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402209ff | 1 | /* Natural loop discovery code for GNU compiler. |
d1e082c2 | 2 | Copyright (C) 2000-2013 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" |
a310245f | 25 | #include "function.h" |
402209ff | 26 | #include "basic-block.h" |
3d436d2a | 27 | #include "cfgloop.h" |
718f9c0f | 28 | #include "diagnostic-core.h" |
3d436d2a | 29 | #include "flags.h" |
6de9cd9a | 30 | #include "tree.h" |
442b4905 | 31 | #include "gimple.h" |
5be5c238 | 32 | #include "gimple-iterator.h" |
442b4905 | 33 | #include "gimple-ssa.h" |
89f8f30f | 34 | #include "pointer-set.h" |
9e2f83a5 | 35 | #include "ggc.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 | ||
e0082a72 | 50 | FOR_EACH_BB (bb) |
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 ZD |
159 | loop_iterator li; |
160 | struct loop *loop; | |
402209ff | 161 | |
d73be268 | 162 | if (!current_loops || ! file) |
402209ff JH |
163 | return; |
164 | ||
0fc822d0 | 165 | fprintf (file, ";; %d loops found\n", number_of_loops (cfun)); |
2ecfd709 | 166 | |
42fd6772 | 167 | FOR_EACH_LOOP (li, loop, LI_INCLUDE_ROOT) |
402209ff | 168 | { |
2ecfd709 | 169 | flow_loop_dump (loop, file, loop_dump_aux, verbose); |
402209ff JH |
170 | } |
171 | ||
172 | if (verbose) | |
d73be268 | 173 | flow_loops_cfg_dump (file); |
402209ff JH |
174 | } |
175 | ||
2ecfd709 | 176 | /* Free data allocated for LOOP. */ |
9e2f83a5 | 177 | |
35b07080 | 178 | void |
d329e058 | 179 | flow_loop_free (struct loop *loop) |
2ecfd709 | 180 | { |
6270df4c ZD |
181 | struct loop_exit *exit, *next; |
182 | ||
9771b263 | 183 | vec_free (loop->superloops); |
6270df4c ZD |
184 | |
185 | /* Break the list of the loop exit records. They will be freed when the | |
186 | corresponding edge is rescanned or removed, and this avoids | |
187 | accessing the (already released) head of the list stored in the | |
188 | loop structure. */ | |
9e2f83a5 | 189 | for (exit = loop->exits->next; exit != loop->exits; exit = next) |
6270df4c ZD |
190 | { |
191 | next = exit->next; | |
192 | exit->next = exit; | |
193 | exit->prev = exit; | |
194 | } | |
9e2f83a5 ZD |
195 | |
196 | ggc_free (loop->exits); | |
197 | ggc_free (loop); | |
2ecfd709 ZD |
198 | } |
199 | ||
402209ff JH |
200 | /* Free all the memory allocated for LOOPS. */ |
201 | ||
202 | void | |
d329e058 | 203 | flow_loops_free (struct loops *loops) |
402209ff | 204 | { |
42fd6772 | 205 | if (loops->larray) |
402209ff | 206 | { |
3d436d2a | 207 | unsigned i; |
42fd6772 | 208 | loop_p loop; |
402209ff JH |
209 | |
210 | /* Free the loop descriptors. */ | |
9771b263 | 211 | FOR_EACH_VEC_SAFE_ELT (loops->larray, i, loop) |
402209ff | 212 | { |
2ecfd709 ZD |
213 | if (!loop) |
214 | continue; | |
215 | ||
216 | flow_loop_free (loop); | |
402209ff | 217 | } |
5f0d2358 | 218 | |
9771b263 | 219 | vec_free (loops->larray); |
402209ff JH |
220 | } |
221 | } | |
222 | ||
2ecfd709 ZD |
223 | /* Find the nodes contained within the LOOP with header HEADER. |
224 | Return the number of nodes within the loop. */ | |
402209ff | 225 | |
2b271002 | 226 | int |
d329e058 | 227 | flow_loop_nodes_find (basic_block header, struct loop *loop) |
402209ff | 228 | { |
6e1aa848 | 229 | vec<basic_block> stack = vNULL; |
2ecfd709 | 230 | int num_nodes = 1; |
89f8f30f ZD |
231 | edge latch; |
232 | edge_iterator latch_ei; | |
402209ff | 233 | |
2ecfd709 | 234 | header->loop_father = loop; |
402209ff | 235 | |
89f8f30f | 236 | FOR_EACH_EDGE (latch, latch_ei, loop->header->preds) |
402209ff | 237 | { |
89f8f30f ZD |
238 | if (latch->src->loop_father == loop |
239 | || !dominated_by_p (CDI_DOMINATORS, latch->src, loop->header)) | |
240 | continue; | |
241 | ||
402209ff | 242 | num_nodes++; |
9771b263 | 243 | stack.safe_push (latch->src); |
89f8f30f | 244 | latch->src->loop_father = loop; |
d329e058 | 245 | |
9771b263 | 246 | while (!stack.is_empty ()) |
402209ff | 247 | { |
2ecfd709 ZD |
248 | basic_block node; |
249 | edge e; | |
628f6a4e | 250 | edge_iterator ei; |
402209ff | 251 | |
9771b263 | 252 | node = stack.pop (); |
d329e058 | 253 | |
628f6a4e | 254 | FOR_EACH_EDGE (e, ei, node->preds) |
402209ff | 255 | { |
2ecfd709 ZD |
256 | basic_block ancestor = e->src; |
257 | ||
89f8f30f | 258 | if (ancestor->loop_father != loop) |
2ecfd709 ZD |
259 | { |
260 | ancestor->loop_father = loop; | |
2ecfd709 | 261 | num_nodes++; |
9771b263 | 262 | stack.safe_push (ancestor); |
2ecfd709 | 263 | } |
402209ff JH |
264 | } |
265 | } | |
266 | } | |
9771b263 | 267 | stack.release (); |
89f8f30f | 268 | |
402209ff JH |
269 | return num_nodes; |
270 | } | |
271 | ||
9ba025a2 ZD |
272 | /* Records the vector of superloops of the loop LOOP, whose immediate |
273 | superloop is FATHER. */ | |
274 | ||
35b07080 | 275 | static void |
9ba025a2 | 276 | establish_preds (struct loop *loop, struct loop *father) |
35b07080 | 277 | { |
9ba025a2 ZD |
278 | loop_p ploop; |
279 | unsigned depth = loop_depth (father) + 1; | |
280 | unsigned i; | |
a310245f | 281 | |
9771b263 DN |
282 | loop->superloops = 0; |
283 | vec_alloc (loop->superloops, depth); | |
284 | FOR_EACH_VEC_SAFE_ELT (father->superloops, i, ploop) | |
285 | loop->superloops->quick_push (ploop); | |
286 | loop->superloops->quick_push (father); | |
35b07080 ZD |
287 | |
288 | for (ploop = loop->inner; ploop; ploop = ploop->next) | |
9ba025a2 | 289 | establish_preds (ploop, loop); |
35b07080 ZD |
290 | } |
291 | ||
2ecfd709 | 292 | /* Add LOOP to the loop hierarchy tree where FATHER is father of the |
35b07080 ZD |
293 | added loop. If LOOP has some children, take care of that their |
294 | pred field will be initialized correctly. */ | |
402209ff | 295 | |
2ecfd709 | 296 | void |
d329e058 | 297 | flow_loop_tree_node_add (struct loop *father, struct loop *loop) |
402209ff | 298 | { |
2ecfd709 ZD |
299 | loop->next = father->inner; |
300 | father->inner = loop; | |
2ecfd709 | 301 | |
9ba025a2 | 302 | establish_preds (loop, father); |
402209ff JH |
303 | } |
304 | ||
2ecfd709 | 305 | /* Remove LOOP from the loop hierarchy tree. */ |
402209ff | 306 | |
2ecfd709 | 307 | void |
d329e058 | 308 | flow_loop_tree_node_remove (struct loop *loop) |
402209ff | 309 | { |
2ecfd709 | 310 | struct loop *prev, *father; |
402209ff | 311 | |
9ba025a2 | 312 | father = loop_outer (loop); |
402209ff | 313 | |
2ecfd709 ZD |
314 | /* Remove loop from the list of sons. */ |
315 | if (father->inner == loop) | |
316 | father->inner = loop->next; | |
317 | else | |
318 | { | |
9ba025a2 ZD |
319 | for (prev = father->inner; prev->next != loop; prev = prev->next) |
320 | continue; | |
2ecfd709 ZD |
321 | prev->next = loop->next; |
322 | } | |
402209ff | 323 | |
9771b263 | 324 | loop->superloops = NULL; |
402209ff JH |
325 | } |
326 | ||
6270df4c ZD |
327 | /* Allocates and returns new loop structure. */ |
328 | ||
329 | struct loop * | |
330 | alloc_loop (void) | |
331 | { | |
a9429e29 | 332 | struct loop *loop = ggc_alloc_cleared_loop (); |
9e2f83a5 | 333 | |
a9429e29 | 334 | loop->exits = ggc_alloc_cleared_loop_exit (); |
9e2f83a5 | 335 | loop->exits->next = loop->exits->prev = loop->exits; |
204b560f | 336 | loop->can_be_parallel = false; |
6270df4c | 337 | |
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 (); | |
dd366ec3 RB |
355 | root->num_nodes = n_basic_blocks_for_function (fn); |
356 | root->latch = EXIT_BLOCK_PTR_FOR_FUNCTION (fn); | |
357 | root->header = ENTRY_BLOCK_PTR_FOR_FUNCTION (fn); | |
358 | ENTRY_BLOCK_PTR_FOR_FUNCTION (fn)->loop_father = root; | |
359 | EXIT_BLOCK_PTR_FOR_FUNCTION (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; | |
386 | if (latch != ENTRY_BLOCK_PTR | |
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; | |
409 | vec<loop_p> larray; | |
402209ff | 410 | |
4ed88ee3 ZD |
411 | /* Ensure that the dominators are computed. */ |
