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402209ff | 1 | /* Natural loop discovery code for GNU compiler. |
5624e564 | 2 | Copyright (C) 2000-2015 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 ZW |
22 | #include "coretypes.h" |
23 | #include "tm.h" | |
402209ff | 24 | #include "rtl.h" |
40e23961 | 25 | #include "symtab.h" |
83685514 | 26 | #include "hard-reg-set.h" |
a310245f | 27 | #include "function.h" |
60393bbc AM |
28 | #include "predict.h" |
29 | #include "dominance.h" | |
30 | #include "cfg.h" | |
31 | #include "cfganal.h" | |
402209ff | 32 | #include "basic-block.h" |
3d436d2a | 33 | #include "cfgloop.h" |
718f9c0f | 34 | #include "diagnostic-core.h" |
3d436d2a | 35 | #include "flags.h" |
6de9cd9a | 36 | #include "tree.h" |
40e23961 | 37 | #include "fold-const.h" |
2fb9a547 AM |
38 | #include "tree-ssa-alias.h" |
39 | #include "internal-fn.h" | |
40 | #include "gimple-expr.h" | |
442b4905 | 41 | #include "gimple.h" |
5be5c238 | 42 | #include "gimple-iterator.h" |
442b4905 | 43 | #include "gimple-ssa.h" |
7ee2468b | 44 | #include "dumpfile.h" |
f470c378 | 45 | |
d73be268 | 46 | static void flow_loops_cfg_dump (FILE *); |
402209ff JH |
47 | \f |
48 | /* Dump loop related CFG information. */ | |
49 | ||
50 | static void | |
d73be268 | 51 | flow_loops_cfg_dump (FILE *file) |
402209ff | 52 | { |
e0082a72 | 53 | basic_block bb; |
402209ff | 54 | |
d73be268 | 55 | if (!file) |
402209ff JH |
56 | return; |
57 | ||
11cd3bed | 58 | FOR_EACH_BB_FN (bb, cfun) |
402209ff JH |
59 | { |
60 | edge succ; | |
628f6a4e | 61 | edge_iterator ei; |
402209ff | 62 | |
e0082a72 | 63 | fprintf (file, ";; %d succs { ", bb->index); |
628f6a4e | 64 | FOR_EACH_EDGE (succ, ei, bb->succs) |
0b17ab2f | 65 | fprintf (file, "%d ", succ->dest->index); |
2ecfd709 | 66 | fprintf (file, "}\n"); |
402209ff | 67 | } |
402209ff JH |
68 | } |
69 | ||
da7d8304 | 70 | /* Return nonzero if the nodes of LOOP are a subset of OUTER. */ |
402209ff | 71 | |
2ecfd709 | 72 | bool |
d329e058 | 73 | flow_loop_nested_p (const struct loop *outer, const struct loop *loop) |
402209ff | 74 | { |
9ba025a2 ZD |
75 | unsigned odepth = loop_depth (outer); |
76 | ||
77 | return (loop_depth (loop) > odepth | |
9771b263 | 78 | && (*loop->superloops)[odepth] == outer); |
402209ff JH |
79 | } |
80 | ||
1ad03593 SP |
81 | /* Returns the loop such that LOOP is nested DEPTH (indexed from zero) |
82 | loops within LOOP. */ | |
a7e5372d ZD |
83 | |
84 | struct loop * | |
85 | superloop_at_depth (struct loop *loop, unsigned depth) | |
86 | { | |
9ba025a2 ZD |
87 | unsigned ldepth = loop_depth (loop); |
88 | ||
89 | gcc_assert (depth <= ldepth); | |
a7e5372d | 90 | |
9ba025a2 | 91 | if (depth == ldepth) |
a7e5372d ZD |
92 | return loop; |
93 | ||
9771b263 | 94 | return (*loop->superloops)[depth]; |
a7e5372d ZD |
95 | } |
96 | ||
89f8f30f ZD |
97 | /* Returns the list of the latch edges of LOOP. */ |
98 | ||
9771b263 | 99 | static vec<edge> |
89f8f30f ZD |
100 | get_loop_latch_edges (const struct loop *loop) |
101 | { | |
102 | edge_iterator ei; | |
103 | edge e; | |
6e1aa848 | 104 | vec<edge> ret = vNULL; |
89f8f30f ZD |
105 | |
106 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
107 | { | |
108 | if (dominated_by_p (CDI_DOMINATORS, e->src, loop->header)) | |
9771b263 | 109 | ret.safe_push (e); |
89f8f30f ZD |
110 | } |
111 | ||
112 | return ret; | |
113 | } | |
114 | ||
402209ff JH |
115 | /* Dump the loop information specified by LOOP to the stream FILE |
116 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
117 | ||
118 | void | |
d329e058 AJ |
119 | flow_loop_dump (const struct loop *loop, FILE *file, |
120 | void (*loop_dump_aux) (const struct loop *, FILE *, int), | |
121 | int verbose) | |
402209ff | 122 | { |
2ecfd709 | 123 | basic_block *bbs; |
3d436d2a | 124 | unsigned i; |
9771b263 | 125 | vec<edge> latches; |
89f8f30f | 126 | edge e; |
2ecfd709 | 127 | |
402209ff JH |
128 | if (! loop || ! loop->header) |
129 | return; | |
130 | ||
7490e6c4 | 131 | fprintf (file, ";;\n;; Loop %d\n", loop->num); |
402209ff | 132 | |
89f8f30f ZD |
133 | fprintf (file, ";; header %d, ", loop->header->index); |
134 | if (loop->latch) | |
135 | fprintf (file, "latch %d\n", loop->latch->index); | |
136 | else | |
137 | { | |
138 | fprintf (file, "multiple latches:"); | |
139 | latches = get_loop_latch_edges (loop); | |
9771b263 | 140 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f | 141 | fprintf (file, " %d", e->src->index); |
9771b263 | 142 | latches.release (); |
89f8f30f ZD |
143 | fprintf (file, "\n"); |
144 | } | |
145 | ||
99f8a411 | 146 | fprintf (file, ";; depth %d, outer %ld\n", |
9ba025a2 ZD |
147 | loop_depth (loop), (long) (loop_outer (loop) |
148 | ? loop_outer (loop)->num : -1)); | |
402209ff | 149 | |
2ecfd709 ZD |
150 | fprintf (file, ";; nodes:"); |
151 | bbs = get_loop_body (loop); | |
152 | for (i = 0; i < loop->num_nodes; i++) | |
153 | fprintf (file, " %d", bbs[i]->index); | |
154 | free (bbs); | |
155 | fprintf (file, "\n"); | |
5f0d2358 | 156 | |
402209ff JH |
157 | if (loop_dump_aux) |
158 | loop_dump_aux (loop, file, verbose); | |
159 | } | |
160 | ||
d73be268 | 161 | /* Dump the loop information about loops to the stream FILE, |
402209ff JH |
162 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ |
163 | ||
164 | void | |
d73be268 | 165 | flow_loops_dump (FILE *file, void (*loop_dump_aux) (const struct loop *, FILE *, int), int verbose) |
402209ff | 166 | { |
42fd6772 | 167 | struct loop *loop; |
402209ff | 168 | |
d73be268 | 169 | if (!current_loops || ! file) |
402209ff JH |
170 | return; |
171 | ||
0fc822d0 | 172 | fprintf (file, ";; %d loops found\n", number_of_loops (cfun)); |
2ecfd709 | 173 | |
f0bd40b1 | 174 | FOR_EACH_LOOP (loop, LI_INCLUDE_ROOT) |
402209ff | 175 | { |
2ecfd709 | 176 | flow_loop_dump (loop, file, loop_dump_aux, verbose); |
402209ff JH |
177 | } |
178 | ||
179 | if (verbose) | |
d73be268 | 180 | flow_loops_cfg_dump (file); |
402209ff JH |
181 | } |
182 | ||
2ecfd709 | 183 | /* Free data allocated for LOOP. */ |
9e2f83a5 | 184 | |
35b07080 | 185 | void |
d329e058 | 186 | flow_loop_free (struct loop *loop) |
2ecfd709 | 187 | { |
6270df4c ZD |
188 | struct loop_exit *exit, *next; |
189 | ||
9771b263 | 190 | vec_free (loop->superloops); |
6270df4c ZD |
191 | |
192 | /* Break the list of the loop exit records. They will be freed when the | |
193 | corresponding edge is rescanned or removed, and this avoids | |
194 | accessing the (already released) head of the list stored in the | |
195 | loop structure. */ | |
9e2f83a5 | 196 | for (exit = loop->exits->next; exit != loop->exits; exit = next) |
6270df4c ZD |
197 | { |
198 | next = exit->next; | |
199 | exit->next = exit; | |
200 | exit->prev = exit; | |
201 | } | |
9e2f83a5 ZD |
202 | |
203 | ggc_free (loop->exits); | |
204 | ggc_free (loop); | |
2ecfd709 ZD |
205 | } |
206 | ||
402209ff JH |
207 | /* Free all the memory allocated for LOOPS. */ |
208 | ||
209 | void | |
d329e058 | 210 | flow_loops_free (struct loops *loops) |
402209ff | 211 | { |
42fd6772 | 212 | if (loops->larray) |
402209ff | 213 | { |
3d436d2a | 214 | unsigned i; |
42fd6772 | 215 | loop_p loop; |
402209ff JH |
216 | |
217 | /* Free the loop descriptors. */ | |
9771b263 | 218 | FOR_EACH_VEC_SAFE_ELT (loops->larray, i, loop) |
402209ff | 219 | { |
2ecfd709 ZD |
220 | if (!loop) |
221 | continue; | |
222 | ||
223 | flow_loop_free (loop); | |
402209ff | 224 | } |
5f0d2358 | 225 | |
9771b263 | 226 | vec_free (loops->larray); |
402209ff JH |
227 | } |
228 | } | |
229 | ||
2ecfd709 ZD |
230 | /* Find the nodes contained within the LOOP with header HEADER. |
231 | Return the number of nodes within the loop. */ | |
402209ff | 232 | |
2b271002 | 233 | int |
d329e058 | 234 | flow_loop_nodes_find (basic_block header, struct loop *loop) |
402209ff | 235 | { |
6e1aa848 | 236 | vec<basic_block> stack = vNULL; |
2ecfd709 | 237 | int num_nodes = 1; |
89f8f30f ZD |
238 | edge latch; |
239 | edge_iterator latch_ei; | |
402209ff | 240 | |
2ecfd709 | 241 | header->loop_father = loop; |
402209ff | 242 | |
89f8f30f | 243 | FOR_EACH_EDGE (latch, latch_ei, loop->header->preds) |
