Mercurial > hg > CbC > CbC_gcc
annotate gcc/dce.c @ 56:3c8a44c06a95
Added tag gcc-4.4.5 for changeset 77e2b8dfacca
| author | ryoma <e075725@ie.u-ryukyu.ac.jp> |
|---|---|
| date | Fri, 12 Feb 2010 23:41:23 +0900 |
| parents | 77e2b8dfacca |
| children | f6334be47118 |
| rev | line source |
|---|---|
| 0 | 1 /* RTL dead code elimination. |
| 2 Copyright (C) 2005, 2006, 2007, 2008, 2009 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 "hashtab.h" | |
| 24 #include "tm.h" | |
| 25 #include "rtl.h" | |
| 26 #include "tree.h" | |
| 27 #include "regs.h" | |
| 28 #include "hard-reg-set.h" | |
| 29 #include "flags.h" | |
|
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30 #include "except.h" |
| 0 | 31 #include "df.h" |
| 32 #include "cselib.h" | |
| 33 #include "dce.h" | |
| 34 #include "timevar.h" | |
| 35 #include "tree-pass.h" | |
| 36 #include "dbgcnt.h" | |
| 37 #include "tm_p.h" | |
| 38 | |
| 39 | |
| 40 /* ------------------------------------------------------------------------- | |
| 41 Core mark/delete routines | |
| 42 ------------------------------------------------------------------------- */ | |
| 43 | |
| 44 /* True if we are invoked while the df engine is running; in this case, | |
| 45 we don't want to reenter it. */ | |
| 46 static bool df_in_progress = false; | |
| 47 | |
| 48 /* Instructions that have been marked but whose dependencies have not | |
| 49 yet been processed. */ | |
| 50 static VEC(rtx,heap) *worklist; | |
| 51 | |
| 52 /* Bitmap of instructions marked as needed indexed by INSN_UID. */ | |
| 53 static sbitmap marked; | |
| 54 | |
| 55 /* Bitmap obstacks used for block processing by the fast algorithm. */ | |
| 56 static bitmap_obstack dce_blocks_bitmap_obstack; | |
| 57 static bitmap_obstack dce_tmp_bitmap_obstack; | |
| 58 | |
| 59 static bool find_call_stack_args (rtx, bool, bool, bitmap); | |
| 60 | |
| 61 /* A subroutine for which BODY is part of the instruction being tested; | |
| 62 either the top-level pattern, or an element of a PARALLEL. The | |
| 63 instruction is known not to be a bare USE or CLOBBER. */ | |
| 64 | |
| 65 static bool | |
| 66 deletable_insn_p_1 (rtx body) | |
| 67 { | |
| 68 switch (GET_CODE (body)) | |
| 69 { | |
| 70 case PREFETCH: | |
| 71 case TRAP_IF: | |
| 72 /* The UNSPEC case was added here because the ia-64 claims that | |
| 73 USEs do not work after reload and generates UNSPECS rather | |
| 74 than USEs. Since dce is run after reload we need to avoid | |
| 75 deleting these even if they are dead. If it turns out that | |
| 76 USEs really do work after reload, the ia-64 should be | |
| 77 changed, and the UNSPEC case can be removed. */ | |
| 78 case UNSPEC: | |
| 79 return false; | |
| 80 | |
| 81 default: | |
|
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82 return !volatile_refs_p (body); |
| 0 | 83 } |
| 84 } | |
| 85 | |
| 86 | |
| 87 /* Return true if INSN is a normal instruction that can be deleted by | |
| 88 the DCE pass. */ | |
| 89 | |
| 90 static bool | |
| 91 deletable_insn_p (rtx insn, bool fast, bitmap arg_stores) | |
| 92 { | |
| 93 rtx body, x; | |
| 94 int i; | |
| 95 | |
|
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96 /* Don't delete jumps, notes and the like. */ |
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97 if (!NONJUMP_INSN_P (insn)) |
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98 return false; |
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99 |
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100 /* Don't delete insns that can throw. */ |
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101 if (!insn_nothrow_p (insn)) |
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102 return false; |
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103 |
| 0 | 104 if (CALL_P (insn) |
| 105 /* We cannot delete calls inside of the recursive dce because | |
| 106 this may cause basic blocks to be deleted and this messes up | |
| 107 the rest of the stack of optimization passes. */ | |
| 108 && (!df_in_progress) | |
| 109 /* We cannot delete pure or const sibling calls because it is | |
| 110 hard to see the result. */ | |
| 111 && (!SIBLING_CALL_P (insn)) | |
| 112 /* We can delete dead const or pure calls as long as they do not | |
| 113 infinite loop. */ | |
| 114 && (RTL_CONST_OR_PURE_CALL_P (insn) | |
| 115 && !RTL_LOOPING_CONST_OR_PURE_CALL_P (insn))) | |
| 116 return find_call_stack_args (insn, false, fast, arg_stores); | |
| 117 | |
| 118 body = PATTERN (insn); | |
| 119 switch (GET_CODE (body)) | |
| 120 { | |
| 121 case USE: | |
|
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122 case VAR_LOCATION: |
| 0 | 123 return false; |
| 124 | |
| 125 case CLOBBER: | |
| 126 if (fast) | |
| 127 { | |
| 128 /* A CLOBBER of a dead pseudo register serves no purpose. | |
| 129 That is not necessarily true for hard registers until | |
| 130 after reload. */ | |
| 131 x = XEXP (body, 0); | |
| 132 return REG_P (x) && (!HARD_REGISTER_P (x) || reload_completed); | |
| 133 } | |
