Mercurial > hg > CbC > CbC_gcc
annotate gcc/cfgloopmanip.c @ 55:77e2b8dfacca gcc-4.4.5
update it from 4.4.3 to 4.5.0
| author | ryoma <e075725@ie.u-ryukyu.ac.jp> |
|---|---|
| date | Fri, 12 Feb 2010 23:39:51 +0900 |
| parents | a06113de4d67 |
| children | f6334be47118 |
| rev | line source |
|---|---|
| 0 | 1 /* Loop manipulation code for GNU compiler. |
| 2 Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008, 2009 Free Software | |
| 3 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 "basic-block.h" | |
| 29 #include "cfgloop.h" | |
| 30 #include "cfglayout.h" | |
| 31 #include "cfghooks.h" | |
| 32 #include "output.h" | |
| 33 #include "tree-flow.h" | |
| 34 | |
| 35 static void copy_loops_to (struct loop **, int, | |
| 36 struct loop *); | |
| 37 static void loop_redirect_edge (edge, basic_block); | |
| 38 static void remove_bbs (basic_block *, int); | |
| 39 static bool rpe_enum_p (const_basic_block, const void *); | |
| 40 static int find_path (edge, basic_block **); | |
| 41 static void fix_loop_placements (struct loop *, bool *); | |
| 42 static bool fix_bb_placement (basic_block); | |
| 43 static void fix_bb_placements (basic_block, bool *); | |
| 44 static void unloop (struct loop *, bool *); | |
| 45 | |
| 46 #define RDIV(X,Y) (((X) + (Y) / 2) / (Y)) | |
| 47 | |
| 48 /* Checks whether basic block BB is dominated by DATA. */ | |
| 49 static bool | |
| 50 rpe_enum_p (const_basic_block bb, const void *data) | |
| 51 { | |
| 52 return dominated_by_p (CDI_DOMINATORS, bb, (const_basic_block) data); | |
| 53 } | |
| 54 | |
| 55 /* Remove basic blocks BBS. NBBS is the number of the basic blocks. */ | |
| 56 | |
| 57 static void | |
| 58 remove_bbs (basic_block *bbs, int nbbs) | |
| 59 { | |
| 60 int i; | |
| 61 | |
| 62 for (i = 0; i < nbbs; i++) | |
| 63 delete_basic_block (bbs[i]); | |
| 64 } | |
| 65 | |
| 66 /* Find path -- i.e. the basic blocks dominated by edge E and put them | |
| 67 into array BBS, that will be allocated large enough to contain them. | |
| 68 E->dest must have exactly one predecessor for this to work (it is | |
| 69 easy to achieve and we do not put it here because we do not want to | |
| 70 alter anything by this function). The number of basic blocks in the | |
| 71 path is returned. */ | |
| 72 static int | |
| 73 find_path (edge e, basic_block **bbs) | |
| 74 { | |
| 75 gcc_assert (EDGE_COUNT (e->dest->preds) <= 1); | |
| 76 | |
| 77 /* Find bbs in the path. */ | |
| 78 *bbs = XCNEWVEC (basic_block, n_basic_blocks); | |
| 79 return dfs_enumerate_from (e->dest, 0, rpe_enum_p, *bbs, | |
| 80 n_basic_blocks, e->dest); | |
| 81 } | |
| 82 | |
| 83 /* Fix placement of basic block BB inside loop hierarchy -- | |
| 84 Let L be a loop to that BB belongs. Then every successor of BB must either | |
| 85 1) belong to some superloop of loop L, or | |
| 86 2) be a header of loop K such that K->outer is superloop of L | |
| 87 Returns true if we had to move BB into other loop to enforce this condition, | |
| 88 false if the placement of BB was already correct (provided that placements | |
| 89 of its successors are correct). */ | |
| 90 static bool | |
| 91 fix_bb_placement (basic_block bb) | |
| 92 { | |
| 93 edge e; | |
| 94 edge_iterator ei; | |
| 95 struct loop *loop = current_loops->tree_root, *act; | |
| 96 | |
| 97 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 98 { | |
| 99 if (e->dest == EXIT_BLOCK_PTR) | |
| 100 continue; | |
| 101 | |
| 102 act = e->dest->loop_father; | |
| 103 if (act->header == e->dest) | |
| 104 act = loop_outer (act); | |
| 105 | |
| 106 if (flow_loop_nested_p (loop, act)) | |
| 107 loop = act; | |
| 108 } | |
| 109 | |
| 110 if (loop == bb->loop_father) | |
| 111 return false; | |
| 112 | |
| 113 remove_bb_from_loops (bb); | |
| 114 add_bb_to_loop (bb, loop); | |
| 115 | |
| 116 return true; | |
| 117 } | |
| 118 | |
| 119 /* Fix placement of LOOP inside loop tree, i.e. find the innermost superloop | |
| 120 of LOOP to that leads at least one exit edge of LOOP, and set it | |
| 121 as the immediate superloop of LOOP. Return true if the immediate superloop | |
| 122 of LOOP changed. */ | |
| 123 | |
| 124 static bool | |
| 125 fix_loop_placement (struct loop *loop) | |
| 126 { | |
| 127 unsigned i; | |
| 128 edge e; | |
| 129 VEC (edge, heap) *exits = get_loop_exit_edges (loop); | |
| 130 struct loop *father = current_loops->tree_root, *act; | |
| 131 bool ret = false; | |
| 132 | |
| 133 for (i = 0; VEC_iterate (edge, exits, i, e); i++) | |
| 134 { | |
| 135 act = find_common_loop (loop, e->dest->loop_father); | |
| 136 if (flow_loop_nested_p (father, act)) | |
| 137 father = act; | |
| 138 } | |
| 139 | |
| 140 if (father != loop_outer (loop)) | |
| 141 { | |
| 142 for (act = loop_outer (loop); act != father; act = loop_outer (act)) | |
| 143 act->num_nodes -= loop->num_nodes; | |
| 144 flow_loop_tree_node_remove (loop); | |
| 145 flow_loop_tree_node_add (father, loop); | |
| 146 | |
| 147 /* The exit edges of LOOP no longer exits its original immediate | |
| 148 superloops; remove them from the appropriate exit lists. */ | |
| 149 for (i = 0; VEC_iterate (edge, exits, i, e); i++) | |
| 150 rescan_loop_exit (e, false, false); | |
| 151 | |
| 152 ret = true; | |
| 153 } | |
| 154 | |
| 155 VEC_free (edge, heap, exits); | |
| 156 return ret; | |
| 157 } | |
| 158 | |
| 159 /* Fix placements of basic blocks inside loop hierarchy stored in loops; i.e. | |
| 160 enforce condition condition stated in description of fix_bb_placement. We | |
| 161 start from basic block FROM that had some of its successors removed, so that | |
| 162 his placement no longer has to be correct, and iteratively fix placement of | |
| 163 its predecessors that may change if placement of FROM changed. Also fix | |
| 164 placement of subloops of FROM->loop_father, that might also be altered due | |
| 165 to this change; the condition for them is similar, except that instead of | |
| 166 successors we consider edges coming out of the loops. | |
|
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parents:
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167 |
| 0 | 168 If the changes may invalidate the information about irreducible regions, |
| 169 IRRED_INVALIDATED is set to true. */ | |
| 170 | |
| 171 static void | |
| 172 fix_bb_placements (basic_block from, | |
| 173 bool *irred_invalidated) | |
| 174 { | |
| 175 sbitmap in_queue; | |
| 176 basic_block *queue, *qtop, *qbeg, *qend; | |
| 177 struct loop *base_loop; | |
| 178 edge e; | |
| 179 | |
| 180 /* We pass through blocks back-reachable from FROM, testing whether some | |
| 181 of their successors moved to outer loop. It may be necessary to | |
| 182 iterate several times, but it is finite, as we stop unless we move | |
| 183 the basic block up the loop structure. The whole story is a bit | |
| 184 more complicated due to presence of subloops, those are moved using | |
| 185 fix_loop_placement. */ | |
| 186 | |
| 187 base_loop = from->loop_father; | |
| 188 if (base_loop == current_loops->tree_root) | |
| 189 return; | |
| 190 | |
| 191 in_queue = sbitmap_alloc (last_basic_block); | |
| 192 sbitmap_zero (in_queue); | |
| 193 SET_BIT (in_queue, from->index); | |
| 194 /* Prevent us from going out of the base_loop. */ | |
| 195 SET_BIT (in_queue, base_loop->header->index); | |
| 196 | |
| 197 queue = XNEWVEC (basic_block, base_loop->num_nodes + 1); | |
| 198 qtop = queue + base_loop->num_nodes + 1; | |
| 199 qbeg = queue; | |
| 200 qend = queue + 1; | |
| 201 *qbeg = from; | |
| 202 | |
| 203 while (qbeg != qend) | |
| 204 { | |
| 205 edge_iterator ei; | |
| 206 from = *qbeg; | |
| 207 qbeg++; | |
| 208 if (qbeg == qtop) | |
| 209 qbeg = queue; | |
| 210 RESET_BIT (in_queue, from->index); | |
| 211 | |
| 212 if (from->loop_father->header == from) | |
| 213 { | |
| 214 /* Subloop header, maybe move the loop upward. */ | |
| 215 if (!fix_loop_placement (from->loop_father)) | |
| 216 continue; | |
| 217 } | |
| 218 else | |
| 219 { | |
| 220 /* Ordinary basic block. */ | |
| 221 if (!fix_bb_placement (from)) | |
| 222 continue; | |
| 223 } | |
| 224 | |
| 225 FOR_EACH_EDGE (e, ei, from->succs) | |
| 226 { | |
| 227 if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
| 228 *irred_invalidated = true; | |
| 229 } | |
| 230 | |
| 231 /* Something has changed, insert predecessors into queue. */ | |
| 232 FOR_EACH_EDGE (e, ei, from->preds) | |
| 233 { | |
| 234 basic_block pred = e->src; | |
| 235 struct loop *nca; | |
