Mercurial > hg > CbC > CbC_gcc
annotate gcc/cfgloop.c @ 128:fe568345ddd5
fix CbC-example
author | mir3636 |
---|---|
date | Wed, 11 Apr 2018 19:32:28 +0900 |
parents | 04ced10e8804 |
children | 84e7813d76e9 |
rev | line source |
---|---|
0 | 1 /* Natural loop discovery code for GNU compiler. |
111 | 2 Copyright (C) 2000-2017 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 | |
62 flow_loop_nested_p (const struct loop *outer, const struct loop *loop) | |
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 | |
73 struct loop * | |
74 superloop_at_depth (struct loop *loop, unsigned depth) | |
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> |
0 | 89 get_loop_latch_edges (const struct loop *loop) |
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 | |
108 flow_loop_dump (const struct loop *loop, FILE *file, | |
109 void (*loop_dump_aux) (const struct loop *, FILE *, int), | |
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 | |
163 flow_loops_dump (FILE *file, void (*loop_dump_aux) (const struct loop *, FILE *, int), int verbose) | |
164 { | |
165 struct loop *loop; | |
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 | |
184 flow_loop_free (struct loop *loop) | |
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 | |
232 flow_loop_nodes_find (basic_block header, struct loop *loop) | |
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 | |
281 establish_preds (struct loop *loop, struct loop *father) | |
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 | |
299 pred field will be initialized correctly. */ | |
300 | |
301 void | |
302 flow_loop_tree_node_add (struct loop *father, struct loop *loop) | |
303 { | |
304 loop->next = father->inner; | |
305 father->inner = loop; | |
306 | |
307 establish_preds (loop, father); | |
308 } | |
309 | |
310 /* Remove LOOP from the loop hierarchy tree. */ | |
311 | |
312 void | |
313 flow_loop_tree_node_remove (struct loop *loop) | |
314 { | |
315 struct loop *prev, *father; | |
316 | |
317 father = loop_outer (loop); | |
318 | |
319 /* Remove loop from the list of sons. */ | |
320 if (father->inner == loop) | |
321 father->inner = loop->next; | |
322 else | |
323 { | |
324 for (prev = father->inner; prev->next != loop; prev = prev->next) | |
325 continue; | |
326 prev->next = loop->next; | |
327 } | |
328 | |
111 | 329 loop->superloops = NULL; |
0 | 330 } |
331 | |
332 /* Allocates and returns new loop structure. */ | |
333 | |
334 struct loop * | |
335 alloc_loop (void) | |
336 { | |
111 | 337 struct loop *loop = ggc_cleared_alloc<struct loop> (); |
0 | 338 |
111 | 339 loop->exits = ggc_cleared_alloc<loop_exit> (); |
0 | 340 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
|
341 loop->can_be_parallel = false; |
111 | 342 loop->constraints = 0; |
343 loop->nb_iterations_upper_bound = 0; | |
344 loop->nb_iterations_likely_upper_bound = 0; | |
345 loop->nb_iterations_estimate = 0; | |
0 | 346 return loop; |
347 } | |
348 | |
349 /* Initializes loops structure LOOPS, reserving place for NUM_LOOPS loops | |
350 (including the root of the loop tree). */ | |
351 | |
111 | 352 void |
353 init_loops_structure (struct function *fn, | |
354 struct loops *loops, unsigned num_loops) | |
0 | 355 { |
356 struct loop *root; | |
357 | |
358 memset (loops, 0, sizeof *loops); | |
111 | 359 vec_alloc (loops->larray, num_loops); |
0 | 360 |
361 /* Dummy loop containing whole function. */ | |
362 root = alloc_loop (); | |
111 | 363 root->num_nodes = n_basic_blocks_for_fn (fn); |
364 root->latch = EXIT_BLOCK_PTR_FOR_FN (fn); | |
365 root->header = ENTRY_BLOCK_PTR_FOR_FN (fn); | |
366 ENTRY_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
367 EXIT_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
368 | |
369 loops->larray->quick_push (root); | |
370 loops->tree_root = root; | |
371 } | |
372 | |
373 /* Returns whether HEADER is a loop header. */ | |
374 | |
375 bool | |
376 bb_loop_header_p (basic_block header) | |
377 { | |
378 edge_iterator ei; | |
379 edge e; | |
0 | 380 |
111 | 381 /* If we have an abnormal predecessor, do not consider the |
382 loop (not worth the problems). */ | |
383 if (bb_has_abnormal_pred (header)) | |
384 return false; | |
385 | |
386 /* Look for back edges where a predecessor is dominated | |
387 by this block. A natural loop has a single entry | |
388 node (header) that dominates all the nodes in the | |
389 loop. It also has single back edge to the header | |
390 from a latch node. */ | |
391 FOR_EACH_EDGE (e, ei, header->preds) | |
392 { | |
393 basic_block latch = e->src; | |
394 if (latch != ENTRY_BLOCK_PTR_FOR_FN (cfun) | |
395 && dominated_by_p (CDI_DOMINATORS, latch, header)) | |
396 return true; | |
397 } | |
398 | |
399 return false; | |
0 | 400 } |
401 | |
402 /* Find all the natural loops in the function and save in LOOPS structure and | |
111 | 403 recalculate loop_father information in basic block structures. |
404 If LOOPS is non-NULL then the loop structures for already recorded loops | |
405 will be re-used and their number will not change. We assume that no | |
406 stale loops exist in LOOPS. | |
407 When LOOPS is NULL it is allocated and re-built from scratch. | |
408 Return the built LOOPS structure. */ | |
0 | 409 |
111 | 410 struct loops * |
0 | 411 flow_loops_find (struct loops *loops) |
412 { | |
111 | 413 bool from_scratch = (loops == NULL); |
414 int *rc_order; | |
0 | 415 int b; |
111 | 416 unsigned i; |
0 | 417 |
418 /* Ensure that the dominators are computed. */ | |
419 calculate_dominance_info (CDI_DOMINATORS); | |
420 | |
111 | 421 if (!loops) |
0 | 422 { |
111 | 423 loops = ggc_cleared_alloc<struct loops> (); |
424 init_loops_structure (cfun, loops, 1); | |
0 | 425 } |
426 | |
111 | 427 /* Ensure that loop exits were released. */ |
428 gcc_assert (loops->exits == NULL); | |
429 | |
430 /* Taking care of this degenerate case makes the rest of | |
431 this code simpler. */ | |
432 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) | |
433 return loops; | |
434 | |
435 /* The root loop node contains all basic-blocks. */ | |
436 loops->tree_root->num_nodes = n_basic_blocks_for_fn (cfun); | |
0 | 437 |
111 | 438 /* Compute depth first search order of the CFG so that outer |
439 natural loops will be found before inner natural loops. */ | |
440 rc_order = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); | |
441 pre_and_rev_post_order_compute (NULL, rc_order, false); | |
442 | |
443 /* Gather all loop headers in reverse completion order and allocate | |
444 loop structures for loops that are not already present. */ | |
445 auto_vec<loop_p> larray (loops->larray->length ()); | |
446 for (b = 0; b < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; b++) | |
447 { | |
448 basic_block header = BASIC_BLOCK_FOR_FN (cfun, rc_order[b]); | |
449 if (bb_loop_header_p (header)) | |
450 { | |
451 struct loop *loop; | |
0 | 452 |
111 | 453 /* The current active loop tree has valid loop-fathers for |
454 header blocks. */ | |
455 if (!from_scratch | |
456 && header->loop_father->header == header) | |
457 { | |
458 loop = header->loop_father; | |
459 /* If we found an existing loop remove it from the | |
460 loop tree. It is going to be inserted again | |
461 below. */ | |
462 flow_loop_tree_node_remove (loop); | |
463 } | |
464 else | |
465 { | |
466 /* Otherwise allocate a new loop structure for the loop. */ | |
467 loop = alloc_loop (); | |
468 /* ??? We could re-use unused loop slots here. */ | |
469 loop->num = loops->larray->length (); | |
470 vec_safe_push (loops->larray, loop); | |