| 134 else | |
| 135 /* Because of the way that use-def chains are built, it is not | |
| 136 possible to tell if the clobber is dead because it can | |
| 137 never be the target of a use-def chain. */ | |
| 138 return false; | |
| 139 | |
| 140 case PARALLEL: | |
| 141 for (i = XVECLEN (body, 0) - 1; i >= 0; i--) | |
| 142 if (!deletable_insn_p_1 (XVECEXP (body, 0, i))) | |
| 143 return false; | |
| 144 return true; | |
| 145 | |
| 146 default: | |
| 147 return deletable_insn_p_1 (body); | |
| 148 } | |
| 149 } | |
| 150 | |
| 151 | |
| 152 /* Return true if INSN has been marked as needed. */ | |
| 153 | |
| 154 static inline int | |
| 155 marked_insn_p (rtx insn) | |
| 156 { | |
| 157 /* Artificial defs are always needed and they do not have an insn. | |
| 158 We should never see them here. */ | |
| 159 gcc_assert (insn); | |
| 160 return TEST_BIT (marked, INSN_UID (insn)); | |
| 161 } | |
| 162 | |
| 163 | |
| 164 /* If INSN has not yet been marked as needed, mark it now, and add it to | |
| 165 the worklist. */ | |
| 166 | |
| 167 static void | |
| 168 mark_insn (rtx insn, bool fast) | |
| 169 { | |
| 170 if (!marked_insn_p (insn)) | |
| 171 { | |
| 172 if (!fast) | |
| 173 VEC_safe_push (rtx, heap, worklist, insn); | |
| 174 SET_BIT (marked, INSN_UID (insn)); | |
| 175 if (dump_file) | |
| 176 fprintf (dump_file, " Adding insn %d to worklist\n", INSN_UID (insn)); | |
| 177 if (CALL_P (insn) | |
| 178 && !df_in_progress | |
| 179 && !SIBLING_CALL_P (insn) | |
| 180 && (RTL_CONST_OR_PURE_CALL_P (insn) | |
| 181 && !RTL_LOOPING_CONST_OR_PURE_CALL_P (insn))) | |
| 182 find_call_stack_args (insn, true, fast, NULL); | |
| 183 } | |
| 184 } | |
| 185 | |
| 186 | |
| 187 /* A note_stores callback used by mark_nonreg_stores. DATA is the | |
| 188 instruction containing DEST. */ | |
| 189 | |
| 190 static void | |
| 191 mark_nonreg_stores_1 (rtx dest, const_rtx pattern, void *data) | |
| 192 { | |
| 193 if (GET_CODE (pattern) != CLOBBER && !REG_P (dest)) | |
| 194 mark_insn ((rtx) data, true); | |
| 195 } | |
| 196 | |
| 197 | |
| 198 /* A note_stores callback used by mark_nonreg_stores. DATA is the | |
| 199 instruction containing DEST. */ | |
| 200 | |
| 201 static void | |
| 202 mark_nonreg_stores_2 (rtx dest, const_rtx pattern, void *data) | |
| 203 { | |
| 204 if (GET_CODE (pattern) != CLOBBER && !REG_P (dest)) | |
| 205 mark_insn ((rtx) data, false); | |
| 206 } | |
| 207 | |
| 208 | |
| 209 /* Mark INSN if BODY stores to a non-register destination. */ | |
| 210 | |
| 211 static void | |
| 212 mark_nonreg_stores (rtx body, rtx insn, bool fast) | |
| 213 { | |
| 214 if (fast) | |
| 215 note_stores (body, mark_nonreg_stores_1, insn); | |
| 216 else | |
| 217 note_stores (body, mark_nonreg_stores_2, insn); | |
| 218 } | |
| 219 | |
| 220 | |
| 221 /* Try to find all stack stores of CALL_INSN arguments if | |
| 222 ACCUMULATE_OUTGOING_ARGS. If all stack stores have been found | |
| 223 and it is therefore safe to eliminate the call, return true, | |
| 224 otherwise return false. This function should be first called | |
| 225 with DO_MARK false, and only when the CALL_INSN is actually | |
| 226 going to be marked called again with DO_MARK true. */ | |
| 227 | |
| 228 static bool | |
| 229 find_call_stack_args (rtx call_insn, bool do_mark, bool fast, | |
| 230 bitmap arg_stores) | |
| 231 { | |
| 232 rtx p, insn, prev_insn; | |
| 233 bool ret; | |
| 234 HOST_WIDE_INT min_sp_off, max_sp_off; | |
| 235 bitmap sp_bytes; | |
| 236 | |
| 237 gcc_assert (CALL_P (call_insn)); | |
| 238 if (!ACCUMULATE_OUTGOING_ARGS) | |
| 239 return true; | |
| 240 | |
| 241 if (!do_mark) | |
| 242 { | |
| 243 gcc_assert (arg_stores); | |
| 244 bitmap_clear (arg_stores); | |
| 245 } | |
| 246 | |
| 247 min_sp_off = INTTYPE_MAXIMUM (HOST_WIDE_INT); | |
| 248 max_sp_off = 0; | |
| 249 | |
| 250 /* First determine the minimum and maximum offset from sp for | |
| 251 stored arguments. */ | |
| 252 for (p = CALL_INSN_FUNCTION_USAGE (call_insn); p; p = XEXP (p, 1)) | |
| 253 if (GET_CODE (XEXP (p, 0)) == USE | |
| 254 && MEM_P (XEXP (XEXP (p, 0), 0))) | |
| 255 { | |
| 256 rtx mem = XEXP (XEXP (p, 0), 0), addr, size; | |
| 257 HOST_WIDE_INT off = 0; | |
| 258 size = MEM_SIZE (mem); | |
| 259 if (size == NULL_RTX) | |
| 260 return false; | |
| 261 addr = XEXP (mem, 0); | |
| 262 if (GET_CODE (addr) == PLUS | |
| 263 && REG_P (XEXP (addr, 0)) | |
| 264 && CONST_INT_P (XEXP (addr, 1))) | |
| 265 { | |
| 266 off = INTVAL (XEXP (addr, 1)); | |
| 267 addr = XEXP (addr, 0); | |
| 268 } | |
| 269 if (addr != stack_pointer_rtx) | |
| 270 { | |
| 271 if (!REG_P (addr)) | |
| 272 return false; | |
| 273 /* If not fast, use chains to see if addr wasn't set to | |
| 274 sp + offset. */ | |
| 275 if (!fast) | |
| 276 { | |
| 277 df_ref *use_rec; | |
| 278 struct df_link *defs; | |
| 279 rtx set; | |
| 280 | |
| 281 for (use_rec = DF_INSN_USES (call_insn); *use_rec; use_rec++) | |
| 282 if (rtx_equal_p (addr, DF_REF_REG (*use_rec))) | |
| 283 break; | |
| 284 | |
