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65f34de5 | 1 | /* Natural loop discovery code for GNU compiler. |
fbd26352 | 2 | Copyright (C) 2000-2019 Free Software Foundation, Inc. |
65f34de5 | 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 | |
8c4c00c1 | 8 | Software Foundation; either version 3, or (at your option) any later |
65f34de5 | 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 | |
8c4c00c1 | 17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
65f34de5 | 19 | |
20 | #include "config.h" | |
21 | #include "system.h" | |
805e22b2 | 22 | #include "coretypes.h" |
9ef16211 | 23 | #include "backend.h" |
7c29e30e | 24 | #include "rtl.h" |
9ef16211 | 25 | #include "tree.h" |
26 | #include "gimple.h" | |
7c29e30e | 27 | #include "cfghooks.h" |
28 | #include "gimple-ssa.h" | |
29 | #include "diagnostic-core.h" | |
94ea8568 | 30 | #include "cfganal.h" |
862be747 | 31 | #include "cfgloop.h" |
dcf1a1ec | 32 | #include "gimple-iterator.h" |
b9ed1410 | 33 | #include "dumpfile.h" |
5f5d4cd1 | 34 | |
7194de72 | 35 | static void flow_loops_cfg_dump (FILE *); |
65f34de5 | 36 | \f |
37 | /* Dump loop related CFG information. */ | |
38 | ||
39 | static void | |
7194de72 | 40 | flow_loops_cfg_dump (FILE *file) |
65f34de5 | 41 | { |
4c26117a | 42 | basic_block bb; |
65f34de5 | 43 | |
7194de72 | 44 | if (!file) |
65f34de5 | 45 | return; |
46 | ||
fc00614f | 47 | FOR_EACH_BB_FN (bb, cfun) |
65f34de5 | 48 | { |
49 | edge succ; | |
cd665a06 | 50 | edge_iterator ei; |
65f34de5 | 51 | |
4c26117a | 52 | fprintf (file, ";; %d succs { ", bb->index); |
cd665a06 | 53 | FOR_EACH_EDGE (succ, ei, bb->succs) |
b3d6de89 | 54 | fprintf (file, "%d ", succ->dest->index); |
7fb12188 | 55 | fprintf (file, "}\n"); |
65f34de5 | 56 | } |
65f34de5 | 57 | } |
58 | ||
d10cfa8d | 59 | /* Return nonzero if the nodes of LOOP are a subset of OUTER. */ |
65f34de5 | 60 | |
7fb12188 | 61 | bool |
4c9e08a4 | 62 | flow_loop_nested_p (const struct loop *outer, const struct loop *loop) |
65f34de5 | 63 | { |
9e3536f4 | 64 | unsigned odepth = loop_depth (outer); |
65 | ||
66 | return (loop_depth (loop) > odepth | |
f1f41a6c | 67 | && (*loop->superloops)[odepth] == outer); |
65f34de5 | 68 | } |
69 | ||
b4d679c5 | 70 | /* Returns the loop such that LOOP is nested DEPTH (indexed from zero) |
71 | loops within LOOP. */ | |
7d23383d | 72 | |
73 | struct loop * | |
74 | superloop_at_depth (struct loop *loop, unsigned depth) | |
75 | { | |
9e3536f4 | 76 | unsigned ldepth = loop_depth (loop); |
77 | ||
78 | gcc_assert (depth <= ldepth); | |
7d23383d | 79 | |
9e3536f4 | 80 | if (depth == ldepth) |
7d23383d | 81 | return loop; |
82 | ||
f1f41a6c | 83 | return (*loop->superloops)[depth]; |
7d23383d | 84 | } |
85 | ||
4a6f9e19 | 86 | /* Returns the list of the latch edges of LOOP. */ |
87 | ||
f1f41a6c | 88 | static vec<edge> |
4a6f9e19 | 89 | get_loop_latch_edges (const struct loop *loop) |
90 | { | |
91 | edge_iterator ei; | |
92 | edge e; | |
1e094109 | 93 | vec<edge> ret = vNULL; |
4a6f9e19 | 94 | |
95 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
96 | { | |
97 | if (dominated_by_p (CDI_DOMINATORS, e->src, loop->header)) | |
f1f41a6c | 98 | ret.safe_push (e); |
4a6f9e19 | 99 | } |
100 | ||
101 | return ret; | |
102 | } | |
103 | ||
65f34de5 | 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 | |
4c9e08a4 | 108 | flow_loop_dump (const struct loop *loop, FILE *file, |
109 | void (*loop_dump_aux) (const struct loop *, FILE *, int), | |
110 | int verbose) | |
65f34de5 | 111 | { |
7fb12188 | 112 | basic_block *bbs; |
862be747 | 113 | unsigned i; |
f1f41a6c | 114 | vec<edge> latches; |
4a6f9e19 | 115 | edge e; |
7fb12188 | 116 | |
65f34de5 | 117 | if (! loop || ! loop->header) |
118 | return; | |
119 | ||
58b3f902 | 120 | fprintf (file, ";;\n;; Loop %d\n", loop->num); |
65f34de5 | 121 | |
4a6f9e19 | 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); | |
f1f41a6c | 129 | FOR_EACH_VEC_ELT (latches, i, e) |
4a6f9e19 | 130 | fprintf (file, " %d", e->src->index); |
f1f41a6c | 131 | latches.release (); |
4a6f9e19 | 132 | fprintf (file, "\n"); |
133 | } | |
134 | ||
8543a448 | 135 | fprintf (file, ";; depth %d, outer %ld\n", |
9e3536f4 | 136 | loop_depth (loop), (long) (loop_outer (loop) |
137 | ? loop_outer (loop)->num : -1)); | |
65f34de5 | 138 | |
fbf561f4 | 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) | |
eac41296 | 144 | fprintf (file, ";; profile-based iteration count: %" PRIu64 "\n", |
145 | (uint64_t) nit); | |
fbf561f4 | 146 | } |
147 | ||
7fb12188 | 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"); | |
5cc577b6 | 154 | |
65f34de5 | 155 | if (loop_dump_aux) |
156 | loop_dump_aux (loop, file, verbose); | |
157 | } | |
158 | ||
7194de72 | 159 | /* Dump the loop information about loops to the stream FILE, |
65f34de5 | 160 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ |
161 | ||
162 | void | |
7194de72 | 163 | flow_loops_dump (FILE *file, void (*loop_dump_aux) (const struct loop *, FILE *, int), int verbose) |
65f34de5 | 164 | { |
17519ba0 | 165 | struct loop *loop; |
65f34de5 | 166 | |
7194de72 | 167 | if (!current_loops || ! file) |
65f34de5 | 168 | return; |
169 | ||
41f75a99 | 170 | fprintf (file, ";; %d loops found\n", number_of_loops (cfun)); |
7fb12188 | 171 | |
f21d4d00 | 172 | FOR_EACH_LOOP (loop, LI_INCLUDE_ROOT) |
65f34de5 | 173 | { |
7fb12188 | 174 | flow_loop_dump (loop, file, loop_dump_aux, verbose); |
65f34de5 | 175 | } |
176 | ||
177 | if (verbose) | |
7194de72 | 178 | flow_loops_cfg_dump (file); |
65f34de5 | 179 | } |
180 | ||
7fb12188 | 181 | /* Free data allocated for LOOP. */ |
ccae4f9f | 182 | |
a5414ff5 | 183 | void |
4c9e08a4 | 184 | flow_loop_free (struct loop *loop) |
7fb12188 | 185 | { |
dce58e66 | 186 | struct loop_exit *exit, *next; |
187 | ||
f1f41a6c | 188 | vec_free (loop->superloops); |
dce58e66 | 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. */ | |
ccae4f9f | 194 | for (exit = loop->exits->next; exit != loop->exits; exit = next) |
dce58e66 | 195 | { |
196 | next = exit->next; | |
197 | exit->next = exit; | |
198 | exit->prev = exit; | |
199 | } | |
ccae4f9f | 200 | |
201 | ggc_free (loop->exits); | |
202 | ggc_free (loop); | |
7fb12188 | 203 | } |
204 | ||
65f34de5 | 205 | /* Free all the memory allocated for LOOPS. */ |
206 | ||
207 | void | |
4c9e08a4 | 208 | flow_loops_free (struct loops *loops) |
65f34de5 | 209 | { |
17519ba0 | 210 | if (loops->larray) |
65f34de5 | 211 | { |
862be747 | 212 | unsigned i; |
17519ba0 | 213 | loop_p loop; |
65f34de5 | 214 | |
215 | /* Free the loop descriptors. */ | |
f1f41a6c | 216 | FOR_EACH_VEC_SAFE_ELT (loops->larray, i, loop) |
65f34de5 | 217 | { |
7fb12188 | 218 | if (!loop) |
219 | continue; | |
220 | ||
221 | flow_loop_free (loop); | |
65f34de5 | 222 | } |
5cc577b6 | 223 | |
f1f41a6c | 224 | vec_free (loops->larray); |
65f34de5 | 225 | } |
226 | } | |
227 | ||
7fb12188 | 228 | /* Find the nodes contained within the LOOP with header HEADER. |
229 | Return the number of nodes within the loop. */ | |
65f34de5 | 230 | |
053fdd99 | 231 | int |
4c9e08a4 | 232 | flow_loop_nodes_find (basic_block header, struct loop *loop) |
65f34de5 | 233 | { |
1e094109 | 234 | vec<basic_block> stack = vNULL; |
7fb12188 | 235 | int num_nodes = 1; |
4a6f9e19 | 236 | edge latch; |
237 | edge_iterator latch_ei; | |
65f34de5 | 238 | |
7fb12188 | 239 | header->loop_father = loop; |
65f34de5 | 240 | |
4a6f9e19 | 241 | FOR_EACH_EDGE (latch, latch_ei, loop->header->preds) |
65f34de5 | 242 | { |
4a6f9e19 | 243 | if (latch->src->loop_father == loop |
244 | || !dominated_by_p (CDI_DOMINATORS, latch->src, loop->header)) | |
245 | continue; | |
246 | ||
65f34de5 | 247 | num_nodes++; |
f1f41a6c | 248 | stack.safe_push (latch->src); |
4a6f9e19 | 249 | latch->src->loop_father = loop; |
4c9e08a4 | 250 | |
f1f41a6c | 251 | while (!stack.is_empty ()) |
65f34de5 | 252 | { |
7fb12188 | 253 | basic_block node; |
254 | edge e; | |
cd665a06 | 255 | edge_iterator ei; |
65f34de5 | 256 | |
f1f41a6c | 257 | node = stack.pop (); |
4c9e08a4 | 258 | |
cd665a06 | 259 | FOR_EACH_EDGE (e, ei, node->preds) |
65f34de5 | 260 | { |
7fb12188 | 261 | basic_block ancestor = e->src; |
262 | ||
4a6f9e19 | 263 | if (ancestor->loop_father != loop) |
7fb12188 | 264 | { |
265 | ancestor->loop_father = loop; | |