| 236 | |
| 237 if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
| 238 *irred_invalidated = true; | |
| 239 | |
| 240 if (TEST_BIT (in_queue, pred->index)) | |
| 241 continue; | |
| 242 | |
| 243 /* If it is subloop, then it either was not moved, or | |
| 244 the path up the loop tree from base_loop do not contain | |
| 245 it. */ | |
| 246 nca = find_common_loop (pred->loop_father, base_loop); | |
| 247 if (pred->loop_father != base_loop | |
| 248 && (nca == base_loop | |
| 249 || nca != pred->loop_father)) | |
| 250 pred = pred->loop_father->header; | |
| 251 else if (!flow_loop_nested_p (from->loop_father, pred->loop_father)) | |
| 252 { | |
| 253 /* No point in processing it. */ | |
| 254 continue; | |
| 255 } | |
| 256 | |
| 257 if (TEST_BIT (in_queue, pred->index)) | |
| 258 continue; | |
| 259 | |
| 260 /* Schedule the basic block. */ | |
| 261 *qend = pred; | |
| 262 qend++; | |
| 263 if (qend == qtop) | |
| 264 qend = queue; | |
| 265 SET_BIT (in_queue, pred->index); | |
| 266 } | |
| 267 } | |
| 268 free (in_queue); | |
| 269 free (queue); | |
| 270 } | |
| 271 | |
| 272 /* Removes path beginning at edge E, i.e. remove basic blocks dominated by E | |
| 273 and update loop structures and dominators. Return true if we were able | |
| 274 to remove the path, false otherwise (and nothing is affected then). */ | |
| 275 bool | |
| 276 remove_path (edge e) | |
| 277 { | |
| 278 edge ae; | |
| 279 basic_block *rem_bbs, *bord_bbs, from, bb; | |
| 280 VEC (basic_block, heap) *dom_bbs; | |
|
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281 int i, nrem, n_bord_bbs; |
| 0 | 282 sbitmap seen; |
| 283 bool irred_invalidated = false; | |
| 284 | |
| 285 if (!can_remove_branch_p (e)) | |
| 286 return false; | |
| 287 | |
| 288 /* Keep track of whether we need to update information about irreducible | |
| 289 regions. This is the case if the removed area is a part of the | |
| 290 irreducible region, or if the set of basic blocks that belong to a loop | |
| 291 that is inside an irreducible region is changed, or if such a loop is | |
| 292 removed. */ | |
| 293 if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
| 294 irred_invalidated = true; | |
| 295 | |
| 296 /* We need to check whether basic blocks are dominated by the edge | |
| 297 e, but we only have basic block dominators. This is easy to | |
| 298 fix -- when e->dest has exactly one predecessor, this corresponds | |
| 299 to blocks dominated by e->dest, if not, split the edge. */ | |
| 300 if (!single_pred_p (e->dest)) | |
| 301 e = single_pred_edge (split_edge (e)); | |
| 302 | |
| 303 /* It may happen that by removing path we remove one or more loops | |
| 304 we belong to. In this case first unloop the loops, then proceed | |
| 305 normally. We may assume that e->dest is not a header of any loop, | |
| 306 as it now has exactly one predecessor. */ | |
| 307 while (loop_outer (e->src->loop_father) | |
| 308 && dominated_by_p (CDI_DOMINATORS, | |
| 309 e->src->loop_father->latch, e->dest)) | |
| 310 unloop (e->src->loop_father, &irred_invalidated); | |
| 311 | |
| 312 /* Identify the path. */ | |
| 313 nrem = find_path (e, &rem_bbs); | |
| 314 | |
| 315 n_bord_bbs = 0; | |
| 316 bord_bbs = XCNEWVEC (basic_block, n_basic_blocks); | |
| 317 seen = sbitmap_alloc (last_basic_block); | |
| 318 sbitmap_zero (seen); | |
| 319 | |
| 320 /* Find "border" hexes -- i.e. those with predecessor in removed path. */ | |
| 321 for (i = 0; i < nrem; i++) | |
| 322 SET_BIT (seen, rem_bbs[i]->index); | |
| 323 for (i = 0; i < nrem; i++) | |
| 324 { | |
| 325 edge_iterator ei; | |
| 326 bb = rem_bbs[i]; | |
| 327 FOR_EACH_EDGE (ae, ei, rem_bbs[i]->succs) | |
| 328 if (ae->dest != EXIT_BLOCK_PTR && !TEST_BIT (seen, ae->dest->index)) | |
| 329 { | |
| 330 SET_BIT (seen, ae->dest->index); | |
| 331 bord_bbs[n_bord_bbs++] = ae->dest; | |
|
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ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
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diff
changeset
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332 |
| 0 | 333 if (ae->flags & EDGE_IRREDUCIBLE_LOOP) |
| 334 irred_invalidated = true; | |
| 335 } | |
| 336 } | |
| 337 | |
| 338 /* Remove the path. */ | |
| 339 from = e->src; | |
| 340 remove_branch (e); | |
| 341 dom_bbs = NULL; | |
| 342 | |
| 343 /* Cancel loops contained in the path. */ | |
| 344 for (i = 0; i < nrem; i++) | |
| 345 if (rem_bbs[i]->loop_father->header == rem_bbs[i]) | |
|
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77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
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346 cancel_loop_tree (rem_bbs[i]->loop_father); |
| 0 | 347 |
| 348 remove_bbs (rem_bbs, nrem); | |
| 349 free (rem_bbs); | |
| 350 | |
| 351 /* Find blocks whose dominators may be affected. */ | |
| 352 sbitmap_zero (seen); | |
| 353 for (i = 0; i < n_bord_bbs; i++) | |
| 354 { | |
| 355 basic_block ldom; | |
| 356 | |
| 357 bb = get_immediate_dominator (CDI_DOMINATORS, bord_bbs[i]); | |
| 358 if (TEST_BIT (seen, bb->index)) | |
| 359 continue; | |
| 360 SET_BIT (seen, bb->index); | |
| 361 | |
| 362 for (ldom = first_dom_son (CDI_DOMINATORS, bb); | |
| 363 ldom; | |
| 364 ldom = next_dom_son (CDI_DOMINATORS, ldom)) | |
| 365 if (!dominated_by_p (CDI_DOMINATORS, from, ldom)) | |
| 366 VEC_safe_push (basic_block, heap, dom_bbs, ldom); | |
| 367 } | |
| 368 | |
| 369 free (seen); | |
| 370 | |
| 371 /* Recount dominators. */ | |
| 372 iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, true); | |
| 373 VEC_free (basic_block, heap, dom_bbs); | |
| 374 free (bord_bbs); | |
| 375 | |
| 376 /* Fix placements of basic blocks inside loops and the placement of | |
| 377 loops in the loop tree. */ | |
| 378 fix_bb_placements (from, &irred_invalidated); | |
| 379 fix_loop_placements (from->loop_father, &irred_invalidated); | |
| 380 | |
| 381 if (irred_invalidated | |
| 382 && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) | |
| 383 mark_irreducible_loops (); | |
| 384 | |
| 385 return true; | |
| 386 } | |
| 387 | |
| 388 /* Creates place for a new LOOP in loops structure. */ | |
| 389 | |
| 390 static void | |
| 391 place_new_loop (struct loop *loop) | |
| 392 { | |
| 393 loop->num = number_of_loops (); | |
| 394 VEC_safe_push (loop_p, gc, current_loops->larray, loop); | |
| 395 } | |
| 396 | |
| 397 /* Given LOOP structure with filled header and latch, find the body of the | |
| 398 corresponding loop and add it to loops tree. Insert the LOOP as a son of | |
| 399 outer. */ | |
| 400 | |
| 401 void | |
| 402 add_loop (struct loop *loop, struct loop *outer) | |
| 403 { | |
| 404 basic_block *bbs; | |
| 405 int i, n; | |
| 406 struct loop *subloop; | |
| 407 edge e; | |
| 408 edge_iterator ei; | |
| 409 | |
| 410 /* Add it to loop structure. */ | |
| 411 place_new_loop (loop); | |
| 412 flow_loop_tree_node_add (outer, loop); | |
| 413 | |
| 414 /* Find its nodes. */ | |
| 415 bbs = XNEWVEC (basic_block, n_basic_blocks); | |
| 416 n = get_loop_body_with_size (loop, bbs, n_basic_blocks); | |
| 417 | |
| 418 for (i = 0; i < n; i++) | |
| 419 { | |
| 420 if (bbs[i]->loop_father == outer) | |
| 421 { | |
| 422 remove_bb_from_loops (bbs[i]); | |
| 423 add_bb_to_loop (bbs[i], loop); | |
| 424 continue; | |
| 425 } | |
| 426 | |
| 427 loop->num_nodes++; | |
| 428 | |
| 429 /* If we find a direct subloop of OUTER, move it to LOOP. */ | |
| 430 subloop = bbs[i]->loop_father; | |
| 431 if (loop_outer (subloop) == outer | |
| 432 && subloop->header == bbs[i]) | |
| 433 { | |
| 434 flow_loop_tree_node_remove (subloop); | |
| 435 flow_loop_tree_node_add (loop, subloop); | |
| 436 } | |
| 437 } | |
| 438 | |
| 439 /* Update the information about loop exit edges. */ | |
| 440 for (i = 0; i < n; i++) | |
| 441 { | |
| 442 FOR_EACH_EDGE (e, ei, bbs[i]->succs) | |
| 443 { | |
| 444 rescan_loop_exit (e, false, false); | |
| 445 } | |
| 446 } | |
| 447 | |
| 448 free (bbs); | |
| 449 } | |
| 450 | |
| 451 /* Multiply all frequencies in LOOP by NUM/DEN. */ | |
| 452 void | |
| 453 scale_loop_frequencies (struct loop *loop, int num, int den) | |
| 454 { | |
| 455 basic_block *bbs; | |
| 456 | |
| 457 bbs = get_loop_body (loop); | |
| 458 scale_bbs_frequencies_int (bbs, loop->num_nodes, num, den); | |
| 459 free (bbs); | |
| 460 } | |
| 461 | |
| 462 /* Recompute dominance information for basic blocks outside LOOP. */ | |
| 463 | |
| 464 static void | |
