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51385f30 | 1 | /* Tail merging for gimple. |
d353bf18 | 2 | Copyright (C) 2011-2015 Free Software Foundation, Inc. |
51385f30 | 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) | |
95 | 6 [100.0%] (fallthru,exec) | |
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), | |
100 | .MEMD.3923_18(6)> | |
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 | ||
a441795e | 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 | ||
51385f30 | 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" | |
191 | #include "tm.h" | |
b20a8bb4 | 192 | #include "hash-set.h" |
193 | #include "machmode.h" | |
194 | #include "vec.h" | |
195 | #include "double-int.h" | |
196 | #include "input.h" | |
197 | #include "alias.h" | |
198 | #include "symtab.h" | |
199 | #include "wide-int.h" | |
200 | #include "inchash.h" | |
201 | #include "real.h" | |
51385f30 | 202 | #include "tree.h" |
b20a8bb4 | 203 | #include "fold-const.h" |
9ed99284 | 204 | #include "stor-layout.h" |
205 | #include "trans-mem.h" | |
6b214d09 | 206 | #include "inchash.h" |
51385f30 | 207 | #include "tm_p.h" |
94ea8568 | 208 | #include "predict.h" |
a3020f2f | 209 | #include "hard-reg-set.h" |
210 | #include "input.h" | |
51385f30 | 211 | #include "function.h" |
94ea8568 | 212 | #include "dominance.h" |
213 | #include "cfg.h" | |
214 | #include "cfganal.h" | |
215 | #include "cfgcleanup.h" | |
216 | #include "basic-block.h" | |
217 | #include "flags.h" | |
bc61cadb | 218 | #include "hash-table.h" |
219 | #include "tree-ssa-alias.h" | |
220 | #include "internal-fn.h" | |
221 | #include "tree-eh.h" | |
222 | #include "gimple-expr.h" | |
223 | #include "is-a.h" | |
073c1fd5 | 224 | #include "gimple.h" |
dcf1a1ec | 225 | #include "gimple-iterator.h" |
073c1fd5 | 226 | #include "gimple-ssa.h" |
227 | #include "tree-cfg.h" | |
228 | #include "tree-phinodes.h" | |
229 | #include "ssa-iterators.h" | |
230 | #include "tree-into-ssa.h" | |
51385f30 | 231 | #include "params.h" |
51385f30 | 232 | #include "gimple-pretty-print.h" |
233 | #include "tree-ssa-sccvn.h" | |
234 | #include "tree-dump.h" | |
f6568ea4 | 235 | #include "cfgloop.h" |
b9ed1410 | 236 | #include "tree-pass.h" |
e797f49f | 237 | #include "trans-mem.h" |
b9ed1410 | 238 | |
51385f30 | 239 | /* Describes a group of bbs with the same successors. The successor bbs are |
240 | cached in succs, and the successor edge flags are cached in succ_flags. | |
ee5b36af | 241 | If a bb has the EDGE_TRUE/FALSE_VALUE flags swapped compared to succ_flags, |
51385f30 | 242 | it's marked in inverse. |
243 | Additionally, the hash value for the struct is cached in hashval, and | |
244 | in_worklist indicates whether it's currently part of worklist. */ | |
245 | ||
246 | struct same_succ_def | |
247 | { | |
248 | /* The bbs that have the same successor bbs. */ | |
249 | bitmap bbs; | |
250 | /* The successor bbs. */ | |
251 | bitmap succs; | |
252 | /* Indicates whether the EDGE_TRUE/FALSE_VALUEs of succ_flags are swapped for | |
253 | bb. */ | |
254 | bitmap inverse; | |
255 | /* The edge flags for each of the successor bbs. */ | |
f1f41a6c | 256 | vec<int> succ_flags; |
51385f30 | 257 | /* Indicates whether the struct is currently in the worklist. */ |
258 | bool in_worklist; | |
259 | /* The hash value of the struct. */ | |
260 | hashval_t hashval; | |
494bbaae | 261 | |
262 | /* hash_table support. */ | |
9969c043 | 263 | typedef same_succ_def *value_type; |
264 | typedef same_succ_def *compare_type; | |
265 | static inline hashval_t hash (const same_succ_def *); | |
266 | static int equal (const same_succ_def *, const same_succ_def *); | |
267 | static void remove (same_succ_def *); | |
51385f30 | 268 | }; |
269 | typedef struct same_succ_def *same_succ; | |
270 | typedef const struct same_succ_def *const_same_succ; | |
271 | ||
494bbaae | 272 | /* hash routine for hash_table support, returns hashval of E. */ |
273 | ||
274 | inline hashval_t | |
9969c043 | 275 | same_succ_def::hash (const same_succ_def *e) |
494bbaae | 276 | { |
277 | return e->hashval; | |
278 | } | |
279 | ||
51385f30 | 280 | /* A group of bbs where 1 bb from bbs can replace the other bbs. */ |
281 | ||
282 | struct bb_cluster_def | |
283 | { | |
284 | /* The bbs in the cluster. */ | |
285 | bitmap bbs; | |
286 | /* The preds of the bbs in the cluster. */ | |
287 | bitmap preds; | |
288 | /* Index in all_clusters vector. */ | |
289 | int index; | |
290 | /* The bb to replace the cluster with. */ | |
291 | basic_block rep_bb; | |
292 | }; | |
293 | typedef struct bb_cluster_def *bb_cluster; | |
294 | typedef const struct bb_cluster_def *const_bb_cluster; | |
295 | ||
296 | /* Per bb-info. */ | |
297 | ||
298 | struct aux_bb_info | |
299 | { | |
300 | /* The number of non-debug statements in the bb. */ | |
301 | int size; | |
302 | /* The same_succ that this bb is a member of. */ | |
303 | same_succ bb_same_succ; | |
304 | /* The cluster that this bb is a member of. */ | |
305 | bb_cluster cluster; | |
306 | /* The vop state at the exit of a bb. This is shortlived data, used to | |
307 | communicate data between update_block_by and update_vuses. */ | |
308 | tree vop_at_exit; | |
309 | /* The bb that either contains or is dominated by the dependencies of the | |
310 | bb. */ | |
311 | basic_block dep_bb; | |
312 | }; | |
313 | ||
314 | /* Macros to access the fields of struct aux_bb_info. */ | |
315 | ||
316 | #define BB_SIZE(bb) (((struct aux_bb_info *)bb->aux)->size) | |
317 | #define BB_SAME_SUCC(bb) (((struct aux_bb_info *)bb->aux)->bb_same_succ) | |
318 | #define BB_CLUSTER(bb) (((struct aux_bb_info *)bb->aux)->cluster) | |
319 | #define BB_VOP_AT_EXIT(bb) (((struct aux_bb_info *)bb->aux)->vop_at_exit) | |
320 | #define BB_DEP_BB(bb) (((struct aux_bb_info *)bb->aux)->dep_bb) | |
321 | ||
162fb1a4 | 322 | /* Returns true if the only effect a statement STMT has, is to define locally |
323 | used SSA_NAMEs. */ | |
324 | ||
325 | static bool | |
326 | stmt_local_def (gimple stmt) | |
327 | { | |
328 | basic_block bb, def_bb; | |
329 | imm_use_iterator iter; | |
330 | use_operand_p use_p; | |
331 | tree val; | |
332 | def_operand_p def_p; | |
333 | ||
89c1152a | 334 | if (gimple_vdef (stmt) != NULL_TREE |
335 | || gimple_has_side_effects (stmt) | |
cac6d71b | 336 | || gimple_could_trap_p_1 (stmt, false, false) |
337 | || gimple_vuse (stmt) != NULL_TREE) | |
162fb1a4 | 338 | return false; |
339 | ||
340 | def_p = SINGLE_SSA_DEF_OPERAND (stmt, SSA_OP_DEF); | |
341 | if (def_p == NULL) | |
342 | return false; | |
343 | ||
344 | val = DEF_FROM_PTR (def_p); | |
345 | if (val == NULL_TREE || TREE_CODE (val) != SSA_NAME) | |
346 | return false; | |
347 | ||
348 | def_bb = gimple_bb (stmt); | |
349 | ||
350 | FOR_EACH_IMM_USE_FAST (use_p, iter, val) | |
