Mercurial > hg > CbC > CbC_gcc
annotate gcc/cfgloop.c @ 127:4c56639505ff
fix function.c and add CbC-example Makefile
| author | mir3636 |
|---|---|
| date | Wed, 11 Apr 2018 18:46:58 +0900 |
| parents | 04ced10e8804 |
| children | 84e7813d76e9 |
| rev | line source |
|---|---|
| 0 | 1 /* Natural loop discovery code for GNU compiler. |
| 111 | 2 Copyright (C) 2000-2017 Free Software Foundation, Inc. |
| 0 | 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 | |
| 8 Software Foundation; either version 3, or (at your option) any later | |
| 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 | |
| 17 along with GCC; see the file COPYING3. If not see | |
| 18 <http://www.gnu.org/licenses/>. */ | |
| 19 | |
| 20 #include "config.h" | |
| 21 #include "system.h" | |
| 22 #include "coretypes.h" | |
| 111 | 23 #include "backend.h" |
| 0 | 24 #include "rtl.h" |
| 111 | 25 #include "tree.h" |
| 26 #include "gimple.h" | |
| 27 #include "cfghooks.h" | |
| 28 #include "gimple-ssa.h" | |
| 29 #include "diagnostic-core.h" | |
| 30 #include "cfganal.h" | |
| 0 | 31 #include "cfgloop.h" |
| 111 | 32 #include "gimple-iterator.h" |
| 33 #include "dumpfile.h" | |
| 0 | 34 |
| 35 static void flow_loops_cfg_dump (FILE *); | |
| 36 | |
| 37 /* Dump loop related CFG information. */ | |
| 38 | |
| 39 static void | |
| 40 flow_loops_cfg_dump (FILE *file) | |
| 41 { | |
| 42 basic_block bb; | |
| 43 | |
| 44 if (!file) | |
| 45 return; | |
| 46 | |
| 111 | 47 FOR_EACH_BB_FN (bb, cfun) |
| 0 | 48 { |
| 49 edge succ; | |
| 50 edge_iterator ei; | |
| 51 | |
| 52 fprintf (file, ";; %d succs { ", bb->index); | |
| 53 FOR_EACH_EDGE (succ, ei, bb->succs) | |
| 54 fprintf (file, "%d ", succ->dest->index); | |
| 55 fprintf (file, "}\n"); | |
| 56 } | |
| 57 } | |
| 58 | |
| 59 /* Return nonzero if the nodes of LOOP are a subset of OUTER. */ | |
| 60 | |
| 61 bool | |
| 62 flow_loop_nested_p (const struct loop *outer, const struct loop *loop) | |
| 63 { | |
| 64 unsigned odepth = loop_depth (outer); | |
| 65 | |
| 66 return (loop_depth (loop) > odepth | |
| 111 | 67 && (*loop->superloops)[odepth] == outer); |
| 0 | 68 } |
| 69 | |
| 70 /* Returns the loop such that LOOP is nested DEPTH (indexed from zero) | |
| 71 loops within LOOP. */ | |
| 72 | |
| 73 struct loop * | |
| 74 superloop_at_depth (struct loop *loop, unsigned depth) | |
| 75 { | |
| 76 unsigned ldepth = loop_depth (loop); | |
| 77 | |
| 78 gcc_assert (depth <= ldepth); | |
| 79 | |
| 80 if (depth == ldepth) | |
| 81 return loop; | |
| 82 | |
| 111 | 83 return (*loop->superloops)[depth]; |
| 0 | 84 } |
| 85 | |
| 86 /* Returns the list of the latch edges of LOOP. */ | |
| 87 | |
| 111 | 88 static vec<edge> |
| 0 | 89 get_loop_latch_edges (const struct loop *loop) |
| 90 { | |
| 91 edge_iterator ei; | |
| 92 edge e; | |
| 111 | 93 vec<edge> ret = vNULL; |
| 0 | 94 |
| 95 FOR_EACH_EDGE (e, ei, loop->header->preds) | |
| 96 { | |
| 97 if (dominated_by_p (CDI_DOMINATORS, e->src, loop->header)) | |
| 111 | 98 ret.safe_push (e); |
| 0 | 99 } |
| 100 | |
| 101 return ret; | |
| 102 } | |
| 103 | |
| 104 /* Dump the loop information specified by LOOP to the stream FILE | |
| 105 using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
| 106 | |
| 107 void | |
| 108 flow_loop_dump (const struct loop *loop, FILE *file, | |
| 109 void (*loop_dump_aux) (const struct loop *, FILE *, int), | |
| 110 int verbose) | |
| 111 { | |
| 112 basic_block *bbs; | |
| 113 unsigned i; | |
| 111 | 114 vec<edge> latches; |
| 0 | 115 edge e; |
| 116 | |
| 117 if (! loop || ! loop->header) | |
| 118 return; | |
| 119 | |
| 120 fprintf (file, ";;\n;; Loop %d\n", loop->num); | |
| 121 | |
| 122 fprintf (file, ";; header %d, ", loop->header->index); | |
| 123 if (loop->latch) | |
| 124 fprintf (file, "latch %d\n", loop->latch->index); | |
| 125 else | |
| 126 { | |
| 127 fprintf (file, "multiple latches:"); | |
| 128 latches = get_loop_latch_edges (loop); | |
| 111 | 129 FOR_EACH_VEC_ELT (latches, i, e) |
| 0 | 130 fprintf (file, " %d", e->src->index); |
| 111 | 131 latches.release (); |
| 0 | 132 fprintf (file, "\n"); |
| 133 } | |
| 134 | |
| 135 fprintf (file, ";; depth %d, outer %ld\n", | |
| 136 loop_depth (loop), (long) (loop_outer (loop) | |
| 137 ? loop_outer (loop)->num : -1)); | |
| 138 | |
| 111 | 139 if (loop->latch) |
| 140 { | |
| 141 bool read_profile_p; | |
| 142 gcov_type nit = expected_loop_iterations_unbounded (loop, &read_profile_p); | |
| 143 if (read_profile_p && !loop->any_estimate) | |
| 144 fprintf (file, ";; profile-based iteration count: %" PRIu64 "\n", | |
| 145 (uint64_t) nit); | |
| 146 } | |
| 147 | |
| 0 | 148 fprintf (file, ";; nodes:"); |
| 149 bbs = get_loop_body (loop); | |
| 150 for (i = 0; i < loop->num_nodes; i++) | |
| 151 fprintf (file, " %d", bbs[i]->index); | |
| 152 free (bbs); | |
| 153 fprintf (file, "\n"); | |
| 154 | |
| 155 if (loop_dump_aux) | |
| 156 loop_dump_aux (loop, file, verbose); | |
| 157 } | |
| 158 | |
| 159 /* Dump the loop information about loops to the stream FILE, | |
| 160 using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
| 161 | |
| 162 void | |
| 163 flow_loops_dump (FILE *file, void (*loop_dump_aux) (const struct loop *, FILE *, int), int verbose) | |
| 164 { | |
| 165 struct loop *loop; | |
| 166 | |
| 167 if (!current_loops || ! file) | |
| 168 return; | |
| 169 | |
| 111 | 170 fprintf (file, ";; %d loops found\n", number_of_loops (cfun)); |
| 0 | 171 |
| 111 | 172 FOR_EACH_LOOP (loop, LI_INCLUDE_ROOT) |
| 0 | 173 { |
| 174 flow_loop_dump (loop, file, loop_dump_aux, verbose); | |
| 175 } | |
| 176 | |
| 177 if (verbose) | |
| 178 flow_loops_cfg_dump (file); | |
| 179 } | |
| 180 | |
| 181 /* Free data allocated for LOOP. */ | |
| 182 | |
| 183 void | |
| 184 flow_loop_free (struct loop *loop) | |
| 185 { | |
| 186 struct loop_exit *exit, *next; | |
| 187 | |
| 111 | 188 vec_free (loop->superloops); |
| 0 | 189 |
| 190 /* Break the list of the loop exit records. They will be freed when the | |
| 191 corresponding edge is rescanned or removed, and this avoids | |
| 192 accessing the (already released) head of the list stored in the | |
| 193 loop structure. */ | |
| 194 for (exit = loop->exits->next; exit != loop->exits; exit = next) | |
| 195 { | |
| 196 next = exit->next; | |
| 197 exit->next = exit; | |
| 198 exit->prev = exit; | |
| 199 } | |
| 200 | |
| 201 ggc_free (loop->exits); | |
| 202 ggc_free (loop); | |
| 203 } | |
| 204 | |
| 205 /* Free all the memory allocated for LOOPS. */ | |
| 206 | |
| 207 void | |
| 208 flow_loops_free (struct loops *loops) | |
| 209 { | |
| 210 if (loops->larray) | |
| 211 { | |
| 212 unsigned i; | |
| 213 loop_p loop; | |
| 214 | |
| 215 /* Free the loop descriptors. */ | |
| 111 | 216 FOR_EACH_VEC_SAFE_ELT (loops->larray, i, loop) |
| 0 | 217 { |
| 218 if (!loop) | |
| 219 continue; | |
| 220 | |
| 221 flow_loop_free (loop); | |
| 222 } | |
| 223 | |
| 111 | 224 vec_free (loops->larray); |
| 0 | 225 } |
| 226 } | |
| 227 | |
| 228 /* Find the nodes contained within the LOOP with header HEADER. | |
| 229 Return the number of nodes within the loop. */ | |
| 230 | |
| 231 int | |
| 232 flow_loop_nodes_find (basic_block header, struct loop *loop) | |
| 233 { | |
| 111 | 234 vec<basic_block> stack = vNULL; |
| 0 | 235 int num_nodes = 1; |
| 236 edge latch; | |
| 237 edge_iterator latch_ei; | |
| 238 | |
| 239 header->loop_father = loop; | |
| 240 | |
| 241 FOR_EACH_EDGE (latch, latch_ei, loop->header->preds) | |
| 242 { | |
| 243 if (latch->src->loop_father == loop | |
| 244 || !dominated_by_p (CDI_DOMINATORS, latch->src, loop->header)) | |
| 245 continue; | |
| 246 | |
| 247 num_nodes++; | |
| 111 | 248 stack.safe_push (latch->src); |
| 0 | 249 latch->src->loop_father = loop; |
| 250 | |
| 111 | 251 while (!stack.is_empty ()) |
| 0 | 252 { |
| 253 basic_block node; | |
| 254 edge e; | |
| 255 edge_iterator ei; | |
| 256 | |
| 111 | 257 node = stack.pop (); |
| 0 | 258 |
| 259 FOR_EACH_EDGE (e, ei, node->preds) | |
| 260 { | |
| 261 basic_block ancestor = e->src; | |
| 262 | |
| 263 if (ancestor->loop_father != loop) | |
| 264 { | |
| 265 ancestor->loop_father = loop; | |
| 266 num_nodes++; | |
| 111 | 267 stack.safe_push (ancestor); |
| 0 | 268 } |
| 269 } | |
| 270 } | |
| 271 } | |
| 111 | 272 stack.release (); |
| 0 | 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 | |
| 111 | 287 loop->superloops = 0; |
| 288 vec_alloc (loop->superloops, depth); | |
| 289 FOR_EACH_VEC_SAFE_ELT (father->superloops, i, ploop) | |
| 290 loop->superloops->quick_push (ploop); | |
| 291 loop->superloops->quick_push (father); | |
| 0 | 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 | |
| 111 | 329 loop->superloops = NULL; |
| 0 | 330 } |
| 331 | |
| 332 /* Allocates and returns new loop structure. */ | |
| 333 | |
| 334 struct loop * | |
| 335 alloc_loop (void) | |
| 336 { | |