| 465 update_dominators_in_loop (struct loop *loop) | |
| 466 { | |
| 467 VEC (basic_block, heap) *dom_bbs = NULL; | |
| 468 sbitmap seen; | |
| 469 basic_block *body; | |
| 470 unsigned i; | |
| 471 | |
| 472 seen = sbitmap_alloc (last_basic_block); | |
| 473 sbitmap_zero (seen); | |
| 474 body = get_loop_body (loop); | |
| 475 | |
| 476 for (i = 0; i < loop->num_nodes; i++) | |
| 477 SET_BIT (seen, body[i]->index); | |
| 478 | |
| 479 for (i = 0; i < loop->num_nodes; i++) | |
| 480 { | |
| 481 basic_block ldom; | |
| 482 | |
| 483 for (ldom = first_dom_son (CDI_DOMINATORS, body[i]); | |
| 484 ldom; | |
| 485 ldom = next_dom_son (CDI_DOMINATORS, ldom)) | |
| 486 if (!TEST_BIT (seen, ldom->index)) | |
| 487 { | |
| 488 SET_BIT (seen, ldom->index); | |
| 489 VEC_safe_push (basic_block, heap, dom_bbs, ldom); | |
| 490 } | |
| 491 } | |
| 492 | |
| 493 iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, false); | |
| 494 free (body); | |
| 495 free (seen); | |
| 496 VEC_free (basic_block, heap, dom_bbs); | |
| 497 } | |
| 498 | |
| 499 /* Creates an if region as shown above. CONDITION is used to create | |
|
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77e2b8dfacca
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ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
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diff
changeset
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500 the test for the if. |
| 0 | 501 |
| 502 | | |
| 503 | ------------- ------------- | |
| 504 | | pred_bb | | pred_bb | | |
| 505 | ------------- ------------- | |
| 506 | | | | |
| 507 | | | ENTRY_EDGE | |
| 508 | | ENTRY_EDGE V | |
| 509 | | ====> ------------- | |
| 510 | | | cond_bb | | |
| 511 | | | CONDITION | | |
| 512 | | ------------- | |
| 513 | V / \ | |
| 514 | ------------- e_false / \ e_true | |
| 515 | | succ_bb | V V | |
| 516 | ------------- ----------- ----------- | |
| 517 | | false_bb | | true_bb | | |
| 518 | ----------- ----------- | |
| 519 | \ / | |
| 520 | \ / | |
| 521 | V V | |
| 522 | ------------- | |
| 523 | | join_bb | | |
| 524 | ------------- | |
| 525 | | exit_edge (result) | |
| 526 | V | |
| 527 | ----------- | |
| 528 | | succ_bb | | |
| 529 | ----------- | |
| 530 | | |
| 531 */ | |
| 532 | |
| 533 edge | |
| 534 create_empty_if_region_on_edge (edge entry_edge, tree condition) | |
| 535 { | |
| 536 | |
|
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ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
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diff
changeset
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537 basic_block cond_bb, true_bb, false_bb, join_bb; |
| 0 | 538 edge e_true, e_false, exit_edge; |
| 539 gimple cond_stmt; | |
| 540 tree simple_cond; | |
| 541 gimple_stmt_iterator gsi; | |
| 542 | |
| 543 cond_bb = split_edge (entry_edge); | |
|
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544 |
| 0 | 545 /* Insert condition in cond_bb. */ |
| 546 gsi = gsi_last_bb (cond_bb); | |
| 547 simple_cond = | |
| 548 force_gimple_operand_gsi (&gsi, condition, true, NULL, | |
| 549 false, GSI_NEW_STMT); | |
| 550 cond_stmt = gimple_build_cond_from_tree (simple_cond, NULL_TREE, NULL_TREE); | |
| 551 gsi = gsi_last_bb (cond_bb); | |
| 552 gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT); | |
|
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553 |
| 0 | 554 join_bb = split_edge (single_succ_edge (cond_bb)); |
| 555 | |
| 556 e_true = single_succ_edge (cond_bb); | |
| 557 true_bb = split_edge (e_true); | |
| 558 | |
| 559 e_false = make_edge (cond_bb, join_bb, 0); | |
| 560 false_bb = split_edge (e_false); | |
| 561 | |
| 562 e_true->flags &= ~EDGE_FALLTHRU; | |
| 563 e_true->flags |= EDGE_TRUE_VALUE; | |
| 564 e_false->flags &= ~EDGE_FALLTHRU; | |
| 565 e_false->flags |= EDGE_FALSE_VALUE; | |
| 566 | |
| 567 set_immediate_dominator (CDI_DOMINATORS, cond_bb, entry_edge->src); | |
| 568 set_immediate_dominator (CDI_DOMINATORS, true_bb, cond_bb); | |
| 569 set_immediate_dominator (CDI_DOMINATORS, false_bb, cond_bb); | |
| 570 set_immediate_dominator (CDI_DOMINATORS, join_bb, cond_bb); | |
| 571 | |
| 572 exit_edge = single_succ_edge (join_bb); | |
| 573 | |
| 574 if (single_pred_p (exit_edge->dest)) | |
| 575 set_immediate_dominator (CDI_DOMINATORS, exit_edge->dest, join_bb); | |
| 576 | |
| 577 return exit_edge; | |
| 578 } | |
| 579 | |
| 580 /* create_empty_loop_on_edge | |
| 581 | | |
|
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582 | - pred_bb - ------ pred_bb ------ |
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583 | | | | iv0 = initial_value | |
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584 | -----|----- ---------|----------- |
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585 | | ______ | entry_edge |
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586 | | entry_edge / | | |
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587 | | ====> | -V---V- loop_header ------------- |
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588 | V | | iv_before = phi (iv0, iv_after) | |
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589 | - succ_bb - | ---|----------------------------- |
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590 | | | | | |
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591 | ----------- | ---V--- loop_body --------------- |
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592 | | | iv_after = iv_before + stride | |
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593 | | | if (iv_before < upper_bound) | |
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594 | | ---|--------------\-------------- |
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595 | | | \ exit_e |
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596 | | V \ |
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597 | | - loop_latch - V- succ_bb - |
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598 | | | | | | |
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599 | | /------------- ----------- |
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600 | \ ___ / |
| 0 | 601 |
| 602 Creates an empty loop as shown above, the IV_BEFORE is the SSA_NAME | |
|
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603 that is used before the increment of IV. IV_BEFORE should be used for |
| 0 | 604 adding code to the body that uses the IV. OUTER is the outer loop in |
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605 which the new loop should be inserted. |
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606 |
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607 Both INITIAL_VALUE and UPPER_BOUND expressions are gimplified and |
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608 inserted on the loop entry edge. This implies that this function |
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609 should be used only when the UPPER_BOUND expression is a loop |
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610 invariant. */ |
| 0 | 611 |
| 612 struct loop * | |
|
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613 create_empty_loop_on_edge (edge entry_edge, |
| 0 | 614 tree initial_value, |
| 615 tree stride, tree upper_bound, | |
| 616 tree iv, | |
| 617 tree *iv_before, | |
|
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618 tree *iv_after, |
| 0 | 619 struct loop *outer) |
| 620 { | |
| 621 basic_block loop_header, loop_latch, succ_bb, pred_bb; | |
| 622 struct loop *loop; | |
| 623 gimple_stmt_iterator gsi; | |
| 624 gimple_seq stmts; | |
| 625 gimple cond_expr; | |
| 626 tree exit_test; | |
| 627 edge exit_e; | |
| 628 int prob; | |
|
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629 |
| 0 | 630 gcc_assert (entry_edge && initial_value && stride && upper_bound && iv); |
| 631 | |
| 632 /* Create header, latch and wire up the loop. */ | |
| 633 pred_bb = entry_edge->src; | |
| 634 loop_header = split_edge (entry_edge); | |
| 635 loop_latch = split_edge (single_succ_edge (loop_header)); | |
| 636 succ_bb = single_succ (loop_latch); | |
| 637 make_edge (loop_header, succ_bb, 0); | |
| 638 redirect_edge_succ_nodup (single_succ_edge (loop_latch), loop_header); | |
| 639 | |
| 640 /* Set immediate dominator information. */ | |
| 641 set_immediate_dominator (CDI_DOMINATORS, loop_header, pred_bb); | |
| 642 set_immediate_dominator (CDI_DOMINATORS, loop_latch, loop_header); | |
| 643 set_immediate_dominator (CDI_DOMINATORS, succ_bb, loop_header); | |