351 | { | |
352 | if (is_gimple_debug (USE_STMT (use_p))) | |
353 | continue; | |
354 | bb = gimple_bb (USE_STMT (use_p)); | |
355 | if (bb == def_bb) | |
356 | continue; | |
357 | ||
358 | if (gimple_code (USE_STMT (use_p)) == GIMPLE_PHI | |
359 | && EDGE_PRED (bb, PHI_ARG_INDEX_FROM_USE (use_p))->src == def_bb) | |
360 | continue; | |
361 | ||
362 | return false; | |
363 | } | |
364 | ||
365 | return true; | |
366 | } | |
367 | ||
368 | /* Let GSI skip forwards over local defs. */ | |
369 | ||
370 | static void | |
371 | gsi_advance_fw_nondebug_nonlocal (gimple_stmt_iterator *gsi) | |
372 | { | |
373 | gimple stmt; | |
374 | ||
375 | while (true) | |
376 | { | |
377 | if (gsi_end_p (*gsi)) | |
378 | return; | |
379 | stmt = gsi_stmt (*gsi); | |
380 | if (!stmt_local_def (stmt)) | |
381 | return; | |
382 | gsi_next_nondebug (gsi); | |
383 | } | |
384 | } | |
385 | ||
51385f30 | 386 | /* VAL1 and VAL2 are either: |
387 | - uses in BB1 and BB2, or | |
388 | - phi alternatives for BB1 and BB2. | |
389 | Return true if the uses have the same gvn value. */ | |
390 | ||
391 | static bool | |
392 | gvn_uses_equal (tree val1, tree val2) | |
393 | { | |
394 | gcc_checking_assert (val1 != NULL_TREE && val2 != NULL_TREE); | |
395 | ||
396 | if (val1 == val2) | |
397 | return true; | |
398 | ||
399 | if (vn_valueize (val1) != vn_valueize (val2)) | |
400 | return false; | |
401 | ||
402 | return ((TREE_CODE (val1) == SSA_NAME || CONSTANT_CLASS_P (val1)) | |
403 | && (TREE_CODE (val2) == SSA_NAME || CONSTANT_CLASS_P (val2))); | |
404 | } | |
405 | ||
406 | /* Prints E to FILE. */ | |
407 | ||
408 | static void | |
409 | same_succ_print (FILE *file, const same_succ e) | |
410 | { | |
411 | unsigned int i; | |
412 | bitmap_print (file, e->bbs, "bbs:", "\n"); | |
413 | bitmap_print (file, e->succs, "succs:", "\n"); | |
414 | bitmap_print (file, e->inverse, "inverse:", "\n"); | |
415 | fprintf (file, "flags:"); | |
f1f41a6c | 416 | for (i = 0; i < e->succ_flags.length (); ++i) |
417 | fprintf (file, " %x", e->succ_flags[i]); | |
51385f30 | 418 | fprintf (file, "\n"); |
419 | } | |
420 | ||
421 | /* Prints same_succ VE to VFILE. */ | |
422 | ||
2b15d2ba | 423 | inline int |
424 | ssa_same_succ_print_traverse (same_succ *pe, FILE *file) | |
51385f30 | 425 | { |
2b15d2ba | 426 | const same_succ e = *pe; |
51385f30 | 427 | same_succ_print (file, e); |
428 | return 1; | |
429 | } | |
430 | ||
431 | /* Update BB_DEP_BB (USE_BB), given a use of VAL in USE_BB. */ | |
432 | ||
433 | static void | |
434 | update_dep_bb (basic_block use_bb, tree val) | |
435 | { | |
436 | basic_block dep_bb; | |
437 | ||
438 | /* Not a dep. */ | |
439 | if (TREE_CODE (val) != SSA_NAME) | |
440 | return; | |
441 | ||
442 | /* Skip use of global def. */ | |
443 | if (SSA_NAME_IS_DEFAULT_DEF (val)) | |
444 | return; | |
445 | ||
446 | /* Skip use of local def. */ | |
447 | dep_bb = gimple_bb (SSA_NAME_DEF_STMT (val)); | |
448 | if (dep_bb == use_bb) | |
449 | return; | |
450 | ||
451 | if (BB_DEP_BB (use_bb) == NULL | |
452 | || dominated_by_p (CDI_DOMINATORS, dep_bb, BB_DEP_BB (use_bb))) | |
453 | BB_DEP_BB (use_bb) = dep_bb; | |
454 | } | |
455 | ||
456 | /* Update BB_DEP_BB, given the dependencies in STMT. */ | |
457 | ||
458 | static void | |
459 | stmt_update_dep_bb (gimple stmt) | |
460 | { | |
461 | ssa_op_iter iter; | |
462 | use_operand_p use; | |
463 | ||
464 | FOR_EACH_SSA_USE_OPERAND (use, stmt, iter, SSA_OP_USE) | |
465 | update_dep_bb (gimple_bb (stmt), USE_FROM_PTR (use)); | |
466 | } | |
467 | ||
51385f30 | 468 | /* Calculates hash value for same_succ VE. */ |
469 | ||
494bbaae | 470 | static hashval_t |
471 | same_succ_hash (const_same_succ e) | |
51385f30 | 472 | { |
13c579bb | 473 | inchash::hash hstate (bitmap_hash (e->succs)); |
51385f30 | 474 | int flags; |
475 | unsigned int i; | |
476 | unsigned int first = bitmap_first_set_bit (e->bbs); | |
f5a6b05f | 477 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, first); |
51385f30 | 478 | int size = 0; |
51385f30 | 479 | gimple stmt; |
480 | tree arg; | |
481 | unsigned int s; | |
482 | bitmap_iterator bs; | |
483 | ||
1a91d914 | 484 | for (gimple_stmt_iterator gsi = gsi_start_nondebug_bb (bb); |
51385f30 | 485 | !gsi_end_p (gsi); gsi_next_nondebug (&gsi)) |
486 | { | |
487 | stmt = gsi_stmt (gsi); | |
488 | stmt_update_dep_bb (stmt); | |
162fb1a4 | 489 | if (stmt_local_def (stmt)) |
51385f30 | 490 | continue; |
491 | size++; | |
492 | ||
13c579bb | 493 | hstate.add_int (gimple_code (stmt)); |
51385f30 | 494 | if (is_gimple_assign (stmt)) |
13c579bb | 495 | hstate.add_int (gimple_assign_rhs_code (stmt)); |
51385f30 | 496 | if (!is_gimple_call (stmt)) |
497 | continue; | |
498 | if (gimple_call_internal_p (stmt)) | |
13c579bb | 499 | hstate.add_int (gimple_call_internal_fn (stmt)); |
51385f30 | 500 | else |
4be182b9 | 501 | { |
13c579bb | 502 | inchash::add_expr (gimple_call_fn (stmt), hstate); |
4be182b9 | 503 | if (gimple_call_chain (stmt)) |
13c579bb | 504 | inchash::add_expr (gimple_call_chain (stmt), hstate); |
4be182b9 | 505 | } |
51385f30 | 506 | for (i = 0; i < gimple_call_num_args (stmt); i++) |
507 | { | |
508 | arg = gimple_call_arg (stmt, i); | |
509 | arg = vn_valueize (arg); | |
13c579bb | 510 | inchash::add_expr (arg, hstate); |
51385f30 | 511 | } |
512 | } | |
513 | ||
13c579bb | 514 | hstate.add_int (size); |
51385f30 | 515 | BB_SIZE (bb) = size; |
516 | ||
f1f41a6c | 517 | for (i = 0; i < e->succ_flags.length (); ++i) |
51385f30 | 518 | { |
f1f41a6c | 519 | flags = e->succ_flags[i]; |
51385f30 | 520 | flags = flags & ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); |
13c579bb | 521 | hstate.add_int (flags); |
51385f30 | 522 | } |
523 | ||
524 | EXECUTE_IF_SET_IN_BITMAP (e->succs, 0, s, bs) | |
525 | { | |
f5a6b05f | 526 | int n = find_edge (bb, BASIC_BLOCK_FOR_FN (cfun, s))->dest_idx; |
1a91d914 | 527 | for (gphi_iterator gsi = gsi_start_phis (BASIC_BLOCK_FOR_FN (cfun, s)); |
528 | !gsi_end_p (gsi); | |
51385f30 | 529 | gsi_next (&gsi)) |
530 | { | |
1a91d914 | 531 | gphi *phi = gsi.phi (); |
51385f30 | 532 | tree lhs = gimple_phi_result (phi); |
533 | tree val = gimple_phi_arg_def (phi, n); | |
534 | ||
7c782c9b | 535 | if (virtual_operand_p (lhs)) |
51385f30 | 536 | continue; |
537 | update_dep_bb (bb, val); | |
538 | } | |
539 | } | |
540 | ||
13c579bb | 541 | return hstate.end (); |
51385f30 | 542 | } |
543 | ||
544 | /* Returns true if E1 and E2 have 2 successors, and if the successor flags | |
545 | are inverse for the EDGE_TRUE_VALUE and EDGE_FALSE_VALUE flags, and equal for | |
546 | the other edge flags. */ | |
547 | ||
548 | static bool | |
549 | inverse_flags (const_same_succ e1, const_same_succ e2) | |
550 | { | |
551 | int f1a, f1b, f2a, f2b; | |
552 | int mask = ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); | |