| 285 if (*use_rec == NULL) | |
| 286 return false; | |
| 287 | |
| 288 for (defs = DF_REF_CHAIN (*use_rec); defs; defs = defs->next) | |
| 289 if (! DF_REF_IS_ARTIFICIAL (defs->ref)) | |
| 290 break; | |
| 291 | |
| 292 if (defs == NULL) | |
| 293 return false; | |
| 294 | |
| 295 set = single_set (DF_REF_INSN (defs->ref)); | |
| 296 if (!set) | |
| 297 return false; | |
| 298 | |
| 299 if (GET_CODE (SET_SRC (set)) != PLUS | |
| 300 || XEXP (SET_SRC (set), 0) != stack_pointer_rtx | |
| 301 || !CONST_INT_P (XEXP (SET_SRC (set), 1))) | |
| 302 return false; | |
| 303 | |
| 304 off += INTVAL (XEXP (SET_SRC (set), 1)); | |
| 305 } | |
| 306 else | |
| 307 return false; | |
| 308 } | |
| 309 min_sp_off = MIN (min_sp_off, off); | |
| 310 max_sp_off = MAX (max_sp_off, off + INTVAL (size)); | |
| 311 } | |
| 312 | |
| 313 if (min_sp_off >= max_sp_off) | |
| 314 return true; | |
| 315 sp_bytes = BITMAP_ALLOC (NULL); | |
| 316 | |
| 317 /* Set bits in SP_BYTES bitmap for bytes relative to sp + min_sp_off | |
| 318 which contain arguments. Checking has been done in the previous | |
| 319 loop. */ | |
| 320 for (p = CALL_INSN_FUNCTION_USAGE (call_insn); p; p = XEXP (p, 1)) | |
| 321 if (GET_CODE (XEXP (p, 0)) == USE | |
| 322 && MEM_P (XEXP (XEXP (p, 0), 0))) | |
| 323 { | |
| 324 rtx mem = XEXP (XEXP (p, 0), 0), addr; | |
| 325 HOST_WIDE_INT off = 0, byte; | |
| 326 addr = XEXP (mem, 0); | |
| 327 if (GET_CODE (addr) == PLUS | |
| 328 && REG_P (XEXP (addr, 0)) | |
| 329 && CONST_INT_P (XEXP (addr, 1))) | |
| 330 { | |
| 331 off = INTVAL (XEXP (addr, 1)); | |
| 332 addr = XEXP (addr, 0); | |
| 333 } | |
| 334 if (addr != stack_pointer_rtx) | |
| 335 { | |
| 336 df_ref *use_rec; | |
| 337 struct df_link *defs; | |
| 338 rtx set; | |
| 339 | |
| 340 for (use_rec = DF_INSN_USES (call_insn); *use_rec; use_rec++) | |
| 341 if (rtx_equal_p (addr, DF_REF_REG (*use_rec))) | |
| 342 break; | |
| 343 | |
| 344 for (defs = DF_REF_CHAIN (*use_rec); defs; defs = defs->next) | |
| 345 if (! DF_REF_IS_ARTIFICIAL (defs->ref)) | |
| 346 break; | |
| 347 | |
| 348 set = single_set (DF_REF_INSN (defs->ref)); | |
| 349 off += INTVAL (XEXP (SET_SRC (set), 1)); | |
| 350 } | |
| 351 for (byte = off; byte < off + INTVAL (MEM_SIZE (mem)); byte++) | |
| 352 { | |
|
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353 if (!bitmap_set_bit (sp_bytes, byte - min_sp_off)) |
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354 gcc_unreachable (); |
| 0 | 355 } |
| 356 } | |
| 357 | |
| 358 /* Walk backwards, looking for argument stores. The search stops | |
| 359 when seeing another call, sp adjustment or memory store other than | |
| 360 argument store. */ | |
| 361 ret = false; | |
| 362 for (insn = PREV_INSN (call_insn); insn; insn = prev_insn) | |
| 363 { | |
| 364 rtx set, mem, addr; | |
| 365 HOST_WIDE_INT off, byte; | |
| 366 | |
| 367 if (insn == BB_HEAD (BLOCK_FOR_INSN (call_insn))) | |
| 368 prev_insn = NULL_RTX; | |
| 369 else | |
| 370 prev_insn = PREV_INSN (insn); | |
| 371 | |
| 372 if (CALL_P (insn)) | |
| 373 break; | |
| 374 | |
| 375 if (!INSN_P (insn)) | |
| 376 continue; | |
| 377 | |
| 378 set = single_set (insn); | |
| 379 if (!set || SET_DEST (set) == stack_pointer_rtx) | |
| 380 break; | |
| 381 | |
| 382 if (!MEM_P (SET_DEST (set))) | |
| 383 continue; | |
| 384 | |
| 385 mem = SET_DEST (set); | |
| 386 addr = XEXP (mem, 0); | |
| 387 off = 0; | |
| 388 if (GET_CODE (addr) == PLUS | |
| 389 && REG_P (XEXP (addr, 0)) | |
| 390 && CONST_INT_P (XEXP (addr, 1))) | |
| 391 { | |
| 392 off = INTVAL (XEXP (addr, 1)); | |
| 393 addr = XEXP (addr, 0); | |
| 394 } | |
| 395 if (addr != stack_pointer_rtx) | |
| 396 { | |
| 397 if (!REG_P (addr)) | |
| 398 break; | |
| 399 if (!fast) | |
| 400 { | |
| 401 df_ref *use_rec; | |
| 402 struct df_link *defs; | |
| 403 rtx set; | |
| 404 | |
| 405 for (use_rec = DF_INSN_USES (insn); *use_rec; use_rec++) | |
| 406 if (rtx_equal_p (addr, DF_REF_REG (*use_rec))) | |
| 407 break; | |
| 408 | |
| 409 if (*use_rec == NULL) | |
| 410 break; | |
| 411 | |
| 412 for (defs = DF_REF_CHAIN (*use_rec); defs; defs = defs->next) | |
| 413 if (! DF_REF_IS_ARTIFICIAL (defs->ref)) | |
| 414 break; | |
| 415 | |
| 416 if (defs == NULL) | |
| 417 break; | |
| 418 | |
| 419 set = single_set (DF_REF_INSN (defs->ref)); | |
| 420 if (!set) | |
| 421 break; | |
| 422 | |
| 423 if (GET_CODE (SET_SRC (set)) != PLUS | |
| 424 || XEXP (SET_SRC (set), 0) != stack_pointer_rtx | |
| 425 || !CONST_INT_P (XEXP (SET_SRC (set), 1))) | |
| 426 break; | |
| 427 | |
| 428 off += INTVAL (XEXP (SET_SRC (set), 1)); | |
| 429 } | |
| 430 else | |
| 431 break; | |
| 432 } | |
| 433 | |
| 434 if (GET_MODE_SIZE (GET_MODE (mem)) == 0) | |
| 435 break; | |
| 436 | |
| 437 for (byte = off; byte < off + GET_MODE_SIZE (GET_MODE (mem)); byte++) | |
| 438 { | |
| 439 if (byte < min_sp_off | |
| 440 || byte >= max_sp_off | |
|
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441 || !bitmap_clear_bit (sp_bytes, byte - min_sp_off)) |
| 0 | 442 break; |