7fb12188 | 266 | num_nodes++; |
f1f41a6c | 267 | stack.safe_push (ancestor); |
7fb12188 | 268 | } |
65f34de5 | 269 | } |
270 | } | |
271 | } | |
f1f41a6c | 272 | stack.release (); |
4a6f9e19 | 273 | |
65f34de5 | 274 | return num_nodes; |
275 | } | |
276 | ||
9e3536f4 | 277 | /* Records the vector of superloops of the loop LOOP, whose immediate |
278 | superloop is FATHER. */ | |
279 | ||
a5414ff5 | 280 | static void |
9e3536f4 | 281 | establish_preds (struct loop *loop, struct loop *father) |
a5414ff5 | 282 | { |
9e3536f4 | 283 | loop_p ploop; |
284 | unsigned depth = loop_depth (father) + 1; | |
285 | unsigned i; | |
b811afb0 | 286 | |
f1f41a6c | 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); | |
a5414ff5 | 292 | |
293 | for (ploop = loop->inner; ploop; ploop = ploop->next) | |
9e3536f4 | 294 | establish_preds (ploop, loop); |
a5414ff5 | 295 | } |
296 | ||
7fb12188 | 297 | /* Add LOOP to the loop hierarchy tree where FATHER is father of the |
a5414ff5 | 298 | added loop. If LOOP has some children, take care of that their |
baf1c4a6 | 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. */ | |
65f34de5 | 303 | |
7fb12188 | 304 | void |
baf1c4a6 | 305 | flow_loop_tree_node_add (struct loop *father, struct loop *loop, |
306 | struct loop *after) | |
65f34de5 | 307 | { |
baf1c4a6 | 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 | } | |
7fb12188 | 318 | |
9e3536f4 | 319 | establish_preds (loop, father); |
65f34de5 | 320 | } |
321 | ||
7fb12188 | 322 | /* Remove LOOP from the loop hierarchy tree. */ |
65f34de5 | 323 | |
7fb12188 | 324 | void |
4c9e08a4 | 325 | flow_loop_tree_node_remove (struct loop *loop) |
65f34de5 | 326 | { |
7fb12188 | 327 | struct loop *prev, *father; |
65f34de5 | 328 | |
9e3536f4 | 329 | father = loop_outer (loop); |
65f34de5 | 330 | |
7fb12188 | 331 | /* Remove loop from the list of sons. */ |
332 | if (father->inner == loop) | |
333 | father->inner = loop->next; | |
334 | else | |
335 | { | |
9e3536f4 | 336 | for (prev = father->inner; prev->next != loop; prev = prev->next) |
337 | continue; | |
7fb12188 | 338 | prev->next = loop->next; |
339 | } | |
65f34de5 | 340 | |
f1f41a6c | 341 | loop->superloops = NULL; |
65f34de5 | 342 | } |
343 | ||
dce58e66 | 344 | /* Allocates and returns new loop structure. */ |
345 | ||
346 | struct loop * | |
347 | alloc_loop (void) | |
348 | { | |
25a27413 | 349 | struct loop *loop = ggc_cleared_alloc<struct loop> (); |
ccae4f9f | 350 | |
25a27413 | 351 | loop->exits = ggc_cleared_alloc<loop_exit> (); |
ccae4f9f | 352 | loop->exits->next = loop->exits->prev = loop->exits; |
26c166eb | 353 | loop->can_be_parallel = false; |
85168485 | 354 | loop->constraints = 0; |
e913b5cd | 355 | loop->nb_iterations_upper_bound = 0; |
332409d3 | 356 | loop->nb_iterations_likely_upper_bound = 0; |
e913b5cd | 357 | loop->nb_iterations_estimate = 0; |
dce58e66 | 358 | return loop; |
359 | } | |
360 | ||
a8a97201 | 361 | /* Initializes loops structure LOOPS, reserving place for NUM_LOOPS loops |
362 | (including the root of the loop tree). */ | |
363 | ||
7a569539 | 364 | void |
365 | init_loops_structure (struct function *fn, | |
366 | struct loops *loops, unsigned num_loops) | |
a8a97201 | 367 | { |
368 | struct loop *root; | |
369 | ||
370 | memset (loops, 0, sizeof *loops); | |
f1f41a6c | 371 | vec_alloc (loops->larray, num_loops); |
a8a97201 | 372 | |
373 | /* Dummy loop containing whole function. */ | |
374 | root = alloc_loop (); | |
a28770e1 | 375 | root->num_nodes = n_basic_blocks_for_fn (fn); |
34154e27 | 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; | |
a8a97201 | 380 | |
f1f41a6c | 381 | loops->larray->quick_push (root); |
a8a97201 | 382 | loops->tree_root = root; |
383 | } | |
384 | ||
ff829efa | 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; | |
392 | ||
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; | |
34154e27 | 406 | if (latch != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
ff829efa | 407 | && dominated_by_p (CDI_DOMINATORS, latch, header)) |
408 | return true; | |
409 | } | |
410 | ||
411 | return false; | |
412 | } | |
413 | ||
5cc577b6 | 414 | /* Find all the natural loops in the function and save in LOOPS structure and |
6b42039a | 415 | recalculate loop_father information in basic block structures. |
ff829efa | 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. */ | |
65f34de5 | 421 | |
ff829efa | 422 | struct loops * |
ffc6b5d5 | 423 | flow_loops_find (struct loops *loops) |
65f34de5 | 424 | { |
ff829efa | 425 | bool from_scratch = (loops == NULL); |
65f34de5 | 426 | int *rc_order; |
ff829efa | 427 | int b; |
428 | unsigned i; | |
65f34de5 | 429 | |
a8a97201 | 430 | /* Ensure that the dominators are computed. */ |
431 | calculate_dominance_info (CDI_DOMINATORS); | |
65f34de5 | 432 | |
ff829efa | 433 | if (!loops) |
a8a97201 | 434 | { |
25a27413 | 435 | loops = ggc_cleared_alloc<struct loops> (); |
7a569539 | 436 | init_loops_structure (cfun, loops, 1); |
a8a97201 | 437 | } |
65f34de5 | 438 | |
ff829efa | 439 | /* Ensure that loop exits were released. */ |
440 | gcc_assert (loops->exits == NULL); | |
65f34de5 | 441 | |
ff829efa | 442 | /* Taking care of this degenerate case makes the rest of |
443 | this code simpler. */ | |
a28770e1 | 444 | if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) |
ff829efa | 445 | return loops; |
7fb12188 | 446 | |
ff829efa | 447 | /* The root loop node contains all basic-blocks. */ |
a28770e1 | 448 | loops->tree_root->num_nodes = n_basic_blocks_for_fn (cfun); |
4c9e08a4 | 449 | |
ff829efa | 450 | /* Compute depth first search order of the CFG so that outer |
451 | natural loops will be found before inner natural loops. */ | |
a28770e1 | 452 | rc_order = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); |
ff829efa | 453 | pre_and_rev_post_order_compute (NULL, rc_order, false); |
743f4ee2 | 454 | |
ff829efa | 455 | /* Gather all loop headers in reverse completion order and allocate |
456 | loop structures for loops that are not already present. */ | |
c2078b80 | 457 | auto_vec<loop_p> larray (loops->larray->length ()); |
a28770e1 | 458 | for (b = 0; b < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; b++) |
ff829efa | 459 | { |
f5a6b05f | 460 | basic_block header = BASIC_BLOCK_FOR_FN (cfun, rc_order[b]); |
ff829efa | 461 | if (bb_loop_header_p (header)) |
65f34de5 | 462 | { |
ff829efa | 463 | struct loop *loop; |
7fb12188 | 464 | |
ff829efa | 465 | /* The current active loop tree has valid loop-fathers for |
466 | header blocks. */ | |
467 | if (!from_scratch | |
468 | && header->loop_father->header == header) | |
7fb12188 | 469 | { |
ff829efa | 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); | |
7fb12188 | 475 | } |
ff829efa | 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; | |
484 | ||
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 | } | |
b375c775 | 491 | /* Reset latch, we recompute it below. */ |
492 | loop->latch = NULL; | |
ff829efa | 493 | larray.safe_push (loop); |
65f34de5 | 494 | } |
65f34de5 | 495 | |
ff829efa | 496 | /* Make blocks part of the loop root node at start. */ |
497 | header->loop_father = loops->tree_root; | |
498 | } | |
7fb12188 | 499 | |
ff829efa | 500 | free (rc_order); |
7fb12188 | 501 | |
ff829efa | 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) | |
65f34de5 | 505 | { |
ff829efa | 506 | struct loop *loop = larray[i]; |
507 | basic_block header = loop->header; | |
fcc86201 | 508 | edge_iterator ei; |
509 | edge e; | |
65f34de5 | 510 | |
ff829efa | 511 | flow_loop_tree_node_add (header->loop_father, loop); |
512 | loop->num_nodes = flow_loop_nodes_find (loop->header, loop); | |
fcc86201 | 513 | |
514 | /* Look for the latch for this header block, if it has just a | |
515 | single one. */ | |
516 | FOR_EACH_EDGE (e, ei, header->preds) | |
517 | { | |
518 | basic_block latch = e->src; | |
519 | ||
520 | if (flow_bb_inside_loop_p (loop, latch)) | |
521 | { | |
522 | if (loop->latch != NULL) | |
523 | { | |
524 | /* More than one latch edge. */ | |
525 | loop->latch = NULL; | |
526 | break; | |
527 | } | |
528 | loop->latch = latch; | |
529 | } | |
530 | } | |
7fb12188 | 531 | } |
862be747 | 532 | |
ff829efa | 533 | return loops; |
65f34de5 | 534 | } |
535 | ||
