Mercurial > hg > CbC > CbC_gcc
annotate gcc/cfgloop.c @ 56:3c8a44c06a95
Added tag gcc-4.4.5 for changeset 77e2b8dfacca
| author | ryoma <e075725@ie.u-ryukyu.ac.jp> |
|---|---|
| date | Fri, 12 Feb 2010 23:41:23 +0900 |
| parents | 77e2b8dfacca |
| children | f6334be47118 |
| rev | line source |
|---|---|
| 0 | 1 /* Natural loop discovery code for GNU compiler. |
| 2 Copyright (C) 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008 | |
| 3 Free Software Foundation, Inc. | |
| 4 | |
| 5 This file is part of GCC. | |
| 6 | |
| 7 GCC is free software; you can redistribute it and/or modify it under | |
| 8 the terms of the GNU General Public License as published by the Free | |
| 9 Software Foundation; either version 3, or (at your option) any later | |
| 10 version. | |
| 11 | |
| 12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
| 13 WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 15 for more details. | |
| 16 | |
| 17 You should have received a copy of the GNU General Public License | |
| 18 along with GCC; see the file COPYING3. If not see | |
| 19 <http://www.gnu.org/licenses/>. */ | |
| 20 | |
| 21 #include "config.h" | |
| 22 #include "system.h" | |
| 23 #include "coretypes.h" | |
| 24 #include "tm.h" | |
| 25 #include "rtl.h" | |
| 26 #include "hard-reg-set.h" | |
| 27 #include "obstack.h" | |
| 28 #include "function.h" | |
| 29 #include "basic-block.h" | |
| 30 #include "toplev.h" | |
| 31 #include "cfgloop.h" | |
| 32 #include "flags.h" | |
| 33 #include "tree.h" | |
| 34 #include "tree-flow.h" | |
| 35 #include "pointer-set.h" | |
| 36 #include "output.h" | |
| 37 #include "ggc.h" | |
| 38 | |
| 39 static void flow_loops_cfg_dump (FILE *); | |
| 40 | |
| 41 /* Dump loop related CFG information. */ | |
| 42 | |
| 43 static void | |
| 44 flow_loops_cfg_dump (FILE *file) | |
| 45 { | |
| 46 basic_block bb; | |
| 47 | |
| 48 if (!file) | |
| 49 return; | |
| 50 | |
| 51 FOR_EACH_BB (bb) | |
| 52 { | |
| 53 edge succ; | |
| 54 edge_iterator ei; | |
| 55 | |
| 56 fprintf (file, ";; %d succs { ", bb->index); | |
| 57 FOR_EACH_EDGE (succ, ei, bb->succs) | |
| 58 fprintf (file, "%d ", succ->dest->index); | |
| 59 fprintf (file, "}\n"); | |
| 60 } | |
| 61 } | |
| 62 | |
| 63 /* Return nonzero if the nodes of LOOP are a subset of OUTER. */ | |
| 64 | |
| 65 bool | |
| 66 flow_loop_nested_p (const struct loop *outer, const struct loop *loop) | |
| 67 { | |
| 68 unsigned odepth = loop_depth (outer); | |
| 69 | |
| 70 return (loop_depth (loop) > odepth | |
| 71 && VEC_index (loop_p, loop->superloops, odepth) == outer); | |
| 72 } | |
| 73 | |
| 74 /* Returns the loop such that LOOP is nested DEPTH (indexed from zero) | |
| 75 loops within LOOP. */ | |
| 76 | |
| 77 struct loop * | |
| 78 superloop_at_depth (struct loop *loop, unsigned depth) | |
| 79 { | |
| 80 unsigned ldepth = loop_depth (loop); | |
| 81 | |
| 82 gcc_assert (depth <= ldepth); | |
| 83 | |
| 84 if (depth == ldepth) | |
| 85 return loop; | |
| 86 | |
| 87 return VEC_index (loop_p, loop->superloops, depth); | |
| 88 } | |
| 89 | |
| 90 /* Returns the list of the latch edges of LOOP. */ | |
| 91 | |
| 92 static VEC (edge, heap) * | |
| 93 get_loop_latch_edges (const struct loop *loop) | |
| 94 { | |
| 95 edge_iterator ei; | |
| 96 edge e; | |
| 97 VEC (edge, heap) *ret = NULL; | |
| 98 | |
| 99 FOR_EACH_EDGE (e, ei, loop->header->preds) | |
| 100 { | |
| 101 if (dominated_by_p (CDI_DOMINATORS, e->src, loop->header)) | |
| 102 VEC_safe_push (edge, heap, ret, e); | |
| 103 } | |
| 104 | |
| 105 return ret; | |
| 106 } | |
| 107 | |
| 108 /* Dump the loop information specified by LOOP to the stream FILE | |
| 109 using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
| 110 | |
| 111 void | |
| 112 flow_loop_dump (const struct loop *loop, FILE *file, | |
| 113 void (*loop_dump_aux) (const struct loop *, FILE *, int), | |
| 114 int verbose) | |
| 115 { | |
| 116 basic_block *bbs; | |
| 117 unsigned i; | |
| 118 VEC (edge, heap) *latches; | |
| 119 edge e; | |
| 120 | |
| 121 if (! loop || ! loop->header) | |
| 122 return; | |
| 123 | |
| 124 fprintf (file, ";;\n;; Loop %d\n", loop->num); | |
| 125 | |
| 126 fprintf (file, ";; header %d, ", loop->header->index); | |
| 127 if (loop->latch) | |
| 128 fprintf (file, "latch %d\n", loop->latch->index); | |
| 129 else | |
| 130 { | |
| 131 fprintf (file, "multiple latches:"); | |
| 132 latches = get_loop_latch_edges (loop); | |
| 133 for (i = 0; VEC_iterate (edge, latches, i, e); i++) | |
| 134 fprintf (file, " %d", e->src->index); | |
| 135 VEC_free (edge, heap, latches); | |
| 136 fprintf (file, "\n"); | |
| 137 } | |
| 138 | |
| 139 fprintf (file, ";; depth %d, outer %ld\n", | |
| 140 loop_depth (loop), (long) (loop_outer (loop) | |
| 141 ? loop_outer (loop)->num : -1)); | |
| 142 | |
| 143 fprintf (file, ";; nodes:"); | |
| 144 bbs = get_loop_body (loop); | |
| 145 for (i = 0; i < loop->num_nodes; i++) | |
| 146 fprintf (file, " %d", bbs[i]->index); | |
| 147 free (bbs); | |
| 148 fprintf (file, "\n"); | |
| 149 | |
| 150 if (loop_dump_aux) | |
| 151 loop_dump_aux (loop, file, verbose); | |
| 152 } | |
| 153 | |
| 154 /* Dump the loop information about loops to the stream FILE, | |
| 155 using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
| 156 | |
| 157 void | |
| 158 flow_loops_dump (FILE *file, void (*loop_dump_aux) (const struct loop *, FILE *, int), int verbose) | |
| 159 { | |
| 160 loop_iterator li; | |
| 161 struct loop *loop; | |
| 162 | |
| 163 if (!current_loops || ! file) | |
| 164 return; | |
| 165 | |
| 166 fprintf (file, ";; %d loops found\n", number_of_loops ()); | |
| 167 | |
| 168 FOR_EACH_LOOP (li, loop, LI_INCLUDE_ROOT) | |
| 169 { | |
| 170 flow_loop_dump (loop, file, loop_dump_aux, verbose); | |
| 171 } | |
| 172 | |
| 173 if (verbose) | |
| 174 flow_loops_cfg_dump (file); | |
| 175 } | |
| 176 | |
| 177 /* Free data allocated for LOOP. */ | |
| 178 | |
| 179 void | |
| 180 flow_loop_free (struct loop *loop) | |
| 181 { | |
| 182 struct loop_exit *exit, *next; | |
| 183 | |
| 184 VEC_free (loop_p, gc, loop->superloops); | |
| 185 | |
| 186 /* Break the list of the loop exit records. They will be freed when the | |
| 187 corresponding edge is rescanned or removed, and this avoids | |
| 188 accessing the (already released) head of the list stored in the | |
| 189 loop structure. */ | |
| 190 for (exit = loop->exits->next; exit != loop->exits; exit = next) | |
| 191 { | |
| 192 next = exit->next; | |
| 193 exit->next = exit; | |
| 194 exit->prev = exit; | |
| 195 } | |
| 196 | |
| 197 ggc_free (loop->exits); | |
| 198 ggc_free (loop); | |
| 199 } | |
| 200 | |
| 201 /* Free all the memory allocated for LOOPS. */ | |
