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65f34de5 | 1 | /* Natural loop discovery code for GNU compiler. |
d91f7526 | 2 | Copyright (C) 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2010 |
3072d30e | 3 | Free Software Foundation, Inc. |
65f34de5 | 4 | |
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
8c4c00c1 | 9 | Software Foundation; either version 3, or (at your option) any later |
65f34de5 | 10 | version. |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
65f34de5 | 20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
805e22b2 | 23 | #include "coretypes.h" |
24 | #include "tm.h" | |
65f34de5 | 25 | #include "rtl.h" |
26 | #include "hard-reg-set.h" | |
42fe97ed | 27 | #include "obstack.h" |
b811afb0 | 28 | #include "function.h" |
65f34de5 | 29 | #include "basic-block.h" |
862be747 | 30 | #include "cfgloop.h" |
0b205f4c | 31 | #include "diagnostic-core.h" |
862be747 | 32 | #include "flags.h" |
4ee9c684 | 33 | #include "tree.h" |
34 | #include "tree-flow.h" | |
4a6f9e19 | 35 | #include "pointer-set.h" |
ccae4f9f | 36 | #include "ggc.h" |
5f5d4cd1 | 37 | |
7194de72 | 38 | static void flow_loops_cfg_dump (FILE *); |
65f34de5 | 39 | \f |
40 | /* Dump loop related CFG information. */ | |
41 | ||
42 | static void | |
7194de72 | 43 | flow_loops_cfg_dump (FILE *file) |
65f34de5 | 44 | { |
4c26117a | 45 | basic_block bb; |
65f34de5 | 46 | |
7194de72 | 47 | if (!file) |
65f34de5 | 48 | return; |
49 | ||
4c26117a | 50 | FOR_EACH_BB (bb) |
65f34de5 | 51 | { |
52 | edge succ; | |
cd665a06 | 53 | edge_iterator ei; |
65f34de5 | 54 | |
4c26117a | 55 | fprintf (file, ";; %d succs { ", bb->index); |
cd665a06 | 56 | FOR_EACH_EDGE (succ, ei, bb->succs) |
b3d6de89 | 57 | fprintf (file, "%d ", succ->dest->index); |
7fb12188 | 58 | fprintf (file, "}\n"); |
65f34de5 | 59 | } |
65f34de5 | 60 | } |
61 | ||
d10cfa8d | 62 | /* Return nonzero if the nodes of LOOP are a subset of OUTER. */ |
65f34de5 | 63 | |
7fb12188 | 64 | bool |
4c9e08a4 | 65 | flow_loop_nested_p (const struct loop *outer, const struct loop *loop) |
65f34de5 | 66 | { |
9e3536f4 | 67 | unsigned odepth = loop_depth (outer); |
68 | ||
69 | return (loop_depth (loop) > odepth | |
70 | && VEC_index (loop_p, loop->superloops, odepth) == outer); | |
65f34de5 | 71 | } |
72 | ||
b4d679c5 | 73 | /* Returns the loop such that LOOP is nested DEPTH (indexed from zero) |
74 | loops within LOOP. */ | |
7d23383d | 75 | |
76 | struct loop * | |
77 | superloop_at_depth (struct loop *loop, unsigned depth) | |
78 | { | |
9e3536f4 | 79 | unsigned ldepth = loop_depth (loop); |
80 | ||
81 | gcc_assert (depth <= ldepth); | |
7d23383d | 82 | |
9e3536f4 | 83 | if (depth == ldepth) |
7d23383d | 84 | return loop; |
85 | ||
9e3536f4 | 86 | return VEC_index (loop_p, loop->superloops, depth); |
7d23383d | 87 | } |
88 | ||
4a6f9e19 | 89 | /* Returns the list of the latch edges of LOOP. */ |
90 | ||
91 | static VEC (edge, heap) * | |
92 | get_loop_latch_edges (const struct loop *loop) | |
93 | { | |
94 | edge_iterator ei; | |
95 | edge e; | |
96 | VEC (edge, heap) *ret = NULL; | |
97 | ||
98 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
99 | { | |
100 | if (dominated_by_p (CDI_DOMINATORS, e->src, loop->header)) | |
101 | VEC_safe_push (edge, heap, ret, e); | |
102 | } | |
103 | ||
104 | return ret; | |
105 | } | |
106 | ||
65f34de5 | 107 | /* Dump the loop information specified by LOOP to the stream FILE |
108 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
109 | ||
110 | void | |
4c9e08a4 | 111 | flow_loop_dump (const struct loop *loop, FILE *file, |
112 | void (*loop_dump_aux) (const struct loop *, FILE *, int), | |
113 | int verbose) | |
65f34de5 | 114 | { |
7fb12188 | 115 | basic_block *bbs; |
862be747 | 116 | unsigned i; |
4a6f9e19 | 117 | VEC (edge, heap) *latches; |
118 | edge e; | |
7fb12188 | 119 | |
65f34de5 | 120 | if (! loop || ! loop->header) |
121 | return; | |
122 | ||
58b3f902 | 123 | fprintf (file, ";;\n;; Loop %d\n", loop->num); |
65f34de5 | 124 | |
4a6f9e19 | 125 | fprintf (file, ";; header %d, ", loop->header->index); |
126 | if (loop->latch) | |
127 | fprintf (file, "latch %d\n", loop->latch->index); | |
128 | else | |
129 | { | |
130 | fprintf (file, "multiple latches:"); | |
131 | latches = get_loop_latch_edges (loop); | |
48148244 | 132 | FOR_EACH_VEC_ELT (edge, latches, i, e) |
4a6f9e19 | 133 | fprintf (file, " %d", e->src->index); |
134 | VEC_free (edge, heap, latches); | |
135 | fprintf (file, "\n"); | |
136 | } | |
137 | ||
8543a448 | 138 | fprintf (file, ";; depth %d, outer %ld\n", |
9e3536f4 | 139 | loop_depth (loop), (long) (loop_outer (loop) |
140 | ? loop_outer (loop)->num : -1)); | |
65f34de5 | 141 | |
7fb12188 | 142 | fprintf (file, ";; nodes:"); |
143 | bbs = get_loop_body (loop); | |
144 | for (i = 0; i < loop->num_nodes; i++) | |
145 | fprintf (file, " %d", bbs[i]->index); | |
146 | free (bbs); | |
147 | fprintf (file, "\n"); | |
5cc577b6 | 148 | |
65f34de5 | 149 | if (loop_dump_aux) |
150 | loop_dump_aux (loop, file, verbose); | |
151 | } | |
152 | ||
7194de72 | 153 | /* Dump the loop information about loops to the stream FILE, |
65f34de5 | 154 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ |
155 | ||
156 | void | |
7194de72 | 157 | flow_loops_dump (FILE *file, void (*loop_dump_aux) (const struct loop *, FILE *, int), int verbose) |
65f34de5 | 158 | { |
17519ba0 | 159 | loop_iterator li; |
160 | struct loop *loop; | |
65f34de5 | 161 | |
7194de72 | 162 | if (!current_loops || ! file) |
65f34de5 | 163 | return; |
164 | ||
17519ba0 | 165 | fprintf (file, ";; %d loops found\n", number_of_loops ()); |
7fb12188 | 166 | |
17519ba0 | 167 | FOR_EACH_LOOP (li, loop, LI_INCLUDE_ROOT) |
65f34de5 | 168 | { |
7fb12188 | 169 | flow_loop_dump (loop, file, loop_dump_aux, verbose); |
65f34de5 | 170 | } |
171 | ||
172 | if (verbose) | |
7194de72 | 173 | flow_loops_cfg_dump (file); |
65f34de5 | 174 | } |
175 | ||
7fb12188 | 176 | /* Free data allocated for LOOP. */ |
ccae4f9f | 177 | |
a5414ff5 | 178 | void |
4c9e08a4 | 179 | flow_loop_free (struct loop *loop) |
7fb12188 | 180 | { |
dce58e66 | 181 | struct loop_exit *exit, *next; |
182 | ||
ccae4f9f | 183 | VEC_free (loop_p, gc, loop->superloops); |
dce58e66 | 184 | |
185 | /* Break the list of the loop exit records. They will be freed when the | |
186 | corresponding edge is rescanned or removed, and this avoids | |
187 | accessing the (already released) head of the list stored in the | |
188 | loop structure. */ | |
ccae4f9f | 189 | for (exit = loop->exits->next; exit != loop->exits; exit = next) |
dce58e66 | 190 | { |
191 | next = exit->next; | |
192 | exit->next = exit; | |
193 | exit->prev = exit; | |
194 | } | |
ccae4f9f | 195 | |
196 | ggc_free (loop->exits); | |
197 | ggc_free (loop); | |
7fb12188 | 198 | } |
199 | ||
65f34de5 | 200 | /* Free all the memory allocated for LOOPS. */ |
201 | ||
202 | void | |
4c9e08a4 | 203 | flow_loops_free (struct loops *loops) |
65f34de5 | 204 | { |
17519ba0 | 205 | if (loops->larray) |
65f34de5 | 206 | { |
862be747 | 207 | unsigned i; |
17519ba0 | 208 | loop_p loop; |
65f34de5 | 209 | |
210 | /* Free the loop descriptors. */ | |
48148244 | 211 | FOR_EACH_VEC_ELT (loop_p, loops->larray, i, loop) |
65f34de5 | 212 | { |
7fb12188 | 213 | if (!loop) |
214 | continue; | |