471 loop->header = header; | |
0 | 472 |
111 | 473 if (!from_scratch |
474 && dump_file && (dump_flags & TDF_DETAILS)) | |
475 fprintf (dump_file, "flow_loops_find: discovered new " | |
476 "loop %d with header %d\n", | |
477 loop->num, header->index); | |
478 } | |
479 /* Reset latch, we recompute it below. */ | |
480 loop->latch = NULL; | |
481 larray.safe_push (loop); | |
482 } | |
483 | |
484 /* Make blocks part of the loop root node at start. */ | |
485 header->loop_father = loops->tree_root; | |
486 } | |
0 | 487 |
111 | 488 free (rc_order); |
0 | 489 |
111 | 490 /* Now iterate over the loops found, insert them into the loop tree |
491 and assign basic-block ownership. */ | |
492 for (i = 0; i < larray.length (); ++i) | |
493 { | |
494 struct loop *loop = larray[i]; | |
495 basic_block header = loop->header; | |
496 edge_iterator ei; | |
497 edge e; | |
498 | |
499 flow_loop_tree_node_add (header->loop_father, loop); | |
500 loop->num_nodes = flow_loop_nodes_find (loop->header, loop); | |
501 | |
502 /* Look for the latch for this header block, if it has just a | |
503 single one. */ | |
0 | 504 FOR_EACH_EDGE (e, ei, header->preds) |
505 { | |
506 basic_block latch = e->src; | |
507 | |
111 | 508 if (flow_bb_inside_loop_p (loop, latch)) |
0 | 509 { |
111 | 510 if (loop->latch != NULL) |
511 { | |
512 /* More than one latch edge. */ | |
513 loop->latch = NULL; | |
514 break; | |
515 } | |
516 loop->latch = latch; | |
0 | 517 } |
518 } | |
519 } | |
520 | |
111 | 521 return loops; |
522 } | |
0 | 523 |
111 | 524 /* qsort helper for sort_sibling_loops. */ |
0 | 525 |
111 | 526 static int *sort_sibling_loops_cmp_rpo; |
527 static int | |
528 sort_sibling_loops_cmp (const void *la_, const void *lb_) | |
529 { | |
530 const struct loop *la = *(const struct loop * const *)la_; | |
531 const struct loop *lb = *(const struct loop * const *)lb_; | |
532 return (sort_sibling_loops_cmp_rpo[la->header->index] | |
533 - sort_sibling_loops_cmp_rpo[lb->header->index]); | |
534 } | |
0 | 535 |
111 | 536 /* Sort sibling loops in RPO order. */ |
0 | 537 |
111 | 538 void |
539 sort_sibling_loops (function *fn) | |
540 { | |
541 /* Match flow_loops_find in the order we sort sibling loops. */ | |
542 sort_sibling_loops_cmp_rpo = XNEWVEC (int, last_basic_block_for_fn (cfun)); | |
543 int *rc_order = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); | |
544 pre_and_rev_post_order_compute_fn (fn, NULL, rc_order, false); | |
545 for (int i = 0; i < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; ++i) | |
546 sort_sibling_loops_cmp_rpo[rc_order[i]] = i; | |
547 free (rc_order); | |
0 | 548 |
111 | 549 auto_vec<loop_p, 3> siblings; |
550 loop_p loop; | |
551 FOR_EACH_LOOP_FN (fn, loop, LI_INCLUDE_ROOT) | |
552 if (loop->inner && loop->inner->next) | |
553 { | |
554 loop_p sibling = loop->inner; | |
555 do | |
556 { | |
557 siblings.safe_push (sibling); | |
558 sibling = sibling->next; | |
559 } | |
560 while (sibling); | |
561 siblings.qsort (sort_sibling_loops_cmp); | |
562 loop_p *siblingp = &loop->inner; | |
563 for (unsigned i = 0; i < siblings.length (); ++i) | |
564 { | |
565 *siblingp = siblings[i]; | |
566 siblingp = &(*siblingp)->next; | |
567 } | |
568 *siblingp = NULL; | |
569 siblings.truncate (0); | |
570 } | |
0 | 571 |
111 | 572 free (sort_sibling_loops_cmp_rpo); |
573 sort_sibling_loops_cmp_rpo = NULL; | |
0 | 574 } |
575 | |
576 /* Ratio of frequencies of edges so that one of more latch edges is | |
577 considered to belong to inner loop with same header. */ | |
578 #define HEAVY_EDGE_RATIO 8 | |
579 | |
580 /* Minimum number of samples for that we apply | |
581 find_subloop_latch_edge_by_profile heuristics. */ | |
582 #define HEAVY_EDGE_MIN_SAMPLES 10 | |
583 | |
584 /* If the profile info is available, finds an edge in LATCHES that much more | |
585 frequent than the remaining edges. Returns such an edge, or NULL if we do | |
586 not find one. | |
587 | |
588 We do not use guessed profile here, only the measured one. The guessed | |
589 profile is usually too flat and unreliable for this (and it is mostly based | |
590 on the loop structure of the program, so it does not make much sense to | |
591 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
|
592 |
0 | 593 static edge |
111 | 594 find_subloop_latch_edge_by_profile (vec<edge> latches) |
0 | 595 { |
596 unsigned i; | |
597 edge e, me = NULL; | |
111 | 598 profile_count mcount = profile_count::zero (), tcount = profile_count::zero (); |
0 | 599 |
111 | 600 FOR_EACH_VEC_ELT (latches, i, e) |
0 | 601 { |
111 | 602 if (e->count ()> mcount) |
0 | 603 { |
604 me = e; | |
111 | 605 mcount = e->count(); |
0 | 606 } |
111 | 607 tcount += e->count(); |
0 | 608 } |
609 | |
111 | 610 if (!tcount.initialized_p () || tcount < HEAVY_EDGE_MIN_SAMPLES |
611 || (tcount - mcount).apply_scale (HEAVY_EDGE_RATIO, 1) > tcount) | |
0 | 612 return NULL; |
613 | |
614 if (dump_file) | |
615 fprintf (dump_file, | |
616 "Found latch edge %d -> %d using profile information.\n", | |
617 me->src->index, me->dest->index); | |
618 return me; | |
619 } | |
620 | |
621 /* Among LATCHES, guesses a latch edge of LOOP corresponding to subloop, based | |
622 on the structure of induction variables. Returns this edge, or NULL if we | |
623 do not find any. | |
624 | |
625 We are quite conservative, and look just for an obvious simple innermost | |
626 loop (which is the case where we would lose the most performance by not | |
627 disambiguating the loop). More precisely, we look for the following | |
628 situation: The source of the chosen latch edge dominates sources of all | |
629 the other latch edges. Additionally, the header does not contain a phi node | |
630 such that the argument from the chosen edge is equal to the argument from | |
631 another edge. */ | |
632 | |
633 static edge | |
111 | 634 find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, vec<edge> latches) |
0 | 635 { |
111 | 636 edge e, latch = latches[0]; |
0 | 637 unsigned i; |
111 | 638 gphi *phi; |
639 gphi_iterator psi; | |
0 | 640 tree lop; |
641 basic_block bb; | |
642 | |
643 /* Find the candidate for the latch edge. */ | |
111 | 644 for (i = 1; latches.iterate (i, &e); i++) |
0 | 645 if (dominated_by_p (CDI_DOMINATORS, latch->src, e->src)) |
646 latch = e; | |
647 | |
648 /* Verify that it dominates all the latch edges. */ | |
111 | 649 FOR_EACH_VEC_ELT (latches, i, e) |
0 | 650 if (!dominated_by_p (CDI_DOMINATORS, e->src, latch->src)) |
651 return NULL; | |
652 | |
653 /* Check for a phi node that would deny that this is a latch edge of | |
654 a subloop. */ | |
655 for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) | |
656 { | |
111 | 657 phi = psi.phi (); |
0 | 658 lop = PHI_ARG_DEF_FROM_EDGE (phi, latch); |
659 | |
660 /* Ignore the values that are not changed inside the subloop. */ | |
661 if (TREE_CODE (lop) != SSA_NAME | |
662 || SSA_NAME_DEF_STMT (lop) == phi) | |
663 continue; | |
664 bb = gimple_bb (SSA_NAME_DEF_STMT (lop)); | |
665 if (!bb || !flow_bb_inside_loop_p (loop, bb)) | |
666 continue; | |
667 | |
111 | 668 FOR_EACH_VEC_ELT (latches, i, e) |
0 | 669 if (e != latch |
670 && PHI_ARG_DEF_FROM_EDGE (phi, e) == lop) | |
671 return NULL; | |
672 } | |
673 | |
674 if (dump_file) | |
675 fprintf (dump_file, | |
676 "Found latch edge %d -> %d using iv structure.\n", | |
677 latch->src->index, latch->dest->index); | |
678 return latch; | |
679 } | |
680 | |
681 /* If we can determine that one of the several latch edges of LOOP behaves | |
682 as a latch edge of a separate subloop, returns this edge. Otherwise | |