| 202 | |
| 203 void | |
| 204 flow_loops_free (struct loops *loops) | |
| 205 { | |
| 206 if (loops->larray) | |
| 207 { | |
| 208 unsigned i; | |
| 209 loop_p loop; | |
| 210 | |
| 211 /* Free the loop descriptors. */ | |
| 212 for (i = 0; VEC_iterate (loop_p, loops->larray, i, loop); i++) | |
| 213 { | |
| 214 if (!loop) | |
| 215 continue; | |
| 216 | |
| 217 flow_loop_free (loop); | |
| 218 } | |
| 219 | |
| 220 VEC_free (loop_p, gc, loops->larray); | |
| 221 } | |
| 222 } | |
| 223 | |
| 224 /* Find the nodes contained within the LOOP with header HEADER. | |
| 225 Return the number of nodes within the loop. */ | |
| 226 | |
| 227 int | |
| 228 flow_loop_nodes_find (basic_block header, struct loop *loop) | |
| 229 { | |
| 230 VEC (basic_block, heap) *stack = NULL; | |
| 231 int num_nodes = 1; | |
| 232 edge latch; | |
| 233 edge_iterator latch_ei; | |
| 234 unsigned depth = loop_depth (loop); | |
| 235 | |
| 236 header->loop_father = loop; | |
| 237 header->loop_depth = depth; | |
| 238 | |
| 239 FOR_EACH_EDGE (latch, latch_ei, loop->header->preds) | |
| 240 { | |
| 241 if (latch->src->loop_father == loop | |
| 242 || !dominated_by_p (CDI_DOMINATORS, latch->src, loop->header)) | |
| 243 continue; | |
| 244 | |
| 245 num_nodes++; | |
| 246 VEC_safe_push (basic_block, heap, stack, latch->src); | |
| 247 latch->src->loop_father = loop; | |
| 248 latch->src->loop_depth = depth; | |
| 249 | |
| 250 while (!VEC_empty (basic_block, stack)) | |
| 251 { | |
| 252 basic_block node; | |
| 253 edge e; | |
| 254 edge_iterator ei; | |
| 255 | |
| 256 node = VEC_pop (basic_block, stack); | |
| 257 | |
| 258 FOR_EACH_EDGE (e, ei, node->preds) | |
| 259 { | |
| 260 basic_block ancestor = e->src; | |
| 261 | |
| 262 if (ancestor->loop_father != loop) | |
| 263 { | |
| 264 ancestor->loop_father = loop; | |
| 265 ancestor->loop_depth = depth; | |
| 266 num_nodes++; | |
| 267 VEC_safe_push (basic_block, heap, stack, ancestor); | |
| 268 } | |
| 269 } | |
| 270 } | |
| 271 } | |
| 272 VEC_free (basic_block, heap, stack); | |
| 273 | |
| 274 return num_nodes; | |
| 275 } | |
| 276 | |
| 277 /* Records the vector of superloops of the loop LOOP, whose immediate | |
| 278 superloop is FATHER. */ | |
| 279 | |
| 280 static void | |
| 281 establish_preds (struct loop *loop, struct loop *father) | |
| 282 { | |
| 283 loop_p ploop; | |
| 284 unsigned depth = loop_depth (father) + 1; | |
| 285 unsigned i; | |
| 286 | |
| 287 VEC_truncate (loop_p, loop->superloops, 0); | |
| 288 VEC_reserve (loop_p, gc, loop->superloops, depth); | |
| 289 for (i = 0; VEC_iterate (loop_p, father->superloops, i, ploop); i++) | |
| 290 VEC_quick_push (loop_p, loop->superloops, ploop); | |
| 291 VEC_quick_push (loop_p, loop->superloops, father); | |
| 292 | |
| 293 for (ploop = loop->inner; ploop; ploop = ploop->next) | |
| 294 establish_preds (ploop, loop); | |
| 295 } | |
| 296 | |
| 297 /* Add LOOP to the loop hierarchy tree where FATHER is father of the | |
| 298 added loop. If LOOP has some children, take care of that their | |
| 299 pred field will be initialized correctly. */ | |
| 300 | |
| 301 void | |
| 302 flow_loop_tree_node_add (struct loop *father, struct loop *loop) | |
| 303 { | |
| 304 loop->next = father->inner; | |
| 305 father->inner = loop; | |
| 306 | |
| 307 establish_preds (loop, father); | |
| 308 } | |
| 309 | |
| 310 /* Remove LOOP from the loop hierarchy tree. */ | |
| 311 | |
| 312 void | |
| 313 flow_loop_tree_node_remove (struct loop *loop) | |
| 314 { | |
| 315 struct loop *prev, *father; | |
| 316 | |
| 317 father = loop_outer (loop); | |
| 318 | |
| 319 /* Remove loop from the list of sons. */ | |
| 320 if (father->inner == loop) | |
| 321 father->inner = loop->next; | |
| 322 else | |
| 323 { | |
| 324 for (prev = father->inner; prev->next != loop; prev = prev->next) | |
| 325 continue; | |
| 326 prev->next = loop->next; | |
| 327 } | |
| 328 | |
| 329 VEC_truncate (loop_p, loop->superloops, 0); | |
| 330 } | |
| 331 | |
| 332 /* Allocates and returns new loop structure. */ | |
| 333 | |
| 334 struct loop * | |
| 335 alloc_loop (void) | |
| 336 { | |
| 337 struct loop *loop = GGC_CNEW (struct loop); | |
| 338 | |
| 339 loop->exits = GGC_CNEW (struct loop_exit); | |
| 340 loop->exits->next = loop->exits->prev = loop->exits; | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
341 loop->can_be_parallel = false; |
|
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
342 loop->single_iv = NULL_TREE; |
| 0 | 343 |
| 344 return loop; | |
| 345 } | |
| 346 | |
| 347 /* Initializes loops structure LOOPS, reserving place for NUM_LOOPS loops | |
| 348 (including the root of the loop tree). */ | |
| 349 | |
| 350 static void | |
| 351 init_loops_structure (struct loops *loops, unsigned num_loops) | |
| 352 { | |
| 353 struct loop *root; | |
| 354 | |
| 355 memset (loops, 0, sizeof *loops); | |
| 356 loops->larray = VEC_alloc (loop_p, gc, num_loops); | |
| 357 | |
| 358 /* Dummy loop containing whole function. */ | |
| 359 root = alloc_loop (); | |
| 360 root->num_nodes = n_basic_blocks; | |
| 361 root->latch = EXIT_BLOCK_PTR; | |
| 362 root->header = ENTRY_BLOCK_PTR; | |
| 363 ENTRY_BLOCK_PTR->loop_father = root; | |
| 364 EXIT_BLOCK_PTR->loop_father = root; | |
| 365 | |
| 366 VEC_quick_push (loop_p, loops->larray, root); | |
| 367 loops->tree_root = root; | |
| 368 } | |
| 369 | |
| 370 /* Find all the natural loops in the function and save in LOOPS structure and | |
| 371 recalculate loop_depth information in basic block structures. | |
| 372 Return the number of natural loops found. */ | |
| 373 | |
| 374 int | |
| 375 flow_loops_find (struct loops *loops) | |
| 376 { | |
| 377 int b; | |
| 378 int num_loops; | |
| 379 edge e; | |
| 380 sbitmap headers; | |
| 381 int *dfs_order; | |
| 382 int *rc_order; | |
| 383 basic_block header; | |
| 384 basic_block bb; | |
| 385 | |
| 386 /* Ensure that the dominators are computed. */ | |
| 387 calculate_dominance_info (CDI_DOMINATORS); | |
| 388 | |
| 389 /* Taking care of this degenerate case makes the rest of | |
| 390 this code simpler. */ | |
| 391 if (n_basic_blocks == NUM_FIXED_BLOCKS) | |
| 392 { | |
| 393 init_loops_structure (loops, 1); | |
| 394 return 1; | |
| 395 } | |
| 396 | |
| 397 dfs_order = NULL; | |
| 398 rc_order = NULL; | |
| 399 | |
| 400 /* Count the number of loop headers. This should be the | |
| 401 same as the number of natural loops. */ | |
| 402 headers = sbitmap_alloc (last_basic_block); | |
| 403 sbitmap_zero (headers); | |
| 404 | |
| 405 num_loops = 0; | |
| 406 FOR_EACH_BB (header) | |
| 407 { | |
| 408 edge_iterator ei; | |
| 409 | |
| 410 header->loop_depth = 0; | |
