | return; | |
710 | ||
711 | same->in_worklist = true; | |
9771b263 | 712 | worklist.safe_push (same); |
c9e93168 TV |
713 | } |
714 | ||
715 | /* Add BB to same_succ_htab. */ | |
716 | ||
717 | static void | |
526ceb68 | 718 | find_same_succ_bb (basic_block bb, same_succ **same_p) |
c9e93168 TV |
719 | { |
720 | unsigned int j; | |
721 | bitmap_iterator bj; | |
526ceb68 TS |
722 | same_succ *same = *same_p; |
723 | same_succ **slot; | |
c9e93168 TV |
724 | edge_iterator ei; |
725 | edge e; | |
726 | ||
4752be46 | 727 | if (bb == NULL) |
c9e93168 TV |
728 | return; |
729 | bitmap_set_bit (same->bbs, bb->index); | |
730 | FOR_EACH_EDGE (e, ei, bb->succs) | |
731 | { | |
732 | int index = e->dest->index; | |
733 | bitmap_set_bit (same->succs, index); | |
be086ff5 | 734 | same_succ_edge_flags[index] = (e->flags & ~ignore_edge_flags); |
c9e93168 TV |
735 | } |
736 | EXECUTE_IF_SET_IN_BITMAP (same->succs, 0, j, bj) | |
9771b263 | 737 | same->succ_flags.safe_push (same_succ_edge_flags[j]); |
c9e93168 | 738 | |
5deac340 | 739 | same->hashval = same_succ_hash (same); |
c9e93168 | 740 | |
c203e8a7 | 741 | slot = same_succ_htab->find_slot_with_hash (same, same->hashval, INSERT); |
c9e93168 TV |
742 | if (*slot == NULL) |
743 | { | |
744 | *slot = same; | |
745 | BB_SAME_SUCC (bb) = same; | |
746 | add_to_worklist (same); | |
747 | *same_p = NULL; | |
748 | } | |
749 | else | |
750 | { | |
751 | bitmap_set_bit ((*slot)->bbs, bb->index); | |
752 | BB_SAME_SUCC (bb) = *slot; | |
753 | add_to_worklist (*slot); | |
754 | if (inverse_flags (same, *slot)) | |
755 | bitmap_set_bit ((*slot)->inverse, bb->index); | |
756 | same_succ_reset (same); | |
757 | } | |
758 | } | |
759 | ||
760 | /* Find bbs with same successors. */ | |
761 | ||
762 | static void | |
763 | find_same_succ (void) | |
764 | { | |
526ceb68 | 765 | same_succ *same = same_succ_alloc (); |
c9e93168 TV |
766 | basic_block bb; |
767 | ||
11cd3bed | 768 | FOR_EACH_BB_FN (bb, cfun) |
c9e93168 TV |
769 | { |
770 | find_same_succ_bb (bb, &same); | |
771 | if (same == NULL) | |
772 | same = same_succ_alloc (); | |
773 | } | |
774 | ||
526ceb68 | 775 | same_succ::remove (same); |
c9e93168 TV |
776 | } |
777 | ||
778 | /* Initializes worklist administration. */ | |
779 | ||
780 | static void | |
781 | init_worklist (void) | |
782 | { | |
783 | alloc_aux_for_blocks (sizeof (struct aux_bb_info)); | |
526ceb68 | 784 | same_succ_htab = new hash_table<same_succ> (n_basic_blocks_for_fn (cfun)); |
8b1c6fd7 | 785 | same_succ_edge_flags = XCNEWVEC (int, last_basic_block_for_fn (cfun)); |
c9e93168 TV |
786 | deleted_bbs = BITMAP_ALLOC (NULL); |
787 | deleted_bb_preds = BITMAP_ALLOC (NULL); | |
0cae8d31 | 788 | worklist.create (n_basic_blocks_for_fn (cfun)); |
c9e93168 TV |
789 | find_same_succ (); |
790 | ||
791 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
792 | { | |
793 | fprintf (dump_file, "initial worklist:\n"); | |
794 | print_worklist (dump_file); | |
795 | } | |
796 | } | |
797 | ||
798 | /* Deletes worklist administration. */ | |
799 | ||
800 | static void | |
801 | delete_worklist (void) | |
802 | { | |
803 | free_aux_for_blocks (); | |
c203e8a7 TS |
804 | delete same_succ_htab; |
805 | same_succ_htab = NULL; | |
c9e93168 TV |
806 | XDELETEVEC (same_succ_edge_flags); |
807 | same_succ_edge_flags = NULL; | |
808 | BITMAP_FREE (deleted_bbs); | |
809 | BITMAP_FREE (deleted_bb_preds); | |
9771b263 | 810 | worklist.release (); |
c9e93168 TV |
811 | } |
812 | ||
813 | /* Mark BB as deleted, and mark its predecessors. */ | |
814 | ||
815 | static void | |
643400b8 | 816 | mark_basic_block_deleted (basic_block bb) |
c9e93168 TV |
817 | { |
818 | edge e; | |
819 | edge_iterator ei; | |
820 | ||
821 | bitmap_set_bit (deleted_bbs, bb->index); | |
822 | ||
823 | FOR_EACH_EDGE (e, ei, bb->preds) | |
824 | bitmap_set_bit (deleted_bb_preds, e->src->index); | |
825 | } | |
826 | ||
4cbdcd40 TV |
827 | /* Removes BB from its corresponding same_succ. */ |
828 | ||
829 | static void | |
830 | same_succ_flush_bb (basic_block bb) | |
831 | { | |
526ceb68 | 832 | same_succ *same = BB_SAME_SUCC (bb); |
0bbfd554 TV |
833 | if (! same) |
834 | return; | |
835 | ||
4cbdcd40 TV |
836 | BB_SAME_SUCC (bb) = NULL; |
837 | if (bitmap_single_bit_set_p (same->bbs)) | |
c203e8a7 | 838 | same_succ_htab->remove_elt_with_hash (same, same->hashval); |
4cbdcd40 TV |
839 | else |
840 | bitmap_clear_bit (same->bbs, bb->index); | |
841 | } | |
842 | ||
c9e93168 TV |
843 | /* Removes all bbs in BBS from their corresponding same_succ. */ |
844 | ||
845 | static void | |
846 | same_succ_flush_bbs (bitmap bbs) | |
847 | { | |
848 | unsigned int i; | |
849 | bitmap_iterator bi; | |
850 | ||
851 | EXECUTE_IF_SET_IN_BITMAP (bbs, 0, i, bi) | |
06e28de2 | 852 | same_succ_flush_bb (BASIC_BLOCK_FOR_FN (cfun, i)); |
c9e93168 TV |
853 | } |
854 | ||
fcddd80e RG |
855 | /* Release the last vdef in BB, either normal or phi result. */ |
856 | ||
857 | static void | |
858 | release_last_vdef (basic_block bb) | |