553 | ||
f1f41a6c | 554 | if (e1->succ_flags.length () != 2) |
51385f30 | 555 | return false; |
556 | ||
f1f41a6c | 557 | f1a = e1->succ_flags[0]; |
558 | f1b = e1->succ_flags[1]; | |
559 | f2a = e2->succ_flags[0]; | |
560 | f2b = e2->succ_flags[1]; | |
51385f30 | 561 | |
562 | if (f1a == f2a && f1b == f2b) | |
563 | return false; | |
564 | ||
565 | return (f1a & mask) == (f2a & mask) && (f1b & mask) == (f2b & mask); | |
566 | } | |
567 | ||
494bbaae | 568 | /* Compares SAME_SUCCs E1 and E2. */ |
51385f30 | 569 | |
2b15d2ba | 570 | int |
9969c043 | 571 | same_succ_def::equal (const same_succ_def *e1, const same_succ_def *e2) |
51385f30 | 572 | { |
51385f30 | 573 | unsigned int i, first1, first2; |
574 | gimple_stmt_iterator gsi1, gsi2; | |
575 | gimple s1, s2; | |
576 | basic_block bb1, bb2; | |
577 | ||
578 | if (e1->hashval != e2->hashval) | |
579 | return 0; | |
580 | ||
f1f41a6c | 581 | if (e1->succ_flags.length () != e2->succ_flags.length ()) |
51385f30 | 582 | return 0; |
583 | ||
584 | if (!bitmap_equal_p (e1->succs, e2->succs)) | |
585 | return 0; | |
586 | ||
587 | if (!inverse_flags (e1, e2)) | |
588 | { | |
f1f41a6c | 589 | for (i = 0; i < e1->succ_flags.length (); ++i) |
fd2e7f43 | 590 | if (e1->succ_flags[i] != e2->succ_flags[i]) |
51385f30 | 591 | return 0; |
592 | } | |
593 | ||
594 | first1 = bitmap_first_set_bit (e1->bbs); | |
595 | first2 = bitmap_first_set_bit (e2->bbs); | |
596 | ||
f5a6b05f | 597 | bb1 = BASIC_BLOCK_FOR_FN (cfun, first1); |
598 | bb2 = BASIC_BLOCK_FOR_FN (cfun, first2); | |
51385f30 | 599 | |
600 | if (BB_SIZE (bb1) != BB_SIZE (bb2)) | |
601 | return 0; | |
602 | ||
603 | gsi1 = gsi_start_nondebug_bb (bb1); | |
604 | gsi2 = gsi_start_nondebug_bb (bb2); | |
162fb1a4 | 605 | gsi_advance_fw_nondebug_nonlocal (&gsi1); |
606 | gsi_advance_fw_nondebug_nonlocal (&gsi2); | |
51385f30 | 607 | while (!(gsi_end_p (gsi1) || gsi_end_p (gsi2))) |
608 | { | |
609 | s1 = gsi_stmt (gsi1); | |
610 | s2 = gsi_stmt (gsi2); | |
611 | if (gimple_code (s1) != gimple_code (s2)) | |
612 | return 0; | |
613 | if (is_gimple_call (s1) && !gimple_call_same_target_p (s1, s2)) | |
614 | return 0; | |
615 | gsi_next_nondebug (&gsi1); | |
616 | gsi_next_nondebug (&gsi2); | |
162fb1a4 | 617 | gsi_advance_fw_nondebug_nonlocal (&gsi1); |
618 | gsi_advance_fw_nondebug_nonlocal (&gsi2); | |
51385f30 | 619 | } |
620 | ||
621 | return 1; | |
622 | } | |
623 | ||
624 | /* Alloc and init a new SAME_SUCC. */ | |
625 | ||
626 | static same_succ | |
627 | same_succ_alloc (void) | |
628 | { | |
629 | same_succ same = XNEW (struct same_succ_def); | |
630 | ||
631 | same->bbs = BITMAP_ALLOC (NULL); | |
632 | same->succs = BITMAP_ALLOC (NULL); | |
633 | same->inverse = BITMAP_ALLOC (NULL); | |
f1f41a6c | 634 | same->succ_flags.create (10); |
51385f30 | 635 | same->in_worklist = false; |
636 | ||
637 | return same; | |
638 | } | |
639 | ||
494bbaae | 640 | /* Delete same_succ E. */ |
51385f30 | 641 | |
494bbaae | 642 | void |
643 | same_succ_def::remove (same_succ e) | |
51385f30 | 644 | { |
51385f30 | 645 | BITMAP_FREE (e->bbs); |
646 | BITMAP_FREE (e->succs); | |
647 | BITMAP_FREE (e->inverse); | |
f1f41a6c | 648 | e->succ_flags.release (); |
51385f30 | 649 | |
2b15d2ba | 650 | XDELETE (e); |
51385f30 | 651 | } |
652 | ||
653 | /* Reset same_succ SAME. */ | |
654 | ||
655 | static void | |
656 | same_succ_reset (same_succ same) | |
657 | { | |
658 | bitmap_clear (same->bbs); | |
659 | bitmap_clear (same->succs); | |
660 | bitmap_clear (same->inverse); | |
f1f41a6c | 661 | same->succ_flags.truncate (0); |
51385f30 | 662 | } |
663 | ||
c1f445d2 | 664 | static hash_table<same_succ_def> *same_succ_htab; |
51385f30 | 665 | |
666 | /* Array that is used to store the edge flags for a successor. */ | |
667 | ||
668 | static int *same_succ_edge_flags; | |
669 | ||
670 | /* Bitmap that is used to mark bbs that are recently deleted. */ | |
671 | ||
672 | static bitmap deleted_bbs; | |
673 | ||
674 | /* Bitmap that is used to mark predecessors of bbs that are | |
675 | deleted. */ | |
676 | ||
677 | static bitmap deleted_bb_preds; | |
678 | ||
679 | /* Prints same_succ_htab to stderr. */ | |
680 | ||
681 | extern void debug_same_succ (void); | |
682 | DEBUG_FUNCTION void | |
683 | debug_same_succ ( void) | |
684 | { | |
c1f445d2 | 685 | same_succ_htab->traverse <FILE *, ssa_same_succ_print_traverse> (stderr); |
51385f30 | 686 | } |
687 | ||
51385f30 | 688 | |
689 | /* Vector of bbs to process. */ | |
690 | ||
f1f41a6c | 691 | static vec<same_succ> worklist; |
51385f30 | 692 | |
693 | /* Prints worklist to FILE. */ | |
694 | ||
695 | static void | |
696 | print_worklist (FILE *file) | |
697 | { | |
698 | unsigned int i; | |
f1f41a6c | 699 | for (i = 0; i < worklist.length (); ++i) |
700 | same_succ_print (file, worklist[i]); | |
51385f30 | 701 | } |
702 | ||
703 | /* Adds SAME to worklist. */ | |
704 | ||
705 | static void | |
706 | add_to_worklist (same_succ same) | |
707 | { | |
708 | if (same->in_worklist) | |
709 | return; | |
710 | ||
711 | if (bitmap_count_bits (same->bbs) < 2) | |
712 | return; | |
713 | ||
714 | same->in_worklist = true; | |
f1f41a6c | 715 | worklist.safe_push (same); |
51385f30 | 716 | } |
717 | ||
718 | /* Add BB to same_succ_htab. */ | |
719 | ||
720 | static void | |
721 | find_same_succ_bb (basic_block bb, same_succ *same_p) | |
722 | { | |
723 | unsigned int j; | |
724 | bitmap_iterator bj; | |
725 | same_succ same = *same_p; | |
726 | same_succ *slot; | |
727 | edge_iterator ei; | |
728 | edge e; | |
729 | ||
c48f77d5 | 730 | if (bb == NULL |
731 | /* Be conservative with loop structure. It's not evident that this test | |
732 | is sufficient. Before tail-merge, we've just called | |
733 | loop_optimizer_finalize, and LOOPS_MAY_HAVE_MULTIPLE_LATCHES is now | |
734 | set, so there's no guarantee that the loop->latch value is still valid. | |
735 | But we assume that, since we've forced LOOPS_HAVE_SIMPLE_LATCHES at the | |
736 | start of pre, we've kept that property intact throughout pre, and are | |
737 | keeping it throughout tail-merge using this test. */ | |
738 | || bb->loop_father->latch == bb) | |
51385f30 | 739 | return; |
740 | bitmap_set_bit (same->bbs, bb->index); | |
741 | FOR_EACH_EDGE (e, ei, bb->succs) | |
742 | { | |
743 | int index = e->dest->index; | |
744 | bitmap_set_bit (same->succs, index); | |
745 | same_succ_edge_flags[index] = e->flags; | |
746 | } | |
747 | EXECUTE_IF_SET_IN_BITMAP (same->succs, 0, j, bj) | |
f1f41a6c | 748 | same->succ_flags.safe_push (same_succ_edge_flags[j]); |
51385f30 | 749 | |
494bbaae | 750 | same->hashval = same_succ_hash (same); |
51385f30 | 751 | |
c1f445d2 | 752 | slot = same_succ_htab->find_slot_with_hash (same, same->hashval, INSERT); |
51385f30 | 753 | if (*slot == NULL) |
754 | { | |