412 | calculate_dominance_info (CDI_DOMINATORS); | |
402209ff | 413 | |
0375167b | 414 | if (!loops) |
4ed88ee3 | 415 | { |
0375167b | 416 | loops = ggc_alloc_cleared_loops (); |
dd366ec3 | 417 | init_loops_structure (cfun, loops, 1); |
4ed88ee3 | 418 | } |
402209ff | 419 | |
0375167b RB |
420 | /* Ensure that loop exits were released. */ |
421 | gcc_assert (loops->exits == NULL); | |
402209ff | 422 | |
0375167b RB |
423 | /* Taking care of this degenerate case makes the rest of |
424 | this code simpler. */ | |
425 | if (n_basic_blocks == NUM_FIXED_BLOCKS) | |
426 | return loops; | |
2ecfd709 | 427 | |
0375167b RB |
428 | /* The root loop node contains all basic-blocks. */ |
429 | loops->tree_root->num_nodes = n_basic_blocks; | |
d329e058 | 430 | |
0375167b RB |
431 | /* Compute depth first search order of the CFG so that outer |
432 | natural loops will be found before inner natural loops. */ | |
433 | rc_order = XNEWVEC (int, n_basic_blocks); | |
434 | pre_and_rev_post_order_compute (NULL, rc_order, false); | |
16f2b86a | 435 | |
0375167b RB |
436 | /* Gather all loop headers in reverse completion order and allocate |
437 | loop structures for loops that are not already present. */ | |
c3284718 | 438 | larray.create (loops->larray->length ()); |
0375167b RB |
439 | for (b = 0; b < n_basic_blocks - NUM_FIXED_BLOCKS; b++) |
440 | { | |
441 | basic_block header = BASIC_BLOCK (rc_order[b]); | |
442 | if (bb_loop_header_p (header)) | |
402209ff | 443 | { |
0375167b | 444 | struct loop *loop; |
2ecfd709 | 445 | |
0375167b RB |
446 | /* The current active loop tree has valid loop-fathers for |
447 | header blocks. */ | |
448 | if (!from_scratch | |
449 | && header->loop_father->header == header) | |
2ecfd709 | 450 | { |
0375167b RB |
451 | loop = header->loop_father; |
452 | /* If we found an existing loop remove it from the | |
453 | loop tree. It is going to be inserted again | |
454 | below. */ | |
455 | flow_loop_tree_node_remove (loop); | |
2ecfd709 | 456 | } |
0375167b RB |
457 | else |
458 | { | |
459 | /* Otherwise allocate a new loop structure for the loop. */ | |
460 | loop = alloc_loop (); | |
461 | /* ??? We could re-use unused loop slots here. */ | |
462 | loop->num = loops->larray->length (); | |
463 | vec_safe_push (loops->larray, loop); | |
464 | loop->header = header; | |
465 | ||
466 | if (!from_scratch | |
467 | && dump_file && (dump_flags & TDF_DETAILS)) | |
468 | fprintf (dump_file, "flow_loops_find: discovered new " | |
469 | "loop %d with header %d\n", | |
470 | loop->num, header->index); | |
471 | } | |
6aaf596b RB |
472 | /* Reset latch, we recompute it below. */ |
473 | loop->latch = NULL; | |
0375167b | 474 | larray.safe_push (loop); |
402209ff | 475 | } |
402209ff | 476 | |
0375167b RB |
477 | /* Make blocks part of the loop root node at start. */ |
478 | header->loop_father = loops->tree_root; | |
479 | } | |
2ecfd709 | 480 | |
0375167b | 481 | free (rc_order); |
2ecfd709 | 482 | |
0375167b RB |
483 | /* Now iterate over the loops found, insert them into the loop tree |
484 | and assign basic-block ownership. */ | |
485 | for (i = 0; i < larray.length (); ++i) | |
402209ff | 486 | { |
0375167b RB |
487 | struct loop *loop = larray[i]; |
488 | basic_block header = loop->header; | |
489 | edge_iterator ei; | |
490 | edge e; | |
402209ff | 491 | |
0375167b RB |
492 | flow_loop_tree_node_add (header->loop_father, loop); |
493 | loop->num_nodes = flow_loop_nodes_find (loop->header, loop); | |
402209ff | 494 | |
0375167b RB |
495 | /* Look for the latch for this header block, if it has just a |
496 | single one. */ | |
497 | FOR_EACH_EDGE (e, ei, header->preds) | |
402209ff | 498 | { |
0375167b | 499 | basic_block latch = e->src; |
89f8f30f | 500 | |
0375167b | 501 | if (flow_bb_inside_loop_p (loop, latch)) |
402209ff | 502 | { |
0375167b | 503 | if (loop->latch != NULL) |
402209ff | 504 | { |
0375167b RB |
505 | /* More than one latch edge. */ |
506 | loop->latch = NULL; | |
507 | break; | |
402209ff | 508 | } |
0375167b | 509 | loop->latch = latch; |
402209ff | 510 | } |
402209ff | 511 | } |
2ecfd709 | 512 | } |
3d436d2a | 513 | |
c3284718 | 514 | larray.release (); |
36579663 | 515 | |
0375167b | 516 | return loops; |
402209ff JH |
517 | } |
518 | ||
89f8f30f ZD |
519 | /* Ratio of frequencies of edges so that one of more latch edges is |
520 | considered to belong to inner loop with same header. */ | |
521 | #define HEAVY_EDGE_RATIO 8 | |
522 | ||
523 | /* Minimum number of samples for that we apply | |
524 | find_subloop_latch_edge_by_profile heuristics. */ | |
525 | #define HEAVY_EDGE_MIN_SAMPLES 10 | |
526 | ||
527 | /* If the profile info is available, finds an edge in LATCHES that much more | |
528 | frequent than the remaining edges. Returns such an edge, or NULL if we do | |
529 | not find one. | |
530 | ||
531 | We do not use guessed profile here, only the measured one. The guessed | |
532 | profile is usually too flat and unreliable for this (and it is mostly based | |
533 | on the loop structure of the program, so it does not make much sense to | |
534 | derive the loop structure from it). */ | |
b8698a0f | 535 | |
89f8f30f | 536 | static edge |
9771b263 | 537 | find_subloop_latch_edge_by_profile (vec<edge> latches) |
89f8f30f ZD |
538 | { |
539 | unsigned i; | |
540 | edge e, me = NULL; | |
541 | gcov_type mcount = 0, tcount = 0; | |
542 | ||
9771b263 | 543 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f ZD |
544 | { |
545 | if (e->count > mcount) | |
546 | { | |
547 | me = e; | |
548 | mcount = e->count; | |
549 | } | |
550 | tcount += e->count; | |
551 | } | |
552 | ||
553 | if (tcount < HEAVY_EDGE_MIN_SAMPLES | |
554 | || (tcount - mcount) * HEAVY_EDGE_RATIO > tcount) | |
555 | return NULL; | |
556 | ||
557 | if (dump_file) | |
558 | fprintf (dump_file, | |
559 | "Found latch edge %d -> %d using profile information.\n", | |
560 | me->src->index, me->dest->index); | |
561 | return me; | |
562 | } | |
563 | ||
564 | /* Among LATCHES, guesses a latch edge of LOOP corresponding to subloop, based | |
565 | on the structure of induction variables. Returns this edge, or NULL if we | |
566 | do not find any. | |
567 | ||
568 | We are quite conservative, and look just for an obvious simple innermost | |
569 | loop (which is the case where we would lose the most performance by not | |
570 | disambiguating the loop). More precisely, we look for the following | |
571 | situation: The source of the chosen latch edge dominates sources of all | |
572 | the other latch edges. Additionally, the header does not contain a phi node | |
573 | such that the argument from the chosen edge is equal to the argument from | |
574 | another edge. */ | |
575 | ||
576 | static edge | |
9771b263 | 577 | find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, vec<edge> latches) |
89f8f30f | 578 | { |
9771b263 | 579 | edge e, latch = latches[0]; |
89f8f30f | 580 | unsigned i; |
726a989a RB |
581 | gimple phi; |
582 | gimple_stmt_iterator psi; | |
583 | tree lop; | |
89f8f30f ZD |
584 | basic_block bb; |
585 | ||
586 | /* Find the candidate for the latch edge. */ | |
9771b263 | 587 | for (i = 1; latches.iterate (i, &e); i++) |
89f8f30f ZD |
588 | if (dominated_by_p (CDI_DOMINATORS, latch->src, e->src)) |
589 | latch = e; | |
590 | ||
591 | /* Verify that it dominates all the latch edges. */ | |
9771b263 | 592 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f ZD |
593 | if (!dominated_by_p (CDI_DOMINATORS, e->src, latch->src)) |
594 | return NULL; | |
595 | ||
596 | /* Check for a phi node that would deny that this is a latch edge of | |
597 | a subloop. */ | |
726a989a | 598 | for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) |
89f8f30f | 599 | { |
726a989a | 600 | phi = gsi_stmt (psi); |
89f8f30f ZD |
601 | lop = PHI_ARG_DEF_FROM_EDGE (phi, latch); |
