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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" |
b811afb0 | 25 | #include "function.h" |
65f34de5 | 26 | #include "basic-block.h" |
862be747 | 27 | #include "cfgloop.h" |
0b205f4c | 28 | #include "diagnostic-core.h" |
862be747 | 29 | #include "flags.h" |
4ee9c684 | 30 | #include "tree.h" |
bc61cadb | 31 | #include "pointer-set.h" |
32 | #include "tree-ssa-alias.h" | |
33 | #include "internal-fn.h" | |
34 | #include "gimple-expr.h" | |
35 | #include "is-a.h" | |
073c1fd5 | 36 | #include "gimple.h" |
dcf1a1ec | 37 | #include "gimple-iterator.h" |
073c1fd5 | 38 | #include "gimple-ssa.h" |
b9ed1410 | 39 | #include "dumpfile.h" |
5f5d4cd1 | 40 | |
7194de72 | 41 | static void flow_loops_cfg_dump (FILE *); |
65f34de5 | 42 | \f |
43 | /* Dump loop related CFG information. */ | |
44 | ||
45 | static void | |
7194de72 | 46 | flow_loops_cfg_dump (FILE *file) |
65f34de5 | 47 | { |
4c26117a | 48 | basic_block bb; |
65f34de5 | 49 | |
7194de72 | 50 | if (!file) |
65f34de5 | 51 | return; |
52 | ||
fc00614f | 53 | FOR_EACH_BB_FN (bb, cfun) |
65f34de5 | 54 | { |
55 | edge succ; | |
cd665a06 | 56 | edge_iterator ei; |
65f34de5 | 57 | |
4c26117a | 58 | fprintf (file, ";; %d succs { ", bb->index); |
cd665a06 | 59 | FOR_EACH_EDGE (succ, ei, bb->succs) |
b3d6de89 | 60 | fprintf (file, "%d ", succ->dest->index); |
7fb12188 | 61 | fprintf (file, "}\n"); |
65f34de5 | 62 | } |
65f34de5 | 63 | } |
64 | ||
d10cfa8d | 65 | /* Return nonzero if the nodes of LOOP are a subset of OUTER. */ |
65f34de5 | 66 | |
7fb12188 | 67 | bool |
4c9e08a4 | 68 | flow_loop_nested_p (const struct loop *outer, const struct loop *loop) |
65f34de5 | 69 | { |
9e3536f4 | 70 | unsigned odepth = loop_depth (outer); |
71 | ||
72 | return (loop_depth (loop) > odepth | |
f1f41a6c | 73 | && (*loop->superloops)[odepth] == outer); |
65f34de5 | 74 | } |
75 | ||
b4d679c5 | 76 | /* Returns the loop such that LOOP is nested DEPTH (indexed from zero) |
77 | loops within LOOP. */ | |
7d23383d | 78 | |
79 | struct loop * | |
80 | superloop_at_depth (struct loop *loop, unsigned depth) | |
81 | { | |
9e3536f4 | 82 | unsigned ldepth = loop_depth (loop); |
83 | ||
84 | gcc_assert (depth <= ldepth); | |
7d23383d | 85 | |
9e3536f4 | 86 | if (depth == ldepth) |
7d23383d | 87 | return loop; |
88 | ||
f1f41a6c | 89 | return (*loop->superloops)[depth]; |
7d23383d | 90 | } |
91 | ||
4a6f9e19 | 92 | /* Returns the list of the latch edges of LOOP. */ |
93 | ||
f1f41a6c | 94 | static vec<edge> |
4a6f9e19 | 95 | get_loop_latch_edges (const struct loop *loop) |
96 | { | |
97 | edge_iterator ei; | |
98 | edge e; | |
1e094109 | 99 | vec<edge> ret = vNULL; |
4a6f9e19 | 100 | |
101 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
102 | { | |
103 | if (dominated_by_p (CDI_DOMINATORS, e->src, loop->header)) | |
f1f41a6c | 104 | ret.safe_push (e); |
4a6f9e19 | 105 | } |
106 | ||
107 | return ret; | |
108 | } | |
109 | ||
65f34de5 | 110 | /* Dump the loop information specified by LOOP to the stream FILE |
111 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
112 | ||
113 | void | |
4c9e08a4 | 114 | flow_loop_dump (const struct loop *loop, FILE *file, |
115 | void (*loop_dump_aux) (const struct loop *, FILE *, int), | |
116 | int verbose) | |
65f34de5 | 117 | { |
7fb12188 | 118 | basic_block *bbs; |
862be747 | 119 | unsigned i; |
f1f41a6c | 120 | vec<edge> latches; |
4a6f9e19 | 121 | edge e; |
7fb12188 | 122 | |
65f34de5 | 123 | if (! loop || ! loop->header) |
124 | return; | |
125 | ||
58b3f902 | 126 | fprintf (file, ";;\n;; Loop %d\n", loop->num); |
65f34de5 | 127 | |
4a6f9e19 | 128 | fprintf (file, ";; header %d, ", loop->header->index); |
129 | if (loop->latch) | |
130 | fprintf (file, "latch %d\n", loop->latch->index); | |
131 | else | |
132 | { | |
133 | fprintf (file, "multiple latches:"); | |
134 | latches = get_loop_latch_edges (loop); | |
f1f41a6c | 135 | FOR_EACH_VEC_ELT (latches, i, e) |
4a6f9e19 | 136 | fprintf (file, " %d", e->src->index); |
f1f41a6c | 137 | latches.release (); |
4a6f9e19 | 138 | fprintf (file, "\n"); |
139 | } | |
140 | ||
8543a448 | 141 | fprintf (file, ";; depth %d, outer %ld\n", |
9e3536f4 | 142 | loop_depth (loop), (long) (loop_outer (loop) |
143 | ? loop_outer (loop)->num : -1)); | |
65f34de5 | 144 | |
7fb12188 | 145 | fprintf (file, ";; nodes:"); |
146 | bbs = get_loop_body (loop); | |
147 | for (i = 0; i < loop->num_nodes; i++) | |
148 | fprintf (file, " %d", bbs[i]->index); | |
149 | free (bbs); | |
150 | fprintf (file, "\n"); | |
5cc577b6 | 151 | |
65f34de5 | 152 | if (loop_dump_aux) |
153 | loop_dump_aux (loop, file, verbose); | |
154 | } | |
155 | ||
7194de72 | 156 | /* Dump the loop information about loops to the stream FILE, |
65f34de5 | 157 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ |
158 | ||
159 | void | |
7194de72 | 160 | flow_loops_dump (FILE *file, void (*loop_dump_aux) (const struct loop *, FILE *, int), int verbose) |
65f34de5 | 161 | { |
17519ba0 | 162 | struct loop *loop; |
65f34de5 | 163 | |
7194de72 | 164 | if (!current_loops || ! file) |
65f34de5 | 165 | return; |
166 | ||
41f75a99 | 167 | fprintf (file, ";; %d loops found\n", number_of_loops (cfun)); |
7fb12188 | 168 | |
f21d4d00 | 169 | FOR_EACH_LOOP (loop, LI_INCLUDE_ROOT) |
65f34de5 | 170 | { |
7fb12188 | 171 | flow_loop_dump (loop, file, loop_dump_aux, verbose); |
65f34de5 | 172 | } |
173 | ||
174 | if (verbose) | |
7194de72 | 175 | flow_loops_cfg_dump (file); |
65f34de5 | 176 | } |
177 | ||
7fb12188 | 178 | /* Free data allocated for LOOP. */ |
ccae4f9f | 179 | |
a5414ff5 | 180 | void |
4c9e08a4 | 181 | flow_loop_free (struct loop *loop) |
7fb12188 | 182 | { |
dce58e66 | 183 | struct loop_exit *exit, *next; |
184 | ||
f1f41a6c | 185 | vec_free (loop->superloops); |
dce58e66 | 186 | |
187 | /* Break the list of the loop exit records. They will be freed when the | |
188 | corresponding edge is rescanned or removed, and this avoids | |
189 | accessing the (already released) head of the list stored in the | |
190 | loop structure. */ | |
ccae4f9f | 191 | for (exit = loop->exits->next; exit != loop->exits; exit = next) |
dce58e66 | 192 | { |
193 | next = exit->next; | |
194 | exit->next = exit; | |
195 | exit->prev = exit; | |
196 | } | |
ccae4f9f | 197 | |
198 | ggc_free (loop->exits); | |
199 | ggc_free (loop); | |
7fb12188 | 200 | } |
201 | ||
65f34de5 | 202 | /* Free all the memory allocated for LOOPS. */ |
203 | ||
204 | void | |
4c9e08a4 | 205 | flow_loops_free (struct loops *loops) |
65f34de5 | 206 | { |
17519ba0 | 207 | if (loops->larray) |
65f34de5 | 208 | { |
862be747 | 209 | unsigned i; |
17519ba0 | 210 | loop_p loop; |
65f34de5 | 211 | |
212 | /* Free the loop descriptors. */ | |
f1f41a6c | 213 | FOR_EACH_VEC_SAFE_ELT (loops->larray, i, loop) |
65f34de5 | 214 | { |
7fb12188 | 215 | if (!loop) |
216 | continue; | |
217 | ||
218 | flow_loop_free (loop); | |
65f34de5 | 219 | } |
5cc577b6 | 220 | |
f1f41a6c | 221 | vec_free (loops->larray); |
65f34de5 | 222 | } |
223 | } | |
224 | ||
7fb12188 | 225 | /* Find the nodes contained within the LOOP with header HEADER. |
226 | Return the number of nodes within the loop. */ | |
65f34de5 | 227 | |
053fdd99 | 228 | int |
4c9e08a4 | 229 | flow_loop_nodes_find (basic_block header, struct loop *loop) |
65f34de5 | 230 | { |
1e094109 | 231 | vec<basic_block> stack = vNULL; |
7fb12188 | 232 | int num_nodes = 1; |
4a6f9e19 | 233 | edge latch; |
234 | edge_iterator latch_ei; | |
65f34de5 | 235 | |
7fb12188 | 236 | header->loop_father = loop; |
65f34de5 | 237 | |
4a6f9e19 | 238 | FOR_EACH_EDGE (latch, latch_ei, loop->header->preds) |
65f34de5 | 239 | { |
4a6f9e19 | 240 | if (latch->src->loop_father == loop |
241 | || !dominated_by_p (CDI_DOMINATORS, latch->src, loop->header)) | |
242 | continue; | |
243 | ||
65f34de5 | 244 | num_nodes++; |
f1f41a6c | 245 | stack.safe_push (latch->src); |
4a6f9e19 | 246 | latch->src->loop_father = loop; |
4c9e08a4 | 247 | |
f1f41a6c | 248 | while (!stack.is_empty ()) |
65f34de5 | 249 | { |
7fb12188 | 250 | basic_block node; |
251 | edge e; | |
cd665a06 | 252 | edge_iterator ei; |
65f34de5 | 253 | |
f1f41a6c | 254 | node = stack.pop (); |
4c9e08a4 | 255 | |
cd665a06 | 256 | FOR_EACH_EDGE (e, ei, node->preds) |
65f34de5 | 257 | { |
7fb12188 | 258 | basic_block ancestor = e->src; |
259 | ||
4a6f9e19 | 260 | if (ancestor->loop_father != loop) |
7fb12188 | 261 | { |
262 | ancestor->loop_father = loop; | |
7fb12188 | 263 | num_nodes++; |
f1f41a6c | 264 | stack.safe_push (ancestor); |
7fb12188 | 265 | } |
65f34de5 | 266 | } |
267 | } | |
268 | } | |
f1f41a6c | 269 | stack.release (); |
4a6f9e19 | 270 | |
65f34de5 | 271 | return num_nodes; |
