| File: | build/gcc/cprop.cc |
| Warning: | line 296, column 24 Although the value stored to 'set' is used in the enclosing expression, the value is never actually read from 'set' |
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| 1 | /* Global constant/copy propagation for RTL. |
| 2 | Copyright (C) 1997-2023 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 "cfghooks.h" |
| 26 | #include "df.h" |
| 27 | #include "insn-config.h" |
| 28 | #include "memmodel.h" |
| 29 | #include "emit-rtl.h" |
| 30 | #include "recog.h" |
| 31 | #include "diagnostic-core.h" |
| 32 | #include "toplev.h" |
| 33 | #include "cfgrtl.h" |
| 34 | #include "cfganal.h" |
| 35 | #include "lcm.h" |
| 36 | #include "cfgcleanup.h" |
| 37 | #include "cselib.h" |
| 38 | #include "intl.h" |
| 39 | #include "tree-pass.h" |
| 40 | #include "dbgcnt.h" |
| 41 | #include "cfgloop.h" |
| 42 | #include "gcse.h" |
| 43 | |
| 44 | |
| 45 | /* An obstack for our working variables. */ |
| 46 | static struct obstack cprop_obstack; |
| 47 | |
| 48 | /* Occurrence of an expression. |
| 49 | There is one per basic block. If a pattern appears more than once the |
| 50 | last appearance is used. */ |
| 51 | |
| 52 | struct cprop_occr |
| 53 | { |
| 54 | /* Next occurrence of this expression. */ |
| 55 | struct cprop_occr *next; |
| 56 | /* The insn that computes the expression. */ |
| 57 | rtx_insn *insn; |
| 58 | }; |
| 59 | |
| 60 | /* Hash table entry for assignment expressions. */ |
| 61 | |
| 62 | struct cprop_expr |
| 63 | { |
| 64 | /* The expression (DEST := SRC). */ |
| 65 | rtx dest; |
| 66 | rtx src; |
| 67 | |
| 68 | /* Index in the available expression bitmaps. */ |
| 69 | int bitmap_index; |
| 70 | /* Next entry with the same hash. */ |
| 71 | struct cprop_expr *next_same_hash; |
| 72 | /* List of available occurrence in basic blocks in the function. |
| 73 | An "available occurrence" is one that is the last occurrence in the |
| 74 | basic block and whose operands are not modified by following statements |
| 75 | in the basic block [including this insn]. */ |
| 76 | struct cprop_occr *avail_occr; |
| 77 | }; |
| 78 | |
| 79 | /* Hash table for copy propagation expressions. |
| 80 | Each hash table is an array of buckets. |
| 81 | ??? It is known that if it were an array of entries, structure elements |
| 82 | `next_same_hash' and `bitmap_index' wouldn't be necessary. However, it is |
| 83 | not clear whether in the final analysis a sufficient amount of memory would |
| 84 | be saved as the size of the available expression bitmaps would be larger |
| 85 | [one could build a mapping table without holes afterwards though]. |
| 86 | Someday I'll perform the computation and figure it out. */ |
| 87 | |
| 88 | struct hash_table_d |
| 89 | { |
| 90 | /* The table itself. |
| 91 | This is an array of `set_hash_table_size' elements. */ |
| 92 | struct cprop_expr **table; |
| 93 | |
| 94 | /* Size of the hash table, in elements. */ |
| 95 | unsigned int size; |
| 96 | |
| 97 | /* Number of hash table elements. */ |
| 98 | unsigned int n_elems; |
| 99 | }; |
| 100 | |
| 101 | /* Copy propagation hash table. */ |
| 102 | static struct hash_table_d set_hash_table; |
| 103 | |
| 104 | /* Array of implicit set patterns indexed by basic block index. */ |
| 105 | static rtx *implicit_sets; |
| 106 | |
| 107 | /* Array of indexes of expressions for implicit set patterns indexed by basic |
| 108 | block index. In other words, implicit_set_indexes[i] is the bitmap_index |
| 109 | of the expression whose RTX is implicit_sets[i]. */ |
| 110 | static int *implicit_set_indexes; |
| 111 | |
| 112 | /* Bitmap containing one bit for each register in the program. |
| 113 | Used when performing GCSE to track which registers have been set since |
| 114 | the start or end of the basic block while traversing that block. */ |
| 115 | static regset reg_set_bitmap; |
| 116 | |
| 117 | /* Various variables for statistics gathering. */ |
| 118 | |
| 119 | /* Memory used in a pass. |
| 120 | This isn't intended to be absolutely precise. Its intent is only |
| 121 | to keep an eye on memory usage. */ |
| 122 | static int bytes_used; |
| 123 | |
| 124 | /* Number of local constants propagated. */ |
| 125 | static int local_const_prop_count; |
| 126 | /* Number of local copies propagated. */ |
| 127 | static int local_copy_prop_count; |
| 128 | /* Number of global constants propagated. */ |
| 129 | static int global_const_prop_count; |
| 130 | /* Number of global copies propagated. */ |
| 131 | static int global_copy_prop_count; |
| 132 | |
| 133 | #define GOBNEW(T)((T *) cprop_alloc (sizeof (T))) ((T *) cprop_alloc (sizeof (T))) |
| 134 | #define GOBNEWVAR(T, S)((T *) cprop_alloc ((S))) ((T *) cprop_alloc ((S))) |
| 135 | |
| 136 | /* Cover function to obstack_alloc. */ |
| 137 | |
| 138 | static void * |
| 139 | cprop_alloc (unsigned long size) |
| 140 | { |
| 141 | bytes_used += size; |
| 142 | return obstack_alloc (&cprop_obstack, size)__extension__ ({ struct obstack *__h = (&cprop_obstack); __extension__ ({ struct obstack *__o = (__h); size_t __len = ((size)); if ( __extension__ ({ struct obstack const *__o1 = (__o); (size_t) (__o1->chunk_limit - __o1->next_free); }) < __len) _obstack_newchunk (__o, __len); ((void) ((__o)->next_free += (__len))); }); __extension__ ({ struct obstack *__o1 = (__h); void *__value = (void *) __o1->object_base; if (__o1->next_free == __value ) __o1->maybe_empty_object = 1; __o1->next_free = (sizeof (ptrdiff_t) < sizeof (void *) ? ((__o1->object_base) + (((__o1->next_free) - (__o1->object_base) + (__o1-> alignment_mask)) & ~(__o1->alignment_mask))) : (char * ) (((ptrdiff_t) (__o1->next_free) + (__o1->alignment_mask )) & ~(__o1->alignment_mask))); if ((size_t) (__o1-> next_free - (char *) __o1->chunk) > (size_t) (__o1-> chunk_limit - (char *) __o1->chunk)) __o1->next_free = __o1 ->chunk_limit; __o1->object_base = __o1->next_free; __value ; }); }); |
| 143 | } |
| 144 | |
| 145 | /* Return nonzero if register X is unchanged from INSN to the end |
| 146 | of INSN's basic block. */ |
| 147 | |
| 148 | static int |
| 149 | reg_available_p (const_rtx x, const rtx_insn *insn ATTRIBUTE_UNUSED__attribute__ ((__unused__))) |
| 150 | { |
| 151 | return ! REGNO_REG_SET_P (reg_set_bitmap, REGNO (x))bitmap_bit_p (reg_set_bitmap, (rhs_regno(x))); |
| 152 | } |
| 153 | |
| 154 | /* Hash a set of register REGNO. |
| 155 | |
| 156 | Sets are hashed on the register that is set. This simplifies the PRE copy |
| 157 | propagation code. |
| 158 | |
| 159 | ??? May need to make things more elaborate. Later, as necessary. */ |
| 160 | |
| 161 | static unsigned int |
| 162 | hash_mod (int regno, int hash_table_size) |
| 163 | { |
| 164 | return (unsigned) regno % hash_table_size; |
| 165 | } |
| 166 | |
| 167 | /* Insert assignment DEST:=SET from INSN in the hash table. |
| 168 | DEST is a register and SET is a register or a suitable constant. |
| 169 | If the assignment is already present in the table, record it as |
| 170 | the last occurrence in INSN's basic block. |
| 171 | IMPLICIT is true if it's an implicit set, false otherwise. */ |
| 172 | |
| 173 | static void |
| 174 | insert_set_in_table (rtx dest, rtx src, rtx_insn *insn, |
| 175 | struct hash_table_d *table, bool implicit) |
| 176 | { |
| 177 | bool found = false; |
| 178 | unsigned int hash; |
| 179 | struct cprop_expr *cur_expr, *last_expr = NULL__null; |
| 180 | struct cprop_occr *cur_occr; |
| 181 | |
| 182 | hash = hash_mod (REGNO (dest)(rhs_regno(dest)), table->size); |
| 183 | |
| 184 | for (cur_expr = table->table[hash]; cur_expr; |
| 185 | cur_expr = cur_expr->next_same_hash) |
| 186 | { |
| 187 | if (dest == cur_expr->dest |
| 188 | && src == cur_expr->src) |
| 189 | { |
| 190 | found = true; |
| 191 | break; |
| 192 | } |
| 193 | last_expr = cur_expr; |
| 194 | } |
| 195 | |
| 196 | if (! found) |
| 197 | { |
| 198 | cur_expr = GOBNEW (struct cprop_expr)((struct cprop_expr *) cprop_alloc (sizeof (struct cprop_expr ))); |
| 199 | bytes_used += sizeof (struct cprop_expr); |
| 200 | if (table->table[hash] == NULL__null) |
| 201 | /* This is the first pattern that hashed to this index. */ |
| 202 | table->table[hash] = cur_expr; |
| 203 | else |
| 204 | /* Add EXPR to end of this hash chain. */ |
| 205 | last_expr->next_same_hash = cur_expr; |
| 206 | |
| 207 | /* Set the fields of the expr element. |
| 208 | We must copy X because it can be modified when copy propagation is |
| 209 | performed on its operands. */ |
| 210 | cur_expr->dest = copy_rtx (dest); |
| 211 | cur_expr->src = copy_rtx (src); |
| 212 | cur_expr->bitmap_index = table->n_elems++; |
| 213 | cur_expr->next_same_hash = NULL__null; |
| 214 | cur_expr->avail_occr = NULL__null; |
| 215 | } |
| 216 | |
| 217 | /* Now record the occurrence. */ |
| 218 | cur_occr = cur_expr->avail_occr; |
| 219 | |
| 220 | if (cur_occr |
| 221 | && BLOCK_FOR_INSN (cur_occr->insn) == BLOCK_FOR_INSN (insn)) |
| 222 | { |
| 223 | /* Found another instance of the expression in the same basic block. |
| 224 | Prefer this occurrence to the currently recorded one. We want |
| 225 | the last one in the block and the block is scanned from start |
| 226 | to end. */ |
| 227 | cur_occr->insn = insn; |
| 228 | } |
| 229 | else |
| 230 | { |
| 231 | /* First occurrence of this expression in this basic block. */ |
| 232 | cur_occr = GOBNEW (struct cprop_occr)((struct cprop_occr *) cprop_alloc (sizeof (struct cprop_occr ))); |
| 233 | bytes_used += sizeof (struct cprop_occr); |
| 234 | cur_occr->insn = insn; |
| 235 | cur_occr->next = cur_expr->avail_occr; |
| 236 | cur_expr->avail_occr = cur_occr; |
| 237 | } |
| 238 | |
| 239 | /* Record bitmap_index of the implicit set in implicit_set_indexes. */ |
| 240 | if (implicit) |
| 241 | implicit_set_indexes[BLOCK_FOR_INSN (insn)->index] |
| 242 | = cur_expr->bitmap_index; |
| 243 | } |
| 244 | |
| 245 | /* Determine whether the rtx X should be treated as a constant for CPROP. |
| 246 | Since X might be inserted more than once we have to take care that it |
| 247 | is sharable. */ |
| 248 | |
| 249 | static bool |
| 250 | cprop_constant_p (const_rtx x) |
| 251 | { |
| 252 | return CONSTANT_P (x)((rtx_class[(int) (((enum rtx_code) (x)->code))]) == RTX_CONST_OBJ ) && (GET_CODE (x)((enum rtx_code) (x)->code) != CONST || shared_const_p (x)); |
| 253 | } |
| 254 | |
