Mercurial > hg > CbC > CbC_gcc
annotate gcc/cfgloop.c @ 158:494b0b89df80 default tip
...
author | Shinji KONO <kono@ie.u-ryukyu.ac.jp> |
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date | Mon, 25 May 2020 18:13:55 +0900 |
parents | 1830386684a0 |
children |
rev | line source |
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0 | 1 /* Natural loop discovery code for GNU compiler. |
145 | 2 Copyright (C) 2000-2020 Free Software Foundation, Inc. |
0 | 3 |
4 This file is part of GCC. | |
5 | |
6 GCC is free software; you can redistribute it and/or modify it under | |
7 the terms of the GNU General Public License as published by the Free | |
8 Software Foundation; either version 3, or (at your option) any later | |
9 version. | |
10 | |
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 for more details. | |
15 | |
16 You should have received a copy of the GNU General Public License | |
17 along with GCC; see the file COPYING3. If not see | |
18 <http://www.gnu.org/licenses/>. */ | |
19 | |
20 #include "config.h" | |
21 #include "system.h" | |
22 #include "coretypes.h" | |
111 | 23 #include "backend.h" |
0 | 24 #include "rtl.h" |
111 | 25 #include "tree.h" |
26 #include "gimple.h" | |
27 #include "cfghooks.h" | |
28 #include "gimple-ssa.h" | |
29 #include "diagnostic-core.h" | |
30 #include "cfganal.h" | |
0 | 31 #include "cfgloop.h" |
111 | 32 #include "gimple-iterator.h" |
33 #include "dumpfile.h" | |
0 | 34 |
35 static void flow_loops_cfg_dump (FILE *); | |
36 | |
37 /* Dump loop related CFG information. */ | |
38 | |
39 static void | |
40 flow_loops_cfg_dump (FILE *file) | |
41 { | |
42 basic_block bb; | |
43 | |
44 if (!file) | |
45 return; | |
46 | |
111 | 47 FOR_EACH_BB_FN (bb, cfun) |
0 | 48 { |
49 edge succ; | |
50 edge_iterator ei; | |
51 | |
52 fprintf (file, ";; %d succs { ", bb->index); | |
53 FOR_EACH_EDGE (succ, ei, bb->succs) | |
54 fprintf (file, "%d ", succ->dest->index); | |
55 fprintf (file, "}\n"); | |
56 } | |
57 } | |
58 | |
59 /* Return nonzero if the nodes of LOOP are a subset of OUTER. */ | |
60 | |
61 bool | |
145 | 62 flow_loop_nested_p (const class loop *outer, const class loop *loop) |
0 | 63 { |
64 unsigned odepth = loop_depth (outer); | |
65 | |
66 return (loop_depth (loop) > odepth | |
111 | 67 && (*loop->superloops)[odepth] == outer); |
0 | 68 } |
69 | |
70 /* Returns the loop such that LOOP is nested DEPTH (indexed from zero) | |
71 loops within LOOP. */ | |
72 | |
145 | 73 class loop * |
74 superloop_at_depth (class loop *loop, unsigned depth) | |
0 | 75 { |
76 unsigned ldepth = loop_depth (loop); | |
77 | |
78 gcc_assert (depth <= ldepth); | |
79 | |
80 if (depth == ldepth) | |
81 return loop; | |
82 | |
111 | 83 return (*loop->superloops)[depth]; |
0 | 84 } |
85 | |
86 /* Returns the list of the latch edges of LOOP. */ | |
87 | |
111 | 88 static vec<edge> |
145 | 89 get_loop_latch_edges (const class loop *loop) |
0 | 90 { |
91 edge_iterator ei; | |
92 edge e; | |
111 | 93 vec<edge> ret = vNULL; |
0 | 94 |
95 FOR_EACH_EDGE (e, ei, loop->header->preds) | |
96 { | |
97 if (dominated_by_p (CDI_DOMINATORS, e->src, loop->header)) | |
111 | 98 ret.safe_push (e); |
0 | 99 } |
100 | |
101 return ret; | |
102 } | |
103 | |
104 /* Dump the loop information specified by LOOP to the stream FILE | |
105 using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
106 | |
107 void | |
145 | 108 flow_loop_dump (const class loop *loop, FILE *file, |
109 void (*loop_dump_aux) (const class loop *, FILE *, int), | |
0 | 110 int verbose) |
111 { | |
112 basic_block *bbs; | |
113 unsigned i; | |
111 | 114 vec<edge> latches; |
0 | 115 edge e; |
116 | |
117 if (! loop || ! loop->header) | |
118 return; | |
119 | |
120 fprintf (file, ";;\n;; Loop %d\n", loop->num); | |
121 | |
122 fprintf (file, ";; header %d, ", loop->header->index); | |
123 if (loop->latch) | |
124 fprintf (file, "latch %d\n", loop->latch->index); | |
125 else | |
126 { | |
127 fprintf (file, "multiple latches:"); | |
128 latches = get_loop_latch_edges (loop); | |
111 | 129 FOR_EACH_VEC_ELT (latches, i, e) |
0 | 130 fprintf (file, " %d", e->src->index); |
111 | 131 latches.release (); |
0 | 132 fprintf (file, "\n"); |
133 } | |
134 | |
135 fprintf (file, ";; depth %d, outer %ld\n", | |
136 loop_depth (loop), (long) (loop_outer (loop) | |
137 ? loop_outer (loop)->num : -1)); | |
138 | |
111 | 139 if (loop->latch) |
140 { | |
141 bool read_profile_p; | |
142 gcov_type nit = expected_loop_iterations_unbounded (loop, &read_profile_p); | |
143 if (read_profile_p && !loop->any_estimate) | |
144 fprintf (file, ";; profile-based iteration count: %" PRIu64 "\n", | |
145 (uint64_t) nit); | |
146 } | |
147 | |
0 | 148 fprintf (file, ";; nodes:"); |
149 bbs = get_loop_body (loop); | |
150 for (i = 0; i < loop->num_nodes; i++) | |
151 fprintf (file, " %d", bbs[i]->index); | |
152 free (bbs); | |
153 fprintf (file, "\n"); | |
154 | |
155 if (loop_dump_aux) | |
156 loop_dump_aux (loop, file, verbose); | |
157 } | |
158 | |
159 /* Dump the loop information about loops to the stream FILE, | |
160 using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
161 | |
162 void | |
145 | 163 flow_loops_dump (FILE *file, void (*loop_dump_aux) (const class loop *, FILE *, int), int verbose) |
0 | 164 { |
145 | 165 class loop *loop; |
0 | 166 |
167 if (!current_loops || ! file) | |
168 return; | |
169 | |
111 | 170 fprintf (file, ";; %d loops found\n", number_of_loops (cfun)); |
0 | 171 |
111 | 172 FOR_EACH_LOOP (loop, LI_INCLUDE_ROOT) |
0 | 173 { |
174 flow_loop_dump (loop, file, loop_dump_aux, verbose); | |
175 } | |
176 | |
177 if (verbose) | |
178 flow_loops_cfg_dump (file); | |
179 } | |
180 | |
181 /* Free data allocated for LOOP. */ | |
182 | |
183 void | |
145 | 184 flow_loop_free (class loop *loop) |
0 | 185 { |
186 struct loop_exit *exit, *next; | |
187 | |
111 | 188 vec_free (loop->superloops); |
0 | 189 |
190 /* Break the list of the loop exit records. They will be freed when the | |
191 corresponding edge is rescanned or removed, and this avoids | |
192 accessing the (already released) head of the list stored in the | |
193 loop structure. */ | |
194 for (exit = loop->exits->next; exit != loop->exits; exit = next) | |
195 { | |
196 next = exit->next; | |
197 exit->next = exit; | |
198 exit->prev = exit; | |
199 } | |
200 | |
201 ggc_free (loop->exits); | |
202 ggc_free (loop); | |
203 } | |
204 | |
205 /* Free all the memory allocated for LOOPS. */ | |
206 | |
207 void | |
208 flow_loops_free (struct loops *loops) | |
209 { | |
210 if (loops->larray) | |
211 { | |
212 unsigned i; | |
213 loop_p loop; | |
214 | |
215 /* Free the loop descriptors. */ | |
111 | 216 FOR_EACH_VEC_SAFE_ELT (loops->larray, i, loop) |
0 | 217 { |
218 if (!loop) | |
219 continue; | |
220 | |
221 flow_loop_free (loop); | |
222 } | |
223 | |
111 | 224 vec_free (loops->larray); |
0 | 225 } |
226 } | |
227 | |
228 /* Find the nodes contained within the LOOP with header HEADER. | |
229 Return the number of nodes within the loop. */ | |
230 | |
231 int | |
145 | 232 flow_loop_nodes_find (basic_block header, class loop *loop) |
0 | 233 { |
111 | 234 vec<basic_block> stack = vNULL; |
0 | 235 int num_nodes = 1; |
236 edge latch; | |
237 edge_iterator latch_ei; | |
238 | |
239 header->loop_father = loop; | |
240 | |
241 FOR_EACH_EDGE (latch, latch_ei, loop->header->preds) | |
242 { | |
243 if (latch->src->loop_father == loop | |
244 || !dominated_by_p (CDI_DOMINATORS, latch->src, loop->header)) | |
245 continue; | |
246 | |
247 num_nodes++; | |
111 | 248 stack.safe_push (latch->src); |
0 | 249 latch->src->loop_father = loop; |
250 | |
111 | 251 while (!stack.is_empty ()) |
0 | 252 { |
253 basic_block node; | |
254 edge e; | |
255 edge_iterator ei; | |
256 | |
111 | 257 node = stack.pop (); |
0 | 258 |
259 FOR_EACH_EDGE (e, ei, node->preds) | |
260 { | |
261 basic_block ancestor = e->src; | |
262 | |
263 if (ancestor->loop_father != loop) | |
264 { | |
265 ancestor->loop_father = loop; | |
266 num_nodes++; | |
111 | 267 stack.safe_push (ancestor); |
0 | 268 } |
269 } | |
270 } | |
271 } | |
111 | 272 stack.release (); |
0 | 273 |
274 return num_nodes; | |
275 } | |
276 | |
277 /* Records the vector of superloops of the loop LOOP, whose immediate | |
278 superloop is FATHER. */ | |
279 | |
280 static void | |
145 | 281 establish_preds (class loop *loop, class loop *father) |
0 | 282 { |
283 loop_p ploop; | |
284 unsigned depth = loop_depth (father) + 1; | |
285 unsigned i; | |
286 | |
111 | 287 loop->superloops = 0; |
288 vec_alloc (loop->superloops, depth); | |
289 FOR_EACH_VEC_SAFE_ELT (father->superloops, i, ploop) | |
290 loop->superloops->quick_push (ploop); | |
291 loop->superloops->quick_push (father); | |
0 | 292 |
293 for (ploop = loop->inner; ploop; ploop = ploop->next) | |