272 | } | |
273 | ||
9e3536f4 | 274 | /* Records the vector of superloops of the loop LOOP, whose immediate |
275 | superloop is FATHER. */ | |
276 | ||
a5414ff5 | 277 | static void |
9e3536f4 | 278 | establish_preds (struct loop *loop, struct loop *father) |
a5414ff5 | 279 | { |
9e3536f4 | 280 | loop_p ploop; |
281 | unsigned depth = loop_depth (father) + 1; | |
282 | unsigned i; | |
b811afb0 | 283 | |
f1f41a6c | 284 | loop->superloops = 0; |
285 | vec_alloc (loop->superloops, depth); | |
286 | FOR_EACH_VEC_SAFE_ELT (father->superloops, i, ploop) | |
287 | loop->superloops->quick_push (ploop); | |
288 | loop->superloops->quick_push (father); | |
a5414ff5 | 289 | |
290 | for (ploop = loop->inner; ploop; ploop = ploop->next) | |
9e3536f4 | 291 | establish_preds (ploop, loop); |
a5414ff5 | 292 | } |
293 | ||
7fb12188 | 294 | /* Add LOOP to the loop hierarchy tree where FATHER is father of the |
a5414ff5 | 295 | added loop. If LOOP has some children, take care of that their |
296 | pred field will be initialized correctly. */ | |
65f34de5 | 297 | |
7fb12188 | 298 | void |
4c9e08a4 | 299 | flow_loop_tree_node_add (struct loop *father, struct loop *loop) |
65f34de5 | 300 | { |
7fb12188 | 301 | loop->next = father->inner; |
302 | father->inner = loop; | |
7fb12188 | 303 | |
9e3536f4 | 304 | establish_preds (loop, father); |
65f34de5 | 305 | } |
306 | ||
7fb12188 | 307 | /* Remove LOOP from the loop hierarchy tree. */ |
65f34de5 | 308 | |
7fb12188 | 309 | void |
4c9e08a4 | 310 | flow_loop_tree_node_remove (struct loop *loop) |
65f34de5 | 311 | { |
7fb12188 | 312 | struct loop *prev, *father; |
65f34de5 | 313 | |
9e3536f4 | 314 | father = loop_outer (loop); |
65f34de5 | 315 | |
7fb12188 | 316 | /* Remove loop from the list of sons. */ |
317 | if (father->inner == loop) | |
318 | father->inner = loop->next; | |
319 | else | |
320 | { | |
9e3536f4 | 321 | for (prev = father->inner; prev->next != loop; prev = prev->next) |
322 | continue; | |
7fb12188 | 323 | prev->next = loop->next; |
324 | } | |
65f34de5 | 325 | |
f1f41a6c | 326 | loop->superloops = NULL; |
65f34de5 | 327 | } |
328 | ||
dce58e66 | 329 | /* Allocates and returns new loop structure. */ |
330 | ||
331 | struct loop * | |
332 | alloc_loop (void) | |
333 | { | |
ba72912a | 334 | struct loop *loop = ggc_alloc_cleared_loop (); |
ccae4f9f | 335 | |
ba72912a | 336 | loop->exits = ggc_alloc_cleared_loop_exit (); |
ccae4f9f | 337 | loop->exits->next = loop->exits->prev = loop->exits; |
26c166eb | 338 | loop->can_be_parallel = false; |
e913b5cd | 339 | loop->nb_iterations_upper_bound = 0; |
340 | loop->nb_iterations_estimate = 0; | |
dce58e66 | 341 | return loop; |
342 | } | |
343 | ||
a8a97201 | 344 | /* Initializes loops structure LOOPS, reserving place for NUM_LOOPS loops |
345 | (including the root of the loop tree). */ | |
346 | ||
7a569539 | 347 | void |
348 | init_loops_structure (struct function *fn, | |
349 | struct loops *loops, unsigned num_loops) | |
a8a97201 | 350 | { |
351 | struct loop *root; | |
352 | ||
353 | memset (loops, 0, sizeof *loops); | |
f1f41a6c | 354 | vec_alloc (loops->larray, num_loops); |
a8a97201 | 355 | |
356 | /* Dummy loop containing whole function. */ | |
357 | root = alloc_loop (); | |
a28770e1 | 358 | root->num_nodes = n_basic_blocks_for_fn (fn); |
34154e27 | 359 | root->latch = EXIT_BLOCK_PTR_FOR_FN (fn); |
360 | root->header = ENTRY_BLOCK_PTR_FOR_FN (fn); | |
361 | ENTRY_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
362 | EXIT_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
a8a97201 | 363 | |
f1f41a6c | 364 | loops->larray->quick_push (root); |
a8a97201 | 365 | loops->tree_root = root; |
366 | } | |
367 | ||
ff829efa | 368 | /* Returns whether HEADER is a loop header. */ |
369 | ||
370 | bool | |
371 | bb_loop_header_p (basic_block header) | |
372 | { | |
373 | edge_iterator ei; | |
374 | edge e; | |
375 | ||
376 | /* If we have an abnormal predecessor, do not consider the | |
377 | loop (not worth the problems). */ | |
378 | if (bb_has_abnormal_pred (header)) | |
379 | return false; | |
380 | ||
381 | /* Look for back edges where a predecessor is dominated | |
382 | by this block. A natural loop has a single entry | |
383 | node (header) that dominates all the nodes in the | |
384 | loop. It also has single back edge to the header | |
385 | from a latch node. */ | |
386 | FOR_EACH_EDGE (e, ei, header->preds) | |
387 | { | |
388 | basic_block latch = e->src; | |
34154e27 | 389 | if (latch != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
ff829efa | 390 | && dominated_by_p (CDI_DOMINATORS, latch, header)) |
391 | return true; | |
392 | } | |
393 | ||
394 | return false; | |
395 | } | |
396 | ||
5cc577b6 | 397 | /* Find all the natural loops in the function and save in LOOPS structure and |
6b42039a | 398 | recalculate loop_father information in basic block structures. |
ff829efa | 399 | If LOOPS is non-NULL then the loop structures for already recorded loops |
400 | will be re-used and their number will not change. We assume that no | |
401 | stale loops exist in LOOPS. | |
402 | When LOOPS is NULL it is allocated and re-built from scratch. | |
403 | Return the built LOOPS structure. */ | |
65f34de5 | 404 | |
ff829efa | 405 | struct loops * |
ffc6b5d5 | 406 | flow_loops_find (struct loops *loops) |
65f34de5 | 407 | { |
ff829efa | 408 | bool from_scratch = (loops == NULL); |
65f34de5 | 409 | int *rc_order; |
ff829efa | 410 | int b; |
411 | unsigned i; | |
65f34de5 | 412 | |
a8a97201 | 413 | /* Ensure that the dominators are computed. */ |
414 | calculate_dominance_info (CDI_DOMINATORS); | |
65f34de5 | 415 | |
ff829efa | 416 | if (!loops) |
a8a97201 | 417 | { |
ff829efa | 418 | loops = ggc_alloc_cleared_loops (); |
7a569539 | 419 | init_loops_structure (cfun, loops, 1); |
a8a97201 | 420 | } |
65f34de5 | 421 | |
ff829efa | 422 | /* Ensure that loop exits were released. */ |
423 | gcc_assert (loops->exits == NULL); | |
65f34de5 | 424 | |
ff829efa | 425 | /* Taking care of this degenerate case makes the rest of |
426 | this code simpler. */ | |
a28770e1 | 427 | if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) |
ff829efa | 428 | return loops; |
7fb12188 | 429 | |
ff829efa | 430 | /* The root loop node contains all basic-blocks. */ |
a28770e1 | 431 | loops->tree_root->num_nodes = n_basic_blocks_for_fn (cfun); |
4c9e08a4 | 432 | |
ff829efa | 433 | /* Compute depth first search order of the CFG so that outer |
434 | natural loops will be found before inner natural loops. */ | |
a28770e1 | 435 | rc_order = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); |
ff829efa | 436 | pre_and_rev_post_order_compute (NULL, rc_order, false); |
743f4ee2 | 437 | |
ff829efa | 438 | /* Gather all loop headers in reverse completion order and allocate |
439 | loop structures for loops that are not already present. */ | |
c2078b80 | 440 | auto_vec<loop_p> larray (loops->larray->length ()); |
a28770e1 | 441 | for (b = 0; b < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; b++) |
ff829efa | 442 | { |
f5a6b05f | 443 | basic_block header = BASIC_BLOCK_FOR_FN (cfun, rc_order[b]); |
ff829efa | 444 | if (bb_loop_header_p (header)) |
65f34de5 | 445 | { |
ff829efa | 446 | struct loop *loop; |
7fb12188 | 447 | |
ff829efa | 448 | /* The current active loop tree has valid loop-fathers for |
449 | header blocks. */ | |
450 | if (!from_scratch | |
451 | && header->loop_father->header == header) | |
7fb12188 | 452 | { |
ff829efa | 453 | loop = header->loop_father; |
454 | /* If we found an existing loop remove it from the | |
455 | loop tree. It is going to be inserted again | |
456 | below. */ | |
457 | flow_loop_tree_node_remove (loop); | |
7fb12188 | 458 | } |
ff829efa | 459 | else |
460 | { | |
461 | /* Otherwise allocate a new loop structure for the loop. */ | |
462 | loop = alloc_loop (); | |
463 | /* ??? We could re-use unused loop slots here. */ | |
464 | loop->num = loops->larray->length (); | |
465 | vec_safe_push (loops->larray, loop); | |
466 | loop->header = header; | |
467 | ||
468 | if (!from_scratch | |
469 | && dump_file && (dump_flags & TDF_DETAILS)) | |
470 | fprintf (dump_file, "flow_loops_find: discovered new " | |
471 | "loop %d with header %d\n", | |
472 | loop->num, header->index); | |
473 | } | |
b375c775 | 474 | /* Reset latch, we recompute it below. */ |
475 | loop->latch = NULL; | |
ff829efa | 476 | larray.safe_push (loop); |
65f34de5 | 477 | } |
65f34de5 | 478 | |
ff829efa | 479 | /* Make blocks part of the loop root node at start. */ |
480 | header->loop_father = loops->tree_root; | |
481 | } | |
7fb12188 | 482 | |
ff829efa | 483 | free (rc_order); |
7fb12188 | 484 | |