215 | ||
216 | flow_loop_free (loop); | |
65f34de5 | 217 | } |
5cc577b6 | 218 | |
ccae4f9f | 219 | VEC_free (loop_p, gc, loops->larray); |
65f34de5 | 220 | } |
221 | } | |
222 | ||
7fb12188 | 223 | /* Find the nodes contained within the LOOP with header HEADER. |
224 | Return the number of nodes within the loop. */ | |
65f34de5 | 225 | |
053fdd99 | 226 | int |
4c9e08a4 | 227 | flow_loop_nodes_find (basic_block header, struct loop *loop) |
65f34de5 | 228 | { |
4a6f9e19 | 229 | VEC (basic_block, heap) *stack = NULL; |
7fb12188 | 230 | int num_nodes = 1; |
4a6f9e19 | 231 | edge latch; |
232 | edge_iterator latch_ei; | |
9e3536f4 | 233 | unsigned depth = loop_depth (loop); |
65f34de5 | 234 | |
7fb12188 | 235 | header->loop_father = loop; |
9e3536f4 | 236 | header->loop_depth = depth; |
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++; |
4a6f9e19 | 245 | VEC_safe_push (basic_block, heap, stack, latch->src); |
246 | latch->src->loop_father = loop; | |
9e3536f4 | 247 | latch->src->loop_depth = depth; |
4c9e08a4 | 248 | |
4a6f9e19 | 249 | while (!VEC_empty (basic_block, stack)) |
65f34de5 | 250 | { |
7fb12188 | 251 | basic_block node; |
252 | edge e; | |
cd665a06 | 253 | edge_iterator ei; |
65f34de5 | 254 | |
4a6f9e19 | 255 | node = VEC_pop (basic_block, stack); |
4c9e08a4 | 256 | |
cd665a06 | 257 | FOR_EACH_EDGE (e, ei, node->preds) |
65f34de5 | 258 | { |
7fb12188 | 259 | basic_block ancestor = e->src; |
260 | ||
4a6f9e19 | 261 | if (ancestor->loop_father != loop) |
7fb12188 | 262 | { |
263 | ancestor->loop_father = loop; | |
9e3536f4 | 264 | ancestor->loop_depth = depth; |
7fb12188 | 265 | num_nodes++; |
4a6f9e19 | 266 | VEC_safe_push (basic_block, heap, stack, ancestor); |
7fb12188 | 267 | } |
65f34de5 | 268 | } |
269 | } | |
270 | } | |
4a6f9e19 | 271 | VEC_free (basic_block, heap, stack); |
272 | ||
65f34de5 | 273 | return num_nodes; |
274 | } | |
275 | ||
9e3536f4 | 276 | /* Records the vector of superloops of the loop LOOP, whose immediate |
277 | superloop is FATHER. */ | |
278 | ||
a5414ff5 | 279 | static void |
9e3536f4 | 280 | establish_preds (struct loop *loop, struct loop *father) |
a5414ff5 | 281 | { |
9e3536f4 | 282 | loop_p ploop; |
283 | unsigned depth = loop_depth (father) + 1; | |
284 | unsigned i; | |
b811afb0 | 285 | |
9e3536f4 | 286 | VEC_truncate (loop_p, loop->superloops, 0); |
ccae4f9f | 287 | VEC_reserve (loop_p, gc, loop->superloops, depth); |
48148244 | 288 | FOR_EACH_VEC_ELT (loop_p, father->superloops, i, ploop) |
9e3536f4 | 289 | VEC_quick_push (loop_p, loop->superloops, ploop); |
290 | VEC_quick_push (loop_p, loop->superloops, father); | |
a5414ff5 | 291 | |
292 | for (ploop = loop->inner; ploop; ploop = ploop->next) | |
9e3536f4 | 293 | establish_preds (ploop, loop); |
a5414ff5 | 294 | } |
295 | ||
7fb12188 | 296 | /* Add LOOP to the loop hierarchy tree where FATHER is father of the |
a5414ff5 | 297 | added loop. If LOOP has some children, take care of that their |
298 | pred field will be initialized correctly. */ | |
65f34de5 | 299 | |
7fb12188 | 300 | void |
4c9e08a4 | 301 | flow_loop_tree_node_add (struct loop *father, struct loop *loop) |
65f34de5 | 302 | { |
7fb12188 | 303 | loop->next = father->inner; |
304 | father->inner = loop; | |
7fb12188 | 305 | |
9e3536f4 | 306 | establish_preds (loop, father); |
65f34de5 | 307 | } |
308 | ||
7fb12188 | 309 | /* Remove LOOP from the loop hierarchy tree. */ |
65f34de5 | 310 | |
7fb12188 | 311 | void |
4c9e08a4 | 312 | flow_loop_tree_node_remove (struct loop *loop) |
65f34de5 | 313 | { |
7fb12188 | 314 | struct loop *prev, *father; |
65f34de5 | 315 | |
9e3536f4 | 316 | father = loop_outer (loop); |
65f34de5 | 317 | |
7fb12188 | 318 | /* Remove loop from the list of sons. */ |
319 | if (father->inner == loop) | |
320 | father->inner = loop->next; | |
321 | else | |
322 | { | |
9e3536f4 | 323 | for (prev = father->inner; prev->next != loop; prev = prev->next) |
324 | continue; | |
7fb12188 | 325 | prev->next = loop->next; |
326 | } | |
65f34de5 | 327 | |
9e3536f4 | 328 | VEC_truncate (loop_p, loop->superloops, 0); |
65f34de5 | 329 | } |
330 | ||
dce58e66 | 331 | /* Allocates and returns new loop structure. */ |
332 | ||
333 | struct loop * | |
334 | alloc_loop (void) | |
335 | { | |
ba72912a | 336 | struct loop *loop = ggc_alloc_cleared_loop (); |
ccae4f9f | 337 | |
ba72912a | 338 | loop->exits = ggc_alloc_cleared_loop_exit (); |
ccae4f9f | 339 | loop->exits->next = loop->exits->prev = loop->exits; |
26c166eb | 340 | loop->can_be_parallel = false; |
dce58e66 | 341 | |
dce58e66 | 342 | return loop; |
343 | } | |
344 | ||
a8a97201 | 345 | /* Initializes loops structure LOOPS, reserving place for NUM_LOOPS loops |
346 | (including the root of the loop tree). */ | |
347 | ||
348 | static void | |
349 | init_loops_structure (struct loops *loops, unsigned num_loops) | |
350 | { | |
351 | struct loop *root; | |
352 | ||
353 | memset (loops, 0, sizeof *loops); | |
354 | loops->larray = VEC_alloc (loop_p, gc, num_loops); | |
355 | ||
356 | /* Dummy loop containing whole function. */ | |
357 | root = alloc_loop (); | |
358 | root->num_nodes = n_basic_blocks; | |
359 | root->latch = EXIT_BLOCK_PTR; | |
360 | root->header = ENTRY_BLOCK_PTR; | |
361 | ENTRY_BLOCK_PTR->loop_father = root; | |
362 | EXIT_BLOCK_PTR->loop_father = root; | |
363 | ||
364 | VEC_quick_push (loop_p, loops->larray, root); | |
365 | loops->tree_root = root; | |
366 | } | |
367 | ||
5cc577b6 | 368 | /* Find all the natural loops in the function and save in LOOPS structure and |
ffc6b5d5 | 369 | recalculate loop_depth information in basic block structures. |
370 | Return the number of natural loops found. */ | |
65f34de5 | 371 | |
372 | int | |
ffc6b5d5 | 373 | flow_loops_find (struct loops *loops) |
65f34de5 | 374 | { |
b3d6de89 | 375 | int b; |
65f34de5 | 376 | int num_loops; |
377 | edge e; | |
378 | sbitmap headers; | |
65f34de5 | 379 | int *dfs_order; |
380 | int *rc_order; | |
89d75d78 | 381 | basic_block header; |
382 | basic_block bb; | |
65f34de5 | 383 | |
a8a97201 | 384 | /* Ensure that the dominators are computed. */ |
385 | calculate_dominance_info (CDI_DOMINATORS); | |
65f34de5 | 386 | |
387 | /* Taking care of this degenerate case makes the rest of | |
388 | this code simpler. */ | |
4d2e5d52 | 389 | if (n_basic_blocks == NUM_FIXED_BLOCKS) |
a8a97201 | 390 | { |
391 | init_loops_structure (loops, 1); | |
392 | return 1; | |
393 | } | |
65f34de5 | 394 | |
395 | dfs_order = NULL; | |
396 | rc_order = NULL; | |
397 | ||
7fb12188 | 398 | /* Count the number of loop headers. This should be the |
65f34de5 | 399 | same as the number of natural loops. */ |
7fb12188 | 400 | headers = sbitmap_alloc (last_basic_block); |
401 | sbitmap_zero (headers); | |
402 | ||
65f34de5 | 403 | num_loops = 0; |
4c26117a | 404 | FOR_EACH_BB (header) |
65f34de5 | 405 | { |
cd665a06 | 406 | edge_iterator ei; |
4c9e08a4 | 407 | |
65f34de5 | 408 | header->loop_depth = 0; |
409 | ||
743f4ee2 | 410 | /* If we have an abnormal predecessor, do not consider the |
411 | loop (not worth the problems). */ | |
f1047120 | 412 | if (bb_has_abnormal_pred (header)) |
743f4ee2 | 413 | continue; |
414 | ||
cd665a06 | 415 | FOR_EACH_EDGE (e, ei, header->preds) |
65f34de5 | 416 | { |
417 | basic_block latch = e->src; | |
418 | ||
