Mercurial > hg > CbC > CbC_gcc
annotate gcc/tree-ssa-loop-im.c @ 47:3bfb6c00c1e0
update it from 4.4.2 to 4.4.3.
| author | kent <kent@cr.ie.u-ryukyu.ac.jp> |
|---|---|
| date | Sun, 07 Feb 2010 17:44:34 +0900 |
| parents | a06113de4d67 |
| children | 77e2b8dfacca |
| rev | line source |
|---|---|
| 0 | 1 /* Loop invariant motion. |
| 2 Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 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 | |
| 8 under the terms of the GNU General Public License as published by the | |
| 9 Free Software Foundation; either version 3, or (at your option) any | |
| 10 later version. | |
| 11 | |
| 12 GCC is distributed in the hope that it will be useful, but WITHOUT | |
| 13 ANY 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 "tree.h" | |
| 26 #include "rtl.h" | |
| 27 #include "tm_p.h" | |
| 28 #include "hard-reg-set.h" | |
| 29 #include "basic-block.h" | |
| 30 #include "output.h" | |
| 31 #include "diagnostic.h" | |
| 32 #include "tree-flow.h" | |
| 33 #include "tree-dump.h" | |
| 34 #include "timevar.h" | |
| 35 #include "cfgloop.h" | |
| 36 #include "domwalk.h" | |
| 37 #include "params.h" | |
| 38 #include "tree-pass.h" | |
| 39 #include "flags.h" | |
| 40 #include "real.h" | |
| 41 #include "hashtab.h" | |
| 42 #include "tree-affine.h" | |
| 43 #include "pointer-set.h" | |
| 44 #include "tree-ssa-propagate.h" | |
| 45 | |
| 46 /* TODO: Support for predicated code motion. I.e. | |
| 47 | |
| 48 while (1) | |
| 49 { | |
| 50 if (cond) | |
| 51 { | |
| 52 a = inv; | |
| 53 something; | |
| 54 } | |
| 55 } | |
| 56 | |
| 57 Where COND and INV are is invariants, but evaluating INV may trap or be | |
| 58 invalid from some other reason if !COND. This may be transformed to | |
| 59 | |
| 60 if (cond) | |
| 61 a = inv; | |
| 62 while (1) | |
| 63 { | |
| 64 if (cond) | |
| 65 something; | |
| 66 } */ | |
| 67 | |
| 68 /* A type for the list of statements that have to be moved in order to be able | |
| 69 to hoist an invariant computation. */ | |
| 70 | |
| 71 struct depend | |
| 72 { | |
| 73 gimple stmt; | |
| 74 struct depend *next; | |
| 75 }; | |
| 76 | |
| 77 /* The auxiliary data kept for each statement. */ | |
| 78 | |
| 79 struct lim_aux_data | |
| 80 { | |
| 81 struct loop *max_loop; /* The outermost loop in that the statement | |
| 82 is invariant. */ | |
| 83 | |
| 84 struct loop *tgt_loop; /* The loop out of that we want to move the | |
| 85 invariant. */ | |
| 86 | |
| 87 struct loop *always_executed_in; | |
| 88 /* The outermost loop for that we are sure | |
| 89 the statement is executed if the loop | |
| 90 is entered. */ | |
| 91 | |
| 92 unsigned cost; /* Cost of the computation performed by the | |
| 93 statement. */ | |
| 94 | |
| 95 struct depend *depends; /* List of statements that must be also hoisted | |
| 96 out of the loop when this statement is | |
| 97 hoisted; i.e. those that define the operands | |
| 98 of the statement and are inside of the | |
| 99 MAX_LOOP loop. */ | |
| 100 }; | |
| 101 | |
| 102 /* Maps statements to their lim_aux_data. */ | |
| 103 | |
| 104 static struct pointer_map_t *lim_aux_data_map; | |
| 105 | |
| 106 /* Description of a memory reference location. */ | |
| 107 | |
| 108 typedef struct mem_ref_loc | |
| 109 { | |
| 110 tree *ref; /* The reference itself. */ | |
| 111 gimple stmt; /* The statement in that it occurs. */ | |
| 112 } *mem_ref_loc_p; | |
| 113 | |
| 114 DEF_VEC_P(mem_ref_loc_p); | |
| 115 DEF_VEC_ALLOC_P(mem_ref_loc_p, heap); | |
| 116 | |
| 117 /* The list of memory reference locations in a loop. */ | |
| 118 | |
| 119 typedef struct mem_ref_locs | |
| 120 { | |
| 121 VEC (mem_ref_loc_p, heap) *locs; | |
| 122 } *mem_ref_locs_p; | |
| 123 | |
| 124 DEF_VEC_P(mem_ref_locs_p); | |
| 125 DEF_VEC_ALLOC_P(mem_ref_locs_p, heap); | |
| 126 | |
| 127 /* Description of a memory reference. */ | |
| 128 | |
| 129 typedef struct mem_ref | |
| 130 { | |
| 131 tree mem; /* The memory itself. */ | |
| 132 unsigned id; /* ID assigned to the memory reference | |
| 133 (its index in memory_accesses.refs_list) */ | |
| 134 hashval_t hash; /* Its hash value. */ | |
| 135 bitmap stored; /* The set of loops in that this memory location | |
| 136 is stored to. */ | |
| 137 VEC (mem_ref_locs_p, heap) *accesses_in_loop; | |
| 138 /* The locations of the accesses. Vector | |
| 139 indexed by the loop number. */ | |
| 140 bitmap vops; /* Vops corresponding to this memory | |
| 141 location. */ | |
| 142 | |
| 143 /* The following sets are computed on demand. We keep both set and | |
| 144 its complement, so that we know whether the information was | |
| 145 already computed or not. */ | |
| 146 bitmap indep_loop; /* The set of loops in that the memory | |
| 147 reference is independent, meaning: | |
| 148 If it is stored in the loop, this store | |
| 149 is independent on all other loads and | |
| 150 stores. | |
| 151 If it is only loaded, then it is independent | |
| 152 on all stores in the loop. */ | |
| 153 bitmap dep_loop; /* The complement of INDEP_LOOP. */ | |
| 154 | |
| 155 bitmap indep_ref; /* The set of memory references on that | |
| 156 this reference is independent. */ | |
| 157 bitmap dep_ref; /* The complement of DEP_REF. */ | |
| 158 } *mem_ref_p; | |
| 159 | |
| 160 DEF_VEC_P(mem_ref_p); | |
| 161 DEF_VEC_ALLOC_P(mem_ref_p, heap); | |
| 162 | |
| 163 DEF_VEC_P(bitmap); | |
| 164 DEF_VEC_ALLOC_P(bitmap, heap); | |
| 165 | |
| 166 DEF_VEC_P(htab_t); | |
| 167 DEF_VEC_ALLOC_P(htab_t, heap); | |
| 168 | |
| 169 /* Description of memory accesses in loops. */ | |
| 170 | |
| 171 static struct | |
| 172 { | |
| 173 /* The hash table of memory references accessed in loops. */ | |
| 174 htab_t refs; | |
| 175 | |
| 176 /* The list of memory references. */ | |
| 177 VEC (mem_ref_p, heap) *refs_list; | |
| 178 | |
| 179 /* The set of memory references accessed in each loop. */ | |
| 180 VEC (bitmap, heap) *refs_in_loop; | |
| 181 | |
| 182 /* The set of memory references accessed in each loop, including | |
| 183 subloops. */ | |
| 184 VEC (bitmap, heap) *all_refs_in_loop; | |
| 185 | |
| 186 /* The set of virtual operands clobbered in a given loop. */ | |
| 187 VEC (bitmap, heap) *clobbered_vops; | |
| 188 | |
| 189 /* Map from the pair (loop, virtual operand) to the set of refs that | |
| 190 touch the virtual operand in the loop. */ | |
| 191 VEC (htab_t, heap) *vop_ref_map; | |
| 192 | |
| 193 /* Cache for expanding memory addresses. */ | |
| 194 struct pointer_map_t *ttae_cache; | |
| 195 } memory_accesses; | |
| 196 | |
| 197 static bool ref_indep_loop_p (struct loop *, mem_ref_p); | |
| 198 | |
| 199 /* Minimum cost of an expensive expression. */ | |
| 200 #define LIM_EXPENSIVE ((unsigned) PARAM_VALUE (PARAM_LIM_EXPENSIVE)) | |
| 201 | |
| 202 /* The outermost loop for that execution of the header guarantees that the | |
| 203 block will be executed. */ | |
| 204 #define ALWAYS_EXECUTED_IN(BB) ((struct loop *) (BB)->aux) | |
| 205 | |
| 206 static struct lim_aux_data * | |
| 207 init_lim_data (gimple stmt) | |
| 208 { | |
| 209 void **p = pointer_map_insert (lim_aux_data_map, stmt); | |
| 210 | |
| 211 *p = XCNEW (struct lim_aux_data); | |
| 212 return (struct lim_aux_data *) *p; | |
| 213 } | |
| 214 | |
| 215 static struct lim_aux_data * | |
| 216 get_lim_data (gimple stmt) | |
| 217 { | |
| 218 void **p = pointer_map_contains (lim_aux_data_map, stmt); | |
| 219 if (!p) | |
| 220 return NULL; | |
| 221 | |
| 222 return (struct lim_aux_data *) *p; | |
| 223 } | |
| 224 | |
| 225 /* Releases the memory occupied by DATA. */ | |
| 226 | |
| 227 static void | |
| 228 free_lim_aux_data (struct lim_aux_data *data) | |
| 229 { | |
| 230 struct depend *dep, *next; | |
| 231 | |
| 232 for (dep = data->depends; dep; dep = next) | |
| 233 { | |
| 234 next = dep->next; | |
| 235 free (dep); | |
| 236 } | |
| 237 free (data); | |
| 238 } | |
| 239 | |
| 240 static void | |
| 241 clear_lim_data (gimple stmt) | |
| 242 { | |
| 243 void **p = pointer_map_contains (lim_aux_data_map, stmt); | |
| 244 if (!p) | |
| 245 return; | |
| 246 | |
| 247 free_lim_aux_data ((struct lim_aux_data *) *p); | |
| 248 *p = NULL; | |
| 249 } | |
| 250 | |
| 251 /* Calls CBCK for each index in memory reference ADDR_P. There are two | |
| 252 kinds situations handled; in each of these cases, the memory reference | |
| 253 and DATA are passed to the callback: | |
| 254 | |
| 255 Access to an array: ARRAY_{RANGE_}REF (base, index). In this case we also | |
| 256 pass the pointer to the index to the callback. | |
| 257 | |
| 258 Pointer dereference: INDIRECT_REF (addr). In this case we also pass the | |
| 259 pointer to addr to the callback. | |
| 260 | |
| 261 If the callback returns false, the whole search stops and false is returned. | |
| 262 Otherwise the function returns true after traversing through the whole | |
| 263 reference *ADDR_P. */ | |
| 264 | |
| 265 bool | |
| 266 for_each_index (tree *addr_p, bool (*cbck) (tree, tree *, void *), void *data) | |
| 267 { | |
| 268 tree *nxt, *idx; | |
| 269 | |
| 270 for (; ; addr_p = nxt) | |
| 271 { | |
| 272 switch (TREE_CODE (*addr_p)) | |
| 273 { | |
| 274 case SSA_NAME: | |
| 275 return cbck (*addr_p, addr_p, data); | |
| 276 | |
| 277 case MISALIGNED_INDIRECT_REF: | |
| 278 case ALIGN_INDIRECT_REF: | |
| 279 case INDIRECT_REF: | |
| 280 nxt = &TREE_OPERAND (*addr_p, 0); | |
| 281 return cbck (*addr_p, nxt, data); | |
| 282 | |
| 283 case BIT_FIELD_REF: | |
| 284 case VIEW_CONVERT_EXPR: | |
| 285 case REALPART_EXPR: | |
| 286 case IMAGPART_EXPR: | |
| 287 nxt = &TREE_OPERAND (*addr_p, 0); | |
| 288 break; | |
| 289 | |
| 290 case COMPONENT_REF: | |
| 291 /* If the component has varying offset, it behaves like index | |
| 292 as well. */ | |
| 293 idx = &TREE_OPERAND (*addr_p, 2); | |
| 294 if (*idx | |
| 295 && !cbck (*addr_p, idx, data)) | |
| 296 return false; | |
| 297 | |
| 298 nxt = &TREE_OPERAND (*addr_p, 0); | |
| 299 break; | |
| 300 | |
| 301 case ARRAY_REF: | |
| 302 case ARRAY_RANGE_REF: | |
| 303 nxt = &TREE_OPERAND (*addr_p, 0); | |
| 304 if (!cbck (*addr_p, &TREE_OPERAND (*addr_p, 1), data)) | |
| 305 return false; | |
| 306 break; | |
| 307 | |
| 308 case VAR_DECL: | |
| 309 case PARM_DECL: | |
| 310 case STRING_CST: | |
| 311 case RESULT_DECL: | |
| 312 case VECTOR_CST: | |
| 313 case COMPLEX_CST: | |
