| File: | build/gcc/store-motion.c |
| Warning: | line 682, column 12 Although the value stored to 'tmp' is used in the enclosing expression, the value is never actually read from 'tmp' |
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| 1 | /* Store motion via Lazy Code Motion on the reverse CFG. |
| 2 | Copyright (C) 1997-2021 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GCC. |
| 5 | |
| 6 | GCC is free software; you can redistribute it and/or modify it under |
| 7 | the terms of the GNU General Public License as published by the Free |
| 8 | Software Foundation; either version 3, or (at your option) any later |
| 9 | version. |
| 10 | |
| 11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
| 12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with GCC; see the file COPYING3. If not see |
| 18 | <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "config.h" |
| 21 | #include "system.h" |
| 22 | #include "coretypes.h" |
| 23 | #include "backend.h" |
| 24 | #include "rtl.h" |
| 25 | #include "tree.h" |
| 26 | #include "predict.h" |
| 27 | #include "df.h" |
| 28 | #include "toplev.h" |
| 29 | |
| 30 | #include "cfgrtl.h" |
| 31 | #include "cfganal.h" |
| 32 | #include "lcm.h" |
| 33 | #include "cfgcleanup.h" |
| 34 | #include "expr.h" |
| 35 | #include "tree-pass.h" |
| 36 | #include "dbgcnt.h" |
| 37 | #include "rtl-iter.h" |
| 38 | #include "print-rtl.h" |
| 39 | |
| 40 | /* This pass implements downward store motion. |
| 41 | As of May 1, 2009, the pass is not enabled by default on any target, |
| 42 | but bootstrap completes on ia64 and x86_64 with the pass enabled. */ |
| 43 | |
| 44 | /* TODO: |
| 45 | - remove_reachable_equiv_notes is an incomprehensible pile of goo and |
| 46 | a compile time hog that needs a rewrite (maybe cache st_exprs to |
| 47 | invalidate REG_EQUAL/REG_EQUIV notes for?). |
| 48 | - pattern_regs in st_expr should be a regset (on its own obstack). |
| 49 | - store_motion_mems should be a vec instead of a list. |
| 50 | - there should be an alloc pool for struct st_expr objects. |
| 51 | - investigate whether it is helpful to make the address of an st_expr |
| 52 | a cselib VALUE. |
| 53 | - when GIMPLE alias information is exported, the effectiveness of this |
| 54 | pass should be re-evaluated. |
| 55 | */ |
| 56 | |
| 57 | /* This is a list of store expressions (MEMs). The structure is used |
| 58 | as an expression table to track stores which look interesting, and |
| 59 | might be moveable towards the exit block. */ |
| 60 | |
| 61 | struct st_expr |
| 62 | { |
| 63 | /* Pattern of this mem. */ |
| 64 | rtx pattern; |
| 65 | /* List of registers mentioned by the mem. */ |
| 66 | vec<rtx> pattern_regs; |
| 67 | /* INSN list of stores that are locally anticipatable. */ |
| 68 | vec<rtx_insn *> antic_stores; |
| 69 | /* INSN list of stores that are locally available. */ |
| 70 | vec<rtx_insn *> avail_stores; |
| 71 | /* Next in the list. */ |
| 72 | struct st_expr * next; |
| 73 | /* Store ID in the dataflow bitmaps. */ |
| 74 | int index; |
| 75 | /* Hash value for the hash table. */ |
| 76 | unsigned int hash_index; |
| 77 | /* Register holding the stored expression when a store is moved. |
| 78 | This field is also used as a cache in find_moveable_store, see |
| 79 | LAST_AVAIL_CHECK_FAILURE below. */ |
| 80 | rtx reaching_reg; |
| 81 | }; |
| 82 | |
| 83 | /* Head of the list of load/store memory refs. */ |
| 84 | static struct st_expr * store_motion_mems = NULLnullptr; |
| 85 | |
| 86 | /* These bitmaps will hold the local dataflow properties per basic block. */ |
| 87 | static sbitmap *st_kill, *st_avloc, *st_antloc, *st_transp; |
| 88 | |
| 89 | /* Nonzero for expressions which should be inserted on a specific edge. */ |
| 90 | static sbitmap *st_insert_map; |
| 91 | |
| 92 | /* Nonzero for expressions which should be deleted in a specific block. */ |
| 93 | static sbitmap *st_delete_map; |
| 94 | |
| 95 | /* Global holding the number of store expressions we are dealing with. */ |
| 96 | static int num_stores; |
| 97 | |
| 98 | /* Contains the edge_list returned by pre_edge_lcm. */ |
| 99 | static struct edge_list *edge_list; |
| 100 | |
| 101 | /* Hashtable helpers. */ |
| 102 | |
| 103 | struct st_expr_hasher : nofree_ptr_hash <st_expr> |
| 104 | { |
| 105 | static inline hashval_t hash (const st_expr *); |
| 106 | static inline bool equal (const st_expr *, const st_expr *); |
| 107 | }; |
| 108 | |
| 109 | inline hashval_t |
| 110 | st_expr_hasher::hash (const st_expr *x) |
| 111 | { |
| 112 | int do_not_record_p = 0; |
| 113 | return hash_rtx (x->pattern, GET_MODE (x->pattern)((machine_mode) (x->pattern)->mode), &do_not_record_p, NULLnullptr, false); |
| 114 | } |
| 115 | |
| 116 | inline bool |
| 117 | st_expr_hasher::equal (const st_expr *ptr1, const st_expr *ptr2) |
| 118 | { |
| 119 | return exp_equiv_p (ptr1->pattern, ptr2->pattern, 0, true); |
| 120 | } |
| 121 | |
| 122 | /* Hashtable for the load/store memory refs. */ |
| 123 | static hash_table<st_expr_hasher> *store_motion_mems_table; |
| 124 | |
| 125 | /* This will search the st_expr list for a matching expression. If it |
| 126 | doesn't find one, we create one and initialize it. */ |
| 127 | |
| 128 | static struct st_expr * |
| 129 | st_expr_entry (rtx x) |
| 130 | { |
| 131 | int do_not_record_p = 0; |
| 132 | struct st_expr * ptr; |
| 133 | unsigned int hash; |
| 134 | st_expr **slot; |
| 135 | struct st_expr e; |
| 136 | |
| 137 | hash = hash_rtx (x, GET_MODE (x)((machine_mode) (x)->mode), &do_not_record_p, |
| 138 | NULLnullptr, /*have_reg_qty=*/false); |
| 139 | |
| 140 | e.pattern = x; |
| 141 | slot = store_motion_mems_table->find_slot_with_hash (&e, hash, INSERT); |
| 142 | if (*slot) |
| 143 | return *slot; |
| 144 | |
| 145 | ptr = XNEW (struct st_expr)((struct st_expr *) xmalloc (sizeof (struct st_expr))); |
| 146 | |
| 147 | ptr->next = store_motion_mems; |
| 148 | ptr->pattern = x; |
| 149 | ptr->pattern_regs.create (0); |
| 150 | ptr->antic_stores.create (0); |
| 151 | ptr->avail_stores.create (0); |
| 152 | ptr->reaching_reg = NULL_RTX(rtx) 0; |
| 153 | ptr->index = 0; |
| 154 | ptr->hash_index = hash; |
| 155 | store_motion_mems = ptr; |
| 156 | *slot = ptr; |
| 157 | |
| 158 | return ptr; |
| 159 | } |
| 160 | |
| 161 | /* Free up an individual st_expr entry. */ |
| 162 | |
| 163 | static void |
| 164 | free_st_expr_entry (struct st_expr * ptr) |
| 165 | { |
| 166 | ptr->antic_stores.release (); |
| 167 | ptr->avail_stores.release (); |
| 168 | ptr->pattern_regs.release (); |