859 | { | |
538dd0b7 DM |
860 | for (gimple_stmt_iterator i = gsi_last_bb (bb); !gsi_end_p (i); |
861 | gsi_prev_nondebug (&i)) | |
fcddd80e | 862 | { |
355fe088 | 863 | gimple *stmt = gsi_stmt (i); |
fcddd80e RG |
864 | if (gimple_vdef (stmt) == NULL_TREE) |
865 | continue; | |
866 | ||
867 | mark_virtual_operand_for_renaming (gimple_vdef (stmt)); | |
868 | return; | |
869 | } | |
870 | ||
538dd0b7 DM |
871 | for (gphi_iterator i = gsi_start_phis (bb); !gsi_end_p (i); |
872 | gsi_next (&i)) | |
fcddd80e | 873 | { |
538dd0b7 | 874 | gphi *phi = i.phi (); |
fcddd80e RG |
875 | tree res = gimple_phi_result (phi); |
876 | ||
ea057359 | 877 | if (!virtual_operand_p (res)) |
fcddd80e RG |
878 | continue; |
879 | ||
880 | mark_virtual_phi_result_for_renaming (phi); | |
881 | return; | |
882 | } | |
fcddd80e RG |
883 | } |
884 | ||
c9e93168 TV |
885 | /* For deleted_bb_preds, find bbs with same successors. */ |
886 | ||
887 | static void | |
888 | update_worklist (void) | |
889 | { | |
890 | unsigned int i; | |
891 | bitmap_iterator bi; | |
892 | basic_block bb; | |
526ceb68 | 893 | same_succ *same; |
c9e93168 | 894 | |
643400b8 TV |
895 | bitmap_and_compl_into (deleted_bb_preds, deleted_bbs); |
896 | bitmap_clear (deleted_bbs); | |
897 | ||
c9e93168 TV |
898 | bitmap_clear_bit (deleted_bb_preds, ENTRY_BLOCK); |
899 | same_succ_flush_bbs (deleted_bb_preds); | |
900 | ||
901 | same = same_succ_alloc (); | |
902 | EXECUTE_IF_SET_IN_BITMAP (deleted_bb_preds, 0, i, bi) | |
903 | { | |
06e28de2 | 904 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
c9e93168 TV |
905 | gcc_assert (bb != NULL); |
906 | find_same_succ_bb (bb, &same); | |
907 | if (same == NULL) | |
908 | same = same_succ_alloc (); | |
909 | } | |
526ceb68 | 910 | same_succ::remove (same); |
c9e93168 TV |
911 | bitmap_clear (deleted_bb_preds); |
912 | } | |
913 | ||
914 | /* Prints cluster C to FILE. */ | |
915 | ||
916 | static void | |
526ceb68 | 917 | print_cluster (FILE *file, bb_cluster *c) |
c9e93168 TV |
918 | { |
919 | if (c == NULL) | |
920 | return; | |
921 | bitmap_print (file, c->bbs, "bbs:", "\n"); | |
922 | bitmap_print (file, c->preds, "preds:", "\n"); | |
923 | } | |
924 | ||
925 | /* Prints cluster C to stderr. */ | |
926 | ||
526ceb68 | 927 | extern void debug_cluster (bb_cluster *); |
c9e93168 | 928 | DEBUG_FUNCTION void |
526ceb68 | 929 | debug_cluster (bb_cluster *c) |
c9e93168 TV |
930 | { |
931 | print_cluster (stderr, c); | |
932 | } | |
933 | ||
934 | /* Update C->rep_bb, given that BB is added to the cluster. */ | |
935 | ||
936 | static void | |
526ceb68 | 937 | update_rep_bb (bb_cluster *c, basic_block bb) |
c9e93168 TV |
938 | { |
939 | /* Initial. */ | |
940 | if (c->rep_bb == NULL) | |
941 | { | |
942 | c->rep_bb = bb; | |
943 | return; | |
944 | } | |
945 | ||
946 | /* Current needs no deps, keep it. */ | |
947 | if (BB_DEP_BB (c->rep_bb) == NULL) | |
948 | return; | |
949 | ||
950 | /* Bb needs no deps, change rep_bb. */ | |
951 | if (BB_DEP_BB (bb) == NULL) | |
952 | { | |
953 | c->rep_bb = bb; | |
954 | return; | |
955 | } | |
956 | ||
957 | /* Bb needs last deps earlier than current, change rep_bb. A potential | |
958 | problem with this, is that the first deps might also be earlier, which | |
959 | would mean we prefer longer lifetimes for the deps. To be able to check | |
960 | for this, we would have to trace BB_FIRST_DEP_BB as well, besides | |
961 | BB_DEP_BB, which is really BB_LAST_DEP_BB. | |
962 | The benefit of choosing the bb with last deps earlier, is that it can | |
963 | potentially be used as replacement for more bbs. */ | |
964 | if (dominated_by_p (CDI_DOMINATORS, BB_DEP_BB (c->rep_bb), BB_DEP_BB (bb))) | |
965 | c->rep_bb = bb; | |
966 | } | |
967 | ||
968 | /* Add BB to cluster C. Sets BB in C->bbs, and preds of BB in C->preds. */ | |
969 | ||
970 | static void | |
526ceb68 | 971 | add_bb_to_cluster (bb_cluster *c, basic_block bb) |
c9e93168 TV |
972 | { |
973 | edge e; | |
974 | edge_iterator ei; | |
975 | ||
976 | bitmap_set_bit (c->bbs, bb->index); | |
977 | ||
978 | FOR_EACH_EDGE (e, ei, bb->preds) | |
979 | bitmap_set_bit (c->preds, e->src->index); | |
980 | ||
981 | update_rep_bb (c, bb); | |
982 | } | |
983 | ||
984 | /* Allocate and init new cluster. */ | |
985 | ||
526ceb68 | 986 | static bb_cluster * |
c9e93168 TV |
987 | new_cluster (void) |
988 | { | |
526ceb68 TS |
989 | bb_cluster *c; |
990 | c = XCNEW (bb_cluster); | |
c9e93168 TV |
991 | c->bbs = BITMAP_ALLOC (NULL); |
992 | c->preds = BITMAP_ALLOC (NULL); | |
993 | c->rep_bb = NULL; | |
994 | return c; | |
995 | } | |
996 | ||
997 | /* Delete clusters. */ | |
998 | ||
999 | static void | |
526ceb68 | 1000 | delete_cluster (bb_cluster *c) |
c9e93168 TV |
1001 | { |
1002 | if (c == NULL) | |
1003 | return; | |
1004 | BITMAP_FREE (c->bbs); | |
1005 | BITMAP_FREE (c->preds); | |
1006 | XDELETE (c); | |
1007 | } | |
1008 | ||
c9e93168 TV |
1009 | |
1010 | /* Array that contains all clusters. */ | |
1011 | ||
