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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 | 22 | #include "coretypes.h" |
c7131fb2 | 23 | #include "backend.h" |
9fdcd34e | 24 | #include "cfghooks.h" |
c7131fb2 AM |
25 | #include "tree.h" |
26 | #include "gimple.h" | |
402209ff | 27 | #include "rtl.h" |
60393bbc | 28 | #include "cfganal.h" |
3d436d2a | 29 | #include "cfgloop.h" |
718f9c0f | 30 | #include "diagnostic-core.h" |
3d436d2a | 31 | #include "flags.h" |
40e23961 | 32 | #include "fold-const.h" |
2fb9a547 | 33 | #include "internal-fn.h" |
5be5c238 | 34 | #include "gimple-iterator.h" |
442b4905 | 35 | #include "gimple-ssa.h" |
7ee2468b | 36 | #include "dumpfile.h" |
f470c378 | 37 | |
d73be268 | 38 | static void flow_loops_cfg_dump (FILE *); |
402209ff JH |
39 | \f |
40 | /* Dump loop related CFG information. */ | |
41 | ||
42 | static void | |
d73be268 | 43 | flow_loops_cfg_dump (FILE *file) |
402209ff | 44 | { |
e0082a72 | 45 | basic_block bb; |
402209ff | 46 | |
d73be268 | 47 | if (!file) |
402209ff JH |
48 | return; |
49 | ||
11cd3bed | 50 | FOR_EACH_BB_FN (bb, cfun) |
402209ff JH |
51 | { |
52 | edge succ; | |
628f6a4e | 53 | edge_iterator ei; |
402209ff | 54 | |
e0082a72 | 55 | fprintf (file, ";; %d succs { ", bb->index); |
628f6a4e | 56 | FOR_EACH_EDGE (succ, ei, bb->succs) |
0b17ab2f | 57 | fprintf (file, "%d ", succ->dest->index); |
2ecfd709 | 58 | fprintf (file, "}\n"); |
402209ff | 59 | } |
402209ff JH |
60 | } |
61 | ||
da7d8304 | 62 | /* Return nonzero if the nodes of LOOP are a subset of OUTER. */ |
402209ff | 63 | |
2ecfd709 | 64 | bool |
d329e058 | 65 | flow_loop_nested_p (const struct loop *outer, const struct loop *loop) |
402209ff | 66 | { |
9ba025a2 ZD |
67 | unsigned odepth = loop_depth (outer); |
68 | ||
69 | return (loop_depth (loop) > odepth | |
9771b263 | 70 | && (*loop->superloops)[odepth] == outer); |
402209ff JH |
71 | } |
72 | ||
1ad03593 SP |
73 | /* Returns the loop such that LOOP is nested DEPTH (indexed from zero) |
74 | loops within LOOP. */ | |
a7e5372d ZD |
75 | |
76 | struct loop * | |
77 | superloop_at_depth (struct loop *loop, unsigned depth) | |
78 | { | |
9ba025a2 ZD |
79 | unsigned ldepth = loop_depth (loop); |
80 | ||
81 | gcc_assert (depth <= ldepth); | |
a7e5372d | 82 | |
9ba025a2 | 83 | if (depth == ldepth) |
a7e5372d ZD |
84 | return loop; |
85 | ||
9771b263 | 86 | return (*loop->superloops)[depth]; |
a7e5372d ZD |
87 | } |
88 | ||
89f8f30f ZD |
89 | /* Returns the list of the latch edges of LOOP. */ |
90 | ||
9771b263 | 91 | static vec<edge> |
89f8f30f ZD |
92 | get_loop_latch_edges (const struct loop *loop) |
93 | { | |
94 | edge_iterator ei; | |
95 | edge e; | |
6e1aa848 | 96 | vec<edge> ret = vNULL; |
89f8f30f ZD |
97 | |
98 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
99 | { | |
100 | if (dominated_by_p (CDI_DOMINATORS, e->src, loop->header)) | |
9771b263 | 101 | ret.safe_push (e); |
89f8f30f ZD |
102 | } |
103 | ||
104 | return ret; | |
105 | } | |
106 | ||
402209ff JH |
107 | /* Dump the loop information specified by LOOP to the stream FILE |
108 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
109 | ||
110 | void | |
d329e058 AJ |
111 | flow_loop_dump (const struct loop *loop, FILE *file, |
112 | void (*loop_dump_aux) (const struct loop *, FILE *, int), | |
113 | int verbose) | |
402209ff | 114 | { |
2ecfd709 | 115 | basic_block *bbs; |
3d436d2a | 116 | unsigned i; |
9771b263 | 117 | vec<edge> latches; |
89f8f30f | 118 | edge e; |
2ecfd709 | 119 | |
402209ff JH |
120 | if (! loop || ! loop->header) |
121 | return; | |
122 | ||
7490e6c4 | 123 | fprintf (file, ";;\n;; Loop %d\n", loop->num); |
402209ff | 124 | |
89f8f30f ZD |
125 | fprintf (file, ";; header %d, ", loop->header->index); |
126 | if (loop->latch) | |
127 | fprintf (file, "latch %d\n", loop->latch->index); | |
128 | else | |
129 | { | |
130 | fprintf (file, "multiple latches:"); | |
131 | latches = get_loop_latch_edges (loop); | |
9771b263 | 132 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f | 133 | fprintf (file, " %d", e->src->index); |
9771b263 | 134 | latches.release (); |
89f8f30f ZD |
135 | fprintf (file, "\n"); |
136 | } | |
137 | ||
99f8a411 | 138 | fprintf (file, ";; depth %d, outer %ld\n", |
9ba025a2 ZD |
139 | loop_depth (loop), (long) (loop_outer (loop) |
140 | ? loop_outer (loop)->num : -1)); | |
402209ff | 141 | |
2ecfd709 ZD |
142 | fprintf (file, ";; nodes:"); |
143 | bbs = get_loop_body (loop); | |
144 | for (i = 0; i < loop->num_nodes; i++) | |
145 | fprintf (file, " %d", bbs[i]->index); | |
146 | free (bbs); | |
147 | fprintf (file, "\n"); | |
5f0d2358 | 148 | |
402209ff JH |
149 | if (loop_dump_aux) |
150 | loop_dump_aux (loop, file, verbose); | |
151 | } | |
152 | ||
d73be268 | 153 | /* Dump the loop information about loops to the stream FILE, |
402209ff JH |
154 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ |
155 | ||
156 | void | |
d73be268 | 157 | flow_loops_dump (FILE *file, void (*loop_dump_aux) (const struct loop *, FILE *, int), int verbose) |
402209ff | 158 | { |
42fd6772 | 159 | struct loop *loop; |
402209ff | 160 | |
d73be268 | 161 | if (!current_loops || ! file) |
402209ff JH |
162 | return; |
163 | ||
0fc822d0 | 164 | fprintf (file, ";; %d loops found\n", number_of_loops (cfun)); |
2ecfd709 | 165 | |
f0bd40b1 | 166 | FOR_EACH_LOOP (loop, LI_INCLUDE_ROOT) |
402209ff | 167 | { |
2ecfd709 | 168 | flow_loop_dump (loop, file, loop_dump_aux, verbose); |
402209ff JH |
169 | } |
170 | ||
171 | if (verbose) | |
d73be268 | 172 | flow_loops_cfg_dump (file); |
402209ff JH |
173 | } |
174 | ||
2ecfd709 | 175 | /* Free data allocated for LOOP. */ |
9e2f83a5 | 176 | |
35b07080 | 177 | void |
d329e058 | 178 | flow_loop_free (struct loop *loop) |
2ecfd709 | 179 | { |
6270df4c ZD |
180 | struct loop_exit *exit, *next; |
181 | ||
9771b263 | 182 | vec_free (loop->superloops); |
6270df4c ZD |
183 | |
184 | /* Break the list of the loop exit records. They will be freed when the | |
185 | corresponding edge is rescanned or removed, and this avoids | |
186 | accessing the (already released) head of the list stored in the | |
187 | loop structure. */ | |
9e2f83a5 | 188 | for (exit = loop->exits->next; exit != loop->exits; exit = next) |
6270df4c ZD |
189 | { |
190 | next = exit->next; | |
191 | exit->next = exit; | |
192 | exit->prev = exit; | |
193 | } | |
9e2f83a5 ZD |
194 | |
195 | ggc_free (loop->exits); | |
196 | ggc_free (loop); | |
2ecfd709 ZD |
197 | } |
198 | ||
402209ff JH |
199 | /* Free all the memory allocated for LOOPS. */ |
200 | ||
201 | void | |
d329e058 | 202 | flow_loops_free (struct loops *loops) |
402209ff | 203 | { |
42fd6772 | 204 | if (loops->larray) |
402209ff | 205 | { |
3d436d2a | 206 | unsigned i; |
42fd6772 | 207 | loop_p loop; |
402209ff JH |
208 | |
209 | /* Free the loop descriptors. */ | |
9771b263 | 210 | FOR_EACH_VEC_SAFE_ELT (loops->larray, i, loop) |
402209ff | 211 | { |
2ecfd709 ZD |
212 | if (!loop) |
213 | continue; | |
214 | ||
215 | flow_loop_free (loop); | |
402209ff | 216 | } |
5f0d2358 | 217 | |
9771b263 | 218 | vec_free (loops->larray); |
402209ff JH |
219 | } |
220 | } | |
221 | ||
2ecfd709 ZD |
222 | /* Find the nodes contained within the LOOP with header HEADER. |
223 | Return the number of nodes within the loop. */ | |
402209ff | 224 | |
2b271002 | 225 | int |
d329e058 | 226 | flow_loop_nodes_find (basic_block header, struct loop *loop) |
402209ff | 227 | { |
6e1aa848 | 228 | vec<basic_block> stack = vNULL; |
2ecfd709 | 229 | int num_nodes = 1; |
89f8f30f ZD |
230 | edge latch; |
231 | edge_iterator latch_ei; | |
402209ff | 232 | |
2ecfd709 | 233 | header->loop_father = loop; |
402209ff | 234 | |
89f8f30f | 235 | FOR_EACH_EDGE (latch, latch_ei, loop->header->preds) |
402209ff | 236 | { |
89f8f30f ZD |
237 | if (latch->src->loop_father == loop |
238 | || !dominated_by_p (CDI_DOMINATORS, latch->src, loop->header)) | |
239 | continue; | |
240 | ||
402209ff | 241 | num_nodes++; |
9771b263 | 242 | stack.safe_push (latch->src); |
89f8f30f | 243 | latch->src->loop_father = loop; |
d329e058 | 244 | |
9771b263 | 245 | while (!stack.is_empty ()) |
402209ff | 246 | { |
2ecfd709 ZD |
247 | basic_block node; |
248 | edge e; | |
628f6a4e | 249 | edge_iterator ei; |
402209ff | 250 | |
9771b263 | 251 | node = stack.pop (); |
d329e058 | 252 | |
628f6a4e | 253 | FOR_EACH_EDGE (e, ei, node->preds) |
402209ff | 254 | { |
2ecfd709 ZD |
255 | basic_block ancestor = e->src; |
256 | ||
89f8f30f | 257 | if (ancestor->loop_father != loop) |
2ecfd709 ZD |
258 | { |
259 | ancestor->loop_father = loop; | |
2ecfd709 | 260 | num_nodes++; |
9771b263 | 261 | stack.safe_push (ancestor); |
2ecfd709 | 262 | } |
402209ff JH |
263 | } |
264 | } | |
265 | } | |
9771b263 | 266 | stack.release (); |
89f8f30f | 267 | |
402209ff JH |
268 | return num_nodes; |
269 | } | |
270 | ||
9ba025a2 ZD |
271 | /* Records the vector of superloops of the loop LOOP, whose immediate |