| 411 | |
| 412 /* If we have an abnormal predecessor, do not consider the | |
| 413 loop (not worth the problems). */ | |
| 414 FOR_EACH_EDGE (e, ei, header->preds) | |
| 415 if (e->flags & EDGE_ABNORMAL) | |
| 416 break; | |
| 417 if (e) | |
| 418 continue; | |
| 419 | |
| 420 FOR_EACH_EDGE (e, ei, header->preds) | |
| 421 { | |
| 422 basic_block latch = e->src; | |
| 423 | |
| 424 gcc_assert (!(e->flags & EDGE_ABNORMAL)); | |
| 425 | |
| 426 /* Look for back edges where a predecessor is dominated | |
| 427 by this block. A natural loop has a single entry | |
| 428 node (header) that dominates all the nodes in the | |
| 429 loop. It also has single back edge to the header | |
| 430 from a latch node. */ | |
| 431 if (latch != ENTRY_BLOCK_PTR | |
| 432 && dominated_by_p (CDI_DOMINATORS, latch, header)) | |
| 433 { | |
| 434 /* Shared headers should be eliminated by now. */ | |
| 435 SET_BIT (headers, header->index); | |
| 436 num_loops++; | |
| 437 } | |
| 438 } | |
| 439 } | |
| 440 | |
| 441 /* Allocate loop structures. */ | |
| 442 init_loops_structure (loops, num_loops + 1); | |
| 443 | |
| 444 /* Find and record information about all the natural loops | |
| 445 in the CFG. */ | |
| 446 FOR_EACH_BB (bb) | |
| 447 bb->loop_father = loops->tree_root; | |
| 448 | |
| 449 if (num_loops) | |
| 450 { | |
| 451 /* Compute depth first search order of the CFG so that outer | |
| 452 natural loops will be found before inner natural loops. */ | |
| 453 dfs_order = XNEWVEC (int, n_basic_blocks); | |
| 454 rc_order = XNEWVEC (int, n_basic_blocks); | |
| 455 pre_and_rev_post_order_compute (dfs_order, rc_order, false); | |
| 456 | |
| 457 num_loops = 1; | |
| 458 | |
| 459 for (b = 0; b < n_basic_blocks - NUM_FIXED_BLOCKS; b++) | |
| 460 { | |
| 461 struct loop *loop; | |
| 462 edge_iterator ei; | |
| 463 | |
| 464 /* Search the nodes of the CFG in reverse completion order | |
| 465 so that we can find outer loops first. */ | |
| 466 if (!TEST_BIT (headers, rc_order[b])) | |
| 467 continue; | |
| 468 | |
| 469 header = BASIC_BLOCK (rc_order[b]); | |
| 470 | |
| 471 loop = alloc_loop (); | |
| 472 VEC_quick_push (loop_p, loops->larray, loop); | |
| 473 | |
| 474 loop->header = header; | |
| 475 loop->num = num_loops; | |
| 476 num_loops++; | |
| 477 | |
| 478 flow_loop_tree_node_add (header->loop_father, loop); | |
| 479 loop->num_nodes = flow_loop_nodes_find (loop->header, loop); | |
| 480 | |
| 481 /* Look for the latch for this header block, if it has just a | |
| 482 single one. */ | |
| 483 FOR_EACH_EDGE (e, ei, header->preds) | |
| 484 { | |
| 485 basic_block latch = e->src; | |
| 486 | |
| 487 if (flow_bb_inside_loop_p (loop, latch)) | |
| 488 { | |
| 489 if (loop->latch != NULL) | |
| 490 { | |
| 491 /* More than one latch edge. */ | |
| 492 loop->latch = NULL; | |
| 493 break; | |
| 494 } | |
| 495 loop->latch = latch; | |
| 496 } | |
| 497 } | |
| 498 } | |
| 499 | |
| 500 free (dfs_order); | |
| 501 free (rc_order); | |
| 502 } | |
| 503 | |
| 504 sbitmap_free (headers); | |
| 505 | |
| 506 loops->exits = NULL; | |
| 507 return VEC_length (loop_p, loops->larray); | |
| 508 } | |
| 509 | |
| 510 /* Ratio of frequencies of edges so that one of more latch edges is | |
| 511 considered to belong to inner loop with same header. */ | |
| 512 #define HEAVY_EDGE_RATIO 8 | |
| 513 | |
| 514 /* Minimum number of samples for that we apply | |
| 515 find_subloop_latch_edge_by_profile heuristics. */ | |
| 516 #define HEAVY_EDGE_MIN_SAMPLES 10 | |
| 517 | |
| 518 /* If the profile info is available, finds an edge in LATCHES that much more | |
| 519 frequent than the remaining edges. Returns such an edge, or NULL if we do | |
| 520 not find one. | |
| 521 | |
| 522 We do not use guessed profile here, only the measured one. The guessed | |
| 523 profile is usually too flat and unreliable for this (and it is mostly based | |
| 524 on the loop structure of the program, so it does not make much sense to | |
| 525 derive the loop structure from it). */ | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
526 |
| 0 | 527 static edge |
| 528 find_subloop_latch_edge_by_profile (VEC (edge, heap) *latches) | |
| 529 { | |
| 530 unsigned i; | |
| 531 edge e, me = NULL; | |
| 532 gcov_type mcount = 0, tcount = 0; | |
| 533 | |
| 534 for (i = 0; VEC_iterate (edge, latches, i, e); i++) | |
| 535 { | |
| 536 if (e->count > mcount) | |
| 537 { | |
| 538 me = e; | |
| 539 mcount = e->count; | |
| 540 } | |
| 541 tcount += e->count; | |
| 542 } | |
| 543 | |
| 544 if (tcount < HEAVY_EDGE_MIN_SAMPLES | |
| 545 || (tcount - mcount) * HEAVY_EDGE_RATIO > tcount) | |
| 546 return NULL; | |
| 547 | |
| 548 if (dump_file) | |
| 549 fprintf (dump_file, | |
| 550 "Found latch edge %d -> %d using profile information.\n", | |
| 551 me->src->index, me->dest->index); | |
| 552 return me; | |
| 553 } | |
| 554 | |
| 555 /* Among LATCHES, guesses a latch edge of LOOP corresponding to subloop, based | |
| 556 on the structure of induction variables. Returns this edge, or NULL if we | |
| 557 do not find any. | |
| 558 | |
| 559 We are quite conservative, and look just for an obvious simple innermost | |
| 560 loop (which is the case where we would lose the most performance by not | |
| 561 disambiguating the loop). More precisely, we look for the following | |
| 562 situation: The source of the chosen latch edge dominates sources of all | |
| 563 the other latch edges. Additionally, the header does not contain a phi node | |
| 564 such that the argument from the chosen edge is equal to the argument from | |
| 565 another edge. */ | |
| 566 | |
| 567 static edge | |
| 568 find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, VEC (edge, heap) *latches) | |
| 569 { | |
| 570 edge e, latch = VEC_index (edge, latches, 0); | |
| 571 unsigned i; | |
| 572 gimple phi; | |
| 573 gimple_stmt_iterator psi; | |
| 574 tree lop; | |
| 575 basic_block bb; | |
| 576 | |
| 577 /* Find the candidate for the latch edge. */ | |
| 578 for (i = 1; VEC_iterate (edge, latches, i, e); i++) | |
| 579 if (dominated_by_p (CDI_DOMINATORS, latch->src, e->src)) | |
| 580 latch = e; | |
| 581 | |
| 582 /* Verify that it dominates all the latch edges. */ | |
| 583 for (i = 0; VEC_iterate (edge, latches, i, e); i++) | |
| 584 if (!dominated_by_p (CDI_DOMINATORS, e->src, latch->src)) | |
| 585 return NULL; | |
| 586 | |
| 587 /* Check for a phi node that would deny that this is a latch edge of | |
| 588 a subloop. */ | |
| 589 for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) | |
| 590 { | |
| 591 phi = gsi_stmt (psi); | |
| 592 lop = PHI_ARG_DEF_FROM_EDGE (phi, latch); | |
| 593 | |
