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65f34de5 | 1 | /* Natural loop discovery code for GNU compiler. |
3aea1f79 | 2 | Copyright (C) 2000-2014 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" |
23 | #include "tm.h" | |
65f34de5 | 24 | #include "rtl.h" |
a3020f2f | 25 | #include "hashtab.h" |
26 | #include "hash-set.h" | |
27 | #include "vec.h" | |
28 | #include "machmode.h" | |
29 | #include "hard-reg-set.h" | |
30 | #include "input.h" | |
b811afb0 | 31 | #include "function.h" |
94ea8568 | 32 | #include "predict.h" |
33 | #include "dominance.h" | |
34 | #include "cfg.h" | |
35 | #include "cfganal.h" | |
65f34de5 | 36 | #include "basic-block.h" |
862be747 | 37 | #include "cfgloop.h" |
0b205f4c | 38 | #include "diagnostic-core.h" |
862be747 | 39 | #include "flags.h" |
4ee9c684 | 40 | #include "tree.h" |
bc61cadb | 41 | #include "tree-ssa-alias.h" |
42 | #include "internal-fn.h" | |
43 | #include "gimple-expr.h" | |
44 | #include "is-a.h" | |
073c1fd5 | 45 | #include "gimple.h" |
dcf1a1ec | 46 | #include "gimple-iterator.h" |
073c1fd5 | 47 | #include "gimple-ssa.h" |
b9ed1410 | 48 | #include "dumpfile.h" |
5f5d4cd1 | 49 | |
7194de72 | 50 | static void flow_loops_cfg_dump (FILE *); |
65f34de5 | 51 | \f |
52 | /* Dump loop related CFG information. */ | |
53 | ||
54 | static void | |
7194de72 | 55 | flow_loops_cfg_dump (FILE *file) |
65f34de5 | 56 | { |
4c26117a | 57 | basic_block bb; |
65f34de5 | 58 | |
7194de72 | 59 | if (!file) |
65f34de5 | 60 | return; |
61 | ||
fc00614f | 62 | FOR_EACH_BB_FN (bb, cfun) |
65f34de5 | 63 | { |
64 | edge succ; | |
cd665a06 | 65 | edge_iterator ei; |
65f34de5 | 66 | |
4c26117a | 67 | fprintf (file, ";; %d succs { ", bb->index); |
cd665a06 | 68 | FOR_EACH_EDGE (succ, ei, bb->succs) |
b3d6de89 | 69 | fprintf (file, "%d ", succ->dest->index); |
7fb12188 | 70 | fprintf (file, "}\n"); |
65f34de5 | 71 | } |
65f34de5 | 72 | } |
73 | ||
d10cfa8d | 74 | /* Return nonzero if the nodes of LOOP are a subset of OUTER. */ |
65f34de5 | 75 | |
7fb12188 | 76 | bool |
4c9e08a4 | 77 | flow_loop_nested_p (const struct loop *outer, const struct loop *loop) |
65f34de5 | 78 | { |
9e3536f4 | 79 | unsigned odepth = loop_depth (outer); |
80 | ||
81 | return (loop_depth (loop) > odepth | |
f1f41a6c | 82 | && (*loop->superloops)[odepth] == outer); |
65f34de5 | 83 | } |
84 | ||
b4d679c5 | 85 | /* Returns the loop such that LOOP is nested DEPTH (indexed from zero) |
86 | loops within LOOP. */ | |
7d23383d | 87 | |
88 | struct loop * | |
89 | superloop_at_depth (struct loop *loop, unsigned depth) | |
90 | { | |
9e3536f4 | 91 | unsigned ldepth = loop_depth (loop); |
92 | ||
93 | gcc_assert (depth <= ldepth); | |
7d23383d | 94 | |
9e3536f4 | 95 | if (depth == ldepth) |
7d23383d | 96 | return loop; |
97 | ||
f1f41a6c | 98 | return (*loop->superloops)[depth]; |
7d23383d | 99 | } |
100 | ||
4a6f9e19 | 101 | /* Returns the list of the latch edges of LOOP. */ |
102 | ||
f1f41a6c | 103 | static vec<edge> |
4a6f9e19 | 104 | get_loop_latch_edges (const struct loop *loop) |
105 | { | |
106 | edge_iterator ei; | |
107 | edge e; | |
1e094109 | 108 | vec<edge> ret = vNULL; |
4a6f9e19 | 109 | |
110 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
111 | { | |
112 | if (dominated_by_p (CDI_DOMINATORS, e->src, loop->header)) | |
f1f41a6c | 113 | ret.safe_push (e); |
4a6f9e19 | 114 | } |
115 | ||
116 | return ret; | |
117 | } | |
118 | ||
65f34de5 | 119 | /* Dump the loop information specified by LOOP to the stream FILE |
120 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
121 | ||
122 | void | |
4c9e08a4 | 123 | flow_loop_dump (const struct loop *loop, FILE *file, |
124 | void (*loop_dump_aux) (const struct loop *, FILE *, int), | |
125 | int verbose) | |
65f34de5 | 126 | { |
7fb12188 | 127 | basic_block *bbs; |
862be747 | 128 | unsigned i; |
f1f41a6c | 129 | vec<edge> latches; |
4a6f9e19 | 130 | edge e; |
7fb12188 | 131 | |
65f34de5 | 132 | if (! loop || ! loop->header) |
133 | return; | |
134 | ||
58b3f902 | 135 | fprintf (file, ";;\n;; Loop %d\n", loop->num); |
65f34de5 | 136 | |
4a6f9e19 | 137 | fprintf (file, ";; header %d, ", loop->header->index); |
138 | if (loop->latch) | |
139 | fprintf (file, "latch %d\n", loop->latch->index); | |
140 | else | |
141 | { | |
142 | fprintf (file, "multiple latches:"); | |
143 | latches = get_loop_latch_edges (loop); | |
f1f41a6c | 144 | FOR_EACH_VEC_ELT (latches, i, e) |
4a6f9e19 | 145 | fprintf (file, " %d", e->src->index); |
f1f41a6c | 146 | latches.release (); |
4a6f9e19 | 147 | fprintf (file, "\n"); |
148 | } | |
149 | ||
8543a448 | 150 | fprintf (file, ";; depth %d, outer %ld\n", |
9e3536f4 | 151 | loop_depth (loop), (long) (loop_outer (loop) |
152 | ? loop_outer (loop)->num : -1)); | |
65f34de5 | 153 | |
7fb12188 | 154 | fprintf (file, ";; nodes:"); |
155 | bbs = get_loop_body (loop); | |
156 | for (i = 0; i < loop->num_nodes; i++) | |
157 | fprintf (file, " %d", bbs[i]->index); | |
158 | free (bbs); | |
159 | fprintf (file, "\n"); | |
5cc577b6 | 160 | |
65f34de5 | 161 | if (loop_dump_aux) |
162 | loop_dump_aux (loop, file, verbose); | |
163 | } | |
164 | ||
7194de72 | 165 | /* Dump the loop information about loops to the stream FILE, |
65f34de5 | 166 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ |
167 | ||
168 | void | |
7194de72 | 169 | flow_loops_dump (FILE *file, void (*loop_dump_aux) (const struct loop *, FILE *, int), int verbose) |
65f34de5 | 170 | { |
17519ba0 | 171 | struct loop *loop; |
65f34de5 | 172 | |
7194de72 | 173 | if (!current_loops || ! file) |
65f34de5 | 174 | return; |
175 | ||
41f75a99 | 176 | fprintf (file, ";; %d loops found\n", number_of_loops (cfun)); |
7fb12188 | 177 | |
f21d4d00 | 178 | FOR_EACH_LOOP (loop, LI_INCLUDE_ROOT) |
65f34de5 | 179 | { |
7fb12188 | 180 | flow_loop_dump (loop, file, loop_dump_aux, verbose); |
65f34de5 | 181 | } |
182 | ||
183 | if (verbose) | |
7194de72 | 184 | flow_loops_cfg_dump (file); |
65f34de5 | 185 | } |
186 | ||
7fb12188 | 187 | /* Free data allocated for LOOP. */ |
ccae4f9f | 188 | |
a5414ff5 | 189 | void |
4c9e08a4 | 190 | flow_loop_free (struct loop *loop) |
7fb12188 | 191 | { |
dce58e66 | 192 | struct loop_exit *exit, *next; |
193 | ||
f1f41a6c | 194 | vec_free (loop->superloops); |
dce58e66 | 195 | |
196 | /* Break the list of the loop exit records. They will be freed when the | |
197 | corresponding edge is rescanned or removed, and this avoids | |
198 | accessing the (already released) head of the list stored in the | |
199 | loop structure. */ | |
ccae4f9f | 200 | for (exit = loop->exits->next; exit != loop->exits; exit = next) |
dce58e66 | 201 | { |
202 | next = exit->next; | |
203 | exit->next = exit; | |
204 | exit->prev = exit; | |
205 | } | |
ccae4f9f | 206 | |
207 | ggc_free (loop->exits); | |
208 | ggc_free (loop); | |
7fb12188 | 209 | } |
210 | ||
65f34de5 | 211 | /* Free all the memory allocated for LOOPS. */ |
212 | ||
213 | void | |
4c9e08a4 | 214 | flow_loops_free (struct loops *loops) |
65f34de5 | 215 | { |
17519ba0 | 216 | if (loops->larray) |
65f34de5 | 217 | { |
862be747 | 218 | unsigned i; |
17519ba0 | 219 | loop_p loop; |
65f34de5 | 220 | |
221 | /* Free the loop descriptors. */ | |
f1f41a6c | 222 | FOR_EACH_VEC_SAFE_ELT (loops->larray, i, loop) |
65f34de5 | 223 | { |
7fb12188 | 224 | if (!loop) |
225 | continue; | |
226 | ||
227 | flow_loop_free (loop); | |
65f34de5 | 228 | } |
5cc577b6 | 229 | |
f1f41a6c | 230 | vec_free (loops->larray); |
65f34de5 | 231 | } |
232 | } | |
233 | ||
7fb12188 | 234 | /* Find the nodes contained within the LOOP with header HEADER. |
235 | Return the number of nodes within the loop. */ | |
65f34de5 | 236 | |
053fdd99 | 237 | int |
4c9e08a4 | 238 | flow_loop_nodes_find (basic_block header, struct loop *loop) |
65f34de5 | 239 | { |
1e094109 | 240 | vec<basic_block> stack = vNULL; |
7fb12188 | 241 | int num_nodes = 1; |
4a6f9e19 | 242 | edge latch; |
243 | edge_iterator latch_ei; | |
65f34de5 | 244 | |
7fb12188 | 245 | header->loop_father = loop; |
65f34de5 | 246 | |
4a6f9e19 | 247 | FOR_EACH_EDGE (latch, latch_ei, loop->header->preds) |
65f34de5 | 248 | { |
4a6f9e19 | 249 | if (latch->src->loop_father == loop |
250 | || !dominated_by_p (CDI_DOMINATORS, latch->src, loop->header)) | |
251 | continue; | |
252 | ||
65f34de5 | 253 | num_nodes++; |
f1f41a6c | 254 | stack.safe_push (latch->src); |
4a6f9e19 | 255 | latch->src->loop_father = loop; |
4c9e08a4 | 256 | |
f1f41a6c | 257 | while (!stack.is_empty ()) |
65f34de5 | 258 | { |
7fb12188 | 259 | basic_block node; |
260 | edge e; | |
cd665a06 | 261 | edge_iterator ei; |
65f34de5 | 262 | |
f1f41a6c | 263 | node = stack.pop (); |
4c9e08a4 | 264 | |
cd665a06 | 265 | FOR_EACH_EDGE (e, ei, node->preds) |
65f34de5 | 266 | { |
7fb12188 | 267 | basic_block ancestor = e->src; |
