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8fe17e23 | 1 | /* Support routines for Splitting Paths to loop backedges |
8d9254fc | 2 | Copyright (C) 2015-2020 Free Software Foundation, Inc. |
8fe17e23 AA |
3 | Contributed by Ajit Kumar Agarwal <ajitkum@xilinx.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 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "backend.h" | |
25 | #include "tree.h" | |
26 | #include "gimple.h" | |
27 | #include "tree-pass.h" | |
8981d712 | 28 | #include "tree-cfg.h" |
8fe17e23 AA |
29 | #include "cfganal.h" |
30 | #include "cfgloop.h" | |
31 | #include "gimple-iterator.h" | |
32 | #include "tracer.h" | |
72ca20f9 | 33 | #include "predict.h" |
10b70b8e RB |
34 | #include "gimple-ssa.h" |
35 | #include "tree-phinodes.h" | |
36 | #include "ssa-iterators.h" | |
8fe17e23 AA |
37 | |
38 | /* Given LATCH, the latch block in a loop, see if the shape of the | |
39 | path reaching LATCH is suitable for being split by duplication. | |
40 | If so, return the block that will be duplicated into its predecessor | |
41 | paths. Else return NULL. */ | |
42 | ||
43 | static basic_block | |
44 | find_block_to_duplicate_for_splitting_paths (basic_block latch) | |
45 | { | |
46 | /* We should have simple latches at this point. So the latch should | |
47 | have a single successor. This implies the predecessor of the latch | |
48 | likely has the loop exit. And it's that predecessor we're most | |
49 | interested in. To keep things simple, we're going to require that | |
50 | the latch have a single predecessor too. */ | |
51 | if (single_succ_p (latch) && single_pred_p (latch)) | |
52 | { | |
53 | basic_block bb = get_immediate_dominator (CDI_DOMINATORS, latch); | |
54 | gcc_assert (single_pred_edge (latch)->src == bb); | |
55 | ||
56 | /* If BB has been marked as not to be duplicated, then honor that | |
57 | request. */ | |
58 | if (ignore_bb_p (bb)) | |
59 | return NULL; | |
60 | ||
61 | gimple *last = gsi_stmt (gsi_last_nondebug_bb (bb)); | |
62 | /* The immediate dominator of the latch must end in a conditional. */ | |
63 | if (!last || gimple_code (last) != GIMPLE_COND) | |
64 | return NULL; | |
65 | ||
66 | /* We're hoping that BB is a join point for an IF-THEN-ELSE diamond | |
67 | region. Verify that it is. | |
68 | ||
69 | First, verify that BB has two predecessors (each arm of the | |
aaf1ee48 RB |
70 | IF-THEN-ELSE) and two successors (the latch and exit) and that |
71 | all edges are normal. */ | |
72 | if (EDGE_COUNT (bb->preds) == 2 | |
73 | && !(EDGE_PRED (bb, 0)->flags & EDGE_COMPLEX) | |
74 | && !(EDGE_PRED (bb, 1)->flags & EDGE_COMPLEX) | |
75 | && EDGE_COUNT (bb->succs) == 2 | |
76 | && !(EDGE_SUCC (bb, 0)->flags & EDGE_COMPLEX) | |
77 | && !(EDGE_SUCC (bb, 1)->flags & EDGE_COMPLEX)) | |
8fe17e23 AA |
78 | { |
79 | /* Now verify that BB's immediate dominator ends in a | |
80 | conditional as well. */ | |
81 | basic_block bb_idom = get_immediate_dominator (CDI_DOMINATORS, bb); | |
82 | gimple *last = gsi_stmt (gsi_last_nondebug_bb (bb_idom)); | |
83 | if (!last || gimple_code (last) != GIMPLE_COND) | |
84 | return NULL; | |
85 | ||
86 | /* And that BB's immediate dominator's successors are the | |
1174b21b RB |
87 | predecessors of BB or BB itself. */ |
88 | if (!(EDGE_PRED (bb, 0)->src == bb_idom | |
89 | || find_edge (bb_idom, EDGE_PRED (bb, 0)->src)) | |
90 | || !(EDGE_PRED (bb, 1)->src == bb_idom | |