cc636d56 | 419 | gcc_assert (!(e->flags & EDGE_ABNORMAL)); |
7fb12188 | 420 | |
65f34de5 | 421 | /* Look for back edges where a predecessor is dominated |
422 | by this block. A natural loop has a single entry | |
423 | node (header) that dominates all the nodes in the | |
424 | loop. It also has single back edge to the header | |
7fb12188 | 425 | from a latch node. */ |
0051c76a | 426 | if (latch != ENTRY_BLOCK_PTR |
427 | && dominated_by_p (CDI_DOMINATORS, latch, header)) | |
7fb12188 | 428 | { |
429 | /* Shared headers should be eliminated by now. */ | |
7fb12188 | 430 | SET_BIT (headers, header->index); |
431 | num_loops++; | |
432 | } | |
65f34de5 | 433 | } |
434 | } | |
435 | ||
7fb12188 | 436 | /* Allocate loop structures. */ |
a8a97201 | 437 | init_loops_structure (loops, num_loops + 1); |
7fb12188 | 438 | |
439 | /* Find and record information about all the natural loops | |
440 | in the CFG. */ | |
7fb12188 | 441 | FOR_EACH_BB (bb) |
442 | bb->loop_father = loops->tree_root; | |
443 | ||
65f34de5 | 444 | if (num_loops) |
445 | { | |
446 | /* Compute depth first search order of the CFG so that outer | |
447 | natural loops will be found before inner natural loops. */ | |
4c36ffe6 | 448 | dfs_order = XNEWVEC (int, n_basic_blocks); |
449 | rc_order = XNEWVEC (int, n_basic_blocks); | |
6180f28d | 450 | pre_and_rev_post_order_compute (dfs_order, rc_order, false); |
65f34de5 | 451 | |
7fb12188 | 452 | num_loops = 1; |
65f34de5 | 453 | |
4d2e5d52 | 454 | for (b = 0; b < n_basic_blocks - NUM_FIXED_BLOCKS; b++) |
65f34de5 | 455 | { |
7fb12188 | 456 | struct loop *loop; |
cd665a06 | 457 | edge_iterator ei; |
65f34de5 | 458 | |
459 | /* Search the nodes of the CFG in reverse completion order | |
460 | so that we can find outer loops first. */ | |
7fb12188 | 461 | if (!TEST_BIT (headers, rc_order[b])) |
462 | continue; | |
463 | ||
464 | header = BASIC_BLOCK (rc_order[b]); | |
4c9e08a4 | 465 | |
dce58e66 | 466 | loop = alloc_loop (); |
17519ba0 | 467 | VEC_quick_push (loop_p, loops->larray, loop); |
65f34de5 | 468 | |
7fb12188 | 469 | loop->header = header; |
470 | loop->num = num_loops; | |
471 | num_loops++; | |
472 | ||
4a6f9e19 | 473 | flow_loop_tree_node_add (header->loop_father, loop); |
474 | loop->num_nodes = flow_loop_nodes_find (loop->header, loop); | |
475 | ||
476 | /* Look for the latch for this header block, if it has just a | |
477 | single one. */ | |
cd665a06 | 478 | FOR_EACH_EDGE (e, ei, header->preds) |
65f34de5 | 479 | { |
7fb12188 | 480 | basic_block latch = e->src; |
481 | ||
4a6f9e19 | 482 | if (flow_bb_inside_loop_p (loop, latch)) |
65f34de5 | 483 | { |
4a6f9e19 | 484 | if (loop->latch != NULL) |
485 | { | |
486 | /* More than one latch edge. */ | |
487 | loop->latch = NULL; | |
488 | break; | |
489 | } | |
65f34de5 | 490 | loop->latch = latch; |
65f34de5 | 491 | } |
492 | } | |
65f34de5 | 493 | } |
494 | ||
88e6f696 | 495 | free (dfs_order); |
496 | free (rc_order); | |
7fb12188 | 497 | } |
862be747 | 498 | |
dcd8fd01 | 499 | sbitmap_free (headers); |
500 | ||
dce58e66 | 501 | loops->exits = NULL; |
17519ba0 | 502 | return VEC_length (loop_p, loops->larray); |
65f34de5 | 503 | } |
504 | ||
4a6f9e19 | 505 | /* Ratio of frequencies of edges so that one of more latch edges is |
506 | considered to belong to inner loop with same header. */ | |
507 | #define HEAVY_EDGE_RATIO 8 | |
508 | ||
509 | /* Minimum number of samples for that we apply | |
510 | find_subloop_latch_edge_by_profile heuristics. */ | |
511 | #define HEAVY_EDGE_MIN_SAMPLES 10 | |
512 | ||
513 | /* If the profile info is available, finds an edge in LATCHES that much more | |
514 | frequent than the remaining edges. Returns such an edge, or NULL if we do | |
515 | not find one. | |
516 | ||
517 | We do not use guessed profile here, only the measured one. The guessed | |
518 | profile is usually too flat and unreliable for this (and it is mostly based | |
519 | on the loop structure of the program, so it does not make much sense to | |
520 | derive the loop structure from it). */ | |
48e1416a | 521 | |
4a6f9e19 | 522 | static edge |
523 | find_subloop_latch_edge_by_profile (VEC (edge, heap) *latches) | |
524 | { | |
525 | unsigned i; | |
526 | edge e, me = NULL; | |
527 | gcov_type mcount = 0, tcount = 0; | |
528 | ||
48148244 | 529 | FOR_EACH_VEC_ELT (edge, latches, i, e) |
4a6f9e19 | 530 | { |
531 | if (e->count > mcount) | |
532 | { | |
533 | me = e; | |
534 | mcount = e->count; | |
535 | } | |
536 | tcount += e->count; | |
537 | } | |
538 | ||
539 | if (tcount < HEAVY_EDGE_MIN_SAMPLES | |
540 | || (tcount - mcount) * HEAVY_EDGE_RATIO > tcount) | |
541 | return NULL; | |
542 | ||
543 | if (dump_file) | |
544 | fprintf (dump_file, | |
545 | "Found latch edge %d -> %d using profile information.\n", | |
546 | me->src->index, me->dest->index); | |
547 | return me; | |
548 | } | |
549 | ||
550 | /* Among LATCHES, guesses a latch edge of LOOP corresponding to subloop, based | |
551 | on the structure of induction variables. Returns this edge, or NULL if we | |
552 | do not find any. | |
553 | ||
554 | We are quite conservative, and look just for an obvious simple innermost | |
555 | loop (which is the case where we would lose the most performance by not | |
556 | disambiguating the loop). More precisely, we look for the following | |
557 | situation: The source of the chosen latch edge dominates sources of all | |
558 | the other latch edges. Additionally, the header does not contain a phi node | |
559 | such that the argument from the chosen edge is equal to the argument from | |
560 | another edge. */ | |
561 | ||
562 | static edge | |
75a70cf9 | 563 | find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, VEC (edge, heap) *latches) |
4a6f9e19 | 564 | { |
565 | edge e, latch = VEC_index (edge, latches, 0); | |
566 | unsigned i; | |
75a70cf9 | 567 | gimple phi; |
568 | gimple_stmt_iterator psi; | |
569 | tree lop; | |
4a6f9e19 | 570 | basic_block bb; |
571 | ||
572 | /* Find the candidate for the latch edge. */ | |
573 | for (i = 1; VEC_iterate (edge, latches, i, e); i++) | |
574 | if (dominated_by_p (CDI_DOMINATORS, latch->src, e->src)) | |
575 | latch = e; | |
576 | ||
577 | /* Verify that it dominates all the latch edges. */ | |
48148244 | 578 | FOR_EACH_VEC_ELT (edge, latches, i, e) |
4a6f9e19 | 579 | if (!dominated_by_p (CDI_DOMINATORS, e->src, latch->src)) |
580 | return NULL; | |
581 | ||
582 | /* Check for a phi node that would deny that this is a latch edge of | |
583 | a subloop. */ | |
75a70cf9 | 584 | for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) |
4a6f9e19 | 585 | { |
75a70cf9 | 586 | phi = gsi_stmt (psi); |
4a6f9e19 | 587 | lop = PHI_ARG_DEF_FROM_EDGE (phi, latch); |
588 | ||
589 | /* Ignore the values that are not changed inside the subloop. */ | |
590 | if (TREE_CODE (lop) != SSA_NAME | |
591 | || SSA_NAME_DEF_STMT (lop) == phi) | |
592 | continue; | |
75a70cf9 | 593 | bb = gimple_bb (SSA_NAME_DEF_STMT (lop)); |
4a6f9e19 | 594 | if (!bb || !flow_bb_inside_loop_p (loop, bb)) |
595 | continue; | |
596 | ||
48148244 | 597 | FOR_EACH_VEC_ELT (edge, latches, i, e) |
4a6f9e19 | 598 | if (e != latch |
599 | && PHI_ARG_DEF_FROM_EDGE (phi, e) == lop) | |
600 | return NULL; | |
601 | } | |
602 | ||
603 | if (dump_file) | |
604 | fprintf (dump_file, | |