683 returns NULL. */ | |
684 | |
685 static edge | |
686 find_subloop_latch_edge (struct loop *loop) | |
687 { | |
111 | 688 vec<edge> latches = get_loop_latch_edges (loop); |
0 | 689 edge latch = NULL; |
690 | |
111 | 691 if (latches.length () > 1) |
0 | 692 { |
693 latch = find_subloop_latch_edge_by_profile (latches); | |
694 | |
695 if (!latch | |
696 /* We consider ivs to guess the latch edge only in SSA. Perhaps we | |
697 should use cfghook for this, but it is hard to imagine it would | |
698 be useful elsewhere. */ | |
699 && current_ir_type () == IR_GIMPLE) | |
700 latch = find_subloop_latch_edge_by_ivs (loop, latches); | |
701 } | |
702 | |
111 | 703 latches.release (); |
0 | 704 return latch; |
705 } | |
706 | |
707 /* Callback for make_forwarder_block. Returns true if the edge E is marked | |
708 in the set MFB_REIS_SET. */ | |
709 | |
111 | 710 static hash_set<edge> *mfb_reis_set; |
0 | 711 static bool |
712 mfb_redirect_edges_in_set (edge e) | |
713 { | |
111 | 714 return mfb_reis_set->contains (e); |
0 | 715 } |
716 | |
717 /* Creates a subloop of LOOP with latch edge LATCH. */ | |
718 | |
719 static void | |
720 form_subloop (struct loop *loop, edge latch) | |
721 { | |
722 edge_iterator ei; | |
723 edge e, new_entry; | |
724 struct loop *new_loop; | |
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725 |
111 | 726 mfb_reis_set = new hash_set<edge>; |
0 | 727 FOR_EACH_EDGE (e, ei, loop->header->preds) |
728 { | |
729 if (e != latch) | |
111 | 730 mfb_reis_set->add (e); |
0 | 731 } |
732 new_entry = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
733 NULL); | |
111 | 734 delete mfb_reis_set; |
0 | 735 |
736 loop->header = new_entry->src; | |
737 | |
738 /* Find the blocks and subloops that belong to the new loop, and add it to | |
739 the appropriate place in the loop tree. */ | |
740 new_loop = alloc_loop (); | |
741 new_loop->header = new_entry->dest; | |
742 new_loop->latch = latch->src; | |
743 add_loop (new_loop, loop); | |
744 } | |
745 | |
746 /* Make all the latch edges of LOOP to go to a single forwarder block -- | |
747 a new latch of LOOP. */ | |
748 | |
749 static void | |
750 merge_latch_edges (struct loop *loop) | |
751 { | |
111 | 752 vec<edge> latches = get_loop_latch_edges (loop); |
0 | 753 edge latch, e; |
754 unsigned i; | |
755 | |
111 | 756 gcc_assert (latches.length () > 0); |
0 | 757 |
111 | 758 if (latches.length () == 1) |
759 loop->latch = latches[0]->src; | |
0 | 760 else |
761 { | |
762 if (dump_file) | |
763 fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num); | |
764 | |
111 | 765 mfb_reis_set = new hash_set<edge>; |
766 FOR_EACH_VEC_ELT (latches, i, e) | |
767 mfb_reis_set->add (e); | |
0 | 768 latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, |
769 NULL); | |
111 | 770 delete mfb_reis_set; |
0 | 771 |
772 loop->header = latch->dest; | |
773 loop->latch = latch->src; | |
774 } | |
775 | |
111 | 776 latches.release (); |
0 | 777 } |
778 | |
779 /* LOOP may have several latch edges. Transform it into (possibly several) | |
780 loops with single latch edge. */ | |
781 | |
782 static void | |
783 disambiguate_multiple_latches (struct loop *loop) | |
784 { | |
785 edge e; | |
786 | |
787 /* We eliminate the multiple latches by splitting the header to the forwarder | |
788 block F and the rest R, and redirecting the edges. There are two cases: | |
789 | |
790 1) If there is a latch edge E that corresponds to a subloop (we guess | |
791 that based on profile -- if it is taken much more often than the | |
792 remaining edges; and on trees, using the information about induction | |
793 variables of the loops), we redirect E to R, all the remaining edges to | |
794 F, then rescan the loops and try again for the outer loop. | |
795 2) If there is no such edge, we redirect all latch edges to F, and the | |
796 entry edges to R, thus making F the single latch of the loop. */ | |
797 | |
798 if (dump_file) | |
799 fprintf (dump_file, "Disambiguating loop %d with multiple latches\n", | |
800 loop->num); | |
801 | |
802 /* During latch merging, we may need to redirect the entry edges to a new | |
803 block. This would cause problems if the entry edge was the one from the | |
804 entry block. To avoid having to handle this case specially, split | |
805 such entry edge. */ | |
111 | 806 e = find_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), loop->header); |
0 | 807 if (e) |
808 split_edge (e); | |
809 | |
810 while (1) | |
811 { | |
812 e = find_subloop_latch_edge (loop); | |
813 if (!e) | |
814 break; | |
815 | |
816 form_subloop (loop, e); | |
817 } | |
818 | |
819 merge_latch_edges (loop); | |
820 } | |
821 | |
822 /* Split loops with multiple latch edges. */ | |
823 | |
824 void | |
825 disambiguate_loops_with_multiple_latches (void) | |
826 { | |
827 struct loop *loop; | |
828 | |
111 | 829 FOR_EACH_LOOP (loop, 0) |
0 | 830 { |
831 if (!loop->latch) | |
832 disambiguate_multiple_latches (loop); | |
833 } | |
834 } | |
835 | |
836 /* Return nonzero if basic block BB belongs to LOOP. */ | |
837 bool | |
838 flow_bb_inside_loop_p (const struct loop *loop, const_basic_block bb) | |
839 { | |
840 struct loop *source_loop; | |
841 | |
111 | 842 if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
843 || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
0 | 844 return 0; |
845 | |
846 source_loop = bb->loop_father; | |
847 return loop == source_loop || flow_loop_nested_p (loop, source_loop); | |
848 } | |
849 | |
850 /* Enumeration predicate for get_loop_body_with_size. */ | |
851 static bool | |
852 glb_enum_p (const_basic_block bb, const void *glb_loop) | |
853 { | |
854 const struct loop *const loop = (const struct loop *) glb_loop; | |
855 return (bb != loop->header | |
856 && dominated_by_p (CDI_DOMINATORS, bb, loop->header)); | |
857 } | |
858 | |
859 /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
860 order against direction of edges from latch. Specially, if | |
861 header != latch, latch is the 1-st block. LOOP cannot be the fake | |
862 loop tree root, and its size must be at most MAX_SIZE. The blocks | |
863 in the LOOP body are stored to BODY, and the size of the LOOP is | |
864 returned. */ | |
865 | |
866 unsigned | |
867 get_loop_body_with_size (const struct loop *loop, basic_block *body, | |
868 unsigned max_size) | |
869 { | |
870 return dfs_enumerate_from (loop->header, 1, glb_enum_p, | |
871 body, max_size, loop); | |
872 } | |
873 | |
874 /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
875 order against direction of edges from latch. Specially, if | |
876 header != latch, latch is the 1-st block. */ | |
877 | |
878 basic_block * | |
879 get_loop_body (const struct loop *loop) | |
880 { | |
881 basic_block *body, bb; | |
882 unsigned tv = 0; | |
883 | |
884 gcc_assert (loop->num_nodes); | |
885 | |
111 | 886 body = XNEWVEC (basic_block, loop->num_nodes); |
0 | 887 |
111 | 888 if (loop->latch == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
0 | 889 { |
890 /* There may be blocks unreachable from EXIT_BLOCK, hence we need to | |
891 special-case the fake loop that contains the whole function. */ | |
111 | 892 gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks_for_fn (cfun)); |
0 | 893 body[tv++] = loop->header; |
111 | 894 body[tv++] = EXIT_BLOCK_PTR_FOR_FN (cfun); |
895 FOR_EACH_BB_FN (bb, cfun) | |
0 | 896 body[tv++] = bb; |
897 } | |
898 else | |
899 tv = get_loop_body_with_size (loop, body, loop->num_nodes); | |
900 | |
901 gcc_assert (tv == loop->num_nodes); | |
902 return body; | |