| 443 } | |
| 444 | |
| 445 if (!deletable_insn_p (insn, fast, NULL)) | |
| 446 break; | |
| 447 | |
| 448 if (do_mark) | |
| 449 mark_insn (insn, fast); | |
| 450 else | |
| 451 bitmap_set_bit (arg_stores, INSN_UID (insn)); | |
| 452 | |
| 453 if (bitmap_empty_p (sp_bytes)) | |
| 454 { | |
| 455 ret = true; | |
| 456 break; | |
| 457 } | |
| 458 } | |
| 459 | |
| 460 BITMAP_FREE (sp_bytes); | |
| 461 if (!ret && arg_stores) | |
| 462 bitmap_clear (arg_stores); | |
| 463 | |
| 464 return ret; | |
| 465 } | |
| 466 | |
| 467 | |
| 468 /* Delete all REG_EQUAL notes of the registers INSN writes, to prevent | |
| 469 bad dangling REG_EQUAL notes. */ | |
| 470 | |
| 471 static void | |
| 472 delete_corresponding_reg_eq_notes (rtx insn) | |
| 473 { | |
| 474 df_ref *def_rec; | |
| 475 for (def_rec = DF_INSN_DEFS (insn); *def_rec; def_rec++) | |
| 476 { | |
| 477 df_ref def = *def_rec; | |
| 478 unsigned int regno = DF_REF_REGNO (def); | |
| 479 /* This loop is a little tricky. We cannot just go down the | |
| 480 chain because it is being modified by the actions in the | |
| 481 loop. So we just get the head. We plan to drain the list | |
| 482 anyway. */ | |
| 483 while (DF_REG_EQ_USE_CHAIN (regno)) | |
| 484 { | |
| 485 df_ref eq_use = DF_REG_EQ_USE_CHAIN (regno); | |
| 486 rtx noted_insn = DF_REF_INSN (eq_use); | |
| 487 rtx note = find_reg_note (noted_insn, REG_EQUAL, NULL_RTX); | |
| 488 if (!note) | |
| 489 note = find_reg_note (noted_insn, REG_EQUIV, NULL_RTX); | |
| 490 | |
| 491 /* This assert is generally triggered when someone deletes a | |
| 492 REG_EQUAL or REG_EQUIV note by hacking the list manually | |
| 493 rather than calling remove_note. */ | |
| 494 gcc_assert (note); | |
| 495 remove_note (noted_insn, note); | |
| 496 } | |
| 497 } | |
| 498 } | |
| 499 | |
| 500 | |
| 501 /* Delete every instruction that hasn't been marked. */ | |
| 502 | |
| 503 static void | |
| 504 delete_unmarked_insns (void) | |
| 505 { | |
| 506 basic_block bb; | |
| 507 rtx insn, next; | |
| 508 bool must_clean = false; | |
| 509 | |
| 510 FOR_EACH_BB_REVERSE (bb) | |
| 511 FOR_BB_INSNS_REVERSE_SAFE (bb, insn, next) | |
| 512 if (INSN_P (insn)) | |
| 513 { | |
| 514 /* Always delete no-op moves. */ | |
| 515 if (noop_move_p (insn)) | |
| 516 ; | |
| 517 | |
| 518 /* Otherwise rely only on the DCE algorithm. */ | |
| 519 else if (marked_insn_p (insn)) | |
| 520 continue; | |
| 521 | |
| 522 /* Beware that reaching a dbg counter limit here can result | |
| 523 in miscompiled file. This occurs when a group of insns | |
| 524 must be deleted together, typically because the kept insn | |
| 525 depends on the output from the deleted insn. Deleting | |
| 526 this insns in reverse order (both at the bb level and | |
| 527 when looking at the blocks) minimizes this, but does not | |
| 528 eliminate it, since it is possible for the using insn to | |
| 529 be top of a block and the producer to be at the bottom of | |
| 530 the block. However, in most cases this will only result | |
| 531 in an uninitialized use of an insn that is dead anyway. | |
| 532 | |
| 533 However, there is one rare case that will cause a | |
| 534 miscompile: deletion of non-looping pure and constant | |
| 535 calls on a machine where ACCUMULATE_OUTGOING_ARGS is true. | |
| 536 In this case it is possible to remove the call, but leave | |
| 537 the argument pushes to the stack. Because of the changes | |
| 538 to the stack pointer, this will almost always lead to a | |
| 539 miscompile. */ | |
| 540 if (!dbg_cnt (dce)) | |
| 541 continue; | |
| 542 | |
| 543 if (dump_file) | |
| 544 fprintf (dump_file, "DCE: Deleting insn %d\n", INSN_UID (insn)); | |
| 545 | |
| 546 /* Before we delete the insn we have to delete REG_EQUAL notes | |
| 547 for the destination regs in order to avoid dangling notes. */ | |
| 548 delete_corresponding_reg_eq_notes (insn); | |
| 549 | |
| 550 /* If a pure or const call is deleted, this may make the cfg | |
| 551 have unreachable blocks. We rememeber this and call | |
| 552 delete_unreachable_blocks at the end. */ | |
| 553 if (CALL_P (insn)) | |
| 554 must_clean = true; | |
| 555 | |
| 556 /* Now delete the insn. */ | |
| 557 delete_insn_and_edges (insn); | |
| 558 } | |
| 559 | |
| 560 /* Deleted a pure or const call. */ | |
| 561 if (must_clean) | |
| 562 delete_unreachable_blocks (); | |
| 563 } | |
| 564 | |
| 565 | |
| 566 /* Go through the instructions and mark those whose necessity is not | |
| 567 dependent on inter-instruction information. Make sure all other | |
| 568 instructions are not marked. */ | |
| 569 | |
| 570 static void | |
| 571 prescan_insns_for_dce (bool fast) | |
| 572 { | |
| 573 basic_block bb; | |
| 574 rtx insn, prev; | |
| 575 bitmap arg_stores = NULL; | |
| 576 | |
| 577 if (dump_file) | |
| 578 fprintf (dump_file, "Finding needed instructions:\n"); | |
| 579 | |
| 580 if (!df_in_progress && ACCUMULATE_OUTGOING_ARGS) | |
| 581 arg_stores = BITMAP_ALLOC (NULL); | |
| 582 | |
| 583 FOR_EACH_BB (bb) | |
| 584 { | |