| 111 | 337 struct loop *loop = ggc_cleared_alloc<struct loop> (); |
| 0 | 338 |
| 111 | 339 loop->exits = ggc_cleared_alloc<loop_exit> (); |
| 0 | 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; |
| 111 | 342 loop->constraints = 0; |
| 343 loop->nb_iterations_upper_bound = 0; | |
| 344 loop->nb_iterations_likely_upper_bound = 0; | |
| 345 loop->nb_iterations_estimate = 0; | |
| 0 | 346 return loop; |
| 347 } | |
| 348 | |
| 349 /* Initializes loops structure LOOPS, reserving place for NUM_LOOPS loops | |
| 350 (including the root of the loop tree). */ | |
| 351 | |
| 111 | 352 void |
| 353 init_loops_structure (struct function *fn, | |
| 354 struct loops *loops, unsigned num_loops) | |
| 0 | 355 { |
| 356 struct loop *root; | |
| 357 | |
| 358 memset (loops, 0, sizeof *loops); | |
| 111 | 359 vec_alloc (loops->larray, num_loops); |
| 0 | 360 |
| 361 /* Dummy loop containing whole function. */ | |
| 362 root = alloc_loop (); | |
| 111 | 363 root->num_nodes = n_basic_blocks_for_fn (fn); |
| 364 root->latch = EXIT_BLOCK_PTR_FOR_FN (fn); | |
| 365 root->header = ENTRY_BLOCK_PTR_FOR_FN (fn); | |
| 366 ENTRY_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
| 367 EXIT_BLOCK_PTR_FOR_FN (fn)->loop_father = root; | |
| 368 | |
| 369 loops->larray->quick_push (root); | |
| 370 loops->tree_root = root; | |
| 371 } | |
| 372 | |
| 373 /* Returns whether HEADER is a loop header. */ | |
| 374 | |
| 375 bool | |
| 376 bb_loop_header_p (basic_block header) | |
| 377 { | |
| 378 edge_iterator ei; | |
| 379 edge e; | |
| 0 | 380 |
| 111 | 381 /* If we have an abnormal predecessor, do not consider the |
| 382 loop (not worth the problems). */ | |
| 383 if (bb_has_abnormal_pred (header)) | |
| 384 return false; | |
| 385 | |
| 386 /* Look for back edges where a predecessor is dominated | |
| 387 by this block. A natural loop has a single entry | |
| 388 node (header) that dominates all the nodes in the | |
| 389 loop. It also has single back edge to the header | |
| 390 from a latch node. */ | |
| 391 FOR_EACH_EDGE (e, ei, header->preds) | |
| 392 { | |
| 393 basic_block latch = e->src; | |
| 394 if (latch != ENTRY_BLOCK_PTR_FOR_FN (cfun) | |
| 395 && dominated_by_p (CDI_DOMINATORS, latch, header)) | |
| 396 return true; | |
| 397 } | |
| 398 | |
| 399 return false; | |
| 0 | 400 } |
| 401 | |
| 402 /* Find all the natural loops in the function and save in LOOPS structure and | |
| 111 | 403 recalculate loop_father information in basic block structures. |
| 404 If LOOPS is non-NULL then the loop structures for already recorded loops | |
| 405 will be re-used and their number will not change. We assume that no | |
| 406 stale loops exist in LOOPS. | |
| 407 When LOOPS is NULL it is allocated and re-built from scratch. | |
| 408 Return the built LOOPS structure. */ | |
| 0 | 409 |
| 111 | 410 struct loops * |
| 0 | 411 flow_loops_find (struct loops *loops) |
| 412 { | |
| 111 | 413 bool from_scratch = (loops == NULL); |
| 414 int *rc_order; | |
| 0 | 415 int b; |
| 111 | 416 unsigned i; |
| 0 | 417 |
| 418 /* Ensure that the dominators are computed. */ | |
| 419 calculate_dominance_info (CDI_DOMINATORS); | |
| 420 | |
| 111 | 421 if (!loops) |
| 0 | 422 { |
| 111 | 423 loops = ggc_cleared_alloc<struct loops> (); |
| 424 init_loops_structure (cfun, loops, 1); | |
| 0 | 425 } |
| 426 | |
| 111 | 427 /* Ensure that loop exits were released. */ |
| 428 gcc_assert (loops->exits == NULL); | |
| 429 | |
| 430 /* Taking care of this degenerate case makes the rest of | |
| 431 this code simpler. */ | |
| 432 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) | |
| 433 return loops; | |
| 434 | |
| 435 /* The root loop node contains all basic-blocks. */ | |
| 436 loops->tree_root->num_nodes = n_basic_blocks_for_fn (cfun); | |
| 0 | 437 |
| 111 | 438 /* Compute depth first search order of the CFG so that outer |
| 439 natural loops will be found before inner natural loops. */ | |
| 440 rc_order = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); | |
| 441 pre_and_rev_post_order_compute (NULL, rc_order, false); | |
| 442 | |
| 443 /* Gather all loop headers in reverse completion order and allocate | |
| 444 loop structures for loops that are not already present. */ | |
| 445 auto_vec<loop_p> larray (loops->larray->length ()); | |
| 446 for (b = 0; b < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; b++) | |
| 447 { | |
| 448 basic_block header = BASIC_BLOCK_FOR_FN (cfun, rc_order[b]); | |
| 449 if (bb_loop_header_p (header)) | |
| 450 { | |
| 451 struct loop *loop; | |
| 0 | 452 |
| 111 | 453 /* The current active loop tree has valid loop-fathers for |
| 454 header blocks. */ | |
| 455 if (!from_scratch | |
| 456 && header->loop_father->header == header) | |
| 457 { | |
| 458 loop = header->loop_father; | |
| 459 /* If we found an existing loop remove it from the | |
| 460 loop tree. It is going to be inserted again | |
| 461 below. */ | |
| 462 flow_loop_tree_node_remove (loop); | |
| 463 } | |
| 464 else | |
| 465 { | |
| 466 /* Otherwise allocate a new loop structure for the loop. */ | |
| 467 loop = alloc_loop (); | |
| 468 /* ??? We could re-use unused loop slots here. */ | |
| 469 loop->num = loops->larray->length (); | |
| 470 vec_safe_push (loops->larray, loop); | |
| 471 loop->header = header; | |
| 0 | 472 |
| 111 | 473 if (!from_scratch |
| 474 && dump_file && (dump_flags & TDF_DETAILS)) | |
| 475 fprintf (dump_file, "flow_loops_find: discovered new " | |
| 476 "loop %d with header %d\n", | |
| 477 loop->num, header->index); | |
| 478 } | |
| 479 /* Reset latch, we recompute it below. */ | |
| 480 loop->latch = NULL; | |
| 481 larray.safe_push (loop); | |
| 482 } | |
| 483 | |
| 484 /* Make blocks part of the loop root node at start. */ | |
| 485 header->loop_father = loops->tree_root; | |
| 486 } | |
| 0 | 487 |
| 111 | 488 free (rc_order); |
| 0 | 489 |
| 111 | 490 /* Now iterate over the loops found, insert them into the loop tree |
| 491 and assign basic-block ownership. */ | |
| 492 for (i = 0; i < larray.length (); ++i) | |
| 493 { | |
| 494 struct loop *loop = larray[i]; | |
| 495 basic_block header = loop->header; | |
| 496 edge_iterator ei; | |
| 497 edge e; | |
| 498 | |
| 499 flow_loop_tree_node_add (header->loop_father, loop); | |
| 500 loop->num_nodes = flow_loop_nodes_find (loop->header, loop); | |
| 501 | |
| 502 /* Look for the latch for this header block, if it has just a | |
| 503 single one. */ | |
| 0 | 504 FOR_EACH_EDGE (e, ei, header->preds) |
| 505 { | |
| 506 basic_block latch = e->src; | |
| 507 | |
| 111 | 508 if (flow_bb_inside_loop_p (loop, latch)) |
| 0 | 509 { |
| 111 | 510 if (loop->latch != NULL) |
| 511 { | |
| 512 /* More than one latch edge. */ | |
| 513 loop->latch = NULL; | |
| 514 break; | |
| 515 } | |
| 516 loop->latch = latch; | |
| 0 | 517 } |
| 518 } | |
| 519 } | |
| 520 | |
| 111 | 521 return loops; |
| 522 } | |
| 0 | 523 |
| 111 | 524 /* qsort helper for sort_sibling_loops. */ |
| 0 | 525 |
| 111 | 526 static int *sort_sibling_loops_cmp_rpo; |
| 527 static int | |
| 528 sort_sibling_loops_cmp (const void *la_, const void *lb_) | |
| 529 { | |
| 530 const struct loop *la = *(const struct loop * const *)la_; | |
| 531 const struct loop *lb = *(const struct loop * const *)lb_; | |
| 532 return (sort_sibling_loops_cmp_rpo[la->header->index] | |
| 533 - sort_sibling_loops_cmp_rpo[lb->header->index]); | |
| 534 } | |
| 0 | 535 |
| 111 | 536 /* Sort sibling loops in RPO order. */ |
| 0 | 537 |
| 111 | 538 void |
| 539 sort_sibling_loops (function *fn) | |
| 540 { | |
| 541 /* Match flow_loops_find in the order we sort sibling loops. */ | |
| 542 sort_sibling_loops_cmp_rpo = XNEWVEC (int, last_basic_block_for_fn (cfun)); | |
| 543 int *rc_order = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); | |
| 544 pre_and_rev_post_order_compute_fn (fn, NULL, rc_order, false); | |
| 545 for (int i = 0; i < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; ++i) | |
| 546 sort_sibling_loops_cmp_rpo[rc_order[i]] = i; | |
| 547 free (rc_order); | |
| 0 | 548 |
| 111 | 549 auto_vec<loop_p, 3> siblings; |
| 550 loop_p loop; | |
| 551 FOR_EACH_LOOP_FN (fn, loop, LI_INCLUDE_ROOT) | |
| 552 if (loop->inner && loop->inner->next) | |
| 553 { | |
| 554 loop_p sibling = loop->inner; | |
| 555 do | |
| 556 { | |
| 557 siblings.safe_push (sibling); | |
| 558 sibling = sibling->next; | |
| 559 } | |
| 560 while (sibling); | |
| 561 siblings.qsort (sort_sibling_loops_cmp); | |
| 562 loop_p *siblingp = &loop->inner; | |
| 563 for (unsigned i = 0; i < siblings.length (); ++i) | |
| 564 { | |
| 565 *siblingp = siblings[i]; | |
| 566 siblingp = &(*siblingp)->next; | |
| 567 } | |
| 568 *siblingp = NULL; | |
| 569 siblings.truncate (0); | |
| 570 } | |
| 0 | 571 |
| 111 | 572 free (sort_sibling_loops_cmp_rpo); |
| 573 sort_sibling_loops_cmp_rpo = NULL; | |