602 | ||
603 | /* Ignore the values that are not changed inside the subloop. */ | |
604 | if (TREE_CODE (lop) != SSA_NAME | |
605 | || SSA_NAME_DEF_STMT (lop) == phi) | |
606 | continue; | |
726a989a | 607 | bb = gimple_bb (SSA_NAME_DEF_STMT (lop)); |
89f8f30f ZD |
608 | if (!bb || !flow_bb_inside_loop_p (loop, bb)) |
609 | continue; | |
610 | ||
9771b263 | 611 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f ZD |
612 | if (e != latch |
613 | && PHI_ARG_DEF_FROM_EDGE (phi, e) == lop) | |
614 | return NULL; | |
615 | } | |
616 | ||
617 | if (dump_file) | |
618 | fprintf (dump_file, | |
619 | "Found latch edge %d -> %d using iv structure.\n", | |
620 | latch->src->index, latch->dest->index); | |
621 | return latch; | |
622 | } | |
623 | ||
624 | /* If we can determine that one of the several latch edges of LOOP behaves | |
625 | as a latch edge of a separate subloop, returns this edge. Otherwise | |
626 | returns NULL. */ | |
627 | ||
628 | static edge | |
629 | find_subloop_latch_edge (struct loop *loop) | |
630 | { | |
9771b263 | 631 | vec<edge> latches = get_loop_latch_edges (loop); |
89f8f30f ZD |
632 | edge latch = NULL; |
633 | ||
9771b263 | 634 | if (latches.length () > 1) |
89f8f30f ZD |
635 | { |
636 | latch = find_subloop_latch_edge_by_profile (latches); | |
637 | ||
638 | if (!latch | |
639 | /* We consider ivs to guess the latch edge only in SSA. Perhaps we | |
640 | should use cfghook for this, but it is hard to imagine it would | |
641 | be useful elsewhere. */ | |
642 | && current_ir_type () == IR_GIMPLE) | |
643 | latch = find_subloop_latch_edge_by_ivs (loop, latches); | |
644 | } | |
645 | ||
9771b263 | 646 | latches.release (); |
89f8f30f ZD |
647 | return latch; |
648 | } | |
649 | ||
650 | /* Callback for make_forwarder_block. Returns true if the edge E is marked | |
651 | in the set MFB_REIS_SET. */ | |
652 | ||
653 | static struct pointer_set_t *mfb_reis_set; | |
654 | static bool | |
655 | mfb_redirect_edges_in_set (edge e) | |
656 | { | |
657 | return pointer_set_contains (mfb_reis_set, e); | |
658 | } | |
659 | ||
660 | /* Creates a subloop of LOOP with latch edge LATCH. */ | |
661 | ||
662 | static void | |
663 | form_subloop (struct loop *loop, edge latch) | |
664 | { | |
665 | edge_iterator ei; | |
666 | edge e, new_entry; | |
667 | struct loop *new_loop; | |
b8698a0f | 668 | |
89f8f30f ZD |
669 | mfb_reis_set = pointer_set_create (); |
670 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
671 | { | |
672 | if (e != latch) | |
673 | pointer_set_insert (mfb_reis_set, e); | |
674 | } | |
675 | new_entry = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
676 | NULL); | |
677 | pointer_set_destroy (mfb_reis_set); | |
678 | ||
679 | loop->header = new_entry->src; | |
680 | ||
681 | /* Find the blocks and subloops that belong to the new loop, and add it to | |
682 | the appropriate place in the loop tree. */ | |
683 | new_loop = alloc_loop (); | |
684 | new_loop->header = new_entry->dest; | |
685 | new_loop->latch = latch->src; | |
686 | add_loop (new_loop, loop); | |
687 | } | |
688 | ||
689 | /* Make all the latch edges of LOOP to go to a single forwarder block -- | |
690 | a new latch of LOOP. */ | |
691 | ||
692 | static void | |
693 | merge_latch_edges (struct loop *loop) | |
694 | { | |
9771b263 | 695 | vec<edge> latches = get_loop_latch_edges (loop); |
89f8f30f ZD |
696 | edge latch, e; |
697 | unsigned i; | |
698 | ||
9771b263 | 699 | gcc_assert (latches.length () > 0); |
89f8f30f | 700 | |
9771b263 DN |
701 | if (latches.length () == 1) |
702 | loop->latch = latches[0]->src; | |
89f8f30f ZD |
703 | else |
704 | { | |
705 | if (dump_file) | |
706 | fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num); | |
707 | ||
708 | mfb_reis_set = pointer_set_create (); | |
9771b263 | 709 | FOR_EACH_VEC_ELT (latches, i, e) |
89f8f30f ZD |
710 | pointer_set_insert (mfb_reis_set, e); |
711 | latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
712 | NULL); | |
713 | pointer_set_destroy (mfb_reis_set); | |
714 | ||
715 | loop->header = latch->dest; | |
716 | loop->latch = latch->src; | |
717 | } | |
718 | ||
9771b263 | 719 | latches.release (); |
89f8f30f ZD |
720 | } |
721 | ||
722 | /* LOOP may have several latch edges. Transform it into (possibly several) | |
723 | loops with single latch edge. */ | |
724 | ||
725 | static void | |
726 | disambiguate_multiple_latches (struct loop *loop) | |
727 | { | |
728 | edge e; | |
729 | ||
ea2c620c | 730 | /* We eliminate the multiple latches by splitting the header to the forwarder |
89f8f30f ZD |
731 | block F and the rest R, and redirecting the edges. There are two cases: |
732 | ||
733 | 1) If there is a latch edge E that corresponds to a subloop (we guess | |
734 | that based on profile -- if it is taken much more often than the | |
735 | remaining edges; and on trees, using the information about induction | |
736 | variables of the loops), we redirect E to R, all the remaining edges to | |
737 | F, then rescan the loops and try again for the outer loop. | |
738 | 2) If there is no such edge, we redirect all latch edges to F, and the | |
739 | entry edges to R, thus making F the single latch of the loop. */ | |
740 | ||
741 | if (dump_file) | |
742 | fprintf (dump_file, "Disambiguating loop %d with multiple latches\n", | |
743 | loop->num); | |
744 | ||
745 | /* During latch merging, we may need to redirect the entry edges to a new | |
746 | block. This would cause problems if the entry edge was the one from the | |
747 | entry block. To avoid having to handle this case specially, split | |
748 | such entry edge. */ | |
749 | e = find_edge (ENTRY_BLOCK_PTR, loop->header); | |
750 | if (e) | |
751 | split_edge (e); | |
752 | ||
753 | while (1) | |
754 | { | |
755 | e = find_subloop_latch_edge (loop); | |
756 | if (!e) | |
757 | break; | |
758 | ||
759 | form_subloop (loop, e); | |
760 | } | |
761 | ||
762 | merge_latch_edges (loop); | |
763 | } | |
764 | ||
765 | /* Split loops with multiple latch edges. */ | |
766 | ||
767 | void | |
768 | disambiguate_loops_with_multiple_latches (void) | |
769 | { | |
770 | loop_iterator li; | |
771 | struct loop *loop; | |
772 | ||
773 | FOR_EACH_LOOP (li, loop, 0) | |
774 | { | |
775 | if (!loop->latch) | |
776 | disambiguate_multiple_latches (loop); | |
777 | } | |
778 | } | |
779 | ||
da7d8304 | 780 | /* Return nonzero if basic block BB belongs to LOOP. */ |
2ecfd709 | 781 | bool |
ed7a4b4b | 782 | flow_bb_inside_loop_p (const struct loop *loop, const_basic_block bb) |
2ecfd709 ZD |
783 | { |
784 | struct loop *source_loop; | |
785 | ||
786 | if (bb == ENTRY_BLOCK_PTR || bb == EXIT_BLOCK_PTR) | |
787 | return 0; | |
788 | ||
789 | source_loop = bb->loop_father; | |
790 | return loop == source_loop || flow_loop_nested_p (loop, source_loop); | |
791 | } | |
792 | ||
89f8f30f | 793 | /* Enumeration predicate for get_loop_body_with_size. */ |
2ecfd709 | 794 | static bool |
ed7a4b4b | 795 | glb_enum_p (const_basic_block bb, const void *glb_loop) |
2ecfd709 | 796 | { |
ed7a4b4b | 797 | const struct loop *const loop = (const struct loop *) glb_loop; |
89f8f30f ZD |
798 | return (bb != loop->header |
799 | && dominated_by_p (CDI_DOMINATORS, bb, loop->header)); | |
800 | } | |
801 | ||
802 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
803 | order against direction of edges from latch. Specially, if | |
804 | header != latch, latch is the 1-st block. LOOP cannot be the fake | |
805 | loop tree root, and its size must be at most MAX_SIZE. The blocks | |
806 | in the LOOP body are stored to BODY, and the size of the LOOP is | |
807 | returned. */ | |
808 | ||
809 | unsigned | |
810 | get_loop_body_with_size (const struct loop *loop, basic_block *body, | |
811 | unsigned max_size) | |
812 | { | |
813 | return dfs_enumerate_from (loop->header, 1, glb_enum_p, | |
