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51385f30 | 1 | /* Tail merging for gimple. |
711789cc | 2 | Copyright (C) 2011-2013 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" | |
192 | #include "tree.h" | |
9ed99284 | 193 | #include "stor-layout.h" |
194 | #include "trans-mem.h" | |
51385f30 | 195 | #include "tm_p.h" |
196 | #include "basic-block.h" | |
51385f30 | 197 | #include "flags.h" |
198 | #include "function.h" | |
bc61cadb | 199 | #include "hash-table.h" |
200 | #include "tree-ssa-alias.h" | |
201 | #include "internal-fn.h" | |
202 | #include "tree-eh.h" | |
203 | #include "gimple-expr.h" | |
204 | #include "is-a.h" | |
073c1fd5 | 205 | #include "gimple.h" |
dcf1a1ec | 206 | #include "gimple-iterator.h" |
073c1fd5 | 207 | #include "gimple-ssa.h" |
208 | #include "tree-cfg.h" | |
209 | #include "tree-phinodes.h" | |
210 | #include "ssa-iterators.h" | |
211 | #include "tree-into-ssa.h" | |
51385f30 | 212 | #include "params.h" |
51385f30 | 213 | #include "gimple-pretty-print.h" |
214 | #include "tree-ssa-sccvn.h" | |
215 | #include "tree-dump.h" | |
f6568ea4 | 216 | #include "cfgloop.h" |
b9ed1410 | 217 | #include "tree-pass.h" |
e797f49f | 218 | #include "trans-mem.h" |
b9ed1410 | 219 | |
51385f30 | 220 | /* Describes a group of bbs with the same successors. The successor bbs are |
221 | cached in succs, and the successor edge flags are cached in succ_flags. | |
222 | If a bb has the EDGE_TRUE/VALSE_VALUE flags swapped compared to succ_flags, | |
223 | it's marked in inverse. | |
224 | Additionally, the hash value for the struct is cached in hashval, and | |
225 | in_worklist indicates whether it's currently part of worklist. */ | |
226 | ||
227 | struct same_succ_def | |
228 | { | |
229 | /* The bbs that have the same successor bbs. */ | |
230 | bitmap bbs; | |
231 | /* The successor bbs. */ | |
232 | bitmap succs; | |
233 | /* Indicates whether the EDGE_TRUE/FALSE_VALUEs of succ_flags are swapped for | |
234 | bb. */ | |
235 | bitmap inverse; | |
236 | /* The edge flags for each of the successor bbs. */ | |
f1f41a6c | 237 | vec<int> succ_flags; |
51385f30 | 238 | /* Indicates whether the struct is currently in the worklist. */ |
239 | bool in_worklist; | |
240 | /* The hash value of the struct. */ | |
241 | hashval_t hashval; | |
494bbaae | 242 | |
243 | /* hash_table support. */ | |
c580da87 | 244 | typedef same_succ_def value_type; |
245 | typedef same_succ_def compare_type; | |
246 | static inline hashval_t hash (const value_type *); | |
247 | static int equal (const value_type *, const compare_type *); | |
248 | static void remove (value_type *); | |
51385f30 | 249 | }; |
250 | typedef struct same_succ_def *same_succ; | |
251 | typedef const struct same_succ_def *const_same_succ; | |
252 | ||
494bbaae | 253 | /* hash routine for hash_table support, returns hashval of E. */ |
254 | ||
255 | inline hashval_t | |
c580da87 | 256 | same_succ_def::hash (const value_type *e) |
494bbaae | 257 | { |
258 | return e->hashval; | |
259 | } | |
260 | ||
51385f30 | 261 | /* A group of bbs where 1 bb from bbs can replace the other bbs. */ |
262 | ||
263 | struct bb_cluster_def | |
264 | { | |
265 | /* The bbs in the cluster. */ | |
266 | bitmap bbs; | |
267 | /* The preds of the bbs in the cluster. */ | |
268 | bitmap preds; | |
269 | /* Index in all_clusters vector. */ | |
270 | int index; | |
271 | /* The bb to replace the cluster with. */ | |
272 | basic_block rep_bb; | |
273 | }; | |
274 | typedef struct bb_cluster_def *bb_cluster; | |
275 | typedef const struct bb_cluster_def *const_bb_cluster; | |
276 | ||
277 | /* Per bb-info. */ | |
278 | ||
279 | struct aux_bb_info | |
280 | { | |
281 | /* The number of non-debug statements in the bb. */ | |
282 | int size; | |
283 | /* The same_succ that this bb is a member of. */ | |
284 | same_succ bb_same_succ; | |
285 | /* The cluster that this bb is a member of. */ | |
286 | bb_cluster cluster; | |
287 | /* The vop state at the exit of a bb. This is shortlived data, used to | |
288 | communicate data between update_block_by and update_vuses. */ | |
289 | tree vop_at_exit; | |
290 | /* The bb that either contains or is dominated by the dependencies of the | |
291 | bb. */ | |
292 | basic_block dep_bb; | |
293 | }; | |
294 | ||
295 | /* Macros to access the fields of struct aux_bb_info. */ | |
296 | ||
297 | #define BB_SIZE(bb) (((struct aux_bb_info *)bb->aux)->size) | |
298 | #define BB_SAME_SUCC(bb) (((struct aux_bb_info *)bb->aux)->bb_same_succ) | |
299 | #define BB_CLUSTER(bb) (((struct aux_bb_info *)bb->aux)->cluster) | |
300 | #define BB_VOP_AT_EXIT(bb) (((struct aux_bb_info *)bb->aux)->vop_at_exit) | |
301 | #define BB_DEP_BB(bb) (((struct aux_bb_info *)bb->aux)->dep_bb) | |
302 | ||
162fb1a4 | 303 | /* Returns true if the only effect a statement STMT has, is to define locally |
304 | used SSA_NAMEs. */ | |
305 | ||
306 | static bool | |
307 | stmt_local_def (gimple stmt) | |
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 | ||
888da683 | 315 | if (gimple_has_side_effects (stmt) |
02b28afa | 316 | || stmt_could_throw_p (stmt) |
888da683 | 317 | || gimple_vdef (stmt) != NULL_TREE) |
162fb1a4 | 318 | return false; |
319 | ||
320 | def_p = SINGLE_SSA_DEF_OPERAND (stmt, SSA_OP_DEF); | |
321 | if (def_p == NULL) | |
322 | return false; | |
323 | ||
324 | val = DEF_FROM_PTR (def_p); | |
325 | if (val == NULL_TREE || TREE_CODE (val) != SSA_NAME) | |
326 | return false; | |
327 | ||
328 | def_bb = gimple_bb (stmt); | |
329 | ||
330 | FOR_EACH_IMM_USE_FAST (use_p, iter, val) | |
331 | { | |
332 | if (is_gimple_debug (USE_STMT (use_p))) | |
333 | continue; | |
334 | bb = gimple_bb (USE_STMT (use_p)); | |
335 | if (bb == def_bb) | |
336 | continue; | |
337 | ||
338 | if (gimple_code (USE_STMT (use_p)) == GIMPLE_PHI | |
339 | && EDGE_PRED (bb, PHI_ARG_INDEX_FROM_USE (use_p))->src == def_bb) | |
340 | continue; | |
341 | ||
342 | return false; | |
343 | } | |
344 | ||
345 | return true; | |
346 | } | |
347 | ||
348 | /* Let GSI skip forwards over local defs. */ | |
349 | ||
350 | static void | |
351 | gsi_advance_fw_nondebug_nonlocal (gimple_stmt_iterator *gsi) | |
352 | { | |
353 | gimple stmt; | |
354 | ||
355 | while (true) | |
356 | { | |
357 | if (gsi_end_p (*gsi)) | |
358 | return; | |
359 | stmt = gsi_stmt (*gsi); | |
360 | if (!stmt_local_def (stmt)) | |
361 | return; | |
362 | gsi_next_nondebug (gsi); | |
363 | } | |
364 | } | |
365 | ||
51385f30 | 366 | /* VAL1 and VAL2 are either: |
367 | - uses in BB1 and BB2, or | |
368 | - phi alternatives for BB1 and BB2. | |
369 | Return true if the uses have the same gvn value. */ | |
370 | ||
371 | static bool | |
372 | gvn_uses_equal (tree val1, tree val2) | |
373 | { | |