402209ff | 244 | { |
89f8f30f ZD |
245 | if (latch->src->loop_father == loop |
246 | || !dominated_by_p (CDI_DOMINATORS, latch->src, loop->header)) | |
247 | continue; | |
248 | ||
402209ff | 249 | num_nodes++; |
9771b263 | 250 | stack.safe_push (latch->src); |
89f8f30f | 251 | latch->src->loop_father = loop; |
d329e058 | 252 | |
9771b263 | 253 | while (!stack.is_empty ()) |
402209ff | 254 | { |
2ecfd709 ZD |
255 | basic_block node; |
256 | edge e; | |
628f6a4e | 257 | edge_iterator ei; |
402209ff | 258 | |
9771b263 | 259 | node = stack.pop (); |
d329e058 | 260 | |
628f6a4e | 261 | FOR_EACH_EDGE (e, ei, node->preds) |
402209ff | 262 | { |
2ecfd709 ZD |
263 | basic_block ancestor = e->src; |
264 | ||
89f8f30f | 265 | if (ancestor->loop_father != loop) |
2ecfd709 ZD |
266 | { |
267 | ancestor->loop_father = loop; | |
2ecfd709 | 268 | num_nodes++; |
9771b263 | 269 | stack.safe_push (ancestor); |
2ecfd709 | 270 | } |
402209ff JH |
271 | } |
272 | } | |
273 | } | |
9771b263 | 274 | stack.release (); |
89f8f30f | 275 | |
402209ff JH |
276 | return num_nodes; |
277 | } | |
278 | ||
9ba025a2 ZD |
279 | /* Records the vector of superloops of the loop LOOP, whose immediate |
280 | superloop is FATHER. */ | |
281 | ||
35b07080 | 282 | static void |
9ba025a2 | 283 | establish_preds (struct loop *loop, struct loop *father) |
35b07080 | 284 | { |
9ba025a2 ZD |
285 | loop_p ploop; |
286 | unsigned depth = loop_depth (father) + 1; | |
287 | unsigned i; | |
a310245f | 288 | |
9771b263 DN |
289 | loop->superloops = 0; |
290 | vec_alloc (loop->superloops, depth); | |
291 | FOR_EACH_VEC_SAFE_ELT (father->superloops, i, ploop) | |
292 | loop->superloops->quick_push (ploop); | |
293 | loop->superloops->quick_push (father); | |
35b07080 ZD |
294 | |
295 | for (ploop = loop->inner; ploop; ploop = ploop->next) | |
9ba025a2 | 296 | establish_preds (ploop, loop); |
35b07080 ZD |
297 | } |
298 | ||
2ecfd709 | 299 | /* Add LOOP to the loop hierarchy tree where FATHER is father of the |
35b07080 ZD |
300 | added loop. If LOOP has some children, take care of that their |
301 | pred field will be initialized correctly. */ | |
402209ff | 302 | |
2ecfd709 | 303 | void |
d329e058 | 304 | flow_loop_tree_node_add (struct loop *father, struct loop *loop) |
402209ff | 305 | { |
2ecfd709 ZD |
306 | loop->next = father->inner; |
307 | father->inner = loop; | |
2ecfd709 | 308 | |
9ba025a2 | 309 | establish_preds (loop, father); |
402209ff JH |
310 | } |
311 | ||
2ecfd709 | 312 | /* Remove LOOP from the loop hierarchy tree. */ |
402209ff | 313 | |
2ecfd709 | 314 | void |
d329e058 | 315 | flow_loop_tree_node_remove (struct loop *loop) |
402209ff | 316 | { |
2ecfd709 | 317 | struct loop *prev, *father; |
402209ff | 318 | |
9ba025a2 | 319 | father = loop_outer (loop); |
402209ff | 320 | |
2ecfd709 ZD |
321 | /* Remove loop from the list of sons. */ |
322 | if (father->inner == loop) | |
323 | father->inner = loop->next; | |
324 | else | |
325 | { | |
9ba025a2 ZD |
326 | for (prev = father->inner; prev->next != loop; prev = prev->next) |
327 | continue; | |
2ecfd709 ZD |
328 | prev->next = loop->next; |
329 | } | |
402209ff | 330 | |
9771b263 | 331 | loop->superloops = NULL; |
402209ff JH |
332 | } |
333 | ||
6270df4c ZD |
334 | /* Allocates and returns new loop structure. */ |
335 | ||
336 | struct loop * | |
337 | alloc_loop (void) | |
338 | { | |
766090c2 | 339 | struct loop *loop = ggc_cleared_alloc<struct loop> (); |
9e2f83a5 | 340 | |
766090c2 | 341 | loop->exits = ggc_cleared_alloc<loop_exit> (); |
9e2f83a5 | 342 | loop->exits->next = loop->exits->prev = loop->exits; |
204b560f | 343 | loop->can_be_parallel = false; |
807e902e KZ |
344 | loop->nb_iterations_upper_bound = 0; |
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; | |
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); | |
402209ff | 501 | |
0375167b RB |
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) | |
402209ff | 505 | { |
0375167b | 506 | basic_block latch = e->src; |
89f8f30f | 507 | |
0375167b | 508 | if (flow_bb_inside_loop_p (loop, latch)) |
402209ff | 509 | { |
0375167b | 510 | if (loop->latch != NULL) |
402209ff | 511 | { |
0375167b RB |
512 | /* More than one latch edge. */ |
513 | loop->latch = NULL; | |
514 | break; | |
402209ff | 515 | } |
0375167b | 516 | loop->latch = latch; |
402209ff | 517 | } |
402209ff | 518 | } |
2ecfd709 | 519 | } |
3d436d2a | 520 | |
0375167b | 521 | return loops; |
402209ff JH |
522 | } |
523 | ||
89f8f30f ZD |
524 | /* Ratio of frequencies of edges so that one of more latch edges is |
525 | considered to belong to inner loop with same header. */ | |
526 | #define HEAVY_EDGE_RATIO 8 | |
527 | ||
528 | /* Minimum number of samples for that we apply | |
529 | find_subloop_latch_edge_by_profile heuristics. */ | |
530 | #define HEAVY_EDGE_MIN_SAMPLES 10 | |
531 | ||
532 | /* If the profile info is available, finds an edge in LATCHES that much more | |
533 | frequent than the remaining edges. Returns such an edge, or NULL if we do | |
534 | not find one. | |
535 | ||
536 | We do not use guessed profile here, only the measured one. The guessed | |
537 | profile is usually too flat and unreliable for this (and it is mostly based | |
538 | on the loop structure of the program, so it does not make much sense to | |
539 | derive the loop structure from it). */ | |
b8698a0f | 540 | |
89f8f30f | 541 | static edge |
9771b263 | 542 | find_subloop_latch_edge_by_profile (vec<edge> latches) |
89f8f30f ZD |
543 | { |
544 | unsigned i; | |
545 | edge e, me = NULL; | |
546 | gcov_type mcount = 0, tcount = 0; | |
547 | ||
9771b263 | 548 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f ZD |
549 | { |
550 | if (e->count > mcount) | |
551 | { | |
552 | me = e; | |
553 | mcount = e->count; | |
554 | } | |
555 | tcount += e->count; | |
556 | } | |
557 | ||
558 | if (tcount < HEAVY_EDGE_MIN_SAMPLES | |
559 | || (tcount - mcount) * HEAVY_EDGE_RATIO > tcount) | |
560 | return NULL; | |
561 | ||
562 | if (dump_file) | |
563 | fprintf (dump_file, | |
564 | "Found latch edge %d -> %d using profile information.\n", | |
565 | me->src->index, me->dest->index); | |
566 | return me; | |
567 | } | |
568 | ||
569 | /* Among LATCHES, guesses a latch edge of LOOP corresponding to subloop, based | |
570 | on the structure of induction variables. Returns this edge, or NULL if we | |
571 | do not find any. | |
572 | ||
573 | We are quite conservative, and look just for an obvious simple innermost | |
574 | loop (which is the case where we would lose the most performance by not | |
575 | disambiguating the loop). More precisely, we look for the following | |
576 | situation: The source of the chosen latch edge dominates sources of all | |
577 | the other latch edges. Additionally, the header does not contain a phi node | |
578 | such that the argument from the chosen edge is equal to the argument from | |
579 | another edge. */ | |
580 | ||
581 | static edge | |
9771b263 | 582 | find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, vec<edge> latches) |
89f8f30f | 583 | { |
9771b263 | 584 | edge e, latch = latches[0]; |
89f8f30f | 585 | unsigned i; |
538dd0b7 DM |
586 | gphi *phi; |
587 | gphi_iterator psi; | |
726a989a | 588 | tree lop; |
89f8f30f ZD |
589 | basic_block bb; |
590 | ||
591 | /* Find the candidate for the latch edge. */ | |
9771b263 | 592 | for (i = 1; latches.iterate (i, &e); i++) |
89f8f30f ZD |
593 | if (dominated_by_p (CDI_DOMINATORS, latch->src, e->src)) |
594 | latch = e; | |
595 | ||
596 | /* Verify that it dominates all the latch edges. */ | |
9771b263 | 597 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f ZD |
598 | if (!dominated_by_p (CDI_DOMINATORS, e->src, latch->src)) |
599 | return NULL; | |
600 | ||
601 | /* Check for a phi node that would deny that this is a latch edge of | |
602 | a subloop. */ | |
726a989a | 603 | for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) |
89f8f30f | 604 | { |
538dd0b7 | 605 | phi = psi.phi (); |
89f8f30f ZD |
606 | lop = PHI_ARG_DEF_FROM_EDGE (phi, latch); |
607 | ||