903 } | |
904 | |
905 /* Fills dominance descendants inside LOOP of the basic block BB into | |
906 array TOVISIT from index *TV. */ | |
907 | |
908 static void | |
909 fill_sons_in_loop (const struct loop *loop, basic_block bb, | |
910 basic_block *tovisit, int *tv) | |
911 { | |
912 basic_block son, postpone = NULL; | |
913 | |
914 tovisit[(*tv)++] = bb; | |
915 for (son = first_dom_son (CDI_DOMINATORS, bb); | |
916 son; | |
917 son = next_dom_son (CDI_DOMINATORS, son)) | |
918 { | |
919 if (!flow_bb_inside_loop_p (loop, son)) | |
920 continue; | |
921 | |
922 if (dominated_by_p (CDI_DOMINATORS, loop->latch, son)) | |
923 { | |
924 postpone = son; | |
925 continue; | |
926 } | |
927 fill_sons_in_loop (loop, son, tovisit, tv); | |
928 } | |
929 | |
930 if (postpone) | |
931 fill_sons_in_loop (loop, postpone, tovisit, tv); | |
932 } | |
933 | |
934 /* Gets body of a LOOP (that must be different from the outermost loop) | |
935 sorted by dominance relation. Additionally, if a basic block s dominates | |
936 the latch, then only blocks dominated by s are be after it. */ | |
937 | |
938 basic_block * | |
939 get_loop_body_in_dom_order (const struct loop *loop) | |
940 { | |
941 basic_block *tovisit; | |
942 int tv; | |
943 | |
944 gcc_assert (loop->num_nodes); | |
945 | |
111 | 946 tovisit = XNEWVEC (basic_block, loop->num_nodes); |
0 | 947 |
111 | 948 gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
0 | 949 |
950 tv = 0; | |
951 fill_sons_in_loop (loop, loop->header, tovisit, &tv); | |
952 | |
953 gcc_assert (tv == (int) loop->num_nodes); | |
954 | |
955 return tovisit; | |
956 } | |
957 | |
958 /* Gets body of a LOOP sorted via provided BB_COMPARATOR. */ | |
959 | |
960 basic_block * | |
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961 get_loop_body_in_custom_order (const struct loop *loop, |
0 | 962 int (*bb_comparator) (const void *, const void *)) |
963 { | |
964 basic_block *bbs = get_loop_body (loop); | |
965 | |
966 qsort (bbs, loop->num_nodes, sizeof (basic_block), bb_comparator); | |
967 | |
968 return bbs; | |
969 } | |
970 | |
971 /* Get body of a LOOP in breadth first sort order. */ | |
972 | |
973 basic_block * | |
974 get_loop_body_in_bfs_order (const struct loop *loop) | |
975 { | |
976 basic_block *blocks; | |
977 basic_block bb; | |
111 | 978 unsigned int i = 1; |
979 unsigned int vc = 0; | |
0 | 980 |
981 gcc_assert (loop->num_nodes); | |
111 | 982 gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
0 | 983 |
111 | 984 blocks = XNEWVEC (basic_block, loop->num_nodes); |
985 auto_bitmap visited; | |
986 blocks[0] = loop->header; | |
987 bitmap_set_bit (visited, loop->header->index); | |
0 | 988 while (i < loop->num_nodes) |
989 { | |
990 edge e; | |
991 edge_iterator ei; | |
111 | 992 gcc_assert (i > vc); |
993 bb = blocks[vc++]; | |
0 | 994 |
995 FOR_EACH_EDGE (e, ei, bb->succs) | |
996 { | |
997 if (flow_bb_inside_loop_p (loop, e->dest)) | |
998 { | |
111 | 999 /* This bb is now visited. */ |
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1000 if (bitmap_set_bit (visited, e->dest->index)) |
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1001 blocks[i++] = e->dest; |
0 | 1002 } |
1003 } | |
1004 } | |
1005 | |
1006 return blocks; | |
1007 } | |
1008 | |
1009 /* Hash function for struct loop_exit. */ | |
1010 | |
111 | 1011 hashval_t |
1012 loop_exit_hasher::hash (loop_exit *exit) | |
0 | 1013 { |
1014 return htab_hash_pointer (exit->e); | |
1015 } | |
1016 | |
1017 /* Equality function for struct loop_exit. Compares with edge. */ | |
1018 | |
111 | 1019 bool |
1020 loop_exit_hasher::equal (loop_exit *exit, edge e) | |
0 | 1021 { |
1022 return exit->e == e; | |
1023 } | |
1024 | |
1025 /* Frees the list of loop exit descriptions EX. */ | |
1026 | |
111 | 1027 void |
1028 loop_exit_hasher::remove (loop_exit *exit) | |
0 | 1029 { |
111 | 1030 loop_exit *next; |
0 | 1031 for (; exit; exit = next) |
1032 { | |
1033 next = exit->next_e; | |
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1034 |
0 | 1035 exit->next->prev = exit->prev; |
1036 exit->prev->next = exit->next; | |
1037 | |
1038 ggc_free (exit); | |
1039 } | |
1040 } | |
1041 | |
1042 /* Returns the list of records for E as an exit of a loop. */ | |
1043 | |
1044 static struct loop_exit * | |
1045 get_exit_descriptions (edge e) | |
1046 { | |
111 | 1047 return current_loops->exits->find_with_hash (e, htab_hash_pointer (e)); |
0 | 1048 } |
1049 | |
1050 /* Updates the lists of loop exits in that E appears. | |
1051 If REMOVED is true, E is being removed, and we | |
1052 just remove it from the lists of exits. | |
1053 If NEW_EDGE is true and E is not a loop exit, we | |
1054 do not try to remove it from loop exit lists. */ | |
1055 | |
1056 void | |
1057 rescan_loop_exit (edge e, bool new_edge, bool removed) | |
1058 { | |
1059 struct loop_exit *exits = NULL, *exit; | |
1060 struct loop *aloop, *cloop; | |
1061 | |
1062 if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
1063 return; | |
1064 | |
1065 if (!removed | |
1066 && e->src->loop_father != NULL | |
1067 && e->dest->loop_father != NULL | |
1068 && !flow_bb_inside_loop_p (e->src->loop_father, e->dest)) | |
1069 { | |
1070 cloop = find_common_loop (e->src->loop_father, e->dest->loop_father); | |
1071 for (aloop = e->src->loop_father; | |
1072 aloop != cloop; | |
1073 aloop = loop_outer (aloop)) | |
1074 { | |
111 | 1075 exit = ggc_alloc<loop_exit> (); |
0 | 1076 exit->e = e; |
1077 | |
1078 exit->next = aloop->exits->next; | |
1079 exit->prev = aloop->exits; | |
1080 exit->next->prev = exit; | |
1081 exit->prev->next = exit; | |
1082 | |
1083 exit->next_e = exits; | |
1084 exits = exit; | |
1085 } | |
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1086 } |
0 | 1087 |
1088 if (!exits && new_edge) | |
1089 return; | |
1090 | |
111 | 1091 loop_exit **slot |
1092 = current_loops->exits->find_slot_with_hash (e, htab_hash_pointer (e), | |
1093 exits ? INSERT : NO_INSERT); | |
0 | 1094 if (!slot) |
1095 return; | |
1096 | |
1097 if (exits) | |
1098 { | |
1099 if (*slot) | |
111 | 1100 loop_exit_hasher::remove (*slot); |
0 | 1101 *slot = exits; |
1102 } | |
1103 else | |
111 | 1104 current_loops->exits->clear_slot (slot); |
0 | 1105 } |
1106 | |
1107 /* For each loop, record list of exit edges, and start maintaining these | |
1108 lists. */ | |
1109 | |
1110 void | |
1111 record_loop_exits (void) | |
1112 { | |
1113 basic_block bb; | |
1114 edge_iterator ei; | |
1115 edge e; | |
1116 | |
1117 if (!current_loops) | |
1118 return; | |
1119 | |
1120 if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
1121 return; | |
1122 loops_state_set (LOOPS_HAVE_RECORDED_EXITS); | |
1123 | |
1124 gcc_assert (current_loops->exits == NULL); | |
111 | 1125 current_loops->exits |
1126 = hash_table<loop_exit_hasher>::create_ggc (2 * number_of_loops (cfun)); | |
0 | 1127 |
111 | 1128 FOR_EACH_BB_FN (bb, cfun) |
0 | 1129 { |
1130 FOR_EACH_EDGE (e, ei, bb->succs) | |
1131 { | |
1132 rescan_loop_exit (e, true, false); | |
1133 } | |
1134 } | |
1135 } | |
1136 | |
1137 /* Dumps information about the exit in *SLOT to FILE. | |
1138 Callback for htab_traverse. */ | |
1139 | |
111 | 1140 int |
1141 dump_recorded_exit (loop_exit **slot, FILE *file) | |
0 | 1142 { |
111 | 1143 struct loop_exit *exit = *slot; |
0 | 1144 unsigned n = 0; |
1145 edge e = exit->e; | |
1146 | |
1147 for (; exit != NULL; exit = exit->next_e) | |
1148 n++; | |
1149 | |
111 | 1150 fprintf (file, "Edge %d->%d exits %u loops\n", |
0 | 1151 e->src->index, e->dest->index, n); |
1152 | |
1153 return 1; | |