ff829efa | 485 | /* Now iterate over the loops found, insert them into the loop tree |
486 | and assign basic-block ownership. */ | |
487 | for (i = 0; i < larray.length (); ++i) | |
65f34de5 | 488 | { |
ff829efa | 489 | struct loop *loop = larray[i]; |
490 | basic_block header = loop->header; | |
491 | edge_iterator ei; | |
492 | edge e; | |
65f34de5 | 493 | |
ff829efa | 494 | flow_loop_tree_node_add (header->loop_father, loop); |
495 | loop->num_nodes = flow_loop_nodes_find (loop->header, loop); | |
65f34de5 | 496 | |
ff829efa | 497 | /* Look for the latch for this header block, if it has just a |
498 | single one. */ | |
499 | FOR_EACH_EDGE (e, ei, header->preds) | |
65f34de5 | 500 | { |
ff829efa | 501 | basic_block latch = e->src; |
4a6f9e19 | 502 | |
ff829efa | 503 | if (flow_bb_inside_loop_p (loop, latch)) |
65f34de5 | 504 | { |
ff829efa | 505 | if (loop->latch != NULL) |
65f34de5 | 506 | { |
ff829efa | 507 | /* More than one latch edge. */ |
508 | loop->latch = NULL; | |
509 | break; | |
65f34de5 | 510 | } |
ff829efa | 511 | loop->latch = latch; |
65f34de5 | 512 | } |
65f34de5 | 513 | } |
7fb12188 | 514 | } |
862be747 | 515 | |
ff829efa | 516 | return loops; |
65f34de5 | 517 | } |
518 | ||
4a6f9e19 | 519 | /* Ratio of frequencies of edges so that one of more latch edges is |
520 | considered to belong to inner loop with same header. */ | |
521 | #define HEAVY_EDGE_RATIO 8 | |
522 | ||
523 | /* Minimum number of samples for that we apply | |
524 | find_subloop_latch_edge_by_profile heuristics. */ | |
525 | #define HEAVY_EDGE_MIN_SAMPLES 10 | |
526 | ||
527 | /* If the profile info is available, finds an edge in LATCHES that much more | |
528 | frequent than the remaining edges. Returns such an edge, or NULL if we do | |
529 | not find one. | |
530 | ||
531 | We do not use guessed profile here, only the measured one. The guessed | |
532 | profile is usually too flat and unreliable for this (and it is mostly based | |
533 | on the loop structure of the program, so it does not make much sense to | |
534 | derive the loop structure from it). */ | |
48e1416a | 535 | |
4a6f9e19 | 536 | static edge |
f1f41a6c | 537 | find_subloop_latch_edge_by_profile (vec<edge> latches) |
4a6f9e19 | 538 | { |
539 | unsigned i; | |
540 | edge e, me = NULL; | |
541 | gcov_type mcount = 0, tcount = 0; | |
542 | ||
f1f41a6c | 543 | FOR_EACH_VEC_ELT (latches, i, e) |
4a6f9e19 | 544 | { |
545 | if (e->count > mcount) | |
546 | { | |
547 | me = e; | |
548 | mcount = e->count; | |
549 | } | |
550 | tcount += e->count; | |
551 | } | |
552 | ||
553 | if (tcount < HEAVY_EDGE_MIN_SAMPLES | |
554 | || (tcount - mcount) * HEAVY_EDGE_RATIO > tcount) | |
555 | return NULL; | |
556 | ||
557 | if (dump_file) | |
558 | fprintf (dump_file, | |
559 | "Found latch edge %d -> %d using profile information.\n", | |
560 | me->src->index, me->dest->index); | |
561 | return me; | |
562 | } | |
563 | ||
564 | /* Among LATCHES, guesses a latch edge of LOOP corresponding to subloop, based | |
565 | on the structure of induction variables. Returns this edge, or NULL if we | |
566 | do not find any. | |
567 | ||
568 | We are quite conservative, and look just for an obvious simple innermost | |
569 | loop (which is the case where we would lose the most performance by not | |
570 | disambiguating the loop). More precisely, we look for the following | |
571 | situation: The source of the chosen latch edge dominates sources of all | |
572 | the other latch edges. Additionally, the header does not contain a phi node | |
573 | such that the argument from the chosen edge is equal to the argument from | |
574 | another edge. */ | |
575 | ||
576 | static edge | |
f1f41a6c | 577 | find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, vec<edge> latches) |
4a6f9e19 | 578 | { |
f1f41a6c | 579 | edge e, latch = latches[0]; |
4a6f9e19 | 580 | unsigned i; |
75a70cf9 | 581 | gimple phi; |
582 | gimple_stmt_iterator psi; | |
583 | tree lop; | |
4a6f9e19 | 584 | basic_block bb; |
585 | ||
586 | /* Find the candidate for the latch edge. */ | |
f1f41a6c | 587 | for (i = 1; latches.iterate (i, &e); i++) |
4a6f9e19 | 588 | if (dominated_by_p (CDI_DOMINATORS, latch->src, e->src)) |
589 | latch = e; | |
590 | ||
591 | /* Verify that it dominates all the latch edges. */ | |
f1f41a6c | 592 | FOR_EACH_VEC_ELT (latches, i, e) |
4a6f9e19 | 593 | if (!dominated_by_p (CDI_DOMINATORS, e->src, latch->src)) |
594 | return NULL; | |
595 | ||
596 | /* Check for a phi node that would deny that this is a latch edge of | |
597 | a subloop. */ | |
75a70cf9 | 598 | for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) |
4a6f9e19 | 599 | { |
75a70cf9 | 600 | phi = gsi_stmt (psi); |
4a6f9e19 | 601 | lop = PHI_ARG_DEF_FROM_EDGE (phi, latch); |
602 | ||
603 | /* Ignore the values that are not changed inside the subloop. */ | |
604 | if (TREE_CODE (lop) != SSA_NAME | |
605 | || SSA_NAME_DEF_STMT (lop) == phi) | |
606 | continue; | |
75a70cf9 | 607 | bb = gimple_bb (SSA_NAME_DEF_STMT (lop)); |
4a6f9e19 | 608 | if (!bb || !flow_bb_inside_loop_p (loop, bb)) |
609 | continue; | |
610 | ||
f1f41a6c | 611 | FOR_EACH_VEC_ELT (latches, i, e) |
4a6f9e19 | 612 | if (e != latch |
613 | && PHI_ARG_DEF_FROM_EDGE (phi, e) == lop) | |
614 | return NULL; | |
615 | } | |
616 | ||
617 | if (dump_file) | |
618 | fprintf (dump_file, | |
619 | "Found latch edge %d -> %d using iv structure.\n", | |
620 | latch->src->index, latch->dest->index); | |
621 | return latch; | |
622 | } | |
623 | ||
624 | /* If we can determine that one of the several latch edges of LOOP behaves | |
625 | as a latch edge of a separate subloop, returns this edge. Otherwise | |
626 | returns NULL. */ | |
627 | ||
628 | static edge | |
629 | find_subloop_latch_edge (struct loop *loop) | |
630 | { | |
f1f41a6c | 631 | vec<edge> latches = get_loop_latch_edges (loop); |
4a6f9e19 | 632 | edge latch = NULL; |
633 | ||
f1f41a6c | 634 | if (latches.length () > 1) |
4a6f9e19 | 635 | { |
636 | latch = find_subloop_latch_edge_by_profile (latches); | |
637 | ||
638 | if (!latch | |
639 | /* We consider ivs to guess the latch edge only in SSA. Perhaps we | |
640 | should use cfghook for this, but it is hard to imagine it would | |
641 | be useful elsewhere. */ | |
642 | && current_ir_type () == IR_GIMPLE) | |
643 | latch = find_subloop_latch_edge_by_ivs (loop, latches); | |
644 | } | |
645 | ||
f1f41a6c | 646 | latches.release (); |
4a6f9e19 | 647 | return latch; |
648 | } | |
649 | ||
650 | /* Callback for make_forwarder_block. Returns true if the edge E is marked | |
651 | in the set MFB_REIS_SET. */ | |
652 | ||
653 | static struct pointer_set_t *mfb_reis_set; | |
654 | static bool | |
655 | mfb_redirect_edges_in_set (edge e) | |
656 | { | |
657 | return pointer_set_contains (mfb_reis_set, e); | |
658 | } | |
659 | ||
660 | /* Creates a subloop of LOOP with latch edge LATCH. */ | |
661 | ||
662 | static void | |
663 | form_subloop (struct loop *loop, edge latch) | |
664 | { | |
665 | edge_iterator ei; | |
666 | edge e, new_entry; | |
667 | struct loop *new_loop; | |
48e1416a | 668 | |
4a6f9e19 | 669 | mfb_reis_set = pointer_set_create (); |
670 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
671 | { | |
672 | if (e != latch) | |
673 | pointer_set_insert (mfb_reis_set, e); | |
674 | } | |
675 | new_entry = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
676 | NULL); | |
677 | pointer_set_destroy (mfb_reis_set); | |
678 | ||
679 | loop->header = new_entry->src; | |
680 | ||
681 | /* Find the blocks and subloops that belong to the new loop, and add it to | |
682 | the appropriate place in the loop tree. */ | |
683 | new_loop = alloc_loop (); | |
684 | new_loop->header = new_entry->dest; | |
685 | new_loop->latch = latch->src; | |
686 | add_loop (new_loop, loop); | |
687 | } | |
688 | ||
689 | /* Make all the latch edges of LOOP to go to a single forwarder block -- | |
690 | a new latch of LOOP. */ | |
691 | ||
692 | static void | |
693 | merge_latch_edges (struct loop *loop) | |
694 | { | |
f1f41a6c | 695 | vec<edge> latches = get_loop_latch_edges (loop); |
4a6f9e19 | 696 | edge latch, e; |
697 | unsigned i; | |
698 | ||
f1f41a6c | 699 | gcc_assert (latches.length () > 0); |
4a6f9e19 | 700 | |
f1f41a6c | 701 | if (latches.length () == 1) |
702 | loop->latch = latches[0]->src; | |
4a6f9e19 | 703 | else |
704 | { | |
705 | if (dump_file) | |
706 | fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num); | |
707 | ||
708 | mfb_reis_set = pointer_set_create (); | |
f1f41a6c | 709 | FOR_EACH_VEC_ELT (latches, i, e) |
4a6f9e19 | 710 | pointer_set_insert (mfb_reis_set, e); |
711 | latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
712 | NULL); | |
713 | pointer_set_destroy (mfb_reis_set); | |