608 | /* Ignore the values that are not changed inside the subloop. */ | |
609 | if (TREE_CODE (lop) != SSA_NAME | |
610 | || SSA_NAME_DEF_STMT (lop) == phi) | |
611 | continue; | |
726a989a | 612 | bb = gimple_bb (SSA_NAME_DEF_STMT (lop)); |
89f8f30f ZD |
613 | if (!bb || !flow_bb_inside_loop_p (loop, bb)) |
614 | continue; | |
615 | ||
9771b263 | 616 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f ZD |
617 | if (e != latch |
618 | && PHI_ARG_DEF_FROM_EDGE (phi, e) == lop) | |
619 | return NULL; | |
620 | } | |
621 | ||
622 | if (dump_file) | |
623 | fprintf (dump_file, | |
624 | "Found latch edge %d -> %d using iv structure.\n", | |
625 | latch->src->index, latch->dest->index); | |
626 | return latch; | |
627 | } | |
628 | ||
629 | /* If we can determine that one of the several latch edges of LOOP behaves | |
630 | as a latch edge of a separate subloop, returns this edge. Otherwise | |
631 | returns NULL. */ | |
632 | ||
633 | static edge | |
634 | find_subloop_latch_edge (struct loop *loop) | |
635 | { | |
9771b263 | 636 | vec<edge> latches = get_loop_latch_edges (loop); |
89f8f30f ZD |
637 | edge latch = NULL; |
638 | ||
9771b263 | 639 | if (latches.length () > 1) |
89f8f30f ZD |
640 | { |
641 | latch = find_subloop_latch_edge_by_profile (latches); | |
642 | ||
643 | if (!latch | |
644 | /* We consider ivs to guess the latch edge only in SSA. Perhaps we | |
645 | should use cfghook for this, but it is hard to imagine it would | |
646 | be useful elsewhere. */ | |
647 | && current_ir_type () == IR_GIMPLE) | |
648 | latch = find_subloop_latch_edge_by_ivs (loop, latches); | |
649 | } | |
650 | ||
9771b263 | 651 | latches.release (); |
89f8f30f ZD |
652 | return latch; |
653 | } | |
654 | ||
655 | /* Callback for make_forwarder_block. Returns true if the edge E is marked | |
656 | in the set MFB_REIS_SET. */ | |
657 | ||
6e2830c3 | 658 | static hash_set<edge> *mfb_reis_set; |
89f8f30f ZD |
659 | static bool |
660 | mfb_redirect_edges_in_set (edge e) | |
661 | { | |
6e2830c3 | 662 | return mfb_reis_set->contains (e); |
89f8f30f ZD |
663 | } |
664 | ||
665 | /* Creates a subloop of LOOP with latch edge LATCH. */ | |
666 | ||
667 | static void | |
668 | form_subloop (struct loop *loop, edge latch) | |
669 | { | |
670 | edge_iterator ei; | |
671 | edge e, new_entry; | |
672 | struct loop *new_loop; | |
b8698a0f | 673 | |
6e2830c3 | 674 | mfb_reis_set = new hash_set<edge>; |
89f8f30f ZD |
675 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
676 | { | |
677 | if (e != latch) | |
6e2830c3 | 678 | mfb_reis_set->add (e); |
89f8f30f ZD |
679 | } |
680 | new_entry = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
681 | NULL); | |
6e2830c3 | 682 | delete mfb_reis_set; |
89f8f30f ZD |
683 | |
684 | loop->header = new_entry->src; | |
685 | ||
686 | /* Find the blocks and subloops that belong to the new loop, and add it to | |
687 | the appropriate place in the loop tree. */ | |
688 | new_loop = alloc_loop (); | |
689 | new_loop->header = new_entry->dest; | |
690 | new_loop->latch = latch->src; | |
691 | add_loop (new_loop, loop); | |
692 | } | |
693 | ||
694 | /* Make all the latch edges of LOOP to go to a single forwarder block -- | |
695 | a new latch of LOOP. */ | |
696 | ||
697 | static void | |
698 | merge_latch_edges (struct loop *loop) | |
699 | { | |
9771b263 | 700 | vec<edge> latches = get_loop_latch_edges (loop); |
89f8f30f ZD |
701 | edge latch, e; |
702 | unsigned i; | |
703 | ||
9771b263 | 704 | gcc_assert (latches.length () > 0); |
89f8f30f | 705 | |
9771b263 DN |
706 | if (latches.length () == 1) |
707 | loop->latch = latches[0]->src; | |
89f8f30f ZD |
708 | else |
709 | { | |
710 | if (dump_file) | |
711 | fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num); | |
712 | ||
6e2830c3 | 713 | mfb_reis_set = new hash_set<edge>; |
9771b263 | 714 | FOR_EACH_VEC_ELT (latches, i, e) |
6e2830c3 | 715 | mfb_reis_set->add (e); |
89f8f30f ZD |
716 | latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, |
717 | NULL); | |
6e2830c3 | 718 | delete mfb_reis_set; |
89f8f30f ZD |
719 | |
720 | loop->header = latch->dest; | |
721 | loop->latch = latch->src; | |
722 | } | |
723 | ||
9771b263 | 724 | latches.release (); |
89f8f30f ZD |
725 | } |
726 | ||
727 | /* LOOP may have several latch edges. Transform it into (possibly several) | |
728 | loops with single latch edge. */ | |
729 | ||
730 | static void | |
731 | disambiguate_multiple_latches (struct loop *loop) | |
732 | { | |
733 | edge e; | |
734 | ||
ea2c620c | 735 | /* We eliminate the multiple latches by splitting the header to the forwarder |
89f8f30f ZD |
736 | block F and the rest R, and redirecting the edges. There are two cases: |
737 | ||
738 | 1) If there is a latch edge E that corresponds to a subloop (we guess | |
739 | that based on profile -- if it is taken much more often than the | |
740 | remaining edges; and on trees, using the information about induction | |
741 | variables of the loops), we redirect E to R, all the remaining edges to | |
742 | F, then rescan the loops and try again for the outer loop. | |
743 | 2) If there is no such edge, we redirect all latch edges to F, and the | |
744 | entry edges to R, thus making F the single latch of the loop. */ | |
745 | ||
746 | if (dump_file) | |
747 | fprintf (dump_file, "Disambiguating loop %d with multiple latches\n", | |
748 | loop->num); | |
749 | ||
750 | /* During latch merging, we may need to redirect the entry edges to a new | |
751 | block. This would cause problems if the entry edge was the one from the | |
752 | entry block. To avoid having to handle this case specially, split | |
753 | such entry edge. */ | |
fefa31b5 | 754 | e = find_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), loop->header); |
89f8f30f ZD |
755 | if (e) |
756 | split_edge (e); | |
757 | ||
758 | while (1) | |
759 | { | |
760 | e = find_subloop_latch_edge (loop); | |
761 | if (!e) | |
762 | break; | |
763 | ||
764 | form_subloop (loop, e); | |
765 | } | |
766 | ||
767 | merge_latch_edges (loop); | |
768 | } | |
769 | ||
770 | /* Split loops with multiple latch edges. */ | |
771 | ||
772 | void | |
773 | disambiguate_loops_with_multiple_latches (void) | |
774 | { | |
89f8f30f ZD |
775 | struct loop *loop; |
776 | ||
f0bd40b1 | 777 | FOR_EACH_LOOP (loop, 0) |
89f8f30f ZD |
778 | { |
779 | if (!loop->latch) | |
780 | disambiguate_multiple_latches (loop); | |
781 | } | |
782 | } | |
783 | ||
da7d8304 | 784 | /* Return nonzero if basic block BB belongs to LOOP. */ |
2ecfd709 | 785 | bool |
ed7a4b4b | 786 | flow_bb_inside_loop_p (const struct loop *loop, const_basic_block bb) |
2ecfd709 ZD |
787 | { |
788 | struct loop *source_loop; | |
789 | ||
fefa31b5 DM |
790 | if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
791 | || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
2ecfd709 ZD |
792 | return 0; |
793 | ||
794 | source_loop = bb->loop_father; | |
795 | return loop == source_loop || flow_loop_nested_p (loop, source_loop); | |
796 | } | |
797 | ||
89f8f30f | 798 | /* Enumeration predicate for get_loop_body_with_size. */ |
2ecfd709 | 799 | static bool |
ed7a4b4b | 800 | glb_enum_p (const_basic_block bb, const void *glb_loop) |
2ecfd709 | 801 | { |
ed7a4b4b | 802 | const struct loop *const loop = (const struct loop *) glb_loop; |
89f8f30f ZD |
803 | return (bb != loop->header |
804 | && dominated_by_p (CDI_DOMINATORS, bb, loop->header)); | |
805 | } | |
806 | ||
807 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
808 | order against direction of edges from latch. Specially, if | |
809 | header != latch, latch is the 1-st block. LOOP cannot be the fake | |
810 | loop tree root, and its size must be at most MAX_SIZE. The blocks | |
811 | in the LOOP body are stored to BODY, and the size of the LOOP is | |
812 | returned. */ | |
813 | ||
814 | unsigned | |
815 | get_loop_body_with_size (const struct loop *loop, basic_block *body, | |
816 | unsigned max_size) | |
817 | { | |
818 | return dfs_enumerate_from (loop->header, 1, glb_enum_p, | |
ed7a4b4b | 819 | body, max_size, loop); |
2ecfd709 ZD |
820 | } |
821 | ||
8d28e87d ZD |