| 0 | 574 } |
| 575 | |
| 576 /* Ratio of frequencies of edges so that one of more latch edges is | |
| 577 considered to belong to inner loop with same header. */ | |
| 578 #define HEAVY_EDGE_RATIO 8 | |
| 579 | |
| 580 /* Minimum number of samples for that we apply | |
| 581 find_subloop_latch_edge_by_profile heuristics. */ | |
| 582 #define HEAVY_EDGE_MIN_SAMPLES 10 | |
| 583 | |
| 584 /* If the profile info is available, finds an edge in LATCHES that much more | |
| 585 frequent than the remaining edges. Returns such an edge, or NULL if we do | |
| 586 not find one. | |
| 587 | |
| 588 We do not use guessed profile here, only the measured one. The guessed | |
| 589 profile is usually too flat and unreliable for this (and it is mostly based | |
| 590 on the loop structure of the program, so it does not make much sense to | |
| 591 derive the loop structure from it). */ | |
|
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592 |
| 0 | 593 static edge |
| 111 | 594 find_subloop_latch_edge_by_profile (vec<edge> latches) |
| 0 | 595 { |
| 596 unsigned i; | |
| 597 edge e, me = NULL; | |
| 111 | 598 profile_count mcount = profile_count::zero (), tcount = profile_count::zero (); |
| 0 | 599 |
| 111 | 600 FOR_EACH_VEC_ELT (latches, i, e) |
| 0 | 601 { |
| 111 | 602 if (e->count ()> mcount) |
| 0 | 603 { |
| 604 me = e; | |
| 111 | 605 mcount = e->count(); |
| 0 | 606 } |
| 111 | 607 tcount += e->count(); |
| 0 | 608 } |
| 609 | |
| 111 | 610 if (!tcount.initialized_p () || tcount < HEAVY_EDGE_MIN_SAMPLES |
| 611 || (tcount - mcount).apply_scale (HEAVY_EDGE_RATIO, 1) > tcount) | |
| 0 | 612 return NULL; |
| 613 | |
| 614 if (dump_file) | |
| 615 fprintf (dump_file, | |
| 616 "Found latch edge %d -> %d using profile information.\n", | |
| 617 me->src->index, me->dest->index); | |
| 618 return me; | |
| 619 } | |
| 620 | |
| 621 /* Among LATCHES, guesses a latch edge of LOOP corresponding to subloop, based | |
| 622 on the structure of induction variables. Returns this edge, or NULL if we | |
| 623 do not find any. | |
| 624 | |
| 625 We are quite conservative, and look just for an obvious simple innermost | |
| 626 loop (which is the case where we would lose the most performance by not | |
| 627 disambiguating the loop). More precisely, we look for the following | |
| 628 situation: The source of the chosen latch edge dominates sources of all | |
| 629 the other latch edges. Additionally, the header does not contain a phi node | |
| 630 such that the argument from the chosen edge is equal to the argument from | |
| 631 another edge. */ | |
| 632 | |
| 633 static edge | |
| 111 | 634 find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, vec<edge> latches) |
| 0 | 635 { |
| 111 | 636 edge e, latch = latches[0]; |
| 0 | 637 unsigned i; |
| 111 | 638 gphi *phi; |
| 639 gphi_iterator psi; | |
| 0 | 640 tree lop; |
| 641 basic_block bb; | |
| 642 | |
| 643 /* Find the candidate for the latch edge. */ | |
| 111 | 644 for (i = 1; latches.iterate (i, &e); i++) |
| 0 | 645 if (dominated_by_p (CDI_DOMINATORS, latch->src, e->src)) |
| 646 latch = e; | |
| 647 | |
| 648 /* Verify that it dominates all the latch edges. */ | |
| 111 | 649 FOR_EACH_VEC_ELT (latches, i, e) |
| 0 | 650 if (!dominated_by_p (CDI_DOMINATORS, e->src, latch->src)) |
| 651 return NULL; | |
| 652 | |
| 653 /* Check for a phi node that would deny that this is a latch edge of | |
| 654 a subloop. */ | |
| 655 for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) | |
| 656 { | |
| 111 | 657 phi = psi.phi (); |
| 0 | 658 lop = PHI_ARG_DEF_FROM_EDGE (phi, latch); |
| 659 | |
| 660 /* Ignore the values that are not changed inside the subloop. */ | |
| 661 if (TREE_CODE (lop) != SSA_NAME | |
| 662 || SSA_NAME_DEF_STMT (lop) == phi) | |
| 663 continue; | |
| 664 bb = gimple_bb (SSA_NAME_DEF_STMT (lop)); | |
| 665 if (!bb || !flow_bb_inside_loop_p (loop, bb)) | |
| 666 continue; | |
| 667 | |
| 111 | 668 FOR_EACH_VEC_ELT (latches, i, e) |
| 0 | 669 if (e != latch |
| 670 && PHI_ARG_DEF_FROM_EDGE (phi, e) == lop) | |
| 671 return NULL; | |
| 672 } | |
| 673 | |
| 674 if (dump_file) | |
| 675 fprintf (dump_file, | |
| 676 "Found latch edge %d -> %d using iv structure.\n", | |
| 677 latch->src->index, latch->dest->index); | |
| 678 return latch; | |
| 679 } | |
| 680 | |
| 681 /* If we can determine that one of the several latch edges of LOOP behaves | |
| 682 as a latch edge of a separate subloop, returns this edge. Otherwise | |
| 683 returns NULL. */ | |
| 684 | |
| 685 static edge | |
| 686 find_subloop_latch_edge (struct loop *loop) | |
| 687 { | |
| 111 | 688 vec<edge> latches = get_loop_latch_edges (loop); |
| 0 | 689 edge latch = NULL; |
| 690 | |
| 111 | 691 if (latches.length () > 1) |
| 0 | 692 { |
| 693 latch = find_subloop_latch_edge_by_profile (latches); | |
| 694 | |
| 695 if (!latch | |
| 696 /* We consider ivs to guess the latch edge only in SSA. Perhaps we | |
| 697 should use cfghook for this, but it is hard to imagine it would | |
| 698 be useful elsewhere. */ | |
| 699 && current_ir_type () == IR_GIMPLE) | |
| 700 latch = find_subloop_latch_edge_by_ivs (loop, latches); | |
| 701 } | |
| 702 | |
| 111 | 703 latches.release (); |
| 0 | 704 return latch; |
| 705 } | |
| 706 | |
| 707 /* Callback for make_forwarder_block. Returns true if the edge E is marked | |
| 708 in the set MFB_REIS_SET. */ | |
| 709 | |
| 111 | 710 static hash_set<edge> *mfb_reis_set; |
| 0 | 711 static bool |
| 712 mfb_redirect_edges_in_set (edge e) | |
| 713 { | |
| 111 | 714 return mfb_reis_set->contains (e); |
| 0 | 715 } |
| 716 | |
| 717 /* Creates a subloop of LOOP with latch edge LATCH. */ | |
| 718 | |
| 719 static void | |
| 720 form_subloop (struct loop *loop, edge latch) | |
| 721 { | |
| 722 edge_iterator ei; | |
| 723 edge e, new_entry; | |
| 724 struct loop *new_loop; | |
|
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725 |
| 111 | 726 mfb_reis_set = new hash_set<edge>; |
| 0 | 727 FOR_EACH_EDGE (e, ei, loop->header->preds) |
| 728 { | |
| 729 if (e != latch) | |
| 111 | 730 mfb_reis_set->add (e); |
| 0 | 731 } |
| 732 new_entry = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, | |
| 733 NULL); | |
| 111 | 734 delete mfb_reis_set; |
| 0 | 735 |
| 736 loop->header = new_entry->src; | |
| 737 | |
| 738 /* Find the blocks and subloops that belong to the new loop, and add it to | |
| 739 the appropriate place in the loop tree. */ | |
| 740 new_loop = alloc_loop (); | |
| 741 new_loop->header = new_entry->dest; | |
| 742 new_loop->latch = latch->src; | |
| 743 add_loop (new_loop, loop); | |
| 744 } | |
| 745 | |
| 746 /* Make all the latch edges of LOOP to go to a single forwarder block -- | |
| 747 a new latch of LOOP. */ | |
| 748 | |
| 749 static void | |
| 750 merge_latch_edges (struct loop *loop) | |
| 751 { | |
| 111 | 752 vec<edge> latches = get_loop_latch_edges (loop); |
| 0 | 753 edge latch, e; |
| 754 unsigned i; | |
| 755 | |
| 111 | 756 gcc_assert (latches.length () > 0); |
| 0 | 757 |
| 111 | 758 if (latches.length () == 1) |
| 759 loop->latch = latches[0]->src; | |
| 0 | 760 else |
| 761 { | |
| 762 if (dump_file) | |
| 763 fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num); | |
| 764 | |
| 111 | 765 mfb_reis_set = new hash_set<edge>; |
| 766 FOR_EACH_VEC_ELT (latches, i, e) | |
| 767 mfb_reis_set->add (e); | |
| 0 | 768 latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set, |
| 769 NULL); | |
| 111 | 770 delete mfb_reis_set; |
| 0 | 771 |
| 772 loop->header = latch->dest; | |
| 773 loop->latch = latch->src; | |
| 774 } | |
| 775 | |
| 111 | 776 latches.release (); |
| 0 | 777 } |
| 778 | |
| 779 /* LOOP may have several latch edges. Transform it into (possibly several) | |
| 780 loops with single latch edge. */ | |
| 781 | |
| 782 static void | |
| 783 disambiguate_multiple_latches (struct loop *loop) | |
| 784 { | |
| 785 edge e; | |
| 786 | |
| 787 /* We eliminate the multiple latches by splitting the header to the forwarder | |
| 788 block F and the rest R, and redirecting the edges. There are two cases: | |
| 789 | |
| 790 1) If there is a latch edge E that corresponds to a subloop (we guess | |
| 791 that based on profile -- if it is taken much more often than the | |
| 792 remaining edges; and on trees, using the information about induction | |
| 793 variables of the loops), we redirect E to R, all the remaining edges to | |
| 794 F, then rescan the loops and try again for the outer loop. | |
| 795 2) If there is no such edge, we redirect all latch edges to F, and the | |
| 796 entry edges to R, thus making F the single latch of the loop. */ | |
| 797 | |
| 798 if (dump_file) | |
| 799 fprintf (dump_file, "Disambiguating loop %d with multiple latches\n", | |
| 800 loop->num); | |
| 801 | |
| 802 /* During latch merging, we may need to redirect the entry edges to a new | |