| 255 | /* Determine whether the rtx X should be treated as a register that can |
| 256 | be propagated. Any pseudo-register is fine. */ |
| 257 | |
| 258 | static bool |
| 259 | cprop_reg_p (const_rtx x) |
| 260 | { |
| 261 | return REG_P (x)(((enum rtx_code) (x)->code) == REG) && !HARD_REGISTER_P (x)((((rhs_regno(x))) < 76)); |
| 262 | } |
| 263 | |
| 264 | /* Scan SET present in INSN and add an entry to the hash TABLE. |
| 265 | IMPLICIT is true if it's an implicit set, false otherwise. */ |
| 266 | |
| 267 | static void |
| 268 | hash_scan_set (rtx set, rtx_insn *insn, struct hash_table_d *table, |
| 269 | bool implicit) |
| 270 | { |
| 271 | rtx src = SET_SRC (set)(((set)->u.fld[1]).rt_rtx); |
| 272 | rtx dest = SET_DEST (set)(((set)->u.fld[0]).rt_rtx); |
| 273 | |
| 274 | if (cprop_reg_p (dest) |
| 275 | && reg_available_p (dest, insn) |
| 276 | && can_copy_p (GET_MODE (dest)((machine_mode) (dest)->mode))) |
| 277 | { |
| 278 | /* See if a REG_EQUAL note shows this equivalent to a simpler expression. |
| 279 | |
| 280 | This allows us to do a single CPROP pass and still eliminate |
| 281 | redundant constants, addresses or other expressions that are |
| 282 | constructed with multiple instructions. |
| 283 | |
| 284 | However, keep the original SRC if INSN is a simple reg-reg move. In |
| 285 | In this case, there will almost always be a REG_EQUAL note on the |
| 286 | insn that sets SRC. By recording the REG_EQUAL value here as SRC |
| 287 | for INSN, we miss copy propagation opportunities. |
| 288 | |
| 289 | Note that this does not impede profitable constant propagations. We |
| 290 | "look through" reg-reg sets in lookup_set. */ |
| 291 | rtx note = find_reg_equal_equiv_note (insn); |
| 292 | if (note != 0 |
| 293 | && REG_NOTE_KIND (note)((enum reg_note) ((machine_mode) (note)->mode)) == REG_EQUAL |
| 294 | && !REG_P (src)(((enum rtx_code) (src)->code) == REG) |
| 295 | && cprop_constant_p (XEXP (note, 0)(((note)->u.fld[0]).rt_rtx))) |
| 296 | src = XEXP (note, 0)(((note)->u.fld[0]).rt_rtx), set = gen_rtx_SET (dest, src)gen_rtx_fmt_ee_stat ((SET), (((void) 0, E_VOIDmode)), ((dest) ), ((src)) ); |
Although the value stored to 'set' is used in the enclosing expression, the value is never actually read from 'set' | |
| 297 | |
| 298 | /* Record sets for constant/copy propagation. */ |
| 299 | if ((cprop_reg_p (src) |
| 300 | && src != dest |
| 301 | && reg_available_p (src, insn)) |
| 302 | || cprop_constant_p (src)) |
| 303 | insert_set_in_table (dest, src, insn, table, implicit); |
| 304 | } |
| 305 | } |
| 306 | |
| 307 | /* Process INSN and add hash table entries as appropriate. */ |
| 308 | |
| 309 | static void |
| 310 | hash_scan_insn (rtx_insn *insn, struct hash_table_d *table) |
| 311 | { |
| 312 | rtx pat = PATTERN (insn); |
| 313 | int i; |
| 314 | |
| 315 | /* Pick out the sets of INSN and for other forms of instructions record |
| 316 | what's been modified. */ |
| 317 | |
| 318 | if (GET_CODE (pat)((enum rtx_code) (pat)->code) == SET) |
| 319 | hash_scan_set (pat, insn, table, false); |
| 320 | else if (GET_CODE (pat)((enum rtx_code) (pat)->code) == PARALLEL) |
| 321 | for (i = 0; i < XVECLEN (pat, 0)(((((pat)->u.fld[0]).rt_rtvec))->num_elem); i++) |
| 322 | { |
| 323 | rtx x = XVECEXP (pat, 0, i)(((((pat)->u.fld[0]).rt_rtvec))->elem[i]); |
| 324 | |
| 325 | if (GET_CODE (x)((enum rtx_code) (x)->code) == SET) |
| 326 | hash_scan_set (x, insn, table, false); |
| 327 | } |
| 328 | } |
| 329 | |
| 330 | /* Dump the hash table TABLE to file FILE under the name NAME. */ |
| 331 | |
| 332 | static void |
| 333 | dump_hash_table (FILE *file, const char *name, struct hash_table_d *table) |
| 334 | { |
| 335 | int i; |
| 336 | /* Flattened out table, so it's printed in proper order. */ |
| 337 | struct cprop_expr **flat_table; |
| 338 | unsigned int *hash_val; |
| 339 | struct cprop_expr *expr; |
| 340 | |
| 341 | flat_table = XCNEWVEC (struct cprop_expr *, table->n_elems)((struct cprop_expr * *) xcalloc ((table->n_elems), sizeof (struct cprop_expr *))); |
| 342 | hash_val = XNEWVEC (unsigned int, table->n_elems)((unsigned int *) xmalloc (sizeof (unsigned int) * (table-> n_elems))); |
| 343 | |
| 344 | for (i = 0; i < (int) table->size; i++) |
| 345 | for (expr = table->table[i]; expr != NULL__null; expr = expr->next_same_hash) |
| 346 | { |
| 347 | flat_table[expr->bitmap_index] = expr; |
| 348 | hash_val[expr->bitmap_index] = i; |
| 349 | } |
| 350 | |
| 351 | fprintf (file, "%s hash table (%d buckets, %d entries)\n", |
| 352 | name, table->size, table->n_elems); |
| 353 | |
| 354 | for (i = 0; i < (int) table->n_elems; i++) |
| 355 | if (flat_table[i] != 0) |
| 356 | { |
| 357 | expr = flat_table[i]; |
| 358 | fprintf (file, "Index %d (hash value %d)\n ", |
| 359 | expr->bitmap_index, hash_val[i]); |
| 360 | print_rtl (file, expr->dest); |
| 361 | fprintf (file, " := "); |
| 362 | print_rtl (file, expr->src); |
| 363 | fprintf (file, "\n"); |
| 364 | } |
| 365 | |
| 366 | fprintf (file, "\n"); |
| 367 | |
| 368 | free (flat_table); |
| 369 | free (hash_val); |
| 370 | } |
| 371 | |
| 372 | /* Record as unavailable all registers that are DEF operands of INSN. */ |
| 373 | |
| 374 | static void |
| 375 | make_set_regs_unavailable (rtx_insn *insn) |
| 376 | { |
| 377 | df_ref def; |
| 378 | |
| 379 | FOR_EACH_INSN_DEF (def, insn)for (def = (((df->insns[(INSN_UID (insn))]))->defs); def ; def = ((def)->base.next_loc)) |
| 380 | SET_REGNO_REG_SET (reg_set_bitmap, DF_REF_REGNO (def))bitmap_set_bit (reg_set_bitmap, ((def)->base.regno)); |
| 381 | } |
| 382 | |
| 383 | /* Top level function to create an assignment hash table. |
| 384 | |
| 385 | Assignment entries are placed in the hash table if |
| 386 | - they are of the form (set (pseudo-reg) src), |
| 387 | - src is something we want to perform const/copy propagation on, |
| 388 | - none of the operands or target are subsequently modified in the block |
| 389 | |
| 390 | Currently src must be a pseudo-reg or a const_int. |
| 391 | |
| 392 | TABLE is the table computed. */ |
| 393 | |
| 394 | static void |
| 395 | compute_hash_table_work (struct hash_table_d *table) |
| 396 | { |
| 397 | basic_block bb; |
| 398 | |
| 399 | /* Allocate vars to track sets of regs. */ |
| 400 | reg_set_bitmap = ALLOC_REG_SET (NULL)bitmap_alloc (__null); |
| 401 | |
| 402 | 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) |
| 403 | { |
| 404 | rtx_insn *insn; |
| 405 | |
| 406 | /* Reset tables used to keep track of what's not yet invalid [since |
| 407 | the end of the block]. */ |
| 408 | CLEAR_REG_SET (reg_set_bitmap)bitmap_clear (reg_set_bitmap); |
| 409 | |
| 410 | /* Go over all insns from the last to the first. This is convenient |
| 411 | for tracking available registers, i.e. not set between INSN and |
| 412 | the end of the basic block BB. */ |
| 413 | FOR_BB_INSNS_REVERSE (bb, insn)for ((insn) = (bb)->il.x.rtl->end_; (insn) && ( insn) != PREV_INSN ((bb)->il.x.head_); (insn) = PREV_INSN ( insn)) |
| 414 | { |
| 415 | /* Only real insns are interesting. */ |
| 416 | 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))) |
| 417 | continue; |
| 418 | |
| 419 | /* Record interesting sets from INSN in the hash table. */ |
| 420 | hash_scan_insn (insn, table); |
| 421 | |
| 422 | /* Any registers set in INSN will make SETs above it not AVAIL. */ |
| 423 | make_set_regs_unavailable (insn); |
| 424 | } |
| 425 | |
| 426 | /* Insert implicit sets in the hash table, pretending they appear as |
| 427 | insns at the head of the basic block. */ |
| 428 | if (implicit_sets[bb->index] != NULL_RTX(rtx) 0) |
| 429 | hash_scan_set (implicit_sets[bb->index], BB_HEAD (bb)(bb)->il.x.head_, table, true); |
| 430 | } |
| 431 | |
| 432 | FREE_REG_SET (reg_set_bitmap)((void) (bitmap_obstack_free ((bitmap) reg_set_bitmap), (reg_set_bitmap ) = (bitmap) __null)); |
| 433 | } |
| 434 | |
| 435 | /* Allocate space for the set/expr hash TABLE. |
| 436 | It is used to determine the number of buckets to use. */ |
| 437 | |
| 438 | static void |
| 439 | alloc_hash_table (struct hash_table_d *table) |
| 440 | { |
| 441 | int n; |
| 442 | |
| 443 | n = get_max_insn_count (); |
| 444 | |
| 445 | table->size = n / 4; |
| 446 | if (table->size < 11) |
| 447 | table->size = 11; |
| 448 | |
| 449 | /* Attempt to maintain efficient use of hash table. |
| 450 | Making it an odd number is simplest for now. |
| 451 | ??? Later take some measurements. */ |
| 452 | table->size |= 1; |
| 453 | n = table->size * sizeof (struct cprop_expr *); |
| 454 | table->table = XNEWVAR (struct cprop_expr *, n)((struct cprop_expr * *) xmalloc ((n))); |
| 455 | } |
| 456 | |
| 457 | /* Free things allocated by alloc_hash_table. */ |
| 458 | |
| 459 | static void |
| 460 | free_hash_table (struct hash_table_d *table) |
| 461 | { |
| 462 | free (table->table); |
| 463 | } |
| 464 | |
| 465 | /* Compute the hash TABLE for doing copy/const propagation or |
| 466 | expression hash table. */ |
| 467 | |
| 468 | static void |
| 469 | compute_hash_table (struct hash_table_d *table) |
| 470 | { |
| 471 | /* Initialize count of number of entries in hash table. */ |
| 472 | table->n_elems = 0; |
| 473 | memset (table->table, 0, table->size * sizeof (struct cprop_expr *)); |
| 474 | |
| 475 | compute_hash_table_work (table); |
| 476 | } |
| 477 | |
| 478 | /* Expression tracking support. */ |
| 479 | |
| 480 | /* Lookup REGNO in the set TABLE. The result is a pointer to the |
| 481 | table entry, or NULL if not found. */ |
| 482 | |
| 483 | static struct cprop_expr * |
| 484 | lookup_set (unsigned int regno, struct hash_table_d *table) |
| 485 | { |
| 486 | unsigned int hash = hash_mod (regno, table->size); |
| 487 | struct cprop_expr *expr; |
| 488 | |
| 489 | expr = table->table[hash]; |
| 490 | |
| 491 | while (expr && REGNO (expr->dest)(rhs_regno(expr->dest)) != regno) |
| 492 | expr = expr->next_same_hash; |
| 493 | |
| 494 | return expr; |
| 495 | } |
| 496 | |
| 497 | /* Return the next entry for REGNO in list EXPR. */ |
| 498 | |
| 499 | static struct cprop_expr * |
| 500 | next_set (unsigned int regno, struct cprop_expr *expr) |
| 501 | { |
| 502 | do |
| 503 | expr = expr->next_same_hash; |
| 504 | while (expr && REGNO (expr->dest)(rhs_regno(expr->dest)) != regno); |
| 505 | |
| 506 | return expr; |
| 507 | } |
| 508 | |
| 509 | /* Reset tables used to keep track of what's still available [since the |