ed7a4b4b | 814 | body, max_size, loop); |
2ecfd709 ZD |
815 | } |
816 | ||
8d28e87d ZD |
817 | /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs |
818 | order against direction of edges from latch. Specially, if | |
819 | header != latch, latch is the 1-st block. */ | |
89f8f30f | 820 | |
2ecfd709 | 821 | basic_block * |
d329e058 | 822 | get_loop_body (const struct loop *loop) |
2ecfd709 | 823 | { |
89f8f30f | 824 | basic_block *body, bb; |
3d436d2a | 825 | unsigned tv = 0; |
2ecfd709 | 826 | |
341c100f | 827 | gcc_assert (loop->num_nodes); |
2ecfd709 | 828 | |
c302207e | 829 | body = XNEWVEC (basic_block, loop->num_nodes); |
2ecfd709 ZD |
830 | |
831 | if (loop->latch == EXIT_BLOCK_PTR) | |
832 | { | |
89f8f30f ZD |
833 | /* There may be blocks unreachable from EXIT_BLOCK, hence we need to |
834 | special-case the fake loop that contains the whole function. */ | |
24bd1a0b | 835 | gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks); |
89f8f30f ZD |
836 | body[tv++] = loop->header; |
837 | body[tv++] = EXIT_BLOCK_PTR; | |
2ecfd709 | 838 | FOR_EACH_BB (bb) |
89f8f30f | 839 | body[tv++] = bb; |
2ecfd709 | 840 | } |
89f8f30f ZD |
841 | else |
842 | tv = get_loop_body_with_size (loop, body, loop->num_nodes); | |
2ecfd709 | 843 | |
341c100f | 844 | gcc_assert (tv == loop->num_nodes); |
89f8f30f | 845 | return body; |
2ecfd709 ZD |
846 | } |
847 | ||
50654f6c ZD |
848 | /* Fills dominance descendants inside LOOP of the basic block BB into |
849 | array TOVISIT from index *TV. */ | |
850 | ||
851 | static void | |
852 | fill_sons_in_loop (const struct loop *loop, basic_block bb, | |
853 | basic_block *tovisit, int *tv) | |
854 | { | |
855 | basic_block son, postpone = NULL; | |
856 | ||
857 | tovisit[(*tv)++] = bb; | |
858 | for (son = first_dom_son (CDI_DOMINATORS, bb); | |
859 | son; | |
860 | son = next_dom_son (CDI_DOMINATORS, son)) | |
861 | { | |
862 | if (!flow_bb_inside_loop_p (loop, son)) | |
863 | continue; | |
864 | ||
865 | if (dominated_by_p (CDI_DOMINATORS, loop->latch, son)) | |
866 | { | |
867 | postpone = son; | |
868 | continue; | |
869 | } | |
870 | fill_sons_in_loop (loop, son, tovisit, tv); | |
871 | } | |
872 | ||
873 | if (postpone) | |
874 | fill_sons_in_loop (loop, postpone, tovisit, tv); | |
875 | } | |
876 | ||
877 | /* Gets body of a LOOP (that must be different from the outermost loop) | |
878 | sorted by dominance relation. Additionally, if a basic block s dominates | |
879 | the latch, then only blocks dominated by s are be after it. */ | |
880 | ||
881 | basic_block * | |
882 | get_loop_body_in_dom_order (const struct loop *loop) | |
883 | { | |
884 | basic_block *tovisit; | |
885 | int tv; | |
886 | ||
341c100f | 887 | gcc_assert (loop->num_nodes); |
50654f6c | 888 | |
c302207e | 889 | tovisit = XNEWVEC (basic_block, loop->num_nodes); |
50654f6c | 890 | |
341c100f | 891 | gcc_assert (loop->latch != EXIT_BLOCK_PTR); |
50654f6c ZD |
892 | |
893 | tv = 0; | |
894 | fill_sons_in_loop (loop, loop->header, tovisit, &tv); | |
895 | ||
341c100f | 896 | gcc_assert (tv == (int) loop->num_nodes); |
50654f6c ZD |
897 | |
898 | return tovisit; | |
899 | } | |
900 | ||
e855c69d AB |
901 | /* Gets body of a LOOP sorted via provided BB_COMPARATOR. */ |
902 | ||
903 | basic_block * | |
b8698a0f | 904 | get_loop_body_in_custom_order (const struct loop *loop, |
e855c69d AB |
905 | int (*bb_comparator) (const void *, const void *)) |
906 | { | |
907 | basic_block *bbs = get_loop_body (loop); | |
908 | ||
909 | qsort (bbs, loop->num_nodes, sizeof (basic_block), bb_comparator); | |
910 | ||
911 | return bbs; | |
912 | } | |
913 | ||
40923b20 DP |
914 | /* Get body of a LOOP in breadth first sort order. */ |
915 | ||
916 | basic_block * | |
917 | get_loop_body_in_bfs_order (const struct loop *loop) | |
918 | { | |
919 | basic_block *blocks; | |
920 | basic_block bb; | |
921 | bitmap visited; | |
922 | unsigned int i = 0; | |
923 | unsigned int vc = 1; | |
924 | ||
341c100f NS |
925 | gcc_assert (loop->num_nodes); |
926 | gcc_assert (loop->latch != EXIT_BLOCK_PTR); | |
40923b20 | 927 | |
c302207e | 928 | blocks = XNEWVEC (basic_block, loop->num_nodes); |
8bdbfff5 | 929 | visited = BITMAP_ALLOC (NULL); |
40923b20 DP |
930 | |
931 | bb = loop->header; | |
932 | while (i < loop->num_nodes) | |
933 | { | |
934 | edge e; | |
628f6a4e | 935 | edge_iterator ei; |
c22cacf3 | 936 | |
fcaa4ca4 NF |
937 | if (bitmap_set_bit (visited, bb->index)) |
938 | /* This basic block is now visited */ | |
939 | blocks[i++] = bb; | |
c22cacf3 | 940 | |
628f6a4e | 941 | FOR_EACH_EDGE (e, ei, bb->succs) |
c22cacf3 MS |
942 | { |
943 | if (flow_bb_inside_loop_p (loop, e->dest)) | |
944 | { | |
fcaa4ca4 NF |
945 | if (bitmap_set_bit (visited, e->dest->index)) |
946 | blocks[i++] = e->dest; | |
c22cacf3 MS |
947 | } |
948 | } | |
949 | ||
341c100f | 950 | gcc_assert (i >= vc); |
c22cacf3 | 951 | |
40923b20 DP |
952 | bb = blocks[vc++]; |
953 | } | |
c22cacf3 | 954 | |
8bdbfff5 | 955 | BITMAP_FREE (visited); |
40923b20 DP |
956 | return blocks; |
957 | } | |
958 | ||
6270df4c ZD |
959 | /* Hash function for struct loop_exit. */ |
960 | ||
961 | static hashval_t | |
962 | loop_exit_hash (const void *ex) | |
963 | { | |
5f754896 | 964 | const struct loop_exit *const exit = (const struct loop_exit *) ex; |
6270df4c ZD |
965 | |
966 | return htab_hash_pointer (exit->e); | |
967 | } | |
968 | ||
969 | /* Equality function for struct loop_exit. Compares with edge. */ | |
970 | ||
971 | static int | |
972 | loop_exit_eq (const void *ex, const void *e) | |
973 | { | |
5f754896 | 974 | const struct loop_exit *const exit = (const struct loop_exit *) ex; |
6270df4c ZD |
975 | |
976 | return exit->e == e; | |
977 | } | |
978 | ||
979 | /* Frees the list of loop exit descriptions EX. */ | |
980 | ||
981 | static void | |
982 | loop_exit_free (void *ex) | |
983 | { | |
984 | struct loop_exit *exit = (struct loop_exit *) ex, *next; | |
985 | ||
986 | for (; exit; exit = next) | |
987 | { | |
988 | next = exit->next_e; | |
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 | { | |
ae50c0cb TN |
1002 | return (struct loop_exit *) htab_find_with_hash (current_loops->exits, e, |
1003 | htab_hash_pointer (e)); | |
6270df4c ZD |
1004 | } |
1005 | ||
1006 | /* Updates the lists of loop exits in that E appears. | |
1007 | If REMOVED is true, E is being removed, and we | |
1008 | just remove it from the lists of exits. | |
1009 | If NEW_EDGE is true and E is not a loop exit, we | |
1010 | do not try to remove it from loop exit lists. */ | |
1011 | ||
1012 | void | |
1013 | rescan_loop_exit (edge e, bool new_edge, bool removed) | |
1014 | { | |
1015 | void **slot; | |
1016 | struct loop_exit *exits = NULL, *exit; | |
1017 | struct loop *aloop, *cloop; | |
1018 | ||
f87000d0 | 1019 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c ZD |
1020 | return; |
1021 | ||
1022 | if (!removed | |
1023 | && e->src->loop_father != NULL | |
1024 | && e->dest->loop_father != NULL | |
1025 | && !flow_bb_inside_loop_p (e->src->loop_father, e->dest)) | |
1026 | { | |
1027 | cloop = find_common_loop (e->src->loop_father, e->dest->loop_father); | |
1028 | for (aloop = e->src->loop_father; | |
1029 | aloop != cloop; | |
9ba025a2 | 1030 | aloop = loop_outer (aloop)) |
6270df4c | 1031 | { |
a9429e29 | 1032 | exit = ggc_alloc_loop_exit (); |
6270df4c ZD |
1033 | exit->e = e; |
1034 | ||
9e2f83a5 ZD |
1035 | exit->next = aloop->exits->next; |
1036 | exit->prev = aloop->exits; | |
6270df4c ZD |
1037 | exit->next->prev = exit; |
1038 | exit->prev->next = exit; | |
1039 | ||
1040 | exit->next_e = exits; | |
1041 | exits = exit; | |
1042 | } | |
b8698a0f | 1043 | } |
6270df4c ZD |
1044 | |
1045 | if (!exits && new_edge) | |
1046 | return; | |
1047 | ||
1048 | slot = htab_find_slot_with_hash (current_loops->exits, e, | |