| 803 block. This would cause problems if the entry edge was the one from the | |
| 804 entry block. To avoid having to handle this case specially, split | |
| 805 such entry edge. */ | |
| 111 | 806 e = find_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), loop->header); |
| 0 | 807 if (e) |
| 808 split_edge (e); | |
| 809 | |
| 810 while (1) | |
| 811 { | |
| 812 e = find_subloop_latch_edge (loop); | |
| 813 if (!e) | |
| 814 break; | |
| 815 | |
| 816 form_subloop (loop, e); | |
| 817 } | |
| 818 | |
| 819 merge_latch_edges (loop); | |
| 820 } | |
| 821 | |
| 822 /* Split loops with multiple latch edges. */ | |
| 823 | |
| 824 void | |
| 825 disambiguate_loops_with_multiple_latches (void) | |
| 826 { | |
| 827 struct loop *loop; | |
| 828 | |
| 111 | 829 FOR_EACH_LOOP (loop, 0) |
| 0 | 830 { |
| 831 if (!loop->latch) | |
| 832 disambiguate_multiple_latches (loop); | |
| 833 } | |
| 834 } | |
| 835 | |
| 836 /* Return nonzero if basic block BB belongs to LOOP. */ | |
| 837 bool | |
| 838 flow_bb_inside_loop_p (const struct loop *loop, const_basic_block bb) | |
| 839 { | |
| 840 struct loop *source_loop; | |
| 841 | |
| 111 | 842 if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
| 843 || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
| 0 | 844 return 0; |
| 845 | |
| 846 source_loop = bb->loop_father; | |
| 847 return loop == source_loop || flow_loop_nested_p (loop, source_loop); | |
| 848 } | |
| 849 | |
| 850 /* Enumeration predicate for get_loop_body_with_size. */ | |
| 851 static bool | |
| 852 glb_enum_p (const_basic_block bb, const void *glb_loop) | |
| 853 { | |
| 854 const struct loop *const loop = (const struct loop *) glb_loop; | |
| 855 return (bb != loop->header | |
| 856 && dominated_by_p (CDI_DOMINATORS, bb, loop->header)); | |
| 857 } | |
| 858 | |
| 859 /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
| 860 order against direction of edges from latch. Specially, if | |
| 861 header != latch, latch is the 1-st block. LOOP cannot be the fake | |
| 862 loop tree root, and its size must be at most MAX_SIZE. The blocks | |
| 863 in the LOOP body are stored to BODY, and the size of the LOOP is | |
| 864 returned. */ | |
| 865 | |
| 866 unsigned | |
| 867 get_loop_body_with_size (const struct loop *loop, basic_block *body, | |
| 868 unsigned max_size) | |
| 869 { | |
| 870 return dfs_enumerate_from (loop->header, 1, glb_enum_p, | |
| 871 body, max_size, loop); | |
| 872 } | |
| 873 | |
| 874 /* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs | |
| 875 order against direction of edges from latch. Specially, if | |
| 876 header != latch, latch is the 1-st block. */ | |
| 877 | |
| 878 basic_block * | |
| 879 get_loop_body (const struct loop *loop) | |
| 880 { | |
| 881 basic_block *body, bb; | |
| 882 unsigned tv = 0; | |
| 883 | |
| 884 gcc_assert (loop->num_nodes); | |
| 885 | |
| 111 | 886 body = XNEWVEC (basic_block, loop->num_nodes); |
| 0 | 887 |
| 111 | 888 if (loop->latch == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
| 0 | 889 { |
| 890 /* There may be blocks unreachable from EXIT_BLOCK, hence we need to | |
| 891 special-case the fake loop that contains the whole function. */ | |
| 111 | 892 gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks_for_fn (cfun)); |
| 0 | 893 body[tv++] = loop->header; |
| 111 | 894 body[tv++] = EXIT_BLOCK_PTR_FOR_FN (cfun); |
| 895 FOR_EACH_BB_FN (bb, cfun) | |
| 0 | 896 body[tv++] = bb; |
| 897 } | |
| 898 else | |
| 899 tv = get_loop_body_with_size (loop, body, loop->num_nodes); | |
| 900 | |
| 901 gcc_assert (tv == loop->num_nodes); | |
| 902 return body; | |
| 903 } | |
| 904 | |
| 905 /* Fills dominance descendants inside LOOP of the basic block BB into | |
| 906 array TOVISIT from index *TV. */ | |
| 907 | |
| 908 static void | |
| 909 fill_sons_in_loop (const struct loop *loop, basic_block bb, | |
| 910 basic_block *tovisit, int *tv) | |
| 911 { | |
| 912 basic_block son, postpone = NULL; | |
| 913 | |
| 914 tovisit[(*tv)++] = bb; | |
| 915 for (son = first_dom_son (CDI_DOMINATORS, bb); | |
| 916 son; | |
| 917 son = next_dom_son (CDI_DOMINATORS, son)) | |
| 918 { | |
| 919 if (!flow_bb_inside_loop_p (loop, son)) | |
| 920 continue; | |
| 921 | |
| 922 if (dominated_by_p (CDI_DOMINATORS, loop->latch, son)) | |
| 923 { | |
| 924 postpone = son; | |
| 925 continue; | |
| 926 } | |
| 927 fill_sons_in_loop (loop, son, tovisit, tv); | |
| 928 } | |
| 929 | |
| 930 if (postpone) | |
| 931 fill_sons_in_loop (loop, postpone, tovisit, tv); | |
| 932 } | |
| 933 | |
| 934 /* Gets body of a LOOP (that must be different from the outermost loop) | |
| 935 sorted by dominance relation. Additionally, if a basic block s dominates | |
| 936 the latch, then only blocks dominated by s are be after it. */ | |
| 937 | |
| 938 basic_block * | |
| 939 get_loop_body_in_dom_order (const struct loop *loop) | |
| 940 { | |
| 941 basic_block *tovisit; | |
| 942 int tv; | |
| 943 | |
| 944 gcc_assert (loop->num_nodes); | |
| 945 | |
| 111 | 946 tovisit = XNEWVEC (basic_block, loop->num_nodes); |
| 0 | 947 |
| 111 | 948 gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
| 0 | 949 |
| 950 tv = 0; | |
| 951 fill_sons_in_loop (loop, loop->header, tovisit, &tv); | |
| 952 | |
| 953 gcc_assert (tv == (int) loop->num_nodes); | |
| 954 | |
| 955 return tovisit; | |
| 956 } | |
| 957 | |
| 958 /* Gets body of a LOOP sorted via provided BB_COMPARATOR. */ | |
| 959 | |
| 960 basic_block * | |
|
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961 get_loop_body_in_custom_order (const struct loop *loop, |
| 0 | 962 int (*bb_comparator) (const void *, const void *)) |
| 963 { | |
| 964 basic_block *bbs = get_loop_body (loop); | |
| 965 | |
| 966 qsort (bbs, loop->num_nodes, sizeof (basic_block), bb_comparator); | |
| 967 | |
| 968 return bbs; | |
| 969 } | |
| 970 | |
| 971 /* Get body of a LOOP in breadth first sort order. */ | |
| 972 | |
| 973 basic_block * | |
| 974 get_loop_body_in_bfs_order (const struct loop *loop) | |
| 975 { | |
| 976 basic_block *blocks; | |
| 977 basic_block bb; | |
| 111 | 978 unsigned int i = 1; |
| 979 unsigned int vc = 0; | |
| 0 | 980 |
| 981 gcc_assert (loop->num_nodes); | |
| 111 | 982 gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
| 0 | 983 |
| 111 | 984 blocks = XNEWVEC (basic_block, loop->num_nodes); |
| 985 auto_bitmap visited; | |
| 986 blocks[0] = loop->header; | |
| 987 bitmap_set_bit (visited, loop->header->index); | |
| 0 | 988 while (i < loop->num_nodes) |
| 989 { | |
| 990 edge e; | |
| 991 edge_iterator ei; | |
| 111 | 992 gcc_assert (i > vc); |
| 993 bb = blocks[vc++]; | |
| 0 | 994 |
| 995 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 996 { | |
| 997 if (flow_bb_inside_loop_p (loop, e->dest)) | |
| 998 { | |
| 111 | 999 /* This bb is now visited. */ |
|
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1000 if (bitmap_set_bit (visited, e->dest->index)) |
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1001 blocks[i++] = e->dest; |
| 0 | 1002 } |
| 1003 } | |
| 1004 } | |
| 1005 | |
| 1006 return blocks; | |
| 1007 } | |
| 1008 | |
| 1009 /* Hash function for struct loop_exit. */ | |
| 1010 | |
| 111 | 1011 hashval_t |
| 1012 loop_exit_hasher::hash (loop_exit *exit) | |
| 0 | 1013 { |
| 1014 return htab_hash_pointer (exit->e); | |
| 1015 } | |
| 1016 | |
| 1017 /* Equality function for struct loop_exit. Compares with edge. */ | |
| 1018 | |
| 111 | 1019 bool |
| 1020 loop_exit_hasher::equal (loop_exit *exit, edge e) | |
| 0 | 1021 { |
| 1022 return exit->e == e; | |
| 1023 } | |
| 1024 | |
| 1025 /* Frees the list of loop exit descriptions EX. */ | |
| 1026 | |
| 111 | 1027 void |
| 1028 loop_exit_hasher::remove (loop_exit *exit) | |
| 0 | 1029 { |
| 111 | 1030 loop_exit *next; |
| 0 | 1031 for (; exit; exit = next) |
| 1032 { | |
| 1033 next = exit->next_e; | |
|
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1034 |
| 0 | 1035 exit->next->prev = exit->prev; |
| 1036 exit->prev->next = exit->next; | |
| 1037 | |
| 1038 ggc_free (exit); | |
| 1039 } | |
| 1040 } | |
| 1041 | |
| 1042 /* Returns the list of records for E as an exit of a loop. */ | |
| 1043 | |
| 1044 static struct loop_exit * | |
| 1045 get_exit_descriptions (edge e) | |
| 1046 { | |
| 111 | 1047 return current_loops->exits->find_with_hash (e, htab_hash_pointer (e)); |
| 0 | 1048 } |
| 1049 | |
| 1050 /* Updates the lists of loop exits in that E appears. | |
| 1051 If REMOVED is true, E is being removed, and we | |
| 1052 just remove it from the lists of exits. | |
| 1053 If NEW_EDGE is true and E is not a loop exit, we | |
| 1054 do not try to remove it from loop exit lists. */ | |
| 1055 | |
| 1056 void | |
| 1057 rescan_loop_exit (edge e, bool new_edge, bool removed) | |
| 1058 { | |
| 1059 struct loop_exit *exits = NULL, *exit; | |
| 1060 struct loop *aloop, *cloop; | |