| 594 /* Ignore the values that are not changed inside the subloop. */ | |
| 595 if (TREE_CODE (lop) != SSA_NAME | |
| 596 || SSA_NAME_DEF_STMT (lop) == phi) | |
| 597 continue; | |
| 598 bb = gimple_bb (SSA_NAME_DEF_STMT (lop)); | |
| 599 if (!bb || !flow_bb_inside_loop_p (loop, bb)) | |
| 600 continue; | |
| 601 | |
| 602 for (i = 0; VEC_iterate (edge, latches, i, e); i++) | |
| 603 if (e != latch | |
| 604 && PHI_ARG_DEF_FROM_EDGE (phi, e) == lop) | |
| 605 return NULL; | |
| 606 } | |
| 607 | |
| 608 if (dump_file) | |
| 609 fprintf (dump_file, | |
| 610 "Found latch edge %d -> %d using iv structure.\n", | |
| 611 latch->src->index, latch->dest->index); | |
| 612 return latch; | |
| 613 } | |
| 614 | |
| 615 /* If we can determine that one of the several latch edges of LOOP behaves | |
| 616 as a latch edge of a separate subloop, returns this edge. Otherwise | |
| 617 returns NULL. */ | |
| 618 | |
| 619 static edge | |
| 620 find_subloop_latch_edge (struct loop *loop) | |
| 621 { | |
| 622 VEC (edge, heap) *latches = get_loop_latch_edges (loop); | |
| 623 edge latch = NULL; | |
| 624 | |
| 625 if (VEC_length (edge, latches) > 1) | |
| 626 { | |
| 627 latch = find_subloop_latch_edge_by_profile (latches); | |
| 628 | |
| 629 if (!latch | |
| 630 /* We consider ivs to guess the latch edge only in SSA. Perhaps we | |
| 631 should use cfghook for this, but it is hard to imagine it would | |
| 632 be useful elsewhere. */ | |
| 633 && current_ir_type () == IR_GIMPLE) | |
| 634 latch = find_subloop_latch_edge_by_ivs (loop, latches); | |
| 635 } | |
| 636 | |
| 637 VEC_free (edge, heap, latches); | |
| 638 return latch; | |
| 639 } | |
| 640 | |
| 641 /* Callback for make_forwarder_block. Returns true if the edge E is marked | |
| 642 in the set MFB_REIS_SET. */ | |
| 643 | |
| 644 static struct pointer_set_t *mfb_reis_set; | |
| 645 static bool | |
| 646 mfb_redirect_edges_in_set (edge e) | |
| 647 { | |
| 648 return pointer_set_contains (mfb_reis_set, e); | |
| 649 } | |
| 650 | |
| 651 /* Creates a subloop of LOOP with latch edge LATCH. */ | |
| 652 | |
| 653 static void | |
| 654 form_subloop (struct loop *loop, edge latch) | |
| 655 { | |
| 656 edge_iterator ei; | |
| 657 edge e, new_entry; | |
| 658 struct loop *new_loop; | |
|
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659 |
| 0 | 660 mfb_reis_set = pointer_set_create (); |
| 661 FOR_EACH_EDGE (e, ei, loop->header->preds) | |
| 662 { | |
| 663 if (e != latch) | |
| 664 pointer_set_insert (mfb_reis_set, e); | |
| 665 } | |
| 666 new_entry = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
| 667 NULL); | |
| 668 pointer_set_destroy (mfb_reis_set); | |
| 669 | |
| 670 loop->header = new_entry->src; | |
| 671 | |
| 672 /* Find the blocks and subloops that belong to the new loop, and add it to | |
| 673 the appropriate place in the loop tree. */ | |
| 674 new_loop = alloc_loop (); | |
| 675 new_loop->header = new_entry->dest; | |
| 676 new_loop->latch = latch->src; | |
| 677 add_loop (new_loop, loop); | |
| 678 } | |
| 679 | |
| 680 /* Make all the latch edges of LOOP to go to a single forwarder block -- | |
| 681 a new latch of LOOP. */ | |
| 682 | |
| 683 static void | |
| 684 merge_latch_edges (struct loop *loop) | |
| 685 { | |
| 686 VEC (edge, heap) *latches = get_loop_latch_edges (loop); | |
| 687 edge latch, e; | |
| 688 unsigned i; | |
| 689 | |
| 690 gcc_assert (VEC_length (edge, latches) > 0); | |
| 691 | |
| 692 if (VEC_length (edge, latches) == 1) | |
| 693 loop->latch = VEC_index (edge, latches, 0)->src; | |
| 694 else | |
| 695 { | |
| 696 if (dump_file) | |
| 697 fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num); | |
| 698 | |
| 699 mfb_reis_set = pointer_set_create (); | |
| 700 for (i = 0; VEC_iterate (edge, latches, i, e); i++) | |
| 701 pointer_set_insert (mfb_reis_set, e); | |
| 702 latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
| 703 NULL); | |
| 704 pointer_set_destroy (mfb_reis_set); | |
| 705 | |
| 706 loop->header = latch->dest; | |
| 707 loop->latch = latch->src; | |
| 708 } | |
| 709 | |
| 710 VEC_free (edge, heap, latches); | |
| 711 } | |
| 712 | |
| 713 /* LOOP may have several latch edges. Transform it into (possibly several) | |
| 714 loops with single latch edge. */ | |
| 715 | |
| 716 static void | |
| 717 disambiguate_multiple_latches (struct loop *loop) | |
| 718 { | |
| 719 edge e; | |
| 720 | |
| 721 /* We eliminate the multiple latches by splitting the header to the forwarder | |
| 722 block F and the rest R, and redirecting the edges. There are two cases: | |
| 723 | |
| 724 1) If there is a latch edge E that corresponds to a subloop (we guess | |
| 725 that based on profile -- if it is taken much more often than the | |
| 726 remaining edges; and on trees, using the information about induction | |
| 727 variables of the loops), we redirect E to R, all the remaining edges to | |
| 728 F, then rescan the loops and try again for the outer loop. | |
| 729 2) If there is no such edge, we redirect all latch edges to F, and the | |
| 730 entry edges to R, thus making F the single latch of the loop. */ | |
| 731 | |
| 732 if (dump_file) | |
| 733 fprintf (dump_file, "Disambiguating loop %d with multiple latches\n", | |
| 734 loop->num); | |
| 735 | |
| 736 /* During latch merging, we may need to redirect the entry edges to a new | |
| 737 block. This would cause problems if the entry edge was the one from the | |
| 738 entry block. To avoid having to handle this case specially, split | |
| 739 such entry edge. */ | |
| 740 e = find_edge (ENTRY_BLOCK_PTR, loop->header); | |
| 741 if (e) | |
| 742 split_edge (e); | |
| 743 | |
| 744 while (1) | |
| 745 { | |
| 746 e = find_subloop_latch_edge (loop); | |
| 747 if (!e) | |
| 748 break; | |
| 749 | |
| 750 form_subloop (loop, e); | |
| 751 } | |
| 752 | |
| 753 merge_latch_edges (loop); | |
| 754 } | |
| 755 | |
| 756 /* Split loops with multiple latch edges. */ | |
| 757 | |
| 758 void | |
| 759 disambiguate_loops_with_multiple_latches (void) | |
| 760 { | |
| 761 loop_iterator li; | |
| 762 struct loop *loop; | |
| 763 | |
| 764 FOR_EACH_LOOP (li, loop, 0) | |
| 765 { | |
| 766 if (!loop->latch) | |
| 767 disambiguate_multiple_latches (loop); | |
| 768 } | |
| 769 } | |
| 770 | |
| 771 /* Return nonzero if basic block BB belongs to LOOP. */ | |
| 772 bool | |
| 773 flow_bb_inside_loop_p (const struct loop *loop, const_basic_block bb) | |
| 774 { | |
| 775 struct loop *source_loop; | |
| 776 | |
| 777 if (bb == ENTRY_BLOCK_PTR || bb == EXIT_BLOCK_PTR) | |
| 778 return 0; | |
| 779 | |
| 780 source_loop = bb->loop_father; | |
| 781 return loop == source_loop || flow_loop_nested_p (loop, source_loop); | |