| 314 case INTEGER_CST: | |
| 315 case REAL_CST: | |
| 316 case FIXED_CST: | |
| 317 case CONSTRUCTOR: | |
| 318 return true; | |
| 319 | |
| 320 case ADDR_EXPR: | |
| 321 gcc_assert (is_gimple_min_invariant (*addr_p)); | |
| 322 return true; | |
| 323 | |
| 324 case TARGET_MEM_REF: | |
| 325 idx = &TMR_BASE (*addr_p); | |
| 326 if (*idx | |
| 327 && !cbck (*addr_p, idx, data)) | |
| 328 return false; | |
| 329 idx = &TMR_INDEX (*addr_p); | |
| 330 if (*idx | |
| 331 && !cbck (*addr_p, idx, data)) | |
| 332 return false; | |
| 333 return true; | |
| 334 | |
| 335 default: | |
| 336 gcc_unreachable (); | |
| 337 } | |
| 338 } | |
| 339 } | |
| 340 | |
| 341 /* If it is possible to hoist the statement STMT unconditionally, | |
| 342 returns MOVE_POSSIBLE. | |
| 343 If it is possible to hoist the statement STMT, but we must avoid making | |
| 344 it executed if it would not be executed in the original program (e.g. | |
| 345 because it may trap), return MOVE_PRESERVE_EXECUTION. | |
| 346 Otherwise return MOVE_IMPOSSIBLE. */ | |
| 347 | |
| 348 enum move_pos | |
| 349 movement_possibility (gimple stmt) | |
| 350 { | |
| 351 tree lhs; | |
| 352 enum move_pos ret = MOVE_POSSIBLE; | |
| 353 | |
| 354 if (flag_unswitch_loops | |
| 355 && gimple_code (stmt) == GIMPLE_COND) | |
| 356 { | |
| 357 /* If we perform unswitching, force the operands of the invariant | |
| 358 condition to be moved out of the loop. */ | |
| 359 return MOVE_POSSIBLE; | |
| 360 } | |
| 361 | |
| 362 if (gimple_get_lhs (stmt) == NULL_TREE) | |
| 363 return MOVE_IMPOSSIBLE; | |
| 364 | |
| 365 if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_DEFS)) | |
| 366 return MOVE_IMPOSSIBLE; | |
| 367 | |
| 368 if (stmt_ends_bb_p (stmt) | |
| 369 || gimple_has_volatile_ops (stmt) | |
| 370 || gimple_has_side_effects (stmt) | |
| 371 || stmt_could_throw_p (stmt)) | |
| 372 return MOVE_IMPOSSIBLE; | |
| 373 | |
| 374 if (is_gimple_call (stmt)) | |
| 375 { | |
| 376 /* While pure or const call is guaranteed to have no side effects, we | |
| 377 cannot move it arbitrarily. Consider code like | |
| 378 | |
| 379 char *s = something (); | |
| 380 | |
| 381 while (1) | |
| 382 { | |
| 383 if (s) | |
| 384 t = strlen (s); | |
| 385 else | |
| 386 t = 0; | |
| 387 } | |
| 388 | |
| 389 Here the strlen call cannot be moved out of the loop, even though | |
| 390 s is invariant. In addition to possibly creating a call with | |
| 391 invalid arguments, moving out a function call that is not executed | |
| 392 may cause performance regressions in case the call is costly and | |
| 393 not executed at all. */ | |
| 394 ret = MOVE_PRESERVE_EXECUTION; | |
| 395 lhs = gimple_call_lhs (stmt); | |
| 396 } | |
| 397 else if (is_gimple_assign (stmt)) | |
| 398 lhs = gimple_assign_lhs (stmt); | |
| 399 else | |
| 400 return MOVE_IMPOSSIBLE; | |
| 401 | |
| 402 if (TREE_CODE (lhs) == SSA_NAME | |
| 403 && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
| 404 return MOVE_IMPOSSIBLE; | |
| 405 | |
| 406 if (TREE_CODE (lhs) != SSA_NAME | |
| 407 || gimple_could_trap_p (stmt)) | |
| 408 return MOVE_PRESERVE_EXECUTION; | |
| 409 | |
| 410 return ret; | |
| 411 } | |
| 412 | |
| 413 /* Suppose that operand DEF is used inside the LOOP. Returns the outermost | |
| 414 loop to that we could move the expression using DEF if it did not have | |
| 415 other operands, i.e. the outermost loop enclosing LOOP in that the value | |
| 416 of DEF is invariant. */ | |
| 417 | |
| 418 static struct loop * | |
| 419 outermost_invariant_loop (tree def, struct loop *loop) | |
| 420 { | |
| 421 gimple def_stmt; | |
| 422 basic_block def_bb; | |
| 423 struct loop *max_loop; | |
| 424 struct lim_aux_data *lim_data; | |
| 425 | |
| 426 if (!def) | |
| 427 return superloop_at_depth (loop, 1); | |
| 428 | |
| 429 if (TREE_CODE (def) != SSA_NAME) | |
| 430 { | |
| 431 gcc_assert (is_gimple_min_invariant (def)); | |
| 432 return superloop_at_depth (loop, 1); | |
| 433 } | |
| 434 | |
| 435 def_stmt = SSA_NAME_DEF_STMT (def); | |
| 436 def_bb = gimple_bb (def_stmt); | |
| 437 if (!def_bb) | |
| 438 return superloop_at_depth (loop, 1); | |
| 439 | |
| 440 max_loop = find_common_loop (loop, def_bb->loop_father); | |
| 441 | |
| 442 lim_data = get_lim_data (def_stmt); | |
| 443 if (lim_data != NULL && lim_data->max_loop != NULL) | |
| 444 max_loop = find_common_loop (max_loop, | |
| 445 loop_outer (lim_data->max_loop)); | |
| 446 if (max_loop == loop) | |
| 447 return NULL; | |
| 448 max_loop = superloop_at_depth (loop, loop_depth (max_loop) + 1); | |
| 449 | |
| 450 return max_loop; | |
| 451 } | |
| 452 | |
| 453 /* DATA is a structure containing information associated with a statement | |
| 454 inside LOOP. DEF is one of the operands of this statement. | |
| 455 | |
| 456 Find the outermost loop enclosing LOOP in that value of DEF is invariant | |
| 457 and record this in DATA->max_loop field. If DEF itself is defined inside | |
| 458 this loop as well (i.e. we need to hoist it out of the loop if we want | |
| 459 to hoist the statement represented by DATA), record the statement in that | |
| 460 DEF is defined to the DATA->depends list. Additionally if ADD_COST is true, | |
| 461 add the cost of the computation of DEF to the DATA->cost. | |
| 462 | |
| 463 If DEF is not invariant in LOOP, return false. Otherwise return TRUE. */ | |
| 464 | |
| 465 static bool | |
| 466 add_dependency (tree def, struct lim_aux_data *data, struct loop *loop, | |
| 467 bool add_cost) | |
| 468 { | |
| 469 gimple def_stmt = SSA_NAME_DEF_STMT (def); | |
| 470 basic_block def_bb = gimple_bb (def_stmt); | |
| 471 struct loop *max_loop; | |
| 472 struct depend *dep; | |
| 473 struct lim_aux_data *def_data; | |
| 474 | |
| 475 if (!def_bb) | |
| 476 return true; | |
| 477 | |
| 478 max_loop = outermost_invariant_loop (def, loop); | |
| 479 if (!max_loop) | |
| 480 return false; | |
| 481 | |
| 482 if (flow_loop_nested_p (data->max_loop, max_loop)) | |
| 483 data->max_loop = max_loop; | |
| 484 | |
| 485 def_data = get_lim_data (def_stmt); | |
| 486 if (!def_data) | |
| 487 return true; | |
| 488 | |
| 489 if (add_cost | |
| 490 /* Only add the cost if the statement defining DEF is inside LOOP, | |
| 491 i.e. if it is likely that by moving the invariants dependent | |
| 492 on it, we will be able to avoid creating a new register for | |
| 493 it (since it will be only used in these dependent invariants). */ | |
| 494 && def_bb->loop_father == loop) | |
| 495 data->cost += def_data->cost; | |
| 496 | |
| 497 dep = XNEW (struct depend); | |
| 498 dep->stmt = def_stmt; | |
| 499 dep->next = data->depends; | |
| 500 data->depends = dep; | |
| 501 | |
| 502 return true; | |
| 503 } | |
| 504 | |
| 505 /* Returns an estimate for a cost of statement STMT. TODO -- the values here | |
| 506 are just ad-hoc constants. The estimates should be based on target-specific | |
| 507 values. */ | |
| 508 | |
| 509 static unsigned | |
| 510 stmt_cost (gimple stmt) | |
| 511 { | |
| 512 tree fndecl; | |
| 513 unsigned cost = 1; | |
| 514 | |
| 515 /* Always try to create possibilities for unswitching. */ | |
| 516 if (gimple_code (stmt) == GIMPLE_COND) | |
| 517 return LIM_EXPENSIVE; | |
| 518 | |
| 519 /* Hoisting memory references out should almost surely be a win. */ | |
| 520 if (gimple_references_memory_p (stmt)) | |
| 521 cost += 20; | |
| 522 | |
| 523 if (is_gimple_call (stmt)) | |
| 524 { | |
| 525 /* We should be hoisting calls if possible. */ | |
| 526 | |
| 527 /* Unless the call is a builtin_constant_p; this always folds to a | |
| 528 constant, so moving it is useless. */ | |
| 529 fndecl = gimple_call_fndecl (stmt); | |
| 530 if (fndecl | |
| 531 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL | |
| 532 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P) | |
| 533 return 0; | |
| 534 | |
| 535 return cost + 20; | |
| 536 } | |
| 537 | |
| 538 if (gimple_code (stmt) != GIMPLE_ASSIGN) | |
| 539 return cost; | |
| 540 | |
| 541 switch (gimple_assign_rhs_code (stmt)) | |
| 542 { | |
| 543 case MULT_EXPR: | |
| 544 case TRUNC_DIV_EXPR: | |
| 545 case CEIL_DIV_EXPR: | |
| 546 case FLOOR_DIV_EXPR: | |
| 547 case ROUND_DIV_EXPR: | |
| 548 case EXACT_DIV_EXPR: | |
| 549 case CEIL_MOD_EXPR: | |
| 550 case FLOOR_MOD_EXPR: | |
| 551 case ROUND_MOD_EXPR: | |
| 552 case TRUNC_MOD_EXPR: | |
| 553 case RDIV_EXPR: | |
| 554 /* Division and multiplication are usually expensive. */ | |
| 555 cost += 20; | |
| 556 break; | |
| 557 | |
| 558 case LSHIFT_EXPR: | |
| 559 case RSHIFT_EXPR: | |
| 560 cost += 20; | |
| 561 break; | |
| 562 | |
| 563 default: | |
| 564 break; | |
| 565 } | |
| 566 | |
| 567 return cost; | |
| 568 } | |
| 569 | |
| 570 /* Finds the outermost loop between OUTER and LOOP in that the memory reference | |
| 571 REF is independent. If REF is not independent in LOOP, NULL is returned | |
| 572 instead. */ | |
| 573 | |
| 574 static struct loop * | |
| 575 outermost_indep_loop (struct loop *outer, struct loop *loop, mem_ref_p ref) | |
| 576 { | |
| 577 struct loop *aloop; | |
| 578 | |
| 579 if (bitmap_bit_p (ref->stored, loop->num)) | |
| 580 return NULL; | |
| 581 | |
| 582 for (aloop = outer; | |
| 583 aloop != loop; | |
| 584 aloop = superloop_at_depth (loop, loop_depth (aloop) + 1)) | |
| 585 if (!bitmap_bit_p (ref->stored, aloop->num) | |
| 586 && ref_indep_loop_p (aloop, ref)) | |
| 587 return aloop; | |
| 588 | |
| 589 if (ref_indep_loop_p (loop, ref)) | |
| 590 return loop; | |
| 591 else | |
| 592 return NULL; | |
| 593 } | |
| 594 | |
| 595 /* If there is a simple load or store to a memory reference in STMT, returns | |
| 596 the location of the memory reference, and sets IS_STORE according to whether | |
| 597 it is a store or load. Otherwise, returns NULL. */ | |
| 598 | |
| 599 static tree * | |
| 600 simple_mem_ref_in_stmt (gimple stmt, bool *is_store) | |
| 601 { | |
| 602 tree *lhs; | |
| 603 enum tree_code code; | |
| 604 | |
| 605 /* Recognize MEM = (SSA_NAME | invariant) and SSA_NAME = MEM patterns. */ | |
| 606 if (gimple_code (stmt) != GIMPLE_ASSIGN) | |
| 607 return NULL; | |
| 608 | |
| 609 code = gimple_assign_rhs_code (stmt); | |
| 610 | |
| 611 lhs = gimple_assign_lhs_ptr (stmt); | |
| 612 | |
| 613 if (TREE_CODE (*lhs) == SSA_NAME) | |
| 614 { | |
| 615 if (get_gimple_rhs_class (code) != GIMPLE_SINGLE_RHS | |