91 | || find_edge (bb_idom, EDGE_PRED (bb, 1)->src))) | |
8fe17e23 AA |
92 | return NULL; |
93 | ||
1174b21b RB |
94 | /* And that the predecessors of BB each have a single successor |
95 | or are BB's immediate domiator itself. */ | |
96 | if (!(EDGE_PRED (bb, 0)->src == bb_idom | |
97 | || single_succ_p (EDGE_PRED (bb, 0)->src)) | |
98 | || !(EDGE_PRED (bb, 1)->src == bb_idom | |
99 | || single_succ_p (EDGE_PRED (bb, 1)->src))) | |
8981d712 JL |
100 | return NULL; |
101 | ||
8fe17e23 AA |
102 | /* So at this point we have a simple diamond for an IF-THEN-ELSE |
103 | construct starting at BB_IDOM, with a join point at BB. BB | |
104 | pass control outside the loop or to the loop latch. | |
105 | ||
106 | We're going to want to create two duplicates of BB, one for | |
107 | each successor of BB_IDOM. */ | |
108 | return bb; | |
109 | } | |
110 | } | |
111 | return NULL; | |
112 | } | |
113 | ||
8981d712 JL |
114 | /* Return the number of non-debug statements in a block. */ |
115 | static unsigned int | |
116 | count_stmts_in_block (basic_block bb) | |
117 | { | |
118 | gimple_stmt_iterator gsi; | |
119 | unsigned int num_stmts = 0; | |
120 | ||
121 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
122 | { | |
123 | gimple *stmt = gsi_stmt (gsi); | |
124 | if (!is_gimple_debug (stmt)) | |
125 | num_stmts++; | |
126 | } | |
127 | return num_stmts; | |
128 | } | |
129 | ||
130 | /* Return TRUE if CODE represents a tree code that is not likely to | |
131 | be easily if-convertable because it likely expands into multiple | |
132 | insns, FALSE otherwise. */ | |
133 | static bool | |
134 | poor_ifcvt_candidate_code (enum tree_code code) | |
135 | { | |
136 | return (code == MIN_EXPR | |
137 | || code == MAX_EXPR | |
138 | || code == ABS_EXPR | |
139 | || code == COND_EXPR | |
140 | || code == CALL_EXPR); | |
141 | } | |
142 | ||
8fe17e23 AA |
143 | /* Return TRUE if BB is a reasonable block to duplicate by examining |
144 | its size, false otherwise. BB will always be a loop latch block. | |
145 | ||
8981d712 JL |
146 | Things to consider: |
147 | ||
148 | We do not want to spoil if-conversion if at all possible. | |
149 | ||
150 | Most of the benefit seems to be from eliminating the unconditional | |
151 | jump rather than CSE/DCE opportunities. So favor duplicating | |
152 | small latches. A latch with just a conditional branch is ideal. | |
153 | ||
154 | CSE/DCE opportunties crop up when statements from the predecessors | |
155 | feed statements in the latch and allow statements in the latch to | |
156 | simplify. */ | |
8fe17e23 AA |
157 | |
158 | static bool | |
159 | is_feasible_trace (basic_block bb) | |
160 | { | |
8981d712 JL |
161 | basic_block pred1 = EDGE_PRED (bb, 0)->src; |
162 | basic_block pred2 = EDGE_PRED (bb, 1)->src; | |
163 | int num_stmts_in_join = count_stmts_in_block (bb); | |
1174b21b RB |
164 | int num_stmts_in_pred1 |
165 | = EDGE_COUNT (pred1->succs) == 1 ? count_stmts_in_block (pred1) : 0; | |
166 | int num_stmts_in_pred2 | |
167 | = EDGE_COUNT (pred2->succs) == 1 ? count_stmts_in_block (pred2) : 0; | |
8981d712 JL |
168 | |
169 | /* This is meant to catch cases that are likely opportunities for | |
170 | if-conversion. Essentially we look for the case where | |
171 | BB's predecessors are both single statement blocks where | |
172 | the output of that statement feed the same PHI in BB. */ | |
173 | if (num_stmts_in_pred1 == 1 && num_stmts_in_pred2 == 1) | |