| 510 | start of the block]. */ |
| 511 | |
| 512 | static void |
| 513 | reset_opr_set_tables (void) |
| 514 | { |
| 515 | /* Maintain a bitmap of which regs have been set since beginning of |
| 516 | the block. */ |
| 517 | CLEAR_REG_SET (reg_set_bitmap)bitmap_clear (reg_set_bitmap); |
| 518 | } |
| 519 | |
| 520 | /* Return nonzero if the register X has not been set yet [since the |
| 521 | start of the basic block containing INSN]. */ |
| 522 | |
| 523 | static int |
| 524 | reg_not_set_p (const_rtx x, const rtx_insn *insn ATTRIBUTE_UNUSED__attribute__ ((__unused__))) |
| 525 | { |
| 526 | return ! REGNO_REG_SET_P (reg_set_bitmap, REGNO (x))bitmap_bit_p (reg_set_bitmap, (rhs_regno(x))); |
| 527 | } |
| 528 | |
| 529 | /* Record things set by INSN. |
| 530 | This data is used by reg_not_set_p. */ |
| 531 | |
| 532 | static void |
| 533 | mark_oprs_set (rtx_insn *insn) |
| 534 | { |
| 535 | df_ref def; |
| 536 | |
| 537 | FOR_EACH_INSN_DEF (def, insn)for (def = (((df->insns[(INSN_UID (insn))]))->defs); def ; def = ((def)->base.next_loc)) |
| 538 | SET_REGNO_REG_SET (reg_set_bitmap, DF_REF_REGNO (def))bitmap_set_bit (reg_set_bitmap, ((def)->base.regno)); |
| 539 | } |
| 540 | |
| 541 | /* Compute copy/constant propagation working variables. */ |
| 542 | |
| 543 | /* Local properties of assignments. */ |
| 544 | static sbitmap *cprop_avloc; |
| 545 | static sbitmap *cprop_kill; |
| 546 | |
| 547 | /* Global properties of assignments (computed from the local properties). */ |
| 548 | static sbitmap *cprop_avin; |
| 549 | static sbitmap *cprop_avout; |
| 550 | |
| 551 | /* Allocate vars used for copy/const propagation. N_BLOCKS is the number of |
| 552 | basic blocks. N_SETS is the number of sets. */ |
| 553 | |
| 554 | static void |
| 555 | alloc_cprop_mem (int n_blocks, int n_sets) |
| 556 | { |
| 557 | cprop_avloc = sbitmap_vector_alloc (n_blocks, n_sets); |
| 558 | cprop_kill = sbitmap_vector_alloc (n_blocks, n_sets); |
| 559 | |
| 560 | cprop_avin = sbitmap_vector_alloc (n_blocks, n_sets); |
| 561 | cprop_avout = sbitmap_vector_alloc (n_blocks, n_sets); |
| 562 | } |
| 563 | |
| 564 | /* Free vars used by copy/const propagation. */ |
| 565 | |
| 566 | static void |
| 567 | free_cprop_mem (void) |
| 568 | { |
| 569 | sbitmap_vector_free (cprop_avloc); |
| 570 | sbitmap_vector_free (cprop_kill); |
| 571 | sbitmap_vector_free (cprop_avin); |
| 572 | sbitmap_vector_free (cprop_avout); |
| 573 | } |
| 574 | |
| 575 | /* Compute the local properties of each recorded expression. |
| 576 | |
| 577 | Local properties are those that are defined by the block, irrespective of |
| 578 | other blocks. |
| 579 | |
| 580 | An expression is killed in a block if its operands, either DEST or SRC, are |
| 581 | modified in the block. |
| 582 | |
| 583 | An expression is computed (locally available) in a block if it is computed |
| 584 | at least once and expression would contain the same value if the |
| 585 | computation was moved to the end of the block. |
| 586 | |
| 587 | KILL and COMP are destination sbitmaps for recording local properties. */ |
| 588 | |
| 589 | static void |
| 590 | compute_local_properties (sbitmap *kill, sbitmap *comp, |
| 591 | struct hash_table_d *table) |
| 592 | { |
| 593 | unsigned int i; |
| 594 | |
| 595 | /* Initialize the bitmaps that were passed in. */ |
| 596 | bitmap_vector_clear (kill, last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block)); |
| 597 | bitmap_vector_clear (comp, last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block)); |
| 598 | |
| 599 | for (i = 0; i < table->size; i++) |
| 600 | { |
| 601 | struct cprop_expr *expr; |
| 602 | |
| 603 | for (expr = table->table[i]; expr != NULL__null; expr = expr->next_same_hash) |
| 604 | { |
| 605 | int indx = expr->bitmap_index; |
| 606 | df_ref def; |
| 607 | struct cprop_occr *occr; |
| 608 | |
| 609 | /* For each definition of the destination pseudo-reg, the expression |
| 610 | is killed in the block where the definition is. */ |
| 611 | for (def = DF_REG_DEF_CHAIN (REGNO (expr->dest))(df->def_regs[((rhs_regno(expr->dest)))]->reg_chain); |
| 612 | def; def = DF_REF_NEXT_REG (def)((def)->base.next_reg)) |
| 613 | bitmap_set_bit (kill[DF_REF_BB (def)((((def)->base.cl) == DF_REF_ARTIFICIAL) ? (def)->artificial_ref .bb : BLOCK_FOR_INSN (((def)->base.insn_info->insn)))->index], indx); |
| 614 | |
| 615 | /* If the source is a pseudo-reg, for each definition of the source, |
| 616 | the expression is killed in the block where the definition is. */ |
| 617 | if (REG_P (expr->src)(((enum rtx_code) (expr->src)->code) == REG)) |
| 618 | for (def = DF_REG_DEF_CHAIN (REGNO (expr->src))(df->def_regs[((rhs_regno(expr->src)))]->reg_chain); |
| 619 | def; def = DF_REF_NEXT_REG (def)((def)->base.next_reg)) |
| 620 | bitmap_set_bit (kill[DF_REF_BB (def)((((def)->base.cl) == DF_REF_ARTIFICIAL) ? (def)->artificial_ref .bb : BLOCK_FOR_INSN (((def)->base.insn_info->insn)))->index], indx); |
| 621 | |
| 622 | /* The occurrences recorded in avail_occr are exactly those that |
| 623 | are locally available in the block where they are. */ |
| 624 | for (occr = expr->avail_occr; occr != NULL__null; occr = occr->next) |
| 625 | { |
| 626 | bitmap_set_bit (comp[BLOCK_FOR_INSN (occr->insn)->index], indx); |
| 627 | } |
| 628 | } |
| 629 | } |
| 630 | } |
| 631 | |
| 632 | /* Hash table support. */ |
| 633 | |
| 634 | /* Top level routine to do the dataflow analysis needed by copy/const |
| 635 | propagation. */ |
| 636 | |
| 637 | static void |
| 638 | compute_cprop_data (void) |
| 639 | { |
| 640 | basic_block bb; |
| 641 | |
| 642 | compute_local_properties (cprop_kill, cprop_avloc, &set_hash_table); |
| 643 | compute_available (cprop_avloc, cprop_kill, cprop_avout, cprop_avin); |
| 644 | |
| 645 | /* Merge implicit sets into CPROP_AVIN. They are always available at the |
| 646 | entry of their basic block. We need to do this because 1) implicit sets |
| 647 | aren't recorded for the local pass so they cannot be propagated within |
| 648 | their basic block by this pass and 2) the global pass would otherwise |
| 649 | propagate them only in the successors of their basic block. */ |
| 650 | 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) |
| 651 | { |
| 652 | int index = implicit_set_indexes[bb->index]; |
| 653 | if (index != -1) |
| 654 | bitmap_set_bit (cprop_avin[bb->index], index); |
| 655 | } |
| 656 | } |
| 657 | |
| 658 | /* Copy/constant propagation. */ |
| 659 | |
| 660 | /* Maximum number of register uses in an insn that we handle. */ |
| 661 | #define MAX_USES8 8 |
| 662 | |
| 663 | /* Table of uses (registers, both hard and pseudo) found in an insn. |
| 664 | Allocated statically to avoid alloc/free complexity and overhead. */ |
| 665 | static rtx reg_use_table[MAX_USES8]; |
| 666 | |
| 667 | /* Index into `reg_use_table' while building it. */ |
| 668 | static unsigned reg_use_count; |
| 669 | |
| 670 | /* Set up a list of register numbers used in INSN. The found uses are stored |
| 671 | in `reg_use_table'. `reg_use_count' is initialized to zero before entry, |
| 672 | and contains the number of uses in the table upon exit. |
| 673 | |
| 674 | ??? If a register appears multiple times we will record it multiple times. |
| 675 | This doesn't hurt anything but it will slow things down. */ |
| 676 | |
| 677 | static void |
| 678 | find_used_regs (rtx *xptr, void *data ATTRIBUTE_UNUSED__attribute__ ((__unused__))) |
| 679 | { |
| 680 | int i, j; |
| 681 | enum rtx_code code; |
| 682 | const char *fmt; |
| 683 | rtx x = *xptr; |
| 684 | |
| 685 | /* repeat is used to turn tail-recursion into iteration since GCC |
| 686 | can't do it when there's no return value. */ |
| 687 | repeat: |
| 688 | if (x == 0) |
| 689 | return; |
| 690 | |
| 691 | code = GET_CODE (x)((enum rtx_code) (x)->code); |
| 692 | if (REG_P (x)(((enum rtx_code) (x)->code) == REG)) |
| 693 | { |
| 694 | if (reg_use_count == MAX_USES8) |
| 695 | return; |
| 696 | |
| 697 | reg_use_table[reg_use_count] = x; |
| 698 | reg_use_count++; |
| 699 | } |
| 700 | |
| 701 | /* Recursively scan the operands of this expression. */ |
| 702 | |
| 703 | for (i = GET_RTX_LENGTH (code)(rtx_length[(int) (code)]) - 1, fmt = GET_RTX_FORMAT (code)(rtx_format[(int) (code)]); i >= 0; i--) |
| 704 | { |
| 705 | if (fmt[i] == 'e') |
| 706 | { |
| 707 | /* If we are about to do the last recursive call |
| 708 | needed at this level, change it into iteration. |
| 709 | This function is called enough to be worth it. */ |
| 710 | if (i == 0) |
| 711 | { |
| 712 | x = XEXP (x, 0)(((x)->u.fld[0]).rt_rtx); |
| 713 | goto repeat; |
| 714 | } |
| 715 | |
| 716 | find_used_regs (&XEXP (x, i)(((x)->u.fld[i]).rt_rtx), data); |
| 717 | } |
| 718 | else if (fmt[i] == 'E') |
| 719 | for (j = 0; j < XVECLEN (x, i)(((((x)->u.fld[i]).rt_rtvec))->num_elem); j++) |
| 720 | find_used_regs (&XVECEXP (x, i, j)(((((x)->u.fld[i]).rt_rtvec))->elem[j]), data); |
| 721 | } |
| 722 | } |
| 723 | |
| 724 | /* Try to replace all uses of FROM in INSN with TO. |
| 725 | Return nonzero if successful. */ |
| 726 | |
| 727 | static int |
| 728 | try_replace_reg (rtx from, rtx to, rtx_insn *insn) |
| 729 | { |
| 730 | rtx note = find_reg_equal_equiv_note (insn); |
| 731 | rtx src = 0; |
| 732 | int success = 0; |
| 733 | rtx set = single_set (insn); |
| 734 | |
| 735 | bool check_rtx_costs = true; |
| 736 | bool speed = optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn)); |
| 737 | int old_cost = set ? set_rtx_cost (set, speed) : 0; |
| 738 | |
| 739 | if (!set |
| 740 | || CONSTANT_P (SET_SRC (set))((rtx_class[(int) (((enum rtx_code) ((((set)->u.fld[1]).rt_rtx ))->code))]) == RTX_CONST_OBJ) |
| 741 | || (note != 0 |
| 742 | && REG_NOTE_KIND (note)((enum reg_note) ((machine_mode) (note)->mode)) == REG_EQUAL |
| 743 | && (GET_CODE (XEXP (note, 0))((enum rtx_code) ((((note)->u.fld[0]).rt_rtx))->code) == CONST |
| 744 | || CONSTANT_P (XEXP (note, 0))((rtx_class[(int) (((enum rtx_code) ((((note)->u.fld[0]).rt_rtx ))->code))]) == RTX_CONST_OBJ)))) |
| 745 | check_rtx_costs = false; |
| 746 | |
| 747 | /* Usually we substitute easy stuff, so we won't copy everything. |
| 748 | We however need to take care to not duplicate non-trivial CONST |
| 749 | expressions. */ |
| 750 | to = copy_rtx (to); |
| 751 | |
| 752 | validate_replace_src_group (from, to, insn); |