| 616 || !is_gimple_addressable (gimple_assign_rhs1 (stmt))) | |
| 617 return NULL; | |
| 618 | |
| 619 *is_store = false; | |
| 620 return gimple_assign_rhs1_ptr (stmt); | |
| 621 } | |
| 622 else if (code == SSA_NAME | |
| 623 || (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS | |
| 624 && is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))) | |
| 625 { | |
| 626 *is_store = true; | |
| 627 return lhs; | |
| 628 } | |
| 629 else | |
| 630 return NULL; | |
| 631 } | |
| 632 | |
| 633 /* Returns the memory reference contained in STMT. */ | |
| 634 | |
| 635 static mem_ref_p | |
| 636 mem_ref_in_stmt (gimple stmt) | |
| 637 { | |
| 638 bool store; | |
| 639 tree *mem = simple_mem_ref_in_stmt (stmt, &store); | |
| 640 hashval_t hash; | |
| 641 mem_ref_p ref; | |
| 642 | |
| 643 if (!mem) | |
| 644 return NULL; | |
| 645 gcc_assert (!store); | |
| 646 | |
| 647 hash = iterative_hash_expr (*mem, 0); | |
| 648 ref = (mem_ref_p) htab_find_with_hash (memory_accesses.refs, *mem, hash); | |
| 649 | |
| 650 gcc_assert (ref != NULL); | |
| 651 return ref; | |
| 652 } | |
| 653 | |
| 654 /* Determine the outermost loop to that it is possible to hoist a statement | |
| 655 STMT and store it to LIM_DATA (STMT)->max_loop. To do this we determine | |
| 656 the outermost loop in that the value computed by STMT is invariant. | |
| 657 If MUST_PRESERVE_EXEC is true, additionally choose such a loop that | |
| 658 we preserve the fact whether STMT is executed. It also fills other related | |
| 659 information to LIM_DATA (STMT). | |
| 660 | |
| 661 The function returns false if STMT cannot be hoisted outside of the loop it | |
| 662 is defined in, and true otherwise. */ | |
| 663 | |
| 664 static bool | |
| 665 determine_max_movement (gimple stmt, bool must_preserve_exec) | |
| 666 { | |
| 667 basic_block bb = gimple_bb (stmt); | |
| 668 struct loop *loop = bb->loop_father; | |
| 669 struct loop *level; | |
| 670 struct lim_aux_data *lim_data = get_lim_data (stmt); | |
| 671 tree val; | |
| 672 ssa_op_iter iter; | |
| 673 | |
| 674 if (must_preserve_exec) | |
| 675 level = ALWAYS_EXECUTED_IN (bb); | |
| 676 else | |
| 677 level = superloop_at_depth (loop, 1); | |
| 678 lim_data->max_loop = level; | |
| 679 | |
| 680 FOR_EACH_SSA_TREE_OPERAND (val, stmt, iter, SSA_OP_USE) | |
| 681 if (!add_dependency (val, lim_data, loop, true)) | |
| 682 return false; | |
| 683 | |
| 684 if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_USES)) | |
| 685 { | |
| 686 mem_ref_p ref = mem_ref_in_stmt (stmt); | |
| 687 | |
| 688 if (ref) | |
| 689 { | |
| 690 lim_data->max_loop | |
| 691 = outermost_indep_loop (lim_data->max_loop, loop, ref); | |
| 692 if (!lim_data->max_loop) | |
| 693 return false; | |
| 694 } | |
| 695 else | |
| 696 { | |
| 697 FOR_EACH_SSA_TREE_OPERAND (val, stmt, iter, SSA_OP_VIRTUAL_USES) | |
| 698 { | |
| 699 if (!add_dependency (val, lim_data, loop, false)) | |
| 700 return false; | |
| 701 } | |
| 702 } | |
| 703 } | |
| 704 | |
| 705 lim_data->cost += stmt_cost (stmt); | |
| 706 | |
| 707 return true; | |
| 708 } | |
| 709 | |
| 710 /* Suppose that some statement in ORIG_LOOP is hoisted to the loop LEVEL, | |
| 711 and that one of the operands of this statement is computed by STMT. | |
| 712 Ensure that STMT (together with all the statements that define its | |
| 713 operands) is hoisted at least out of the loop LEVEL. */ | |
| 714 | |
| 715 static void | |
| 716 set_level (gimple stmt, struct loop *orig_loop, struct loop *level) | |
| 717 { | |
| 718 struct loop *stmt_loop = gimple_bb (stmt)->loop_father; | |
| 719 struct depend *dep; | |
| 720 struct lim_aux_data *lim_data; | |
| 721 | |
| 722 stmt_loop = find_common_loop (orig_loop, stmt_loop); | |
| 723 lim_data = get_lim_data (stmt); | |
| 724 if (lim_data != NULL && lim_data->tgt_loop != NULL) | |
| 725 stmt_loop = find_common_loop (stmt_loop, | |
| 726 loop_outer (lim_data->tgt_loop)); | |
| 727 if (flow_loop_nested_p (stmt_loop, level)) | |
| 728 return; | |
| 729 | |
| 730 gcc_assert (level == lim_data->max_loop | |
| 731 || flow_loop_nested_p (lim_data->max_loop, level)); | |
| 732 | |
| 733 lim_data->tgt_loop = level; | |
| 734 for (dep = lim_data->depends; dep; dep = dep->next) | |
| 735 set_level (dep->stmt, orig_loop, level); | |
| 736 } | |
| 737 | |
| 738 /* Determines an outermost loop from that we want to hoist the statement STMT. | |
| 739 For now we chose the outermost possible loop. TODO -- use profiling | |
| 740 information to set it more sanely. */ | |
| 741 | |
| 742 static void | |
| 743 set_profitable_level (gimple stmt) | |
| 744 { | |
| 745 set_level (stmt, gimple_bb (stmt)->loop_father, get_lim_data (stmt)->max_loop); | |
| 746 } | |
| 747 | |
| 748 /* Returns true if STMT is a call that has side effects. */ | |
| 749 | |
| 750 static bool | |
| 751 nonpure_call_p (gimple stmt) | |
| 752 { | |
| 753 if (gimple_code (stmt) != GIMPLE_CALL) | |
| 754 return false; | |
| 755 | |
| 756 return gimple_has_side_effects (stmt); | |
| 757 } | |
| 758 | |
| 759 /* Rewrite a/b to a*(1/b). Return the invariant stmt to process. */ | |
| 760 | |
| 761 static gimple | |
| 762 rewrite_reciprocal (gimple_stmt_iterator *bsi) | |
| 763 { | |
| 764 gimple stmt, stmt1, stmt2; | |
| 765 tree var, name, lhs, type; | |
| 766 tree real_one; | |
| 767 | |
| 768 stmt = gsi_stmt (*bsi); | |
| 769 lhs = gimple_assign_lhs (stmt); | |
| 770 type = TREE_TYPE (lhs); | |
| 771 | |
| 772 var = create_tmp_var (type, "reciptmp"); | |
| 773 add_referenced_var (var); | |
| 774 DECL_GIMPLE_REG_P (var) = 1; | |
| 775 | |
| 776 /* For vectors, create a VECTOR_CST full of 1's. */ | |
| 777 if (TREE_CODE (type) == VECTOR_TYPE) | |
| 778 { | |
| 779 int i, len; | |
| 780 tree list = NULL_TREE; | |
| 781 real_one = build_real (TREE_TYPE (type), dconst1); | |
| 782 len = TYPE_VECTOR_SUBPARTS (type); | |
| 783 for (i = 0; i < len; i++) | |
| 784 list = tree_cons (NULL, real_one, list); | |
| 785 real_one = build_vector (type, list); | |
| 786 } | |
| 787 else | |
| 788 real_one = build_real (type, dconst1); | |
| 789 | |
| 790 stmt1 = gimple_build_assign_with_ops (RDIV_EXPR, | |
| 791 var, real_one, gimple_assign_rhs2 (stmt)); | |
| 792 name = make_ssa_name (var, stmt1); | |
| 793 gimple_assign_set_lhs (stmt1, name); | |
| 794 | |
| 795 stmt2 = gimple_build_assign_with_ops (MULT_EXPR, lhs, name, | |
| 796 gimple_assign_rhs1 (stmt)); | |
| 797 | |
| 798 /* Replace division stmt with reciprocal and multiply stmts. | |
| 799 The multiply stmt is not invariant, so update iterator | |
| 800 and avoid rescanning. */ | |
| 801 gsi_replace (bsi, stmt1, true); | |
| 802 gsi_insert_after (bsi, stmt2, GSI_NEW_STMT); | |
| 803 | |
| 804 /* Continue processing with invariant reciprocal statement. */ | |
| 805 return stmt1; | |
| 806 } | |
| 807 | |
| 808 /* Check if the pattern at *BSI is a bittest of the form | |
| 809 (A >> B) & 1 != 0 and in this case rewrite it to A & (1 << B) != 0. */ | |
| 810 | |
| 811 static gimple | |
| 812 rewrite_bittest (gimple_stmt_iterator *bsi) | |
| 813 { | |
| 814 gimple stmt, use_stmt, stmt1, stmt2; | |
| 815 tree lhs, var, name, t, a, b; | |
| 816 use_operand_p use; | |
| 817 | |
| 818 stmt = gsi_stmt (*bsi); | |
| 819 lhs = gimple_assign_lhs (stmt); | |
| 820 | |
| 821 /* Verify that the single use of lhs is a comparison against zero. */ | |
| 822 if (TREE_CODE (lhs) != SSA_NAME | |
| 823 || !single_imm_use (lhs, &use, &use_stmt) | |
| 824 || gimple_code (use_stmt) != GIMPLE_COND) | |
| 825 return stmt; | |
| 826 if (gimple_cond_lhs (use_stmt) != lhs | |
| 827 || (gimple_cond_code (use_stmt) != NE_EXPR | |
| 828 && gimple_cond_code (use_stmt) != EQ_EXPR) | |
| 829 || !integer_zerop (gimple_cond_rhs (use_stmt))) | |
| 830 return stmt; | |
| 831 | |
| 832 /* Get at the operands of the shift. The rhs is TMP1 & 1. */ | |
| 833 stmt1 = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt)); | |
| 834 if (gimple_code (stmt1) != GIMPLE_ASSIGN) | |
| 835 return stmt; | |
| 836 | |
| 837 /* There is a conversion in between possibly inserted by fold. */ | |
| 838 if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt1))) | |
| 839 { | |
| 840 t = gimple_assign_rhs1 (stmt1); | |
| 841 if (TREE_CODE (t) != SSA_NAME | |
| 842 || !has_single_use (t)) | |
| 843 return stmt; | |
| 844 stmt1 = SSA_NAME_DEF_STMT (t); | |
| 845 if (gimple_code (stmt1) != GIMPLE_ASSIGN) | |
| 846 return stmt; | |
| 847 } | |
| 848 | |
| 849 /* Verify that B is loop invariant but A is not. Verify that with | |
| 850 all the stmt walking we are still in the same loop. */ | |
| 851 if (gimple_assign_rhs_code (stmt1) != RSHIFT_EXPR | |
| 852 || loop_containing_stmt (stmt1) != loop_containing_stmt (stmt)) | |
| 853 return stmt; | |
| 854 | |
| 855 a = gimple_assign_rhs1 (stmt1); | |
| 856 b = gimple_assign_rhs2 (stmt1); | |
| 857 | |
| 858 if (outermost_invariant_loop (b, loop_containing_stmt (stmt1)) != NULL | |
| 859 && outermost_invariant_loop (a, loop_containing_stmt (stmt1)) == NULL) | |
| 860 { | |
| 861 /* 1 << B */ | |
| 862 var = create_tmp_var (TREE_TYPE (a), "shifttmp"); | |
| 863 add_referenced_var (var); | |
| 864 t = fold_build2 (LSHIFT_EXPR, TREE_TYPE (a), | |
| 865 build_int_cst (TREE_TYPE (a), 1), b); | |
| 866 stmt1 = gimple_build_assign (var, t); | |
| 867 name = make_ssa_name (var, stmt1); | |
| 868 gimple_assign_set_lhs (stmt1, name); | |
| 869 | |
| 870 /* A & (1 << B) */ | |
| 871 t = fold_build2 (BIT_AND_EXPR, TREE_TYPE (a), a, name); | |
| 872 stmt2 = gimple_build_assign (var, t); | |
| 873 name = make_ssa_name (var, stmt2); | |
| 874 gimple_assign_set_lhs (stmt2, name); | |
| 875 | |
| 876 /* Replace the SSA_NAME we compare against zero. Adjust | |
| 877 the type of zero accordingly. */ | |
| 878 SET_USE (use, name); | |
| 879 gimple_cond_set_rhs (use_stmt, build_int_cst_type (TREE_TYPE (name), 0)); | |
| 880 | |
| 881 gsi_insert_before (bsi, stmt1, GSI_SAME_STMT); | |
| 882 gsi_replace (bsi, stmt2, true); | |
| 883 | |
| 884 return stmt1; | |
| 885 } | |
| 886 | |
| 887 return stmt; | |
| 888 } | |
| 889 | |
| 890 | |
| 891 /* Determine the outermost loops in that statements in basic block BB are | |
| 892 invariant, and record them to the LIM_DATA associated with the statements. | |
| 893 Callback for walk_dominator_tree. */ | |
| 894 | |
| 895 static void | |