268 | ||
4a6f9e19 | 269 | if (ancestor->loop_father != loop) |
7fb12188 | 270 | { |
271 | ancestor->loop_father = loop; | |
7fb12188 | 272 | num_nodes++; |
f1f41a6c | 273 | stack.safe_push (ancestor); |
7fb12188 | 274 | } |
65f34de5 | 275 | } |
276 | } | |
277 | } | |
f1f41a6c | 278 | stack.release (); |
4a6f9e19 | 279 | |
65f34de5 | 280 | return num_nodes; |
281 | } | |
282 | ||
9e3536f4 | 283 | /* Records the vector of superloops of the loop LOOP, whose immediate |
284 | superloop is FATHER. */ | |
285 | ||
a5414ff5 | 286 | static void |
9e3536f4 | 287 | establish_preds (struct loop *loop, struct loop *father) |
a5414ff5 | 288 | { |
9e3536f4 | 289 | loop_p ploop; |
290 | unsigned depth = loop_depth (father) + 1; | |
291 | unsigned i; | |
b811afb0 | 292 | |
f1f41a6c | 293 | loop->superloops = 0; |
294 | vec_alloc (loop->superloops, depth); | |
295 | FOR_EACH_VEC_SAFE_ELT (father->superloops, i, ploop) | |
296 | loop->superloops->quick_push (ploop); | |
297 | loop->superloops->quick_push (father); | |
a5414ff5 | 298 | |
299 | for (ploop = loop->inner; ploop; ploop = ploop->next) | |
9e3536f4 | 300 | establish_preds (ploop, loop); |
a5414ff5 | 301 | } |
302 | ||
7fb12188 | 303 | /* Add LOOP to the loop hierarchy tree where FATHER is father of the |
a5414ff5 | 304 | added loop. If LOOP has some children, take care of that their |
305 | pred field will be initialized correctly. */ | |
65f34de5 | 306 | |
7fb12188 | 307 | void |
4c9e08a4 | 308 | flow_loop_tree_node_add (struct loop *father, struct loop *loop) |
65f34de5 | 309 | { |
7fb12188 | 310 | loop->next = father->inner; |
311 | father->inner = loop; | |
7fb12188 | 312 | |
9e3536f4 | 313 | establish_preds (loop, father); |
65f34de5 | 314 | } |
315 | ||
7fb12188 | 316 | /* Remove LOOP from the loop hierarchy tree. */ |
65f34de5 | 317 | |
7fb12188 | 318 | void |
4c9e08a4 | 319 | flow_loop_tree_node_remove (struct loop *loop) |
65f34de5 | 320 | { |
7fb12188 | 321 | struct loop *prev, *father; |
65f34de5 | 322 | |
9e3536f4 | 323 | father = loop_outer (loop); |
65f34de5 | 324 | |
7fb12188 | 325 | /* Remove loop from the list of sons. */ |
326 | if (father->inner == loop) | |
327 | father->inner = loop->next; | |
328 | else | |
329 | { | |
9e3536f4 | 330 | for (prev = father->inner; prev->next != loop; prev = prev->next) |
331 | continue; | |
7fb12188 | 332 | prev->next = loop->next; |
333 | } | |
65f34de5 | 334 | |
f1f41a6c | 335 | loop->superloops = NULL; |
65f34de5 | 336 | } |
337 | ||
dce58e66 | 338 | /* Allocates and returns new loop structure. */ |
339 | ||
340 | struct loop * | |
341 | alloc_loop (void) | |
342 | { | |
25a27413 | 343 | struct loop *loop = ggc_cleared_alloc<struct loop> (); |
ccae4f9f | 344 | |
25a27413 | 345 | loop->exits = ggc_cleared_alloc<loop_exit> (); |
ccae4f9f | 346 | loop->exits->next = loop->exits->prev = loop->exits; |
26c166eb | 347 | loop->can_be_parallel = false; |
e913b5cd | 348 | loop->nb_iterations_upper_bound = 0; |
349 | loop->nb_iterations_estimate = 0; | |
dce58e66 | 350 | return loop; |
351 | } | |
352 | ||
a8a97201 | 353 | /* Initializes loops structure LOOPS, reserving place for NUM_LOOPS loops |
354 | (including the root of the loop tree). */ | |
355 | ||
7a569539 | 356 | void |
357 | init_loops_structure (struct function *fn, | |
358 | struct loops *loops, unsigned num_loops) | |
a8a97201 | 359 | { |
360 | struct loop *root; | |
361 | ||
362 | memset (loops, 0, sizeof *loops); | |
f1f41a6c | 363 | vec_alloc (loops->larray, num_loops); |
a8a97201 | 364 | |
365 | /* Dummy loop containing whole function. */ | |
366 | root = alloc_loop (); | |
a28770e1 | 367 | root->num_nodes = n_basic_blocks_for_fn (fn); |
34154e27 | 368 | root->latch = EXIT_BLOCK_PTR_FOR_FN (fn); |
369 | root->header = ENTRY_BLOCK_PTR_FOR_FN (fn); | |
370 | ENTRY_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
371 | EXIT_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
a8a97201 | 372 | |
f1f41a6c | 373 | loops->larray->quick_push (root); |
a8a97201 | 374 | loops->tree_root = root; |
375 | } | |
376 | ||
ff829efa | 377 | /* Returns whether HEADER is a loop header. */ |
378 | ||
379 | bool | |
380 | bb_loop_header_p (basic_block header) | |
381 | { | |
382 | edge_iterator ei; | |
383 | edge e; | |
384 | ||
385 | /* If we have an abnormal predecessor, do not consider the | |
386 | loop (not worth the problems). */ | |
387 | if (bb_has_abnormal_pred (header)) | |
388 | return false; | |
389 | ||
390 | /* Look for back edges where a predecessor is dominated | |
391 | by this block. A natural loop has a single entry | |
392 | node (header) that dominates all the nodes in the | |
393 | loop. It also has single back edge to the header | |
394 | from a latch node. */ | |
395 | FOR_EACH_EDGE (e, ei, header->preds) | |
396 | { | |
397 | basic_block latch = e->src; | |
34154e27 | 398 | if (latch != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
ff829efa | 399 | && dominated_by_p (CDI_DOMINATORS, latch, header)) |
400 | return true; | |
401 | } | |
402 | ||
403 | return false; | |
404 | } | |
405 | ||
5cc577b6 | 406 | /* Find all the natural loops in the function and save in LOOPS structure and |
6b42039a | 407 | recalculate loop_father information in basic block structures. |
ff829efa | 408 | If LOOPS is non-NULL then the loop structures for already recorded loops |
409 | will be re-used and their number will not change. We assume that no | |
410 | stale loops exist in LOOPS. | |
411 | When LOOPS is NULL it is allocated and re-built from scratch. | |
412 | Return the built LOOPS structure. */ | |
65f34de5 | 413 | |
ff829efa | 414 | struct loops * |
ffc6b5d5 | 415 | flow_loops_find (struct loops *loops) |
65f34de5 | 416 | { |
ff829efa | 417 | bool from_scratch = (loops == NULL); |
65f34de5 | 418 | int *rc_order; |
ff829efa | 419 | int b; |
420 | unsigned i; | |
65f34de5 | 421 | |
a8a97201 | 422 | /* Ensure that the dominators are computed. */ |
423 | calculate_dominance_info (CDI_DOMINATORS); | |
65f34de5 | 424 | |
ff829efa | 425 | if (!loops) |
a8a97201 | 426 | { |
25a27413 | 427 | loops = ggc_cleared_alloc<struct loops> (); |
7a569539 | 428 | init_loops_structure (cfun, loops, 1); |
a8a97201 | 429 | } |
65f34de5 | 430 | |
ff829efa | 431 | /* Ensure that loop exits were released. */ |
432 | gcc_assert (loops->exits == NULL); | |
65f34de5 | 433 | |
ff829efa | 434 | /* Taking care of this degenerate case makes the rest of |
435 | this code simpler. */ | |
a28770e1 | 436 | if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) |
ff829efa | 437 | return loops; |
7fb12188 | 438 | |
ff829efa | 439 | /* The root loop node contains all basic-blocks. */ |
a28770e1 | 440 | loops->tree_root->num_nodes = n_basic_blocks_for_fn (cfun); |
4c9e08a4 | 441 | |
ff829efa | 442 | /* Compute depth first search order of the CFG so that outer |
443 | natural loops will be found before inner natural loops. */ | |
a28770e1 | 444 | rc_order = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); |
ff829efa | 445 | pre_and_rev_post_order_compute (NULL, rc_order, false); |
743f4ee2 | 446 | |
ff829efa | 447 | /* Gather all loop headers in reverse completion order and allocate |
448 | loop structures for loops that are not already present. */ | |
c2078b80 | 449 | auto_vec<loop_p> larray (loops->larray->length ()); |
a28770e1 | 450 | for (b = 0; b < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; b++) |
ff829efa | 451 | { |
f5a6b05f | 452 | basic_block header = BASIC_BLOCK_FOR_FN (cfun, rc_order[b]); |
ff829efa | 453 | if (bb_loop_header_p (header)) |
65f34de5 | 454 | { |
ff829efa | 455 | struct loop *loop; |
7fb12188 | 456 | |
ff829efa | 457 | /* The current active loop tree has valid loop-fathers for |
458 | header blocks. */ | |
459 | if (!from_scratch | |
460 | && header->loop_father->header == header) | |
7fb12188 | 461 | { |
ff829efa | 462 | loop = header->loop_father; |
463 | /* If we found an existing loop remove it from the | |
464 | loop tree. It is going to be inserted again | |
465 | below. */ | |
466 | flow_loop_tree_node_remove (loop); | |
7fb12188 | 467 | } |
ff829efa | 468 | else |
469 | { | |
470 | /* Otherwise allocate a new loop structure for the loop. */ | |
471 | loop = alloc_loop (); | |
472 | /* ??? We could re-use unused loop slots here. */ | |
473 | loop->num = loops->larray->length (); | |
474 | vec_safe_push (loops->larray, loop); | |
475 | loop->header = header; | |
476 | ||
477 | if (!from_scratch | |
478 | && dump_file && (dump_flags & TDF_DETAILS)) | |
479 | fprintf (dump_file, "flow_loops_find: discovered new " | |
480 | "loop %d with header %d\n", | |
481 | loop->num, header->index); | |
482 | } | |
b375c775 | 483 | /* Reset latch, we recompute it below. */ |
484 | loop->latch = NULL; | |
ff829efa | 485 | larray.safe_push (loop); |