714 | ||
715 | loop->header = latch->dest; | |
716 | loop->latch = latch->src; | |
717 | } | |
718 | ||
f1f41a6c | 719 | latches.release (); |
4a6f9e19 | 720 | } |
721 | ||
722 | /* LOOP may have several latch edges. Transform it into (possibly several) | |
723 | loops with single latch edge. */ | |
724 | ||
725 | static void | |
726 | disambiguate_multiple_latches (struct loop *loop) | |
727 | { | |
728 | edge e; | |
729 | ||
85694bac | 730 | /* We eliminate the multiple latches by splitting the header to the forwarder |
4a6f9e19 | 731 | block F and the rest R, and redirecting the edges. There are two cases: |
732 | ||
733 | 1) If there is a latch edge E that corresponds to a subloop (we guess | |
734 | that based on profile -- if it is taken much more often than the | |
735 | remaining edges; and on trees, using the information about induction | |
736 | variables of the loops), we redirect E to R, all the remaining edges to | |
737 | F, then rescan the loops and try again for the outer loop. | |
738 | 2) If there is no such edge, we redirect all latch edges to F, and the | |
739 | entry edges to R, thus making F the single latch of the loop. */ | |
740 | ||
741 | if (dump_file) | |
742 | fprintf (dump_file, "Disambiguating loop %d with multiple latches\n", | |
743 | loop->num); | |
744 | ||
745 | /* During latch merging, we may need to redirect the entry edges to a new | |
746 | block. This would cause problems if the entry edge was the one from the | |
747 | entry block. To avoid having to handle this case specially, split | |
748 | such entry edge. */ | |
34154e27 | 749 | e = find_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), loop->header); |
4a6f9e19 | 750 | if (e) |
751 | split_edge (e); | |
752 | ||
753 | while (1) | |
754 | { | |
755 | e = find_subloop_latch_edge (loop); | |
756 | if (!e) | |
757 | break; | |
758 | ||
759 | form_subloop (loop, e); | |
760 | } | |
761 | ||
762 | merge_latch_edges (loop); | |
763 | } | |
764 | ||
765 | /* Split loops with multiple latch edges. */ | |
766 | ||
767 | void | |
768 | disambiguate_loops_with_multiple_latches (void) | |
769 | { | |
4a6f9e19 | 770 | struct loop *loop; |
771 | ||
f21d4d00 | 772 | FOR_EACH_LOOP (loop, 0) |
4a6f9e19 | 773 | { |
774 | if (!loop->latch) | |
775 | disambiguate_multiple_latches (loop); | |
776 | } | |
777 | } | |
778 | ||
d10cfa8d | 779 | /* Return nonzero if basic block BB belongs to LOOP. */ |
7fb12188 | 780 | bool |
7ecb5bb2 | 781 | flow_bb_inside_loop_p (const struct loop *loop, const_basic_block bb) |
7fb12188 | 782 | { |
783 | struct loop *source_loop; | |
784 | ||
34154e27 | 785 | if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
786 | || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
7fb12188 | 787 | return 0; |
788 | ||
789 | source_loop = bb->loop_father; | |
790 | return loop == source_loop || flow_loop_nested_p (loop, source_loop); | |
791 | } | |
792 | ||
4a6f9e19 | 793 | /* Enumeration predicate for get_loop_body_with_size. */ |
7fb12188 | 794 | static bool |
7ecb5bb2 | 795 | glb_enum_p (const_basic_block bb, const void *glb_loop) |
7fb12188 | 796 | { |
7ecb5bb2 | 797 | const struct loop *const loop = (const struct loop *) glb_loop; |
4a6f9e19 | 798 | return (bb != loop->header |
799 | && dominated_by_p (CDI_DOMINATORS, bb, loop->header)); | |
800 | } | |
801 | ||
802 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
803 | order against direction of edges from latch. Specially, if | |
804 | header != latch, latch is the 1-st block. LOOP cannot be the fake | |
805 | loop tree root, and its size must be at most MAX_SIZE. The blocks | |
806 | in the LOOP body are stored to BODY, and the size of the LOOP is | |
807 | returned. */ | |
808 | ||
809 | unsigned | |
810 | get_loop_body_with_size (const struct loop *loop, basic_block *body, | |
811 | unsigned max_size) | |
812 | { | |
813 | return dfs_enumerate_from (loop->header, 1, glb_enum_p, | |
7ecb5bb2 | 814 | body, max_size, loop); |
7fb12188 | 815 | } |
816 | ||
dbfc1664 | 817 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs |
818 | order against direction of edges from latch. Specially, if | |
819 | header != latch, latch is the 1-st block. */ | |
4a6f9e19 | 820 | |
7fb12188 | 821 | basic_block * |
4c9e08a4 | 822 | get_loop_body (const struct loop *loop) |
7fb12188 | 823 | { |
4a6f9e19 | 824 | basic_block *body, bb; |
862be747 | 825 | unsigned tv = 0; |
7fb12188 | 826 | |
cc636d56 | 827 | gcc_assert (loop->num_nodes); |
7fb12188 | 828 | |
ed7e2206 | 829 | body = XNEWVEC (basic_block, loop->num_nodes); |
7fb12188 | 830 | |
34154e27 | 831 | if (loop->latch == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
7fb12188 | 832 | { |
4a6f9e19 | 833 | /* There may be blocks unreachable from EXIT_BLOCK, hence we need to |
834 | special-case the fake loop that contains the whole function. */ | |
a28770e1 | 835 | gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks_for_fn (cfun)); |
4a6f9e19 | 836 | body[tv++] = loop->header; |
34154e27 | 837 | body[tv++] = EXIT_BLOCK_PTR_FOR_FN (cfun); |
fc00614f | 838 | FOR_EACH_BB_FN (bb, cfun) |
4a6f9e19 | 839 | body[tv++] = bb; |
7fb12188 | 840 | } |
4a6f9e19 | 841 | else |
842 | tv = get_loop_body_with_size (loop, body, loop->num_nodes); | |
7fb12188 | 843 | |
cc636d56 | 844 | gcc_assert (tv == loop->num_nodes); |
4a6f9e19 | 845 | return body; |
7fb12188 | 846 | } |
847 | ||
f9cce2dc | 848 | /* Fills dominance descendants inside LOOP of the basic block BB into |
849 | array TOVISIT from index *TV. */ | |
850 | ||
851 | static void | |
852 | fill_sons_in_loop (const struct loop *loop, basic_block bb, | |
853 | basic_block *tovisit, int *tv) | |
854 | { | |
855 | basic_block son, postpone = NULL; | |
856 | ||
857 | tovisit[(*tv)++] = bb; | |
858 | for (son = first_dom_son (CDI_DOMINATORS, bb); | |
859 | son; | |
860 | son = next_dom_son (CDI_DOMINATORS, son)) | |
861 | { | |
862 | if (!flow_bb_inside_loop_p (loop, son)) | |
863 | continue; | |
864 | ||
865 | if (dominated_by_p (CDI_DOMINATORS, loop->latch, son)) | |
866 | { | |
867 | postpone = son; | |
868 | continue; | |
869 | } | |
870 | fill_sons_in_loop (loop, son, tovisit, tv); | |
871 | } | |
872 | ||
873 | if (postpone) | |
874 | fill_sons_in_loop (loop, postpone, tovisit, tv); | |
875 | } | |
876 | ||
877 | /* Gets body of a LOOP (that must be different from the outermost loop) | |
878 | sorted by dominance relation. Additionally, if a basic block s dominates | |
879 | the latch, then only blocks dominated by s are be after it. */ | |
880 | ||
881 | basic_block * | |
882 | get_loop_body_in_dom_order (const struct loop *loop) | |
883 | { | |
884 | basic_block *tovisit; | |
885 | int tv; | |
886 | ||
cc636d56 | 887 | gcc_assert (loop->num_nodes); |
f9cce2dc | 888 | |
ed7e2206 | 889 | tovisit = XNEWVEC (basic_block, loop->num_nodes); |
f9cce2dc | 890 | |
34154e27 | 891 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
f9cce2dc | 892 | |
893 | tv = 0; | |
894 | fill_sons_in_loop (loop, loop->header, tovisit, &tv); | |
895 | ||
cc636d56 | 896 | gcc_assert (tv == (int) loop->num_nodes); |
f9cce2dc | 897 | |
898 | return tovisit; | |
899 | } | |
900 | ||
e1ab7874 | 901 | /* Gets body of a LOOP sorted via provided BB_COMPARATOR. */ |
902 | ||
903 | basic_block * | |
48e1416a | 904 | get_loop_body_in_custom_order (const struct loop *loop, |
e1ab7874 | 905 | int (*bb_comparator) (const void *, const void *)) |
906 | { | |
907 | basic_block *bbs = get_loop_body (loop); | |
908 | ||
909 | qsort (bbs, loop->num_nodes, sizeof (basic_block), bb_comparator); | |
910 | ||
911 | return bbs; | |
912 | } | |
913 | ||
07c03fb0 | 914 | /* Get body of a LOOP in breadth first sort order. */ |
915 | ||
916 | basic_block * | |
917 | get_loop_body_in_bfs_order (const struct loop *loop) | |
918 | { | |
919 | basic_block *blocks; | |
920 | basic_block bb; | |
921 | bitmap visited; | |
922 | unsigned int i = 0; | |
923 | unsigned int vc = 1; | |
924 | ||
cc636d56 | 925 | gcc_assert (loop->num_nodes); |
34154e27 | 926 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
07c03fb0 | 927 | |
ed7e2206 | 928 | blocks = XNEWVEC (basic_block, loop->num_nodes); |
27335ffd | 929 | visited = BITMAP_ALLOC (NULL); |
07c03fb0 | 930 | |
931 | bb = loop->header; | |
932 | while (i < loop->num_nodes) | |
933 | { | |
934 | edge e; | |
cd665a06 | 935 | edge_iterator ei; |
a0c938f0 | 936 | |
6ef9bbe0 | 937 | if (bitmap_set_bit (visited, bb->index)) |
938 | /* This basic block is now visited */ | |
939 | blocks[i++] = bb; | |
a0c938f0 | 940 | |
cd665a06 | 941 | FOR_EACH_EDGE (e, ei, bb->succs) |
a0c938f0 | 942 | { |
943 | if (flow_bb_inside_loop_p (loop, e->dest)) | |