| 169 | |
| 170 | free (ptr); |
| 171 | } |
| 172 | |
| 173 | /* Free up all memory associated with the st_expr list. */ |
| 174 | |
| 175 | static void |
| 176 | free_store_motion_mems (void) |
| 177 | { |
| 178 | delete store_motion_mems_table; |
| 179 | store_motion_mems_table = NULLnullptr; |
| 180 | |
| 181 | while (store_motion_mems) |
| 182 | { |
| 183 | struct st_expr * tmp = store_motion_mems; |
| 184 | store_motion_mems = store_motion_mems->next; |
| 185 | free_st_expr_entry (tmp); |
| 186 | } |
| 187 | store_motion_mems = NULLnullptr; |
| 188 | } |
| 189 | |
| 190 | /* Assign each element of the list of mems a monotonically increasing value. */ |
| 191 | |
| 192 | static int |
| 193 | enumerate_store_motion_mems (void) |
| 194 | { |
| 195 | struct st_expr * ptr; |
| 196 | int n = 0; |
| 197 | |
| 198 | for (ptr = store_motion_mems; ptr != NULLnullptr; ptr = ptr->next) |
| 199 | ptr->index = n++; |
| 200 | |
| 201 | return n; |
| 202 | } |
| 203 | |
| 204 | /* Return first item in the list. */ |
| 205 | |
| 206 | static inline struct st_expr * |
| 207 | first_st_expr (void) |
| 208 | { |
| 209 | return store_motion_mems; |
| 210 | } |
| 211 | |
| 212 | /* Return the next item in the list after the specified one. */ |
| 213 | |
| 214 | static inline struct st_expr * |
| 215 | next_st_expr (struct st_expr * ptr) |
| 216 | { |
| 217 | return ptr->next; |
| 218 | } |
| 219 | |
| 220 | /* Dump debugging info about the store_motion_mems list. */ |
| 221 | |
| 222 | static void |
| 223 | print_store_motion_mems (FILE * file) |
| 224 | { |
| 225 | struct st_expr * ptr; |
| 226 | |
| 227 | fprintf (dump_file, "STORE_MOTION list of MEM exprs considered:\n"); |
| 228 | |
| 229 | for (ptr = first_st_expr (); ptr != NULLnullptr; ptr = next_st_expr (ptr)) |
| 230 | { |
| 231 | fprintf (file, " Pattern (%3d): ", ptr->index); |
| 232 | |
| 233 | print_rtl (file, ptr->pattern); |
| 234 | |
| 235 | fprintf (file, "\n ANTIC stores : "); |
| 236 | print_rtx_insn_vec (file, ptr->antic_stores); |
| 237 | |
| 238 | fprintf (file, "\n AVAIL stores : "); |
| 239 | |
| 240 | print_rtx_insn_vec (file, ptr->avail_stores); |
| 241 | |
| 242 | fprintf (file, "\n\n"); |
| 243 | } |
| 244 | |
| 245 | fprintf (file, "\n"); |
| 246 | } |
| 247 | |
| 248 | /* Return zero if some of the registers in list X are killed |
| 249 | due to set of registers in bitmap REGS_SET. */ |
| 250 | |
| 251 | static bool |
| 252 | store_ops_ok (const vec<rtx> &x, int *regs_set) |
| 253 | { |
| 254 | unsigned int i; |
| 255 | rtx temp; |
| 256 | FOR_EACH_VEC_ELT (x, i, temp)for (i = 0; (x).iterate ((i), &(temp)); ++(i)) |
| 257 | if (regs_set[REGNO (temp)(rhs_regno(temp))]) |
| 258 | return false; |
| 259 | |
| 260 | return true; |
| 261 | } |
| 262 | |
| 263 | /* Returns a list of registers mentioned in X. |
| 264 | FIXME: A regset would be prettier and less expensive. */ |
| 265 | |
| 266 | static void |
| 267 | extract_mentioned_regs (rtx x, vec<rtx> *mentioned_regs) |
| 268 | { |
| 269 | subrtx_var_iterator::array_type array; |
| 270 | FOR_EACH_SUBRTX_VAR (iter, array, x, NONCONST)for (subrtx_var_iterator iter (array, x, rtx_nonconst_subrtx_bounds ); !iter.at_end (); iter.next ()) |
| 271 | { |
| 272 | rtx x = *iter; |
| 273 | if (REG_P (x)(((enum rtx_code) (x)->code) == REG)) |
| 274 | mentioned_regs->safe_push (x); |
| 275 | } |
| 276 | } |
| 277 | |
| 278 | /* Check to see if the load X is aliased with STORE_PATTERN. |
| 279 | AFTER is true if we are checking the case when STORE_PATTERN occurs |
| 280 | after the X. */ |
| 281 | |
| 282 | static bool |
| 283 | load_kills_store (const_rtx x, const_rtx store_pattern, int after) |
| 284 | { |
| 285 | if (after) |
| 286 | return anti_dependence (x, store_pattern); |
| 287 | else |
| 288 | return true_dependence (store_pattern, GET_MODE (store_pattern)((machine_mode) (store_pattern)->mode), x); |
| 289 | } |
| 290 | |
| 291 | /* Go through the entire rtx X, looking for any loads which might alias |
| 292 | STORE_PATTERN. Return true if found. |
| 293 | AFTER is true if we are checking the case when STORE_PATTERN occurs |
| 294 | after the insn X. */ |
| 295 | |
| 296 | static bool |
| 297 | find_loads (const_rtx x, const_rtx store_pattern, int after) |
| 298 | { |
| 299 | const char * fmt; |
| 300 | int i, j; |
| 301 | int ret = false; |
| 302 | |
| 303 | if (!x) |
| 304 | return false; |
| 305 | |
| 306 | if (GET_CODE (x)((enum rtx_code) (x)->code) == SET) |
| 307 | x = SET_SRC (x)(((x)->u.fld[1]).rt_rtx); |
| 308 | |
| 309 | if (MEM_P (x)(((enum rtx_code) (x)->code) == MEM)) |
| 310 | { |
| 311 | if (load_kills_store (x, store_pattern, after)) |
| 312 | return true; |
| 313 | } |
| 314 | |
| 315 | /* Recursively process the insn. */ |
| 316 | fmt = GET_RTX_FORMAT (GET_CODE (x))(rtx_format[(int) (((enum rtx_code) (x)->code))]); |
| 317 | |
| 318 | for (i = GET_RTX_LENGTH (GET_CODE (x))(rtx_length[(int) (((enum rtx_code) (x)->code))]) - 1; i >= 0 && !ret; i--) |
| 319 | { |
| 320 | if (fmt[i] == 'e') |
| 321 | ret |= find_loads (XEXP (x, i)(((x)->u.fld[i]).rt_rtx), store_pattern, after); |
| 322 | else if (fmt[i] == 'E') |
| 323 | for (j = XVECLEN (x, i)(((((x)->u.fld[i]).rt_rtvec))->num_elem) - 1; j >= 0; j--) |
| 324 | ret |= find_loads (XVECEXP (x, i, j)(((((x)->u.fld[i]).rt_rtvec))->elem[j]), store_pattern, after); |
| 325 | } |
| 326 | return ret; |
| 327 | } |
| 328 | |
| 329 | /* Go through pattern PAT looking for any loads which might kill the |
| 330 | store in X. Return true if found. |
| 331 | AFTER is true if we are checking the case when loads kill X occurs |
| 332 | after the insn for PAT. */ |
| 333 | |
| 334 | static inline bool |
| 335 | store_killed_in_pat (const_rtx x, const_rtx pat, int after) |
| 336 | { |
| 337 | if (GET_CODE (pat)((enum rtx_code) (pat)->code) == SET) |
| 338 | { |
| 339 | rtx dest = SET_DEST (pat)(((pat)->u.fld[0]).rt_rtx); |
| 340 | |
| 341 | if (GET_CODE (dest)((enum rtx_code) (dest)->code) == ZERO_EXTRACT) |
| 342 | dest = XEXP (dest, 0)(((dest)->u.fld[0]).rt_rtx); |
| 343 | |
| 344 | /* Check for memory stores to aliased objects. */ |
| 345 | if (MEM_P (dest)(((enum rtx_code) (dest)->code) == MEM) |
| 346 | && !exp_equiv_p (dest, x, 0, true)) |
| 347 | { |
| 348 | if (after) |
| 349 | { |
| 350 | if (output_dependence (dest, x)) |
| 351 | return true; |
| 352 | } |
| 353 | else |
| 354 | { |
| 355 | if (output_dependence (x, dest)) |
| 356 | return true; |
| 357 | } |
| 358 | } |
| 359 | } |
| 360 | |
| 361 | if (find_loads (pat, x, after)) |
