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402209ff | 1 | /* Natural loop discovery code for GNU compiler. |
cbe34bb5 | 2 | Copyright (C) 2000-2017 Free Software Foundation, Inc. |
402209ff JH |
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 | |
9dcd6f09 | 8 | Software Foundation; either version 3, or (at your option) any later |
402209ff JH |
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 | |
9dcd6f09 NC |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
402209ff JH |
19 | |
20 | #include "config.h" | |
21 | #include "system.h" | |
4977bab6 | 22 | #include "coretypes.h" |
c7131fb2 | 23 | #include "backend.h" |
957060b5 | 24 | #include "rtl.h" |
c7131fb2 AM |
25 | #include "tree.h" |
26 | #include "gimple.h" | |
957060b5 AM |
27 | #include "cfghooks.h" |
28 | #include "gimple-ssa.h" | |
29 | #include "diagnostic-core.h" | |
60393bbc | 30 | #include "cfganal.h" |
3d436d2a | 31 | #include "cfgloop.h" |
5be5c238 | 32 | #include "gimple-iterator.h" |
7ee2468b | 33 | #include "dumpfile.h" |
f470c378 | 34 | |
d73be268 | 35 | static void flow_loops_cfg_dump (FILE *); |
402209ff JH |
36 | \f |
37 | /* Dump loop related CFG information. */ | |
38 | ||
39 | static void | |
d73be268 | 40 | flow_loops_cfg_dump (FILE *file) |
402209ff | 41 | { |
e0082a72 | 42 | basic_block bb; |
402209ff | 43 | |
d73be268 | 44 | if (!file) |
402209ff JH |
45 | return; |
46 | ||
11cd3bed | 47 | FOR_EACH_BB_FN (bb, cfun) |
402209ff JH |
48 | { |
49 | edge succ; | |
628f6a4e | 50 | edge_iterator ei; |
402209ff | 51 | |
e0082a72 | 52 | fprintf (file, ";; %d succs { ", bb->index); |
628f6a4e | 53 | FOR_EACH_EDGE (succ, ei, bb->succs) |
0b17ab2f | 54 | fprintf (file, "%d ", succ->dest->index); |
2ecfd709 | 55 | fprintf (file, "}\n"); |
402209ff | 56 | } |
402209ff JH |
57 | } |
58 | ||
da7d8304 | 59 | /* Return nonzero if the nodes of LOOP are a subset of OUTER. */ |
402209ff | 60 | |
2ecfd709 | 61 | bool |
d329e058 | 62 | flow_loop_nested_p (const struct loop *outer, const struct loop *loop) |
402209ff | 63 | { |
9ba025a2 ZD |
64 | unsigned odepth = loop_depth (outer); |
65 | ||
66 | return (loop_depth (loop) > odepth | |
9771b263 | 67 | && (*loop->superloops)[odepth] == outer); |
402209ff JH |
68 | } |
69 | ||
1ad03593 SP |
70 | /* Returns the loop such that LOOP is nested DEPTH (indexed from zero) |
71 | loops within LOOP. */ | |
a7e5372d ZD |
72 | |
73 | struct loop * | |
74 | superloop_at_depth (struct loop *loop, unsigned depth) | |
75 | { | |
9ba025a2 ZD |
76 | unsigned ldepth = loop_depth (loop); |
77 | ||
78 | gcc_assert (depth <= ldepth); | |
a7e5372d | 79 | |
9ba025a2 | 80 | if (depth == ldepth) |
a7e5372d ZD |
81 | return loop; |
82 | ||
9771b263 | 83 | return (*loop->superloops)[depth]; |
a7e5372d ZD |
84 | } |
85 | ||
89f8f30f ZD |
86 | /* Returns the list of the latch edges of LOOP. */ |
87 | ||
9771b263 | 88 | static vec<edge> |
89f8f30f ZD |
89 | get_loop_latch_edges (const struct loop *loop) |
90 | { | |
91 | edge_iterator ei; | |
92 | edge e; | |
6e1aa848 | 93 | vec<edge> ret = vNULL; |
89f8f30f ZD |
94 | |
95 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
96 | { | |
97 | if (dominated_by_p (CDI_DOMINATORS, e->src, loop->header)) | |
9771b263 | 98 | ret.safe_push (e); |
89f8f30f ZD |
99 | } |
100 | ||
101 | return ret; | |
102 | } | |
103 | ||
402209ff JH |
104 | /* Dump the loop information specified by LOOP to the stream FILE |
105 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
106 | ||
107 | void | |
d329e058 AJ |
108 | flow_loop_dump (const struct loop *loop, FILE *file, |
109 | void (*loop_dump_aux) (const struct loop *, FILE *, int), | |
110 | int verbose) | |
402209ff | 111 | { |
2ecfd709 | 112 | basic_block *bbs; |
3d436d2a | 113 | unsigned i; |
9771b263 | 114 | vec<edge> latches; |
89f8f30f | 115 | edge e; |
2ecfd709 | 116 | |
402209ff JH |
117 | if (! loop || ! loop->header) |
118 | return; | |
119 | ||
7490e6c4 | 120 | fprintf (file, ";;\n;; Loop %d\n", loop->num); |
402209ff | 121 | |
89f8f30f ZD |
122 | fprintf (file, ";; header %d, ", loop->header->index); |
123 | if (loop->latch) | |
124 | fprintf (file, "latch %d\n", loop->latch->index); | |
125 | else | |
126 | { | |
127 | fprintf (file, "multiple latches:"); | |
128 | latches = get_loop_latch_edges (loop); | |
9771b263 | 129 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f | 130 | fprintf (file, " %d", e->src->index); |
9771b263 | 131 | latches.release (); |
89f8f30f ZD |
132 | fprintf (file, "\n"); |
133 | } | |
134 | ||
99f8a411 | 135 | fprintf (file, ";; depth %d, outer %ld\n", |
9ba025a2 ZD |
136 | loop_depth (loop), (long) (loop_outer (loop) |
137 | ? loop_outer (loop)->num : -1)); | |
402209ff | 138 | |
199b1891 ML |
139 | if (loop->latch) |
140 | { | |
141 | bool read_profile_p; | |
142 | gcov_type nit = expected_loop_iterations_unbounded (loop, &read_profile_p); | |
143 | if (read_profile_p && !loop->any_estimate) | |
65e009bb JJ |
144 | fprintf (file, ";; profile-based iteration count: %" PRIu64 "\n", |
145 | (uint64_t) nit); | |
199b1891 ML |
146 | } |
147 | ||
2ecfd709 ZD |
148 | fprintf (file, ";; nodes:"); |
149 | bbs = get_loop_body (loop); | |
150 | for (i = 0; i < loop->num_nodes; i++) | |
151 | fprintf (file, " %d", bbs[i]->index); | |
152 | free (bbs); | |
153 | fprintf (file, "\n"); | |
5f0d2358 | 154 | |
402209ff JH |
155 | if (loop_dump_aux) |
156 | loop_dump_aux (loop, file, verbose); | |
157 | } | |
158 | ||
d73be268 | 159 | /* Dump the loop information about loops to the stream FILE, |
402209ff JH |
160 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ |
161 | ||
162 | void | |
d73be268 | 163 | flow_loops_dump (FILE *file, void (*loop_dump_aux) (const struct loop *, FILE *, int), int verbose) |
402209ff | 164 | { |
42fd6772 | 165 | struct loop *loop; |
402209ff | 166 | |
d73be268 | 167 | if (!current_loops || ! file) |
402209ff JH |
168 | return; |
169 | ||
0fc822d0 | 170 | fprintf (file, ";; %d loops found\n", number_of_loops (cfun)); |
2ecfd709 | 171 | |
f0bd40b1 | 172 | FOR_EACH_LOOP (loop, LI_INCLUDE_ROOT) |
402209ff | 173 | { |
2ecfd709 | 174 | flow_loop_dump (loop, file, loop_dump_aux, verbose); |
402209ff JH |
175 | } |
176 | ||
177 | if (verbose) | |
d73be268 | 178 | flow_loops_cfg_dump (file); |
402209ff JH |
179 | } |
180 | ||
2ecfd709 | 181 | /* Free data allocated for LOOP. */ |
9e2f83a5 | 182 | |
35b07080 | 183 | void |
d329e058 | 184 | flow_loop_free (struct loop *loop) |
2ecfd709 | 185 | { |
6270df4c ZD |
186 | struct loop_exit *exit, *next; |
187 | ||
9771b263 | 188 | vec_free (loop->superloops); |
6270df4c ZD |
189 | |
190 | /* Break the list of the loop exit records. They will be freed when the | |
191 | corresponding edge is rescanned or removed, and this avoids | |
192 | accessing the (already released) head of the list stored in the | |
193 | loop structure. */ | |
9e2f83a5 | 194 | for (exit = loop->exits->next; exit != loop->exits; exit = next) |
6270df4c ZD |
195 | { |
196 | next = exit->next; | |
197 | exit->next = exit; | |
198 | exit->prev = exit; | |
199 | } | |
9e2f83a5 ZD |
200 | |
201 | ggc_free (loop->exits); | |
202 | ggc_free (loop); | |
2ecfd709 ZD |
203 | } |
204 | ||
402209ff JH |
205 | /* Free all the memory allocated for LOOPS. */ |
206 | ||
207 | void | |
d329e058 | 208 | flow_loops_free (struct loops *loops) |
402209ff | 209 | { |
42fd6772 | 210 | if (loops->larray) |
402209ff | 211 | { |
3d436d2a | 212 | unsigned i; |
42fd6772 | 213 | loop_p loop; |
402209ff JH |
214 | |
215 | /* Free the loop descriptors. */ | |
9771b263 | 216 | FOR_EACH_VEC_SAFE_ELT (loops->larray, i, loop) |
402209ff | 217 | { |
2ecfd709 ZD |
218 | if (!loop) |
219 | continue; | |
220 | ||
221 | flow_loop_free (loop); | |
402209ff | 222 | } |
5f0d2358 | 223 | |
9771b263 | 224 | vec_free (loops->larray); |
402209ff JH |
225 | } |
226 | } | |
227 | ||
2ecfd709 ZD |
228 | /* Find the nodes contained within the LOOP with header HEADER. |
229 | Return the number of nodes within the loop. */ | |
402209ff | 230 | |
2b271002 | 231 | int |
d329e058 | 232 | flow_loop_nodes_find (basic_block header, struct loop *loop) |
402209ff | 233 | { |
6e1aa848 | 234 | vec<basic_block> stack = vNULL; |
2ecfd709 | 235 | int num_nodes = 1; |
89f8f30f ZD |
236 | edge latch; |
237 | edge_iterator latch_ei; | |
402209ff | 238 | |
2ecfd709 | 239 | header->loop_father = loop; |
402209ff | 240 | |
89f8f30f | 241 | FOR_EACH_EDGE (latch, latch_ei, loop->header->preds) |
402209ff | 242 | { |
89f8f30f ZD |
243 | if (latch->src->loop_father == loop |
244 | || !dominated_by_p (CDI_DOMINATORS, latch->src, loop->header)) | |
245 | continue; | |
246 | ||
402209ff | 247 | num_nodes++; |
9771b263 | 248 | stack.safe_push (latch->src); |
89f8f30f | 249 | latch->src->loop_father = loop; |
d329e058 | 250 | |
9771b263 | 251 | while (!stack.is_empty ()) |
402209ff | 252 | { |
2ecfd709 ZD |
253 | basic_block node; |
254 | edge e; | |
628f6a4e | 255 | edge_iterator ei; |
402209ff | 256 | |
9771b263 | 257 | node = stack.pop (); |
d329e058 | 258 | |
628f6a4e | 259 | FOR_EACH_EDGE (e, ei, node->preds) |
402209ff | 260 | { |
2ecfd709 ZD |
261 | basic_block ancestor = e->src; |
262 | ||
89f8f30f | 263 | if (ancestor->loop_father != loop) |
2ecfd709 ZD |
264 | { |
265 | ancestor->loop_father = loop; | |
2ecfd709 | 266 | num_nodes++; |
9771b263 | 267 | stack.safe_push (ancestor); |
2ecfd709 | 268 | } |
402209ff JH |
269 | } |
270 | } | |
271 | } | |
9771b263 | 272 | stack.release (); |
89f8f30f | 273 | |
402209ff JH |
274 | return num_nodes; |
275 | } | |
276 | ||
9ba025a2 ZD |
277 | /* Records the vector of superloops of the loop LOOP, whose immediate |