| 896 determine_invariantness_stmt (struct dom_walk_data *dw_data ATTRIBUTE_UNUSED, | |
| 897 basic_block bb) | |
| 898 { | |
| 899 enum move_pos pos; | |
| 900 gimple_stmt_iterator bsi; | |
| 901 gimple stmt; | |
| 902 bool maybe_never = ALWAYS_EXECUTED_IN (bb) == NULL; | |
| 903 struct loop *outermost = ALWAYS_EXECUTED_IN (bb); | |
| 904 struct lim_aux_data *lim_data; | |
| 905 | |
| 906 if (!loop_outer (bb->loop_father)) | |
| 907 return; | |
| 908 | |
| 909 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 910 fprintf (dump_file, "Basic block %d (loop %d -- depth %d):\n\n", | |
| 911 bb->index, bb->loop_father->num, loop_depth (bb->loop_father)); | |
| 912 | |
| 913 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) | |
| 914 { | |
| 915 stmt = gsi_stmt (bsi); | |
| 916 | |
| 917 pos = movement_possibility (stmt); | |
| 918 if (pos == MOVE_IMPOSSIBLE) | |
| 919 { | |
| 920 if (nonpure_call_p (stmt)) | |
| 921 { | |
| 922 maybe_never = true; | |
| 923 outermost = NULL; | |
| 924 } | |
| 925 /* Make sure to note always_executed_in for stores to make | |
| 926 store-motion work. */ | |
| 927 else if (stmt_makes_single_store (stmt)) | |
| 928 { | |
| 929 struct lim_aux_data *lim_data = init_lim_data (stmt); | |
| 930 lim_data->always_executed_in = outermost; | |
| 931 } | |
| 932 continue; | |
| 933 } | |
| 934 | |
| 935 if (is_gimple_assign (stmt) | |
| 936 && (get_gimple_rhs_class (gimple_assign_rhs_code (stmt)) | |
| 937 == GIMPLE_BINARY_RHS)) | |
| 938 { | |
| 939 tree op0 = gimple_assign_rhs1 (stmt); | |
| 940 tree op1 = gimple_assign_rhs2 (stmt); | |
| 941 struct loop *ol1 = outermost_invariant_loop (op1, | |
| 942 loop_containing_stmt (stmt)); | |
| 943 | |
| 944 /* If divisor is invariant, convert a/b to a*(1/b), allowing reciprocal | |
| 945 to be hoisted out of loop, saving expensive divide. */ | |
| 946 if (pos == MOVE_POSSIBLE | |
| 947 && gimple_assign_rhs_code (stmt) == RDIV_EXPR | |
| 948 && flag_unsafe_math_optimizations | |
| 949 && !flag_trapping_math | |
| 950 && ol1 != NULL | |
| 951 && outermost_invariant_loop (op0, ol1) == NULL) | |
| 952 stmt = rewrite_reciprocal (&bsi); | |
| 953 | |
| 954 /* If the shift count is invariant, convert (A >> B) & 1 to | |
| 955 A & (1 << B) allowing the bit mask to be hoisted out of the loop | |
| 956 saving an expensive shift. */ | |
| 957 if (pos == MOVE_POSSIBLE | |
| 958 && gimple_assign_rhs_code (stmt) == BIT_AND_EXPR | |
| 959 && integer_onep (op1) | |
| 960 && TREE_CODE (op0) == SSA_NAME | |
| 961 && has_single_use (op0)) | |
| 962 stmt = rewrite_bittest (&bsi); | |
| 963 } | |
| 964 | |
| 965 lim_data = init_lim_data (stmt); | |
| 966 lim_data->always_executed_in = outermost; | |
| 967 | |
| 968 if (maybe_never && pos == MOVE_PRESERVE_EXECUTION) | |
| 969 continue; | |
| 970 | |
| 971 if (!determine_max_movement (stmt, pos == MOVE_PRESERVE_EXECUTION)) | |
| 972 { | |
| 973 lim_data->max_loop = NULL; | |
| 974 continue; | |
| 975 } | |
| 976 | |
| 977 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 978 { | |
| 979 print_gimple_stmt (dump_file, stmt, 2, 0); | |
| 980 fprintf (dump_file, " invariant up to level %d, cost %d.\n\n", | |
| 981 loop_depth (lim_data->max_loop), | |
| 982 lim_data->cost); | |
| 983 } | |
| 984 | |
| 985 if (lim_data->cost >= LIM_EXPENSIVE) | |
| 986 set_profitable_level (stmt); | |
| 987 } | |
| 988 } | |
| 989 | |
| 990 /* For each statement determines the outermost loop in that it is invariant, | |
| 991 statements on whose motion it depends and the cost of the computation. | |
| 992 This information is stored to the LIM_DATA structure associated with | |
| 993 each statement. */ | |
| 994 | |
| 995 static void | |
| 996 determine_invariantness (void) | |
| 997 { | |
| 998 struct dom_walk_data walk_data; | |
| 999 | |
| 1000 memset (&walk_data, 0, sizeof (struct dom_walk_data)); | |
| 1001 walk_data.dom_direction = CDI_DOMINATORS; | |
| 1002 walk_data.before_dom_children_before_stmts = determine_invariantness_stmt; | |
| 1003 | |
| 1004 init_walk_dominator_tree (&walk_data); | |
| 1005 walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR); | |
| 1006 fini_walk_dominator_tree (&walk_data); | |
| 1007 } | |
| 1008 | |
| 1009 /* Hoist the statements in basic block BB out of the loops prescribed by | |
| 1010 data stored in LIM_DATA structures associated with each statement. Callback | |
| 1011 for walk_dominator_tree. */ | |
| 1012 | |
| 1013 static void | |
| 1014 move_computations_stmt (struct dom_walk_data *dw_data ATTRIBUTE_UNUSED, | |
| 1015 basic_block bb) | |
| 1016 { | |
| 1017 struct loop *level; | |
| 1018 gimple_stmt_iterator bsi; | |
| 1019 gimple stmt; | |
| 1020 unsigned cost = 0; | |
| 1021 struct lim_aux_data *lim_data; | |
| 1022 | |
| 1023 if (!loop_outer (bb->loop_father)) | |
| 1024 return; | |
| 1025 | |
| 1026 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); ) | |
| 1027 { | |
| 1028 stmt = gsi_stmt (bsi); | |
| 1029 | |
| 1030 lim_data = get_lim_data (stmt); | |
| 1031 if (lim_data == NULL) | |
| 1032 { | |
| 1033 gsi_next (&bsi); | |
| 1034 continue; | |
| 1035 } | |
| 1036 | |
| 1037 cost = lim_data->cost; | |
| 1038 level = lim_data->tgt_loop; | |
| 1039 clear_lim_data (stmt); | |
| 1040 | |
| 1041 if (!level) | |
| 1042 { | |
| 1043 gsi_next (&bsi); | |
| 1044 continue; | |
| 1045 } | |
| 1046 | |
| 1047 /* We do not really want to move conditionals out of the loop; we just | |
| 1048 placed it here to force its operands to be moved if necessary. */ | |
| 1049 if (gimple_code (stmt) == GIMPLE_COND) | |
| 1050 continue; | |
| 1051 | |
| 1052 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 1053 { | |
| 1054 fprintf (dump_file, "Moving statement\n"); | |
| 1055 print_gimple_stmt (dump_file, stmt, 0, 0); | |
| 1056 fprintf (dump_file, "(cost %u) out of loop %d.\n\n", | |
| 1057 cost, level->num); | |
| 1058 } | |
| 1059 | |
| 1060 mark_virtual_ops_for_renaming (stmt); | |
| 1061 gsi_insert_on_edge (loop_preheader_edge (level), stmt); | |
| 1062 gsi_remove (&bsi, false); | |
| 1063 } | |
| 1064 } | |
| 1065 | |
| 1066 /* Hoist the statements out of the loops prescribed by data stored in | |
| 1067 LIM_DATA structures associated with each statement.*/ | |
| 1068 | |
| 1069 static void | |
| 1070 move_computations (void) | |
| 1071 { | |
| 1072 struct dom_walk_data walk_data; | |
| 1073 | |
| 1074 memset (&walk_data, 0, sizeof (struct dom_walk_data)); | |
| 1075 walk_data.dom_direction = CDI_DOMINATORS; | |
| 1076 walk_data.before_dom_children_before_stmts = move_computations_stmt; | |
| 1077 | |
| 1078 init_walk_dominator_tree (&walk_data); | |
| 1079 walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR); | |
| 1080 fini_walk_dominator_tree (&walk_data); | |
| 1081 | |
| 1082 gsi_commit_edge_inserts (); | |
| 1083 if (need_ssa_update_p ()) | |
| 1084 rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa); | |
| 1085 } | |
| 1086 | |
| 1087 /* Checks whether the statement defining variable *INDEX can be hoisted | |
| 1088 out of the loop passed in DATA. Callback for for_each_index. */ | |
| 1089 | |
| 1090 static bool | |
| 1091 may_move_till (tree ref, tree *index, void *data) | |
| 1092 { | |
| 1093 struct loop *loop = (struct loop *) data, *max_loop; | |
| 1094 | |
| 1095 /* If REF is an array reference, check also that the step and the lower | |
| 1096 bound is invariant in LOOP. */ | |
| 1097 if (TREE_CODE (ref) == ARRAY_REF) | |
| 1098 { | |
| 1099 tree step = TREE_OPERAND (ref, 3); | |
| 1100 tree lbound = TREE_OPERAND (ref, 2); | |
| 1101 | |
| 1102 max_loop = outermost_invariant_loop (step, loop); | |
| 1103 if (!max_loop) | |
| 1104 return false; | |
| 1105 | |
| 1106 max_loop = outermost_invariant_loop (lbound, loop); | |
| 1107 if (!max_loop) | |
| 1108 return false; | |
| 1109 } | |
| 1110 | |
| 1111 max_loop = outermost_invariant_loop (*index, loop); | |
| 1112 if (!max_loop) | |
| 1113 return false; | |
| 1114 | |
| 1115 return true; | |
| 1116 } | |
| 1117 | |
| 1118 /* If OP is SSA NAME, force the statement that defines it to be | |
| 1119 moved out of the LOOP. ORIG_LOOP is the loop in that EXPR is used. */ | |
| 1120 | |
| 1121 static void | |
| 1122 force_move_till_op (tree op, struct loop *orig_loop, struct loop *loop) | |
| 1123 { | |
| 1124 gimple stmt; | |
| 1125 | |
| 1126 if (!op | |
| 1127 || is_gimple_min_invariant (op)) | |
| 1128 return; | |
| 1129 | |
| 1130 gcc_assert (TREE_CODE (op) == SSA_NAME); | |
| 1131 | |
| 1132 stmt = SSA_NAME_DEF_STMT (op); | |
| 1133 if (gimple_nop_p (stmt)) | |
| 1134 return; | |
| 1135 | |
| 1136 set_level (stmt, orig_loop, loop); | |
| 1137 } | |
| 1138 | |
| 1139 /* Forces statement defining invariants in REF (and *INDEX) to be moved out of | |
| 1140 the LOOP. The reference REF is used in the loop ORIG_LOOP. Callback for | |
| 1141 for_each_index. */ | |
| 1142 | |
| 1143 struct fmt_data | |
| 1144 { | |
| 1145 struct loop *loop; | |
| 1146 struct loop *orig_loop; | |
| 1147 }; | |
| 1148 | |
| 1149 static bool | |
| 1150 force_move_till (tree ref, tree *index, void *data) | |
| 1151 { | |
| 1152 struct fmt_data *fmt_data = (struct fmt_data *) data; | |
| 1153 | |
| 1154 if (TREE_CODE (ref) == ARRAY_REF) | |
| 1155 { | |
| 1156 tree step = TREE_OPERAND (ref, 3); | |
| 1157 tree lbound = TREE_OPERAND (ref, 2); | |
| 1158 | |
| 1159 force_move_till_op (step, fmt_data->orig_loop, fmt_data->loop); | |
| 1160 force_move_till_op (lbound, fmt_data->orig_loop, fmt_data->loop); | |
| 1161 } | |
| 1162 | |
| 1163 force_move_till_op (*index, fmt_data->orig_loop, fmt_data->loop); | |
| 1164 | |
| 1165 return true; | |
| 1166 } | |
| 1167 | |
| 1168 /* A hash function for struct mem_ref object OBJ. */ | |
| 1169 | |
| 1170 static hashval_t | |
| 1171 memref_hash (const void *obj) | |
| 1172 { | |
| 1173 const struct mem_ref *const mem = (const struct mem_ref *) obj; | |
| 1174 | |
| 1175 return mem->hash; | |
| 1176 } | |
| 1177 | |
| 1178 /* An equality function for struct mem_ref object OBJ1 with | |
| 1179 memory reference OBJ2. */ | |
| 1180 | |
| 1181 static int | |
| 1182 memref_eq (const void *obj1, const void *obj2) | |
| 1183 { | |
| 1184 const struct mem_ref *const mem1 = (const struct mem_ref *) obj1; | |
| 1185 | |
| 1186 return operand_equal_p (mem1->mem, (const_tree) obj2, 0); | |
| 1187 } | |
| 1188 | |