1154 } | |
1155 | |
1156 /* Dumps the recorded exits of loops to FILE. */ | |
1157 | |
1158 extern void dump_recorded_exits (FILE *); | |
1159 void | |
1160 dump_recorded_exits (FILE *file) | |
1161 { | |
1162 if (!current_loops->exits) | |
1163 return; | |
111 | 1164 current_loops->exits->traverse<FILE *, dump_recorded_exit> (file); |
0 | 1165 } |
1166 | |
1167 /* Releases lists of loop exits. */ | |
1168 | |
1169 void | |
111 | 1170 release_recorded_exits (function *fn) |
0 | 1171 { |
111 | 1172 gcc_assert (loops_state_satisfies_p (fn, LOOPS_HAVE_RECORDED_EXITS)); |
1173 loops_for_fn (fn)->exits->empty (); | |
1174 loops_for_fn (fn)->exits = NULL; | |
1175 loops_state_clear (fn, LOOPS_HAVE_RECORDED_EXITS); | |
0 | 1176 } |
1177 | |
1178 /* Returns the list of the exit edges of a LOOP. */ | |
1179 | |
111 | 1180 vec<edge> |
0 | 1181 get_loop_exit_edges (const struct loop *loop) |
1182 { | |
111 | 1183 vec<edge> edges = vNULL; |
0 | 1184 edge e; |
1185 unsigned i; | |
1186 basic_block *body; | |
1187 edge_iterator ei; | |
1188 struct loop_exit *exit; | |
1189 | |
111 | 1190 gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
0 | 1191 |
1192 /* If we maintain the lists of exits, use them. Otherwise we must | |
1193 scan the body of the loop. */ | |
1194 if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
1195 { | |
1196 for (exit = loop->exits->next; exit->e; exit = exit->next) | |
111 | 1197 edges.safe_push (exit->e); |
0 | 1198 } |
1199 else | |
1200 { | |
1201 body = get_loop_body (loop); | |
1202 for (i = 0; i < loop->num_nodes; i++) | |
1203 FOR_EACH_EDGE (e, ei, body[i]->succs) | |
1204 { | |
1205 if (!flow_bb_inside_loop_p (loop, e->dest)) | |
111 | 1206 edges.safe_push (e); |
0 | 1207 } |
1208 free (body); | |
1209 } | |
1210 | |
1211 return edges; | |
1212 } | |
1213 | |
1214 /* Counts the number of conditional branches inside LOOP. */ | |
1215 | |
1216 unsigned | |
1217 num_loop_branches (const struct loop *loop) | |
1218 { | |
1219 unsigned i, n; | |
1220 basic_block * body; | |
1221 | |
111 | 1222 gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
0 | 1223 |
1224 body = get_loop_body (loop); | |
1225 n = 0; | |
1226 for (i = 0; i < loop->num_nodes; i++) | |
1227 if (EDGE_COUNT (body[i]->succs) >= 2) | |
1228 n++; | |
1229 free (body); | |
1230 | |
1231 return n; | |
1232 } | |
1233 | |
1234 /* Adds basic block BB to LOOP. */ | |
1235 void | |
1236 add_bb_to_loop (basic_block bb, struct loop *loop) | |
1237 { | |
1238 unsigned i; | |
1239 loop_p ploop; | |
1240 edge_iterator ei; | |
1241 edge e; | |
1242 | |
1243 gcc_assert (bb->loop_father == NULL); | |
1244 bb->loop_father = loop; | |
1245 loop->num_nodes++; | |
111 | 1246 FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
0 | 1247 ploop->num_nodes++; |
1248 | |
1249 FOR_EACH_EDGE (e, ei, bb->succs) | |
1250 { | |
1251 rescan_loop_exit (e, true, false); | |
1252 } | |
1253 FOR_EACH_EDGE (e, ei, bb->preds) | |
1254 { | |
1255 rescan_loop_exit (e, true, false); | |
1256 } | |
1257 } | |
1258 | |
1259 /* Remove basic block BB from loops. */ | |
1260 void | |
1261 remove_bb_from_loops (basic_block bb) | |
1262 { | |
111 | 1263 unsigned i; |
0 | 1264 struct loop *loop = bb->loop_father; |
1265 loop_p ploop; | |
1266 edge_iterator ei; | |
1267 edge e; | |
1268 | |
1269 gcc_assert (loop != NULL); | |
1270 loop->num_nodes--; | |
111 | 1271 FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
0 | 1272 ploop->num_nodes--; |
1273 bb->loop_father = NULL; | |
1274 | |
1275 FOR_EACH_EDGE (e, ei, bb->succs) | |
1276 { | |
1277 rescan_loop_exit (e, false, true); | |
1278 } | |
1279 FOR_EACH_EDGE (e, ei, bb->preds) | |
1280 { | |
1281 rescan_loop_exit (e, false, true); | |
1282 } | |
1283 } | |
1284 | |
1285 /* Finds nearest common ancestor in loop tree for given loops. */ | |
1286 struct loop * | |
1287 find_common_loop (struct loop *loop_s, struct loop *loop_d) | |
1288 { | |
1289 unsigned sdepth, ddepth; | |
1290 | |
1291 if (!loop_s) return loop_d; | |
1292 if (!loop_d) return loop_s; | |
1293 | |
1294 sdepth = loop_depth (loop_s); | |
1295 ddepth = loop_depth (loop_d); | |
1296 | |
1297 if (sdepth < ddepth) | |
111 | 1298 loop_d = (*loop_d->superloops)[sdepth]; |
0 | 1299 else if (sdepth > ddepth) |
111 | 1300 loop_s = (*loop_s->superloops)[ddepth]; |
0 | 1301 |
1302 while (loop_s != loop_d) | |
1303 { | |
1304 loop_s = loop_outer (loop_s); | |
1305 loop_d = loop_outer (loop_d); | |
1306 } | |
1307 return loop_s; | |
1308 } | |
1309 | |
1310 /* Removes LOOP from structures and frees its data. */ | |
1311 | |
1312 void | |
1313 delete_loop (struct loop *loop) | |
1314 { | |
1315 /* Remove the loop from structure. */ | |
1316 flow_loop_tree_node_remove (loop); | |
1317 | |
1318 /* Remove loop from loops array. */ | |
111 | 1319 (*current_loops->larray)[loop->num] = NULL; |
0 | 1320 |
1321 /* Free loop data. */ | |
1322 flow_loop_free (loop); | |
1323 } | |
1324 | |
1325 /* Cancels the LOOP; it must be innermost one. */ | |
1326 | |
1327 static void | |
1328 cancel_loop (struct loop *loop) | |
1329 { | |
1330 basic_block *bbs; | |
1331 unsigned i; | |
1332 struct loop *outer = loop_outer (loop); | |
1333 | |
1334 gcc_assert (!loop->inner); | |
1335 | |
1336 /* Move blocks up one level (they should be removed as soon as possible). */ | |
1337 bbs = get_loop_body (loop); | |
1338 for (i = 0; i < loop->num_nodes; i++) | |
1339 bbs[i]->loop_father = outer; | |
1340 | |
111 | 1341 free (bbs); |
0 | 1342 delete_loop (loop); |
1343 } | |
1344 | |
1345 /* Cancels LOOP and all its subloops. */ | |
1346 void | |
1347 cancel_loop_tree (struct loop *loop) | |
1348 { | |
1349 while (loop->inner) | |
1350 cancel_loop_tree (loop->inner); | |
1351 cancel_loop (loop); | |
1352 } | |
1353 | |
1354 /* Checks that information about loops is correct | |
1355 -- sizes of loops are all right | |
1356 -- results of get_loop_body really belong to the loop | |
1357 -- loop header have just single entry edge and single latch edge | |
1358 -- loop latches have only single successor that is header of their loop | |
1359 -- irreducible loops are correctly marked | |
111 | 1360 -- the cached loop depth and loop father of each bb is correct |
0 | 1361 */ |
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1362 DEBUG_FUNCTION void |
0 | 1363 verify_loop_structure (void) |
1364 { | |
1365 unsigned *sizes, i, j; | |
111 | 1366 basic_block bb, *bbs; |
0 | 1367 struct loop *loop; |
1368 int err = 0; | |
1369 edge e; | |
111 | 1370 unsigned num = number_of_loops (cfun); |
0 | 1371 struct loop_exit *exit, *mexit; |
111 | 1372 bool dom_available = dom_info_available_p (CDI_DOMINATORS); |
1373 | |
1374 if (loops_state_satisfies_p (LOOPS_NEED_FIXUP)) | |
1375 { | |
1376 error ("loop verification on loop tree that needs fixup"); | |
1377 err = 1; | |
1378 } | |
0 | 1379 |
111 | 1380 /* We need up-to-date dominators, compute or verify them. */ |
1381 if (!dom_available) | |
1382 calculate_dominance_info (CDI_DOMINATORS); | |
1383 else | |
1384 verify_dominators (CDI_DOMINATORS); | |
1385 | |
1386 /* Check the loop tree root. */ | |
1387 if (current_loops->tree_root->header != ENTRY_BLOCK_PTR_FOR_FN (cfun) | |
1388 || current_loops->tree_root->latch != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
1389 || (current_loops->tree_root->num_nodes | |
1390 != (unsigned) n_basic_blocks_for_fn (cfun))) | |
1391 { | |
1392 error ("corrupt loop tree root"); | |
1393 err = 1; | |
1394 } | |
0 | 1395 |
111 | 1396 /* Check the headers. */ |
1397 FOR_EACH_BB_FN (bb, cfun) | |