d6f263c0 | 536 | /* qsort helper for sort_sibling_loops. */ |
537 | ||
538 | static int *sort_sibling_loops_cmp_rpo; | |
539 | static int | |
540 | sort_sibling_loops_cmp (const void *la_, const void *lb_) | |
541 | { | |
542 | const struct loop *la = *(const struct loop * const *)la_; | |
543 | const struct loop *lb = *(const struct loop * const *)lb_; | |
544 | return (sort_sibling_loops_cmp_rpo[la->header->index] | |
545 | - sort_sibling_loops_cmp_rpo[lb->header->index]); | |
546 | } | |
547 | ||
548 | /* Sort sibling loops in RPO order. */ | |
549 | ||
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); | |
560 | ||
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 | } | |
583 | ||
584 | free (sort_sibling_loops_cmp_rpo); | |
585 | sort_sibling_loops_cmp_rpo = NULL; | |
586 | } | |
587 | ||
4a6f9e19 | 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). */ | |
48e1416a | 604 | |
4a6f9e19 | 605 | static edge |
f1f41a6c | 606 | find_subloop_latch_edge_by_profile (vec<edge> latches) |
4a6f9e19 | 607 | { |
608 | unsigned i; | |
609 | edge e, me = NULL; | |
db9cef39 | 610 | profile_count mcount = profile_count::zero (), tcount = profile_count::zero (); |
4a6f9e19 | 611 | |
f1f41a6c | 612 | FOR_EACH_VEC_ELT (latches, i, e) |
4a6f9e19 | 613 | { |
ea5d3981 | 614 | if (e->count ()> mcount) |
4a6f9e19 | 615 | { |
616 | me = e; | |
ea5d3981 | 617 | mcount = e->count(); |
4a6f9e19 | 618 | } |
ea5d3981 | 619 | tcount += e->count(); |
4a6f9e19 | 620 | } |
621 | ||
205ce1aa | 622 | if (!tcount.initialized_p () || !(tcount.ipa () > HEAVY_EDGE_MIN_SAMPLES) |
db9cef39 | 623 | || (tcount - mcount).apply_scale (HEAVY_EDGE_RATIO, 1) > tcount) |
4a6f9e19 | 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 | |
f1f41a6c | 646 | find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, vec<edge> latches) |
4a6f9e19 | 647 | { |
f1f41a6c | 648 | edge e, latch = latches[0]; |
4a6f9e19 | 649 | unsigned i; |
1a91d914 | 650 | gphi *phi; |
651 | gphi_iterator psi; | |
75a70cf9 | 652 | tree lop; |
4a6f9e19 | 653 | basic_block bb; |
654 | ||
655 | /* Find the candidate for the latch edge. */ | |
f1f41a6c | 656 | for (i = 1; latches.iterate (i, &e); i++) |
4a6f9e19 | 657 | if (dominated_by_p (CDI_DOMINATORS, latch->src, e->src)) |
658 | latch = e; | |
659 | ||
660 | /* Verify that it dominates all the latch edges. */ | |
f1f41a6c | 661 | FOR_EACH_VEC_ELT (latches, i, e) |
4a6f9e19 | 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. */ | |
75a70cf9 | 667 | for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) |
4a6f9e19 | 668 | { |
1a91d914 | 669 | phi = psi.phi (); |
4a6f9e19 | 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; | |
75a70cf9 | 676 | bb = gimple_bb (SSA_NAME_DEF_STMT (lop)); |
4a6f9e19 | 677 | if (!bb || !flow_bb_inside_loop_p (loop, bb)) |
678 | continue; | |
679 | ||
f1f41a6c | 680 | FOR_EACH_VEC_ELT (latches, i, e) |
4a6f9e19 | 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 | |
698 | find_subloop_latch_edge (struct loop *loop) | |
699 | { | |
f1f41a6c | 700 | vec<edge> latches = get_loop_latch_edges (loop); |
4a6f9e19 | 701 | edge latch = NULL; |
702 | ||
f1f41a6c | 703 | if (latches.length () > 1) |
4a6f9e19 | 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 | ||
f1f41a6c | 715 | latches.release (); |
4a6f9e19 | 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 | ||
431205b7 | 722 | static hash_set<edge> *mfb_reis_set; |
4a6f9e19 | 723 | static bool |
724 | mfb_redirect_edges_in_set (edge e) | |
725 | { | |
431205b7 | 726 | return mfb_reis_set->contains (e); |
4a6f9e19 | 727 | } |
728 | ||
729 | /* Creates a subloop of LOOP with latch edge LATCH. */ | |
730 | ||
731 | static void | |
732 | form_subloop (struct loop *loop, edge latch) | |
733 | { | |
734 | edge_iterator ei; | |
735 | edge e, new_entry; | |
736 | struct loop *new_loop; | |
48e1416a | 737 | |
431205b7 | 738 | mfb_reis_set = new hash_set<edge>; |
4a6f9e19 | 739 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
740 | { | |
741 | if (e != latch) | |
431205b7 | 742 | mfb_reis_set->add (e); |
4a6f9e19 | 743 | } |
744 | new_entry = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
745 | NULL); | |
431205b7 | 746 | delete mfb_reis_set; |
4a6f9e19 | 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 | |
762 | merge_latch_edges (struct loop *loop) | |
763 | { | |
f1f41a6c | 764 | vec<edge> latches = get_loop_latch_edges (loop); |
4a6f9e19 | 765 | edge latch, e; |
766 | unsigned i; | |
767 | ||
f1f41a6c | 768 | gcc_assert (latches.length () > 0); |
4a6f9e19 | 769 | |
f1f41a6c | 770 | if (latches.length () == 1) |
771 | loop->latch = latches[0]->src; | |
4a6f9e19 | 772 | else |
773 | { | |
774 | if (dump_file) | |
775 | fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num); | |
776 | ||
431205b7 | 777 | mfb_reis_set = new hash_set<edge>; |
f1f41a6c | 778 | FOR_EACH_VEC_ELT (latches, i, e) |
431205b7 | 779 | mfb_reis_set->add (e); |
4a6f9e19 | 780 | latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, |
781 | NULL); | |
431205b7 | 782 | delete mfb_reis_set; |
4a6f9e19 | 783 | |
784 | loop->header = latch->dest; | |
785 | loop->latch = latch->src; | |
786 | } | |
787 | ||
f1f41a6c | 788 | latches.release (); |
4a6f9e19 | 789 | } |
790 | ||
791 | /* LOOP may have several latch edges. Transform it into (possibly several) | |
792 | loops with single latch edge. */ | |
793 | ||
794 | static void | |
795 | disambiguate_multiple_latches (struct loop *loop) | |
796 | { | |
797 | edge e; | |
798 | ||
85694bac | 799 | /* We eliminate the multiple latches by splitting the header to the forwarder |
4a6f9e19 | 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. */ | |
34154e27 | 818 | e = find_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), loop->header); |
4a6f9e19 | 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 | { | |
4a6f9e19 | 839 | struct loop *loop; |
840 | ||
f21d4d00 | 841 | FOR_EACH_LOOP (loop, 0) |
4a6f9e19 | 842 | { |
843 | if (!loop->latch) | |
844 | disambiguate_multiple_latches (loop); | |
845 | } | |
846 | } | |
847 | ||
d10cfa8d | 848 | /* Return nonzero if basic block BB belongs to LOOP. */ |
7fb12188 | 849 | bool |
7ecb5bb2 | 850 | flow_bb_inside_loop_p (const struct loop *loop, const_basic_block bb) |
7fb12188 | 851 | { |
852 | struct loop *source_loop; | |
853 | ||
34154e27 | 854 | if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
855 | || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
7fb12188 | 856 | return 0; |
857 | ||
858 | source_loop = bb->loop_father; | |
859 | return loop == source_loop || flow_loop_nested_p (loop, source_loop); | |
860 | } | |
861 | ||
4a6f9e19 | 862 | /* Enumeration predicate for get_loop_body_with_size. */ |
7fb12188 | 863 | static bool |
7ecb5bb2 | 864 | glb_enum_p (const_basic_block bb, const void *glb_loop) |
7fb12188 | 865 | { |
7ecb5bb2 | 866 | const struct loop *const loop = (const struct loop *) glb_loop; |
4a6f9e19 | 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 | |
879 | get_loop_body_with_size (const struct loop *loop, basic_block *body, | |
880 | unsigned max_size) | |
881 | { | |
882 | return dfs_enumerate_from (loop->header, 1, glb_enum_p, | |
7ecb5bb2 | 883 | body, max_size, loop); |
7fb12188 | 884 | } |
885 | ||
dbfc1664 | 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. */ | |
4a6f9e19 | 889 | |
7fb12188 | 890 | basic_block * |
4c9e08a4 | 891 | get_loop_body (const struct loop *loop) |
7fb12188 | 892 | { |
4a6f9e19 | 893 | basic_block *body, bb; |
862be747 | 894 | unsigned tv = 0; |
7fb12188 | 895 | |
cc636d56 | 896 | gcc_assert (loop->num_nodes); |
7fb12188 | 897 | |
ed7e2206 | 898 | body = XNEWVEC (basic_block, loop->num_nodes); |
7fb12188 | 899 | |
34154e27 | 900 | if (loop->latch == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
7fb12188 | 901 | { |
4a6f9e19 | 902 | /* There may be blocks unreachable from EXIT_BLOCK, hence we need to |
903 | special-case the fake loop that contains the whole function. */ | |
a28770e1 | 904 | gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks_for_fn (cfun)); |
4a6f9e19 | 905 | body[tv++] = loop->header; |
34154e27 | 906 | body[tv++] = EXIT_BLOCK_PTR_FOR_FN (cfun); |
fc00614f | 907 | FOR_EACH_BB_FN (bb, cfun) |
4a6f9e19 | 908 | body[tv++] = bb; |
7fb12188 | 909 | } |
4a6f9e19 | 910 | else |