278 | superloop is FATHER. */ | |
279 | ||
35b07080 | 280 | static void |
9ba025a2 | 281 | establish_preds (struct loop *loop, struct loop *father) |
35b07080 | 282 | { |
9ba025a2 ZD |
283 | loop_p ploop; |
284 | unsigned depth = loop_depth (father) + 1; | |
285 | unsigned i; | |
a310245f | 286 | |
9771b263 DN |
287 | loop->superloops = 0; |
288 | vec_alloc (loop->superloops, depth); | |
289 | FOR_EACH_VEC_SAFE_ELT (father->superloops, i, ploop) | |
290 | loop->superloops->quick_push (ploop); | |
291 | loop->superloops->quick_push (father); | |
35b07080 ZD |
292 | |
293 | for (ploop = loop->inner; ploop; ploop = ploop->next) | |
9ba025a2 | 294 | establish_preds (ploop, loop); |
35b07080 ZD |
295 | } |
296 | ||
2ecfd709 | 297 | /* Add LOOP to the loop hierarchy tree where FATHER is father of the |
35b07080 ZD |
298 | added loop. If LOOP has some children, take care of that their |
299 | pred field will be initialized correctly. */ | |
402209ff | 300 | |
2ecfd709 | 301 | void |
d329e058 | 302 | flow_loop_tree_node_add (struct loop *father, struct loop *loop) |
402209ff | 303 | { |
2ecfd709 ZD |
304 | loop->next = father->inner; |
305 | father->inner = loop; | |
2ecfd709 | 306 | |
9ba025a2 | 307 | establish_preds (loop, father); |
402209ff JH |
308 | } |
309 | ||
2ecfd709 | 310 | /* Remove LOOP from the loop hierarchy tree. */ |
402209ff | 311 | |
2ecfd709 | 312 | void |
d329e058 | 313 | flow_loop_tree_node_remove (struct loop *loop) |
402209ff | 314 | { |
2ecfd709 | 315 | struct loop *prev, *father; |
402209ff | 316 | |
9ba025a2 | 317 | father = loop_outer (loop); |
402209ff | 318 | |
2ecfd709 ZD |
319 | /* Remove loop from the list of sons. */ |
320 | if (father->inner == loop) | |
321 | father->inner = loop->next; | |
322 | else | |
323 | { | |
9ba025a2 ZD |
324 | for (prev = father->inner; prev->next != loop; prev = prev->next) |
325 | continue; | |
2ecfd709 ZD |
326 | prev->next = loop->next; |
327 | } | |
402209ff | 328 | |
9771b263 | 329 | loop->superloops = NULL; |
402209ff JH |
330 | } |
331 | ||
6270df4c ZD |
332 | /* Allocates and returns new loop structure. */ |
333 | ||
334 | struct loop * | |
335 | alloc_loop (void) | |
336 | { | |
766090c2 | 337 | struct loop *loop = ggc_cleared_alloc<struct loop> (); |
9e2f83a5 | 338 | |
766090c2 | 339 | loop->exits = ggc_cleared_alloc<loop_exit> (); |
9e2f83a5 | 340 | loop->exits->next = loop->exits->prev = loop->exits; |
204b560f | 341 | loop->can_be_parallel = false; |
18767ebc | 342 | loop->constraints = 0; |
807e902e | 343 | loop->nb_iterations_upper_bound = 0; |
200eafbf | 344 | loop->nb_iterations_likely_upper_bound = 0; |
807e902e | 345 | loop->nb_iterations_estimate = 0; |
6270df4c ZD |
346 | return loop; |
347 | } | |
348 | ||
4ed88ee3 ZD |
349 | /* Initializes loops structure LOOPS, reserving place for NUM_LOOPS loops |
350 | (including the root of the loop tree). */ | |
351 | ||
dd366ec3 RB |
352 | void |
353 | init_loops_structure (struct function *fn, | |
354 | struct loops *loops, unsigned num_loops) | |
4ed88ee3 ZD |
355 | { |
356 | struct loop *root; | |
357 | ||
358 | memset (loops, 0, sizeof *loops); | |
9771b263 | 359 | vec_alloc (loops->larray, num_loops); |
4ed88ee3 ZD |
360 | |
361 | /* Dummy loop containing whole function. */ | |
362 | root = alloc_loop (); | |
0cae8d31 | 363 | root->num_nodes = n_basic_blocks_for_fn (fn); |
fefa31b5 DM |
364 | root->latch = EXIT_BLOCK_PTR_FOR_FN (fn); |
365 | root->header = ENTRY_BLOCK_PTR_FOR_FN (fn); | |
366 | ENTRY_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
367 | EXIT_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
4ed88ee3 | 368 | |
9771b263 | 369 | loops->larray->quick_push (root); |
4ed88ee3 ZD |
370 | loops->tree_root = root; |
371 | } | |
372 | ||
0375167b RB |
373 | /* Returns whether HEADER is a loop header. */ |
374 | ||
375 | bool | |
376 | bb_loop_header_p (basic_block header) | |
377 | { | |
378 | edge_iterator ei; | |
379 | edge e; | |
380 | ||
381 | /* If we have an abnormal predecessor, do not consider the | |
382 | loop (not worth the problems). */ | |
383 | if (bb_has_abnormal_pred (header)) | |
384 | return false; | |
385 | ||
386 | /* Look for back edges where a predecessor is dominated | |
387 | by this block. A natural loop has a single entry | |
388 | node (header) that dominates all the nodes in the | |
389 | loop. It also has single back edge to the header | |
390 | from a latch node. */ | |
391 | FOR_EACH_EDGE (e, ei, header->preds) | |
392 | { | |
393 | basic_block latch = e->src; | |
fefa31b5 | 394 | if (latch != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
0375167b RB |
395 | && dominated_by_p (CDI_DOMINATORS, latch, header)) |
396 | return true; | |
397 | } | |
398 | ||
399 | return false; | |
400 | } | |
401 | ||
5f0d2358 | 402 | /* Find all the natural loops in the function and save in LOOPS structure and |
391886c8 | 403 | recalculate loop_father information in basic block structures. |
0375167b RB |
404 | If LOOPS is non-NULL then the loop structures for already recorded loops |
405 | will be re-used and their number will not change. We assume that no | |
406 | stale loops exist in LOOPS. | |
407 | When LOOPS is NULL it is allocated and re-built from scratch. | |
408 | Return the built LOOPS structure. */ | |
402209ff | 409 | |
0375167b | 410 | struct loops * |
70388d94 | 411 | flow_loops_find (struct loops *loops) |
402209ff | 412 | { |
0375167b | 413 | bool from_scratch = (loops == NULL); |
402209ff | 414 | int *rc_order; |
0375167b RB |
415 | int b; |
416 | unsigned i; | |
402209ff | 417 | |
4ed88ee3 ZD |
418 | /* Ensure that the dominators are computed. */ |
419 | calculate_dominance_info (CDI_DOMINATORS); | |
402209ff | 420 | |
0375167b | 421 | if (!loops) |
4ed88ee3 | 422 | { |
766090c2 | 423 | loops = ggc_cleared_alloc<struct loops> (); |
dd366ec3 | 424 | init_loops_structure (cfun, loops, 1); |
4ed88ee3 | 425 | } |
402209ff | 426 | |
0375167b RB |
427 | /* Ensure that loop exits were released. */ |
428 | gcc_assert (loops->exits == NULL); | |
402209ff | 429 | |
0375167b RB |
430 | /* Taking care of this degenerate case makes the rest of |
431 | this code simpler. */ | |
0cae8d31 | 432 | if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) |
0375167b | 433 | return loops; |
2ecfd709 | 434 | |
0375167b | 435 | /* The root loop node contains all basic-blocks. */ |
0cae8d31 | 436 | loops->tree_root->num_nodes = n_basic_blocks_for_fn (cfun); |
d329e058 | 437 | |
0375167b RB |
438 | /* Compute depth first search order of the CFG so that outer |
439 | natural loops will be found before inner natural loops. */ | |
0cae8d31 | 440 | rc_order = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); |
0375167b | 441 | pre_and_rev_post_order_compute (NULL, rc_order, false); |
16f2b86a | 442 | |
0375167b RB |
443 | /* Gather all loop headers in reverse completion order and allocate |
444 | loop structures for loops that are not already present. */ | |
ef062b13 | 445 | auto_vec<loop_p> larray (loops->larray->length ()); |
0cae8d31 | 446 | for (b = 0; b < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; b++) |
0375167b | 447 | { |
06e28de2 | 448 | basic_block header = BASIC_BLOCK_FOR_FN (cfun, rc_order[b]); |
0375167b | 449 | if (bb_loop_header_p (header)) |
402209ff | 450 | { |
0375167b | 451 | struct loop *loop; |
2ecfd709 | 452 | |
0375167b RB |
453 | /* The current active loop tree has valid loop-fathers for |
454 | header blocks. */ | |
455 | if (!from_scratch | |
456 | && header->loop_father->header == header) | |
2ecfd709 | 457 | { |
0375167b RB |
458 | loop = header->loop_father; |
459 | /* If we found an existing loop remove it from the | |
460 | loop tree. It is going to be inserted again | |
461 | below. */ | |
462 | flow_loop_tree_node_remove (loop); | |
2ecfd709 | 463 | } |
0375167b RB |
464 | else |
465 | { | |
466 | /* Otherwise allocate a new loop structure for the loop. */ | |
467 | loop = alloc_loop (); | |
468 | /* ??? We could re-use unused loop slots here. */ | |
469 | loop->num = loops->larray->length (); | |
470 | vec_safe_push (loops->larray, loop); | |
471 | loop->header = header; | |
472 | ||
473 | if (!from_scratch | |
474 | && dump_file && (dump_flags & TDF_DETAILS)) | |
475 | fprintf (dump_file, "flow_loops_find: discovered new " | |
476 | "loop %d with header %d\n", | |
477 | loop->num, header->index); | |
478 | } | |
6aaf596b RB |
479 | /* Reset latch, we recompute it below. */ |
480 | loop->latch = NULL; | |
0375167b | 481 | larray.safe_push (loop); |
402209ff | 482 | } |
402209ff | 483 | |
0375167b RB |
484 | /* Make blocks part of the loop root node at start. */ |
485 | header->loop_father = loops->tree_root; | |
486 | } | |
2ecfd709 | 487 | |
0375167b | 488 | free (rc_order); |
2ecfd709 | 489 | |
0375167b RB |
490 | /* Now iterate over the loops found, insert them into the loop tree |
491 | and assign basic-block ownership. */ | |
492 | for (i = 0; i < larray.length (); ++i) | |
402209ff | 493 | { |
0375167b RB |
494 | struct loop *loop = larray[i]; |
495 | basic_block header = loop->header; | |
09c5c12e TV |
496 | edge_iterator ei; |
497 | edge e; | |
402209ff | 498 | |
0375167b RB |
499 | flow_loop_tree_node_add (header->loop_father, loop); |
500 | loop->num_nodes = flow_loop_nodes_find (loop->header, loop); | |
09c5c12e TV |
501 | |
502 | /* Look for the latch for this header block, if it has just a | |
503 | single one. */ | |
504 | FOR_EACH_EDGE (e, ei, header->preds) | |
505 | { | |
506 | basic_block latch = e->src; | |
507 | ||
508 | if (flow_bb_inside_loop_p (loop, latch)) | |