| 1061 | |
| 1062 if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
| 1063 return; | |
| 1064 | |
| 1065 if (!removed | |
| 1066 && e->src->loop_father != NULL | |
| 1067 && e->dest->loop_father != NULL | |
| 1068 && !flow_bb_inside_loop_p (e->src->loop_father, e->dest)) | |
| 1069 { | |
| 1070 cloop = find_common_loop (e->src->loop_father, e->dest->loop_father); | |
| 1071 for (aloop = e->src->loop_father; | |
| 1072 aloop != cloop; | |
| 1073 aloop = loop_outer (aloop)) | |
| 1074 { | |
| 111 | 1075 exit = ggc_alloc<loop_exit> (); |
| 0 | 1076 exit->e = e; |
| 1077 | |
| 1078 exit->next = aloop->exits->next; | |
| 1079 exit->prev = aloop->exits; | |
| 1080 exit->next->prev = exit; | |
| 1081 exit->prev->next = exit; | |
| 1082 | |
| 1083 exit->next_e = exits; | |
| 1084 exits = exit; | |
| 1085 } | |
|
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|
1086 } |
| 0 | 1087 |
| 1088 if (!exits && new_edge) | |
| 1089 return; | |
| 1090 | |
| 111 | 1091 loop_exit **slot |
| 1092 = current_loops->exits->find_slot_with_hash (e, htab_hash_pointer (e), | |
| 1093 exits ? INSERT : NO_INSERT); | |
| 0 | 1094 if (!slot) |
| 1095 return; | |
| 1096 | |
| 1097 if (exits) | |
| 1098 { | |
| 1099 if (*slot) | |
| 111 | 1100 loop_exit_hasher::remove (*slot); |
| 0 | 1101 *slot = exits; |
| 1102 } | |
| 1103 else | |
| 111 | 1104 current_loops->exits->clear_slot (slot); |
| 0 | 1105 } |
| 1106 | |
| 1107 /* For each loop, record list of exit edges, and start maintaining these | |
| 1108 lists. */ | |
| 1109 | |
| 1110 void | |
| 1111 record_loop_exits (void) | |
| 1112 { | |
| 1113 basic_block bb; | |
| 1114 edge_iterator ei; | |
| 1115 edge e; | |
| 1116 | |
| 1117 if (!current_loops) | |
| 1118 return; | |
| 1119 | |
| 1120 if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
| 1121 return; | |
| 1122 loops_state_set (LOOPS_HAVE_RECORDED_EXITS); | |
| 1123 | |
| 1124 gcc_assert (current_loops->exits == NULL); | |
| 111 | 1125 current_loops->exits |
| 1126 = hash_table<loop_exit_hasher>::create_ggc (2 * number_of_loops (cfun)); | |
| 0 | 1127 |
| 111 | 1128 FOR_EACH_BB_FN (bb, cfun) |
| 0 | 1129 { |
| 1130 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 1131 { | |
| 1132 rescan_loop_exit (e, true, false); | |
| 1133 } | |
| 1134 } | |
| 1135 } | |
| 1136 | |
| 1137 /* Dumps information about the exit in *SLOT to FILE. | |
| 1138 Callback for htab_traverse. */ | |
| 1139 | |
| 111 | 1140 int |
| 1141 dump_recorded_exit (loop_exit **slot, FILE *file) | |
| 0 | 1142 { |
| 111 | 1143 struct loop_exit *exit = *slot; |
| 0 | 1144 unsigned n = 0; |
| 1145 edge e = exit->e; | |
| 1146 | |
| 1147 for (; exit != NULL; exit = exit->next_e) | |
| 1148 n++; | |
| 1149 | |
| 111 | 1150 fprintf (file, "Edge %d->%d exits %u loops\n", |
| 0 | 1151 e->src->index, e->dest->index, n); |
| 1152 | |
| 1153 return 1; | |
| 1154 } | |
| 1155 | |
| 1156 /* Dumps the recorded exits of loops to FILE. */ | |
| 1157 | |
| 1158 extern void dump_recorded_exits (FILE *); | |
| 1159 void | |
| 1160 dump_recorded_exits (FILE *file) | |
| 1161 { | |
| 1162 if (!current_loops->exits) | |
| 1163 return; | |
| 111 | 1164 current_loops->exits->traverse<FILE *, dump_recorded_exit> (file); |
| 0 | 1165 } |
| 1166 | |
| 1167 /* Releases lists of loop exits. */ | |
| 1168 | |
| 1169 void | |
| 111 | 1170 release_recorded_exits (function *fn) |
| 0 | 1171 { |
| 111 | 1172 gcc_assert (loops_state_satisfies_p (fn, LOOPS_HAVE_RECORDED_EXITS)); |
| 1173 loops_for_fn (fn)->exits->empty (); | |
| 1174 loops_for_fn (fn)->exits = NULL; | |
| 1175 loops_state_clear (fn, LOOPS_HAVE_RECORDED_EXITS); | |
| 0 | 1176 } |
| 1177 | |
| 1178 /* Returns the list of the exit edges of a LOOP. */ | |
| 1179 | |
| 111 | 1180 vec<edge> |
| 0 | 1181 get_loop_exit_edges (const struct loop *loop) |
| 1182 { | |
| 111 | 1183 vec<edge> edges = vNULL; |
| 0 | 1184 edge e; |
| 1185 unsigned i; | |
| 1186 basic_block *body; | |
| 1187 edge_iterator ei; | |
| 1188 struct loop_exit *exit; | |
| 1189 | |
| 111 | 1190 gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
| 0 | 1191 |
| 1192 /* If we maintain the lists of exits, use them. Otherwise we must | |
| 1193 scan the body of the loop. */ | |
| 1194 if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
| 1195 { | |
| 1196 for (exit = loop->exits->next; exit->e; exit = exit->next) | |
| 111 | 1197 edges.safe_push (exit->e); |
| 0 | 1198 } |
| 1199 else | |
| 1200 { | |
| 1201 body = get_loop_body (loop); | |
| 1202 for (i = 0; i < loop->num_nodes; i++) | |
| 1203 FOR_EACH_EDGE (e, ei, body[i]->succs) | |
| 1204 { | |
| 1205 if (!flow_bb_inside_loop_p (loop, e->dest)) | |
| 111 | 1206 edges.safe_push (e); |
| 0 | 1207 } |
| 1208 free (body); | |
| 1209 } | |
| 1210 | |
| 1211 return edges; | |
| 1212 } | |
| 1213 | |
| 1214 /* Counts the number of conditional branches inside LOOP. */ | |
| 1215 | |
| 1216 unsigned | |
| 1217 num_loop_branches (const struct loop *loop) | |
| 1218 { | |
| 1219 unsigned i, n; | |
| 1220 basic_block * body; | |
| 1221 | |
| 111 | 1222 gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
| 0 | 1223 |
| 1224 body = get_loop_body (loop); | |
| 1225 n = 0; | |
| 1226 for (i = 0; i < loop->num_nodes; i++) | |
| 1227 if (EDGE_COUNT (body[i]->succs) >= 2) | |
| 1228 n++; | |
| 1229 free (body); | |
| 1230 | |
| 1231 return n; | |
| 1232 } | |
| 1233 | |
| 1234 /* Adds basic block BB to LOOP. */ | |
| 1235 void | |
| 1236 add_bb_to_loop (basic_block bb, struct loop *loop) | |
| 1237 { | |
| 1238 unsigned i; | |
| 1239 loop_p ploop; | |
| 1240 edge_iterator ei; | |
| 1241 edge e; | |
| 1242 | |
| 1243 gcc_assert (bb->loop_father == NULL); | |
| 1244 bb->loop_father = loop; | |
| 1245 loop->num_nodes++; | |
| 111 | 1246 FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
| 0 | 1247 ploop->num_nodes++; |
| 1248 | |
| 1249 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 1250 { | |
| 1251 rescan_loop_exit (e, true, false); | |
| 1252 } | |
| 1253 FOR_EACH_EDGE (e, ei, bb->preds) | |
| 1254 { | |
| 1255 rescan_loop_exit (e, true, false); | |
| 1256 } | |
| 1257 } | |
| 1258 | |
| 1259 /* Remove basic block BB from loops. */ | |
| 1260 void | |
| 1261 remove_bb_from_loops (basic_block bb) | |
| 1262 { | |
| 111 | 1263 unsigned i; |
| 0 | 1264 struct loop *loop = bb->loop_father; |
| 1265 loop_p ploop; | |
| 1266 edge_iterator ei; | |
| 1267 edge e; | |
| 1268 | |
| 1269 gcc_assert (loop != NULL); | |
| 1270 loop->num_nodes--; | |
| 111 | 1271 FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop) |
| 0 | 1272 ploop->num_nodes--; |
| 1273 bb->loop_father = NULL; | |
| 1274 | |
| 1275 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 1276 { | |
| 1277 rescan_loop_exit (e, false, true); | |
| 1278 } | |
| 1279 FOR_EACH_EDGE (e, ei, bb->preds) | |
| 1280 { | |
| 1281 rescan_loop_exit (e, false, true); | |
| 1282 } | |
| 1283 } | |
| 1284 | |
| 1285 /* Finds nearest common ancestor in loop tree for given loops. */ | |
| 1286 struct loop * | |
| 1287 find_common_loop (struct loop *loop_s, struct loop *loop_d) | |
| 1288 { | |
| 1289 unsigned sdepth, ddepth; | |
| 1290 | |
| 1291 if (!loop_s) return loop_d; | |
| 1292 if (!loop_d) return loop_s; | |
| 1293 | |
| 1294 sdepth = loop_depth (loop_s); | |
| 1295 ddepth = loop_depth (loop_d); | |
| 1296 | |
| 1297 if (sdepth < ddepth) | |
| 111 | 1298 loop_d = (*loop_d->superloops)[sdepth]; |
| 0 | 1299 else if (sdepth > ddepth) |
| 111 | 1300 loop_s = (*loop_s->superloops)[ddepth]; |
| 0 | 1301 |
| 1302 while (loop_s != loop_d) | |
| 1303 { | |
| 1304 loop_s = loop_outer (loop_s); | |
| 1305 loop_d = loop_outer (loop_d); | |
| 1306 } | |
| 1307 return loop_s; | |
| 1308 } | |
| 1309 | |
| 1310 /* Removes LOOP from structures and frees its data. */ | |
| 1311 | |
| 1312 void | |
| 1313 delete_loop (struct loop *loop) | |
| 1314 { | |
| 1315 /* Remove the loop from structure. */ | |
| 1316 flow_loop_tree_node_remove (loop); | |
| 1317 | |
| 1318 /* Remove loop from loops array. */ | |
| 111 | 1319 (*current_loops->larray)[loop->num] = NULL; |
| 0 | 1320 |
| 1321 /* Free loop data. */ | |
| 1322 flow_loop_free (loop); | |
| 1323 } | |
| 1324 | |
| 1325 /* Cancels the LOOP; it must be innermost one. */ | |
| 1326 | |
| 1327 static void | |
| 1328 cancel_loop (struct loop *loop) | |
| 1329 { | |
| 1330 basic_block *bbs; | |
| 1331 unsigned i; | |
| 1332 struct loop *outer = loop_outer (loop); | |
| 1333 | |
| 1334 gcc_assert (!loop->inner); | |
| 1335 | |
| 1336 /* Move blocks up one level (they should be removed as soon as possible). */ | |
| 1337 bbs = get_loop_body (loop); | |
| 1338 for (i = 0; i < loop->num_nodes; i++) | |
| 1339 bbs[i]->loop_father = outer; | |
| 1340 | |
| 111 | 1341 free (bbs); |
| 0 | 1342 delete_loop (loop); |
| 1343 } | |
| 1344 | |
| 1345 /* Cancels LOOP and all its subloops. */ | |
| 1346 void | |