| 1189 /* Releases list of memory reference locations ACCS. */ | |
| 1190 | |
| 1191 static void | |
| 1192 free_mem_ref_locs (mem_ref_locs_p accs) | |
| 1193 { | |
| 1194 unsigned i; | |
| 1195 mem_ref_loc_p loc; | |
| 1196 | |
| 1197 if (!accs) | |
| 1198 return; | |
| 1199 | |
| 1200 for (i = 0; VEC_iterate (mem_ref_loc_p, accs->locs, i, loc); i++) | |
| 1201 free (loc); | |
| 1202 VEC_free (mem_ref_loc_p, heap, accs->locs); | |
| 1203 free (accs); | |
| 1204 } | |
| 1205 | |
| 1206 /* A function to free the mem_ref object OBJ. */ | |
| 1207 | |
| 1208 static void | |
| 1209 memref_free (void *obj) | |
| 1210 { | |
| 1211 struct mem_ref *const mem = (struct mem_ref *) obj; | |
| 1212 unsigned i; | |
| 1213 mem_ref_locs_p accs; | |
| 1214 | |
| 1215 BITMAP_FREE (mem->stored); | |
| 1216 BITMAP_FREE (mem->indep_loop); | |
| 1217 BITMAP_FREE (mem->dep_loop); | |
| 1218 BITMAP_FREE (mem->indep_ref); | |
| 1219 BITMAP_FREE (mem->dep_ref); | |
| 1220 | |
| 1221 for (i = 0; VEC_iterate (mem_ref_locs_p, mem->accesses_in_loop, i, accs); i++) | |
| 1222 free_mem_ref_locs (accs); | |
| 1223 VEC_free (mem_ref_locs_p, heap, mem->accesses_in_loop); | |
| 1224 | |
| 1225 BITMAP_FREE (mem->vops); | |
| 1226 free (mem); | |
| 1227 } | |
| 1228 | |
| 1229 /* Allocates and returns a memory reference description for MEM whose hash | |
| 1230 value is HASH and id is ID. */ | |
| 1231 | |
| 1232 static mem_ref_p | |
| 1233 mem_ref_alloc (tree mem, unsigned hash, unsigned id) | |
| 1234 { | |
| 1235 mem_ref_p ref = XNEW (struct mem_ref); | |
| 1236 ref->mem = mem; | |
| 1237 ref->id = id; | |
| 1238 ref->hash = hash; | |
| 1239 ref->stored = BITMAP_ALLOC (NULL); | |
| 1240 ref->indep_loop = BITMAP_ALLOC (NULL); | |
| 1241 ref->dep_loop = BITMAP_ALLOC (NULL); | |
| 1242 ref->indep_ref = BITMAP_ALLOC (NULL); | |
| 1243 ref->dep_ref = BITMAP_ALLOC (NULL); | |
| 1244 ref->accesses_in_loop = NULL; | |
| 1245 ref->vops = BITMAP_ALLOC (NULL); | |
| 1246 | |
| 1247 return ref; | |
| 1248 } | |
| 1249 | |
| 1250 /* Allocates and returns the new list of locations. */ | |
| 1251 | |
| 1252 static mem_ref_locs_p | |
| 1253 mem_ref_locs_alloc (void) | |
| 1254 { | |
| 1255 mem_ref_locs_p accs = XNEW (struct mem_ref_locs); | |
| 1256 accs->locs = NULL; | |
| 1257 return accs; | |
| 1258 } | |
| 1259 | |
| 1260 /* Records memory reference location *LOC in LOOP to the memory reference | |
| 1261 description REF. The reference occurs in statement STMT. */ | |
| 1262 | |
| 1263 static void | |
| 1264 record_mem_ref_loc (mem_ref_p ref, struct loop *loop, gimple stmt, tree *loc) | |
| 1265 { | |
| 1266 mem_ref_loc_p aref = XNEW (struct mem_ref_loc); | |
| 1267 mem_ref_locs_p accs; | |
| 1268 bitmap ril = VEC_index (bitmap, memory_accesses.refs_in_loop, loop->num); | |
| 1269 | |
| 1270 if (VEC_length (mem_ref_locs_p, ref->accesses_in_loop) | |
| 1271 <= (unsigned) loop->num) | |
| 1272 VEC_safe_grow_cleared (mem_ref_locs_p, heap, ref->accesses_in_loop, | |
| 1273 loop->num + 1); | |
| 1274 accs = VEC_index (mem_ref_locs_p, ref->accesses_in_loop, loop->num); | |
| 1275 if (!accs) | |
| 1276 { | |
| 1277 accs = mem_ref_locs_alloc (); | |
| 1278 VEC_replace (mem_ref_locs_p, ref->accesses_in_loop, loop->num, accs); | |
| 1279 } | |
| 1280 | |
| 1281 aref->stmt = stmt; | |
| 1282 aref->ref = loc; | |
| 1283 | |
| 1284 VEC_safe_push (mem_ref_loc_p, heap, accs->locs, aref); | |
| 1285 bitmap_set_bit (ril, ref->id); | |
| 1286 } | |
| 1287 | |
| 1288 /* Marks reference REF as stored in LOOP. */ | |
| 1289 | |
| 1290 static void | |
| 1291 mark_ref_stored (mem_ref_p ref, struct loop *loop) | |
| 1292 { | |
| 1293 for (; | |
| 1294 loop != current_loops->tree_root | |
| 1295 && !bitmap_bit_p (ref->stored, loop->num); | |
| 1296 loop = loop_outer (loop)) | |
| 1297 bitmap_set_bit (ref->stored, loop->num); | |
| 1298 } | |
| 1299 | |
| 1300 /* Gathers memory references in statement STMT in LOOP, storing the | |
| 1301 information about them in the memory_accesses structure. Marks | |
| 1302 the vops accessed through unrecognized statements there as | |
| 1303 well. */ | |
| 1304 | |
| 1305 static void | |
| 1306 gather_mem_refs_stmt (struct loop *loop, gimple stmt) | |
| 1307 { | |
| 1308 tree *mem = NULL; | |
| 1309 hashval_t hash; | |
| 1310 PTR *slot; | |
| 1311 mem_ref_p ref; | |
| 1312 ssa_op_iter oi; | |
| 1313 tree vname; | |
| 1314 bool is_stored; | |
| 1315 bitmap clvops; | |
| 1316 unsigned id; | |
| 1317 | |
| 1318 if (ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS)) | |
| 1319 return; | |
| 1320 | |
| 1321 mem = simple_mem_ref_in_stmt (stmt, &is_stored); | |
| 1322 if (!mem) | |
| 1323 goto fail; | |
| 1324 | |
| 1325 hash = iterative_hash_expr (*mem, 0); | |
| 1326 slot = htab_find_slot_with_hash (memory_accesses.refs, *mem, hash, INSERT); | |
| 1327 | |
| 1328 if (*slot) | |
| 1329 { | |
| 1330 ref = (mem_ref_p) *slot; | |
| 1331 id = ref->id; | |
| 1332 } | |
| 1333 else | |
| 1334 { | |
| 1335 id = VEC_length (mem_ref_p, memory_accesses.refs_list); | |
| 1336 ref = mem_ref_alloc (*mem, hash, id); | |
| 1337 VEC_safe_push (mem_ref_p, heap, memory_accesses.refs_list, ref); | |
| 1338 *slot = ref; | |
| 1339 | |
| 1340 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 1341 { | |
| 1342 fprintf (dump_file, "Memory reference %u: ", id); | |
| 1343 print_generic_expr (dump_file, ref->mem, TDF_SLIM); | |
| 1344 fprintf (dump_file, "\n"); | |
| 1345 } | |
| 1346 } | |
| 1347 if (is_stored) | |
| 1348 mark_ref_stored (ref, loop); | |
| 1349 | |
| 1350 FOR_EACH_SSA_TREE_OPERAND (vname, stmt, oi, SSA_OP_VIRTUAL_USES) | |
| 1351 bitmap_set_bit (ref->vops, DECL_UID (SSA_NAME_VAR (vname))); | |
| 1352 record_mem_ref_loc (ref, loop, stmt, mem); | |
| 1353 return; | |
| 1354 | |
| 1355 fail: | |
| 1356 clvops = VEC_index (bitmap, memory_accesses.clobbered_vops, loop->num); | |
| 1357 FOR_EACH_SSA_TREE_OPERAND (vname, stmt, oi, SSA_OP_VIRTUAL_USES) | |
| 1358 bitmap_set_bit (clvops, DECL_UID (SSA_NAME_VAR (vname))); | |
| 1359 } | |
| 1360 | |
| 1361 /* Gathers memory references in loops. */ | |
| 1362 | |
| 1363 static void | |
| 1364 gather_mem_refs_in_loops (void) | |
| 1365 { | |
| 1366 gimple_stmt_iterator bsi; | |
| 1367 basic_block bb; | |
| 1368 struct loop *loop; | |
| 1369 loop_iterator li; | |
| 1370 bitmap clvo, clvi; | |
| 1371 bitmap lrefs, alrefs, alrefso; | |
| 1372 | |
| 1373 FOR_EACH_BB (bb) | |
| 1374 { | |
| 1375 loop = bb->loop_father; | |
| 1376 if (loop == current_loops->tree_root) | |
| 1377 continue; | |
| 1378 | |
| 1379 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) | |
| 1380 gather_mem_refs_stmt (loop, gsi_stmt (bsi)); | |
| 1381 } | |
| 1382 | |
| 1383 /* Propagate the information about clobbered vops and accessed memory | |
| 1384 references up the loop hierarchy. */ | |
| 1385 FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST) | |
| 1386 { | |
| 1387 lrefs = VEC_index (bitmap, memory_accesses.refs_in_loop, loop->num); | |
| 1388 alrefs = VEC_index (bitmap, memory_accesses.all_refs_in_loop, loop->num); | |
| 1389 bitmap_ior_into (alrefs, lrefs); | |
| 1390 | |
| 1391 if (loop_outer (loop) == current_loops->tree_root) | |
| 1392 continue; | |
| 1393 | |
| 1394 clvi = VEC_index (bitmap, memory_accesses.clobbered_vops, loop->num); | |
| 1395 clvo = VEC_index (bitmap, memory_accesses.clobbered_vops, | |
| 1396 loop_outer (loop)->num); | |
| 1397 bitmap_ior_into (clvo, clvi); | |
| 1398 | |
| 1399 alrefso = VEC_index (bitmap, memory_accesses.all_refs_in_loop, | |
| 1400 loop_outer (loop)->num); | |
| 1401 bitmap_ior_into (alrefso, alrefs); | |
| 1402 } | |
| 1403 } | |
| 1404 | |
| 1405 /* Element of the hash table that maps vops to memory references. */ | |
| 1406 | |
| 1407 struct vop_to_refs_elt | |
| 1408 { | |
| 1409 /* DECL_UID of the vop. */ | |
| 1410 unsigned uid; | |
| 1411 | |
| 1412 /* List of the all references. */ | |
| 1413 bitmap refs_all; | |
| 1414 | |
| 1415 /* List of stored references. */ | |
| 1416 bitmap refs_stored; | |
| 1417 }; | |
| 1418 | |
| 1419 /* A hash function for struct vop_to_refs_elt object OBJ. */ | |
| 1420 | |
| 1421 static hashval_t | |
| 1422 vtoe_hash (const void *obj) | |
| 1423 { | |
| 1424 const struct vop_to_refs_elt *const vtoe = | |
| 1425 (const struct vop_to_refs_elt *) obj; | |
| 1426 | |
| 1427 return vtoe->uid; | |
| 1428 } | |
| 1429 | |
| 1430 /* An equality function for struct vop_to_refs_elt object OBJ1 with | |
| 1431 uid of a vop OBJ2. */ | |
| 1432 | |
| 1433 static int | |
| 1434 vtoe_eq (const void *obj1, const void *obj2) | |
| 1435 { | |
| 1436 const struct vop_to_refs_elt *const vtoe = | |
| 1437 (const struct vop_to_refs_elt *) obj1; | |
| 1438 const unsigned *const uid = (const unsigned *) obj2; | |
| 1439 | |
| 1440 return vtoe->uid == *uid; | |
| 1441 } | |
| 1442 | |
| 1443 /* A function to free the struct vop_to_refs_elt object. */ | |
| 1444 | |
| 1445 static void | |
| 1446 vtoe_free (void *obj) | |
| 1447 { | |
| 1448 struct vop_to_refs_elt *const vtoe = | |
| 1449 (struct vop_to_refs_elt *) obj; | |
| 1450 | |
| 1451 BITMAP_FREE (vtoe->refs_all); | |
| 1452 BITMAP_FREE (vtoe->refs_stored); | |
| 1453 free (vtoe); | |
| 1454 } | |
| 1455 | |
| 1456 /* Records REF to hashtable VOP_TO_REFS for the index VOP. STORED is true | |
| 1457 if the reference REF is stored. */ | |
| 1458 | |
| 1459 static void | |
| 1460 record_vop_access (htab_t vop_to_refs, unsigned vop, unsigned ref, bool stored) | |
| 1461 { | |
| 1462 void **slot = htab_find_slot_with_hash (vop_to_refs, &vop, vop, INSERT); | |
| 1463 struct vop_to_refs_elt *vtoe; | |
| 1464 | |
| 1465 if (!*slot) | |
| 1466 { | |
| 1467 vtoe = XNEW (struct vop_to_refs_elt); | |
| 1468 vtoe->uid = vop; | |
| 1469 vtoe->refs_all = BITMAP_ALLOC (NULL); | |
| 1470 vtoe->refs_stored = BITMAP_ALLOC (NULL); | |
| 1471 *slot = vtoe; | |
| 1472 } | |
| 1473 else | |
| 1474 vtoe = (struct vop_to_refs_elt *) *slot; | |
| 1475 | |
| 1476 bitmap_set_bit (vtoe->refs_all, ref); | |
| 1477 if (stored) | |
| 1478 bitmap_set_bit (vtoe->refs_stored, ref); | |
| 1479 } | |
| 1480 | |
| 1481 /* Returns the set of references that access VOP according to the table | |
| 1482 VOP_TO_REFS. */ | |
| 1483 | |
| 1484 static bitmap | |
| 1485 get_vop_accesses (htab_t vop_to_refs, unsigned vop) | |
| 1486 { | |