509 | { | |
510 | if (loop->latch != NULL) | |
511 | { | |
512 | /* More than one latch edge. */ | |
513 | loop->latch = NULL; | |
514 | break; | |
515 | } | |
516 | loop->latch = latch; | |
517 | } | |
518 | } | |
2ecfd709 | 519 | } |
3d436d2a | 520 | |
0375167b | 521 | return loops; |
402209ff JH |
522 | } |
523 | ||
26993e95 RB |
524 | /* qsort helper for sort_sibling_loops. */ |
525 | ||
526 | static int *sort_sibling_loops_cmp_rpo; | |
527 | static int | |
528 | sort_sibling_loops_cmp (const void *la_, const void *lb_) | |
529 | { | |
530 | const struct loop *la = *(const struct loop * const *)la_; | |
531 | const struct loop *lb = *(const struct loop * const *)lb_; | |
532 | return (sort_sibling_loops_cmp_rpo[la->header->index] | |
533 | - sort_sibling_loops_cmp_rpo[lb->header->index]); | |
534 | } | |
535 | ||
536 | /* Sort sibling loops in RPO order. */ | |
537 | ||
538 | void | |
539 | sort_sibling_loops (function *fn) | |
540 | { | |
541 | /* Match flow_loops_find in the order we sort sibling loops. */ | |
542 | sort_sibling_loops_cmp_rpo = XNEWVEC (int, last_basic_block_for_fn (cfun)); | |
543 | int *rc_order = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); | |
544 | pre_and_rev_post_order_compute_fn (fn, NULL, rc_order, false); | |
545 | for (int i = 0; i < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; ++i) | |
546 | sort_sibling_loops_cmp_rpo[rc_order[i]] = i; | |
547 | free (rc_order); | |
548 | ||
549 | auto_vec<loop_p, 3> siblings; | |
550 | loop_p loop; | |
551 | FOR_EACH_LOOP_FN (fn, loop, LI_INCLUDE_ROOT) | |
552 | if (loop->inner && loop->inner->next) | |
553 | { | |
554 | loop_p sibling = loop->inner; | |
555 | do | |
556 | { | |
557 | siblings.safe_push (sibling); | |
558 | sibling = sibling->next; | |
559 | } | |
560 | while (sibling); | |
561 | siblings.qsort (sort_sibling_loops_cmp); | |
562 | loop_p *siblingp = &loop->inner; | |
563 | for (unsigned i = 0; i < siblings.length (); ++i) | |
564 | { | |
565 | *siblingp = siblings[i]; | |
566 | siblingp = &(*siblingp)->next; | |
567 | } | |
568 | *siblingp = NULL; | |
569 | siblings.truncate (0); | |
570 | } | |
571 | ||
572 | free (sort_sibling_loops_cmp_rpo); | |
573 | sort_sibling_loops_cmp_rpo = NULL; | |
574 | } | |
575 | ||
89f8f30f ZD |
576 | /* Ratio of frequencies of edges so that one of more latch edges is |
577 | considered to belong to inner loop with same header. */ | |
578 | #define HEAVY_EDGE_RATIO 8 | |
579 | ||
580 | /* Minimum number of samples for that we apply | |
581 | find_subloop_latch_edge_by_profile heuristics. */ | |
582 | #define HEAVY_EDGE_MIN_SAMPLES 10 | |
583 | ||
584 | /* If the profile info is available, finds an edge in LATCHES that much more | |
585 | frequent than the remaining edges. Returns such an edge, or NULL if we do | |
586 | not find one. | |
587 | ||
588 | We do not use guessed profile here, only the measured one. The guessed | |
589 | profile is usually too flat and unreliable for this (and it is mostly based | |
590 | on the loop structure of the program, so it does not make much sense to | |
591 | derive the loop structure from it). */ | |
b8698a0f | 592 | |
89f8f30f | 593 | static edge |
9771b263 | 594 | find_subloop_latch_edge_by_profile (vec<edge> latches) |
89f8f30f ZD |
595 | { |
596 | unsigned i; | |
597 | edge e, me = NULL; | |
3995f3a2 | 598 | profile_count mcount = profile_count::zero (), tcount = profile_count::zero (); |
89f8f30f | 599 | |
9771b263 | 600 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f | 601 | { |
ef30ab83 | 602 | if (e->count ()> mcount) |
89f8f30f ZD |
603 | { |
604 | me = e; | |
ef30ab83 | 605 | mcount = e->count(); |
89f8f30f | 606 | } |
ef30ab83 | 607 | tcount += e->count(); |
89f8f30f ZD |
608 | } |
609 | ||
3995f3a2 JH |
610 | if (!tcount.initialized_p () || tcount < HEAVY_EDGE_MIN_SAMPLES |
611 | || (tcount - mcount).apply_scale (HEAVY_EDGE_RATIO, 1) > tcount) | |
89f8f30f ZD |
612 | return NULL; |
613 | ||
614 | if (dump_file) | |
615 | fprintf (dump_file, | |
616 | "Found latch edge %d -> %d using profile information.\n", | |
617 | me->src->index, me->dest->index); | |
618 | return me; | |
619 | } | |
620 | ||
621 | /* Among LATCHES, guesses a latch edge of LOOP corresponding to subloop, based | |
622 | on the structure of induction variables. Returns this edge, or NULL if we | |
623 | do not find any. | |
624 | ||
625 | We are quite conservative, and look just for an obvious simple innermost | |
626 | loop (which is the case where we would lose the most performance by not | |
627 | disambiguating the loop). More precisely, we look for the following | |
628 | situation: The source of the chosen latch edge dominates sources of all | |
629 | the other latch edges. Additionally, the header does not contain a phi node | |
630 | such that the argument from the chosen edge is equal to the argument from | |
631 | another edge. */ | |
632 | ||
633 | static edge | |
9771b263 | 634 | find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, vec<edge> latches) |
89f8f30f | 635 | { |
9771b263 | 636 | edge e, latch = latches[0]; |
89f8f30f | 637 | unsigned i; |
538dd0b7 DM |
638 | gphi *phi; |
639 | gphi_iterator psi; | |
726a989a | 640 | tree lop; |
89f8f30f ZD |
641 | basic_block bb; |
642 | ||
643 | /* Find the candidate for the latch edge. */ | |
9771b263 | 644 | for (i = 1; latches.iterate (i, &e); i++) |
89f8f30f ZD |
645 | if (dominated_by_p (CDI_DOMINATORS, latch->src, e->src)) |
646 | latch = e; | |
647 | ||
648 | /* Verify that it dominates all the latch edges. */ | |
9771b263 | 649 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f ZD |
650 | if (!dominated_by_p (CDI_DOMINATORS, e->src, latch->src)) |
651 | return NULL; | |
652 | ||
653 | /* Check for a phi node that would deny that this is a latch edge of | |
654 | a subloop. */ | |
726a989a | 655 | for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) |
89f8f30f | 656 | { |
538dd0b7 | 657 | phi = psi.phi (); |
89f8f30f ZD |
658 | lop = PHI_ARG_DEF_FROM_EDGE (phi, latch); |
659 | ||
660 | /* Ignore the values that are not changed inside the subloop. */ | |
661 | if (TREE_CODE (lop) != SSA_NAME | |
662 | || SSA_NAME_DEF_STMT (lop) == phi) | |
663 | continue; | |
726a989a | 664 | bb = gimple_bb (SSA_NAME_DEF_STMT (lop)); |
89f8f30f ZD |
665 | if (!bb || !flow_bb_inside_loop_p (loop, bb)) |
666 | continue; | |
667 | ||
9771b263 | 668 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f ZD |
669 | if (e != latch |
670 | && PHI_ARG_DEF_FROM_EDGE (phi, e) == lop) | |
671 | return NULL; | |
672 | } | |
673 | ||
674 | if (dump_file) | |
675 | fprintf (dump_file, | |
676 | "Found latch edge %d -> %d using iv structure.\n", | |
677 | latch->src->index, latch->dest->index); | |
678 | return latch; | |
679 | } | |
680 | ||
681 | /* If we can determine that one of the several latch edges of LOOP behaves | |
682 | as a latch edge of a separate subloop, returns this edge. Otherwise | |
683 | returns NULL. */ | |
684 | ||
685 | static edge | |
686 | find_subloop_latch_edge (struct loop *loop) | |
687 | { | |
9771b263 | 688 | vec<edge> latches = get_loop_latch_edges (loop); |
89f8f30f ZD |
689 | edge latch = NULL; |
690 | ||
9771b263 | 691 | if (latches.length () > 1) |
89f8f30f ZD |
692 | { |
693 | latch = find_subloop_latch_edge_by_profile (latches); | |
694 | ||
695 | if (!latch | |
696 | /* We consider ivs to guess the latch edge only in SSA. Perhaps we | |
697 | should use cfghook for this, but it is hard to imagine it would | |
698 | be useful elsewhere. */ | |
699 | && current_ir_type () == IR_GIMPLE) | |
700 | latch = find_subloop_latch_edge_by_ivs (loop, latches); | |
701 | } | |
702 | ||
9771b263 | 703 | latches.release (); |
89f8f30f ZD |
704 | return latch; |
705 | } | |
706 | ||
707 | /* Callback for make_forwarder_block. Returns true if the edge E is marked | |
708 | in the set MFB_REIS_SET. */ | |
709 | ||
6e2830c3 | 710 | static hash_set<edge> *mfb_reis_set; |
89f8f30f ZD |
711 | static bool |
712 | mfb_redirect_edges_in_set (edge e) | |
713 | { | |
6e2830c3 | 714 | return mfb_reis_set->contains (e); |
89f8f30f ZD |
715 | } |
716 | ||
717 | /* Creates a subloop of LOOP with latch edge LATCH. */ | |
718 | ||
719 | static void | |
720 | form_subloop (struct loop *loop, edge latch) | |
721 | { | |
722 | edge_iterator ei; | |
723 | edge e, new_entry; | |
724 | struct loop *new_loop; | |
b8698a0f | 725 | |
6e2830c3 | 726 | mfb_reis_set = new hash_set<edge>; |
89f8f30f ZD |
727 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
728 | { | |
729 | if (e != latch) | |
6e2830c3 | 730 | mfb_reis_set->add (e); |
89f8f30f ZD |
731 | } |
732 | new_entry = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
733 | NULL); | |
6e2830c3 | 734 | delete mfb_reis_set; |
89f8f30f ZD |
735 | |
736 | loop->header = new_entry->src; | |
737 | ||
738 | /* Find the blocks and subloops that belong to the new loop, and add it to | |
739 | the appropriate place in the loop tree. */ | |
740 | new_loop = alloc_loop (); | |
741 | new_loop->header = new_entry->dest; | |
742 | new_loop->latch = latch->src; | |
743 | add_loop (new_loop, loop); | |
744 | } | |
745 | ||
746 | /* Make all the latch edges of LOOP to go to a single forwarder block -- | |
747 | a new latch of LOOP. */ | |
748 | ||
749 | static void | |
750 | merge_latch_edges (struct loop *loop) | |
751 | { | |
9771b263 | 752 | vec<edge> latches = get_loop_latch_edges (loop); |
89f8f30f ZD |
753 | edge latch, e; |
754 | unsigned i; | |
755 | ||
9771b263 | 756 | gcc_assert (latches.length () > 0); |
89f8f30f | 757 | |
9771b263 DN |