374 | gcc_checking_assert (val1 != NULL_TREE && val2 != NULL_TREE); | |
375 | ||
376 | if (val1 == val2) | |
377 | return true; | |
378 | ||
379 | if (vn_valueize (val1) != vn_valueize (val2)) | |
380 | return false; | |
381 | ||
382 | return ((TREE_CODE (val1) == SSA_NAME || CONSTANT_CLASS_P (val1)) | |
383 | && (TREE_CODE (val2) == SSA_NAME || CONSTANT_CLASS_P (val2))); | |
384 | } | |
385 | ||
386 | /* Prints E to FILE. */ | |
387 | ||
388 | static void | |
389 | same_succ_print (FILE *file, const same_succ e) | |
390 | { | |
391 | unsigned int i; | |
392 | bitmap_print (file, e->bbs, "bbs:", "\n"); | |
393 | bitmap_print (file, e->succs, "succs:", "\n"); | |
394 | bitmap_print (file, e->inverse, "inverse:", "\n"); | |
395 | fprintf (file, "flags:"); | |
f1f41a6c | 396 | for (i = 0; i < e->succ_flags.length (); ++i) |
397 | fprintf (file, " %x", e->succ_flags[i]); | |
51385f30 | 398 | fprintf (file, "\n"); |
399 | } | |
400 | ||
401 | /* Prints same_succ VE to VFILE. */ | |
402 | ||
2b15d2ba | 403 | inline int |
404 | ssa_same_succ_print_traverse (same_succ *pe, FILE *file) | |
51385f30 | 405 | { |
2b15d2ba | 406 | const same_succ e = *pe; |
51385f30 | 407 | same_succ_print (file, e); |
408 | return 1; | |
409 | } | |
410 | ||
411 | /* Update BB_DEP_BB (USE_BB), given a use of VAL in USE_BB. */ | |
412 | ||
413 | static void | |
414 | update_dep_bb (basic_block use_bb, tree val) | |
415 | { | |
416 | basic_block dep_bb; | |
417 | ||
418 | /* Not a dep. */ | |
419 | if (TREE_CODE (val) != SSA_NAME) | |
420 | return; | |
421 | ||
422 | /* Skip use of global def. */ | |
423 | if (SSA_NAME_IS_DEFAULT_DEF (val)) | |
424 | return; | |
425 | ||
426 | /* Skip use of local def. */ | |
427 | dep_bb = gimple_bb (SSA_NAME_DEF_STMT (val)); | |
428 | if (dep_bb == use_bb) | |
429 | return; | |
430 | ||
431 | if (BB_DEP_BB (use_bb) == NULL | |
432 | || dominated_by_p (CDI_DOMINATORS, dep_bb, BB_DEP_BB (use_bb))) | |
433 | BB_DEP_BB (use_bb) = dep_bb; | |
434 | } | |
435 | ||
436 | /* Update BB_DEP_BB, given the dependencies in STMT. */ | |
437 | ||
438 | static void | |
439 | stmt_update_dep_bb (gimple stmt) | |
440 | { | |
441 | ssa_op_iter iter; | |
442 | use_operand_p use; | |
443 | ||
444 | FOR_EACH_SSA_USE_OPERAND (use, stmt, iter, SSA_OP_USE) | |
445 | update_dep_bb (gimple_bb (stmt), USE_FROM_PTR (use)); | |
446 | } | |
447 | ||
51385f30 | 448 | /* Calculates hash value for same_succ VE. */ |
449 | ||
494bbaae | 450 | static hashval_t |
451 | same_succ_hash (const_same_succ e) | |
51385f30 | 452 | { |
51385f30 | 453 | hashval_t hashval = bitmap_hash (e->succs); |
454 | int flags; | |
455 | unsigned int i; | |
456 | unsigned int first = bitmap_first_set_bit (e->bbs); | |
f5a6b05f | 457 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, first); |
51385f30 | 458 | int size = 0; |
459 | gimple_stmt_iterator gsi; | |
460 | gimple stmt; | |
461 | tree arg; | |
462 | unsigned int s; | |
463 | bitmap_iterator bs; | |
464 | ||
465 | for (gsi = gsi_start_nondebug_bb (bb); | |
466 | !gsi_end_p (gsi); gsi_next_nondebug (&gsi)) | |
467 | { | |
468 | stmt = gsi_stmt (gsi); | |
469 | stmt_update_dep_bb (stmt); | |
162fb1a4 | 470 | if (stmt_local_def (stmt)) |
51385f30 | 471 | continue; |
472 | size++; | |
473 | ||
474 | hashval = iterative_hash_hashval_t (gimple_code (stmt), hashval); | |
475 | if (is_gimple_assign (stmt)) | |
476 | hashval = iterative_hash_hashval_t (gimple_assign_rhs_code (stmt), | |
477 | hashval); | |
478 | if (!is_gimple_call (stmt)) | |
479 | continue; | |
480 | if (gimple_call_internal_p (stmt)) | |
481 | hashval = iterative_hash_hashval_t | |
482 | ((hashval_t) gimple_call_internal_fn (stmt), hashval); | |
483 | else | |
484 | hashval = iterative_hash_expr (gimple_call_fn (stmt), hashval); | |
485 | for (i = 0; i < gimple_call_num_args (stmt); i++) | |
486 | { | |
487 | arg = gimple_call_arg (stmt, i); | |
488 | arg = vn_valueize (arg); | |
489 | hashval = iterative_hash_expr (arg, hashval); | |
490 | } | |
491 | } | |
492 | ||
493 | hashval = iterative_hash_hashval_t (size, hashval); | |
494 | BB_SIZE (bb) = size; | |
495 | ||
f1f41a6c | 496 | for (i = 0; i < e->succ_flags.length (); ++i) |
51385f30 | 497 | { |
f1f41a6c | 498 | flags = e->succ_flags[i]; |
51385f30 | 499 | flags = flags & ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); |
500 | hashval = iterative_hash_hashval_t (flags, hashval); | |
501 | } | |
502 | ||
503 | EXECUTE_IF_SET_IN_BITMAP (e->succs, 0, s, bs) | |
504 | { | |
f5a6b05f | 505 | int n = find_edge (bb, BASIC_BLOCK_FOR_FN (cfun, s))->dest_idx; |
506 | for (gsi = gsi_start_phis (BASIC_BLOCK_FOR_FN (cfun, s)); !gsi_end_p (gsi); | |
51385f30 | 507 | gsi_next (&gsi)) |
508 | { | |
509 | gimple phi = gsi_stmt (gsi); | |
510 | tree lhs = gimple_phi_result (phi); | |
511 | tree val = gimple_phi_arg_def (phi, n); | |
512 | ||
7c782c9b | 513 | if (virtual_operand_p (lhs)) |
51385f30 | 514 | continue; |
515 | update_dep_bb (bb, val); | |
516 | } | |
517 | } | |
518 | ||
519 | return hashval; | |
520 | } | |
521 | ||
522 | /* Returns true if E1 and E2 have 2 successors, and if the successor flags | |
523 | are inverse for the EDGE_TRUE_VALUE and EDGE_FALSE_VALUE flags, and equal for | |
524 | the other edge flags. */ | |
525 | ||
526 | static bool | |
527 | inverse_flags (const_same_succ e1, const_same_succ e2) | |
528 | { | |
529 | int f1a, f1b, f2a, f2b; | |
530 | int mask = ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); | |
531 | ||
f1f41a6c | 532 | if (e1->succ_flags.length () != 2) |
51385f30 | 533 | return false; |
534 | ||
f1f41a6c | 535 | f1a = e1->succ_flags[0]; |
536 | f1b = e1->succ_flags[1]; | |
537 | f2a = e2->succ_flags[0]; | |
538 | f2b = e2->succ_flags[1]; | |
51385f30 | 539 | |
540 | if (f1a == f2a && f1b == f2b) | |
541 | return false; | |
542 | ||
543 | return (f1a & mask) == (f2a & mask) && (f1b & mask) == (f2b & mask); | |
544 | } | |
545 | ||
494bbaae | 546 | /* Compares SAME_SUCCs E1 and E2. */ |
51385f30 | 547 | |
2b15d2ba | 548 | int |
c580da87 | 549 | same_succ_def::equal (const value_type *e1, const compare_type *e2) |
51385f30 | 550 | { |
51385f30 | 551 | unsigned int i, first1, first2; |
552 | gimple_stmt_iterator gsi1, gsi2; | |
553 | gimple s1, s2; | |
554 | basic_block bb1, bb2; | |
555 | ||
556 | if (e1->hashval != e2->hashval) | |
557 | return 0; | |
558 | ||
f1f41a6c | 559 | if (e1->succ_flags.length () != e2->succ_flags.length ()) |
51385f30 | 560 | return 0; |
561 | ||
562 | if (!bitmap_equal_p (e1->succs, e2->succs)) | |
563 | return 0; | |
564 | ||
565 | if (!inverse_flags (e1, e2)) | |
566 | { | |
f1f41a6c | 567 | for (i = 0; i < e1->succ_flags.length (); ++i) |
568 | if (e1->succ_flags[i] != e1->succ_flags[i]) | |