8fe17e23 | 174 | { |
8981d712 JL |
175 | gimple *stmt1 = last_and_only_stmt (pred1); |
176 | gimple *stmt2 = last_and_only_stmt (pred2); | |
177 | ||
178 | if (stmt1 && stmt2 | |
179 | && gimple_code (stmt1) == GIMPLE_ASSIGN | |
180 | && gimple_code (stmt2) == GIMPLE_ASSIGN) | |
181 | { | |
182 | enum tree_code code1 = gimple_assign_rhs_code (stmt1); | |
183 | enum tree_code code2 = gimple_assign_rhs_code (stmt2); | |
184 | ||
185 | if (!poor_ifcvt_candidate_code (code1) | |
186 | && !poor_ifcvt_candidate_code (code2)) | |
187 | { | |
188 | tree lhs1 = gimple_assign_lhs (stmt1); | |
189 | tree lhs2 = gimple_assign_lhs (stmt2); | |
190 | gimple_stmt_iterator gsi; | |
191 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
192 | { | |
193 | gimple *phi = gsi_stmt (gsi); | |
194 | if ((gimple_phi_arg_def (phi, 0) == lhs1 | |
195 | && gimple_phi_arg_def (phi, 1) == lhs2) | |
196 | || (gimple_phi_arg_def (phi, 1) == lhs1 | |
197 | && gimple_phi_arg_def (phi, 0) == lhs2)) | |
198 | { | |
199 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
200 | fprintf (dump_file, | |
201 | "Block %d appears to be a join point for " | |
202 | "if-convertable diamond.\n", | |
203 | bb->index); | |
204 | return false; | |
205 | } | |
206 | } | |
207 | } | |
208 | } | |
8fe17e23 AA |
209 | } |
210 | ||
7b1ff601 JL |
211 | /* Canonicalize the form. */ |
212 | if (num_stmts_in_pred1 == 0 && num_stmts_in_pred2 == 1) | |
213 | { | |
214 | std::swap (pred1, pred2); | |
215 | std::swap (num_stmts_in_pred1, num_stmts_in_pred2); | |
216 | } | |
217 | ||
7b1ff601 JL |
218 | /* Another variant. This one is half-diamond. */ |
219 | if (num_stmts_in_pred1 == 1 && num_stmts_in_pred2 == 0 | |
220 | && dominated_by_p (CDI_DOMINATORS, pred1, pred2)) | |
221 | { | |
222 | gimple *stmt1 = last_and_only_stmt (pred1); | |
223 | ||
224 | /* The only statement in PRED1 must be an assignment that is | |
225 | not a good candidate for if-conversion. This may need some | |
226 | generalization. */ | |
227 | if (stmt1 && gimple_code (stmt1) == GIMPLE_ASSIGN) | |
228 | { | |
229 | enum tree_code code1 = gimple_assign_rhs_code (stmt1); | |
230 | ||
231 | if (!poor_ifcvt_candidate_code (code1)) | |
232 | { | |
233 | tree lhs1 = gimple_assign_lhs (stmt1); | |
234 | tree rhs1 = gimple_assign_rhs1 (stmt1); | |
235 | ||
236 | gimple_stmt_iterator gsi; | |
237 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
238 | { | |
239 | gimple *phi = gsi_stmt (gsi); | |
240 | if ((gimple_phi_arg_def (phi, 0) == lhs1 | |
241 | && gimple_phi_arg_def (phi, 1) == rhs1) | |
242 | || (gimple_phi_arg_def (phi, 1) == lhs1 | |
243 | && gimple_phi_arg_def (phi, 0) == rhs1)) | |
244 | { | |
245 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
246 | fprintf (dump_file, | |
247 | "Block %d appears to be a join point for " | |
248 | "if-convertable half-diamond.\n", | |
249 | bb->index); | |
250 | return false; | |
251 | } | |
252 | } | |
253 | } | |
254 | } | |
255 | } | |
256 | ||
10b70b8e RB |
257 | /* If the joiner has no PHIs with useful uses there is zero chance |
258 | of CSE/DCE/jump-threading possibilities exposed by duplicating it. */ | |
259 | bool found_useful_phi = false; | |
260 | for (gphi_iterator si = gsi_start_phis (bb); ! gsi_end_p (si); | |
261 | gsi_next (&si)) | |
262 | { | |
263 | gphi *phi = si.phi (); | |
264 | use_operand_p use_p; | |
265 | imm_use_iterator iter; | |