294 establish_preds (ploop, loop); | |
295 } | |
296 | |
297 /* Add LOOP to the loop hierarchy tree where FATHER is father of the | |
298 added loop. If LOOP has some children, take care of that their | |
131 | 299 pred field will be initialized correctly. If AFTER is non-null |
300 then it's expected it's a pointer into FATHERs inner sibling | |
301 list and LOOP is added behind AFTER, otherwise it's added in front | |
302 of FATHERs siblings. */ | |
0 | 303 |
304 void | |
145 | 305 flow_loop_tree_node_add (class loop *father, class loop *loop, |
306 class loop *after) | |
0 | 307 { |
131 | 308 if (after) |
309 { | |
310 loop->next = after->next; | |
311 after->next = loop; | |
312 } | |
313 else | |
314 { | |
315 loop->next = father->inner; | |
316 father->inner = loop; | |
317 } | |
0 | 318 |
319 establish_preds (loop, father); | |
320 } | |
321 | |
322 /* Remove LOOP from the loop hierarchy tree. */ | |
323 | |
324 void | |
145 | 325 flow_loop_tree_node_remove (class loop *loop) |
0 | 326 { |
145 | 327 class loop *prev, *father; |
0 | 328 |
329 father = loop_outer (loop); | |
330 | |
331 /* Remove loop from the list of sons. */ | |
332 if (father->inner == loop) | |
333 father->inner = loop->next; | |
334 else | |
335 { | |
336 for (prev = father->inner; prev->next != loop; prev = prev->next) | |
337 continue; | |
338 prev->next = loop->next; | |
339 } | |
340 | |
111 | 341 loop->superloops = NULL; |
0 | 342 } |
343 | |
344 /* Allocates and returns new loop structure. */ | |
345 | |
145 | 346 class loop * |
0 | 347 alloc_loop (void) |
348 { | |
145 | 349 class loop *loop = ggc_cleared_alloc<class loop> (); |
0 | 350 |
111 | 351 loop->exits = ggc_cleared_alloc<loop_exit> (); |
0 | 352 loop->exits->next = loop->exits->prev = loop->exits; |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
353 loop->can_be_parallel = false; |
111 | 354 loop->constraints = 0; |
355 loop->nb_iterations_upper_bound = 0; | |
356 loop->nb_iterations_likely_upper_bound = 0; | |
357 loop->nb_iterations_estimate = 0; | |
0 | 358 return loop; |
359 } | |
360 | |
361 /* Initializes loops structure LOOPS, reserving place for NUM_LOOPS loops | |
362 (including the root of the loop tree). */ | |
363 | |
111 | 364 void |
365 init_loops_structure (struct function *fn, | |
366 struct loops *loops, unsigned num_loops) | |
0 | 367 { |
145 | 368 class loop *root; |
0 | 369 |
370 memset (loops, 0, sizeof *loops); | |
111 | 371 vec_alloc (loops->larray, num_loops); |
0 | 372 |
373 /* Dummy loop containing whole function. */ | |
374 root = alloc_loop (); | |
111 | 375 root->num_nodes = n_basic_blocks_for_fn (fn); |
376 root->latch = EXIT_BLOCK_PTR_FOR_FN (fn); | |
377 root->header = ENTRY_BLOCK_PTR_FOR_FN (fn); | |
378 ENTRY_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
379 EXIT_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
380 | |
381 loops->larray->quick_push (root); | |
382 loops->tree_root = root; | |
383 } | |
384 | |
385 /* Returns whether HEADER is a loop header. */ | |
386 | |
387 bool | |
388 bb_loop_header_p (basic_block header) | |
389 { | |
390 edge_iterator ei; | |
391 edge e; | |
0 | 392 |
111 | 393 /* If we have an abnormal predecessor, do not consider the |
394 loop (not worth the problems). */ | |
395 if (bb_has_abnormal_pred (header)) | |
396 return false; | |
397 | |
398 /* Look for back edges where a predecessor is dominated | |
399 by this block. A natural loop has a single entry | |
400 node (header) that dominates all the nodes in the | |
401 loop. It also has single back edge to the header | |
402 from a latch node. */ | |
403 FOR_EACH_EDGE (e, ei, header->preds) | |
404 { | |
405 basic_block latch = e->src; | |
406 if (latch != ENTRY_BLOCK_PTR_FOR_FN (cfun) | |
407 && dominated_by_p (CDI_DOMINATORS, latch, header)) | |
408 return true; | |
409 } | |
410 | |
411 return false; | |
0 | 412 } |
413 | |
414 /* Find all the natural loops in the function and save in LOOPS structure and | |
111 | 415 recalculate loop_father information in basic block structures. |
416 If LOOPS is non-NULL then the loop structures for already recorded loops | |
417 will be re-used and their number will not change. We assume that no | |
418 stale loops exist in LOOPS. | |
419 When LOOPS is NULL it is allocated and re-built from scratch. | |
420 Return the built LOOPS structure. */ | |
0 | 421 |
111 | 422 struct loops * |
0 | 423 flow_loops_find (struct loops *loops) |
424 { | |
111 | 425 bool from_scratch = (loops == NULL); |
426 int *rc_order; | |
0 | 427 int b; |
111 | 428 unsigned i; |
0 | 429 |
430 /* Ensure that the dominators are computed. */ | |
431 calculate_dominance_info (CDI_DOMINATORS); | |
432 | |
111 | 433 if (!loops) |
0 | 434 { |
111 | 435 loops = ggc_cleared_alloc<struct loops> (); |
436 init_loops_structure (cfun, loops, 1); | |
0 | 437 } |
438 | |
111 | 439 /* Ensure that loop exits were released. */ |
440 gcc_assert (loops->exits == NULL); | |
441 | |
442 /* Taking care of this degenerate case makes the rest of | |
443 this code simpler. */ | |
444 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) | |
445 return loops; | |
446 | |
447 /* The root loop node contains all basic-blocks. */ | |
448 loops->tree_root->num_nodes = n_basic_blocks_for_fn (cfun); | |
0 | 449 |
111 | 450 /* Compute depth first search order of the CFG so that outer |
451 natural loops will be found before inner natural loops. */ | |
452 rc_order = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); | |
453 pre_and_rev_post_order_compute (NULL, rc_order, false); | |
454 | |
455 /* Gather all loop headers in reverse completion order and allocate | |
456 loop structures for loops that are not already present. */ | |
457 auto_vec<loop_p> larray (loops->larray->length ()); | |
458 for (b = 0; b < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; b++) | |
459 { | |
460 basic_block header = BASIC_BLOCK_FOR_FN (cfun, rc_order[b]); | |
461 if (bb_loop_header_p (header)) | |
462 { | |
145 | 463 class loop *loop; |
0 | 464 |
111 | 465 /* The current active loop tree has valid loop-fathers for |
466 header blocks. */ | |
467 if (!from_scratch | |
468 && header->loop_father->header == header) | |
469 { | |
470 loop = header->loop_father; | |
471 /* If we found an existing loop remove it from the | |
472 loop tree. It is going to be inserted again | |
473 below. */ | |
474 flow_loop_tree_node_remove (loop); | |
475 } | |
476 else | |
477 { | |
478 /* Otherwise allocate a new loop structure for the loop. */ | |
479 loop = alloc_loop (); | |
480 /* ??? We could re-use unused loop slots here. */ | |
481 loop->num = loops->larray->length (); | |
482 vec_safe_push (loops->larray, loop); | |
483 loop->header = header; | |
0 | 484 |
111 | 485 if (!from_scratch |
486 && dump_file && (dump_flags & TDF_DETAILS)) | |
487 fprintf (dump_file, "flow_loops_find: discovered new " | |
488 "loop %d with header %d\n", | |
489 loop->num, header->index); | |
490 } | |
491 /* Reset latch, we recompute it below. */ | |
492 loop->latch = NULL; | |
493 larray.safe_push (loop); | |
494 } | |
495 | |
496 /* Make blocks part of the loop root node at start. */ | |
497 header->loop_father = loops->tree_root; | |
498 } | |
0 | 499 |
111 | 500 free (rc_order); |
0 | 501 |
111 | 502 /* Now iterate over the loops found, insert them into the loop tree |
503 and assign basic-block ownership. */ | |
504 for (i = 0; i < larray.length (); ++i) | |
505 { | |
145 | 506 class loop *loop = larray[i]; |
111 | 507 basic_block header = loop->header; |
508 edge_iterator ei; | |
509 edge e; | |
510 | |
511 flow_loop_tree_node_add (header->loop_father, loop); | |
512 loop->num_nodes = flow_loop_nodes_find (loop->header, loop); | |
513 | |
514 /* Look for the latch for this header block, if it has just a | |
515 single one. */ | |
0 | 516 FOR_EACH_EDGE (e, ei, header->preds) |
517 { | |
518 basic_block latch = e->src; | |
519 | |
111 | 520 if (flow_bb_inside_loop_p (loop, latch)) |
0 | 521 { |
111 | 522 if (loop->latch != NULL) |
523 { | |
524 /* More than one latch edge. */ | |
525 loop->latch = NULL; | |
526 break; | |
527 } | |
528 loop->latch = latch; | |
0 | 529 } |
530 } | |
531 } | |
532 | |
111 | 533 return loops; |
534 } | |
0 | 535 |
111 | 536 /* qsort helper for sort_sibling_loops. */ |
0 | 537 |
111 | 538 static int *sort_sibling_loops_cmp_rpo; |
539 static int | |
540 sort_sibling_loops_cmp (const void *la_, const void *lb_) | |
541 { | |
145 | 542 const class loop *la = *(const class loop * const *)la_; |
543 const class loop *lb = *(const class loop * const *)lb_; | |
111 | 544 return (sort_sibling_loops_cmp_rpo[la->header->index] |
545 - sort_sibling_loops_cmp_rpo[lb->header->index]); | |
546 } | |
0 | 547 |
111 | 548 /* Sort sibling loops in RPO order. */ |
0 | 549 |
111 | 550 void |