272 | superloop is FATHER. */ | |
273 | ||
35b07080 | 274 | static void |
9ba025a2 | 275 | establish_preds (struct loop *loop, struct loop *father) |
35b07080 | 276 | { |
9ba025a2 ZD |
277 | loop_p ploop; |
278 | unsigned depth = loop_depth (father) + 1; | |
279 | unsigned i; | |
a310245f | 280 | |
9771b263 DN |
281 | loop->superloops = 0; |
282 | vec_alloc (loop->superloops, depth); | |
283 | FOR_EACH_VEC_SAFE_ELT (father->superloops, i, ploop) | |
284 | loop->superloops->quick_push (ploop); | |
285 | loop->superloops->quick_push (father); | |
35b07080 ZD |
286 | |
287 | for (ploop = loop->inner; ploop; ploop = ploop->next) | |
9ba025a2 | 288 | establish_preds (ploop, loop); |
35b07080 ZD |
289 | } |
290 | ||
2ecfd709 | 291 | /* Add LOOP to the loop hierarchy tree where FATHER is father of the |
35b07080 ZD |
292 | added loop. If LOOP has some children, take care of that their |
293 | pred field will be initialized correctly. */ | |
402209ff | 294 | |
2ecfd709 | 295 | void |
d329e058 | 296 | flow_loop_tree_node_add (struct loop *father, struct loop *loop) |
402209ff | 297 | { |
2ecfd709 ZD |
298 | loop->next = father->inner; |
299 | father->inner = loop; | |
2ecfd709 | 300 | |
9ba025a2 | 301 | establish_preds (loop, father); |
402209ff JH |
302 | } |
303 | ||
2ecfd709 | 304 | /* Remove LOOP from the loop hierarchy tree. */ |
402209ff | 305 | |
2ecfd709 | 306 | void |
d329e058 | 307 | flow_loop_tree_node_remove (struct loop *loop) |
402209ff | 308 | { |
2ecfd709 | 309 | struct loop *prev, *father; |
402209ff | 310 | |
9ba025a2 | 311 | father = loop_outer (loop); |
402209ff | 312 | |
2ecfd709 ZD |
313 | /* Remove loop from the list of sons. */ |
314 | if (father->inner == loop) | |
315 | father->inner = loop->next; | |
316 | else | |
317 | { | |
9ba025a2 ZD |
318 | for (prev = father->inner; prev->next != loop; prev = prev->next) |
319 | continue; | |
2ecfd709 ZD |
320 | prev->next = loop->next; |
321 | } | |
402209ff | 322 | |
9771b263 | 323 | loop->superloops = NULL; |
402209ff JH |
324 | } |
325 | ||
6270df4c ZD |
326 | /* Allocates and returns new loop structure. */ |
327 | ||
328 | struct loop * | |
329 | alloc_loop (void) | |
330 | { | |
766090c2 | 331 | struct loop *loop = ggc_cleared_alloc<struct loop> (); |
9e2f83a5 | 332 | |
766090c2 | 333 | loop->exits = ggc_cleared_alloc<loop_exit> (); |
9e2f83a5 | 334 | loop->exits->next = loop->exits->prev = loop->exits; |
204b560f | 335 | loop->can_be_parallel = false; |
807e902e KZ |
336 | loop->nb_iterations_upper_bound = 0; |
337 | loop->nb_iterations_estimate = 0; | |
6270df4c ZD |
338 | return loop; |
339 | } | |
340 | ||
4ed88ee3 ZD |
341 | /* Initializes loops structure LOOPS, reserving place for NUM_LOOPS loops |
342 | (including the root of the loop tree). */ | |
343 | ||
dd366ec3 RB |
344 | void |
345 | init_loops_structure (struct function *fn, | |
346 | struct loops *loops, unsigned num_loops) | |
4ed88ee3 ZD |
347 | { |
348 | struct loop *root; | |
349 | ||
350 | memset (loops, 0, sizeof *loops); | |
9771b263 | 351 | vec_alloc (loops->larray, num_loops); |
4ed88ee3 ZD |
352 | |
353 | /* Dummy loop containing whole function. */ | |
354 | root = alloc_loop (); | |
0cae8d31 | 355 | root->num_nodes = n_basic_blocks_for_fn (fn); |
fefa31b5 DM |
356 | root->latch = EXIT_BLOCK_PTR_FOR_FN (fn); |
357 | root->header = ENTRY_BLOCK_PTR_FOR_FN (fn); | |
358 | ENTRY_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
359 | EXIT_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
4ed88ee3 | 360 | |
9771b263 | 361 | loops->larray->quick_push (root); |
4ed88ee3 ZD |
362 | loops->tree_root = root; |
363 | } | |
364 | ||
0375167b RB |
365 | /* Returns whether HEADER is a loop header. */ |
366 | ||
367 | bool | |
368 | bb_loop_header_p (basic_block header) | |
369 | { | |
370 | edge_iterator ei; | |
371 | edge e; | |
372 | ||
373 | /* If we have an abnormal predecessor, do not consider the | |
374 | loop (not worth the problems). */ | |
375 | if (bb_has_abnormal_pred (header)) | |
376 | return false; | |
377 | ||
378 | /* Look for back edges where a predecessor is dominated | |
379 | by this block. A natural loop has a single entry | |
380 | node (header) that dominates all the nodes in the | |
381 | loop. It also has single back edge to the header | |
382 | from a latch node. */ | |
383 | FOR_EACH_EDGE (e, ei, header->preds) | |
384 | { | |
385 | basic_block latch = e->src; | |
fefa31b5 | 386 | if (latch != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
0375167b RB |
387 | && dominated_by_p (CDI_DOMINATORS, latch, header)) |
388 | return true; | |
389 | } | |
390 | ||
391 | return false; | |
392 | } | |
393 | ||
5f0d2358 | 394 | /* Find all the natural loops in the function and save in LOOPS structure and |
391886c8 | 395 | recalculate loop_father information in basic block structures. |
0375167b RB |
396 | If LOOPS is non-NULL then the loop structures for already recorded loops |
397 | will be re-used and their number will not change. We assume that no | |
398 | stale loops exist in LOOPS. | |
399 | When LOOPS is NULL it is allocated and re-built from scratch. | |
400 | Return the built LOOPS structure. */ | |
402209ff | 401 | |
0375167b | 402 | struct loops * |
70388d94 | 403 | flow_loops_find (struct loops *loops) |
402209ff | 404 | { |
0375167b | 405 | bool from_scratch = (loops == NULL); |
402209ff | 406 | int *rc_order; |
0375167b RB |
407 | int b; |
408 | unsigned i; | |
402209ff | 409 | |
4ed88ee3 ZD |
410 | /* Ensure that the dominators are computed. */ |
411 | calculate_dominance_info (CDI_DOMINATORS); | |
402209ff | 412 | |
0375167b | 413 | if (!loops) |
4ed88ee3 | 414 | { |
766090c2 | 415 | loops = ggc_cleared_alloc<struct loops> (); |
dd366ec3 | 416 | init_loops_structure (cfun, loops, 1); |
4ed88ee3 | 417 | } |
402209ff | 418 | |
0375167b RB |
419 | /* Ensure that loop exits were released. */ |
420 | gcc_assert (loops->exits == NULL); | |
402209ff | 421 | |
0375167b RB |
422 | /* Taking care of this degenerate case makes the rest of |
423 | this code simpler. */ | |
0cae8d31 | 424 | if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) |
0375167b | 425 | return loops; |
2ecfd709 | 426 | |
0375167b | 427 | /* The root loop node contains all basic-blocks. */ |
0cae8d31 | 428 | loops->tree_root->num_nodes = n_basic_blocks_for_fn (cfun); |
d329e058 | 429 | |
0375167b RB |
430 | /* Compute depth first search order of the CFG so that outer |
431 | natural loops will be found before inner natural loops. */ | |
0cae8d31 | 432 | rc_order = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); |
0375167b | 433 | pre_and_rev_post_order_compute (NULL, rc_order, false); |
16f2b86a | 434 | |
0375167b RB |
435 | /* Gather all loop headers in reverse completion order and allocate |
436 | loop structures for loops that are not already present. */ | |
ef062b13 | 437 | auto_vec<loop_p> larray (loops->larray->length ()); |
0cae8d31 | 438 | for (b = 0; b < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; b++) |
0375167b | 439 | { |
06e28de2 | 440 | basic_block header = BASIC_BLOCK_FOR_FN (cfun, rc_order[b]); |
0375167b | 441 | if (bb_loop_header_p (header)) |
402209ff | 442 | { |
0375167b | 443 | struct loop *loop; |
2ecfd709 | 444 | |
0375167b RB |
445 | /* The current active loop tree has valid loop-fathers for |
446 | header blocks. */ | |
447 | if (!from_scratch | |
448 | && header->loop_father->header == header) | |
2ecfd709 | 449 | { |
0375167b RB |
450 | loop = header->loop_father; |
451 | /* If we found an existing loop remove it from the | |
452 | loop tree. It is going to be inserted again | |
453 | below. */ | |
454 | flow_loop_tree_node_remove (loop); | |
2ecfd709 | 455 | } |
0375167b RB |
456 | else |
457 | { | |
458 | /* Otherwise allocate a new loop structure for the loop. */ | |
459 | loop = alloc_loop (); | |
460 | /* ??? We could re-use unused loop slots here. */ | |
461 | loop->num = loops->larray->length (); | |
462 | vec_safe_push (loops->larray, loop); | |
463 | loop->header = header; | |
464 | ||
465 | if (!from_scratch | |
466 | && dump_file && (dump_flags & TDF_DETAILS)) | |
467 | fprintf (dump_file, "flow_loops_find: discovered new " | |
468 | "loop %d with header %d\n", | |
469 | loop->num, header->index); | |
470 | } | |
6aaf596b RB |
471 | /* Reset latch, we recompute it below. */ |
472 | loop->latch = NULL; | |
0375167b | 473 | larray.safe_push (loop); |
402209ff | 474 | } |
402209ff | 475 | |
0375167b RB |
476 | /* Make blocks part of the loop root node at start. */ |
477 | header->loop_father = loops->tree_root; | |
478 | } | |
2ecfd709 | 479 | |
0375167b | 480 | free (rc_order); |
2ecfd709 | 481 | |
0375167b RB |
482 | /* Now iterate over the loops found, insert them into the loop tree |
483 | and assign basic-block ownership. */ | |
484 | for (i = 0; i < larray.length (); ++i) | |