266 | FOR_EACH_IMM_USE_FAST (use_p, iter, gimple_phi_result (phi)) | |
267 | { | |
268 | gimple *stmt = USE_STMT (use_p); | |
269 | if (is_gimple_debug (stmt)) | |
270 | continue; | |
271 | /* If there's a use in the joiner this might be a CSE/DCE | |
d3640534 JL |
272 | opportunity, but not if the use is in a conditional |
273 | which makes this a likely if-conversion candidate. */ | |
274 | if (gimple_bb (stmt) == bb | |
275 | && (!is_gimple_assign (stmt) | |
276 | || (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)) | |
277 | != tcc_comparison))) | |
10b70b8e RB |
278 | { |
279 | found_useful_phi = true; | |
280 | break; | |
281 | } | |
282 | /* If the use is on a loop header PHI and on one path the | |
283 | value is unchanged this might expose a jump threading | |
284 | opportunity. */ | |
285 | if (gimple_code (stmt) == GIMPLE_PHI | |
286 | && gimple_bb (stmt) == bb->loop_father->header | |
287 | /* But for memory the PHI alone isn't good enough. */ | |
288 | && ! virtual_operand_p (gimple_phi_result (stmt))) | |
289 | { | |
7699e88f | 290 | bool found_unchanged_path = false; |
10b70b8e RB |
291 | for (unsigned i = 0; i < gimple_phi_num_args (phi); ++i) |
292 | if (gimple_phi_arg_def (phi, i) == gimple_phi_result (stmt)) | |
293 | { | |
7699e88f | 294 | found_unchanged_path = true; |
10b70b8e RB |
295 | break; |
296 | } | |
7699e88f RB |
297 | /* If we found an unchanged path this can only be a threading |
298 | opportunity if we have uses of the loop header PHI result | |
299 | in a stmt dominating the merge block. Otherwise the | |
300 | splitting may prevent if-conversion. */ | |
301 | if (found_unchanged_path) | |
302 | { | |
303 | use_operand_p use2_p; | |
304 | imm_use_iterator iter2; | |
305 | FOR_EACH_IMM_USE_FAST (use2_p, iter2, gimple_phi_result (stmt)) | |
306 | { | |
7f7e9dae RB |
307 | gimple *use_stmt = USE_STMT (use2_p); |
308 | if (is_gimple_debug (use_stmt)) | |
d0815217 | 309 | continue; |
7f7e9dae | 310 | basic_block use_bb = gimple_bb (use_stmt); |
7699e88f RB |
311 | if (use_bb != bb |
312 | && dominated_by_p (CDI_DOMINATORS, bb, use_bb)) | |
313 | { | |
7f7e9dae RB |
314 | if (gcond *cond = dyn_cast <gcond *> (use_stmt)) |
315 | if (gimple_cond_code (cond) == EQ_EXPR | |
316 | || gimple_cond_code (cond) == NE_EXPR) | |
317 | found_useful_phi = true; | |
7699e88f RB |
318 | break; |
319 | } | |
320 | } | |
321 | } | |
10b70b8e RB |
322 | if (found_useful_phi) |
323 | break; | |
324 | } | |
325 | } | |
326 | if (found_useful_phi) | |
327 | break; | |
328 | } | |
7699e88f RB |
329 | /* There is one exception namely a controlling condition we can propagate |
330 | an equivalence from to the joiner. */ | |
331 | bool found_cprop_opportunity = false; | |
332 | basic_block dom = get_immediate_dominator (CDI_DOMINATORS, bb); | |
333 | gcond *cond = as_a <gcond *> (last_stmt (dom)); | |
334 | if (gimple_cond_code (cond) == EQ_EXPR | |
335 | || gimple_cond_code (cond) == NE_EXPR) | |
336 | for (unsigned i = 0; i < 2; ++i) | |
337 | { | |
338 | tree op = gimple_op (cond, i); | |
339 | if (TREE_CODE (op) == SSA_NAME) | |
340 | { | |
341 | use_operand_p use_p; | |
342 | imm_use_iterator iter; | |
343 | FOR_EACH_IMM_USE_FAST (use_p, iter, op) | |
d0815217 RB |
344 | { |
345 | if (is_gimple_debug (USE_STMT (use_p))) | |
346 | continue; | |
347 | if (gimple_bb (USE_STMT (use_p)) == bb) | |
348 | { | |
349 | found_cprop_opportunity = true; | |