551 sort_sibling_loops (function *fn) | |
552 { | |
553 /* Match flow_loops_find in the order we sort sibling loops. */ | |
554 sort_sibling_loops_cmp_rpo = XNEWVEC (int, last_basic_block_for_fn (cfun)); | |
555 int *rc_order = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); | |
556 pre_and_rev_post_order_compute_fn (fn, NULL, rc_order, false); | |
557 for (int i = 0; i < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; ++i) | |
558 sort_sibling_loops_cmp_rpo[rc_order[i]] = i; | |
559 free (rc_order); | |
0 | 560 |
111 | 561 auto_vec<loop_p, 3> siblings; |
562 loop_p loop; | |
563 FOR_EACH_LOOP_FN (fn, loop, LI_INCLUDE_ROOT) | |
564 if (loop->inner && loop->inner->next) | |
565 { | |
566 loop_p sibling = loop->inner; | |
567 do | |
568 { | |
569 siblings.safe_push (sibling); | |
570 sibling = sibling->next; | |
571 } | |
572 while (sibling); | |
573 siblings.qsort (sort_sibling_loops_cmp); | |
574 loop_p *siblingp = &loop->inner; | |
575 for (unsigned i = 0; i < siblings.length (); ++i) | |
576 { | |
577 *siblingp = siblings[i]; | |
578 siblingp = &(*siblingp)->next; | |
579 } | |
580 *siblingp = NULL; | |
581 siblings.truncate (0); | |
582 } | |
0 | 583 |
111 | 584 free (sort_sibling_loops_cmp_rpo); |
585 sort_sibling_loops_cmp_rpo = NULL; | |
0 | 586 } |
587 | |
588 /* Ratio of frequencies of edges so that one of more latch edges is | |
589 considered to belong to inner loop with same header. */ | |
590 #define HEAVY_EDGE_RATIO 8 | |
591 | |
592 /* Minimum number of samples for that we apply | |
593 find_subloop_latch_edge_by_profile heuristics. */ | |
594 #define HEAVY_EDGE_MIN_SAMPLES 10 | |
595 | |
596 /* If the profile info is available, finds an edge in LATCHES that much more | |
597 frequent than the remaining edges. Returns such an edge, or NULL if we do | |
598 not find one. | |
599 | |
600 We do not use guessed profile here, only the measured one. The guessed | |
601 profile is usually too flat and unreliable for this (and it is mostly based | |
602 on the loop structure of the program, so it does not make much sense to | |
603 derive the loop structure from it). */ | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
604 |
0 | 605 static edge |
111 | 606 find_subloop_latch_edge_by_profile (vec<edge> latches) |
0 | 607 { |
608 unsigned i; | |
609 edge e, me = NULL; | |
111 | 610 profile_count mcount = profile_count::zero (), tcount = profile_count::zero (); |
0 | 611 |
111 | 612 FOR_EACH_VEC_ELT (latches, i, e) |
0 | 613 { |
111 | 614 if (e->count ()> mcount) |
0 | 615 { |
616 me = e; | |
111 | 617 mcount = e->count(); |
0 | 618 } |
111 | 619 tcount += e->count(); |
0 | 620 } |
621 | |
131 | 622 if (!tcount.initialized_p () || !(tcount.ipa () > HEAVY_EDGE_MIN_SAMPLES) |
111 | 623 || (tcount - mcount).apply_scale (HEAVY_EDGE_RATIO, 1) > tcount) |
0 | 624 return NULL; |
625 | |
626 if (dump_file) | |
627 fprintf (dump_file, | |
628 "Found latch edge %d -> %d using profile information.\n", | |
629 me->src->index, me->dest->index); | |
630 return me; | |
631 } | |
632 | |
633 /* Among LATCHES, guesses a latch edge of LOOP corresponding to subloop, based | |
634 on the structure of induction variables. Returns this edge, or NULL if we | |
635 do not find any. | |
636 | |
637 We are quite conservative, and look just for an obvious simple innermost | |
638 loop (which is the case where we would lose the most performance by not | |
639 disambiguating the loop). More precisely, we look for the following | |
640 situation: The source of the chosen latch edge dominates sources of all | |
641 the other latch edges. Additionally, the header does not contain a phi node | |
642 such that the argument from the chosen edge is equal to the argument from | |
643 another edge. */ | |
644 | |
645 static edge | |
145 | 646 find_subloop_latch_edge_by_ivs (class loop *loop ATTRIBUTE_UNUSED, vec<edge> latches) |
0 | 647 { |
111 | 648 edge e, latch = latches[0]; |
0 | 649 unsigned i; |
111 | 650 gphi *phi; |
651 gphi_iterator psi; | |
0 | 652 tree lop; |
653 basic_block bb; | |
654 | |
655 /* Find the candidate for the latch edge. */ | |
111 | 656 for (i = 1; latches.iterate (i, &e); i++) |
0 | 657 if (dominated_by_p (CDI_DOMINATORS, latch->src, e->src)) |
658 latch = e; | |
659 | |
660 /* Verify that it dominates all the latch edges. */ | |
111 | 661 FOR_EACH_VEC_ELT (latches, i, e) |
0 | 662 if (!dominated_by_p (CDI_DOMINATORS, e->src, latch->src)) |
663 return NULL; | |
664 | |
665 /* Check for a phi node that would deny that this is a latch edge of | |
666 a subloop. */ | |
667 for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) | |
668 { | |
111 | 669 phi = psi.phi (); |
0 | 670 lop = PHI_ARG_DEF_FROM_EDGE (phi, latch); |
671 | |
672 /* Ignore the values that are not changed inside the subloop. */ | |
673 if (TREE_CODE (lop) != SSA_NAME | |
674 || SSA_NAME_DEF_STMT (lop) == phi) | |
675 continue; | |
676 bb = gimple_bb (SSA_NAME_DEF_STMT (lop)); | |
677 if (!bb || !flow_bb_inside_loop_p (loop, bb)) | |
678 continue; | |
679 | |
111 | 680 FOR_EACH_VEC_ELT (latches, i, e) |
0 | 681 if (e != latch |
682 && PHI_ARG_DEF_FROM_EDGE (phi, e) == lop) | |
683 return NULL; | |
684 } | |
685 | |
686 if (dump_file) | |
687 fprintf (dump_file, | |
688 "Found latch edge %d -> %d using iv structure.\n", | |
689 latch->src->index, latch->dest->index); | |
690 return latch; | |
691 } | |
692 | |
693 /* If we can determine that one of the several latch edges of LOOP behaves | |
694 as a latch edge of a separate subloop, returns this edge. Otherwise | |
695 returns NULL. */ | |
696 | |
697 static edge | |
145 | 698 find_subloop_latch_edge (class loop *loop) |
0 | 699 { |
111 | 700 vec<edge> latches = get_loop_latch_edges (loop); |
0 | 701 edge latch = NULL; |
702 | |
111 | 703 if (latches.length () > 1) |
0 | 704 { |
705 latch = find_subloop_latch_edge_by_profile (latches); | |
706 | |
707 if (!latch | |
708 /* We consider ivs to guess the latch edge only in SSA. Perhaps we | |
709 should use cfghook for this, but it is hard to imagine it would | |
710 be useful elsewhere. */ | |
711 && current_ir_type () == IR_GIMPLE) | |
712 latch = find_subloop_latch_edge_by_ivs (loop, latches); | |
713 } | |
714 | |
111 | 715 latches.release (); |
0 | 716 return latch; |
717 } | |
718 | |
719 /* Callback for make_forwarder_block. Returns true if the edge E is marked | |
720 in the set MFB_REIS_SET. */ | |
721 | |
111 | 722 static hash_set<edge> *mfb_reis_set; |
0 | 723 static bool |
724 mfb_redirect_edges_in_set (edge e) | |
725 { | |
111 | 726 return mfb_reis_set->contains (e); |
0 | 727 } |
728 | |
729 /* Creates a subloop of LOOP with latch edge LATCH. */ | |
730 | |
731 static void | |
145 | 732 form_subloop (class loop *loop, edge latch) |
0 | 733 { |
734 edge_iterator ei; | |
735 edge e, new_entry; | |
145 | 736 class loop *new_loop; |
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737 |
111 | 738 mfb_reis_set = new hash_set<edge>; |
0 | 739 FOR_EACH_EDGE (e, ei, loop->header->preds) |
740 { | |
741 if (e != latch) | |
111 | 742 mfb_reis_set->add (e); |
0 | 743 } |
744 new_entry = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
745 NULL); | |
111 | 746 delete mfb_reis_set; |
0 | 747 |
748 loop->header = new_entry->src; | |
749 | |
750 /* Find the blocks and subloops that belong to the new loop, and add it to | |
751 the appropriate place in the loop tree. */ | |
752 new_loop = alloc_loop (); | |
753 new_loop->header = new_entry->dest; | |
754 new_loop->latch = latch->src; | |
755 add_loop (new_loop, loop); | |
756 } | |
757 | |
758 /* Make all the latch edges of LOOP to go to a single forwarder block -- | |
759 a new latch of LOOP. */ | |
760 | |
761 static void | |
145 | 762 merge_latch_edges (class loop *loop) |
0 | 763 { |
111 | 764 vec<edge> latches = get_loop_latch_edges (loop); |
0 | 765 edge latch, e; |
766 unsigned i; | |
767 | |
111 | 768 gcc_assert (latches.length () > 0); |
0 | 769 |
111 | 770 if (latches.length () == 1) |
771 loop->latch = latches[0]->src; | |
0 | 772 else |
773 { | |
774 if (dump_file) | |
775 fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num); | |
776 | |
111 | 777 mfb_reis_set = new hash_set<edge>; |
778 FOR_EACH_VEC_ELT (latches, i, e) | |
779 mfb_reis_set->add (e); | |
0 | 780 latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, |
781 NULL); | |
111 | 782 delete mfb_reis_set; |
0 | 783 |
784 loop->header = latch->dest; | |
785 loop->latch = latch->src; | |
786 } | |
787 | |
111 | 788 latches.release (); |
0 | 789 } |
790 | |
791 /* LOOP may have several latch edges. Transform it into (possibly several) | |
792 loops with single latch edge. */ | |
793 | |
794 static void | |
145 | 795 disambiguate_multiple_latches (class loop *loop) |
0 | 796 { |
797 edge e; | |
798 | |