822 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs |
823 | order against direction of edges from latch. Specially, if | |
824 | header != latch, latch is the 1-st block. */ | |
89f8f30f | 825 | |
2ecfd709 | 826 | basic_block * |
d329e058 | 827 | get_loop_body (const struct loop *loop) |
2ecfd709 | 828 | { |
89f8f30f | 829 | basic_block *body, bb; |
3d436d2a | 830 | unsigned tv = 0; |
2ecfd709 | 831 | |
341c100f | 832 | gcc_assert (loop->num_nodes); |
2ecfd709 | 833 | |
c302207e | 834 | body = XNEWVEC (basic_block, loop->num_nodes); |
2ecfd709 | 835 | |
fefa31b5 | 836 | if (loop->latch == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
2ecfd709 | 837 | { |
89f8f30f ZD |
838 | /* There may be blocks unreachable from EXIT_BLOCK, hence we need to |
839 | special-case the fake loop that contains the whole function. */ | |
0cae8d31 | 840 | gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks_for_fn (cfun)); |
89f8f30f | 841 | body[tv++] = loop->header; |
fefa31b5 | 842 | body[tv++] = EXIT_BLOCK_PTR_FOR_FN (cfun); |
11cd3bed | 843 | FOR_EACH_BB_FN (bb, cfun) |
89f8f30f | 844 | body[tv++] = bb; |
2ecfd709 | 845 | } |
89f8f30f ZD |
846 | else |
847 | tv = get_loop_body_with_size (loop, body, loop->num_nodes); | |
2ecfd709 | 848 | |
341c100f | 849 | gcc_assert (tv == loop->num_nodes); |
89f8f30f | 850 | return body; |
2ecfd709 ZD |
851 | } |
852 | ||
50654f6c ZD |
853 | /* Fills dominance descendants inside LOOP of the basic block BB into |
854 | array TOVISIT from index *TV. */ | |
855 | ||
856 | static void | |
857 | fill_sons_in_loop (const struct loop *loop, basic_block bb, | |
858 | basic_block *tovisit, int *tv) | |
859 | { | |
860 | basic_block son, postpone = NULL; | |
861 | ||
862 | tovisit[(*tv)++] = bb; | |
863 | for (son = first_dom_son (CDI_DOMINATORS, bb); | |
864 | son; | |
865 | son = next_dom_son (CDI_DOMINATORS, son)) | |
866 | { | |
867 | if (!flow_bb_inside_loop_p (loop, son)) | |
868 | continue; | |
869 | ||
870 | if (dominated_by_p (CDI_DOMINATORS, loop->latch, son)) | |
871 | { | |
872 | postpone = son; | |
873 | continue; | |
874 | } | |
875 | fill_sons_in_loop (loop, son, tovisit, tv); | |
876 | } | |
877 | ||
878 | if (postpone) | |
879 | fill_sons_in_loop (loop, postpone, tovisit, tv); | |
880 | } | |
881 | ||
882 | /* Gets body of a LOOP (that must be different from the outermost loop) | |
883 | sorted by dominance relation. Additionally, if a basic block s dominates | |
884 | the latch, then only blocks dominated by s are be after it. */ | |
885 | ||
886 | basic_block * | |
887 | get_loop_body_in_dom_order (const struct loop *loop) | |
888 | { | |
889 | basic_block *tovisit; | |
890 | int tv; | |
891 | ||
341c100f | 892 | gcc_assert (loop->num_nodes); |
50654f6c | 893 | |
c302207e | 894 | tovisit = XNEWVEC (basic_block, loop->num_nodes); |
50654f6c | 895 | |
fefa31b5 | 896 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
50654f6c ZD |
897 | |
898 | tv = 0; | |
899 | fill_sons_in_loop (loop, loop->header, tovisit, &tv); | |
900 | ||
341c100f | 901 | gcc_assert (tv == (int) loop->num_nodes); |
50654f6c ZD |
902 | |
903 | return tovisit; | |
904 | } | |
905 | ||
e855c69d AB |
906 | /* Gets body of a LOOP sorted via provided BB_COMPARATOR. */ |
907 | ||
908 | basic_block * | |
b8698a0f | 909 | get_loop_body_in_custom_order (const struct loop *loop, |
e855c69d AB |
910 | int (*bb_comparator) (const void *, const void *)) |
911 | { | |
912 | basic_block *bbs = get_loop_body (loop); | |
913 | ||
914 | qsort (bbs, loop->num_nodes, sizeof (basic_block), bb_comparator); | |
915 | ||
916 | return bbs; | |
917 | } | |
918 | ||
40923b20 DP |
919 | /* Get body of a LOOP in breadth first sort order. */ |
920 | ||
921 | basic_block * | |
922 | get_loop_body_in_bfs_order (const struct loop *loop) | |
923 | { | |
924 | basic_block *blocks; | |
925 | basic_block bb; | |
926 | bitmap visited; | |
927 | unsigned int i = 0; | |
928 | unsigned int vc = 1; | |
929 | ||
341c100f | 930 | gcc_assert (loop->num_nodes); |
fefa31b5 | 931 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
40923b20 | 932 | |
c302207e | 933 | blocks = XNEWVEC (basic_block, loop->num_nodes); |
8bdbfff5 | 934 | visited = BITMAP_ALLOC (NULL); |
40923b20 DP |
935 | |
936 | bb = loop->header; | |
937 | while (i < loop->num_nodes) | |
938 | { | |
939 | edge e; | |
628f6a4e | 940 | edge_iterator ei; |
c22cacf3 | 941 | |
fcaa4ca4 NF |
942 | if (bitmap_set_bit (visited, bb->index)) |
943 | /* This basic block is now visited */ | |
944 | blocks[i++] = bb; | |
c22cacf3 | 945 | |
628f6a4e | 946 | FOR_EACH_EDGE (e, ei, bb->succs) |
c22cacf3 MS |
947 | { |
948 | if (flow_bb_inside_loop_p (loop, e->dest)) | |
949 | { | |
fcaa4ca4 NF |
950 | if (bitmap_set_bit (visited, e->dest->index)) |
951 | blocks[i++] = e->dest; | |
c22cacf3 MS |
952 | } |
953 | } | |
954 | ||
d9c16ed2 | 955 | gcc_assert (i > vc); |
c22cacf3 | 956 | |
40923b20 DP |
957 | bb = blocks[vc++]; |
958 | } | |
c22cacf3 | 959 | |
8bdbfff5 | 960 | BITMAP_FREE (visited); |
40923b20 DP |
961 | return blocks; |
962 | } | |
963 | ||
6270df4c ZD |
964 | /* Hash function for struct loop_exit. */ |
965 | ||
2a22f99c TS |
966 | hashval_t |
967 | loop_exit_hasher::hash (loop_exit *exit) | |
6270df4c | 968 | { |
6270df4c ZD |
969 | return htab_hash_pointer (exit->e); |
970 | } | |
971 | ||
972 | /* Equality function for struct loop_exit. Compares with edge. */ | |
973 | ||
2a22f99c TS |
974 | bool |
975 | loop_exit_hasher::equal (loop_exit *exit, edge e) | |
6270df4c | 976 | { |
6270df4c ZD |
977 | return exit->e == e; |
978 | } | |
979 | ||
980 | /* Frees the list of loop exit descriptions EX. */ | |
981 | ||
2a22f99c TS |
982 | void |
983 | loop_exit_hasher::remove (loop_exit *exit) | |
6270df4c | 984 | { |
2a22f99c | 985 | loop_exit *next; |
6270df4c ZD |
986 | for (; exit; exit = next) |
987 | { | |
988 | next = exit->next_e; | |
b8698a0f | 989 | |
6270df4c ZD |
990 | exit->next->prev = exit->prev; |
991 | exit->prev->next = exit->next; | |
992 | ||
9e2f83a5 | 993 | ggc_free (exit); |
6270df4c ZD |
994 | } |
995 | } | |
996 | ||
997 | /* Returns the list of records for E as an exit of a loop. */ | |
998 | ||
999 | static struct loop_exit * | |
1000 | get_exit_descriptions (edge e) | |
1001 | { | |
2a22f99c | 1002 | return current_loops->exits->find_with_hash (e, htab_hash_pointer (e)); |
6270df4c ZD |
1003 | } |
1004 | ||
1005 | /* Updates the lists of loop exits in that E appears. | |
1006 | If REMOVED is true, E is being removed, and we | |
1007 | just remove it from the lists of exits. | |
1008 | If NEW_EDGE is true and E is not a loop exit, we | |
1009 | do not try to remove it from loop exit lists. */ | |
1010 | ||
1011 | void | |
1012 | rescan_loop_exit (edge e, bool new_edge, bool removed) | |
1013 | { | |
6270df4c ZD |
1014 | struct loop_exit *exits = NULL, *exit; |
1015 | struct loop *aloop, *cloop; | |
1016 | ||
f87000d0 | 1017 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c ZD |
1018 | return; |
1019 | ||
1020 | if (!removed | |
1021 | && e->src->loop_father != NULL | |
1022 | && e->dest->loop_father != NULL | |
1023 | && !flow_bb_inside_loop_p (e->src->loop_father, e->dest)) | |
1024 | { | |
1025 | cloop = find_common_loop (e->src->loop_father, e->dest->loop_father); | |
1026 | for (aloop = e->src->loop_father; | |
1027 | aloop != cloop; | |
9ba025a2 | 1028 | aloop = loop_outer (aloop)) |
6270df4c | 1029 | { |
766090c2 | 1030 | exit = ggc_alloc<loop_exit> (); |
6270df4c ZD |
1031 | exit->e = e; |
1032 | ||
9e2f83a5 ZD |
1033 | exit->next = aloop->exits->next; |
1034 | exit->prev = aloop->exits; | |
6270df4c ZD |
1035 | exit->next->prev = exit; |
1036 | exit->prev->next = exit; | |
1037 | ||
1038 | exit->next_e = exits; | |
1039 | exits = exit; | |
1040 | } | |
b8698a0f | 1041 | } |
6270df4c ZD |
1042 | |
1043 | if (!exits && new_edge) | |
1044 | return; | |
1045 | ||
2a22f99c TS |
1046 | loop_exit **slot |
1047 | = current_loops->exits->find_slot_with_hash (e, htab_hash_pointer (e), | |
1048 | exits ? INSERT : NO_INSERT); | |
6270df4c ZD |
1049 | if (!slot) |
1050 | return; | |
1051 | ||
1052 | if (exits) | |
1053 | { | |