| 753 | |
| 754 | /* If TO is a constant, check the cost of the set after propagation |
| 755 | to the cost of the set before the propagation. If the cost is |
| 756 | higher, then do not replace FROM with TO. */ |
| 757 | |
| 758 | if (check_rtx_costs |
| 759 | && CONSTANT_P (to)((rtx_class[(int) (((enum rtx_code) (to)->code))]) == RTX_CONST_OBJ ) |
| 760 | && set_rtx_cost (set, speed) > old_cost) |
| 761 | { |
| 762 | cancel_changes (0); |
| 763 | return false; |
| 764 | } |
| 765 | |
| 766 | |
| 767 | if (num_changes_pending () && apply_change_group ()) |
| 768 | success = 1; |
| 769 | |
| 770 | /* Try to simplify SET_SRC if we have substituted a constant. */ |
| 771 | if (success && set && CONSTANT_P (to)((rtx_class[(int) (((enum rtx_code) (to)->code))]) == RTX_CONST_OBJ )) |
| 772 | { |
| 773 | src = simplify_rtx (SET_SRC (set)(((set)->u.fld[1]).rt_rtx)); |
| 774 | |
| 775 | if (src) |
| 776 | validate_change (insn, &SET_SRC (set)(((set)->u.fld[1]).rt_rtx), src, 0); |
| 777 | } |
| 778 | |
| 779 | /* If there is already a REG_EQUAL note, update the expression in it |
| 780 | with our replacement. */ |
| 781 | if (note != 0 && REG_NOTE_KIND (note)((enum reg_note) ((machine_mode) (note)->mode)) == REG_EQUAL) |
| 782 | set_unique_reg_note (insn, REG_EQUAL, |
| 783 | simplify_replace_rtx (XEXP (note, 0)(((note)->u.fld[0]).rt_rtx), from, to)); |
| 784 | if (!success && set && reg_mentioned_p (from, SET_SRC (set)(((set)->u.fld[1]).rt_rtx))) |
| 785 | { |
| 786 | /* If above failed and this is a single set, try to simplify the source |
| 787 | of the set given our substitution. We could perhaps try this for |
| 788 | multiple SETs, but it probably won't buy us anything. */ |
| 789 | src = simplify_replace_rtx (SET_SRC (set)(((set)->u.fld[1]).rt_rtx), from, to); |
| 790 | |
| 791 | if (!rtx_equal_p (src, SET_SRC (set)(((set)->u.fld[1]).rt_rtx)) |
| 792 | && validate_change (insn, &SET_SRC (set)(((set)->u.fld[1]).rt_rtx), src, 0)) |
| 793 | success = 1; |
| 794 | |
| 795 | /* If we've failed perform the replacement, have a single SET to |
| 796 | a REG destination and don't yet have a note, add a REG_EQUAL note |
| 797 | to not lose information. */ |
| 798 | if (!success && note == 0 && set != 0 && REG_P (SET_DEST (set))(((enum rtx_code) ((((set)->u.fld[0]).rt_rtx))->code) == REG)) |
| 799 | note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (src)); |
| 800 | } |
| 801 | |
| 802 | if (set && MEM_P (SET_DEST (set))(((enum rtx_code) ((((set)->u.fld[0]).rt_rtx))->code) == MEM) && reg_mentioned_p (from, SET_DEST (set)(((set)->u.fld[0]).rt_rtx))) |
| 803 | { |
| 804 | /* Registers can also appear as uses in SET_DEST if it is a MEM. |
| 805 | We could perhaps try this for multiple SETs, but it probably |
| 806 | won't buy us anything. */ |
| 807 | rtx dest = simplify_replace_rtx (SET_DEST (set)(((set)->u.fld[0]).rt_rtx), from, to); |
| 808 | |
| 809 | if (!rtx_equal_p (dest, SET_DEST (set)(((set)->u.fld[0]).rt_rtx)) |
| 810 | && validate_change (insn, &SET_DEST (set)(((set)->u.fld[0]).rt_rtx), dest, 0)) |
| 811 | success = 1; |
| 812 | } |
| 813 | |
| 814 | /* REG_EQUAL may get simplified into register. |
| 815 | We don't allow that. Remove that note. This code ought |
| 816 | not to happen, because previous code ought to synthesize |
| 817 | reg-reg move, but be on the safe side. */ |
| 818 | if (note && REG_NOTE_KIND (note)((enum reg_note) ((machine_mode) (note)->mode)) == REG_EQUAL && REG_P (XEXP (note, 0))(((enum rtx_code) ((((note)->u.fld[0]).rt_rtx))->code) == REG)) |
| 819 | remove_note (insn, note); |
| 820 | |
| 821 | return success; |
| 822 | } |
| 823 | |
| 824 | /* Find a set of REGNOs that are available on entry to INSN's block. If found, |
| 825 | SET_RET[0] will be assigned a set with a register source and SET_RET[1] a |
| 826 | set with a constant source. If not found the corresponding entry is set to |
| 827 | NULL. */ |
| 828 | |
| 829 | static void |
| 830 | find_avail_set (int regno, rtx_insn *insn, struct cprop_expr *set_ret[2]) |
| 831 | { |
| 832 | set_ret[0] = set_ret[1] = NULL__null; |
| 833 | |
| 834 | /* Loops are not possible here. To get a loop we would need two sets |
| 835 | available at the start of the block containing INSN. i.e. we would |
| 836 | need two sets like this available at the start of the block: |
| 837 | |
| 838 | (set (reg X) (reg Y)) |
| 839 | (set (reg Y) (reg X)) |
| 840 | |
| 841 | This cannot happen since the set of (reg Y) would have killed the |
| 842 | set of (reg X) making it unavailable at the start of this block. */ |
| 843 | while (1) |
| 844 | { |
| 845 | rtx src; |
| 846 | struct cprop_expr *set = lookup_set (regno, &set_hash_table); |
| 847 | |
| 848 | /* Find a set that is available at the start of the block |
| 849 | which contains INSN. */ |
| 850 | while (set) |
| 851 | { |
| 852 | if (bitmap_bit_p (cprop_avin[BLOCK_FOR_INSN (insn)->index], |
| 853 | set->bitmap_index)) |
| 854 | break; |
| 855 | set = next_set (regno, set); |
| 856 | } |
| 857 | |
| 858 | /* If no available set was found we've reached the end of the |
| 859 | (possibly empty) copy chain. */ |
| 860 | if (set == 0) |
| 861 | break; |
| 862 | |
| 863 | src = set->src; |
| 864 | |
| 865 | /* We know the set is available. |
| 866 | Now check that SRC is locally anticipatable (i.e. none of the |
| 867 | source operands have changed since the start of the block). |
| 868 | |
| 869 | If the source operand changed, we may still use it for the next |
| 870 | iteration of this loop, but we may not use it for substitutions. */ |
| 871 | |
| 872 | if (cprop_constant_p (src)) |
| 873 | set_ret[1] = set; |
| 874 | else if (reg_not_set_p (src, insn)) |
| 875 | set_ret[0] = set; |
| 876 | |
| 877 | /* If the source of the set is anything except a register, then |
| 878 | we have reached the end of the copy chain. */ |
| 879 | if (! REG_P (src)(((enum rtx_code) (src)->code) == REG)) |
| 880 | break; |
| 881 | |
| 882 | /* Follow the copy chain, i.e. start another iteration of the loop |
| 883 | and see if we have an available copy into SRC. */ |
| 884 | regno = REGNO (src)(rhs_regno(src)); |
| 885 | } |
| 886 | } |
| 887 | |
| 888 | /* Subroutine of cprop_insn that tries to propagate constants into |
| 889 | JUMP_INSNS. JUMP must be a conditional jump. If SETCC is non-NULL |
| 890 | it is the instruction that immediately precedes JUMP, and must be a |
| 891 | single SET of a register. FROM is what we will try to replace, |
| 892 | SRC is the constant we will try to substitute for it. Return nonzero |
| 893 | if a change was made. */ |
| 894 | |
| 895 | static int |
| 896 | cprop_jump (basic_block bb, rtx_insn *setcc, rtx_insn *jump, rtx from, rtx src) |
| 897 | { |
| 898 | rtx new_rtx, set_src, note_src; |
| 899 | rtx set = pc_set (jump); |
| 900 | rtx note = find_reg_equal_equiv_note (jump); |
| 901 | |
| 902 | if (note) |
| 903 | { |
| 904 | note_src = XEXP (note, 0)(((note)->u.fld[0]).rt_rtx); |
| 905 | if (GET_CODE (note_src)((enum rtx_code) (note_src)->code) == EXPR_LIST) |
| 906 | note_src = NULL_RTX(rtx) 0; |
| 907 | } |
| 908 | else note_src = NULL_RTX(rtx) 0; |
| 909 | |
| 910 | /* Prefer REG_EQUAL notes except those containing EXPR_LISTs. */ |
| 911 | set_src = note_src ? note_src : SET_SRC (set)(((set)->u.fld[1]).rt_rtx); |
| 912 | |
| 913 | /* First substitute the SETCC condition into the JUMP instruction, |
| 914 | then substitute that given values into this expanded JUMP. */ |
| 915 | if (setcc != NULL_RTX(rtx) 0 |
| 916 | && !modified_between_p (from, setcc, jump) |
| 917 | && !modified_between_p (src, setcc, jump)) |
| 918 | { |
| 919 | rtx setcc_src; |
| 920 | rtx setcc_set = single_set (setcc); |
| 921 | rtx setcc_note = find_reg_equal_equiv_note (setcc); |
| 922 | setcc_src = (setcc_note && GET_CODE (XEXP (setcc_note, 0))((enum rtx_code) ((((setcc_note)->u.fld[0]).rt_rtx))->code ) != EXPR_LIST) |
| 923 | ? XEXP (setcc_note, 0)(((setcc_note)->u.fld[0]).rt_rtx) : SET_SRC (setcc_set)(((setcc_set)->u.fld[1]).rt_rtx); |
| 924 | set_src = simplify_replace_rtx (set_src, SET_DEST (setcc_set)(((setcc_set)->u.fld[0]).rt_rtx), |
| 925 | setcc_src); |
| 926 | } |
| 927 | else |
| 928 | setcc = NULL__null; |
| 929 | |
| 930 | new_rtx = simplify_replace_rtx (set_src, from, src); |
| 931 | |
| 932 | /* If no simplification can be made, then try the next register. */ |
| 933 | if (rtx_equal_p (new_rtx, SET_SRC (set)(((set)->u.fld[1]).rt_rtx))) |
| 934 | return 0; |
| 935 | |
| 936 | /* If this is now a no-op delete it, otherwise this must be a valid insn. */ |
| 937 | if (new_rtx == pc_rtx) |
| 938 | delete_insn (jump); |
| 939 | else |
| 940 | { |
| 941 | /* Ensure the value computed inside the jump insn to be equivalent |
| 942 | to one computed by setcc. */ |
| 943 | if (setcc && modified_in_p (new_rtx, setcc)) |
| 944 | return 0; |
| 945 | if (! validate_unshare_change (jump, &SET_SRC (set)(((set)->u.fld[1]).rt_rtx), new_rtx, 0)) |
| 946 | { |
| 947 | /* When (some) constants are not valid in a comparison, and there |
| 948 | are two registers to be replaced by constants before the entire |
| 949 | comparison can be folded into a constant, we need to keep |
| 950 | intermediate information in REG_EQUAL notes. For targets with |
| 951 | separate compare insns, such notes are added by try_replace_reg. |
| 952 | When we have a combined compare-and-branch instruction, however, |
| 953 | we need to attach a note to the branch itself to make this |
| 954 | optimization work. */ |
| 955 | |
| 956 | if (!rtx_equal_p (new_rtx, note_src)) |
| 957 | set_unique_reg_note (jump, REG_EQUAL, copy_rtx (new_rtx)); |
| 958 | return 0; |
| 959 | } |
| 960 | |
| 961 | /* Remove REG_EQUAL note after simplification. */ |
| 962 | if (note_src) |
| 963 | remove_note (jump, note); |
| 964 | } |
| 965 | |
| 966 | global_const_prop_count++; |
| 967 | if (dump_file != NULL__null) |
| 968 | { |
| 969 | fprintf (dump_file, |
| 970 | "GLOBAL CONST-PROP: Replacing reg %d in jump_insn %d with " |
| 971 | "constant ", REGNO (from)(rhs_regno(from)), INSN_UID (jump)); |
| 972 | print_rtl (dump_file, src); |
| 973 | fprintf (dump_file, "\n"); |
| 974 | } |
| 975 | purge_dead_edges (bb); |
| 976 | |
| 977 | /* If a conditional jump has been changed into unconditional jump, remove |
| 978 | the jump and make the edge fallthru - this is always called in |
| 979 | cfglayout mode. */ |