911 | tv = get_loop_body_with_size (loop, body, loop->num_nodes); | |
7fb12188 | 912 | |
cc636d56 | 913 | gcc_assert (tv == loop->num_nodes); |
4a6f9e19 | 914 | return body; |
7fb12188 | 915 | } |
916 | ||
f9cce2dc | 917 | /* Fills dominance descendants inside LOOP of the basic block BB into |
918 | array TOVISIT from index *TV. */ | |
919 | ||
920 | static void | |
921 | fill_sons_in_loop (const struct loop *loop, basic_block bb, | |
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 * | |
951 | get_loop_body_in_dom_order (const struct loop *loop) | |
952 | { | |
953 | basic_block *tovisit; | |
954 | int tv; | |
955 | ||
cc636d56 | 956 | gcc_assert (loop->num_nodes); |
f9cce2dc | 957 | |
ed7e2206 | 958 | tovisit = XNEWVEC (basic_block, loop->num_nodes); |
f9cce2dc | 959 | |
34154e27 | 960 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
f9cce2dc | 961 | |
962 | tv = 0; | |
963 | fill_sons_in_loop (loop, loop->header, tovisit, &tv); | |
964 | ||
cc636d56 | 965 | gcc_assert (tv == (int) loop->num_nodes); |
f9cce2dc | 966 | |
967 | return tovisit; | |
968 | } | |
969 | ||
e1ab7874 | 970 | /* Gets body of a LOOP sorted via provided BB_COMPARATOR. */ |
971 | ||
972 | basic_block * | |
48e1416a | 973 | get_loop_body_in_custom_order (const struct loop *loop, |
e1ab7874 | 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 | ||
07c03fb0 | 983 | /* Get body of a LOOP in breadth first sort order. */ |
984 | ||
985 | basic_block * | |
986 | get_loop_body_in_bfs_order (const struct loop *loop) | |
987 | { | |
988 | basic_block *blocks; | |
989 | basic_block bb; | |
6674f8f4 | 990 | unsigned int i = 1; |
991 | unsigned int vc = 0; | |
07c03fb0 | 992 | |
cc636d56 | 993 | gcc_assert (loop->num_nodes); |
34154e27 | 994 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
07c03fb0 | 995 | |
ed7e2206 | 996 | blocks = XNEWVEC (basic_block, loop->num_nodes); |
035def86 | 997 | auto_bitmap visited; |
6674f8f4 | 998 | blocks[0] = loop->header; |
999 | bitmap_set_bit (visited, loop->header->index); | |
07c03fb0 | 1000 | while (i < loop->num_nodes) |
1001 | { | |
1002 | edge e; | |
cd665a06 | 1003 | edge_iterator ei; |
6674f8f4 | 1004 | gcc_assert (i > vc); |
1005 | bb = blocks[vc++]; | |
a0c938f0 | 1006 | |
cd665a06 | 1007 | FOR_EACH_EDGE (e, ei, bb->succs) |
a0c938f0 | 1008 | { |
1009 | if (flow_bb_inside_loop_p (loop, e->dest)) | |
1010 | { | |
6674f8f4 | 1011 | /* This bb is now visited. */ |
6ef9bbe0 | 1012 | if (bitmap_set_bit (visited, e->dest->index)) |
1013 | blocks[i++] = e->dest; | |
a0c938f0 | 1014 | } |
1015 | } | |
07c03fb0 | 1016 | } |
a0c938f0 | 1017 | |
07c03fb0 | 1018 | return blocks; |
1019 | } | |
1020 | ||
dce58e66 | 1021 | /* Hash function for struct loop_exit. */ |
1022 | ||
2ef51f0e | 1023 | hashval_t |
1024 | loop_exit_hasher::hash (loop_exit *exit) | |
dce58e66 | 1025 | { |
dce58e66 | 1026 | return htab_hash_pointer (exit->e); |
1027 | } | |
1028 | ||
1029 | /* Equality function for struct loop_exit. Compares with edge. */ | |
1030 | ||
2ef51f0e | 1031 | bool |
1032 | loop_exit_hasher::equal (loop_exit *exit, edge e) | |
dce58e66 | 1033 | { |
dce58e66 | 1034 | return exit->e == e; |
1035 | } | |
1036 | ||
1037 | /* Frees the list of loop exit descriptions EX. */ | |
1038 | ||
2ef51f0e | 1039 | void |
1040 | loop_exit_hasher::remove (loop_exit *exit) | |
dce58e66 | 1041 | { |
2ef51f0e | 1042 | loop_exit *next; |
dce58e66 | 1043 | for (; exit; exit = next) |
1044 | { | |
1045 | next = exit->next_e; | |
48e1416a | 1046 | |
dce58e66 | 1047 | exit->next->prev = exit->prev; |
1048 | exit->prev->next = exit->next; | |
1049 | ||
ccae4f9f | 1050 | ggc_free (exit); |
dce58e66 | 1051 | } |
1052 | } | |
1053 | ||
1054 | /* Returns the list of records for E as an exit of a loop. */ | |
1055 | ||
1056 | static struct loop_exit * | |
1057 | get_exit_descriptions (edge e) | |
1058 | { | |
2ef51f0e | 1059 | return current_loops->exits->find_with_hash (e, htab_hash_pointer (e)); |
dce58e66 | 1060 | } |
1061 | ||
1062 | /* Updates the lists of loop exits in that E appears. | |
1063 | If REMOVED is true, E is being removed, and we | |
1064 | just remove it from the lists of exits. | |
1065 | If NEW_EDGE is true and E is not a loop exit, we | |
1066 | do not try to remove it from loop exit lists. */ | |
1067 | ||
1068 | void | |
1069 | rescan_loop_exit (edge e, bool new_edge, bool removed) | |
1070 | { | |
dce58e66 | 1071 | struct loop_exit *exits = NULL, *exit; |
1072 | struct loop *aloop, *cloop; | |
1073 | ||
f24ec26f | 1074 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1075 | return; |
1076 | ||
1077 | if (!removed | |
1078 | && e->src->loop_father != NULL | |
1079 | && e->dest->loop_father != NULL | |
1080 | && !flow_bb_inside_loop_p (e->src->loop_father, e->dest)) | |
1081 | { | |
1082 | cloop = find_common_loop (e->src->loop_father, e->dest->loop_father); | |
1083 | for (aloop = e->src->loop_father; | |
1084 | aloop != cloop; | |
9e3536f4 | 1085 | aloop = loop_outer (aloop)) |
dce58e66 | 1086 | { |
25a27413 | 1087 | exit = ggc_alloc<loop_exit> (); |
dce58e66 | 1088 | exit->e = e; |
1089 | ||
ccae4f9f | 1090 | exit->next = aloop->exits->next; |
1091 | exit->prev = aloop->exits; | |
dce58e66 | 1092 | exit->next->prev = exit; |
1093 | exit->prev->next = exit; | |
1094 | ||
1095 | exit->next_e = exits; | |
1096 | exits = exit; | |
1097 | } | |
48e1416a | 1098 | } |
dce58e66 | 1099 | |
1100 | if (!exits && new_edge) | |
1101 | return; | |
1102 | ||
2ef51f0e | 1103 | loop_exit **slot |
1104 | = current_loops->exits->find_slot_with_hash (e, htab_hash_pointer (e), | |
1105 | exits ? INSERT : NO_INSERT); | |
dce58e66 | 1106 | if (!slot) |
1107 | return; | |
1108 | ||
1109 | if (exits) | |
1110 | { | |
1111 | if (*slot) | |
2ef51f0e | 1112 | loop_exit_hasher::remove (*slot); |
dce58e66 | 1113 | *slot = exits; |
1114 | } | |
1115 | else | |
2ef51f0e | 1116 | current_loops->exits->clear_slot (slot); |
dce58e66 | 1117 | } |
1118 | ||
1119 | /* For each loop, record list of exit edges, and start maintaining these | |
1120 | lists. */ | |
1121 | ||
1122 | void | |
1123 | record_loop_exits (void) | |
1124 | { | |
1125 | basic_block bb; | |
1126 | edge_iterator ei; | |
1127 | edge e; | |
1128 | ||
d500fef3 | 1129 | if (!current_loops) |
1130 | return; | |
1131 | ||
f24ec26f | 1132 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1133 | return; |
f24ec26f | 1134 | loops_state_set (LOOPS_HAVE_RECORDED_EXITS); |
dce58e66 | 1135 | |
1136 | gcc_assert (current_loops->exits == NULL); | |
2ef51f0e | 1137 | current_loops->exits |
1138 | = hash_table<loop_exit_hasher>::create_ggc (2 * number_of_loops (cfun)); | |
dce58e66 | 1139 | |
fc00614f | 1140 | FOR_EACH_BB_FN (bb, cfun) |
dce58e66 | 1141 | { |
1142 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1143 | { | |
1144 | rescan_loop_exit (e, true, false); | |
1145 | } | |
1146 | } | |
1147 | } | |
1148 | ||
1149 | /* Dumps information about the exit in *SLOT to FILE. | |
1150 | Callback for htab_traverse. */ | |
1151 | ||
2ef51f0e | 1152 | int |
1153 | dump_recorded_exit (loop_exit **slot, FILE *file) | |
dce58e66 | 1154 | { |
2ef51f0e | 1155 | struct loop_exit *exit = *slot; |
dce58e66 | 1156 | unsigned n = 0; |
1157 | edge e = exit->e; | |
1158 | ||
1159 | for (; exit != NULL; exit = exit->next_e) | |
1160 | n++; | |
1161 | ||
2ef51f0e | 1162 | fprintf (file, "Edge %d->%d exits %u loops\n", |
dce58e66 | 1163 | e->src->index, e->dest->index, n); |
1164 | ||
1165 | return 1; | |
1166 | } | |
1167 | ||
1168 | /* Dumps the recorded exits of loops to FILE. */ | |
1169 | ||
1170 | extern void dump_recorded_exits (FILE *); | |
1171 | void | |
1172 | dump_recorded_exits (FILE *file) | |
1173 | { | |
1174 | if (!current_loops->exits) | |
1175 | return; | |
2ef51f0e | 1176 | current_loops->exits->traverse<FILE *, dump_recorded_exit> (file); |
dce58e66 | 1177 | } |
1178 | ||
1179 | /* Releases lists of loop exits. */ | |
1180 | ||
1181 | void | |
d4f078b5 | 1182 | release_recorded_exits (function *fn) |
dce58e66 | 1183 | { |
d4f078b5 | 1184 | gcc_assert (loops_state_satisfies_p (fn, LOOPS_HAVE_RECORDED_EXITS)); |
1185 | loops_for_fn (fn)->exits->empty (); | |
1186 | loops_for_fn (fn)->exits = NULL; | |
1187 | loops_state_clear (fn, LOOPS_HAVE_RECORDED_EXITS); | |
dce58e66 | 1188 | } |