| 1347 cancel_loop_tree (struct loop *loop) | |
| 1348 { | |
| 1349 while (loop->inner) | |
| 1350 cancel_loop_tree (loop->inner); | |
| 1351 cancel_loop (loop); | |
| 1352 } | |
| 1353 | |
| 1354 /* Checks that information about loops is correct | |
| 1355 -- sizes of loops are all right | |
| 1356 -- results of get_loop_body really belong to the loop | |
| 1357 -- loop header have just single entry edge and single latch edge | |
| 1358 -- loop latches have only single successor that is header of their loop | |
| 1359 -- irreducible loops are correctly marked | |
| 111 | 1360 -- the cached loop depth and loop father of each bb is correct |
| 0 | 1361 */ |
|
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parents:
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diff
changeset
|
1362 DEBUG_FUNCTION void |
| 0 | 1363 verify_loop_structure (void) |
| 1364 { | |
| 1365 unsigned *sizes, i, j; | |
| 111 | 1366 basic_block bb, *bbs; |
| 0 | 1367 struct loop *loop; |
| 1368 int err = 0; | |
| 1369 edge e; | |
| 111 | 1370 unsigned num = number_of_loops (cfun); |
| 0 | 1371 struct loop_exit *exit, *mexit; |
| 111 | 1372 bool dom_available = dom_info_available_p (CDI_DOMINATORS); |
| 1373 | |
| 1374 if (loops_state_satisfies_p (LOOPS_NEED_FIXUP)) | |
| 1375 { | |
| 1376 error ("loop verification on loop tree that needs fixup"); | |
| 1377 err = 1; | |
| 1378 } | |
| 0 | 1379 |
| 111 | 1380 /* We need up-to-date dominators, compute or verify them. */ |
| 1381 if (!dom_available) | |
| 1382 calculate_dominance_info (CDI_DOMINATORS); | |
| 1383 else | |
| 1384 verify_dominators (CDI_DOMINATORS); | |
| 1385 | |
| 1386 /* Check the loop tree root. */ | |
| 1387 if (current_loops->tree_root->header != ENTRY_BLOCK_PTR_FOR_FN (cfun) | |
| 1388 || current_loops->tree_root->latch != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
| 1389 || (current_loops->tree_root->num_nodes | |
| 1390 != (unsigned) n_basic_blocks_for_fn (cfun))) | |
| 1391 { | |
| 1392 error ("corrupt loop tree root"); | |
| 1393 err = 1; | |
| 1394 } | |
| 0 | 1395 |
| 111 | 1396 /* Check the headers. */ |
| 1397 FOR_EACH_BB_FN (bb, cfun) | |
| 1398 if (bb_loop_header_p (bb)) | |
| 1399 { | |
| 1400 if (bb->loop_father->header == NULL) | |
| 1401 { | |
| 1402 error ("loop with header %d marked for removal", bb->index); | |
| 1403 err = 1; | |
| 1404 } | |
| 1405 else if (bb->loop_father->header != bb) | |
| 1406 { | |
| 1407 error ("loop with header %d not in loop tree", bb->index); | |
| 1408 err = 1; | |
| 1409 } | |
| 1410 } | |
| 1411 else if (bb->loop_father->header == bb) | |
| 1412 { | |
| 1413 error ("non-loop with header %d not marked for removal", bb->index); | |
| 1414 err = 1; | |
| 1415 } | |
| 0 | 1416 |
| 111 | 1417 /* Check the recorded loop father and sizes of loops. */ |
| 1418 auto_sbitmap visited (last_basic_block_for_fn (cfun)); | |
| 1419 bitmap_clear (visited); | |
| 1420 bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); | |
| 1421 FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) | |
| 0 | 1422 { |
| 111 | 1423 unsigned n; |
| 0 | 1424 |
| 111 | 1425 if (loop->header == NULL) |
| 1426 { | |
| 1427 error ("removed loop %d in loop tree", loop->num); | |
| 1428 err = 1; | |
| 1429 continue; | |
| 1430 } | |
| 1431 | |
| 1432 n = get_loop_body_with_size (loop, bbs, n_basic_blocks_for_fn (cfun)); | |
| 1433 if (loop->num_nodes != n) | |
| 0 | 1434 { |
| 1435 error ("size of loop %d should be %d, not %d", | |
| 111 | 1436 loop->num, n, loop->num_nodes); |
| 0 | 1437 err = 1; |
| 1438 } | |
| 111 | 1439 |
| 1440 for (j = 0; j < n; j++) | |
| 1441 { | |
| 1442 bb = bbs[j]; | |
| 0 | 1443 |
| 111 | 1444 if (!flow_bb_inside_loop_p (loop, bb)) |
| 1445 { | |
| 1446 error ("bb %d does not belong to loop %d", | |
| 1447 bb->index, loop->num); | |
| 1448 err = 1; | |
| 1449 } | |
| 0 | 1450 |
| 111 | 1451 /* Ignore this block if it is in an inner loop. */ |
| 1452 if (bitmap_bit_p (visited, bb->index)) | |
| 1453 continue; | |
| 1454 bitmap_set_bit (visited, bb->index); | |
| 1455 | |
| 1456 if (bb->loop_father != loop) | |
| 1457 { | |
| 1458 error ("bb %d has father loop %d, should be loop %d", | |
| 1459 bb->index, bb->loop_father->num, loop->num); | |
| 1460 err = 1; | |
| 1461 } | |
| 1462 } | |
| 0 | 1463 } |
| 111 | 1464 free (bbs); |
| 0 | 1465 |
| 1466 /* Check headers and latches. */ | |
| 111 | 1467 FOR_EACH_LOOP (loop, 0) |
| 0 | 1468 { |
| 1469 i = loop->num; | |
| 111 | 1470 if (loop->header == NULL) |
| 1471 continue; | |
| 1472 if (!bb_loop_header_p (loop->header)) | |
| 1473 { | |
| 1474 error ("loop %d%'s header is not a loop header", i); | |
| 1475 err = 1; | |
| 1476 } | |
| 0 | 1477 if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
| 1478 && EDGE_COUNT (loop->header->preds) != 2) | |
| 1479 { | |
|
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nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
55
diff
changeset
|
1480 error ("loop %d%'s header does not have exactly 2 entries", i); |
| 0 | 1481 err = 1; |
| 1482 } | |
| 111 | 1483 if (loop->latch) |
| 1484 { | |
| 1485 if (!find_edge (loop->latch, loop->header)) | |
| 1486 { | |
| 1487 error ("loop %d%'s latch does not have an edge to its header", i); | |
| 1488 err = 1; | |
| 1489 } | |
| 1490 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, loop->header)) | |
| 1491 { | |
| 1492 error ("loop %d%'s latch is not dominated by its header", i); | |
| 1493 err = 1; | |
| 1494 } | |
| 1495 } | |
| 0 | 1496 if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
| 1497 { | |
| 1498 if (!single_succ_p (loop->latch)) | |
| 1499 { | |
|
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nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
55
diff
changeset
|
1500 error ("loop %d%'s latch does not have exactly 1 successor", i); |
| 0 | 1501 err = 1; |
| 1502 } | |
| 1503 if (single_succ (loop->latch) != loop->header) | |
| 1504 { | |
|
67
f6334be47118
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nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
55
diff
changeset
|
1505 error ("loop %d%'s latch does not have header as successor", i); |
| 0 | 1506 err = 1; |
| 1507 } | |
| 1508 if (loop->latch->loop_father != loop) | |
| 1509 { | |
|
67
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nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
55
diff
changeset
|
1510 error ("loop %d%'s latch does not belong directly to it", i); |
| 0 | 1511 err = 1; |
| 1512 } | |
| 1513 } | |
| 1514 if (loop->header->loop_father != loop) | |
| 1515 { | |
|
67
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nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
55
diff
changeset
|
1516 error ("loop %d%'s header does not belong directly to it", i); |
| 0 | 1517 err = 1; |
| 1518 } | |
| 1519 if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) | |
| 1520 && (loop_latch_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)) | |
| 1521 { | |
|
67
f6334be47118
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nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
55
diff
changeset
|
1522 error ("loop %d%'s latch is marked as part of irreducible region", i); |
| 0 | 1523 err = 1; |
| 1524 } | |
| 1525 } | |
| 1526 | |
| 1527 /* Check irreducible loops. */ | |
| 1528 if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) | |
| 1529 { | |
| 1530 /* Record old info. */ | |
| 111 | 1531 auto_sbitmap irreds (last_basic_block_for_fn (cfun)); |
| 1532 FOR_EACH_BB_FN (bb, cfun) | |
| 0 | 1533 { |
| 1534 edge_iterator ei; | |
| 1535 if (bb->flags & BB_IRREDUCIBLE_LOOP) | |
| 111 | 1536 bitmap_set_bit (irreds, bb->index); |
| 0 | 1537 else |
| 111 | 1538 bitmap_clear_bit (irreds, bb->index); |
| 0 | 1539 FOR_EACH_EDGE (e, ei, bb->succs) |
| 1540 if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
| 1541 e->flags |= EDGE_ALL_FLAGS + 1; | |
| 1542 } | |
| 1543 | |
| 1544 /* Recount it. */ | |
| 1545 mark_irreducible_loops (); | |
| 1546 | |
| 1547 /* Compare. */ | |
| 111 | 1548 FOR_EACH_BB_FN (bb, cfun) |
| 0 | 1549 { |
| 1550 edge_iterator ei; | |
| 1551 | |
| 1552 if ((bb->flags & BB_IRREDUCIBLE_LOOP) | |
| 111 | 1553 && !bitmap_bit_p (irreds, bb->index)) |
| 0 | 1554 { |
| 1555 error ("basic block %d should be marked irreducible", bb->index); | |
| 1556 err = 1; | |
| 1557 } | |
| 1558 else if (!(bb->flags & BB_IRREDUCIBLE_LOOP) | |
| 111 | 1559 && bitmap_bit_p (irreds, bb->index)) |
| 0 | 1560 { |
| 1561 error ("basic block %d should not be marked irreducible", bb->index); | |
| 1562 err = 1; | |
| 1563 } | |
| 1564 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 1565 { | |
| 1566 if ((e->flags & EDGE_IRREDUCIBLE_LOOP) | |
| 1567 && !(e->flags & (EDGE_ALL_FLAGS + 1))) | |
| 1568 { | |
| 1569 error ("edge from %d to %d should be marked irreducible", | |
| 1570 e->src->index, e->dest->index); | |