350 | break; | |
351 | } | |
352 | } | |
7699e88f RB |
353 | } |
354 | if (found_cprop_opportunity) | |
355 | break; | |
356 | } | |
357 | ||
358 | if (! found_useful_phi && ! found_cprop_opportunity) | |
10b70b8e RB |
359 | { |
360 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
361 | fprintf (dump_file, | |
362 | "Block %d is a join that does not expose CSE/DCE/jump-thread " | |
363 | "opportunities when duplicated.\n", | |
364 | bb->index); | |
365 | return false; | |
366 | } | |
367 | ||
8981d712 JL |
368 | /* We may want something here which looks at dataflow and tries |
369 | to guess if duplication of BB is likely to result in simplification | |
370 | of instructions in BB in either the original or the duplicate. */ | |
371 | ||
372 | /* Upper Hard limit on the number statements to copy. */ | |
373 | if (num_stmts_in_join | |
028d4092 | 374 | >= param_max_jump_thread_duplication_stmts) |
8981d712 | 375 | return false; |
8fe17e23 | 376 | |
8981d712 | 377 | return true; |
8fe17e23 AA |
378 | } |
379 | ||
380 | /* If the immediate dominator of the latch of the loop is | |
381 | block with conditional branch, then the loop latch is | |
382 | duplicated to its predecessors path preserving the SSA | |
383 | semantics. | |
384 | ||
385 | CFG before transformation. | |
386 | ||
387 | 2 | |
388 | | | |
389 | | | |
390 | +---->3 | |
391 | | / \ | |
392 | | / \ | |
393 | | 4 5 | |
394 | | \ / | |
395 | | \ / | |
396 | | 6 | |
397 | | / \ | |
398 | | / \ | |
399 | | 8 7 | |
400 | | | | | |
401 | ---+ E | |
402 | ||
403 | ||
404 | ||
405 | Block 8 is the latch. We're going to make copies of block 6 (9 & 10) | |
406 | and wire things up so they look like this: | |
407 | ||
408 | 2 | |
409 | | | |
410 | | | |
411 | +---->3 | |
412 | | / \ | |
413 | | / \ | |
414 | | 4 5 | |
415 | | | | | |
416 | | | | | |
417 | | 9 10 | |
418 | | |\ /| | |
419 | | | \ / | | |
420 | | | 7 | | |
421 | | | | | | |
422 | | | E | | |
423 | | | | | |
424 | | \ / | |
425 | | \ / | |
426 | +-----8 | |
427 | ||
428 | ||
429 | Blocks 9 and 10 will get merged into blocks 4 & 5 respectively which | |
430 | enables CSE, DCE and other optimizations to occur on a larger block | |
431 | of code. */ | |
432 | ||
433 | static bool | |
434 | split_paths () | |
435 | { | |
436 | bool changed = false; | |
437 | loop_p loop; | |
438 | ||
439 | loop_optimizer_init (LOOPS_NORMAL | LOOPS_HAVE_RECORDED_EXITS); | |
440 | initialize_original_copy_tables (); | |
441 | calculate_dominance_info (CDI_DOMINATORS); | |
442 | ||
443 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) | |
444 | { | |
72ca20f9 JL |
445 | /* Only split paths if we are optimizing this loop for speed. */ |
446 | if (!optimize_loop_for_speed_p (loop)) | |
447 | continue; | |
448 | ||
8fe17e23 AA |
449 | /* See if there is a block that we can duplicate to split the |
450 | path to the loop latch. */ | |
72ca20f9 JL |
451 | basic_block bb |
452 | = find_block_to_duplicate_for_splitting_paths (loop->latch); | |
8fe17e23 AA |
453 | |
454 | /* BB is the merge point for an IF-THEN-ELSE we want to transform. | |
455 | ||
9edb6bb8 JL |
456 | Essentially we want to create a duplicate of bb and redirect the |
457 | first predecessor of BB to the duplicate (leaving the second | |
458 | predecessor as is. This will split the path leading to the latch | |
459 | re-using BB to avoid useless copying. */ | |
8fe17e23 AA |
460 | if (bb && is_feasible_trace (bb)) |