758 | if (latches.length () == 1) |
759 | loop->latch = latches[0]->src; | |
89f8f30f ZD |
760 | else |
761 | { | |
762 | if (dump_file) | |
763 | fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num); | |
764 | ||
6e2830c3 | 765 | mfb_reis_set = new hash_set<edge>; |
9771b263 | 766 | FOR_EACH_VEC_ELT (latches, i, e) |
6e2830c3 | 767 | mfb_reis_set->add (e); |
89f8f30f ZD |
768 | latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, |
769 | NULL); | |
6e2830c3 | 770 | delete mfb_reis_set; |
89f8f30f ZD |
771 | |
772 | loop->header = latch->dest; | |
773 | loop->latch = latch->src; | |
774 | } | |
775 | ||
9771b263 | 776 | latches.release (); |
89f8f30f ZD |
777 | } |
778 | ||
779 | /* LOOP may have several latch edges. Transform it into (possibly several) | |
780 | loops with single latch edge. */ | |
781 | ||
782 | static void | |
783 | disambiguate_multiple_latches (struct loop *loop) | |
784 | { | |
785 | edge e; | |
786 | ||
ea2c620c | 787 | /* We eliminate the multiple latches by splitting the header to the forwarder |
89f8f30f ZD |
788 | block F and the rest R, and redirecting the edges. There are two cases: |
789 | ||
790 | 1) If there is a latch edge E that corresponds to a subloop (we guess | |
791 | that based on profile -- if it is taken much more often than the | |
792 | remaining edges; and on trees, using the information about induction | |
793 | variables of the loops), we redirect E to R, all the remaining edges to | |
794 | F, then rescan the loops and try again for the outer loop. | |
795 | 2) If there is no such edge, we redirect all latch edges to F, and the | |
796 | entry edges to R, thus making F the single latch of the loop. */ | |
797 | ||
798 | if (dump_file) | |
799 | fprintf (dump_file, "Disambiguating loop %d with multiple latches\n", | |
800 | loop->num); | |
801 | ||
802 | /* During latch merging, we may need to redirect the entry edges to a new | |
803 | block. This would cause problems if the entry edge was the one from the | |
804 | entry block. To avoid having to handle this case specially, split | |
805 | such entry edge. */ | |
fefa31b5 | 806 | e = find_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), loop->header); |
89f8f30f ZD |
807 | if (e) |
808 | split_edge (e); | |
809 | ||
810 | while (1) | |
811 | { | |
812 | e = find_subloop_latch_edge (loop); | |
813 | if (!e) | |
814 | break; | |
815 | ||
816 | form_subloop (loop, e); | |
817 | } | |
818 | ||
819 | merge_latch_edges (loop); | |
820 | } | |
821 | ||
822 | /* Split loops with multiple latch edges. */ | |
823 | ||
824 | void | |
825 | disambiguate_loops_with_multiple_latches (void) | |
826 | { | |
89f8f30f ZD |
827 | struct loop *loop; |
828 | ||
f0bd40b1 | 829 | FOR_EACH_LOOP (loop, 0) |
89f8f30f ZD |
830 | { |
831 | if (!loop->latch) | |
832 | disambiguate_multiple_latches (loop); | |
833 | } | |
834 | } | |
835 | ||
da7d8304 | 836 | /* Return nonzero if basic block BB belongs to LOOP. */ |
2ecfd709 | 837 | bool |
ed7a4b4b | 838 | flow_bb_inside_loop_p (const struct loop *loop, const_basic_block bb) |
2ecfd709 ZD |
839 | { |
840 | struct loop *source_loop; | |
841 | ||
fefa31b5 DM |
842 | if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
843 | || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
2ecfd709 ZD |
844 | return 0; |
845 | ||
846 | source_loop = bb->loop_father; | |
847 | return loop == source_loop || flow_loop_nested_p (loop, source_loop); | |
848 | } | |
849 | ||
89f8f30f | 850 | /* Enumeration predicate for get_loop_body_with_size. */ |
2ecfd709 | 851 | static bool |
ed7a4b4b | 852 | glb_enum_p (const_basic_block bb, const void *glb_loop) |
2ecfd709 | 853 | { |
ed7a4b4b | 854 | const struct loop *const loop = (const struct loop *) glb_loop; |
89f8f30f ZD |
855 | return (bb != loop->header |
856 | && dominated_by_p (CDI_DOMINATORS, bb, loop->header)); | |
857 | } | |
858 | ||
859 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
860 | order against direction of edges from latch. Specially, if | |
861 | header != latch, latch is the 1-st block. LOOP cannot be the fake | |
862 | loop tree root, and its size must be at most MAX_SIZE. The blocks | |
863 | in the LOOP body are stored to BODY, and the size of the LOOP is | |
864 | returned. */ | |
865 | ||
866 | unsigned | |
867 | get_loop_body_with_size (const struct loop *loop, basic_block *body, | |
868 | unsigned max_size) | |
869 | { | |
870 | return dfs_enumerate_from (loop->header, 1, glb_enum_p, | |
ed7a4b4b | 871 | body, max_size, loop); |
2ecfd709 ZD |
872 | } |
873 | ||
8d28e87d ZD |
874 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs |
875 | order against direction of edges from latch. Specially, if | |
876 | header != latch, latch is the 1-st block. */ | |
89f8f30f | 877 | |
2ecfd709 | 878 | basic_block * |
d329e058 | 879 | get_loop_body (const struct loop *loop) |
2ecfd709 | 880 | { |
89f8f30f | 881 | basic_block *body, bb; |
3d436d2a | 882 | unsigned tv = 0; |
2ecfd709 | 883 | |
341c100f | 884 | gcc_assert (loop->num_nodes); |
2ecfd709 | 885 | |
c302207e | 886 | body = XNEWVEC (basic_block, loop->num_nodes); |
2ecfd709 | 887 | |
fefa31b5 | 888 | if (loop->latch == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
2ecfd709 | 889 | { |
89f8f30f ZD |
890 | /* There may be blocks unreachable from EXIT_BLOCK, hence we need to |
891 | special-case the fake loop that contains the whole function. */ | |
0cae8d31 | 892 | gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks_for_fn (cfun)); |
89f8f30f | 893 | body[tv++] = loop->header; |
fefa31b5 | 894 | body[tv++] = EXIT_BLOCK_PTR_FOR_FN (cfun); |
11cd3bed | 895 | FOR_EACH_BB_FN (bb, cfun) |
89f8f30f | 896 | body[tv++] = bb; |
2ecfd709 | 897 | } |
89f8f30f ZD |
898 | else |
899 | tv = get_loop_body_with_size (loop, body, loop->num_nodes); | |
2ecfd709 | 900 | |
341c100f | 901 | gcc_assert (tv == loop->num_nodes); |
89f8f30f | 902 | return body; |
2ecfd709 ZD |
903 | } |
904 | ||
50654f6c ZD |
905 | /* Fills dominance descendants inside LOOP of the basic block BB into |
906 | array TOVISIT from index *TV. */ | |
907 | ||
908 | static void | |
909 | fill_sons_in_loop (const struct loop *loop, basic_block bb, | |
910 | basic_block *tovisit, int *tv) | |
911 | { | |
912 | basic_block son, postpone = NULL; | |
913 | ||
914 | tovisit[(*tv)++] = bb; | |
915 | for (son = first_dom_son (CDI_DOMINATORS, bb); | |
916 | son; | |
917 | son = next_dom_son (CDI_DOMINATORS, son)) | |
918 | { | |
919 | if (!flow_bb_inside_loop_p (loop, son)) | |
920 | continue; | |
921 | ||
922 | if (dominated_by_p (CDI_DOMINATORS, loop->latch, son)) | |
923 | { | |
924 | postpone = son; | |
925 | continue; | |
926 | } | |
927 | fill_sons_in_loop (loop, son, tovisit, tv); | |
928 | } | |
929 | ||
930 | if (postpone) | |
931 | fill_sons_in_loop (loop, postpone, tovisit, tv); | |
932 | } | |
933 | ||
934 | /* Gets body of a LOOP (that must be different from the outermost loop) | |
935 | sorted by dominance relation. Additionally, if a basic block s dominates | |
936 | the latch, then only blocks dominated by s are be after it. */ | |
937 | ||
938 | basic_block * | |
939 | get_loop_body_in_dom_order (const struct loop *loop) | |
940 | { | |
941 | basic_block *tovisit; | |
942 | int tv; | |
943 | ||
341c100f | 944 | gcc_assert (loop->num_nodes); |
50654f6c | 945 | |
c302207e | 946 | tovisit = XNEWVEC (basic_block, loop->num_nodes); |
50654f6c | 947 | |
fefa31b5 | 948 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
50654f6c ZD |
949 | |
950 | tv = 0; | |
951 | fill_sons_in_loop (loop, loop->header, tovisit, &tv); | |
952 | ||
341c100f | 953 | gcc_assert (tv == (int) loop->num_nodes); |
50654f6c ZD |
954 | |
955 | return tovisit; | |
956 | } | |
957 | ||
e855c69d AB |
958 | /* Gets body of a LOOP sorted via provided BB_COMPARATOR. */ |
959 | ||
960 | basic_block * | |
b8698a0f | 961 | get_loop_body_in_custom_order (const struct loop *loop, |
e855c69d AB |
962 | int (*bb_comparator) (const void *, const void *)) |
963 | { | |
964 | basic_block *bbs = get_loop_body (loop); | |
965 | ||
966 | qsort (bbs, loop->num_nodes, sizeof (basic_block), bb_comparator); | |
967 | ||
968 | return bbs; | |
969 | } | |
970 | ||
40923b20 DP |
971 | /* Get body of a LOOP in breadth first sort order. */ |
972 | ||
973 | basic_block * | |
974 | get_loop_body_in_bfs_order (const struct loop *loop) | |
975 | { | |
976 | basic_block *blocks; | |
977 | basic_block bb; | |
895548a5 KT |
978 | unsigned int i = 1; |
979 | unsigned int vc = 0; | |
40923b20 | 980 | |
341c100f | 981 | gcc_assert (loop->num_nodes); |
fefa31b5 | 982 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
40923b20 | 983 | |
c302207e | 984 | blocks = XNEWVEC (basic_block, loop->num_nodes); |
0e3de1d4 | 985 | auto_bitmap visited; |
895548a5 KT |
986 | blocks[0] = loop->header; |
987 | bitmap_set_bit (visited, loop->header->index); | |
40923b20 DP |
988 | while (i < loop->num_nodes) |
989 | { | |
990 | edge e; | |
628f6a4e | 991 | edge_iterator ei; |
895548a5 KT |
992 | gcc_assert (i > vc); |
993 | bb = blocks[vc++]; | |
c22cacf3 | 994 | |
628f6a4e | 995 | FOR_EACH_EDGE (e, ei, bb->succs) |
c22cacf3 MS |
996 | { |
997 | if (flow_bb_inside_loop_p (loop, e->dest)) | |
998 | { | |
895548a5 | 999 | /* This bb is now visited. */ |
fcaa4ca4 NF |
1000 | if (bitmap_set_bit (visited, e->dest->index)) |
1001 | blocks[i++] = e->dest; | |
c22cacf3 MS |
1002 | } |
1003 | } | |
40923b20 | 1004 | } |
c22cacf3 | 1005 | |
40923b20 DP |
1006 | return blocks; |
1007 | } | |
1008 | ||
6270df4c ZD |
1009 | /* Hash function for struct loop_exit. */ |
1010 | ||
2a22f99c TS |