799 /* We eliminate the multiple latches by splitting the header to the forwarder | |
800 block F and the rest R, and redirecting the edges. There are two cases: | |
801 | |
802 1) If there is a latch edge E that corresponds to a subloop (we guess | |
803 that based on profile -- if it is taken much more often than the | |
804 remaining edges; and on trees, using the information about induction | |
805 variables of the loops), we redirect E to R, all the remaining edges to | |
806 F, then rescan the loops and try again for the outer loop. | |
807 2) If there is no such edge, we redirect all latch edges to F, and the | |
808 entry edges to R, thus making F the single latch of the loop. */ | |
809 | |
810 if (dump_file) | |
811 fprintf (dump_file, "Disambiguating loop %d with multiple latches\n", | |
812 loop->num); | |
813 | |
814 /* During latch merging, we may need to redirect the entry edges to a new | |
815 block. This would cause problems if the entry edge was the one from the | |
816 entry block. To avoid having to handle this case specially, split | |
817 such entry edge. */ | |
111 | 818 e = find_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), loop->header); |
0 | 819 if (e) |
820 split_edge (e); | |
821 | |
822 while (1) | |
823 { | |
824 e = find_subloop_latch_edge (loop); | |
825 if (!e) | |
826 break; | |
827 | |
828 form_subloop (loop, e); | |
829 } | |
830 | |
831 merge_latch_edges (loop); | |
832 } | |
833 | |
834 /* Split loops with multiple latch edges. */ | |
835 | |
836 void | |
837 disambiguate_loops_with_multiple_latches (void) | |
838 { | |
145 | 839 class loop *loop; |
0 | 840 |
111 | 841 FOR_EACH_LOOP (loop, 0) |
0 | 842 { |
843 if (!loop->latch) | |
844 disambiguate_multiple_latches (loop); | |
845 } | |
846 } | |
847 | |
848 /* Return nonzero if basic block BB belongs to LOOP. */ | |
849 bool | |
145 | 850 flow_bb_inside_loop_p (const class loop *loop, const_basic_block bb) |
0 | 851 { |
145 | 852 class loop *source_loop; |
0 | 853 |
111 | 854 if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
855 || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
0 | 856 return 0; |
857 | |
858 source_loop = bb->loop_father; | |
859 return loop == source_loop || flow_loop_nested_p (loop, source_loop); | |
860 } | |
861 | |
862 /* Enumeration predicate for get_loop_body_with_size. */ | |
863 static bool | |
864 glb_enum_p (const_basic_block bb, const void *glb_loop) | |
865 { | |
145 | 866 const class loop *const loop = (const class loop *) glb_loop; |
0 | 867 return (bb != loop->header |
868 && dominated_by_p (CDI_DOMINATORS, bb, loop->header)); | |
869 } | |
870 | |
871 /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
872 order against direction of edges from latch. Specially, if | |
873 header != latch, latch is the 1-st block. LOOP cannot be the fake | |
874 loop tree root, and its size must be at most MAX_SIZE. The blocks | |
875 in the LOOP body are stored to BODY, and the size of the LOOP is | |
876 returned. */ | |
877 | |
878 unsigned | |
145 | 879 get_loop_body_with_size (const class loop *loop, basic_block *body, |
0 | 880 unsigned max_size) |
881 { | |
882 return dfs_enumerate_from (loop->header, 1, glb_enum_p, | |
883 body, max_size, loop); | |
884 } | |
885 | |
886 /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
887 order against direction of edges from latch. Specially, if | |
888 header != latch, latch is the 1-st block. */ | |
889 | |
890 basic_block * | |
145 | 891 get_loop_body (const class loop *loop) |
0 | 892 { |
893 basic_block *body, bb; | |
894 unsigned tv = 0; | |
895 | |
896 gcc_assert (loop->num_nodes); | |
897 | |
111 | 898 body = XNEWVEC (basic_block, loop->num_nodes); |
0 | 899 |
111 | 900 if (loop->latch == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
0 | 901 { |
902 /* There may be blocks unreachable from EXIT_BLOCK, hence we need to | |
903 special-case the fake loop that contains the whole function. */ | |
111 | 904 gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks_for_fn (cfun)); |
0 | 905 body[tv++] = loop->header; |
111 | 906 body[tv++] = EXIT_BLOCK_PTR_FOR_FN (cfun); |
907 FOR_EACH_BB_FN (bb, cfun) | |
0 | 908 body[tv++] = bb; |
909 } | |
910 else | |
911 tv = get_loop_body_with_size (loop, body, loop->num_nodes); | |
912 | |
913 gcc_assert (tv == loop->num_nodes); | |
914 return body; | |
915 } | |
916 | |
917 /* Fills dominance descendants inside LOOP of the basic block BB into | |
918 array TOVISIT from index *TV. */ | |
919 | |
920 static void | |
145 | 921 fill_sons_in_loop (const class loop *loop, basic_block bb, |
0 | 922 basic_block *tovisit, int *tv) |
923 { | |
924 basic_block son, postpone = NULL; | |
925 | |
926 tovisit[(*tv)++] = bb; | |
927 for (son = first_dom_son (CDI_DOMINATORS, bb); | |
928 son; | |
929 son = next_dom_son (CDI_DOMINATORS, son)) | |
930 { | |
931 if (!flow_bb_inside_loop_p (loop, son)) | |
932 continue; | |
933 | |
934 if (dominated_by_p (CDI_DOMINATORS, loop->latch, son)) | |
935 { | |
936 postpone = son; | |
937 continue; | |
938 } | |
939 fill_sons_in_loop (loop, son, tovisit, tv); | |
940 } | |
941 | |
942 if (postpone) | |
943 fill_sons_in_loop (loop, postpone, tovisit, tv); | |
944 } | |
945 | |
946 /* Gets body of a LOOP (that must be different from the outermost loop) | |
947 sorted by dominance relation. Additionally, if a basic block s dominates | |
948 the latch, then only blocks dominated by s are be after it. */ | |
949 | |
950 basic_block * | |
145 | 951 get_loop_body_in_dom_order (const class loop *loop) |
0 | 952 { |
953 basic_block *tovisit; | |
954 int tv; | |
955 | |
956 gcc_assert (loop->num_nodes); | |
957 | |
111 | 958 tovisit = XNEWVEC (basic_block, loop->num_nodes); |
0 | 959 |
111 | 960 gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
0 | 961 |
962 tv = 0; | |
963 fill_sons_in_loop (loop, loop->header, tovisit, &tv); | |
964 | |
965 gcc_assert (tv == (int) loop->num_nodes); | |
966 | |
967 return tovisit; | |
968 } | |
969 | |
970 /* Gets body of a LOOP sorted via provided BB_COMPARATOR. */ | |
971 | |
972 basic_block * | |
145 | 973 get_loop_body_in_custom_order (const class loop *loop, |
0 | 974 int (*bb_comparator) (const void *, const void *)) |
975 { | |
976 basic_block *bbs = get_loop_body (loop); | |
977 | |
978 qsort (bbs, loop->num_nodes, sizeof (basic_block), bb_comparator); | |
979 | |
980 return bbs; | |
981 } | |
982 | |
145 | 983 /* Same as above, but use gcc_sort_r instead of qsort. */ |
984 | |
985 basic_block * | |
986 get_loop_body_in_custom_order (const class loop *loop, void *data, | |
987 int (*bb_comparator) (const void *, const void *, void *)) | |
988 { | |
989 basic_block *bbs = get_loop_body (loop); | |
990 | |
991 gcc_sort_r (bbs, loop->num_nodes, sizeof (basic_block), bb_comparator, data); | |
992 | |
993 return bbs; | |
994 } | |
995 | |
0 | 996 /* Get body of a LOOP in breadth first sort order. */ |
997 | |
998 basic_block * | |
145 | 999 get_loop_body_in_bfs_order (const class loop *loop) |
0 | 1000 { |
1001 basic_block *blocks; | |
1002 basic_block bb; | |
111 | 1003 unsigned int i = 1; |
1004 unsigned int vc = 0; | |
0 | 1005 |
1006 gcc_assert (loop->num_nodes); | |
111 | 1007 gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
0 | 1008 |
111 | 1009 blocks = XNEWVEC (basic_block, loop->num_nodes); |
1010 auto_bitmap visited; | |
1011 blocks[0] = loop->header; | |
1012 bitmap_set_bit (visited, loop->header->index); | |
0 | 1013 while (i < loop->num_nodes) |
1014 { | |
1015 edge e; | |
1016 edge_iterator ei; | |
111 | 1017 gcc_assert (i > vc); |
1018 bb = blocks[vc++]; | |
0 | 1019 |
1020 FOR_EACH_EDGE (e, ei, bb->succs) | |
1021 { | |
1022 if (flow_bb_inside_loop_p (loop, e->dest)) | |
1023 { | |
111 | 1024 /* This bb is now visited. */ |
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1025 if (bitmap_set_bit (visited, e->dest->index)) |
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1026 blocks[i++] = e->dest; |
0 | 1027 } |
1028 } | |
1029 } | |
1030 | |
1031 return blocks; | |
1032 } | |
1033 | |
1034 /* Hash function for struct loop_exit. */ | |
1035 | |
111 | 1036 hashval_t |
1037 loop_exit_hasher::hash (loop_exit *exit) | |
0 | 1038 { |
1039 return htab_hash_pointer (exit->e); | |
1040 } | |
1041 | |
1042 /* Equality function for struct loop_exit. Compares with edge. */ | |
1043 | |
111 | 1044 bool |
1045 loop_exit_hasher::equal (loop_exit *exit, edge e) | |
0 | 1046 { |
1047 return exit->e == e; | |
1048 } | |
1049 | |
1050 /* Frees the list of loop exit descriptions EX. */ | |
1051 | |
111 | 1052 void |
1053 loop_exit_hasher::remove (loop_exit *exit) | |
0 | 1054 { |
111 | 1055 loop_exit *next; |
0 | 1056 for (; exit; exit = next) |
1057 { | |
1058 next = exit->next_e; | |
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1059 |