755 | *slot = same; | |
756 | BB_SAME_SUCC (bb) = same; | |
757 | add_to_worklist (same); | |
758 | *same_p = NULL; | |
759 | } | |
760 | else | |
761 | { | |
762 | bitmap_set_bit ((*slot)->bbs, bb->index); | |
763 | BB_SAME_SUCC (bb) = *slot; | |
764 | add_to_worklist (*slot); | |
765 | if (inverse_flags (same, *slot)) | |
766 | bitmap_set_bit ((*slot)->inverse, bb->index); | |
767 | same_succ_reset (same); | |
768 | } | |
769 | } | |
770 | ||
771 | /* Find bbs with same successors. */ | |
772 | ||
773 | static void | |
774 | find_same_succ (void) | |
775 | { | |
776 | same_succ same = same_succ_alloc (); | |
777 | basic_block bb; | |
778 | ||
fc00614f | 779 | FOR_EACH_BB_FN (bb, cfun) |
51385f30 | 780 | { |
781 | find_same_succ_bb (bb, &same); | |
782 | if (same == NULL) | |
783 | same = same_succ_alloc (); | |
784 | } | |
785 | ||
494bbaae | 786 | same_succ_def::remove (same); |
51385f30 | 787 | } |
788 | ||
789 | /* Initializes worklist administration. */ | |
790 | ||
791 | static void | |
792 | init_worklist (void) | |
793 | { | |
794 | alloc_aux_for_blocks (sizeof (struct aux_bb_info)); | |
c1f445d2 | 795 | same_succ_htab = new hash_table<same_succ_def> (n_basic_blocks_for_fn (cfun)); |
fe672ac0 | 796 | same_succ_edge_flags = XCNEWVEC (int, last_basic_block_for_fn (cfun)); |
51385f30 | 797 | deleted_bbs = BITMAP_ALLOC (NULL); |
798 | deleted_bb_preds = BITMAP_ALLOC (NULL); | |
a28770e1 | 799 | worklist.create (n_basic_blocks_for_fn (cfun)); |
51385f30 | 800 | find_same_succ (); |
801 | ||
802 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
803 | { | |
804 | fprintf (dump_file, "initial worklist:\n"); | |
805 | print_worklist (dump_file); | |
806 | } | |
807 | } | |
808 | ||
809 | /* Deletes worklist administration. */ | |
810 | ||
811 | static void | |
812 | delete_worklist (void) | |
813 | { | |
814 | free_aux_for_blocks (); | |
c1f445d2 | 815 | delete same_succ_htab; |
816 | same_succ_htab = NULL; | |
51385f30 | 817 | XDELETEVEC (same_succ_edge_flags); |
818 | same_succ_edge_flags = NULL; | |
819 | BITMAP_FREE (deleted_bbs); | |
820 | BITMAP_FREE (deleted_bb_preds); | |
f1f41a6c | 821 | worklist.release (); |
51385f30 | 822 | } |
823 | ||
824 | /* Mark BB as deleted, and mark its predecessors. */ | |
825 | ||
826 | static void | |
b1ad75f0 | 827 | mark_basic_block_deleted (basic_block bb) |
51385f30 | 828 | { |
829 | edge e; | |
830 | edge_iterator ei; | |
831 | ||
832 | bitmap_set_bit (deleted_bbs, bb->index); | |
833 | ||
834 | FOR_EACH_EDGE (e, ei, bb->preds) | |
835 | bitmap_set_bit (deleted_bb_preds, e->src->index); | |
836 | } | |
837 | ||
d2e5e5c3 | 838 | /* Removes BB from its corresponding same_succ. */ |
839 | ||
840 | static void | |
841 | same_succ_flush_bb (basic_block bb) | |
842 | { | |
843 | same_succ same = BB_SAME_SUCC (bb); | |
844 | BB_SAME_SUCC (bb) = NULL; | |
845 | if (bitmap_single_bit_set_p (same->bbs)) | |
c1f445d2 | 846 | same_succ_htab->remove_elt_with_hash (same, same->hashval); |
d2e5e5c3 | 847 | else |
848 | bitmap_clear_bit (same->bbs, bb->index); | |
849 | } | |
850 | ||
51385f30 | 851 | /* Removes all bbs in BBS from their corresponding same_succ. */ |
852 | ||
853 | static void | |
854 | same_succ_flush_bbs (bitmap bbs) | |
855 | { | |
856 | unsigned int i; | |
857 | bitmap_iterator bi; | |
858 | ||
859 | EXECUTE_IF_SET_IN_BITMAP (bbs, 0, i, bi) | |
f5a6b05f | 860 | same_succ_flush_bb (BASIC_BLOCK_FOR_FN (cfun, i)); |
51385f30 | 861 | } |
862 | ||
ff11bbd5 | 863 | /* Release the last vdef in BB, either normal or phi result. */ |
864 | ||
865 | static void | |
866 | release_last_vdef (basic_block bb) | |
867 | { | |
1a91d914 | 868 | for (gimple_stmt_iterator i = gsi_last_bb (bb); !gsi_end_p (i); |
869 | gsi_prev_nondebug (&i)) | |
ff11bbd5 | 870 | { |
871 | gimple stmt = gsi_stmt (i); | |
872 | if (gimple_vdef (stmt) == NULL_TREE) | |
873 | continue; | |
874 | ||
875 | mark_virtual_operand_for_renaming (gimple_vdef (stmt)); | |
876 | return; | |
877 | } | |
878 | ||
1a91d914 | 879 | for (gphi_iterator i = gsi_start_phis (bb); !gsi_end_p (i); |
880 | gsi_next (&i)) | |
ff11bbd5 | 881 | { |
1a91d914 | 882 | gphi *phi = i.phi (); |
ff11bbd5 | 883 | tree res = gimple_phi_result (phi); |
884 | ||
7c782c9b | 885 | if (!virtual_operand_p (res)) |
ff11bbd5 | 886 | continue; |
887 | ||
888 | mark_virtual_phi_result_for_renaming (phi); | |
889 | return; | |
890 | } | |
891 | ||
892 | } | |
893 | ||
51385f30 | 894 | /* For deleted_bb_preds, find bbs with same successors. */ |
895 | ||
896 | static void | |
897 | update_worklist (void) | |
898 | { | |
899 | unsigned int i; | |
900 | bitmap_iterator bi; | |
901 | basic_block bb; | |
902 | same_succ same; | |
903 | ||
b1ad75f0 | 904 | bitmap_and_compl_into (deleted_bb_preds, deleted_bbs); |
905 | bitmap_clear (deleted_bbs); | |
906 | ||
51385f30 | 907 | bitmap_clear_bit (deleted_bb_preds, ENTRY_BLOCK); |
908 | same_succ_flush_bbs (deleted_bb_preds); | |
909 | ||
910 | same = same_succ_alloc (); | |
911 | EXECUTE_IF_SET_IN_BITMAP (deleted_bb_preds, 0, i, bi) | |
912 | { | |
f5a6b05f | 913 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
51385f30 | 914 | gcc_assert (bb != NULL); |
915 | find_same_succ_bb (bb, &same); | |
916 | if (same == NULL) | |
917 | same = same_succ_alloc (); | |
918 | } | |
494bbaae | 919 | same_succ_def::remove (same); |
51385f30 | 920 | bitmap_clear (deleted_bb_preds); |
921 | } | |
922 | ||
923 | /* Prints cluster C to FILE. */ | |
924 | ||
925 | static void | |
926 | print_cluster (FILE *file, bb_cluster c) | |
927 | { | |
928 | if (c == NULL) | |
929 | return; | |
930 | bitmap_print (file, c->bbs, "bbs:", "\n"); | |
931 | bitmap_print (file, c->preds, "preds:", "\n"); | |
932 | } | |
933 | ||
934 | /* Prints cluster C to stderr. */ | |
935 | ||
936 | extern void debug_cluster (bb_cluster); | |
937 | DEBUG_FUNCTION void | |
938 | debug_cluster (bb_cluster c) | |
939 | { | |
940 | print_cluster (stderr, c); | |
941 | } | |
942 | ||
943 | /* Update C->rep_bb, given that BB is added to the cluster. */ | |
944 | ||
945 | static void | |
946 | update_rep_bb (bb_cluster c, basic_block bb) | |
947 | { | |
948 | /* Initial. */ | |
949 | if (c->rep_bb == NULL) | |
950 | { | |
951 | c->rep_bb = bb; | |
952 | return; | |
953 | } | |
954 | ||
955 | /* Current needs no deps, keep it. */ | |
956 | if (BB_DEP_BB (c->rep_bb) == NULL) | |
957 | return; | |
958 | ||
959 | /* Bb needs no deps, change rep_bb. */ | |
960 | if (BB_DEP_BB (bb) == NULL) | |
961 | { | |
962 | c->rep_bb = bb; | |
963 | return; | |
964 | } | |
965 | ||
966 | /* Bb needs last deps earlier than current, change rep_bb. A potential | |
967 | problem with this, is that the first deps might also be earlier, which | |
968 | would mean we prefer longer lifetimes for the deps. To be able to check | |