| 1487 struct vop_to_refs_elt *const vtoe = | |
| 1488 (struct vop_to_refs_elt *) htab_find_with_hash (vop_to_refs, &vop, vop); | |
| 1489 return vtoe->refs_all; | |
| 1490 } | |
| 1491 | |
| 1492 /* Returns the set of stores that access VOP according to the table | |
| 1493 VOP_TO_REFS. */ | |
| 1494 | |
| 1495 static bitmap | |
| 1496 get_vop_stores (htab_t vop_to_refs, unsigned vop) | |
| 1497 { | |
| 1498 struct vop_to_refs_elt *const vtoe = | |
| 1499 (struct vop_to_refs_elt *) htab_find_with_hash (vop_to_refs, &vop, vop); | |
| 1500 return vtoe->refs_stored; | |
| 1501 } | |
| 1502 | |
| 1503 /* Adds REF to mapping from virtual operands to references in LOOP. */ | |
| 1504 | |
| 1505 static void | |
| 1506 add_vop_ref_mapping (struct loop *loop, mem_ref_p ref) | |
| 1507 { | |
| 1508 htab_t map = VEC_index (htab_t, memory_accesses.vop_ref_map, loop->num); | |
| 1509 bool stored = bitmap_bit_p (ref->stored, loop->num); | |
| 1510 bitmap clobbers = VEC_index (bitmap, memory_accesses.clobbered_vops, | |
| 1511 loop->num); | |
| 1512 bitmap_iterator bi; | |
| 1513 unsigned vop; | |
| 1514 | |
| 1515 EXECUTE_IF_AND_COMPL_IN_BITMAP (ref->vops, clobbers, 0, vop, bi) | |
| 1516 { | |
| 1517 record_vop_access (map, vop, ref->id, stored); | |
| 1518 } | |
| 1519 } | |
| 1520 | |
| 1521 /* Create a mapping from virtual operands to references that touch them | |
| 1522 in LOOP. */ | |
| 1523 | |
| 1524 static void | |
| 1525 create_vop_ref_mapping_loop (struct loop *loop) | |
| 1526 { | |
| 1527 bitmap refs = VEC_index (bitmap, memory_accesses.refs_in_loop, loop->num); | |
| 1528 struct loop *sloop; | |
| 1529 bitmap_iterator bi; | |
| 1530 unsigned i; | |
| 1531 mem_ref_p ref; | |
| 1532 | |
| 1533 EXECUTE_IF_SET_IN_BITMAP (refs, 0, i, bi) | |
| 1534 { | |
| 1535 ref = VEC_index (mem_ref_p, memory_accesses.refs_list, i); | |
| 1536 for (sloop = loop; sloop != current_loops->tree_root; sloop = loop_outer (sloop)) | |
| 1537 add_vop_ref_mapping (sloop, ref); | |
| 1538 } | |
| 1539 } | |
| 1540 | |
| 1541 /* For each non-clobbered virtual operand and each loop, record the memory | |
| 1542 references in this loop that touch the operand. */ | |
| 1543 | |
| 1544 static void | |
| 1545 create_vop_ref_mapping (void) | |
| 1546 { | |
| 1547 loop_iterator li; | |
| 1548 struct loop *loop; | |
| 1549 | |
| 1550 FOR_EACH_LOOP (li, loop, 0) | |
| 1551 { | |
| 1552 create_vop_ref_mapping_loop (loop); | |
| 1553 } | |
| 1554 } | |
| 1555 | |
| 1556 /* Gathers information about memory accesses in the loops. */ | |
| 1557 | |
| 1558 static void | |
| 1559 analyze_memory_references (void) | |
| 1560 { | |
| 1561 unsigned i; | |
| 1562 bitmap empty; | |
| 1563 htab_t hempty; | |
| 1564 | |
| 1565 memory_accesses.refs | |
| 1566 = htab_create (100, memref_hash, memref_eq, memref_free); | |
| 1567 memory_accesses.refs_list = NULL; | |
| 1568 memory_accesses.refs_in_loop = VEC_alloc (bitmap, heap, | |
| 1569 number_of_loops ()); | |
| 1570 memory_accesses.all_refs_in_loop = VEC_alloc (bitmap, heap, | |
| 1571 number_of_loops ()); | |
| 1572 memory_accesses.clobbered_vops = VEC_alloc (bitmap, heap, | |
| 1573 number_of_loops ()); | |
| 1574 memory_accesses.vop_ref_map = VEC_alloc (htab_t, heap, | |
| 1575 number_of_loops ()); | |
| 1576 | |
| 1577 for (i = 0; i < number_of_loops (); i++) | |
| 1578 { | |
| 1579 empty = BITMAP_ALLOC (NULL); | |
| 1580 VEC_quick_push (bitmap, memory_accesses.refs_in_loop, empty); | |
| 1581 empty = BITMAP_ALLOC (NULL); | |
| 1582 VEC_quick_push (bitmap, memory_accesses.all_refs_in_loop, empty); | |
| 1583 empty = BITMAP_ALLOC (NULL); | |
| 1584 VEC_quick_push (bitmap, memory_accesses.clobbered_vops, empty); | |
| 1585 hempty = htab_create (10, vtoe_hash, vtoe_eq, vtoe_free); | |
| 1586 VEC_quick_push (htab_t, memory_accesses.vop_ref_map, hempty); | |
| 1587 } | |
| 1588 | |
| 1589 memory_accesses.ttae_cache = NULL; | |
| 1590 | |
| 1591 gather_mem_refs_in_loops (); | |
| 1592 create_vop_ref_mapping (); | |
| 1593 } | |
| 1594 | |
| 1595 /* Returns true if a region of size SIZE1 at position 0 and a region of | |
| 1596 size SIZE2 at position DIFF cannot overlap. */ | |
| 1597 | |
| 1598 static bool | |
| 1599 cannot_overlap_p (aff_tree *diff, double_int size1, double_int size2) | |
| 1600 { | |
| 1601 double_int d, bound; | |
| 1602 | |
| 1603 /* Unless the difference is a constant, we fail. */ | |
| 1604 if (diff->n != 0) | |
| 1605 return false; | |
| 1606 | |
| 1607 d = diff->offset; | |
| 1608 if (double_int_negative_p (d)) | |
| 1609 { | |
| 1610 /* The second object is before the first one, we succeed if the last | |
| 1611 element of the second object is before the start of the first one. */ | |
| 1612 bound = double_int_add (d, double_int_add (size2, double_int_minus_one)); | |
| 1613 return double_int_negative_p (bound); | |
| 1614 } | |
| 1615 else | |
| 1616 { | |
| 1617 /* We succeed if the second object starts after the first one ends. */ | |
| 1618 return double_int_scmp (size1, d) <= 0; | |
| 1619 } | |
| 1620 } | |
| 1621 | |
| 1622 /* Returns true if MEM1 and MEM2 may alias. TTAE_CACHE is used as a cache in | |
| 1623 tree_to_aff_combination_expand. */ | |
| 1624 | |
| 1625 static bool | |
| 1626 mem_refs_may_alias_p (tree mem1, tree mem2, struct pointer_map_t **ttae_cache) | |
| 1627 { | |
| 1628 /* Perform BASE + OFFSET analysis -- if MEM1 and MEM2 are based on the same | |
| 1629 object and their offset differ in such a way that the locations cannot | |
| 1630 overlap, then they cannot alias. */ | |
| 1631 double_int size1, size2; | |
| 1632 aff_tree off1, off2; | |
| 1633 | |
| 1634 /* Perform basic offset and type-based disambiguation. */ | |
| 1635 if (!refs_may_alias_p (mem1, mem2)) | |
| 1636 return false; | |
| 1637 | |
| 1638 /* The expansion of addresses may be a bit expensive, thus we only do | |
| 1639 the check at -O2 and higher optimization levels. */ | |
| 1640 if (optimize < 2) | |
| 1641 return true; | |
| 1642 | |
| 1643 get_inner_reference_aff (mem1, &off1, &size1); | |
| 1644 get_inner_reference_aff (mem2, &off2, &size2); | |
| 1645 aff_combination_expand (&off1, ttae_cache); | |
| 1646 aff_combination_expand (&off2, ttae_cache); | |
| 1647 aff_combination_scale (&off1, double_int_minus_one); | |
| 1648 aff_combination_add (&off2, &off1); | |
| 1649 | |
| 1650 if (cannot_overlap_p (&off2, size1, size2)) | |
| 1651 return false; | |
| 1652 | |
| 1653 return true; | |
| 1654 } | |
| 1655 | |
| 1656 /* Rewrites location LOC by TMP_VAR. */ | |
| 1657 | |
| 1658 static void | |
| 1659 rewrite_mem_ref_loc (mem_ref_loc_p loc, tree tmp_var) | |
| 1660 { | |
| 1661 mark_virtual_ops_for_renaming (loc->stmt); | |
| 1662 *loc->ref = tmp_var; | |
| 1663 update_stmt (loc->stmt); | |
| 1664 } | |
| 1665 | |
| 1666 /* Adds all locations of REF in LOOP and its subloops to LOCS. */ | |
| 1667 | |
| 1668 static void | |
| 1669 get_all_locs_in_loop (struct loop *loop, mem_ref_p ref, | |
| 1670 VEC (mem_ref_loc_p, heap) **locs) | |
| 1671 { | |
| 1672 mem_ref_locs_p accs; | |
| 1673 unsigned i; | |
| 1674 mem_ref_loc_p loc; | |
| 1675 bitmap refs = VEC_index (bitmap, memory_accesses.all_refs_in_loop, | |
| 1676 loop->num); | |
| 1677 struct loop *subloop; | |
| 1678 | |
| 1679 if (!bitmap_bit_p (refs, ref->id)) | |
| 1680 return; | |
| 1681 | |
| 1682 if (VEC_length (mem_ref_locs_p, ref->accesses_in_loop) | |
| 1683 > (unsigned) loop->num) | |
| 1684 { | |
| 1685 accs = VEC_index (mem_ref_locs_p, ref->accesses_in_loop, loop->num); | |
| 1686 if (accs) | |
| 1687 { | |
| 1688 for (i = 0; VEC_iterate (mem_ref_loc_p, accs->locs, i, loc); i++) | |
| 1689 VEC_safe_push (mem_ref_loc_p, heap, *locs, loc); | |
| 1690 } | |
| 1691 } | |
| 1692 | |
| 1693 for (subloop = loop->inner; subloop != NULL; subloop = subloop->next) | |
| 1694 get_all_locs_in_loop (subloop, ref, locs); | |
| 1695 } | |
| 1696 | |
| 1697 /* Rewrites all references to REF in LOOP by variable TMP_VAR. */ | |
| 1698 | |
| 1699 static void | |
| 1700 rewrite_mem_refs (struct loop *loop, mem_ref_p ref, tree tmp_var) | |
| 1701 { | |
| 1702 unsigned i; | |
| 1703 mem_ref_loc_p loc; | |
| 1704 VEC (mem_ref_loc_p, heap) *locs = NULL; | |
| 1705 | |
| 1706 get_all_locs_in_loop (loop, ref, &locs); | |
| 1707 for (i = 0; VEC_iterate (mem_ref_loc_p, locs, i, loc); i++) | |
| 1708 rewrite_mem_ref_loc (loc, tmp_var); | |
| 1709 VEC_free (mem_ref_loc_p, heap, locs); | |
| 1710 } | |
| 1711 | |
| 1712 /* The name and the length of the currently generated variable | |
| 1713 for lsm. */ | |
| 1714 #define MAX_LSM_NAME_LENGTH 40 | |
| 1715 static char lsm_tmp_name[MAX_LSM_NAME_LENGTH + 1]; | |
| 1716 static int lsm_tmp_name_length; | |
| 1717 | |
| 1718 /* Adds S to lsm_tmp_name. */ | |
| 1719 | |
| 1720 static void | |
| 1721 lsm_tmp_name_add (const char *s) | |
| 1722 { | |
| 1723 int l = strlen (s) + lsm_tmp_name_length; | |
| 1724 if (l > MAX_LSM_NAME_LENGTH) | |
| 1725 return; | |
| 1726 | |
| 1727 strcpy (lsm_tmp_name + lsm_tmp_name_length, s); | |
| 1728 lsm_tmp_name_length = l; | |
| 1729 } | |
| 1730 | |
| 1731 /* Stores the name for temporary variable that replaces REF to | |
| 1732 lsm_tmp_name. */ | |
| 1733 | |
| 1734 static void | |
| 1735 gen_lsm_tmp_name (tree ref) | |
| 1736 { | |
| 1737 const char *name; | |
| 1738 | |
| 1739 switch (TREE_CODE (ref)) | |
| 1740 { | |
| 1741 case MISALIGNED_INDIRECT_REF: | |
| 1742 case ALIGN_INDIRECT_REF: | |
| 1743 case INDIRECT_REF: | |
| 1744 gen_lsm_tmp_name (TREE_OPERAND (ref, 0)); | |
| 1745 lsm_tmp_name_add ("_"); | |
| 1746 break; | |
| 1747 | |
| 1748 case BIT_FIELD_REF: | |
| 1749 case VIEW_CONVERT_EXPR: | |
| 1750 case ARRAY_RANGE_REF: | |
| 1751 gen_lsm_tmp_name (TREE_OPERAND (ref, 0)); | |
| 1752 break; | |
| 1753 | |
| 1754 case REALPART_EXPR: | |
| 1755 gen_lsm_tmp_name (TREE_OPERAND (ref, 0)); | |
| 1756 lsm_tmp_name_add ("_RE"); | |
| 1757 break; | |
| 1758 | |
| 1759 case IMAGPART_EXPR: | |
| 1760 gen_lsm_tmp_name (TREE_OPERAND (ref, 0)); | |
| 1761 lsm_tmp_name_add ("_IM"); | |
| 1762 break; | |
| 1763 | |
| 1764 case COMPONENT_REF: | |
| 1765 gen_lsm_tmp_name (TREE_OPERAND (ref, 0)); | |
| 1766 lsm_tmp_name_add ("_"); | |
| 1767 name = get_name (TREE_OPERAND (ref, 1)); | |
| 1768 if (!name) | |
| 1769 name = "F"; | |
| 1770 lsm_tmp_name_add (name); | |
|
47
3bfb6c00c1e0
update it from 4.4.2 to 4.4.3.