| 782 } | |
| 783 | |
| 784 /* Enumeration predicate for get_loop_body_with_size. */ | |
| 785 static bool | |
| 786 glb_enum_p (const_basic_block bb, const void *glb_loop) | |
| 787 { | |
| 788 const struct loop *const loop = (const struct loop *) glb_loop; | |
| 789 return (bb != loop->header | |
| 790 && dominated_by_p (CDI_DOMINATORS, bb, loop->header)); | |
| 791 } | |
| 792 | |
| 793 /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
| 794 order against direction of edges from latch. Specially, if | |
| 795 header != latch, latch is the 1-st block. LOOP cannot be the fake | |
| 796 loop tree root, and its size must be at most MAX_SIZE. The blocks | |
| 797 in the LOOP body are stored to BODY, and the size of the LOOP is | |
| 798 returned. */ | |
| 799 | |
| 800 unsigned | |
| 801 get_loop_body_with_size (const struct loop *loop, basic_block *body, | |
| 802 unsigned max_size) | |
| 803 { | |
| 804 return dfs_enumerate_from (loop->header, 1, glb_enum_p, | |
| 805 body, max_size, loop); | |
| 806 } | |
| 807 | |
| 808 /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
| 809 order against direction of edges from latch. Specially, if | |
| 810 header != latch, latch is the 1-st block. */ | |
| 811 | |
| 812 basic_block * | |
| 813 get_loop_body (const struct loop *loop) | |
| 814 { | |
| 815 basic_block *body, bb; | |
| 816 unsigned tv = 0; | |
| 817 | |
| 818 gcc_assert (loop->num_nodes); | |
| 819 | |
| 820 body = XCNEWVEC (basic_block, loop->num_nodes); | |
| 821 | |
| 822 if (loop->latch == EXIT_BLOCK_PTR) | |
| 823 { | |
| 824 /* There may be blocks unreachable from EXIT_BLOCK, hence we need to | |
| 825 special-case the fake loop that contains the whole function. */ | |
| 826 gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks); | |
| 827 body[tv++] = loop->header; | |
| 828 body[tv++] = EXIT_BLOCK_PTR; | |
| 829 FOR_EACH_BB (bb) | |
| 830 body[tv++] = bb; | |
| 831 } | |
| 832 else | |
| 833 tv = get_loop_body_with_size (loop, body, loop->num_nodes); | |
| 834 | |
| 835 gcc_assert (tv == loop->num_nodes); | |
| 836 return body; | |
| 837 } | |
| 838 | |
| 839 /* Fills dominance descendants inside LOOP of the basic block BB into | |
| 840 array TOVISIT from index *TV. */ | |
| 841 | |
| 842 static void | |
| 843 fill_sons_in_loop (const struct loop *loop, basic_block bb, | |
| 844 basic_block *tovisit, int *tv) | |
| 845 { | |
| 846 basic_block son, postpone = NULL; | |
| 847 | |
| 848 tovisit[(*tv)++] = bb; | |
| 849 for (son = first_dom_son (CDI_DOMINATORS, bb); | |
| 850 son; | |
| 851 son = next_dom_son (CDI_DOMINATORS, son)) | |
| 852 { | |
| 853 if (!flow_bb_inside_loop_p (loop, son)) | |
| 854 continue; | |
| 855 | |
| 856 if (dominated_by_p (CDI_DOMINATORS, loop->latch, son)) | |
| 857 { | |
| 858 postpone = son; | |
| 859 continue; | |
| 860 } | |
| 861 fill_sons_in_loop (loop, son, tovisit, tv); | |
| 862 } | |
| 863 | |
| 864 if (postpone) | |
| 865 fill_sons_in_loop (loop, postpone, tovisit, tv); | |
| 866 } | |
| 867 | |
| 868 /* Gets body of a LOOP (that must be different from the outermost loop) | |
| 869 sorted by dominance relation. Additionally, if a basic block s dominates | |
| 870 the latch, then only blocks dominated by s are be after it. */ | |
| 871 | |
| 872 basic_block * | |
| 873 get_loop_body_in_dom_order (const struct loop *loop) | |
| 874 { | |
| 875 basic_block *tovisit; | |
| 876 int tv; | |
| 877 | |
| 878 gcc_assert (loop->num_nodes); | |
| 879 | |
| 880 tovisit = XCNEWVEC (basic_block, loop->num_nodes); | |
| 881 | |
| 882 gcc_assert (loop->latch != EXIT_BLOCK_PTR); | |
| 883 | |
| 884 tv = 0; | |
| 885 fill_sons_in_loop (loop, loop->header, tovisit, &tv); | |
| 886 | |
| 887 gcc_assert (tv == (int) loop->num_nodes); | |
| 888 | |
| 889 return tovisit; | |
| 890 } | |
| 891 | |
| 892 /* Gets body of a LOOP sorted via provided BB_COMPARATOR. */ | |
| 893 | |
| 894 basic_block * | |
|
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895 get_loop_body_in_custom_order (const struct loop *loop, |
| 0 | 896 int (*bb_comparator) (const void *, const void *)) |
| 897 { | |
| 898 basic_block *bbs = get_loop_body (loop); | |
| 899 | |
| 900 qsort (bbs, loop->num_nodes, sizeof (basic_block), bb_comparator); | |
| 901 | |
| 902 return bbs; | |
| 903 } | |
| 904 | |
| 905 /* Get body of a LOOP in breadth first sort order. */ | |
| 906 | |
| 907 basic_block * | |
| 908 get_loop_body_in_bfs_order (const struct loop *loop) | |
| 909 { | |
| 910 basic_block *blocks; | |
| 911 basic_block bb; | |
| 912 bitmap visited; | |
| 913 unsigned int i = 0; | |
| 914 unsigned int vc = 1; | |
| 915 | |
| 916 gcc_assert (loop->num_nodes); | |
| 917 gcc_assert (loop->latch != EXIT_BLOCK_PTR); | |
| 918 | |
| 919 blocks = XCNEWVEC (basic_block, loop->num_nodes); | |
| 920 visited = BITMAP_ALLOC (NULL); | |
| 921 | |
| 922 bb = loop->header; | |
| 923 while (i < loop->num_nodes) | |
| 924 { | |
| 925 edge e; | |
| 926 edge_iterator ei; | |
| 927 | |
| 928 if (!bitmap_bit_p (visited, bb->index)) | |
| 929 { | |
| 930 /* This basic block is now visited */ | |
| 931 bitmap_set_bit (visited, bb->index); | |
| 932 blocks[i++] = bb; | |
| 933 } | |
| 934 | |
| 935 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 936 { | |
| 937 if (flow_bb_inside_loop_p (loop, e->dest)) | |
| 938 { | |
| 939 if (!bitmap_bit_p (visited, e->dest->index)) | |
| 940 { | |
| 941 bitmap_set_bit (visited, e->dest->index); | |
| 942 blocks[i++] = e->dest; | |
| 943 } | |
| 944 } | |
| 945 } | |
| 946 | |
| 947 gcc_assert (i >= vc); | |
| 948 | |
| 949 bb = blocks[vc++]; | |
| 950 } | |
| 951 | |
| 952 BITMAP_FREE (visited); | |
| 953 return blocks; | |
| 954 } | |
| 955 | |
| 956 /* Hash function for struct loop_exit. */ | |
| 957 | |
| 958 static hashval_t | |
| 959 loop_exit_hash (const void *ex) | |
| 960 { | |
| 961 const struct loop_exit *const exit = (const struct loop_exit *) ex; | |
| 962 | |
| 963 return htab_hash_pointer (exit->e); | |
| 964 } | |
| 965 | |
| 966 /* Equality function for struct loop_exit. Compares with edge. */ | |
| 967 | |
| 968 static int | |
| 969 loop_exit_eq (const void *ex, const void *e) | |
| 970 { | |
| 971 const struct loop_exit *const exit = (const struct loop_exit *) ex; | |
| 972 | |
| 973 return exit->e == e; | |
| 974 } | |
| 975 | |
| 976 /* Frees the list of loop exit descriptions EX. */ | |
| 977 | |
| 978 static void | |
| 979 loop_exit_free (void *ex) | |
| 980 { | |
| 981 struct loop_exit *exit = (struct loop_exit *) ex, *next; | |
| 982 | |
| 983 for (; exit; exit = next) | |
| 984 { | |
| 985 next = exit->next_e; | |
|
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986 |