402209ff | 485 | { |
0375167b RB |
486 | struct loop *loop = larray[i]; |
487 | basic_block header = loop->header; | |
488 | edge_iterator ei; | |
489 | edge e; | |
402209ff | 490 | |
0375167b RB |
491 | flow_loop_tree_node_add (header->loop_father, loop); |
492 | loop->num_nodes = flow_loop_nodes_find (loop->header, loop); | |
402209ff | 493 | |
0375167b RB |
494 | /* Look for the latch for this header block, if it has just a |
495 | single one. */ | |
496 | FOR_EACH_EDGE (e, ei, header->preds) | |
402209ff | 497 | { |
0375167b | 498 | basic_block latch = e->src; |
89f8f30f | 499 | |
0375167b | 500 | if (flow_bb_inside_loop_p (loop, latch)) |
402209ff | 501 | { |
0375167b | 502 | if (loop->latch != NULL) |
402209ff | 503 | { |
0375167b RB |
504 | /* More than one latch edge. */ |
505 | loop->latch = NULL; | |
506 | break; | |
402209ff | 507 | } |
0375167b | 508 | loop->latch = latch; |
402209ff | 509 | } |
402209ff | 510 | } |
2ecfd709 | 511 | } |
3d436d2a | 512 | |
0375167b | 513 | return loops; |
402209ff JH |
514 | } |
515 | ||
89f8f30f ZD |
516 | /* Ratio of frequencies of edges so that one of more latch edges is |
517 | considered to belong to inner loop with same header. */ | |
518 | #define HEAVY_EDGE_RATIO 8 | |
519 | ||
520 | /* Minimum number of samples for that we apply | |
521 | find_subloop_latch_edge_by_profile heuristics. */ | |
522 | #define HEAVY_EDGE_MIN_SAMPLES 10 | |
523 | ||
524 | /* If the profile info is available, finds an edge in LATCHES that much more | |
525 | frequent than the remaining edges. Returns such an edge, or NULL if we do | |
526 | not find one. | |
527 | ||
528 | We do not use guessed profile here, only the measured one. The guessed | |
529 | profile is usually too flat and unreliable for this (and it is mostly based | |
530 | on the loop structure of the program, so it does not make much sense to | |
531 | derive the loop structure from it). */ | |
b8698a0f | 532 | |
89f8f30f | 533 | static edge |
9771b263 | 534 | find_subloop_latch_edge_by_profile (vec<edge> latches) |
89f8f30f ZD |
535 | { |
536 | unsigned i; | |
537 | edge e, me = NULL; | |
538 | gcov_type mcount = 0, tcount = 0; | |
539 | ||
9771b263 | 540 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f ZD |
541 | { |
542 | if (e->count > mcount) | |
543 | { | |
544 | me = e; | |
545 | mcount = e->count; | |
546 | } | |
547 | tcount += e->count; | |
548 | } | |
549 | ||
550 | if (tcount < HEAVY_EDGE_MIN_SAMPLES | |
551 | || (tcount - mcount) * HEAVY_EDGE_RATIO > tcount) | |
552 | return NULL; | |
553 | ||
554 | if (dump_file) | |
555 | fprintf (dump_file, | |
556 | "Found latch edge %d -> %d using profile information.\n", | |
557 | me->src->index, me->dest->index); | |
558 | return me; | |
559 | } | |
560 | ||
561 | /* Among LATCHES, guesses a latch edge of LOOP corresponding to subloop, based | |
562 | on the structure of induction variables. Returns this edge, or NULL if we | |
563 | do not find any. | |
564 | ||
565 | We are quite conservative, and look just for an obvious simple innermost | |
566 | loop (which is the case where we would lose the most performance by not | |
567 | disambiguating the loop). More precisely, we look for the following | |
568 | situation: The source of the chosen latch edge dominates sources of all | |
569 | the other latch edges. Additionally, the header does not contain a phi node | |
570 | such that the argument from the chosen edge is equal to the argument from | |
571 | another edge. */ | |
572 | ||
573 | static edge | |
9771b263 | 574 | find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, vec<edge> latches) |
89f8f30f | 575 | { |
9771b263 | 576 | edge e, latch = latches[0]; |
89f8f30f | 577 | unsigned i; |
538dd0b7 DM |
578 | gphi *phi; |
579 | gphi_iterator psi; | |
726a989a | 580 | tree lop; |
89f8f30f ZD |
581 | basic_block bb; |
582 | ||
583 | /* Find the candidate for the latch edge. */ | |
9771b263 | 584 | for (i = 1; latches.iterate (i, &e); i++) |
89f8f30f ZD |
585 | if (dominated_by_p (CDI_DOMINATORS, latch->src, e->src)) |
586 | latch = e; | |
587 | ||
588 | /* Verify that it dominates all the latch edges. */ | |
9771b263 | 589 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f ZD |
590 | if (!dominated_by_p (CDI_DOMINATORS, e->src, latch->src)) |
591 | return NULL; | |
592 | ||
593 | /* Check for a phi node that would deny that this is a latch edge of | |
594 | a subloop. */ | |
726a989a | 595 | for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) |
89f8f30f | 596 | { |
538dd0b7 | 597 | phi = psi.phi (); |
89f8f30f ZD |
598 | lop = PHI_ARG_DEF_FROM_EDGE (phi, latch); |
599 | ||
600 | /* Ignore the values that are not changed inside the subloop. */ | |
601 | if (TREE_CODE (lop) != SSA_NAME | |
602 | || SSA_NAME_DEF_STMT (lop) == phi) | |
603 | continue; | |
726a989a | 604 | bb = gimple_bb (SSA_NAME_DEF_STMT (lop)); |
89f8f30f ZD |
605 | if (!bb || !flow_bb_inside_loop_p (loop, bb)) |
606 | continue; | |
607 | ||
9771b263 | 608 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f ZD |
609 | if (e != latch |
610 | && PHI_ARG_DEF_FROM_EDGE (phi, e) == lop) | |
611 | return NULL; | |
612 | } | |
613 | ||
614 | if (dump_file) | |
615 | fprintf (dump_file, | |
616 | "Found latch edge %d -> %d using iv structure.\n", | |
617 | latch->src->index, latch->dest->index); | |
618 | return latch; | |
619 | } | |
620 | ||
621 | /* If we can determine that one of the several latch edges of LOOP behaves | |
622 | as a latch edge of a separate subloop, returns this edge. Otherwise | |
623 | returns NULL. */ | |
624 | ||
625 | static edge | |
626 | find_subloop_latch_edge (struct loop *loop) | |
627 | { | |
9771b263 | 628 | vec<edge> latches = get_loop_latch_edges (loop); |
89f8f30f ZD |
629 | edge latch = NULL; |
630 | ||
9771b263 | 631 | if (latches.length () > 1) |
89f8f30f ZD |
632 | { |
633 | latch = find_subloop_latch_edge_by_profile (latches); | |
634 | ||
635 | if (!latch | |
636 | /* We consider ivs to guess the latch edge only in SSA. Perhaps we | |
637 | should use cfghook for this, but it is hard to imagine it would | |
638 | be useful elsewhere. */ | |
639 | && current_ir_type () == IR_GIMPLE) | |
640 | latch = find_subloop_latch_edge_by_ivs (loop, latches); | |
641 | } | |
642 | ||
9771b263 | 643 | latches.release (); |
89f8f30f ZD |
644 | return latch; |
645 | } | |
646 | ||
647 | /* Callback for make_forwarder_block. Returns true if the edge E is marked | |
648 | in the set MFB_REIS_SET. */ | |
649 | ||
6e2830c3 | 650 | static hash_set<edge> *mfb_reis_set; |
89f8f30f ZD |
651 | static bool |
652 | mfb_redirect_edges_in_set (edge e) | |
653 | { | |
6e2830c3 | 654 | return mfb_reis_set->contains (e); |
89f8f30f ZD |
655 | } |
656 | ||
657 | /* Creates a subloop of LOOP with latch edge LATCH. */ | |
658 | ||
659 | static void | |
660 | form_subloop (struct loop *loop, edge latch) | |
661 | { | |
662 | edge_iterator ei; | |
663 | edge e, new_entry; | |
664 | struct loop *new_loop; | |
b8698a0f | 665 | |
6e2830c3 | 666 | mfb_reis_set = new hash_set<edge>; |
89f8f30f ZD |
667 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
668 | { | |
669 | if (e != latch) | |
6e2830c3 | 670 | mfb_reis_set->add (e); |
89f8f30f ZD |
671 | } |
672 | new_entry = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
673 | NULL); | |
6e2830c3 | 674 | delete mfb_reis_set; |
89f8f30f ZD |
675 | |
676 | loop->header = new_entry->src; | |
677 | ||
678 | /* Find the blocks and subloops that belong to the new loop, and add it to | |
679 | the appropriate place in the loop tree. */ | |
680 | new_loop = alloc_loop (); | |
681 | new_loop->header = new_entry->dest; | |
682 | new_loop->latch = latch->src; | |
683 | add_loop (new_loop, loop); | |
684 | } | |
685 | ||
686 | /* Make all the latch edges of LOOP to go to a single forwarder block -- | |
687 | a new latch of LOOP. */ | |
688 | ||
689 | static void | |
690 | merge_latch_edges (struct loop *loop) | |
691 | { | |
9771b263 | 692 | vec<edge> latches = get_loop_latch_edges (loop); |
89f8f30f ZD |
693 | edge latch, e; |
694 | unsigned i; | |
695 | ||
9771b263 | 696 | gcc_assert (latches.length () > 0); |
89f8f30f | 697 | |
9771b263 DN |
698 | if (latches.length () == 1) |
699 | loop->latch = latches[0]->src; | |
89f8f30f ZD |
700 | else |
701 | { | |
702 | if (dump_file) | |
703 | fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num); | |
704 | ||
6e2830c3 | 705 | mfb_reis_set = new hash_set<edge>; |
9771b263 | 706 | FOR_EACH_VEC_ELT (latches, i, e) |
6e2830c3 | 707 | mfb_reis_set->add (e); |
89f8f30f ZD |
708 | latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, |
709 | NULL); | |
6e2830c3 | 710 | delete mfb_reis_set; |
89f8f30f ZD |
711 | |
712 | loop->header = latch->dest; | |
713 | loop->latch = latch->src; | |
714 | } | |
715 | ||
9771b263 | 716 | latches.release (); |
89f8f30f ZD |
717 | } |
718 | ||