0 | 1060 exit->next->prev = exit->prev; |
1061 exit->prev->next = exit->next; | |
1062 | |
1063 ggc_free (exit); | |
1064 } | |
1065 } | |
1066 | |
1067 /* Returns the list of records for E as an exit of a loop. */ | |
1068 | |
1069 static struct loop_exit * | |
1070 get_exit_descriptions (edge e) | |
1071 { | |
111 | 1072 return current_loops->exits->find_with_hash (e, htab_hash_pointer (e)); |
0 | 1073 } |
1074 | |
1075 /* Updates the lists of loop exits in that E appears. | |
1076 If REMOVED is true, E is being removed, and we | |
1077 just remove it from the lists of exits. | |
1078 If NEW_EDGE is true and E is not a loop exit, we | |
1079 do not try to remove it from loop exit lists. */ | |
1080 | |
1081 void | |
1082 rescan_loop_exit (edge e, bool new_edge, bool removed) | |
1083 { | |
1084 struct loop_exit *exits = NULL, *exit; | |
145 | 1085 class loop *aloop, *cloop; |
0 | 1086 |
1087 if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
1088 return; | |
1089 | |
1090 if (!removed | |
1091 && e->src->loop_father != NULL | |
1092 && e->dest->loop_father != NULL | |
1093 && !flow_bb_inside_loop_p (e->src->loop_father, e->dest)) | |
1094 { | |
1095 cloop = find_common_loop (e->src->loop_father, e->dest->loop_father); | |
1096 for (aloop = e->src->loop_father; | |
1097 aloop != cloop; | |
1098 aloop = loop_outer (aloop)) | |
1099 { | |
111 | 1100 exit = ggc_alloc<loop_exit> (); |
0 | 1101 exit->e = e; |
1102 | |
1103 exit->next = aloop->exits->next; | |
1104 exit->prev = aloop->exits; | |
1105 exit->next->prev = exit; | |
1106 exit->prev->next = exit; | |
1107 | |
1108 exit->next_e = exits; | |
1109 exits = exit; | |
1110 } | |
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1111 } |
0 | 1112 |
1113 if (!exits && new_edge) | |
1114 return; | |
1115 | |
111 | 1116 loop_exit **slot |
1117 = current_loops->exits->find_slot_with_hash (e, htab_hash_pointer (e), | |
1118 exits ? INSERT : NO_INSERT); | |
0 | 1119 if (!slot) |
1120 return; | |
1121 | |
1122 if (exits) | |
1123 { | |
1124 if (*slot) | |
111 | 1125 loop_exit_hasher::remove (*slot); |
0 | 1126 *slot = exits; |
1127 } | |
1128 else | |
111 | 1129 current_loops->exits->clear_slot (slot); |
0 | 1130 } |
1131 | |
1132 /* For each loop, record list of exit edges, and start maintaining these | |
1133 lists. */ | |
1134 | |
1135 void | |
1136 record_loop_exits (void) | |
1137 { | |
1138 basic_block bb; | |
1139 edge_iterator ei; | |
1140 edge e; | |
1141 | |
1142 if (!current_loops) | |
1143 return; | |
1144 | |
1145 if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
1146 return; | |
1147 loops_state_set (LOOPS_HAVE_RECORDED_EXITS); | |
1148 | |
1149 gcc_assert (current_loops->exits == NULL); | |
111 | 1150 current_loops->exits |
1151 = hash_table<loop_exit_hasher>::create_ggc (2 * number_of_loops (cfun)); | |
0 | 1152 |
111 | 1153 FOR_EACH_BB_FN (bb, cfun) |
0 | 1154 { |
1155 FOR_EACH_EDGE (e, ei, bb->succs) | |
1156 { | |
1157 rescan_loop_exit (e, true, false); | |
1158 } | |
1159 } | |
1160 } | |
1161 | |
1162 /* Dumps information about the exit in *SLOT to FILE. | |
1163 Callback for htab_traverse. */ | |
1164 | |
111 | 1165 int |
1166 dump_recorded_exit (loop_exit **slot, FILE *file) | |
0 | 1167 { |
111 | 1168 struct loop_exit *exit = *slot; |
0 | 1169 unsigned n = 0; |
1170 edge e = exit->e; | |
1171 | |
1172 for (; exit != NULL; exit = exit->next_e) | |
1173 n++; | |
1174 | |
111 | 1175 fprintf (file, "Edge %d->%d exits %u loops\n", |
0 | 1176 e->src->index, e->dest->index, n); |
1177 | |
1178 return 1; | |
1179 } | |
1180 | |
1181 /* Dumps the recorded exits of loops to FILE. */ | |
1182 | |
1183 extern void dump_recorded_exits (FILE *); | |
1184 void | |
1185 dump_recorded_exits (FILE *file) | |
1186 { | |
1187 if (!current_loops->exits) | |
1188 return; | |
111 | 1189 current_loops->exits->traverse<FILE *, dump_recorded_exit> (file); |
0 | 1190 } |
1191 | |
1192 /* Releases lists of loop exits. */ | |
1193 | |
1194 void | |
111 | 1195 release_recorded_exits (function *fn) |
0 | 1196 { |
111 | 1197 gcc_assert (loops_state_satisfies_p (fn, LOOPS_HAVE_RECORDED_EXITS)); |
1198 loops_for_fn (fn)->exits->empty (); | |
1199 loops_for_fn (fn)->exits = NULL; | |
1200 loops_state_clear (fn, LOOPS_HAVE_RECORDED_EXITS); | |
0 | 1201 } |
1202 | |
1203 /* Returns the list of the exit edges of a LOOP. */ | |
1204 | |
111 | 1205 vec<edge> |
145 | 1206 get_loop_exit_edges (const class loop *loop, basic_block *body) |
0 | 1207 { |
111 | 1208 vec<edge> edges = vNULL; |
0 | 1209 edge e; |
1210 unsigned i; | |
1211 edge_iterator ei; | |
1212 struct loop_exit *exit; | |
1213 | |
111 | 1214 gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
0 | 1215 |
1216 /* If we maintain the lists of exits, use them. Otherwise we must | |
1217 scan the body of the loop. */ | |
1218 if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
1219 { | |
1220 for (exit = loop->exits->next; exit->e; exit = exit->next) | |
111 | 1221 edges.safe_push (exit->e); |
0 | 1222 } |
1223 else | |
1224 { | |
145 | 1225 bool body_from_caller = true; |
1226 if (!body) | |
1227 { | |
1228 body = get_loop_body (loop); | |
1229 body_from_caller = false; | |
1230 } | |
0 | 1231 for (i = 0; i < loop->num_nodes; i++) |
1232 FOR_EACH_EDGE (e, ei, body[i]->succs) | |
1233 { | |
1234 if (!flow_bb_inside_loop_p (loop, e->dest)) | |
111 | 1235 edges.safe_push (e); |
0 | 1236 } |
145 | 1237 if (!body_from_caller) |
1238 free (body); | |
0 | 1239 } |
1240 | |
1241 return edges; | |
1242 } | |
1243 | |
1244 /* Counts the number of conditional branches inside LOOP. */ | |
1245 | |
1246 unsigned | |
145 | 1247 num_loop_branches (const class loop *loop) |
0 | 1248 { |
1249 unsigned i, n; | |
1250 basic_block * body; | |
1251 | |
111 | 1252 gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
0 | 1253 |
1254 body = get_loop_body (loop); | |
1255 n = 0; | |
1256 for (i = 0; i < loop->num_nodes; i++) | |
1257 if (EDGE_COUNT (body[i]->succs) >= 2) | |
1258 n++; | |
1259 free (body); | |
1260 | |
1261 return n; | |
1262 } | |
1263 | |
1264 /* Adds basic block BB to LOOP. */ | |
1265 void | |
145 | 1266 add_bb_to_loop (basic_block bb, class loop *loop) |
0 | 1267 { |
1268 unsigned i; | |
1269 loop_p ploop; | |
1270 edge_iterator ei; | |
1271 edge e; | |
1272 | |
1273 gcc_assert (bb->loop_father == NULL); | |
1274 bb->loop_father = loop; | |
1275 loop->num_nodes++; | |
111 | 1276 FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
0 | 1277 ploop->num_nodes++; |
1278 | |
1279 FOR_EACH_EDGE (e, ei, bb->succs) | |
1280 { | |
1281 rescan_loop_exit (e, true, false); | |
1282 } | |
1283 FOR_EACH_EDGE (e, ei, bb->preds) | |
1284 { | |
1285 rescan_loop_exit (e, true, false); | |
1286 } | |
1287 } | |
1288 | |
1289 /* Remove basic block BB from loops. */ | |
1290 void | |
1291 remove_bb_from_loops (basic_block bb) | |
1292 { | |
111 | 1293 unsigned i; |
145 | 1294 class loop *loop = bb->loop_father; |
0 | 1295 loop_p ploop; |
1296 edge_iterator ei; | |
1297 edge e; | |
1298 | |
1299 gcc_assert (loop != NULL); | |
1300 loop->num_nodes--; | |
111 | 1301 FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
0 | 1302 ploop->num_nodes--; |
1303 bb->loop_father = NULL; | |
1304 | |
1305 FOR_EACH_EDGE (e, ei, bb->succs) | |
1306 { | |
1307 rescan_loop_exit (e, false, true); | |
1308 } | |
1309 FOR_EACH_EDGE (e, ei, bb->preds) | |
1310 { | |
1311 rescan_loop_exit (e, false, true); | |
1312 } | |
1313 } | |
1314 | |
1315 /* Finds nearest common ancestor in loop tree for given loops. */ | |
145 | 1316 class loop * |
1317 find_common_loop (class loop *loop_s, class loop *loop_d) | |
0 | 1318 { |
1319 unsigned sdepth, ddepth; | |
1320 | |
1321 if (!loop_s) return loop_d; | |
1322 if (!loop_d) return loop_s; | |
1323 | |
1324 sdepth = loop_depth (loop_s); | |
1325 ddepth = loop_depth (loop_d); | |
1326 | |
1327 if (sdepth < ddepth) | |
111 | 1328 loop_d = (*loop_d->superloops)[sdepth]; |
0 | 1329 else if (sdepth > ddepth) |
111 | 1330 loop_s = (*loop_s->superloops)[ddepth]; |
0 | 1331 |
1332 while (loop_s != loop_d) | |
1333 { | |
1334 loop_s = loop_outer (loop_s); | |
1335 loop_d = loop_outer (loop_d); | |
1336 } | |
1337 return loop_s; | |
1338 } | |
1339 | |
1340 /* Removes LOOP from structures and frees its data. */ | |
1341 | |
1342 void | |
145 | 1343 delete_loop (class loop *loop) |
0 | 1344 { |
1345 /* Remove the loop from structure. */ | |
1346 flow_loop_tree_node_remove (loop); | |
1347 | |
1348 /* Remove loop from loops array. */ | |
111 | 1349 (*current_loops->larray)[loop->num] = NULL; |
0 | 1350 |
1351 /* Free loop data. */ | |
1352 flow_loop_free (loop); | |
1353 } | |
1354 | |
1355 /* Cancels the LOOP; it must be innermost one. */ | |
1356 | |
1357 static void | |
145 | 1358 cancel_loop (class loop *loop) |
0 | 1359 { |
1360 basic_block *bbs; | |