| 0 | 987 exit->next->prev = exit->prev; |
| 988 exit->prev->next = exit->next; | |
| 989 | |
| 990 ggc_free (exit); | |
| 991 } | |
| 992 } | |
| 993 | |
| 994 /* Returns the list of records for E as an exit of a loop. */ | |
| 995 | |
| 996 static struct loop_exit * | |
| 997 get_exit_descriptions (edge e) | |
| 998 { | |
| 999 return (struct loop_exit *) htab_find_with_hash (current_loops->exits, e, | |
| 1000 htab_hash_pointer (e)); | |
| 1001 } | |
| 1002 | |
| 1003 /* Updates the lists of loop exits in that E appears. | |
| 1004 If REMOVED is true, E is being removed, and we | |
| 1005 just remove it from the lists of exits. | |
| 1006 If NEW_EDGE is true and E is not a loop exit, we | |
| 1007 do not try to remove it from loop exit lists. */ | |
| 1008 | |
| 1009 void | |
| 1010 rescan_loop_exit (edge e, bool new_edge, bool removed) | |
| 1011 { | |
| 1012 void **slot; | |
| 1013 struct loop_exit *exits = NULL, *exit; | |
| 1014 struct loop *aloop, *cloop; | |
| 1015 | |
| 1016 if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
| 1017 return; | |
| 1018 | |
| 1019 if (!removed | |
| 1020 && e->src->loop_father != NULL | |
| 1021 && e->dest->loop_father != NULL | |
| 1022 && !flow_bb_inside_loop_p (e->src->loop_father, e->dest)) | |
| 1023 { | |
| 1024 cloop = find_common_loop (e->src->loop_father, e->dest->loop_father); | |
| 1025 for (aloop = e->src->loop_father; | |
| 1026 aloop != cloop; | |
| 1027 aloop = loop_outer (aloop)) | |
| 1028 { | |
| 1029 exit = GGC_NEW (struct loop_exit); | |
| 1030 exit->e = e; | |
| 1031 | |
| 1032 exit->next = aloop->exits->next; | |
| 1033 exit->prev = aloop->exits; | |
| 1034 exit->next->prev = exit; | |
| 1035 exit->prev->next = exit; | |
| 1036 | |
| 1037 exit->next_e = exits; | |
| 1038 exits = exit; | |
| 1039 } | |
|
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|
1040 } |
| 0 | 1041 |
| 1042 if (!exits && new_edge) | |
| 1043 return; | |
| 1044 | |
| 1045 slot = htab_find_slot_with_hash (current_loops->exits, e, | |
| 1046 htab_hash_pointer (e), | |
| 1047 exits ? INSERT : NO_INSERT); | |
| 1048 if (!slot) | |
| 1049 return; | |
| 1050 | |
| 1051 if (exits) | |
| 1052 { | |
| 1053 if (*slot) | |
| 1054 loop_exit_free (*slot); | |
| 1055 *slot = exits; | |
| 1056 } | |
| 1057 else | |
| 1058 htab_clear_slot (current_loops->exits, slot); | |
| 1059 } | |
| 1060 | |
| 1061 /* For each loop, record list of exit edges, and start maintaining these | |
| 1062 lists. */ | |
| 1063 | |
| 1064 void | |
| 1065 record_loop_exits (void) | |
| 1066 { | |
| 1067 basic_block bb; | |
| 1068 edge_iterator ei; | |
| 1069 edge e; | |
| 1070 | |
| 1071 if (!current_loops) | |
| 1072 return; | |
| 1073 | |
| 1074 if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
| 1075 return; | |
| 1076 loops_state_set (LOOPS_HAVE_RECORDED_EXITS); | |
| 1077 | |
| 1078 gcc_assert (current_loops->exits == NULL); | |
| 1079 current_loops->exits = htab_create_alloc (2 * number_of_loops (), | |
| 1080 loop_exit_hash, | |
| 1081 loop_exit_eq, | |
| 1082 loop_exit_free, | |
| 1083 ggc_calloc, ggc_free); | |
| 1084 | |
| 1085 FOR_EACH_BB (bb) | |
| 1086 { | |
| 1087 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 1088 { | |
| 1089 rescan_loop_exit (e, true, false); | |
| 1090 } | |
| 1091 } | |
| 1092 } | |
| 1093 | |
| 1094 /* Dumps information about the exit in *SLOT to FILE. | |
| 1095 Callback for htab_traverse. */ | |
| 1096 | |
| 1097 static int | |
| 1098 dump_recorded_exit (void **slot, void *file) | |
| 1099 { | |
| 1100 struct loop_exit *exit = (struct loop_exit *) *slot; | |
| 1101 unsigned n = 0; | |
| 1102 edge e = exit->e; | |
| 1103 | |
| 1104 for (; exit != NULL; exit = exit->next_e) | |
| 1105 n++; | |
| 1106 | |
| 1107 fprintf ((FILE*) file, "Edge %d->%d exits %u loops\n", | |
| 1108 e->src->index, e->dest->index, n); | |
| 1109 | |
| 1110 return 1; | |
| 1111 } | |
| 1112 | |
| 1113 /* Dumps the recorded exits of loops to FILE. */ | |
| 1114 | |
| 1115 extern void dump_recorded_exits (FILE *); | |
| 1116 void | |
| 1117 dump_recorded_exits (FILE *file) | |
| 1118 { | |
| 1119 if (!current_loops->exits) | |
| 1120 return; | |
| 1121 htab_traverse (current_loops->exits, dump_recorded_exit, file); | |
| 1122 } | |
| 1123 | |
| 1124 /* Releases lists of loop exits. */ | |
| 1125 | |
| 1126 void | |
| 1127 release_recorded_exits (void) | |
| 1128 { | |
| 1129 gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)); | |
| 1130 htab_delete (current_loops->exits); | |
| 1131 current_loops->exits = NULL; | |
| 1132 loops_state_clear (LOOPS_HAVE_RECORDED_EXITS); | |
| 1133 } | |
| 1134 | |
| 1135 /* Returns the list of the exit edges of a LOOP. */ | |
| 1136 | |
| 1137 VEC (edge, heap) * | |
| 1138 get_loop_exit_edges (const struct loop *loop) | |
| 1139 { | |
| 1140 VEC (edge, heap) *edges = NULL; | |
| 1141 edge e; | |
| 1142 unsigned i; | |
| 1143 basic_block *body; | |
| 1144 edge_iterator ei; | |
| 1145 struct loop_exit *exit; | |
| 1146 | |
| 1147 gcc_assert (loop->latch != EXIT_BLOCK_PTR); | |
| 1148 | |
| 1149 /* If we maintain the lists of exits, use them. Otherwise we must | |
| 1150 scan the body of the loop. */ | |
| 1151 if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
| 1152 { | |
| 1153 for (exit = loop->exits->next; exit->e; exit = exit->next) | |
| 1154 VEC_safe_push (edge, heap, edges, exit->e); | |
| 1155 } | |
| 1156 else | |
| 1157 { | |
| 1158 body = get_loop_body (loop); | |
| 1159 for (i = 0; i < loop->num_nodes; i++) | |
| 1160 FOR_EACH_EDGE (e, ei, body[i]->succs) | |
| 1161 { | |
| 1162 if (!flow_bb_inside_loop_p (loop, e->dest)) | |
| 1163 VEC_safe_push (edge, heap, edges, e); | |
| 1164 } | |
| 1165 free (body); | |
| 1166 } | |
| 1167 | |
| 1168 return edges; | |
| 1169 } | |
| 1170 | |
| 1171 /* Counts the number of conditional branches inside LOOP. */ | |
| 1172 | |
| 1173 unsigned | |
| 1174 num_loop_branches (const struct loop *loop) | |
| 1175 { | |
| 1176 unsigned i, n; | |
| 1177 basic_block * body; | |
| 1178 | |
| 1179 gcc_assert (loop->latch != EXIT_BLOCK_PTR); | |
| 1180 | |
| 1181 body = get_loop_body (loop); | |
| 1182 n = 0; | |
| 1183 for (i = 0; i < loop->num_nodes; i++) | |
| 1184 if (EDGE_COUNT (body[i]->succs) >= 2) | |
| 1185 n++; | |
| 1186 free (body); | |
| 1187 | |
| 1188 return n; | |
| 1189 } | |
| 1190 | |
| 1191 /* Adds basic block BB to LOOP. */ | |
| 1192 void | |
| 1193 add_bb_to_loop (basic_block bb, struct loop *loop) | |
| 1194 { | |
| 1195 unsigned i; | |
| 1196 loop_p ploop; | |
| 1197 edge_iterator ei; | |
| 1198 edge e; | |
| 1199 | |
| 1200 gcc_assert (bb->loop_father == NULL); | |
| 1201 bb->loop_father = loop; | |