605 | "Found latch edge %d -> %d using iv structure.\n", | |
606 | latch->src->index, latch->dest->index); | |
607 | return latch; | |
608 | } | |
609 | ||
610 | /* If we can determine that one of the several latch edges of LOOP behaves | |
611 | as a latch edge of a separate subloop, returns this edge. Otherwise | |
612 | returns NULL. */ | |
613 | ||
614 | static edge | |
615 | find_subloop_latch_edge (struct loop *loop) | |
616 | { | |
617 | VEC (edge, heap) *latches = get_loop_latch_edges (loop); | |
618 | edge latch = NULL; | |
619 | ||
620 | if (VEC_length (edge, latches) > 1) | |
621 | { | |
622 | latch = find_subloop_latch_edge_by_profile (latches); | |
623 | ||
624 | if (!latch | |
625 | /* We consider ivs to guess the latch edge only in SSA. Perhaps we | |
626 | should use cfghook for this, but it is hard to imagine it would | |
627 | be useful elsewhere. */ | |
628 | && current_ir_type () == IR_GIMPLE) | |
629 | latch = find_subloop_latch_edge_by_ivs (loop, latches); | |
630 | } | |
631 | ||
632 | VEC_free (edge, heap, latches); | |
633 | return latch; | |
634 | } | |
635 | ||
636 | /* Callback for make_forwarder_block. Returns true if the edge E is marked | |
637 | in the set MFB_REIS_SET. */ | |
638 | ||
639 | static struct pointer_set_t *mfb_reis_set; | |
640 | static bool | |
641 | mfb_redirect_edges_in_set (edge e) | |
642 | { | |
643 | return pointer_set_contains (mfb_reis_set, e); | |
644 | } | |
645 | ||
646 | /* Creates a subloop of LOOP with latch edge LATCH. */ | |
647 | ||
648 | static void | |
649 | form_subloop (struct loop *loop, edge latch) | |
650 | { | |
651 | edge_iterator ei; | |
652 | edge e, new_entry; | |
653 | struct loop *new_loop; | |
48e1416a | 654 | |
4a6f9e19 | 655 | mfb_reis_set = pointer_set_create (); |
656 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
657 | { | |
658 | if (e != latch) | |
659 | pointer_set_insert (mfb_reis_set, e); | |
660 | } | |
661 | new_entry = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
662 | NULL); | |
663 | pointer_set_destroy (mfb_reis_set); | |
664 | ||
665 | loop->header = new_entry->src; | |
666 | ||
667 | /* Find the blocks and subloops that belong to the new loop, and add it to | |
668 | the appropriate place in the loop tree. */ | |
669 | new_loop = alloc_loop (); | |
670 | new_loop->header = new_entry->dest; | |
671 | new_loop->latch = latch->src; | |
672 | add_loop (new_loop, loop); | |
673 | } | |
674 | ||
675 | /* Make all the latch edges of LOOP to go to a single forwarder block -- | |
676 | a new latch of LOOP. */ | |
677 | ||
678 | static void | |
679 | merge_latch_edges (struct loop *loop) | |
680 | { | |
681 | VEC (edge, heap) *latches = get_loop_latch_edges (loop); | |
682 | edge latch, e; | |
683 | unsigned i; | |
684 | ||
685 | gcc_assert (VEC_length (edge, latches) > 0); | |
686 | ||
687 | if (VEC_length (edge, latches) == 1) | |
688 | loop->latch = VEC_index (edge, latches, 0)->src; | |
689 | else | |
690 | { | |
691 | if (dump_file) | |
692 | fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num); | |
693 | ||
694 | mfb_reis_set = pointer_set_create (); | |
48148244 | 695 | FOR_EACH_VEC_ELT (edge, latches, i, e) |
4a6f9e19 | 696 | pointer_set_insert (mfb_reis_set, e); |
697 | latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
698 | NULL); | |
699 | pointer_set_destroy (mfb_reis_set); | |
700 | ||
701 | loop->header = latch->dest; | |
702 | loop->latch = latch->src; | |
703 | } | |
704 | ||
705 | VEC_free (edge, heap, latches); | |
706 | } | |
707 | ||
708 | /* LOOP may have several latch edges. Transform it into (possibly several) | |
709 | loops with single latch edge. */ | |
710 | ||
711 | static void | |
712 | disambiguate_multiple_latches (struct loop *loop) | |
713 | { | |
714 | edge e; | |
715 | ||
85694bac | 716 | /* We eliminate the multiple latches by splitting the header to the forwarder |
4a6f9e19 | 717 | block F and the rest R, and redirecting the edges. There are two cases: |
718 | ||
719 | 1) If there is a latch edge E that corresponds to a subloop (we guess | |
720 | that based on profile -- if it is taken much more often than the | |
721 | remaining edges; and on trees, using the information about induction | |
722 | variables of the loops), we redirect E to R, all the remaining edges to | |
723 | F, then rescan the loops and try again for the outer loop. | |
724 | 2) If there is no such edge, we redirect all latch edges to F, and the | |
725 | entry edges to R, thus making F the single latch of the loop. */ | |
726 | ||
727 | if (dump_file) | |
728 | fprintf (dump_file, "Disambiguating loop %d with multiple latches\n", | |
729 | loop->num); | |
730 | ||
731 | /* During latch merging, we may need to redirect the entry edges to a new | |
732 | block. This would cause problems if the entry edge was the one from the | |
733 | entry block. To avoid having to handle this case specially, split | |
734 | such entry edge. */ | |
735 | e = find_edge (ENTRY_BLOCK_PTR, loop->header); | |
736 | if (e) | |
737 | split_edge (e); | |
738 | ||
739 | while (1) | |
740 | { | |
741 | e = find_subloop_latch_edge (loop); | |
742 | if (!e) | |
743 | break; | |
744 | ||
745 | form_subloop (loop, e); | |
746 | } | |
747 | ||
748 | merge_latch_edges (loop); | |
749 | } | |
750 | ||
751 | /* Split loops with multiple latch edges. */ | |
752 | ||
753 | void | |
754 | disambiguate_loops_with_multiple_latches (void) | |
755 | { | |
756 | loop_iterator li; | |
757 | struct loop *loop; | |
758 | ||
759 | FOR_EACH_LOOP (li, loop, 0) | |
760 | { | |
761 | if (!loop->latch) | |
762 | disambiguate_multiple_latches (loop); | |
763 | } | |
764 | } | |
765 | ||
d10cfa8d | 766 | /* Return nonzero if basic block BB belongs to LOOP. */ |
7fb12188 | 767 | bool |
7ecb5bb2 | 768 | flow_bb_inside_loop_p (const struct loop *loop, const_basic_block bb) |
7fb12188 | 769 | { |
770 | struct loop *source_loop; | |
771 | ||
772 | if (bb == ENTRY_BLOCK_PTR || bb == EXIT_BLOCK_PTR) | |
773 | return 0; | |
774 | ||
775 | source_loop = bb->loop_father; | |
776 | return loop == source_loop || flow_loop_nested_p (loop, source_loop); | |
777 | } | |
778 | ||
4a6f9e19 | 779 | /* Enumeration predicate for get_loop_body_with_size. */ |
7fb12188 | 780 | static bool |
7ecb5bb2 | 781 | glb_enum_p (const_basic_block bb, const void *glb_loop) |
7fb12188 | 782 | { |
7ecb5bb2 | 783 | const struct loop *const loop = (const struct loop *) glb_loop; |
4a6f9e19 | 784 | return (bb != loop->header |
785 | && dominated_by_p (CDI_DOMINATORS, bb, loop->header)); | |
786 | } | |
787 | ||
788 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
789 | order against direction of edges from latch. Specially, if | |
790 | header != latch, latch is the 1-st block. LOOP cannot be the fake | |
791 | loop tree root, and its size must be at most MAX_SIZE. The blocks | |
792 | in the LOOP body are stored to BODY, and the size of the LOOP is | |
793 | returned. */ | |
794 | ||
795 | unsigned | |
796 | get_loop_body_with_size (const struct loop *loop, basic_block *body, | |
797 | unsigned max_size) | |
798 | { | |
799 | return dfs_enumerate_from (loop->header, 1, glb_enum_p, | |
7ecb5bb2 | 800 | body, max_size, loop); |
7fb12188 | 801 | } |
802 | ||