1054 | if (*slot) | |
2a22f99c | 1055 | loop_exit_hasher::remove (*slot); |
6270df4c ZD |
1056 | *slot = exits; |
1057 | } | |
1058 | else | |
2a22f99c | 1059 | current_loops->exits->clear_slot (slot); |
6270df4c ZD |
1060 | } |
1061 | ||
1062 | /* For each loop, record list of exit edges, and start maintaining these | |
1063 | lists. */ | |
1064 | ||
1065 | void | |
1066 | record_loop_exits (void) | |
1067 | { | |
1068 | basic_block bb; | |
1069 | edge_iterator ei; | |
1070 | edge e; | |
1071 | ||
4839cb59 ZD |
1072 | if (!current_loops) |
1073 | return; | |
1074 | ||
f87000d0 | 1075 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1076 | return; |
f87000d0 | 1077 | loops_state_set (LOOPS_HAVE_RECORDED_EXITS); |
6270df4c ZD |
1078 | |
1079 | gcc_assert (current_loops->exits == NULL); | |
2a22f99c TS |
1080 | current_loops->exits |
1081 | = hash_table<loop_exit_hasher>::create_ggc (2 * number_of_loops (cfun)); | |
6270df4c | 1082 | |
11cd3bed | 1083 | FOR_EACH_BB_FN (bb, cfun) |
6270df4c ZD |
1084 | { |
1085 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1086 | { | |
1087 | rescan_loop_exit (e, true, false); | |
1088 | } | |
1089 | } | |
1090 | } | |
1091 | ||
1092 | /* Dumps information about the exit in *SLOT to FILE. | |
1093 | Callback for htab_traverse. */ | |
1094 | ||
2a22f99c TS |
1095 | int |
1096 | dump_recorded_exit (loop_exit **slot, FILE *file) | |
6270df4c | 1097 | { |
2a22f99c | 1098 | struct loop_exit *exit = *slot; |
6270df4c ZD |
1099 | unsigned n = 0; |
1100 | edge e = exit->e; | |
1101 | ||
1102 | for (; exit != NULL; exit = exit->next_e) | |
1103 | n++; | |
1104 | ||
2a22f99c | 1105 | fprintf (file, "Edge %d->%d exits %u loops\n", |
6270df4c ZD |
1106 | e->src->index, e->dest->index, n); |
1107 | ||
1108 | return 1; | |
1109 | } | |
1110 | ||
1111 | /* Dumps the recorded exits of loops to FILE. */ | |
1112 | ||
1113 | extern void dump_recorded_exits (FILE *); | |
1114 | void | |
1115 | dump_recorded_exits (FILE *file) | |
1116 | { | |
1117 | if (!current_loops->exits) | |
1118 | return; | |
2a22f99c | 1119 | current_loops->exits->traverse<FILE *, dump_recorded_exit> (file); |
6270df4c ZD |
1120 | } |
1121 | ||
1122 | /* Releases lists of loop exits. */ | |
1123 | ||
1124 | void | |
1125 | release_recorded_exits (void) | |
1126 | { | |
f87000d0 | 1127 | gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)); |
2a22f99c | 1128 | current_loops->exits->empty (); |
6270df4c | 1129 | current_loops->exits = NULL; |
f87000d0 | 1130 | loops_state_clear (LOOPS_HAVE_RECORDED_EXITS); |
6270df4c ZD |
1131 | } |
1132 | ||
ca83d385 ZD |
1133 | /* Returns the list of the exit edges of a LOOP. */ |
1134 | ||
9771b263 | 1135 | vec<edge> |
ca83d385 | 1136 | get_loop_exit_edges (const struct loop *loop) |
35b07080 | 1137 | { |
6e1aa848 | 1138 | vec<edge> edges = vNULL; |
ca83d385 ZD |
1139 | edge e; |
1140 | unsigned i; | |
1141 | basic_block *body; | |
628f6a4e | 1142 | edge_iterator ei; |
6270df4c | 1143 | struct loop_exit *exit; |
35b07080 | 1144 | |
fefa31b5 | 1145 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
35b07080 | 1146 | |
6270df4c ZD |
1147 | /* If we maintain the lists of exits, use them. Otherwise we must |
1148 | scan the body of the loop. */ | |
f87000d0 | 1149 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1150 | { |
9e2f83a5 | 1151 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
9771b263 | 1152 | edges.safe_push (exit->e); |
6270df4c ZD |
1153 | } |
1154 | else | |
1155 | { | |
1156 | body = get_loop_body (loop); | |
1157 | for (i = 0; i < loop->num_nodes; i++) | |
1158 | FOR_EACH_EDGE (e, ei, body[i]->succs) | |
1159 | { | |
1160 | if (!flow_bb_inside_loop_p (loop, e->dest)) | |
9771b263 | 1161 | edges.safe_push (e); |
6270df4c ZD |
1162 | } |
1163 | free (body); | |
1164 | } | |
35b07080 ZD |
1165 | |
1166 | return edges; | |
1167 | } | |
1168 | ||
50654f6c ZD |
1169 | /* Counts the number of conditional branches inside LOOP. */ |
1170 | ||
1171 | unsigned | |
1172 | num_loop_branches (const struct loop *loop) | |
1173 | { | |
1174 | unsigned i, n; | |
1175 | basic_block * body; | |
1176 | ||
fefa31b5 | 1177 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
50654f6c ZD |
1178 | |
1179 | body = get_loop_body (loop); | |
1180 | n = 0; | |
1181 | for (i = 0; i < loop->num_nodes; i++) | |
628f6a4e | 1182 | if (EDGE_COUNT (body[i]->succs) >= 2) |
50654f6c ZD |
1183 | n++; |
1184 | free (body); | |
1185 | ||
1186 | return n; | |
1187 | } | |
1188 | ||
2ecfd709 ZD |
1189 | /* Adds basic block BB to LOOP. */ |
1190 | void | |
d329e058 AJ |
1191 | add_bb_to_loop (basic_block bb, struct loop *loop) |
1192 | { | |
9ba025a2 ZD |
1193 | unsigned i; |
1194 | loop_p ploop; | |
6270df4c ZD |
1195 | edge_iterator ei; |
1196 | edge e; | |
1197 | ||
1198 | gcc_assert (bb->loop_father == NULL); | |
1199 | bb->loop_father = loop; | |
6270df4c | 1200 | loop->num_nodes++; |
9771b263 | 1201 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9ba025a2 | 1202 | ploop->num_nodes++; |
6270df4c ZD |
1203 | |
1204 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1205 | { | |
1206 | rescan_loop_exit (e, true, false); | |
1207 | } | |
1208 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1209 | { | |
1210 | rescan_loop_exit (e, true, false); | |
1211 | } | |
598ec7bd | 1212 | } |
2ecfd709 ZD |
1213 | |
1214 | /* Remove basic block BB from loops. */ | |
1215 | void | |
d329e058 AJ |
1216 | remove_bb_from_loops (basic_block bb) |
1217 | { | |
9771b263 | 1218 | unsigned i; |
6270df4c | 1219 | struct loop *loop = bb->loop_father; |
9ba025a2 | 1220 | loop_p ploop; |
6270df4c ZD |
1221 | edge_iterator ei; |
1222 | edge e; | |
1223 | ||
1224 | gcc_assert (loop != NULL); | |
1225 | loop->num_nodes--; | |
9771b263 | 1226 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9ba025a2 | 1227 | ploop->num_nodes--; |
6270df4c | 1228 | bb->loop_father = NULL; |
6270df4c ZD |
1229 | |
1230 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1231 | { | |
1232 | rescan_loop_exit (e, false, true); | |
1233 | } | |
1234 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1235 | { | |
1236 | rescan_loop_exit (e, false, true); | |
1237 | } | |
a310245f | 1238 | } |
2ecfd709 ZD |
1239 | |
1240 | /* Finds nearest common ancestor in loop tree for given loops. */ | |
1241 | struct loop * | |
d329e058 | 1242 | find_common_loop (struct loop *loop_s, struct loop *loop_d) |
2ecfd709 | 1243 | { |
9ba025a2 ZD |
1244 | unsigned sdepth, ddepth; |
1245 | ||
2ecfd709 ZD |
1246 | if (!loop_s) return loop_d; |
1247 | if (!loop_d) return loop_s; | |
d329e058 | 1248 | |
9ba025a2 ZD |
1249 | sdepth = loop_depth (loop_s); |
1250 | ddepth = loop_depth (loop_d); | |
1251 | ||
1252 | if (sdepth < ddepth) | |
9771b263 | 1253 | loop_d = (*loop_d->superloops)[sdepth]; |
9ba025a2 | 1254 | else if (sdepth > ddepth) |
9771b263 | 1255 | loop_s = (*loop_s->superloops)[ddepth]; |
2ecfd709 ZD |
1256 | |
1257 | while (loop_s != loop_d) | |
1258 | { | |
9ba025a2 ZD |
1259 | loop_s = loop_outer (loop_s); |
1260 | loop_d = loop_outer (loop_d); | |
2ecfd709 ZD |
1261 | } |
1262 | return loop_s; | |
1263 | } | |
1264 | ||
42fd6772 ZD |
1265 | /* Removes LOOP from structures and frees its data. */ |
1266 | ||
1267 | void | |
1268 | delete_loop (struct loop *loop) | |
1269 | { | |
1270 | /* Remove the loop from structure. */ | |
1271 | flow_loop_tree_node_remove (loop); | |
1272 | ||
1273 | /* Remove loop from loops array. */ | |
9771b263 | 1274 | (*current_loops->larray)[loop->num] = NULL; |
42fd6772 ZD |
1275 | |
1276 | /* Free loop data. */ | |
1277 | flow_loop_free (loop); | |
1278 | } | |
1279 | ||
3d436d2a | 1280 | /* Cancels the LOOP; it must be innermost one. */ |
b00bf166 KH |
1281 | |
1282 | static void | |
d73be268 | 1283 | cancel_loop (struct loop *loop) |
3d436d2a ZD |
1284 | { |
1285 | basic_block *bbs; | |
1286 | unsigned i; | |
9ba025a2 | 1287 | struct loop *outer = loop_outer (loop); |
3d436d2a | 1288 | |
341c100f | 1289 | gcc_assert (!loop->inner); |
3d436d2a ZD |
1290 | |
1291 | /* Move blocks up one level (they should be removed as soon as possible). */ | |