1011 | hashval_t |
1012 | loop_exit_hasher::hash (loop_exit *exit) | |
6270df4c | 1013 | { |
6270df4c ZD |
1014 | return htab_hash_pointer (exit->e); |
1015 | } | |
1016 | ||
1017 | /* Equality function for struct loop_exit. Compares with edge. */ | |
1018 | ||
2a22f99c TS |
1019 | bool |
1020 | loop_exit_hasher::equal (loop_exit *exit, edge e) | |
6270df4c | 1021 | { |
6270df4c ZD |
1022 | return exit->e == e; |
1023 | } | |
1024 | ||
1025 | /* Frees the list of loop exit descriptions EX. */ | |
1026 | ||
2a22f99c TS |
1027 | void |
1028 | loop_exit_hasher::remove (loop_exit *exit) | |
6270df4c | 1029 | { |
2a22f99c | 1030 | loop_exit *next; |
6270df4c ZD |
1031 | for (; exit; exit = next) |
1032 | { | |
1033 | next = exit->next_e; | |
b8698a0f | 1034 | |
6270df4c ZD |
1035 | exit->next->prev = exit->prev; |
1036 | exit->prev->next = exit->next; | |
1037 | ||
9e2f83a5 | 1038 | ggc_free (exit); |
6270df4c ZD |
1039 | } |
1040 | } | |
1041 | ||
1042 | /* Returns the list of records for E as an exit of a loop. */ | |
1043 | ||
1044 | static struct loop_exit * | |
1045 | get_exit_descriptions (edge e) | |
1046 | { | |
2a22f99c | 1047 | return current_loops->exits->find_with_hash (e, htab_hash_pointer (e)); |
6270df4c ZD |
1048 | } |
1049 | ||
1050 | /* Updates the lists of loop exits in that E appears. | |
1051 | If REMOVED is true, E is being removed, and we | |
1052 | just remove it from the lists of exits. | |
1053 | If NEW_EDGE is true and E is not a loop exit, we | |
1054 | do not try to remove it from loop exit lists. */ | |
1055 | ||
1056 | void | |
1057 | rescan_loop_exit (edge e, bool new_edge, bool removed) | |
1058 | { | |
6270df4c ZD |
1059 | struct loop_exit *exits = NULL, *exit; |
1060 | struct loop *aloop, *cloop; | |
1061 | ||
f87000d0 | 1062 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c ZD |
1063 | return; |
1064 | ||
1065 | if (!removed | |
1066 | && e->src->loop_father != NULL | |
1067 | && e->dest->loop_father != NULL | |
1068 | && !flow_bb_inside_loop_p (e->src->loop_father, e->dest)) | |
1069 | { | |
1070 | cloop = find_common_loop (e->src->loop_father, e->dest->loop_father); | |
1071 | for (aloop = e->src->loop_father; | |
1072 | aloop != cloop; | |
9ba025a2 | 1073 | aloop = loop_outer (aloop)) |
6270df4c | 1074 | { |
766090c2 | 1075 | exit = ggc_alloc<loop_exit> (); |
6270df4c ZD |
1076 | exit->e = e; |
1077 | ||
9e2f83a5 ZD |
1078 | exit->next = aloop->exits->next; |
1079 | exit->prev = aloop->exits; | |
6270df4c ZD |
1080 | exit->next->prev = exit; |
1081 | exit->prev->next = exit; | |
1082 | ||
1083 | exit->next_e = exits; | |
1084 | exits = exit; | |
1085 | } | |
b8698a0f | 1086 | } |
6270df4c ZD |
1087 | |
1088 | if (!exits && new_edge) | |
1089 | return; | |
1090 | ||
2a22f99c TS |
1091 | loop_exit **slot |
1092 | = current_loops->exits->find_slot_with_hash (e, htab_hash_pointer (e), | |
1093 | exits ? INSERT : NO_INSERT); | |
6270df4c ZD |
1094 | if (!slot) |
1095 | return; | |
1096 | ||
1097 | if (exits) | |
1098 | { | |
1099 | if (*slot) | |
2a22f99c | 1100 | loop_exit_hasher::remove (*slot); |
6270df4c ZD |
1101 | *slot = exits; |
1102 | } | |
1103 | else | |
2a22f99c | 1104 | current_loops->exits->clear_slot (slot); |
6270df4c ZD |
1105 | } |
1106 | ||
1107 | /* For each loop, record list of exit edges, and start maintaining these | |
1108 | lists. */ | |
1109 | ||
1110 | void | |
1111 | record_loop_exits (void) | |
1112 | { | |
1113 | basic_block bb; | |
1114 | edge_iterator ei; | |
1115 | edge e; | |
1116 | ||
4839cb59 ZD |
1117 | if (!current_loops) |
1118 | return; | |
1119 | ||
f87000d0 | 1120 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1121 | return; |
f87000d0 | 1122 | loops_state_set (LOOPS_HAVE_RECORDED_EXITS); |
6270df4c ZD |
1123 | |
1124 | gcc_assert (current_loops->exits == NULL); | |
2a22f99c TS |
1125 | current_loops->exits |
1126 | = hash_table<loop_exit_hasher>::create_ggc (2 * number_of_loops (cfun)); | |
6270df4c | 1127 | |
11cd3bed | 1128 | FOR_EACH_BB_FN (bb, cfun) |
6270df4c ZD |
1129 | { |
1130 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1131 | { | |
1132 | rescan_loop_exit (e, true, false); | |
1133 | } | |
1134 | } | |
1135 | } | |
1136 | ||
1137 | /* Dumps information about the exit in *SLOT to FILE. | |
1138 | Callback for htab_traverse. */ | |
1139 | ||
2a22f99c TS |
1140 | int |
1141 | dump_recorded_exit (loop_exit **slot, FILE *file) | |
6270df4c | 1142 | { |
2a22f99c | 1143 | struct loop_exit *exit = *slot; |
6270df4c ZD |
1144 | unsigned n = 0; |
1145 | edge e = exit->e; | |
1146 | ||
1147 | for (; exit != NULL; exit = exit->next_e) | |
1148 | n++; | |
1149 | ||
2a22f99c | 1150 | fprintf (file, "Edge %d->%d exits %u loops\n", |
6270df4c ZD |
1151 | e->src->index, e->dest->index, n); |
1152 | ||
1153 | return 1; | |
1154 | } | |
1155 | ||
1156 | /* Dumps the recorded exits of loops to FILE. */ | |
1157 | ||
1158 | extern void dump_recorded_exits (FILE *); | |
1159 | void | |
1160 | dump_recorded_exits (FILE *file) | |
1161 | { | |
1162 | if (!current_loops->exits) | |
1163 | return; | |
2a22f99c | 1164 | current_loops->exits->traverse<FILE *, dump_recorded_exit> (file); |
6270df4c ZD |
1165 | } |
1166 | ||
1167 | /* Releases lists of loop exits. */ | |
1168 | ||
1169 | void | |
61183076 | 1170 | release_recorded_exits (function *fn) |
6270df4c | 1171 | { |
61183076 RB |
1172 | gcc_assert (loops_state_satisfies_p (fn, LOOPS_HAVE_RECORDED_EXITS)); |
1173 | loops_for_fn (fn)->exits->empty (); | |
1174 | loops_for_fn (fn)->exits = NULL; | |
1175 | loops_state_clear (fn, LOOPS_HAVE_RECORDED_EXITS); | |
6270df4c ZD |
1176 | } |
1177 | ||
ca83d385 ZD |
1178 | /* Returns the list of the exit edges of a LOOP. */ |
1179 | ||
9771b263 | 1180 | vec<edge> |
ca83d385 | 1181 | get_loop_exit_edges (const struct loop *loop) |
35b07080 | 1182 | { |
6e1aa848 | 1183 | vec<edge> edges = vNULL; |
ca83d385 ZD |
1184 | edge e; |
1185 | unsigned i; | |
1186 | basic_block *body; | |
628f6a4e | 1187 | edge_iterator ei; |
6270df4c | 1188 | struct loop_exit *exit; |
35b07080 | 1189 | |
fefa31b5 | 1190 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
35b07080 | 1191 | |
6270df4c ZD |
1192 | /* If we maintain the lists of exits, use them. Otherwise we must |
1193 | scan the body of the loop. */ | |
f87000d0 | 1194 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1195 | { |
9e2f83a5 | 1196 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
9771b263 | 1197 | edges.safe_push (exit->e); |
6270df4c ZD |
1198 | } |
1199 | else | |
1200 | { | |
1201 | body = get_loop_body (loop); | |
1202 | for (i = 0; i < loop->num_nodes; i++) | |
1203 | FOR_EACH_EDGE (e, ei, body[i]->succs) | |
1204 | { | |
1205 | if (!flow_bb_inside_loop_p (loop, e->dest)) | |
9771b263 | 1206 | edges.safe_push (e); |
6270df4c ZD |
1207 | } |
1208 | free (body); | |
1209 | } | |
35b07080 ZD |
1210 | |
1211 | return edges; | |
1212 | } | |
1213 | ||
50654f6c ZD |
1214 | /* Counts the number of conditional branches inside LOOP. */ |
1215 | ||
1216 | unsigned | |
1217 | num_loop_branches (const struct loop *loop) | |
1218 | { | |
1219 | unsigned i, n; | |
1220 | basic_block * body; | |
1221 | ||
fefa31b5 | 1222 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
50654f6c ZD |
1223 | |
1224 | body = get_loop_body (loop); | |
1225 | n = 0; | |
1226 | for (i = 0; i < loop->num_nodes; i++) | |
628f6a4e | 1227 | if (EDGE_COUNT (body[i]->succs) >= 2) |
50654f6c ZD |
1228 | n++; |
1229 | free (body); | |
1230 | ||
1231 | return n; | |
1232 | } | |
1233 | ||
2ecfd709 ZD |
1234 | /* Adds basic block BB to LOOP. */ |
1235 | void | |
d329e058 AJ |
1236 | add_bb_to_loop (basic_block bb, struct loop *loop) |
1237 | { | |
9ba025a2 ZD |
1238 | unsigned i; |
1239 | loop_p ploop; | |
6270df4c ZD |
1240 | edge_iterator ei; |
1241 | edge e; | |
1242 | ||
1243 | gcc_assert (bb->loop_father == NULL); | |
1244 | bb->loop_father = loop; | |
6270df4c | 1245 | loop->num_nodes++; |
9771b263 | 1246 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9ba025a2 | 1247 | ploop->num_nodes++; |
6270df4c ZD |
1248 | |
1249 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1250 | { | |
1251 | rescan_loop_exit (e, true, false); | |
1252 | } | |
1253 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1254 | { | |
1255 | rescan_loop_exit (e, true, false); | |
1256 | } | |
598ec7bd | 1257 | } |
2ecfd709 ZD |
1258 | |
1259 | /* Remove basic block BB from loops. */ | |
1260 | void | |
d329e058 AJ |
1261 | remove_bb_from_loops (basic_block bb) |
1262 | { | |
9771b263 | 1263 | unsigned i; |
6270df4c | 1264 | struct loop *loop = bb->loop_father; |
9ba025a2 | 1265 | loop_p ploop; |
6270df4c ZD |
1266 | edge_iterator ei; |
1267 | edge e; | |
1268 | ||
1269 | gcc_assert (loop != NULL); | |
1270 | loop->num_nodes--; | |
9771b263 | 1271 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9ba025a2 | 1272 | ploop->num_nodes--; |
6270df4c | 1273 | bb->loop_father = NULL; |
6270df4c ZD |
1274 | |
1275 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1276 | { | |
1277 | rescan_loop_exit (e, false, true); | |
1278 | } | |
1279 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1280 | { | |
1281 | rescan_loop_exit (e, false, true); | |
1282 | } | |
a310245f | 1283 | } |
2ecfd709 ZD |
1284 | |
1285 | /* Finds nearest common ancestor in loop tree for given loops. */ | |
1286 | struct loop * | |
d329e058 | 1287 | find_common_loop (struct loop *loop_s, struct loop *loop_d) |
2ecfd709 | 1288 | { |
9ba025a2 ZD |
1289 | unsigned sdepth, ddepth; |
1290 | ||
2ecfd709 ZD |
1291 | if (!loop_s) return loop_d; |