1049 | htab_hash_pointer (e), | |
1050 | exits ? INSERT : NO_INSERT); | |
1051 | if (!slot) | |
1052 | return; | |
1053 | ||
1054 | if (exits) | |
1055 | { | |
1056 | if (*slot) | |
1057 | loop_exit_free (*slot); | |
1058 | *slot = exits; | |
1059 | } | |
1060 | else | |
1061 | htab_clear_slot (current_loops->exits, slot); | |
1062 | } | |
1063 | ||
1064 | /* For each loop, record list of exit edges, and start maintaining these | |
1065 | lists. */ | |
1066 | ||
1067 | void | |
1068 | record_loop_exits (void) | |
1069 | { | |
1070 | basic_block bb; | |
1071 | edge_iterator ei; | |
1072 | edge e; | |
1073 | ||
4839cb59 ZD |
1074 | if (!current_loops) |
1075 | return; | |
1076 | ||
f87000d0 | 1077 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1078 | return; |
f87000d0 | 1079 | loops_state_set (LOOPS_HAVE_RECORDED_EXITS); |
6270df4c ZD |
1080 | |
1081 | gcc_assert (current_loops->exits == NULL); | |
0fc822d0 | 1082 | current_loops->exits = htab_create_ggc (2 * number_of_loops (cfun), |
a9429e29 LB |
1083 | loop_exit_hash, loop_exit_eq, |
1084 | loop_exit_free); | |
6270df4c ZD |
1085 | |
1086 | FOR_EACH_BB (bb) | |
1087 | { | |
1088 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1089 | { | |
1090 | rescan_loop_exit (e, true, false); | |
1091 | } | |
1092 | } | |
1093 | } | |
1094 | ||
1095 | /* Dumps information about the exit in *SLOT to FILE. | |
1096 | Callback for htab_traverse. */ | |
1097 | ||
1098 | static int | |
1099 | dump_recorded_exit (void **slot, void *file) | |
1100 | { | |
ae50c0cb | 1101 | struct loop_exit *exit = (struct loop_exit *) *slot; |
6270df4c ZD |
1102 | unsigned n = 0; |
1103 | edge e = exit->e; | |
1104 | ||
1105 | for (; exit != NULL; exit = exit->next_e) | |
1106 | n++; | |
1107 | ||
ae50c0cb | 1108 | fprintf ((FILE*) file, "Edge %d->%d exits %u loops\n", |
6270df4c ZD |
1109 | e->src->index, e->dest->index, n); |
1110 | ||
1111 | return 1; | |
1112 | } | |
1113 | ||
1114 | /* Dumps the recorded exits of loops to FILE. */ | |
1115 | ||
1116 | extern void dump_recorded_exits (FILE *); | |
1117 | void | |
1118 | dump_recorded_exits (FILE *file) | |
1119 | { | |
1120 | if (!current_loops->exits) | |
1121 | return; | |
1122 | htab_traverse (current_loops->exits, dump_recorded_exit, file); | |
1123 | } | |
1124 | ||
1125 | /* Releases lists of loop exits. */ | |
1126 | ||
1127 | void | |
1128 | release_recorded_exits (void) | |
1129 | { | |
f87000d0 | 1130 | gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)); |
6270df4c ZD |
1131 | htab_delete (current_loops->exits); |
1132 | current_loops->exits = NULL; | |
f87000d0 | 1133 | loops_state_clear (LOOPS_HAVE_RECORDED_EXITS); |
6270df4c ZD |
1134 | } |
1135 | ||
ca83d385 ZD |
1136 | /* Returns the list of the exit edges of a LOOP. */ |
1137 | ||
9771b263 | 1138 | vec<edge> |
ca83d385 | 1139 | get_loop_exit_edges (const struct loop *loop) |
35b07080 | 1140 | { |
6e1aa848 | 1141 | vec<edge> edges = vNULL; |
ca83d385 ZD |
1142 | edge e; |
1143 | unsigned i; | |
1144 | basic_block *body; | |
628f6a4e | 1145 | edge_iterator ei; |
6270df4c | 1146 | struct loop_exit *exit; |
35b07080 | 1147 | |
341c100f | 1148 | gcc_assert (loop->latch != EXIT_BLOCK_PTR); |
35b07080 | 1149 | |
6270df4c ZD |
1150 | /* If we maintain the lists of exits, use them. Otherwise we must |
1151 | scan the body of the loop. */ | |
f87000d0 | 1152 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1153 | { |
9e2f83a5 | 1154 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
9771b263 | 1155 | edges.safe_push (exit->e); |
6270df4c ZD |
1156 | } |
1157 | else | |
1158 | { | |
1159 | body = get_loop_body (loop); | |
1160 | for (i = 0; i < loop->num_nodes; i++) | |
1161 | FOR_EACH_EDGE (e, ei, body[i]->succs) | |
1162 | { | |
1163 | if (!flow_bb_inside_loop_p (loop, e->dest)) | |
9771b263 | 1164 | edges.safe_push (e); |
6270df4c ZD |
1165 | } |
1166 | free (body); | |
1167 | } | |
35b07080 ZD |
1168 | |
1169 | return edges; | |
1170 | } | |
1171 | ||
50654f6c ZD |
1172 | /* Counts the number of conditional branches inside LOOP. */ |
1173 | ||
1174 | unsigned | |
1175 | num_loop_branches (const struct loop *loop) | |
1176 | { | |
1177 | unsigned i, n; | |
1178 | basic_block * body; | |
1179 | ||
341c100f | 1180 | gcc_assert (loop->latch != EXIT_BLOCK_PTR); |
50654f6c ZD |
1181 | |
1182 | body = get_loop_body (loop); | |
1183 | n = 0; | |
1184 | for (i = 0; i < loop->num_nodes; i++) | |
628f6a4e | 1185 | if (EDGE_COUNT (body[i]->succs) >= 2) |
50654f6c ZD |
1186 | n++; |
1187 | free (body); | |
1188 | ||
1189 | return n; | |
1190 | } | |
1191 | ||
2ecfd709 ZD |
1192 | /* Adds basic block BB to LOOP. */ |
1193 | void | |
d329e058 AJ |
1194 | add_bb_to_loop (basic_block bb, struct loop *loop) |
1195 | { | |
9ba025a2 ZD |
1196 | unsigned i; |
1197 | loop_p ploop; | |
6270df4c ZD |
1198 | edge_iterator ei; |
1199 | edge e; | |
1200 | ||
1201 | gcc_assert (bb->loop_father == NULL); | |
1202 | bb->loop_father = loop; | |
6270df4c | 1203 | loop->num_nodes++; |
9771b263 | 1204 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9ba025a2 | 1205 | ploop->num_nodes++; |
6270df4c ZD |
1206 | |
1207 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1208 | { | |
1209 | rescan_loop_exit (e, true, false); | |
1210 | } | |
1211 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1212 | { | |
1213 | rescan_loop_exit (e, true, false); | |
1214 | } | |
598ec7bd | 1215 | } |
2ecfd709 ZD |
1216 | |
1217 | /* Remove basic block BB from loops. */ | |
1218 | void | |
d329e058 AJ |
1219 | remove_bb_from_loops (basic_block bb) |
1220 | { | |
9771b263 | 1221 | unsigned i; |
6270df4c | 1222 | struct loop *loop = bb->loop_father; |
9ba025a2 | 1223 | loop_p ploop; |
6270df4c ZD |
1224 | edge_iterator ei; |
1225 | edge e; | |
1226 | ||
1227 | gcc_assert (loop != NULL); | |
1228 | loop->num_nodes--; | |
9771b263 | 1229 | FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
9ba025a2 | 1230 | ploop->num_nodes--; |
6270df4c | 1231 | bb->loop_father = NULL; |
6270df4c ZD |
1232 | |
1233 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1234 | { | |
1235 | rescan_loop_exit (e, false, true); | |
1236 | } | |
1237 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1238 | { | |
1239 | rescan_loop_exit (e, false, true); | |
1240 | } | |
a310245f | 1241 | } |
2ecfd709 ZD |
1242 | |
1243 | /* Finds nearest common ancestor in loop tree for given loops. */ | |
1244 | struct loop * | |
d329e058 | 1245 | find_common_loop (struct loop *loop_s, struct loop *loop_d) |
2ecfd709 | 1246 | { |
9ba025a2 ZD |
1247 | unsigned sdepth, ddepth; |
1248 | ||
2ecfd709 ZD |
1249 | if (!loop_s) return loop_d; |
1250 | if (!loop_d) return loop_s; | |
d329e058 | 1251 | |
9ba025a2 ZD |
1252 | sdepth = loop_depth (loop_s); |
1253 | ddepth = loop_depth (loop_d); | |
1254 | ||
1255 | if (sdepth < ddepth) | |
9771b263 | 1256 | loop_d = (*loop_d->superloops)[sdepth]; |
9ba025a2 | 1257 | else if (sdepth > ddepth) |
9771b263 | 1258 | loop_s = (*loop_s->superloops)[ddepth]; |
2ecfd709 ZD |
1259 | |
1260 | while (loop_s != loop_d) | |
1261 | { | |
9ba025a2 ZD |
1262 | loop_s = loop_outer (loop_s); |
1263 | loop_d = loop_outer (loop_d); | |
2ecfd709 ZD |
1264 | } |
1265 | return loop_s; | |
1266 | } | |
1267 | ||
42fd6772 ZD |
1268 | /* Removes LOOP from structures and frees its data. */ |
1269 | ||
1270 | void | |
1271 | delete_loop (struct loop *loop) | |
1272 | { | |
1273 | /* Remove the loop from structure. */ | |
1274 | flow_loop_tree_node_remove (loop); | |
1275 | ||
1276 | /* Remove loop from loops array. */ | |
9771b263 | 1277 | (*current_loops->larray)[loop->num] = NULL; |
42fd6772 ZD |
1278 | |
1279 | /* Free loop data. */ | |
1280 | flow_loop_free (loop); | |
1281 | } | |
1282 | ||
3d436d2a | 1283 | /* Cancels the LOOP; it must be innermost one. */ |
b00bf166 KH |
1284 | |