65f34de5 | 486 | } |
65f34de5 | 487 | |
ff829efa | 488 | /* Make blocks part of the loop root node at start. */ |
489 | header->loop_father = loops->tree_root; | |
490 | } | |
7fb12188 | 491 | |
ff829efa | 492 | free (rc_order); |
7fb12188 | 493 | |
ff829efa | 494 | /* Now iterate over the loops found, insert them into the loop tree |
495 | and assign basic-block ownership. */ | |
496 | for (i = 0; i < larray.length (); ++i) | |
65f34de5 | 497 | { |
ff829efa | 498 | struct loop *loop = larray[i]; |
499 | basic_block header = loop->header; | |
500 | edge_iterator ei; | |
501 | edge e; | |
65f34de5 | 502 | |
ff829efa | 503 | flow_loop_tree_node_add (header->loop_father, loop); |
504 | loop->num_nodes = flow_loop_nodes_find (loop->header, loop); | |
65f34de5 | 505 | |
ff829efa | 506 | /* Look for the latch for this header block, if it has just a |
507 | single one. */ | |
508 | FOR_EACH_EDGE (e, ei, header->preds) | |
65f34de5 | 509 | { |
ff829efa | 510 | basic_block latch = e->src; |
4a6f9e19 | 511 | |
ff829efa | 512 | if (flow_bb_inside_loop_p (loop, latch)) |
65f34de5 | 513 | { |
ff829efa | 514 | if (loop->latch != NULL) |
65f34de5 | 515 | { |
ff829efa | 516 | /* More than one latch edge. */ |
517 | loop->latch = NULL; | |
518 | break; | |
65f34de5 | 519 | } |
ff829efa | 520 | loop->latch = latch; |
65f34de5 | 521 | } |
65f34de5 | 522 | } |
7fb12188 | 523 | } |
862be747 | 524 | |
ff829efa | 525 | return loops; |
65f34de5 | 526 | } |
527 | ||
4a6f9e19 | 528 | /* Ratio of frequencies of edges so that one of more latch edges is |
529 | considered to belong to inner loop with same header. */ | |
530 | #define HEAVY_EDGE_RATIO 8 | |
531 | ||
532 | /* Minimum number of samples for that we apply | |
533 | find_subloop_latch_edge_by_profile heuristics. */ | |
534 | #define HEAVY_EDGE_MIN_SAMPLES 10 | |
535 | ||
536 | /* If the profile info is available, finds an edge in LATCHES that much more | |
537 | frequent than the remaining edges. Returns such an edge, or NULL if we do | |
538 | not find one. | |
539 | ||
540 | We do not use guessed profile here, only the measured one. The guessed | |
541 | profile is usually too flat and unreliable for this (and it is mostly based | |
542 | on the loop structure of the program, so it does not make much sense to | |
543 | derive the loop structure from it). */ | |
48e1416a | 544 | |
4a6f9e19 | 545 | static edge |
f1f41a6c | 546 | find_subloop_latch_edge_by_profile (vec<edge> latches) |
4a6f9e19 | 547 | { |
548 | unsigned i; | |
549 | edge e, me = NULL; | |
550 | gcov_type mcount = 0, tcount = 0; | |
551 | ||
f1f41a6c | 552 | FOR_EACH_VEC_ELT (latches, i, e) |
4a6f9e19 | 553 | { |
554 | if (e->count > mcount) | |
555 | { | |
556 | me = e; | |
557 | mcount = e->count; | |
558 | } | |
559 | tcount += e->count; | |
560 | } | |
561 | ||
562 | if (tcount < HEAVY_EDGE_MIN_SAMPLES | |
563 | || (tcount - mcount) * HEAVY_EDGE_RATIO > tcount) | |
564 | return NULL; | |
565 | ||
566 | if (dump_file) | |
567 | fprintf (dump_file, | |
568 | "Found latch edge %d -> %d using profile information.\n", | |
569 | me->src->index, me->dest->index); | |
570 | return me; | |
571 | } | |
572 | ||
573 | /* Among LATCHES, guesses a latch edge of LOOP corresponding to subloop, based | |
574 | on the structure of induction variables. Returns this edge, or NULL if we | |
575 | do not find any. | |
576 | ||
577 | We are quite conservative, and look just for an obvious simple innermost | |
578 | loop (which is the case where we would lose the most performance by not | |
579 | disambiguating the loop). More precisely, we look for the following | |
580 | situation: The source of the chosen latch edge dominates sources of all | |
581 | the other latch edges. Additionally, the header does not contain a phi node | |
582 | such that the argument from the chosen edge is equal to the argument from | |
583 | another edge. */ | |
584 | ||
585 | static edge | |
f1f41a6c | 586 | find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, vec<edge> latches) |
4a6f9e19 | 587 | { |
f1f41a6c | 588 | edge e, latch = latches[0]; |
4a6f9e19 | 589 | unsigned i; |
1a91d914 | 590 | gphi *phi; |
591 | gphi_iterator psi; | |
75a70cf9 | 592 | tree lop; |
4a6f9e19 | 593 | basic_block bb; |
594 | ||
595 | /* Find the candidate for the latch edge. */ | |
f1f41a6c | 596 | for (i = 1; latches.iterate (i, &e); i++) |
4a6f9e19 | 597 | if (dominated_by_p (CDI_DOMINATORS, latch->src, e->src)) |
598 | latch = e; | |
599 | ||
600 | /* Verify that it dominates all the latch edges. */ | |
f1f41a6c | 601 | FOR_EACH_VEC_ELT (latches, i, e) |
4a6f9e19 | 602 | if (!dominated_by_p (CDI_DOMINATORS, e->src, latch->src)) |
603 | return NULL; | |
604 | ||
605 | /* Check for a phi node that would deny that this is a latch edge of | |
606 | a subloop. */ | |
75a70cf9 | 607 | for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) |
4a6f9e19 | 608 | { |
1a91d914 | 609 | phi = psi.phi (); |
4a6f9e19 | 610 | lop = PHI_ARG_DEF_FROM_EDGE (phi, latch); |
611 | ||
612 | /* Ignore the values that are not changed inside the subloop. */ | |
613 | if (TREE_CODE (lop) != SSA_NAME | |
614 | || SSA_NAME_DEF_STMT (lop) == phi) | |
615 | continue; | |
75a70cf9 | 616 | bb = gimple_bb (SSA_NAME_DEF_STMT (lop)); |
4a6f9e19 | 617 | if (!bb || !flow_bb_inside_loop_p (loop, bb)) |
618 | continue; | |
619 | ||
f1f41a6c | 620 | FOR_EACH_VEC_ELT (latches, i, e) |
4a6f9e19 | 621 | if (e != latch |
622 | && PHI_ARG_DEF_FROM_EDGE (phi, e) == lop) | |
623 | return NULL; | |
624 | } | |
625 | ||
626 | if (dump_file) | |
627 | fprintf (dump_file, | |
628 | "Found latch edge %d -> %d using iv structure.\n", | |
629 | latch->src->index, latch->dest->index); | |
630 | return latch; | |
631 | } | |
632 | ||
633 | /* If we can determine that one of the several latch edges of LOOP behaves | |
634 | as a latch edge of a separate subloop, returns this edge. Otherwise | |
635 | returns NULL. */ | |
636 | ||
637 | static edge | |
638 | find_subloop_latch_edge (struct loop *loop) | |
639 | { | |
f1f41a6c | 640 | vec<edge> latches = get_loop_latch_edges (loop); |
4a6f9e19 | 641 | edge latch = NULL; |
642 | ||
f1f41a6c | 643 | if (latches.length () > 1) |
4a6f9e19 | 644 | { |
645 | latch = find_subloop_latch_edge_by_profile (latches); | |
646 | ||
647 | if (!latch | |
648 | /* We consider ivs to guess the latch edge only in SSA. Perhaps we | |
649 | should use cfghook for this, but it is hard to imagine it would | |
650 | be useful elsewhere. */ | |
651 | && current_ir_type () == IR_GIMPLE) | |
652 | latch = find_subloop_latch_edge_by_ivs (loop, latches); | |
653 | } | |
654 | ||
f1f41a6c | 655 | latches.release (); |
4a6f9e19 | 656 | return latch; |
657 | } | |
658 | ||
659 | /* Callback for make_forwarder_block. Returns true if the edge E is marked | |
660 | in the set MFB_REIS_SET. */ | |
661 | ||
431205b7 | 662 | static hash_set<edge> *mfb_reis_set; |
4a6f9e19 | 663 | static bool |
664 | mfb_redirect_edges_in_set (edge e) | |
665 | { | |
431205b7 | 666 | return mfb_reis_set->contains (e); |
4a6f9e19 | 667 | } |
668 | ||
669 | /* Creates a subloop of LOOP with latch edge LATCH. */ | |
670 | ||
671 | static void | |
672 | form_subloop (struct loop *loop, edge latch) | |
673 | { | |
674 | edge_iterator ei; | |
675 | edge e, new_entry; | |
676 | struct loop *new_loop; | |
48e1416a | 677 | |
431205b7 | 678 | mfb_reis_set = new hash_set<edge>; |
4a6f9e19 | 679 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
680 | { | |
681 | if (e != latch) | |
431205b7 | 682 | mfb_reis_set->add (e); |
4a6f9e19 | 683 | } |
684 | new_entry = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
685 | NULL); | |
431205b7 | 686 | delete mfb_reis_set; |
4a6f9e19 | 687 | |
688 | loop->header = new_entry->src; | |
689 | ||
690 | /* Find the blocks and subloops that belong to the new loop, and add it to | |
691 | the appropriate place in the loop tree. */ | |
692 | new_loop = alloc_loop (); | |
693 | new_loop->header = new_entry->dest; | |
694 | new_loop->latch = latch->src; | |
695 | add_loop (new_loop, loop); | |
696 | } | |
697 | ||
698 | /* Make all the latch edges of LOOP to go to a single forwarder block -- | |
699 | a new latch of LOOP. */ | |
700 | ||
701 | static void | |
702 | merge_latch_edges (struct loop *loop) | |
703 | { | |
f1f41a6c | 704 | vec<edge> latches = get_loop_latch_edges (loop); |
4a6f9e19 | 705 | edge latch, e; |
706 | unsigned i; | |
707 | ||
f1f41a6c | 708 | gcc_assert (latches.length () > 0); |
4a6f9e19 | 709 | |
f1f41a6c | 710 | if (latches.length () == 1) |
711 | loop->latch = latches[0]->src; | |
4a6f9e19 | 712 | else |
713 | { | |
714 | if (dump_file) | |
715 | fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num); | |
716 | ||
431205b7 | 717 | mfb_reis_set = new hash_set<edge>; |