| 362 | return true; |
| 363 | |
| 364 | return false; |
| 365 | } |
| 366 | |
| 367 | /* Check if INSN kills the store pattern X (is aliased with it). |
| 368 | AFTER is true if we are checking the case when store X occurs |
| 369 | after the insn. Return true if it does. */ |
| 370 | |
| 371 | static bool |
| 372 | store_killed_in_insn (const_rtx x, const vec<rtx> &x_regs, |
| 373 | const rtx_insn *insn, int after) |
| 374 | { |
| 375 | const_rtx note, pat; |
| 376 | |
| 377 | if (! NONDEBUG_INSN_P (insn)((((enum rtx_code) (insn)->code) == INSN) || (((enum rtx_code ) (insn)->code) == JUMP_INSN) || (((enum rtx_code) (insn)-> code) == CALL_INSN))) |
| 378 | return false; |
| 379 | |
| 380 | if (CALL_P (insn)(((enum rtx_code) (insn)->code) == CALL_INSN)) |
| 381 | { |
| 382 | /* A normal or pure call might read from pattern, |
| 383 | but a const call will not. */ |
| 384 | if (!RTL_CONST_CALL_P (insn)(__extension__ ({ __typeof ((insn)) const _rtx = ((insn)); if (((enum rtx_code) (_rtx)->code) != CALL_INSN) rtl_check_failed_flag ("RTL_CONST_CALL_P", _rtx, "/home/marxin/BIG/buildbot/buildworker/marxinbox-gcc-clang-static-analyzer/build/gcc/store-motion.c" , 384, __FUNCTION__); _rtx; })->unchanging)) |
| 385 | return true; |
| 386 | |
| 387 | /* But even a const call reads its parameters. Check whether the |
| 388 | base of some of registers used in mem is stack pointer. */ |
| 389 | rtx temp; |
| 390 | unsigned int i; |
| 391 | FOR_EACH_VEC_ELT (x_regs, i, temp)for (i = 0; (x_regs).iterate ((i), &(temp)); ++(i)) |
| 392 | if (may_be_sp_based_p (temp)) |
| 393 | return true; |
| 394 | |
| 395 | return false; |
| 396 | } |
| 397 | |
| 398 | pat = PATTERN (insn); |
| 399 | if (GET_CODE (pat)((enum rtx_code) (pat)->code) == SET) |
| 400 | { |
| 401 | if (store_killed_in_pat (x, pat, after)) |
| 402 | return true; |
| 403 | } |
| 404 | else if (GET_CODE (pat)((enum rtx_code) (pat)->code) == PARALLEL) |
| 405 | { |
| 406 | int i; |
| 407 | |
| 408 | for (i = 0; i < XVECLEN (pat, 0)(((((pat)->u.fld[0]).rt_rtvec))->num_elem); i++) |
| 409 | if (store_killed_in_pat (x, XVECEXP (pat, 0, i)(((((pat)->u.fld[0]).rt_rtvec))->elem[i]), after)) |
| 410 | return true; |
| 411 | } |
| 412 | else if (find_loads (PATTERN (insn), x, after)) |
| 413 | return true; |
| 414 | |
| 415 | /* If this insn has a REG_EQUAL or REG_EQUIV note referencing a memory |
| 416 | location aliased with X, then this insn kills X. */ |
| 417 | note = find_reg_equal_equiv_note (insn); |
| 418 | if (! note) |
| 419 | return false; |
| 420 | note = XEXP (note, 0)(((note)->u.fld[0]).rt_rtx); |
| 421 | |
| 422 | /* However, if the note represents a must alias rather than a may |
| 423 | alias relationship, then it does not kill X. */ |
| 424 | if (exp_equiv_p (note, x, 0, true)) |
| 425 | return false; |
| 426 | |
| 427 | /* See if there are any aliased loads in the note. */ |
| 428 | return find_loads (note, x, after); |
| 429 | } |
| 430 | |
| 431 | /* Returns true if the expression X is loaded or clobbered on or after INSN |
| 432 | within basic block BB. REGS_SET_AFTER is bitmap of registers set in |
| 433 | or after the insn. X_REGS is list of registers mentioned in X. If the store |
| 434 | is killed, return the last insn in that it occurs in FAIL_INSN. */ |
| 435 | |
| 436 | static bool |
| 437 | store_killed_after (const_rtx x, const vec<rtx> &x_regs, |
| 438 | const rtx_insn *insn, const_basic_block bb, |
| 439 | int *regs_set_after, rtx *fail_insn) |
| 440 | { |
| 441 | rtx_insn *last = BB_END (bb)(bb)->il.x.rtl->end_, *act; |
| 442 | |
| 443 | if (!store_ops_ok (x_regs, regs_set_after)) |
| 444 | { |
| 445 | /* We do not know where it will happen. */ |
| 446 | if (fail_insn) |
| 447 | *fail_insn = NULL_RTX(rtx) 0; |
| 448 | return true; |
| 449 | } |
| 450 | |
| 451 | /* Scan from the end, so that fail_insn is determined correctly. */ |
| 452 | for (act = last; act != PREV_INSN (insn); act = PREV_INSN (act)) |
| 453 | if (store_killed_in_insn (x, x_regs, act, false)) |
| 454 | { |
| 455 | if (fail_insn) |
| 456 | *fail_insn = act; |
| 457 | return true; |
| 458 | } |
| 459 | |
| 460 | return false; |
| 461 | } |
| 462 | |
| 463 | /* Returns true if the expression X is loaded or clobbered on or before INSN |
| 464 | within basic block BB. X_REGS is list of registers mentioned in X. |
| 465 | REGS_SET_BEFORE is bitmap of registers set before or in this insn. */ |
| 466 | static bool |
| 467 | store_killed_before (const_rtx x, const vec<rtx> &x_regs, |
| 468 | const rtx_insn *insn, const_basic_block bb, |
| 469 | int *regs_set_before) |
| 470 | { |
| 471 | rtx_insn *first = BB_HEAD (bb)(bb)->il.x.head_; |
| 472 | |
| 473 | if (!store_ops_ok (x_regs, regs_set_before)) |
| 474 | return true; |
| 475 | |
| 476 | for ( ; insn != PREV_INSN (first); insn = PREV_INSN (insn)) |
| 477 | if (store_killed_in_insn (x, x_regs, insn, true)) |
| 478 | return true; |
| 479 | |
| 480 | return false; |
| 481 | } |
| 482 | |
| 483 | /* The last insn in the basic block that compute_store_table is processing, |
| 484 | where store_killed_after is true for X. |
| 485 | Since we go through the basic block from BB_END to BB_HEAD, this is |
| 486 | also the available store at the end of the basic block. Therefore |
| 487 | this is in effect a cache, to avoid calling store_killed_after for |
| 488 | equivalent aliasing store expressions. |
| 489 | This value is only meaningful during the computation of the store |
| 490 | table. We hi-jack the REACHING_REG field of struct st_expr to save |
| 491 | a bit of memory. */ |
| 492 | #define LAST_AVAIL_CHECK_FAILURE(x) ((x)->reaching_reg) |
| 493 | |
| 494 | /* Determine whether INSN is MEM store pattern that we will consider moving. |
| 495 | REGS_SET_BEFORE is bitmap of registers set before (and including) the |
| 496 | current insn, REGS_SET_AFTER is bitmap of registers set after (and |
| 497 | including) the insn in this basic block. We must be passing through BB from |
| 498 | head to end, as we are using this fact to speed things up. |
| 499 | |
| 500 | The results are stored this way: |
| 501 | |
| 502 | -- the first anticipatable expression is added into ANTIC_STORES |
| 503 | -- if the processed expression is not anticipatable, NULL_RTX is added |
| 504 | there instead, so that we can use it as indicator that no further |
| 505 | expression of this type may be anticipatable |
| 506 | -- if the expression is available, it is added as head of AVAIL_STORES; |
| 507 | consequently, all of them but this head are dead and may be deleted. |