1361 unsigned i; | |
145 | 1362 class loop *outer = loop_outer (loop); |
0 | 1363 |
1364 gcc_assert (!loop->inner); | |
1365 | |
1366 /* Move blocks up one level (they should be removed as soon as possible). */ | |
1367 bbs = get_loop_body (loop); | |
1368 for (i = 0; i < loop->num_nodes; i++) | |
1369 bbs[i]->loop_father = outer; | |
1370 | |
111 | 1371 free (bbs); |
0 | 1372 delete_loop (loop); |
1373 } | |
1374 | |
1375 /* Cancels LOOP and all its subloops. */ | |
1376 void | |
145 | 1377 cancel_loop_tree (class loop *loop) |
0 | 1378 { |
1379 while (loop->inner) | |
1380 cancel_loop_tree (loop->inner); | |
1381 cancel_loop (loop); | |
1382 } | |
1383 | |
145 | 1384 /* Disable warnings about missing quoting in GCC diagnostics for |
1385 the verification errors. Their format strings don't follow GCC | |
1386 diagnostic conventions and the calls are ultimately followed by | |
1387 a deliberate ICE triggered by a failed assertion. */ | |
1388 #if __GNUC__ >= 10 | |
1389 # pragma GCC diagnostic push | |
1390 # pragma GCC diagnostic ignored "-Wformat-diag" | |
1391 #endif | |
1392 | |
0 | 1393 /* Checks that information about loops is correct |
1394 -- sizes of loops are all right | |
1395 -- results of get_loop_body really belong to the loop | |
1396 -- loop header have just single entry edge and single latch edge | |
1397 -- loop latches have only single successor that is header of their loop | |
1398 -- irreducible loops are correctly marked | |
111 | 1399 -- the cached loop depth and loop father of each bb is correct |
0 | 1400 */ |
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|
1401 DEBUG_FUNCTION void |
0 | 1402 verify_loop_structure (void) |
1403 { | |
1404 unsigned *sizes, i, j; | |
111 | 1405 basic_block bb, *bbs; |
145 | 1406 class loop *loop; |
0 | 1407 int err = 0; |
1408 edge e; | |
111 | 1409 unsigned num = number_of_loops (cfun); |
0 | 1410 struct loop_exit *exit, *mexit; |
111 | 1411 bool dom_available = dom_info_available_p (CDI_DOMINATORS); |
1412 | |
1413 if (loops_state_satisfies_p (LOOPS_NEED_FIXUP)) | |
1414 { | |
1415 error ("loop verification on loop tree that needs fixup"); | |
1416 err = 1; | |
1417 } | |
0 | 1418 |
111 | 1419 /* We need up-to-date dominators, compute or verify them. */ |
1420 if (!dom_available) | |
1421 calculate_dominance_info (CDI_DOMINATORS); | |
1422 else | |
1423 verify_dominators (CDI_DOMINATORS); | |
1424 | |
1425 /* Check the loop tree root. */ | |
1426 if (current_loops->tree_root->header != ENTRY_BLOCK_PTR_FOR_FN (cfun) | |
1427 || current_loops->tree_root->latch != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
1428 || (current_loops->tree_root->num_nodes | |
1429 != (unsigned) n_basic_blocks_for_fn (cfun))) | |
1430 { | |
1431 error ("corrupt loop tree root"); | |
1432 err = 1; | |
1433 } | |
0 | 1434 |
111 | 1435 /* Check the headers. */ |
1436 FOR_EACH_BB_FN (bb, cfun) | |
1437 if (bb_loop_header_p (bb)) | |
1438 { | |
1439 if (bb->loop_father->header == NULL) | |
1440 { | |
1441 error ("loop with header %d marked for removal", bb->index); | |
1442 err = 1; | |
1443 } | |
1444 else if (bb->loop_father->header != bb) | |
1445 { | |
1446 error ("loop with header %d not in loop tree", bb->index); | |
1447 err = 1; | |
1448 } | |
1449 } | |
1450 else if (bb->loop_father->header == bb) | |
1451 { | |
1452 error ("non-loop with header %d not marked for removal", bb->index); | |
1453 err = 1; | |
1454 } | |
0 | 1455 |
111 | 1456 /* Check the recorded loop father and sizes of loops. */ |
1457 auto_sbitmap visited (last_basic_block_for_fn (cfun)); | |
1458 bitmap_clear (visited); | |
1459 bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); | |
1460 FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) | |
0 | 1461 { |
111 | 1462 unsigned n; |
0 | 1463 |
111 | 1464 if (loop->header == NULL) |
1465 { | |
1466 error ("removed loop %d in loop tree", loop->num); | |
1467 err = 1; | |
1468 continue; | |
1469 } | |
1470 | |
1471 n = get_loop_body_with_size (loop, bbs, n_basic_blocks_for_fn (cfun)); | |
1472 if (loop->num_nodes != n) | |
0 | 1473 { |
1474 error ("size of loop %d should be %d, not %d", | |
111 | 1475 loop->num, n, loop->num_nodes); |
0 | 1476 err = 1; |
1477 } | |
111 | 1478 |
1479 for (j = 0; j < n; j++) | |
1480 { | |
1481 bb = bbs[j]; | |
0 | 1482 |
111 | 1483 if (!flow_bb_inside_loop_p (loop, bb)) |
1484 { | |
1485 error ("bb %d does not belong to loop %d", | |
1486 bb->index, loop->num); | |
1487 err = 1; | |
1488 } | |
0 | 1489 |
111 | 1490 /* Ignore this block if it is in an inner loop. */ |
1491 if (bitmap_bit_p (visited, bb->index)) | |
1492 continue; | |
1493 bitmap_set_bit (visited, bb->index); | |
1494 | |
1495 if (bb->loop_father != loop) | |
1496 { | |
1497 error ("bb %d has father loop %d, should be loop %d", | |
1498 bb->index, bb->loop_father->num, loop->num); | |
1499 err = 1; | |
1500 } | |
1501 } | |
0 | 1502 } |
111 | 1503 free (bbs); |
0 | 1504 |
1505 /* Check headers and latches. */ | |
111 | 1506 FOR_EACH_LOOP (loop, 0) |
0 | 1507 { |
1508 i = loop->num; | |
111 | 1509 if (loop->header == NULL) |
1510 continue; | |
1511 if (!bb_loop_header_p (loop->header)) | |
1512 { | |
1513 error ("loop %d%'s header is not a loop header", i); | |
1514 err = 1; | |
1515 } | |
0 | 1516 if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
1517 && EDGE_COUNT (loop->header->preds) != 2) | |
1518 { | |
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parents:
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diff
changeset
|
1519 error ("loop %d%'s header does not have exactly 2 entries", i); |
0 | 1520 err = 1; |
1521 } | |
111 | 1522 if (loop->latch) |
1523 { | |
1524 if (!find_edge (loop->latch, loop->header)) | |
1525 { | |
1526 error ("loop %d%'s latch does not have an edge to its header", i); | |
1527 err = 1; | |
1528 } | |
1529 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, loop->header)) | |
1530 { | |
1531 error ("loop %d%'s latch is not dominated by its header", i); | |
1532 err = 1; | |
1533 } | |
1534 } | |
0 | 1535 if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
1536 { | |
1537 if (!single_succ_p (loop->latch)) | |
1538 { | |
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parents:
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diff
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|
1539 error ("loop %d%'s latch does not have exactly 1 successor", i); |
0 | 1540 err = 1; |
1541 } | |
1542 if (single_succ (loop->latch) != loop->header) | |
1543 { | |
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parents:
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diff
changeset
|
1544 error ("loop %d%'s latch does not have header as successor", i); |
0 | 1545 err = 1; |
1546 } | |
1547 if (loop->latch->loop_father != loop) | |
1548 { | |
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parents:
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diff
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|
1549 error ("loop %d%'s latch does not belong directly to it", i); |
0 | 1550 err = 1; |
1551 } | |
1552 } | |
1553 if (loop->header->loop_father != loop) | |
1554 { | |
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parents:
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diff
changeset
|
1555 error ("loop %d%'s header does not belong directly to it", i); |
0 | 1556 err = 1; |
1557 } | |
1558 if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) | |
1559 && (loop_latch_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)) | |
1560 { | |
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nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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diff
changeset
|
1561 error ("loop %d%'s latch is marked as part of irreducible region", i); |
0 | 1562 err = 1; |
1563 } | |
1564 } | |
1565 | |
1566 /* Check irreducible loops. */ | |
1567 if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) | |
1568 { | |
131 | 1569 auto_edge_flag saved_irr_mask (cfun); |
0 | 1570 /* Record old info. */ |
111 | 1571 auto_sbitmap irreds (last_basic_block_for_fn (cfun)); |
1572 FOR_EACH_BB_FN (bb, cfun) | |
0 | 1573 { |
1574 edge_iterator ei; | |
1575 if (bb->flags & BB_IRREDUCIBLE_LOOP) | |
111 | 1576 bitmap_set_bit (irreds, bb->index); |
0 | 1577 else |
111 | 1578 bitmap_clear_bit (irreds, bb->index); |
0 | 1579 FOR_EACH_EDGE (e, ei, bb->succs) |
1580 if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
131 | 1581 e->flags |= saved_irr_mask; |
0 | 1582 } |
1583 | |
1584 /* Recount it. */ | |
1585 mark_irreducible_loops (); | |
1586 | |
1587 /* Compare. */ | |
111 | 1588 FOR_EACH_BB_FN (bb, cfun) |
0 | 1589 { |
1590 edge_iterator ei; | |
1591 | |
1592 if ((bb->flags & BB_IRREDUCIBLE_LOOP) | |
111 | 1593 && !bitmap_bit_p (irreds, bb->index)) |