1189 | ||
749ea85f | 1190 | /* Returns the list of the exit edges of a LOOP. */ |
1191 | ||
f1f41a6c | 1192 | vec<edge> |
749ea85f | 1193 | get_loop_exit_edges (const struct loop *loop) |
a5414ff5 | 1194 | { |
1e094109 | 1195 | vec<edge> edges = vNULL; |
749ea85f | 1196 | edge e; |
1197 | unsigned i; | |
1198 | basic_block *body; | |
cd665a06 | 1199 | edge_iterator ei; |
dce58e66 | 1200 | struct loop_exit *exit; |
a5414ff5 | 1201 | |
34154e27 | 1202 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
a5414ff5 | 1203 | |
dce58e66 | 1204 | /* If we maintain the lists of exits, use them. Otherwise we must |
1205 | scan the body of the loop. */ | |
f24ec26f | 1206 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1207 | { |
ccae4f9f | 1208 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
f1f41a6c | 1209 | edges.safe_push (exit->e); |
dce58e66 | 1210 | } |
1211 | else | |
1212 | { | |
1213 | body = get_loop_body (loop); | |
1214 | for (i = 0; i < loop->num_nodes; i++) | |
1215 | FOR_EACH_EDGE (e, ei, body[i]->succs) | |
1216 | { | |
1217 | if (!flow_bb_inside_loop_p (loop, e->dest)) | |
f1f41a6c | 1218 | edges.safe_push (e); |
dce58e66 | 1219 | } |
1220 | free (body); | |
1221 | } | |
a5414ff5 | 1222 | |
1223 | return edges; | |
1224 | } | |
1225 | ||
f9cce2dc | 1226 | /* Counts the number of conditional branches inside LOOP. */ |
1227 | ||
1228 | unsigned | |
1229 | num_loop_branches (const struct loop *loop) | |
1230 | { | |
1231 | unsigned i, n; | |
1232 | basic_block * body; | |
1233 | ||
34154e27 | 1234 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
f9cce2dc | 1235 | |
1236 | body = get_loop_body (loop); | |
1237 | n = 0; | |
1238 | for (i = 0; i < loop->num_nodes; i++) | |
cd665a06 | 1239 | if (EDGE_COUNT (body[i]->succs) >= 2) |
f9cce2dc | 1240 | n++; |
1241 | free (body); | |
1242 | ||
1243 | return n; | |
1244 | } | |
1245 | ||
7fb12188 | 1246 | /* Adds basic block BB to LOOP. */ |
1247 | void | |
4c9e08a4 | 1248 | add_bb_to_loop (basic_block bb, struct loop *loop) |
1249 | { | |
9e3536f4 | 1250 | unsigned i; |
1251 | loop_p ploop; | |
dce58e66 | 1252 | edge_iterator ei; |
1253 | edge e; | |
1254 | ||
1255 | gcc_assert (bb->loop_father == NULL); | |
1256 | bb->loop_father = loop; | |
dce58e66 | 1257 | loop->num_nodes++; |
f1f41a6c | 1258 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9e3536f4 | 1259 | ploop->num_nodes++; |
dce58e66 | 1260 | |
1261 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1262 | { | |
1263 | rescan_loop_exit (e, true, false); | |
1264 | } | |
1265 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1266 | { | |
1267 | rescan_loop_exit (e, true, false); | |
1268 | } | |
88e6f696 | 1269 | } |
7fb12188 | 1270 | |
1271 | /* Remove basic block BB from loops. */ | |
1272 | void | |
4c9e08a4 | 1273 | remove_bb_from_loops (basic_block bb) |
1274 | { | |
f1f41a6c | 1275 | unsigned i; |
dce58e66 | 1276 | struct loop *loop = bb->loop_father; |
9e3536f4 | 1277 | loop_p ploop; |
dce58e66 | 1278 | edge_iterator ei; |
1279 | edge e; | |
1280 | ||
1281 | gcc_assert (loop != NULL); | |
1282 | loop->num_nodes--; | |
f1f41a6c | 1283 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9e3536f4 | 1284 | ploop->num_nodes--; |
dce58e66 | 1285 | bb->loop_father = NULL; |
dce58e66 | 1286 | |
1287 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1288 | { | |
1289 | rescan_loop_exit (e, false, true); | |
1290 | } | |
1291 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1292 | { | |
1293 | rescan_loop_exit (e, false, true); | |
1294 | } | |
b811afb0 | 1295 | } |
7fb12188 | 1296 | |
1297 | /* Finds nearest common ancestor in loop tree for given loops. */ | |
1298 | struct loop * | |
4c9e08a4 | 1299 | find_common_loop (struct loop *loop_s, struct loop *loop_d) |
7fb12188 | 1300 | { |
9e3536f4 | 1301 | unsigned sdepth, ddepth; |
1302 | ||
7fb12188 | 1303 | if (!loop_s) return loop_d; |
1304 | if (!loop_d) return loop_s; | |
4c9e08a4 | 1305 | |
9e3536f4 | 1306 | sdepth = loop_depth (loop_s); |
1307 | ddepth = loop_depth (loop_d); | |
1308 | ||
1309 | if (sdepth < ddepth) | |
f1f41a6c | 1310 | loop_d = (*loop_d->superloops)[sdepth]; |
9e3536f4 | 1311 | else if (sdepth > ddepth) |
f1f41a6c | 1312 | loop_s = (*loop_s->superloops)[ddepth]; |
7fb12188 | 1313 | |
1314 | while (loop_s != loop_d) | |
1315 | { | |
9e3536f4 | 1316 | loop_s = loop_outer (loop_s); |
1317 | loop_d = loop_outer (loop_d); | |
7fb12188 | 1318 | } |
1319 | return loop_s; | |
1320 | } | |
1321 | ||
17519ba0 | 1322 | /* Removes LOOP from structures and frees its data. */ |
1323 | ||
1324 | void | |
1325 | delete_loop (struct loop *loop) | |
1326 | { | |
1327 | /* Remove the loop from structure. */ | |
1328 | flow_loop_tree_node_remove (loop); | |
1329 | ||
1330 | /* Remove loop from loops array. */ | |
f1f41a6c | 1331 | (*current_loops->larray)[loop->num] = NULL; |
17519ba0 | 1332 | |
1333 | /* Free loop data. */ | |
1334 | flow_loop_free (loop); | |
1335 | } | |
1336 | ||
862be747 | 1337 | /* Cancels the LOOP; it must be innermost one. */ |
77cbebb3 | 1338 | |
1339 | static void | |
7194de72 | 1340 | cancel_loop (struct loop *loop) |
862be747 | 1341 | { |
1342 | basic_block *bbs; | |
1343 | unsigned i; | |
9e3536f4 | 1344 | struct loop *outer = loop_outer (loop); |
862be747 | 1345 | |
cc636d56 | 1346 | gcc_assert (!loop->inner); |
862be747 | 1347 | |
1348 | /* Move blocks up one level (they should be removed as soon as possible). */ | |
1349 | bbs = get_loop_body (loop); | |
1350 | for (i = 0; i < loop->num_nodes; i++) | |
9e3536f4 | 1351 | bbs[i]->loop_father = outer; |
862be747 | 1352 | |
bf4b25d7 | 1353 | free (bbs); |
17519ba0 | 1354 | delete_loop (loop); |
862be747 | 1355 | } |
1356 | ||
1357 | /* Cancels LOOP and all its subloops. */ | |
1358 | void | |
7194de72 | 1359 | cancel_loop_tree (struct loop *loop) |
862be747 | 1360 | { |
1361 | while (loop->inner) | |
7194de72 | 1362 | cancel_loop_tree (loop->inner); |
1363 | cancel_loop (loop); | |
862be747 | 1364 | } |
1365 | ||
62c34df8 | 1366 | /* Disable warnings about missing quoting in GCC diagnostics for |
1367 | the verification errors. Their format strings don't follow GCC | |
1368 | diagnostic conventions and the calls are ultimately followed by | |
1369 | a deliberate ICE triggered by a failed assertion. */ | |
1370 | #if __GNUC__ >= 10 | |
1371 | # pragma GCC diagnostic push | |
1372 | # pragma GCC diagnostic ignored "-Wformat-diag" | |
1373 | #endif | |
1374 | ||
7194de72 | 1375 | /* Checks that information about loops is correct |
d01481af | 1376 | -- sizes of loops are all right |
7fb12188 | 1377 | -- results of get_loop_body really belong to the loop |
1378 | -- loop header have just single entry edge and single latch edge | |
1379 | -- loop latches have only single successor that is header of their loop | |
862be747 | 1380 | -- irreducible loops are correctly marked |
4e976818 | 1381 | -- the cached loop depth and loop father of each bb is correct |
7fb12188 | 1382 | */ |
4b987fac | 1383 | DEBUG_FUNCTION void |
7194de72 | 1384 | verify_loop_structure (void) |
7fb12188 | 1385 | { |
862be747 | 1386 | unsigned *sizes, i, j; |
cd9916a9 | 1387 | basic_block bb, *bbs; |
7fb12188 | 1388 | struct loop *loop; |
1389 | int err = 0; | |
a5414ff5 | 1390 | edge e; |
41f75a99 | 1391 | unsigned num = number_of_loops (cfun); |
dce58e66 | 1392 | struct loop_exit *exit, *mexit; |
79f958cb | 1393 | bool dom_available = dom_info_available_p (CDI_DOMINATORS); |
7fb12188 | 1394 | |
f6568ea4 | 1395 | if (loops_state_satisfies_p (LOOPS_NEED_FIXUP)) |
1396 | { | |
1397 | error ("loop verification on loop tree that needs fixup"); | |
1398 | err = 1; | |
1399 | } | |
1400 | ||
79f958cb | 1401 | /* We need up-to-date dominators, compute or verify them. */ |
1402 | if (!dom_available) | |
1403 | calculate_dominance_info (CDI_DOMINATORS); | |
1404 | else | |
1405 | verify_dominators (CDI_DOMINATORS); | |
ef0e6535 | 1406 | |
1ebce849 | 1407 | /* Check the loop tree root. */ |
1408 | if (current_loops->tree_root->header != ENTRY_BLOCK_PTR_FOR_FN (cfun) | |
1409 | || current_loops->tree_root->latch != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
1410 | || (current_loops->tree_root->num_nodes | |
1411 | != (unsigned) n_basic_blocks_for_fn (cfun))) | |
1412 | { | |