| 644 | |
| 645 /* Initialize a loop structure and put it in a loop hierarchy. */ | |
| 646 loop = alloc_loop (); | |
| 647 loop->header = loop_header; | |
| 648 loop->latch = loop_latch; | |
| 649 add_loop (loop, outer); | |
| 650 | |
| 651 /* TODO: Fix frequencies and counts. */ | |
| 652 prob = REG_BR_PROB_BASE / 2; | |
| 653 | |
| 654 scale_loop_frequencies (loop, REG_BR_PROB_BASE - prob, REG_BR_PROB_BASE); | |
| 655 | |
| 656 /* Update dominators. */ | |
| 657 update_dominators_in_loop (loop); | |
| 658 | |
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659 /* Modify edge flags. */ |
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660 exit_e = single_exit (loop); |
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661 exit_e->flags = EDGE_LOOP_EXIT | EDGE_FALSE_VALUE; |
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662 single_pred_edge (loop_latch)->flags = EDGE_TRUE_VALUE; |
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663 |
| 0 | 664 /* Construct IV code in loop. */ |
| 665 initial_value = force_gimple_operand (initial_value, &stmts, true, iv); | |
| 666 if (stmts) | |
| 667 { | |
| 668 gsi_insert_seq_on_edge (loop_preheader_edge (loop), stmts); | |
| 669 gsi_commit_edge_inserts (); | |
| 670 } | |
| 671 | |
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672 upper_bound = force_gimple_operand (upper_bound, &stmts, true, NULL); |
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673 if (stmts) |
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674 { |
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675 gsi_insert_seq_on_edge (loop_preheader_edge (loop), stmts); |
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676 gsi_commit_edge_inserts (); |
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677 } |
| 0 | 678 |
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679 gsi = gsi_last_bb (loop_header); |
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680 create_iv (initial_value, stride, iv, loop, &gsi, false, |
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681 iv_before, iv_after); |
| 0 | 682 |
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683 /* Insert loop exit condition. */ |
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684 cond_expr = gimple_build_cond |
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685 (LT_EXPR, *iv_before, upper_bound, NULL_TREE, NULL_TREE); |
| 0 | 686 |
| 687 exit_test = gimple_cond_lhs (cond_expr); | |
| 688 exit_test = force_gimple_operand_gsi (&gsi, exit_test, true, NULL, | |
| 689 false, GSI_NEW_STMT); | |
| 690 gimple_cond_set_lhs (cond_expr, exit_test); | |
| 691 gsi = gsi_last_bb (exit_e->src); | |
| 692 gsi_insert_after (&gsi, cond_expr, GSI_NEW_STMT); | |
| 693 | |
|
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694 split_block_after_labels (loop_header); |
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695 |
| 0 | 696 return loop; |
| 697 } | |
| 698 | |
| 699 /* Make area between HEADER_EDGE and LATCH_EDGE a loop by connecting | |
| 700 latch to header and update loop tree and dominators | |
| 701 accordingly. Everything between them plus LATCH_EDGE destination must | |
| 702 be dominated by HEADER_EDGE destination, and back-reachable from | |
| 703 LATCH_EDGE source. HEADER_EDGE is redirected to basic block SWITCH_BB, | |
| 704 FALSE_EDGE of SWITCH_BB to original destination of HEADER_EDGE and | |
| 705 TRUE_EDGE of SWITCH_BB to original destination of LATCH_EDGE. | |
| 706 Returns the newly created loop. Frequencies and counts in the new loop | |
| 707 are scaled by FALSE_SCALE and in the old one by TRUE_SCALE. */ | |
| 708 | |
| 709 struct loop * | |
| 710 loopify (edge latch_edge, edge header_edge, | |
| 711 basic_block switch_bb, edge true_edge, edge false_edge, | |
| 712 bool redirect_all_edges, unsigned true_scale, unsigned false_scale) | |
| 713 { | |
| 714 basic_block succ_bb = latch_edge->dest; | |
| 715 basic_block pred_bb = header_edge->src; | |
| 716 struct loop *loop = alloc_loop (); | |
| 717 struct loop *outer = loop_outer (succ_bb->loop_father); | |
| 718 int freq; | |
| 719 gcov_type cnt; | |
| 720 edge e; | |
| 721 edge_iterator ei; | |
| 722 | |
| 723 loop->header = header_edge->dest; | |
| 724 loop->latch = latch_edge->src; | |
| 725 | |
| 726 freq = EDGE_FREQUENCY (header_edge); | |
| 727 cnt = header_edge->count; | |
| 728 | |
| 729 /* Redirect edges. */ | |
| 730 loop_redirect_edge (latch_edge, loop->header); | |
| 731 loop_redirect_edge (true_edge, succ_bb); | |
| 732 | |
| 733 /* During loop versioning, one of the switch_bb edge is already properly | |
| 734 set. Do not redirect it again unless redirect_all_edges is true. */ | |
| 735 if (redirect_all_edges) | |
| 736 { | |
| 737 loop_redirect_edge (header_edge, switch_bb); | |
| 738 loop_redirect_edge (false_edge, loop->header); | |
| 739 | |
| 740 /* Update dominators. */ | |
| 741 set_immediate_dominator (CDI_DOMINATORS, switch_bb, pred_bb); | |
| 742 set_immediate_dominator (CDI_DOMINATORS, loop->header, switch_bb); | |
| 743 } | |
| 744 | |
| 745 set_immediate_dominator (CDI_DOMINATORS, succ_bb, switch_bb); | |
| 746 | |
| 747 /* Compute new loop. */ | |
| 748 add_loop (loop, outer); | |
| 749 | |
| 750 /* Add switch_bb to appropriate loop. */ | |
| 751 if (switch_bb->loop_father) | |
| 752 remove_bb_from_loops (switch_bb); | |
| 753 add_bb_to_loop (switch_bb, outer); | |
| 754 | |
| 755 /* Fix frequencies. */ | |
| 756 if (redirect_all_edges) | |
| 757 { | |
| 758 switch_bb->frequency = freq; | |
| 759 switch_bb->count = cnt; | |
| 760 FOR_EACH_EDGE (e, ei, switch_bb->succs) | |
| 761 { | |
| 762 e->count = (switch_bb->count * e->probability) / REG_BR_PROB_BASE; | |
| 763 } | |
| 764 } | |
| 765 scale_loop_frequencies (loop, false_scale, REG_BR_PROB_BASE); | |
| 766 scale_loop_frequencies (succ_bb->loop_father, true_scale, REG_BR_PROB_BASE); | |
| 767 update_dominators_in_loop (loop); | |
| 768 | |
| 769 return loop; | |
| 770 } | |
| 771 | |
| 772 /* Remove the latch edge of a LOOP and update loops to indicate that | |
| 773 the LOOP was removed. After this function, original loop latch will | |
| 774 have no successor, which caller is expected to fix somehow. | |
| 775 | |
| 776 If this may cause the information about irreducible regions to become | |
| 777 invalid, IRRED_INVALIDATED is set to true. */ | |
| 778 | |
| 779 static void | |
| 780 unloop (struct loop *loop, bool *irred_invalidated) | |
| 781 { | |
| 782 basic_block *body; | |
| 783 struct loop *ploop; | |
| 784 unsigned i, n; | |
| 785 basic_block latch = loop->latch; | |
| 786 bool dummy = false; | |
| 787 | |
| 788 if (loop_preheader_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP) | |
| 789 *irred_invalidated = true; | |
| 790 | |
| 791 /* This is relatively straightforward. The dominators are unchanged, as | |
| 792 loop header dominates loop latch, so the only thing we have to care of | |
| 793 is the placement of loops and basic blocks inside the loop tree. We | |
| 794 move them all to the loop->outer, and then let fix_bb_placements do | |
| 795 its work. */ | |
| 796 | |
| 797 body = get_loop_body (loop); | |
| 798 n = loop->num_nodes; | |
| 799 for (i = 0; i < n; i++) | |
| 800 if (body[i]->loop_father == loop) | |
| 801 { | |
| 802 remove_bb_from_loops (body[i]); | |
| 803 add_bb_to_loop (body[i], loop_outer (loop)); | |
| 804 } | |
| 805 free(body); | |
| 806 | |
| 807 while (loop->inner) | |
| 808 { | |
| 809 ploop = loop->inner; | |
| 810 flow_loop_tree_node_remove (ploop); | |
| 811 flow_loop_tree_node_add (loop_outer (loop), ploop); | |
| 812 } | |
| 813 | |
| 814 /* Remove the loop and free its data. */ | |
| 815 delete_loop (loop); | |
| 816 | |
| 817 remove_edge (single_succ_edge (latch)); | |
| 818 | |
| 819 /* We do not pass IRRED_INVALIDATED to fix_bb_placements here, as even if | |
| 820 there is an irreducible region inside the cancelled loop, the flags will | |
| 821 be still correct. */ | |
| 822 fix_bb_placements (latch, &dummy); | |
| 823 } | |
| 824 | |
| 825 /* Fix placement of superloops of LOOP inside loop tree, i.e. ensure that | |
| 826 condition stated in description of fix_loop_placement holds for them. | |
| 827 It is used in case when we removed some edges coming out of LOOP, which | |
| 828 may cause the right placement of LOOP inside loop tree to change. | |
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829 |
| 0 | 830 IRRED_INVALIDATED is set to true if a change in the loop structures might |