kent <kent@cr.ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
1771 break; |
| 0 | 1772 |
| 1773 case ARRAY_REF: | |
| 1774 gen_lsm_tmp_name (TREE_OPERAND (ref, 0)); | |
| 1775 lsm_tmp_name_add ("_I"); | |
| 1776 break; | |
| 1777 | |
| 1778 case SSA_NAME: | |
| 1779 ref = SSA_NAME_VAR (ref); | |
| 1780 /* Fallthru. */ | |
| 1781 | |
| 1782 case VAR_DECL: | |
| 1783 case PARM_DECL: | |
| 1784 name = get_name (ref); | |
| 1785 if (!name) | |
| 1786 name = "D"; | |
| 1787 lsm_tmp_name_add (name); | |
| 1788 break; | |
| 1789 | |
| 1790 case STRING_CST: | |
| 1791 lsm_tmp_name_add ("S"); | |
| 1792 break; | |
| 1793 | |
| 1794 case RESULT_DECL: | |
| 1795 lsm_tmp_name_add ("R"); | |
| 1796 break; | |
| 1797 | |
| 1798 default: | |
| 1799 gcc_unreachable (); | |
| 1800 } | |
| 1801 } | |
| 1802 | |
| 1803 /* Determines name for temporary variable that replaces REF. | |
| 1804 The name is accumulated into the lsm_tmp_name variable. | |
| 1805 N is added to the name of the temporary. */ | |
| 1806 | |
| 1807 char * | |
| 1808 get_lsm_tmp_name (tree ref, unsigned n) | |
| 1809 { | |
| 1810 char ns[2]; | |
| 1811 | |
| 1812 lsm_tmp_name_length = 0; | |
| 1813 gen_lsm_tmp_name (ref); | |
| 1814 lsm_tmp_name_add ("_lsm"); | |
| 1815 if (n < 10) | |
| 1816 { | |
| 1817 ns[0] = '0' + n; | |
| 1818 ns[1] = 0; | |
| 1819 lsm_tmp_name_add (ns); | |
| 1820 } | |
| 1821 return lsm_tmp_name; | |
| 1822 } | |
| 1823 | |
| 1824 /* Executes store motion of memory reference REF from LOOP. | |
| 1825 Exits from the LOOP are stored in EXITS. The initialization of the | |
| 1826 temporary variable is put to the preheader of the loop, and assignments | |
| 1827 to the reference from the temporary variable are emitted to exits. */ | |
| 1828 | |
| 1829 static void | |
| 1830 execute_sm (struct loop *loop, VEC (edge, heap) *exits, mem_ref_p ref) | |
| 1831 { | |
| 1832 tree tmp_var; | |
| 1833 unsigned i; | |
| 1834 gimple load, store; | |
| 1835 struct fmt_data fmt_data; | |
| 1836 edge ex; | |
| 1837 struct lim_aux_data *lim_data; | |
| 1838 | |
| 1839 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 1840 { | |
| 1841 fprintf (dump_file, "Executing store motion of "); | |
| 1842 print_generic_expr (dump_file, ref->mem, 0); | |
| 1843 fprintf (dump_file, " from loop %d\n", loop->num); | |
| 1844 } | |
| 1845 | |
| 1846 tmp_var = make_rename_temp (TREE_TYPE (ref->mem), | |
| 1847 get_lsm_tmp_name (ref->mem, ~0)); | |
| 1848 | |
| 1849 fmt_data.loop = loop; | |
| 1850 fmt_data.orig_loop = loop; | |
| 1851 for_each_index (&ref->mem, force_move_till, &fmt_data); | |
| 1852 | |
| 1853 rewrite_mem_refs (loop, ref, tmp_var); | |
| 1854 | |
| 1855 /* Emit the load & stores. */ | |
| 1856 load = gimple_build_assign (tmp_var, unshare_expr (ref->mem)); | |
| 1857 lim_data = init_lim_data (load); | |
| 1858 lim_data->max_loop = loop; | |
| 1859 lim_data->tgt_loop = loop; | |
| 1860 | |
| 1861 /* Put this into the latch, so that we are sure it will be processed after | |
| 1862 all dependencies. */ | |
| 1863 gsi_insert_on_edge (loop_latch_edge (loop), load); | |
| 1864 | |
| 1865 for (i = 0; VEC_iterate (edge, exits, i, ex); i++) | |
| 1866 { | |
| 1867 store = gimple_build_assign (unshare_expr (ref->mem), tmp_var); | |
| 1868 gsi_insert_on_edge (ex, store); | |
| 1869 } | |
| 1870 } | |
| 1871 | |
| 1872 /* Hoists memory references MEM_REFS out of LOOP. EXITS is the list of exit | |
| 1873 edges of the LOOP. */ | |
| 1874 | |
| 1875 static void | |
| 1876 hoist_memory_references (struct loop *loop, bitmap mem_refs, | |
| 1877 VEC (edge, heap) *exits) | |
| 1878 { | |
| 1879 mem_ref_p ref; | |
| 1880 unsigned i; | |
| 1881 bitmap_iterator bi; | |
| 1882 | |
| 1883 EXECUTE_IF_SET_IN_BITMAP (mem_refs, 0, i, bi) | |
| 1884 { | |
| 1885 ref = VEC_index (mem_ref_p, memory_accesses.refs_list, i); | |
| 1886 execute_sm (loop, exits, ref); | |
| 1887 } | |
| 1888 } | |
| 1889 | |
| 1890 /* Returns true if REF is always accessed in LOOP. */ | |
| 1891 | |
| 1892 static bool | |
| 1893 ref_always_accessed_p (struct loop *loop, mem_ref_p ref) | |
| 1894 { | |
| 1895 VEC (mem_ref_loc_p, heap) *locs = NULL; | |
| 1896 unsigned i; | |
| 1897 mem_ref_loc_p loc; | |
| 1898 bool ret = false; | |
| 1899 struct loop *must_exec; | |
| 1900 | |
| 1901 get_all_locs_in_loop (loop, ref, &locs); | |
| 1902 for (i = 0; VEC_iterate (mem_ref_loc_p, locs, i, loc); i++) | |
| 1903 { | |
| 1904 if (!get_lim_data (loc->stmt)) | |
| 1905 continue; | |
| 1906 | |
| 1907 must_exec = get_lim_data (loc->stmt)->always_executed_in; | |
| 1908 if (!must_exec) | |
| 1909 continue; | |
| 1910 | |
| 1911 if (must_exec == loop | |
| 1912 || flow_loop_nested_p (must_exec, loop)) | |
| 1913 { | |
| 1914 ret = true; | |
| 1915 break; | |
| 1916 } | |
| 1917 } | |
| 1918 VEC_free (mem_ref_loc_p, heap, locs); | |
| 1919 | |
| 1920 return ret; | |
| 1921 } | |
| 1922 | |
| 1923 /* Returns true if REF1 and REF2 are independent. */ | |
| 1924 | |
| 1925 static bool | |
| 1926 refs_independent_p (mem_ref_p ref1, mem_ref_p ref2) | |
| 1927 { | |
| 1928 if (ref1 == ref2 | |
| 1929 || bitmap_bit_p (ref1->indep_ref, ref2->id)) | |
| 1930 return true; | |
| 1931 if (bitmap_bit_p (ref1->dep_ref, ref2->id)) | |
| 1932 return false; | |
| 1933 | |
| 1934 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 1935 fprintf (dump_file, "Querying dependency of refs %u and %u: ", | |
| 1936 ref1->id, ref2->id); | |
| 1937 | |
| 1938 if (mem_refs_may_alias_p (ref1->mem, ref2->mem, | |
| 1939 &memory_accesses.ttae_cache)) | |
| 1940 { | |
| 1941 bitmap_set_bit (ref1->dep_ref, ref2->id); | |
| 1942 bitmap_set_bit (ref2->dep_ref, ref1->id); | |
| 1943 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 1944 fprintf (dump_file, "dependent.\n"); | |
| 1945 return false; | |
| 1946 } | |
| 1947 else | |
| 1948 { | |
| 1949 bitmap_set_bit (ref1->indep_ref, ref2->id); | |
| 1950 bitmap_set_bit (ref2->indep_ref, ref1->id); | |
| 1951 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 1952 fprintf (dump_file, "independent.\n"); | |
| 1953 return true; | |
| 1954 } | |
| 1955 } | |
| 1956 | |
| 1957 /* Records the information whether REF is independent in LOOP (according | |
| 1958 to INDEP). */ | |
| 1959 | |
| 1960 static void | |
| 1961 record_indep_loop (struct loop *loop, mem_ref_p ref, bool indep) | |
| 1962 { | |
| 1963 if (indep) | |
| 1964 bitmap_set_bit (ref->indep_loop, loop->num); | |
| 1965 else | |
| 1966 bitmap_set_bit (ref->dep_loop, loop->num); | |
| 1967 } | |
| 1968 | |
| 1969 /* Returns true if REF is independent on all other memory references in | |
| 1970 LOOP. */ | |
| 1971 | |
| 1972 static bool | |
| 1973 ref_indep_loop_p_1 (struct loop *loop, mem_ref_p ref) | |
| 1974 { | |
| 1975 bitmap clobbers, refs_to_check, refs; | |
| 1976 unsigned i; | |
| 1977 bitmap_iterator bi; | |
| 1978 bool ret = true, stored = bitmap_bit_p (ref->stored, loop->num); | |
| 1979 htab_t map; | |
| 1980 mem_ref_p aref; | |
| 1981 | |
| 1982 /* If the reference is clobbered, it is not independent. */ | |
| 1983 clobbers = VEC_index (bitmap, memory_accesses.clobbered_vops, loop->num); | |
| 1984 if (bitmap_intersect_p (ref->vops, clobbers)) | |
| 1985 return false; | |
| 1986 | |
| 1987 refs_to_check = BITMAP_ALLOC (NULL); | |
| 1988 | |
| 1989 map = VEC_index (htab_t, memory_accesses.vop_ref_map, loop->num); | |
| 1990 EXECUTE_IF_AND_COMPL_IN_BITMAP (ref->vops, clobbers, 0, i, bi) | |
| 1991 { | |
| 1992 if (stored) | |
| 1993 refs = get_vop_accesses (map, i); | |
| 1994 else | |
| 1995 refs = get_vop_stores (map, i); | |
| 1996 | |
| 1997 bitmap_ior_into (refs_to_check, refs); | |
| 1998 } | |
| 1999 | |
| 2000 EXECUTE_IF_SET_IN_BITMAP (refs_to_check, 0, i, bi) | |
| 2001 { | |
| 2002 aref = VEC_index (mem_ref_p, memory_accesses.refs_list, i); | |
| 2003 if (!refs_independent_p (ref, aref)) | |
| 2004 { | |
| 2005 ret = false; | |
| 2006 record_indep_loop (loop, aref, false); | |
| 2007 break; | |
| 2008 } | |
| 2009 } | |
| 2010 | |
| 2011 BITMAP_FREE (refs_to_check); | |
| 2012 return ret; | |
| 2013 } | |
| 2014 | |
| 2015 /* Returns true if REF is independent on all other memory references in | |
| 2016 LOOP. Wrapper over ref_indep_loop_p_1, caching its results. */ | |
| 2017 | |
| 2018 static bool | |
| 2019 ref_indep_loop_p (struct loop *loop, mem_ref_p ref) | |
| 2020 { | |
| 2021 bool ret; | |
| 2022 | |
| 2023 if (bitmap_bit_p (ref->indep_loop, loop->num)) | |
| 2024 return true; | |
| 2025 if (bitmap_bit_p (ref->dep_loop, loop->num)) | |
| 2026 return false; | |
| 2027 | |
| 2028 ret = ref_indep_loop_p_1 (loop, ref); | |
| 2029 | |
| 2030 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 2031 fprintf (dump_file, "Querying dependencies of ref %u in loop %d: %s\n", | |
| 2032 ref->id, loop->num, ret ? "independent" : "dependent"); | |
| 2033 | |
| 2034 record_indep_loop (loop, ref, ret); | |
| 2035 | |
| 2036 return ret; | |
| 2037 } | |
| 2038 | |
| 2039 /* Returns true if we can perform store motion of REF from LOOP. */ | |
| 2040 | |
| 2041 static bool | |
| 2042 can_sm_ref_p (struct loop *loop, mem_ref_p ref) | |
| 2043 { | |
| 2044 /* Unless the reference is stored in the loop, there is nothing to do. */ | |
| 2045 if (!bitmap_bit_p (ref->stored, loop->num)) | |