1413 | error ("corrupt loop tree root"); | |
1414 | err = 1; | |
1415 | } | |
1416 | ||
14a0d8d7 | 1417 | /* Check the headers. */ |
fc00614f | 1418 | FOR_EACH_BB_FN (bb, cfun) |
cd9916a9 | 1419 | if (bb_loop_header_p (bb)) |
14a0d8d7 | 1420 | { |
cd9916a9 | 1421 | if (bb->loop_father->header == NULL) |
1422 | { | |
1423 | error ("loop with header %d marked for removal", bb->index); | |
1424 | err = 1; | |
1425 | } | |
1426 | else if (bb->loop_father->header != bb) | |
1427 | { | |
1428 | error ("loop with header %d not in loop tree", bb->index); | |
1429 | err = 1; | |
1430 | } | |
1431 | } | |
1432 | else if (bb->loop_father->header == bb) | |
1433 | { | |
1434 | error ("non-loop with header %d not marked for removal", bb->index); | |
14a0d8d7 | 1435 | err = 1; |
1436 | } | |
1437 | ||
cd9916a9 | 1438 | /* Check the recorded loop father and sizes of loops. */ |
3c6549f8 | 1439 | auto_sbitmap visited (last_basic_block_for_fn (cfun)); |
53c5d9d4 | 1440 | bitmap_clear (visited); |
a28770e1 | 1441 | bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); |
f21d4d00 | 1442 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) |
4e976818 | 1443 | { |
cd9916a9 | 1444 | unsigned n; |
4e976818 | 1445 | |
cd9916a9 | 1446 | if (loop->header == NULL) |
1447 | { | |
1448 | error ("removed loop %d in loop tree", loop->num); | |
1449 | err = 1; | |
1450 | continue; | |
1451 | } | |
1452 | ||
a28770e1 | 1453 | n = get_loop_body_with_size (loop, bbs, n_basic_blocks_for_fn (cfun)); |
cd9916a9 | 1454 | if (loop->num_nodes != n) |
1455 | { | |
1456 | error ("size of loop %d should be %d, not %d", | |
1457 | loop->num, n, loop->num_nodes); | |
1458 | err = 1; | |
1459 | } | |
1460 | ||
1461 | for (j = 0; j < n; j++) | |
4e976818 | 1462 | { |
1463 | bb = bbs[j]; | |
1464 | ||
ff829efa | 1465 | if (!flow_bb_inside_loop_p (loop, bb)) |
1466 | { | |
1467 | error ("bb %d does not belong to loop %d", | |
1468 | bb->index, loop->num); | |
1469 | err = 1; | |
1470 | } | |
1471 | ||
4e976818 | 1472 | /* Ignore this block if it is in an inner loop. */ |
08b7917c | 1473 | if (bitmap_bit_p (visited, bb->index)) |
4e976818 | 1474 | continue; |
08b7917c | 1475 | bitmap_set_bit (visited, bb->index); |
4e976818 | 1476 | |
1477 | if (bb->loop_father != loop) | |
1478 | { | |
1479 | error ("bb %d has father loop %d, should be loop %d", | |
1480 | bb->index, bb->loop_father->num, loop->num); | |
1481 | err = 1; | |
1482 | } | |
1483 | } | |
4e976818 | 1484 | } |
cd9916a9 | 1485 | free (bbs); |
7fb12188 | 1486 | |
1487 | /* Check headers and latches. */ | |
f21d4d00 | 1488 | FOR_EACH_LOOP (loop, 0) |
7fb12188 | 1489 | { |
17519ba0 | 1490 | i = loop->num; |
cd9916a9 | 1491 | if (loop->header == NULL) |
1492 | continue; | |
ff829efa | 1493 | if (!bb_loop_header_p (loop->header)) |
1494 | { | |
1495 | error ("loop %d%'s header is not a loop header", i); | |
1496 | err = 1; | |
1497 | } | |
f24ec26f | 1498 | if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
cd665a06 | 1499 | && EDGE_COUNT (loop->header->preds) != 2) |
7fb12188 | 1500 | { |
bf776685 | 1501 | error ("loop %d%'s header does not have exactly 2 entries", i); |
7fb12188 | 1502 | err = 1; |
1503 | } | |
b375c775 | 1504 | if (loop->latch) |
1505 | { | |
1506 | if (!find_edge (loop->latch, loop->header)) | |
1507 | { | |
1508 | error ("loop %d%'s latch does not have an edge to its header", i); | |
1509 | err = 1; | |
1510 | } | |
1511 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, loop->header)) | |
1512 | { | |
1513 | error ("loop %d%'s latch is not dominated by its header", i); | |
1514 | err = 1; | |
1515 | } | |
1516 | } | |
f24ec26f | 1517 | if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
7fb12188 | 1518 | { |
ea091dfd | 1519 | if (!single_succ_p (loop->latch)) |
7fb12188 | 1520 | { |
bf776685 | 1521 | error ("loop %d%'s latch does not have exactly 1 successor", i); |
7fb12188 | 1522 | err = 1; |
1523 | } | |
ea091dfd | 1524 | if (single_succ (loop->latch) != loop->header) |
7fb12188 | 1525 | { |
bf776685 | 1526 | error ("loop %d%'s latch does not have header as successor", i); |
7fb12188 | 1527 | err = 1; |
1528 | } | |
1529 | if (loop->latch->loop_father != loop) | |
1530 | { | |
bf776685 | 1531 | error ("loop %d%'s latch does not belong directly to it", i); |
7fb12188 | 1532 | err = 1; |
1533 | } | |
1534 | } | |
1535 | if (loop->header->loop_father != loop) | |
1536 | { | |
bf776685 | 1537 | error ("loop %d%'s header does not belong directly to it", i); |
7fb12188 | 1538 | err = 1; |
1539 | } | |
f24ec26f | 1540 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) |
a5414ff5 | 1541 | && (loop_latch_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)) |
1542 | { | |
bf776685 | 1543 | error ("loop %d%'s latch is marked as part of irreducible region", i); |
a5414ff5 | 1544 | err = 1; |
1545 | } | |
7fb12188 | 1546 | } |
1547 | ||
862be747 | 1548 | /* Check irreducible loops. */ |
f24ec26f | 1549 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
862be747 | 1550 | { |
2515797e | 1551 | auto_edge_flag saved_irr_mask (cfun); |
862be747 | 1552 | /* Record old info. */ |
3c6549f8 | 1553 | auto_sbitmap irreds (last_basic_block_for_fn (cfun)); |
fc00614f | 1554 | FOR_EACH_BB_FN (bb, cfun) |
a5414ff5 | 1555 | { |
cd665a06 | 1556 | edge_iterator ei; |
a5414ff5 | 1557 | if (bb->flags & BB_IRREDUCIBLE_LOOP) |
08b7917c | 1558 | bitmap_set_bit (irreds, bb->index); |
a5414ff5 | 1559 | else |
08b7917c | 1560 | bitmap_clear_bit (irreds, bb->index); |
cd665a06 | 1561 | FOR_EACH_EDGE (e, ei, bb->succs) |
a5414ff5 | 1562 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) |
2515797e | 1563 | e->flags |= saved_irr_mask; |
a5414ff5 | 1564 | } |
862be747 | 1565 | |
1566 | /* Recount it. */ | |
7194de72 | 1567 | mark_irreducible_loops (); |
862be747 | 1568 | |
1569 | /* Compare. */ | |
fc00614f | 1570 | FOR_EACH_BB_FN (bb, cfun) |
862be747 | 1571 | { |
cd665a06 | 1572 | edge_iterator ei; |
1573 | ||
862be747 | 1574 | if ((bb->flags & BB_IRREDUCIBLE_LOOP) |
08b7917c | 1575 | && !bitmap_bit_p (irreds, bb->index)) |
862be747 | 1576 | { |
0a81f5a0 | 1577 | error ("basic block %d should be marked irreducible", bb->index); |
862be747 | 1578 | err = 1; |
1579 | } | |
1580 | else if (!(bb->flags & BB_IRREDUCIBLE_LOOP) | |
08b7917c | 1581 | && bitmap_bit_p (irreds, bb->index)) |
862be747 | 1582 | { |
0a81f5a0 | 1583 | error ("basic block %d should not be marked irreducible", bb->index); |
862be747 | 1584 | err = 1; |
1585 | } | |
cd665a06 | 1586 | FOR_EACH_EDGE (e, ei, bb->succs) |
a5414ff5 | 1587 | { |
1588 | if ((e->flags & EDGE_IRREDUCIBLE_LOOP) | |
2515797e | 1589 | && !(e->flags & saved_irr_mask)) |
a5414ff5 | 1590 | { |
0a81f5a0 | 1591 | error ("edge from %d to %d should be marked irreducible", |
a5414ff5 | 1592 | e->src->index, e->dest->index); |
1593 | err = 1; | |
1594 | } | |
1595 | else if (!(e->flags & EDGE_IRREDUCIBLE_LOOP) | |
2515797e | 1596 | && (e->flags & saved_irr_mask)) |
a5414ff5 | 1597 | { |
0a81f5a0 | 1598 | error ("edge from %d to %d should not be marked irreducible", |
a5414ff5 | 1599 | e->src->index, e->dest->index); |
1600 | err = 1; | |
1601 | } | |
2515797e | 1602 | e->flags &= ~saved_irr_mask; |
a5414ff5 | 1603 | } |
862be747 | 1604 | } |
862be747 | 1605 | } |
1606 | ||
dce58e66 | 1607 | /* Check the recorded loop exits. */ |
f21d4d00 | 1608 | FOR_EACH_LOOP (loop, 0) |
bb445479 | 1609 | { |
ccae4f9f | 1610 | if (!loop->exits || loop->exits->e != NULL) |
dce58e66 | 1611 | { |
1612 | error ("corrupted head of the exits list of loop %d", | |
1613 | loop->num); | |
1614 | err = 1; | |
1615 | } | |
1616 | else | |
1617 | { | |
1618 | /* Check that the list forms a cycle, and all elements except | |
1619 | for the head are nonnull. */ | |
ccae4f9f | 1620 | for (mexit = loop->exits, exit = mexit->next, i = 0; |
dce58e66 | 1621 | exit->e && exit != mexit; |
1622 | exit = exit->next) | |
1623 | { | |
1624 | if (i++ & 1) | |
1625 | mexit = mexit->next; | |
1626 | } | |
1627 | ||
ccae4f9f | 1628 | if (exit != loop->exits) |
dce58e66 | 1629 | { |
1630 | error ("corrupted exits list of loop %d", loop->num); | |
1631 | err = 1; | |
1632 | } | |
1633 | } | |
1634 | ||
f24ec26f | 1635 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1636 | { |