1292 | if (!loop_d) return loop_s; | |
d329e058 | 1293 | |
9ba025a2 ZD |
1294 | sdepth = loop_depth (loop_s); |
1295 | ddepth = loop_depth (loop_d); | |
1296 | ||
1297 | if (sdepth < ddepth) | |
9771b263 | 1298 | loop_d = (*loop_d->superloops)[sdepth]; |
9ba025a2 | 1299 | else if (sdepth > ddepth) |
9771b263 | 1300 | loop_s = (*loop_s->superloops)[ddepth]; |
2ecfd709 ZD |
1301 | |
1302 | while (loop_s != loop_d) | |
1303 | { | |
9ba025a2 ZD |
1304 | loop_s = loop_outer (loop_s); |
1305 | loop_d = loop_outer (loop_d); | |
2ecfd709 ZD |
1306 | } |
1307 | return loop_s; | |
1308 | } | |
1309 | ||
42fd6772 ZD |
1310 | /* Removes LOOP from structures and frees its data. */ |
1311 | ||
1312 | void | |
1313 | delete_loop (struct loop *loop) | |
1314 | { | |
1315 | /* Remove the loop from structure. */ | |
1316 | flow_loop_tree_node_remove (loop); | |
1317 | ||
1318 | /* Remove loop from loops array. */ | |
9771b263 | 1319 | (*current_loops->larray)[loop->num] = NULL; |
42fd6772 ZD |
1320 | |
1321 | /* Free loop data. */ | |
1322 | flow_loop_free (loop); | |
1323 | } | |
1324 | ||
3d436d2a | 1325 | /* Cancels the LOOP; it must be innermost one. */ |
b00bf166 KH |
1326 | |
1327 | static void | |
d73be268 | 1328 | cancel_loop (struct loop *loop) |
3d436d2a ZD |
1329 | { |
1330 | basic_block *bbs; | |
1331 | unsigned i; | |
9ba025a2 | 1332 | struct loop *outer = loop_outer (loop); |
3d436d2a | 1333 | |
341c100f | 1334 | gcc_assert (!loop->inner); |
3d436d2a ZD |
1335 | |
1336 | /* Move blocks up one level (they should be removed as soon as possible). */ | |
1337 | bbs = get_loop_body (loop); | |
1338 | for (i = 0; i < loop->num_nodes; i++) | |
9ba025a2 | 1339 | bbs[i]->loop_father = outer; |
3d436d2a | 1340 | |
b78384e0 | 1341 | free (bbs); |
42fd6772 | 1342 | delete_loop (loop); |
3d436d2a ZD |
1343 | } |
1344 | ||
1345 | /* Cancels LOOP and all its subloops. */ | |
1346 | void | |
d73be268 | 1347 | cancel_loop_tree (struct loop *loop) |
3d436d2a ZD |
1348 | { |
1349 | while (loop->inner) | |
d73be268 ZD |
1350 | cancel_loop_tree (loop->inner); |
1351 | cancel_loop (loop); | |
3d436d2a ZD |
1352 | } |
1353 | ||
d73be268 | 1354 | /* Checks that information about loops is correct |
e0bb17a8 | 1355 | -- sizes of loops are all right |
2ecfd709 ZD |
1356 | -- results of get_loop_body really belong to the loop |
1357 | -- loop header have just single entry edge and single latch edge | |
1358 | -- loop latches have only single successor that is header of their loop | |
3d436d2a | 1359 | -- irreducible loops are correctly marked |
cc360b36 | 1360 | -- the cached loop depth and loop father of each bb is correct |
2ecfd709 | 1361 | */ |
24e47c76 | 1362 | DEBUG_FUNCTION void |
d73be268 | 1363 | verify_loop_structure (void) |
2ecfd709 | 1364 | { |
3d436d2a | 1365 | unsigned *sizes, i, j; |
a271b42d | 1366 | basic_block bb, *bbs; |
2ecfd709 ZD |
1367 | struct loop *loop; |
1368 | int err = 0; | |
35b07080 | 1369 | edge e; |
0fc822d0 | 1370 | unsigned num = number_of_loops (cfun); |
6270df4c | 1371 | struct loop_exit *exit, *mexit; |
7d776ee2 | 1372 | bool dom_available = dom_info_available_p (CDI_DOMINATORS); |
2ecfd709 | 1373 | |
a9e0d843 RB |
1374 | if (loops_state_satisfies_p (LOOPS_NEED_FIXUP)) |
1375 | { | |
1376 | error ("loop verification on loop tree that needs fixup"); | |
1377 | err = 1; | |
1378 | } | |
1379 | ||
7d776ee2 RG |
1380 | /* We need up-to-date dominators, compute or verify them. */ |
1381 | if (!dom_available) | |
1382 | calculate_dominance_info (CDI_DOMINATORS); | |
1383 | else | |
1384 | verify_dominators (CDI_DOMINATORS); | |
510dbcce | 1385 | |
b0dd8c90 RB |
1386 | /* Check the loop tree root. */ |
1387 | if (current_loops->tree_root->header != ENTRY_BLOCK_PTR_FOR_FN (cfun) | |
1388 | || current_loops->tree_root->latch != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
1389 | || (current_loops->tree_root->num_nodes | |
1390 | != (unsigned) n_basic_blocks_for_fn (cfun))) | |
1391 | { | |
1392 | error ("corrupt loop tree root"); | |
1393 | err = 1; | |
1394 | } | |
1395 | ||
f64fb0fa | 1396 | /* Check the headers. */ |
11cd3bed | 1397 | FOR_EACH_BB_FN (bb, cfun) |
a271b42d | 1398 | if (bb_loop_header_p (bb)) |
f64fb0fa | 1399 | { |
a271b42d RB |
1400 | if (bb->loop_father->header == NULL) |
1401 | { | |
1402 | error ("loop with header %d marked for removal", bb->index); | |
1403 | err = 1; | |
1404 | } | |
1405 | else if (bb->loop_father->header != bb) | |
1406 | { | |
1407 | error ("loop with header %d not in loop tree", bb->index); | |
1408 | err = 1; | |
1409 | } | |
1410 | } | |
1411 | else if (bb->loop_father->header == bb) | |
1412 | { | |
1413 | error ("non-loop with header %d not marked for removal", bb->index); | |
f64fb0fa MP |
1414 | err = 1; |
1415 | } | |
1416 | ||
a271b42d | 1417 | /* Check the recorded loop father and sizes of loops. */ |
7ba9e72d | 1418 | auto_sbitmap visited (last_basic_block_for_fn (cfun)); |
f61e445a | 1419 | bitmap_clear (visited); |
0cae8d31 | 1420 | bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); |
f0bd40b1 | 1421 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) |
cc360b36 | 1422 | { |
a271b42d | 1423 | unsigned n; |
cc360b36 | 1424 | |
a271b42d RB |
1425 | if (loop->header == NULL) |
1426 | { | |
1427 | error ("removed loop %d in loop tree", loop->num); | |
1428 | err = 1; | |
1429 | continue; | |
1430 | } | |
1431 | ||
0cae8d31 | 1432 | n = get_loop_body_with_size (loop, bbs, n_basic_blocks_for_fn (cfun)); |
a271b42d RB |
1433 | if (loop->num_nodes != n) |
1434 | { | |
1435 | error ("size of loop %d should be %d, not %d", | |
1436 | loop->num, n, loop->num_nodes); | |
1437 | err = 1; | |
1438 | } | |
1439 | ||
1440 | for (j = 0; j < n; j++) | |
cc360b36 SB |
1441 | { |
1442 | bb = bbs[j]; | |
1443 | ||
0375167b RB |
1444 | if (!flow_bb_inside_loop_p (loop, bb)) |
1445 | { | |
1446 | error ("bb %d does not belong to loop %d", | |
1447 | bb->index, loop->num); | |
1448 | err = 1; | |
1449 | } | |
1450 | ||
cc360b36 | 1451 | /* Ignore this block if it is in an inner loop. */ |
d7c028c0 | 1452 | if (bitmap_bit_p (visited, bb->index)) |
cc360b36 | 1453 | continue; |
d7c028c0 | 1454 | bitmap_set_bit (visited, bb->index); |
cc360b36 SB |
1455 | |
1456 | if (bb->loop_father != loop) | |
1457 | { | |
1458 | error ("bb %d has father loop %d, should be loop %d", | |
1459 | bb->index, bb->loop_father->num, loop->num); | |
1460 | err = 1; | |
1461 | } | |
1462 | } | |
cc360b36 | 1463 | } |
a271b42d | 1464 | free (bbs); |
2ecfd709 ZD |
1465 | |
1466 | /* Check headers and latches. */ | |
f0bd40b1 | 1467 | FOR_EACH_LOOP (loop, 0) |
2ecfd709 | 1468 | { |
42fd6772 | 1469 | i = loop->num; |
a271b42d RB |
1470 | if (loop->header == NULL) |
1471 | continue; | |
0375167b RB |
1472 | if (!bb_loop_header_p (loop->header)) |
1473 | { | |
1474 | error ("loop %d%'s header is not a loop header", i); | |
1475 | err = 1; | |
1476 | } | |
f87000d0 | 1477 | if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
628f6a4e | 1478 | && EDGE_COUNT (loop->header->preds) != 2) |
2ecfd709 | 1479 | { |
d8a07487 | 1480 | error ("loop %d%'s header does not have exactly 2 entries", i); |
2ecfd709 ZD |
1481 | err = 1; |
1482 | } | |
6aaf596b RB |
1483 | if (loop->latch) |
1484 | { | |
1485 | if (!find_edge (loop->latch, loop->header)) | |
1486 | { | |
1487 | error ("loop %d%'s latch does not have an edge to its header", i); | |
1488 | err = 1; | |
1489 | } | |
1490 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, loop->header)) | |
1491 | { | |
1492 | error ("loop %d%'s latch is not dominated by its header", i); | |
1493 | err = 1; | |
1494 | } | |
1495 | } | |
f87000d0 | 1496 | if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
2ecfd709 | 1497 | { |
c5cbcccf | 1498 | if (!single_succ_p (loop->latch)) |
2ecfd709 | 1499 | { |
d8a07487 | 1500 | error ("loop %d%'s latch does not have exactly 1 successor", i); |
2ecfd709 ZD |
1501 | err = 1; |
1502 | } | |
c5cbcccf | 1503 | if (single_succ (loop->latch) != loop->header) |
2ecfd709 | 1504 | { |
d8a07487 | 1505 | error ("loop %d%'s latch does not have header as successor", i); |
2ecfd709 ZD |
1506 | err = 1; |
1507 | } | |
1508 | if (loop->latch->loop_father != loop) | |
1509 | { | |
d8a07487 | 1510 | error ("loop %d%'s latch does not belong directly to it", i); |
2ecfd709 ZD |
1511 | err = 1; |
1512 | } | |
1513 | } | |
1514 | if (loop->header->loop_father != loop) | |
1515 | { | |
d8a07487 | 1516 | error ("loop %d%'s header does not belong directly to it", i); |
2ecfd709 ZD |
1517 | err = 1; |
1518 | } | |
f87000d0 | 1519 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) |
35b07080 ZD |
1520 | && (loop_latch_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)) |
1521 | { | |
d8a07487 | 1522 | error ("loop %d%'s latch is marked as part of irreducible region", i); |
35b07080 ZD |
1523 | err = 1; |
1524 | } | |
2ecfd709 ZD |
1525 | } |
1526 | ||
3d436d2a | 1527 | /* Check irreducible loops. */ |
f87000d0 | 1528 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
3d436d2a ZD |
1529 | { |
1530 | /* Record old info. */ | |
7ba9e72d | 1531 | auto_sbitmap irreds (last_basic_block_for_fn (cfun)); |
11cd3bed | 1532 | FOR_EACH_BB_FN (bb, cfun) |
35b07080 | 1533 | { |
628f6a4e | 1534 | edge_iterator ei; |
35b07080 | 1535 | if (bb->flags & BB_IRREDUCIBLE_LOOP) |
d7c028c0 | 1536 | bitmap_set_bit (irreds, bb->index); |
35b07080 | 1537 | else |
d7c028c0 | 1538 | bitmap_clear_bit (irreds, bb->index); |
628f6a4e | 1539 | FOR_EACH_EDGE (e, ei, bb->succs) |
35b07080 | 1540 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) |
d329e058 | 1541 | e->flags |= EDGE_ALL_FLAGS + 1; |