f1f41a6c | 718 | FOR_EACH_VEC_ELT (latches, i, e) |
431205b7 | 719 | mfb_reis_set->add (e); |
4a6f9e19 | 720 | latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, |
721 | NULL); | |
431205b7 | 722 | delete mfb_reis_set; |
4a6f9e19 | 723 | |
724 | loop->header = latch->dest; | |
725 | loop->latch = latch->src; | |
726 | } | |
727 | ||
f1f41a6c | 728 | latches.release (); |
4a6f9e19 | 729 | } |
730 | ||
731 | /* LOOP may have several latch edges. Transform it into (possibly several) | |
732 | loops with single latch edge. */ | |
733 | ||
734 | static void | |
735 | disambiguate_multiple_latches (struct loop *loop) | |
736 | { | |
737 | edge e; | |
738 | ||
85694bac | 739 | /* We eliminate the multiple latches by splitting the header to the forwarder |
4a6f9e19 | 740 | block F and the rest R, and redirecting the edges. There are two cases: |
741 | ||
742 | 1) If there is a latch edge E that corresponds to a subloop (we guess | |
743 | that based on profile -- if it is taken much more often than the | |
744 | remaining edges; and on trees, using the information about induction | |
745 | variables of the loops), we redirect E to R, all the remaining edges to | |
746 | F, then rescan the loops and try again for the outer loop. | |
747 | 2) If there is no such edge, we redirect all latch edges to F, and the | |
748 | entry edges to R, thus making F the single latch of the loop. */ | |
749 | ||
750 | if (dump_file) | |
751 | fprintf (dump_file, "Disambiguating loop %d with multiple latches\n", | |
752 | loop->num); | |
753 | ||
754 | /* During latch merging, we may need to redirect the entry edges to a new | |
755 | block. This would cause problems if the entry edge was the one from the | |
756 | entry block. To avoid having to handle this case specially, split | |
757 | such entry edge. */ | |
34154e27 | 758 | e = find_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), loop->header); |
4a6f9e19 | 759 | if (e) |
760 | split_edge (e); | |
761 | ||
762 | while (1) | |
763 | { | |
764 | e = find_subloop_latch_edge (loop); | |
765 | if (!e) | |
766 | break; | |
767 | ||
768 | form_subloop (loop, e); | |
769 | } | |
770 | ||
771 | merge_latch_edges (loop); | |
772 | } | |
773 | ||
774 | /* Split loops with multiple latch edges. */ | |
775 | ||
776 | void | |
777 | disambiguate_loops_with_multiple_latches (void) | |
778 | { | |
4a6f9e19 | 779 | struct loop *loop; |
780 | ||
f21d4d00 | 781 | FOR_EACH_LOOP (loop, 0) |
4a6f9e19 | 782 | { |
783 | if (!loop->latch) | |
784 | disambiguate_multiple_latches (loop); | |
785 | } | |
786 | } | |
787 | ||
d10cfa8d | 788 | /* Return nonzero if basic block BB belongs to LOOP. */ |
7fb12188 | 789 | bool |
7ecb5bb2 | 790 | flow_bb_inside_loop_p (const struct loop *loop, const_basic_block bb) |
7fb12188 | 791 | { |
792 | struct loop *source_loop; | |
793 | ||
34154e27 | 794 | if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
795 | || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
7fb12188 | 796 | return 0; |
797 | ||
798 | source_loop = bb->loop_father; | |
799 | return loop == source_loop || flow_loop_nested_p (loop, source_loop); | |
800 | } | |
801 | ||
4a6f9e19 | 802 | /* Enumeration predicate for get_loop_body_with_size. */ |
7fb12188 | 803 | static bool |
7ecb5bb2 | 804 | glb_enum_p (const_basic_block bb, const void *glb_loop) |
7fb12188 | 805 | { |
7ecb5bb2 | 806 | const struct loop *const loop = (const struct loop *) glb_loop; |
4a6f9e19 | 807 | return (bb != loop->header |
808 | && dominated_by_p (CDI_DOMINATORS, bb, loop->header)); | |
809 | } | |
810 | ||
811 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
812 | order against direction of edges from latch. Specially, if | |
813 | header != latch, latch is the 1-st block. LOOP cannot be the fake | |
814 | loop tree root, and its size must be at most MAX_SIZE. The blocks | |
815 | in the LOOP body are stored to BODY, and the size of the LOOP is | |
816 | returned. */ | |
817 | ||
818 | unsigned | |
819 | get_loop_body_with_size (const struct loop *loop, basic_block *body, | |
820 | unsigned max_size) | |
821 | { | |
822 | return dfs_enumerate_from (loop->header, 1, glb_enum_p, | |
7ecb5bb2 | 823 | body, max_size, loop); |
7fb12188 | 824 | } |
825 | ||
dbfc1664 | 826 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs |
827 | order against direction of edges from latch. Specially, if | |
828 | header != latch, latch is the 1-st block. */ | |
4a6f9e19 | 829 | |
7fb12188 | 830 | basic_block * |
4c9e08a4 | 831 | get_loop_body (const struct loop *loop) |
7fb12188 | 832 | { |
4a6f9e19 | 833 | basic_block *body, bb; |
862be747 | 834 | unsigned tv = 0; |
7fb12188 | 835 | |
cc636d56 | 836 | gcc_assert (loop->num_nodes); |
7fb12188 | 837 | |
ed7e2206 | 838 | body = XNEWVEC (basic_block, loop->num_nodes); |
7fb12188 | 839 | |
34154e27 | 840 | if (loop->latch == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
7fb12188 | 841 | { |
4a6f9e19 | 842 | /* There may be blocks unreachable from EXIT_BLOCK, hence we need to |
843 | special-case the fake loop that contains the whole function. */ | |
a28770e1 | 844 | gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks_for_fn (cfun)); |
4a6f9e19 | 845 | body[tv++] = loop->header; |
34154e27 | 846 | body[tv++] = EXIT_BLOCK_PTR_FOR_FN (cfun); |
fc00614f | 847 | FOR_EACH_BB_FN (bb, cfun) |
4a6f9e19 | 848 | body[tv++] = bb; |
7fb12188 | 849 | } |
4a6f9e19 | 850 | else |
851 | tv = get_loop_body_with_size (loop, body, loop->num_nodes); | |
7fb12188 | 852 | |
cc636d56 | 853 | gcc_assert (tv == loop->num_nodes); |
4a6f9e19 | 854 | return body; |
7fb12188 | 855 | } |
856 | ||
f9cce2dc | 857 | /* Fills dominance descendants inside LOOP of the basic block BB into |
858 | array TOVISIT from index *TV. */ | |
859 | ||
860 | static void | |
861 | fill_sons_in_loop (const struct loop *loop, basic_block bb, | |
862 | basic_block *tovisit, int *tv) | |
863 | { | |
864 | basic_block son, postpone = NULL; | |
865 | ||
866 | tovisit[(*tv)++] = bb; | |
867 | for (son = first_dom_son (CDI_DOMINATORS, bb); | |
868 | son; | |
869 | son = next_dom_son (CDI_DOMINATORS, son)) | |
870 | { | |
871 | if (!flow_bb_inside_loop_p (loop, son)) | |
872 | continue; | |
873 | ||
874 | if (dominated_by_p (CDI_DOMINATORS, loop->latch, son)) | |
875 | { | |
876 | postpone = son; | |
877 | continue; | |
878 | } | |
879 | fill_sons_in_loop (loop, son, tovisit, tv); | |
880 | } | |
881 | ||
882 | if (postpone) | |
883 | fill_sons_in_loop (loop, postpone, tovisit, tv); | |
884 | } | |
885 | ||
886 | /* Gets body of a LOOP (that must be different from the outermost loop) | |
887 | sorted by dominance relation. Additionally, if a basic block s dominates | |
888 | the latch, then only blocks dominated by s are be after it. */ | |
889 | ||
890 | basic_block * | |
891 | get_loop_body_in_dom_order (const struct loop *loop) | |
892 | { | |
893 | basic_block *tovisit; | |
894 | int tv; | |
895 | ||
cc636d56 | 896 | gcc_assert (loop->num_nodes); |
f9cce2dc | 897 | |
ed7e2206 | 898 | tovisit = XNEWVEC (basic_block, loop->num_nodes); |
f9cce2dc | 899 | |
34154e27 | 900 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
f9cce2dc | 901 | |
902 | tv = 0; | |
903 | fill_sons_in_loop (loop, loop->header, tovisit, &tv); | |
904 | ||
cc636d56 | 905 | gcc_assert (tv == (int) loop->num_nodes); |
f9cce2dc | 906 | |
907 | return tovisit; | |
908 | } | |
909 | ||
e1ab7874 | 910 | /* Gets body of a LOOP sorted via provided BB_COMPARATOR. */ |
911 | ||
912 | basic_block * | |
48e1416a | 913 | get_loop_body_in_custom_order (const struct loop *loop, |
e1ab7874 | 914 | int (*bb_comparator) (const void *, const void *)) |
915 | { | |
916 | basic_block *bbs = get_loop_body (loop); | |
917 | ||
918 | qsort (bbs, loop->num_nodes, sizeof (basic_block), bb_comparator); | |
919 | ||
920 | return bbs; | |
921 | } | |
922 | ||
07c03fb0 | 923 | /* Get body of a LOOP in breadth first sort order. */ |
924 | ||
925 | basic_block * | |
926 | get_loop_body_in_bfs_order (const struct loop *loop) | |
927 | { | |
928 | basic_block *blocks; | |
929 | basic_block bb; | |
930 | bitmap visited; | |
931 | unsigned int i = 0; | |
932 | unsigned int vc = 1; | |
933 | ||
cc636d56 | 934 | gcc_assert (loop->num_nodes); |
34154e27 | 935 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
07c03fb0 | 936 | |
ed7e2206 | 937 | blocks = XNEWVEC (basic_block, loop->num_nodes); |
27335ffd | 938 | visited = BITMAP_ALLOC (NULL); |
07c03fb0 | 939 | |
940 | bb = loop->header; | |
941 | while (i < loop->num_nodes) | |
942 | { | |
943 | edge e; | |
cd665a06 | 944 | edge_iterator ei; |
a0c938f0 | 945 | |
6ef9bbe0 | 946 | if (bitmap_set_bit (visited, bb->index)) |
947 | /* This basic block is now visited */ | |
948 | blocks[i++] = bb; | |