ccae4f9f | 1637 | if (loop->exits->next != loop->exits) |
dce58e66 | 1638 | { |
1639 | error ("nonempty exits list of loop %d, but exits are not recorded", | |
1640 | loop->num); | |
1641 | err = 1; | |
1642 | } | |
1643 | } | |
1644 | } | |
1645 | ||
f24ec26f | 1646 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1647 | { |
1648 | unsigned n_exits = 0, eloops; | |
1649 | ||
cd9916a9 | 1650 | sizes = XCNEWVEC (unsigned, num); |
17519ba0 | 1651 | memset (sizes, 0, sizeof (unsigned) * num); |
fc00614f | 1652 | FOR_EACH_BB_FN (bb, cfun) |
bb445479 | 1653 | { |
cd665a06 | 1654 | edge_iterator ei; |
7194de72 | 1655 | if (bb->loop_father == current_loops->tree_root) |
bb445479 | 1656 | continue; |
cd665a06 | 1657 | FOR_EACH_EDGE (e, ei, bb->succs) |
bb445479 | 1658 | { |
bb445479 | 1659 | if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) |
1660 | continue; | |
1661 | ||
dce58e66 | 1662 | n_exits++; |
1663 | exit = get_exit_descriptions (e); | |
1664 | if (!exit) | |
1665 | { | |
bf776685 | 1666 | error ("exit %d->%d not recorded", |
dce58e66 | 1667 | e->src->index, e->dest->index); |
1668 | err = 1; | |
1669 | } | |
1670 | eloops = 0; | |
1671 | for (; exit; exit = exit->next_e) | |
1672 | eloops++; | |
1673 | ||
bb445479 | 1674 | for (loop = bb->loop_father; |
1032e48d | 1675 | loop != e->dest->loop_father |
1676 | /* When a loop exit is also an entry edge which | |
1677 | can happen when avoiding CFG manipulations | |
1678 | then the last loop exited is the outer loop | |
1679 | of the loop entered. */ | |
1680 | && loop != loop_outer (e->dest->loop_father); | |
9e3536f4 | 1681 | loop = loop_outer (loop)) |
bb445479 | 1682 | { |
dce58e66 | 1683 | eloops--; |
bb445479 | 1684 | sizes[loop->num]++; |
dce58e66 | 1685 | } |
1686 | ||
1687 | if (eloops != 0) | |
1688 | { | |
62c34df8 | 1689 | error ("wrong list of exited loops for edge %d->%d", |
dce58e66 | 1690 | e->src->index, e->dest->index); |
1691 | err = 1; | |
bb445479 | 1692 | } |
1693 | } | |
1694 | } | |
1695 | ||
2ef51f0e | 1696 | if (n_exits != current_loops->exits->elements ()) |
bb445479 | 1697 | { |
bf776685 | 1698 | error ("too many loop exits recorded"); |
dce58e66 | 1699 | err = 1; |
1700 | } | |
bb445479 | 1701 | |
f21d4d00 | 1702 | FOR_EACH_LOOP (loop, 0) |
dce58e66 | 1703 | { |
1704 | eloops = 0; | |
ccae4f9f | 1705 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
dce58e66 | 1706 | eloops++; |
1707 | if (eloops != sizes[loop->num]) | |
bb445479 | 1708 | { |
dce58e66 | 1709 | error ("%d exits recorded for loop %d (having %d exits)", |
1710 | eloops, loop->num, sizes[loop->num]); | |
bb445479 | 1711 | err = 1; |
1712 | } | |
1713 | } | |
cd9916a9 | 1714 | |
1715 | free (sizes); | |
bb445479 | 1716 | } |
1717 | ||
cc636d56 | 1718 | gcc_assert (!err); |
bb445479 | 1719 | |
79f958cb | 1720 | if (!dom_available) |
1721 | free_dominance_info (CDI_DOMINATORS); | |
7fb12188 | 1722 | } |
1723 | ||
62c34df8 | 1724 | #if __GNUC__ >= 10 |
1725 | # pragma GCC diagnostic pop | |
1726 | #endif | |
1727 | ||
7fb12188 | 1728 | /* Returns latch edge of LOOP. */ |
1729 | edge | |
4c9e08a4 | 1730 | loop_latch_edge (const struct loop *loop) |
7fb12188 | 1731 | { |
c6356c17 | 1732 | return find_edge (loop->latch, loop->header); |
65f34de5 | 1733 | } |
7fb12188 | 1734 | |
1735 | /* Returns preheader edge of LOOP. */ | |
1736 | edge | |
4c9e08a4 | 1737 | loop_preheader_edge (const struct loop *loop) |
7fb12188 | 1738 | { |
1739 | edge e; | |
cd665a06 | 1740 | edge_iterator ei; |
7fb12188 | 1741 | |
453841f9 | 1742 | gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
1743 | && ! loops_state_satisfies_p (LOOPS_MAY_HAVE_MULTIPLE_LATCHES)); | |
d8a0d6b8 | 1744 | |
cd665a06 | 1745 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
1746 | if (e->src != loop->latch) | |
1747 | break; | |
7fb12188 | 1748 | |
453841f9 | 1749 | if (! e) |
1750 | { | |
1751 | gcc_assert (! loop_outer (loop)); | |
1752 | return single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
1753 | } | |
1754 | ||
7fb12188 | 1755 | return e; |
1756 | } | |
ffc6b5d5 | 1757 | |
1758 | /* Returns true if E is an exit of LOOP. */ | |
1759 | ||
1760 | bool | |
7ecb5bb2 | 1761 | loop_exit_edge_p (const struct loop *loop, const_edge e) |
ffc6b5d5 | 1762 | { |
1763 | return (flow_bb_inside_loop_p (loop, e->src) | |
1764 | && !flow_bb_inside_loop_p (loop, e->dest)); | |
1765 | } | |
d9e7e1a2 | 1766 | |
1767 | /* Returns the single exit edge of LOOP, or NULL if LOOP has either no exit | |
dce58e66 | 1768 | or more than one exit. If loops do not have the exits recorded, NULL |
1769 | is returned always. */ | |
d9e7e1a2 | 1770 | |
1771 | edge | |
1772 | single_exit (const struct loop *loop) | |
1773 | { | |
ccae4f9f | 1774 | struct loop_exit *exit = loop->exits->next; |
d9e7e1a2 | 1775 | |
f24ec26f | 1776 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1777 | return NULL; |
d9e7e1a2 | 1778 | |
ccae4f9f | 1779 | if (exit->e && exit->next == loop->exits) |
dce58e66 | 1780 | return exit->e; |
1781 | else | |
1782 | return NULL; | |
d9e7e1a2 | 1783 | } |
255b6be7 | 1784 | |
259c0e44 | 1785 | /* Returns true when BB has an incoming edge exiting LOOP. */ |
255b6be7 | 1786 | |
1787 | bool | |
259c0e44 | 1788 | loop_exits_to_bb_p (struct loop *loop, basic_block bb) |
255b6be7 | 1789 | { |
1790 | edge e; | |
1791 | edge_iterator ei; | |
1792 | ||
1793 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1794 | if (loop_exit_edge_p (loop, e)) | |
1795 | return true; | |
1796 | ||
1797 | return false; | |
1798 | } | |
259c0e44 | 1799 | |
1800 | /* Returns true when BB has an outgoing edge exiting LOOP. */ | |
1801 | ||
1802 | bool | |
1803 | loop_exits_from_bb_p (struct loop *loop, basic_block bb) | |
1804 | { | |
1805 | edge e; | |
1806 | edge_iterator ei; | |
1807 | ||
1808 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1809 | if (loop_exit_edge_p (loop, e)) | |
1810 | return true; | |
1811 | ||
1812 | return false; | |
1813 | } | |
f55775aa | 1814 | |
1815 | /* Return location corresponding to the loop control condition if possible. */ | |
1816 | ||
c309657f | 1817 | dump_user_location_t |
f55775aa | 1818 | get_loop_location (struct loop *loop) |
1819 | { | |
cb534875 | 1820 | rtx_insn *insn = NULL; |
f55775aa | 1821 | struct niter_desc *desc = NULL; |
1822 | edge exit; | |
1823 | ||
1824 | /* For a for or while loop, we would like to return the location | |
1825 | of the for or while statement, if possible. To do this, look | |
1826 | for the branch guarding the loop back-edge. */ | |
1827 | ||
1828 | /* If this is a simple loop with an in_edge, then the loop control | |
1829 | branch is typically at the end of its source. */ | |
1830 | desc = get_simple_loop_desc (loop); | |
1831 | if (desc->in_edge) | |
1832 | { | |
1833 | FOR_BB_INSNS_REVERSE (desc->in_edge->src, insn) | |
1834 | { | |
1835 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
c309657f | 1836 | return insn; |
f55775aa | 1837 | } |
1838 | } | |
1839 | /* If loop has a single exit, then the loop control branch | |
1840 | must be at the end of its source. */ | |
1841 | if ((exit = single_exit (loop))) | |
1842 | { | |
1843 | FOR_BB_INSNS_REVERSE (exit->src, insn) | |
1844 | { | |
1845 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
c309657f | 1846 | return insn; |
f55775aa | 1847 | } |
1848 | } | |
1849 | /* Next check the latch, to see if it is non-empty. */ | |
1850 | FOR_BB_INSNS_REVERSE (loop->latch, insn) | |
1851 | { | |
1852 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
c309657f | 1853 | return insn; |
f55775aa | 1854 | } |
1855 | /* Finally, if none of the above identifies the loop control branch, | |
1856 | return the first location in the loop header. */ | |
1857 | FOR_BB_INSNS (loop->header, insn) | |
1858 | { | |
1859 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
c309657f | 1860 | return insn; |
f55775aa | 1861 | } |
1862 | /* If all else fails, simply return the current function location. */ | |
c309657f | 1863 | return dump_user_location_t::from_function_decl (current_function_decl); |
f55775aa | 1864 | } |
1865 | ||
f86b328b | 1866 | /* Records that every statement in LOOP is executed I_BOUND times. |
1867 | REALISTIC is true if I_BOUND is expected to be close to the real number | |