| 980 | if (new_rtx != pc_rtx && simplejump_p (jump)) |
| 981 | { |
| 982 | edge e; |
| 983 | edge_iterator ei; |
| 984 | |
| 985 | FOR_EACH_EDGE (e, ei, bb->succs)for ((ei) = ei_start_1 (&((bb->succs))); ei_cond ((ei) , &(e)); ei_next (&(ei))) |
| 986 | if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)(((cfun + 0))->cfg->x_exit_block_ptr) |
| 987 | && BB_HEAD (e->dest)(e->dest)->il.x.head_ == JUMP_LABEL (jump)(((jump)->u.fld[7]).rt_rtx)) |
| 988 | { |
| 989 | e->flags |= EDGE_FALLTHRU; |
| 990 | break; |
| 991 | } |
| 992 | delete_insn (jump); |
| 993 | } |
| 994 | |
| 995 | return 1; |
| 996 | } |
| 997 | |
| 998 | /* Subroutine of cprop_insn that tries to propagate constants. FROM is what |
| 999 | we will try to replace, SRC is the constant we will try to substitute for |
| 1000 | it and INSN is the instruction where this will be happening. */ |
| 1001 | |
| 1002 | static int |
| 1003 | constprop_register (rtx from, rtx src, rtx_insn *insn) |
| 1004 | { |
| 1005 | rtx sset; |
| 1006 | rtx_insn *next_insn; |
| 1007 | |
| 1008 | /* Check for reg setting instructions followed by conditional branch |
| 1009 | instructions first. */ |
| 1010 | if ((sset = single_set (insn)) != NULL__null |
| 1011 | && (next_insn = next_nondebug_insn (insn)) != NULL__null |
| 1012 | && any_condjump_p (next_insn) |
| 1013 | && onlyjump_p (next_insn)) |
| 1014 | { |
| 1015 | rtx dest = SET_DEST (sset)(((sset)->u.fld[0]).rt_rtx); |
| 1016 | if (REG_P (dest)(((enum rtx_code) (dest)->code) == REG) |
| 1017 | && cprop_jump (BLOCK_FOR_INSN (insn), insn, next_insn, |
| 1018 | from, src)) |
| 1019 | return 1; |
| 1020 | } |
| 1021 | |
| 1022 | /* Handle normal insns next. */ |
| 1023 | if (NONJUMP_INSN_P (insn)(((enum rtx_code) (insn)->code) == INSN) && try_replace_reg (from, src, insn)) |
| 1024 | return 1; |
| 1025 | |
| 1026 | /* Try to propagate a CONST_INT into a conditional jump. |
| 1027 | We're pretty specific about what we will handle in this |
| 1028 | code, we can extend this as necessary over time. |
| 1029 | |
| 1030 | Right now the insn in question must look like |
| 1031 | (set (pc) (if_then_else ...)) */ |
| 1032 | else if (any_condjump_p (insn) && onlyjump_p (insn)) |
| 1033 | return cprop_jump (BLOCK_FOR_INSN (insn), NULL__null, insn, from, src); |
| 1034 | return 0; |
| 1035 | } |
| 1036 | |
| 1037 | /* Perform constant and copy propagation on INSN. |
| 1038 | Return nonzero if a change was made. */ |
| 1039 | |
| 1040 | static int |
| 1041 | cprop_insn (rtx_insn *insn) |
| 1042 | { |
| 1043 | unsigned i; |
| 1044 | int changed = 0, changed_this_round; |
| 1045 | rtx note; |
| 1046 | |
| 1047 | do |
| 1048 | { |
| 1049 | changed_this_round = 0; |
| 1050 | reg_use_count = 0; |
| 1051 | note_uses (&PATTERN (insn), find_used_regs, NULL__null); |
| 1052 | |
| 1053 | /* We may win even when propagating constants into notes. */ |
| 1054 | note = find_reg_equal_equiv_note (insn); |
| 1055 | if (note) |
| 1056 | find_used_regs (&XEXP (note, 0)(((note)->u.fld[0]).rt_rtx), NULL__null); |
| 1057 | |
| 1058 | for (i = 0; i < reg_use_count; i++) |
| 1059 | { |
| 1060 | rtx reg_used = reg_use_table[i]; |
| 1061 | unsigned int regno = REGNO (reg_used)(rhs_regno(reg_used)); |
| 1062 | rtx src_cst = NULL__null, src_reg = NULL__null; |
| 1063 | struct cprop_expr *set[2]; |
| 1064 | |
| 1065 | /* If the register has already been set in this block, there's |
| 1066 | nothing we can do. */ |
| 1067 | if (! reg_not_set_p (reg_used, insn)) |
| 1068 | continue; |
| 1069 | |
| 1070 | /* Find an assignment that sets reg_used and is available |
| 1071 | at the start of the block. */ |
| 1072 | find_avail_set (regno, insn, set); |
| 1073 | if (set[0]) |
| 1074 | src_reg = set[0]->src; |
| 1075 | if (set[1]) |
| 1076 | src_cst = set[1]->src; |
| 1077 | |
| 1078 | /* Constant propagation. */ |
| 1079 | if (src_cst && cprop_constant_p (src_cst) |
| 1080 | && constprop_register (reg_used, src_cst, insn)) |
| 1081 | { |
| 1082 | changed_this_round = changed = 1; |
| 1083 | global_const_prop_count++; |
| 1084 | if (dump_file != NULL__null) |
| 1085 | { |
| 1086 | fprintf (dump_file, |
| 1087 | "GLOBAL CONST-PROP: Replacing reg %d in ", regno); |
| 1088 | fprintf (dump_file, "insn %d with constant ", |
| 1089 | INSN_UID (insn)); |
| 1090 | print_rtl (dump_file, src_cst); |
| 1091 | fprintf (dump_file, "\n"); |
| 1092 | } |
| 1093 | if (insn->deleted ()) |
| 1094 | return 1; |
| 1095 | } |
| 1096 | /* Copy propagation. */ |
| 1097 | else if (src_reg && cprop_reg_p (src_reg) |
| 1098 | && REGNO (src_reg)(rhs_regno(src_reg)) != regno |
| 1099 | && try_replace_reg (reg_used, src_reg, insn)) |
| 1100 | { |
| 1101 | changed_this_round = changed = 1; |
| 1102 | global_copy_prop_count++; |
| 1103 | if (dump_file != NULL__null) |
| 1104 | { |
| 1105 | fprintf (dump_file, |
| 1106 | "GLOBAL COPY-PROP: Replacing reg %d in insn %d", |
| 1107 | regno, INSN_UID (insn)); |
| 1108 | fprintf (dump_file, " with reg %d\n", REGNO (src_reg)(rhs_regno(src_reg))); |
| 1109 | } |
| 1110 | |
| 1111 | /* The original insn setting reg_used may or may not now be |
| 1112 | deletable. We leave the deletion to DCE. */ |
| 1113 | /* FIXME: If it turns out that the insn isn't deletable, |
| 1114 | then we may have unnecessarily extended register lifetimes |
| 1115 | and made things worse. */ |
| 1116 | } |
| 1117 | } |
| 1118 | } |
| 1119 | /* If try_replace_reg simplified the insn, the regs found by find_used_regs |
| 1120 | may not be valid anymore. Start over. */ |
| 1121 | while (changed_this_round); |
| 1122 | |
| 1123 | if (changed && DEBUG_INSN_P (insn)(((enum rtx_code) (insn)->code) == DEBUG_INSN)) |
| 1124 | return 0; |
| 1125 | |
| 1126 | return changed; |
| 1127 | } |
| 1128 | |
| 1129 | /* Like find_used_regs, but avoid recording uses that appear in |
| 1130 | input-output contexts such as zero_extract or pre_dec. This |
| 1131 | restricts the cases we consider to those for which local cprop |
| 1132 | can legitimately make replacements. */ |
| 1133 | |
| 1134 | static void |
| 1135 | local_cprop_find_used_regs (rtx *xptr, void *data) |
| 1136 | { |
| 1137 | rtx x = *xptr; |
| 1138 | |
| 1139 | if (x == 0) |
| 1140 | return; |
| 1141 | |
| 1142 | switch (GET_CODE (x)((enum rtx_code) (x)->code)) |
| 1143 | { |
| 1144 | case ZERO_EXTRACT: |
| 1145 | case SIGN_EXTRACT: |
| 1146 | case STRICT_LOW_PART: |
| 1147 | return; |
| 1148 | |
| 1149 | case PRE_DEC: |
| 1150 | case PRE_INC: |
| 1151 | case POST_DEC: |
| 1152 | case POST_INC: |
| 1153 | case PRE_MODIFY: |
| 1154 | case POST_MODIFY: |
| 1155 | /* Can only legitimately appear this early in the context of |
| 1156 | stack pushes for function arguments, but handle all of the |
| 1157 | codes nonetheless. */ |
| 1158 | return; |
| 1159 | |
| 1160 | case SUBREG: |
| 1161 | if (read_modify_subreg_p (x)) |
| 1162 | return; |
| 1163 | break; |
| 1164 | |
| 1165 | default: |
| 1166 | break; |
| 1167 | } |
| 1168 | |
| 1169 | find_used_regs (xptr, data); |
| 1170 | } |
| 1171 | |
| 1172 | /* Try to perform local const/copy propagation on X in INSN. */ |
| 1173 | |
| 1174 | static bool |
| 1175 | do_local_cprop (rtx x, rtx_insn *insn) |
| 1176 | { |
| 1177 | rtx newreg = NULL__null, newcnst = NULL__null; |
| 1178 | |
| 1179 | /* Rule out USE instructions and ASM statements as we don't want to |
| 1180 | change the hard registers mentioned. */ |
| 1181 | if (REG_P (x)(((enum rtx_code) (x)->code) == REG) |
| 1182 | && (cprop_reg_p (x) |
| 1183 | || (GET_CODE (PATTERN (insn))((enum rtx_code) (PATTERN (insn))->code) != USE |
| 1184 | && asm_noperands (PATTERN (insn)) < 0))) |
| 1185 | { |
| 1186 | cselib_val *val = cselib_lookup (x, GET_MODE (x)((machine_mode) (x)->mode), 0, VOIDmode((void) 0, E_VOIDmode)); |
| 1187 | struct elt_loc_list *l; |
| 1188 | |
| 1189 | if (!val) |
| 1190 | return false; |
| 1191 | for (l = val->locs; l; l = l->next) |
| 1192 | { |
| 1193 | rtx this_rtx = l->loc; |
| 1194 | rtx note; |
| 1195 | |
| 1196 | if (cprop_constant_p (this_rtx)) |
| 1197 | newcnst = this_rtx; |
| 1198 | if (cprop_reg_p (this_rtx) |
| 1199 | /* Don't copy propagate if it has attached REG_EQUIV note. |
| 1200 | At this point this only function parameters should have |
| 1201 | REG_EQUIV notes and if the argument slot is used somewhere |
| 1202 | explicitly, it means address of parameter has been taken, |
| 1203 | so we should not extend the lifetime of the pseudo. */ |
| 1204 | && (!(note = find_reg_note (l->setting_insn, REG_EQUIV, NULL_RTX(rtx) 0)) |
| 1205 | || ! MEM_P (XEXP (note, 0))(((enum rtx_code) ((((note)->u.fld[0]).rt_rtx))->code) == MEM))) |
| 1206 | newreg = this_rtx; |
| 1207 | } |
| 1208 | if (newcnst && constprop_register (x, newcnst, insn)) |
| 1209 | { |
| 1210 | if (dump_file != NULL__null) |
| 1211 | { |
| 1212 | fprintf (dump_file, "LOCAL CONST-PROP: Replacing reg %d in ", |
| 1213 | REGNO (x)(rhs_regno(x))); |
| 1214 | fprintf (dump_file, "insn %d with constant ", |
| 1215 | INSN_UID (insn)); |
| 1216 | print_rtl (dump_file, newcnst); |
| 1217 | fprintf (dump_file, "\n"); |
| 1218 | } |
| 1219 | local_const_prop_count++; |
| 1220 | return true; |
| 1221 | } |
| 1222 | else if (newreg && newreg != x && try_replace_reg (x, newreg, insn)) |
| 1223 | { |
| 1224 | if (dump_file != NULL__null) |
| 1225 | { |
| 1226 | fprintf (dump_file, |
| 1227 | "LOCAL COPY-PROP: Replacing reg %d in insn %d", |
| 1228 | REGNO (x)(rhs_regno(x)), INSN_UID (insn)); |
| 1229 | fprintf (dump_file, " with reg %d\n", REGNO (newreg)(rhs_regno(newreg))); |
| 1230 | } |
| 1231 | local_copy_prop_count++; |
| 1232 | return true; |
| 1233 | } |
| 1234 | } |
| 1235 | return false; |
| 1236 | } |
| 1237 | |
| 1238 | /* Do local const/copy propagation (i.e. within each basic block). */ |
| 1239 | |
| 1240 | static int |
| 1241 | local_cprop_pass (void) |
| 1242 | { |
| 1243 | basic_block bb; |
| 1244 | rtx_insn *insn; |
| 1245 | bool changed = false; |
| 1246 | unsigned i; |
| 1247 | |
| 1248 | auto_vec<rtx_insn *> uncond_traps; |
| 1249 | |
| 1250 | cselib_init (0); |
| 1251 | 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) |
| 1252 | { |
| 1253 | FOR_BB_INSNS (bb, insn)for ((insn) = (bb)->il.x.head_; (insn) && (insn) != NEXT_INSN ((bb)->il.x.rtl->end_); (insn) = NEXT_INSN ( insn)) |
| 1254 | { |