| 831 invalidate the information about irreducible regions. */ | |
| 832 | |
| 833 static void | |
| 834 fix_loop_placements (struct loop *loop, bool *irred_invalidated) | |
| 835 { | |
| 836 struct loop *outer; | |
| 837 | |
| 838 while (loop_outer (loop)) | |
| 839 { | |
| 840 outer = loop_outer (loop); | |
| 841 if (!fix_loop_placement (loop)) | |
| 842 break; | |
| 843 | |
| 844 /* Changing the placement of a loop in the loop tree may alter the | |
| 845 validity of condition 2) of the description of fix_bb_placement | |
| 846 for its preheader, because the successor is the header and belongs | |
| 847 to the loop. So call fix_bb_placements to fix up the placement | |
| 848 of the preheader and (possibly) of its predecessors. */ | |
| 849 fix_bb_placements (loop_preheader_edge (loop)->src, | |
| 850 irred_invalidated); | |
| 851 loop = outer; | |
| 852 } | |
| 853 } | |
| 854 | |
| 855 /* Copies copy of LOOP as subloop of TARGET loop, placing newly | |
| 856 created loop into loops structure. */ | |
| 857 struct loop * | |
| 858 duplicate_loop (struct loop *loop, struct loop *target) | |
| 859 { | |
| 860 struct loop *cloop; | |
| 861 cloop = alloc_loop (); | |
| 862 place_new_loop (cloop); | |
| 863 | |
| 864 /* Mark the new loop as copy of LOOP. */ | |
| 865 set_loop_copy (loop, cloop); | |
| 866 | |
| 867 /* Add it to target. */ | |
| 868 flow_loop_tree_node_add (target, cloop); | |
| 869 | |
| 870 return cloop; | |
| 871 } | |
| 872 | |
| 873 /* Copies structure of subloops of LOOP into TARGET loop, placing | |
| 874 newly created loops into loop tree. */ | |
|
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update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
875 void |
| 0 | 876 duplicate_subloops (struct loop *loop, struct loop *target) |
| 877 { | |
| 878 struct loop *aloop, *cloop; | |
| 879 | |
| 880 for (aloop = loop->inner; aloop; aloop = aloop->next) | |
| 881 { | |
| 882 cloop = duplicate_loop (aloop, target); | |
| 883 duplicate_subloops (aloop, cloop); | |
| 884 } | |
| 885 } | |
| 886 | |
| 887 /* Copies structure of subloops of N loops, stored in array COPIED_LOOPS, | |
| 888 into TARGET loop, placing newly created loops into loop tree. */ | |
| 889 static void | |
| 890 copy_loops_to (struct loop **copied_loops, int n, struct loop *target) | |
| 891 { | |
| 892 struct loop *aloop; | |
| 893 int i; | |
| 894 | |
| 895 for (i = 0; i < n; i++) | |
| 896 { | |
| 897 aloop = duplicate_loop (copied_loops[i], target); | |
| 898 duplicate_subloops (copied_loops[i], aloop); | |
| 899 } | |
| 900 } | |
| 901 | |
| 902 /* Redirects edge E to basic block DEST. */ | |
| 903 static void | |
| 904 loop_redirect_edge (edge e, basic_block dest) | |
| 905 { | |
| 906 if (e->dest == dest) | |
| 907 return; | |
| 908 | |
| 909 redirect_edge_and_branch_force (e, dest); | |
| 910 } | |
| 911 | |
| 912 /* Check whether LOOP's body can be duplicated. */ | |
| 913 bool | |
| 914 can_duplicate_loop_p (const struct loop *loop) | |
| 915 { | |
| 916 int ret; | |
| 917 basic_block *bbs = get_loop_body (loop); | |
| 918 | |
| 919 ret = can_copy_bbs_p (bbs, loop->num_nodes); | |
| 920 free (bbs); | |
| 921 | |
| 922 return ret; | |
| 923 } | |
| 924 | |
| 925 /* Sets probability and count of edge E to zero. The probability and count | |
| 926 is redistributed evenly to the remaining edges coming from E->src. */ | |
| 927 | |
| 928 static void | |
| 929 set_zero_probability (edge e) | |
| 930 { | |
| 931 basic_block bb = e->src; | |
| 932 edge_iterator ei; | |
| 933 edge ae, last = NULL; | |
| 934 unsigned n = EDGE_COUNT (bb->succs); | |
| 935 gcov_type cnt = e->count, cnt1; | |
| 936 unsigned prob = e->probability, prob1; | |
| 937 | |
| 938 gcc_assert (n > 1); | |
| 939 cnt1 = cnt / (n - 1); | |
| 940 prob1 = prob / (n - 1); | |
| 941 | |
| 942 FOR_EACH_EDGE (ae, ei, bb->succs) | |
| 943 { | |
| 944 if (ae == e) | |
| 945 continue; | |
| 946 | |
| 947 ae->probability += prob1; | |
| 948 ae->count += cnt1; | |
| 949 last = ae; | |
| 950 } | |
| 951 | |
| 952 /* Move the rest to one of the edges. */ | |
| 953 last->probability += prob % (n - 1); | |
| 954 last->count += cnt % (n - 1); | |
| 955 | |
| 956 e->probability = 0; | |
| 957 e->count = 0; | |
| 958 } | |
| 959 | |
| 960 /* Duplicates body of LOOP to given edge E NDUPL times. Takes care of updating | |
| 961 loop structure and dominators. E's destination must be LOOP header for | |
| 962 this to work, i.e. it must be entry or latch edge of this loop; these are | |
| 963 unique, as the loops must have preheaders for this function to work | |
| 964 correctly (in case E is latch, the function unrolls the loop, if E is entry | |
| 965 edge, it peels the loop). Store edges created by copying ORIG edge from | |
| 966 copies corresponding to set bits in WONT_EXIT bitmap (bit 0 corresponds to | |
| 967 original LOOP body, the other copies are numbered in order given by control | |
| 968 flow through them) into TO_REMOVE array. Returns false if duplication is | |
| 969 impossible. */ | |
| 970 | |
| 971 bool | |
| 972 duplicate_loop_to_header_edge (struct loop *loop, edge e, | |
| 973 unsigned int ndupl, sbitmap wont_exit, | |
| 974 edge orig, VEC (edge, heap) **to_remove, | |
| 975 int flags) | |
| 976 { | |
| 977 struct loop *target, *aloop; | |
| 978 struct loop **orig_loops; | |
| 979 unsigned n_orig_loops; | |
| 980 basic_block header = loop->header, latch = loop->latch; | |
| 981 basic_block *new_bbs, *bbs, *first_active; | |
| 982 basic_block new_bb, bb, first_active_latch = NULL; | |
| 983 edge ae, latch_edge; | |
| 984 edge spec_edges[2], new_spec_edges[2]; | |
| 985 #define SE_LATCH 0 | |
| 986 #define SE_ORIG 1 | |
| 987 unsigned i, j, n; | |
| 988 int is_latch = (latch == e->src); | |
| 989 int scale_act = 0, *scale_step = NULL, scale_main = 0; | |
| 990 int scale_after_exit = 0; | |
| 991 int p, freq_in, freq_le, freq_out_orig; | |
| 992 int prob_pass_thru, prob_pass_wont_exit, prob_pass_main; | |
| 993 int add_irreducible_flag; | |
| 994 basic_block place_after; | |
| 995 bitmap bbs_to_scale = NULL; | |
| 996 bitmap_iterator bi; | |
| 997 | |
| 998 gcc_assert (e->dest == loop->header); | |
| 999 gcc_assert (ndupl > 0); | |
| 1000 | |
| 1001 if (orig) | |
| 1002 { | |
| 1003 /* Orig must be edge out of the loop. */ | |
| 1004 gcc_assert (flow_bb_inside_loop_p (loop, orig->src)); | |
| 1005 gcc_assert (!flow_bb_inside_loop_p (loop, orig->dest)); | |
| 1006 } | |
| 1007 | |
| 1008 n = loop->num_nodes; | |
| 1009 bbs = get_loop_body_in_dom_order (loop); | |
| 1010 gcc_assert (bbs[0] == loop->header); | |
| 1011 gcc_assert (bbs[n - 1] == loop->latch); | |
| 1012 | |
| 1013 /* Check whether duplication is possible. */ | |
| 1014 if (!can_copy_bbs_p (bbs, loop->num_nodes)) | |
| 1015 { | |
| 1016 free (bbs); | |
| 1017 return false; | |
| 1018 } | |
| 1019 new_bbs = XNEWVEC (basic_block, loop->num_nodes); | |
| 1020 | |
| 1021 /* In case we are doing loop peeling and the loop is in the middle of | |
| 1022 irreducible region, the peeled copies will be inside it too. */ | |
| 1023 add_irreducible_flag = e->flags & EDGE_IRREDUCIBLE_LOOP; | |
| 1024 gcc_assert (!is_latch || !add_irreducible_flag); | |
| 1025 | |
| 1026 /* Find edge from latch. */ | |
| 1027 latch_edge = loop_latch_edge (loop); | |
| 1028 | |
| 1029 if (flags & DLTHE_FLAG_UPDATE_FREQ) | |
| 1030 { | |
| 1031 /* Calculate coefficients by that we have to scale frequencies | |
| 1032 of duplicated loop bodies. */ | |
| 1033 freq_in = header->frequency; | |
| 1034 freq_le = EDGE_FREQUENCY (latch_edge); | |
| 1035 if (freq_in == 0) | |
| 1036 freq_in = 1; | |
| 1037 if (freq_in < freq_le) | |
| 1038 freq_in = freq_le; | |
| 1039 freq_out_orig = orig ? EDGE_FREQUENCY (orig) : freq_in - freq_le; | |
| 1040 if (freq_out_orig > freq_in - freq_le) | |
| 1041 freq_out_orig = freq_in - freq_le; | |
| 1042 prob_pass_thru = RDIV (REG_BR_PROB_BASE * freq_le, freq_in); | |
| 1043 prob_pass_wont_exit = | |
| 1044 RDIV (REG_BR_PROB_BASE * (freq_le + freq_out_orig), freq_in); | |
| 1045 | |
| 1046 if (orig | |
| 1047 && REG_BR_PROB_BASE - orig->probability != 0) | |
| 1048 { | |
| 1049 /* The blocks that are dominated by a removed exit edge ORIG have | |
| 1050 frequencies scaled by this. */ | |
| 1051 scale_after_exit = RDIV (REG_BR_PROB_BASE * REG_BR_PROB_BASE, | |
| 1052 REG_BR_PROB_BASE - orig->probability); | |
| 1053 bbs_to_scale = BITMAP_ALLOC (NULL); | |