| 585 FOR_BB_INSNS_REVERSE_SAFE (bb, insn, prev) | |
| 586 if (INSN_P (insn)) | |
| 587 { | |
| 588 /* Don't mark argument stores now. They will be marked | |
| 589 if needed when the associated CALL is marked. */ | |
| 590 if (arg_stores && bitmap_bit_p (arg_stores, INSN_UID (insn))) | |
| 591 continue; | |
| 592 if (deletable_insn_p (insn, fast, arg_stores)) | |
| 593 mark_nonreg_stores (PATTERN (insn), insn, fast); | |
| 594 else | |
| 595 mark_insn (insn, fast); | |
| 596 } | |
| 597 /* find_call_stack_args only looks at argument stores in the | |
| 598 same bb. */ | |
| 599 if (arg_stores) | |
| 600 bitmap_clear (arg_stores); | |
| 601 } | |
| 602 | |
| 603 if (arg_stores) | |
| 604 BITMAP_FREE (arg_stores); | |
| 605 | |
| 606 if (dump_file) | |
| 607 fprintf (dump_file, "Finished finding needed instructions:\n"); | |
| 608 } | |
| 609 | |
| 610 | |
| 611 /* UD-based DSE routines. */ | |
| 612 | |
| 613 /* Mark instructions that define artificially-used registers, such as | |
| 614 the frame pointer and the stack pointer. */ | |
| 615 | |
| 616 static void | |
| 617 mark_artificial_uses (void) | |
| 618 { | |
| 619 basic_block bb; | |
| 620 struct df_link *defs; | |
| 621 df_ref *use_rec; | |
| 622 | |
| 623 FOR_ALL_BB (bb) | |
| 624 { | |
|
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625 for (use_rec = df_get_artificial_uses (bb->index); |
| 0 | 626 *use_rec; use_rec++) |
| 627 for (defs = DF_REF_CHAIN (*use_rec); defs; defs = defs->next) | |
| 628 if (! DF_REF_IS_ARTIFICIAL (defs->ref)) | |
| 629 mark_insn (DF_REF_INSN (defs->ref), false); | |
| 630 } | |
| 631 } | |
| 632 | |
| 633 | |
| 634 /* Mark every instruction that defines a register value that INSN uses. */ | |
| 635 | |
| 636 static void | |
| 637 mark_reg_dependencies (rtx insn) | |
| 638 { | |
| 639 struct df_link *defs; | |
| 640 df_ref *use_rec; | |
| 641 | |
|
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642 if (DEBUG_INSN_P (insn)) |
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643 return; |
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644 |
| 0 | 645 for (use_rec = DF_INSN_USES (insn); *use_rec; use_rec++) |
| 646 { | |
| 647 df_ref use = *use_rec; | |
| 648 if (dump_file) | |
| 649 { | |
| 650 fprintf (dump_file, "Processing use of "); | |
| 651 print_simple_rtl (dump_file, DF_REF_REG (use)); | |
| 652 fprintf (dump_file, " in insn %d:\n", INSN_UID (insn)); | |
| 653 } | |
| 654 for (defs = DF_REF_CHAIN (use); defs; defs = defs->next) | |
| 655 if (! DF_REF_IS_ARTIFICIAL (defs->ref)) | |
| 656 mark_insn (DF_REF_INSN (defs->ref), false); | |
| 657 } | |
| 658 } | |
| 659 | |
| 660 | |
| 661 /* Initialize global variables for a new DCE pass. */ | |
| 662 | |
| 663 static void | |
| 664 init_dce (bool fast) | |
| 665 { | |
| 666 if (!df_in_progress) | |
| 667 { | |
| 668 if (!fast) | |
| 669 df_chain_add_problem (DF_UD_CHAIN); | |
| 670 df_analyze (); | |
| 671 } | |
| 672 | |
| 673 if (dump_file) | |
| 674 df_dump (dump_file); | |
| 675 | |
| 676 if (fast) | |
| 677 { | |
| 678 bitmap_obstack_initialize (&dce_blocks_bitmap_obstack); | |
| 679 bitmap_obstack_initialize (&dce_tmp_bitmap_obstack); | |
| 680 } | |
| 681 | |
| 682 marked = sbitmap_alloc (get_max_uid () + 1); | |
| 683 sbitmap_zero (marked); | |
| 684 } | |
| 685 | |
| 686 | |
| 687 /* Free the data allocated by init_dce. */ | |
| 688 | |
| 689 static void | |
| 690 fini_dce (bool fast) | |
| 691 { | |
| 692 sbitmap_free (marked); | |
| 693 | |
| 694 if (fast) | |
| 695 { | |
| 696 bitmap_obstack_release (&dce_blocks_bitmap_obstack); | |
| 697 bitmap_obstack_release (&dce_tmp_bitmap_obstack); | |
| 698 } | |
| 699 } | |
| 700 | |
| 701 | |
| 702 /* UD-chain based DCE. */ | |
| 703 | |
| 704 static unsigned int | |
| 705 rest_of_handle_ud_dce (void) | |
| 706 { | |
| 707 rtx insn; | |
| 708 | |
| 709 init_dce (false); | |
| 710 | |
| 711 prescan_insns_for_dce (false); | |
| 712 mark_artificial_uses (); | |
| 713 while (VEC_length (rtx, worklist) > 0) | |
| 714 { | |
| 715 insn = VEC_pop (rtx, worklist); | |
| 716 mark_reg_dependencies (insn); | |
| 717 } | |
| 718 VEC_free (rtx, heap, worklist); | |
| 719 | |
| 720 /* Before any insns are deleted, we must remove the chains since | |
| 721 they are not bidirectional. */ | |
| 722 df_remove_problem (df_chain); | |
| 723 delete_unmarked_insns (); | |
| 724 | |
| 725 fini_dce (false); | |
| 726 return 0; | |
| 727 } | |
| 728 | |
| 729 | |
| 730 static bool | |
| 731 gate_ud_dce (void) | |
| 732 { | |
| 733 return optimize > 1 && flag_dce | |
| 734 && dbg_cnt (dce_ud); | |
| 735 } | |
| 736 | |
| 737 struct rtl_opt_pass pass_ud_rtl_dce = | |
| 738 { | |
| 739 { | |
| 740 RTL_PASS, | |
|
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741 "ud dce", /* name */ |
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742 gate_ud_dce, /* gate */ |
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743 rest_of_handle_ud_dce, /* execute */ |
| 0 | 744 NULL, /* sub */ |
| 745 NULL, /* next */ | |
| 746 0, /* static_pass_number */ | |