0 | 1594 { |
1595 error ("basic block %d should be marked irreducible", bb->index); | |
1596 err = 1; | |
1597 } | |
1598 else if (!(bb->flags & BB_IRREDUCIBLE_LOOP) | |
111 | 1599 && bitmap_bit_p (irreds, bb->index)) |
0 | 1600 { |
1601 error ("basic block %d should not be marked irreducible", bb->index); | |
1602 err = 1; | |
1603 } | |
1604 FOR_EACH_EDGE (e, ei, bb->succs) | |
1605 { | |
1606 if ((e->flags & EDGE_IRREDUCIBLE_LOOP) | |
131 | 1607 && !(e->flags & saved_irr_mask)) |
0 | 1608 { |
1609 error ("edge from %d to %d should be marked irreducible", | |
1610 e->src->index, e->dest->index); | |
1611 err = 1; | |
1612 } | |
1613 else if (!(e->flags & EDGE_IRREDUCIBLE_LOOP) | |
131 | 1614 && (e->flags & saved_irr_mask)) |
0 | 1615 { |
1616 error ("edge from %d to %d should not be marked irreducible", | |
1617 e->src->index, e->dest->index); | |
1618 err = 1; | |
1619 } | |
131 | 1620 e->flags &= ~saved_irr_mask; |
0 | 1621 } |
1622 } | |
1623 } | |
1624 | |
1625 /* Check the recorded loop exits. */ | |
111 | 1626 FOR_EACH_LOOP (loop, 0) |
0 | 1627 { |
1628 if (!loop->exits || loop->exits->e != NULL) | |
1629 { | |
1630 error ("corrupted head of the exits list of loop %d", | |
1631 loop->num); | |
1632 err = 1; | |
1633 } | |
1634 else | |
1635 { | |
1636 /* Check that the list forms a cycle, and all elements except | |
1637 for the head are nonnull. */ | |
1638 for (mexit = loop->exits, exit = mexit->next, i = 0; | |
1639 exit->e && exit != mexit; | |
1640 exit = exit->next) | |
1641 { | |
1642 if (i++ & 1) | |
1643 mexit = mexit->next; | |
1644 } | |
1645 | |
1646 if (exit != loop->exits) | |
1647 { | |
1648 error ("corrupted exits list of loop %d", loop->num); | |
1649 err = 1; | |
1650 } | |
1651 } | |
1652 | |
1653 if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
1654 { | |
1655 if (loop->exits->next != loop->exits) | |
1656 { | |
1657 error ("nonempty exits list of loop %d, but exits are not recorded", | |
1658 loop->num); | |
1659 err = 1; | |
1660 } | |
1661 } | |
1662 } | |
1663 | |
1664 if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
1665 { | |
1666 unsigned n_exits = 0, eloops; | |
1667 | |
111 | 1668 sizes = XCNEWVEC (unsigned, num); |
0 | 1669 memset (sizes, 0, sizeof (unsigned) * num); |
111 | 1670 FOR_EACH_BB_FN (bb, cfun) |
0 | 1671 { |
1672 edge_iterator ei; | |
1673 if (bb->loop_father == current_loops->tree_root) | |
1674 continue; | |
1675 FOR_EACH_EDGE (e, ei, bb->succs) | |
1676 { | |
1677 if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) | |
1678 continue; | |
1679 | |
1680 n_exits++; | |
1681 exit = get_exit_descriptions (e); | |
1682 if (!exit) | |
1683 { | |
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nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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diff
changeset
|
1684 error ("exit %d->%d not recorded", |
0 | 1685 e->src->index, e->dest->index); |
1686 err = 1; | |
1687 } | |
1688 eloops = 0; | |
1689 for (; exit; exit = exit->next_e) | |
1690 eloops++; | |
1691 | |
1692 for (loop = bb->loop_father; | |
111 | 1693 loop != e->dest->loop_father |
1694 /* When a loop exit is also an entry edge which | |
1695 can happen when avoiding CFG manipulations | |
1696 then the last loop exited is the outer loop | |
1697 of the loop entered. */ | |
1698 && loop != loop_outer (e->dest->loop_father); | |
0 | 1699 loop = loop_outer (loop)) |
1700 { | |
1701 eloops--; | |
1702 sizes[loop->num]++; | |
1703 } | |
1704 | |
1705 if (eloops != 0) | |
1706 { | |
145 | 1707 error ("wrong list of exited loops for edge %d->%d", |
0 | 1708 e->src->index, e->dest->index); |
1709 err = 1; | |
1710 } | |
1711 } | |
1712 } | |
1713 | |
111 | 1714 if (n_exits != current_loops->exits->elements ()) |
0 | 1715 { |
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parents:
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diff
changeset
|
1716 error ("too many loop exits recorded"); |
0 | 1717 err = 1; |
1718 } | |
1719 | |
111 | 1720 FOR_EACH_LOOP (loop, 0) |
0 | 1721 { |
1722 eloops = 0; | |
1723 for (exit = loop->exits->next; exit->e; exit = exit->next) | |
1724 eloops++; | |
1725 if (eloops != sizes[loop->num]) | |
1726 { | |
1727 error ("%d exits recorded for loop %d (having %d exits)", | |
1728 eloops, loop->num, sizes[loop->num]); | |
1729 err = 1; | |
1730 } | |
1731 } | |
111 | 1732 |
1733 free (sizes); | |
0 | 1734 } |
1735 | |
1736 gcc_assert (!err); | |
1737 | |
111 | 1738 if (!dom_available) |
1739 free_dominance_info (CDI_DOMINATORS); | |
0 | 1740 } |
1741 | |
145 | 1742 #if __GNUC__ >= 10 |
1743 # pragma GCC diagnostic pop | |
1744 #endif | |
1745 | |
0 | 1746 /* Returns latch edge of LOOP. */ |
1747 edge | |
145 | 1748 loop_latch_edge (const class loop *loop) |
0 | 1749 { |
1750 return find_edge (loop->latch, loop->header); | |
1751 } | |
1752 | |
1753 /* Returns preheader edge of LOOP. */ | |
1754 edge | |
145 | 1755 loop_preheader_edge (const class loop *loop) |
0 | 1756 { |
1757 edge e; | |
1758 edge_iterator ei; | |
1759 | |
111 | 1760 gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
1761 && ! loops_state_satisfies_p (LOOPS_MAY_HAVE_MULTIPLE_LATCHES)); | |
0 | 1762 |
1763 FOR_EACH_EDGE (e, ei, loop->header->preds) | |
1764 if (e->src != loop->latch) | |
1765 break; | |
1766 | |
111 | 1767 if (! e) |
1768 { | |
1769 gcc_assert (! loop_outer (loop)); | |
1770 return single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
1771 } | |
1772 | |
0 | 1773 return e; |
1774 } | |
1775 | |
1776 /* Returns true if E is an exit of LOOP. */ | |
1777 | |
1778 bool | |
145 | 1779 loop_exit_edge_p (const class loop *loop, const_edge e) |
0 | 1780 { |
1781 return (flow_bb_inside_loop_p (loop, e->src) | |
1782 && !flow_bb_inside_loop_p (loop, e->dest)); | |
1783 } | |
1784 | |
1785 /* Returns the single exit edge of LOOP, or NULL if LOOP has either no exit | |
1786 or more than one exit. If loops do not have the exits recorded, NULL | |
1787 is returned always. */ | |
1788 | |
1789 edge | |
145 | 1790 single_exit (const class loop *loop) |
0 | 1791 { |
1792 struct loop_exit *exit = loop->exits->next; | |
1793 | |
1794 if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
1795 return NULL; | |
1796 | |
1797 if (exit->e && exit->next == loop->exits) | |
1798 return exit->e; | |
1799 else | |
1800 return NULL; | |
1801 } | |
1802 | |
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1803 /* Returns true when BB has an incoming edge exiting LOOP. */ |
0 | 1804 |
1805 bool | |
145 | 1806 loop_exits_to_bb_p (class loop *loop, basic_block bb) |
0 | 1807 { |
1808 edge e; | |
1809 edge_iterator ei; | |
1810 | |
1811 FOR_EACH_EDGE (e, ei, bb->preds) | |
1812 if (loop_exit_edge_p (loop, e)) | |
1813 return true; | |
1814 | |
1815 return false; | |
1816 } | |
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1817 |
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1818 /* Returns true when BB has an outgoing edge exiting LOOP. */ |
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1819 |
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1820 bool |
145 | 1821 loop_exits_from_bb_p (class loop *loop, basic_block bb) |
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1822 { |
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1823 edge e; |
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1824 edge_iterator ei; |
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1825 |
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1826 FOR_EACH_EDGE (e, ei, bb->succs) |
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1827 if (loop_exit_edge_p (loop, e)) |
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1828 return true; |
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1829 |
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1830 return false; |
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1831 } |
111 | 1832 |
1833 /* Return location corresponding to the loop control condition if possible. */ | |
1834 | |
131 | 1835 dump_user_location_t |
145 | 1836 get_loop_location (class loop *loop) |
111 | 1837 { |
1838 rtx_insn *insn = NULL; | |
145 | 1839 class niter_desc *desc = NULL; |
111 | 1840 edge exit; |
1841 | |
1842 /* For a for or while loop, we would like to return the location | |
1843 of the for or while statement, if possible. To do this, look | |
1844 for the branch guarding the loop back-edge. */ | |
1845 | |
1846 /* If this is a simple loop with an in_edge, then the loop control | |
1847 branch is typically at the end of its source. */ | |
1848 desc = get_simple_loop_desc (loop); | |
1849 if (desc->in_edge) | |
1850 { | |
1851 FOR_BB_INSNS_REVERSE (desc->in_edge->src, insn) | |
1852 { | |
1853 if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
131 | 1854 return insn; |
111 | 1855 } |