526ceb68 | 1012 | static vec<bb_cluster *> all_clusters; |
c9e93168 TV |
1013 | |
1014 | /* Allocate all cluster vectors. */ | |
1015 | ||
1016 | static void | |
1017 | alloc_cluster_vectors (void) | |
1018 | { | |
0cae8d31 | 1019 | all_clusters.create (n_basic_blocks_for_fn (cfun)); |
c9e93168 TV |
1020 | } |
1021 | ||
1022 | /* Reset all cluster vectors. */ | |
1023 | ||
1024 | static void | |
1025 | reset_cluster_vectors (void) | |
1026 | { | |
1027 | unsigned int i; | |
1028 | basic_block bb; | |
9771b263 DN |
1029 | for (i = 0; i < all_clusters.length (); ++i) |
1030 | delete_cluster (all_clusters[i]); | |
1031 | all_clusters.truncate (0); | |
11cd3bed | 1032 | FOR_EACH_BB_FN (bb, cfun) |
c9e93168 TV |
1033 | BB_CLUSTER (bb) = NULL; |
1034 | } | |
1035 | ||
1036 | /* Delete all cluster vectors. */ | |
1037 | ||
1038 | static void | |
1039 | delete_cluster_vectors (void) | |
1040 | { | |
1041 | unsigned int i; | |
9771b263 DN |
1042 | for (i = 0; i < all_clusters.length (); ++i) |
1043 | delete_cluster (all_clusters[i]); | |
1044 | all_clusters.release (); | |
c9e93168 TV |
1045 | } |
1046 | ||
1047 | /* Merge cluster C2 into C1. */ | |
1048 | ||
1049 | static void | |
526ceb68 | 1050 | merge_clusters (bb_cluster *c1, bb_cluster *c2) |
c9e93168 TV |
1051 | { |
1052 | bitmap_ior_into (c1->bbs, c2->bbs); | |
1053 | bitmap_ior_into (c1->preds, c2->preds); | |
1054 | } | |
1055 | ||
1056 | /* Register equivalence of BB1 and BB2 (members of cluster C). Store c in | |
1057 | all_clusters, or merge c with existing cluster. */ | |
1058 | ||
1059 | static void | |
1060 | set_cluster (basic_block bb1, basic_block bb2) | |
1061 | { | |
1062 | basic_block merge_bb, other_bb; | |
526ceb68 | 1063 | bb_cluster *merge, *old, *c; |
c9e93168 TV |
1064 | |
1065 | if (BB_CLUSTER (bb1) == NULL && BB_CLUSTER (bb2) == NULL) | |
1066 | { | |
1067 | c = new_cluster (); | |
1068 | add_bb_to_cluster (c, bb1); | |
1069 | add_bb_to_cluster (c, bb2); | |
1070 | BB_CLUSTER (bb1) = c; | |
1071 | BB_CLUSTER (bb2) = c; | |
9771b263 DN |
1072 | c->index = all_clusters.length (); |
1073 | all_clusters.safe_push (c); | |
c9e93168 TV |
1074 | } |
1075 | else if (BB_CLUSTER (bb1) == NULL || BB_CLUSTER (bb2) == NULL) | |
1076 | { | |
1077 | merge_bb = BB_CLUSTER (bb1) == NULL ? bb2 : bb1; | |
1078 | other_bb = BB_CLUSTER (bb1) == NULL ? bb1 : bb2; | |
1079 | merge = BB_CLUSTER (merge_bb); | |
1080 | add_bb_to_cluster (merge, other_bb); | |
1081 | BB_CLUSTER (other_bb) = merge; | |
1082 | } | |
1083 | else if (BB_CLUSTER (bb1) != BB_CLUSTER (bb2)) | |
1084 | { | |
1085 | unsigned int i; | |
1086 | bitmap_iterator bi; | |
1087 | ||
1088 | old = BB_CLUSTER (bb2); | |
1089 | merge = BB_CLUSTER (bb1); | |
1090 | merge_clusters (merge, old); | |
1091 | EXECUTE_IF_SET_IN_BITMAP (old->bbs, 0, i, bi) | |
06e28de2 | 1092 | BB_CLUSTER (BASIC_BLOCK_FOR_FN (cfun, i)) = merge; |
9771b263 | 1093 | all_clusters[old->index] = NULL; |
c9e93168 TV |
1094 | update_rep_bb (merge, old->rep_bb); |
1095 | delete_cluster (old); | |
1096 | } | |
1097 | else | |
1098 | gcc_unreachable (); | |
1099 | } | |
1100 | ||
b6366520 TV |
1101 | /* Return true if gimple operands T1 and T2 have the same value. */ |
1102 | ||
1103 | static bool | |
1104 | gimple_operand_equal_value_p (tree t1, tree t2) | |
1105 | { | |
1106 | if (t1 == t2) | |
1107 | return true; | |
1108 | ||
1109 | if (t1 == NULL_TREE | |
1110 | || t2 == NULL_TREE) | |
1111 | return false; | |
1112 | ||
2a8e3358 | 1113 | if (operand_equal_p (t1, t2, OEP_MATCH_SIDE_EFFECTS)) |
b6366520 TV |
1114 | return true; |
1115 | ||
1116 | return gvn_uses_equal (t1, t2); | |
1117 | } | |
1118 | ||
c9e93168 TV |
1119 | /* Return true if gimple statements S1 and S2 are equal. Gimple_bb (s1) and |
1120 | gimple_bb (s2) are members of SAME_SUCC. */ | |
1121 | ||
1122 | static bool | |
526ceb68 | 1123 | gimple_equal_p (same_succ *same_succ, gimple *s1, gimple *s2) |
c9e93168 TV |
1124 | { |
1125 | unsigned int i; | |
1126 | tree lhs1, lhs2; | |
1127 | basic_block bb1 = gimple_bb (s1), bb2 = gimple_bb (s2); | |
1128 | tree t1, t2; | |
2f1aee04 | 1129 | bool inv_cond; |
c9e93168 TV |
1130 | enum tree_code code1, code2; |
1131 | ||
1132 | if (gimple_code (s1) != gimple_code (s2)) | |
1133 | return false; | |
1134 | ||
1135 | switch (gimple_code (s1)) | |
1136 | { | |
1137 | case GIMPLE_CALL: | |
c9e93168 | 1138 | if (!gimple_call_same_target_p (s1, s2)) |
daf347dd | 1139 | return false; |
c9e93168 | 1140 | |
51d2abeb EB |
1141 | t1 = gimple_call_chain (s1); |
1142 | t2 = gimple_call_chain (s2); | |
1143 | if (!gimple_operand_equal_value_p (t1, t2)) | |
1144 | return false; | |
1145 | ||
1146 | if (gimple_call_num_args (s1) != gimple_call_num_args (s2)) | |
1147 | return false; | |
1148 | ||
c9e93168 TV |
1149 | for (i = 0; i < gimple_call_num_args (s1); ++i) |
1150 | { | |
1151 | t1 = gimple_call_arg (s1, i); | |
1152 | t2 = gimple_call_arg (s2, i); | |
51d2abeb EB |
1153 | if (!gimple_operand_equal_value_p (t1, t2)) |
1154 | return false; | |