a0c938f0 | 949 | |
cd665a06 | 950 | FOR_EACH_EDGE (e, ei, bb->succs) |
a0c938f0 | 951 | { |
952 | if (flow_bb_inside_loop_p (loop, e->dest)) | |
953 | { | |
6ef9bbe0 | 954 | if (bitmap_set_bit (visited, e->dest->index)) |
955 | blocks[i++] = e->dest; | |
a0c938f0 | 956 | } |
957 | } | |
958 | ||
cc636d56 | 959 | gcc_assert (i >= vc); |
a0c938f0 | 960 | |
07c03fb0 | 961 | bb = blocks[vc++]; |
962 | } | |
a0c938f0 | 963 | |
27335ffd | 964 | BITMAP_FREE (visited); |
07c03fb0 | 965 | return blocks; |
966 | } | |
967 | ||
dce58e66 | 968 | /* Hash function for struct loop_exit. */ |
969 | ||
2ef51f0e | 970 | hashval_t |
971 | loop_exit_hasher::hash (loop_exit *exit) | |
dce58e66 | 972 | { |
dce58e66 | 973 | return htab_hash_pointer (exit->e); |
974 | } | |
975 | ||
976 | /* Equality function for struct loop_exit. Compares with edge. */ | |
977 | ||
2ef51f0e | 978 | bool |
979 | loop_exit_hasher::equal (loop_exit *exit, edge e) | |
dce58e66 | 980 | { |
dce58e66 | 981 | return exit->e == e; |
982 | } | |
983 | ||
984 | /* Frees the list of loop exit descriptions EX. */ | |
985 | ||
2ef51f0e | 986 | void |
987 | loop_exit_hasher::remove (loop_exit *exit) | |
dce58e66 | 988 | { |
2ef51f0e | 989 | loop_exit *next; |
dce58e66 | 990 | for (; exit; exit = next) |
991 | { | |
992 | next = exit->next_e; | |
48e1416a | 993 | |
dce58e66 | 994 | exit->next->prev = exit->prev; |
995 | exit->prev->next = exit->next; | |
996 | ||
ccae4f9f | 997 | ggc_free (exit); |
dce58e66 | 998 | } |
999 | } | |
1000 | ||
1001 | /* Returns the list of records for E as an exit of a loop. */ | |
1002 | ||
1003 | static struct loop_exit * | |
1004 | get_exit_descriptions (edge e) | |
1005 | { | |
2ef51f0e | 1006 | return current_loops->exits->find_with_hash (e, htab_hash_pointer (e)); |
dce58e66 | 1007 | } |
1008 | ||
1009 | /* Updates the lists of loop exits in that E appears. | |
1010 | If REMOVED is true, E is being removed, and we | |
1011 | just remove it from the lists of exits. | |
1012 | If NEW_EDGE is true and E is not a loop exit, we | |
1013 | do not try to remove it from loop exit lists. */ | |
1014 | ||
1015 | void | |
1016 | rescan_loop_exit (edge e, bool new_edge, bool removed) | |
1017 | { | |
dce58e66 | 1018 | struct loop_exit *exits = NULL, *exit; |
1019 | struct loop *aloop, *cloop; | |
1020 | ||
f24ec26f | 1021 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1022 | return; |
1023 | ||
1024 | if (!removed | |
1025 | && e->src->loop_father != NULL | |
1026 | && e->dest->loop_father != NULL | |
1027 | && !flow_bb_inside_loop_p (e->src->loop_father, e->dest)) | |
1028 | { | |
1029 | cloop = find_common_loop (e->src->loop_father, e->dest->loop_father); | |
1030 | for (aloop = e->src->loop_father; | |
1031 | aloop != cloop; | |
9e3536f4 | 1032 | aloop = loop_outer (aloop)) |
dce58e66 | 1033 | { |
25a27413 | 1034 | exit = ggc_alloc<loop_exit> (); |
dce58e66 | 1035 | exit->e = e; |
1036 | ||
ccae4f9f | 1037 | exit->next = aloop->exits->next; |
1038 | exit->prev = aloop->exits; | |
dce58e66 | 1039 | exit->next->prev = exit; |
1040 | exit->prev->next = exit; | |
1041 | ||
1042 | exit->next_e = exits; | |
1043 | exits = exit; | |
1044 | } | |
48e1416a | 1045 | } |
dce58e66 | 1046 | |
1047 | if (!exits && new_edge) | |
1048 | return; | |
1049 | ||
2ef51f0e | 1050 | loop_exit **slot |
1051 | = current_loops->exits->find_slot_with_hash (e, htab_hash_pointer (e), | |
1052 | exits ? INSERT : NO_INSERT); | |
dce58e66 | 1053 | if (!slot) |
1054 | return; | |
1055 | ||
1056 | if (exits) | |
1057 | { | |
1058 | if (*slot) | |
2ef51f0e | 1059 | loop_exit_hasher::remove (*slot); |
dce58e66 | 1060 | *slot = exits; |
1061 | } | |
1062 | else | |
2ef51f0e | 1063 | current_loops->exits->clear_slot (slot); |
dce58e66 | 1064 | } |
1065 | ||
1066 | /* For each loop, record list of exit edges, and start maintaining these | |
1067 | lists. */ | |
1068 | ||
1069 | void | |
1070 | record_loop_exits (void) | |
1071 | { | |
1072 | basic_block bb; | |
1073 | edge_iterator ei; | |
1074 | edge e; | |
1075 | ||
d500fef3 | 1076 | if (!current_loops) |
1077 | return; | |
1078 | ||
f24ec26f | 1079 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1080 | return; |
f24ec26f | 1081 | loops_state_set (LOOPS_HAVE_RECORDED_EXITS); |
dce58e66 | 1082 | |
1083 | gcc_assert (current_loops->exits == NULL); | |
2ef51f0e | 1084 | current_loops->exits |
1085 | = hash_table<loop_exit_hasher>::create_ggc (2 * number_of_loops (cfun)); | |
dce58e66 | 1086 | |
fc00614f | 1087 | FOR_EACH_BB_FN (bb, cfun) |
dce58e66 | 1088 | { |
1089 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1090 | { | |
1091 | rescan_loop_exit (e, true, false); | |
1092 | } | |
1093 | } | |
1094 | } | |
1095 | ||
1096 | /* Dumps information about the exit in *SLOT to FILE. | |
1097 | Callback for htab_traverse. */ | |
1098 | ||
2ef51f0e | 1099 | int |
1100 | dump_recorded_exit (loop_exit **slot, FILE *file) | |
dce58e66 | 1101 | { |
2ef51f0e | 1102 | struct loop_exit *exit = *slot; |
dce58e66 | 1103 | unsigned n = 0; |
1104 | edge e = exit->e; | |
1105 | ||
1106 | for (; exit != NULL; exit = exit->next_e) | |
1107 | n++; | |
1108 | ||
2ef51f0e | 1109 | fprintf (file, "Edge %d->%d exits %u loops\n", |
dce58e66 | 1110 | e->src->index, e->dest->index, n); |
1111 | ||
1112 | return 1; | |
1113 | } | |
1114 | ||
1115 | /* Dumps the recorded exits of loops to FILE. */ | |
1116 | ||
1117 | extern void dump_recorded_exits (FILE *); | |
1118 | void | |
1119 | dump_recorded_exits (FILE *file) | |
1120 | { | |
1121 | if (!current_loops->exits) | |
1122 | return; | |
2ef51f0e | 1123 | current_loops->exits->traverse<FILE *, dump_recorded_exit> (file); |
dce58e66 | 1124 | } |
1125 | ||
1126 | /* Releases lists of loop exits. */ | |
1127 | ||
1128 | void | |
1129 | release_recorded_exits (void) | |
1130 | { | |
f24ec26f | 1131 | gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)); |
2ef51f0e | 1132 | current_loops->exits->empty (); |
dce58e66 | 1133 | current_loops->exits = NULL; |
f24ec26f | 1134 | loops_state_clear (LOOPS_HAVE_RECORDED_EXITS); |
dce58e66 | 1135 | } |
1136 | ||
749ea85f | 1137 | /* Returns the list of the exit edges of a LOOP. */ |
1138 | ||
f1f41a6c | 1139 | vec<edge> |
749ea85f | 1140 | get_loop_exit_edges (const struct loop *loop) |
a5414ff5 | 1141 | { |
1e094109 | 1142 | vec<edge> edges = vNULL; |
749ea85f | 1143 | edge e; |
1144 | unsigned i; | |
1145 | basic_block *body; | |
cd665a06 | 1146 | edge_iterator ei; |
dce58e66 | 1147 | struct loop_exit *exit; |
a5414ff5 | 1148 | |
34154e27 | 1149 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
a5414ff5 | 1150 | |
dce58e66 | 1151 | /* If we maintain the lists of exits, use them. Otherwise we must |
1152 | scan the body of the loop. */ | |
f24ec26f | 1153 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1154 | { |
ccae4f9f | 1155 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
f1f41a6c | 1156 | edges.safe_push (exit->e); |
dce58e66 | 1157 | } |
1158 | else | |
1159 | { | |
1160 | body = get_loop_body (loop); | |
1161 | for (i = 0; i < loop->num_nodes; i++) | |
1162 | FOR_EACH_EDGE (e, ei, body[i]->succs) | |
1163 | { | |
1164 | if (!flow_bb_inside_loop_p (loop, e->dest)) | |
f1f41a6c | 1165 | edges.safe_push (e); |
dce58e66 | 1166 | } |
1167 | free (body); | |
1168 | } | |
a5414ff5 | 1169 | |
1170 | return edges; | |
1171 | } | |
1172 | ||
f9cce2dc | 1173 | /* Counts the number of conditional branches inside LOOP. */ |
1174 | ||
1175 | unsigned | |
1176 | num_loop_branches (const struct loop *loop) | |
1177 | { | |
1178 | unsigned i, n; | |
1179 | basic_block * body; | |
1180 | ||
34154e27 | 1181 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
f9cce2dc | 1182 | |
1183 | body = get_loop_body (loop); | |
1184 | n = 0; | |
1185 | for (i = 0; i < loop->num_nodes; i++) | |
cd665a06 | 1186 | if (EDGE_COUNT (body[i]->succs) >= 2) |
f9cce2dc | 1187 | n++; |
1188 | free (body); | |
1189 | ||
1190 | return n; | |
1191 | } | |
1192 | ||
7fb12188 | 1193 | /* Adds basic block BB to LOOP. */ |
1194 | void | |
4c9e08a4 | 1195 | add_bb_to_loop (basic_block bb, struct loop *loop) |
1196 | { | |
9e3536f4 | 1197 | unsigned i; |
1198 | loop_p ploop; | |
dce58e66 | 1199 | edge_iterator ei; |
1200 | edge e; | |
1201 | ||
1202 | gcc_assert (bb->loop_father == NULL); | |
1203 | bb->loop_father = loop; | |
dce58e66 | 1204 | loop->num_nodes++; |
f1f41a6c | 1205 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9e3536f4 | 1206 | ploop->num_nodes++; |
dce58e66 | 1207 | |
1208 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1209 | { | |
1210 | rescan_loop_exit (e, true, false); | |
1211 | } | |
1212 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1213 | { | |
1214 | rescan_loop_exit (e, true, false); | |
1215 | } | |
88e6f696 | 1216 | } |