35b07080 | 1542 | } |
3d436d2a ZD |
1543 | |
1544 | /* Recount it. */ | |
d73be268 | 1545 | mark_irreducible_loops (); |
3d436d2a ZD |
1546 | |
1547 | /* Compare. */ | |
11cd3bed | 1548 | FOR_EACH_BB_FN (bb, cfun) |
3d436d2a | 1549 | { |
628f6a4e BE |
1550 | edge_iterator ei; |
1551 | ||
3d436d2a | 1552 | if ((bb->flags & BB_IRREDUCIBLE_LOOP) |
d7c028c0 | 1553 | && !bitmap_bit_p (irreds, bb->index)) |
3d436d2a | 1554 | { |
ab532386 | 1555 | error ("basic block %d should be marked irreducible", bb->index); |
3d436d2a ZD |
1556 | err = 1; |
1557 | } | |
1558 | else if (!(bb->flags & BB_IRREDUCIBLE_LOOP) | |
d7c028c0 | 1559 | && bitmap_bit_p (irreds, bb->index)) |
3d436d2a | 1560 | { |
ab532386 | 1561 | error ("basic block %d should not be marked irreducible", bb->index); |
3d436d2a ZD |
1562 | err = 1; |
1563 | } | |
628f6a4e | 1564 | FOR_EACH_EDGE (e, ei, bb->succs) |
35b07080 ZD |
1565 | { |
1566 | if ((e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1567 | && !(e->flags & (EDGE_ALL_FLAGS + 1))) | |
1568 | { | |
ab532386 | 1569 | error ("edge from %d to %d should be marked irreducible", |
35b07080 ZD |
1570 | e->src->index, e->dest->index); |
1571 | err = 1; | |
1572 | } | |
1573 | else if (!(e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1574 | && (e->flags & (EDGE_ALL_FLAGS + 1))) | |
1575 | { | |
ab532386 | 1576 | error ("edge from %d to %d should not be marked irreducible", |
35b07080 ZD |
1577 | e->src->index, e->dest->index); |
1578 | err = 1; | |
1579 | } | |
1580 | e->flags &= ~(EDGE_ALL_FLAGS + 1); | |
1581 | } | |
3d436d2a | 1582 | } |
3d436d2a ZD |
1583 | } |
1584 | ||
6270df4c | 1585 | /* Check the recorded loop exits. */ |
f0bd40b1 | 1586 | FOR_EACH_LOOP (loop, 0) |
82b85a85 | 1587 | { |
9e2f83a5 | 1588 | if (!loop->exits || loop->exits->e != NULL) |
6270df4c ZD |
1589 | { |
1590 | error ("corrupted head of the exits list of loop %d", | |
1591 | loop->num); | |
1592 | err = 1; | |
1593 | } | |
1594 | else | |
1595 | { | |
1596 | /* Check that the list forms a cycle, and all elements except | |
1597 | for the head are nonnull. */ | |
9e2f83a5 | 1598 | for (mexit = loop->exits, exit = mexit->next, i = 0; |
6270df4c ZD |
1599 | exit->e && exit != mexit; |
1600 | exit = exit->next) | |
1601 | { | |
1602 | if (i++ & 1) | |
1603 | mexit = mexit->next; | |
1604 | } | |
1605 | ||
9e2f83a5 | 1606 | if (exit != loop->exits) |
6270df4c ZD |
1607 | { |
1608 | error ("corrupted exits list of loop %d", loop->num); | |
1609 | err = 1; | |
1610 | } | |
1611 | } | |
1612 | ||
f87000d0 | 1613 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1614 | { |
9e2f83a5 | 1615 | if (loop->exits->next != loop->exits) |
6270df4c ZD |
1616 | { |
1617 | error ("nonempty exits list of loop %d, but exits are not recorded", | |
1618 | loop->num); | |
1619 | err = 1; | |
1620 | } | |
1621 | } | |
1622 | } | |
1623 | ||
f87000d0 | 1624 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c ZD |
1625 | { |
1626 | unsigned n_exits = 0, eloops; | |
1627 | ||
a271b42d | 1628 | sizes = XCNEWVEC (unsigned, num); |
42fd6772 | 1629 | memset (sizes, 0, sizeof (unsigned) * num); |
11cd3bed | 1630 | FOR_EACH_BB_FN (bb, cfun) |
82b85a85 | 1631 | { |
628f6a4e | 1632 | edge_iterator ei; |
d73be268 | 1633 | if (bb->loop_father == current_loops->tree_root) |
82b85a85 | 1634 | continue; |
628f6a4e | 1635 | FOR_EACH_EDGE (e, ei, bb->succs) |
82b85a85 | 1636 | { |
82b85a85 ZD |
1637 | if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) |
1638 | continue; | |
1639 | ||
6270df4c ZD |
1640 | n_exits++; |
1641 | exit = get_exit_descriptions (e); | |
1642 | if (!exit) | |
1643 | { | |
d8a07487 | 1644 | error ("exit %d->%d not recorded", |
6270df4c ZD |
1645 | e->src->index, e->dest->index); |
1646 | err = 1; | |
1647 | } | |
1648 | eloops = 0; | |
1649 | for (; exit; exit = exit->next_e) | |
1650 | eloops++; | |
1651 | ||
82b85a85 | 1652 | for (loop = bb->loop_father; |
661bc682 RB |
1653 | loop != e->dest->loop_father |
1654 | /* When a loop exit is also an entry edge which | |
1655 | can happen when avoiding CFG manipulations | |
1656 | then the last loop exited is the outer loop | |
1657 | of the loop entered. */ | |
1658 | && loop != loop_outer (e->dest->loop_father); | |
9ba025a2 | 1659 | loop = loop_outer (loop)) |
82b85a85 | 1660 | { |
6270df4c | 1661 | eloops--; |
82b85a85 | 1662 | sizes[loop->num]++; |
6270df4c ZD |
1663 | } |
1664 | ||
1665 | if (eloops != 0) | |
1666 | { | |
d8a07487 | 1667 | error ("wrong list of exited loops for edge %d->%d", |
6270df4c ZD |
1668 | e->src->index, e->dest->index); |
1669 | err = 1; | |
82b85a85 ZD |
1670 | } |
1671 | } | |
1672 | } | |
1673 | ||
2a22f99c | 1674 | if (n_exits != current_loops->exits->elements ()) |
82b85a85 | 1675 | { |
d8a07487 | 1676 | error ("too many loop exits recorded"); |
6270df4c ZD |
1677 | err = 1; |
1678 | } | |
82b85a85 | 1679 | |
f0bd40b1 | 1680 | FOR_EACH_LOOP (loop, 0) |
6270df4c ZD |
1681 | { |
1682 | eloops = 0; | |
9e2f83a5 | 1683 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
6270df4c ZD |
1684 | eloops++; |
1685 | if (eloops != sizes[loop->num]) | |
82b85a85 | 1686 | { |
6270df4c ZD |
1687 | error ("%d exits recorded for loop %d (having %d exits)", |
1688 | eloops, loop->num, sizes[loop->num]); | |
82b85a85 ZD |
1689 | err = 1; |
1690 | } | |
1691 | } | |
a271b42d RB |
1692 | |
1693 | free (sizes); | |
82b85a85 ZD |
1694 | } |
1695 | ||
341c100f | 1696 | gcc_assert (!err); |
82b85a85 | 1697 | |
7d776ee2 RG |
1698 | if (!dom_available) |
1699 | free_dominance_info (CDI_DOMINATORS); | |
2ecfd709 ZD |
1700 | } |
1701 | ||
1702 | /* Returns latch edge of LOOP. */ | |
1703 | edge | |
d329e058 | 1704 | loop_latch_edge (const struct loop *loop) |
2ecfd709 | 1705 | { |
9ff3d2de | 1706 | return find_edge (loop->latch, loop->header); |
402209ff | 1707 | } |
2ecfd709 ZD |
1708 | |
1709 | /* Returns preheader edge of LOOP. */ | |
1710 | edge | |
d329e058 | 1711 | loop_preheader_edge (const struct loop *loop) |
2ecfd709 ZD |
1712 | { |
1713 | edge e; | |
628f6a4e | 1714 | edge_iterator ei; |
2ecfd709 | 1715 | |
a68f286c RB |
1716 | gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
1717 | && ! loops_state_satisfies_p (LOOPS_MAY_HAVE_MULTIPLE_LATCHES)); | |
c7b852c8 | 1718 | |
628f6a4e BE |
1719 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
1720 | if (e->src != loop->latch) | |
1721 | break; | |
2ecfd709 | 1722 | |
a68f286c RB |
1723 | if (! e) |
1724 | { | |
1725 | gcc_assert (! loop_outer (loop)); | |
1726 | return single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
1727 | } | |
1728 | ||
2ecfd709 ZD |
1729 | return e; |
1730 | } | |
70388d94 ZD |
1731 | |
1732 | /* Returns true if E is an exit of LOOP. */ | |
1733 | ||
1734 | bool | |
ed7a4b4b | 1735 | loop_exit_edge_p (const struct loop *loop, const_edge e) |
70388d94 ZD |
1736 | { |
1737 | return (flow_bb_inside_loop_p (loop, e->src) | |
1738 | && !flow_bb_inside_loop_p (loop, e->dest)); | |
1739 | } | |
ac8f6c69 ZD |
1740 | |
1741 | /* Returns the single exit edge of LOOP, or NULL if LOOP has either no exit | |
6270df4c ZD |
1742 | or more than one exit. If loops do not have the exits recorded, NULL |
1743 | is returned always. */ | |
ac8f6c69 ZD |
1744 | |
1745 | edge | |
1746 | single_exit (const struct loop *loop) | |
1747 | { | |
9e2f83a5 | 1748 | struct loop_exit *exit = loop->exits->next; |
ac8f6c69 | 1749 | |
f87000d0 | 1750 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1751 | return NULL; |
ac8f6c69 | 1752 | |
9e2f83a5 | 1753 | if (exit->e && exit->next == loop->exits) |
6270df4c ZD |
1754 | return exit->e; |
1755 | else | |
1756 | return NULL; | |
ac8f6c69 | 1757 | } |
f8bf9252 | 1758 | |
f4ce375d | 1759 | /* Returns true when BB has an incoming edge exiting LOOP. */ |
f8bf9252 SP |
1760 | |
1761 | bool | |
f4ce375d | 1762 | loop_exits_to_bb_p (struct loop *loop, basic_block bb) |
f8bf9252 SP |
1763 | { |
1764 | edge e; | |
1765 | edge_iterator ei; | |
1766 | ||
1767 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1768 | if (loop_exit_edge_p (loop, e)) | |
1769 | return true; | |
1770 | ||
1771 | return false; | |
1772 | } | |
f4ce375d VK |
1773 | |
1774 | /* Returns true when BB has an outgoing edge exiting LOOP. */ | |
1775 | ||
1776 | bool | |
1777 | loop_exits_from_bb_p (struct loop *loop, basic_block bb) | |
1778 | { | |
1779 | edge e; | |
1780 | edge_iterator ei; | |
1781 | ||
1782 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1783 | if (loop_exit_edge_p (loop, e)) | |
1784 | return true; | |
1785 | ||
1786 | return false; | |
1787 | } | |
e25a6711 TJ |
1788 | |
1789 | /* Return location corresponding to the loop control condition if possible. */ | |
1790 | ||
1791 | location_t | |
1792 | get_loop_location (struct loop *loop) | |
1793 | { | |
9d56eaa2 | 1794 | rtx_insn *insn = NULL; |
e25a6711 TJ |
1795 | struct niter_desc *desc = NULL; |
1796 | edge exit; | |
1797 | ||
1798 | /* For a for or while loop, we would like to return the location | |
1799 | of the for or while statement, if possible. To do this, look | |
1800 | for the branch guarding the loop back-edge. */ | |
1801 | ||
1802 | /* If this is a simple loop with an in_edge, then the loop control | |
1803 | branch is typically at the end of its source. */ | |
1804 | desc = get_simple_loop_desc (loop); | |
1805 | if (desc->in_edge) | |
1806 | { | |
1807 | FOR_BB_INSNS_REVERSE (desc->in_edge->src, insn) | |
1808 | { | |
1809 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1810 | return INSN_LOCATION (insn); | |
1811 | } | |
1812 | } | |