1856 } | |
1857 /* If loop has a single exit, then the loop control branch | |
1858 must be at the end of its source. */ | |
1859 if ((exit = single_exit (loop))) | |
1860 { | |
1861 FOR_BB_INSNS_REVERSE (exit->src, insn) | |
1862 { | |
1863 if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
131 | 1864 return insn; |
111 | 1865 } |
1866 } | |
1867 /* Next check the latch, to see if it is non-empty. */ | |
1868 FOR_BB_INSNS_REVERSE (loop->latch, insn) | |
1869 { | |
1870 if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
131 | 1871 return insn; |
111 | 1872 } |
1873 /* Finally, if none of the above identifies the loop control branch, | |
1874 return the first location in the loop header. */ | |
1875 FOR_BB_INSNS (loop->header, insn) | |
1876 { | |
1877 if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
131 | 1878 return insn; |
111 | 1879 } |
1880 /* If all else fails, simply return the current function location. */ | |
131 | 1881 return dump_user_location_t::from_function_decl (current_function_decl); |
111 | 1882 } |
1883 | |
1884 /* Records that every statement in LOOP is executed I_BOUND times. | |
1885 REALISTIC is true if I_BOUND is expected to be close to the real number | |
1886 of iterations. UPPER is true if we are sure the loop iterates at most | |
1887 I_BOUND times. */ | |
1888 | |
1889 void | |
145 | 1890 record_niter_bound (class loop *loop, const widest_int &i_bound, |
111 | 1891 bool realistic, bool upper) |
1892 { | |
1893 /* Update the bounds only when there is no previous estimation, or when the | |
1894 current estimation is smaller. */ | |
1895 if (upper | |
1896 && (!loop->any_upper_bound | |
1897 || wi::ltu_p (i_bound, loop->nb_iterations_upper_bound))) | |
1898 { | |
1899 loop->any_upper_bound = true; | |
1900 loop->nb_iterations_upper_bound = i_bound; | |
1901 if (!loop->any_likely_upper_bound) | |
1902 { | |
1903 loop->any_likely_upper_bound = true; | |
1904 loop->nb_iterations_likely_upper_bound = i_bound; | |
1905 } | |
1906 } | |
1907 if (realistic | |
1908 && (!loop->any_estimate | |
1909 || wi::ltu_p (i_bound, loop->nb_iterations_estimate))) | |
1910 { | |
1911 loop->any_estimate = true; | |
1912 loop->nb_iterations_estimate = i_bound; | |
1913 } | |
1914 if (!realistic | |
1915 && (!loop->any_likely_upper_bound | |
1916 || wi::ltu_p (i_bound, loop->nb_iterations_likely_upper_bound))) | |
1917 { | |
1918 loop->any_likely_upper_bound = true; | |
1919 loop->nb_iterations_likely_upper_bound = i_bound; | |
1920 } | |
1921 | |
1922 /* If an upper bound is smaller than the realistic estimate of the | |
1923 number of iterations, use the upper bound instead. */ | |
1924 if (loop->any_upper_bound | |
1925 && loop->any_estimate | |
1926 && wi::ltu_p (loop->nb_iterations_upper_bound, | |
1927 loop->nb_iterations_estimate)) | |
1928 loop->nb_iterations_estimate = loop->nb_iterations_upper_bound; | |
1929 if (loop->any_upper_bound | |
1930 && loop->any_likely_upper_bound | |
1931 && wi::ltu_p (loop->nb_iterations_upper_bound, | |
1932 loop->nb_iterations_likely_upper_bound)) | |
1933 loop->nb_iterations_likely_upper_bound = loop->nb_iterations_upper_bound; | |
1934 } | |
1935 | |
1936 /* Similar to get_estimated_loop_iterations, but returns the estimate only | |
1937 if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
1938 on the number of iterations of LOOP could not be derived, returns -1. */ | |
1939 | |
1940 HOST_WIDE_INT | |
145 | 1941 get_estimated_loop_iterations_int (class loop *loop) |
111 | 1942 { |
1943 widest_int nit; | |
1944 HOST_WIDE_INT hwi_nit; | |
1945 | |
1946 if (!get_estimated_loop_iterations (loop, &nit)) | |
1947 return -1; | |
1948 | |
1949 if (!wi::fits_shwi_p (nit)) | |
1950 return -1; | |
1951 hwi_nit = nit.to_shwi (); | |
1952 | |
1953 return hwi_nit < 0 ? -1 : hwi_nit; | |
1954 } | |
1955 | |
1956 /* Returns an upper bound on the number of executions of statements | |
1957 in the LOOP. For statements before the loop exit, this exceeds | |
1958 the number of execution of the latch by one. */ | |
1959 | |
1960 HOST_WIDE_INT | |
145 | 1961 max_stmt_executions_int (class loop *loop) |
111 | 1962 { |
1963 HOST_WIDE_INT nit = get_max_loop_iterations_int (loop); | |
1964 HOST_WIDE_INT snit; | |
1965 | |
1966 if (nit == -1) | |
1967 return -1; | |
1968 | |
1969 snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
1970 | |
1971 /* If the computation overflows, return -1. */ | |
1972 return snit < 0 ? -1 : snit; | |
1973 } | |
1974 | |
1975 /* Returns an likely upper bound on the number of executions of statements | |
1976 in the LOOP. For statements before the loop exit, this exceeds | |
1977 the number of execution of the latch by one. */ | |
1978 | |
1979 HOST_WIDE_INT | |
145 | 1980 likely_max_stmt_executions_int (class loop *loop) |
111 | 1981 { |
1982 HOST_WIDE_INT nit = get_likely_max_loop_iterations_int (loop); | |
1983 HOST_WIDE_INT snit; | |
1984 | |
1985 if (nit == -1) | |
1986 return -1; | |
1987 | |
1988 snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
1989 | |
1990 /* If the computation overflows, return -1. */ | |
1991 return snit < 0 ? -1 : snit; | |
1992 } | |
1993 | |
1994 /* Sets NIT to the estimated number of executions of the latch of the | |
1995 LOOP. If we have no reliable estimate, the function returns false, otherwise | |
1996 returns true. */ | |
1997 | |
1998 bool | |
145 | 1999 get_estimated_loop_iterations (class loop *loop, widest_int *nit) |
111 | 2000 { |
2001 /* Even if the bound is not recorded, possibly we can derrive one from | |
2002 profile. */ | |
2003 if (!loop->any_estimate) | |
2004 { | |
2005 if (loop->header->count.reliable_p ()) | |
2006 { | |
2007 *nit = gcov_type_to_wide_int | |
2008 (expected_loop_iterations_unbounded (loop) + 1); | |
2009 return true; | |
2010 } | |
2011 return false; | |
2012 } | |
2013 | |
2014 *nit = loop->nb_iterations_estimate; | |
2015 return true; | |
2016 } | |
2017 | |
2018 /* Sets NIT to an upper bound for the maximum number of executions of the | |
2019 latch of the LOOP. If we have no reliable estimate, the function returns | |
2020 false, otherwise returns true. */ | |
2021 | |
2022 bool | |
145 | 2023 get_max_loop_iterations (const class loop *loop, widest_int *nit) |
111 | 2024 { |
2025 if (!loop->any_upper_bound) | |
2026 return false; | |
2027 | |
2028 *nit = loop->nb_iterations_upper_bound; | |
2029 return true; | |
2030 } | |
2031 | |
2032 /* Similar to get_max_loop_iterations, but returns the estimate only | |
2033 if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
2034 on the number of iterations of LOOP could not be derived, returns -1. */ | |
2035 | |
2036 HOST_WIDE_INT | |
145 | 2037 get_max_loop_iterations_int (const class loop *loop) |
111 | 2038 { |
2039 widest_int nit; | |
2040 HOST_WIDE_INT hwi_nit; | |
2041 | |
2042 if (!get_max_loop_iterations (loop, &nit)) | |
2043 return -1; | |
2044 | |
2045 if (!wi::fits_shwi_p (nit)) | |
2046 return -1; | |
2047 hwi_nit = nit.to_shwi (); | |
2048 | |
2049 return hwi_nit < 0 ? -1 : hwi_nit; | |
2050 } | |
2051 | |
2052 /* Sets NIT to an upper bound for the maximum number of executions of the | |
2053 latch of the LOOP. If we have no reliable estimate, the function returns | |
2054 false, otherwise returns true. */ | |
2055 | |
2056 bool | |
145 | 2057 get_likely_max_loop_iterations (class loop *loop, widest_int *nit) |
111 | 2058 { |
2059 if (!loop->any_likely_upper_bound) | |
2060 return false; | |
2061 | |
2062 *nit = loop->nb_iterations_likely_upper_bound; | |
2063 return true; | |
2064 } | |
2065 | |
2066 /* Similar to get_max_loop_iterations, but returns the estimate only | |
2067 if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
2068 on the number of iterations of LOOP could not be derived, returns -1. */ | |
2069 | |
2070 HOST_WIDE_INT | |
145 | 2071 get_likely_max_loop_iterations_int (class loop *loop) |
111 | 2072 { |
2073 widest_int nit; | |
2074 HOST_WIDE_INT hwi_nit; | |
2075 | |
2076 if (!get_likely_max_loop_iterations (loop, &nit)) | |
2077 return -1; | |
2078 | |
2079 if (!wi::fits_shwi_p (nit)) | |
2080 return -1; | |
2081 hwi_nit = nit.to_shwi (); | |
2082 | |
2083 return hwi_nit < 0 ? -1 : hwi_nit; | |
2084 } | |
2085 | |
2086 /* Returns the loop depth of the loop BB belongs to. */ | |
2087 | |
2088 int | |
2089 bb_loop_depth (const_basic_block bb) | |
2090 { | |
2091 return bb->loop_father ? loop_depth (bb->loop_father) : 0; | |
2092 } | |
2093 | |
2094 /* Marks LOOP for removal and sets LOOPS_NEED_FIXUP. */ | |
2095 | |
2096 void | |
2097 mark_loop_for_removal (loop_p loop) | |
2098 { | |
2099 if (loop->header == NULL) | |
2100 return; | |
2101 loop->former_header = loop->header; | |
2102 loop->header = NULL; | |
2103 loop->latch = NULL; | |
2104 loops_state_set (LOOPS_NEED_FIXUP); | |
2105 } |