1398 if (bb_loop_header_p (bb)) | |
1399 { | |
1400 if (bb->loop_father->header == NULL) | |
1401 { | |
1402 error ("loop with header %d marked for removal", bb->index); | |
1403 err = 1; | |
1404 } | |
1405 else if (bb->loop_father->header != bb) | |
1406 { | |
1407 error ("loop with header %d not in loop tree", bb->index); | |
1408 err = 1; | |
1409 } | |
1410 } | |
1411 else if (bb->loop_father->header == bb) | |
1412 { | |
1413 error ("non-loop with header %d not marked for removal", bb->index); | |
1414 err = 1; | |
1415 } | |
0 | 1416 |
111 | 1417 /* Check the recorded loop father and sizes of loops. */ |
1418 auto_sbitmap visited (last_basic_block_for_fn (cfun)); | |
1419 bitmap_clear (visited); | |
1420 bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); | |
1421 FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) | |
0 | 1422 { |
111 | 1423 unsigned n; |
0 | 1424 |
111 | 1425 if (loop->header == NULL) |
1426 { | |
1427 error ("removed loop %d in loop tree", loop->num); | |
1428 err = 1; | |
1429 continue; | |
1430 } | |
1431 | |
1432 n = get_loop_body_with_size (loop, bbs, n_basic_blocks_for_fn (cfun)); | |
1433 if (loop->num_nodes != n) | |
0 | 1434 { |
1435 error ("size of loop %d should be %d, not %d", | |
111 | 1436 loop->num, n, loop->num_nodes); |
0 | 1437 err = 1; |
1438 } | |
111 | 1439 |
1440 for (j = 0; j < n; j++) | |
1441 { | |
1442 bb = bbs[j]; | |
0 | 1443 |
111 | 1444 if (!flow_bb_inside_loop_p (loop, bb)) |
1445 { | |
1446 error ("bb %d does not belong to loop %d", | |
1447 bb->index, loop->num); | |
1448 err = 1; | |
1449 } | |
0 | 1450 |
111 | 1451 /* Ignore this block if it is in an inner loop. */ |
1452 if (bitmap_bit_p (visited, bb->index)) | |
1453 continue; | |
1454 bitmap_set_bit (visited, bb->index); | |
1455 | |
1456 if (bb->loop_father != loop) | |
1457 { | |
1458 error ("bb %d has father loop %d, should be loop %d", | |
1459 bb->index, bb->loop_father->num, loop->num); | |
1460 err = 1; | |
1461 } | |
1462 } | |
0 | 1463 } |
111 | 1464 free (bbs); |
0 | 1465 |
1466 /* Check headers and latches. */ | |
111 | 1467 FOR_EACH_LOOP (loop, 0) |
0 | 1468 { |
1469 i = loop->num; | |
111 | 1470 if (loop->header == NULL) |
1471 continue; | |
1472 if (!bb_loop_header_p (loop->header)) | |
1473 { | |
1474 error ("loop %d%'s header is not a loop header", i); | |
1475 err = 1; | |
1476 } | |
0 | 1477 if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
1478 && EDGE_COUNT (loop->header->preds) != 2) | |
1479 { | |
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1480 error ("loop %d%'s header does not have exactly 2 entries", i); |
0 | 1481 err = 1; |
1482 } | |
111 | 1483 if (loop->latch) |
1484 { | |
1485 if (!find_edge (loop->latch, loop->header)) | |
1486 { | |
1487 error ("loop %d%'s latch does not have an edge to its header", i); | |
1488 err = 1; | |
1489 } | |
1490 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, loop->header)) | |
1491 { | |
1492 error ("loop %d%'s latch is not dominated by its header", i); | |
1493 err = 1; | |
1494 } | |
1495 } | |
0 | 1496 if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
1497 { | |
1498 if (!single_succ_p (loop->latch)) | |
1499 { | |
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1500 error ("loop %d%'s latch does not have exactly 1 successor", i); |
0 | 1501 err = 1; |
1502 } | |
1503 if (single_succ (loop->latch) != loop->header) | |
1504 { | |
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|
1505 error ("loop %d%'s latch does not have header as successor", i); |
0 | 1506 err = 1; |
1507 } | |
1508 if (loop->latch->loop_father != loop) | |
1509 { | |
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|
1510 error ("loop %d%'s latch does not belong directly to it", i); |
0 | 1511 err = 1; |
1512 } | |
1513 } | |
1514 if (loop->header->loop_father != loop) | |
1515 { | |
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|
1516 error ("loop %d%'s header does not belong directly to it", i); |
0 | 1517 err = 1; |
1518 } | |
1519 if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) | |
1520 && (loop_latch_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)) | |
1521 { | |
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|
1522 error ("loop %d%'s latch is marked as part of irreducible region", i); |
0 | 1523 err = 1; |
1524 } | |
1525 } | |
1526 | |
1527 /* Check irreducible loops. */ | |
1528 if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) | |
1529 { | |
1530 /* Record old info. */ | |
111 | 1531 auto_sbitmap irreds (last_basic_block_for_fn (cfun)); |
1532 FOR_EACH_BB_FN (bb, cfun) | |
0 | 1533 { |
1534 edge_iterator ei; | |
1535 if (bb->flags & BB_IRREDUCIBLE_LOOP) | |
111 | 1536 bitmap_set_bit (irreds, bb->index); |
0 | 1537 else |
111 | 1538 bitmap_clear_bit (irreds, bb->index); |
0 | 1539 FOR_EACH_EDGE (e, ei, bb->succs) |
1540 if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1541 e->flags |= EDGE_ALL_FLAGS + 1; | |
1542 } | |
1543 | |
1544 /* Recount it. */ | |
1545 mark_irreducible_loops (); | |
1546 | |
1547 /* Compare. */ | |
111 | 1548 FOR_EACH_BB_FN (bb, cfun) |
0 | 1549 { |
1550 edge_iterator ei; | |
1551 | |
1552 if ((bb->flags & BB_IRREDUCIBLE_LOOP) | |
111 | 1553 && !bitmap_bit_p (irreds, bb->index)) |
0 | 1554 { |
1555 error ("basic block %d should be marked irreducible", bb->index); | |
1556 err = 1; | |
1557 } | |
1558 else if (!(bb->flags & BB_IRREDUCIBLE_LOOP) | |
111 | 1559 && bitmap_bit_p (irreds, bb->index)) |
0 | 1560 { |
1561 error ("basic block %d should not be marked irreducible", bb->index); | |
1562 err = 1; | |
1563 } | |
1564 FOR_EACH_EDGE (e, ei, bb->succs) | |
1565 { | |
1566 if ((e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1567 && !(e->flags & (EDGE_ALL_FLAGS + 1))) | |
1568 { | |
1569 error ("edge from %d to %d should be marked irreducible", | |
1570 e->src->index, e->dest->index); | |
1571 err = 1; | |
1572 } | |
1573 else if (!(e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1574 && (e->flags & (EDGE_ALL_FLAGS + 1))) | |
1575 { | |
1576 error ("edge from %d to %d should not be marked irreducible", | |
1577 e->src->index, e->dest->index); | |
1578 err = 1; | |
1579 } | |
1580 e->flags &= ~(EDGE_ALL_FLAGS + 1); | |
1581 } | |
1582 } | |
1583 } | |
1584 | |
1585 /* Check the recorded loop exits. */ | |
111 | 1586 FOR_EACH_LOOP (loop, 0) |
0 | 1587 { |
1588 if (!loop->exits || loop->exits->e != NULL) | |
1589 { | |
1590 error ("corrupted head of the exits list of loop %d", | |
1591 loop->num); | |
1592 err = 1; | |
1593 } | |
1594 else | |
1595 { | |
1596 /* Check that the list forms a cycle, and all elements except | |
1597 for the head are nonnull. */ | |
1598 for (mexit = loop->exits, exit = mexit->next, i = 0; | |
1599 exit->e && exit != mexit; | |
1600 exit = exit->next) | |
1601 { | |
1602 if (i++ & 1) | |
1603 mexit = mexit->next; | |
1604 } | |
1605 | |
1606 if (exit != loop->exits) | |
1607 { | |
1608 error ("corrupted exits list of loop %d", loop->num); | |
1609 err = 1; | |
1610 } | |
1611 } | |
1612 | |
1613 if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
1614 { | |
1615 if (loop->exits->next != loop->exits) | |
1616 { | |
1617 error ("nonempty exits list of loop %d, but exits are not recorded", | |
1618 loop->num); | |
1619 err = 1; | |
1620 } | |
1621 } | |
1622 } | |
1623 | |
1624 if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
1625 { | |
1626 unsigned n_exits = 0, eloops; | |
1627 | |
111 | 1628 sizes = XCNEWVEC (unsigned, num); |
0 | 1629 memset (sizes, 0, sizeof (unsigned) * num); |
111 | 1630 FOR_EACH_BB_FN (bb, cfun) |