1292 | bbs = get_loop_body (loop); | |
1293 | for (i = 0; i < loop->num_nodes; i++) | |
9ba025a2 | 1294 | bbs[i]->loop_father = outer; |
3d436d2a | 1295 | |
b78384e0 | 1296 | free (bbs); |
42fd6772 | 1297 | delete_loop (loop); |
3d436d2a ZD |
1298 | } |
1299 | ||
1300 | /* Cancels LOOP and all its subloops. */ | |
1301 | void | |
d73be268 | 1302 | cancel_loop_tree (struct loop *loop) |
3d436d2a ZD |
1303 | { |
1304 | while (loop->inner) | |
d73be268 ZD |
1305 | cancel_loop_tree (loop->inner); |
1306 | cancel_loop (loop); | |
3d436d2a ZD |
1307 | } |
1308 | ||
d73be268 | 1309 | /* Checks that information about loops is correct |
e0bb17a8 | 1310 | -- sizes of loops are all right |
2ecfd709 ZD |
1311 | -- results of get_loop_body really belong to the loop |
1312 | -- loop header have just single entry edge and single latch edge | |
1313 | -- loop latches have only single successor that is header of their loop | |
3d436d2a | 1314 | -- irreducible loops are correctly marked |
cc360b36 | 1315 | -- the cached loop depth and loop father of each bb is correct |
2ecfd709 | 1316 | */ |
24e47c76 | 1317 | DEBUG_FUNCTION void |
d73be268 | 1318 | verify_loop_structure (void) |
2ecfd709 | 1319 | { |
3d436d2a ZD |
1320 | unsigned *sizes, i, j; |
1321 | sbitmap irreds; | |
a271b42d | 1322 | basic_block bb, *bbs; |
2ecfd709 ZD |
1323 | struct loop *loop; |
1324 | int err = 0; | |
35b07080 | 1325 | edge e; |
0fc822d0 | 1326 | unsigned num = number_of_loops (cfun); |
6270df4c | 1327 | struct loop_exit *exit, *mexit; |
7d776ee2 | 1328 | bool dom_available = dom_info_available_p (CDI_DOMINATORS); |
0375167b | 1329 | sbitmap visited; |
2ecfd709 | 1330 | |
a9e0d843 RB |
1331 | if (loops_state_satisfies_p (LOOPS_NEED_FIXUP)) |
1332 | { | |
1333 | error ("loop verification on loop tree that needs fixup"); | |
1334 | err = 1; | |
1335 | } | |
1336 | ||
7d776ee2 RG |
1337 | /* We need up-to-date dominators, compute or verify them. */ |
1338 | if (!dom_available) | |
1339 | calculate_dominance_info (CDI_DOMINATORS); | |
1340 | else | |
1341 | verify_dominators (CDI_DOMINATORS); | |
510dbcce | 1342 | |
b0dd8c90 RB |
1343 | /* Check the loop tree root. */ |
1344 | if (current_loops->tree_root->header != ENTRY_BLOCK_PTR_FOR_FN (cfun) | |
1345 | || current_loops->tree_root->latch != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
1346 | || (current_loops->tree_root->num_nodes | |
1347 | != (unsigned) n_basic_blocks_for_fn (cfun))) | |
1348 | { | |
1349 | error ("corrupt loop tree root"); | |
1350 | err = 1; | |
1351 | } | |
1352 | ||
f64fb0fa | 1353 | /* Check the headers. */ |
11cd3bed | 1354 | FOR_EACH_BB_FN (bb, cfun) |
a271b42d | 1355 | if (bb_loop_header_p (bb)) |
f64fb0fa | 1356 | { |
a271b42d RB |
1357 | if (bb->loop_father->header == NULL) |
1358 | { | |
1359 | error ("loop with header %d marked for removal", bb->index); | |
1360 | err = 1; | |
1361 | } | |
1362 | else if (bb->loop_father->header != bb) | |
1363 | { | |
1364 | error ("loop with header %d not in loop tree", bb->index); | |
1365 | err = 1; | |
1366 | } | |
1367 | } | |
1368 | else if (bb->loop_father->header == bb) | |
1369 | { | |
1370 | error ("non-loop with header %d not marked for removal", bb->index); | |
f64fb0fa MP |
1371 | err = 1; |
1372 | } | |
1373 | ||
a271b42d | 1374 | /* Check the recorded loop father and sizes of loops. */ |
8b1c6fd7 | 1375 | visited = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
f61e445a | 1376 | bitmap_clear (visited); |
0cae8d31 | 1377 | bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); |
f0bd40b1 | 1378 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) |
cc360b36 | 1379 | { |
a271b42d | 1380 | unsigned n; |
cc360b36 | 1381 | |
a271b42d RB |
1382 | if (loop->header == NULL) |
1383 | { | |
1384 | error ("removed loop %d in loop tree", loop->num); | |
1385 | err = 1; | |
1386 | continue; | |
1387 | } | |
1388 | ||
0cae8d31 | 1389 | n = get_loop_body_with_size (loop, bbs, n_basic_blocks_for_fn (cfun)); |
a271b42d RB |
1390 | if (loop->num_nodes != n) |
1391 | { | |
1392 | error ("size of loop %d should be %d, not %d", | |
1393 | loop->num, n, loop->num_nodes); | |
1394 | err = 1; | |
1395 | } | |
1396 | ||
1397 | for (j = 0; j < n; j++) | |
cc360b36 SB |
1398 | { |
1399 | bb = bbs[j]; | |
1400 | ||
0375167b RB |
1401 | if (!flow_bb_inside_loop_p (loop, bb)) |
1402 | { | |
1403 | error ("bb %d does not belong to loop %d", | |
1404 | bb->index, loop->num); | |
1405 | err = 1; | |
1406 | } | |
1407 | ||
cc360b36 | 1408 | /* Ignore this block if it is in an inner loop. */ |
d7c028c0 | 1409 | if (bitmap_bit_p (visited, bb->index)) |
cc360b36 | 1410 | continue; |
d7c028c0 | 1411 | bitmap_set_bit (visited, bb->index); |
cc360b36 SB |
1412 | |
1413 | if (bb->loop_father != loop) | |
1414 | { | |
1415 | error ("bb %d has father loop %d, should be loop %d", | |
1416 | bb->index, bb->loop_father->num, loop->num); | |
1417 | err = 1; | |
1418 | } | |
1419 | } | |
cc360b36 | 1420 | } |
a271b42d | 1421 | free (bbs); |
0375167b | 1422 | sbitmap_free (visited); |
2ecfd709 ZD |
1423 | |
1424 | /* Check headers and latches. */ | |
f0bd40b1 | 1425 | FOR_EACH_LOOP (loop, 0) |
2ecfd709 | 1426 | { |
42fd6772 | 1427 | i = loop->num; |
a271b42d RB |
1428 | if (loop->header == NULL) |
1429 | continue; | |
0375167b RB |
1430 | if (!bb_loop_header_p (loop->header)) |
1431 | { | |
1432 | error ("loop %d%'s header is not a loop header", i); | |
1433 | err = 1; | |
1434 | } | |
f87000d0 | 1435 | if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
628f6a4e | 1436 | && EDGE_COUNT (loop->header->preds) != 2) |
2ecfd709 | 1437 | { |
d8a07487 | 1438 | error ("loop %d%'s header does not have exactly 2 entries", i); |
2ecfd709 ZD |
1439 | err = 1; |
1440 | } | |
6aaf596b RB |
1441 | if (loop->latch) |
1442 | { | |
1443 | if (!find_edge (loop->latch, loop->header)) | |
1444 | { | |
1445 | error ("loop %d%'s latch does not have an edge to its header", i); | |
1446 | err = 1; | |
1447 | } | |
1448 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, loop->header)) | |
1449 | { | |
1450 | error ("loop %d%'s latch is not dominated by its header", i); | |
1451 | err = 1; | |
1452 | } | |
1453 | } | |
f87000d0 | 1454 | if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
2ecfd709 | 1455 | { |
c5cbcccf | 1456 | if (!single_succ_p (loop->latch)) |
2ecfd709 | 1457 | { |
d8a07487 | 1458 | error ("loop %d%'s latch does not have exactly 1 successor", i); |
2ecfd709 ZD |
1459 | err = 1; |
1460 | } | |
c5cbcccf | 1461 | if (single_succ (loop->latch) != loop->header) |
2ecfd709 | 1462 | { |
d8a07487 | 1463 | error ("loop %d%'s latch does not have header as successor", i); |
2ecfd709 ZD |
1464 | err = 1; |
1465 | } | |
1466 | if (loop->latch->loop_father != loop) | |
1467 | { | |
d8a07487 | 1468 | error ("loop %d%'s latch does not belong directly to it", i); |
2ecfd709 ZD |
1469 | err = 1; |
1470 | } | |
1471 | } | |
1472 | if (loop->header->loop_father != loop) | |
1473 | { | |
d8a07487 | 1474 | error ("loop %d%'s header does not belong directly to it", i); |
2ecfd709 ZD |
1475 | err = 1; |
1476 | } | |
f87000d0 | 1477 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) |
35b07080 ZD |
1478 | && (loop_latch_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)) |
1479 | { | |
d8a07487 | 1480 | error ("loop %d%'s latch is marked as part of irreducible region", i); |
35b07080 ZD |
1481 | err = 1; |
1482 | } | |
2ecfd709 ZD |
1483 | } |
1484 | ||
3d436d2a | 1485 | /* Check irreducible loops. */ |
f87000d0 | 1486 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
3d436d2a ZD |
1487 | { |
1488 | /* Record old info. */ | |
8b1c6fd7 | 1489 | irreds = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
11cd3bed | 1490 | FOR_EACH_BB_FN (bb, cfun) |
35b07080 | 1491 | { |
628f6a4e | 1492 | edge_iterator ei; |
35b07080 | 1493 | if (bb->flags & BB_IRREDUCIBLE_LOOP) |
d7c028c0 | 1494 | bitmap_set_bit (irreds, bb->index); |
35b07080 | 1495 | else |
d7c028c0 | 1496 | bitmap_clear_bit (irreds, bb->index); |
628f6a4e | 1497 | FOR_EACH_EDGE (e, ei, bb->succs) |
35b07080 | 1498 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) |