| 508 | -- if the expression is not available, the insn due to that it fails to be |
| 509 | available is stored in REACHING_REG (via LAST_AVAIL_CHECK_FAILURE). |
| 510 | |
| 511 | The things are complicated a bit by fact that there already may be stores |
| 512 | to the same MEM from other blocks; also caller must take care of the |
| 513 | necessary cleanup of the temporary markers after end of the basic block. |
| 514 | */ |
| 515 | |
| 516 | static void |
| 517 | find_moveable_store (rtx_insn *insn, int *regs_set_before, int *regs_set_after) |
| 518 | { |
| 519 | struct st_expr * ptr; |
| 520 | rtx dest, set; |
| 521 | int check_anticipatable, check_available; |
| 522 | basic_block bb = BLOCK_FOR_INSN (insn); |
| 523 | |
| 524 | set = single_set (insn); |
| 525 | if (!set) |
| 526 | return; |
| 527 | |
| 528 | dest = SET_DEST (set)(((set)->u.fld[0]).rt_rtx); |
| 529 | |
| 530 | if (! MEM_P (dest)(((enum rtx_code) (dest)->code) == MEM) || MEM_VOLATILE_P (dest)(__extension__ ({ __typeof ((dest)) const _rtx = ((dest)); if (((enum rtx_code) (_rtx)->code) != MEM && ((enum rtx_code ) (_rtx)->code) != ASM_OPERANDS && ((enum rtx_code ) (_rtx)->code) != ASM_INPUT) rtl_check_failed_flag ("MEM_VOLATILE_P" , _rtx, "/home/marxin/BIG/buildbot/buildworker/marxinbox-gcc-clang-static-analyzer/build/gcc/store-motion.c" , 530, __FUNCTION__); _rtx; })->volatil) |
| 531 | || GET_MODE (dest)((machine_mode) (dest)->mode) == BLKmode((void) 0, E_BLKmode)) |
| 532 | return; |
| 533 | |
| 534 | if (side_effects_p (dest)) |
| 535 | return; |
| 536 | |
| 537 | /* If we are handling exceptions, we must be careful with memory references |
| 538 | that may trap. If we are not, the behavior is undefined, so we may just |
| 539 | continue. */ |
| 540 | if (cfun(cfun + 0)->can_throw_non_call_exceptions && may_trap_p (dest)) |
| 541 | return; |
| 542 | |
| 543 | /* Even if the destination cannot trap, the source may. In this case we'd |
| 544 | need to handle updating the REG_EH_REGION note. */ |
| 545 | if (find_reg_note (insn, REG_EH_REGION, NULL_RTX(rtx) 0)) |
| 546 | return; |
| 547 | |
| 548 | /* Make sure that the SET_SRC of this store insns can be assigned to |
| 549 | a register, or we will fail later on in replace_store_insn, which |
| 550 | assumes that we can do this. But sometimes the target machine has |
| 551 | oddities like MEM read-modify-write instruction. See for example |
| 552 | PR24257. */ |
| 553 | if (!can_assign_to_reg_without_clobbers_p (SET_SRC (set)(((set)->u.fld[1]).rt_rtx), |
| 554 | GET_MODE (SET_SRC (set))((machine_mode) ((((set)->u.fld[1]).rt_rtx))->mode))) |
| 555 | return; |
| 556 | |
| 557 | ptr = st_expr_entry (dest); |
| 558 | if (ptr->pattern_regs.is_empty ()) |
| 559 | extract_mentioned_regs (dest, &ptr->pattern_regs); |
| 560 | |
| 561 | /* Do not check for anticipatability if we either found one anticipatable |
| 562 | store already, or tested for one and found out that it was killed. */ |
| 563 | check_anticipatable = 0; |
| 564 | if (ptr->antic_stores.is_empty ()) |
| 565 | check_anticipatable = 1; |
| 566 | else |
| 567 | { |
| 568 | rtx_insn *tmp = ptr->antic_stores.last (); |
| 569 | if (tmp != NULL_RTX(rtx) 0 |
| 570 | && BLOCK_FOR_INSN (tmp) != bb) |
| 571 | check_anticipatable = 1; |
| 572 | } |
| 573 | if (check_anticipatable) |
| 574 | { |
| 575 | rtx_insn *tmp; |
| 576 | if (store_killed_before (dest, ptr->pattern_regs, insn, bb, regs_set_before)) |
| 577 | tmp = NULLnullptr; |
| 578 | else |
| 579 | tmp = insn; |
| 580 | ptr->antic_stores.safe_push (tmp); |
| 581 | } |
| 582 | |
| 583 | /* It is not necessary to check whether store is available if we did |
| 584 | it successfully before; if we failed before, do not bother to check |
| 585 | until we reach the insn that caused us to fail. */ |
| 586 | check_available = 0; |
| 587 | if (ptr->avail_stores.is_empty ()) |
| 588 | check_available = 1; |
| 589 | else |
| 590 | { |
| 591 | rtx_insn *tmp = ptr->avail_stores.last (); |
| 592 | if (BLOCK_FOR_INSN (tmp) != bb) |
| 593 | check_available = 1; |
| 594 | } |
| 595 | if (check_available) |
| 596 | { |
| 597 | /* Check that we have already reached the insn at that the check |
| 598 | failed last time. */ |
| 599 | if (LAST_AVAIL_CHECK_FAILURE (ptr)) |
| 600 | { |
| 601 | rtx_insn *tmp; |
| 602 | for (tmp = BB_END (bb)(bb)->il.x.rtl->end_; |
| 603 | tmp != insn && tmp != LAST_AVAIL_CHECK_FAILURE (ptr); |
| 604 | tmp = PREV_INSN (tmp)) |
| 605 | continue; |
| 606 | if (tmp == insn) |
| 607 | check_available = 0; |
| 608 | } |
| 609 | else |
| 610 | check_available = store_killed_after (dest, ptr->pattern_regs, insn, |
| 611 | bb, regs_set_after, |
| 612 | &LAST_AVAIL_CHECK_FAILURE (ptr)); |
| 613 | } |
| 614 | if (!check_available) |
| 615 | ptr->avail_stores.safe_push (insn); |
| 616 | } |
| 617 | |
| 618 | /* Find available and anticipatable stores. */ |
| 619 | |
| 620 | static int |
| 621 | compute_store_table (void) |
| 622 | { |
| 623 | int ret; |
| 624 | basic_block bb; |
| 625 | rtx_insn *insn; |
| 626 | rtx_insn *tmp; |
| 627 | df_ref def; |
| 628 | int *last_set_in, *already_set; |
| 629 | struct st_expr * ptr, **prev_next_ptr_ptr; |
| 630 | unsigned int max_gcse_regno = max_reg_num (); |
| 631 | |
| 632 | store_motion_mems = NULLnullptr; |
| 633 | store_motion_mems_table = new hash_table<st_expr_hasher> (13); |
| 634 | last_set_in = XCNEWVEC (int, max_gcse_regno)((int *) xcalloc ((max_gcse_regno), sizeof (int))); |
| 635 | already_set = XNEWVEC (int, max_gcse_regno)((int *) xmalloc (sizeof (int) * (max_gcse_regno))); |
| 636 | |
| 637 | /* Find all the stores we care about. */ |
| 638 | FOR_EACH_BB_FN (bb, cfun)for (bb = ((cfun + 0))->cfg->x_entry_block_ptr->next_bb ; bb != ((cfun + 0))->cfg->x_exit_block_ptr; bb = bb-> next_bb) |
| 639 | { |
| 640 | /* First compute the registers set in this block. */ |
| 641 | FOR_BB_INSNS (bb, insn)for ((insn) = (bb)->il.x.head_; (insn) && (insn) != NEXT_INSN ((bb)->il.x.rtl->end_); (insn) = NEXT_INSN ( insn)) |
| 642 | { |
| 643 | |
| 644 | if (! NONDEBUG_INSN_P (insn)((((enum rtx_code) (insn)->code) == INSN) || (((enum rtx_code ) (insn)->code) == JUMP_INSN) || (((enum rtx_code) (insn)-> code) == CALL_INSN))) |
| 645 | continue; |
| 646 | |
| 647 | FOR_EACH_INSN_DEF (def, insn)for (def = (((df->insns[(INSN_UID (insn))]))->defs); def ; def = ((def)->base.next_loc)) |
| 648 | last_set_in[DF_REF_REGNO (def)((def)->base.regno)] = INSN_UID (insn); |
| 649 | } |
| 650 | |
| 651 | /* Now find the stores. */ |