1285 | static void | |
d73be268 | 1286 | cancel_loop (struct loop *loop) |
3d436d2a ZD |
1287 | { |
1288 | basic_block *bbs; | |
1289 | unsigned i; | |
9ba025a2 | 1290 | struct loop *outer = loop_outer (loop); |
3d436d2a | 1291 | |
341c100f | 1292 | gcc_assert (!loop->inner); |
3d436d2a ZD |
1293 | |
1294 | /* Move blocks up one level (they should be removed as soon as possible). */ | |
1295 | bbs = get_loop_body (loop); | |
1296 | for (i = 0; i < loop->num_nodes; i++) | |
9ba025a2 | 1297 | bbs[i]->loop_father = outer; |
3d436d2a | 1298 | |
b78384e0 | 1299 | free (bbs); |
42fd6772 | 1300 | delete_loop (loop); |
3d436d2a ZD |
1301 | } |
1302 | ||
1303 | /* Cancels LOOP and all its subloops. */ | |
1304 | void | |
d73be268 | 1305 | cancel_loop_tree (struct loop *loop) |
3d436d2a ZD |
1306 | { |
1307 | while (loop->inner) | |
d73be268 ZD |
1308 | cancel_loop_tree (loop->inner); |
1309 | cancel_loop (loop); | |
3d436d2a ZD |
1310 | } |
1311 | ||
d73be268 | 1312 | /* Checks that information about loops is correct |
e0bb17a8 | 1313 | -- sizes of loops are all right |
2ecfd709 ZD |
1314 | -- results of get_loop_body really belong to the loop |
1315 | -- loop header have just single entry edge and single latch edge | |
1316 | -- loop latches have only single successor that is header of their loop | |
3d436d2a | 1317 | -- irreducible loops are correctly marked |
cc360b36 | 1318 | -- the cached loop depth and loop father of each bb is correct |
2ecfd709 | 1319 | */ |
24e47c76 | 1320 | DEBUG_FUNCTION void |
d73be268 | 1321 | verify_loop_structure (void) |
2ecfd709 | 1322 | { |
3d436d2a ZD |
1323 | unsigned *sizes, i, j; |
1324 | sbitmap irreds; | |
a271b42d | 1325 | basic_block bb, *bbs; |
2ecfd709 ZD |
1326 | struct loop *loop; |
1327 | int err = 0; | |
35b07080 | 1328 | edge e; |
0fc822d0 | 1329 | unsigned num = number_of_loops (cfun); |
42fd6772 | 1330 | loop_iterator li; |
6270df4c | 1331 | struct loop_exit *exit, *mexit; |
7d776ee2 | 1332 | bool dom_available = dom_info_available_p (CDI_DOMINATORS); |
0375167b | 1333 | sbitmap visited; |
2ecfd709 | 1334 | |
a9e0d843 RB |
1335 | if (loops_state_satisfies_p (LOOPS_NEED_FIXUP)) |
1336 | { | |
1337 | error ("loop verification on loop tree that needs fixup"); | |
1338 | err = 1; | |
1339 | } | |
1340 | ||
7d776ee2 RG |
1341 | /* We need up-to-date dominators, compute or verify them. */ |
1342 | if (!dom_available) | |
1343 | calculate_dominance_info (CDI_DOMINATORS); | |
1344 | else | |
1345 | verify_dominators (CDI_DOMINATORS); | |
510dbcce | 1346 | |
f64fb0fa MP |
1347 | /* Check the headers. */ |
1348 | FOR_EACH_BB (bb) | |
a271b42d | 1349 | if (bb_loop_header_p (bb)) |
f64fb0fa | 1350 | { |
a271b42d RB |
1351 | if (bb->loop_father->header == NULL) |
1352 | { | |
1353 | error ("loop with header %d marked for removal", bb->index); | |
1354 | err = 1; | |
1355 | } | |
1356 | else if (bb->loop_father->header != bb) | |
1357 | { | |
1358 | error ("loop with header %d not in loop tree", bb->index); | |
1359 | err = 1; | |
1360 | } | |
1361 | } | |
1362 | else if (bb->loop_father->header == bb) | |
1363 | { | |
1364 | error ("non-loop with header %d not marked for removal", bb->index); | |
f64fb0fa MP |
1365 | err = 1; |
1366 | } | |
1367 | ||
a271b42d | 1368 | /* Check the recorded loop father and sizes of loops. */ |
0375167b | 1369 | visited = sbitmap_alloc (last_basic_block); |
f61e445a | 1370 | bitmap_clear (visited); |
a271b42d | 1371 | bbs = XNEWVEC (basic_block, n_basic_blocks); |
cc360b36 SB |
1372 | FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST) |
1373 | { | |
a271b42d | 1374 | unsigned n; |
cc360b36 | 1375 | |
a271b42d RB |
1376 | if (loop->header == NULL) |
1377 | { | |
1378 | error ("removed loop %d in loop tree", loop->num); | |
1379 | err = 1; | |
1380 | continue; | |
1381 | } | |
1382 | ||
1383 | n = get_loop_body_with_size (loop, bbs, n_basic_blocks); | |
1384 | if (loop->num_nodes != n) | |
1385 | { | |
1386 | error ("size of loop %d should be %d, not %d", | |
1387 | loop->num, n, loop->num_nodes); | |
1388 | err = 1; | |
1389 | } | |
1390 | ||
1391 | for (j = 0; j < n; j++) | |
cc360b36 SB |
1392 | { |
1393 | bb = bbs[j]; | |
1394 | ||
0375167b RB |
1395 | if (!flow_bb_inside_loop_p (loop, bb)) |
1396 | { | |
1397 | error ("bb %d does not belong to loop %d", | |
1398 | bb->index, loop->num); | |
1399 | err = 1; | |
1400 | } | |
1401 | ||
cc360b36 | 1402 | /* Ignore this block if it is in an inner loop. */ |
d7c028c0 | 1403 | if (bitmap_bit_p (visited, bb->index)) |
cc360b36 | 1404 | continue; |
d7c028c0 | 1405 | bitmap_set_bit (visited, bb->index); |
cc360b36 SB |
1406 | |
1407 | if (bb->loop_father != loop) | |
1408 | { | |
1409 | error ("bb %d has father loop %d, should be loop %d", | |
1410 | bb->index, bb->loop_father->num, loop->num); | |
1411 | err = 1; | |
1412 | } | |
1413 | } | |
cc360b36 | 1414 | } |
a271b42d | 1415 | free (bbs); |
0375167b | 1416 | sbitmap_free (visited); |
2ecfd709 ZD |
1417 | |
1418 | /* Check headers and latches. */ | |
42fd6772 | 1419 | FOR_EACH_LOOP (li, loop, 0) |
2ecfd709 | 1420 | { |
42fd6772 | 1421 | i = loop->num; |
a271b42d RB |
1422 | if (loop->header == NULL) |
1423 | continue; | |
0375167b RB |
1424 | if (!bb_loop_header_p (loop->header)) |
1425 | { | |
1426 | error ("loop %d%'s header is not a loop header", i); | |
1427 | err = 1; | |
1428 | } | |
f87000d0 | 1429 | if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
628f6a4e | 1430 | && EDGE_COUNT (loop->header->preds) != 2) |
2ecfd709 | 1431 | { |
d8a07487 | 1432 | error ("loop %d%'s header does not have exactly 2 entries", i); |
2ecfd709 ZD |
1433 | err = 1; |
1434 | } | |
6aaf596b RB |
1435 | if (loop->latch) |
1436 | { | |
1437 | if (!find_edge (loop->latch, loop->header)) | |
1438 | { | |
1439 | error ("loop %d%'s latch does not have an edge to its header", i); | |
1440 | err = 1; | |
1441 | } | |
1442 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, loop->header)) | |
1443 | { | |
1444 | error ("loop %d%'s latch is not dominated by its header", i); | |
1445 | err = 1; | |
1446 | } | |
1447 | } | |
f87000d0 | 1448 | if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
2ecfd709 | 1449 | { |
c5cbcccf | 1450 | if (!single_succ_p (loop->latch)) |
2ecfd709 | 1451 | { |
d8a07487 | 1452 | error ("loop %d%'s latch does not have exactly 1 successor", i); |
2ecfd709 ZD |
1453 | err = 1; |
1454 | } | |
c5cbcccf | 1455 | if (single_succ (loop->latch) != loop->header) |
2ecfd709 | 1456 | { |
d8a07487 | 1457 | error ("loop %d%'s latch does not have header as successor", i); |
2ecfd709 ZD |
1458 | err = 1; |
1459 | } | |
1460 | if (loop->latch->loop_father != loop) | |
1461 | { | |
d8a07487 | 1462 | error ("loop %d%'s latch does not belong directly to it", i); |
2ecfd709 ZD |
1463 | err = 1; |
1464 | } | |
1465 | } | |
1466 | if (loop->header->loop_father != loop) | |
1467 | { | |
d8a07487 | 1468 | error ("loop %d%'s header does not belong directly to it", i); |
2ecfd709 ZD |
1469 | err = 1; |
1470 | } | |
f87000d0 | 1471 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) |
35b07080 ZD |
1472 | && (loop_latch_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)) |
1473 | { | |
d8a07487 | 1474 | error ("loop %d%'s latch is marked as part of irreducible region", i); |
35b07080 ZD |
1475 | err = 1; |
1476 | } | |
2ecfd709 ZD |
1477 | } |
1478 | ||
3d436d2a | 1479 | /* Check irreducible loops. */ |
f87000d0 | 1480 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
3d436d2a ZD |
1481 | { |
1482 | /* Record old info. */ | |
1483 | irreds = sbitmap_alloc (last_basic_block); | |
1484 | FOR_EACH_BB (bb) | |
35b07080 | 1485 | { |
628f6a4e | 1486 | edge_iterator ei; |
35b07080 | 1487 | if (bb->flags & BB_IRREDUCIBLE_LOOP) |
d7c028c0 | 1488 | bitmap_set_bit (irreds, bb->index); |
35b07080 | 1489 | else |