| 1054 for (i = 0; i < n; i++) | |
| 1055 { | |
| 1056 if (bbs[i] != orig->src | |
| 1057 && dominated_by_p (CDI_DOMINATORS, bbs[i], orig->src)) | |
| 1058 bitmap_set_bit (bbs_to_scale, i); | |
| 1059 } | |
| 1060 } | |
| 1061 | |
| 1062 scale_step = XNEWVEC (int, ndupl); | |
| 1063 | |
| 1064 for (i = 1; i <= ndupl; i++) | |
| 1065 scale_step[i - 1] = TEST_BIT (wont_exit, i) | |
| 1066 ? prob_pass_wont_exit | |
| 1067 : prob_pass_thru; | |
| 1068 | |
| 1069 /* Complete peeling is special as the probability of exit in last | |
| 1070 copy becomes 1. */ | |
| 1071 if (flags & DLTHE_FLAG_COMPLETTE_PEEL) | |
| 1072 { | |
| 1073 int wanted_freq = EDGE_FREQUENCY (e); | |
| 1074 | |
| 1075 if (wanted_freq > freq_in) | |
| 1076 wanted_freq = freq_in; | |
| 1077 | |
| 1078 gcc_assert (!is_latch); | |
| 1079 /* First copy has frequency of incoming edge. Each subsequent | |
| 1080 frequency should be reduced by prob_pass_wont_exit. Caller | |
| 1081 should've managed the flags so all except for original loop | |
| 1082 has won't exist set. */ | |
| 1083 scale_act = RDIV (wanted_freq * REG_BR_PROB_BASE, freq_in); | |
| 1084 /* Now simulate the duplication adjustments and compute header | |
| 1085 frequency of the last copy. */ | |
| 1086 for (i = 0; i < ndupl; i++) | |
| 1087 wanted_freq = RDIV (wanted_freq * scale_step[i], REG_BR_PROB_BASE); | |
| 1088 scale_main = RDIV (wanted_freq * REG_BR_PROB_BASE, freq_in); | |
| 1089 } | |
| 1090 else if (is_latch) | |
| 1091 { | |
| 1092 prob_pass_main = TEST_BIT (wont_exit, 0) | |
| 1093 ? prob_pass_wont_exit | |
| 1094 : prob_pass_thru; | |
| 1095 p = prob_pass_main; | |
| 1096 scale_main = REG_BR_PROB_BASE; | |
| 1097 for (i = 0; i < ndupl; i++) | |
| 1098 { | |
| 1099 scale_main += p; | |
| 1100 p = RDIV (p * scale_step[i], REG_BR_PROB_BASE); | |
| 1101 } | |
| 1102 scale_main = RDIV (REG_BR_PROB_BASE * REG_BR_PROB_BASE, scale_main); | |
| 1103 scale_act = RDIV (scale_main * prob_pass_main, REG_BR_PROB_BASE); | |
| 1104 } | |
| 1105 else | |
| 1106 { | |
| 1107 scale_main = REG_BR_PROB_BASE; | |
| 1108 for (i = 0; i < ndupl; i++) | |
| 1109 scale_main = RDIV (scale_main * scale_step[i], REG_BR_PROB_BASE); | |
| 1110 scale_act = REG_BR_PROB_BASE - prob_pass_thru; | |
| 1111 } | |
| 1112 for (i = 0; i < ndupl; i++) | |
| 1113 gcc_assert (scale_step[i] >= 0 && scale_step[i] <= REG_BR_PROB_BASE); | |
| 1114 gcc_assert (scale_main >= 0 && scale_main <= REG_BR_PROB_BASE | |
| 1115 && scale_act >= 0 && scale_act <= REG_BR_PROB_BASE); | |
| 1116 } | |
| 1117 | |
| 1118 /* Loop the new bbs will belong to. */ | |
| 1119 target = e->src->loop_father; | |
| 1120 | |
| 1121 /* Original loops. */ | |
| 1122 n_orig_loops = 0; | |
| 1123 for (aloop = loop->inner; aloop; aloop = aloop->next) | |
| 1124 n_orig_loops++; | |
| 1125 orig_loops = XCNEWVEC (struct loop *, n_orig_loops); | |
| 1126 for (aloop = loop->inner, i = 0; aloop; aloop = aloop->next, i++) | |
| 1127 orig_loops[i] = aloop; | |
| 1128 | |
| 1129 set_loop_copy (loop, target); | |
| 1130 | |
| 1131 first_active = XNEWVEC (basic_block, n); | |
| 1132 if (is_latch) | |
| 1133 { | |
| 1134 memcpy (first_active, bbs, n * sizeof (basic_block)); | |
| 1135 first_active_latch = latch; | |
| 1136 } | |
| 1137 | |
| 1138 spec_edges[SE_ORIG] = orig; | |
| 1139 spec_edges[SE_LATCH] = latch_edge; | |
| 1140 | |
| 1141 place_after = e->src; | |
| 1142 for (j = 0; j < ndupl; j++) | |
| 1143 { | |
| 1144 /* Copy loops. */ | |
| 1145 copy_loops_to (orig_loops, n_orig_loops, target); | |
| 1146 | |
| 1147 /* Copy bbs. */ | |
| 1148 copy_bbs (bbs, n, new_bbs, spec_edges, 2, new_spec_edges, loop, | |
| 1149 place_after); | |
| 1150 place_after = new_spec_edges[SE_LATCH]->src; | |
| 1151 | |
| 1152 if (flags & DLTHE_RECORD_COPY_NUMBER) | |
| 1153 for (i = 0; i < n; i++) | |
| 1154 { | |
| 1155 gcc_assert (!new_bbs[i]->aux); | |
| 1156 new_bbs[i]->aux = (void *)(size_t)(j + 1); | |
| 1157 } | |
| 1158 | |
| 1159 /* Note whether the blocks and edges belong to an irreducible loop. */ | |
| 1160 if (add_irreducible_flag) | |
| 1161 { | |
| 1162 for (i = 0; i < n; i++) | |
| 1163 new_bbs[i]->flags |= BB_DUPLICATED; | |
| 1164 for (i = 0; i < n; i++) | |
| 1165 { | |
| 1166 edge_iterator ei; | |
| 1167 new_bb = new_bbs[i]; | |
| 1168 if (new_bb->loop_father == target) | |
| 1169 new_bb->flags |= BB_IRREDUCIBLE_LOOP; | |
| 1170 | |
| 1171 FOR_EACH_EDGE (ae, ei, new_bb->succs) | |
| 1172 if ((ae->dest->flags & BB_DUPLICATED) | |
| 1173 && (ae->src->loop_father == target | |
| 1174 || ae->dest->loop_father == target)) | |
| 1175 ae->flags |= EDGE_IRREDUCIBLE_LOOP; | |
| 1176 } | |
| 1177 for (i = 0; i < n; i++) | |
| 1178 new_bbs[i]->flags &= ~BB_DUPLICATED; | |
| 1179 } | |
| 1180 | |
| 1181 /* Redirect the special edges. */ | |
| 1182 if (is_latch) | |
| 1183 { | |
| 1184 redirect_edge_and_branch_force (latch_edge, new_bbs[0]); | |
| 1185 redirect_edge_and_branch_force (new_spec_edges[SE_LATCH], | |
| 1186 loop->header); | |
| 1187 set_immediate_dominator (CDI_DOMINATORS, new_bbs[0], latch); | |
| 1188 latch = loop->latch = new_bbs[n - 1]; | |
| 1189 e = latch_edge = new_spec_edges[SE_LATCH]; | |
| 1190 } | |
| 1191 else | |
| 1192 { | |
| 1193 redirect_edge_and_branch_force (new_spec_edges[SE_LATCH], | |
| 1194 loop->header); | |
| 1195 redirect_edge_and_branch_force (e, new_bbs[0]); | |
| 1196 set_immediate_dominator (CDI_DOMINATORS, new_bbs[0], e->src); | |
| 1197 e = new_spec_edges[SE_LATCH]; | |
| 1198 } | |
| 1199 | |
| 1200 /* Record exit edge in this copy. */ | |
| 1201 if (orig && TEST_BIT (wont_exit, j + 1)) | |
| 1202 { | |
| 1203 if (to_remove) | |
| 1204 VEC_safe_push (edge, heap, *to_remove, new_spec_edges[SE_ORIG]); | |
| 1205 set_zero_probability (new_spec_edges[SE_ORIG]); | |
| 1206 | |
| 1207 /* Scale the frequencies of the blocks dominated by the exit. */ | |
| 1208 if (bbs_to_scale) | |
| 1209 { | |
| 1210 EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi) | |
| 1211 { | |
| 1212 scale_bbs_frequencies_int (new_bbs + i, 1, scale_after_exit, | |
| 1213 REG_BR_PROB_BASE); | |
| 1214 } | |
| 1215 } | |
| 1216 } | |
| 1217 | |
| 1218 /* Record the first copy in the control flow order if it is not | |
| 1219 the original loop (i.e. in case of peeling). */ | |
| 1220 if (!first_active_latch) | |
| 1221 { | |
| 1222 memcpy (first_active, new_bbs, n * sizeof (basic_block)); | |
| 1223 first_active_latch = new_bbs[n - 1]; | |
| 1224 } | |
| 1225 | |
| 1226 /* Set counts and frequencies. */ | |
| 1227 if (flags & DLTHE_FLAG_UPDATE_FREQ) | |
| 1228 { | |
| 1229 scale_bbs_frequencies_int (new_bbs, n, scale_act, REG_BR_PROB_BASE); | |
| 1230 scale_act = RDIV (scale_act * scale_step[j], REG_BR_PROB_BASE); | |
| 1231 } | |
| 1232 } | |
| 1233 free (new_bbs); | |
| 1234 free (orig_loops); | |
| 1235 | |
| 1236 /* Record the exit edge in the original loop body, and update the frequencies. */ | |
| 1237 if (orig && TEST_BIT (wont_exit, 0)) | |
| 1238 { | |
| 1239 if (to_remove) | |
| 1240 VEC_safe_push (edge, heap, *to_remove, orig); | |
| 1241 set_zero_probability (orig); | |
| 1242 | |
| 1243 /* Scale the frequencies of the blocks dominated by the exit. */ | |
| 1244 if (bbs_to_scale) | |
| 1245 { | |
| 1246 EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi) | |
| 1247 { | |
| 1248 scale_bbs_frequencies_int (bbs + i, 1, scale_after_exit, | |
| 1249 REG_BR_PROB_BASE); | |
| 1250 } | |
| 1251 } | |
| 1252 } | |
| 1253 | |
| 1254 /* Update the original loop. */ | |
| 1255 if (!is_latch) | |
| 1256 set_immediate_dominator (CDI_DOMINATORS, e->dest, e->src); | |
| 1257 if (flags & DLTHE_FLAG_UPDATE_FREQ) | |
| 1258 { | |
| 1259 scale_bbs_frequencies_int (bbs, n, scale_main, REG_BR_PROB_BASE); | |
| 1260 free (scale_step); | |
| 1261 } | |
| 1262 | |
| 1263 /* Update dominators of outer blocks if affected. */ | |
| 1264 for (i = 0; i < n; i++) | |
| 1265 { | |
| 1266 basic_block dominated, dom_bb; | |
| 1267 VEC (basic_block, heap) *dom_bbs; | |
| 1268 unsigned j; | |
| 1269 | |
| 1270 bb = bbs[i]; | |
| 1271 bb->aux = 0; | |
| 1272 | |
| 1273 dom_bbs = get_dominated_by (CDI_DOMINATORS, bb); | |
| 1274 for (j = 0; VEC_iterate (basic_block, dom_bbs, j, dominated); j++) | |
| 1275 { | |
| 1276 if (flow_bb_inside_loop_p (loop, dominated)) | |
| 1277 continue; | |
| 1278 dom_bb = nearest_common_dominator ( | |
| 1279 CDI_DOMINATORS, first_active[i], first_active_latch); | |
| 1280 set_immediate_dominator (CDI_DOMINATORS, dominated, dom_bb); | |