51385f30 | 569 | return 0; |
570 | } | |
571 | ||
572 | first1 = bitmap_first_set_bit (e1->bbs); | |
573 | first2 = bitmap_first_set_bit (e2->bbs); | |
574 | ||
f5a6b05f | 575 | bb1 = BASIC_BLOCK_FOR_FN (cfun, first1); |
576 | bb2 = BASIC_BLOCK_FOR_FN (cfun, first2); | |
51385f30 | 577 | |
578 | if (BB_SIZE (bb1) != BB_SIZE (bb2)) | |
579 | return 0; | |
580 | ||
581 | gsi1 = gsi_start_nondebug_bb (bb1); | |
582 | gsi2 = gsi_start_nondebug_bb (bb2); | |
162fb1a4 | 583 | gsi_advance_fw_nondebug_nonlocal (&gsi1); |
584 | gsi_advance_fw_nondebug_nonlocal (&gsi2); | |
51385f30 | 585 | while (!(gsi_end_p (gsi1) || gsi_end_p (gsi2))) |
586 | { | |
587 | s1 = gsi_stmt (gsi1); | |
588 | s2 = gsi_stmt (gsi2); | |
589 | if (gimple_code (s1) != gimple_code (s2)) | |
590 | return 0; | |
591 | if (is_gimple_call (s1) && !gimple_call_same_target_p (s1, s2)) | |
592 | return 0; | |
593 | gsi_next_nondebug (&gsi1); | |
594 | gsi_next_nondebug (&gsi2); | |
162fb1a4 | 595 | gsi_advance_fw_nondebug_nonlocal (&gsi1); |
596 | gsi_advance_fw_nondebug_nonlocal (&gsi2); | |
51385f30 | 597 | } |
598 | ||
599 | return 1; | |
600 | } | |
601 | ||
602 | /* Alloc and init a new SAME_SUCC. */ | |
603 | ||
604 | static same_succ | |
605 | same_succ_alloc (void) | |
606 | { | |
607 | same_succ same = XNEW (struct same_succ_def); | |
608 | ||
609 | same->bbs = BITMAP_ALLOC (NULL); | |
610 | same->succs = BITMAP_ALLOC (NULL); | |
611 | same->inverse = BITMAP_ALLOC (NULL); | |
f1f41a6c | 612 | same->succ_flags.create (10); |
51385f30 | 613 | same->in_worklist = false; |
614 | ||
615 | return same; | |
616 | } | |
617 | ||
494bbaae | 618 | /* Delete same_succ E. */ |
51385f30 | 619 | |
494bbaae | 620 | void |
621 | same_succ_def::remove (same_succ e) | |
51385f30 | 622 | { |
51385f30 | 623 | BITMAP_FREE (e->bbs); |
624 | BITMAP_FREE (e->succs); | |
625 | BITMAP_FREE (e->inverse); | |
f1f41a6c | 626 | e->succ_flags.release (); |
51385f30 | 627 | |
2b15d2ba | 628 | XDELETE (e); |
51385f30 | 629 | } |
630 | ||
631 | /* Reset same_succ SAME. */ | |
632 | ||
633 | static void | |
634 | same_succ_reset (same_succ same) | |
635 | { | |
636 | bitmap_clear (same->bbs); | |
637 | bitmap_clear (same->succs); | |
638 | bitmap_clear (same->inverse); | |
f1f41a6c | 639 | same->succ_flags.truncate (0); |
51385f30 | 640 | } |
641 | ||
494bbaae | 642 | static hash_table <same_succ_def> same_succ_htab; |
51385f30 | 643 | |
644 | /* Array that is used to store the edge flags for a successor. */ | |
645 | ||
646 | static int *same_succ_edge_flags; | |
647 | ||
648 | /* Bitmap that is used to mark bbs that are recently deleted. */ | |
649 | ||
650 | static bitmap deleted_bbs; | |
651 | ||
652 | /* Bitmap that is used to mark predecessors of bbs that are | |
653 | deleted. */ | |
654 | ||
655 | static bitmap deleted_bb_preds; | |
656 | ||
657 | /* Prints same_succ_htab to stderr. */ | |
658 | ||
659 | extern void debug_same_succ (void); | |
660 | DEBUG_FUNCTION void | |
661 | debug_same_succ ( void) | |
662 | { | |
2b15d2ba | 663 | same_succ_htab.traverse <FILE *, ssa_same_succ_print_traverse> (stderr); |
51385f30 | 664 | } |
665 | ||
51385f30 | 666 | |
667 | /* Vector of bbs to process. */ | |
668 | ||
f1f41a6c | 669 | static vec<same_succ> worklist; |
51385f30 | 670 | |
671 | /* Prints worklist to FILE. */ | |
672 | ||
673 | static void | |
674 | print_worklist (FILE *file) | |
675 | { | |
676 | unsigned int i; | |
f1f41a6c | 677 | for (i = 0; i < worklist.length (); ++i) |
678 | same_succ_print (file, worklist[i]); | |
51385f30 | 679 | } |
680 | ||
681 | /* Adds SAME to worklist. */ | |
682 | ||
683 | static void | |
684 | add_to_worklist (same_succ same) | |
685 | { | |
686 | if (same->in_worklist) | |
687 | return; | |
688 | ||
689 | if (bitmap_count_bits (same->bbs) < 2) | |
690 | return; | |
691 | ||
692 | same->in_worklist = true; | |
f1f41a6c | 693 | worklist.safe_push (same); |
51385f30 | 694 | } |
695 | ||
696 | /* Add BB to same_succ_htab. */ | |
697 | ||
698 | static void | |
699 | find_same_succ_bb (basic_block bb, same_succ *same_p) | |
700 | { | |
701 | unsigned int j; | |
702 | bitmap_iterator bj; | |
703 | same_succ same = *same_p; | |
704 | same_succ *slot; | |
705 | edge_iterator ei; | |
706 | edge e; | |
707 | ||
c48f77d5 | 708 | if (bb == NULL |
709 | /* Be conservative with loop structure. It's not evident that this test | |
710 | is sufficient. Before tail-merge, we've just called | |
711 | loop_optimizer_finalize, and LOOPS_MAY_HAVE_MULTIPLE_LATCHES is now | |
712 | set, so there's no guarantee that the loop->latch value is still valid. | |
713 | But we assume that, since we've forced LOOPS_HAVE_SIMPLE_LATCHES at the | |
714 | start of pre, we've kept that property intact throughout pre, and are | |
715 | keeping it throughout tail-merge using this test. */ | |
716 | || bb->loop_father->latch == bb) | |
51385f30 | 717 | return; |
718 | bitmap_set_bit (same->bbs, bb->index); | |
719 | FOR_EACH_EDGE (e, ei, bb->succs) | |
720 | { | |
721 | int index = e->dest->index; | |
722 | bitmap_set_bit (same->succs, index); | |
723 | same_succ_edge_flags[index] = e->flags; | |
724 | } | |
725 | EXECUTE_IF_SET_IN_BITMAP (same->succs, 0, j, bj) | |
f1f41a6c | 726 | same->succ_flags.safe_push (same_succ_edge_flags[j]); |
51385f30 | 727 | |
494bbaae | 728 | same->hashval = same_succ_hash (same); |
51385f30 | 729 | |
2b15d2ba | 730 | slot = same_succ_htab.find_slot_with_hash (same, same->hashval, INSERT); |
51385f30 | 731 | if (*slot == NULL) |
732 | { | |
733 | *slot = same; | |
734 | BB_SAME_SUCC (bb) = same; | |
735 | add_to_worklist (same); | |
736 | *same_p = NULL; | |
737 | } | |
738 | else | |
739 | { | |
740 | bitmap_set_bit ((*slot)->bbs, bb->index); | |
741 | BB_SAME_SUCC (bb) = *slot; | |
742 | add_to_worklist (*slot); | |
743 | if (inverse_flags (same, *slot)) | |
744 | bitmap_set_bit ((*slot)->inverse, bb->index); | |
745 | same_succ_reset (same); | |
746 | } | |
747 | } | |
748 | ||
749 | /* Find bbs with same successors. */ | |
750 | ||
751 | static void | |
752 | find_same_succ (void) | |
753 | { | |
754 | same_succ same = same_succ_alloc (); | |
755 | basic_block bb; | |
756 | ||
fc00614f | 757 | FOR_EACH_BB_FN (bb, cfun) |
51385f30 | 758 | { |
759 | find_same_succ_bb (bb, &same); | |
760 | if (same == NULL) | |
761 | same = same_succ_alloc (); | |
762 | } | |
763 | ||
494bbaae | 764 | same_succ_def::remove (same); |
51385f30 | 765 | } |
766 | ||
767 | /* Initializes worklist administration. */ | |
768 | ||
769 | static void | |
770 | init_worklist (void) | |
771 | { | |
772 | alloc_aux_for_blocks (sizeof (struct aux_bb_info)); | |
a28770e1 | 773 | same_succ_htab.create (n_basic_blocks_for_fn (cfun)); |