0 | 1631 { |
1632 edge_iterator ei; | |
1633 if (bb->loop_father == current_loops->tree_root) | |
1634 continue; | |
1635 FOR_EACH_EDGE (e, ei, bb->succs) | |
1636 { | |
1637 if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) | |
1638 continue; | |
1639 | |
1640 n_exits++; | |
1641 exit = get_exit_descriptions (e); | |
1642 if (!exit) | |
1643 { | |
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|
1644 error ("exit %d->%d not recorded", |
0 | 1645 e->src->index, e->dest->index); |
1646 err = 1; | |
1647 } | |
1648 eloops = 0; | |
1649 for (; exit; exit = exit->next_e) | |
1650 eloops++; | |
1651 | |
1652 for (loop = bb->loop_father; | |
111 | 1653 loop != e->dest->loop_father |
1654 /* When a loop exit is also an entry edge which | |
1655 can happen when avoiding CFG manipulations | |
1656 then the last loop exited is the outer loop | |
1657 of the loop entered. */ | |
1658 && loop != loop_outer (e->dest->loop_father); | |
0 | 1659 loop = loop_outer (loop)) |
1660 { | |
1661 eloops--; | |
1662 sizes[loop->num]++; | |
1663 } | |
1664 | |
1665 if (eloops != 0) | |
1666 { | |
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diff
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|
1667 error ("wrong list of exited loops for edge %d->%d", |
0 | 1668 e->src->index, e->dest->index); |
1669 err = 1; | |
1670 } | |
1671 } | |
1672 } | |
1673 | |
111 | 1674 if (n_exits != current_loops->exits->elements ()) |
0 | 1675 { |
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|
1676 error ("too many loop exits recorded"); |
0 | 1677 err = 1; |
1678 } | |
1679 | |
111 | 1680 FOR_EACH_LOOP (loop, 0) |
0 | 1681 { |
1682 eloops = 0; | |
1683 for (exit = loop->exits->next; exit->e; exit = exit->next) | |
1684 eloops++; | |
1685 if (eloops != sizes[loop->num]) | |
1686 { | |
1687 error ("%d exits recorded for loop %d (having %d exits)", | |
1688 eloops, loop->num, sizes[loop->num]); | |
1689 err = 1; | |
1690 } | |
1691 } | |
111 | 1692 |
1693 free (sizes); | |
0 | 1694 } |
1695 | |
1696 gcc_assert (!err); | |
1697 | |
111 | 1698 if (!dom_available) |
1699 free_dominance_info (CDI_DOMINATORS); | |
0 | 1700 } |
1701 | |
1702 /* Returns latch edge of LOOP. */ | |
1703 edge | |
1704 loop_latch_edge (const struct loop *loop) | |
1705 { | |
1706 return find_edge (loop->latch, loop->header); | |
1707 } | |
1708 | |
1709 /* Returns preheader edge of LOOP. */ | |
1710 edge | |
1711 loop_preheader_edge (const struct loop *loop) | |
1712 { | |
1713 edge e; | |
1714 edge_iterator ei; | |
1715 | |
111 | 1716 gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
1717 && ! loops_state_satisfies_p (LOOPS_MAY_HAVE_MULTIPLE_LATCHES)); | |
0 | 1718 |
1719 FOR_EACH_EDGE (e, ei, loop->header->preds) | |
1720 if (e->src != loop->latch) | |
1721 break; | |
1722 | |
111 | 1723 if (! e) |
1724 { | |
1725 gcc_assert (! loop_outer (loop)); | |
1726 return single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
1727 } | |
1728 | |
0 | 1729 return e; |
1730 } | |
1731 | |
1732 /* Returns true if E is an exit of LOOP. */ | |
1733 | |
1734 bool | |
1735 loop_exit_edge_p (const struct loop *loop, const_edge e) | |
1736 { | |
1737 return (flow_bb_inside_loop_p (loop, e->src) | |
1738 && !flow_bb_inside_loop_p (loop, e->dest)); | |
1739 } | |
1740 | |
1741 /* Returns the single exit edge of LOOP, or NULL if LOOP has either no exit | |
1742 or more than one exit. If loops do not have the exits recorded, NULL | |
1743 is returned always. */ | |
1744 | |
1745 edge | |
1746 single_exit (const struct loop *loop) | |
1747 { | |
1748 struct loop_exit *exit = loop->exits->next; | |
1749 | |
1750 if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
1751 return NULL; | |
1752 | |
1753 if (exit->e && exit->next == loop->exits) | |
1754 return exit->e; | |
1755 else | |
1756 return NULL; | |
1757 } | |
1758 | |
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|
1759 /* Returns true when BB has an incoming edge exiting LOOP. */ |
0 | 1760 |
1761 bool | |
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1762 loop_exits_to_bb_p (struct loop *loop, basic_block bb) |
0 | 1763 { |
1764 edge e; | |
1765 edge_iterator ei; | |
1766 | |
1767 FOR_EACH_EDGE (e, ei, bb->preds) | |
1768 if (loop_exit_edge_p (loop, e)) | |
1769 return true; | |
1770 | |
1771 return false; | |
1772 } | |
67
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1773 |
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1774 /* Returns true when BB has an outgoing edge exiting LOOP. */ |
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1775 |
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1776 bool |
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1777 loop_exits_from_bb_p (struct loop *loop, basic_block bb) |
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1778 { |
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1779 edge e; |
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1780 edge_iterator ei; |
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1781 |
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1782 FOR_EACH_EDGE (e, ei, bb->succs) |
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1783 if (loop_exit_edge_p (loop, e)) |
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1784 return true; |
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1785 |
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1786 return false; |
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1787 } |
111 | 1788 |
1789 /* Return location corresponding to the loop control condition if possible. */ | |
1790 | |
1791 location_t | |
1792 get_loop_location (struct loop *loop) | |
1793 { | |
1794 rtx_insn *insn = NULL; | |
1795 struct niter_desc *desc = NULL; | |
1796 edge exit; | |
1797 | |
1798 /* For a for or while loop, we would like to return the location | |
1799 of the for or while statement, if possible. To do this, look | |
1800 for the branch guarding the loop back-edge. */ | |
1801 | |
1802 /* If this is a simple loop with an in_edge, then the loop control | |
1803 branch is typically at the end of its source. */ | |
1804 desc = get_simple_loop_desc (loop); | |
1805 if (desc->in_edge) | |
1806 { | |
1807 FOR_BB_INSNS_REVERSE (desc->in_edge->src, insn) | |
1808 { | |
1809 if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1810 return INSN_LOCATION (insn); | |
1811 } | |
1812 } | |
1813 /* If loop has a single exit, then the loop control branch | |
1814 must be at the end of its source. */ | |
1815 if ((exit = single_exit (loop))) | |
1816 { | |
1817 FOR_BB_INSNS_REVERSE (exit->src, insn) | |
1818 { | |
1819 if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1820 return INSN_LOCATION (insn); | |
1821 } | |
1822 } | |
1823 /* Next check the latch, to see if it is non-empty. */ | |
1824 FOR_BB_INSNS_REVERSE (loop->latch, insn) | |
1825 { | |
1826 if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1827 return INSN_LOCATION (insn); | |
1828 } | |
1829 /* Finally, if none of the above identifies the loop control branch, | |
1830 return the first location in the loop header. */ | |
1831 FOR_BB_INSNS (loop->header, insn) | |
1832 { | |
1833 if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1834 return INSN_LOCATION (insn); | |
1835 } | |
1836 /* If all else fails, simply return the current function location. */ | |
1837 return DECL_SOURCE_LOCATION (current_function_decl); | |
1838 } | |
1839 | |
1840 /* Records that every statement in LOOP is executed I_BOUND times. | |
1841 REALISTIC is true if I_BOUND is expected to be close to the real number | |