c9e93168 | 1155 | } |
c9e93168 TV |
1156 | |
1157 | lhs1 = gimple_get_lhs (s1); | |
1158 | lhs2 = gimple_get_lhs (s2); | |
e6fa9204 JJ |
1159 | if (lhs1 == NULL_TREE && lhs2 == NULL_TREE) |
1160 | return true; | |
1161 | if (lhs1 == NULL_TREE || lhs2 == NULL_TREE) | |
1162 | return false; | |
1163 | if (TREE_CODE (lhs1) == SSA_NAME && TREE_CODE (lhs2) == SSA_NAME) | |
86c8eea6 | 1164 | return tail_merge_valueize (lhs1) == tail_merge_valueize (lhs2); |
e6fa9204 | 1165 | return operand_equal_p (lhs1, lhs2, 0); |
c9e93168 TV |
1166 | |
1167 | case GIMPLE_ASSIGN: | |
7b16686e RB |
1168 | if (gimple_assign_rhs_code (s1) != gimple_assign_rhs_code (s2)) |
1169 | return false; | |
1170 | ||
c9e93168 TV |
1171 | lhs1 = gimple_get_lhs (s1); |
1172 | lhs2 = gimple_get_lhs (s2); | |
fcfa87ac RB |
1173 | if (TREE_CODE (lhs1) != SSA_NAME |
1174 | && TREE_CODE (lhs2) != SSA_NAME) | |
030e321a RB |
1175 | return (operand_equal_p (lhs1, lhs2, 0) |
1176 | && gimple_operand_equal_value_p (gimple_assign_rhs1 (s1), | |
1177 | gimple_assign_rhs1 (s2))); | |
7b16686e RB |
1178 | |
1179 | if (TREE_CODE (lhs1) != SSA_NAME | |
1180 | || TREE_CODE (lhs2) != SSA_NAME) | |
1181 | return false; | |
1182 | ||
1183 | gcc_checking_assert (gimple_num_args (s1) == gimple_num_args (s2)); | |
1184 | for (i = 0; i < gimple_num_args (s1); ++i) | |
1185 | { | |
1186 | t1 = gimple_arg (s1, i); | |
1187 | t2 = gimple_arg (s2, i); | |
1188 | if (!gimple_operand_equal_value_p (t1, t2)) | |
1189 | return false; | |
1190 | } | |
1191 | return true; | |
c9e93168 TV |
1192 | |
1193 | case GIMPLE_COND: | |
1194 | t1 = gimple_cond_lhs (s1); | |
1195 | t2 = gimple_cond_lhs (s2); | |
b6366520 | 1196 | if (!gimple_operand_equal_value_p (t1, t2)) |
c9e93168 TV |
1197 | return false; |
1198 | ||
1199 | t1 = gimple_cond_rhs (s1); | |
1200 | t2 = gimple_cond_rhs (s2); | |
b6366520 | 1201 | if (!gimple_operand_equal_value_p (t1, t2)) |
c9e93168 TV |
1202 | return false; |
1203 | ||
4852c326 RB |
1204 | code1 = gimple_cond_code (s1); |
1205 | code2 = gimple_cond_code (s2); | |
c9e93168 TV |
1206 | inv_cond = (bitmap_bit_p (same_succ->inverse, bb1->index) |
1207 | != bitmap_bit_p (same_succ->inverse, bb2->index)); | |
1208 | if (inv_cond) | |
1209 | { | |
1b457aa4 | 1210 | bool honor_nans = HONOR_NANS (t1); |
c9e93168 TV |
1211 | code2 = invert_tree_comparison (code2, honor_nans); |
1212 | } | |
1213 | return code1 == code2; | |
1214 | ||
1215 | default: | |
1216 | return false; | |
1217 | } | |
1218 | } | |
1219 | ||
46301137 TV |
1220 | /* Let GSI skip backwards over local defs. Return the earliest vuse in VUSE. |
1221 | Return true in VUSE_ESCAPED if the vuse influenced a SSA_OP_DEF of one of the | |
1222 | processed statements. */ | |
c9e93168 TV |
1223 | |
1224 | static void | |
46301137 TV |
1225 | gsi_advance_bw_nondebug_nonlocal (gimple_stmt_iterator *gsi, tree *vuse, |
1226 | bool *vuse_escaped) | |
c9e93168 | 1227 | { |
355fe088 | 1228 | gimple *stmt; |
46301137 | 1229 | tree lvuse; |
c9e93168 TV |
1230 | |
1231 | while (true) | |
1232 | { | |
1233 | if (gsi_end_p (*gsi)) | |
1234 | return; | |
1235 | stmt = gsi_stmt (*gsi); | |
46301137 TV |
1236 | |
1237 | lvuse = gimple_vuse (stmt); | |
1238 | if (lvuse != NULL_TREE) | |
1239 | { | |
1240 | *vuse = lvuse; | |
1241 | if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_DEF)) | |
1242 | *vuse_escaped = true; | |
1243 | } | |
1244 | ||
b2b2f160 | 1245 | if (!stmt_local_def (stmt)) |
c9e93168 TV |
1246 | return; |
1247 | gsi_prev_nondebug (gsi); | |
1248 | } | |
1249 | } | |
1250 | ||
3c137fc9 TV |
1251 | /* Return true if equal (in the sense of gimple_equal_p) statements STMT1 and |
1252 | STMT2 are allowed to be merged. */ | |
1253 | ||
1254 | static bool | |
1255 | merge_stmts_p (gimple *stmt1, gimple *stmt2) | |
1256 | { | |
1257 | /* What could be better than this here is to blacklist the bb | |
1258 | containing the stmt, when encountering the stmt f.i. in | |
1259 | same_succ_hash. */ | |
1260 | if (is_tm_ending (stmt1)) | |
1261 | return false; | |
1262 | ||
27947670 ML |
1263 | /* Verify EH landing pads. */ |
1264 | if (lookup_stmt_eh_lp_fn (cfun, stmt1) != lookup_stmt_eh_lp_fn (cfun, stmt2)) | |
1265 | return false; | |
1266 | ||
3c137fc9 TV |
1267 | if (is_gimple_call (stmt1) |
1268 | && gimple_call_internal_p (stmt1)) | |
1269 | switch (gimple_call_internal_fn (stmt1)) | |
1270 | { | |
1271 | case IFN_UBSAN_NULL: | |
1272 | case IFN_UBSAN_BOUNDS: | |
1273 | case IFN_UBSAN_VPTR: | |
1274 | case IFN_UBSAN_CHECK_ADD: | |
1275 | case IFN_UBSAN_CHECK_SUB: | |
1276 | case IFN_UBSAN_CHECK_MUL: | |
1277 | case IFN_UBSAN_OBJECT_SIZE: | |
c9b39a49 | 1278 | case IFN_UBSAN_PTR: |
3c137fc9 TV |
1279 | case IFN_ASAN_CHECK: |
1280 | /* For these internal functions, gimple_location is an implicit | |
1281 | parameter, which will be used explicitly after expansion. | |
1282 | Merging these statements may cause confusing line numbers in | |
1283 | sanitizer messages. */ | |