719 | /* LOOP may have several latch edges. Transform it into (possibly several) | |
720 | loops with single latch edge. */ | |
721 | ||
722 | static void | |
723 | disambiguate_multiple_latches (struct loop *loop) | |
724 | { | |
725 | edge e; | |
726 | ||
ea2c620c | 727 | /* We eliminate the multiple latches by splitting the header to the forwarder |
89f8f30f ZD |
728 | block F and the rest R, and redirecting the edges. There are two cases: |
729 | ||
730 | 1) If there is a latch edge E that corresponds to a subloop (we guess | |
731 | that based on profile -- if it is taken much more often than the | |
732 | remaining edges; and on trees, using the information about induction | |
733 | variables of the loops), we redirect E to R, all the remaining edges to | |
734 | F, then rescan the loops and try again for the outer loop. | |
735 | 2) If there is no such edge, we redirect all latch edges to F, and the | |
736 | entry edges to R, thus making F the single latch of the loop. */ | |
737 | ||
738 | if (dump_file) | |
739 | fprintf (dump_file, "Disambiguating loop %d with multiple latches\n", | |
740 | loop->num); | |
741 | ||
742 | /* During latch merging, we may need to redirect the entry edges to a new | |
743 | block. This would cause problems if the entry edge was the one from the | |
744 | entry block. To avoid having to handle this case specially, split | |
745 | such entry edge. */ | |
fefa31b5 | 746 | e = find_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), loop->header); |
89f8f30f ZD |
747 | if (e) |
748 | split_edge (e); | |
749 | ||
750 | while (1) | |
751 | { | |
752 | e = find_subloop_latch_edge (loop); | |
753 | if (!e) | |
754 | break; | |
755 | ||
756 | form_subloop (loop, e); | |
757 | } | |
758 | ||
759 | merge_latch_edges (loop); | |
760 | } | |
761 | ||
762 | /* Split loops with multiple latch edges. */ | |
763 | ||
764 | void | |
765 | disambiguate_loops_with_multiple_latches (void) | |
766 | { | |
89f8f30f ZD |
767 | struct loop *loop; |
768 | ||
f0bd40b1 | 769 | FOR_EACH_LOOP (loop, 0) |
89f8f30f ZD |
770 | { |
771 | if (!loop->latch) | |
772 | disambiguate_multiple_latches (loop); | |
773 | } | |
774 | } | |
775 | ||
da7d8304 | 776 | /* Return nonzero if basic block BB belongs to LOOP. */ |
2ecfd709 | 777 | bool |
ed7a4b4b | 778 | flow_bb_inside_loop_p (const struct loop *loop, const_basic_block bb) |
2ecfd709 ZD |
779 | { |
780 | struct loop *source_loop; | |
781 | ||
fefa31b5 DM |
782 | if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
783 | || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
2ecfd709 ZD |
784 | return 0; |
785 | ||
786 | source_loop = bb->loop_father; | |
787 | return loop == source_loop || flow_loop_nested_p (loop, source_loop); | |
788 | } | |
789 | ||
89f8f30f | 790 | /* Enumeration predicate for get_loop_body_with_size. */ |
2ecfd709 | 791 | static bool |
ed7a4b4b | 792 | glb_enum_p (const_basic_block bb, const void *glb_loop) |
2ecfd709 | 793 | { |
ed7a4b4b | 794 | const struct loop *const loop = (const struct loop *) glb_loop; |
89f8f30f ZD |
795 | return (bb != loop->header |
796 | && dominated_by_p (CDI_DOMINATORS, bb, loop->header)); | |
797 | } | |
798 | ||
799 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
800 | order against direction of edges from latch. Specially, if | |
801 | header != latch, latch is the 1-st block. LOOP cannot be the fake | |
802 | loop tree root, and its size must be at most MAX_SIZE. The blocks | |
803 | in the LOOP body are stored to BODY, and the size of the LOOP is | |
804 | returned. */ | |
805 | ||
806 | unsigned | |
807 | get_loop_body_with_size (const struct loop *loop, basic_block *body, | |
808 | unsigned max_size) | |
809 | { | |
810 | return dfs_enumerate_from (loop->header, 1, glb_enum_p, | |
ed7a4b4b | 811 | body, max_size, loop); |
2ecfd709 ZD |
812 | } |
813 | ||
8d28e87d ZD |
814 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs |
815 | order against direction of edges from latch. Specially, if | |
816 | header != latch, latch is the 1-st block. */ | |
89f8f30f | 817 | |
2ecfd709 | 818 | basic_block * |
d329e058 | 819 | get_loop_body (const struct loop *loop) |
2ecfd709 | 820 | { |
89f8f30f | 821 | basic_block *body, bb; |
3d436d2a | 822 | unsigned tv = 0; |
2ecfd709 | 823 | |
341c100f | 824 | gcc_assert (loop->num_nodes); |
2ecfd709 | 825 | |
c302207e | 826 | body = XNEWVEC (basic_block, loop->num_nodes); |
2ecfd709 | 827 | |
fefa31b5 | 828 | if (loop->latch == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
2ecfd709 | 829 | { |
89f8f30f ZD |
830 | /* There may be blocks unreachable from EXIT_BLOCK, hence we need to |
831 | special-case the fake loop that contains the whole function. */ | |
0cae8d31 | 832 | gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks_for_fn (cfun)); |
89f8f30f | 833 | body[tv++] = loop->header; |
fefa31b5 | 834 | body[tv++] = EXIT_BLOCK_PTR_FOR_FN (cfun); |
11cd3bed | 835 | FOR_EACH_BB_FN (bb, cfun) |
89f8f30f | 836 | body[tv++] = bb; |
2ecfd709 | 837 | } |
89f8f30f ZD |
838 | else |
839 | tv = get_loop_body_with_size (loop, body, loop->num_nodes); | |
2ecfd709 | 840 | |
341c100f | 841 | gcc_assert (tv == loop->num_nodes); |
89f8f30f | 842 | return body; |
2ecfd709 ZD |
843 | } |
844 | ||
50654f6c ZD |
845 | /* Fills dominance descendants inside LOOP of the basic block BB into |
846 | array TOVISIT from index *TV. */ | |
847 | ||
848 | static void | |
849 | fill_sons_in_loop (const struct loop *loop, basic_block bb, | |
850 | basic_block *tovisit, int *tv) | |
851 | { | |
852 | basic_block son, postpone = NULL; | |
853 | ||
854 | tovisit[(*tv)++] = bb; | |
855 | for (son = first_dom_son (CDI_DOMINATORS, bb); | |
856 | son; | |
857 | son = next_dom_son (CDI_DOMINATORS, son)) | |
858 | { | |
859 | if (!flow_bb_inside_loop_p (loop, son)) | |
860 | continue; | |
861 | ||
862 | if (dominated_by_p (CDI_DOMINATORS, loop->latch, son)) | |
863 | { | |
864 | postpone = son; | |
865 | continue; | |
866 | } | |
867 | fill_sons_in_loop (loop, son, tovisit, tv); | |
868 | } | |
869 | ||
870 | if (postpone) | |
871 | fill_sons_in_loop (loop, postpone, tovisit, tv); | |
872 | } | |
873 | ||
874 | /* Gets body of a LOOP (that must be different from the outermost loop) | |
875 | sorted by dominance relation. Additionally, if a basic block s dominates | |
876 | the latch, then only blocks dominated by s are be after it. */ | |
877 | ||
878 | basic_block * | |
879 | get_loop_body_in_dom_order (const struct loop *loop) | |
880 | { | |
881 | basic_block *tovisit; | |
882 | int tv; | |
883 | ||
341c100f | 884 | gcc_assert (loop->num_nodes); |
50654f6c | 885 | |
c302207e | 886 | tovisit = XNEWVEC (basic_block, loop->num_nodes); |
50654f6c | 887 | |
fefa31b5 | 888 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
50654f6c ZD |
889 | |
890 | tv = 0; | |
891 | fill_sons_in_loop (loop, loop->header, tovisit, &tv); | |
892 | ||
341c100f | 893 | gcc_assert (tv == (int) loop->num_nodes); |
50654f6c ZD |
894 | |
895 | return tovisit; | |
896 | } | |
897 | ||
e855c69d AB |
898 | /* Gets body of a LOOP sorted via provided BB_COMPARATOR. */ |
899 | ||
900 | basic_block * | |
b8698a0f | 901 | get_loop_body_in_custom_order (const struct loop *loop, |
e855c69d AB |
902 | int (*bb_comparator) (const void *, const void *)) |
903 | { | |
904 | basic_block *bbs = get_loop_body (loop); | |
905 | ||
906 | qsort (bbs, loop->num_nodes, sizeof (basic_block), bb_comparator); | |
907 | ||
908 | return bbs; | |
909 | } | |
910 | ||
40923b20 DP |
911 | /* Get body of a LOOP in breadth first sort order. */ |
912 | ||
913 | basic_block * | |
914 | get_loop_body_in_bfs_order (const struct loop *loop) | |
915 | { | |
916 | basic_block *blocks; | |
917 | basic_block bb; | |
918 | bitmap visited; | |
919 | unsigned int i = 0; | |
920 | unsigned int vc = 1; | |
921 | ||
341c100f | 922 | gcc_assert (loop->num_nodes); |
fefa31b5 | 923 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
40923b20 | 924 | |
c302207e | 925 | blocks = XNEWVEC (basic_block, loop->num_nodes); |
8bdbfff5 | 926 | visited = BITMAP_ALLOC (NULL); |
40923b20 DP |
927 | |
928 | bb = loop->header; | |
929 | while (i < loop->num_nodes) | |
930 | { | |
931 | edge e; | |
628f6a4e | 932 | edge_iterator ei; |
c22cacf3 | 933 | |
fcaa4ca4 NF |
934 | if (bitmap_set_bit (visited, bb->index)) |
935 | /* This basic block is now visited */ | |
936 | blocks[i++] = bb; | |
c22cacf3 | 937 | |
628f6a4e | 938 | FOR_EACH_EDGE (e, ei, bb->succs) |
c22cacf3 MS |
939 | { |
940 | if (flow_bb_inside_loop_p (loop, e->dest)) | |
941 | { | |
fcaa4ca4 NF |
942 | if (bitmap_set_bit (visited, e->dest->index)) |
943 | blocks[i++] = e->dest; | |
c22cacf3 MS |
944 | } |
945 | } | |
946 | ||
d9c16ed2 | 947 | gcc_assert (i > vc); |
c22cacf3 | 948 | |
40923b20 DP |
949 | bb = blocks[vc++]; |
950 | } | |
c22cacf3 | 951 | |
8bdbfff5 | 952 | BITMAP_FREE (visited); |
40923b20 DP |
953 | return blocks; |