dbfc1664 | 803 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs |
804 | order against direction of edges from latch. Specially, if | |
805 | header != latch, latch is the 1-st block. */ | |
4a6f9e19 | 806 | |
7fb12188 | 807 | basic_block * |
4c9e08a4 | 808 | get_loop_body (const struct loop *loop) |
7fb12188 | 809 | { |
4a6f9e19 | 810 | basic_block *body, bb; |
862be747 | 811 | unsigned tv = 0; |
7fb12188 | 812 | |
cc636d56 | 813 | gcc_assert (loop->num_nodes); |
7fb12188 | 814 | |
4a6f9e19 | 815 | body = XCNEWVEC (basic_block, loop->num_nodes); |
7fb12188 | 816 | |
817 | if (loop->latch == EXIT_BLOCK_PTR) | |
818 | { | |
4a6f9e19 | 819 | /* There may be blocks unreachable from EXIT_BLOCK, hence we need to |
820 | special-case the fake loop that contains the whole function. */ | |
4d2e5d52 | 821 | gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks); |
4a6f9e19 | 822 | body[tv++] = loop->header; |
823 | body[tv++] = EXIT_BLOCK_PTR; | |
7fb12188 | 824 | FOR_EACH_BB (bb) |
4a6f9e19 | 825 | body[tv++] = bb; |
7fb12188 | 826 | } |
4a6f9e19 | 827 | else |
828 | tv = get_loop_body_with_size (loop, body, loop->num_nodes); | |
7fb12188 | 829 | |
cc636d56 | 830 | gcc_assert (tv == loop->num_nodes); |
4a6f9e19 | 831 | return body; |
7fb12188 | 832 | } |
833 | ||
f9cce2dc | 834 | /* Fills dominance descendants inside LOOP of the basic block BB into |
835 | array TOVISIT from index *TV. */ | |
836 | ||
837 | static void | |
838 | fill_sons_in_loop (const struct loop *loop, basic_block bb, | |
839 | basic_block *tovisit, int *tv) | |
840 | { | |
841 | basic_block son, postpone = NULL; | |
842 | ||
843 | tovisit[(*tv)++] = bb; | |
844 | for (son = first_dom_son (CDI_DOMINATORS, bb); | |
845 | son; | |
846 | son = next_dom_son (CDI_DOMINATORS, son)) | |
847 | { | |
848 | if (!flow_bb_inside_loop_p (loop, son)) | |
849 | continue; | |
850 | ||
851 | if (dominated_by_p (CDI_DOMINATORS, loop->latch, son)) | |
852 | { | |
853 | postpone = son; | |
854 | continue; | |
855 | } | |
856 | fill_sons_in_loop (loop, son, tovisit, tv); | |
857 | } | |
858 | ||
859 | if (postpone) | |
860 | fill_sons_in_loop (loop, postpone, tovisit, tv); | |
861 | } | |
862 | ||
863 | /* Gets body of a LOOP (that must be different from the outermost loop) | |
864 | sorted by dominance relation. Additionally, if a basic block s dominates | |
865 | the latch, then only blocks dominated by s are be after it. */ | |
866 | ||
867 | basic_block * | |
868 | get_loop_body_in_dom_order (const struct loop *loop) | |
869 | { | |
870 | basic_block *tovisit; | |
871 | int tv; | |
872 | ||
cc636d56 | 873 | gcc_assert (loop->num_nodes); |
f9cce2dc | 874 | |
4c36ffe6 | 875 | tovisit = XCNEWVEC (basic_block, loop->num_nodes); |
f9cce2dc | 876 | |
cc636d56 | 877 | gcc_assert (loop->latch != EXIT_BLOCK_PTR); |
f9cce2dc | 878 | |
879 | tv = 0; | |
880 | fill_sons_in_loop (loop, loop->header, tovisit, &tv); | |
881 | ||
cc636d56 | 882 | gcc_assert (tv == (int) loop->num_nodes); |
f9cce2dc | 883 | |
884 | return tovisit; | |
885 | } | |
886 | ||
e1ab7874 | 887 | /* Gets body of a LOOP sorted via provided BB_COMPARATOR. */ |
888 | ||
889 | basic_block * | |
48e1416a | 890 | get_loop_body_in_custom_order (const struct loop *loop, |
e1ab7874 | 891 | int (*bb_comparator) (const void *, const void *)) |
892 | { | |
893 | basic_block *bbs = get_loop_body (loop); | |
894 | ||
895 | qsort (bbs, loop->num_nodes, sizeof (basic_block), bb_comparator); | |
896 | ||
897 | return bbs; | |
898 | } | |
899 | ||
07c03fb0 | 900 | /* Get body of a LOOP in breadth first sort order. */ |
901 | ||
902 | basic_block * | |
903 | get_loop_body_in_bfs_order (const struct loop *loop) | |
904 | { | |
905 | basic_block *blocks; | |
906 | basic_block bb; | |
907 | bitmap visited; | |
908 | unsigned int i = 0; | |
909 | unsigned int vc = 1; | |
910 | ||
cc636d56 | 911 | gcc_assert (loop->num_nodes); |
912 | gcc_assert (loop->latch != EXIT_BLOCK_PTR); | |
07c03fb0 | 913 | |
4c36ffe6 | 914 | blocks = XCNEWVEC (basic_block, loop->num_nodes); |
27335ffd | 915 | visited = BITMAP_ALLOC (NULL); |
07c03fb0 | 916 | |
917 | bb = loop->header; | |
918 | while (i < loop->num_nodes) | |
919 | { | |
920 | edge e; | |
cd665a06 | 921 | edge_iterator ei; |
a0c938f0 | 922 | |
6ef9bbe0 | 923 | if (bitmap_set_bit (visited, bb->index)) |
924 | /* This basic block is now visited */ | |
925 | blocks[i++] = bb; | |
a0c938f0 | 926 | |
cd665a06 | 927 | FOR_EACH_EDGE (e, ei, bb->succs) |
a0c938f0 | 928 | { |
929 | if (flow_bb_inside_loop_p (loop, e->dest)) | |
930 | { | |
6ef9bbe0 | 931 | if (bitmap_set_bit (visited, e->dest->index)) |
932 | blocks[i++] = e->dest; | |
a0c938f0 | 933 | } |
934 | } | |
935 | ||
cc636d56 | 936 | gcc_assert (i >= vc); |
a0c938f0 | 937 | |
07c03fb0 | 938 | bb = blocks[vc++]; |
939 | } | |
a0c938f0 | 940 | |
27335ffd | 941 | BITMAP_FREE (visited); |
07c03fb0 | 942 | return blocks; |
943 | } | |
944 | ||
dce58e66 | 945 | /* Hash function for struct loop_exit. */ |
946 | ||
947 | static hashval_t | |
948 | loop_exit_hash (const void *ex) | |
949 | { | |
c1fdef8e | 950 | const struct loop_exit *const exit = (const struct loop_exit *) ex; |
dce58e66 | 951 | |
952 | return htab_hash_pointer (exit->e); | |
953 | } | |
954 | ||
955 | /* Equality function for struct loop_exit. Compares with edge. */ | |
956 | ||
957 | static int | |
958 | loop_exit_eq (const void *ex, const void *e) | |
959 | { | |
c1fdef8e | 960 | const struct loop_exit *const exit = (const struct loop_exit *) ex; |
dce58e66 | 961 | |
962 | return exit->e == e; | |
963 | } | |
964 | ||
965 | /* Frees the list of loop exit descriptions EX. */ | |
966 | ||
967 | static void | |
968 | loop_exit_free (void *ex) | |
969 | { | |
970 | struct loop_exit *exit = (struct loop_exit *) ex, *next; | |
971 | ||
972 | for (; exit; exit = next) | |
973 | { | |
974 | next = exit->next_e; | |
48e1416a | 975 | |
dce58e66 | 976 | exit->next->prev = exit->prev; |
977 | exit->prev->next = exit->next; | |
978 | ||
ccae4f9f | 979 | ggc_free (exit); |
dce58e66 | 980 | } |
981 | } | |
982 | ||
983 | /* Returns the list of records for E as an exit of a loop. */ | |
984 | ||
985 | static struct loop_exit * | |
986 | get_exit_descriptions (edge e) | |
987 | { | |
f780cc25 | 988 | return (struct loop_exit *) htab_find_with_hash (current_loops->exits, e, |
989 | htab_hash_pointer (e)); | |
dce58e66 | 990 | } |
991 | ||
992 | /* Updates the lists of loop exits in that E appears. | |
993 | If REMOVED is true, E is being removed, and we | |
994 | just remove it from the lists of exits. | |
995 | If NEW_EDGE is true and E is not a loop exit, we | |
996 | do not try to remove it from loop exit lists. */ | |
997 | ||
998 | void | |
999 | rescan_loop_exit (edge e, bool new_edge, bool removed) | |
1000 | { | |
1001 | void **slot; | |
1002 | struct loop_exit *exits = NULL, *exit; | |
1003 | struct loop *aloop, *cloop; | |
1004 | ||
f24ec26f | 1005 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1006 | return; |
1007 | ||
1008 | if (!removed | |
1009 | && e->src->loop_father != NULL | |
1010 | && e->dest->loop_father != NULL | |
1011 | && !flow_bb_inside_loop_p (e->src->loop_father, e->dest)) | |
1012 | { | |
1013 | cloop = find_common_loop (e->src->loop_father, e->dest->loop_father); | |
1014 | for (aloop = e->src->loop_father; | |