1284 | return gimple_location (stmt1) == gimple_location (stmt2); | |
1285 | default: | |
1286 | break; | |
1287 | } | |
1288 | ||
1289 | return true; | |
1290 | } | |
1291 | ||
c9e93168 TV |
1292 | /* Determines whether BB1 and BB2 (members of same_succ) are duplicates. If so, |
1293 | clusters them. */ | |
1294 | ||
1295 | static void | |
526ceb68 | 1296 | find_duplicate (same_succ *same_succ, basic_block bb1, basic_block bb2) |
c9e93168 TV |
1297 | { |
1298 | gimple_stmt_iterator gsi1 = gsi_last_nondebug_bb (bb1); | |
1299 | gimple_stmt_iterator gsi2 = gsi_last_nondebug_bb (bb2); | |
46301137 TV |
1300 | tree vuse1 = NULL_TREE, vuse2 = NULL_TREE; |
1301 | bool vuse_escaped = false; | |
c9e93168 | 1302 | |
46301137 TV |
1303 | gsi_advance_bw_nondebug_nonlocal (&gsi1, &vuse1, &vuse_escaped); |
1304 | gsi_advance_bw_nondebug_nonlocal (&gsi2, &vuse2, &vuse_escaped); | |
c9e93168 TV |
1305 | |
1306 | while (!gsi_end_p (gsi1) && !gsi_end_p (gsi2)) | |
1307 | { | |
355fe088 TS |
1308 | gimple *stmt1 = gsi_stmt (gsi1); |
1309 | gimple *stmt2 = gsi_stmt (gsi2); | |
7ec88701 | 1310 | |
23e025db JJ |
1311 | if (gimple_code (stmt1) == GIMPLE_LABEL |
1312 | && gimple_code (stmt2) == GIMPLE_LABEL) | |
1313 | break; | |
1314 | ||
3c137fc9 | 1315 | if (!gimple_equal_p (same_succ, stmt1, stmt2)) |
7ec88701 RH |
1316 | return; |
1317 | ||
3c137fc9 | 1318 | if (!merge_stmts_p (stmt1, stmt2)) |
c9e93168 TV |
1319 | return; |
1320 | ||
1321 | gsi_prev_nondebug (&gsi1); | |
1322 | gsi_prev_nondebug (&gsi2); | |
46301137 TV |
1323 | gsi_advance_bw_nondebug_nonlocal (&gsi1, &vuse1, &vuse_escaped); |
1324 | gsi_advance_bw_nondebug_nonlocal (&gsi2, &vuse2, &vuse_escaped); | |
c9e93168 TV |
1325 | } |
1326 | ||
23e025db JJ |
1327 | while (!gsi_end_p (gsi1) && gimple_code (gsi_stmt (gsi1)) == GIMPLE_LABEL) |
1328 | { | |
1329 | tree label = gimple_label_label (as_a <glabel *> (gsi_stmt (gsi1))); | |
1330 | if (DECL_NONLOCAL (label) || FORCED_LABEL (label)) | |
1331 | return; | |
67a8d719 | 1332 | gsi_prev (&gsi1); |
23e025db JJ |
1333 | } |
1334 | while (!gsi_end_p (gsi2) && gimple_code (gsi_stmt (gsi2)) == GIMPLE_LABEL) | |
1335 | { | |
1336 | tree label = gimple_label_label (as_a <glabel *> (gsi_stmt (gsi2))); | |
1337 | if (DECL_NONLOCAL (label) || FORCED_LABEL (label)) | |
1338 | return; | |
67a8d719 | 1339 | gsi_prev (&gsi2); |
23e025db | 1340 | } |
c9e93168 TV |
1341 | if (!(gsi_end_p (gsi1) && gsi_end_p (gsi2))) |
1342 | return; | |
1343 | ||
46301137 TV |
1344 | /* If the incoming vuses are not the same, and the vuse escaped into an |
1345 | SSA_OP_DEF, then merging the 2 blocks will change the value of the def, | |
1346 | which potentially means the semantics of one of the blocks will be changed. | |
1347 | TODO: make this check more precise. */ | |
1348 | if (vuse_escaped && vuse1 != vuse2) | |
1349 | return; | |
1350 | ||
c9e93168 TV |
1351 | if (dump_file) |
1352 | fprintf (dump_file, "find_duplicates: <bb %d> duplicate of <bb %d>\n", | |
1353 | bb1->index, bb2->index); | |
1354 | ||
1355 | set_cluster (bb1, bb2); | |
1356 | } | |
1357 | ||
1358 | /* Returns whether for all phis in DEST the phi alternatives for E1 and | |
1359 | E2 are equal. */ | |
1360 | ||
1361 | static bool | |
1362 | same_phi_alternatives_1 (basic_block dest, edge e1, edge e2) | |
1363 | { | |
1364 | int n1 = e1->dest_idx, n2 = e2->dest_idx; | |
538dd0b7 | 1365 | gphi_iterator gsi; |
c9e93168 TV |
1366 | |
1367 | for (gsi = gsi_start_phis (dest); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1368 | { | |
538dd0b7 | 1369 | gphi *phi = gsi.phi (); |
c9e93168 TV |
1370 | tree lhs = gimple_phi_result (phi); |
1371 | tree val1 = gimple_phi_arg_def (phi, n1); | |
1372 | tree val2 = gimple_phi_arg_def (phi, n2); | |
1373 | ||
ea057359 | 1374 | if (virtual_operand_p (lhs)) |
c9e93168 TV |
1375 | continue; |
1376 | ||
1377 | if (operand_equal_for_phi_arg_p (val1, val2)) | |
daf347dd | 1378 | continue; |
c9e93168 TV |
1379 | if (gvn_uses_equal (val1, val2)) |
1380 | continue; | |
1381 | ||
1382 | return false; | |
1383 | } | |
1384 | ||
1385 | return true; | |
1386 | } | |
1387 | ||
1388 | /* Returns whether for all successors of BB1 and BB2 (members of SAME_SUCC), the | |
1389 | phi alternatives for BB1 and BB2 are equal. */ | |
1390 | ||
1391 | static bool | |
526ceb68 | 1392 | same_phi_alternatives (same_succ *same_succ, basic_block bb1, basic_block bb2) |
c9e93168 TV |
1393 | { |
1394 | unsigned int s; | |
1395 | bitmap_iterator bs; | |
1396 | edge e1, e2; | |
1397 | basic_block succ; | |
1398 | ||
1399 | EXECUTE_IF_SET_IN_BITMAP (same_succ->succs, 0, s, bs) | |
1400 | { | |
06e28de2 | 1401 | succ = BASIC_BLOCK_FOR_FN (cfun, s); |
c9e93168 TV |
1402 | e1 = find_edge (bb1, succ); |
1403 | e2 = find_edge (bb2, succ); | |
1404 | if (e1->flags & EDGE_COMPLEX | |
1405 | || e2->flags & EDGE_COMPLEX) | |
1406 | return false; | |
1407 | ||
1408 | /* For all phis in bb, the phi alternatives for e1 and e2 need to have | |
1409 | the same value. */ | |