| 2046 return false; | |
| 2047 | |
| 2048 /* It should be movable. */ | |
| 2049 if (!is_gimple_reg_type (TREE_TYPE (ref->mem)) | |
| 2050 || TREE_THIS_VOLATILE (ref->mem) | |
| 2051 || !for_each_index (&ref->mem, may_move_till, loop)) | |
| 2052 return false; | |
| 2053 | |
| 2054 /* If it can trap, it must be always executed in LOOP. */ | |
| 2055 if (tree_could_trap_p (ref->mem) | |
| 2056 && !ref_always_accessed_p (loop, ref)) | |
| 2057 return false; | |
| 2058 | |
| 2059 /* And it must be independent on all other memory references | |
| 2060 in LOOP. */ | |
| 2061 if (!ref_indep_loop_p (loop, ref)) | |
| 2062 return false; | |
| 2063 | |
| 2064 return true; | |
| 2065 } | |
| 2066 | |
| 2067 /* Marks the references in LOOP for that store motion should be performed | |
| 2068 in REFS_TO_SM. SM_EXECUTED is the set of references for that store | |
| 2069 motion was performed in one of the outer loops. */ | |
| 2070 | |
| 2071 static void | |
| 2072 find_refs_for_sm (struct loop *loop, bitmap sm_executed, bitmap refs_to_sm) | |
| 2073 { | |
| 2074 bitmap refs = VEC_index (bitmap, memory_accesses.all_refs_in_loop, | |
| 2075 loop->num); | |
| 2076 unsigned i; | |
| 2077 bitmap_iterator bi; | |
| 2078 mem_ref_p ref; | |
| 2079 | |
| 2080 EXECUTE_IF_AND_COMPL_IN_BITMAP (refs, sm_executed, 0, i, bi) | |
| 2081 { | |
| 2082 ref = VEC_index (mem_ref_p, memory_accesses.refs_list, i); | |
| 2083 if (can_sm_ref_p (loop, ref)) | |
| 2084 bitmap_set_bit (refs_to_sm, i); | |
| 2085 } | |
| 2086 } | |
| 2087 | |
| 2088 /* Checks whether LOOP (with exits stored in EXITS array) is suitable | |
| 2089 for a store motion optimization (i.e. whether we can insert statement | |
| 2090 on its exits). */ | |
| 2091 | |
| 2092 static bool | |
| 2093 loop_suitable_for_sm (struct loop *loop ATTRIBUTE_UNUSED, | |
| 2094 VEC (edge, heap) *exits) | |
| 2095 { | |
| 2096 unsigned i; | |
| 2097 edge ex; | |
| 2098 | |
| 2099 for (i = 0; VEC_iterate (edge, exits, i, ex); i++) | |
| 2100 if (ex->flags & EDGE_ABNORMAL) | |
| 2101 return false; | |
| 2102 | |
| 2103 return true; | |
| 2104 } | |
| 2105 | |
| 2106 /* Try to perform store motion for all memory references modified inside | |
| 2107 LOOP. SM_EXECUTED is the bitmap of the memory references for that | |
| 2108 store motion was executed in one of the outer loops. */ | |
| 2109 | |
| 2110 static void | |
| 2111 store_motion_loop (struct loop *loop, bitmap sm_executed) | |
| 2112 { | |
| 2113 VEC (edge, heap) *exits = get_loop_exit_edges (loop); | |
| 2114 struct loop *subloop; | |
| 2115 bitmap sm_in_loop = BITMAP_ALLOC (NULL); | |
| 2116 | |
| 2117 if (loop_suitable_for_sm (loop, exits)) | |
| 2118 { | |
| 2119 find_refs_for_sm (loop, sm_executed, sm_in_loop); | |
| 2120 hoist_memory_references (loop, sm_in_loop, exits); | |
| 2121 } | |
| 2122 VEC_free (edge, heap, exits); | |
| 2123 | |
| 2124 bitmap_ior_into (sm_executed, sm_in_loop); | |
| 2125 for (subloop = loop->inner; subloop != NULL; subloop = subloop->next) | |
| 2126 store_motion_loop (subloop, sm_executed); | |
| 2127 bitmap_and_compl_into (sm_executed, sm_in_loop); | |
| 2128 BITMAP_FREE (sm_in_loop); | |
| 2129 } | |
| 2130 | |
| 2131 /* Try to perform store motion for all memory references modified inside | |
| 2132 loops. */ | |
| 2133 | |
| 2134 static void | |
| 2135 store_motion (void) | |
| 2136 { | |
| 2137 struct loop *loop; | |
| 2138 bitmap sm_executed = BITMAP_ALLOC (NULL); | |
| 2139 | |
| 2140 for (loop = current_loops->tree_root->inner; loop != NULL; loop = loop->next) | |
| 2141 store_motion_loop (loop, sm_executed); | |
| 2142 | |
| 2143 BITMAP_FREE (sm_executed); | |
| 2144 gsi_commit_edge_inserts (); | |
| 2145 } | |
| 2146 | |
| 2147 /* Fills ALWAYS_EXECUTED_IN information for basic blocks of LOOP, i.e. | |
| 2148 for each such basic block bb records the outermost loop for that execution | |
| 2149 of its header implies execution of bb. CONTAINS_CALL is the bitmap of | |
| 2150 blocks that contain a nonpure call. */ | |
| 2151 | |
| 2152 static void | |
| 2153 fill_always_executed_in (struct loop *loop, sbitmap contains_call) | |
| 2154 { | |
| 2155 basic_block bb = NULL, *bbs, last = NULL; | |
| 2156 unsigned i; | |
| 2157 edge e; | |
| 2158 struct loop *inn_loop = loop; | |
| 2159 | |
| 2160 if (!loop->header->aux) | |
| 2161 { | |
| 2162 bbs = get_loop_body_in_dom_order (loop); | |
| 2163 | |
| 2164 for (i = 0; i < loop->num_nodes; i++) | |
| 2165 { | |
| 2166 edge_iterator ei; | |
| 2167 bb = bbs[i]; | |
| 2168 | |
| 2169 if (dominated_by_p (CDI_DOMINATORS, loop->latch, bb)) | |
| 2170 last = bb; | |
| 2171 | |
| 2172 if (TEST_BIT (contains_call, bb->index)) | |
| 2173 break; | |
| 2174 | |
| 2175 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 2176 if (!flow_bb_inside_loop_p (loop, e->dest)) | |
| 2177 break; | |
| 2178 if (e) | |
| 2179 break; | |
| 2180 | |
| 2181 /* A loop might be infinite (TODO use simple loop analysis | |
| 2182 to disprove this if possible). */ | |
| 2183 if (bb->flags & BB_IRREDUCIBLE_LOOP) | |
| 2184 break; | |
| 2185 | |
| 2186 if (!flow_bb_inside_loop_p (inn_loop, bb)) | |
| 2187 break; | |
| 2188 | |
| 2189 if (bb->loop_father->header == bb) | |
| 2190 { | |
| 2191 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb)) | |
| 2192 break; | |
| 2193 | |
| 2194 /* In a loop that is always entered we may proceed anyway. | |
| 2195 But record that we entered it and stop once we leave it. */ | |
| 2196 inn_loop = bb->loop_father; | |
| 2197 } | |
| 2198 } | |
| 2199 | |
| 2200 while (1) | |
| 2201 { | |
| 2202 last->aux = loop; | |
| 2203 if (last == loop->header) | |
| 2204 break; | |
| 2205 last = get_immediate_dominator (CDI_DOMINATORS, last); | |
| 2206 } | |
| 2207 | |
| 2208 free (bbs); | |
| 2209 } | |
| 2210 | |
| 2211 for (loop = loop->inner; loop; loop = loop->next) | |
| 2212 fill_always_executed_in (loop, contains_call); | |
| 2213 } | |
| 2214 | |
| 2215 /* Compute the global information needed by the loop invariant motion pass. */ | |
| 2216 | |
| 2217 static void | |
| 2218 tree_ssa_lim_initialize (void) | |
| 2219 { | |
| 2220 sbitmap contains_call = sbitmap_alloc (last_basic_block); | |
| 2221 gimple_stmt_iterator bsi; | |
| 2222 struct loop *loop; | |
| 2223 basic_block bb; | |
| 2224 | |
| 2225 sbitmap_zero (contains_call); | |
| 2226 FOR_EACH_BB (bb) | |
| 2227 { | |
| 2228 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) | |
| 2229 { | |
| 2230 if (nonpure_call_p (gsi_stmt (bsi))) | |
| 2231 break; | |
| 2232 } | |
| 2233 | |
| 2234 if (!gsi_end_p (bsi)) | |
| 2235 SET_BIT (contains_call, bb->index); | |
| 2236 } | |
| 2237 | |
| 2238 for (loop = current_loops->tree_root->inner; loop; loop = loop->next) | |
| 2239 fill_always_executed_in (loop, contains_call); | |
| 2240 | |
| 2241 sbitmap_free (contains_call); | |
| 2242 | |
| 2243 lim_aux_data_map = pointer_map_create (); | |
| 2244 } | |
| 2245 | |
| 2246 /* Cleans up after the invariant motion pass. */ | |
| 2247 | |
| 2248 static void | |
| 2249 tree_ssa_lim_finalize (void) | |
| 2250 { | |
| 2251 basic_block bb; | |
| 2252 unsigned i; | |
| 2253 bitmap b; | |
| 2254 htab_t h; | |
| 2255 | |
| 2256 FOR_EACH_BB (bb) | |
| 2257 { | |
| 2258 bb->aux = NULL; | |
| 2259 } | |
| 2260 | |
| 2261 pointer_map_destroy (lim_aux_data_map); | |
| 2262 | |
| 2263 VEC_free (mem_ref_p, heap, memory_accesses.refs_list); | |
| 2264 htab_delete (memory_accesses.refs); | |
| 2265 | |
| 2266 for (i = 0; VEC_iterate (bitmap, memory_accesses.refs_in_loop, i, b); i++) | |
| 2267 BITMAP_FREE (b); | |
| 2268 VEC_free (bitmap, heap, memory_accesses.refs_in_loop); | |
| 2269 | |
| 2270 for (i = 0; VEC_iterate (bitmap, memory_accesses.all_refs_in_loop, i, b); i++) | |
| 2271 BITMAP_FREE (b); | |
| 2272 VEC_free (bitmap, heap, memory_accesses.all_refs_in_loop); | |
| 2273 | |
| 2274 for (i = 0; VEC_iterate (bitmap, memory_accesses.clobbered_vops, i, b); i++) | |
| 2275 BITMAP_FREE (b); | |
| 2276 VEC_free (bitmap, heap, memory_accesses.clobbered_vops); | |
| 2277 | |
| 2278 for (i = 0; VEC_iterate (htab_t, memory_accesses.vop_ref_map, i, h); i++) | |
| 2279 htab_delete (h); | |
| 2280 VEC_free (htab_t, heap, memory_accesses.vop_ref_map); | |
| 2281 | |
| 2282 if (memory_accesses.ttae_cache) | |
| 2283 pointer_map_destroy (memory_accesses.ttae_cache); | |
| 2284 } | |
| 2285 | |
| 2286 /* Moves invariants from loops. Only "expensive" invariants are moved out -- | |
| 2287 i.e. those that are likely to be win regardless of the register pressure. */ | |
| 2288 | |
| 2289 void | |
| 2290 tree_ssa_lim (void) | |
| 2291 { | |
| 2292 tree_ssa_lim_initialize (); | |
| 2293 | |
| 2294 /* Gathers information about memory accesses in the loops. */ | |
| 2295 analyze_memory_references (); | |
| 2296 | |
| 2297 /* For each statement determine the outermost loop in that it is | |
| 2298 invariant and cost for computing the invariant. */ | |
| 2299 determine_invariantness (); | |
| 2300 | |
| 2301 /* Execute store motion. Force the necessary invariants to be moved | |
| 2302 out of the loops as well. */ | |
| 2303 store_motion (); | |
| 2304 | |
| 2305 /* Move the expressions that are expensive enough. */ | |
| 2306 move_computations (); | |
| 2307 | |
| 2308 tree_ssa_lim_finalize (); | |
| 2309 } |