954 | } | |
955 | ||
6270df4c ZD |
956 | /* Hash function for struct loop_exit. */ |
957 | ||
2a22f99c TS |
958 | hashval_t |
959 | loop_exit_hasher::hash (loop_exit *exit) | |
6270df4c | 960 | { |
6270df4c ZD |
961 | return htab_hash_pointer (exit->e); |
962 | } | |
963 | ||
964 | /* Equality function for struct loop_exit. Compares with edge. */ | |
965 | ||
2a22f99c TS |
966 | bool |
967 | loop_exit_hasher::equal (loop_exit *exit, edge e) | |
6270df4c | 968 | { |
6270df4c ZD |
969 | return exit->e == e; |
970 | } | |
971 | ||
972 | /* Frees the list of loop exit descriptions EX. */ | |
973 | ||
2a22f99c TS |
974 | void |
975 | loop_exit_hasher::remove (loop_exit *exit) | |
6270df4c | 976 | { |
2a22f99c | 977 | loop_exit *next; |
6270df4c ZD |
978 | for (; exit; exit = next) |
979 | { | |
980 | next = exit->next_e; | |
b8698a0f | 981 | |
6270df4c ZD |
982 | exit->next->prev = exit->prev; |
983 | exit->prev->next = exit->next; | |
984 | ||
9e2f83a5 | 985 | ggc_free (exit); |
6270df4c ZD |
986 | } |
987 | } | |
988 | ||
989 | /* Returns the list of records for E as an exit of a loop. */ | |
990 | ||
991 | static struct loop_exit * | |
992 | get_exit_descriptions (edge e) | |
993 | { | |
2a22f99c | 994 | return current_loops->exits->find_with_hash (e, htab_hash_pointer (e)); |
6270df4c ZD |
995 | } |
996 | ||
997 | /* Updates the lists of loop exits in that E appears. | |
998 | If REMOVED is true, E is being removed, and we | |
999 | just remove it from the lists of exits. | |
1000 | If NEW_EDGE is true and E is not a loop exit, we | |
1001 | do not try to remove it from loop exit lists. */ | |
1002 | ||
1003 | void | |
1004 | rescan_loop_exit (edge e, bool new_edge, bool removed) | |
1005 | { | |
6270df4c ZD |
1006 | struct loop_exit *exits = NULL, *exit; |
1007 | struct loop *aloop, *cloop; | |
1008 | ||
f87000d0 | 1009 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c ZD |
1010 | return; |
1011 | ||
1012 | if (!removed | |
1013 | && e->src->loop_father != NULL | |
1014 | && e->dest->loop_father != NULL | |
1015 | && !flow_bb_inside_loop_p (e->src->loop_father, e->dest)) | |
1016 | { | |
1017 | cloop = find_common_loop (e->src->loop_father, e->dest->loop_father); | |
1018 | for (aloop = e->src->loop_father; | |
1019 | aloop != cloop; | |
9ba025a2 | 1020 | aloop = loop_outer (aloop)) |
6270df4c | 1021 | { |
766090c2 | 1022 | exit = ggc_alloc<loop_exit> (); |
6270df4c ZD |
1023 | exit->e = e; |
1024 | ||
9e2f83a5 ZD |
1025 | exit->next = aloop->exits->next; |
1026 | exit->prev = aloop->exits; | |
6270df4c ZD |
1027 | exit->next->prev = exit; |
1028 | exit->prev->next = exit; | |
1029 | ||
1030 | exit->next_e = exits; | |
1031 | exits = exit; | |
1032 | } | |
b8698a0f | 1033 | } |
6270df4c ZD |
1034 | |
1035 | if (!exits && new_edge) | |
1036 | return; | |
1037 | ||
2a22f99c TS |
1038 | loop_exit **slot |
1039 | = current_loops->exits->find_slot_with_hash (e, htab_hash_pointer (e), | |
1040 | exits ? INSERT : NO_INSERT); | |
6270df4c ZD |
1041 | if (!slot) |
1042 | return; | |
1043 | ||
1044 | if (exits) | |
1045 | { | |
1046 | if (*slot) | |
2a22f99c | 1047 | loop_exit_hasher::remove (*slot); |
6270df4c ZD |
1048 | *slot = exits; |
1049 | } | |
1050 | else | |
2a22f99c | 1051 | current_loops->exits->clear_slot (slot); |
6270df4c ZD |
1052 | } |
1053 | ||
1054 | /* For each loop, record list of exit edges, and start maintaining these | |
1055 | lists. */ | |
1056 | ||
1057 | void | |
1058 | record_loop_exits (void) | |
1059 | { | |
1060 | basic_block bb; | |
1061 | edge_iterator ei; | |
1062 | edge e; | |
1063 | ||
4839cb59 ZD |
1064 | if (!current_loops) |
1065 | return; | |
1066 | ||
f87000d0 | 1067 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1068 | return; |
f87000d0 | 1069 | loops_state_set (LOOPS_HAVE_RECORDED_EXITS); |
6270df4c ZD |
1070 | |
1071 | gcc_assert (current_loops->exits == NULL); | |
2a22f99c TS |
1072 | current_loops->exits |
1073 | = hash_table<loop_exit_hasher>::create_ggc (2 * number_of_loops (cfun)); | |
6270df4c | 1074 | |
11cd3bed | 1075 | FOR_EACH_BB_FN (bb, cfun) |
6270df4c ZD |
1076 | { |
1077 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1078 | { | |
1079 | rescan_loop_exit (e, true, false); | |
1080 | } | |
1081 | } | |
1082 | } | |
1083 | ||
1084 | /* Dumps information about the exit in *SLOT to FILE. | |
1085 | Callback for htab_traverse. */ | |
1086 | ||
2a22f99c TS |
1087 | int |
1088 | dump_recorded_exit (loop_exit **slot, FILE *file) | |
6270df4c | 1089 | { |
2a22f99c | 1090 | struct loop_exit *exit = *slot; |
6270df4c ZD |
1091 | unsigned n = 0; |
1092 | edge e = exit->e; | |
1093 | ||
1094 | for (; exit != NULL; exit = exit->next_e) | |
1095 | n++; | |
1096 | ||
2a22f99c | 1097 | fprintf (file, "Edge %d->%d exits %u loops\n", |
6270df4c ZD |
1098 | e->src->index, e->dest->index, n); |
1099 | ||
1100 | return 1; | |
1101 | } | |
1102 | ||
1103 | /* Dumps the recorded exits of loops to FILE. */ | |
1104 | ||
1105 | extern void dump_recorded_exits (FILE *); | |
1106 | void | |
1107 | dump_recorded_exits (FILE *file) | |
1108 | { | |
1109 | if (!current_loops->exits) | |
1110 | return; | |
2a22f99c | 1111 | current_loops->exits->traverse<FILE *, dump_recorded_exit> (file); |
6270df4c ZD |
1112 | } |
1113 | ||
1114 | /* Releases lists of loop exits. */ | |
1115 | ||
1116 | void | |
61183076 | 1117 | release_recorded_exits (function *fn) |
6270df4c | 1118 | { |
61183076 RB |
1119 | gcc_assert (loops_state_satisfies_p (fn, LOOPS_HAVE_RECORDED_EXITS)); |
1120 | loops_for_fn (fn)->exits->empty (); | |
1121 | loops_for_fn (fn)->exits = NULL; | |
1122 | loops_state_clear (fn, LOOPS_HAVE_RECORDED_EXITS); | |
6270df4c ZD |
1123 | } |
1124 | ||
ca83d385 ZD |
1125 | /* Returns the list of the exit edges of a LOOP. */ |
1126 | ||
9771b263 | 1127 | vec<edge> |
ca83d385 | 1128 | get_loop_exit_edges (const struct loop *loop) |
35b07080 | 1129 | { |
6e1aa848 | 1130 | vec<edge> edges = vNULL; |
ca83d385 ZD |
1131 | edge e; |
1132 | unsigned i; | |
1133 | basic_block *body; | |
628f6a4e | 1134 | edge_iterator ei; |
6270df4c | 1135 | struct loop_exit *exit; |
35b07080 | 1136 | |
fefa31b5 | 1137 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
35b07080 | 1138 | |
6270df4c ZD |
1139 | /* If we maintain the lists of exits, use them. Otherwise we must |
1140 | scan the body of the loop. */ | |
f87000d0 | 1141 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1142 | { |
9e2f83a5 | 1143 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
9771b263 | 1144 | edges.safe_push (exit->e); |
6270df4c ZD |
1145 | } |
1146 | else | |
1147 | { | |
1148 | body = get_loop_body (loop); | |
1149 | for (i = 0; i < loop->num_nodes; i++) | |
1150 | FOR_EACH_EDGE (e, ei, body[i]->succs) | |
1151 | { | |
1152 | if (!flow_bb_inside_loop_p (loop, e->dest)) | |
9771b263 | 1153 | edges.safe_push (e); |
6270df4c ZD |
1154 | } |
1155 | free (body); | |
1156 | } | |
35b07080 ZD |
1157 | |
1158 | return edges; | |
1159 | } | |
1160 | ||
50654f6c ZD |
1161 | /* Counts the number of conditional branches inside LOOP. */ |
1162 | ||
1163 | unsigned | |
1164 | num_loop_branches (const struct loop *loop) | |
1165 | { | |
1166 | unsigned i, n; | |
1167 | basic_block * body; | |
1168 | ||
fefa31b5 | 1169 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
50654f6c ZD |
1170 | |
1171 | body = get_loop_body (loop); | |
1172 | n = 0; | |
1173 | for (i = 0; i < loop->num_nodes; i++) | |
628f6a4e | 1174 | if (EDGE_COUNT (body[i]->succs) >= 2) |
50654f6c ZD |
1175 | n++; |
1176 | free (body); | |
1177 | ||
1178 | return n; | |
1179 | } | |
1180 | ||
2ecfd709 ZD |
1181 | /* Adds basic block BB to LOOP. */ |
1182 | void | |
d329e058 AJ |
1183 | add_bb_to_loop (basic_block bb, struct loop *loop) |
1184 | { | |
9ba025a2 ZD |
1185 | unsigned i; |
1186 | loop_p ploop; | |
6270df4c ZD |
1187 | edge_iterator ei; |
1188 | edge e; | |
1189 | ||
1190 | gcc_assert (bb->loop_father == NULL); | |
1191 | bb->loop_father = loop; | |
6270df4c | 1192 | loop->num_nodes++; |
9771b263 | 1193 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9ba025a2 | 1194 | ploop->num_nodes++; |
6270df4c ZD |
1195 | |
1196 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1197 | { | |
1198 | rescan_loop_exit (e, true, false); | |
1199 | } | |
1200 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1201 | { | |
1202 | rescan_loop_exit (e, true, false); | |
1203 | } | |
598ec7bd | 1204 | } |
2ecfd709 ZD |
1205 | |
1206 | /* Remove basic block BB from loops. */ | |
1207 | void | |
d329e058 AJ |
1208 | remove_bb_from_loops (basic_block bb) |
1209 | { | |
9771b263 | 1210 | unsigned i; |
6270df4c | 1211 | struct loop *loop = bb->loop_father; |
9ba025a2 | 1212 | loop_p ploop; |
6270df4c ZD |
1213 | edge_iterator ei; |
1214 | edge e; | |
1215 | ||
1216 | gcc_assert (loop != NULL); | |
1217 | loop->num_nodes--; | |