1410 | if (!same_phi_alternatives_1 (succ, e1, e2)) | |
1411 | return false; | |
1412 | } | |
1413 | ||
1414 | return true; | |
1415 | } | |
1416 | ||
1417 | /* Return true if BB has non-vop phis. */ | |
1418 | ||
1419 | static bool | |
1420 | bb_has_non_vop_phi (basic_block bb) | |
1421 | { | |
1422 | gimple_seq phis = phi_nodes (bb); | |
355fe088 | 1423 | gimple *phi; |
c9e93168 TV |
1424 | |
1425 | if (phis == NULL) | |
1426 | return false; | |
1427 | ||
1428 | if (!gimple_seq_singleton_p (phis)) | |
1429 | return true; | |
1430 | ||
1431 | phi = gimple_seq_first_stmt (phis); | |
ea057359 | 1432 | return !virtual_operand_p (gimple_phi_result (phi)); |
c9e93168 TV |
1433 | } |
1434 | ||
1435 | /* Returns true if redirecting the incoming edges of FROM to TO maintains the | |
1436 | invariant that uses in FROM are dominates by their defs. */ | |
1437 | ||
1438 | static bool | |
1439 | deps_ok_for_redirect_from_bb_to_bb (basic_block from, basic_block to) | |
1440 | { | |
1441 | basic_block cd, dep_bb = BB_DEP_BB (to); | |
1442 | edge_iterator ei; | |
1443 | edge e; | |
c9e93168 TV |
1444 | |
1445 | if (dep_bb == NULL) | |
1446 | return true; | |
1447 | ||
f8a06e24 | 1448 | bitmap from_preds = BITMAP_ALLOC (NULL); |
c9e93168 TV |
1449 | FOR_EACH_EDGE (e, ei, from->preds) |
1450 | bitmap_set_bit (from_preds, e->src->index); | |
1451 | cd = nearest_common_dominator_for_set (CDI_DOMINATORS, from_preds); | |
1452 | BITMAP_FREE (from_preds); | |
1453 | ||
1454 | return dominated_by_p (CDI_DOMINATORS, dep_bb, cd); | |
1455 | } | |
1456 | ||
1457 | /* Returns true if replacing BB1 (or its replacement bb) by BB2 (or its | |
1458 | replacement bb) and vice versa maintains the invariant that uses in the | |
1459 | replacement are dominates by their defs. */ | |
1460 | ||
1461 | static bool | |
1462 | deps_ok_for_redirect (basic_block bb1, basic_block bb2) | |
1463 | { | |
1464 | if (BB_CLUSTER (bb1) != NULL) | |
1465 | bb1 = BB_CLUSTER (bb1)->rep_bb; | |
1466 | ||
1467 | if (BB_CLUSTER (bb2) != NULL) | |
1468 | bb2 = BB_CLUSTER (bb2)->rep_bb; | |
1469 | ||
1470 | return (deps_ok_for_redirect_from_bb_to_bb (bb1, bb2) | |
1471 | && deps_ok_for_redirect_from_bb_to_bb (bb2, bb1)); | |
1472 | } | |
1473 | ||
1474 | /* Within SAME_SUCC->bbs, find clusters of bbs which can be merged. */ | |
1475 | ||
1476 | static void | |
526ceb68 | 1477 | find_clusters_1 (same_succ *same_succ) |
c9e93168 TV |
1478 | { |
1479 | basic_block bb1, bb2; | |
1480 | unsigned int i, j; | |
1481 | bitmap_iterator bi, bj; | |
1482 | int nr_comparisons; | |
028d4092 | 1483 | int max_comparisons = param_max_tail_merge_comparisons; |
c9e93168 TV |
1484 | |
1485 | EXECUTE_IF_SET_IN_BITMAP (same_succ->bbs, 0, i, bi) | |
1486 | { | |
06e28de2 | 1487 | bb1 = BASIC_BLOCK_FOR_FN (cfun, i); |
c9e93168 TV |
1488 | |
1489 | /* TODO: handle blocks with phi-nodes. We'll have to find corresponding | |
1490 | phi-nodes in bb1 and bb2, with the same alternatives for the same | |
1491 | preds. */ | |
71b7c365 TV |
1492 | if (bb_has_non_vop_phi (bb1) || bb_has_eh_pred (bb1) |
1493 | || bb_has_abnormal_pred (bb1)) | |
c9e93168 TV |
1494 | continue; |
1495 | ||
1496 | nr_comparisons = 0; | |
1497 | EXECUTE_IF_SET_IN_BITMAP (same_succ->bbs, i + 1, j, bj) | |
1498 | { | |
06e28de2 | 1499 | bb2 = BASIC_BLOCK_FOR_FN (cfun, j); |
c9e93168 | 1500 | |
71b7c365 TV |
1501 | if (bb_has_non_vop_phi (bb2) || bb_has_eh_pred (bb2) |
1502 | || bb_has_abnormal_pred (bb2)) | |
c9e93168 TV |
1503 | continue; |
1504 | ||
1505 | if (BB_CLUSTER (bb1) != NULL && BB_CLUSTER (bb1) == BB_CLUSTER (bb2)) | |
1506 | continue; | |
1507 | ||
9c582551 | 1508 | /* Limit quadratic behavior. */ |
c9e93168 TV |
1509 | nr_comparisons++; |
1510 | if (nr_comparisons > max_comparisons) | |
1511 | break; | |
1512 | ||
1513 | /* This is a conservative dependency check. We could test more | |
1514 | precise for allowed replacement direction. */ | |
1515 | if (!deps_ok_for_redirect (bb1, bb2)) | |
1516 | continue; | |
1517 | ||
1518 | if (!(same_phi_alternatives (same_succ, bb1, bb2))) | |
1519 | continue; | |
1520 | ||
1521 | find_duplicate (same_succ, bb1, bb2); | |
daf347dd | 1522 | } |
c9e93168 TV |
1523 | } |
1524 | } | |
1525 | ||
1526 | /* Find clusters of bbs which can be merged. */ | |
1527 | ||
1528 | static void | |
1529 | find_clusters (void) | |
1530 | { | |
526ceb68 | 1531 | same_succ *same; |
c9e93168 | 1532 | |
9771b263 | 1533 | while (!worklist.is_empty ()) |
c9e93168 | 1534 | { |
9771b263 | 1535 | same = worklist.pop (); |
c9e93168 TV |
1536 | same->in_worklist = false; |
1537 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1538 | { | |
1539 | fprintf (dump_file, "processing worklist entry\n"); | |
1540 | same_succ_print (dump_file, same); | |
1541 | } | |
1542 | find_clusters_1 (same); | |
1543 | } | |
1544 | } | |
1545 | ||
c9e93168 TV |
1546 | /* Returns the vop phi of BB, if any. */ |
1547 | ||
538dd0b7 | 1548 | static gphi * |
c9e93168 TV |
1549 | vop_phi (basic_block bb) |
1550 | { | |
538dd0b7 DM |