| 1281 } | |
| 1282 VEC_free (basic_block, heap, dom_bbs); | |
| 1283 } | |
| 1284 free (first_active); | |
| 1285 | |
| 1286 free (bbs); | |
| 1287 BITMAP_FREE (bbs_to_scale); | |
| 1288 | |
| 1289 return true; | |
| 1290 } | |
| 1291 | |
| 1292 /* A callback for make_forwarder block, to redirect all edges except for | |
| 1293 MFB_KJ_EDGE to the entry part. E is the edge for that we should decide | |
| 1294 whether to redirect it. */ | |
| 1295 | |
| 1296 edge mfb_kj_edge; | |
| 1297 bool | |
| 1298 mfb_keep_just (edge e) | |
| 1299 { | |
| 1300 return e != mfb_kj_edge; | |
| 1301 } | |
| 1302 | |
| 1303 /* True when a candidate preheader BLOCK has predecessors from LOOP. */ | |
| 1304 | |
| 1305 static bool | |
| 1306 has_preds_from_loop (basic_block block, struct loop *loop) | |
| 1307 { | |
| 1308 edge e; | |
| 1309 edge_iterator ei; | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
1310 |
| 0 | 1311 FOR_EACH_EDGE (e, ei, block->preds) |
| 1312 if (e->src->loop_father == loop) | |
| 1313 return true; | |
| 1314 return false; | |
| 1315 } | |
| 1316 | |
| 1317 /* Creates a pre-header for a LOOP. Returns newly created block. Unless | |
| 1318 CP_SIMPLE_PREHEADERS is set in FLAGS, we only force LOOP to have single | |
| 1319 entry; otherwise we also force preheader block to have only one successor. | |
| 1320 When CP_FALLTHRU_PREHEADERS is set in FLAGS, we force the preheader block | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
1321 to be a fallthru predecessor to the loop header and to have only |
| 0 | 1322 predecessors from outside of the loop. |
| 1323 The function also updates dominators. */ | |
| 1324 | |
| 1325 basic_block | |
| 1326 create_preheader (struct loop *loop, int flags) | |
| 1327 { | |
| 1328 edge e, fallthru; | |
| 1329 basic_block dummy; | |
| 1330 int nentry = 0; | |
| 1331 bool irred = false; | |
| 1332 bool latch_edge_was_fallthru; | |
| 1333 edge one_succ_pred = NULL, single_entry = NULL; | |
| 1334 edge_iterator ei; | |
| 1335 | |
| 1336 FOR_EACH_EDGE (e, ei, loop->header->preds) | |
| 1337 { | |
| 1338 if (e->src == loop->latch) | |
| 1339 continue; | |
| 1340 irred |= (e->flags & EDGE_IRREDUCIBLE_LOOP) != 0; | |
| 1341 nentry++; | |
| 1342 single_entry = e; | |
| 1343 if (single_succ_p (e->src)) | |
| 1344 one_succ_pred = e; | |
| 1345 } | |
| 1346 gcc_assert (nentry); | |
| 1347 if (nentry == 1) | |
| 1348 { | |
| 1349 bool need_forwarder_block = false; | |
|
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|
1350 |
| 0 | 1351 /* We do not allow entry block to be the loop preheader, since we |
| 1352 cannot emit code there. */ | |
| 1353 if (single_entry->src == ENTRY_BLOCK_PTR) | |
| 1354 need_forwarder_block = true; | |
| 1355 else | |
| 1356 { | |
| 1357 /* If we want simple preheaders, also force the preheader to have | |
| 1358 just a single successor. */ | |
| 1359 if ((flags & CP_SIMPLE_PREHEADERS) | |
| 1360 && !single_succ_p (single_entry->src)) | |
| 1361 need_forwarder_block = true; | |
| 1362 /* If we want fallthru preheaders, also create forwarder block when | |
| 1363 preheader ends with a jump or has predecessors from loop. */ | |
| 1364 else if ((flags & CP_FALLTHRU_PREHEADERS) | |
| 1365 && (JUMP_P (BB_END (single_entry->src)) | |
| 1366 || has_preds_from_loop (single_entry->src, loop))) | |
| 1367 need_forwarder_block = true; | |
| 1368 } | |
| 1369 if (! need_forwarder_block) | |
| 1370 return NULL; | |
| 1371 } | |
| 1372 | |
| 1373 mfb_kj_edge = loop_latch_edge (loop); | |
| 1374 latch_edge_was_fallthru = (mfb_kj_edge->flags & EDGE_FALLTHRU) != 0; | |
| 1375 fallthru = make_forwarder_block (loop->header, mfb_keep_just, NULL); | |
| 1376 dummy = fallthru->src; | |
| 1377 loop->header = fallthru->dest; | |
| 1378 | |
| 1379 /* Try to be clever in placing the newly created preheader. The idea is to | |
| 1380 avoid breaking any "fallthruness" relationship between blocks. | |
| 1381 | |
| 1382 The preheader was created just before the header and all incoming edges | |
| 1383 to the header were redirected to the preheader, except the latch edge. | |
| 1384 So the only problematic case is when this latch edge was a fallthru | |
| 1385 edge: it is not anymore after the preheader creation so we have broken | |
| 1386 the fallthruness. We're therefore going to look for a better place. */ | |
| 1387 if (latch_edge_was_fallthru) | |
| 1388 { | |
| 1389 if (one_succ_pred) | |
| 1390 e = one_succ_pred; | |
| 1391 else | |
| 1392 e = EDGE_PRED (dummy, 0); | |
| 1393 | |
| 1394 move_block_after (dummy, e->src); | |
| 1395 } | |
| 1396 | |
| 1397 if (irred) | |
| 1398 { | |
| 1399 dummy->flags |= BB_IRREDUCIBLE_LOOP; | |
| 1400 single_succ_edge (dummy)->flags |= EDGE_IRREDUCIBLE_LOOP; | |
| 1401 } | |
| 1402 | |
| 1403 if (dump_file) | |
| 1404 fprintf (dump_file, "Created preheader block for loop %i\n", | |
| 1405 loop->num); | |
|
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1406 |
| 0 | 1407 if (flags & CP_FALLTHRU_PREHEADERS) |
| 1408 gcc_assert ((single_succ_edge (dummy)->flags & EDGE_FALLTHRU) | |
| 1409 && !JUMP_P (BB_END (dummy))); | |
| 1410 | |
| 1411 return dummy; | |
| 1412 } | |
| 1413 | |
| 1414 /* Create preheaders for each loop; for meaning of FLAGS see create_preheader. */ | |
| 1415 | |
| 1416 void | |
| 1417 create_preheaders (int flags) | |
| 1418 { | |
| 1419 loop_iterator li; | |
| 1420 struct loop *loop; | |
| 1421 | |
| 1422 if (!current_loops) | |
| 1423 return; | |
| 1424 | |
| 1425 FOR_EACH_LOOP (li, loop, 0) | |
| 1426 create_preheader (loop, flags); | |
| 1427 loops_state_set (LOOPS_HAVE_PREHEADERS); | |
| 1428 } | |
| 1429 | |
| 1430 /* Forces all loop latches to have only single successor. */ | |
| 1431 | |
| 1432 void | |
| 1433 force_single_succ_latches (void) | |
| 1434 { | |
| 1435 loop_iterator li; | |
| 1436 struct loop *loop; | |
| 1437 edge e; | |
| 1438 | |
| 1439 FOR_EACH_LOOP (li, loop, 0) | |
| 1440 { | |
| 1441 if (loop->latch != loop->header && single_succ_p (loop->latch)) | |
| 1442 continue; | |
| 1443 | |
| 1444 e = find_edge (loop->latch, loop->header); | |
| 1445 | |
| 1446 split_edge (e); | |
| 1447 } | |
| 1448 loops_state_set (LOOPS_HAVE_SIMPLE_LATCHES); | |
| 1449 } | |
| 1450 | |
| 1451 /* This function is called from loop_version. It splits the entry edge | |
| 1452 of the loop we want to version, adds the versioning condition, and | |
| 1453 adjust the edges to the two versions of the loop appropriately. | |
| 1454 e is an incoming edge. Returns the basic block containing the | |
| 1455 condition. | |
| 1456 | |
| 1457 --- edge e ---- > [second_head] | |
| 1458 | |
| 1459 Split it and insert new conditional expression and adjust edges. | |
| 1460 | |
| 1461 --- edge e ---> [cond expr] ---> [first_head] | |
| 1462 | | |
| 1463 +---------> [second_head] | |
| 1464 | |
| 1465 THEN_PROB is the probability of then branch of the condition. */ | |
| 1466 | |
| 1467 static basic_block | |
| 1468 lv_adjust_loop_entry_edge (basic_block first_head, basic_block second_head, | |
| 1469 edge e, void *cond_expr, unsigned then_prob) | |
| 1470 { | |
| 1471 basic_block new_head = NULL; | |
| 1472 edge e1; | |
| 1473 | |
| 1474 gcc_assert (e->dest == second_head); | |
| 1475 | |
| 1476 /* Split edge 'e'. This will create a new basic block, where we can | |
| 1477 insert conditional expr. */ | |
| 1478 new_head = split_edge (e); | |
| 1479 | |
| 1480 lv_add_condition_to_bb (first_head, second_head, new_head, | |
| 1481 cond_expr); | |
| 1482 | |
| 1483 /* Don't set EDGE_TRUE_VALUE in RTL mode, as it's invalid there. */ | |
| 1484 e = single_succ_edge (new_head); | |
| 1485 e1 = make_edge (new_head, first_head, | |
| 1486 current_ir_type () == IR_GIMPLE ? EDGE_TRUE_VALUE : 0); | |
| 1487 e1->probability = then_prob; | |
| 1488 e->probability = REG_BR_PROB_BASE - then_prob; | |
| 1489 e1->count = RDIV (e->count * e1->probability, REG_BR_PROB_BASE); | |
| 1490 e->count = RDIV (e->count * e->probability, REG_BR_PROB_BASE); | |
| 1491 | |
| 1492 set_immediate_dominator (CDI_DOMINATORS, first_head, new_head); | |
| 1493 set_immediate_dominator (CDI_DOMINATORS, second_head, new_head); | |
| 1494 | |
| 1495 /* Adjust loop header phi nodes. */ | |
| 1496 lv_adjust_loop_header_phi (first_head, second_head, new_head, e1); | |
| 1497 | |
| 1498 return new_head; | |
| 1499 } | |
| 1500 | |
| 1501 /* Main entry point for Loop Versioning transformation. | |
| 1502 | |
| 1503 This transformation given a condition and a loop, creates | |