7fb12188 | 1217 | |
1218 | /* Remove basic block BB from loops. */ | |
1219 | void | |
4c9e08a4 | 1220 | remove_bb_from_loops (basic_block bb) |
1221 | { | |
f1f41a6c | 1222 | unsigned i; |
dce58e66 | 1223 | struct loop *loop = bb->loop_father; |
9e3536f4 | 1224 | loop_p ploop; |
dce58e66 | 1225 | edge_iterator ei; |
1226 | edge e; | |
1227 | ||
1228 | gcc_assert (loop != NULL); | |
1229 | loop->num_nodes--; | |
f1f41a6c | 1230 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9e3536f4 | 1231 | ploop->num_nodes--; |
dce58e66 | 1232 | bb->loop_father = NULL; |
dce58e66 | 1233 | |
1234 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1235 | { | |
1236 | rescan_loop_exit (e, false, true); | |
1237 | } | |
1238 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1239 | { | |
1240 | rescan_loop_exit (e, false, true); | |
1241 | } | |
b811afb0 | 1242 | } |
7fb12188 | 1243 | |
1244 | /* Finds nearest common ancestor in loop tree for given loops. */ | |
1245 | struct loop * | |
4c9e08a4 | 1246 | find_common_loop (struct loop *loop_s, struct loop *loop_d) |
7fb12188 | 1247 | { |
9e3536f4 | 1248 | unsigned sdepth, ddepth; |
1249 | ||
7fb12188 | 1250 | if (!loop_s) return loop_d; |
1251 | if (!loop_d) return loop_s; | |
4c9e08a4 | 1252 | |
9e3536f4 | 1253 | sdepth = loop_depth (loop_s); |
1254 | ddepth = loop_depth (loop_d); | |
1255 | ||
1256 | if (sdepth < ddepth) | |
f1f41a6c | 1257 | loop_d = (*loop_d->superloops)[sdepth]; |
9e3536f4 | 1258 | else if (sdepth > ddepth) |
f1f41a6c | 1259 | loop_s = (*loop_s->superloops)[ddepth]; |
7fb12188 | 1260 | |
1261 | while (loop_s != loop_d) | |
1262 | { | |
9e3536f4 | 1263 | loop_s = loop_outer (loop_s); |
1264 | loop_d = loop_outer (loop_d); | |
7fb12188 | 1265 | } |
1266 | return loop_s; | |
1267 | } | |
1268 | ||
17519ba0 | 1269 | /* Removes LOOP from structures and frees its data. */ |
1270 | ||
1271 | void | |
1272 | delete_loop (struct loop *loop) | |
1273 | { | |
1274 | /* Remove the loop from structure. */ | |
1275 | flow_loop_tree_node_remove (loop); | |
1276 | ||
1277 | /* Remove loop from loops array. */ | |
f1f41a6c | 1278 | (*current_loops->larray)[loop->num] = NULL; |
17519ba0 | 1279 | |
1280 | /* Free loop data. */ | |
1281 | flow_loop_free (loop); | |
1282 | } | |
1283 | ||
862be747 | 1284 | /* Cancels the LOOP; it must be innermost one. */ |
77cbebb3 | 1285 | |
1286 | static void | |
7194de72 | 1287 | cancel_loop (struct loop *loop) |
862be747 | 1288 | { |
1289 | basic_block *bbs; | |
1290 | unsigned i; | |
9e3536f4 | 1291 | struct loop *outer = loop_outer (loop); |
862be747 | 1292 | |
cc636d56 | 1293 | gcc_assert (!loop->inner); |
862be747 | 1294 | |
1295 | /* Move blocks up one level (they should be removed as soon as possible). */ | |
1296 | bbs = get_loop_body (loop); | |
1297 | for (i = 0; i < loop->num_nodes; i++) | |
9e3536f4 | 1298 | bbs[i]->loop_father = outer; |
862be747 | 1299 | |
bf4b25d7 | 1300 | free (bbs); |
17519ba0 | 1301 | delete_loop (loop); |
862be747 | 1302 | } |
1303 | ||
1304 | /* Cancels LOOP and all its subloops. */ | |
1305 | void | |
7194de72 | 1306 | cancel_loop_tree (struct loop *loop) |
862be747 | 1307 | { |
1308 | while (loop->inner) | |
7194de72 | 1309 | cancel_loop_tree (loop->inner); |
1310 | cancel_loop (loop); | |
862be747 | 1311 | } |
1312 | ||
7194de72 | 1313 | /* Checks that information about loops is correct |
d01481af | 1314 | -- sizes of loops are all right |
7fb12188 | 1315 | -- results of get_loop_body really belong to the loop |
1316 | -- loop header have just single entry edge and single latch edge | |
1317 | -- loop latches have only single successor that is header of their loop | |
862be747 | 1318 | -- irreducible loops are correctly marked |
4e976818 | 1319 | -- the cached loop depth and loop father of each bb is correct |
7fb12188 | 1320 | */ |
4b987fac | 1321 | DEBUG_FUNCTION void |
7194de72 | 1322 | verify_loop_structure (void) |
7fb12188 | 1323 | { |
862be747 | 1324 | unsigned *sizes, i, j; |
1325 | sbitmap irreds; | |
cd9916a9 | 1326 | basic_block bb, *bbs; |
7fb12188 | 1327 | struct loop *loop; |
1328 | int err = 0; | |
a5414ff5 | 1329 | edge e; |
41f75a99 | 1330 | unsigned num = number_of_loops (cfun); |
dce58e66 | 1331 | struct loop_exit *exit, *mexit; |
79f958cb | 1332 | bool dom_available = dom_info_available_p (CDI_DOMINATORS); |
ff829efa | 1333 | sbitmap visited; |
7fb12188 | 1334 | |
f6568ea4 | 1335 | if (loops_state_satisfies_p (LOOPS_NEED_FIXUP)) |
1336 | { | |
1337 | error ("loop verification on loop tree that needs fixup"); | |
1338 | err = 1; | |
1339 | } | |
1340 | ||
79f958cb | 1341 | /* We need up-to-date dominators, compute or verify them. */ |
1342 | if (!dom_available) | |
1343 | calculate_dominance_info (CDI_DOMINATORS); | |
1344 | else | |
1345 | verify_dominators (CDI_DOMINATORS); | |
ef0e6535 | 1346 | |
14a0d8d7 | 1347 | /* Check the headers. */ |
fc00614f | 1348 | FOR_EACH_BB_FN (bb, cfun) |
cd9916a9 | 1349 | if (bb_loop_header_p (bb)) |
14a0d8d7 | 1350 | { |
cd9916a9 | 1351 | if (bb->loop_father->header == NULL) |
1352 | { | |
1353 | error ("loop with header %d marked for removal", bb->index); | |
1354 | err = 1; | |
1355 | } | |
1356 | else if (bb->loop_father->header != bb) | |
1357 | { | |
1358 | error ("loop with header %d not in loop tree", bb->index); | |
1359 | err = 1; | |
1360 | } | |
1361 | } | |
1362 | else if (bb->loop_father->header == bb) | |
1363 | { | |
1364 | error ("non-loop with header %d not marked for removal", bb->index); | |
14a0d8d7 | 1365 | err = 1; |
1366 | } | |
1367 | ||
cd9916a9 | 1368 | /* Check the recorded loop father and sizes of loops. */ |
fe672ac0 | 1369 | visited = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
53c5d9d4 | 1370 | bitmap_clear (visited); |
a28770e1 | 1371 | bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); |
f21d4d00 | 1372 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) |
4e976818 | 1373 | { |
cd9916a9 | 1374 | unsigned n; |
4e976818 | 1375 | |
cd9916a9 | 1376 | if (loop->header == NULL) |
1377 | { | |
1378 | error ("removed loop %d in loop tree", loop->num); | |
1379 | err = 1; | |
1380 | continue; | |
1381 | } | |
1382 | ||
a28770e1 | 1383 | n = get_loop_body_with_size (loop, bbs, n_basic_blocks_for_fn (cfun)); |
cd9916a9 | 1384 | if (loop->num_nodes != n) |
1385 | { | |
1386 | error ("size of loop %d should be %d, not %d", | |
1387 | loop->num, n, loop->num_nodes); | |
1388 | err = 1; | |
1389 | } | |
1390 | ||
1391 | for (j = 0; j < n; j++) | |
4e976818 | 1392 | { |
1393 | bb = bbs[j]; | |
1394 | ||
ff829efa | 1395 | if (!flow_bb_inside_loop_p (loop, bb)) |
1396 | { | |
1397 | error ("bb %d does not belong to loop %d", | |
1398 | bb->index, loop->num); | |
1399 | err = 1; | |
1400 | } | |
1401 | ||
4e976818 | 1402 | /* Ignore this block if it is in an inner loop. */ |
08b7917c | 1403 | if (bitmap_bit_p (visited, bb->index)) |
4e976818 | 1404 | continue; |
08b7917c | 1405 | bitmap_set_bit (visited, bb->index); |
4e976818 | 1406 | |
1407 | if (bb->loop_father != loop) | |
1408 | { | |
1409 | error ("bb %d has father loop %d, should be loop %d", | |
1410 | bb->index, bb->loop_father->num, loop->num); | |
1411 | err = 1; | |
1412 | } | |
1413 | } | |
4e976818 | 1414 | } |
cd9916a9 | 1415 | free (bbs); |
ff829efa | 1416 | sbitmap_free (visited); |
7fb12188 | 1417 | |
1418 | /* Check headers and latches. */ | |
f21d4d00 | 1419 | FOR_EACH_LOOP (loop, 0) |
7fb12188 | 1420 | { |
17519ba0 | 1421 | i = loop->num; |
cd9916a9 | 1422 | if (loop->header == NULL) |
1423 | continue; | |
ff829efa | 1424 | if (!bb_loop_header_p (loop->header)) |
1425 | { | |
1426 | error ("loop %d%'s header is not a loop header", i); | |
1427 | err = 1; | |
1428 | } | |
f24ec26f | 1429 | if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
cd665a06 | 1430 | && EDGE_COUNT (loop->header->preds) != 2) |
7fb12188 | 1431 | { |
bf776685 | 1432 | error ("loop %d%'s header does not have exactly 2 entries", i); |
7fb12188 | 1433 | err = 1; |
1434 | } | |
b375c775 | 1435 | if (loop->latch) |
1436 | { | |
1437 | if (!find_edge (loop->latch, loop->header)) | |
1438 | { | |
1439 | error ("loop %d%'s latch does not have an edge to its header", i); | |
1440 | err = 1; | |
1441 | } | |
1442 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, loop->header)) | |
1443 | { | |
1444 | error ("loop %d%'s latch is not dominated by its header", i); | |
1445 | err = 1; | |
1446 | } | |
1447 | } | |
f24ec26f | 1448 | if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
7fb12188 | 1449 | { |
ea091dfd | 1450 | if (!single_succ_p (loop->latch)) |
7fb12188 | 1451 | { |
bf776685 | 1452 | error ("loop %d%'s latch does not have exactly 1 successor", i); |
7fb12188 | 1453 | err = 1; |
1454 | } | |
ea091dfd | 1455 | if (single_succ (loop->latch) != loop->header) |