1551 | gphi *stmt; |
1552 | gphi_iterator gsi; | |
c9e93168 TV |
1553 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
1554 | { | |
538dd0b7 | 1555 | stmt = gsi.phi (); |
ea057359 | 1556 | if (! virtual_operand_p (gimple_phi_result (stmt))) |
c9e93168 TV |
1557 | continue; |
1558 | return stmt; | |
1559 | } | |
1560 | return NULL; | |
1561 | } | |
1562 | ||
643400b8 | 1563 | /* Redirect all edges from BB1 to BB2, removes BB1 and marks it as removed. */ |
c9e93168 TV |
1564 | |
1565 | static void | |
643400b8 | 1566 | replace_block_by (basic_block bb1, basic_block bb2) |
c9e93168 TV |
1567 | { |
1568 | edge pred_edge; | |
1569 | unsigned int i; | |
538dd0b7 | 1570 | gphi *bb2_phi; |
40f73edd | 1571 | |
643400b8 | 1572 | bb2_phi = vop_phi (bb2); |
c9e93168 | 1573 | |
643400b8 TV |
1574 | /* Mark the basic block as deleted. */ |
1575 | mark_basic_block_deleted (bb1); | |
c9e93168 TV |
1576 | |
1577 | /* Redirect the incoming edges of bb1 to bb2. */ | |
1578 | for (i = EDGE_COUNT (bb1->preds); i > 0 ; --i) | |
1579 | { | |
1580 | pred_edge = EDGE_PRED (bb1, i - 1); | |
1581 | pred_edge = redirect_edge_and_branch (pred_edge, bb2); | |
1582 | gcc_assert (pred_edge != NULL); | |
643400b8 TV |
1583 | |
1584 | if (bb2_phi == NULL) | |
1585 | continue; | |
1586 | ||
1587 | /* The phi might have run out of capacity when the redirect added an | |
1588 | argument, which means it could have been replaced. Refresh it. */ | |
1589 | bb2_phi = vop_phi (bb2); | |
1590 | ||
1591 | add_phi_arg (bb2_phi, SSA_NAME_VAR (gimple_phi_result (bb2_phi)), | |
9e227d60 | 1592 | pred_edge, UNKNOWN_LOCATION); |
c9e93168 TV |
1593 | } |
1594 | ||
fa405d7b | 1595 | |
adc7a812 | 1596 | /* Merge the outgoing edge counts from bb1 onto bb2. */ |
e7a74006 | 1597 | edge e1, e2; |
f38b3647 | 1598 | edge_iterator ei; |
deca6d60 | 1599 | |
f38b3647 JH |
1600 | if (bb2->count.initialized_p ()) |
1601 | FOR_EACH_EDGE (e1, ei, bb1->succs) | |
1602 | { | |
1603 | e2 = find_edge (bb2, e1->dest); | |
1604 | gcc_assert (e2); | |
1605 | ||
1606 | /* If probabilities are same, we are done. | |
1607 | If counts are nonzero we can distribute accordingly. In remaining | |
1608 | cases just avreage the values and hope for the best. */ | |
97c07987 JH |
1609 | e2->probability = e1->probability.combine_with_count |
1610 | (bb1->count, e2->probability, bb2->count); | |
f38b3647 JH |
1611 | } |
1612 | bb2->count += bb1->count; | |
adc7a812 | 1613 | |
23e025db JJ |
1614 | /* Move over any user labels from bb1 after the bb2 labels. */ |
1615 | gimple_stmt_iterator gsi1 = gsi_start_bb (bb1); | |
1616 | if (!gsi_end_p (gsi1) && gimple_code (gsi_stmt (gsi1)) == GIMPLE_LABEL) | |
1617 | { | |
1618 | gimple_stmt_iterator gsi2 = gsi_after_labels (bb2); | |
1619 | while (!gsi_end_p (gsi1) | |
1620 | && gimple_code (gsi_stmt (gsi1)) == GIMPLE_LABEL) | |
1621 | { | |
1622 | tree label = gimple_label_label (as_a <glabel *> (gsi_stmt (gsi1))); | |
1623 | gcc_assert (!DECL_NONLOCAL (label) && !FORCED_LABEL (label)); | |
1624 | if (DECL_ARTIFICIAL (label)) | |
1625 | gsi_next (&gsi1); | |
1626 | else | |
1627 | gsi_move_before (&gsi1, &gsi2); | |
1628 | } | |
1629 | } | |
1630 | ||
6ea2f74c MP |
1631 | /* Clear range info from all stmts in BB2 -- this transformation |
1632 | could make them out of date. */ | |
1633 | reset_flow_sensitive_info_in_bb (bb2); | |
1634 | ||
a31895d7 | 1635 | /* Do updates that use bb1, before deleting bb1. */ |
fcddd80e | 1636 | release_last_vdef (bb1); |
a31895d7 TV |
1637 | same_succ_flush_bb (bb1); |
1638 | ||
643400b8 | 1639 | delete_basic_block (bb1); |
c9e93168 TV |
1640 | } |
1641 | ||
1642 | /* Bbs for which update_debug_stmt need to be called. */ | |
1643 | ||
1644 | static bitmap update_bbs; | |
1645 | ||
1646 | /* For each cluster in all_clusters, merge all cluster->bbs. Returns | |
643400b8 | 1647 | number of bbs removed. */ |
c9e93168 TV |
1648 | |
1649 | static int | |
643400b8 | 1650 | apply_clusters (void) |
c9e93168 TV |
1651 | { |
1652 | basic_block bb1, bb2; | |
526ceb68 | 1653 | bb_cluster *c; |
c9e93168 TV |
1654 | unsigned int i, j; |
1655 | bitmap_iterator bj; | |
1656 | int nr_bbs_removed = 0; | |
1657 | ||
9771b263 | 1658 | for (i = 0; i < all_clusters.length (); ++i) |
c9e93168 | 1659 | { |
9771b263 | 1660 | c = all_clusters[i]; |
c9e93168 TV |
1661 | if (c == NULL) |
1662 | continue; | |
1663 | ||
1664 | bb2 = c->rep_bb; | |
1665 | bitmap_set_bit (update_bbs, bb2->index); | |
1666 | ||
1667 | bitmap_clear_bit (c->bbs, bb2->index); | |
1668 | EXECUTE_IF_SET_IN_BITMAP (c->bbs, 0, j, bj) | |
1669 | { | |
06e28de2 | 1670 | bb1 = BASIC_BLOCK_FOR_FN (cfun, j); |
c9e93168 TV |
1671 | bitmap_clear_bit (update_bbs, bb1->index); |
1672 | ||
643400b8 | 1673 | replace_block_by (bb1, bb2); |
c9e93168 TV |
1674 | nr_bbs_removed++; |
1675 | } | |
1676 | } | |
1677 | ||
1678 | return nr_bbs_removed; | |
1679 | } | |
1680 | ||
1681 | /* Resets debug statement STMT if it has uses that are not dominated by their | |
1682 | defs. */ | |