461 | { | |
462 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
463 | fprintf (dump_file, | |
464 | "Duplicating join block %d into predecessor paths\n", | |
465 | bb->index); | |
466 | basic_block pred0 = EDGE_PRED (bb, 0)->src; | |
1174b21b RB |
467 | if (EDGE_COUNT (pred0->succs) != 1) |
468 | pred0 = EDGE_PRED (bb, 1)->src; | |
8fe17e23 | 469 | transform_duplicate (pred0, bb); |
8fe17e23 | 470 | changed = true; |
0c6072a3 JL |
471 | |
472 | /* If BB has an outgoing edge marked as IRREDUCIBLE, then | |
473 | duplicating BB may result in an irreducible region turning | |
474 | into a natural loop. | |
475 | ||
476 | Long term we might want to hook this into the block | |
477 | duplication code, but as we've seen with similar changes | |
478 | for edge removal, that can be somewhat risky. */ | |
479 | if (EDGE_SUCC (bb, 0)->flags & EDGE_IRREDUCIBLE_LOOP | |
480 | || EDGE_SUCC (bb, 1)->flags & EDGE_IRREDUCIBLE_LOOP) | |
481 | { | |
482 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
483 | fprintf (dump_file, | |
484 | "Join block %d has EDGE_IRREDUCIBLE_LOOP set. " | |
485 | "Scheduling loop fixups.\n", | |
486 | bb->index); | |
487 | loops_state_set (LOOPS_NEED_FIXUP); | |
488 | } | |
8fe17e23 AA |
489 | } |
490 | } | |
491 | ||
492 | loop_optimizer_finalize (); | |
493 | free_original_copy_tables (); | |
494 | return changed; | |
495 | } | |
496 | ||
497 | /* Main entry point for splitting paths. Returns TODO_cleanup_cfg if any | |
498 | paths where split, otherwise return zero. */ | |
499 | ||
500 | static unsigned int | |
501 | execute_split_paths () | |
502 | { | |
503 | /* If we don't have at least 2 real blocks and backedges in the | |
504 | CFG, then there's no point in trying to perform path splitting. */ | |
505 | if (n_basic_blocks_for_fn (cfun) <= NUM_FIXED_BLOCKS + 1 | |
506 | || !mark_dfs_back_edges ()) | |
507 | return 0; | |
508 | ||
509 | bool changed = split_paths(); | |
510 | if (changed) | |
511 | free_dominance_info (CDI_DOMINATORS); | |
512 | ||
513 | return changed ? TODO_cleanup_cfg : 0; | |
514 | } | |
515 | ||
516 | static bool | |
517 | gate_split_paths () | |
518 | { | |
519 | return flag_split_paths; | |
520 | } | |
521 | ||
522 | namespace { | |
523 | ||
524 | const pass_data pass_data_split_paths = | |
525 | { | |
526 | GIMPLE_PASS, /* type */ | |
527 | "split-paths", /* name */ | |
528 | OPTGROUP_NONE, /* optinfo_flags */ | |
529 | TV_SPLIT_PATHS, /* tv_id */ | |
530 | PROP_ssa, /* properties_required */ | |
531 | 0, /* properties_provided */ | |
532 | 0, /* properties_destroyed */ | |
533 | 0, /* todo_flags_start */ | |
534 | TODO_update_ssa, /* todo_flags_finish */ | |
535 | }; | |
536 | ||
537 | class pass_split_paths : public gimple_opt_pass | |
538 | { | |
539 | public: | |
540 | pass_split_paths (gcc::context *ctxt) | |
541 | : gimple_opt_pass (pass_data_split_paths, ctxt) | |
542 | {} | |
543 | /* opt_pass methods: */ | |
544 | opt_pass * clone () { return new pass_split_paths (m_ctxt); } | |
545 | virtual bool gate (function *) { return gate_split_paths (); } | |
546 | virtual unsigned int execute (function *) { return execute_split_paths (); } | |
547 | ||
548 | }; // class pass_split_paths | |
549 | ||
550 | } // anon namespace | |
551 | ||
552 | gimple_opt_pass * | |
553 | make_pass_split_paths (gcc::context *ctxt) | |
554 | { | |
555 | return new pass_split_paths (ctxt); | |
556 | } |