969 | for this, we would have to trace BB_FIRST_DEP_BB as well, besides | |
970 | BB_DEP_BB, which is really BB_LAST_DEP_BB. | |
971 | The benefit of choosing the bb with last deps earlier, is that it can | |
972 | potentially be used as replacement for more bbs. */ | |
973 | if (dominated_by_p (CDI_DOMINATORS, BB_DEP_BB (c->rep_bb), BB_DEP_BB (bb))) | |
974 | c->rep_bb = bb; | |
975 | } | |
976 | ||
977 | /* Add BB to cluster C. Sets BB in C->bbs, and preds of BB in C->preds. */ | |
978 | ||
979 | static void | |
980 | add_bb_to_cluster (bb_cluster c, basic_block bb) | |
981 | { | |
982 | edge e; | |
983 | edge_iterator ei; | |
984 | ||
985 | bitmap_set_bit (c->bbs, bb->index); | |
986 | ||
987 | FOR_EACH_EDGE (e, ei, bb->preds) | |
988 | bitmap_set_bit (c->preds, e->src->index); | |
989 | ||
990 | update_rep_bb (c, bb); | |
991 | } | |
992 | ||
993 | /* Allocate and init new cluster. */ | |
994 | ||
995 | static bb_cluster | |
996 | new_cluster (void) | |
997 | { | |
998 | bb_cluster c; | |
999 | c = XCNEW (struct bb_cluster_def); | |
1000 | c->bbs = BITMAP_ALLOC (NULL); | |
1001 | c->preds = BITMAP_ALLOC (NULL); | |
1002 | c->rep_bb = NULL; | |
1003 | return c; | |
1004 | } | |
1005 | ||
1006 | /* Delete clusters. */ | |
1007 | ||
1008 | static void | |
1009 | delete_cluster (bb_cluster c) | |
1010 | { | |
1011 | if (c == NULL) | |
1012 | return; | |
1013 | BITMAP_FREE (c->bbs); | |
1014 | BITMAP_FREE (c->preds); | |
1015 | XDELETE (c); | |
1016 | } | |
1017 | ||
51385f30 | 1018 | |
1019 | /* Array that contains all clusters. */ | |
1020 | ||
f1f41a6c | 1021 | static vec<bb_cluster> all_clusters; |
51385f30 | 1022 | |
1023 | /* Allocate all cluster vectors. */ | |
1024 | ||
1025 | static void | |
1026 | alloc_cluster_vectors (void) | |
1027 | { | |
a28770e1 | 1028 | all_clusters.create (n_basic_blocks_for_fn (cfun)); |
51385f30 | 1029 | } |
1030 | ||
1031 | /* Reset all cluster vectors. */ | |
1032 | ||
1033 | static void | |
1034 | reset_cluster_vectors (void) | |
1035 | { | |
1036 | unsigned int i; | |
1037 | basic_block bb; | |
f1f41a6c | 1038 | for (i = 0; i < all_clusters.length (); ++i) |
1039 | delete_cluster (all_clusters[i]); | |
1040 | all_clusters.truncate (0); | |
fc00614f | 1041 | FOR_EACH_BB_FN (bb, cfun) |
51385f30 | 1042 | BB_CLUSTER (bb) = NULL; |
1043 | } | |
1044 | ||
1045 | /* Delete all cluster vectors. */ | |
1046 | ||
1047 | static void | |
1048 | delete_cluster_vectors (void) | |
1049 | { | |
1050 | unsigned int i; | |
f1f41a6c | 1051 | for (i = 0; i < all_clusters.length (); ++i) |
1052 | delete_cluster (all_clusters[i]); | |
1053 | all_clusters.release (); | |
51385f30 | 1054 | } |
1055 | ||
1056 | /* Merge cluster C2 into C1. */ | |
1057 | ||
1058 | static void | |
1059 | merge_clusters (bb_cluster c1, bb_cluster c2) | |
1060 | { | |
1061 | bitmap_ior_into (c1->bbs, c2->bbs); | |
1062 | bitmap_ior_into (c1->preds, c2->preds); | |
1063 | } | |
1064 | ||
1065 | /* Register equivalence of BB1 and BB2 (members of cluster C). Store c in | |
1066 | all_clusters, or merge c with existing cluster. */ | |
1067 | ||
1068 | static void | |
1069 | set_cluster (basic_block bb1, basic_block bb2) | |
1070 | { | |
1071 | basic_block merge_bb, other_bb; | |
1072 | bb_cluster merge, old, c; | |
1073 | ||
1074 | if (BB_CLUSTER (bb1) == NULL && BB_CLUSTER (bb2) == NULL) | |
1075 | { | |
1076 | c = new_cluster (); | |
1077 | add_bb_to_cluster (c, bb1); | |
1078 | add_bb_to_cluster (c, bb2); | |
1079 | BB_CLUSTER (bb1) = c; | |
1080 | BB_CLUSTER (bb2) = c; | |
f1f41a6c | 1081 | c->index = all_clusters.length (); |
1082 | all_clusters.safe_push (c); | |
51385f30 | 1083 | } |
1084 | else if (BB_CLUSTER (bb1) == NULL || BB_CLUSTER (bb2) == NULL) | |
1085 | { | |
1086 | merge_bb = BB_CLUSTER (bb1) == NULL ? bb2 : bb1; | |
1087 | other_bb = BB_CLUSTER (bb1) == NULL ? bb1 : bb2; | |
1088 | merge = BB_CLUSTER (merge_bb); | |
1089 | add_bb_to_cluster (merge, other_bb); | |
1090 | BB_CLUSTER (other_bb) = merge; | |
1091 | } | |
1092 | else if (BB_CLUSTER (bb1) != BB_CLUSTER (bb2)) | |
1093 | { | |
1094 | unsigned int i; | |
1095 | bitmap_iterator bi; | |
1096 | ||
1097 | old = BB_CLUSTER (bb2); | |
1098 | merge = BB_CLUSTER (bb1); | |
1099 | merge_clusters (merge, old); | |
1100 | EXECUTE_IF_SET_IN_BITMAP (old->bbs, 0, i, bi) | |
f5a6b05f | 1101 | BB_CLUSTER (BASIC_BLOCK_FOR_FN (cfun, i)) = merge; |
f1f41a6c | 1102 | all_clusters[old->index] = NULL; |
51385f30 | 1103 | update_rep_bb (merge, old->rep_bb); |
1104 | delete_cluster (old); | |
1105 | } | |
1106 | else | |
1107 | gcc_unreachable (); | |
1108 | } | |
1109 | ||
ba09ff60 | 1110 | /* Return true if gimple operands T1 and T2 have the same value. */ |
1111 | ||
1112 | static bool | |
1113 | gimple_operand_equal_value_p (tree t1, tree t2) | |
1114 | { | |
1115 | if (t1 == t2) | |
1116 | return true; | |
1117 | ||
1118 | if (t1 == NULL_TREE | |
1119 | || t2 == NULL_TREE) | |
1120 | return false; | |
1121 | ||
1122 | if (operand_equal_p (t1, t2, 0)) | |
1123 | return true; | |
1124 | ||
1125 | return gvn_uses_equal (t1, t2); | |
1126 | } | |
1127 | ||
51385f30 | 1128 | /* Return true if gimple statements S1 and S2 are equal. Gimple_bb (s1) and |
1129 | gimple_bb (s2) are members of SAME_SUCC. */ | |
1130 | ||
1131 | static bool | |
1132 | gimple_equal_p (same_succ same_succ, gimple s1, gimple s2) | |
1133 | { | |
1134 | unsigned int i; | |
1135 | tree lhs1, lhs2; | |
1136 | basic_block bb1 = gimple_bb (s1), bb2 = gimple_bb (s2); | |
1137 | tree t1, t2; | |
01f93827 | 1138 | bool inv_cond; |
51385f30 | 1139 | enum tree_code code1, code2; |
1140 | ||
1141 | if (gimple_code (s1) != gimple_code (s2)) | |
1142 | return false; | |
1143 | ||
1144 | switch (gimple_code (s1)) | |
1145 | { | |
1146 | case GIMPLE_CALL: | |
51385f30 | 1147 | if (!gimple_call_same_target_p (s1, s2)) |
1148 | return false; | |
1149 | ||
4be182b9 | 1150 | t1 = gimple_call_chain (s1); |
1151 | t2 = gimple_call_chain (s2); | |
1152 | if (!gimple_operand_equal_value_p (t1, t2)) | |
1153 | return false; | |
1154 | ||
1155 | if (gimple_call_num_args (s1) != gimple_call_num_args (s2)) | |
1156 | return false; | |
1157 | ||
51385f30 | 1158 | for (i = 0; i < gimple_call_num_args (s1); ++i) |
1159 | { | |
1160 | t1 = gimple_call_arg (s1, i); | |
1161 | t2 = gimple_call_arg (s2, i); | |
4be182b9 | 1162 | if (!gimple_operand_equal_value_p (t1, t2)) |
1163 | return false; | |
51385f30 | 1164 | } |
51385f30 | 1165 | |
1166 | lhs1 = gimple_get_lhs (s1); | |
1167 | lhs2 = gimple_get_lhs (s2); | |
87af2d00 | 1168 | if (lhs1 == NULL_TREE && lhs2 == NULL_TREE) |
1169 | return true; | |
1170 | if (lhs1 == NULL_TREE || lhs2 == NULL_TREE) | |
1171 | return false; | |
1172 | if (TREE_CODE (lhs1) == SSA_NAME && TREE_CODE (lhs2) == SSA_NAME) | |
1173 | return vn_valueize (lhs1) == vn_valueize (lhs2); | |