944 | { | |
6ef9bbe0 | 945 | if (bitmap_set_bit (visited, e->dest->index)) |
946 | blocks[i++] = e->dest; | |
a0c938f0 | 947 | } |
948 | } | |
949 | ||
cc636d56 | 950 | gcc_assert (i >= vc); |
a0c938f0 | 951 | |
07c03fb0 | 952 | bb = blocks[vc++]; |
953 | } | |
a0c938f0 | 954 | |
27335ffd | 955 | BITMAP_FREE (visited); |
07c03fb0 | 956 | return blocks; |
957 | } | |
958 | ||
dce58e66 | 959 | /* Hash function for struct loop_exit. */ |
960 | ||
961 | static hashval_t | |
962 | loop_exit_hash (const void *ex) | |
963 | { | |
c1fdef8e | 964 | const struct loop_exit *const exit = (const struct loop_exit *) ex; |
dce58e66 | 965 | |
966 | return htab_hash_pointer (exit->e); | |
967 | } | |
968 | ||
969 | /* Equality function for struct loop_exit. Compares with edge. */ | |
970 | ||
971 | static int | |
972 | loop_exit_eq (const void *ex, const void *e) | |
973 | { | |
c1fdef8e | 974 | const struct loop_exit *const exit = (const struct loop_exit *) ex; |
dce58e66 | 975 | |
976 | return exit->e == e; | |
977 | } | |
978 | ||
979 | /* Frees the list of loop exit descriptions EX. */ | |
980 | ||
981 | static void | |
982 | loop_exit_free (void *ex) | |
983 | { | |
984 | struct loop_exit *exit = (struct loop_exit *) ex, *next; | |
985 | ||
986 | for (; exit; exit = next) | |
987 | { | |
988 | next = exit->next_e; | |
48e1416a | 989 | |
dce58e66 | 990 | exit->next->prev = exit->prev; |
991 | exit->prev->next = exit->next; | |
992 | ||
ccae4f9f | 993 | ggc_free (exit); |
dce58e66 | 994 | } |
995 | } | |
996 | ||
997 | /* Returns the list of records for E as an exit of a loop. */ | |
998 | ||
999 | static struct loop_exit * | |
1000 | get_exit_descriptions (edge e) | |
1001 | { | |
f780cc25 | 1002 | return (struct loop_exit *) htab_find_with_hash (current_loops->exits, e, |
1003 | htab_hash_pointer (e)); | |
dce58e66 | 1004 | } |
1005 | ||
1006 | /* Updates the lists of loop exits in that E appears. | |
1007 | If REMOVED is true, E is being removed, and we | |
1008 | just remove it from the lists of exits. | |
1009 | If NEW_EDGE is true and E is not a loop exit, we | |
1010 | do not try to remove it from loop exit lists. */ | |
1011 | ||
1012 | void | |
1013 | rescan_loop_exit (edge e, bool new_edge, bool removed) | |
1014 | { | |
1015 | void **slot; | |
1016 | struct loop_exit *exits = NULL, *exit; | |
1017 | struct loop *aloop, *cloop; | |
1018 | ||
f24ec26f | 1019 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1020 | return; |
1021 | ||
1022 | if (!removed | |
1023 | && e->src->loop_father != NULL | |
1024 | && e->dest->loop_father != NULL | |
1025 | && !flow_bb_inside_loop_p (e->src->loop_father, e->dest)) | |
1026 | { | |
1027 | cloop = find_common_loop (e->src->loop_father, e->dest->loop_father); | |
1028 | for (aloop = e->src->loop_father; | |
1029 | aloop != cloop; | |
9e3536f4 | 1030 | aloop = loop_outer (aloop)) |
dce58e66 | 1031 | { |
ba72912a | 1032 | exit = ggc_alloc_loop_exit (); |
dce58e66 | 1033 | exit->e = e; |
1034 | ||
ccae4f9f | 1035 | exit->next = aloop->exits->next; |
1036 | exit->prev = aloop->exits; | |
dce58e66 | 1037 | exit->next->prev = exit; |
1038 | exit->prev->next = exit; | |
1039 | ||
1040 | exit->next_e = exits; | |
1041 | exits = exit; | |
1042 | } | |
48e1416a | 1043 | } |
dce58e66 | 1044 | |
1045 | if (!exits && new_edge) | |
1046 | return; | |
1047 | ||
1048 | slot = htab_find_slot_with_hash (current_loops->exits, e, | |
1049 | htab_hash_pointer (e), | |
1050 | exits ? INSERT : NO_INSERT); | |
1051 | if (!slot) | |
1052 | return; | |
1053 | ||
1054 | if (exits) | |
1055 | { | |
1056 | if (*slot) | |
1057 | loop_exit_free (*slot); | |
1058 | *slot = exits; | |
1059 | } | |
1060 | else | |
1061 | htab_clear_slot (current_loops->exits, slot); | |
1062 | } | |
1063 | ||
1064 | /* For each loop, record list of exit edges, and start maintaining these | |
1065 | lists. */ | |
1066 | ||
1067 | void | |
1068 | record_loop_exits (void) | |
1069 | { | |
1070 | basic_block bb; | |
1071 | edge_iterator ei; | |
1072 | edge e; | |
1073 | ||
d500fef3 | 1074 | if (!current_loops) |
1075 | return; | |
1076 | ||
f24ec26f | 1077 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1078 | return; |
f24ec26f | 1079 | loops_state_set (LOOPS_HAVE_RECORDED_EXITS); |
dce58e66 | 1080 | |
1081 | gcc_assert (current_loops->exits == NULL); | |
41f75a99 | 1082 | current_loops->exits = htab_create_ggc (2 * number_of_loops (cfun), |
ba72912a | 1083 | loop_exit_hash, loop_exit_eq, |
1084 | loop_exit_free); | |
dce58e66 | 1085 | |
fc00614f | 1086 | FOR_EACH_BB_FN (bb, cfun) |
dce58e66 | 1087 | { |
1088 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1089 | { | |
1090 | rescan_loop_exit (e, true, false); | |
1091 | } | |
1092 | } | |
1093 | } | |
1094 | ||
1095 | /* Dumps information about the exit in *SLOT to FILE. | |
1096 | Callback for htab_traverse. */ | |
1097 | ||
1098 | static int | |
1099 | dump_recorded_exit (void **slot, void *file) | |
1100 | { | |
f780cc25 | 1101 | struct loop_exit *exit = (struct loop_exit *) *slot; |
dce58e66 | 1102 | unsigned n = 0; |
1103 | edge e = exit->e; | |
1104 | ||
1105 | for (; exit != NULL; exit = exit->next_e) | |
1106 | n++; | |
1107 | ||
f780cc25 | 1108 | fprintf ((FILE*) file, "Edge %d->%d exits %u loops\n", |
dce58e66 | 1109 | e->src->index, e->dest->index, n); |
1110 | ||
1111 | return 1; | |
1112 | } | |
1113 | ||
1114 | /* Dumps the recorded exits of loops to FILE. */ | |
1115 | ||
1116 | extern void dump_recorded_exits (FILE *); | |
1117 | void | |
1118 | dump_recorded_exits (FILE *file) | |
1119 | { | |
1120 | if (!current_loops->exits) | |
1121 | return; | |
1122 | htab_traverse (current_loops->exits, dump_recorded_exit, file); | |
1123 | } | |
1124 | ||
1125 | /* Releases lists of loop exits. */ | |
1126 | ||
1127 | void | |
1128 | release_recorded_exits (void) | |
1129 | { | |
f24ec26f | 1130 | gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)); |
dce58e66 | 1131 | htab_delete (current_loops->exits); |
1132 | current_loops->exits = NULL; | |
f24ec26f | 1133 | loops_state_clear (LOOPS_HAVE_RECORDED_EXITS); |
dce58e66 | 1134 | } |
1135 | ||
749ea85f | 1136 | /* Returns the list of the exit edges of a LOOP. */ |
1137 | ||
f1f41a6c | 1138 | vec<edge> |
749ea85f | 1139 | get_loop_exit_edges (const struct loop *loop) |
a5414ff5 | 1140 | { |
1e094109 | 1141 | vec<edge> edges = vNULL; |
749ea85f | 1142 | edge e; |
1143 | unsigned i; | |
1144 | basic_block *body; | |
cd665a06 | 1145 | edge_iterator ei; |
dce58e66 | 1146 | struct loop_exit *exit; |
a5414ff5 | 1147 | |
34154e27 | 1148 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
a5414ff5 | 1149 | |
dce58e66 | 1150 | /* If we maintain the lists of exits, use them. Otherwise we must |
1151 | scan the body of the loop. */ | |
f24ec26f | 1152 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1153 | { |
ccae4f9f | 1154 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
f1f41a6c | 1155 | edges.safe_push (exit->e); |
dce58e66 | 1156 | } |
1157 | else | |
1158 | { | |
1159 | body = get_loop_body (loop); | |
1160 | for (i = 0; i < loop->num_nodes; i++) | |
1161 | FOR_EACH_EDGE (e, ei, body[i]->succs) | |
1162 | { | |
1163 | if (!flow_bb_inside_loop_p (loop, e->dest)) | |
f1f41a6c | 1164 | edges.safe_push (e); |
dce58e66 | 1165 | } |
1166 | free (body); | |
1167 | } | |
a5414ff5 | 1168 | |
1169 | return edges; | |
1170 | } | |
1171 | ||
f9cce2dc | 1172 | /* Counts the number of conditional branches inside LOOP. */ |
1173 | ||
1174 | unsigned | |
1175 | num_loop_branches (const struct loop *loop) | |
1176 | { | |
1177 | unsigned i, n; | |
1178 | basic_block * body; | |
1179 | ||
34154e27 | 1180 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
f9cce2dc | 1181 | |
1182 | body = get_loop_body (loop); | |
1183 | n = 0; | |
1184 | for (i = 0; i < loop->num_nodes; i++) | |
cd665a06 | 1185 | if (EDGE_COUNT (body[i]->succs) >= 2) |
f9cce2dc | 1186 | n++; |
1187 | free (body); | |
1188 | ||
1189 | return n; | |
1190 | } | |
1191 | ||
7fb12188 | 1192 | /* Adds basic block BB to LOOP. */ |
1193 | void | |
4c9e08a4 | 1194 | add_bb_to_loop (basic_block bb, struct loop *loop) |
1195 | { | |
9e3536f4 | 1196 | unsigned i; |
1197 | loop_p ploop; | |
dce58e66 | 1198 | edge_iterator ei; |
1199 | edge e; | |
1200 | ||
1201 | gcc_assert (bb->loop_father == NULL); | |
1202 | bb->loop_father = loop; | |
dce58e66 | 1203 | loop->num_nodes++; |
f1f41a6c | 1204 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9e3536f4 | 1205 | ploop->num_nodes++; |
dce58e66 | 1206 | |
1207 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1208 | { | |
1209 | rescan_loop_exit (e, true, false); | |
1210 | } | |