1015 | aloop != cloop; | |
9e3536f4 | 1016 | aloop = loop_outer (aloop)) |
dce58e66 | 1017 | { |
ba72912a | 1018 | exit = ggc_alloc_loop_exit (); |
dce58e66 | 1019 | exit->e = e; |
1020 | ||
ccae4f9f | 1021 | exit->next = aloop->exits->next; |
1022 | exit->prev = aloop->exits; | |
dce58e66 | 1023 | exit->next->prev = exit; |
1024 | exit->prev->next = exit; | |
1025 | ||
1026 | exit->next_e = exits; | |
1027 | exits = exit; | |
1028 | } | |
48e1416a | 1029 | } |
dce58e66 | 1030 | |
1031 | if (!exits && new_edge) | |
1032 | return; | |
1033 | ||
1034 | slot = htab_find_slot_with_hash (current_loops->exits, e, | |
1035 | htab_hash_pointer (e), | |
1036 | exits ? INSERT : NO_INSERT); | |
1037 | if (!slot) | |
1038 | return; | |
1039 | ||
1040 | if (exits) | |
1041 | { | |
1042 | if (*slot) | |
1043 | loop_exit_free (*slot); | |
1044 | *slot = exits; | |
1045 | } | |
1046 | else | |
1047 | htab_clear_slot (current_loops->exits, slot); | |
1048 | } | |
1049 | ||
1050 | /* For each loop, record list of exit edges, and start maintaining these | |
1051 | lists. */ | |
1052 | ||
1053 | void | |
1054 | record_loop_exits (void) | |
1055 | { | |
1056 | basic_block bb; | |
1057 | edge_iterator ei; | |
1058 | edge e; | |
1059 | ||
d500fef3 | 1060 | if (!current_loops) |
1061 | return; | |
1062 | ||
f24ec26f | 1063 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1064 | return; |
f24ec26f | 1065 | loops_state_set (LOOPS_HAVE_RECORDED_EXITS); |
dce58e66 | 1066 | |
1067 | gcc_assert (current_loops->exits == NULL); | |
ba72912a | 1068 | current_loops->exits = htab_create_ggc (2 * number_of_loops (), |
1069 | loop_exit_hash, loop_exit_eq, | |
1070 | loop_exit_free); | |
dce58e66 | 1071 | |
1072 | FOR_EACH_BB (bb) | |
1073 | { | |
1074 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1075 | { | |
1076 | rescan_loop_exit (e, true, false); | |
1077 | } | |
1078 | } | |
1079 | } | |
1080 | ||
1081 | /* Dumps information about the exit in *SLOT to FILE. | |
1082 | Callback for htab_traverse. */ | |
1083 | ||
1084 | static int | |
1085 | dump_recorded_exit (void **slot, void *file) | |
1086 | { | |
f780cc25 | 1087 | struct loop_exit *exit = (struct loop_exit *) *slot; |
dce58e66 | 1088 | unsigned n = 0; |
1089 | edge e = exit->e; | |
1090 | ||
1091 | for (; exit != NULL; exit = exit->next_e) | |
1092 | n++; | |
1093 | ||
f780cc25 | 1094 | fprintf ((FILE*) file, "Edge %d->%d exits %u loops\n", |
dce58e66 | 1095 | e->src->index, e->dest->index, n); |
1096 | ||
1097 | return 1; | |
1098 | } | |
1099 | ||
1100 | /* Dumps the recorded exits of loops to FILE. */ | |
1101 | ||
1102 | extern void dump_recorded_exits (FILE *); | |
1103 | void | |
1104 | dump_recorded_exits (FILE *file) | |
1105 | { | |
1106 | if (!current_loops->exits) | |
1107 | return; | |
1108 | htab_traverse (current_loops->exits, dump_recorded_exit, file); | |
1109 | } | |
1110 | ||
1111 | /* Releases lists of loop exits. */ | |
1112 | ||
1113 | void | |
1114 | release_recorded_exits (void) | |
1115 | { | |
f24ec26f | 1116 | gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)); |
dce58e66 | 1117 | htab_delete (current_loops->exits); |
1118 | current_loops->exits = NULL; | |
f24ec26f | 1119 | loops_state_clear (LOOPS_HAVE_RECORDED_EXITS); |
dce58e66 | 1120 | } |
1121 | ||
749ea85f | 1122 | /* Returns the list of the exit edges of a LOOP. */ |
1123 | ||
1124 | VEC (edge, heap) * | |
1125 | get_loop_exit_edges (const struct loop *loop) | |
a5414ff5 | 1126 | { |
749ea85f | 1127 | VEC (edge, heap) *edges = NULL; |
1128 | edge e; | |
1129 | unsigned i; | |
1130 | basic_block *body; | |
cd665a06 | 1131 | edge_iterator ei; |
dce58e66 | 1132 | struct loop_exit *exit; |
a5414ff5 | 1133 | |
cc636d56 | 1134 | gcc_assert (loop->latch != EXIT_BLOCK_PTR); |
a5414ff5 | 1135 | |
dce58e66 | 1136 | /* If we maintain the lists of exits, use them. Otherwise we must |
1137 | scan the body of the loop. */ | |
f24ec26f | 1138 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1139 | { |
ccae4f9f | 1140 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
dce58e66 | 1141 | VEC_safe_push (edge, heap, edges, exit->e); |
1142 | } | |
1143 | else | |
1144 | { | |
1145 | body = get_loop_body (loop); | |
1146 | for (i = 0; i < loop->num_nodes; i++) | |
1147 | FOR_EACH_EDGE (e, ei, body[i]->succs) | |
1148 | { | |
1149 | if (!flow_bb_inside_loop_p (loop, e->dest)) | |
1150 | VEC_safe_push (edge, heap, edges, e); | |
1151 | } | |
1152 | free (body); | |
1153 | } | |
a5414ff5 | 1154 | |
1155 | return edges; | |
1156 | } | |
1157 | ||
f9cce2dc | 1158 | /* Counts the number of conditional branches inside LOOP. */ |
1159 | ||
1160 | unsigned | |
1161 | num_loop_branches (const struct loop *loop) | |
1162 | { | |
1163 | unsigned i, n; | |
1164 | basic_block * body; | |
1165 | ||
cc636d56 | 1166 | gcc_assert (loop->latch != EXIT_BLOCK_PTR); |
f9cce2dc | 1167 | |
1168 | body = get_loop_body (loop); | |
1169 | n = 0; | |
1170 | for (i = 0; i < loop->num_nodes; i++) | |
cd665a06 | 1171 | if (EDGE_COUNT (body[i]->succs) >= 2) |
f9cce2dc | 1172 | n++; |
1173 | free (body); | |
1174 | ||
1175 | return n; | |
1176 | } | |
1177 | ||
7fb12188 | 1178 | /* Adds basic block BB to LOOP. */ |
1179 | void | |
4c9e08a4 | 1180 | add_bb_to_loop (basic_block bb, struct loop *loop) |
1181 | { | |
9e3536f4 | 1182 | unsigned i; |
1183 | loop_p ploop; | |
dce58e66 | 1184 | edge_iterator ei; |
1185 | edge e; | |
1186 | ||
1187 | gcc_assert (bb->loop_father == NULL); | |
1188 | bb->loop_father = loop; | |
9e3536f4 | 1189 | bb->loop_depth = loop_depth (loop); |
dce58e66 | 1190 | loop->num_nodes++; |
48148244 | 1191 | FOR_EACH_VEC_ELT (loop_p, loop->superloops, i, ploop) |
9e3536f4 | 1192 | ploop->num_nodes++; |
dce58e66 | 1193 | |
1194 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1195 | { | |
1196 | rescan_loop_exit (e, true, false); | |
1197 | } | |
1198 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1199 | { | |
1200 | rescan_loop_exit (e, true, false); | |
1201 | } | |
88e6f696 | 1202 | } |
7fb12188 | 1203 | |
1204 | /* Remove basic block BB from loops. */ | |
1205 | void | |
4c9e08a4 | 1206 | remove_bb_from_loops (basic_block bb) |
1207 | { | |
dce58e66 | 1208 | int i; |
1209 | struct loop *loop = bb->loop_father; | |
9e3536f4 | 1210 | loop_p ploop; |
dce58e66 | 1211 | edge_iterator ei; |
1212 | edge e; | |
1213 | ||
1214 | gcc_assert (loop != NULL); | |
1215 | loop->num_nodes--; | |
48148244 | 1216 | FOR_EACH_VEC_ELT (loop_p, loop->superloops, i, ploop) |
9e3536f4 | 1217 | ploop->num_nodes--; |
dce58e66 | 1218 | bb->loop_father = NULL; |
1219 | bb->loop_depth = 0; | |
1220 | ||
1221 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1222 | { | |
1223 | rescan_loop_exit (e, false, true); | |
1224 | } | |
1225 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1226 | { | |
1227 | rescan_loop_exit (e, false, true); | |
1228 | } | |
b811afb0 | 1229 | } |
7fb12188 | 1230 | |
1231 | /* Finds nearest common ancestor in loop tree for given loops. */ | |
1232 | struct loop * | |
4c9e08a4 | 1233 | find_common_loop (struct loop *loop_s, struct loop *loop_d) |
7fb12188 | 1234 | { |
9e3536f4 | 1235 | unsigned sdepth, ddepth; |
1236 | ||
7fb12188 | 1237 | if (!loop_s) return loop_d; |
1238 | if (!loop_d) return loop_s; | |
4c9e08a4 | 1239 | |