d329e058 | 1499 | e->flags |= EDGE_ALL_FLAGS + 1; |
35b07080 | 1500 | } |
3d436d2a ZD |
1501 | |
1502 | /* Recount it. */ | |
d73be268 | 1503 | mark_irreducible_loops (); |
3d436d2a ZD |
1504 | |
1505 | /* Compare. */ | |
11cd3bed | 1506 | FOR_EACH_BB_FN (bb, cfun) |
3d436d2a | 1507 | { |
628f6a4e BE |
1508 | edge_iterator ei; |
1509 | ||
3d436d2a | 1510 | if ((bb->flags & BB_IRREDUCIBLE_LOOP) |
d7c028c0 | 1511 | && !bitmap_bit_p (irreds, bb->index)) |
3d436d2a | 1512 | { |
ab532386 | 1513 | error ("basic block %d should be marked irreducible", bb->index); |
3d436d2a ZD |
1514 | err = 1; |
1515 | } | |
1516 | else if (!(bb->flags & BB_IRREDUCIBLE_LOOP) | |
d7c028c0 | 1517 | && bitmap_bit_p (irreds, bb->index)) |
3d436d2a | 1518 | { |
ab532386 | 1519 | error ("basic block %d should not be marked irreducible", bb->index); |
3d436d2a ZD |
1520 | err = 1; |
1521 | } | |
628f6a4e | 1522 | FOR_EACH_EDGE (e, ei, bb->succs) |
35b07080 ZD |
1523 | { |
1524 | if ((e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1525 | && !(e->flags & (EDGE_ALL_FLAGS + 1))) | |
1526 | { | |
ab532386 | 1527 | error ("edge from %d to %d should be marked irreducible", |
35b07080 ZD |
1528 | e->src->index, e->dest->index); |
1529 | err = 1; | |
1530 | } | |
1531 | else if (!(e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1532 | && (e->flags & (EDGE_ALL_FLAGS + 1))) | |
1533 | { | |
ab532386 | 1534 | error ("edge from %d to %d should not be marked irreducible", |
35b07080 ZD |
1535 | e->src->index, e->dest->index); |
1536 | err = 1; | |
1537 | } | |
1538 | e->flags &= ~(EDGE_ALL_FLAGS + 1); | |
1539 | } | |
3d436d2a ZD |
1540 | } |
1541 | free (irreds); | |
1542 | } | |
1543 | ||
6270df4c | 1544 | /* Check the recorded loop exits. */ |
f0bd40b1 | 1545 | FOR_EACH_LOOP (loop, 0) |
82b85a85 | 1546 | { |
9e2f83a5 | 1547 | if (!loop->exits || loop->exits->e != NULL) |
6270df4c ZD |
1548 | { |
1549 | error ("corrupted head of the exits list of loop %d", | |
1550 | loop->num); | |
1551 | err = 1; | |
1552 | } | |
1553 | else | |
1554 | { | |
1555 | /* Check that the list forms a cycle, and all elements except | |
1556 | for the head are nonnull. */ | |
9e2f83a5 | 1557 | for (mexit = loop->exits, exit = mexit->next, i = 0; |
6270df4c ZD |
1558 | exit->e && exit != mexit; |
1559 | exit = exit->next) | |
1560 | { | |
1561 | if (i++ & 1) | |
1562 | mexit = mexit->next; | |
1563 | } | |
1564 | ||
9e2f83a5 | 1565 | if (exit != loop->exits) |
6270df4c ZD |
1566 | { |
1567 | error ("corrupted exits list of loop %d", loop->num); | |
1568 | err = 1; | |
1569 | } | |
1570 | } | |
1571 | ||
f87000d0 | 1572 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1573 | { |
9e2f83a5 | 1574 | if (loop->exits->next != loop->exits) |
6270df4c ZD |
1575 | { |
1576 | error ("nonempty exits list of loop %d, but exits are not recorded", | |
1577 | loop->num); | |
1578 | err = 1; | |
1579 | } | |
1580 | } | |
1581 | } | |
1582 | ||
f87000d0 | 1583 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c ZD |
1584 | { |
1585 | unsigned n_exits = 0, eloops; | |
1586 | ||
a271b42d | 1587 | sizes = XCNEWVEC (unsigned, num); |
42fd6772 | 1588 | memset (sizes, 0, sizeof (unsigned) * num); |
11cd3bed | 1589 | FOR_EACH_BB_FN (bb, cfun) |
82b85a85 | 1590 | { |
628f6a4e | 1591 | edge_iterator ei; |
d73be268 | 1592 | if (bb->loop_father == current_loops->tree_root) |
82b85a85 | 1593 | continue; |
628f6a4e | 1594 | FOR_EACH_EDGE (e, ei, bb->succs) |
82b85a85 | 1595 | { |
82b85a85 ZD |
1596 | if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) |
1597 | continue; | |
1598 | ||
6270df4c ZD |
1599 | n_exits++; |
1600 | exit = get_exit_descriptions (e); | |
1601 | if (!exit) | |
1602 | { | |
d8a07487 | 1603 | error ("exit %d->%d not recorded", |
6270df4c ZD |
1604 | e->src->index, e->dest->index); |
1605 | err = 1; | |
1606 | } | |
1607 | eloops = 0; | |
1608 | for (; exit; exit = exit->next_e) | |
1609 | eloops++; | |
1610 | ||
82b85a85 | 1611 | for (loop = bb->loop_father; |
661bc682 RB |
1612 | loop != e->dest->loop_father |
1613 | /* When a loop exit is also an entry edge which | |
1614 | can happen when avoiding CFG manipulations | |
1615 | then the last loop exited is the outer loop | |
1616 | of the loop entered. */ | |
1617 | && loop != loop_outer (e->dest->loop_father); | |
9ba025a2 | 1618 | loop = loop_outer (loop)) |
82b85a85 | 1619 | { |
6270df4c | 1620 | eloops--; |
82b85a85 | 1621 | sizes[loop->num]++; |
6270df4c ZD |
1622 | } |
1623 | ||
1624 | if (eloops != 0) | |
1625 | { | |
d8a07487 | 1626 | error ("wrong list of exited loops for edge %d->%d", |
6270df4c ZD |
1627 | e->src->index, e->dest->index); |
1628 | err = 1; | |
82b85a85 ZD |
1629 | } |
1630 | } | |
1631 | } | |
1632 | ||
2a22f99c | 1633 | if (n_exits != current_loops->exits->elements ()) |
82b85a85 | 1634 | { |
d8a07487 | 1635 | error ("too many loop exits recorded"); |
6270df4c ZD |
1636 | err = 1; |
1637 | } | |
82b85a85 | 1638 | |
f0bd40b1 | 1639 | FOR_EACH_LOOP (loop, 0) |
6270df4c ZD |
1640 | { |
1641 | eloops = 0; | |
9e2f83a5 | 1642 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
6270df4c ZD |
1643 | eloops++; |
1644 | if (eloops != sizes[loop->num]) | |
82b85a85 | 1645 | { |
6270df4c ZD |
1646 | error ("%d exits recorded for loop %d (having %d exits)", |
1647 | eloops, loop->num, sizes[loop->num]); | |
82b85a85 ZD |
1648 | err = 1; |
1649 | } | |
1650 | } | |
a271b42d RB |
1651 | |
1652 | free (sizes); | |
82b85a85 ZD |
1653 | } |
1654 | ||
341c100f | 1655 | gcc_assert (!err); |
82b85a85 | 1656 | |
7d776ee2 RG |
1657 | if (!dom_available) |
1658 | free_dominance_info (CDI_DOMINATORS); | |
2ecfd709 ZD |
1659 | } |
1660 | ||
1661 | /* Returns latch edge of LOOP. */ | |
1662 | edge | |
d329e058 | 1663 | loop_latch_edge (const struct loop *loop) |
2ecfd709 | 1664 | { |
9ff3d2de | 1665 | return find_edge (loop->latch, loop->header); |
402209ff | 1666 | } |
2ecfd709 ZD |
1667 | |
1668 | /* Returns preheader edge of LOOP. */ | |
1669 | edge | |
d329e058 | 1670 | loop_preheader_edge (const struct loop *loop) |
2ecfd709 ZD |
1671 | { |
1672 | edge e; | |
628f6a4e | 1673 | edge_iterator ei; |
2ecfd709 | 1674 | |
f87000d0 | 1675 | gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)); |
c7b852c8 | 1676 | |
628f6a4e BE |
1677 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
1678 | if (e->src != loop->latch) | |
1679 | break; | |
2ecfd709 ZD |
1680 | |
1681 | return e; | |
1682 | } | |
70388d94 ZD |
1683 | |
1684 | /* Returns true if E is an exit of LOOP. */ | |
1685 | ||
1686 | bool | |
ed7a4b4b | 1687 | loop_exit_edge_p (const struct loop *loop, const_edge e) |
70388d94 ZD |
1688 | { |
1689 | return (flow_bb_inside_loop_p (loop, e->src) | |
1690 | && !flow_bb_inside_loop_p (loop, e->dest)); | |
1691 | } | |
ac8f6c69 ZD |
1692 | |
1693 | /* Returns the single exit edge of LOOP, or NULL if LOOP has either no exit | |
6270df4c ZD |
1694 | or more than one exit. If loops do not have the exits recorded, NULL |
1695 | is returned always. */ | |
ac8f6c69 ZD |
1696 | |
1697 | edge | |
1698 | single_exit (const struct loop *loop) | |
1699 | { | |
9e2f83a5 | 1700 | struct loop_exit *exit = loop->exits->next; |
ac8f6c69 | 1701 | |
f87000d0 | 1702 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1703 | return NULL; |
ac8f6c69 | 1704 | |
9e2f83a5 | 1705 | if (exit->e && exit->next == loop->exits) |
6270df4c ZD |
1706 | return exit->e; |
1707 | else | |
1708 | return NULL; | |
ac8f6c69 | 1709 | } |
f8bf9252 | 1710 | |
f4ce375d | 1711 | /* Returns true when BB has an incoming edge exiting LOOP. */ |
f8bf9252 SP |
1712 | |
1713 | bool | |
f4ce375d | 1714 | loop_exits_to_bb_p (struct loop *loop, basic_block bb) |
f8bf9252 SP |
1715 | { |
1716 | edge e; | |
1717 | edge_iterator ei; | |
1718 | ||
1719 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1720 | if (loop_exit_edge_p (loop, e)) | |
1721 | return true; | |
1722 | ||
1723 | return false; | |
1724 | } | |
f4ce375d VK |
1725 | |
1726 | /* Returns true when BB has an outgoing edge exiting LOOP. */ | |
1727 | ||
1728 | bool | |