| 747 TV_DCE, /* tv_id */ | |
| 748 0, /* properties_required */ | |
| 749 0, /* properties_provided */ | |
| 750 0, /* properties_destroyed */ | |
| 751 0, /* todo_flags_start */ | |
| 752 TODO_dump_func | | |
| 753 TODO_df_finish | TODO_verify_rtl_sharing | | |
| 754 TODO_ggc_collect /* todo_flags_finish */ | |
| 755 } | |
| 756 }; | |
| 757 | |
| 758 | |
| 759 /* ------------------------------------------------------------------------- | |
| 760 Fast DCE functions | |
| 761 ------------------------------------------------------------------------- */ | |
| 762 | |
| 763 /* Process basic block BB. Return true if the live_in set has | |
| 764 changed. REDO_OUT is true if the info at the bottom of the block | |
| 765 needs to be recalculated before starting. AU is the proper set of | |
| 766 artificial uses. */ | |
| 767 | |
| 768 static bool | |
| 769 byte_dce_process_block (basic_block bb, bool redo_out, bitmap au) | |
| 770 { | |
| 771 bitmap local_live = BITMAP_ALLOC (&dce_tmp_bitmap_obstack); | |
| 772 rtx insn; | |
| 773 bool block_changed; | |
| 774 df_ref *def_rec; | |
| 775 | |
| 776 if (redo_out) | |
| 777 { | |
| 778 /* Need to redo the live_out set of this block if when one of | |
| 779 the succs of this block has had a change in it live in | |
| 780 set. */ | |
| 781 edge e; | |
| 782 edge_iterator ei; | |
| 783 df_confluence_function_n con_fun_n = df_byte_lr->problem->con_fun_n; | |
| 784 bitmap_clear (DF_BYTE_LR_OUT (bb)); | |
| 785 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 786 (*con_fun_n) (e); | |
| 787 } | |
| 788 | |
| 789 if (dump_file) | |
| 790 { | |
| 791 fprintf (dump_file, "processing block %d live out = ", bb->index); | |
| 792 df_print_byte_regset (dump_file, DF_BYTE_LR_OUT (bb)); | |
| 793 } | |
| 794 | |
| 795 bitmap_copy (local_live, DF_BYTE_LR_OUT (bb)); | |
| 796 | |
| 797 df_byte_lr_simulate_artificial_refs_at_end (bb, local_live); | |
| 798 | |
| 799 FOR_BB_INSNS_REVERSE (bb, insn) | |
| 800 if (INSN_P (insn)) | |
| 801 { | |
| 802 /* The insn is needed if there is someone who uses the output. */ | |
| 803 for (def_rec = DF_INSN_DEFS (insn); *def_rec; def_rec++) | |
| 804 { | |
| 805 df_ref def = *def_rec; | |
| 806 unsigned int last; | |
| 807 unsigned int dregno = DF_REF_REGNO (def); | |
| 808 unsigned int start = df_byte_lr_get_regno_start (dregno); | |
| 809 unsigned int len = df_byte_lr_get_regno_len (dregno); | |
| 810 | |
| 811 unsigned int sb; | |
| 812 unsigned int lb; | |
| 813 /* This is one of the only places where DF_MM_MAY should | |
| 814 be used for defs. Need to make sure that we are | |
| 815 checking for all of the bits that may be used. */ | |
| 816 | |
| 817 if (!df_compute_accessed_bytes (def, DF_MM_MAY, &sb, &lb)) | |
| 818 { | |
| 819 start += sb; | |
| 820 len = lb - sb; | |
| 821 } | |
| 822 | |
| 823 if (bitmap_bit_p (au, dregno)) | |
| 824 { | |
| 825 mark_insn (insn, true); | |
| 826 goto quickexit; | |
| 827 } | |
|
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828 |
| 0 | 829 last = start + len; |
| 830 while (start < last) | |
| 831 if (bitmap_bit_p (local_live, start++)) | |
| 832 { | |
| 833 mark_insn (insn, true); | |
| 834 goto quickexit; | |
| 835 } | |
| 836 } | |
|
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837 |
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838 quickexit: |
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839 |
| 0 | 840 /* No matter if the instruction is needed or not, we remove |
| 841 any regno in the defs from the live set. */ | |
| 842 df_byte_lr_simulate_defs (insn, local_live); | |
| 843 | |
| 844 /* On the other hand, we do not allow the dead uses to set | |
| 845 anything in local_live. */ | |
| 846 if (marked_insn_p (insn)) | |
| 847 df_byte_lr_simulate_uses (insn, local_live); | |
| 848 | |
| 849 if (dump_file) | |
| 850 { | |
|
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851 fprintf (dump_file, "finished processing insn %d live out = ", |
| 0 | 852 INSN_UID (insn)); |
| 853 df_print_byte_regset (dump_file, local_live); | |
| 854 } | |
| 855 } | |
|
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856 |
| 0 | 857 df_byte_lr_simulate_artificial_refs_at_top (bb, local_live); |
| 858 | |
| 859 block_changed = !bitmap_equal_p (local_live, DF_BYTE_LR_IN (bb)); | |
| 860 if (block_changed) | |
| 861 bitmap_copy (DF_BYTE_LR_IN (bb), local_live); | |
| 862 BITMAP_FREE (local_live); | |
| 863 return block_changed; | |
| 864 } | |
| 865 | |
| 866 | |
| 867 /* Process basic block BB. Return true if the live_in set has | |
| 868 changed. REDO_OUT is true if the info at the bottom of the block | |
| 869 needs to be recalculated before starting. AU is the proper set of | |
| 870 artificial uses. */ | |
| 871 | |
| 872 static bool | |
| 873 dce_process_block (basic_block bb, bool redo_out, bitmap au) | |
| 874 { | |
| 875 bitmap local_live = BITMAP_ALLOC (&dce_tmp_bitmap_obstack); | |
| 876 rtx insn; | |
| 877 bool block_changed; | |
| 878 df_ref *def_rec; | |
| 879 | |