| 1504 -if (condition) { loop_copy1 } else { loop_copy2 }, | |
| 1505 where loop_copy1 is the loop transformed in one way, and loop_copy2 | |
| 1506 is the loop transformed in another way (or unchanged). 'condition' | |
| 1507 may be a run time test for things that were not resolved by static | |
| 1508 analysis (overlapping ranges (anti-aliasing), alignment, etc.). | |
| 1509 | |
| 1510 THEN_PROB is the probability of the then edge of the if. THEN_SCALE | |
| 1511 is the ratio by that the frequencies in the original loop should | |
| 1512 be scaled. ELSE_SCALE is the ratio by that the frequencies in the | |
| 1513 new loop should be scaled. | |
|
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|
1514 |
| 0 | 1515 If PLACE_AFTER is true, we place the new loop after LOOP in the |
| 1516 instruction stream, otherwise it is placed before LOOP. */ | |
| 1517 | |
| 1518 struct loop * | |
| 1519 loop_version (struct loop *loop, | |
| 1520 void *cond_expr, basic_block *condition_bb, | |
| 1521 unsigned then_prob, unsigned then_scale, unsigned else_scale, | |
| 1522 bool place_after) | |
| 1523 { | |
| 1524 basic_block first_head, second_head; | |
| 1525 edge entry, latch_edge, true_edge, false_edge; | |
| 1526 int irred_flag; | |
| 1527 struct loop *nloop; | |
| 1528 basic_block cond_bb; | |
| 1529 | |
| 1530 /* Record entry and latch edges for the loop */ | |
| 1531 entry = loop_preheader_edge (loop); | |
| 1532 irred_flag = entry->flags & EDGE_IRREDUCIBLE_LOOP; | |
| 1533 entry->flags &= ~EDGE_IRREDUCIBLE_LOOP; | |
| 1534 | |
| 1535 /* Note down head of loop as first_head. */ | |
| 1536 first_head = entry->dest; | |
| 1537 | |
| 1538 /* Duplicate loop. */ | |
| 1539 if (!cfg_hook_duplicate_loop_to_header_edge (loop, entry, 1, | |
| 1540 NULL, NULL, NULL, 0)) | |
| 1541 return NULL; | |
| 1542 | |
| 1543 /* After duplication entry edge now points to new loop head block. | |
| 1544 Note down new head as second_head. */ | |
| 1545 second_head = entry->dest; | |
| 1546 | |
| 1547 /* Split loop entry edge and insert new block with cond expr. */ | |
| 1548 cond_bb = lv_adjust_loop_entry_edge (first_head, second_head, | |
| 1549 entry, cond_expr, then_prob); | |
| 1550 if (condition_bb) | |
| 1551 *condition_bb = cond_bb; | |
| 1552 | |
| 1553 if (!cond_bb) | |
| 1554 { | |
| 1555 entry->flags |= irred_flag; | |
| 1556 return NULL; | |
| 1557 } | |
| 1558 | |
| 1559 latch_edge = single_succ_edge (get_bb_copy (loop->latch)); | |
| 1560 | |
| 1561 extract_cond_bb_edges (cond_bb, &true_edge, &false_edge); | |
| 1562 nloop = loopify (latch_edge, | |
| 1563 single_pred_edge (get_bb_copy (loop->header)), | |
| 1564 cond_bb, true_edge, false_edge, | |
| 1565 false /* Do not redirect all edges. */, | |
| 1566 then_scale, else_scale); | |
| 1567 | |
| 1568 /* loopify redirected latch_edge. Update its PENDING_STMTS. */ | |
| 1569 lv_flush_pending_stmts (latch_edge); | |
| 1570 | |
| 1571 /* loopify redirected condition_bb's succ edge. Update its PENDING_STMTS. */ | |
| 1572 extract_cond_bb_edges (cond_bb, &true_edge, &false_edge); | |
| 1573 lv_flush_pending_stmts (false_edge); | |
| 1574 /* Adjust irreducible flag. */ | |
| 1575 if (irred_flag) | |
| 1576 { | |
| 1577 cond_bb->flags |= BB_IRREDUCIBLE_LOOP; | |
| 1578 loop_preheader_edge (loop)->flags |= EDGE_IRREDUCIBLE_LOOP; | |
| 1579 loop_preheader_edge (nloop)->flags |= EDGE_IRREDUCIBLE_LOOP; | |
| 1580 single_pred_edge (cond_bb)->flags |= EDGE_IRREDUCIBLE_LOOP; | |
| 1581 } | |
| 1582 | |
| 1583 if (place_after) | |
| 1584 { | |
| 1585 basic_block *bbs = get_loop_body_in_dom_order (nloop), after; | |
| 1586 unsigned i; | |
| 1587 | |
| 1588 after = loop->latch; | |
| 1589 | |
| 1590 for (i = 0; i < nloop->num_nodes; i++) | |
| 1591 { | |
| 1592 move_block_after (bbs[i], after); | |
| 1593 after = bbs[i]; | |
| 1594 } | |
| 1595 free (bbs); | |
| 1596 } | |
| 1597 | |
| 1598 /* At this point condition_bb is loop preheader with two successors, | |
| 1599 first_head and second_head. Make sure that loop preheader has only | |
| 1600 one successor. */ | |
| 1601 split_edge (loop_preheader_edge (loop)); | |
| 1602 split_edge (loop_preheader_edge (nloop)); | |
| 1603 | |
| 1604 return nloop; | |
| 1605 } | |
| 1606 | |
| 1607 /* The structure of loops might have changed. Some loops might get removed | |
| 1608 (and their headers and latches were set to NULL), loop exists might get | |
| 1609 removed (thus the loop nesting may be wrong), and some blocks and edges | |
| 1610 were changed (so the information about bb --> loop mapping does not have | |
| 1611 to be correct). But still for the remaining loops the header dominates | |
| 1612 the latch, and loops did not get new subloops (new loops might possibly | |
| 1613 get created, but we are not interested in them). Fix up the mess. | |
| 1614 | |
| 1615 If CHANGED_BBS is not NULL, basic blocks whose loop has changed are | |
| 1616 marked in it. */ | |
| 1617 | |
| 1618 void | |
| 1619 fix_loop_structure (bitmap changed_bbs) | |
| 1620 { | |
| 1621 basic_block bb; | |
| 1622 struct loop *loop, *ploop; | |
| 1623 loop_iterator li; | |
| 1624 bool record_exits = false; | |
| 1625 struct loop **superloop = XNEWVEC (struct loop *, number_of_loops ()); | |
| 1626 | |
| 1627 /* Remove the old bb -> loop mapping. Remember the depth of the blocks in | |
| 1628 the loop hierarchy, so that we can recognize blocks whose loop nesting | |
| 1629 relationship has changed. */ | |
| 1630 FOR_EACH_BB (bb) | |
| 1631 { | |
| 1632 if (changed_bbs) | |
| 1633 bb->aux = (void *) (size_t) loop_depth (bb->loop_father); | |
| 1634 bb->loop_father = current_loops->tree_root; | |
| 1635 } | |
| 1636 | |
| 1637 if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) | |
| 1638 { | |
| 1639 release_recorded_exits (); | |
| 1640 record_exits = true; | |
| 1641 } | |
| 1642 | |
| 1643 /* Remove the dead loops from structures. We start from the innermost | |
| 1644 loops, so that when we remove the loops, we know that the loops inside | |
| 1645 are preserved, and do not waste time relinking loops that will be | |
| 1646 removed later. */ | |
| 1647 FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST) | |
| 1648 { | |
| 1649 if (loop->header) | |
| 1650 continue; | |
| 1651 | |
| 1652 while (loop->inner) | |
| 1653 { | |
| 1654 ploop = loop->inner; | |
| 1655 flow_loop_tree_node_remove (ploop); | |
| 1656 flow_loop_tree_node_add (loop_outer (loop), ploop); | |
| 1657 } | |
| 1658 | |
| 1659 /* Remove the loop and free its data. */ | |
| 1660 delete_loop (loop); | |
| 1661 } | |
| 1662 | |
| 1663 /* Rescan the bodies of loops, starting from the outermost ones. We assume | |
| 1664 that no optimization interchanges the order of the loops, i.e., it cannot | |
| 1665 happen that L1 was superloop of L2 before and it is subloop of L2 now | |
| 1666 (without explicitly updating loop information). At the same time, we also | |
| 1667 determine the new loop structure. */ | |
| 1668 current_loops->tree_root->num_nodes = n_basic_blocks; | |
| 1669 FOR_EACH_LOOP (li, loop, 0) | |
| 1670 { | |
| 1671 superloop[loop->num] = loop->header->loop_father; | |
| 1672 loop->num_nodes = flow_loop_nodes_find (loop->header, loop); | |
| 1673 } | |
| 1674 | |
| 1675 /* Now fix the loop nesting. */ | |
| 1676 FOR_EACH_LOOP (li, loop, 0) | |
| 1677 { | |
| 1678 ploop = superloop[loop->num]; | |
| 1679 if (ploop != loop_outer (loop)) | |
| 1680 { | |
| 1681 flow_loop_tree_node_remove (loop); | |
| 1682 flow_loop_tree_node_add (ploop, loop); | |
| 1683 } | |
| 1684 } | |
| 1685 free (superloop); | |
| 1686 | |
| 1687 /* Mark the blocks whose loop has changed. */ | |
| 1688 if (changed_bbs) | |
| 1689 { | |
| 1690 FOR_EACH_BB (bb) | |
| 1691 { | |
| 1692 if ((void *) (size_t) loop_depth (bb->loop_father) != bb->aux) | |
| 1693 bitmap_set_bit (changed_bbs, bb->index); | |
| 1694 | |
| 1695 bb->aux = NULL; | |
| 1696 } | |
| 1697 } | |
| 1698 | |
| 1699 if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)) | |
| 1700 create_preheaders (CP_SIMPLE_PREHEADERS); | |
| 1701 | |
| 1702 if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) | |
| 1703 force_single_succ_latches (); | |
| 1704 | |
| 1705 if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) | |
| 1706 mark_irreducible_loops (); | |
| 1707 | |
| 1708 if (record_exits) | |
| 1709 record_loop_exits (); | |
| 1710 | |
| 1711 #ifdef ENABLE_CHECKING | |
| 1712 verify_loop_structure (); | |
| 1713 #endif | |
| 1714 } |