1174 | return operand_equal_p (lhs1, lhs2, 0); | |
51385f30 | 1175 | |
1176 | case GIMPLE_ASSIGN: | |
1177 | lhs1 = gimple_get_lhs (s1); | |
1178 | lhs2 = gimple_get_lhs (s2); | |
fad68b9f | 1179 | if (TREE_CODE (lhs1) != SSA_NAME |
1180 | && TREE_CODE (lhs2) != SSA_NAME) | |
d3a35365 | 1181 | return (operand_equal_p (lhs1, lhs2, 0) |
1182 | && gimple_operand_equal_value_p (gimple_assign_rhs1 (s1), | |
1183 | gimple_assign_rhs1 (s2))); | |
fad68b9f | 1184 | else if (TREE_CODE (lhs1) == SSA_NAME |
1185 | && TREE_CODE (lhs2) == SSA_NAME) | |
cac6d71b | 1186 | return operand_equal_p (gimple_assign_rhs1 (s1), |
1187 | gimple_assign_rhs1 (s2), 0); | |
fad68b9f | 1188 | return false; |
51385f30 | 1189 | |
1190 | case GIMPLE_COND: | |
1191 | t1 = gimple_cond_lhs (s1); | |
1192 | t2 = gimple_cond_lhs (s2); | |
ba09ff60 | 1193 | if (!gimple_operand_equal_value_p (t1, t2)) |
51385f30 | 1194 | return false; |
1195 | ||
1196 | t1 = gimple_cond_rhs (s1); | |
1197 | t2 = gimple_cond_rhs (s2); | |
ba09ff60 | 1198 | if (!gimple_operand_equal_value_p (t1, t2)) |
51385f30 | 1199 | return false; |
1200 | ||
1201 | code1 = gimple_expr_code (s1); | |
1202 | code2 = gimple_expr_code (s2); | |
1203 | inv_cond = (bitmap_bit_p (same_succ->inverse, bb1->index) | |
1204 | != bitmap_bit_p (same_succ->inverse, bb2->index)); | |
1205 | if (inv_cond) | |
1206 | { | |
93633022 | 1207 | bool honor_nans = HONOR_NANS (t1); |
51385f30 | 1208 | code2 = invert_tree_comparison (code2, honor_nans); |
1209 | } | |
1210 | return code1 == code2; | |
1211 | ||
1212 | default: | |
1213 | return false; | |
1214 | } | |
1215 | } | |
1216 | ||
cdd84b7c | 1217 | /* Let GSI skip backwards over local defs. Return the earliest vuse in VUSE. |
1218 | Return true in VUSE_ESCAPED if the vuse influenced a SSA_OP_DEF of one of the | |
1219 | processed statements. */ | |
51385f30 | 1220 | |
1221 | static void | |
cdd84b7c | 1222 | gsi_advance_bw_nondebug_nonlocal (gimple_stmt_iterator *gsi, tree *vuse, |
1223 | bool *vuse_escaped) | |
51385f30 | 1224 | { |
1225 | gimple stmt; | |
cdd84b7c | 1226 | tree lvuse; |
51385f30 | 1227 | |
1228 | while (true) | |
1229 | { | |
1230 | if (gsi_end_p (*gsi)) | |
1231 | return; | |
1232 | stmt = gsi_stmt (*gsi); | |
cdd84b7c | 1233 | |
1234 | lvuse = gimple_vuse (stmt); | |
1235 | if (lvuse != NULL_TREE) | |
1236 | { | |
1237 | *vuse = lvuse; | |
1238 | if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_DEF)) | |
1239 | *vuse_escaped = true; | |
1240 | } | |
1241 | ||
162fb1a4 | 1242 | if (!stmt_local_def (stmt)) |
51385f30 | 1243 | return; |
1244 | gsi_prev_nondebug (gsi); | |
1245 | } | |
1246 | } | |
1247 | ||
1248 | /* Determines whether BB1 and BB2 (members of same_succ) are duplicates. If so, | |
1249 | clusters them. */ | |
1250 | ||
1251 | static void | |
1252 | find_duplicate (same_succ same_succ, basic_block bb1, basic_block bb2) | |
1253 | { | |
1254 | gimple_stmt_iterator gsi1 = gsi_last_nondebug_bb (bb1); | |
1255 | gimple_stmt_iterator gsi2 = gsi_last_nondebug_bb (bb2); | |
cdd84b7c | 1256 | tree vuse1 = NULL_TREE, vuse2 = NULL_TREE; |
1257 | bool vuse_escaped = false; | |
51385f30 | 1258 | |
cdd84b7c | 1259 | gsi_advance_bw_nondebug_nonlocal (&gsi1, &vuse1, &vuse_escaped); |
1260 | gsi_advance_bw_nondebug_nonlocal (&gsi2, &vuse2, &vuse_escaped); | |
51385f30 | 1261 | |
1262 | while (!gsi_end_p (gsi1) && !gsi_end_p (gsi2)) | |
1263 | { | |
4b9d4789 | 1264 | gimple stmt1 = gsi_stmt (gsi1); |
1265 | gimple stmt2 = gsi_stmt (gsi2); | |
1266 | ||
50a50143 | 1267 | /* What could be better than to this this here is to blacklist the bb |
1268 | containing the stmt, when encountering the stmt f.i. in | |
1269 | same_succ_hash. */ | |
1270 | if (is_tm_ending (stmt1) | |
1271 | || is_tm_ending (stmt2)) | |
4b9d4789 | 1272 | return; |
1273 | ||
50a50143 | 1274 | if (!gimple_equal_p (same_succ, stmt1, stmt2)) |
51385f30 | 1275 | return; |
1276 | ||
1277 | gsi_prev_nondebug (&gsi1); | |
1278 | gsi_prev_nondebug (&gsi2); | |
cdd84b7c | 1279 | gsi_advance_bw_nondebug_nonlocal (&gsi1, &vuse1, &vuse_escaped); |
1280 | gsi_advance_bw_nondebug_nonlocal (&gsi2, &vuse2, &vuse_escaped); | |
51385f30 | 1281 | } |
1282 | ||
1283 | if (!(gsi_end_p (gsi1) && gsi_end_p (gsi2))) | |
1284 | return; | |
1285 | ||
cdd84b7c | 1286 | /* If the incoming vuses are not the same, and the vuse escaped into an |
1287 | SSA_OP_DEF, then merging the 2 blocks will change the value of the def, | |
1288 | which potentially means the semantics of one of the blocks will be changed. | |
1289 | TODO: make this check more precise. */ | |
1290 | if (vuse_escaped && vuse1 != vuse2) | |
1291 | return; | |
1292 | ||
51385f30 | 1293 | if (dump_file) |
1294 | fprintf (dump_file, "find_duplicates: <bb %d> duplicate of <bb %d>\n", | |
1295 | bb1->index, bb2->index); | |
1296 | ||
1297 | set_cluster (bb1, bb2); | |
1298 | } | |
1299 | ||
1300 | /* Returns whether for all phis in DEST the phi alternatives for E1 and | |
1301 | E2 are equal. */ | |
1302 | ||
1303 | static bool | |
1304 | same_phi_alternatives_1 (basic_block dest, edge e1, edge e2) | |
1305 | { | |
1306 | int n1 = e1->dest_idx, n2 = e2->dest_idx; | |
1a91d914 | 1307 | gphi_iterator gsi; |
51385f30 | 1308 | |
1309 | for (gsi = gsi_start_phis (dest); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1310 | { | |
1a91d914 | 1311 | gphi *phi = gsi.phi (); |
51385f30 | 1312 | tree lhs = gimple_phi_result (phi); |
1313 | tree val1 = gimple_phi_arg_def (phi, n1); | |
1314 | tree val2 = gimple_phi_arg_def (phi, n2); | |
1315 | ||
7c782c9b | 1316 | if (virtual_operand_p (lhs)) |
51385f30 | 1317 | continue; |
1318 | ||
1319 | if (operand_equal_for_phi_arg_p (val1, val2)) | |
1320 | continue; | |
1321 | if (gvn_uses_equal (val1, val2)) | |
1322 | continue; | |
1323 | ||
1324 | return false; | |
1325 | } | |
1326 | ||
1327 | return true; | |
1328 | } | |
1329 | ||
1330 | /* Returns whether for all successors of BB1 and BB2 (members of SAME_SUCC), the | |
1331 | phi alternatives for BB1 and BB2 are equal. */ | |
1332 | ||
1333 | static bool | |
1334 | same_phi_alternatives (same_succ same_succ, basic_block bb1, basic_block bb2) | |
1335 | { | |
1336 | unsigned int s; | |
1337 | bitmap_iterator bs; | |
1338 | edge e1, e2; | |
1339 | basic_block succ; | |
1340 | ||
1341 | EXECUTE_IF_SET_IN_BITMAP (same_succ->succs, 0, s, bs) | |
1342 | { | |
f5a6b05f | 1343 | succ = BASIC_BLOCK_FOR_FN (cfun, s); |
51385f30 | 1344 | e1 = find_edge (bb1, succ); |
1345 | e2 = find_edge (bb2, succ); | |
1346 | if (e1->flags & EDGE_COMPLEX | |
1347 | || e2->flags & EDGE_COMPLEX) | |
1348 | return false; | |
1349 | ||
1350 | /* For all phis in bb, the phi alternatives for e1 and e2 need to have | |
1351 | the same value. */ | |
1352 | if (!same_phi_alternatives_1 (succ, e1, e2)) | |