9771b263 | 1218 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9ba025a2 | 1219 | ploop->num_nodes--; |
6270df4c | 1220 | bb->loop_father = NULL; |
6270df4c ZD |
1221 | |
1222 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1223 | { | |
1224 | rescan_loop_exit (e, false, true); | |
1225 | } | |
1226 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1227 | { | |
1228 | rescan_loop_exit (e, false, true); | |
1229 | } | |
a310245f | 1230 | } |
2ecfd709 ZD |
1231 | |
1232 | /* Finds nearest common ancestor in loop tree for given loops. */ | |
1233 | struct loop * | |
d329e058 | 1234 | find_common_loop (struct loop *loop_s, struct loop *loop_d) |
2ecfd709 | 1235 | { |
9ba025a2 ZD |
1236 | unsigned sdepth, ddepth; |
1237 | ||
2ecfd709 ZD |
1238 | if (!loop_s) return loop_d; |
1239 | if (!loop_d) return loop_s; | |
d329e058 | 1240 | |
9ba025a2 ZD |
1241 | sdepth = loop_depth (loop_s); |
1242 | ddepth = loop_depth (loop_d); | |
1243 | ||
1244 | if (sdepth < ddepth) | |
9771b263 | 1245 | loop_d = (*loop_d->superloops)[sdepth]; |
9ba025a2 | 1246 | else if (sdepth > ddepth) |
9771b263 | 1247 | loop_s = (*loop_s->superloops)[ddepth]; |
2ecfd709 ZD |
1248 | |
1249 | while (loop_s != loop_d) | |
1250 | { | |
9ba025a2 ZD |
1251 | loop_s = loop_outer (loop_s); |
1252 | loop_d = loop_outer (loop_d); | |
2ecfd709 ZD |
1253 | } |
1254 | return loop_s; | |
1255 | } | |
1256 | ||
42fd6772 ZD |
1257 | /* Removes LOOP from structures and frees its data. */ |
1258 | ||
1259 | void | |
1260 | delete_loop (struct loop *loop) | |
1261 | { | |
1262 | /* Remove the loop from structure. */ | |
1263 | flow_loop_tree_node_remove (loop); | |
1264 | ||
1265 | /* Remove loop from loops array. */ | |
9771b263 | 1266 | (*current_loops->larray)[loop->num] = NULL; |
42fd6772 ZD |
1267 | |
1268 | /* Free loop data. */ | |
1269 | flow_loop_free (loop); | |
1270 | } | |
1271 | ||
3d436d2a | 1272 | /* Cancels the LOOP; it must be innermost one. */ |
b00bf166 KH |
1273 | |
1274 | static void | |
d73be268 | 1275 | cancel_loop (struct loop *loop) |
3d436d2a ZD |
1276 | { |
1277 | basic_block *bbs; | |
1278 | unsigned i; | |
9ba025a2 | 1279 | struct loop *outer = loop_outer (loop); |
3d436d2a | 1280 | |
341c100f | 1281 | gcc_assert (!loop->inner); |
3d436d2a ZD |
1282 | |
1283 | /* Move blocks up one level (they should be removed as soon as possible). */ | |
1284 | bbs = get_loop_body (loop); | |
1285 | for (i = 0; i < loop->num_nodes; i++) | |
9ba025a2 | 1286 | bbs[i]->loop_father = outer; |
3d436d2a | 1287 | |
b78384e0 | 1288 | free (bbs); |
42fd6772 | 1289 | delete_loop (loop); |
3d436d2a ZD |
1290 | } |
1291 | ||
1292 | /* Cancels LOOP and all its subloops. */ | |
1293 | void | |
d73be268 | 1294 | cancel_loop_tree (struct loop *loop) |
3d436d2a ZD |
1295 | { |
1296 | while (loop->inner) | |
d73be268 ZD |
1297 | cancel_loop_tree (loop->inner); |
1298 | cancel_loop (loop); | |
3d436d2a ZD |
1299 | } |
1300 | ||
d73be268 | 1301 | /* Checks that information about loops is correct |
e0bb17a8 | 1302 | -- sizes of loops are all right |
2ecfd709 ZD |
1303 | -- results of get_loop_body really belong to the loop |
1304 | -- loop header have just single entry edge and single latch edge | |
1305 | -- loop latches have only single successor that is header of their loop | |
3d436d2a | 1306 | -- irreducible loops are correctly marked |
cc360b36 | 1307 | -- the cached loop depth and loop father of each bb is correct |
2ecfd709 | 1308 | */ |
24e47c76 | 1309 | DEBUG_FUNCTION void |
d73be268 | 1310 | verify_loop_structure (void) |
2ecfd709 | 1311 | { |
3d436d2a ZD |
1312 | unsigned *sizes, i, j; |
1313 | sbitmap irreds; | |
a271b42d | 1314 | basic_block bb, *bbs; |
2ecfd709 ZD |
1315 | struct loop *loop; |
1316 | int err = 0; | |
35b07080 | 1317 | edge e; |
0fc822d0 | 1318 | unsigned num = number_of_loops (cfun); |
6270df4c | 1319 | struct loop_exit *exit, *mexit; |
7d776ee2 | 1320 | bool dom_available = dom_info_available_p (CDI_DOMINATORS); |
0375167b | 1321 | sbitmap visited; |
2ecfd709 | 1322 | |
a9e0d843 RB |
1323 | if (loops_state_satisfies_p (LOOPS_NEED_FIXUP)) |
1324 | { | |
1325 | error ("loop verification on loop tree that needs fixup"); | |
1326 | err = 1; | |
1327 | } | |
1328 | ||
7d776ee2 RG |
1329 | /* We need up-to-date dominators, compute or verify them. */ |
1330 | if (!dom_available) | |
1331 | calculate_dominance_info (CDI_DOMINATORS); | |
1332 | else | |
1333 | verify_dominators (CDI_DOMINATORS); | |
510dbcce | 1334 | |
b0dd8c90 RB |
1335 | /* Check the loop tree root. */ |
1336 | if (current_loops->tree_root->header != ENTRY_BLOCK_PTR_FOR_FN (cfun) | |
1337 | || current_loops->tree_root->latch != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
1338 | || (current_loops->tree_root->num_nodes | |
1339 | != (unsigned) n_basic_blocks_for_fn (cfun))) | |
1340 | { | |
1341 | error ("corrupt loop tree root"); | |
1342 | err = 1; | |
1343 | } | |
1344 | ||
f64fb0fa | 1345 | /* Check the headers. */ |
11cd3bed | 1346 | FOR_EACH_BB_FN (bb, cfun) |
a271b42d | 1347 | if (bb_loop_header_p (bb)) |
f64fb0fa | 1348 | { |
a271b42d RB |
1349 | if (bb->loop_father->header == NULL) |
1350 | { | |
1351 | error ("loop with header %d marked for removal", bb->index); | |
1352 | err = 1; | |
1353 | } | |
1354 | else if (bb->loop_father->header != bb) | |
1355 | { | |
1356 | error ("loop with header %d not in loop tree", bb->index); | |
1357 | err = 1; | |
1358 | } | |
1359 | } | |
1360 | else if (bb->loop_father->header == bb) | |
1361 | { | |
1362 | error ("non-loop with header %d not marked for removal", bb->index); | |
f64fb0fa MP |
1363 | err = 1; |
1364 | } | |
1365 | ||
a271b42d | 1366 | /* Check the recorded loop father and sizes of loops. */ |
8b1c6fd7 | 1367 | visited = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
f61e445a | 1368 | bitmap_clear (visited); |
0cae8d31 | 1369 | bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); |
f0bd40b1 | 1370 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) |
cc360b36 | 1371 | { |
a271b42d | 1372 | unsigned n; |
cc360b36 | 1373 | |
a271b42d RB |
1374 | if (loop->header == NULL) |
1375 | { | |
1376 | error ("removed loop %d in loop tree", loop->num); | |
1377 | err = 1; | |
1378 | continue; | |
1379 | } | |
1380 | ||
0cae8d31 | 1381 | n = get_loop_body_with_size (loop, bbs, n_basic_blocks_for_fn (cfun)); |
a271b42d RB |
1382 | if (loop->num_nodes != n) |
1383 | { | |
1384 | error ("size of loop %d should be %d, not %d", | |
1385 | loop->num, n, loop->num_nodes); | |
1386 | err = 1; | |
1387 | } | |
1388 | ||
1389 | for (j = 0; j < n; j++) | |
cc360b36 SB |
1390 | { |
1391 | bb = bbs[j]; | |
1392 | ||
0375167b RB |
1393 | if (!flow_bb_inside_loop_p (loop, bb)) |
1394 | { | |
1395 | error ("bb %d does not belong to loop %d", | |
1396 | bb->index, loop->num); | |
1397 | err = 1; | |
1398 | } | |
1399 | ||
cc360b36 | 1400 | /* Ignore this block if it is in an inner loop. */ |
d7c028c0 | 1401 | if (bitmap_bit_p (visited, bb->index)) |
cc360b36 | 1402 | continue; |
d7c028c0 | 1403 | bitmap_set_bit (visited, bb->index); |
cc360b36 SB |
1404 | |
1405 | if (bb->loop_father != loop) | |
1406 | { | |
1407 | error ("bb %d has father loop %d, should be loop %d", | |
1408 | bb->index, bb->loop_father->num, loop->num); | |
1409 | err = 1; | |
1410 | } | |
1411 | } | |
cc360b36 | 1412 | } |
a271b42d | 1413 | free (bbs); |
0375167b | 1414 | sbitmap_free (visited); |
2ecfd709 ZD |
1415 | |
1416 | /* Check headers and latches. */ | |
f0bd40b1 | 1417 | FOR_EACH_LOOP (loop, 0) |
2ecfd709 | 1418 | { |
42fd6772 | 1419 | i = loop->num; |
a271b42d RB |
1420 | if (loop->header == NULL) |
1421 | continue; | |
0375167b RB |
1422 | if (!bb_loop_header_p (loop->header)) |
1423 | { | |
1424 | error ("loop %d%'s header is not a loop header", i); | |
1425 | err = 1; | |
1426 | } | |
f87000d0 | 1427 | if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
628f6a4e | 1428 | && EDGE_COUNT (loop->header->preds) != 2) |
2ecfd709 | 1429 | { |
d8a07487 | 1430 | error ("loop %d%'s header does not have exactly 2 entries", i); |
2ecfd709 ZD |
1431 | err = 1; |
1432 | } | |
6aaf596b RB |
1433 | if (loop->latch) |
1434 | { | |
1435 | if (!find_edge (loop->latch, loop->header)) | |
1436 | { | |
1437 | error ("loop %d%'s latch does not have an edge to its header", i); | |
1438 | err = 1; | |
1439 | } | |
1440 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, loop->header)) | |
1441 | { | |
1442 | error ("loop %d%'s latch is not dominated by its header", i); | |
1443 | err = 1; | |
1444 | } | |
1445 | } | |
f87000d0 | 1446 | if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
2ecfd709 | 1447 | { |
c5cbcccf | 1448 | if (!single_succ_p (loop->latch)) |
2ecfd709 | 1449 | { |
d8a07487 | 1450 | error ("loop %d%'s latch does not have exactly 1 successor", i); |
2ecfd709 ZD |
1451 | err = 1; |
1452 | } | |
c5cbcccf | 1453 | if (single_succ (loop->latch) != loop->header) |