| 1571 err = 1; | |
| 1572 } | |
| 1573 else if (!(e->flags & EDGE_IRREDUCIBLE_LOOP) | |
| 1574 && (e->flags & (EDGE_ALL_FLAGS + 1))) | |
| 1575 { | |
| 1576 error ("edge from %d to %d should not be marked irreducible", | |
| 1577 e->src->index, e->dest->index); | |
| 1578 err = 1; | |
| 1579 } | |
| 1580 e->flags &= ~(EDGE_ALL_FLAGS + 1); | |
| 1581 } | |
| 1582 } | |
| 1583 } | |
| 1584 | |
| 1585 /* Check the recorded loop exits. */ | |
| 111 | 1586 FOR_EACH_LOOP (loop, 0) |
| 0 | 1587 { |
| 1588 if (!loop->exits || loop->exits->e != NULL) | |
| 1589 { | |
| 1590 error ("corrupted head of the exits list of loop %d", | |
| 1591 loop->num); | |
| 1592 err = 1; | |
| 1593 } | |
| 1594 else | |
| 1595 { | |
| 1596 /* Check that the list forms a cycle, and all elements except | |
| 1597 for the head are nonnull. */ | |
| 1598 for (mexit = loop->exits, exit = mexit->next, i = 0; | |
| 1599 exit->e && exit != mexit; | |
| 1600 exit = exit->next) | |
| 1601 { | |
| 1602 if (i++ & 1) | |
| 1603 mexit = mexit->next; | |
| 1604 } | |
| 1605 | |
| 1606 if (exit != loop->exits) | |
| 1607 { | |
| 1608 error ("corrupted exits list of loop %d", loop->num); | |
| 1609 err = 1; | |
| 1610 } | |
| 1611 } | |
| 1612 | |
| 1613 if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
| 1614 { | |
| 1615 if (loop->exits->next != loop->exits) | |
| 1616 { | |
| 1617 error ("nonempty exits list of loop %d, but exits are not recorded", | |
| 1618 loop->num); | |
| 1619 err = 1; | |
| 1620 } | |
| 1621 } | |
| 1622 } | |
| 1623 | |
| 1624 if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
| 1625 { | |
| 1626 unsigned n_exits = 0, eloops; | |
| 1627 | |
| 111 | 1628 sizes = XCNEWVEC (unsigned, num); |
| 0 | 1629 memset (sizes, 0, sizeof (unsigned) * num); |
| 111 | 1630 FOR_EACH_BB_FN (bb, cfun) |
| 0 | 1631 { |
| 1632 edge_iterator ei; | |
| 1633 if (bb->loop_father == current_loops->tree_root) | |
| 1634 continue; | |
| 1635 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 1636 { | |
| 1637 if (flow_bb_inside_loop_p (bb->loop_father, e->dest)) | |
| 1638 continue; | |
| 1639 | |
| 1640 n_exits++; | |
| 1641 exit = get_exit_descriptions (e); | |
| 1642 if (!exit) | |
| 1643 { | |
|
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1644 error ("exit %d->%d not recorded", |
| 0 | 1645 e->src->index, e->dest->index); |
| 1646 err = 1; | |
| 1647 } | |
| 1648 eloops = 0; | |
| 1649 for (; exit; exit = exit->next_e) | |
| 1650 eloops++; | |
| 1651 | |
| 1652 for (loop = bb->loop_father; | |
| 111 | 1653 loop != e->dest->loop_father |
| 1654 /* When a loop exit is also an entry edge which | |
| 1655 can happen when avoiding CFG manipulations | |
| 1656 then the last loop exited is the outer loop | |
| 1657 of the loop entered. */ | |
| 1658 && loop != loop_outer (e->dest->loop_father); | |
| 0 | 1659 loop = loop_outer (loop)) |
| 1660 { | |
| 1661 eloops--; | |
| 1662 sizes[loop->num]++; | |
| 1663 } | |
| 1664 | |
| 1665 if (eloops != 0) | |
| 1666 { | |
|
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1667 error ("wrong list of exited loops for edge %d->%d", |
| 0 | 1668 e->src->index, e->dest->index); |
| 1669 err = 1; | |
| 1670 } | |
| 1671 } | |
| 1672 } | |
| 1673 | |
| 111 | 1674 if (n_exits != current_loops->exits->elements ()) |
| 0 | 1675 { |
|
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|
1676 error ("too many loop exits recorded"); |
| 0 | 1677 err = 1; |
| 1678 } | |
| 1679 | |
| 111 | 1680 FOR_EACH_LOOP (loop, 0) |
| 0 | 1681 { |
| 1682 eloops = 0; | |
| 1683 for (exit = loop->exits->next; exit->e; exit = exit->next) | |
| 1684 eloops++; | |
| 1685 if (eloops != sizes[loop->num]) | |
| 1686 { | |
| 1687 error ("%d exits recorded for loop %d (having %d exits)", | |
| 1688 eloops, loop->num, sizes[loop->num]); | |
| 1689 err = 1; | |
| 1690 } | |
| 1691 } | |
| 111 | 1692 |
| 1693 free (sizes); | |
| 0 | 1694 } |
| 1695 | |
| 1696 gcc_assert (!err); | |
| 1697 | |
| 111 | 1698 if (!dom_available) |
| 1699 free_dominance_info (CDI_DOMINATORS); | |
| 0 | 1700 } |
| 1701 | |
| 1702 /* Returns latch edge of LOOP. */ | |
| 1703 edge | |
| 1704 loop_latch_edge (const struct loop *loop) | |
| 1705 { | |
| 1706 return find_edge (loop->latch, loop->header); | |
| 1707 } | |
| 1708 | |
| 1709 /* Returns preheader edge of LOOP. */ | |
| 1710 edge | |
| 1711 loop_preheader_edge (const struct loop *loop) | |
| 1712 { | |
| 1713 edge e; | |
| 1714 edge_iterator ei; | |
| 1715 | |
| 111 | 1716 gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS) |
| 1717 && ! loops_state_satisfies_p (LOOPS_MAY_HAVE_MULTIPLE_LATCHES)); | |
| 0 | 1718 |
| 1719 FOR_EACH_EDGE (e, ei, loop->header->preds) | |
| 1720 if (e->src != loop->latch) | |
| 1721 break; | |
| 1722 | |
| 111 | 1723 if (! e) |
| 1724 { | |
| 1725 gcc_assert (! loop_outer (loop)); | |
| 1726 return single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
| 1727 } | |
| 1728 | |
| 0 | 1729 return e; |
| 1730 } | |
| 1731 | |
| 1732 /* Returns true if E is an exit of LOOP. */ | |
| 1733 | |
| 1734 bool | |
| 1735 loop_exit_edge_p (const struct loop *loop, const_edge e) | |
| 1736 { | |
| 1737 return (flow_bb_inside_loop_p (loop, e->src) | |
| 1738 && !flow_bb_inside_loop_p (loop, e->dest)); | |
| 1739 } | |
| 1740 | |
| 1741 /* Returns the single exit edge of LOOP, or NULL if LOOP has either no exit | |
| 1742 or more than one exit. If loops do not have the exits recorded, NULL | |
| 1743 is returned always. */ | |
| 1744 | |
| 1745 edge | |
| 1746 single_exit (const struct loop *loop) | |
| 1747 { | |
| 1748 struct loop_exit *exit = loop->exits->next; | |
| 1749 | |
| 1750 if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
| 1751 return NULL; | |
| 1752 | |
| 1753 if (exit->e && exit->next == loop->exits) | |
| 1754 return exit->e; | |
| 1755 else | |
| 1756 return NULL; | |
| 1757 } | |
| 1758 | |
|
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1759 /* Returns true when BB has an incoming edge exiting LOOP. */ |
| 0 | 1760 |
| 1761 bool | |
|
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1762 loop_exits_to_bb_p (struct loop *loop, basic_block bb) |
| 0 | 1763 { |
| 1764 edge e; | |
| 1765 edge_iterator ei; | |
| 1766 | |
| 1767 FOR_EACH_EDGE (e, ei, bb->preds) | |
| 1768 if (loop_exit_edge_p (loop, e)) | |
| 1769 return true; | |
| 1770 | |
| 1771 return false; | |
| 1772 } | |
|
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1773 |
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1774 /* Returns true when BB has an outgoing edge exiting LOOP. */ |
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1775 |
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1776 bool |
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1777 loop_exits_from_bb_p (struct loop *loop, basic_block bb) |
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1778 { |
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1779 edge e; |
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1780 edge_iterator ei; |
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1781 |
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1782 FOR_EACH_EDGE (e, ei, bb->succs) |
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1783 if (loop_exit_edge_p (loop, e)) |
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1784 return true; |
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1785 |
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1786 return false; |
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1787 } |
| 111 | 1788 |
| 1789 /* Return location corresponding to the loop control condition if possible. */ | |
| 1790 | |
| 1791 location_t | |
| 1792 get_loop_location (struct loop *loop) | |
| 1793 { | |
| 1794 rtx_insn *insn = NULL; | |
| 1795 struct niter_desc *desc = NULL; | |
| 1796 edge exit; | |
| 1797 | |
| 1798 /* For a for or while loop, we would like to return the location | |
| 1799 of the for or while statement, if possible. To do this, look | |
| 1800 for the branch guarding the loop back-edge. */ | |
| 1801 | |
| 1802 /* If this is a simple loop with an in_edge, then the loop control | |
| 1803 branch is typically at the end of its source. */ | |
| 1804 desc = get_simple_loop_desc (loop); | |
| 1805 if (desc->in_edge) | |
| 1806 { | |
| 1807 FOR_BB_INSNS_REVERSE (desc->in_edge->src, insn) | |
| 1808 { | |
| 1809 if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
| 1810 return INSN_LOCATION (insn); | |
| 1811 } | |
| 1812 } | |
| 1813 /* If loop has a single exit, then the loop control branch | |
| 1814 must be at the end of its source. */ | |
| 1815 if ((exit = single_exit (loop))) | |
| 1816 { | |
| 1817 FOR_BB_INSNS_REVERSE (exit->src, insn) | |
| 1818 { | |
| 1819 if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
| 1820 return INSN_LOCATION (insn); | |
| 1821 } | |
| 1822 } | |