9e3536f4 | 1240 | sdepth = loop_depth (loop_s); |
1241 | ddepth = loop_depth (loop_d); | |
1242 | ||
1243 | if (sdepth < ddepth) | |
1244 | loop_d = VEC_index (loop_p, loop_d->superloops, sdepth); | |
1245 | else if (sdepth > ddepth) | |
1246 | loop_s = VEC_index (loop_p, loop_s->superloops, ddepth); | |
7fb12188 | 1247 | |
1248 | while (loop_s != loop_d) | |
1249 | { | |
9e3536f4 | 1250 | loop_s = loop_outer (loop_s); |
1251 | loop_d = loop_outer (loop_d); | |
7fb12188 | 1252 | } |
1253 | return loop_s; | |
1254 | } | |
1255 | ||
17519ba0 | 1256 | /* Removes LOOP from structures and frees its data. */ |
1257 | ||
1258 | void | |
1259 | delete_loop (struct loop *loop) | |
1260 | { | |
1261 | /* Remove the loop from structure. */ | |
1262 | flow_loop_tree_node_remove (loop); | |
1263 | ||
1264 | /* Remove loop from loops array. */ | |
1265 | VEC_replace (loop_p, current_loops->larray, loop->num, NULL); | |
1266 | ||
1267 | /* Free loop data. */ | |
1268 | flow_loop_free (loop); | |
1269 | } | |
1270 | ||
862be747 | 1271 | /* Cancels the LOOP; it must be innermost one. */ |
77cbebb3 | 1272 | |
1273 | static void | |
7194de72 | 1274 | cancel_loop (struct loop *loop) |
862be747 | 1275 | { |
1276 | basic_block *bbs; | |
1277 | unsigned i; | |
9e3536f4 | 1278 | struct loop *outer = loop_outer (loop); |
862be747 | 1279 | |
cc636d56 | 1280 | gcc_assert (!loop->inner); |
862be747 | 1281 | |
1282 | /* Move blocks up one level (they should be removed as soon as possible). */ | |
1283 | bbs = get_loop_body (loop); | |
1284 | for (i = 0; i < loop->num_nodes; i++) | |
9e3536f4 | 1285 | bbs[i]->loop_father = outer; |
862be747 | 1286 | |
bf4b25d7 | 1287 | free (bbs); |
17519ba0 | 1288 | delete_loop (loop); |
862be747 | 1289 | } |
1290 | ||
1291 | /* Cancels LOOP and all its subloops. */ | |
1292 | void | |
7194de72 | 1293 | cancel_loop_tree (struct loop *loop) |
862be747 | 1294 | { |
1295 | while (loop->inner) | |
7194de72 | 1296 | cancel_loop_tree (loop->inner); |
1297 | cancel_loop (loop); | |
862be747 | 1298 | } |
1299 | ||
7194de72 | 1300 | /* Checks that information about loops is correct |
d01481af | 1301 | -- sizes of loops are all right |
7fb12188 | 1302 | -- results of get_loop_body really belong to the loop |
1303 | -- loop header have just single entry edge and single latch edge | |
1304 | -- loop latches have only single successor that is header of their loop | |
862be747 | 1305 | -- irreducible loops are correctly marked |
7fb12188 | 1306 | */ |
4b987fac | 1307 | DEBUG_FUNCTION void |
7194de72 | 1308 | verify_loop_structure (void) |
7fb12188 | 1309 | { |
862be747 | 1310 | unsigned *sizes, i, j; |
1311 | sbitmap irreds; | |
7fb12188 | 1312 | basic_block *bbs, bb; |
1313 | struct loop *loop; | |
1314 | int err = 0; | |
a5414ff5 | 1315 | edge e; |
17519ba0 | 1316 | unsigned num = number_of_loops (); |
1317 | loop_iterator li; | |
dce58e66 | 1318 | struct loop_exit *exit, *mexit; |
79f958cb | 1319 | bool dom_available = dom_info_available_p (CDI_DOMINATORS); |
7fb12188 | 1320 | |
79f958cb | 1321 | /* We need up-to-date dominators, compute or verify them. */ |
1322 | if (!dom_available) | |
1323 | calculate_dominance_info (CDI_DOMINATORS); | |
1324 | else | |
1325 | verify_dominators (CDI_DOMINATORS); | |
ef0e6535 | 1326 | |
7fb12188 | 1327 | /* Check sizes. */ |
17519ba0 | 1328 | sizes = XCNEWVEC (unsigned, num); |
7fb12188 | 1329 | sizes[0] = 2; |
1330 | ||
1331 | FOR_EACH_BB (bb) | |
9e3536f4 | 1332 | for (loop = bb->loop_father; loop; loop = loop_outer (loop)) |
7fb12188 | 1333 | sizes[loop->num]++; |
1334 | ||
17519ba0 | 1335 | FOR_EACH_LOOP (li, loop, LI_INCLUDE_ROOT) |
7fb12188 | 1336 | { |
17519ba0 | 1337 | i = loop->num; |
7fb12188 | 1338 | |
17519ba0 | 1339 | if (loop->num_nodes != sizes[i]) |
7fb12188 | 1340 | { |
0a81f5a0 | 1341 | error ("size of loop %d should be %d, not %d", |
17519ba0 | 1342 | i, sizes[i], loop->num_nodes); |
7fb12188 | 1343 | err = 1; |
1344 | } | |
1345 | } | |
1346 | ||
7fb12188 | 1347 | /* Check get_loop_body. */ |
17519ba0 | 1348 | FOR_EACH_LOOP (li, loop, 0) |
7fb12188 | 1349 | { |
7fb12188 | 1350 | bbs = get_loop_body (loop); |
1351 | ||
1352 | for (j = 0; j < loop->num_nodes; j++) | |
1353 | if (!flow_bb_inside_loop_p (loop, bbs[j])) | |
1354 | { | |
0a81f5a0 | 1355 | error ("bb %d do not belong to loop %d", |
17519ba0 | 1356 | bbs[j]->index, loop->num); |
7fb12188 | 1357 | err = 1; |
1358 | } | |
1359 | free (bbs); | |
1360 | } | |
1361 | ||
1362 | /* Check headers and latches. */ | |
17519ba0 | 1363 | FOR_EACH_LOOP (li, loop, 0) |
7fb12188 | 1364 | { |
17519ba0 | 1365 | i = loop->num; |
7fb12188 | 1366 | |
f24ec26f | 1367 | if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
cd665a06 | 1368 | && EDGE_COUNT (loop->header->preds) != 2) |
7fb12188 | 1369 | { |
bf776685 | 1370 | error ("loop %d%'s header does not have exactly 2 entries", i); |
7fb12188 | 1371 | err = 1; |
1372 | } | |
f24ec26f | 1373 | if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
7fb12188 | 1374 | { |
ea091dfd | 1375 | if (!single_succ_p (loop->latch)) |
7fb12188 | 1376 | { |
bf776685 | 1377 | error ("loop %d%'s latch does not have exactly 1 successor", i); |
7fb12188 | 1378 | err = 1; |
1379 | } | |
ea091dfd | 1380 | if (single_succ (loop->latch) != loop->header) |
7fb12188 | 1381 | { |
bf776685 | 1382 | error ("loop %d%'s latch does not have header as successor", i); |
7fb12188 | 1383 | err = 1; |
1384 | } | |
1385 | if (loop->latch->loop_father != loop) | |
1386 | { | |
bf776685 | 1387 | error ("loop %d%'s latch does not belong directly to it", i); |
7fb12188 | 1388 | err = 1; |
1389 | } | |
1390 | } | |
1391 | if (loop->header->loop_father != loop) | |
1392 | { | |
bf776685 | 1393 | error ("loop %d%'s header does not belong directly to it", i); |
7fb12188 | 1394 | err = 1; |
1395 | } | |
f24ec26f | 1396 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) |
a5414ff5 | 1397 | && (loop_latch_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)) |
1398 | { | |
bf776685 | 1399 | error ("loop %d%'s latch is marked as part of irreducible region", i); |
a5414ff5 | 1400 | err = 1; |
1401 | } | |
7fb12188 | 1402 | } |
1403 | ||
862be747 | 1404 | /* Check irreducible loops. */ |
f24ec26f | 1405 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
862be747 | 1406 | { |
1407 | /* Record old info. */ | |
1408 | irreds = sbitmap_alloc (last_basic_block); | |
1409 | FOR_EACH_BB (bb) | |
a5414ff5 | 1410 | { |
cd665a06 | 1411 | edge_iterator ei; |
a5414ff5 | 1412 | if (bb->flags & BB_IRREDUCIBLE_LOOP) |
1413 | SET_BIT (irreds, bb->index); | |
1414 | else | |
1415 | RESET_BIT (irreds, bb->index); | |
cd665a06 | 1416 | FOR_EACH_EDGE (e, ei, bb->succs) |
a5414ff5 | 1417 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) |
4c9e08a4 | 1418 | e->flags |= EDGE_ALL_FLAGS + 1; |
a5414ff5 | 1419 | } |
862be747 | 1420 | |
1421 | /* Recount it. */ | |
7194de72 | 1422 | mark_irreducible_loops (); |
862be747 | 1423 | |
1424 | /* Compare. */ | |
1425 | FOR_EACH_BB (bb) | |
1426 | { | |
cd665a06 | 1427 | edge_iterator ei; |
1428 | ||
862be747 | 1429 | if ((bb->flags & BB_IRREDUCIBLE_LOOP) |
1430 | && !TEST_BIT (irreds, bb->index)) | |
1431 | { | |
0a81f5a0 | 1432 | error ("basic block %d should be marked irreducible", bb->index); |