| 1255 | if (INSN_P (insn)(((((enum rtx_code) (insn)->code) == INSN) || (((enum rtx_code ) (insn)->code) == JUMP_INSN) || (((enum rtx_code) (insn)-> code) == CALL_INSN)) || (((enum rtx_code) (insn)->code) == DEBUG_INSN))) |
| 1256 | { |
| 1257 | bool was_uncond_trap |
| 1258 | = (GET_CODE (PATTERN (insn))((enum rtx_code) (PATTERN (insn))->code) == TRAP_IF |
| 1259 | && XEXP (PATTERN (insn), 0)(((PATTERN (insn))->u.fld[0]).rt_rtx) == const1_rtx(const_int_rtx[64 +1])); |
| 1260 | rtx note = find_reg_equal_equiv_note (insn); |
| 1261 | do |
| 1262 | { |
| 1263 | reg_use_count = 0; |
| 1264 | note_uses (&PATTERN (insn), local_cprop_find_used_regs, |
| 1265 | NULL__null); |
| 1266 | if (note) |
| 1267 | local_cprop_find_used_regs (&XEXP (note, 0)(((note)->u.fld[0]).rt_rtx), NULL__null); |
| 1268 | |
| 1269 | for (i = 0; i < reg_use_count; i++) |
| 1270 | { |
| 1271 | if (do_local_cprop (reg_use_table[i], insn)) |
| 1272 | { |
| 1273 | if (!DEBUG_INSN_P (insn)(((enum rtx_code) (insn)->code) == DEBUG_INSN)) |
| 1274 | changed = true; |
| 1275 | break; |
| 1276 | } |
| 1277 | } |
| 1278 | if (!was_uncond_trap |
| 1279 | && GET_CODE (PATTERN (insn))((enum rtx_code) (PATTERN (insn))->code) == TRAP_IF |
| 1280 | && XEXP (PATTERN (insn), 0)(((PATTERN (insn))->u.fld[0]).rt_rtx) == const1_rtx(const_int_rtx[64 +1])) |
| 1281 | { |
| 1282 | uncond_traps.safe_push (insn); |
| 1283 | break; |
| 1284 | } |
| 1285 | if (insn->deleted ()) |
| 1286 | break; |
| 1287 | } |
| 1288 | while (i < reg_use_count); |
| 1289 | } |
| 1290 | cselib_process_insn (insn); |
| 1291 | } |
| 1292 | |
| 1293 | /* Forget everything at the end of a basic block. */ |
| 1294 | cselib_clear_table (); |
| 1295 | } |
| 1296 | |
| 1297 | cselib_finish (); |
| 1298 | |
| 1299 | while (!uncond_traps.is_empty ()) |
| 1300 | { |
| 1301 | rtx_insn *insn = uncond_traps.pop (); |
| 1302 | basic_block to_split = BLOCK_FOR_INSN (insn); |
| 1303 | remove_edge (split_block (to_split, insn)); |
| 1304 | emit_barrier_after_bb (to_split); |
| 1305 | } |
| 1306 | |
| 1307 | return changed; |
| 1308 | } |
| 1309 | |
| 1310 | /* Similar to get_condition, only the resulting condition must be |
| 1311 | valid at JUMP, instead of at EARLIEST. |
| 1312 | |
| 1313 | This differs from noce_get_condition in ifcvt.cc in that we prefer not to |
| 1314 | settle for the condition variable in the jump instruction being integral. |
| 1315 | We prefer to be able to record the value of a user variable, rather than |
| 1316 | the value of a temporary used in a condition. This could be solved by |
| 1317 | recording the value of *every* register scanned by canonicalize_condition, |
| 1318 | but this would require some code reorganization. */ |
| 1319 | |
| 1320 | rtx |
| 1321 | fis_get_condition (rtx_insn *jump) |
| 1322 | { |
| 1323 | return get_condition (jump, NULL__null, false, true); |
| 1324 | } |
| 1325 | |
| 1326 | /* Check the comparison COND to see if we can safely form an implicit |
| 1327 | set from it. */ |
| 1328 | |
| 1329 | static bool |
| 1330 | implicit_set_cond_p (const_rtx cond) |
| 1331 | { |
| 1332 | machine_mode mode; |
| 1333 | rtx cst; |
| 1334 | |
| 1335 | /* COND must be either an EQ or NE comparison. */ |
| 1336 | if (GET_CODE (cond)((enum rtx_code) (cond)->code) != EQ && GET_CODE (cond)((enum rtx_code) (cond)->code) != NE) |
| 1337 | return false; |
| 1338 | |
| 1339 | /* The first operand of COND must be a register we can propagate. */ |
| 1340 | if (!cprop_reg_p (XEXP (cond, 0)(((cond)->u.fld[0]).rt_rtx))) |
| 1341 | return false; |
| 1342 | |
| 1343 | /* The second operand of COND must be a suitable constant. */ |
| 1344 | mode = GET_MODE (XEXP (cond, 0))((machine_mode) ((((cond)->u.fld[0]).rt_rtx))->mode); |
| 1345 | cst = XEXP (cond, 1)(((cond)->u.fld[1]).rt_rtx); |
| 1346 | |
| 1347 | /* We can't perform this optimization if either operand might be or might |
| 1348 | contain a signed zero. */ |
| 1349 | if (HONOR_SIGNED_ZEROS (mode)) |
| 1350 | { |
| 1351 | /* It is sufficient to check if CST is or contains a zero. We must |
| 1352 | handle float, complex, and vector. If any subpart is a zero, then |
| 1353 | the optimization can't be performed. */ |
| 1354 | /* ??? The complex and vector checks are not implemented yet. We just |
| 1355 | always return zero for them. */ |
| 1356 | if (CONST_DOUBLE_AS_FLOAT_P (cst)(((enum rtx_code) (cst)->code) == CONST_DOUBLE && ( (machine_mode) (cst)->mode) != ((void) 0, E_VOIDmode)) |
| 1357 | && real_equal (CONST_DOUBLE_REAL_VALUE (cst)((const struct real_value *) (&(cst)->u.rv)), &dconst0)) |
| 1358 | return 0; |
| 1359 | else |
| 1360 | return 0; |
| 1361 | } |
| 1362 | |
| 1363 | return cprop_constant_p (cst); |
| 1364 | } |
| 1365 | |
| 1366 | /* Find the implicit sets of a function. An "implicit set" is a constraint |
| 1367 | on the value of a variable, implied by a conditional jump. For example, |
| 1368 | following "if (x == 2)", the then branch may be optimized as though the |
| 1369 | conditional performed an "explicit set", in this example, "x = 2". This |
| 1370 | function records the set patterns that are implicit at the start of each |
| 1371 | basic block. |
| 1372 | |
| 1373 | If an implicit set is found but the set is implicit on a critical edge, |
| 1374 | this critical edge is split. |
| 1375 | |
| 1376 | Return true if the CFG was modified, false otherwise. */ |
| 1377 | |
| 1378 | static bool |
| 1379 | find_implicit_sets (void) |
| 1380 | { |
| 1381 | basic_block bb, dest; |
| 1382 | rtx cond, new_rtx; |
| 1383 | unsigned int count = 0; |
| 1384 | bool edges_split = false; |
| 1385 | size_t implicit_sets_size = last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block) + 10; |
| 1386 | |
| 1387 | implicit_sets = XCNEWVEC (rtx, implicit_sets_size)((rtx *) xcalloc ((implicit_sets_size), sizeof (rtx))); |
| 1388 | |
| 1389 | 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) |
| 1390 | { |
| 1391 | /* Check for more than one successor. */ |
| 1392 | if (EDGE_COUNT (bb->succs)vec_safe_length (bb->succs) <= 1) |
| 1393 | continue; |
| 1394 | |
| 1395 | cond = fis_get_condition (BB_END (bb)(bb)->il.x.rtl->end_); |
| 1396 | |
| 1397 | /* If no condition is found or if it isn't of a suitable form, |
| 1398 | ignore it. */ |
| 1399 | if (! cond || ! implicit_set_cond_p (cond)) |
| 1400 | continue; |
| 1401 | |
| 1402 | dest = GET_CODE (cond)((enum rtx_code) (cond)->code) == EQ |
| 1403 | ? BRANCH_EDGE (bb)((*((bb))->succs)[(0)]->flags & EDGE_FALLTHRU ? (*( (bb))->succs)[(1)] : (*((bb))->succs)[(0)])->dest : FALLTHRU_EDGE (bb)((*((bb))->succs)[(0)]->flags & EDGE_FALLTHRU ? (*( (bb))->succs)[(0)] : (*((bb))->succs)[(1)])->dest; |
| 1404 | |
| 1405 | /* If DEST doesn't go anywhere, ignore it. */ |
| 1406 | if (! dest || dest == EXIT_BLOCK_PTR_FOR_FN (cfun)(((cfun + 0))->cfg->x_exit_block_ptr)) |
| 1407 | continue; |
| 1408 | |
| 1409 | /* We have found a suitable implicit set. Try to record it now as |
| 1410 | a SET in DEST. If DEST has more than one predecessor, the edge |
| 1411 | between BB and DEST is a critical edge and we must split it, |
| 1412 | because we can only record one implicit set per DEST basic block. */ |
| 1413 | if (! single_pred_p (dest)) |
| 1414 | { |
| 1415 | dest = split_edge (find_edge (bb, dest)); |
| 1416 | edges_split = true; |
| 1417 | } |
| 1418 | |
| 1419 | if (implicit_sets_size <= (size_t) dest->index) |
| 1420 | { |
| 1421 | size_t old_implicit_sets_size = implicit_sets_size; |
| 1422 | implicit_sets_size *= 2; |
| 1423 | implicit_sets = XRESIZEVEC (rtx, implicit_sets, implicit_sets_size)((rtx *) xrealloc ((void *) (implicit_sets), sizeof (rtx) * ( implicit_sets_size))); |
| 1424 | memset (implicit_sets + old_implicit_sets_size, 0, |
| 1425 | (implicit_sets_size - old_implicit_sets_size) * sizeof (rtx)); |
| 1426 | } |
| 1427 | |
| 1428 | new_rtx = gen_rtx_SET (XEXP (cond, 0), XEXP (cond, 1))gen_rtx_fmt_ee_stat ((SET), (((void) 0, E_VOIDmode)), (((((cond )->u.fld[0]).rt_rtx))), (((((cond)->u.fld[1]).rt_rtx))) ); |
| 1429 | implicit_sets[dest->index] = new_rtx; |
| 1430 | if (dump_file) |
| 1431 | { |
| 1432 | fprintf (dump_file, "Implicit set of reg %d in ", |
| 1433 | REGNO (XEXP (cond, 0))(rhs_regno((((cond)->u.fld[0]).rt_rtx)))); |
| 1434 | fprintf (dump_file, "basic block %d\n", dest->index); |
| 1435 | } |
| 1436 | count++; |
| 1437 | } |
| 1438 | |
| 1439 | if (dump_file) |
| 1440 | fprintf (dump_file, "Found %d implicit sets\n", count); |
| 1441 | |
| 1442 | /* Confess our sins. */ |
| 1443 | return edges_split; |
| 1444 | } |
| 1445 | |
| 1446 | /* Bypass conditional jumps. */ |
| 1447 | |
| 1448 | /* The value of last_basic_block at the beginning of the jump_bypass |
| 1449 | pass. The use of redirect_edge_and_branch_force may introduce new |
| 1450 | basic blocks, but the data flow analysis is only valid for basic |
| 1451 | block indices less than bypass_last_basic_block. */ |
| 1452 | |
| 1453 | static int bypass_last_basic_block; |
| 1454 | |
| 1455 | /* Find a set of REGNO to a constant that is available at the end of basic |
| 1456 | block BB. Return NULL if no such set is found. Based heavily upon |
| 1457 | find_avail_set. */ |
| 1458 | |
| 1459 | static struct cprop_expr * |
| 1460 | find_bypass_set (int regno, int bb) |
| 1461 | { |
| 1462 | struct cprop_expr *result = 0; |
| 1463 | |
| 1464 | for (;;) |
| 1465 | { |
| 1466 | rtx src; |
| 1467 | struct cprop_expr *set = lookup_set (regno, &set_hash_table); |
| 1468 | |
| 1469 | while (set) |
| 1470 | { |
| 1471 | if (bitmap_bit_p (cprop_avout[bb], set->bitmap_index)) |
| 1472 | break; |
| 1473 | set = next_set (regno, set); |
| 1474 | } |
| 1475 | |
| 1476 | if (set == 0) |
| 1477 | break; |
| 1478 | |
| 1479 | src = set->src; |
| 1480 | if (cprop_constant_p (src)) |
| 1481 | result = set; |
| 1482 | |
| 1483 | if (! REG_P (src)(((enum rtx_code) (src)->code) == REG)) |
| 1484 | break; |
| 1485 | |
| 1486 | regno = REGNO (src)(rhs_regno(src)); |
| 1487 | } |
| 1488 | return result; |
| 1489 | } |
| 1490 | |
| 1491 | /* Subroutine of bypass_block that checks whether a pseudo is killed by |
| 1492 | any of the instructions inserted on an edge. Jump bypassing places |
| 1493 | condition code setters on CFG edges using insert_insn_on_edge. This |
| 1494 | function is required to check that our data flow analysis is still |
| 1495 | valid prior to commit_edge_insertions. */ |
| 1496 | |
| 1497 | static bool |
| 1498 | reg_killed_on_edge (const_rtx reg, const_edge e) |