fe672ac0 | 774 | same_succ_edge_flags = XCNEWVEC (int, last_basic_block_for_fn (cfun)); |
51385f30 | 775 | deleted_bbs = BITMAP_ALLOC (NULL); |
776 | deleted_bb_preds = BITMAP_ALLOC (NULL); | |
a28770e1 | 777 | worklist.create (n_basic_blocks_for_fn (cfun)); |
51385f30 | 778 | find_same_succ (); |
779 | ||
780 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
781 | { | |
782 | fprintf (dump_file, "initial worklist:\n"); | |
783 | print_worklist (dump_file); | |
784 | } | |
785 | } | |
786 | ||
787 | /* Deletes worklist administration. */ | |
788 | ||
789 | static void | |
790 | delete_worklist (void) | |
791 | { | |
792 | free_aux_for_blocks (); | |
2b15d2ba | 793 | same_succ_htab.dispose (); |
51385f30 | 794 | XDELETEVEC (same_succ_edge_flags); |
795 | same_succ_edge_flags = NULL; | |
796 | BITMAP_FREE (deleted_bbs); | |
797 | BITMAP_FREE (deleted_bb_preds); | |
f1f41a6c | 798 | worklist.release (); |
51385f30 | 799 | } |
800 | ||
801 | /* Mark BB as deleted, and mark its predecessors. */ | |
802 | ||
803 | static void | |
b1ad75f0 | 804 | mark_basic_block_deleted (basic_block bb) |
51385f30 | 805 | { |
806 | edge e; | |
807 | edge_iterator ei; | |
808 | ||
809 | bitmap_set_bit (deleted_bbs, bb->index); | |
810 | ||
811 | FOR_EACH_EDGE (e, ei, bb->preds) | |
812 | bitmap_set_bit (deleted_bb_preds, e->src->index); | |
813 | } | |
814 | ||
d2e5e5c3 | 815 | /* Removes BB from its corresponding same_succ. */ |
816 | ||
817 | static void | |
818 | same_succ_flush_bb (basic_block bb) | |
819 | { | |
820 | same_succ same = BB_SAME_SUCC (bb); | |
821 | BB_SAME_SUCC (bb) = NULL; | |
822 | if (bitmap_single_bit_set_p (same->bbs)) | |
2b15d2ba | 823 | same_succ_htab.remove_elt_with_hash (same, same->hashval); |
d2e5e5c3 | 824 | else |
825 | bitmap_clear_bit (same->bbs, bb->index); | |
826 | } | |
827 | ||
51385f30 | 828 | /* Removes all bbs in BBS from their corresponding same_succ. */ |
829 | ||
830 | static void | |
831 | same_succ_flush_bbs (bitmap bbs) | |
832 | { | |
833 | unsigned int i; | |
834 | bitmap_iterator bi; | |
835 | ||
836 | EXECUTE_IF_SET_IN_BITMAP (bbs, 0, i, bi) | |
f5a6b05f | 837 | same_succ_flush_bb (BASIC_BLOCK_FOR_FN (cfun, i)); |
51385f30 | 838 | } |
839 | ||
ff11bbd5 | 840 | /* Release the last vdef in BB, either normal or phi result. */ |
841 | ||
842 | static void | |
843 | release_last_vdef (basic_block bb) | |
844 | { | |
845 | gimple_stmt_iterator i; | |
846 | ||
847 | for (i = gsi_last_bb (bb); !gsi_end_p (i); gsi_prev_nondebug (&i)) | |
848 | { | |
849 | gimple stmt = gsi_stmt (i); | |
850 | if (gimple_vdef (stmt) == NULL_TREE) | |
851 | continue; | |
852 | ||
853 | mark_virtual_operand_for_renaming (gimple_vdef (stmt)); | |
854 | return; | |
855 | } | |
856 | ||
857 | for (i = gsi_start_phis (bb); !gsi_end_p (i); gsi_next (&i)) | |
858 | { | |
859 | gimple phi = gsi_stmt (i); | |
860 | tree res = gimple_phi_result (phi); | |
861 | ||
7c782c9b | 862 | if (!virtual_operand_p (res)) |
ff11bbd5 | 863 | continue; |
864 | ||
865 | mark_virtual_phi_result_for_renaming (phi); | |
866 | return; | |
867 | } | |
868 | ||
869 | } | |
870 | ||
51385f30 | 871 | /* For deleted_bb_preds, find bbs with same successors. */ |
872 | ||
873 | static void | |
874 | update_worklist (void) | |
875 | { | |
876 | unsigned int i; | |
877 | bitmap_iterator bi; | |
878 | basic_block bb; | |
879 | same_succ same; | |
880 | ||
b1ad75f0 | 881 | bitmap_and_compl_into (deleted_bb_preds, deleted_bbs); |
882 | bitmap_clear (deleted_bbs); | |
883 | ||
51385f30 | 884 | bitmap_clear_bit (deleted_bb_preds, ENTRY_BLOCK); |
885 | same_succ_flush_bbs (deleted_bb_preds); | |
886 | ||
887 | same = same_succ_alloc (); | |
888 | EXECUTE_IF_SET_IN_BITMAP (deleted_bb_preds, 0, i, bi) | |
889 | { | |
f5a6b05f | 890 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
51385f30 | 891 | gcc_assert (bb != NULL); |
892 | find_same_succ_bb (bb, &same); | |
893 | if (same == NULL) | |
894 | same = same_succ_alloc (); | |
895 | } | |
494bbaae | 896 | same_succ_def::remove (same); |
51385f30 | 897 | bitmap_clear (deleted_bb_preds); |
898 | } | |
899 | ||
900 | /* Prints cluster C to FILE. */ | |
901 | ||
902 | static void | |
903 | print_cluster (FILE *file, bb_cluster c) | |
904 | { | |
905 | if (c == NULL) | |
906 | return; | |
907 | bitmap_print (file, c->bbs, "bbs:", "\n"); | |
908 | bitmap_print (file, c->preds, "preds:", "\n"); | |
909 | } | |
910 | ||
911 | /* Prints cluster C to stderr. */ | |
912 | ||
913 | extern void debug_cluster (bb_cluster); | |
914 | DEBUG_FUNCTION void | |
915 | debug_cluster (bb_cluster c) | |
916 | { | |
917 | print_cluster (stderr, c); | |
918 | } | |
919 | ||
920 | /* Update C->rep_bb, given that BB is added to the cluster. */ | |
921 | ||
922 | static void | |
923 | update_rep_bb (bb_cluster c, basic_block bb) | |
924 | { | |
925 | /* Initial. */ | |
926 | if (c->rep_bb == NULL) | |
927 | { | |
928 | c->rep_bb = bb; | |
929 | return; | |
930 | } | |
931 | ||
932 | /* Current needs no deps, keep it. */ | |
933 | if (BB_DEP_BB (c->rep_bb) == NULL) | |
934 | return; | |
935 | ||
936 | /* Bb needs no deps, change rep_bb. */ | |
937 | if (BB_DEP_BB (bb) == NULL) | |
938 | { | |
939 | c->rep_bb = bb; | |
940 | return; | |
941 | } | |
942 | ||
943 | /* Bb needs last deps earlier than current, change rep_bb. A potential | |
944 | problem with this, is that the first deps might also be earlier, which | |
945 | would mean we prefer longer lifetimes for the deps. To be able to check | |
946 | for this, we would have to trace BB_FIRST_DEP_BB as well, besides | |
947 | BB_DEP_BB, which is really BB_LAST_DEP_BB. | |
948 | The benefit of choosing the bb with last deps earlier, is that it can | |
949 | potentially be used as replacement for more bbs. */ | |
950 | if (dominated_by_p (CDI_DOMINATORS, BB_DEP_BB (c->rep_bb), BB_DEP_BB (bb))) | |
951 | c->rep_bb = bb; | |
952 | } | |
953 | ||
954 | /* Add BB to cluster C. Sets BB in C->bbs, and preds of BB in C->preds. */ | |
955 | ||
956 | static void | |
957 | add_bb_to_cluster (bb_cluster c, basic_block bb) | |
958 | { | |
959 | edge e; | |
960 | edge_iterator ei; | |
961 | ||
962 | bitmap_set_bit (c->bbs, bb->index); | |
963 | ||
964 | FOR_EACH_EDGE (e, ei, bb->preds) | |
965 | bitmap_set_bit (c->preds, e->src->index); | |
966 | ||
967 | update_rep_bb (c, bb); | |
968 | } | |
969 | ||
970 | /* Allocate and init new cluster. */ | |
971 | ||
972 | static bb_cluster | |
973 | new_cluster (void) | |
974 | { | |
975 | bb_cluster c; | |
976 | c = XCNEW (struct bb_cluster_def); | |
977 | c->bbs = BITMAP_ALLOC (NULL); | |
978 | c->preds = BITMAP_ALLOC (NULL); | |
979 | c->rep_bb = NULL; | |
980 | return c; | |
981 | } | |
982 | ||
983 | /* Delete clusters. */ | |