862be747 | 1433 | err = 1; |
1434 | } | |
1435 | else if (!(bb->flags & BB_IRREDUCIBLE_LOOP) | |
1436 | && TEST_BIT (irreds, bb->index)) | |
1437 | { | |
0a81f5a0 | 1438 | error ("basic block %d should not be marked irreducible", bb->index); |
862be747 | 1439 | err = 1; |
1440 | } | |
cd665a06 | 1441 | FOR_EACH_EDGE (e, ei, bb->succs) |
a5414ff5 | 1442 | { |
1443 | if ((e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1444 | && !(e->flags & (EDGE_ALL_FLAGS + 1))) | |
1445 | { | |
0a81f5a0 | 1446 | error ("edge from %d to %d should be marked irreducible", |
a5414ff5 | 1447 | e->src->index, e->dest->index); |
1448 | err = 1; | |
1449 | } | |
1450 | else if (!(e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1451 | && (e->flags & (EDGE_ALL_FLAGS + 1))) | |
1452 | { | |
0a81f5a0 | 1453 | error ("edge from %d to %d should not be marked irreducible", |
a5414ff5 | 1454 | e->src->index, e->dest->index); |
1455 | err = 1; | |
1456 | } | |
1457 | e->flags &= ~(EDGE_ALL_FLAGS + 1); | |
1458 | } | |
862be747 | 1459 | } |
1460 | free (irreds); | |
1461 | } | |
1462 | ||
dce58e66 | 1463 | /* Check the recorded loop exits. */ |
1464 | FOR_EACH_LOOP (li, loop, 0) | |
bb445479 | 1465 | { |
ccae4f9f | 1466 | if (!loop->exits || loop->exits->e != NULL) |
dce58e66 | 1467 | { |
1468 | error ("corrupted head of the exits list of loop %d", | |
1469 | loop->num); | |
1470 | err = 1; | |
1471 | } | |
1472 | else | |
1473 | { | |
1474 | /* Check that the list forms a cycle, and all elements except | |
1475 | for the head are nonnull. */ | |
ccae4f9f | 1476 | for (mexit = loop->exits, exit = mexit->next, i = 0; |
dce58e66 | 1477 | exit->e && exit != mexit; |
1478 | exit = exit->next) | |
1479 | { | |
1480 | if (i++ & 1) | |
1481 | mexit = mexit->next; | |
1482 | } | |
1483 | ||
ccae4f9f | 1484 | if (exit != loop->exits) |
dce58e66 | 1485 | { |
1486 | error ("corrupted exits list of loop %d", loop->num); | |
1487 | err = 1; | |
1488 | } | |
1489 | } | |
1490 | ||
f24ec26f | 1491 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1492 | { |
ccae4f9f | 1493 | if (loop->exits->next != loop->exits) |
dce58e66 | 1494 | { |
1495 | error ("nonempty exits list of loop %d, but exits are not recorded", | |
1496 | loop->num); | |
1497 | err = 1; | |
1498 | } | |
1499 | } | |
1500 | } | |
1501 | ||
f24ec26f | 1502 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1503 | { |
1504 | unsigned n_exits = 0, eloops; | |
1505 | ||
17519ba0 | 1506 | memset (sizes, 0, sizeof (unsigned) * num); |
bb445479 | 1507 | FOR_EACH_BB (bb) |
1508 | { | |
cd665a06 | 1509 | edge_iterator ei; |
7194de72 | 1510 | if (bb->loop_father == current_loops->tree_root) |
bb445479 | 1511 | continue; |
cd665a06 | 1512 | FOR_EACH_EDGE (e, ei, bb->succs) |
bb445479 | 1513 | { |
bb445479 | 1514 | if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) |
1515 | continue; | |
1516 | ||
dce58e66 | 1517 | n_exits++; |
1518 | exit = get_exit_descriptions (e); | |
1519 | if (!exit) | |
1520 | { | |
bf776685 | 1521 | error ("exit %d->%d not recorded", |
dce58e66 | 1522 | e->src->index, e->dest->index); |
1523 | err = 1; | |
1524 | } | |
1525 | eloops = 0; | |
1526 | for (; exit; exit = exit->next_e) | |
1527 | eloops++; | |
1528 | ||
bb445479 | 1529 | for (loop = bb->loop_father; |
1530 | loop != e->dest->loop_father; | |
9e3536f4 | 1531 | loop = loop_outer (loop)) |
bb445479 | 1532 | { |
dce58e66 | 1533 | eloops--; |
bb445479 | 1534 | sizes[loop->num]++; |
dce58e66 | 1535 | } |
1536 | ||
1537 | if (eloops != 0) | |
1538 | { | |
bf776685 | 1539 | error ("wrong list of exited loops for edge %d->%d", |
dce58e66 | 1540 | e->src->index, e->dest->index); |
1541 | err = 1; | |
bb445479 | 1542 | } |
1543 | } | |
1544 | } | |
1545 | ||
dce58e66 | 1546 | if (n_exits != htab_elements (current_loops->exits)) |
bb445479 | 1547 | { |
bf776685 | 1548 | error ("too many loop exits recorded"); |
dce58e66 | 1549 | err = 1; |
1550 | } | |
bb445479 | 1551 | |
dce58e66 | 1552 | FOR_EACH_LOOP (li, loop, 0) |
1553 | { | |
1554 | eloops = 0; | |
ccae4f9f | 1555 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
dce58e66 | 1556 | eloops++; |
1557 | if (eloops != sizes[loop->num]) | |
bb445479 | 1558 | { |
dce58e66 | 1559 | error ("%d exits recorded for loop %d (having %d exits)", |
1560 | eloops, loop->num, sizes[loop->num]); | |
bb445479 | 1561 | err = 1; |
1562 | } | |
1563 | } | |
1564 | } | |
1565 | ||
cc636d56 | 1566 | gcc_assert (!err); |
bb445479 | 1567 | |
1568 | free (sizes); | |
79f958cb | 1569 | if (!dom_available) |
1570 | free_dominance_info (CDI_DOMINATORS); | |
7fb12188 | 1571 | } |
1572 | ||
1573 | /* Returns latch edge of LOOP. */ | |
1574 | edge | |
4c9e08a4 | 1575 | loop_latch_edge (const struct loop *loop) |
7fb12188 | 1576 | { |
c6356c17 | 1577 | return find_edge (loop->latch, loop->header); |
65f34de5 | 1578 | } |
7fb12188 | 1579 | |
1580 | /* Returns preheader edge of LOOP. */ | |
1581 | edge | |
4c9e08a4 | 1582 | loop_preheader_edge (const struct loop *loop) |
7fb12188 | 1583 | { |
1584 | edge e; | |
cd665a06 | 1585 | edge_iterator ei; |
7fb12188 | 1586 | |
f24ec26f | 1587 | gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)); |
d8a0d6b8 | 1588 | |
cd665a06 | 1589 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
1590 | if (e->src != loop->latch) | |
1591 | break; | |
7fb12188 | 1592 | |
1593 | return e; | |
1594 | } | |
ffc6b5d5 | 1595 | |
1596 | /* Returns true if E is an exit of LOOP. */ | |
1597 | ||
1598 | bool | |
7ecb5bb2 | 1599 | loop_exit_edge_p (const struct loop *loop, const_edge e) |
ffc6b5d5 | 1600 | { |
1601 | return (flow_bb_inside_loop_p (loop, e->src) | |
1602 | && !flow_bb_inside_loop_p (loop, e->dest)); | |
1603 | } | |
d9e7e1a2 | 1604 | |
1605 | /* Returns the single exit edge of LOOP, or NULL if LOOP has either no exit | |
dce58e66 | 1606 | or more than one exit. If loops do not have the exits recorded, NULL |
1607 | is returned always. */ | |
d9e7e1a2 | 1608 | |
1609 | edge | |
1610 | single_exit (const struct loop *loop) | |
1611 | { | |
ccae4f9f | 1612 | struct loop_exit *exit = loop->exits->next; |
d9e7e1a2 | 1613 | |
f24ec26f | 1614 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
dce58e66 | 1615 | return NULL; |
d9e7e1a2 | 1616 | |
ccae4f9f | 1617 | if (exit->e && exit->next == loop->exits) |
dce58e66 | 1618 | return exit->e; |
1619 | else | |
1620 | return NULL; | |
d9e7e1a2 | 1621 | } |
255b6be7 | 1622 | |
259c0e44 | 1623 | /* Returns true when BB has an incoming edge exiting LOOP. */ |
255b6be7 | 1624 | |
1625 | bool | |
259c0e44 | 1626 | loop_exits_to_bb_p (struct loop *loop, basic_block bb) |
255b6be7 | 1627 | { |
1628 | edge e; | |
1629 | edge_iterator ei; | |
1630 | ||
1631 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1632 | if (loop_exit_edge_p (loop, e)) | |
1633 | return true; | |
1634 | ||
1635 | return false; | |
1636 | } | |
259c0e44 | 1637 | |
1638 | /* Returns true when BB has an outgoing edge exiting LOOP. */ | |
1639 | ||
1640 | bool | |
1641 | loop_exits_from_bb_p (struct loop *loop, basic_block bb) | |
1642 | { | |
1643 | edge e; | |
1644 | edge_iterator ei; | |
1645 | ||
1646 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1647 | if (loop_exit_edge_p (loop, e)) | |
1648 | return true; | |
1649 | ||
1650 | return false; | |
1651 | } |