1813 | /* If loop has a single exit, then the loop control branch | |
1814 | must be at the end of its source. */ | |
1815 | if ((exit = single_exit (loop))) | |
1816 | { | |
1817 | FOR_BB_INSNS_REVERSE (exit->src, insn) | |
1818 | { | |
1819 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1820 | return INSN_LOCATION (insn); | |
1821 | } | |
1822 | } | |
1823 | /* Next check the latch, to see if it is non-empty. */ | |
1824 | FOR_BB_INSNS_REVERSE (loop->latch, insn) | |
1825 | { | |
1826 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1827 | return INSN_LOCATION (insn); | |
1828 | } | |
1829 | /* Finally, if none of the above identifies the loop control branch, | |
1830 | return the first location in the loop header. */ | |
1831 | FOR_BB_INSNS (loop->header, insn) | |
1832 | { | |
1833 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1834 | return INSN_LOCATION (insn); | |
1835 | } | |
1836 | /* If all else fails, simply return the current function location. */ | |
1837 | return DECL_SOURCE_LOCATION (current_function_decl); | |
1838 | } | |
1839 | ||
71343877 AM |
1840 | /* Records that every statement in LOOP is executed I_BOUND times. |
1841 | REALISTIC is true if I_BOUND is expected to be close to the real number | |
1842 | of iterations. UPPER is true if we are sure the loop iterates at most | |
1843 | I_BOUND times. */ | |
1844 | ||
1845 | void | |
807e902e KZ |
1846 | record_niter_bound (struct loop *loop, const widest_int &i_bound, |
1847 | bool realistic, bool upper) | |
71343877 AM |
1848 | { |
1849 | /* Update the bounds only when there is no previous estimation, or when the | |
1850 | current estimation is smaller. */ | |
1851 | if (upper | |
1852 | && (!loop->any_upper_bound | |
807e902e | 1853 | || wi::ltu_p (i_bound, loop->nb_iterations_upper_bound))) |
71343877 AM |
1854 | { |
1855 | loop->any_upper_bound = true; | |
1856 | loop->nb_iterations_upper_bound = i_bound; | |
105e29c5 JH |
1857 | if (!loop->any_likely_upper_bound) |
1858 | { | |
1859 | loop->any_likely_upper_bound = true; | |
1860 | loop->nb_iterations_likely_upper_bound = i_bound; | |
1861 | } | |
71343877 AM |
1862 | } |
1863 | if (realistic | |
1864 | && (!loop->any_estimate | |
807e902e | 1865 | || wi::ltu_p (i_bound, loop->nb_iterations_estimate))) |
71343877 AM |
1866 | { |
1867 | loop->any_estimate = true; | |
1868 | loop->nb_iterations_estimate = i_bound; | |
1869 | } | |
105e29c5 JH |
1870 | if (!realistic |
1871 | && (!loop->any_likely_upper_bound | |
1872 | || wi::ltu_p (i_bound, loop->nb_iterations_likely_upper_bound))) | |
1873 | { | |
1874 | loop->any_likely_upper_bound = true; | |
1875 | loop->nb_iterations_likely_upper_bound = i_bound; | |
1876 | } | |
71343877 AM |
1877 | |
1878 | /* If an upper bound is smaller than the realistic estimate of the | |
1879 | number of iterations, use the upper bound instead. */ | |
1880 | if (loop->any_upper_bound | |
1881 | && loop->any_estimate | |
807e902e KZ |
1882 | && wi::ltu_p (loop->nb_iterations_upper_bound, |
1883 | loop->nb_iterations_estimate)) | |
71343877 | 1884 | loop->nb_iterations_estimate = loop->nb_iterations_upper_bound; |
105e29c5 JH |
1885 | if (loop->any_upper_bound |
1886 | && loop->any_likely_upper_bound | |
1887 | && wi::ltu_p (loop->nb_iterations_upper_bound, | |
1888 | loop->nb_iterations_likely_upper_bound)) | |
1889 | loop->nb_iterations_likely_upper_bound = loop->nb_iterations_upper_bound; | |
71343877 AM |
1890 | } |
1891 | ||
1ef88893 | 1892 | /* Similar to get_estimated_loop_iterations, but returns the estimate only |
71343877 AM |
1893 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate |
1894 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
1895 | ||
1896 | HOST_WIDE_INT | |
1ef88893 | 1897 | get_estimated_loop_iterations_int (struct loop *loop) |
71343877 | 1898 | { |
807e902e | 1899 | widest_int nit; |
71343877 AM |
1900 | HOST_WIDE_INT hwi_nit; |
1901 | ||
1902 | if (!get_estimated_loop_iterations (loop, &nit)) | |
1903 | return -1; | |
1904 | ||
807e902e | 1905 | if (!wi::fits_shwi_p (nit)) |
71343877 AM |
1906 | return -1; |
1907 | hwi_nit = nit.to_shwi (); | |
1908 | ||
1909 | return hwi_nit < 0 ? -1 : hwi_nit; | |
1910 | } | |
1911 | ||
1912 | /* Returns an upper bound on the number of executions of statements | |
1913 | in the LOOP. For statements before the loop exit, this exceeds | |
1914 | the number of execution of the latch by one. */ | |
1915 | ||
1916 | HOST_WIDE_INT | |
1917 | max_stmt_executions_int (struct loop *loop) | |
1918 | { | |
1ef88893 | 1919 | HOST_WIDE_INT nit = get_max_loop_iterations_int (loop); |
71343877 AM |
1920 | HOST_WIDE_INT snit; |
1921 | ||
1922 | if (nit == -1) | |
1923 | return -1; | |
1924 | ||
1925 | snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
1926 | ||
1927 | /* If the computation overflows, return -1. */ | |
1928 | return snit < 0 ? -1 : snit; | |
1929 | } | |
1930 | ||
105e29c5 JH |
1931 | /* Returns an likely upper bound on the number of executions of statements |
1932 | in the LOOP. For statements before the loop exit, this exceeds | |
1933 | the number of execution of the latch by one. */ | |
1934 | ||
1935 | HOST_WIDE_INT | |
1936 | likely_max_stmt_executions_int (struct loop *loop) | |
1937 | { | |
1938 | HOST_WIDE_INT nit = get_likely_max_loop_iterations_int (loop); | |
1939 | HOST_WIDE_INT snit; | |
1940 | ||
1941 | if (nit == -1) | |
1942 | return -1; | |
1943 | ||
1944 | snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
1945 | ||
1946 | /* If the computation overflows, return -1. */ | |
1947 | return snit < 0 ? -1 : snit; | |
1948 | } | |
1949 | ||
71343877 AM |
1950 | /* Sets NIT to the estimated number of executions of the latch of the |
1951 | LOOP. If we have no reliable estimate, the function returns false, otherwise | |
1952 | returns true. */ | |
1953 | ||
1954 | bool | |
807e902e | 1955 | get_estimated_loop_iterations (struct loop *loop, widest_int *nit) |
71343877 AM |
1956 | { |
1957 | /* Even if the bound is not recorded, possibly we can derrive one from | |
1958 | profile. */ | |
1959 | if (!loop->any_estimate) | |
1960 | { | |
3995f3a2 | 1961 | if (loop->header->count.reliable_p ()) |
71343877 | 1962 | { |
807e902e | 1963 | *nit = gcov_type_to_wide_int |
71343877 AM |
1964 | (expected_loop_iterations_unbounded (loop) + 1); |
1965 | return true; | |
1966 | } | |
1967 | return false; | |
1968 | } | |
1969 | ||
1970 | *nit = loop->nb_iterations_estimate; | |
1971 | return true; | |
1972 | } | |
1973 | ||
1974 | /* Sets NIT to an upper bound for the maximum number of executions of the | |
1975 | latch of the LOOP. If we have no reliable estimate, the function returns | |
1976 | false, otherwise returns true. */ | |
1977 | ||
1978 | bool | |
199b1891 | 1979 | get_max_loop_iterations (const struct loop *loop, widest_int *nit) |
71343877 AM |
1980 | { |
1981 | if (!loop->any_upper_bound) | |
1982 | return false; | |
1983 | ||
1984 | *nit = loop->nb_iterations_upper_bound; | |
1985 | return true; | |
1986 | } | |
1ef88893 AM |
1987 | |
1988 | /* Similar to get_max_loop_iterations, but returns the estimate only | |
1989 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
1990 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
1991 | ||
1992 | HOST_WIDE_INT | |
199b1891 | 1993 | get_max_loop_iterations_int (const struct loop *loop) |
1ef88893 | 1994 | { |
807e902e | 1995 | widest_int nit; |
1ef88893 AM |
1996 | HOST_WIDE_INT hwi_nit; |
1997 | ||
1998 | if (!get_max_loop_iterations (loop, &nit)) | |
1999 | return -1; | |
2000 | ||
807e902e | 2001 | if (!wi::fits_shwi_p (nit)) |
1ef88893 AM |
2002 | return -1; |
2003 | hwi_nit = nit.to_shwi (); | |
2004 | ||
2005 | return hwi_nit < 0 ? -1 : hwi_nit; | |
2006 | } | |
2007 | ||
105e29c5 JH |
2008 | /* Sets NIT to an upper bound for the maximum number of executions of the |
2009 | latch of the LOOP. If we have no reliable estimate, the function returns | |
2010 | false, otherwise returns true. */ | |
2011 | ||
2012 | bool | |
2013 | get_likely_max_loop_iterations (struct loop *loop, widest_int *nit) | |
2014 | { | |
2015 | if (!loop->any_likely_upper_bound) | |
2016 | return false; | |
2017 | ||
2018 | *nit = loop->nb_iterations_likely_upper_bound; | |
2019 | return true; | |
2020 | } | |
2021 | ||
2022 | /* Similar to get_max_loop_iterations, but returns the estimate only | |
2023 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
2024 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
2025 | ||
2026 | HOST_WIDE_INT | |
2027 | get_likely_max_loop_iterations_int (struct loop *loop) | |
2028 | { | |
2029 | widest_int nit; | |
2030 | HOST_WIDE_INT hwi_nit; | |
2031 | ||
2032 | if (!get_likely_max_loop_iterations (loop, &nit)) | |
2033 | return -1; | |
2034 | ||
2035 | if (!wi::fits_shwi_p (nit)) | |
2036 | return -1; | |
2037 | hwi_nit = nit.to_shwi (); | |
2038 | ||
2039 | return hwi_nit < 0 ? -1 : hwi_nit; | |
2040 | } | |
2041 | ||
4484a35a | 2042 | /* Returns the loop depth of the loop BB belongs to. */ |
1ef88893 | 2043 | |
4484a35a AM |
2044 | int |
2045 | bb_loop_depth (const_basic_block bb) | |
2046 | { | |
2047 | return bb->loop_father ? loop_depth (bb->loop_father) : 0; | |
2048 | } | |
08c13199 RB |
2049 | |
2050 | /* Marks LOOP for removal and sets LOOPS_NEED_FIXUP. */ | |
2051 | ||
2052 | void | |
2053 | mark_loop_for_removal (loop_p loop) | |
2054 | { | |
024660c5 RB |
2055 | if (loop->header == NULL) |
2056 | return; | |
e4ca2139 | 2057 | loop->former_header = loop->header; |
08c13199 RB |
2058 | loop->header = NULL; |
2059 | loop->latch = NULL; | |
2060 | loops_state_set (LOOPS_NEED_FIXUP); | |
2061 | } |