| 1202 bb->loop_depth = loop_depth (loop); | |
| 1203 loop->num_nodes++; | |
| 1204 for (i = 0; VEC_iterate (loop_p, loop->superloops, i, ploop); i++) | |
| 1205 ploop->num_nodes++; | |
| 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 } | |
| 1215 } | |
| 1216 | |
| 1217 /* Remove basic block BB from loops. */ | |
| 1218 void | |
| 1219 remove_bb_from_loops (basic_block bb) | |
| 1220 { | |
| 1221 int i; | |
| 1222 struct loop *loop = bb->loop_father; | |
| 1223 loop_p ploop; | |
| 1224 edge_iterator ei; | |
| 1225 edge e; | |
| 1226 | |
| 1227 gcc_assert (loop != NULL); | |
| 1228 loop->num_nodes--; | |
| 1229 for (i = 0; VEC_iterate (loop_p, loop->superloops, i, ploop); i++) | |
| 1230 ploop->num_nodes--; | |
| 1231 bb->loop_father = NULL; | |
| 1232 bb->loop_depth = 0; | |
| 1233 | |
| 1234 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 1235 { | |
| 1236 rescan_loop_exit (e, false, true); | |
| 1237 } | |
| 1238 FOR_EACH_EDGE (e, ei, bb->preds) | |
| 1239 { | |
| 1240 rescan_loop_exit (e, false, true); | |
| 1241 } | |
| 1242 } | |
| 1243 | |
| 1244 /* Finds nearest common ancestor in loop tree for given loops. */ | |
| 1245 struct loop * | |
| 1246 find_common_loop (struct loop *loop_s, struct loop *loop_d) | |
| 1247 { | |
| 1248 unsigned sdepth, ddepth; | |
| 1249 | |
| 1250 if (!loop_s) return loop_d; | |
| 1251 if (!loop_d) return loop_s; | |
| 1252 | |
| 1253 sdepth = loop_depth (loop_s); | |
| 1254 ddepth = loop_depth (loop_d); | |
| 1255 | |
| 1256 if (sdepth < ddepth) | |
| 1257 loop_d = VEC_index (loop_p, loop_d->superloops, sdepth); | |
| 1258 else if (sdepth > ddepth) | |
| 1259 loop_s = VEC_index (loop_p, loop_s->superloops, ddepth); | |
| 1260 | |
| 1261 while (loop_s != loop_d) | |
| 1262 { | |
| 1263 loop_s = loop_outer (loop_s); | |
| 1264 loop_d = loop_outer (loop_d); | |
| 1265 } | |
| 1266 return loop_s; | |
| 1267 } | |
| 1268 | |
| 1269 /* Removes LOOP from structures and frees its data. */ | |
| 1270 | |
| 1271 void | |
| 1272 delete_loop (struct loop *loop) | |
| 1273 { | |
| 1274 /* Remove the loop from structure. */ | |
| 1275 flow_loop_tree_node_remove (loop); | |
| 1276 | |
| 1277 /* Remove loop from loops array. */ | |
| 1278 VEC_replace (loop_p, current_loops->larray, loop->num, NULL); | |
| 1279 | |
| 1280 /* Free loop data. */ | |
| 1281 flow_loop_free (loop); | |
| 1282 } | |
| 1283 | |
| 1284 /* Cancels the LOOP; it must be innermost one. */ | |
| 1285 | |
| 1286 static void | |
| 1287 cancel_loop (struct loop *loop) | |
| 1288 { | |
| 1289 basic_block *bbs; | |
| 1290 unsigned i; | |
| 1291 struct loop *outer = loop_outer (loop); | |
| 1292 | |
| 1293 gcc_assert (!loop->inner); | |
| 1294 | |
| 1295 /* Move blocks up one level (they should be removed as soon as possible). */ | |
| 1296 bbs = get_loop_body (loop); | |
| 1297 for (i = 0; i < loop->num_nodes; i++) | |
| 1298 bbs[i]->loop_father = outer; | |
| 1299 | |
| 1300 delete_loop (loop); | |
| 1301 } | |
| 1302 | |
| 1303 /* Cancels LOOP and all its subloops. */ | |
| 1304 void | |
| 1305 cancel_loop_tree (struct loop *loop) | |
| 1306 { | |
| 1307 while (loop->inner) | |
| 1308 cancel_loop_tree (loop->inner); | |
| 1309 cancel_loop (loop); | |
| 1310 } | |
| 1311 | |
| 1312 /* Checks that information about loops is correct | |
| 1313 -- sizes of loops are all right | |
| 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 | |
| 1317 -- irreducible loops are correctly marked | |
| 1318 */ | |
| 1319 void | |
| 1320 verify_loop_structure (void) | |
| 1321 { | |
| 1322 unsigned *sizes, i, j; | |
| 1323 sbitmap irreds; | |
| 1324 basic_block *bbs, bb; | |
| 1325 struct loop *loop; | |
| 1326 int err = 0; | |
| 1327 edge e; | |
| 1328 unsigned num = number_of_loops (); | |
| 1329 loop_iterator li; | |
| 1330 struct loop_exit *exit, *mexit; | |
| 1331 | |
| 1332 /* Check sizes. */ | |
| 1333 sizes = XCNEWVEC (unsigned, num); | |
| 1334 sizes[0] = 2; | |
| 1335 | |
| 1336 FOR_EACH_BB (bb) | |
| 1337 for (loop = bb->loop_father; loop; loop = loop_outer (loop)) | |
| 1338 sizes[loop->num]++; | |
| 1339 | |
| 1340 FOR_EACH_LOOP (li, loop, LI_INCLUDE_ROOT) | |
| 1341 { | |
| 1342 i = loop->num; | |
| 1343 | |
| 1344 if (loop->num_nodes != sizes[i]) | |
| 1345 { | |
| 1346 error ("size of loop %d should be %d, not %d", | |
| 1347 i, sizes[i], loop->num_nodes); | |
| 1348 err = 1; | |
| 1349 } | |
| 1350 } | |
| 1351 | |
| 1352 /* Check get_loop_body. */ | |
| 1353 FOR_EACH_LOOP (li, loop, 0) | |
| 1354 { | |
| 1355 bbs = get_loop_body (loop); | |
| 1356 | |
| 1357 for (j = 0; j < loop->num_nodes; j++) | |
| 1358 if (!flow_bb_inside_loop_p (loop, bbs[j])) | |
| 1359 { | |
| 1360 error ("bb %d do not belong to loop %d", | |
| 1361 bbs[j]->index, loop->num); | |
| 1362 err = 1; | |
| 1363 } | |
| 1364 free (bbs); | |
| 1365 } | |
| 1366 | |
| 1367 /* Check headers and latches. */ | |
| 1368 FOR_EACH_LOOP (li, loop, 0) | |
| 1369 { | |
| 1370 i = loop->num; | |
| 1371 | |
| 1372 if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) | |
| 1373 && EDGE_COUNT (loop->header->preds) != 2) | |
| 1374 { | |
| 1375 error ("loop %d's header does not have exactly 2 entries", i); | |
| 1376 err = 1; | |
| 1377 } | |
| 1378 if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) | |
| 1379 { | |
| 1380 if (!single_succ_p (loop->latch)) | |
| 1381 { | |
| 1382 error ("loop %d's latch does not have exactly 1 successor", i); | |
| 1383 err = 1; | |
| 1384 } | |
| 1385 if (single_succ (loop->latch) != loop->header) | |
| 1386 { | |
| 1387 error ("loop %d's latch does not have header as successor", i); | |
| 1388 err = 1; | |
| 1389 } | |
| 1390 if (loop->latch->loop_father != loop) | |
| 1391 { | |
| 1392 error ("loop %d's latch does not belong directly to it", i); | |
| 1393 err = 1; | |
| 1394 } | |
| 1395 } | |
| 1396 if (loop->header->loop_father != loop) | |
| 1397 { | |
| 1398 error ("loop %d's header does not belong directly to it", i); | |
| 1399 err = 1; | |
| 1400 } | |
| 1401 if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) | |
| 1402 && (loop_latch_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)) | |
| 1403 { | |
| 1404 error ("loop %d's latch is marked as part of irreducible region", i); | |
| 1405 err = 1; | |
| 1406 } | |
| 1407 } | |
| 1408 | |
| 1409 /* Check irreducible loops. */ | |
| 1410 if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) | |
| 1411 { | |
| 1412 /* Record old info. */ | |
| 1413 irreds = sbitmap_alloc (last_basic_block); | |
| 1414 FOR_EACH_BB (bb) | |
| 1415 { | |
| 1416 edge_iterator ei; | |
| 1417 if (bb->flags & BB_IRREDUCIBLE_LOOP) | |
| 1418 SET_BIT (irreds, bb->index); | |
| 1419 else | |