| 1823 /* Next check the latch, to see if it is non-empty. */ | |
| 1824 FOR_BB_INSNS_REVERSE (loop->latch, insn) | |
| 1825 { | |
| 1826 if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
| 1827 return INSN_LOCATION (insn); | |
| 1828 } | |
| 1829 /* Finally, if none of the above identifies the loop control branch, | |
| 1830 return the first location in the loop header. */ | |
| 1831 FOR_BB_INSNS (loop->header, insn) | |
| 1832 { | |
| 1833 if (INSN_P (insn) && INSN_HAS_LOCATION (insn)) | |
| 1834 return INSN_LOCATION (insn); | |
| 1835 } | |
| 1836 /* If all else fails, simply return the current function location. */ | |
| 1837 return DECL_SOURCE_LOCATION (current_function_decl); | |
| 1838 } | |
| 1839 | |
| 1840 /* Records that every statement in LOOP is executed I_BOUND times. | |
| 1841 REALISTIC is true if I_BOUND is expected to be close to the real number | |
| 1842 of iterations. UPPER is true if we are sure the loop iterates at most | |
| 1843 I_BOUND times. */ | |
| 1844 | |
| 1845 void | |
| 1846 record_niter_bound (struct loop *loop, const widest_int &i_bound, | |
| 1847 bool realistic, bool upper) | |
| 1848 { | |
| 1849 /* Update the bounds only when there is no previous estimation, or when the | |
| 1850 current estimation is smaller. */ | |
| 1851 if (upper | |
| 1852 && (!loop->any_upper_bound | |
| 1853 || wi::ltu_p (i_bound, loop->nb_iterations_upper_bound))) | |
| 1854 { | |
| 1855 loop->any_upper_bound = true; | |
| 1856 loop->nb_iterations_upper_bound = i_bound; | |
| 1857 if (!loop->any_likely_upper_bound) | |
| 1858 { | |
| 1859 loop->any_likely_upper_bound = true; | |
| 1860 loop->nb_iterations_likely_upper_bound = i_bound; | |
| 1861 } | |
| 1862 } | |
| 1863 if (realistic | |
| 1864 && (!loop->any_estimate | |
| 1865 || wi::ltu_p (i_bound, loop->nb_iterations_estimate))) | |
| 1866 { | |
| 1867 loop->any_estimate = true; | |
| 1868 loop->nb_iterations_estimate = i_bound; | |
| 1869 } | |
| 1870 if (!realistic | |
| 1871 && (!loop->any_likely_upper_bound | |
| 1872 || wi::ltu_p (i_bound, loop->nb_iterations_likely_upper_bound))) | |
| 1873 { | |
| 1874 loop->any_likely_upper_bound = true; | |
| 1875 loop->nb_iterations_likely_upper_bound = i_bound; | |
| 1876 } | |
| 1877 | |
| 1878 /* If an upper bound is smaller than the realistic estimate of the | |
| 1879 number of iterations, use the upper bound instead. */ | |
| 1880 if (loop->any_upper_bound | |
| 1881 && loop->any_estimate | |
| 1882 && wi::ltu_p (loop->nb_iterations_upper_bound, | |
| 1883 loop->nb_iterations_estimate)) | |
| 1884 loop->nb_iterations_estimate = loop->nb_iterations_upper_bound; | |
| 1885 if (loop->any_upper_bound | |
| 1886 && loop->any_likely_upper_bound | |
| 1887 && wi::ltu_p (loop->nb_iterations_upper_bound, | |
| 1888 loop->nb_iterations_likely_upper_bound)) | |
| 1889 loop->nb_iterations_likely_upper_bound = loop->nb_iterations_upper_bound; | |
| 1890 } | |
| 1891 | |
| 1892 /* Similar to get_estimated_loop_iterations, but returns the estimate only | |
| 1893 if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
| 1894 on the number of iterations of LOOP could not be derived, returns -1. */ | |
| 1895 | |
| 1896 HOST_WIDE_INT | |
| 1897 get_estimated_loop_iterations_int (struct loop *loop) | |
| 1898 { | |
| 1899 widest_int nit; | |
| 1900 HOST_WIDE_INT hwi_nit; | |
| 1901 | |
| 1902 if (!get_estimated_loop_iterations (loop, &nit)) | |
| 1903 return -1; | |
| 1904 | |
| 1905 if (!wi::fits_shwi_p (nit)) | |
| 1906 return -1; | |
| 1907 hwi_nit = nit.to_shwi (); | |
| 1908 | |
| 1909 return hwi_nit < 0 ? -1 : hwi_nit; | |
| 1910 } | |
| 1911 | |
| 1912 /* Returns an upper bound on the number of executions of statements | |
| 1913 in the LOOP. For statements before the loop exit, this exceeds | |
| 1914 the number of execution of the latch by one. */ | |
| 1915 | |
| 1916 HOST_WIDE_INT | |
| 1917 max_stmt_executions_int (struct loop *loop) | |
| 1918 { | |
| 1919 HOST_WIDE_INT nit = get_max_loop_iterations_int (loop); | |
| 1920 HOST_WIDE_INT snit; | |
| 1921 | |
| 1922 if (nit == -1) | |
| 1923 return -1; | |
| 1924 | |
| 1925 snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
| 1926 | |
| 1927 /* If the computation overflows, return -1. */ | |
| 1928 return snit < 0 ? -1 : snit; | |
| 1929 } | |
| 1930 | |
| 1931 /* Returns an likely upper bound on the number of executions of statements | |
| 1932 in the LOOP. For statements before the loop exit, this exceeds | |
| 1933 the number of execution of the latch by one. */ | |
| 1934 | |
| 1935 HOST_WIDE_INT | |
| 1936 likely_max_stmt_executions_int (struct loop *loop) | |
| 1937 { | |
| 1938 HOST_WIDE_INT nit = get_likely_max_loop_iterations_int (loop); | |
| 1939 HOST_WIDE_INT snit; | |
| 1940 | |
| 1941 if (nit == -1) | |
| 1942 return -1; | |
| 1943 | |
| 1944 snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); | |
| 1945 | |
| 1946 /* If the computation overflows, return -1. */ | |
| 1947 return snit < 0 ? -1 : snit; | |
| 1948 } | |
| 1949 | |
| 1950 /* Sets NIT to the estimated number of executions of the latch of the | |
| 1951 LOOP. If we have no reliable estimate, the function returns false, otherwise | |
| 1952 returns true. */ | |
| 1953 | |
| 1954 bool | |
| 1955 get_estimated_loop_iterations (struct loop *loop, widest_int *nit) | |
| 1956 { | |
| 1957 /* Even if the bound is not recorded, possibly we can derrive one from | |
| 1958 profile. */ | |
| 1959 if (!loop->any_estimate) | |
| 1960 { | |
| 1961 if (loop->header->count.reliable_p ()) | |
| 1962 { | |
| 1963 *nit = gcov_type_to_wide_int | |
| 1964 (expected_loop_iterations_unbounded (loop) + 1); | |
| 1965 return true; | |
| 1966 } | |
| 1967 return false; | |
| 1968 } | |
| 1969 | |
| 1970 *nit = loop->nb_iterations_estimate; | |
| 1971 return true; | |
| 1972 } | |
| 1973 | |
| 1974 /* Sets NIT to an upper bound for the maximum number of executions of the | |
| 1975 latch of the LOOP. If we have no reliable estimate, the function returns | |
| 1976 false, otherwise returns true. */ | |
| 1977 | |
| 1978 bool | |
| 1979 get_max_loop_iterations (const struct loop *loop, widest_int *nit) | |
| 1980 { | |
| 1981 if (!loop->any_upper_bound) | |
| 1982 return false; | |
| 1983 | |
| 1984 *nit = loop->nb_iterations_upper_bound; | |
| 1985 return true; | |
| 1986 } | |
| 1987 | |
| 1988 /* Similar to get_max_loop_iterations, but returns the estimate only | |
| 1989 if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
| 1990 on the number of iterations of LOOP could not be derived, returns -1. */ | |
| 1991 | |
| 1992 HOST_WIDE_INT | |
| 1993 get_max_loop_iterations_int (const struct loop *loop) | |
| 1994 { | |
| 1995 widest_int nit; | |
| 1996 HOST_WIDE_INT hwi_nit; | |
| 1997 | |
| 1998 if (!get_max_loop_iterations (loop, &nit)) | |
| 1999 return -1; | |
| 2000 | |
| 2001 if (!wi::fits_shwi_p (nit)) | |
| 2002 return -1; | |
| 2003 hwi_nit = nit.to_shwi (); | |
| 2004 | |
| 2005 return hwi_nit < 0 ? -1 : hwi_nit; | |
| 2006 } | |
| 2007 | |
| 2008 /* Sets NIT to an upper bound for the maximum number of executions of the | |
| 2009 latch of the LOOP. If we have no reliable estimate, the function returns | |
| 2010 false, otherwise returns true. */ | |
| 2011 | |
| 2012 bool | |
| 2013 get_likely_max_loop_iterations (struct loop *loop, widest_int *nit) | |
| 2014 { | |
| 2015 if (!loop->any_likely_upper_bound) | |
| 2016 return false; | |
| 2017 | |
| 2018 *nit = loop->nb_iterations_likely_upper_bound; | |
| 2019 return true; | |
| 2020 } | |
| 2021 | |
| 2022 /* Similar to get_max_loop_iterations, but returns the estimate only | |
| 2023 if it fits to HOST_WIDE_INT. If this is not the case, or the estimate | |
| 2024 on the number of iterations of LOOP could not be derived, returns -1. */ | |
| 2025 | |
| 2026 HOST_WIDE_INT | |
| 2027 get_likely_max_loop_iterations_int (struct loop *loop) | |
| 2028 { | |
| 2029 widest_int nit; | |
| 2030 HOST_WIDE_INT hwi_nit; | |
| 2031 | |
| 2032 if (!get_likely_max_loop_iterations (loop, &nit)) | |
| 2033 return -1; | |
| 2034 | |
| 2035 if (!wi::fits_shwi_p (nit)) | |
| 2036 return -1; | |
| 2037 hwi_nit = nit.to_shwi (); | |
| 2038 | |
| 2039 return hwi_nit < 0 ? -1 : hwi_nit; | |
| 2040 } | |
| 2041 | |
| 2042 /* Returns the loop depth of the loop BB belongs to. */ | |
| 2043 | |
| 2044 int | |
| 2045 bb_loop_depth (const_basic_block bb) | |
| 2046 { | |
| 2047 return bb->loop_father ? loop_depth (bb->loop_father) : 0; | |
| 2048 } | |
| 2049 | |
| 2050 /* Marks LOOP for removal and sets LOOPS_NEED_FIXUP. */ | |
| 2051 | |
| 2052 void | |
| 2053 mark_loop_for_removal (loop_p loop) | |
| 2054 { | |
| 2055 if (loop->header == NULL) | |
| 2056 return; | |
| 2057 loop->former_header = loop->header; | |
| 2058 loop->header = NULL; | |
| 2059 loop->latch = NULL; | |
| 2060 loops_state_set (LOOPS_NEED_FIXUP); | |
| 2061 } |