984 | ||
985 | static void | |
986 | delete_cluster (bb_cluster c) | |
987 | { | |
988 | if (c == NULL) | |
989 | return; | |
990 | BITMAP_FREE (c->bbs); | |
991 | BITMAP_FREE (c->preds); | |
992 | XDELETE (c); | |
993 | } | |
994 | ||
51385f30 | 995 | |
996 | /* Array that contains all clusters. */ | |
997 | ||
f1f41a6c | 998 | static vec<bb_cluster> all_clusters; |
51385f30 | 999 | |
1000 | /* Allocate all cluster vectors. */ | |
1001 | ||
1002 | static void | |
1003 | alloc_cluster_vectors (void) | |
1004 | { | |
a28770e1 | 1005 | all_clusters.create (n_basic_blocks_for_fn (cfun)); |
51385f30 | 1006 | } |
1007 | ||
1008 | /* Reset all cluster vectors. */ | |
1009 | ||
1010 | static void | |
1011 | reset_cluster_vectors (void) | |
1012 | { | |
1013 | unsigned int i; | |
1014 | basic_block bb; | |
f1f41a6c | 1015 | for (i = 0; i < all_clusters.length (); ++i) |
1016 | delete_cluster (all_clusters[i]); | |
1017 | all_clusters.truncate (0); | |
fc00614f | 1018 | FOR_EACH_BB_FN (bb, cfun) |
51385f30 | 1019 | BB_CLUSTER (bb) = NULL; |
1020 | } | |
1021 | ||
1022 | /* Delete all cluster vectors. */ | |
1023 | ||
1024 | static void | |
1025 | delete_cluster_vectors (void) | |
1026 | { | |
1027 | unsigned int i; | |
f1f41a6c | 1028 | for (i = 0; i < all_clusters.length (); ++i) |
1029 | delete_cluster (all_clusters[i]); | |
1030 | all_clusters.release (); | |
51385f30 | 1031 | } |
1032 | ||
1033 | /* Merge cluster C2 into C1. */ | |
1034 | ||
1035 | static void | |
1036 | merge_clusters (bb_cluster c1, bb_cluster c2) | |
1037 | { | |
1038 | bitmap_ior_into (c1->bbs, c2->bbs); | |
1039 | bitmap_ior_into (c1->preds, c2->preds); | |
1040 | } | |
1041 | ||
1042 | /* Register equivalence of BB1 and BB2 (members of cluster C). Store c in | |
1043 | all_clusters, or merge c with existing cluster. */ | |
1044 | ||
1045 | static void | |
1046 | set_cluster (basic_block bb1, basic_block bb2) | |
1047 | { | |
1048 | basic_block merge_bb, other_bb; | |
1049 | bb_cluster merge, old, c; | |
1050 | ||
1051 | if (BB_CLUSTER (bb1) == NULL && BB_CLUSTER (bb2) == NULL) | |
1052 | { | |
1053 | c = new_cluster (); | |
1054 | add_bb_to_cluster (c, bb1); | |
1055 | add_bb_to_cluster (c, bb2); | |
1056 | BB_CLUSTER (bb1) = c; | |
1057 | BB_CLUSTER (bb2) = c; | |
f1f41a6c | 1058 | c->index = all_clusters.length (); |
1059 | all_clusters.safe_push (c); | |
51385f30 | 1060 | } |
1061 | else if (BB_CLUSTER (bb1) == NULL || BB_CLUSTER (bb2) == NULL) | |
1062 | { | |
1063 | merge_bb = BB_CLUSTER (bb1) == NULL ? bb2 : bb1; | |
1064 | other_bb = BB_CLUSTER (bb1) == NULL ? bb1 : bb2; | |
1065 | merge = BB_CLUSTER (merge_bb); | |
1066 | add_bb_to_cluster (merge, other_bb); | |
1067 | BB_CLUSTER (other_bb) = merge; | |
1068 | } | |
1069 | else if (BB_CLUSTER (bb1) != BB_CLUSTER (bb2)) | |
1070 | { | |
1071 | unsigned int i; | |
1072 | bitmap_iterator bi; | |
1073 | ||
1074 | old = BB_CLUSTER (bb2); | |
1075 | merge = BB_CLUSTER (bb1); | |
1076 | merge_clusters (merge, old); | |
1077 | EXECUTE_IF_SET_IN_BITMAP (old->bbs, 0, i, bi) | |
f5a6b05f | 1078 | BB_CLUSTER (BASIC_BLOCK_FOR_FN (cfun, i)) = merge; |
f1f41a6c | 1079 | all_clusters[old->index] = NULL; |
51385f30 | 1080 | update_rep_bb (merge, old->rep_bb); |
1081 | delete_cluster (old); | |
1082 | } | |
1083 | else | |
1084 | gcc_unreachable (); | |
1085 | } | |
1086 | ||
ba09ff60 | 1087 | /* Return true if gimple operands T1 and T2 have the same value. */ |
1088 | ||
1089 | static bool | |
1090 | gimple_operand_equal_value_p (tree t1, tree t2) | |
1091 | { | |
1092 | if (t1 == t2) | |
1093 | return true; | |
1094 | ||
1095 | if (t1 == NULL_TREE | |
1096 | || t2 == NULL_TREE) | |
1097 | return false; | |
1098 | ||
1099 | if (operand_equal_p (t1, t2, 0)) | |
1100 | return true; | |
1101 | ||
1102 | return gvn_uses_equal (t1, t2); | |
1103 | } | |
1104 | ||
51385f30 | 1105 | /* Return true if gimple statements S1 and S2 are equal. Gimple_bb (s1) and |
1106 | gimple_bb (s2) are members of SAME_SUCC. */ | |
1107 | ||
1108 | static bool | |
1109 | gimple_equal_p (same_succ same_succ, gimple s1, gimple s2) | |
1110 | { | |
1111 | unsigned int i; | |
1112 | tree lhs1, lhs2; | |
1113 | basic_block bb1 = gimple_bb (s1), bb2 = gimple_bb (s2); | |
1114 | tree t1, t2; | |
01f93827 | 1115 | bool inv_cond; |
51385f30 | 1116 | enum tree_code code1, code2; |
1117 | ||
1118 | if (gimple_code (s1) != gimple_code (s2)) | |
1119 | return false; | |
1120 | ||
1121 | switch (gimple_code (s1)) | |
1122 | { | |
1123 | case GIMPLE_CALL: | |
1124 | if (gimple_call_num_args (s1) != gimple_call_num_args (s2)) | |
1125 | return false; | |
1126 | if (!gimple_call_same_target_p (s1, s2)) | |
1127 | return false; | |
1128 | ||
51385f30 | 1129 | for (i = 0; i < gimple_call_num_args (s1); ++i) |
1130 | { | |
1131 | t1 = gimple_call_arg (s1, i); | |
1132 | t2 = gimple_call_arg (s2, i); | |
ba09ff60 | 1133 | if (gimple_operand_equal_value_p (t1, t2)) |
51385f30 | 1134 | continue; |
01f93827 | 1135 | return false; |
51385f30 | 1136 | } |
51385f30 | 1137 | |
1138 | lhs1 = gimple_get_lhs (s1); | |
1139 | lhs2 = gimple_get_lhs (s2); | |
87af2d00 | 1140 | if (lhs1 == NULL_TREE && lhs2 == NULL_TREE) |
1141 | return true; | |
1142 | if (lhs1 == NULL_TREE || lhs2 == NULL_TREE) | |
1143 | return false; | |
1144 | if (TREE_CODE (lhs1) == SSA_NAME && TREE_CODE (lhs2) == SSA_NAME) | |
1145 | return vn_valueize (lhs1) == vn_valueize (lhs2); | |
1146 | return operand_equal_p (lhs1, lhs2, 0); | |
51385f30 | 1147 | |
1148 | case GIMPLE_ASSIGN: | |
1149 | lhs1 = gimple_get_lhs (s1); | |
1150 | lhs2 = gimple_get_lhs (s2); | |
fad68b9f | 1151 | if (TREE_CODE (lhs1) != SSA_NAME |
1152 | && TREE_CODE (lhs2) != SSA_NAME) | |
b527c406 | 1153 | { |
1154 | /* If the vdef is the same, it's the same statement. */ | |
1155 | if (vn_valueize (gimple_vdef (s1)) | |
1156 | == vn_valueize (gimple_vdef (s2))) | |
1157 | return true; | |
1158 | ||
1159 | /* Test for structural equality. */ | |
1160 | return (operand_equal_p (lhs1, lhs2, 0) | |
1161 | && gimple_operand_equal_value_p (gimple_assign_rhs1 (s1), | |
1162 | gimple_assign_rhs1 (s2))); | |
1163 | } | |
fad68b9f | 1164 | else if (TREE_CODE (lhs1) == SSA_NAME |
1165 | && TREE_CODE (lhs2) == SSA_NAME) | |
1166 | return vn_valueize (lhs1) == vn_valueize (lhs2); | |
1167 | return false; | |
51385f30 | 1168 | |
1169 | case GIMPLE_COND: | |
1170 | t1 = gimple_cond_lhs (s1); | |
1171 | t2 = gimple_cond_lhs (s2); | |
ba09ff60 | 1172 | if (!gimple_operand_equal_value_p (t1, t2)) |
51385f30 | 1173 | return false; |
1174 | ||
1175 | t1 = gimple_cond_rhs (s1); | |
1176 | t2 = gimple_cond_rhs (s2); | |
ba09ff60 | 1177 | if (!gimple_operand_equal_value_p (t1, t2)) |