7fb12188 | 1456 | { |
bf776685 | 1457 | error ("loop %d%'s latch does not have header as successor", i); |
7fb12188 | 1458 | err = 1; |
1459 | } | |
1460 | if (loop->latch->loop_father != loop) | |
1461 | { | |
bf776685 | 1462 | error ("loop %d%'s latch does not belong directly to it", i); |
7fb12188 | 1463 | err = 1; |
1464 | } | |
1465 | } | |
1466 | if (loop->header->loop_father != loop) | |
1467 | { | |
bf776685 | 1468 | error ("loop %d%'s header does not belong directly to it", i); |
7fb12188 | 1469 | err = 1; |
1470 | } | |
f24ec26f | 1471 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) |
a5414ff5 | 1472 | && (loop_latch_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)) |
1473 | { | |
bf776685 | 1474 | error ("loop %d%'s latch is marked as part of irreducible region", i); |
a5414ff5 | 1475 | err = 1; |
1476 | } | |
7fb12188 | 1477 | } |
1478 | ||
862be747 | 1479 | /* Check irreducible loops. */ |
f24ec26f | 1480 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
862be747 | 1481 | { |
1482 | /* Record old info. */ | |
fe672ac0 | 1483 | irreds = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
fc00614f | 1484 | FOR_EACH_BB_FN (bb, cfun) |
a5414ff5 | 1485 | { |
cd665a06 | 1486 | edge_iterator ei; |
a5414ff5 | 1487 | if (bb->flags & BB_IRREDUCIBLE_LOOP) |
08b7917c | 1488 | bitmap_set_bit (irreds, bb->index); |
a5414ff5 | 1489 | else |
08b7917c | 1490 | bitmap_clear_bit (irreds, bb->index); |
cd665a06 | 1491 | FOR_EACH_EDGE (e, ei, bb->succs) |
a5414ff5 | 1492 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) |
4c9e08a4 | 1493 | e->flags |= EDGE_ALL_FLAGS + 1; |
a5414ff5 | 1494 | } |
862be747 | 1495 | |
1496 | /* Recount it. */ | |
7194de72 | 1497 | mark_irreducible_loops (); |
862be747 | 1498 | |
1499 | /* Compare. */ | |
fc00614f | 1500 | FOR_EACH_BB_FN (bb, cfun) |
862be747 | 1501 | { |
cd665a06 | 1502 | edge_iterator ei; |
1503 | ||
862be747 | 1504 | if ((bb->flags & BB_IRREDUCIBLE_LOOP) |
08b7917c | 1505 | && !bitmap_bit_p (irreds, bb->index)) |
862be747 | 1506 | { |
0a81f5a0 | 1507 | error ("basic block %d should be marked irreducible", bb->index); |
862be747 | 1508 | err = 1; |
1509 | } | |
1510 | else if (!(bb->flags & BB_IRREDUCIBLE_LOOP) | |
08b7917c | 1511 | && bitmap_bit_p (irreds, bb->index)) |
862be747 | 1512 | { |
0a81f5a0 | 1513 | error ("basic block %d should not be marked irreducible", bb->index); |
862be747 | 1514 | err = 1; |
1515 | } | |
cd665a06 | 1516 | FOR_EACH_EDGE (e, ei, bb->succs) |
a5414ff5 | 1517 | { |
1518 | if ((e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1519 | && !(e->flags & (EDGE_ALL_FLAGS + 1))) | |
1520 | { | |
0a81f5a0 | 1521 | error ("edge from %d to %d should be marked irreducible", |
a5414ff5 | 1522 | e->src->index, e->dest->index); |
1523 | err = 1; | |
1524 | } | |
1525 | else if (!(e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1526 | && (e->flags & (EDGE_ALL_FLAGS + 1))) | |
1527 | { | |
0a81f5a0 | 1528 | error ("edge from %d to %d should not be marked irreducible", |
a5414ff5 | 1529 | e->src->index, e->dest->index); |
1530 | err = 1; | |
1531 | } | |
1532 | e->flags &= ~(EDGE_ALL_FLAGS + 1); | |
1533 | } | |
862be747 | 1534 | } |
1535 | free (irreds); | |
1536 | } | |
1537 | ||
dce58e66 | 1538 | /* Check the recorded loop exits. */ |
f21d4d00 | 1539 | FOR_EACH_LOOP (loop, 0) |
bb445479 | 1540 | { |
ccae4f9f | 1541 | if (!loop->exits || loop->exits->e != NULL) |
dce58e66 | 1542 | { |
1543 | error ("corrupted head of the exits list of loop %d", | |
1544 | loop->num); | |
1545 | err = 1; | |
1546 | } | |
1547 | else | |
1548 | { | |
1549 | /* Check that the list forms a cycle, and all elements except | |
1550 | for the head are nonnull. */ | |
ccae4f9f | 1551 | for (mexit = loop->exits, exit = mexit->next, i = 0; |
dce58e66 | 1552 | exit->e && exit != mexit; |
1553 | exit = exit->next) | |
1554 | { | |
1555 | if (i++ & 1) | |
1556 | mexit = mexit->next; | |
1557 | } | |
1558 | ||
ccae4f9f | 1559 | if (exit != loop->exits) |
dce58e66 | 1560 | { |
1561 | error ("corrupted exits list of loop %d", loop->num); | |
1562 | err = 1; | |
1563 | } | |
1564 | } | |
1565 | ||
f24ec26f | 1566 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1567 | { |
ccae4f9f | 1568 | if (loop->exits->next != loop->exits) |
dce58e66 | 1569 | { |
1570 | error ("nonempty exits list of loop %d, but exits are not recorded", | |
1571 | loop->num); | |
1572 | err = 1; | |
1573 | } | |
1574 | } | |
1575 | } | |
1576 | ||
f24ec26f | 1577 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1578 | { |
1579 | unsigned n_exits = 0, eloops; | |
1580 | ||
cd9916a9 | 1581 | sizes = XCNEWVEC (unsigned, num); |
17519ba0 | 1582 | memset (sizes, 0, sizeof (unsigned) * num); |
fc00614f | 1583 | FOR_EACH_BB_FN (bb, cfun) |
bb445479 | 1584 | { |
cd665a06 | 1585 | edge_iterator ei; |
7194de72 | 1586 | if (bb->loop_father == current_loops->tree_root) |
bb445479 | 1587 | continue; |
cd665a06 | 1588 | FOR_EACH_EDGE (e, ei, bb->succs) |
bb445479 | 1589 | { |
bb445479 | 1590 | if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) |
1591 | continue; | |
1592 | ||
dce58e66 | 1593 | n_exits++; |
1594 | exit = get_exit_descriptions (e); | |
1595 | if (!exit) | |
1596 | { | |
bf776685 | 1597 | error ("exit %d->%d not recorded", |
dce58e66 | 1598 | e->src->index, e->dest->index); |
1599 | err = 1; | |
1600 | } | |
1601 | eloops = 0; | |
1602 | for (; exit; exit = exit->next_e) | |
1603 | eloops++; | |
1604 | ||
bb445479 | 1605 | for (loop = bb->loop_father; |
1032e48d | 1606 | loop != e->dest->loop_father |
1607 | /* When a loop exit is also an entry edge which | |
1608 | can happen when avoiding CFG manipulations | |
1609 | then the last loop exited is the outer loop | |
1610 | of the loop entered. */ | |
1611 | && loop != loop_outer (e->dest->loop_father); | |
9e3536f4 | 1612 | loop = loop_outer (loop)) |
bb445479 | 1613 | { |
dce58e66 | 1614 | eloops--; |
bb445479 | 1615 | sizes[loop->num]++; |
dce58e66 | 1616 | } |
1617 | ||
1618 | if (eloops != 0) | |
1619 | { | |
bf776685 | 1620 | error ("wrong list of exited loops for edge %d->%d", |
dce58e66 | 1621 | e->src->index, e->dest->index); |
1622 | err = 1; | |
bb445479 | 1623 | } |
1624 | } | |
1625 | } | |
1626 | ||
2ef51f0e | 1627 | if (n_exits != current_loops->exits->elements ()) |
bb445479 | 1628 | { |
bf776685 | 1629 | error ("too many loop exits recorded"); |
dce58e66 | 1630 | err = 1; |
1631 | } | |
bb445479 | 1632 | |
f21d4d00 | 1633 | FOR_EACH_LOOP (loop, 0) |
dce58e66 | 1634 | { |
1635 | eloops = 0; | |
ccae4f9f | 1636 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
dce58e66 | 1637 | eloops++; |
1638 | if (eloops != sizes[loop->num]) | |
bb445479 | 1639 | { |
dce58e66 | 1640 | error ("%d exits recorded for loop %d (having %d exits)", |
1641 | eloops, loop->num, sizes[loop->num]); | |
bb445479 | 1642 | err = 1; |
1643 | } | |
1644 | } | |
cd9916a9 | 1645 | |
1646 | free (sizes); | |
bb445479 | 1647 | } |
1648 | ||
cc636d56 | 1649 | gcc_assert (!err); |
bb445479 | 1650 | |
79f958cb | 1651 | if (!dom_available) |
1652 | free_dominance_info (CDI_DOMINATORS); | |
7fb12188 | 1653 | } |
1654 | ||
1655 | /* Returns latch edge of LOOP. */ | |
1656 | edge | |
4c9e08a4 | 1657 | loop_latch_edge (const struct loop *loop) |
7fb12188 | 1658 | { |
c6356c17 | 1659 | return find_edge (loop->latch, loop->header); |
65f34de5 | 1660 | } |
7fb12188 | 1661 | |
1662 | /* Returns preheader edge of LOOP. */ | |
1663 | edge | |
4c9e08a4 | 1664 | loop_preheader_edge (const struct loop *loop) |
7fb12188 | 1665 | { |
1666 | edge e; | |
cd665a06 | 1667 | edge_iterator ei; |
7fb12188 | 1668 | |
f24ec26f | 1669 | gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)); |
d8a0d6b8 | 1670 | |
cd665a06 | 1671 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
1672 | if (e->src != loop->latch) | |
1673 | break; | |
7fb12188 | 1674 | |
1675 | return e; | |
1676 | } | |
ffc6b5d5 | 1677 | |
1678 | /* Returns true if E is an exit of LOOP. */ | |
1679 | ||
1680 | bool | |
7ecb5bb2 | 1681 | loop_exit_edge_p (const struct loop *loop, const_edge e) |
ffc6b5d5 | 1682 | { |
1683 | return (flow_bb_inside_loop_p (loop, e->src) | |
1684 | && !flow_bb_inside_loop_p (loop, e->dest)); | |
1685 | } | |
d9e7e1a2 | 1686 | |
1687 | /* Returns the single exit edge of LOOP, or NULL if LOOP has either no exit | |
dce58e66 | 1688 | or more than one exit. If loops do not have the exits recorded, NULL |
1689 | is returned always. */ | |
d9e7e1a2 | 1690 | |
1691 | edge | |
1692 | single_exit (const struct loop *loop) | |
1693 | { | |
ccae4f9f | 1694 | struct loop_exit *exit = loop->exits->next; |
d9e7e1a2 | 1695 | |
f24ec26f | 1696 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1697 | return NULL; |
d9e7e1a2 | 1698 | |