d7c028c0 | 1490 | bitmap_clear_bit (irreds, bb->index); |
628f6a4e | 1491 | FOR_EACH_EDGE (e, ei, bb->succs) |
35b07080 | 1492 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) |
d329e058 | 1493 | e->flags |= EDGE_ALL_FLAGS + 1; |
35b07080 | 1494 | } |
3d436d2a ZD |
1495 | |
1496 | /* Recount it. */ | |
d73be268 | 1497 | mark_irreducible_loops (); |
3d436d2a ZD |
1498 | |
1499 | /* Compare. */ | |
1500 | FOR_EACH_BB (bb) | |
1501 | { | |
628f6a4e BE |
1502 | edge_iterator ei; |
1503 | ||
3d436d2a | 1504 | if ((bb->flags & BB_IRREDUCIBLE_LOOP) |
d7c028c0 | 1505 | && !bitmap_bit_p (irreds, bb->index)) |
3d436d2a | 1506 | { |
ab532386 | 1507 | error ("basic block %d should be marked irreducible", bb->index); |
3d436d2a ZD |
1508 | err = 1; |
1509 | } | |
1510 | else if (!(bb->flags & BB_IRREDUCIBLE_LOOP) | |
d7c028c0 | 1511 | && bitmap_bit_p (irreds, bb->index)) |
3d436d2a | 1512 | { |
ab532386 | 1513 | error ("basic block %d should not be marked irreducible", bb->index); |
3d436d2a ZD |
1514 | err = 1; |
1515 | } | |
628f6a4e | 1516 | FOR_EACH_EDGE (e, ei, bb->succs) |
35b07080 ZD |
1517 | { |
1518 | if ((e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1519 | && !(e->flags & (EDGE_ALL_FLAGS + 1))) | |
1520 | { | |
ab532386 | 1521 | error ("edge from %d to %d should be marked irreducible", |
35b07080 ZD |
1522 | e->src->index, e->dest->index); |
1523 | err = 1; | |
1524 | } | |
1525 | else if (!(e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1526 | && (e->flags & (EDGE_ALL_FLAGS + 1))) | |
1527 | { | |
ab532386 | 1528 | error ("edge from %d to %d should not be marked irreducible", |
35b07080 ZD |
1529 | e->src->index, e->dest->index); |
1530 | err = 1; | |
1531 | } | |
1532 | e->flags &= ~(EDGE_ALL_FLAGS + 1); | |
1533 | } | |
3d436d2a ZD |
1534 | } |
1535 | free (irreds); | |
1536 | } | |
1537 | ||
6270df4c ZD |
1538 | /* Check the recorded loop exits. */ |
1539 | FOR_EACH_LOOP (li, loop, 0) | |
82b85a85 | 1540 | { |
9e2f83a5 | 1541 | if (!loop->exits || loop->exits->e != NULL) |
6270df4c ZD |
1542 | { |
1543 | error ("corrupted head of the exits list of loop %d", | |
1544 | loop->num); | |
1545 | err = 1; | |
1546 | } | |
1547 | else | |
1548 | { | |
1549 | /* Check that the list forms a cycle, and all elements except | |
1550 | for the head are nonnull. */ | |
9e2f83a5 | 1551 | for (mexit = loop->exits, exit = mexit->next, i = 0; |
6270df4c ZD |
1552 | exit->e && exit != mexit; |
1553 | exit = exit->next) | |
1554 | { | |
1555 | if (i++ & 1) | |
1556 | mexit = mexit->next; | |
1557 | } | |
1558 | ||
9e2f83a5 | 1559 | if (exit != loop->exits) |
6270df4c ZD |
1560 | { |
1561 | error ("corrupted exits list of loop %d", loop->num); | |
1562 | err = 1; | |
1563 | } | |
1564 | } | |
1565 | ||
f87000d0 | 1566 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1567 | { |
9e2f83a5 | 1568 | if (loop->exits->next != loop->exits) |
6270df4c ZD |
1569 | { |
1570 | error ("nonempty exits list of loop %d, but exits are not recorded", | |
1571 | loop->num); | |
1572 | err = 1; | |
1573 | } | |
1574 | } | |
1575 | } | |
1576 | ||
f87000d0 | 1577 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c ZD |
1578 | { |
1579 | unsigned n_exits = 0, eloops; | |
1580 | ||
a271b42d | 1581 | sizes = XCNEWVEC (unsigned, num); |
42fd6772 | 1582 | memset (sizes, 0, sizeof (unsigned) * num); |
82b85a85 ZD |
1583 | FOR_EACH_BB (bb) |
1584 | { | |
628f6a4e | 1585 | edge_iterator ei; |
d73be268 | 1586 | if (bb->loop_father == current_loops->tree_root) |
82b85a85 | 1587 | continue; |
628f6a4e | 1588 | FOR_EACH_EDGE (e, ei, bb->succs) |
82b85a85 | 1589 | { |
82b85a85 ZD |
1590 | if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) |
1591 | continue; | |
1592 | ||
6270df4c ZD |
1593 | n_exits++; |
1594 | exit = get_exit_descriptions (e); | |
1595 | if (!exit) | |
1596 | { | |
d8a07487 | 1597 | error ("exit %d->%d not recorded", |
6270df4c ZD |
1598 | e->src->index, e->dest->index); |
1599 | err = 1; | |
1600 | } | |
1601 | eloops = 0; | |
1602 | for (; exit; exit = exit->next_e) | |
1603 | eloops++; | |
1604 | ||
82b85a85 | 1605 | for (loop = bb->loop_father; |
661bc682 RB |
1606 | loop != e->dest->loop_father |
1607 | /* When a loop exit is also an entry edge which | |
1608 | can happen when avoiding CFG manipulations | |
1609 | then the last loop exited is the outer loop | |
1610 | of the loop entered. */ | |
1611 | && loop != loop_outer (e->dest->loop_father); | |
9ba025a2 | 1612 | loop = loop_outer (loop)) |
82b85a85 | 1613 | { |
6270df4c | 1614 | eloops--; |
82b85a85 | 1615 | sizes[loop->num]++; |
6270df4c ZD |
1616 | } |
1617 | ||
1618 | if (eloops != 0) | |
1619 | { | |
d8a07487 | 1620 | error ("wrong list of exited loops for edge %d->%d", |
6270df4c ZD |
1621 | e->src->index, e->dest->index); |
1622 | err = 1; | |
82b85a85 ZD |
1623 | } |
1624 | } | |
1625 | } | |
1626 | ||
6270df4c | 1627 | if (n_exits != htab_elements (current_loops->exits)) |
82b85a85 | 1628 | { |
d8a07487 | 1629 | error ("too many loop exits recorded"); |
6270df4c ZD |
1630 | err = 1; |
1631 | } | |
82b85a85 | 1632 | |
6270df4c ZD |
1633 | FOR_EACH_LOOP (li, loop, 0) |
1634 | { | |
1635 | eloops = 0; | |
9e2f83a5 | 1636 | for (exit = loop->exits->next; exit->e; exit = exit->next) |
6270df4c ZD |
1637 | eloops++; |
1638 | if (eloops != sizes[loop->num]) | |
82b85a85 | 1639 | { |
6270df4c ZD |
1640 | error ("%d exits recorded for loop %d (having %d exits)", |
1641 | eloops, loop->num, sizes[loop->num]); | |
82b85a85 ZD |
1642 | err = 1; |
1643 | } | |
1644 | } | |
a271b42d RB |
1645 | |
1646 | free (sizes); | |
82b85a85 ZD |
1647 | } |
1648 | ||
341c100f | 1649 | gcc_assert (!err); |
82b85a85 | 1650 | |
7d776ee2 RG |
1651 | if (!dom_available) |
1652 | free_dominance_info (CDI_DOMINATORS); | |
2ecfd709 ZD |
1653 | } |
1654 | ||
1655 | /* Returns latch edge of LOOP. */ | |
1656 | edge | |
d329e058 | 1657 | loop_latch_edge (const struct loop *loop) |
2ecfd709 | 1658 | { |
9ff3d2de | 1659 | return find_edge (loop->latch, loop->header); |
402209ff | 1660 | } |
2ecfd709 ZD |
1661 | |
1662 | /* Returns preheader edge of LOOP. */ | |
1663 | edge | |
d329e058 | 1664 | loop_preheader_edge (const struct loop *loop) |
2ecfd709 ZD |
1665 | { |
1666 | edge e; | |
628f6a4e | 1667 | edge_iterator ei; |
2ecfd709 | 1668 | |
f87000d0 | 1669 | gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)); |
c7b852c8 | 1670 | |
628f6a4e BE |
1671 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
1672 | if (e->src != loop->latch) | |
1673 | break; | |
2ecfd709 ZD |
1674 | |
1675 | return e; | |
1676 | } | |
70388d94 ZD |
1677 | |
1678 | /* Returns true if E is an exit of LOOP. */ | |
1679 | ||
1680 | bool | |
ed7a4b4b | 1681 | loop_exit_edge_p (const struct loop *loop, const_edge e) |
70388d94 ZD |
1682 | { |
1683 | return (flow_bb_inside_loop_p (loop, e->src) | |
1684 | && !flow_bb_inside_loop_p (loop, e->dest)); | |
1685 | } | |
ac8f6c69 ZD |
1686 | |
1687 | /* Returns the single exit edge of LOOP, or NULL if LOOP has either no exit | |
6270df4c ZD |
1688 | or more than one exit. If loops do not have the exits recorded, NULL |
1689 | is returned always. */ | |
ac8f6c69 ZD |
1690 | |
1691 | edge | |
1692 | single_exit (const struct loop *loop) | |
1693 | { | |
9e2f83a5 | 1694 | struct loop_exit *exit = loop->exits->next; |
ac8f6c69 | 1695 | |
f87000d0 | 1696 | if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
6270df4c | 1697 | return NULL; |
ac8f6c69 | 1698 | |
9e2f83a5 | 1699 | if (exit->e && exit->next == loop->exits) |
6270df4c ZD |
1700 | return exit->e; |
1701 | else | |
1702 | return NULL; | |
ac8f6c69 | 1703 | } |
f8bf9252 | 1704 | |
f4ce375d | 1705 | /* Returns true when BB has an incoming edge exiting LOOP. */ |
f8bf9252 SP |
1706 | |
1707 | bool | |
f4ce375d | 1708 | loop_exits_to_bb_p (struct loop *loop, basic_block bb) |