51385f30 | 1178 | return false; |
1179 | ||
1180 | code1 = gimple_expr_code (s1); | |
1181 | code2 = gimple_expr_code (s2); | |
1182 | inv_cond = (bitmap_bit_p (same_succ->inverse, bb1->index) | |
1183 | != bitmap_bit_p (same_succ->inverse, bb2->index)); | |
1184 | if (inv_cond) | |
1185 | { | |
1186 | bool honor_nans | |
1187 | = HONOR_NANS (TYPE_MODE (TREE_TYPE (gimple_cond_lhs (s1)))); | |
1188 | code2 = invert_tree_comparison (code2, honor_nans); | |
1189 | } | |
1190 | return code1 == code2; | |
1191 | ||
1192 | default: | |
1193 | return false; | |
1194 | } | |
1195 | } | |
1196 | ||
cdd84b7c | 1197 | /* Let GSI skip backwards over local defs. Return the earliest vuse in VUSE. |
1198 | Return true in VUSE_ESCAPED if the vuse influenced a SSA_OP_DEF of one of the | |
1199 | processed statements. */ | |
51385f30 | 1200 | |
1201 | static void | |
cdd84b7c | 1202 | gsi_advance_bw_nondebug_nonlocal (gimple_stmt_iterator *gsi, tree *vuse, |
1203 | bool *vuse_escaped) | |
51385f30 | 1204 | { |
1205 | gimple stmt; | |
cdd84b7c | 1206 | tree lvuse; |
51385f30 | 1207 | |
1208 | while (true) | |
1209 | { | |
1210 | if (gsi_end_p (*gsi)) | |
1211 | return; | |
1212 | stmt = gsi_stmt (*gsi); | |
cdd84b7c | 1213 | |
1214 | lvuse = gimple_vuse (stmt); | |
1215 | if (lvuse != NULL_TREE) | |
1216 | { | |
1217 | *vuse = lvuse; | |
1218 | if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_DEF)) | |
1219 | *vuse_escaped = true; | |
1220 | } | |
1221 | ||
162fb1a4 | 1222 | if (!stmt_local_def (stmt)) |
51385f30 | 1223 | return; |
1224 | gsi_prev_nondebug (gsi); | |
1225 | } | |
1226 | } | |
1227 | ||
1228 | /* Determines whether BB1 and BB2 (members of same_succ) are duplicates. If so, | |
1229 | clusters them. */ | |
1230 | ||
1231 | static void | |
1232 | find_duplicate (same_succ same_succ, basic_block bb1, basic_block bb2) | |
1233 | { | |
1234 | gimple_stmt_iterator gsi1 = gsi_last_nondebug_bb (bb1); | |
1235 | gimple_stmt_iterator gsi2 = gsi_last_nondebug_bb (bb2); | |
cdd84b7c | 1236 | tree vuse1 = NULL_TREE, vuse2 = NULL_TREE; |
1237 | bool vuse_escaped = false; | |
51385f30 | 1238 | |
cdd84b7c | 1239 | gsi_advance_bw_nondebug_nonlocal (&gsi1, &vuse1, &vuse_escaped); |
1240 | gsi_advance_bw_nondebug_nonlocal (&gsi2, &vuse2, &vuse_escaped); | |
51385f30 | 1241 | |
1242 | while (!gsi_end_p (gsi1) && !gsi_end_p (gsi2)) | |
1243 | { | |
4b9d4789 | 1244 | gimple stmt1 = gsi_stmt (gsi1); |
1245 | gimple stmt2 = gsi_stmt (gsi2); | |
1246 | ||
50a50143 | 1247 | /* What could be better than to this this here is to blacklist the bb |
1248 | containing the stmt, when encountering the stmt f.i. in | |
1249 | same_succ_hash. */ | |
1250 | if (is_tm_ending (stmt1) | |
1251 | || is_tm_ending (stmt2)) | |
4b9d4789 | 1252 | return; |
1253 | ||
50a50143 | 1254 | if (!gimple_equal_p (same_succ, stmt1, stmt2)) |
51385f30 | 1255 | return; |
1256 | ||
1257 | gsi_prev_nondebug (&gsi1); | |
1258 | gsi_prev_nondebug (&gsi2); | |
cdd84b7c | 1259 | gsi_advance_bw_nondebug_nonlocal (&gsi1, &vuse1, &vuse_escaped); |
1260 | gsi_advance_bw_nondebug_nonlocal (&gsi2, &vuse2, &vuse_escaped); | |
51385f30 | 1261 | } |
1262 | ||
1263 | if (!(gsi_end_p (gsi1) && gsi_end_p (gsi2))) | |
1264 | return; | |
1265 | ||
cdd84b7c | 1266 | /* If the incoming vuses are not the same, and the vuse escaped into an |
1267 | SSA_OP_DEF, then merging the 2 blocks will change the value of the def, | |
1268 | which potentially means the semantics of one of the blocks will be changed. | |
1269 | TODO: make this check more precise. */ | |
1270 | if (vuse_escaped && vuse1 != vuse2) | |
1271 | return; | |
1272 | ||
51385f30 | 1273 | if (dump_file) |
1274 | fprintf (dump_file, "find_duplicates: <bb %d> duplicate of <bb %d>\n", | |
1275 | bb1->index, bb2->index); | |
1276 | ||
1277 | set_cluster (bb1, bb2); | |
1278 | } | |
1279 | ||
1280 | /* Returns whether for all phis in DEST the phi alternatives for E1 and | |
1281 | E2 are equal. */ | |
1282 | ||
1283 | static bool | |
1284 | same_phi_alternatives_1 (basic_block dest, edge e1, edge e2) | |
1285 | { | |
1286 | int n1 = e1->dest_idx, n2 = e2->dest_idx; | |
1287 | gimple_stmt_iterator gsi; | |
1288 | ||
1289 | for (gsi = gsi_start_phis (dest); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1290 | { | |
1291 | gimple phi = gsi_stmt (gsi); | |
1292 | tree lhs = gimple_phi_result (phi); | |
1293 | tree val1 = gimple_phi_arg_def (phi, n1); | |
1294 | tree val2 = gimple_phi_arg_def (phi, n2); | |
1295 | ||
7c782c9b | 1296 | if (virtual_operand_p (lhs)) |
51385f30 | 1297 | continue; |
1298 | ||
1299 | if (operand_equal_for_phi_arg_p (val1, val2)) | |
1300 | continue; | |
1301 | if (gvn_uses_equal (val1, val2)) | |
1302 | continue; | |
1303 | ||
1304 | return false; | |
1305 | } | |
1306 | ||
1307 | return true; | |
1308 | } | |
1309 | ||
1310 | /* Returns whether for all successors of BB1 and BB2 (members of SAME_SUCC), the | |
1311 | phi alternatives for BB1 and BB2 are equal. */ | |
1312 | ||
1313 | static bool | |
1314 | same_phi_alternatives (same_succ same_succ, basic_block bb1, basic_block bb2) | |
1315 | { | |
1316 | unsigned int s; | |
1317 | bitmap_iterator bs; | |
1318 | edge e1, e2; | |
1319 | basic_block succ; | |
1320 | ||
1321 | EXECUTE_IF_SET_IN_BITMAP (same_succ->succs, 0, s, bs) | |
1322 | { | |
f5a6b05f | 1323 | succ = BASIC_BLOCK_FOR_FN (cfun, s); |
51385f30 | 1324 | e1 = find_edge (bb1, succ); |
1325 | e2 = find_edge (bb2, succ); | |
1326 | if (e1->flags & EDGE_COMPLEX | |
1327 | || e2->flags & EDGE_COMPLEX) | |
1328 | return false; | |
1329 | ||
1330 | /* For all phis in bb, the phi alternatives for e1 and e2 need to have | |
1331 | the same value. */ | |
1332 | if (!same_phi_alternatives_1 (succ, e1, e2)) | |
1333 | return false; | |
1334 | } | |
1335 | ||
1336 | return true; | |
1337 | } | |
1338 | ||
1339 | /* Return true if BB has non-vop phis. */ | |
1340 | ||
1341 | static bool | |
1342 | bb_has_non_vop_phi (basic_block bb) | |
1343 | { | |
1344 | gimple_seq phis = phi_nodes (bb); | |
1345 | gimple phi; | |
1346 | ||
1347 | if (phis == NULL) | |
1348 | return false; | |
1349 | ||
1350 | if (!gimple_seq_singleton_p (phis)) | |
1351 | return true; | |
1352 | ||
1353 | phi = gimple_seq_first_stmt (phis); | |
7c782c9b | 1354 | return !virtual_operand_p (gimple_phi_result (phi)); |
51385f30 | 1355 | } |
1356 | ||
1357 | /* Returns true if redirecting the incoming edges of FROM to TO maintains the | |
1358 | invariant that uses in FROM are dominates by their defs. */ | |
1359 | ||
1360 | static bool | |
1361 | deps_ok_for_redirect_from_bb_to_bb (basic_block from, basic_block to) | |
1362 | { | |
1363 | basic_block cd, dep_bb = BB_DEP_BB (to); | |
1364 | edge_iterator ei; | |
1365 | edge e; | |