| 1499 | { |
| 1500 | rtx_insn *insn; |
| 1501 | |
| 1502 | for (insn = e->insns.r; insn; insn = NEXT_INSN (insn)) |
| 1503 | if (INSN_P (insn)(((((enum rtx_code) (insn)->code) == INSN) || (((enum rtx_code ) (insn)->code) == JUMP_INSN) || (((enum rtx_code) (insn)-> code) == CALL_INSN)) || (((enum rtx_code) (insn)->code) == DEBUG_INSN)) && reg_set_p (reg, insn)) |
| 1504 | return true; |
| 1505 | |
| 1506 | return false; |
| 1507 | } |
| 1508 | |
| 1509 | /* Subroutine of bypass_conditional_jumps that attempts to bypass the given |
| 1510 | basic block BB which has more than one predecessor. If not NULL, SETCC |
| 1511 | is the first instruction of BB, which is immediately followed by JUMP_INSN |
| 1512 | JUMP. Otherwise, SETCC is NULL, and JUMP is the first insn of BB. |
| 1513 | Returns nonzero if a change was made. |
| 1514 | |
| 1515 | During the jump bypassing pass, we may place copies of SETCC instructions |
| 1516 | on CFG edges. The following routine must be careful to pay attention to |
| 1517 | these inserted insns when performing its transformations. */ |
| 1518 | |
| 1519 | static int |
| 1520 | bypass_block (basic_block bb, rtx_insn *setcc, rtx_insn *jump) |
| 1521 | { |
| 1522 | rtx_insn *insn; |
| 1523 | rtx note; |
| 1524 | edge e, edest; |
| 1525 | int change; |
| 1526 | int may_be_loop_header = false; |
| 1527 | unsigned removed_p; |
| 1528 | unsigned i; |
| 1529 | edge_iterator ei; |
| 1530 | |
| 1531 | insn = (setcc != NULL__null) ? setcc : jump; |
| 1532 | |
| 1533 | /* Determine set of register uses in INSN. */ |
| 1534 | reg_use_count = 0; |
| 1535 | note_uses (&PATTERN (insn), find_used_regs, NULL__null); |
| 1536 | note = find_reg_equal_equiv_note (insn); |
| 1537 | if (note) |
| 1538 | find_used_regs (&XEXP (note, 0)(((note)->u.fld[0]).rt_rtx), NULL__null); |
| 1539 | |
| 1540 | if (current_loops((cfun + 0)->x_current_loops)) |
| 1541 | { |
| 1542 | /* If we are to preserve loop structure then do not bypass |
| 1543 | a loop header. This will either rotate the loop, create |
| 1544 | multiple entry loops or even irreducible regions. */ |
| 1545 | if (bb == bb->loop_father->header) |
| 1546 | return 0; |
| 1547 | } |
| 1548 | else |
| 1549 | { |
| 1550 | FOR_EACH_EDGE (e, ei, bb->preds)for ((ei) = ei_start_1 (&((bb->preds))); ei_cond ((ei) , &(e)); ei_next (&(ei))) |
| 1551 | if (e->flags & EDGE_DFS_BACK) |
| 1552 | { |
| 1553 | may_be_loop_header = true; |
| 1554 | break; |
| 1555 | } |
| 1556 | } |
| 1557 | |
| 1558 | change = 0; |
| 1559 | for (ei = ei_start (bb->preds)ei_start_1 (&(bb->preds)); (e = ei_safe_edge (ei)); ) |
| 1560 | { |
| 1561 | removed_p = 0; |
| 1562 | |
| 1563 | if (e->flags & EDGE_COMPLEX(EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH | EDGE_PRESERVE )) |
| 1564 | { |
| 1565 | ei_next (&ei); |
| 1566 | continue; |
| 1567 | } |
| 1568 | |
| 1569 | /* We can't redirect edges from new basic blocks. */ |
| 1570 | if (e->src->index >= bypass_last_basic_block) |
| 1571 | { |
| 1572 | ei_next (&ei); |
| 1573 | continue; |
| 1574 | } |
| 1575 | |
| 1576 | /* The irreducible loops created by redirecting of edges entering the |
| 1577 | loop from outside would decrease effectiveness of some of the |
| 1578 | following optimizations, so prevent this. */ |
| 1579 | if (may_be_loop_header |
| 1580 | && !(e->flags & EDGE_DFS_BACK)) |
| 1581 | { |
| 1582 | ei_next (&ei); |
| 1583 | continue; |
| 1584 | } |
| 1585 | |
| 1586 | for (i = 0; i < reg_use_count; i++) |
| 1587 | { |
| 1588 | rtx reg_used = reg_use_table[i]; |
| 1589 | unsigned int regno = REGNO (reg_used)(rhs_regno(reg_used)); |
| 1590 | basic_block dest, old_dest; |
| 1591 | struct cprop_expr *set; |
| 1592 | rtx src, new_rtx; |
| 1593 | |
| 1594 | set = find_bypass_set (regno, e->src->index); |
| 1595 | |
| 1596 | if (! set) |
| 1597 | continue; |
| 1598 | |
| 1599 | /* Check the data flow is valid after edge insertions. */ |
| 1600 | if (e->insns.r && reg_killed_on_edge (reg_used, e)) |
| 1601 | continue; |
| 1602 | |
| 1603 | src = SET_SRC (pc_set (jump))(((pc_set (jump))->u.fld[1]).rt_rtx); |
| 1604 | |
| 1605 | if (setcc != NULL__null) |
| 1606 | src = simplify_replace_rtx (src, |
| 1607 | SET_DEST (PATTERN (setcc))(((PATTERN (setcc))->u.fld[0]).rt_rtx), |
| 1608 | SET_SRC (PATTERN (setcc))(((PATTERN (setcc))->u.fld[1]).rt_rtx)); |
| 1609 | |
| 1610 | new_rtx = simplify_replace_rtx (src, reg_used, set->src); |
| 1611 | |
| 1612 | /* Jump bypassing may have already placed instructions on |
| 1613 | edges of the CFG. We can't bypass an outgoing edge that |
| 1614 | has instructions associated with it, as these insns won't |
| 1615 | get executed if the incoming edge is redirected. */ |
| 1616 | if (new_rtx == pc_rtx) |
| 1617 | { |
| 1618 | edest = FALLTHRU_EDGE (bb)((*((bb))->succs)[(0)]->flags & EDGE_FALLTHRU ? (*( (bb))->succs)[(0)] : (*((bb))->succs)[(1)]); |
| 1619 | dest = edest->insns.r ? NULL__null : edest->dest; |
| 1620 | } |
| 1621 | else if (GET_CODE (new_rtx)((enum rtx_code) (new_rtx)->code) == LABEL_REF) |
| 1622 | { |
| 1623 | dest = BLOCK_FOR_INSN (XEXP (new_rtx, 0)(((new_rtx)->u.fld[0]).rt_rtx)); |
| 1624 | /* Don't bypass edges containing instructions. */ |
| 1625 | if (dest) |
| 1626 | { |
| 1627 | edest = find_edge (bb, dest); |
| 1628 | if (edest && edest->insns.r) |
| 1629 | dest = NULL__null; |
| 1630 | } |
| 1631 | } |
| 1632 | else |
| 1633 | dest = NULL__null; |
| 1634 | |
| 1635 | /* Avoid unification of the edge with other edges from original |
| 1636 | branch. We would end up emitting the instruction on "both" |
| 1637 | edges. */ |
| 1638 | if (dest && setcc && find_edge (e->src, dest)) |
| 1639 | dest = NULL__null; |
| 1640 | |
| 1641 | old_dest = e->dest; |
| 1642 | if (dest != NULL__null |
| 1643 | && dest != old_dest |
| 1644 | && dest != EXIT_BLOCK_PTR_FOR_FN (cfun)(((cfun + 0))->cfg->x_exit_block_ptr)) |
| 1645 | { |
| 1646 | redirect_edge_and_branch_force (e, dest); |
| 1647 | |
| 1648 | /* Copy the register setter to the redirected edge. */ |
| 1649 | if (setcc) |
| 1650 | { |
| 1651 | rtx pat = PATTERN (setcc); |
| 1652 | insert_insn_on_edge (copy_insn (pat), e); |
| 1653 | } |
| 1654 | |
| 1655 | if (dump_file != NULL__null) |
| 1656 | { |
| 1657 | fprintf (dump_file, "JUMP-BYPASS: Proved reg %d " |
| 1658 | "in jump_insn %d equals constant ", |
| 1659 | regno, INSN_UID (jump)); |
| 1660 | print_rtl (dump_file, set->src); |
| 1661 | fprintf (dump_file, "\n\t when BB %d is entered from " |
| 1662 | "BB %d. Redirect edge %d->%d to %d.\n", |
| 1663 | old_dest->index, e->src->index, e->src->index, |
| 1664 | old_dest->index, dest->index); |
| 1665 | } |
| 1666 | change = 1; |
| 1667 | removed_p = 1; |
| 1668 | break; |
| 1669 | } |
| 1670 | } |
| 1671 | if (!removed_p) |
| 1672 | ei_next (&ei); |
| 1673 | } |
| 1674 | return change; |
| 1675 | } |
| 1676 | |
| 1677 | /* Find basic blocks with more than one predecessor that only contain a |
| 1678 | single conditional jump. If the result of the comparison is known at |
| 1679 | compile-time from any incoming edge, redirect that edge to the |
| 1680 | appropriate target. Return nonzero if a change was made. |
| 1681 | |
| 1682 | This function is now mis-named, because we also handle indirect jumps. */ |
| 1683 | |
| 1684 | static int |
| 1685 | bypass_conditional_jumps (void) |
| 1686 | { |
| 1687 | basic_block bb; |
| 1688 | int changed; |
| 1689 | rtx_insn *setcc; |
| 1690 | rtx_insn *insn; |
| 1691 | rtx dest; |
| 1692 | |
| 1693 | /* Note we start at block 1. */ |
| 1694 | if (ENTRY_BLOCK_PTR_FOR_FN (cfun)(((cfun + 0))->cfg->x_entry_block_ptr)->next_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)(((cfun + 0))->cfg->x_exit_block_ptr)) |
| 1695 | return 0; |
| 1696 | |
| 1697 | mark_dfs_back_edges (); |
| 1698 | |
| 1699 | changed = 0; |
| 1700 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb->next_bb,for (bb = (((cfun + 0))->cfg->x_entry_block_ptr)->next_bb ->next_bb; bb != (((cfun + 0))->cfg->x_exit_block_ptr ); bb = bb->next_bb) |
| 1701 | EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb)for (bb = (((cfun + 0))->cfg->x_entry_block_ptr)->next_bb ->next_bb; bb != (((cfun + 0))->cfg->x_exit_block_ptr ); bb = bb->next_bb) |
| 1702 | { |
| 1703 | /* Check for more than one predecessor. */ |
| 1704 | if (!single_pred_p (bb)) |
| 1705 | { |
| 1706 | setcc = NULL__null; |
| 1707 | FOR_BB_INSNS (bb, insn)for ((insn) = (bb)->il.x.head_; (insn) && (insn) != NEXT_INSN ((bb)->il.x.rtl->end_); (insn) = NEXT_INSN ( insn)) |
| 1708 | if (DEBUG_INSN_P (insn)(((enum rtx_code) (insn)->code) == DEBUG_INSN)) |
| 1709 | continue; |
| 1710 | else if (NONJUMP_INSN_P (insn)(((enum rtx_code) (insn)->code) == INSN)) |
| 1711 | { |
| 1712 | if (setcc) |
| 1713 | break; |
| 1714 | if (GET_CODE (PATTERN (insn))((enum rtx_code) (PATTERN (insn))->code) != SET) |
| 1715 | break; |
| 1716 | |
| 1717 | dest = SET_DEST (PATTERN (insn))(((PATTERN (insn))->u.fld[0]).rt_rtx); |
| 1718 | if (REG_P (dest)(((enum rtx_code) (dest)->code) == REG)) |
| 1719 | setcc = insn; |
| 1720 | else |
| 1721 | break; |
| 1722 | } |
| 1723 | else if (JUMP_P (insn)(((enum rtx_code) (insn)->code) == JUMP_INSN)) |
| 1724 | { |
| 1725 | if ((any_condjump_p (insn) || computed_jump_p (insn)) |
| 1726 | && onlyjump_p (insn)) |
| 1727 | changed |= bypass_block (bb, setcc, insn); |
| 1728 | break; |
| 1729 | } |
| 1730 | else if (INSN_P (insn)(((((enum rtx_code) (insn)->code) == INSN) || (((enum rtx_code ) (insn)->code) == JUMP_INSN) || (((enum rtx_code) (insn)-> code) == CALL_INSN)) || (((enum rtx_code) (insn)->code) == DEBUG_INSN))) |
| 1731 | break; |
| 1732 | } |
| 1733 | } |
| 1734 | |
| 1735 | /* If we bypassed any register setting insns, we inserted a |
| 1736 | copy on the redirected edge. These need to be committed. */ |
| 1737 | if (changed) |
| 1738 | commit_edge_insertions (); |
| 1739 | |
| 1740 | return changed; |
| 1741 | } |
| 1742 | |
| 1743 | /* Main function for the CPROP pass. */ |
| 1744 | |
| 1745 | static int |
| 1746 | one_cprop_pass (void) |
| 1747 | { |
| 1748 | int i; |
| 1749 | int changed = 0; |
| 1750 | |
| 1751 | /* Return if there's nothing to do, or it is too expensive. */ |
| 1752 | if (n_basic_blocks_for_fn (cfun)(((cfun + 0))->cfg->x_n_basic_blocks) <= NUM_FIXED_BLOCKS(2) + 1 |
| 1753 | || gcse_or_cprop_is_too_expensive (_ ("const/copy propagation disabled")gettext ("const/copy propagation disabled"))) |