| 1420 RESET_BIT (irreds, bb->index); | |
| 1421 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 1422 if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
| 1423 e->flags |= EDGE_ALL_FLAGS + 1; | |
| 1424 } | |
| 1425 | |
| 1426 /* Recount it. */ | |
| 1427 mark_irreducible_loops (); | |
| 1428 | |
| 1429 /* Compare. */ | |
| 1430 FOR_EACH_BB (bb) | |
| 1431 { | |
| 1432 edge_iterator ei; | |
| 1433 | |
| 1434 if ((bb->flags & BB_IRREDUCIBLE_LOOP) | |
| 1435 && !TEST_BIT (irreds, bb->index)) | |
| 1436 { | |
| 1437 error ("basic block %d should be marked irreducible", bb->index); | |
| 1438 err = 1; | |
| 1439 } | |
| 1440 else if (!(bb->flags & BB_IRREDUCIBLE_LOOP) | |
| 1441 && TEST_BIT (irreds, bb->index)) | |
| 1442 { | |
| 1443 error ("basic block %d should not be marked irreducible", bb->index); | |
| 1444 err = 1; | |
| 1445 } | |
| 1446 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 1447 { | |
| 1448 if ((e->flags & EDGE_IRREDUCIBLE_LOOP) | |
| 1449 && !(e->flags & (EDGE_ALL_FLAGS + 1))) | |
| 1450 { | |
| 1451 error ("edge from %d to %d should be marked irreducible", | |
| 1452 e->src->index, e->dest->index); | |
| 1453 err = 1; | |
| 1454 } | |
| 1455 else if (!(e->flags & EDGE_IRREDUCIBLE_LOOP) | |
| 1456 && (e->flags & (EDGE_ALL_FLAGS + 1))) | |
| 1457 { | |
| 1458 error ("edge from %d to %d should not be marked irreducible", | |
| 1459 e->src->index, e->dest->index); | |
| 1460 err = 1; | |
| 1461 } | |
| 1462 e->flags &= ~(EDGE_ALL_FLAGS + 1); | |
| 1463 } | |
| 1464 } | |
| 1465 free (irreds); | |
| 1466 } | |
| 1467 | |
| 1468 /* Check the recorded loop exits. */ | |
| 1469 FOR_EACH_LOOP (li, loop, 0) | |
| 1470 { | |
| 1471 if (!loop->exits || loop->exits->e != NULL) | |
| 1472 { | |
| 1473 error ("corrupted head of the exits list of loop %d", | |
| 1474 loop->num); | |
| 1475 err = 1; | |
| 1476 } | |
| 1477 else | |
| 1478 { | |
| 1479 /* Check that the list forms a cycle, and all elements except | |
| 1480 for the head are nonnull. */ | |
| 1481 for (mexit = loop->exits, exit = mexit->next, i = 0; | |
| 1482 exit->e && exit != mexit; | |
| 1483 exit = exit->next) | |
| 1484 { | |
| 1485 if (i++ & 1) | |
| 1486 mexit = mexit->next; | |
| 1487 } | |
| 1488 | |
| 1489 if (exit != loop->exits) | |
| 1490 { | |
| 1491 error ("corrupted exits list of loop %d", loop->num); | |
| 1492 err = 1; | |
| 1493 } | |
| 1494 } | |
| 1495 | |
| 1496 if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
| 1497 { | |
| 1498 if (loop->exits->next != loop->exits) | |
| 1499 { | |
| 1500 error ("nonempty exits list of loop %d, but exits are not recorded", | |
| 1501 loop->num); | |
| 1502 err = 1; | |
| 1503 } | |
| 1504 } | |
| 1505 } | |
| 1506 | |
| 1507 if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
| 1508 { | |
| 1509 unsigned n_exits = 0, eloops; | |
| 1510 | |
| 1511 memset (sizes, 0, sizeof (unsigned) * num); | |
| 1512 FOR_EACH_BB (bb) | |
| 1513 { | |
| 1514 edge_iterator ei; | |
| 1515 if (bb->loop_father == current_loops->tree_root) | |
| 1516 continue; | |
| 1517 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 1518 { | |
| 1519 if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) | |
| 1520 continue; | |
| 1521 | |
| 1522 n_exits++; | |
| 1523 exit = get_exit_descriptions (e); | |
| 1524 if (!exit) | |
| 1525 { | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
1526 error ("Exit %d->%d not recorded", |
| 0 | 1527 e->src->index, e->dest->index); |
| 1528 err = 1; | |
| 1529 } | |
| 1530 eloops = 0; | |
| 1531 for (; exit; exit = exit->next_e) | |
| 1532 eloops++; | |
| 1533 | |
| 1534 for (loop = bb->loop_father; | |
| 1535 loop != e->dest->loop_father; | |
| 1536 loop = loop_outer (loop)) | |
| 1537 { | |
| 1538 eloops--; | |
| 1539 sizes[loop->num]++; | |
| 1540 } | |
| 1541 | |
| 1542 if (eloops != 0) | |
| 1543 { | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
1544 error ("Wrong list of exited loops for edge %d->%d", |
| 0 | 1545 e->src->index, e->dest->index); |
| 1546 err = 1; | |
| 1547 } | |
| 1548 } | |
| 1549 } | |
| 1550 | |
| 1551 if (n_exits != htab_elements (current_loops->exits)) | |
| 1552 { | |
| 1553 error ("Too many loop exits recorded"); | |
| 1554 err = 1; | |
| 1555 } | |
| 1556 | |
| 1557 FOR_EACH_LOOP (li, loop, 0) | |
| 1558 { | |
| 1559 eloops = 0; | |
| 1560 for (exit = loop->exits->next; exit->e; exit = exit->next) | |
| 1561 eloops++; | |
| 1562 if (eloops != sizes[loop->num]) | |
| 1563 { | |
| 1564 error ("%d exits recorded for loop %d (having %d exits)", | |
| 1565 eloops, loop->num, sizes[loop->num]); | |
| 1566 err = 1; | |
| 1567 } | |
| 1568 } | |
| 1569 } | |
| 1570 | |
| 1571 gcc_assert (!err); | |
| 1572 | |
| 1573 free (sizes); | |
| 1574 } | |
| 1575 | |
| 1576 /* Returns latch edge of LOOP. */ | |
| 1577 edge | |
| 1578 loop_latch_edge (const struct loop *loop) | |
| 1579 { | |
| 1580 return find_edge (loop->latch, loop->header); | |
| 1581 } | |
| 1582 | |
| 1583 /* Returns preheader edge of LOOP. */ | |
| 1584 edge | |
| 1585 loop_preheader_edge (const struct loop *loop) | |
| 1586 { | |
| 1587 edge e; | |
| 1588 edge_iterator ei; | |
| 1589 | |
| 1590 gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)); | |
| 1591 | |
| 1592 FOR_EACH_EDGE (e, ei, loop->header->preds) | |
| 1593 if (e->src != loop->latch) | |
| 1594 break; | |
| 1595 | |
| 1596 return e; | |
| 1597 } | |
| 1598 | |
| 1599 /* Returns true if E is an exit of LOOP. */ | |
| 1600 | |
| 1601 bool | |
| 1602 loop_exit_edge_p (const struct loop *loop, const_edge e) | |
| 1603 { | |
| 1604 return (flow_bb_inside_loop_p (loop, e->src) | |
| 1605 && !flow_bb_inside_loop_p (loop, e->dest)); | |
| 1606 } | |
| 1607 | |
| 1608 /* Returns the single exit edge of LOOP, or NULL if LOOP has either no exit | |
| 1609 or more than one exit. If loops do not have the exits recorded, NULL | |
| 1610 is returned always. */ | |
| 1611 | |
| 1612 edge | |
| 1613 single_exit (const struct loop *loop) | |
| 1614 { | |
| 1615 struct loop_exit *exit = loop->exits->next; | |
| 1616 | |
| 1617 if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
| 1618 return NULL; | |
| 1619 | |
| 1620 if (exit->e && exit->next == loop->exits) | |
| 1621 return exit->e; | |
| 1622 else | |
| 1623 return NULL; | |
| 1624 } | |
| 1625 | |
| 1626 /* Returns true when BB has an edge exiting LOOP. */ | |
| 1627 | |
| 1628 bool | |
| 1629 is_loop_exit (struct loop *loop, basic_block bb) | |
| 1630 { | |
| 1631 edge e; | |
| 1632 edge_iterator ei; | |
| 1633 | |
| 1634 FOR_EACH_EDGE (e, ei, bb->preds) | |
| 1635 if (loop_exit_edge_p (loop, e)) | |
| 1636 return true; | |
| 1637 | |
| 1638 return false; | |
| 1639 } |