1683 | ||
1684 | static void | |
355fe088 | 1685 | update_debug_stmt (gimple *stmt) |
c9e93168 TV |
1686 | { |
1687 | use_operand_p use_p; | |
1688 | ssa_op_iter oi; | |
a92bf1b1 | 1689 | basic_block bbuse; |
c9e93168 TV |
1690 | |
1691 | if (!gimple_debug_bind_p (stmt)) | |
1692 | return; | |
1693 | ||
1694 | bbuse = gimple_bb (stmt); | |
1695 | FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, oi, SSA_OP_USE) | |
1696 | { | |
a92bf1b1 | 1697 | tree name = USE_FROM_PTR (use_p); |
355fe088 | 1698 | gimple *def_stmt = SSA_NAME_DEF_STMT (name); |
a92bf1b1 | 1699 | basic_block bbdef = gimple_bb (def_stmt); |
c9e93168 TV |
1700 | if (bbdef == NULL || bbuse == bbdef |
1701 | || dominated_by_p (CDI_DOMINATORS, bbuse, bbdef)) | |
1702 | continue; | |
1703 | ||
1704 | gimple_debug_bind_reset_value (stmt); | |
1705 | update_stmt (stmt); | |
a92bf1b1 | 1706 | break; |
c9e93168 TV |
1707 | } |
1708 | } | |
1709 | ||
1710 | /* Resets all debug statements that have uses that are not | |
1711 | dominated by their defs. */ | |
1712 | ||
1713 | static void | |
1714 | update_debug_stmts (void) | |
1715 | { | |
1716 | basic_block bb; | |
1717 | bitmap_iterator bi; | |
1718 | unsigned int i; | |
1719 | ||
c9e93168 TV |
1720 | EXECUTE_IF_SET_IN_BITMAP (update_bbs, 0, i, bi) |
1721 | { | |
355fe088 | 1722 | gimple *stmt; |
c9e93168 TV |
1723 | gimple_stmt_iterator gsi; |
1724 | ||
06e28de2 | 1725 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
c9e93168 TV |
1726 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
1727 | { | |
1728 | stmt = gsi_stmt (gsi); | |
1729 | if (!is_gimple_debug (stmt)) | |
1730 | continue; | |
1731 | update_debug_stmt (stmt); | |
1732 | } | |
1733 | } | |
1734 | } | |
1735 | ||
1736 | /* Runs tail merge optimization. */ | |
1737 | ||
1738 | unsigned int | |
2f62294d | 1739 | tail_merge_optimize (bool need_crit_edge_split) |
c9e93168 TV |
1740 | { |
1741 | int nr_bbs_removed_total = 0; | |
1742 | int nr_bbs_removed; | |
1743 | bool loop_entered = false; | |
1744 | int iteration_nr = 0; | |
028d4092 | 1745 | int max_iterations = param_max_tail_merge_iterations; |
c9e93168 | 1746 | |
315bbd2e | 1747 | if (!flag_tree_tail_merge |
726338f4 | 1748 | || max_iterations == 0) |
c9e93168 TV |
1749 | return 0; |
1750 | ||
1751 | timevar_push (TV_TREE_TAIL_MERGE); | |
1752 | ||
ebc853de RB |
1753 | /* Re-split critical edges when PRE did a CFG cleanup. */ |
1754 | if (need_crit_edge_split) | |
1755 | split_edges_for_insertion (); | |
7581ce9a | 1756 | |
9c370032 RB |
1757 | if (!dom_info_available_p (CDI_DOMINATORS)) |
1758 | { | |
1759 | /* PRE can leave us with unreachable blocks, remove them now. */ | |
1760 | delete_unreachable_blocks (); | |
1761 | calculate_dominance_info (CDI_DOMINATORS); | |
1762 | } | |
c9e93168 TV |
1763 | init_worklist (); |
1764 | ||
9771b263 | 1765 | while (!worklist.is_empty ()) |
c9e93168 TV |
1766 | { |
1767 | if (!loop_entered) | |
1768 | { | |
1769 | loop_entered = true; | |
1770 | alloc_cluster_vectors (); | |
1771 | update_bbs = BITMAP_ALLOC (NULL); | |
1772 | } | |
1773 | else | |
1774 | reset_cluster_vectors (); | |
1775 | ||
1776 | iteration_nr++; | |
1777 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1778 | fprintf (dump_file, "worklist iteration #%d\n", iteration_nr); | |
1779 | ||
1780 | find_clusters (); | |
9771b263 DN |
1781 | gcc_assert (worklist.is_empty ()); |
1782 | if (all_clusters.is_empty ()) | |
c9e93168 TV |
1783 | break; |
1784 | ||
643400b8 | 1785 | nr_bbs_removed = apply_clusters (); |
c9e93168 TV |
1786 | nr_bbs_removed_total += nr_bbs_removed; |
1787 | if (nr_bbs_removed == 0) | |
1788 | break; | |
1789 | ||
643400b8 | 1790 | free_dominance_info (CDI_DOMINATORS); |
c9e93168 TV |
1791 | |
1792 | if (iteration_nr == max_iterations) | |
1793 | break; | |
1794 | ||
643400b8 | 1795 | calculate_dominance_info (CDI_DOMINATORS); |
c9e93168 TV |
1796 | update_worklist (); |
1797 | } | |
1798 | ||
1799 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1800 | fprintf (dump_file, "htab collision / search: %f\n", | |
c203e8a7 | 1801 | same_succ_htab->collisions ()); |
c9e93168 TV |
1802 | |
1803 | if (nr_bbs_removed_total > 0) | |
1804 | { | |
79e9f721 | 1805 | if (MAY_HAVE_DEBUG_BIND_STMTS) |
643400b8 TV |
1806 | { |
1807 | calculate_dominance_info (CDI_DOMINATORS); | |
1808 | update_debug_stmts (); | |
1809 | } | |
c9e93168 TV |
1810 | |
1811 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1812 | { | |
1813 | fprintf (dump_file, "Before TODOs.\n"); | |
1814 | dump_function_to_file (current_function_decl, dump_file, dump_flags); | |
1815 | } | |
1816 | ||
525174a2 | 1817 | mark_virtual_operands_for_renaming (cfun); |
c9e93168 TV |
1818 | } |
1819 | ||
1820 | delete_worklist (); | |
1821 | if (loop_entered) | |
1822 | { | |
1823 | delete_cluster_vectors (); | |
1824 | BITMAP_FREE (update_bbs); | |
1825 | } | |
1826 | ||
1827 | timevar_pop (TV_TREE_TAIL_MERGE); | |
1828 | ||
2f62294d | 1829 | return 0; |
c9e93168 | 1830 | } |