| 652 | memset (already_set, 0, sizeof (int) * max_gcse_regno); |
| 653 | FOR_BB_INSNS (bb, insn)for ((insn) = (bb)->il.x.head_; (insn) && (insn) != NEXT_INSN ((bb)->il.x.rtl->end_); (insn) = NEXT_INSN ( insn)) |
| 654 | { |
| 655 | if (! NONDEBUG_INSN_P (insn)((((enum rtx_code) (insn)->code) == INSN) || (((enum rtx_code ) (insn)->code) == JUMP_INSN) || (((enum rtx_code) (insn)-> code) == CALL_INSN))) |
| 656 | continue; |
| 657 | |
| 658 | FOR_EACH_INSN_DEF (def, insn)for (def = (((df->insns[(INSN_UID (insn))]))->defs); def ; def = ((def)->base.next_loc)) |
| 659 | already_set[DF_REF_REGNO (def)((def)->base.regno)] = INSN_UID (insn); |
| 660 | |
| 661 | /* Now that we've marked regs, look for stores. */ |
| 662 | find_moveable_store (insn, already_set, last_set_in); |
| 663 | |
| 664 | /* Unmark regs that are no longer set. */ |
| 665 | FOR_EACH_INSN_DEF (def, insn)for (def = (((df->insns[(INSN_UID (insn))]))->defs); def ; def = ((def)->base.next_loc)) |
| 666 | if (last_set_in[DF_REF_REGNO (def)((def)->base.regno)] == INSN_UID (insn)) |
| 667 | last_set_in[DF_REF_REGNO (def)((def)->base.regno)] = 0; |
| 668 | } |
| 669 | |
| 670 | if (flag_checkingglobal_options.x_flag_checking) |
| 671 | { |
| 672 | /* last_set_in should now be all-zero. */ |
| 673 | for (unsigned regno = 0; regno < max_gcse_regno; regno++) |
| 674 | gcc_assert (!last_set_in[regno])((void)(!(!last_set_in[regno]) ? fancy_abort ("/home/marxin/BIG/buildbot/buildworker/marxinbox-gcc-clang-static-analyzer/build/gcc/store-motion.c" , 674, __FUNCTION__), 0 : 0)); |
| 675 | } |
| 676 | |
| 677 | /* Clear temporary marks. */ |
| 678 | for (ptr = first_st_expr (); ptr != NULLnullptr; ptr = next_st_expr (ptr)) |
| 679 | { |
| 680 | LAST_AVAIL_CHECK_FAILURE (ptr) = NULL_RTX(rtx) 0; |
| 681 | if (!ptr->antic_stores.is_empty () |
| 682 | && (tmp = ptr->antic_stores.last ()) == NULLnullptr) |
Although the value stored to 'tmp' is used in the enclosing expression, the value is never actually read from 'tmp' | |
| 683 | ptr->antic_stores.pop (); |
| 684 | } |
| 685 | } |
| 686 | |
| 687 | /* Remove the stores that are not available anywhere, as there will |
| 688 | be no opportunity to optimize them. */ |
| 689 | for (ptr = store_motion_mems, prev_next_ptr_ptr = &store_motion_mems; |
| 690 | ptr != NULLnullptr; |
| 691 | ptr = *prev_next_ptr_ptr) |
| 692 | { |
| 693 | if (ptr->avail_stores.is_empty ()) |
| 694 | { |
| 695 | *prev_next_ptr_ptr = ptr->next; |
| 696 | store_motion_mems_table->remove_elt_with_hash (ptr, ptr->hash_index); |
| 697 | free_st_expr_entry (ptr); |
| 698 | } |
| 699 | else |
| 700 | prev_next_ptr_ptr = &ptr->next; |
| 701 | } |
| 702 | |
| 703 | ret = enumerate_store_motion_mems (); |
| 704 | |
| 705 | if (dump_file) |
| 706 | print_store_motion_mems (dump_file); |
| 707 | |
| 708 | free (last_set_in); |
| 709 | free (already_set); |
| 710 | return ret; |
| 711 | } |
| 712 | |
| 713 | /* In all code following after this, REACHING_REG has its original |
| 714 | meaning again. Avoid confusion, and undef the accessor macro for |
| 715 | the temporary marks usage in compute_store_table. */ |
| 716 | #undef LAST_AVAIL_CHECK_FAILURE |
| 717 | |
| 718 | /* Insert an instruction at the beginning of a basic block, and update |
| 719 | the BB_HEAD if needed. */ |
| 720 | |
| 721 | static void |
| 722 | insert_insn_start_basic_block (rtx_insn *insn, basic_block bb) |
| 723 | { |
| 724 | /* Insert at start of successor block. */ |
| 725 | rtx_insn *prev = PREV_INSN (BB_HEAD (bb)(bb)->il.x.head_); |
| 726 | rtx_insn *before = BB_HEAD (bb)(bb)->il.x.head_; |
| 727 | while (before != 0) |
| 728 | { |
| 729 | if (! LABEL_P (before)(((enum rtx_code) (before)->code) == CODE_LABEL) |
| 730 | && !NOTE_INSN_BASIC_BLOCK_P (before)((((enum rtx_code) (before)->code) == NOTE) && ((( before)->u.fld[4]).rt_int) == NOTE_INSN_BASIC_BLOCK)) |
| 731 | break; |
| 732 | prev = before; |
| 733 | if (prev == BB_END (bb)(bb)->il.x.rtl->end_) |
| 734 | break; |
| 735 | before = NEXT_INSN (before); |
| 736 | } |
| 737 | |
| 738 | insn = emit_insn_after_noloc (insn, prev, bb); |
| 739 | |
| 740 | if (dump_file) |
| 741 | { |
| 742 | fprintf (dump_file, "STORE_MOTION insert store at start of BB %d:\n", |
| 743 | bb->index); |
| 744 | print_inline_rtx (dump_file, insn, 6); |
| 745 | fprintf (dump_file, "\n"); |
| 746 | } |
| 747 | } |
| 748 | |
| 749 | /* This routine will insert a store on an edge. EXPR is the st_expr entry for |
| 750 | the memory reference, and E is the edge to insert it on. Returns nonzero |
| 751 | if an edge insertion was performed. */ |
| 752 | |
| 753 | static int |
| 754 | insert_store (struct st_expr * expr, edge e) |
| 755 | { |
| 756 | rtx reg; |
| 757 | rtx_insn *insn; |
| 758 | basic_block bb; |
| 759 | edge tmp; |
| 760 | edge_iterator ei; |
| 761 | |
| 762 | /* We did all the deleted before this insert, so if we didn't delete a |
| 763 | store, then we haven't set the reaching reg yet either. */ |
| 764 | if (expr->reaching_reg == NULL_RTX(rtx) 0) |
| 765 | return 0; |
| 766 | |
| 767 | if (e->flags & EDGE_FAKE) |
| 768 | return 0; |
| 769 | |
| 770 | reg = expr->reaching_reg; |
| 771 | insn = gen_move_insn (copy_rtx (expr->pattern), reg); |
| 772 | |
| 773 | /* If we are inserting this expression on ALL predecessor edges of a BB, |
| 774 | insert it at the start of the BB, and reset the insert bits on the other |
| 775 | edges so we don't try to insert it on the other edges. */ |
| 776 | bb = e->dest; |
| 777 | FOR_EACH_EDGE (tmp, ei, e->dest->preds)for ((ei) = ei_start_1 (&((e->dest->preds))); ei_cond ((ei), &(tmp)); ei_next (&(ei))) |
| 778 | if (!(tmp->flags & EDGE_FAKE)) |
| 779 | { |
| 780 | int index = EDGE_INDEX (edge_list, tmp->src, tmp->dest)(find_edge_index ((edge_list), (tmp->src), (tmp->dest)) ); |
| 781 | |
| 782 | gcc_assert (index != EDGE_INDEX_NO_EDGE)((void)(!(index != -1) ? fancy_abort ("/home/marxin/BIG/buildbot/buildworker/marxinbox-gcc-clang-static-analyzer/build/gcc/store-motion.c" , 782, __FUNCTION__), 0 : 0)); |
| 783 | if (! bitmap_bit_p (st_insert_map[index], expr->index)) |
| 784 | break; |
| 785 | } |
| 786 | |
| 787 | /* If tmp is NULL, we found an insertion on every edge, blank the |
| 788 | insertion vector for these edges, and insert at the start of the BB. */ |
| 789 | if (!tmp && bb != EXIT_BLOCK_PTR_FOR_FN (cfun)(((cfun + 0))->cfg->x_exit_block_ptr)) |
| 790 | { |
| 791 | FOR_EACH_EDGE (tmp, ei, e->dest->preds)for ((ei) = ei_start_1 (&((e->dest->preds))); ei_cond ((ei), &(tmp)); ei_next (&(ei))) |