1729 | loop_exits_from_bb_p (struct loop *loop, basic_block bb) | |
1730 | { | |
1731 | edge e; | |
1732 | edge_iterator ei; | |
1733 | ||
1734 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1735 | if (loop_exit_edge_p (loop, e)) | |
1736 | return true; | |
1737 | ||
1738 | return false; | |
1739 | } | |
e25a6711 TJ |
1740 | |
1741 | /* Return location corresponding to the loop control condition if possible. */ | |
1742 | ||
1743 | location_t | |
1744 | get_loop_location (struct loop *loop) | |
1745 | { | |
9d56eaa2 | 1746 | rtx_insn *insn = NULL; |
e25a6711 TJ |
1747 | struct niter_desc *desc = NULL; |
1748 | edge exit; | |
1749 | ||
1750 | /* For a for or while loop, we would like to return the location | |
1751 | of the for or while statement, if possible. To do this, look | |
1752 | for the branch guarding the loop back-edge. */ | |
1753 | ||
1754 | /* If this is a simple loop with an in_edge, then the loop control | |
1755 | branch is typically at the end of its source. */ | |
1756 | desc = get_simple_loop_desc (loop); | |
1757 | if (desc->in_edge) | |
1758 | { | |
1759 | FOR_BB_INSNS_REVERSE (desc->in_edge->src, insn) | |
1760 | { | |
1761 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1762 | return INSN_LOCATION (insn); | |
1763 | } | |
1764 | } | |
1765 | /* If loop has a single exit, then the loop control branch | |
1766 | must be at the end of its source. */ | |
1767 | if ((exit = single_exit (loop))) | |
1768 | { | |
1769 | FOR_BB_INSNS_REVERSE (exit->src, insn) | |
1770 | { | |
1771 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1772 | return INSN_LOCATION (insn); | |
1773 | } | |
1774 | } | |
1775 | /* Next check the latch, to see if it is non-empty. */ | |
1776 | FOR_BB_INSNS_REVERSE (loop->latch, insn) | |
1777 | { | |
1778 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1779 | return INSN_LOCATION (insn); | |
1780 | } | |
1781 | /* Finally, if none of the above identifies the loop control branch, | |
1782 | return the first location in the loop header. */ | |
1783 | FOR_BB_INSNS (loop->header, insn) | |
1784 | { | |
1785 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1786 | return INSN_LOCATION (insn); | |
1787 | } | |
1788 | /* If all else fails, simply return the current function location. */ | |
1789 | return DECL_SOURCE_LOCATION (current_function_decl); | |
1790 | } | |
1791 | ||
71343877 AM |
1792 | /* Records that every statement in LOOP is executed I_BOUND times. |
1793 | REALISTIC is true if I_BOUND is expected to be close to the real number | |
1794 | of iterations. UPPER is true if we are sure the loop iterates at most | |
1795 | I_BOUND times. */ | |
1796 | ||
1797 | void | |
807e902e KZ |
1798 | record_niter_bound (struct loop *loop, const widest_int &i_bound, |
1799 | bool realistic, bool upper) | |
71343877 AM |
1800 | { |
1801 | /* Update the bounds only when there is no previous estimation, or when the | |
1802 | current estimation is smaller. */ | |
1803 | if (upper | |
1804 | && (!loop->any_upper_bound | |
807e902e | 1805 | || wi::ltu_p (i_bound, loop->nb_iterations_upper_bound))) |
71343877 AM |
1806 | { |
1807 | loop->any_upper_bound = true; | |
1808 | loop->nb_iterations_upper_bound = i_bound; | |
1809 | } | |
1810 | if (realistic | |
1811 | && (!loop->any_estimate | |
807e902e | 1812 | || wi::ltu_p (i_bound, loop->nb_iterations_estimate))) |
71343877 AM |
1813 | { |
1814 | loop->any_estimate = true; | |
1815 | loop->nb_iterations_estimate = i_bound; | |
1816 | } | |
1817 | ||
1818 | /* If an upper bound is smaller than the realistic estimate of the | |
1819 | number of iterations, use the upper bound instead. */ | |
1820 | if (loop->any_upper_bound | |
1821 | && loop->any_estimate | |
807e902e KZ |
1822 | && wi::ltu_p (loop->nb_iterations_upper_bound, |
1823 | loop->nb_iterations_estimate)) | |
71343877 AM |
1824 | loop->nb_iterations_estimate = loop->nb_iterations_upper_bound; |
1825 | } | |
1826 | ||
1ef88893 | 1827 | /* Similar to get_estimated_loop_iterations, but returns the estimate only |
71343877 AM |
1828 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate |
1829 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
1830 | ||
1831 | HOST_WIDE_INT | |
1ef88893 | 1832 | get_estimated_loop_iterations_int (struct loop *loop) |
71343877 | 1833 | { |
807e902e | 1834 | widest_int nit; |
71343877 AM |
1835 | HOST_WIDE_INT hwi_nit; |
1836 | ||
1837 | if (!get_estimated_loop_iterations (loop, &nit)) | |
1838 | return -1; | |
1839 | ||
807e902e | 1840 | if (!wi::fits_shwi_p (nit)) |
71343877 AM |
1841 | return -1; |
1842 | hwi_nit = nit.to_shwi (); | |
1843 | ||
1844 | return hwi_nit < 0 ? -1 : hwi_nit; | |
1845 | } | |
1846 | ||
1847 | /* Returns an upper bound on the number of executions of statements | |
1848 | in the LOOP. For statements before the loop exit, this exceeds | |
1849 | the number of execution of the latch by one. */ | |
1850 | ||
1851 | HOST_WIDE_INT | |
1852 | max_stmt_executions_int (struct loop *loop) | |
1853 | { | |
1ef88893 | 1854 | HOST_WIDE_INT nit = get_max_loop_iterations_int (loop); |
71343877 AM |
1855 | HOST_WIDE_INT snit; |
1856 | ||
1857 | if (nit == -1) | |
1858 | return -1; | |
1859 | ||
1860 | snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
1861 | ||
1862 | /* If the computation overflows, return -1. */ | |
1863 | return snit < 0 ? -1 : snit; | |
1864 | } | |
1865 | ||
1866 | /* Sets NIT to the estimated number of executions of the latch of the | |
1867 | LOOP. If we have no reliable estimate, the function returns false, otherwise | |
1868 | returns true. */ | |
1869 | ||
1870 | bool | |
807e902e | 1871 | get_estimated_loop_iterations (struct loop *loop, widest_int *nit) |
71343877 AM |
1872 | { |
1873 | /* Even if the bound is not recorded, possibly we can derrive one from | |
1874 | profile. */ | |
1875 | if (!loop->any_estimate) | |
1876 | { | |
1877 | if (loop->header->count) | |
1878 | { | |
807e902e | 1879 | *nit = gcov_type_to_wide_int |
71343877 AM |
1880 | (expected_loop_iterations_unbounded (loop) + 1); |
1881 | return true; | |
1882 | } | |
1883 | return false; | |
1884 | } | |
1885 | ||
1886 | *nit = loop->nb_iterations_estimate; | |
1887 | return true; | |
1888 | } | |
1889 | ||
1890 | /* Sets NIT to an upper bound for the maximum number of executions of the | |
1891 | latch of the LOOP. If we have no reliable estimate, the function returns | |
1892 | false, otherwise returns true. */ | |
1893 | ||
1894 | bool | |
807e902e | 1895 | get_max_loop_iterations (struct loop *loop, widest_int *nit) |
71343877 AM |
1896 | { |
1897 | if (!loop->any_upper_bound) | |
1898 | return false; | |
1899 | ||
1900 | *nit = loop->nb_iterations_upper_bound; | |
1901 | return true; | |
1902 | } | |
1ef88893 AM |
1903 | |
1904 | /* Similar to get_max_loop_iterations, but returns the estimate only | |
1905 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
1906 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
1907 | ||
1908 | HOST_WIDE_INT | |
1909 | get_max_loop_iterations_int (struct loop *loop) | |
1910 | { | |
807e902e | 1911 | widest_int nit; |
1ef88893 AM |
1912 | HOST_WIDE_INT hwi_nit; |
1913 | ||
1914 | if (!get_max_loop_iterations (loop, &nit)) | |
1915 | return -1; | |
1916 | ||
807e902e | 1917 | if (!wi::fits_shwi_p (nit)) |
1ef88893 AM |
1918 | return -1; |
1919 | hwi_nit = nit.to_shwi (); | |
1920 | ||
1921 | return hwi_nit < 0 ? -1 : hwi_nit; | |
1922 | } | |
1923 | ||
4484a35a | 1924 | /* Returns the loop depth of the loop BB belongs to. */ |
1ef88893 | 1925 | |
4484a35a AM |
1926 | int |
1927 | bb_loop_depth (const_basic_block bb) | |
1928 | { | |
1929 | return bb->loop_father ? loop_depth (bb->loop_father) : 0; | |
1930 | } | |
08c13199 RB |
1931 | |
1932 | /* Marks LOOP for removal and sets LOOPS_NEED_FIXUP. */ | |
1933 | ||
1934 | void | |
1935 | mark_loop_for_removal (loop_p loop) | |
1936 | { | |
024660c5 RB |
1937 | if (loop->header == NULL) |
1938 | return; | |
e4ca2139 | 1939 | loop->former_header = loop->header; |
08c13199 RB |
1940 | loop->header = NULL; |
1941 | loop->latch = NULL; | |
1942 | loops_state_set (LOOPS_NEED_FIXUP); | |
1943 | } |