| 880 if (redo_out) | |
| 881 { | |
| 882 /* Need to redo the live_out set of this block if when one of | |
| 883 the succs of this block has had a change in it live in | |
| 884 set. */ | |
| 885 edge e; | |
| 886 edge_iterator ei; | |
| 887 df_confluence_function_n con_fun_n = df_lr->problem->con_fun_n; | |
| 888 bitmap_clear (DF_LR_OUT (bb)); | |
| 889 FOR_EACH_EDGE (e, ei, bb->succs) | |
| 890 (*con_fun_n) (e); | |
| 891 } | |
| 892 | |
| 893 if (dump_file) | |
| 894 { | |
| 895 fprintf (dump_file, "processing block %d lr out = ", bb->index); | |
| 896 df_print_regset (dump_file, DF_LR_OUT (bb)); | |
| 897 } | |
| 898 | |
| 899 bitmap_copy (local_live, DF_LR_OUT (bb)); | |
| 900 | |
| 901 df_simulate_initialize_backwards (bb, local_live); | |
| 902 | |
| 903 FOR_BB_INSNS_REVERSE (bb, insn) | |
| 904 if (INSN_P (insn)) | |
| 905 { | |
| 906 bool needed = false; | |
| 907 | |
| 908 /* The insn is needed if there is someone who uses the output. */ | |
| 909 for (def_rec = DF_INSN_DEFS (insn); *def_rec; def_rec++) | |
| 910 if (bitmap_bit_p (local_live, DF_REF_REGNO (*def_rec)) | |
| 911 || bitmap_bit_p (au, DF_REF_REGNO (*def_rec))) | |
| 912 { | |
| 913 needed = true; | |
| 914 break; | |
| 915 } | |
|
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916 |
| 0 | 917 if (needed) |
| 918 mark_insn (insn, true); | |
|
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919 |
| 0 | 920 /* No matter if the instruction is needed or not, we remove |
| 921 any regno in the defs from the live set. */ | |
| 922 df_simulate_defs (insn, local_live); | |
| 923 | |
| 924 /* On the other hand, we do not allow the dead uses to set | |
| 925 anything in local_live. */ | |
| 926 if (marked_insn_p (insn)) | |
| 927 df_simulate_uses (insn, local_live); | |
| 928 } | |
|
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929 |
| 0 | 930 df_simulate_finalize_backwards (bb, local_live); |
| 931 | |
| 932 block_changed = !bitmap_equal_p (local_live, DF_LR_IN (bb)); | |
| 933 if (block_changed) | |
| 934 bitmap_copy (DF_LR_IN (bb), local_live); | |
| 935 | |
| 936 BITMAP_FREE (local_live); | |
| 937 return block_changed; | |
| 938 } | |
| 939 | |
| 940 | |
| 941 /* Perform fast DCE once initialization is done. If BYTE_LEVEL is | |
| 942 true, use the byte level dce, otherwise do it at the pseudo | |
| 943 level. */ | |
| 944 | |
| 945 static void | |
| 946 fast_dce (bool byte_level) | |
| 947 { | |
| 948 int *postorder = df_get_postorder (DF_BACKWARD); | |
| 949 int n_blocks = df_get_n_blocks (DF_BACKWARD); | |
| 950 /* The set of blocks that have been seen on this iteration. */ | |
| 951 bitmap processed = BITMAP_ALLOC (&dce_blocks_bitmap_obstack); | |
| 952 /* The set of blocks that need to have the out vectors reset because | |
| 953 the in of one of their successors has changed. */ | |
| 954 bitmap redo_out = BITMAP_ALLOC (&dce_blocks_bitmap_obstack); | |
| 955 bitmap all_blocks = BITMAP_ALLOC (&dce_blocks_bitmap_obstack); | |
| 956 bool global_changed = true; | |
| 957 | |
| 958 /* These regs are considered always live so if they end up dying | |
| 959 because of some def, we need to bring the back again. Calling | |
| 960 df_simulate_fixup_sets has the disadvantage of calling | |
| 961 bb_has_eh_pred once per insn, so we cache the information | |
| 962 here. */ | |
| 963 bitmap au = df->regular_block_artificial_uses; | |
| 964 bitmap au_eh = df->eh_block_artificial_uses; | |
| 965 int i; | |
| 966 | |
| 967 prescan_insns_for_dce (true); | |
| 968 | |
| 969 for (i = 0; i < n_blocks; i++) | |
| 970 bitmap_set_bit (all_blocks, postorder[i]); | |
| 971 | |
| 972 while (global_changed) | |
| 973 { | |
| 974 global_changed = false; | |
| 975 | |
| 976 for (i = 0; i < n_blocks; i++) | |
| 977 { | |
| 978 int index = postorder[i]; | |
| 979 basic_block bb = BASIC_BLOCK (index); | |
| 980 bool local_changed; | |
| 981 | |
| 982 if (index < NUM_FIXED_BLOCKS) | |
| 983 { | |
| 984 bitmap_set_bit (processed, index); | |
| 985 continue; | |
| 986 } | |
| 987 | |
| 988 if (byte_level) | |
|
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989 local_changed |
| 0 | 990 = byte_dce_process_block (bb, bitmap_bit_p (redo_out, index), |
| 991 bb_has_eh_pred (bb) ? au_eh : au); | |
| 992 else | |
|
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993 local_changed |
| 0 | 994 = dce_process_block (bb, bitmap_bit_p (redo_out, index), |
| 995 bb_has_eh_pred (bb) ? au_eh : au); | |
| 996 bitmap_set_bit (processed, index); | |
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997 |
| 0 | 998 if (local_changed) |
| 999 { | |
| 1000 edge e; | |
| 1001 edge_iterator ei; | |
| 1002 FOR_EACH_EDGE (e, ei, bb->preds) | |
| 1003 if (bitmap_bit_p (processed, e->src->index)) | |
| 1004 /* Be tricky about when we need to iterate the | |
| 1005 analysis. We only have redo the analysis if the | |
| 1006 bitmaps change at the top of a block that is the | |
| 1007 entry to a loop. */ | |
| 1008 global_changed = true; | |
| 1009 else | |