1211 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1212 | { | |
1213 | rescan_loop_exit (e, true, false); | |
1214 | } | |
88e6f696 | 1215 | } |
7fb12188 | 1216 | |
1217 | /* Remove basic block BB from loops. */ | |
1218 | void | |
4c9e08a4 | 1219 | remove_bb_from_loops (basic_block bb) |
1220 | { | |
f1f41a6c | 1221 | unsigned i; |
dce58e66 | 1222 | struct loop *loop = bb->loop_father; |
9e3536f4 | 1223 | loop_p ploop; |
dce58e66 | 1224 | edge_iterator ei; |
1225 | edge e; | |
1226 | ||
1227 | gcc_assert (loop != NULL); | |
1228 | loop->num_nodes--; | |
f1f41a6c | 1229 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9e3536f4 | 1230 | ploop->num_nodes--; |
dce58e66 | 1231 | bb->loop_father = NULL; |
dce58e66 | 1232 | |
1233 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1234 | { | |
1235 | rescan_loop_exit (e, false, true); | |
1236 | } | |
1237 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1238 | { | |
1239 | rescan_loop_exit (e, false, true); | |
1240 | } | |
b811afb0 | 1241 | } |
7fb12188 | 1242 | |
1243 | /* Finds nearest common ancestor in loop tree for given loops. */ | |
1244 | struct loop * | |
4c9e08a4 | 1245 | find_common_loop (struct loop *loop_s, struct loop *loop_d) |
7fb12188 | 1246 | { |
9e3536f4 | 1247 | unsigned sdepth, ddepth; |
1248 | ||
7fb12188 | 1249 | if (!loop_s) return loop_d; |
1250 | if (!loop_d) return loop_s; | |
4c9e08a4 | 1251 | |
9e3536f4 | 1252 | sdepth = loop_depth (loop_s); |
1253 | ddepth = loop_depth (loop_d); | |
1254 | ||
1255 | if (sdepth < ddepth) | |
f1f41a6c | 1256 | loop_d = (*loop_d->superloops)[sdepth]; |
9e3536f4 | 1257 | else if (sdepth > ddepth) |
f1f41a6c | 1258 | loop_s = (*loop_s->superloops)[ddepth]; |
7fb12188 | 1259 | |
1260 | while (loop_s != loop_d) | |
1261 | { | |
9e3536f4 | 1262 | loop_s = loop_outer (loop_s); |
1263 | loop_d = loop_outer (loop_d); | |
7fb12188 | 1264 | } |
1265 | return loop_s; | |
1266 | } | |
1267 | ||
17519ba0 | 1268 | /* Removes LOOP from structures and frees its data. */ |
1269 | ||
1270 | void | |
1271 | delete_loop (struct loop *loop) | |
1272 | { | |
1273 | /* Remove the loop from structure. */ | |
1274 | flow_loop_tree_node_remove (loop); | |
1275 | ||
1276 | /* Remove loop from loops array. */ | |
f1f41a6c | 1277 | (*current_loops->larray)[loop->num] = NULL; |
17519ba0 | 1278 | |
1279 | /* Free loop data. */ | |
1280 | flow_loop_free (loop); | |
1281 | } | |
1282 | ||
862be747 | 1283 | /* Cancels the LOOP; it must be innermost one. */ |
77cbebb3 | 1284 | |
1285 | static void | |
7194de72 | 1286 | cancel_loop (struct loop *loop) |
862be747 | 1287 | { |
1288 | basic_block *bbs; | |
1289 | unsigned i; | |
9e3536f4 | 1290 | struct loop *outer = loop_outer (loop); |
862be747 | 1291 | |
cc636d56 | 1292 | gcc_assert (!loop->inner); |
862be747 | 1293 | |
1294 | /* Move blocks up one level (they should be removed as soon as possible). */ | |
1295 | bbs = get_loop_body (loop); | |
1296 | for (i = 0; i < loop->num_nodes; i++) | |
9e3536f4 | 1297 | bbs[i]->loop_father = outer; |
862be747 | 1298 | |
bf4b25d7 | 1299 | free (bbs); |
17519ba0 | 1300 | delete_loop (loop); |
862be747 | 1301 | } |
1302 | ||
1303 | /* Cancels LOOP and all its subloops. */ | |
1304 | void | |
7194de72 | 1305 | cancel_loop_tree (struct loop *loop) |
862be747 | 1306 | { |
1307 | while (loop->inner) | |
7194de72 | 1308 | cancel_loop_tree (loop->inner); |
1309 | cancel_loop (loop); | |
862be747 | 1310 | } |
1311 | ||
7194de72 | 1312 | /* Checks that information about loops is correct |
d01481af | 1313 | -- sizes of loops are all right |
7fb12188 | 1314 | -- results of get_loop_body really belong to the loop |
1315 | -- loop header have just single entry edge and single latch edge | |
1316 | -- loop latches have only single successor that is header of their loop | |
862be747 | 1317 | -- irreducible loops are correctly marked |
4e976818 | 1318 | -- the cached loop depth and loop father of each bb is correct |
7fb12188 | 1319 | */ |
4b987fac | 1320 | DEBUG_FUNCTION void |
7194de72 | 1321 | verify_loop_structure (void) |
7fb12188 | 1322 | { |
862be747 | 1323 | unsigned *sizes, i, j; |
1324 | sbitmap irreds; | |
cd9916a9 | 1325 | basic_block bb, *bbs; |
7fb12188 | 1326 | struct loop *loop; |
1327 | int err = 0; | |
a5414ff5 | 1328 | edge e; |
41f75a99 | 1329 | unsigned num = number_of_loops (cfun); |
dce58e66 | 1330 | struct loop_exit *exit, *mexit; |
79f958cb | 1331 | bool dom_available = dom_info_available_p (CDI_DOMINATORS); |
ff829efa | 1332 | sbitmap visited; |
7fb12188 | 1333 | |
f6568ea4 | 1334 | if (loops_state_satisfies_p (LOOPS_NEED_FIXUP)) |
1335 | { | |
1336 | error ("loop verification on loop tree that needs fixup"); | |
1337 | err = 1; | |
1338 | } | |
1339 | ||
79f958cb | 1340 | /* We need up-to-date dominators, compute or verify them. */ |
1341 | if (!dom_available) | |
1342 | calculate_dominance_info (CDI_DOMINATORS); | |
1343 | else | |
1344 | verify_dominators (CDI_DOMINATORS); | |
ef0e6535 | 1345 | |
14a0d8d7 | 1346 | /* Check the headers. */ |
fc00614f | 1347 | FOR_EACH_BB_FN (bb, cfun) |
cd9916a9 | 1348 | if (bb_loop_header_p (bb)) |
14a0d8d7 | 1349 | { |
cd9916a9 | 1350 | if (bb->loop_father->header == NULL) |
1351 | { | |
1352 | error ("loop with header %d marked for removal", bb->index); | |
1353 | err = 1; | |
1354 | } | |
1355 | else if (bb->loop_father->header != bb) | |
1356 | { | |
1357 | error ("loop with header %d not in loop tree", bb->index); | |
1358 | err = 1; | |
1359 | } | |
1360 | } | |
1361 | else if (bb->loop_father->header == bb) | |
1362 | { | |
1363 | error ("non-loop with header %d not marked for removal", bb->index); | |
14a0d8d7 | 1364 | err = 1; |
1365 | } | |
1366 | ||
cd9916a9 | 1367 | /* Check the recorded loop father and sizes of loops. */ |
fe672ac0 | 1368 | visited = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
53c5d9d4 | 1369 | bitmap_clear (visited); |
a28770e1 | 1370 | bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); |
f21d4d00 | 1371 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) |
4e976818 | 1372 | { |
cd9916a9 | 1373 | unsigned n; |
4e976818 | 1374 | |
cd9916a9 | 1375 | if (loop->header == NULL) |
1376 | { | |
1377 | error ("removed loop %d in loop tree", loop->num); | |
1378 | err = 1; | |
1379 | continue; | |
1380 | } | |
1381 | ||
a28770e1 | 1382 | n = get_loop_body_with_size (loop, bbs, n_basic_blocks_for_fn (cfun)); |
cd9916a9 | 1383 | if (loop->num_nodes != n) |
1384 | { | |
1385 | error ("size of loop %d should be %d, not %d", | |
1386 | loop->num, n, loop->num_nodes); | |
1387 | err = 1; | |
1388 | } | |
1389 | ||
1390 | for (j = 0; j < n; j++) | |
4e976818 | 1391 | { |
1392 | bb = bbs[j]; | |
1393 | ||
ff829efa | 1394 | if (!flow_bb_inside_loop_p (loop, bb)) |
1395 | { | |
1396 | error ("bb %d does not belong to loop %d", | |
1397 | bb->index, loop->num); | |
1398 | err = 1; | |
1399 | } | |
1400 | ||
4e976818 | 1401 | /* Ignore this block if it is in an inner loop. */ |
08b7917c | 1402 | if (bitmap_bit_p (visited, bb->index)) |
4e976818 | 1403 | continue; |
08b7917c | 1404 | bitmap_set_bit (visited, bb->index); |
4e976818 | 1405 | |
1406 | if (bb->loop_father != loop) | |
1407 | { | |
1408 | error ("bb %d has father loop %d, should be loop %d", | |
1409 | bb->index, bb->loop_father->num, loop->num); | |
1410 | err = 1; | |
1411 | } | |
1412 | } | |
4e976818 | 1413 | } |
cd9916a9 | 1414 | free (bbs); |
ff829efa | 1415 | sbitmap_free (visited); |
7fb12188 | 1416 | |
1417 | /* Check headers and latches. */ | |
f21d4d00 | 1418 | FOR_EACH_LOOP (loop, 0) |
7fb12188 | 1419 | { |
17519ba0 | 1420 | i = loop->num; |
cd9916a9 | 1421 | if (loop->header == NULL) |
1422 | continue; | |
ff829efa | 1423 | if (!bb_loop_header_p (loop->header)) |
1424 | { | |
1425 | error ("loop %d%'s header is not a loop header", i); | |
1426 | err = 1; | |
1427 | } | |
f24ec26f | 1428 | if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
cd665a06 | 1429 | && EDGE_COUNT (loop->header->preds) != 2) |
7fb12188 | 1430 | { |
bf776685 | 1431 | error ("loop %d%'s header does not have exactly 2 entries", i); |
7fb12188 | 1432 | err = 1; |
1433 | } | |
b375c775 | 1434 | if (loop->latch) |
1435 | { | |
1436 | if (!find_edge (loop->latch, loop->header)) | |
1437 | { | |
1438 | error ("loop %d%'s latch does not have an edge to its header", i); | |
1439 | err = 1; | |
1440 | } | |
1441 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, loop->header)) | |
1442 | { | |
1443 | error ("loop %d%'s latch is not dominated by its header", i); | |
1444 | err = 1; | |
1445 | } | |
1446 | } | |
f24ec26f | 1447 | if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
7fb12188 | 1448 | { |
ea091dfd | 1449 | if (!single_succ_p (loop->latch)) |