| 792 | { |
| 793 | int index = EDGE_INDEX (edge_list, tmp->src, tmp->dest)(find_edge_index ((edge_list), (tmp->src), (tmp->dest)) ); |
| 794 | bitmap_clear_bit (st_insert_map[index], expr->index); |
| 795 | } |
| 796 | insert_insn_start_basic_block (insn, bb); |
| 797 | return 0; |
| 798 | } |
| 799 | |
| 800 | /* We can't put stores in the front of blocks pointed to by abnormal |
| 801 | edges since that may put a store where one didn't used to be. */ |
| 802 | gcc_assert (!(e->flags & EDGE_ABNORMAL))((void)(!(!(e->flags & EDGE_ABNORMAL)) ? fancy_abort ( "/home/marxin/BIG/buildbot/buildworker/marxinbox-gcc-clang-static-analyzer/build/gcc/store-motion.c" , 802, __FUNCTION__), 0 : 0)); |
| 803 | |
| 804 | insert_insn_on_edge (insn, e); |
| 805 | |
| 806 | if (dump_file) |
| 807 | { |
| 808 | fprintf (dump_file, "STORE_MOTION insert insn on edge (%d, %d):\n", |
| 809 | e->src->index, e->dest->index); |
| 810 | print_inline_rtx (dump_file, insn, 6); |
| 811 | fprintf (dump_file, "\n"); |
| 812 | } |
| 813 | |
| 814 | return 1; |
| 815 | } |
| 816 | |
| 817 | /* Remove any REG_EQUAL or REG_EQUIV notes containing a reference to the |
| 818 | memory location in SMEXPR set in basic block BB. |
| 819 | |
| 820 | This could be rather expensive. */ |
| 821 | |
| 822 | static void |
| 823 | remove_reachable_equiv_notes (basic_block bb, struct st_expr *smexpr) |
| 824 | { |
| 825 | edge_iterator *stack, ei; |
| 826 | int sp; |
| 827 | edge act; |
| 828 | auto_sbitmap visited (last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block)); |
| 829 | rtx note; |
| 830 | rtx_insn *insn; |
| 831 | rtx mem = smexpr->pattern; |
| 832 | |
| 833 | stack = XNEWVEC (edge_iterator, n_basic_blocks_for_fn (cfun))((edge_iterator *) xmalloc (sizeof (edge_iterator) * ((((cfun + 0))->cfg->x_n_basic_blocks)))); |
| 834 | sp = 0; |
| 835 | ei = ei_start (bb->succs)ei_start_1 (&(bb->succs)); |
| 836 | |
| 837 | bitmap_clear (visited); |
| 838 | |
| 839 | act = (EDGE_COUNT (ei_container (ei))vec_safe_length (ei_container (ei)) |
| 840 | ? EDGE_I (ei_container (ei), 0)(*ei_container (ei))[(0)] |
| 841 | : NULLnullptr); |
| 842 | for (;;) |
| 843 | { |
| 844 | if (!act) |
| 845 | { |
| 846 | if (!sp) |
| 847 | { |
| 848 | free (stack); |
| 849 | return; |
| 850 | } |
| 851 | act = ei_edge (stack[--sp]); |
| 852 | } |
| 853 | bb = act->dest; |
| 854 | |
| 855 | if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun)(((cfun + 0))->cfg->x_exit_block_ptr) |
| 856 | || bitmap_bit_p (visited, bb->index)) |
| 857 | { |
| 858 | if (!ei_end_p (ei)) |
| 859 | ei_next (&ei); |
| 860 | act = (! ei_end_p (ei)) ? ei_edge (ei) : NULLnullptr; |
| 861 | continue; |
| 862 | } |
| 863 | bitmap_set_bit (visited, bb->index); |
| 864 | |
| 865 | rtx_insn *last; |
| 866 | if (bitmap_bit_p (st_antloc[bb->index], smexpr->index)) |
| 867 | { |
| 868 | unsigned int i; |
| 869 | FOR_EACH_VEC_ELT_REVERSE (smexpr->antic_stores, i, last)for (i = (smexpr->antic_stores).length () - 1; (smexpr-> antic_stores).iterate ((i), &(last)); (i)--) |
| 870 | if (BLOCK_FOR_INSN (last) == bb) |
| 871 | break; |
| 872 | } |
| 873 | else |
| 874 | last = NEXT_INSN (BB_END (bb)(bb)->il.x.rtl->end_); |
| 875 | |
| 876 | for (insn = BB_HEAD (bb)(bb)->il.x.head_; insn != last; insn = NEXT_INSN (insn)) |
| 877 | if (NONDEBUG_INSN_P (insn)((((enum rtx_code) (insn)->code) == INSN) || (((enum rtx_code ) (insn)->code) == JUMP_INSN) || (((enum rtx_code) (insn)-> code) == CALL_INSN))) |
| 878 | { |
| 879 | note = find_reg_equal_equiv_note (insn); |
| 880 | if (!note || !exp_equiv_p (XEXP (note, 0)(((note)->u.fld[0]).rt_rtx), mem, 0, true)) |
| 881 | continue; |
| 882 | |
| 883 | if (dump_file) |
| 884 | fprintf (dump_file, |
| 885 | "STORE_MOTION drop REG_EQUAL note at insn %d:\n", |
| 886 | INSN_UID (insn)); |
| 887 | remove_note (insn, note); |
| 888 | } |
| 889 | |
| 890 | if (!ei_end_p (ei)) |
| 891 | ei_next (&ei); |
| 892 | act = (! ei_end_p (ei)) ? ei_edge (ei) : NULLnullptr; |
| 893 | |
| 894 | if (EDGE_COUNT (bb->succs)vec_safe_length (bb->succs) > 0) |
| 895 | { |
| 896 | if (act) |
| 897 | stack[sp++] = ei; |
| 898 | ei = ei_start (bb->succs)ei_start_1 (&(bb->succs)); |
| 899 | act = (EDGE_COUNT (ei_container (ei))vec_safe_length (ei_container (ei)) |
| 900 | ? EDGE_I (ei_container (ei), 0)(*ei_container (ei))[(0)] |
| 901 | : NULLnullptr); |
| 902 | } |
| 903 | } |
| 904 | } |
| 905 | |
| 906 | /* This routine will replace a store with a SET to a specified register. */ |
| 907 | |
| 908 | static void |
| 909 | replace_store_insn (rtx reg, rtx_insn *del, basic_block bb, |
| 910 | struct st_expr *smexpr) |
| 911 | { |
| 912 | rtx_insn *insn; |
| 913 | rtx mem, note, set; |
| 914 | |
| 915 | insn = prepare_copy_insn (reg, SET_SRC (single_set (del))(((single_set (del))->u.fld[1]).rt_rtx)); |
| 916 | |
| 917 | unsigned int i; |
| 918 | rtx_insn *temp; |
| 919 | FOR_EACH_VEC_ELT_REVERSE (smexpr->antic_stores, i, temp)for (i = (smexpr->antic_stores).length () - 1; (smexpr-> antic_stores).iterate ((i), &(temp)); (i)--) |
| 920 | if (temp == del) |
| 921 | { |
| 922 | smexpr->antic_stores[i] = insn; |
| 923 | break; |
| 924 | } |
| 925 | |
| 926 | /* Move the notes from the deleted insn to its replacement. */ |
| 927 | REG_NOTES (insn)(((insn)->u.fld[6]).rt_rtx) = REG_NOTES (del)(((del)->u.fld[6]).rt_rtx); |
| 928 | |
| 929 | /* Emit the insn AFTER all the notes are transferred. |
| 930 | This is cheaper since we avoid df rescanning for the note change. */ |
| 931 | insn = emit_insn_after (insn, del); |
| 932 | |
| 933 | if (dump_file) |
| 934 | { |
| 935 | fprintf (dump_file, |
| 936 | "STORE_MOTION delete insn in BB %d:\n ", bb->index); |
| 937 | print_inline_rtx (dump_file, del, 6); |
| 938 | fprintf (dump_file, "\nSTORE_MOTION replaced with insn:\n "); |
| 939 | print_inline_rtx (dump_file, insn, 6); |
| 940 | fprintf (dump_file, "\n"); |
| 941 | } |
| 942 | |
| 943 | delete_insn (del); |
| 944 | |
| 945 | /* Now we must handle REG_EQUAL notes whose contents is equal to the mem; |
| 946 | they are no longer accurate provided that they are reached by this |
| 947 | definition, so drop them. */ |
| 948 | mem = smexpr->pattern; |
| 949 | for (; insn != NEXT_INSN (BB_END (bb)(bb)->il.x.rtl->end_); insn = NEXT_INSN (insn)) |
| 950 | if (NONDEBUG_INSN_P (insn)((((enum rtx_code) (insn)->code) == INSN) || (((enum rtx_code ) (insn)->code) == JUMP_INSN) || (((enum rtx_code) (insn)-> code) == CALL_INSN))) |
| 951 | { |
| 952 | set = single_set (insn); |
| 953 | if (!set) |
| 954 | continue; |