1353 | return false; | |
1354 | } | |
1355 | ||
1356 | return true; | |
1357 | } | |
1358 | ||
1359 | /* Return true if BB has non-vop phis. */ | |
1360 | ||
1361 | static bool | |
1362 | bb_has_non_vop_phi (basic_block bb) | |
1363 | { | |
1364 | gimple_seq phis = phi_nodes (bb); | |
1365 | gimple phi; | |
1366 | ||
1367 | if (phis == NULL) | |
1368 | return false; | |
1369 | ||
1370 | if (!gimple_seq_singleton_p (phis)) | |
1371 | return true; | |
1372 | ||
1373 | phi = gimple_seq_first_stmt (phis); | |
7c782c9b | 1374 | return !virtual_operand_p (gimple_phi_result (phi)); |
51385f30 | 1375 | } |
1376 | ||
1377 | /* Returns true if redirecting the incoming edges of FROM to TO maintains the | |
1378 | invariant that uses in FROM are dominates by their defs. */ | |
1379 | ||
1380 | static bool | |
1381 | deps_ok_for_redirect_from_bb_to_bb (basic_block from, basic_block to) | |
1382 | { | |
1383 | basic_block cd, dep_bb = BB_DEP_BB (to); | |
1384 | edge_iterator ei; | |
1385 | edge e; | |
1386 | bitmap from_preds = BITMAP_ALLOC (NULL); | |
1387 | ||
1388 | if (dep_bb == NULL) | |
1389 | return true; | |
1390 | ||
1391 | FOR_EACH_EDGE (e, ei, from->preds) | |
1392 | bitmap_set_bit (from_preds, e->src->index); | |
1393 | cd = nearest_common_dominator_for_set (CDI_DOMINATORS, from_preds); | |
1394 | BITMAP_FREE (from_preds); | |
1395 | ||
1396 | return dominated_by_p (CDI_DOMINATORS, dep_bb, cd); | |
1397 | } | |
1398 | ||
1399 | /* Returns true if replacing BB1 (or its replacement bb) by BB2 (or its | |
1400 | replacement bb) and vice versa maintains the invariant that uses in the | |
1401 | replacement are dominates by their defs. */ | |
1402 | ||
1403 | static bool | |
1404 | deps_ok_for_redirect (basic_block bb1, basic_block bb2) | |
1405 | { | |
1406 | if (BB_CLUSTER (bb1) != NULL) | |
1407 | bb1 = BB_CLUSTER (bb1)->rep_bb; | |
1408 | ||
1409 | if (BB_CLUSTER (bb2) != NULL) | |
1410 | bb2 = BB_CLUSTER (bb2)->rep_bb; | |
1411 | ||
1412 | return (deps_ok_for_redirect_from_bb_to_bb (bb1, bb2) | |
1413 | && deps_ok_for_redirect_from_bb_to_bb (bb2, bb1)); | |
1414 | } | |
1415 | ||
1416 | /* Within SAME_SUCC->bbs, find clusters of bbs which can be merged. */ | |
1417 | ||
1418 | static void | |
1419 | find_clusters_1 (same_succ same_succ) | |
1420 | { | |
1421 | basic_block bb1, bb2; | |
1422 | unsigned int i, j; | |
1423 | bitmap_iterator bi, bj; | |
1424 | int nr_comparisons; | |
1425 | int max_comparisons = PARAM_VALUE (PARAM_MAX_TAIL_MERGE_COMPARISONS); | |
1426 | ||
1427 | EXECUTE_IF_SET_IN_BITMAP (same_succ->bbs, 0, i, bi) | |
1428 | { | |
f5a6b05f | 1429 | bb1 = BASIC_BLOCK_FOR_FN (cfun, i); |
51385f30 | 1430 | |
1431 | /* TODO: handle blocks with phi-nodes. We'll have to find corresponding | |
1432 | phi-nodes in bb1 and bb2, with the same alternatives for the same | |
1433 | preds. */ | |
1434 | if (bb_has_non_vop_phi (bb1)) | |
1435 | continue; | |
1436 | ||
1437 | nr_comparisons = 0; | |
1438 | EXECUTE_IF_SET_IN_BITMAP (same_succ->bbs, i + 1, j, bj) | |
1439 | { | |
f5a6b05f | 1440 | bb2 = BASIC_BLOCK_FOR_FN (cfun, j); |
51385f30 | 1441 | |
1442 | if (bb_has_non_vop_phi (bb2)) | |
1443 | continue; | |
1444 | ||
1445 | if (BB_CLUSTER (bb1) != NULL && BB_CLUSTER (bb1) == BB_CLUSTER (bb2)) | |
1446 | continue; | |
1447 | ||
1448 | /* Limit quadratic behaviour. */ | |
1449 | nr_comparisons++; | |
1450 | if (nr_comparisons > max_comparisons) | |
1451 | break; | |
1452 | ||
1453 | /* This is a conservative dependency check. We could test more | |
1454 | precise for allowed replacement direction. */ | |
1455 | if (!deps_ok_for_redirect (bb1, bb2)) | |
1456 | continue; | |
1457 | ||
1458 | if (!(same_phi_alternatives (same_succ, bb1, bb2))) | |
1459 | continue; | |
1460 | ||
1461 | find_duplicate (same_succ, bb1, bb2); | |
1462 | } | |
1463 | } | |
1464 | } | |
1465 | ||
1466 | /* Find clusters of bbs which can be merged. */ | |
1467 | ||
1468 | static void | |
1469 | find_clusters (void) | |
1470 | { | |
1471 | same_succ same; | |
1472 | ||
f1f41a6c | 1473 | while (!worklist.is_empty ()) |
51385f30 | 1474 | { |
f1f41a6c | 1475 | same = worklist.pop (); |
51385f30 | 1476 | same->in_worklist = false; |
1477 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1478 | { | |
1479 | fprintf (dump_file, "processing worklist entry\n"); | |
1480 | same_succ_print (dump_file, same); | |
1481 | } | |
1482 | find_clusters_1 (same); | |
1483 | } | |
1484 | } | |
1485 | ||
51385f30 | 1486 | /* Returns the vop phi of BB, if any. */ |
1487 | ||
1a91d914 | 1488 | static gphi * |
51385f30 | 1489 | vop_phi (basic_block bb) |
1490 | { | |
1a91d914 | 1491 | gphi *stmt; |
1492 | gphi_iterator gsi; | |
51385f30 | 1493 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
1494 | { | |
1a91d914 | 1495 | stmt = gsi.phi (); |
7c782c9b | 1496 | if (! virtual_operand_p (gimple_phi_result (stmt))) |
51385f30 | 1497 | continue; |
1498 | return stmt; | |
1499 | } | |
1500 | return NULL; | |
1501 | } | |
1502 | ||
b1ad75f0 | 1503 | /* Redirect all edges from BB1 to BB2, removes BB1 and marks it as removed. */ |
51385f30 | 1504 | |
1505 | static void | |
b1ad75f0 | 1506 | replace_block_by (basic_block bb1, basic_block bb2) |
51385f30 | 1507 | { |
1508 | edge pred_edge; | |
2de034ed | 1509 | edge e1, e2; |
bc4d077b | 1510 | edge_iterator ei; |
51385f30 | 1511 | unsigned int i; |
1a91d914 | 1512 | gphi *bb2_phi; |
35bfa3a2 | 1513 | |
b1ad75f0 | 1514 | bb2_phi = vop_phi (bb2); |
51385f30 | 1515 | |
b1ad75f0 | 1516 | /* Mark the basic block as deleted. */ |
1517 | mark_basic_block_deleted (bb1); | |
51385f30 | 1518 | |
1519 | /* Redirect the incoming edges of bb1 to bb2. */ | |
1520 | for (i = EDGE_COUNT (bb1->preds); i > 0 ; --i) | |
1521 | { | |
1522 | pred_edge = EDGE_PRED (bb1, i - 1); | |
1523 | pred_edge = redirect_edge_and_branch (pred_edge, bb2); | |
1524 | gcc_assert (pred_edge != NULL); | |
b1ad75f0 | 1525 | |
1526 | if (bb2_phi == NULL) | |
1527 | continue; | |
1528 | ||
1529 | /* The phi might have run out of capacity when the redirect added an | |
1530 | argument, which means it could have been replaced. Refresh it. */ | |
1531 | bb2_phi = vop_phi (bb2); | |
1532 | ||
1533 | add_phi_arg (bb2_phi, SSA_NAME_VAR (gimple_phi_result (bb2_phi)), | |
60d535d2 | 1534 | pred_edge, UNKNOWN_LOCATION); |
51385f30 | 1535 | } |
1536 | ||
30a29019 | 1537 | bb2->frequency += bb1->frequency; |
1538 | if (bb2->frequency > BB_FREQ_MAX) | |
1539 | bb2->frequency = BB_FREQ_MAX; | |
0fef5355 | 1540 | |
1541 | bb2->count += bb1->count; | |
30a29019 | 1542 | |
bc4d077b | 1543 | /* Merge the outgoing edge counts from bb1 onto bb2. */ |
2de034ed | 1544 | gcov_type out_sum = 0; |
bc4d077b | 1545 | FOR_EACH_EDGE (e1, ei, bb1->succs) |
1546 | { | |
bc4d077b | 1547 | e2 = find_edge (bb2, e1->dest); |