7fb12188 | 1450 | { |
bf776685 | 1451 | error ("loop %d%'s latch does not have exactly 1 successor", i); |
7fb12188 | 1452 | err = 1; |
1453 | } | |
ea091dfd | 1454 | if (single_succ (loop->latch) != loop->header) |
7fb12188 | 1455 | { |
bf776685 | 1456 | error ("loop %d%'s latch does not have header as successor", i); |
7fb12188 | 1457 | err = 1; |
1458 | } | |
1459 | if (loop->latch->loop_father != loop) | |
1460 | { | |
bf776685 | 1461 | error ("loop %d%'s latch does not belong directly to it", i); |
7fb12188 | 1462 | err = 1; |
1463 | } | |
1464 | } | |
1465 | if (loop->header->loop_father != loop) | |
1466 | { | |
bf776685 | 1467 | error ("loop %d%'s header does not belong directly to it", i); |
7fb12188 | 1468 | err = 1; |
1469 | } | |
f24ec26f | 1470 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) |
a5414ff5 | 1471 | && (loop_latch_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)) |
1472 | { | |
bf776685 | 1473 | error ("loop %d%'s latch is marked as part of irreducible region", i); |
a5414ff5 | 1474 | err = 1; |
1475 | } | |
7fb12188 | 1476 | } |
1477 | ||
862be747 | 1478 | /* Check irreducible loops. */ |
f24ec26f | 1479 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
862be747 | 1480 | { |
1481 | /* Record old info. */ | |
fe672ac0 | 1482 | irreds = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
fc00614f | 1483 | FOR_EACH_BB_FN (bb, cfun) |
a5414ff5 | 1484 | { |
cd665a06 | 1485 | edge_iterator ei; |
a5414ff5 | 1486 | if (bb->flags & BB_IRREDUCIBLE_LOOP) |
08b7917c | 1487 | bitmap_set_bit (irreds, bb->index); |
a5414ff5 | 1488 | else |
08b7917c | 1489 | bitmap_clear_bit (irreds, bb->index); |
cd665a06 | 1490 | FOR_EACH_EDGE (e, ei, bb->succs) |
a5414ff5 | 1491 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) |
4c9e08a4 | 1492 | e->flags |= EDGE_ALL_FLAGS + 1; |
a5414ff5 | 1493 | } |
862be747 | 1494 | |
1495 | /* Recount it. */ | |
7194de72 | 1496 | mark_irreducible_loops (); |
862be747 | 1497 | |
1498 | /* Compare. */ | |
fc00614f | 1499 | FOR_EACH_BB_FN (bb, cfun) |
862be747 | 1500 | { |
cd665a06 | 1501 | edge_iterator ei; |
1502 | ||
862be747 | 1503 | if ((bb->flags & BB_IRREDUCIBLE_LOOP) |
08b7917c | 1504 | && !bitmap_bit_p (irreds, bb->index)) |
862be747 | 1505 | { |
0a81f5a0 | 1506 | error ("basic block %d should be marked irreducible", bb->index); |
862be747 | 1507 | err = 1; |
1508 | } | |
1509 | else if (!(bb->flags & BB_IRREDUCIBLE_LOOP) | |
08b7917c | 1510 | && bitmap_bit_p (irreds, bb->index)) |
862be747 | 1511 | { |
0a81f5a0 | 1512 | error ("basic block %d should not be marked irreducible", bb->index); |
862be747 | 1513 | err = 1; |
1514 | } | |
cd665a06 | 1515 | FOR_EACH_EDGE (e, ei, bb->succs) |
a5414ff5 | 1516 | { |
1517 | if ((e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1518 | && !(e->flags & (EDGE_ALL_FLAGS + 1))) | |
1519 | { | |
0a81f5a0 | 1520 | error ("edge from %d to %d should be marked irreducible", |
a5414ff5 | 1521 | e->src->index, e->dest->index); |
1522 | err = 1; | |
1523 | } | |
1524 | else if (!(e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1525 | && (e->flags & (EDGE_ALL_FLAGS + 1))) | |
1526 | { | |
0a81f5a0 | 1527 | error ("edge from %d to %d should not be marked irreducible", |
a5414ff5 | 1528 | e->src->index, e->dest->index); |
1529 | err = 1; | |
1530 | } | |
1531 | e->flags &= ~(EDGE_ALL_FLAGS + 1); | |
1532 | } | |
862be747 | 1533 | } |
1534 | free (irreds); | |
1535 | } | |
1536 | ||
dce58e66 | 1537 | /* Check the recorded loop exits. */ |
f21d4d00 | 1538 | FOR_EACH_LOOP (loop, 0) |
bb445479 | 1539 | { |
ccae4f9f | 1540 | if (!loop->exits || loop->exits->e != NULL) |
dce58e66 | 1541 | { |
1542 | error ("corrupted head of the exits list of loop %d", | |
1543 | loop->num); | |
1544 | err = 1; | |
1545 | } | |
1546 | else | |
1547 | { | |
1548 | /* Check that the list forms a cycle, and all elements except | |
1549 | for the head are nonnull. */ | |
ccae4f9f | 1550 | for (mexit = loop->exits, exit = mexit->next, i = 0; |
dce58e66 | 1551 | exit->e && exit != mexit; |
1552 | exit = exit->next) | |
1553 | { | |
1554 | if (i++ & 1) | |
1555 | mexit = mexit->next; | |
1556 | } | |
1557 | ||
ccae4f9f | 1558 | if (exit != loop->exits) |
dce58e66 | 1559 | { |
1560 | error ("corrupted exits list of loop %d", loop->num); | |
1561 | err = 1; | |
1562 | } | |
1563 | } | |
1564 | ||
f24ec26f | 1565 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1566 | { |
ccae4f9f | 1567 | if (loop->exits->next != loop->exits) |
dce58e66 | 1568 | { |
1569 | error ("nonempty exits list of loop %d, but exits are not recorded", | |
1570 | loop->num); | |
1571 | err = 1; | |
1572 | } | |
1573 | } | |
1574 | } | |
1575 | ||
f24ec26f | 1576 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1577 | { |
1578 | unsigned n_exits = 0, eloops; | |
1579 | ||
cd9916a9 | 1580 | sizes = XCNEWVEC (unsigned, num); |
17519ba0 | 1581 | memset (sizes, 0, sizeof (unsigned) * num); |
fc00614f | 1582 | FOR_EACH_BB_FN (bb, cfun) |
bb445479 | 1583 | { |
cd665a06 | 1584 | edge_iterator ei; |
7194de72 | 1585 | if (bb->loop_father == current_loops->tree_root) |
bb445479 | 1586 | continue; |
cd665a06 | 1587 | FOR_EACH_EDGE (e, ei, bb->succs) |
bb445479 | 1588 | { |
bb445479 | 1589 | if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) |
1590 | continue; | |
1591 | ||
dce58e66 | 1592 | n_exits++; |
1593 | exit = get_exit_descriptions (e); | |
1594 | if (!exit) | |
1595 | { | |
bf776685 | 1596 | error ("exit %d->%d not recorded", |
dce58e66 | 1597 | e->src->index, e->dest->index); |
1598 | err = 1; | |
1599 | } | |
1600 | eloops = 0; | |
1601 | for (; exit; exit = exit->next_e) | |
1602 | eloops++; | |
1603 | ||
bb445479 | 1604 | for (loop = bb->loop_father; |
1032e48d | 1605 | loop != e->dest->loop_father |
1606 | /* When a loop exit is also an entry edge which | |
1607 | can happen when avoiding CFG manipulations | |
1608 | then the last loop exited is the outer loop | |
1609 | of the loop entered. */ | |
1610 | && loop != loop_outer (e->dest->loop_father); | |
9e3536f4 | 1611 | loop = loop_outer (loop)) |
bb445479 | 1612 | { |
dce58e66 | 1613 | eloops--; |
bb445479 | 1614 | sizes[loop->num]++; |
dce58e66 | 1615 | } |
1616 | ||
1617 | if (eloops != 0) | |
1618 | { | |
bf776685 | 1619 | error ("wrong list of exited loops for edge %d->%d", |
dce58e66 | 1620 | e->src->index, e->dest->index); |
1621 | err = 1; | |
bb445479 | 1622 | } |
1623 | } | |
1624 | } | |
1625 | ||
dce58e66 | 1626 | if (n_exits != htab_elements (current_loops->exits)) |
bb445479 | 1627 | { |
bf776685 | 1628 | error ("too many loop exits recorded"); |
dce58e66 | 1629 | err = 1; |
1630 | } | |
bb445479 | 1631 | |
f21d4d00 | 1632 | FOR_EACH_LOOP (loop, 0) |
dce58e66 | 1633 | { |
1634 | eloops = 0; | |
ccae4f9f | 1635 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
dce58e66 | 1636 | eloops++; |
1637 | if (eloops != sizes[loop->num]) | |
bb445479 | 1638 | { |
dce58e66 | 1639 | error ("%d exits recorded for loop %d (having %d exits)", |
1640 | eloops, loop->num, sizes[loop->num]); | |
bb445479 | 1641 | err = 1; |
1642 | } | |
1643 | } | |
cd9916a9 | 1644 | |
1645 | free (sizes); | |
bb445479 | 1646 | } |
1647 | ||
cc636d56 | 1648 | gcc_assert (!err); |
bb445479 | 1649 | |
79f958cb | 1650 | if (!dom_available) |
1651 | free_dominance_info (CDI_DOMINATORS); | |
7fb12188 | 1652 | } |
1653 | ||
1654 | /* Returns latch edge of LOOP. */ | |
1655 | edge | |
4c9e08a4 | 1656 | loop_latch_edge (const struct loop *loop) |
7fb12188 | 1657 | { |
c6356c17 | 1658 | return find_edge (loop->latch, loop->header); |
65f34de5 | 1659 | } |
7fb12188 | 1660 | |
1661 | /* Returns preheader edge of LOOP. */ | |
1662 | edge | |
4c9e08a4 | 1663 | loop_preheader_edge (const struct loop *loop) |
7fb12188 | 1664 | { |
1665 | edge e; | |
cd665a06 | 1666 | edge_iterator ei; |
7fb12188 | 1667 | |
f24ec26f | 1668 | gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)); |
d8a0d6b8 | 1669 | |
cd665a06 | 1670 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
1671 | if (e->src != loop->latch) | |
1672 | break; | |
7fb12188 | 1673 | |
1674 | return e; | |
1675 | } | |
ffc6b5d5 | 1676 | |
1677 | /* Returns true if E is an exit of LOOP. */ | |
1678 | ||
1679 | bool | |
7ecb5bb2 | 1680 | loop_exit_edge_p (const struct loop *loop, const_edge e) |
ffc6b5d5 | 1681 | { |
1682 | return (flow_bb_inside_loop_p (loop, e->src) | |
1683 | && !flow_bb_inside_loop_p (loop, e->dest)); | |
1684 | } | |
d9e7e1a2 | 1685 | |
1686 | /* Returns the single exit edge of LOOP, or NULL if LOOP has either no exit | |
dce58e66 | 1687 | or more than one exit. If loops do not have the exits recorded, NULL |
1688 | is returned always. */ | |
