| 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 ("_"); |
| 1771 | lsm_tmp_name_add (name); |
| 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 | } |