| 955 | if (exp_equiv_p (SET_DEST (set)(((set)->u.fld[0]).rt_rtx), mem, 0, true)) |
| 956 | return; |
| 957 | note = find_reg_equal_equiv_note (insn); |
| 958 | if (!note || !exp_equiv_p (XEXP (note, 0)(((note)->u.fld[0]).rt_rtx), mem, 0, true)) |
| 959 | continue; |
| 960 | |
| 961 | if (dump_file) |
| 962 | fprintf (dump_file, "STORE_MOTION drop REG_EQUAL note at insn %d:\n", |
| 963 | INSN_UID (insn)); |
| 964 | remove_note (insn, note); |
| 965 | } |
| 966 | remove_reachable_equiv_notes (bb, smexpr); |
| 967 | } |
| 968 | |
| 969 | |
| 970 | /* Delete a store, but copy the value that would have been stored into |
| 971 | the reaching_reg for later storing. */ |
| 972 | |
| 973 | static void |
| 974 | delete_store (struct st_expr * expr, basic_block bb) |
| 975 | { |
| 976 | rtx reg; |
| 977 | |
| 978 | if (expr->reaching_reg == NULL_RTX(rtx) 0) |
| 979 | expr->reaching_reg = gen_reg_rtx_and_attrs (expr->pattern); |
| 980 | |
| 981 | reg = expr->reaching_reg; |
| 982 | |
| 983 | unsigned int len = expr->avail_stores.length (); |
| 984 | for (unsigned int i = len - 1; i < len; i--) |
| 985 | { |
| 986 | rtx_insn *del = expr->avail_stores[i]; |
| 987 | if (BLOCK_FOR_INSN (del) == bb) |
| 988 | { |
| 989 | /* We know there is only one since we deleted redundant |
| 990 | ones during the available computation. */ |
| 991 | replace_store_insn (reg, del, bb, expr); |
| 992 | break; |
| 993 | } |
| 994 | } |
| 995 | } |
| 996 | |
| 997 | /* Fill in available, anticipatable, transparent and kill vectors in |
| 998 | STORE_DATA, based on lists of available and anticipatable stores. */ |
| 999 | static void |
| 1000 | build_store_vectors (void) |
| 1001 | { |
| 1002 | basic_block bb; |
| 1003 | int *regs_set_in_block; |
| 1004 | rtx_insn *insn; |
| 1005 | struct st_expr * ptr; |
| 1006 | unsigned int max_gcse_regno = max_reg_num (); |
| 1007 | |
| 1008 | /* Build the gen_vector. This is any store in the table which is not killed |
| 1009 | by aliasing later in its block. */ |
| 1010 | st_avloc = sbitmap_vector_alloc (last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block), |
| 1011 | num_stores); |
| 1012 | bitmap_vector_clear (st_avloc, last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block)); |
| 1013 | |
| 1014 | st_antloc = sbitmap_vector_alloc (last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block), |
| 1015 | num_stores); |
| 1016 | bitmap_vector_clear (st_antloc, last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block)); |
| 1017 | |
| 1018 | for (ptr = first_st_expr (); ptr != NULLnullptr; ptr = next_st_expr (ptr)) |
| 1019 | { |
| 1020 | unsigned int len = ptr->avail_stores.length (); |
| 1021 | for (unsigned int i = len - 1; i < len; i--) |
| 1022 | { |
| 1023 | insn = ptr->avail_stores[i]; |
| 1024 | bb = BLOCK_FOR_INSN (insn); |
| 1025 | |
| 1026 | /* If we've already seen an available expression in this block, |
| 1027 | we can delete this one (It occurs earlier in the block). We'll |
| 1028 | copy the SRC expression to an unused register in case there |
| 1029 | are any side effects. */ |
| 1030 | if (bitmap_bit_p (st_avloc[bb->index], ptr->index)) |
| 1031 | { |
| 1032 | rtx r = gen_reg_rtx_and_attrs (ptr->pattern); |
| 1033 | if (dump_file) |
| 1034 | fprintf (dump_file, "Removing redundant store:\n"); |
| 1035 | replace_store_insn (r, insn, bb, ptr); |
| 1036 | continue; |
| 1037 | } |
| 1038 | bitmap_set_bit (st_avloc[bb->index], ptr->index); |
| 1039 | } |
| 1040 | |
| 1041 | unsigned int i; |
| 1042 | FOR_EACH_VEC_ELT_REVERSE (ptr->antic_stores, i, insn)for (i = (ptr->antic_stores).length () - 1; (ptr->antic_stores ).iterate ((i), &(insn)); (i)--) |
| 1043 | { |
| 1044 | bb = BLOCK_FOR_INSN (insn); |
| 1045 | bitmap_set_bit (st_antloc[bb->index], ptr->index); |
| 1046 | } |
| 1047 | } |
| 1048 | |
| 1049 | st_kill = sbitmap_vector_alloc (last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block), num_stores); |
| 1050 | bitmap_vector_clear (st_kill, last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block)); |
| 1051 | |
| 1052 | st_transp = sbitmap_vector_alloc (last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block), num_stores); |
| 1053 | bitmap_vector_clear (st_transp, last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block)); |
| 1054 | regs_set_in_block = XNEWVEC (int, max_gcse_regno)((int *) xmalloc (sizeof (int) * (max_gcse_regno))); |
| 1055 | |
| 1056 | FOR_EACH_BB_FN (bb, cfun)for (bb = ((cfun + 0))->cfg->x_entry_block_ptr->next_bb ; bb != ((cfun + 0))->cfg->x_exit_block_ptr; bb = bb-> next_bb) |
| 1057 | { |
| 1058 | memset (regs_set_in_block, 0, sizeof (int) * max_gcse_regno); |
| 1059 | |
| 1060 | FOR_BB_INSNS (bb, insn)for ((insn) = (bb)->il.x.head_; (insn) && (insn) != NEXT_INSN ((bb)->il.x.rtl->end_); (insn) = NEXT_INSN ( insn)) |
| 1061 | if (NONDEBUG_INSN_P (insn)((((enum rtx_code) (insn)->code) == INSN) || (((enum rtx_code ) (insn)->code) == JUMP_INSN) || (((enum rtx_code) (insn)-> code) == CALL_INSN))) |
| 1062 | { |
| 1063 | df_ref def; |
| 1064 | FOR_EACH_INSN_DEF (def, insn)for (def = (((df->insns[(INSN_UID (insn))]))->defs); def ; def = ((def)->base.next_loc)) |
| 1065 | { |
| 1066 | unsigned int ref_regno = DF_REF_REGNO (def)((def)->base.regno); |
| 1067 | if (ref_regno < max_gcse_regno) |
| 1068 | regs_set_in_block[DF_REF_REGNO (def)((def)->base.regno)] = 1; |
| 1069 | } |
| 1070 | } |
| 1071 | |
| 1072 | for (ptr = first_st_expr (); ptr != NULLnullptr; ptr = next_st_expr (ptr)) |
| 1073 | { |
| 1074 | if (store_killed_after (ptr->pattern, ptr->pattern_regs, BB_HEAD (bb)(bb)->il.x.head_, |
| 1075 | bb, regs_set_in_block, NULLnullptr)) |
| 1076 | { |
| 1077 | /* It should not be necessary to consider the expression |
| 1078 | killed if it is both anticipatable and available. */ |
| 1079 | if (!bitmap_bit_p (st_antloc[bb->index], ptr->index) |
| 1080 | || !bitmap_bit_p (st_avloc[bb->index], ptr->index)) |
| 1081 | bitmap_set_bit (st_kill[bb->index], ptr->index); |
| 1082 | } |
| 1083 | else |
| 1084 | bitmap_set_bit (st_transp[bb->index], ptr->index); |
| 1085 | } |
| 1086 | } |
| 1087 | |
| 1088 | free (regs_set_in_block); |
| 1089 | |
| 1090 | if (dump_file) |
| 1091 | { |
| 1092 | dump_bitmap_vector (dump_file, "st_antloc", "", st_antloc, |
| 1093 | last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block)); |
| 1094 | dump_bitmap_vector (dump_file, "st_kill", "", st_kill, |
| 1095 | last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block)); |
| 1096 | dump_bitmap_vector (dump_file, "st_transp", "", st_transp, |