f8bf9252 SP |
1709 | { |
1710 | edge e; | |
1711 | edge_iterator ei; | |
1712 | ||
1713 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1714 | if (loop_exit_edge_p (loop, e)) | |
1715 | return true; | |
1716 | ||
1717 | return false; | |
1718 | } | |
f4ce375d VK |
1719 | |
1720 | /* Returns true when BB has an outgoing edge exiting LOOP. */ | |
1721 | ||
1722 | bool | |
1723 | loop_exits_from_bb_p (struct loop *loop, basic_block bb) | |
1724 | { | |
1725 | edge e; | |
1726 | edge_iterator ei; | |
1727 | ||
1728 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1729 | if (loop_exit_edge_p (loop, e)) | |
1730 | return true; | |
1731 | ||
1732 | return false; | |
1733 | } | |
e25a6711 TJ |
1734 | |
1735 | /* Return location corresponding to the loop control condition if possible. */ | |
1736 | ||
1737 | location_t | |
1738 | get_loop_location (struct loop *loop) | |
1739 | { | |
1740 | rtx insn = NULL; | |
1741 | struct niter_desc *desc = NULL; | |
1742 | edge exit; | |
1743 | ||
1744 | /* For a for or while loop, we would like to return the location | |
1745 | of the for or while statement, if possible. To do this, look | |
1746 | for the branch guarding the loop back-edge. */ | |
1747 | ||
1748 | /* If this is a simple loop with an in_edge, then the loop control | |
1749 | branch is typically at the end of its source. */ | |
1750 | desc = get_simple_loop_desc (loop); | |
1751 | if (desc->in_edge) | |
1752 | { | |
1753 | FOR_BB_INSNS_REVERSE (desc->in_edge->src, insn) | |
1754 | { | |
1755 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1756 | return INSN_LOCATION (insn); | |
1757 | } | |
1758 | } | |
1759 | /* If loop has a single exit, then the loop control branch | |
1760 | must be at the end of its source. */ | |
1761 | if ((exit = single_exit (loop))) | |
1762 | { | |
1763 | FOR_BB_INSNS_REVERSE (exit->src, insn) | |
1764 | { | |
1765 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1766 | return INSN_LOCATION (insn); | |
1767 | } | |
1768 | } | |
1769 | /* Next check the latch, to see if it is non-empty. */ | |
1770 | FOR_BB_INSNS_REVERSE (loop->latch, insn) | |
1771 | { | |
1772 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1773 | return INSN_LOCATION (insn); | |
1774 | } | |
1775 | /* Finally, if none of the above identifies the loop control branch, | |
1776 | return the first location in the loop header. */ | |
1777 | FOR_BB_INSNS (loop->header, insn) | |
1778 | { | |
1779 | if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
1780 | return INSN_LOCATION (insn); | |
1781 | } | |
1782 | /* If all else fails, simply return the current function location. */ | |
1783 | return DECL_SOURCE_LOCATION (current_function_decl); | |
1784 | } | |
1785 | ||
71343877 AM |
1786 | /* Records that every statement in LOOP is executed I_BOUND times. |
1787 | REALISTIC is true if I_BOUND is expected to be close to the real number | |
1788 | of iterations. UPPER is true if we are sure the loop iterates at most | |
1789 | I_BOUND times. */ | |
1790 | ||
1791 | void | |
1792 | record_niter_bound (struct loop *loop, double_int i_bound, bool realistic, | |
1793 | bool upper) | |
1794 | { | |
1795 | /* Update the bounds only when there is no previous estimation, or when the | |
1796 | current estimation is smaller. */ | |
1797 | if (upper | |
1798 | && (!loop->any_upper_bound | |
1799 | || i_bound.ult (loop->nb_iterations_upper_bound))) | |
1800 | { | |
1801 | loop->any_upper_bound = true; | |
1802 | loop->nb_iterations_upper_bound = i_bound; | |
1803 | } | |
1804 | if (realistic | |
1805 | && (!loop->any_estimate | |
1806 | || i_bound.ult (loop->nb_iterations_estimate))) | |
1807 | { | |
1808 | loop->any_estimate = true; | |
1809 | loop->nb_iterations_estimate = i_bound; | |
1810 | } | |
1811 | ||
1812 | /* If an upper bound is smaller than the realistic estimate of the | |
1813 | number of iterations, use the upper bound instead. */ | |
1814 | if (loop->any_upper_bound | |
1815 | && loop->any_estimate | |
1816 | && loop->nb_iterations_upper_bound.ult (loop->nb_iterations_estimate)) | |
1817 | loop->nb_iterations_estimate = loop->nb_iterations_upper_bound; | |
1818 | } | |
1819 | ||
1ef88893 | 1820 | /* Similar to get_estimated_loop_iterations, but returns the estimate only |
71343877 AM |
1821 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate |
1822 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
1823 | ||
1824 | HOST_WIDE_INT | |
1ef88893 | 1825 | get_estimated_loop_iterations_int (struct loop *loop) |
71343877 AM |
1826 | { |
1827 | double_int nit; | |
1828 | HOST_WIDE_INT hwi_nit; | |
1829 | ||
1830 | if (!get_estimated_loop_iterations (loop, &nit)) | |
1831 | return -1; | |
1832 | ||
1833 | if (!nit.fits_shwi ()) | |
1834 | return -1; | |
1835 | hwi_nit = nit.to_shwi (); | |
1836 | ||
1837 | return hwi_nit < 0 ? -1 : hwi_nit; | |
1838 | } | |
1839 | ||
1840 | /* Returns an upper bound on the number of executions of statements | |
1841 | in the LOOP. For statements before the loop exit, this exceeds | |
1842 | the number of execution of the latch by one. */ | |
1843 | ||
1844 | HOST_WIDE_INT | |
1845 | max_stmt_executions_int (struct loop *loop) | |
1846 | { | |
1ef88893 | 1847 | HOST_WIDE_INT nit = get_max_loop_iterations_int (loop); |
71343877 AM |
1848 | HOST_WIDE_INT snit; |
1849 | ||
1850 | if (nit == -1) | |
1851 | return -1; | |
1852 | ||
1853 | snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
1854 | ||
1855 | /* If the computation overflows, return -1. */ | |
1856 | return snit < 0 ? -1 : snit; | |
1857 | } | |
1858 | ||
1859 | /* Sets NIT to the estimated number of executions of the latch of the | |
1860 | LOOP. If we have no reliable estimate, the function returns false, otherwise | |
1861 | returns true. */ | |
1862 | ||
1863 | bool | |
1864 | get_estimated_loop_iterations (struct loop *loop, double_int *nit) | |
1865 | { | |
1866 | /* Even if the bound is not recorded, possibly we can derrive one from | |
1867 | profile. */ | |
1868 | if (!loop->any_estimate) | |
1869 | { | |
1870 | if (loop->header->count) | |
1871 | { | |
1872 | *nit = gcov_type_to_double_int | |
1873 | (expected_loop_iterations_unbounded (loop) + 1); | |
1874 | return true; | |
1875 | } | |
1876 | return false; | |
1877 | } | |
1878 | ||
1879 | *nit = loop->nb_iterations_estimate; | |
1880 | return true; | |
1881 | } | |
1882 | ||
1883 | /* Sets NIT to an upper bound for the maximum number of executions of the | |
1884 | latch of the LOOP. If we have no reliable estimate, the function returns | |
1885 | false, otherwise returns true. */ | |
1886 | ||
1887 | bool | |
1888 | get_max_loop_iterations (struct loop *loop, double_int *nit) | |
1889 | { | |
1890 | if (!loop->any_upper_bound) | |
1891 | return false; | |
1892 | ||
1893 | *nit = loop->nb_iterations_upper_bound; | |
1894 | return true; | |
1895 | } | |
1ef88893 AM |
1896 | |
1897 | /* Similar to get_max_loop_iterations, but returns the estimate only | |
1898 | if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
1899 | on the number of iterations of LOOP could not be derived, returns -1. */ | |
1900 | ||
1901 | HOST_WIDE_INT | |
1902 | get_max_loop_iterations_int (struct loop *loop) | |
1903 | { | |
1904 | double_int nit; | |
1905 | HOST_WIDE_INT hwi_nit; | |
1906 | ||
1907 | if (!get_max_loop_iterations (loop, &nit)) | |
1908 | return -1; | |
1909 | ||
1910 | if (!nit.fits_shwi ()) | |
1911 | return -1; | |
1912 | hwi_nit = nit.to_shwi (); | |
1913 | ||
1914 | return hwi_nit < 0 ? -1 : hwi_nit; | |
1915 | } | |
1916 | ||
4484a35a | 1917 | /* Returns the loop depth of the loop BB belongs to. */ |
1ef88893 | 1918 | |
4484a35a AM |
1919 | int |
1920 | bb_loop_depth (const_basic_block bb) | |
1921 | { | |
1922 | return bb->loop_father ? loop_depth (bb->loop_father) : 0; | |
1923 | } |