1366 | bitmap from_preds = BITMAP_ALLOC (NULL); | |
1367 | ||
1368 | if (dep_bb == NULL) | |
1369 | return true; | |
1370 | ||
1371 | FOR_EACH_EDGE (e, ei, from->preds) | |
1372 | bitmap_set_bit (from_preds, e->src->index); | |
1373 | cd = nearest_common_dominator_for_set (CDI_DOMINATORS, from_preds); | |
1374 | BITMAP_FREE (from_preds); | |
1375 | ||
1376 | return dominated_by_p (CDI_DOMINATORS, dep_bb, cd); | |
1377 | } | |
1378 | ||
1379 | /* Returns true if replacing BB1 (or its replacement bb) by BB2 (or its | |
1380 | replacement bb) and vice versa maintains the invariant that uses in the | |
1381 | replacement are dominates by their defs. */ | |
1382 | ||
1383 | static bool | |
1384 | deps_ok_for_redirect (basic_block bb1, basic_block bb2) | |
1385 | { | |
1386 | if (BB_CLUSTER (bb1) != NULL) | |
1387 | bb1 = BB_CLUSTER (bb1)->rep_bb; | |
1388 | ||
1389 | if (BB_CLUSTER (bb2) != NULL) | |
1390 | bb2 = BB_CLUSTER (bb2)->rep_bb; | |
1391 | ||
1392 | return (deps_ok_for_redirect_from_bb_to_bb (bb1, bb2) | |
1393 | && deps_ok_for_redirect_from_bb_to_bb (bb2, bb1)); | |
1394 | } | |
1395 | ||
1396 | /* Within SAME_SUCC->bbs, find clusters of bbs which can be merged. */ | |
1397 | ||
1398 | static void | |
1399 | find_clusters_1 (same_succ same_succ) | |
1400 | { | |
1401 | basic_block bb1, bb2; | |
1402 | unsigned int i, j; | |
1403 | bitmap_iterator bi, bj; | |
1404 | int nr_comparisons; | |
1405 | int max_comparisons = PARAM_VALUE (PARAM_MAX_TAIL_MERGE_COMPARISONS); | |
1406 | ||
1407 | EXECUTE_IF_SET_IN_BITMAP (same_succ->bbs, 0, i, bi) | |
1408 | { | |
f5a6b05f | 1409 | bb1 = BASIC_BLOCK_FOR_FN (cfun, i); |
51385f30 | 1410 | |
1411 | /* TODO: handle blocks with phi-nodes. We'll have to find corresponding | |
1412 | phi-nodes in bb1 and bb2, with the same alternatives for the same | |
1413 | preds. */ | |
1414 | if (bb_has_non_vop_phi (bb1)) | |
1415 | continue; | |
1416 | ||
1417 | nr_comparisons = 0; | |
1418 | EXECUTE_IF_SET_IN_BITMAP (same_succ->bbs, i + 1, j, bj) | |
1419 | { | |
f5a6b05f | 1420 | bb2 = BASIC_BLOCK_FOR_FN (cfun, j); |
51385f30 | 1421 | |
1422 | if (bb_has_non_vop_phi (bb2)) | |
1423 | continue; | |
1424 | ||
1425 | if (BB_CLUSTER (bb1) != NULL && BB_CLUSTER (bb1) == BB_CLUSTER (bb2)) | |
1426 | continue; | |
1427 | ||
1428 | /* Limit quadratic behaviour. */ | |
1429 | nr_comparisons++; | |
1430 | if (nr_comparisons > max_comparisons) | |
1431 | break; | |
1432 | ||
1433 | /* This is a conservative dependency check. We could test more | |
1434 | precise for allowed replacement direction. */ | |
1435 | if (!deps_ok_for_redirect (bb1, bb2)) | |
1436 | continue; | |
1437 | ||
1438 | if (!(same_phi_alternatives (same_succ, bb1, bb2))) | |
1439 | continue; | |
1440 | ||
1441 | find_duplicate (same_succ, bb1, bb2); | |
1442 | } | |
1443 | } | |
1444 | } | |
1445 | ||
1446 | /* Find clusters of bbs which can be merged. */ | |
1447 | ||
1448 | static void | |
1449 | find_clusters (void) | |
1450 | { | |
1451 | same_succ same; | |
1452 | ||
f1f41a6c | 1453 | while (!worklist.is_empty ()) |
51385f30 | 1454 | { |
f1f41a6c | 1455 | same = worklist.pop (); |
51385f30 | 1456 | same->in_worklist = false; |
1457 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1458 | { | |
1459 | fprintf (dump_file, "processing worklist entry\n"); | |
1460 | same_succ_print (dump_file, same); | |
1461 | } | |
1462 | find_clusters_1 (same); | |
1463 | } | |
1464 | } | |
1465 | ||
51385f30 | 1466 | /* Returns the vop phi of BB, if any. */ |
1467 | ||
1468 | static gimple | |
1469 | vop_phi (basic_block bb) | |
1470 | { | |
1471 | gimple stmt; | |
1472 | gimple_stmt_iterator gsi; | |
1473 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1474 | { | |
1475 | stmt = gsi_stmt (gsi); | |
7c782c9b | 1476 | if (! virtual_operand_p (gimple_phi_result (stmt))) |
51385f30 | 1477 | continue; |
1478 | return stmt; | |
1479 | } | |
1480 | return NULL; | |
1481 | } | |
1482 | ||
b1ad75f0 | 1483 | /* Redirect all edges from BB1 to BB2, removes BB1 and marks it as removed. */ |
51385f30 | 1484 | |
1485 | static void | |
b1ad75f0 | 1486 | replace_block_by (basic_block bb1, basic_block bb2) |
51385f30 | 1487 | { |
1488 | edge pred_edge; | |
2de034ed | 1489 | edge e1, e2; |
bc4d077b | 1490 | edge_iterator ei; |
51385f30 | 1491 | unsigned int i; |
b1ad75f0 | 1492 | gimple bb2_phi; |
35bfa3a2 | 1493 | |
b1ad75f0 | 1494 | bb2_phi = vop_phi (bb2); |
51385f30 | 1495 | |
b1ad75f0 | 1496 | /* Mark the basic block as deleted. */ |
1497 | mark_basic_block_deleted (bb1); | |
51385f30 | 1498 | |
1499 | /* Redirect the incoming edges of bb1 to bb2. */ | |
1500 | for (i = EDGE_COUNT (bb1->preds); i > 0 ; --i) | |
1501 | { | |
1502 | pred_edge = EDGE_PRED (bb1, i - 1); | |
1503 | pred_edge = redirect_edge_and_branch (pred_edge, bb2); | |
1504 | gcc_assert (pred_edge != NULL); | |
b1ad75f0 | 1505 | |
1506 | if (bb2_phi == NULL) | |
1507 | continue; | |
1508 | ||
1509 | /* The phi might have run out of capacity when the redirect added an | |
1510 | argument, which means it could have been replaced. Refresh it. */ | |
1511 | bb2_phi = vop_phi (bb2); | |
1512 | ||
1513 | add_phi_arg (bb2_phi, SSA_NAME_VAR (gimple_phi_result (bb2_phi)), | |
60d535d2 | 1514 | pred_edge, UNKNOWN_LOCATION); |
51385f30 | 1515 | } |
1516 | ||
30a29019 | 1517 | bb2->frequency += bb1->frequency; |
1518 | if (bb2->frequency > BB_FREQ_MAX) | |
1519 | bb2->frequency = BB_FREQ_MAX; | |
0fef5355 | 1520 | |
1521 | bb2->count += bb1->count; | |
30a29019 | 1522 | |
bc4d077b | 1523 | /* Merge the outgoing edge counts from bb1 onto bb2. */ |
2de034ed | 1524 | gcov_type out_sum = 0; |
bc4d077b | 1525 | FOR_EACH_EDGE (e1, ei, bb1->succs) |
1526 | { | |
bc4d077b | 1527 | e2 = find_edge (bb2, e1->dest); |
1528 | gcc_assert (e2); | |
1529 | e2->count += e1->count; | |
2de034ed | 1530 | out_sum += e2->count; |
1531 | } | |
1532 | /* Recompute the edge probabilities from the new merged edge count. | |
1533 | Use the sum of the new merged edge counts computed above instead | |
1534 | of bb2's merged count, in case there are profile count insanities | |
1535 | making the bb count inconsistent with the edge weights. */ | |
1536 | FOR_EACH_EDGE (e2, ei, bb2->succs) | |
1537 | { | |
1538 | e2->probability = GCOV_COMPUTE_SCALE (e2->count, out_sum); | |
bc4d077b | 1539 | } |
1540 | ||
9375b71f | 1541 | /* Do updates that use bb1, before deleting bb1. */ |
ff11bbd5 | 1542 | release_last_vdef (bb1); |
9375b71f | 1543 | same_succ_flush_bb (bb1); |
1544 | ||
b1ad75f0 | 1545 | delete_basic_block (bb1); |
51385f30 | 1546 | } |
1547 | ||
1548 | /* Bbs for which update_debug_stmt need to be called. */ | |
1549 | ||
1550 | static bitmap update_bbs; | |
1551 | ||