| 1097 | last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block)); |
| 1098 | dump_bitmap_vector (dump_file, "st_avloc", "", st_avloc, |
| 1099 | last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block)); |
| 1100 | } |
| 1101 | } |
| 1102 | |
| 1103 | /* Free memory used by store motion. */ |
| 1104 | |
| 1105 | static void |
| 1106 | free_store_memory (void) |
| 1107 | { |
| 1108 | free_store_motion_mems (); |
| 1109 | |
| 1110 | if (st_avloc) |
| 1111 | sbitmap_vector_free (st_avloc); |
| 1112 | if (st_kill) |
| 1113 | sbitmap_vector_free (st_kill); |
| 1114 | if (st_transp) |
| 1115 | sbitmap_vector_free (st_transp); |
| 1116 | if (st_antloc) |
| 1117 | sbitmap_vector_free (st_antloc); |
| 1118 | if (st_insert_map) |
| 1119 | sbitmap_vector_free (st_insert_map); |
| 1120 | if (st_delete_map) |
| 1121 | sbitmap_vector_free (st_delete_map); |
| 1122 | |
| 1123 | st_avloc = st_kill = st_transp = st_antloc = NULLnullptr; |
| 1124 | st_insert_map = st_delete_map = NULLnullptr; |
| 1125 | } |
| 1126 | |
| 1127 | /* Perform store motion. Much like gcse, except we move expressions the |
| 1128 | other way by looking at the flowgraph in reverse. |
| 1129 | Return non-zero if transformations are performed by the pass. */ |
| 1130 | |
| 1131 | static int |
| 1132 | one_store_motion_pass (void) |
| 1133 | { |
| 1134 | basic_block bb; |
| 1135 | int x; |
| 1136 | struct st_expr * ptr; |
| 1137 | int did_edge_inserts = 0; |
| 1138 | int n_stores_deleted = 0; |
| 1139 | int n_stores_created = 0; |
| 1140 | |
| 1141 | init_alias_analysis (); |
| 1142 | |
| 1143 | /* Find all the available and anticipatable stores. */ |
| 1144 | num_stores = compute_store_table (); |
| 1145 | if (num_stores == 0) |
| 1146 | { |
| 1147 | delete store_motion_mems_table; |
| 1148 | store_motion_mems_table = NULLnullptr; |
| 1149 | end_alias_analysis (); |
| 1150 | return 0; |
| 1151 | } |
| 1152 | |
| 1153 | /* Now compute kill & transp vectors. */ |
| 1154 | build_store_vectors (); |
| 1155 | add_noreturn_fake_exit_edges (); |
| 1156 | connect_infinite_loops_to_exit (); |
| 1157 | |
| 1158 | edge_list = pre_edge_rev_lcm (num_stores, st_transp, st_avloc, |
| 1159 | st_antloc, st_kill, &st_insert_map, |
| 1160 | &st_delete_map); |
| 1161 | |
| 1162 | /* Now we want to insert the new stores which are going to be needed. */ |
| 1163 | for (ptr = first_st_expr (); ptr != NULLnullptr; ptr = next_st_expr (ptr)) |
| 1164 | { |
| 1165 | /* If any of the edges we have above are abnormal, we can't move this |
| 1166 | store. */ |
| 1167 | for (x = NUM_EDGES (edge_list)((edge_list)->num_edges) - 1; x >= 0; x--) |
| 1168 | if (bitmap_bit_p (st_insert_map[x], ptr->index) |
| 1169 | && (INDEX_EDGE (edge_list, x)((edge_list)->index_to_edge[(x)])->flags & EDGE_ABNORMAL)) |
| 1170 | break; |
| 1171 | |
| 1172 | if (x >= 0) |
| 1173 | { |
| 1174 | if (dump_file != NULLnullptr) |
| 1175 | fprintf (dump_file, |
| 1176 | "Can't replace store %d: abnormal edge from %d to %d\n", |
| 1177 | ptr->index, INDEX_EDGE (edge_list, x)((edge_list)->index_to_edge[(x)])->src->index, |
| 1178 | INDEX_EDGE (edge_list, x)((edge_list)->index_to_edge[(x)])->dest->index); |
| 1179 | continue; |
| 1180 | } |
| 1181 | |
| 1182 | /* Now we want to insert the new stores which are going to be needed. */ |
| 1183 | |
| 1184 | FOR_EACH_BB_FN (bb, cfun)for (bb = ((cfun + 0))->cfg->x_entry_block_ptr->next_bb ; bb != ((cfun + 0))->cfg->x_exit_block_ptr; bb = bb-> next_bb) |
| 1185 | if (bitmap_bit_p (st_delete_map[bb->index], ptr->index)) |
| 1186 | { |
| 1187 | delete_store (ptr, bb); |
| 1188 | n_stores_deleted++; |
| 1189 | } |
| 1190 | |
| 1191 | for (x = 0; x < NUM_EDGES (edge_list)((edge_list)->num_edges); x++) |
| 1192 | if (bitmap_bit_p (st_insert_map[x], ptr->index)) |
| 1193 | { |
| 1194 | did_edge_inserts |= insert_store (ptr, INDEX_EDGE (edge_list, x)((edge_list)->index_to_edge[(x)])); |
| 1195 | n_stores_created++; |
| 1196 | } |
| 1197 | } |
| 1198 | |
| 1199 | if (did_edge_inserts) |
| 1200 | commit_edge_insertions (); |
| 1201 | |
| 1202 | free_store_memory (); |
| 1203 | free_edge_list (edge_list); |
| 1204 | remove_fake_exit_edges (); |
| 1205 | end_alias_analysis (); |
| 1206 | |
| 1207 | if (dump_file) |
| 1208 | { |
| 1209 | fprintf (dump_file, "STORE_MOTION of %s, %d basic blocks, ", |
| 1210 | current_function_name (), n_basic_blocks_for_fn (cfun)(((cfun + 0))->cfg->x_n_basic_blocks)); |
| 1211 | fprintf (dump_file, "%d insns deleted, %d insns created\n", |
| 1212 | n_stores_deleted, n_stores_created); |
| 1213 | } |
| 1214 | |
| 1215 | return (n_stores_deleted > 0 || n_stores_created > 0); |
| 1216 | } |
| 1217 | |
| 1218 | |
| 1219 | static unsigned int |
| 1220 | execute_rtl_store_motion (void) |
| 1221 | { |
| 1222 | delete_unreachable_blocks (); |
| 1223 | df_analyze (); |
| 1224 | flag_rerun_cse_after_global_opts |= one_store_motion_pass (); |
| 1225 | return 0; |
| 1226 | } |
| 1227 | |
| 1228 | namespace { |
| 1229 | |
| 1230 | const pass_data pass_data_rtl_store_motion = |
| 1231 | { |
| 1232 | RTL_PASS, /* type */ |
| 1233 | "store_motion", /* name */ |
| 1234 | OPTGROUP_NONE, /* optinfo_flags */ |
| 1235 | TV_LSM, /* tv_id */ |
| 1236 | PROP_cfglayout(1 << 9), /* properties_required */ |
| 1237 | 0, /* properties_provided */ |
| 1238 | 0, /* properties_destroyed */ |
| 1239 | 0, /* todo_flags_start */ |
| 1240 | TODO_df_finish(1 << 17), /* todo_flags_finish */ |
| 1241 | }; |
| 1242 | |
| 1243 | class pass_rtl_store_motion : public rtl_opt_pass |
| 1244 | { |
| 1245 | public: |
| 1246 | pass_rtl_store_motion (gcc::context *ctxt) |
| 1247 | : rtl_opt_pass (pass_data_rtl_store_motion, ctxt) |
| 1248 | {} |
| 1249 | |
| 1250 | /* opt_pass methods: */ |
| 1251 | virtual bool gate (function *); |
| 1252 | virtual unsigned int execute (function *) |
| 1253 | { |
| 1254 | return execute_rtl_store_motion (); |
| 1255 | } |
| 1256 | |
| 1257 | }; // class pass_rtl_store_motion |
| 1258 | |
| 1259 | bool |
| 1260 | pass_rtl_store_motion::gate (function *fun) |
| 1261 | { |
| 1262 | return optimizeglobal_options.x_optimize > 0 && flag_gcse_smglobal_options.x_flag_gcse_sm |
| 1263 | && !fun->calls_setjmp |
| 1264 | && optimize_function_for_speed_p (fun) |
| 1265 | && dbg_cnt (store_motion); |
| 1266 | } |
| 1267 | |
| 1268 | } // anon namespace |
| 1269 | |
| 1270 | rtl_opt_pass * |
| 1271 | make_pass_rtl_store_motion (gcc::context *ctxt) |
| 1272 | { |
| 1273 | return new pass_rtl_store_motion (ctxt); |
| 1274 | } |