1548 | gcc_assert (e2); | |
1549 | e2->count += e1->count; | |
2de034ed | 1550 | out_sum += e2->count; |
1551 | } | |
1552 | /* Recompute the edge probabilities from the new merged edge count. | |
1553 | Use the sum of the new merged edge counts computed above instead | |
1554 | of bb2's merged count, in case there are profile count insanities | |
1555 | making the bb count inconsistent with the edge weights. */ | |
1556 | FOR_EACH_EDGE (e2, ei, bb2->succs) | |
1557 | { | |
1558 | e2->probability = GCOV_COMPUTE_SCALE (e2->count, out_sum); | |
bc4d077b | 1559 | } |
1560 | ||
9375b71f | 1561 | /* Do updates that use bb1, before deleting bb1. */ |
ff11bbd5 | 1562 | release_last_vdef (bb1); |
9375b71f | 1563 | same_succ_flush_bb (bb1); |
1564 | ||
b1ad75f0 | 1565 | delete_basic_block (bb1); |
51385f30 | 1566 | } |
1567 | ||
1568 | /* Bbs for which update_debug_stmt need to be called. */ | |
1569 | ||
1570 | static bitmap update_bbs; | |
1571 | ||
1572 | /* For each cluster in all_clusters, merge all cluster->bbs. Returns | |
b1ad75f0 | 1573 | number of bbs removed. */ |
51385f30 | 1574 | |
1575 | static int | |
b1ad75f0 | 1576 | apply_clusters (void) |
51385f30 | 1577 | { |
1578 | basic_block bb1, bb2; | |
1579 | bb_cluster c; | |
1580 | unsigned int i, j; | |
1581 | bitmap_iterator bj; | |
1582 | int nr_bbs_removed = 0; | |
1583 | ||
f1f41a6c | 1584 | for (i = 0; i < all_clusters.length (); ++i) |
51385f30 | 1585 | { |
f1f41a6c | 1586 | c = all_clusters[i]; |
51385f30 | 1587 | if (c == NULL) |
1588 | continue; | |
1589 | ||
1590 | bb2 = c->rep_bb; | |
1591 | bitmap_set_bit (update_bbs, bb2->index); | |
1592 | ||
1593 | bitmap_clear_bit (c->bbs, bb2->index); | |
1594 | EXECUTE_IF_SET_IN_BITMAP (c->bbs, 0, j, bj) | |
1595 | { | |
f5a6b05f | 1596 | bb1 = BASIC_BLOCK_FOR_FN (cfun, j); |
51385f30 | 1597 | bitmap_clear_bit (update_bbs, bb1->index); |
1598 | ||
b1ad75f0 | 1599 | replace_block_by (bb1, bb2); |
51385f30 | 1600 | nr_bbs_removed++; |
1601 | } | |
1602 | } | |
1603 | ||
1604 | return nr_bbs_removed; | |
1605 | } | |
1606 | ||
1607 | /* Resets debug statement STMT if it has uses that are not dominated by their | |
1608 | defs. */ | |
1609 | ||
1610 | static void | |
1611 | update_debug_stmt (gimple stmt) | |
1612 | { | |
1613 | use_operand_p use_p; | |
1614 | ssa_op_iter oi; | |
099b097f | 1615 | basic_block bbuse; |
51385f30 | 1616 | |
1617 | if (!gimple_debug_bind_p (stmt)) | |
1618 | return; | |
1619 | ||
1620 | bbuse = gimple_bb (stmt); | |
1621 | FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, oi, SSA_OP_USE) | |
1622 | { | |
099b097f | 1623 | tree name = USE_FROM_PTR (use_p); |
1624 | gimple def_stmt = SSA_NAME_DEF_STMT (name); | |
1625 | basic_block bbdef = gimple_bb (def_stmt); | |
51385f30 | 1626 | if (bbdef == NULL || bbuse == bbdef |
1627 | || dominated_by_p (CDI_DOMINATORS, bbuse, bbdef)) | |
1628 | continue; | |
1629 | ||
1630 | gimple_debug_bind_reset_value (stmt); | |
1631 | update_stmt (stmt); | |
099b097f | 1632 | break; |
51385f30 | 1633 | } |
1634 | } | |
1635 | ||
1636 | /* Resets all debug statements that have uses that are not | |
1637 | dominated by their defs. */ | |
1638 | ||
1639 | static void | |
1640 | update_debug_stmts (void) | |
1641 | { | |
1642 | basic_block bb; | |
1643 | bitmap_iterator bi; | |
1644 | unsigned int i; | |
1645 | ||
51385f30 | 1646 | EXECUTE_IF_SET_IN_BITMAP (update_bbs, 0, i, bi) |
1647 | { | |
1648 | gimple stmt; | |
1649 | gimple_stmt_iterator gsi; | |
1650 | ||
f5a6b05f | 1651 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
51385f30 | 1652 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
1653 | { | |
1654 | stmt = gsi_stmt (gsi); | |
1655 | if (!is_gimple_debug (stmt)) | |
1656 | continue; | |
1657 | update_debug_stmt (stmt); | |
1658 | } | |
1659 | } | |
1660 | } | |
1661 | ||
1662 | /* Runs tail merge optimization. */ | |
1663 | ||
1664 | unsigned int | |
1665 | tail_merge_optimize (unsigned int todo) | |
1666 | { | |
1667 | int nr_bbs_removed_total = 0; | |
1668 | int nr_bbs_removed; | |
1669 | bool loop_entered = false; | |
1670 | int iteration_nr = 0; | |
51385f30 | 1671 | int max_iterations = PARAM_VALUE (PARAM_MAX_TAIL_MERGE_ITERATIONS); |
1672 | ||
c48f77d5 | 1673 | if (!flag_tree_tail_merge |
b3083327 | 1674 | || max_iterations == 0) |
51385f30 | 1675 | return 0; |
1676 | ||
1677 | timevar_push (TV_TREE_TAIL_MERGE); | |
1678 | ||
b74146ca | 1679 | if (!dom_info_available_p (CDI_DOMINATORS)) |
1680 | { | |
1681 | /* PRE can leave us with unreachable blocks, remove them now. */ | |
1682 | delete_unreachable_blocks (); | |
1683 | calculate_dominance_info (CDI_DOMINATORS); | |
1684 | } | |
51385f30 | 1685 | init_worklist (); |
1686 | ||
f1f41a6c | 1687 | while (!worklist.is_empty ()) |
51385f30 | 1688 | { |
1689 | if (!loop_entered) | |
1690 | { | |
1691 | loop_entered = true; | |
1692 | alloc_cluster_vectors (); | |
1693 | update_bbs = BITMAP_ALLOC (NULL); | |
1694 | } | |
1695 | else | |
1696 | reset_cluster_vectors (); | |
1697 | ||
1698 | iteration_nr++; | |
1699 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1700 | fprintf (dump_file, "worklist iteration #%d\n", iteration_nr); | |
1701 | ||
1702 | find_clusters (); | |
f1f41a6c | 1703 | gcc_assert (worklist.is_empty ()); |
1704 | if (all_clusters.is_empty ()) | |
51385f30 | 1705 | break; |
1706 | ||
b1ad75f0 | 1707 | nr_bbs_removed = apply_clusters (); |
51385f30 | 1708 | nr_bbs_removed_total += nr_bbs_removed; |
1709 | if (nr_bbs_removed == 0) | |
1710 | break; | |
1711 | ||
b1ad75f0 | 1712 | free_dominance_info (CDI_DOMINATORS); |
51385f30 | 1713 | |
1714 | if (iteration_nr == max_iterations) | |
1715 | break; | |
1716 | ||
b1ad75f0 | 1717 | calculate_dominance_info (CDI_DOMINATORS); |
51385f30 | 1718 | update_worklist (); |
1719 | } | |
1720 | ||
1721 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1722 | fprintf (dump_file, "htab collision / search: %f\n", | |
c1f445d2 | 1723 | same_succ_htab->collisions ()); |
51385f30 | 1724 | |
1725 | if (nr_bbs_removed_total > 0) | |
1726 | { | |
b1ad75f0 | 1727 | if (MAY_HAVE_DEBUG_STMTS) |
1728 | { | |
1729 | calculate_dominance_info (CDI_DOMINATORS); | |
1730 | update_debug_stmts (); | |
1731 | } | |
51385f30 | 1732 | |
1733 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1734 | { | |
1735 | fprintf (dump_file, "Before TODOs.\n"); | |
1736 | dump_function_to_file (current_function_decl, dump_file, dump_flags); | |
1737 | } | |
1738 | ||
278611f2 | 1739 | mark_virtual_operands_for_renaming (cfun); |
51385f30 | 1740 | } |
1741 | ||
1742 | delete_worklist (); | |
1743 | if (loop_entered) | |
1744 | { | |
1745 | delete_cluster_vectors (); | |
1746 | BITMAP_FREE (update_bbs); | |
1747 | } | |
1748 | ||
1749 | timevar_pop (TV_TREE_TAIL_MERGE); | |
1750 | ||
1751 | return todo; | |
1752 | } |