1552 | /* For each cluster in all_clusters, merge all cluster->bbs. Returns | |
b1ad75f0 | 1553 | number of bbs removed. */ |
51385f30 | 1554 | |
1555 | static int | |
b1ad75f0 | 1556 | apply_clusters (void) |
51385f30 | 1557 | { |
1558 | basic_block bb1, bb2; | |
1559 | bb_cluster c; | |
1560 | unsigned int i, j; | |
1561 | bitmap_iterator bj; | |
1562 | int nr_bbs_removed = 0; | |
1563 | ||
f1f41a6c | 1564 | for (i = 0; i < all_clusters.length (); ++i) |
51385f30 | 1565 | { |
f1f41a6c | 1566 | c = all_clusters[i]; |
51385f30 | 1567 | if (c == NULL) |
1568 | continue; | |
1569 | ||
1570 | bb2 = c->rep_bb; | |
1571 | bitmap_set_bit (update_bbs, bb2->index); | |
1572 | ||
1573 | bitmap_clear_bit (c->bbs, bb2->index); | |
1574 | EXECUTE_IF_SET_IN_BITMAP (c->bbs, 0, j, bj) | |
1575 | { | |
f5a6b05f | 1576 | bb1 = BASIC_BLOCK_FOR_FN (cfun, j); |
51385f30 | 1577 | bitmap_clear_bit (update_bbs, bb1->index); |
1578 | ||
b1ad75f0 | 1579 | replace_block_by (bb1, bb2); |
51385f30 | 1580 | nr_bbs_removed++; |
1581 | } | |
1582 | } | |
1583 | ||
1584 | return nr_bbs_removed; | |
1585 | } | |
1586 | ||
1587 | /* Resets debug statement STMT if it has uses that are not dominated by their | |
1588 | defs. */ | |
1589 | ||
1590 | static void | |
1591 | update_debug_stmt (gimple stmt) | |
1592 | { | |
1593 | use_operand_p use_p; | |
1594 | ssa_op_iter oi; | |
1595 | basic_block bbdef, bbuse; | |
1596 | gimple def_stmt; | |
1597 | tree name; | |
1598 | ||
1599 | if (!gimple_debug_bind_p (stmt)) | |
1600 | return; | |
1601 | ||
1602 | bbuse = gimple_bb (stmt); | |
1603 | FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, oi, SSA_OP_USE) | |
1604 | { | |
1605 | name = USE_FROM_PTR (use_p); | |
1606 | gcc_assert (TREE_CODE (name) == SSA_NAME); | |
1607 | ||
1608 | def_stmt = SSA_NAME_DEF_STMT (name); | |
1609 | gcc_assert (def_stmt != NULL); | |
1610 | ||
1611 | bbdef = gimple_bb (def_stmt); | |
1612 | if (bbdef == NULL || bbuse == bbdef | |
1613 | || dominated_by_p (CDI_DOMINATORS, bbuse, bbdef)) | |
1614 | continue; | |
1615 | ||
1616 | gimple_debug_bind_reset_value (stmt); | |
1617 | update_stmt (stmt); | |
1618 | } | |
1619 | } | |
1620 | ||
1621 | /* Resets all debug statements that have uses that are not | |
1622 | dominated by their defs. */ | |
1623 | ||
1624 | static void | |
1625 | update_debug_stmts (void) | |
1626 | { | |
1627 | basic_block bb; | |
1628 | bitmap_iterator bi; | |
1629 | unsigned int i; | |
1630 | ||
51385f30 | 1631 | EXECUTE_IF_SET_IN_BITMAP (update_bbs, 0, i, bi) |
1632 | { | |
1633 | gimple stmt; | |
1634 | gimple_stmt_iterator gsi; | |
1635 | ||
f5a6b05f | 1636 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
51385f30 | 1637 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
1638 | { | |
1639 | stmt = gsi_stmt (gsi); | |
1640 | if (!is_gimple_debug (stmt)) | |
1641 | continue; | |
1642 | update_debug_stmt (stmt); | |
1643 | } | |
1644 | } | |
1645 | } | |
1646 | ||
1647 | /* Runs tail merge optimization. */ | |
1648 | ||
1649 | unsigned int | |
1650 | tail_merge_optimize (unsigned int todo) | |
1651 | { | |
1652 | int nr_bbs_removed_total = 0; | |
1653 | int nr_bbs_removed; | |
1654 | bool loop_entered = false; | |
1655 | int iteration_nr = 0; | |
51385f30 | 1656 | int max_iterations = PARAM_VALUE (PARAM_MAX_TAIL_MERGE_ITERATIONS); |
1657 | ||
c48f77d5 | 1658 | if (!flag_tree_tail_merge |
1659 | || max_iterations == 0 | |
1660 | /* We try to be conservative with respect to loop structure, since: | |
1661 | - the cases where tail-merging could both affect loop structure and be | |
c31fb425 | 1662 | beneficial are rare, |
c48f77d5 | 1663 | - it prevents us from having to fixup the loops using |
1664 | loops_state_set (LOOPS_NEED_FIXUP), and | |
1665 | - keeping loop structure may allow us to simplify the pass. | |
1666 | In order to be conservative, we need loop information. In rare cases | |
1667 | (about 7 test-cases in the g++ testsuite) there is none (because | |
1668 | loop_optimizer_finalize has been called before tail-merge, and | |
1669 | PROP_loops is not set), so we bail out. */ | |
1670 | || current_loops == NULL) | |
51385f30 | 1671 | return 0; |
1672 | ||
1673 | timevar_push (TV_TREE_TAIL_MERGE); | |
1674 | ||
b74146ca | 1675 | if (!dom_info_available_p (CDI_DOMINATORS)) |
1676 | { | |
1677 | /* PRE can leave us with unreachable blocks, remove them now. */ | |
1678 | delete_unreachable_blocks (); | |
1679 | calculate_dominance_info (CDI_DOMINATORS); | |
1680 | } | |
51385f30 | 1681 | init_worklist (); |
1682 | ||
f1f41a6c | 1683 | while (!worklist.is_empty ()) |
51385f30 | 1684 | { |
1685 | if (!loop_entered) | |
1686 | { | |
1687 | loop_entered = true; | |
1688 | alloc_cluster_vectors (); | |
1689 | update_bbs = BITMAP_ALLOC (NULL); | |
1690 | } | |
1691 | else | |
1692 | reset_cluster_vectors (); | |
1693 | ||
1694 | iteration_nr++; | |
1695 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1696 | fprintf (dump_file, "worklist iteration #%d\n", iteration_nr); | |
1697 | ||
1698 | find_clusters (); | |
f1f41a6c | 1699 | gcc_assert (worklist.is_empty ()); |
1700 | if (all_clusters.is_empty ()) | |
51385f30 | 1701 | break; |
1702 | ||
b1ad75f0 | 1703 | nr_bbs_removed = apply_clusters (); |
51385f30 | 1704 | nr_bbs_removed_total += nr_bbs_removed; |
1705 | if (nr_bbs_removed == 0) | |
1706 | break; | |
1707 | ||
b1ad75f0 | 1708 | free_dominance_info (CDI_DOMINATORS); |
51385f30 | 1709 | |
1710 | if (iteration_nr == max_iterations) | |
1711 | break; | |
1712 | ||
b1ad75f0 | 1713 | calculate_dominance_info (CDI_DOMINATORS); |
51385f30 | 1714 | update_worklist (); |
1715 | } | |
1716 | ||
1717 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1718 | fprintf (dump_file, "htab collision / search: %f\n", | |
2b15d2ba | 1719 | same_succ_htab.collisions ()); |
51385f30 | 1720 | |
1721 | if (nr_bbs_removed_total > 0) | |
1722 | { | |
b1ad75f0 | 1723 | if (MAY_HAVE_DEBUG_STMTS) |
1724 | { | |
1725 | calculate_dominance_info (CDI_DOMINATORS); | |
1726 | update_debug_stmts (); | |
1727 | } | |
51385f30 | 1728 | |
1729 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1730 | { | |
1731 | fprintf (dump_file, "Before TODOs.\n"); | |
1732 | dump_function_to_file (current_function_decl, dump_file, dump_flags); | |
1733 | } | |
1734 | ||
65082f57 | 1735 | todo |= (TODO_verify_ssa | TODO_verify_stmts | TODO_verify_flow); |
278611f2 | 1736 | mark_virtual_operands_for_renaming (cfun); |
51385f30 | 1737 | } |
1738 | ||
1739 | delete_worklist (); | |
1740 | if (loop_entered) | |
1741 | { | |
1742 | delete_cluster_vectors (); | |
1743 | BITMAP_FREE (update_bbs); | |
1744 | } | |
1745 | ||
1746 | timevar_pop (TV_TREE_TAIL_MERGE); | |
1747 | ||
1748 | return todo; | |
1749 | } |