ccae4f9f | 1699 | if (exit->e && exit->next == loop->exits) |
dce58e66 | 1700 | return exit->e; |
1701 | else | |
1702 | return NULL; | |
d9e7e1a2 | 1703 | } |
255b6be7 | 1704 | |
259c0e44 | 1705 | /* Returns true when BB has an incoming edge exiting LOOP. */ |
255b6be7 | 1706 | |
1707 | bool | |
259c0e44 | 1708 | loop_exits_to_bb_p (struct loop *loop, basic_block bb) |
255b6be7 | 1709 | { |
1710 | edge e; | |
1711 | edge_iterator ei; | |
1712 | ||
1713 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1714 | if (loop_exit_edge_p (loop, e)) | |
1715 | return true; | |
1716 | ||
1717 | return false; | |
1718 | } | |
259c0e44 | 1719 | |
1720 | /* Returns true when BB has an outgoing edge exiting LOOP. */ | |
1721 | ||
1722 | bool | |
1723 | loop_exits_from_bb_p (struct loop *loop, basic_block bb) | |
1724 | { | |
1725 | edge e; | |
1726 | edge_iterator ei; | |
1727 | ||
1728 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1729 | if (loop_exit_edge_p (loop, e)) | |
1730 | return true; | |
1731 | ||
1732 | return false; | |
1733 | } | |
f55775aa | 1734 | |
1735 | /* Return location corresponding to the loop control condition if possible. */ | |
1736 | ||
1737 | location_t | |
1738 | get_loop_location (struct loop *loop) | |
1739 | { | |
cb534875 | 1740 | rtx_insn *insn = NULL; |
f55775aa | 1741 | struct niter_desc *desc = NULL; |
1742 | edge exit; | |
1743 | ||
1744 | /* For a for or while loop, we would like to return the location | |
1745 | of the for or while statement, if possible. To do this, look | |
1746 | for the branch guarding the loop back-edge. */ | |
1747 | ||
1748 | /* If this is a simple loop with an in_edge, then the loop control | |
1749 | branch is typically at the end of its source. */ | |
1750 | desc = get_simple_loop_desc (loop); | |
1751 | if (desc->in_edge) | |
1752 | { | |
1753 | FOR_BB_INSNS_REVERSE (desc->in_edge->src, insn) | |
1754 | { | |
1755 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1756 | return INSN_LOCATION (insn); | |
1757 | } | |
1758 | } | |
1759 | /* If loop has a single exit, then the loop control branch | |
1760 | must be at the end of its source. */ | |
1761 | if ((exit = single_exit (loop))) | |
1762 | { | |
1763 | FOR_BB_INSNS_REVERSE (exit->src, insn) | |
1764 | { | |
1765 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1766 | return INSN_LOCATION (insn); | |
1767 | } | |
1768 | } | |
1769 | /* Next check the latch, to see if it is non-empty. */ | |
1770 | FOR_BB_INSNS_REVERSE (loop->latch, insn) | |
1771 | { | |
1772 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1773 | return INSN_LOCATION (insn); | |
1774 | } | |
1775 | /* Finally, if none of the above identifies the loop control branch, | |
1776 | return the first location in the loop header. */ | |
1777 | FOR_BB_INSNS (loop->header, insn) | |
1778 | { | |
1779 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1780 | return INSN_LOCATION (insn); | |
1781 | } | |
1782 | /* If all else fails, simply return the current function location. */ | |
1783 | return DECL_SOURCE_LOCATION (current_function_decl); | |
1784 | } | |
1785 | ||
f86b328b | 1786 | /* Records that every statement in LOOP is executed I_BOUND times. |
1787 | REALISTIC is true if I_BOUND is expected to be close to the real number | |
1788 | of iterations. UPPER is true if we are sure the loop iterates at most | |
1789 | I_BOUND times. */ | |
1790 | ||
1791 | void | |
5de9d3ed | 1792 | record_niter_bound (struct loop *loop, const widest_int &i_bound, |
6b409616 | 1793 | bool realistic, bool upper) |
f86b328b | 1794 | { |
1795 | /* Update the bounds only when there is no previous estimation, or when the | |
1796 | current estimation is smaller. */ | |
1797 | if (upper | |
1798 | && (!loop->any_upper_bound | |
6b409616 | 1799 | || wi::ltu_p (i_bound, loop->nb_iterations_upper_bound))) |
f86b328b | 1800 | { |
1801 | loop->any_upper_bound = true; | |
1802 | loop->nb_iterations_upper_bound = i_bound; | |
1803 | } | |
1804 | if (realistic | |
1805 | && (!loop->any_estimate | |
6b409616 | 1806 | || wi::ltu_p (i_bound, loop->nb_iterations_estimate))) |
f86b328b | 1807 | { |
1808 | loop->any_estimate = true; | |
1809 | loop->nb_iterations_estimate = i_bound; | |
1810 | } | |
1811 | ||
1812 | /* If an upper bound is smaller than the realistic estimate of the | |
1813 | number of iterations, use the upper bound instead. */ | |
1814 | if (loop->any_upper_bound | |
1815 | && loop->any_estimate | |
6b409616 | 1816 | && wi::ltu_p (loop->nb_iterations_upper_bound, |
1817 | loop->nb_iterations_estimate)) | |
f86b328b | 1818 | loop->nb_iterations_estimate = loop->nb_iterations_upper_bound; |
1819 | } | |
1820 | ||
4e948f5a | 1821 | /* Similar to get_estimated_loop_iterations, but returns the estimate only |
f86b328b | 1822 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate |
1823 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
1824 | ||
1825 | HOST_WIDE_INT | |
4e948f5a | 1826 | get_estimated_loop_iterations_int (struct loop *loop) |
f86b328b | 1827 | { |
5de9d3ed | 1828 | widest_int nit; |
f86b328b | 1829 | HOST_WIDE_INT hwi_nit; |
1830 | ||
1831 | if (!get_estimated_loop_iterations (loop, &nit)) | |
1832 | return -1; | |
1833 | ||
6b409616 | 1834 | if (!wi::fits_shwi_p (nit)) |
f86b328b | 1835 | return -1; |
1836 | hwi_nit = nit.to_shwi (); | |
1837 | ||
1838 | return hwi_nit < 0 ? -1 : hwi_nit; | |
1839 | } | |
1840 | ||
1841 | /* Returns an upper bound on the number of executions of statements | |
1842 | in the LOOP. For statements before the loop exit, this exceeds | |
1843 | the number of execution of the latch by one. */ | |
1844 | ||
1845 | HOST_WIDE_INT | |
1846 | max_stmt_executions_int (struct loop *loop) | |
1847 | { | |
4e948f5a | 1848 | HOST_WIDE_INT nit = get_max_loop_iterations_int (loop); |
f86b328b | 1849 | HOST_WIDE_INT snit; |
1850 | ||
1851 | if (nit == -1) | |
1852 | return -1; | |
1853 | ||
1854 | snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
1855 | ||
1856 | /* If the computation overflows, return -1. */ | |
1857 | return snit < 0 ? -1 : snit; | |
1858 | } | |
1859 | ||
1860 | /* Sets NIT to the estimated number of executions of the latch of the | |
1861 | LOOP. If we have no reliable estimate, the function returns false, otherwise | |
1862 | returns true. */ | |
1863 | ||
1864 | bool | |
5de9d3ed | 1865 | get_estimated_loop_iterations (struct loop *loop, widest_int *nit) |
f86b328b | 1866 | { |
1867 | /* Even if the bound is not recorded, possibly we can derrive one from | |
1868 | profile. */ | |
1869 | if (!loop->any_estimate) | |
1870 | { | |
1871 | if (loop->header->count) | |
1872 | { | |
6b409616 | 1873 | *nit = gcov_type_to_wide_int |
f86b328b | 1874 | (expected_loop_iterations_unbounded (loop) + 1); |
1875 | return true; | |
1876 | } | |
1877 | return false; | |
1878 | } | |
1879 | ||
1880 | *nit = loop->nb_iterations_estimate; | |
1881 | return true; | |
1882 | } | |
1883 | ||
1884 | /* Sets NIT to an upper bound for the maximum number of executions of the | |
1885 | latch of the LOOP. If we have no reliable estimate, the function returns | |
1886 | false, otherwise returns true. */ | |
1887 | ||
1888 | bool | |
5de9d3ed | 1889 | get_max_loop_iterations (struct loop *loop, widest_int *nit) |
f86b328b | 1890 | { |
1891 | if (!loop->any_upper_bound) | |
1892 | return false; | |
1893 | ||
1894 | *nit = loop->nb_iterations_upper_bound; | |
1895 | return true; | |
1896 | } | |
4e948f5a | 1897 | |
1898 | /* Similar to get_max_loop_iterations, but returns the estimate only | |
1899 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
1900 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
1901 | ||
1902 | HOST_WIDE_INT | |
1903 | get_max_loop_iterations_int (struct loop *loop) | |
1904 | { | |
5de9d3ed | 1905 | widest_int nit; |
4e948f5a | 1906 | HOST_WIDE_INT hwi_nit; |
1907 | ||
1908 | if (!get_max_loop_iterations (loop, &nit)) | |
1909 | return -1; | |
1910 | ||
6b409616 | 1911 | if (!wi::fits_shwi_p (nit)) |
4e948f5a | 1912 | return -1; |
1913 | hwi_nit = nit.to_shwi (); | |
1914 | ||
1915 | return hwi_nit < 0 ? -1 : hwi_nit; | |
1916 | } | |
1917 | ||
424a4a92 | 1918 | /* Returns the loop depth of the loop BB belongs to. */ |
4e948f5a | 1919 | |
424a4a92 | 1920 | int |
1921 | bb_loop_depth (const_basic_block bb) | |
1922 | { | |
1923 | return bb->loop_father ? loop_depth (bb->loop_father) : 0; | |
1924 | } | |
d25159cc | 1925 | |
1926 | /* Marks LOOP for removal and sets LOOPS_NEED_FIXUP. */ | |
1927 | ||
1928 | void | |
1929 | mark_loop_for_removal (loop_p loop) | |
1930 | { | |
6437689e | 1931 | loop->former_header = loop->header; |
d25159cc | 1932 | loop->header = NULL; |
1933 | loop->latch = NULL; | |
1934 | loops_state_set (LOOPS_NEED_FIXUP); | |
1935 | } | |
6437689e | 1936 |