d9e7e1a2 | 1689 | |
1690 | edge | |
1691 | single_exit (const struct loop *loop) | |
1692 | { | |
ccae4f9f | 1693 | struct loop_exit *exit = loop->exits->next; |
d9e7e1a2 | 1694 | |
f24ec26f | 1695 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1696 | return NULL; |
d9e7e1a2 | 1697 | |
ccae4f9f | 1698 | if (exit->e && exit->next == loop->exits) |
dce58e66 | 1699 | return exit->e; |
1700 | else | |
1701 | return NULL; | |
d9e7e1a2 | 1702 | } |
255b6be7 | 1703 | |
259c0e44 | 1704 | /* Returns true when BB has an incoming edge exiting LOOP. */ |
255b6be7 | 1705 | |
1706 | bool | |
259c0e44 | 1707 | loop_exits_to_bb_p (struct loop *loop, basic_block bb) |
255b6be7 | 1708 | { |
1709 | edge e; | |
1710 | edge_iterator ei; | |
1711 | ||
1712 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1713 | if (loop_exit_edge_p (loop, e)) | |
1714 | return true; | |
1715 | ||
1716 | return false; | |
1717 | } | |
259c0e44 | 1718 | |
1719 | /* Returns true when BB has an outgoing edge exiting LOOP. */ | |
1720 | ||
1721 | bool | |
1722 | loop_exits_from_bb_p (struct loop *loop, basic_block bb) | |
1723 | { | |
1724 | edge e; | |
1725 | edge_iterator ei; | |
1726 | ||
1727 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1728 | if (loop_exit_edge_p (loop, e)) | |
1729 | return true; | |
1730 | ||
1731 | return false; | |
1732 | } | |
f55775aa | 1733 | |
1734 | /* Return location corresponding to the loop control condition if possible. */ | |
1735 | ||
1736 | location_t | |
1737 | get_loop_location (struct loop *loop) | |
1738 | { | |
1739 | rtx insn = NULL; | |
1740 | struct niter_desc *desc = NULL; | |
1741 | edge exit; | |
1742 | ||
1743 | /* For a for or while loop, we would like to return the location | |
1744 | of the for or while statement, if possible. To do this, look | |
1745 | for the branch guarding the loop back-edge. */ | |
1746 | ||
1747 | /* If this is a simple loop with an in_edge, then the loop control | |
1748 | branch is typically at the end of its source. */ | |
1749 | desc = get_simple_loop_desc (loop); | |
1750 | if (desc->in_edge) | |
1751 | { | |
1752 | FOR_BB_INSNS_REVERSE (desc->in_edge->src, insn) | |
1753 | { | |
1754 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1755 | return INSN_LOCATION (insn); | |
1756 | } | |
1757 | } | |
1758 | /* If loop has a single exit, then the loop control branch | |
1759 | must be at the end of its source. */ | |
1760 | if ((exit = single_exit (loop))) | |
1761 | { | |
1762 | FOR_BB_INSNS_REVERSE (exit->src, insn) | |
1763 | { | |
1764 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1765 | return INSN_LOCATION (insn); | |
1766 | } | |
1767 | } | |
1768 | /* Next check the latch, to see if it is non-empty. */ | |
1769 | FOR_BB_INSNS_REVERSE (loop->latch, insn) | |
1770 | { | |
1771 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1772 | return INSN_LOCATION (insn); | |
1773 | } | |
1774 | /* Finally, if none of the above identifies the loop control branch, | |
1775 | return the first location in the loop header. */ | |
1776 | FOR_BB_INSNS (loop->header, insn) | |
1777 | { | |
1778 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1779 | return INSN_LOCATION (insn); | |
1780 | } | |
1781 | /* If all else fails, simply return the current function location. */ | |
1782 | return DECL_SOURCE_LOCATION (current_function_decl); | |
1783 | } | |
1784 | ||
f86b328b | 1785 | /* Records that every statement in LOOP is executed I_BOUND times. |
1786 | REALISTIC is true if I_BOUND is expected to be close to the real number | |
1787 | of iterations. UPPER is true if we are sure the loop iterates at most | |
1788 | I_BOUND times. */ | |
1789 | ||
1790 | void | |
5de9d3ed | 1791 | record_niter_bound (struct loop *loop, const widest_int &i_bound, |
6b409616 | 1792 | bool realistic, bool upper) |
f86b328b | 1793 | { |
1794 | /* Update the bounds only when there is no previous estimation, or when the | |
1795 | current estimation is smaller. */ | |
1796 | if (upper | |
1797 | && (!loop->any_upper_bound | |
6b409616 | 1798 | || wi::ltu_p (i_bound, loop->nb_iterations_upper_bound))) |
f86b328b | 1799 | { |
1800 | loop->any_upper_bound = true; | |
1801 | loop->nb_iterations_upper_bound = i_bound; | |
1802 | } | |
1803 | if (realistic | |
1804 | && (!loop->any_estimate | |
6b409616 | 1805 | || wi::ltu_p (i_bound, loop->nb_iterations_estimate))) |
f86b328b | 1806 | { |
1807 | loop->any_estimate = true; | |
1808 | loop->nb_iterations_estimate = i_bound; | |
1809 | } | |
1810 | ||
1811 | /* If an upper bound is smaller than the realistic estimate of the | |
1812 | number of iterations, use the upper bound instead. */ | |
1813 | if (loop->any_upper_bound | |
1814 | && loop->any_estimate | |
6b409616 | 1815 | && wi::ltu_p (loop->nb_iterations_upper_bound, |
1816 | loop->nb_iterations_estimate)) | |
f86b328b | 1817 | loop->nb_iterations_estimate = loop->nb_iterations_upper_bound; |
1818 | } | |
1819 | ||
4e948f5a | 1820 | /* Similar to get_estimated_loop_iterations, but returns the estimate only |
f86b328b | 1821 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate |
1822 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
1823 | ||
1824 | HOST_WIDE_INT | |
4e948f5a | 1825 | get_estimated_loop_iterations_int (struct loop *loop) |
f86b328b | 1826 | { |
5de9d3ed | 1827 | widest_int nit; |
f86b328b | 1828 | HOST_WIDE_INT hwi_nit; |
1829 | ||
1830 | if (!get_estimated_loop_iterations (loop, &nit)) | |
1831 | return -1; | |
1832 | ||
6b409616 | 1833 | if (!wi::fits_shwi_p (nit)) |
f86b328b | 1834 | return -1; |
1835 | hwi_nit = nit.to_shwi (); | |
1836 | ||
1837 | return hwi_nit < 0 ? -1 : hwi_nit; | |
1838 | } | |
1839 | ||
1840 | /* Returns an upper bound on the number of executions of statements | |
1841 | in the LOOP. For statements before the loop exit, this exceeds | |
1842 | the number of execution of the latch by one. */ | |
1843 | ||
1844 | HOST_WIDE_INT | |
1845 | max_stmt_executions_int (struct loop *loop) | |
1846 | { | |
4e948f5a | 1847 | HOST_WIDE_INT nit = get_max_loop_iterations_int (loop); |
f86b328b | 1848 | HOST_WIDE_INT snit; |
1849 | ||
1850 | if (nit == -1) | |
1851 | return -1; | |
1852 | ||
1853 | snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
1854 | ||
1855 | /* If the computation overflows, return -1. */ | |
1856 | return snit < 0 ? -1 : snit; | |
1857 | } | |
1858 | ||
1859 | /* Sets NIT to the estimated number of executions of the latch of the | |
1860 | LOOP. If we have no reliable estimate, the function returns false, otherwise | |
1861 | returns true. */ | |
1862 | ||
1863 | bool | |
5de9d3ed | 1864 | get_estimated_loop_iterations (struct loop *loop, widest_int *nit) |
f86b328b | 1865 | { |
1866 | /* Even if the bound is not recorded, possibly we can derrive one from | |
1867 | profile. */ | |
1868 | if (!loop->any_estimate) | |
1869 | { | |
1870 | if (loop->header->count) | |
1871 | { | |
6b409616 | 1872 | *nit = gcov_type_to_wide_int |
f86b328b | 1873 | (expected_loop_iterations_unbounded (loop) + 1); |
1874 | return true; | |
1875 | } | |
1876 | return false; | |
1877 | } | |
1878 | ||
1879 | *nit = loop->nb_iterations_estimate; | |
1880 | return true; | |
1881 | } | |
1882 | ||
1883 | /* Sets NIT to an upper bound for the maximum number of executions of the | |
1884 | latch of the LOOP. If we have no reliable estimate, the function returns | |
1885 | false, otherwise returns true. */ | |
1886 | ||
1887 | bool | |
5de9d3ed | 1888 | get_max_loop_iterations (struct loop *loop, widest_int *nit) |
f86b328b | 1889 | { |
1890 | if (!loop->any_upper_bound) | |
1891 | return false; | |
1892 | ||
1893 | *nit = loop->nb_iterations_upper_bound; | |
1894 | return true; | |
1895 | } | |
4e948f5a | 1896 | |
1897 | /* Similar to get_max_loop_iterations, but returns the estimate only | |
1898 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
1899 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
1900 | ||
1901 | HOST_WIDE_INT | |
1902 | get_max_loop_iterations_int (struct loop *loop) | |
1903 | { | |
5de9d3ed | 1904 | widest_int nit; |
4e948f5a | 1905 | HOST_WIDE_INT hwi_nit; |
1906 | ||
1907 | if (!get_max_loop_iterations (loop, &nit)) | |
1908 | return -1; | |
1909 | ||
6b409616 | 1910 | if (!wi::fits_shwi_p (nit)) |
4e948f5a | 1911 | return -1; |
1912 | hwi_nit = nit.to_shwi (); | |
1913 | ||
1914 | return hwi_nit < 0 ? -1 : hwi_nit; | |
1915 | } | |
1916 | ||
424a4a92 | 1917 | /* Returns the loop depth of the loop BB belongs to. */ |
4e948f5a | 1918 | |
424a4a92 | 1919 | int |
1920 | bb_loop_depth (const_basic_block bb) | |
1921 | { | |
1922 | return bb->loop_father ? loop_depth (bb->loop_father) : 0; | |
1923 | } |