1842 of iterations. UPPER is true if we are sure the loop iterates at most | |
1843 I_BOUND times. */ | |
1844 | |
1845 void | |
1846 record_niter_bound (struct loop *loop, const widest_int &i_bound, | |
1847 bool realistic, bool upper) | |
1848 { | |
1849 /* Update the bounds only when there is no previous estimation, or when the | |
1850 current estimation is smaller. */ | |
1851 if (upper | |
1852 && (!loop->any_upper_bound | |
1853 || wi::ltu_p (i_bound, loop->nb_iterations_upper_bound))) | |
1854 { | |
1855 loop->any_upper_bound = true; | |
1856 loop->nb_iterations_upper_bound = i_bound; | |
1857 if (!loop->any_likely_upper_bound) | |
1858 { | |
1859 loop->any_likely_upper_bound = true; | |
1860 loop->nb_iterations_likely_upper_bound = i_bound; | |
1861 } | |
1862 } | |
1863 if (realistic | |
1864 && (!loop->any_estimate | |
1865 || wi::ltu_p (i_bound, loop->nb_iterations_estimate))) | |
1866 { | |
1867 loop->any_estimate = true; | |
1868 loop->nb_iterations_estimate = i_bound; | |
1869 } | |
1870 if (!realistic | |
1871 && (!loop->any_likely_upper_bound | |
1872 || wi::ltu_p (i_bound, loop->nb_iterations_likely_upper_bound))) | |
1873 { | |
1874 loop->any_likely_upper_bound = true; | |
1875 loop->nb_iterations_likely_upper_bound = i_bound; | |
1876 } | |
1877 | |
1878 /* If an upper bound is smaller than the realistic estimate of the | |
1879 number of iterations, use the upper bound instead. */ | |
1880 if (loop->any_upper_bound | |
1881 && loop->any_estimate | |
1882 && wi::ltu_p (loop->nb_iterations_upper_bound, | |
1883 loop->nb_iterations_estimate)) | |
1884 loop->nb_iterations_estimate = loop->nb_iterations_upper_bound; | |
1885 if (loop->any_upper_bound | |
1886 && loop->any_likely_upper_bound | |
1887 && wi::ltu_p (loop->nb_iterations_upper_bound, | |
1888 loop->nb_iterations_likely_upper_bound)) | |
1889 loop->nb_iterations_likely_upper_bound = loop->nb_iterations_upper_bound; | |
1890 } | |
1891 | |
1892 /* Similar to get_estimated_loop_iterations, but returns the estimate only | |
1893 if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
1894 on the number of iterations of LOOP could not be derived, returns -1. */ | |
1895 | |
1896 HOST_WIDE_INT | |
1897 get_estimated_loop_iterations_int (struct loop *loop) | |
1898 { | |
1899 widest_int nit; | |
1900 HOST_WIDE_INT hwi_nit; | |
1901 | |
1902 if (!get_estimated_loop_iterations (loop, &nit)) | |
1903 return -1; | |
1904 | |
1905 if (!wi::fits_shwi_p (nit)) | |
1906 return -1; | |
1907 hwi_nit = nit.to_shwi (); | |
1908 | |
1909 return hwi_nit < 0 ? -1 : hwi_nit; | |
1910 } | |
1911 | |
1912 /* Returns an upper bound on the number of executions of statements | |
1913 in the LOOP. For statements before the loop exit, this exceeds | |
1914 the number of execution of the latch by one. */ | |
1915 | |
1916 HOST_WIDE_INT | |
1917 max_stmt_executions_int (struct loop *loop) | |
1918 { | |
1919 HOST_WIDE_INT nit = get_max_loop_iterations_int (loop); | |
1920 HOST_WIDE_INT snit; | |
1921 | |
1922 if (nit == -1) | |
1923 return -1; | |
1924 | |
1925 snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
1926 | |
1927 /* If the computation overflows, return -1. */ | |
1928 return snit < 0 ? -1 : snit; | |
1929 } | |
1930 | |
1931 /* Returns an likely upper bound on the number of executions of statements | |
1932 in the LOOP. For statements before the loop exit, this exceeds | |
1933 the number of execution of the latch by one. */ | |
1934 | |
1935 HOST_WIDE_INT | |
1936 likely_max_stmt_executions_int (struct loop *loop) | |
1937 { | |
1938 HOST_WIDE_INT nit = get_likely_max_loop_iterations_int (loop); | |
1939 HOST_WIDE_INT snit; | |
1940 | |
1941 if (nit == -1) | |
1942 return -1; | |
1943 | |
1944 snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
1945 | |
1946 /* If the computation overflows, return -1. */ | |
1947 return snit < 0 ? -1 : snit; | |
1948 } | |
1949 | |
1950 /* Sets NIT to the estimated number of executions of the latch of the | |
1951 LOOP. If we have no reliable estimate, the function returns false, otherwise | |
1952 returns true. */ | |
1953 | |
1954 bool | |
1955 get_estimated_loop_iterations (struct loop *loop, widest_int *nit) | |
1956 { | |
1957 /* Even if the bound is not recorded, possibly we can derrive one from | |
1958 profile. */ | |
1959 if (!loop->any_estimate) | |
1960 { | |
1961 if (loop->header->count.reliable_p ()) | |
1962 { | |
1963 *nit = gcov_type_to_wide_int | |
1964 (expected_loop_iterations_unbounded (loop) + 1); | |
1965 return true; | |
1966 } | |
1967 return false; | |
1968 } | |
1969 | |
1970 *nit = loop->nb_iterations_estimate; | |
1971 return true; | |
1972 } | |
1973 | |
1974 /* Sets NIT to an upper bound for the maximum number of executions of the | |
1975 latch of the LOOP. If we have no reliable estimate, the function returns | |
1976 false, otherwise returns true. */ | |
1977 | |
1978 bool | |
1979 get_max_loop_iterations (const struct loop *loop, widest_int *nit) | |
1980 { | |
1981 if (!loop->any_upper_bound) | |
1982 return false; | |
1983 | |
1984 *nit = loop->nb_iterations_upper_bound; | |
1985 return true; | |
1986 } | |
1987 | |
1988 /* Similar to get_max_loop_iterations, but returns the estimate only | |
1989 if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
1990 on the number of iterations of LOOP could not be derived, returns -1. */ | |
1991 | |
1992 HOST_WIDE_INT | |
1993 get_max_loop_iterations_int (const struct loop *loop) | |
1994 { | |
1995 widest_int nit; | |
1996 HOST_WIDE_INT hwi_nit; | |
1997 | |
1998 if (!get_max_loop_iterations (loop, &nit)) | |
1999 return -1; | |
2000 | |
2001 if (!wi::fits_shwi_p (nit)) | |
2002 return -1; | |
2003 hwi_nit = nit.to_shwi (); | |
2004 | |
2005 return hwi_nit < 0 ? -1 : hwi_nit; | |
2006 } | |
2007 | |
2008 /* Sets NIT to an upper bound for the maximum number of executions of the | |
2009 latch of the LOOP. If we have no reliable estimate, the function returns | |
2010 false, otherwise returns true. */ | |
2011 | |
2012 bool | |
2013 get_likely_max_loop_iterations (struct loop *loop, widest_int *nit) | |
2014 { | |
2015 if (!loop->any_likely_upper_bound) | |
2016 return false; | |
2017 | |
2018 *nit = loop->nb_iterations_likely_upper_bound; | |
2019 return true; | |
2020 } | |
2021 | |
2022 /* Similar to get_max_loop_iterations, but returns the estimate only | |
2023 if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
2024 on the number of iterations of LOOP could not be derived, returns -1. */ | |
2025 | |
2026 HOST_WIDE_INT | |
2027 get_likely_max_loop_iterations_int (struct loop *loop) | |
2028 { | |
2029 widest_int nit; | |
2030 HOST_WIDE_INT hwi_nit; | |
2031 | |
2032 if (!get_likely_max_loop_iterations (loop, &nit)) | |
2033 return -1; | |
2034 | |
2035 if (!wi::fits_shwi_p (nit)) | |
2036 return -1; | |
2037 hwi_nit = nit.to_shwi (); | |
2038 | |
2039 return hwi_nit < 0 ? -1 : hwi_nit; | |
2040 } | |
2041 | |
2042 /* Returns the loop depth of the loop BB belongs to. */ | |
2043 | |
2044 int | |
2045 bb_loop_depth (const_basic_block bb) | |
2046 { | |
2047 return bb->loop_father ? loop_depth (bb->loop_father) : 0; | |
2048 } | |
2049 | |
2050 /* Marks LOOP for removal and sets LOOPS_NEED_FIXUP. */ | |
2051 | |
2052 void | |
2053 mark_loop_for_removal (loop_p loop) | |
2054 { | |
2055 if (loop->header == NULL) | |
2056 return; | |
2057 loop->former_header = loop->header; | |
2058 loop->header = NULL; | |
2059 loop->latch = NULL; | |
2060 loops_state_set (LOOPS_NEED_FIXUP); | |
2061 } |