2ecfd709 | 1454 | { |
d8a07487 | 1455 | error ("loop %d%'s latch does not have header as successor", i); |
2ecfd709 ZD |
1456 | err = 1; |
1457 | } | |
1458 | if (loop->latch->loop_father != loop) | |
1459 | { | |
d8a07487 | 1460 | error ("loop %d%'s latch does not belong directly to it", i); |
2ecfd709 ZD |
1461 | err = 1; |
1462 | } | |
1463 | } | |
1464 | if (loop->header->loop_father != loop) | |
1465 | { | |
d8a07487 | 1466 | error ("loop %d%'s header does not belong directly to it", i); |
2ecfd709 ZD |
1467 | err = 1; |
1468 | } | |
f87000d0 | 1469 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) |
35b07080 ZD |
1470 | && (loop_latch_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)) |
1471 | { | |
d8a07487 | 1472 | error ("loop %d%'s latch is marked as part of irreducible region", i); |
35b07080 ZD |
1473 | err = 1; |
1474 | } | |
2ecfd709 ZD |
1475 | } |
1476 | ||
3d436d2a | 1477 | /* Check irreducible loops. */ |
f87000d0 | 1478 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
3d436d2a ZD |
1479 | { |
1480 | /* Record old info. */ | |
8b1c6fd7 | 1481 | irreds = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
11cd3bed | 1482 | FOR_EACH_BB_FN (bb, cfun) |
35b07080 | 1483 | { |
628f6a4e | 1484 | edge_iterator ei; |
35b07080 | 1485 | if (bb->flags & BB_IRREDUCIBLE_LOOP) |
d7c028c0 | 1486 | bitmap_set_bit (irreds, bb->index); |
35b07080 | 1487 | else |
d7c028c0 | 1488 | bitmap_clear_bit (irreds, bb->index); |
628f6a4e | 1489 | FOR_EACH_EDGE (e, ei, bb->succs) |
35b07080 | 1490 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) |
d329e058 | 1491 | e->flags |= EDGE_ALL_FLAGS + 1; |
35b07080 | 1492 | } |
3d436d2a ZD |
1493 | |
1494 | /* Recount it. */ | |
d73be268 | 1495 | mark_irreducible_loops (); |
3d436d2a ZD |
1496 | |
1497 | /* Compare. */ | |
11cd3bed | 1498 | FOR_EACH_BB_FN (bb, cfun) |
3d436d2a | 1499 | { |
628f6a4e BE |
1500 | edge_iterator ei; |
1501 | ||
3d436d2a | 1502 | if ((bb->flags & BB_IRREDUCIBLE_LOOP) |
d7c028c0 | 1503 | && !bitmap_bit_p (irreds, bb->index)) |
3d436d2a | 1504 | { |
ab532386 | 1505 | error ("basic block %d should be marked irreducible", bb->index); |
3d436d2a ZD |
1506 | err = 1; |
1507 | } | |
1508 | else if (!(bb->flags & BB_IRREDUCIBLE_LOOP) | |
d7c028c0 | 1509 | && bitmap_bit_p (irreds, bb->index)) |
3d436d2a | 1510 | { |
ab532386 | 1511 | error ("basic block %d should not be marked irreducible", bb->index); |
3d436d2a ZD |
1512 | err = 1; |
1513 | } | |
628f6a4e | 1514 | FOR_EACH_EDGE (e, ei, bb->succs) |
35b07080 ZD |
1515 | { |
1516 | if ((e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1517 | && !(e->flags & (EDGE_ALL_FLAGS + 1))) | |
1518 | { | |
ab532386 | 1519 | error ("edge from %d to %d should be marked irreducible", |
35b07080 ZD |
1520 | e->src->index, e->dest->index); |
1521 | err = 1; | |
1522 | } | |
1523 | else if (!(e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1524 | && (e->flags & (EDGE_ALL_FLAGS + 1))) | |
1525 | { | |
ab532386 | 1526 | error ("edge from %d to %d should not be marked irreducible", |
35b07080 ZD |
1527 | e->src->index, e->dest->index); |
1528 | err = 1; | |
1529 | } | |
1530 | e->flags &= ~(EDGE_ALL_FLAGS + 1); | |
1531 | } | |
3d436d2a ZD |
1532 | } |
1533 | free (irreds); | |
1534 | } | |
1535 | ||
6270df4c | 1536 | /* Check the recorded loop exits. */ |
f0bd40b1 | 1537 | FOR_EACH_LOOP (loop, 0) |
82b85a85 | 1538 | { |
9e2f83a5 | 1539 | if (!loop->exits || loop->exits->e != NULL) |
6270df4c ZD |
1540 | { |
1541 | error ("corrupted head of the exits list of loop %d", | |
1542 | loop->num); | |
1543 | err = 1; | |
1544 | } | |
1545 | else | |
1546 | { | |
1547 | /* Check that the list forms a cycle, and all elements except | |
1548 | for the head are nonnull. */ | |
9e2f83a5 | 1549 | for (mexit = loop->exits, exit = mexit->next, i = 0; |
6270df4c ZD |
1550 | exit->e && exit != mexit; |
1551 | exit = exit->next) | |
1552 | { | |
1553 | if (i++ & 1) | |
1554 | mexit = mexit->next; | |
1555 | } | |
1556 | ||
9e2f83a5 | 1557 | if (exit != loop->exits) |
6270df4c ZD |
1558 | { |
1559 | error ("corrupted exits list of loop %d", loop->num); | |
1560 | err = 1; | |
1561 | } | |
1562 | } | |
1563 | ||
f87000d0 | 1564 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1565 | { |
9e2f83a5 | 1566 | if (loop->exits->next != loop->exits) |
6270df4c ZD |
1567 | { |
1568 | error ("nonempty exits list of loop %d, but exits are not recorded", | |
1569 | loop->num); | |
1570 | err = 1; | |
1571 | } | |
1572 | } | |
1573 | } | |
1574 | ||
f87000d0 | 1575 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c ZD |
1576 | { |
1577 | unsigned n_exits = 0, eloops; | |
1578 | ||
a271b42d | 1579 | sizes = XCNEWVEC (unsigned, num); |
42fd6772 | 1580 | memset (sizes, 0, sizeof (unsigned) * num); |
11cd3bed | 1581 | FOR_EACH_BB_FN (bb, cfun) |
82b85a85 | 1582 | { |
628f6a4e | 1583 | edge_iterator ei; |
d73be268 | 1584 | if (bb->loop_father == current_loops->tree_root) |
82b85a85 | 1585 | continue; |
628f6a4e | 1586 | FOR_EACH_EDGE (e, ei, bb->succs) |
82b85a85 | 1587 | { |
82b85a85 ZD |
1588 | if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) |
1589 | continue; | |
1590 | ||
6270df4c ZD |
1591 | n_exits++; |
1592 | exit = get_exit_descriptions (e); | |
1593 | if (!exit) | |
1594 | { | |
d8a07487 | 1595 | error ("exit %d->%d not recorded", |
6270df4c ZD |
1596 | e->src->index, e->dest->index); |
1597 | err = 1; | |
1598 | } | |
1599 | eloops = 0; | |
1600 | for (; exit; exit = exit->next_e) | |
1601 | eloops++; | |
1602 | ||
82b85a85 | 1603 | for (loop = bb->loop_father; |
661bc682 RB |
1604 | loop != e->dest->loop_father |
1605 | /* When a loop exit is also an entry edge which | |
1606 | can happen when avoiding CFG manipulations | |
1607 | then the last loop exited is the outer loop | |
1608 | of the loop entered. */ | |
1609 | && loop != loop_outer (e->dest->loop_father); | |
9ba025a2 | 1610 | loop = loop_outer (loop)) |
82b85a85 | 1611 | { |
6270df4c | 1612 | eloops--; |
82b85a85 | 1613 | sizes[loop->num]++; |
6270df4c ZD |
1614 | } |
1615 | ||
1616 | if (eloops != 0) | |
1617 | { | |
d8a07487 | 1618 | error ("wrong list of exited loops for edge %d->%d", |
6270df4c ZD |
1619 | e->src->index, e->dest->index); |
1620 | err = 1; | |
82b85a85 ZD |
1621 | } |
1622 | } | |
1623 | } | |
1624 | ||
2a22f99c | 1625 | if (n_exits != current_loops->exits->elements ()) |
82b85a85 | 1626 | { |
d8a07487 | 1627 | error ("too many loop exits recorded"); |
6270df4c ZD |
1628 | err = 1; |
1629 | } | |
82b85a85 | 1630 | |
f0bd40b1 | 1631 | FOR_EACH_LOOP (loop, 0) |
6270df4c ZD |
1632 | { |
1633 | eloops = 0; | |
9e2f83a5 | 1634 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
6270df4c ZD |
1635 | eloops++; |
1636 | if (eloops != sizes[loop->num]) | |
82b85a85 | 1637 | { |
6270df4c ZD |
1638 | error ("%d exits recorded for loop %d (having %d exits)", |
1639 | eloops, loop->num, sizes[loop->num]); | |
82b85a85 ZD |
1640 | err = 1; |
1641 | } | |
1642 | } | |
a271b42d RB |
1643 | |
1644 | free (sizes); | |
82b85a85 ZD |
1645 | } |
1646 | ||
341c100f | 1647 | gcc_assert (!err); |
82b85a85 | 1648 | |
7d776ee2 RG |
1649 | if (!dom_available) |
1650 | free_dominance_info (CDI_DOMINATORS); | |
2ecfd709 ZD |
1651 | } |
1652 | ||
1653 | /* Returns latch edge of LOOP. */ | |
1654 | edge | |
d329e058 | 1655 | loop_latch_edge (const struct loop *loop) |
2ecfd709 | 1656 | { |
9ff3d2de | 1657 | return find_edge (loop->latch, loop->header); |
402209ff | 1658 | } |
2ecfd709 ZD |
1659 | |
1660 | /* Returns preheader edge of LOOP. */ | |
1661 | edge | |
d329e058 | 1662 | loop_preheader_edge (const struct loop *loop) |
2ecfd709 ZD |
1663 | { |
1664 | edge e; | |
628f6a4e | 1665 | edge_iterator ei; |
2ecfd709 | 1666 | |
f87000d0 | 1667 | gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)); |
c7b852c8 | 1668 | |
628f6a4e BE |
1669 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
1670 | if (e->src != loop->latch) | |
1671 | break; | |
2ecfd709 ZD |
1672 | |
1673 | return e; | |
1674 | } | |
70388d94 ZD |
1675 | |
1676 | /* Returns true if E is an exit of LOOP. */ | |
1677 | ||
1678 | bool | |
ed7a4b4b | 1679 | loop_exit_edge_p (const struct loop *loop, const_edge e) |
70388d94 ZD |
1680 | { |
1681 | return (flow_bb_inside_loop_p (loop, e->src) | |
1682 | && !flow_bb_inside_loop_p (loop, e->dest)); | |
1683 | } | |
ac8f6c69 ZD |
1684 | |
1685 | /* Returns the single exit edge of LOOP, or NULL if LOOP has either no exit | |
6270df4c ZD |
1686 | or more than one exit. If loops do not have the exits recorded, NULL |
1687 | is returned always. */ | |
ac8f6c69 ZD |
1688 | |
1689 | edge | |
1690 | single_exit (const struct loop *loop) | |
1691 | { | |
9e2f83a5 | 1692 | struct loop_exit *exit = loop->exits->next; |
ac8f6c69 | 1693 | |
f87000d0 | 1694 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1695 | return NULL; |
ac8f6c69 | 1696 | |