1868 | of iterations. UPPER is true if we are sure the loop iterates at most | |
1869 | I_BOUND times. */ | |
1870 | ||
1871 | void | |
5de9d3ed | 1872 | record_niter_bound (struct loop *loop, const widest_int &i_bound, |
6b409616 | 1873 | bool realistic, bool upper) |
f86b328b | 1874 | { |
1875 | /* Update the bounds only when there is no previous estimation, or when the | |
1876 | current estimation is smaller. */ | |
1877 | if (upper | |
1878 | && (!loop->any_upper_bound | |
6b409616 | 1879 | || wi::ltu_p (i_bound, loop->nb_iterations_upper_bound))) |
f86b328b | 1880 | { |
1881 | loop->any_upper_bound = true; | |
1882 | loop->nb_iterations_upper_bound = i_bound; | |
8e3ffe30 | 1883 | if (!loop->any_likely_upper_bound) |
1884 | { | |
1885 | loop->any_likely_upper_bound = true; | |
1886 | loop->nb_iterations_likely_upper_bound = i_bound; | |
1887 | } | |
f86b328b | 1888 | } |
1889 | if (realistic | |
1890 | && (!loop->any_estimate | |
6b409616 | 1891 | || wi::ltu_p (i_bound, loop->nb_iterations_estimate))) |
f86b328b | 1892 | { |
1893 | loop->any_estimate = true; | |
1894 | loop->nb_iterations_estimate = i_bound; | |
1895 | } | |
8e3ffe30 | 1896 | if (!realistic |
1897 | && (!loop->any_likely_upper_bound | |
1898 | || wi::ltu_p (i_bound, loop->nb_iterations_likely_upper_bound))) | |
1899 | { | |
1900 | loop->any_likely_upper_bound = true; | |
1901 | loop->nb_iterations_likely_upper_bound = i_bound; | |
1902 | } | |
f86b328b | 1903 | |
1904 | /* If an upper bound is smaller than the realistic estimate of the | |
1905 | number of iterations, use the upper bound instead. */ | |
1906 | if (loop->any_upper_bound | |
1907 | && loop->any_estimate | |
6b409616 | 1908 | && wi::ltu_p (loop->nb_iterations_upper_bound, |
1909 | loop->nb_iterations_estimate)) | |
f86b328b | 1910 | loop->nb_iterations_estimate = loop->nb_iterations_upper_bound; |
8e3ffe30 | 1911 | if (loop->any_upper_bound |
1912 | && loop->any_likely_upper_bound | |
1913 | && wi::ltu_p (loop->nb_iterations_upper_bound, | |
1914 | loop->nb_iterations_likely_upper_bound)) | |
1915 | loop->nb_iterations_likely_upper_bound = loop->nb_iterations_upper_bound; | |
f86b328b | 1916 | } |
1917 | ||
4e948f5a | 1918 | /* Similar to get_estimated_loop_iterations, but returns the estimate only |
f86b328b | 1919 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate |
1920 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
1921 | ||
1922 | HOST_WIDE_INT | |
4e948f5a | 1923 | get_estimated_loop_iterations_int (struct loop *loop) |
f86b328b | 1924 | { |
5de9d3ed | 1925 | widest_int nit; |
f86b328b | 1926 | HOST_WIDE_INT hwi_nit; |
1927 | ||
1928 | if (!get_estimated_loop_iterations (loop, &nit)) | |
1929 | return -1; | |
1930 | ||
6b409616 | 1931 | if (!wi::fits_shwi_p (nit)) |
f86b328b | 1932 | return -1; |
1933 | hwi_nit = nit.to_shwi (); | |
1934 | ||
1935 | return hwi_nit < 0 ? -1 : hwi_nit; | |
1936 | } | |
1937 | ||
1938 | /* Returns an upper bound on the number of executions of statements | |
1939 | in the LOOP. For statements before the loop exit, this exceeds | |
1940 | the number of execution of the latch by one. */ | |
1941 | ||
1942 | HOST_WIDE_INT | |
1943 | max_stmt_executions_int (struct loop *loop) | |
1944 | { | |
4e948f5a | 1945 | HOST_WIDE_INT nit = get_max_loop_iterations_int (loop); |
f86b328b | 1946 | HOST_WIDE_INT snit; |
1947 | ||
1948 | if (nit == -1) | |
1949 | return -1; | |
1950 | ||
1951 | snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
1952 | ||
1953 | /* If the computation overflows, return -1. */ | |
1954 | return snit < 0 ? -1 : snit; | |
1955 | } | |
1956 | ||
8e3ffe30 | 1957 | /* Returns an likely upper bound on the number of executions of statements |
1958 | in the LOOP. For statements before the loop exit, this exceeds | |
1959 | the number of execution of the latch by one. */ | |
1960 | ||
1961 | HOST_WIDE_INT | |
1962 | likely_max_stmt_executions_int (struct loop *loop) | |
1963 | { | |
1964 | HOST_WIDE_INT nit = get_likely_max_loop_iterations_int (loop); | |
1965 | HOST_WIDE_INT snit; | |
1966 | ||
1967 | if (nit == -1) | |
1968 | return -1; | |
1969 | ||
1970 | snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
1971 | ||
1972 | /* If the computation overflows, return -1. */ | |
1973 | return snit < 0 ? -1 : snit; | |
1974 | } | |
1975 | ||
f86b328b | 1976 | /* Sets NIT to the estimated number of executions of the latch of the |
1977 | LOOP. If we have no reliable estimate, the function returns false, otherwise | |
1978 | returns true. */ | |
1979 | ||
1980 | bool | |
5de9d3ed | 1981 | get_estimated_loop_iterations (struct loop *loop, widest_int *nit) |
f86b328b | 1982 | { |
1983 | /* Even if the bound is not recorded, possibly we can derrive one from | |
1984 | profile. */ | |
1985 | if (!loop->any_estimate) | |
1986 | { | |
db9cef39 | 1987 | if (loop->header->count.reliable_p ()) |
f86b328b | 1988 | { |
6b409616 | 1989 | *nit = gcov_type_to_wide_int |
f86b328b | 1990 | (expected_loop_iterations_unbounded (loop) + 1); |
1991 | return true; | |
1992 | } | |
1993 | return false; | |
1994 | } | |
1995 | ||
1996 | *nit = loop->nb_iterations_estimate; | |
1997 | return true; | |
1998 | } | |
1999 | ||
2000 | /* Sets NIT to an upper bound for the maximum number of executions of the | |
2001 | latch of the LOOP. If we have no reliable estimate, the function returns | |
2002 | false, otherwise returns true. */ | |
2003 | ||
2004 | bool | |
fbf561f4 | 2005 | get_max_loop_iterations (const struct loop *loop, widest_int *nit) |
f86b328b | 2006 | { |
2007 | if (!loop->any_upper_bound) | |
2008 | return false; | |
2009 | ||
2010 | *nit = loop->nb_iterations_upper_bound; | |
2011 | return true; | |
2012 | } | |
4e948f5a | 2013 | |
2014 | /* Similar to get_max_loop_iterations, but returns the estimate only | |
2015 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
2016 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
2017 | ||
2018 | HOST_WIDE_INT | |
fbf561f4 | 2019 | get_max_loop_iterations_int (const struct loop *loop) |
4e948f5a | 2020 | { |
5de9d3ed | 2021 | widest_int nit; |
4e948f5a | 2022 | HOST_WIDE_INT hwi_nit; |
2023 | ||
2024 | if (!get_max_loop_iterations (loop, &nit)) | |
2025 | return -1; | |
2026 | ||
6b409616 | 2027 | if (!wi::fits_shwi_p (nit)) |
4e948f5a | 2028 | return -1; |
2029 | hwi_nit = nit.to_shwi (); | |
2030 | ||
2031 | return hwi_nit < 0 ? -1 : hwi_nit; | |
2032 | } | |
2033 | ||
8e3ffe30 | 2034 | /* Sets NIT to an upper bound for the maximum number of executions of the |
2035 | latch of the LOOP. If we have no reliable estimate, the function returns | |
2036 | false, otherwise returns true. */ | |
2037 | ||
2038 | bool | |
2039 | get_likely_max_loop_iterations (struct loop *loop, widest_int *nit) | |
2040 | { | |
2041 | if (!loop->any_likely_upper_bound) | |
2042 | return false; | |
2043 | ||
2044 | *nit = loop->nb_iterations_likely_upper_bound; | |
2045 | return true; | |
2046 | } | |
2047 | ||
2048 | /* Similar to get_max_loop_iterations, but returns the estimate only | |
2049 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
2050 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
2051 | ||
2052 | HOST_WIDE_INT | |
2053 | get_likely_max_loop_iterations_int (struct loop *loop) | |
2054 | { | |
2055 | widest_int nit; | |
2056 | HOST_WIDE_INT hwi_nit; | |
2057 | ||
2058 | if (!get_likely_max_loop_iterations (loop, &nit)) | |
2059 | return -1; | |
2060 | ||
2061 | if (!wi::fits_shwi_p (nit)) | |
2062 | return -1; | |
2063 | hwi_nit = nit.to_shwi (); | |
2064 | ||
2065 | return hwi_nit < 0 ? -1 : hwi_nit; | |
2066 | } | |
2067 | ||
424a4a92 | 2068 | /* Returns the loop depth of the loop BB belongs to. */ |
4e948f5a | 2069 | |
424a4a92 | 2070 | int |
2071 | bb_loop_depth (const_basic_block bb) | |
2072 | { | |
2073 | return bb->loop_father ? loop_depth (bb->loop_father) : 0; | |
2074 | } | |
d25159cc | 2075 | |
2076 | /* Marks LOOP for removal and sets LOOPS_NEED_FIXUP. */ | |
2077 | ||
2078 | void | |
2079 | mark_loop_for_removal (loop_p loop) | |
2080 | { | |
4b42315a | 2081 | if (loop->header == NULL) |
2082 | return; | |
6437689e | 2083 | loop->former_header = loop->header; |
d25159cc | 2084 | loop->header = NULL; |
2085 | loop->latch = NULL; | |
2086 | loops_state_set (LOOPS_NEED_FIXUP); | |
2087 | } |