| 1754 | return 0; |
| 1755 | |
| 1756 | global_const_prop_count = local_const_prop_count = 0; |
| 1757 | global_copy_prop_count = local_copy_prop_count = 0; |
| 1758 | |
| 1759 | bytes_used = 0; |
| 1760 | gcc_obstack_init (&cprop_obstack)_obstack_begin (((&cprop_obstack)), (memory_block_pool::block_size ), (0), (mempool_obstack_chunk_alloc), (mempool_obstack_chunk_free )); |
| 1761 | |
| 1762 | /* Do a local const/copy propagation pass first. The global pass |
| 1763 | only handles global opportunities. |
| 1764 | If the local pass changes something, remove any unreachable blocks |
| 1765 | because the CPROP global dataflow analysis may get into infinite |
| 1766 | loops for CFGs with unreachable blocks. |
| 1767 | |
| 1768 | FIXME: This local pass should not be necessary after CSE (but for |
| 1769 | some reason it still is). It is also (proven) not necessary |
| 1770 | to run the local pass right after FWPWOP. |
| 1771 | |
| 1772 | FIXME: The global analysis would not get into infinite loops if it |
| 1773 | would use the DF solver (via df_simple_dataflow) instead of |
| 1774 | the solver implemented in this file. */ |
| 1775 | changed |= local_cprop_pass (); |
| 1776 | if (changed) |
| 1777 | delete_unreachable_blocks (); |
| 1778 | |
| 1779 | /* Determine implicit sets. This may change the CFG (split critical |
| 1780 | edges if that exposes an implicit set). |
| 1781 | Note that find_implicit_sets() does not rely on up-to-date DF caches |
| 1782 | so that we do not have to re-run df_analyze() even if local CPROP |
| 1783 | changed something. |
| 1784 | ??? This could run earlier so that any uncovered implicit sets |
| 1785 | sets could be exploited in local_cprop_pass() also. Later. */ |
| 1786 | changed |= find_implicit_sets (); |
| 1787 | |
| 1788 | /* If local_cprop_pass() or find_implicit_sets() changed something, |
| 1789 | run df_analyze() to bring all insn caches up-to-date, and to take |
| 1790 | new basic blocks from edge splitting on the DF radar. |
| 1791 | NB: This also runs the fast DCE pass, because execute_rtl_cprop |
| 1792 | sets DF_LR_RUN_DCE. */ |
| 1793 | if (changed) |
| 1794 | df_analyze (); |
| 1795 | |
| 1796 | /* Initialize implicit_set_indexes array. */ |
| 1797 | implicit_set_indexes = XNEWVEC (int, last_basic_block_for_fn (cfun))((int *) xmalloc (sizeof (int) * ((((cfun + 0))->cfg->x_last_basic_block )))); |
| 1798 | for (i = 0; i < last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block); i++) |
| 1799 | implicit_set_indexes[i] = -1; |
| 1800 | |
| 1801 | alloc_hash_table (&set_hash_table); |
| 1802 | compute_hash_table (&set_hash_table); |
| 1803 | |
| 1804 | /* Free implicit_sets before peak usage. */ |
| 1805 | free (implicit_sets); |
| 1806 | implicit_sets = NULL__null; |
| 1807 | |
| 1808 | if (dump_file) |
| 1809 | dump_hash_table (dump_file, "SET", &set_hash_table); |
| 1810 | if (set_hash_table.n_elems > 0) |
| 1811 | { |
| 1812 | basic_block bb; |
| 1813 | auto_vec<rtx_insn *> uncond_traps; |
| 1814 | |
| 1815 | alloc_cprop_mem (last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block), |
| 1816 | set_hash_table.n_elems); |
| 1817 | compute_cprop_data (); |
| 1818 | |
| 1819 | free (implicit_set_indexes); |
| 1820 | implicit_set_indexes = NULL__null; |
| 1821 | |
| 1822 | /* Allocate vars to track sets of regs. */ |
| 1823 | reg_set_bitmap = ALLOC_REG_SET (NULL)bitmap_alloc (__null); |
| 1824 | |
| 1825 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb->next_bb,for (bb = (((cfun + 0))->cfg->x_entry_block_ptr)->next_bb ->next_bb; bb != (((cfun + 0))->cfg->x_exit_block_ptr ); bb = bb->next_bb) |
| 1826 | EXIT_BLOCK_PTR_FOR_FN (cfun),for (bb = (((cfun + 0))->cfg->x_entry_block_ptr)->next_bb ->next_bb; bb != (((cfun + 0))->cfg->x_exit_block_ptr ); bb = bb->next_bb) |
| 1827 | next_bb)for (bb = (((cfun + 0))->cfg->x_entry_block_ptr)->next_bb ->next_bb; bb != (((cfun + 0))->cfg->x_exit_block_ptr ); bb = bb->next_bb) |
| 1828 | { |
| 1829 | bool seen_uncond_trap = false; |
| 1830 | rtx_insn *insn; |
| 1831 | |
| 1832 | /* Reset tables used to keep track of what's still valid [since |
| 1833 | the start of the block]. */ |
| 1834 | reset_opr_set_tables (); |
| 1835 | |
| 1836 | FOR_BB_INSNS (bb, insn)for ((insn) = (bb)->il.x.head_; (insn) && (insn) != NEXT_INSN ((bb)->il.x.rtl->end_); (insn) = NEXT_INSN ( insn)) |
| 1837 | if (INSN_P (insn)(((((enum rtx_code) (insn)->code) == INSN) || (((enum rtx_code ) (insn)->code) == JUMP_INSN) || (((enum rtx_code) (insn)-> code) == CALL_INSN)) || (((enum rtx_code) (insn)->code) == DEBUG_INSN))) |
| 1838 | { |
| 1839 | bool was_uncond_trap |
| 1840 | = (GET_CODE (PATTERN (insn))((enum rtx_code) (PATTERN (insn))->code) == TRAP_IF |
| 1841 | && XEXP (PATTERN (insn), 0)(((PATTERN (insn))->u.fld[0]).rt_rtx) == const1_rtx(const_int_rtx[64 +1])); |
| 1842 | |
| 1843 | changed |= cprop_insn (insn); |
| 1844 | |
| 1845 | /* Keep track of everything modified by this insn. */ |
| 1846 | /* ??? Need to be careful w.r.t. mods done to INSN. |
| 1847 | Don't call mark_oprs_set if we turned the |
| 1848 | insn into a NOTE, or deleted the insn. */ |
| 1849 | if (! NOTE_P (insn)(((enum rtx_code) (insn)->code) == NOTE) && ! insn->deleted ()) |
| 1850 | mark_oprs_set (insn); |
| 1851 | |
| 1852 | if (!was_uncond_trap |
| 1853 | && GET_CODE (PATTERN (insn))((enum rtx_code) (PATTERN (insn))->code) == TRAP_IF |
| 1854 | && XEXP (PATTERN (insn), 0)(((PATTERN (insn))->u.fld[0]).rt_rtx) == const1_rtx(const_int_rtx[64 +1])) |
| 1855 | { |
| 1856 | /* If we have already seen an unconditional trap |
| 1857 | earlier, the rest of the bb is going to be removed |
| 1858 | as unreachable. Just turn it into a note, so that |
| 1859 | RTL verification doesn't complain about it before |
| 1860 | it is finally removed. */ |
| 1861 | if (seen_uncond_trap) |
| 1862 | set_insn_deleted (insn); |
| 1863 | else |
| 1864 | { |
| 1865 | seen_uncond_trap = true; |
| 1866 | uncond_traps.safe_push (insn); |
| 1867 | } |
| 1868 | } |
| 1869 | } |
| 1870 | } |
| 1871 | |
| 1872 | /* Make sure bypass_conditional_jumps will ignore not just its new |
| 1873 | basic blocks, but also the ones after unconditional traps (those are |
| 1874 | unreachable and will be eventually removed as such). */ |
| 1875 | bypass_last_basic_block = last_basic_block_for_fn (cfun)(((cfun + 0))->cfg->x_last_basic_block); |
| 1876 | |
| 1877 | while (!uncond_traps.is_empty ()) |
| 1878 | { |
| 1879 | rtx_insn *insn = uncond_traps.pop (); |
| 1880 | basic_block to_split = BLOCK_FOR_INSN (insn); |
| 1881 | remove_edge (split_block (to_split, insn)); |
| 1882 | emit_barrier_after_bb (to_split); |
| 1883 | } |
| 1884 | |
| 1885 | changed |= bypass_conditional_jumps (); |
| 1886 | |
| 1887 | FREE_REG_SET (reg_set_bitmap)((void) (bitmap_obstack_free ((bitmap) reg_set_bitmap), (reg_set_bitmap ) = (bitmap) __null)); |
| 1888 | free_cprop_mem (); |
| 1889 | } |
| 1890 | else |
| 1891 | { |
| 1892 | free (implicit_set_indexes); |
| 1893 | implicit_set_indexes = NULL__null; |
| 1894 | } |
| 1895 | |
| 1896 | free_hash_table (&set_hash_table); |
| 1897 | obstack_free (&cprop_obstack, NULL)__extension__ ({ struct obstack *__o = (&cprop_obstack); void *__obj = (void *) (__null); if (__obj > (void *) __o-> chunk && __obj < (void *) __o->chunk_limit) __o ->next_free = __o->object_base = (char *) __obj; else _obstack_free (__o, __obj); }); |
| 1898 | |
| 1899 | if (dump_file) |
| 1900 | { |
| 1901 | fprintf (dump_file, "CPROP of %s, %d basic blocks, %d bytes needed, ", |
| 1902 | current_function_name (), n_basic_blocks_for_fn (cfun)(((cfun + 0))->cfg->x_n_basic_blocks), |
| 1903 | bytes_used); |
| 1904 | fprintf (dump_file, "%d local const props, %d local copy props, ", |
| 1905 | local_const_prop_count, local_copy_prop_count); |
| 1906 | fprintf (dump_file, "%d global const props, %d global copy props\n\n", |
| 1907 | global_const_prop_count, global_copy_prop_count); |
| 1908 | } |
| 1909 | |
| 1910 | return changed; |
| 1911 | } |
| 1912 | |
| 1913 | /* All the passes implemented in this file. Each pass has its |
| 1914 | own gate and execute function, and at the end of the file a |
| 1915 | pass definition for passes.cc. |
| 1916 | |
| 1917 | We do not construct an accurate cfg in functions which call |
| 1918 | setjmp, so none of these passes runs if the function calls |
| 1919 | setjmp. |
| 1920 | FIXME: Should just handle setjmp via REG_SETJMP notes. */ |
| 1921 | |
| 1922 | static unsigned int |
| 1923 | execute_rtl_cprop (void) |
| 1924 | { |
| 1925 | int changed; |
| 1926 | delete_unreachable_blocks (); |
| 1927 | df_set_flags (DF_LR_RUN_DCE); |
| 1928 | df_analyze (); |
| 1929 | changed = one_cprop_pass (); |
| 1930 | flag_rerun_cse_after_global_opts |= changed; |
| 1931 | if (changed) |
| 1932 | cleanup_cfg (CLEANUP_CFG_CHANGED64); |
| 1933 | return 0; |
| 1934 | } |
| 1935 | |
| 1936 | namespace { |
| 1937 | |
| 1938 | const pass_data pass_data_rtl_cprop = |
| 1939 | { |
| 1940 | RTL_PASS, /* type */ |
| 1941 | "cprop", /* name */ |
| 1942 | OPTGROUP_NONE, /* optinfo_flags */ |
| 1943 | TV_CPROP, /* tv_id */ |
| 1944 | PROP_cfglayout(1 << 9), /* properties_required */ |
| 1945 | 0, /* properties_provided */ |
| 1946 | 0, /* properties_destroyed */ |
| 1947 | 0, /* todo_flags_start */ |
| 1948 | TODO_df_finish(1 << 17), /* todo_flags_finish */ |
| 1949 | }; |
| 1950 | |
| 1951 | class pass_rtl_cprop : public rtl_opt_pass |
| 1952 | { |
| 1953 | public: |
| 1954 | pass_rtl_cprop (gcc::context *ctxt) |
| 1955 | : rtl_opt_pass (pass_data_rtl_cprop, ctxt) |
| 1956 | {} |
| 1957 | |
| 1958 | /* opt_pass methods: */ |
| 1959 | opt_pass * clone () final override { return new pass_rtl_cprop (m_ctxt); } |
| 1960 | bool gate (function *fun) final override |
| 1961 | { |
| 1962 | return optimizeglobal_options.x_optimize > 0 && flag_gcseglobal_options.x_flag_gcse |
| 1963 | && !fun->calls_setjmp |
| 1964 | && dbg_cnt (cprop); |
| 1965 | } |
| 1966 | |
| 1967 | unsigned int execute (function *) final override |
| 1968 | { |
| 1969 | return execute_rtl_cprop (); |
| 1970 | } |
| 1971 | |
| 1972 | }; // class pass_rtl_cprop |
| 1973 | |
| 1974 | } // anon namespace |
| 1975 | |
| 1976 | rtl_opt_pass * |
| 1977 | make_pass_rtl_cprop (gcc::context *ctxt) |
| 1978 | { |
| 1979 | return new pass_rtl_cprop (ctxt); |
| 1980 | } |