9e2f83a5 | 1697 | if (exit->e && exit->next == loop->exits) |
6270df4c ZD |
1698 | return exit->e; |
1699 | else | |
1700 | return NULL; | |
ac8f6c69 | 1701 | } |
f8bf9252 | 1702 | |
f4ce375d | 1703 | /* Returns true when BB has an incoming edge exiting LOOP. */ |
f8bf9252 SP |
1704 | |
1705 | bool | |
f4ce375d | 1706 | loop_exits_to_bb_p (struct loop *loop, basic_block bb) |
f8bf9252 SP |
1707 | { |
1708 | edge e; | |
1709 | edge_iterator ei; | |
1710 | ||
1711 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1712 | if (loop_exit_edge_p (loop, e)) | |
1713 | return true; | |
1714 | ||
1715 | return false; | |
1716 | } | |
f4ce375d VK |
1717 | |
1718 | /* Returns true when BB has an outgoing edge exiting LOOP. */ | |
1719 | ||
1720 | bool | |
1721 | loop_exits_from_bb_p (struct loop *loop, basic_block bb) | |
1722 | { | |
1723 | edge e; | |
1724 | edge_iterator ei; | |
1725 | ||
1726 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1727 | if (loop_exit_edge_p (loop, e)) | |
1728 | return true; | |
1729 | ||
1730 | return false; | |
1731 | } | |
e25a6711 TJ |
1732 | |
1733 | /* Return location corresponding to the loop control condition if possible. */ | |
1734 | ||
1735 | location_t | |
1736 | get_loop_location (struct loop *loop) | |
1737 | { | |
9d56eaa2 | 1738 | rtx_insn *insn = NULL; |
e25a6711 TJ |
1739 | struct niter_desc *desc = NULL; |
1740 | edge exit; | |
1741 | ||
1742 | /* For a for or while loop, we would like to return the location | |
1743 | of the for or while statement, if possible. To do this, look | |
1744 | for the branch guarding the loop back-edge. */ | |
1745 | ||
1746 | /* If this is a simple loop with an in_edge, then the loop control | |
1747 | branch is typically at the end of its source. */ | |
1748 | desc = get_simple_loop_desc (loop); | |
1749 | if (desc->in_edge) | |
1750 | { | |
1751 | FOR_BB_INSNS_REVERSE (desc->in_edge->src, insn) | |
1752 | { | |
1753 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1754 | return INSN_LOCATION (insn); | |
1755 | } | |
1756 | } | |
1757 | /* If loop has a single exit, then the loop control branch | |
1758 | must be at the end of its source. */ | |
1759 | if ((exit = single_exit (loop))) | |
1760 | { | |
1761 | FOR_BB_INSNS_REVERSE (exit->src, insn) | |
1762 | { | |
1763 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1764 | return INSN_LOCATION (insn); | |
1765 | } | |
1766 | } | |
1767 | /* Next check the latch, to see if it is non-empty. */ | |
1768 | FOR_BB_INSNS_REVERSE (loop->latch, insn) | |
1769 | { | |
1770 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1771 | return INSN_LOCATION (insn); | |
1772 | } | |
1773 | /* Finally, if none of the above identifies the loop control branch, | |
1774 | return the first location in the loop header. */ | |
1775 | FOR_BB_INSNS (loop->header, insn) | |
1776 | { | |
1777 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1778 | return INSN_LOCATION (insn); | |
1779 | } | |
1780 | /* If all else fails, simply return the current function location. */ | |
1781 | return DECL_SOURCE_LOCATION (current_function_decl); | |
1782 | } | |
1783 | ||
71343877 AM |
1784 | /* Records that every statement in LOOP is executed I_BOUND times. |
1785 | REALISTIC is true if I_BOUND is expected to be close to the real number | |
1786 | of iterations. UPPER is true if we are sure the loop iterates at most | |
1787 | I_BOUND times. */ | |
1788 | ||
1789 | void | |
807e902e KZ |
1790 | record_niter_bound (struct loop *loop, const widest_int &i_bound, |
1791 | bool realistic, bool upper) | |
71343877 AM |
1792 | { |
1793 | /* Update the bounds only when there is no previous estimation, or when the | |
1794 | current estimation is smaller. */ | |
1795 | if (upper | |
1796 | && (!loop->any_upper_bound | |
807e902e | 1797 | || wi::ltu_p (i_bound, loop->nb_iterations_upper_bound))) |
71343877 AM |
1798 | { |
1799 | loop->any_upper_bound = true; | |
1800 | loop->nb_iterations_upper_bound = i_bound; | |
1801 | } | |
1802 | if (realistic | |
1803 | && (!loop->any_estimate | |
807e902e | 1804 | || wi::ltu_p (i_bound, loop->nb_iterations_estimate))) |
71343877 AM |
1805 | { |
1806 | loop->any_estimate = true; | |
1807 | loop->nb_iterations_estimate = i_bound; | |
1808 | } | |
1809 | ||
1810 | /* If an upper bound is smaller than the realistic estimate of the | |
1811 | number of iterations, use the upper bound instead. */ | |
1812 | if (loop->any_upper_bound | |
1813 | && loop->any_estimate | |
807e902e KZ |
1814 | && wi::ltu_p (loop->nb_iterations_upper_bound, |
1815 | loop->nb_iterations_estimate)) | |
71343877 AM |
1816 | loop->nb_iterations_estimate = loop->nb_iterations_upper_bound; |
1817 | } | |
1818 | ||
1ef88893 | 1819 | /* Similar to get_estimated_loop_iterations, but returns the estimate only |
71343877 AM |
1820 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate |
1821 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
1822 | ||
1823 | HOST_WIDE_INT | |
1ef88893 | 1824 | get_estimated_loop_iterations_int (struct loop *loop) |
71343877 | 1825 | { |
807e902e | 1826 | widest_int nit; |
71343877 AM |
1827 | HOST_WIDE_INT hwi_nit; |
1828 | ||
1829 | if (!get_estimated_loop_iterations (loop, &nit)) | |
1830 | return -1; | |
1831 | ||
807e902e | 1832 | if (!wi::fits_shwi_p (nit)) |
71343877 AM |
1833 | return -1; |
1834 | hwi_nit = nit.to_shwi (); | |
1835 | ||
1836 | return hwi_nit < 0 ? -1 : hwi_nit; | |
1837 | } | |
1838 | ||
1839 | /* Returns an upper bound on the number of executions of statements | |
1840 | in the LOOP. For statements before the loop exit, this exceeds | |
1841 | the number of execution of the latch by one. */ | |
1842 | ||
1843 | HOST_WIDE_INT | |
1844 | max_stmt_executions_int (struct loop *loop) | |
1845 | { | |
1ef88893 | 1846 | HOST_WIDE_INT nit = get_max_loop_iterations_int (loop); |
71343877 AM |
1847 | HOST_WIDE_INT snit; |
1848 | ||
1849 | if (nit == -1) | |
1850 | return -1; | |
1851 | ||
1852 | snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
1853 | ||
1854 | /* If the computation overflows, return -1. */ | |
1855 | return snit < 0 ? -1 : snit; | |
1856 | } | |
1857 | ||
1858 | /* Sets NIT to the estimated number of executions of the latch of the | |
1859 | LOOP. If we have no reliable estimate, the function returns false, otherwise | |
1860 | returns true. */ | |
1861 | ||
1862 | bool | |
807e902e | 1863 | get_estimated_loop_iterations (struct loop *loop, widest_int *nit) |
71343877 AM |
1864 | { |
1865 | /* Even if the bound is not recorded, possibly we can derrive one from | |
1866 | profile. */ | |
1867 | if (!loop->any_estimate) | |
1868 | { | |
1869 | if (loop->header->count) | |
1870 | { | |
807e902e | 1871 | *nit = gcov_type_to_wide_int |
71343877 AM |
1872 | (expected_loop_iterations_unbounded (loop) + 1); |
1873 | return true; | |
1874 | } | |
1875 | return false; | |
1876 | } | |
1877 | ||
1878 | *nit = loop->nb_iterations_estimate; | |
1879 | return true; | |
1880 | } | |
1881 | ||
1882 | /* Sets NIT to an upper bound for the maximum number of executions of the | |
1883 | latch of the LOOP. If we have no reliable estimate, the function returns | |
1884 | false, otherwise returns true. */ | |
1885 | ||
1886 | bool | |
807e902e | 1887 | get_max_loop_iterations (struct loop *loop, widest_int *nit) |
71343877 AM |
1888 | { |
1889 | if (!loop->any_upper_bound) | |
1890 | return false; | |
1891 | ||
1892 | *nit = loop->nb_iterations_upper_bound; | |
1893 | return true; | |
1894 | } | |
1ef88893 AM |
1895 | |
1896 | /* Similar to get_max_loop_iterations, but returns the estimate only | |
1897 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
1898 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
1899 | ||
1900 | HOST_WIDE_INT | |
1901 | get_max_loop_iterations_int (struct loop *loop) | |
1902 | { | |
807e902e | 1903 | widest_int nit; |
1ef88893 AM |
1904 | HOST_WIDE_INT hwi_nit; |
1905 | ||
1906 | if (!get_max_loop_iterations (loop, &nit)) | |
1907 | return -1; | |
1908 | ||
807e902e | 1909 | if (!wi::fits_shwi_p (nit)) |
1ef88893 AM |
1910 | return -1; |
1911 | hwi_nit = nit.to_shwi (); | |
1912 | ||
1913 | return hwi_nit < 0 ? -1 : hwi_nit; | |
1914 | } | |
1915 | ||
4484a35a | 1916 | /* Returns the loop depth of the loop BB belongs to. */ |
1ef88893 | 1917 | |
4484a35a AM |
1918 | int |
1919 | bb_loop_depth (const_basic_block bb) | |
1920 | { | |
1921 | return bb->loop_father ? loop_depth (bb->loop_father) : 0; | |
1922 | } | |
08c13199 RB |
1923 | |
1924 | /* Marks LOOP for removal and sets LOOPS_NEED_FIXUP. */ | |
1925 | ||
1926 | void | |
1927 | mark_loop_for_removal (loop_p loop) | |
1928 | { | |
024660c5 RB |
1929 | if (loop->header == NULL) |
1930 | return; | |
e4ca2139 | 1931 | loop->former_header = loop->header; |
08c13199 RB |
1932 | loop->header = NULL; |
1933 | loop->latch = NULL; | |
1934 | loops_state_set (LOOPS_NEED_FIXUP); | |
1935 | } |