| 1010 bitmap_set_bit (redo_out, e->src->index); | |
| 1011 } | |
| 1012 } | |
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1013 |
| 0 | 1014 if (global_changed) |
| 1015 { | |
| 1016 /* Turn off the RUN_DCE flag to prevent recursive calls to | |
| 1017 dce. */ | |
| 1018 int old_flag = df_clear_flags (DF_LR_RUN_DCE); | |
| 1019 | |
| 1020 /* So something was deleted that requires a redo. Do it on | |
| 1021 the cheap. */ | |
| 1022 delete_unmarked_insns (); | |
| 1023 sbitmap_zero (marked); | |
| 1024 bitmap_clear (processed); | |
| 1025 bitmap_clear (redo_out); | |
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1026 |
| 0 | 1027 /* We do not need to rescan any instructions. We only need |
| 1028 to redo the dataflow equations for the blocks that had a | |
| 1029 change at the top of the block. Then we need to redo the | |
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1030 iteration. */ |
| 0 | 1031 if (byte_level) |
| 1032 df_analyze_problem (df_byte_lr, all_blocks, postorder, n_blocks); | |
| 1033 else | |
| 1034 df_analyze_problem (df_lr, all_blocks, postorder, n_blocks); | |
| 1035 | |
| 1036 if (old_flag & DF_LR_RUN_DCE) | |
| 1037 df_set_flags (DF_LR_RUN_DCE); | |
| 1038 | |
| 1039 prescan_insns_for_dce (true); | |
| 1040 } | |
| 1041 } | |
| 1042 | |
| 1043 delete_unmarked_insns (); | |
| 1044 | |
| 1045 BITMAP_FREE (processed); | |
| 1046 BITMAP_FREE (redo_out); | |
| 1047 BITMAP_FREE (all_blocks); | |
| 1048 } | |
| 1049 | |
| 1050 | |
| 1051 /* Fast register level DCE. */ | |
| 1052 | |
| 1053 static unsigned int | |
| 1054 rest_of_handle_fast_dce (void) | |
| 1055 { | |
| 1056 init_dce (true); | |
| 1057 fast_dce (false); | |
| 1058 fini_dce (true); | |
| 1059 return 0; | |
| 1060 } | |
| 1061 | |
| 1062 | |
| 1063 /* Fast byte level DCE. */ | |
| 1064 | |
| 1065 static unsigned int | |
| 1066 rest_of_handle_fast_byte_dce (void) | |
| 1067 { | |
| 1068 df_byte_lr_add_problem (); | |
| 1069 init_dce (true); | |
| 1070 fast_dce (true); | |
| 1071 fini_dce (true); | |
| 1072 return 0; | |
| 1073 } | |
| 1074 | |
| 1075 | |
| 1076 /* This is an internal call that is used by the df live register | |
| 1077 problem to run fast dce as a side effect of creating the live | |
| 1078 information. The stack is organized so that the lr problem is run, | |
| 1079 this pass is run, which updates the live info and the df scanning | |
| 1080 info, and then returns to allow the rest of the problems to be run. | |
| 1081 | |
| 1082 This can be called by elsewhere but it will not update the bit | |
| 1083 vectors for any other problems than LR. */ | |
| 1084 | |
| 1085 void | |
| 1086 run_fast_df_dce (void) | |
| 1087 { | |
| 1088 if (flag_dce) | |
| 1089 { | |
| 1090 /* If dce is able to delete something, it has to happen | |
| 1091 immediately. Otherwise there will be problems handling the | |
| 1092 eq_notes. */ | |
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1093 int old_flags = |
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1094 df_clear_flags (DF_DEFER_INSN_RESCAN + DF_NO_INSN_RESCAN); |
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1095 |
| 0 | 1096 df_in_progress = true; |
| 1097 rest_of_handle_fast_dce (); | |
| 1098 df_in_progress = false; | |
| 1099 | |
| 1100 df_set_flags (old_flags); | |
| 1101 } | |
| 1102 } | |
| 1103 | |
| 1104 | |
| 1105 /* Run a fast DCE pass. */ | |
| 1106 | |
| 1107 void | |
| 1108 run_fast_dce (void) | |
| 1109 { | |
| 1110 if (flag_dce) | |
| 1111 rest_of_handle_fast_dce (); | |
| 1112 } | |
| 1113 | |
| 1114 | |
| 1115 static bool | |
| 1116 gate_fast_dce (void) | |
| 1117 { | |
| 1118 return optimize > 0 && flag_dce | |
| 1119 && dbg_cnt (dce_fast); | |
| 1120 } | |
| 1121 | |
| 1122 struct rtl_opt_pass pass_fast_rtl_dce = | |
| 1123 { | |
| 1124 { | |
| 1125 RTL_PASS, | |
|
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1126 "rtl dce", /* name */ |
| 0 | 1127 gate_fast_dce, /* gate */ |
| 1128 rest_of_handle_fast_dce, /* execute */ | |
| 1129 NULL, /* sub */ | |
| 1130 NULL, /* next */ | |
| 1131 0, /* static_pass_number */ | |
| 1132 TV_DCE, /* tv_id */ | |
| 1133 0, /* properties_required */ | |
| 1134 0, /* properties_provided */ | |
| 1135 0, /* properties_destroyed */ | |
| 1136 0, /* todo_flags_start */ | |
| 1137 TODO_dump_func | | |
| 1138 TODO_df_finish | TODO_verify_rtl_sharing | | |
| 1139 TODO_ggc_collect /* todo_flags_finish */ | |
| 1140 } | |
| 1141 }; | |
| 1142 | |
| 1143 struct rtl_opt_pass pass_fast_rtl_byte_dce = | |
| 1144 { | |
| 1145 { | |
| 1146 RTL_PASS, | |
| 1147 "byte-dce", /* name */ | |
| 1148 gate_fast_dce, /* gate */ | |
| 1149 rest_of_handle_fast_byte_dce, /* execute */ | |
| 1150 NULL, /* sub */ | |
| 1151 NULL, /* next */ | |
| 1152 0, /* static_pass_number */ | |
| 1153 TV_DCE, /* tv_id */ | |
| 1154 0, /* properties_required */ | |
| 1155 0, /* properties_provided */ | |
| 1156 0, /* properties_destroyed */ | |
| 1157 0, /* todo_flags_start */ | |
| 1158 TODO_dump_func | | |
| 1159 TODO_df_finish | TODO_verify_rtl_sharing | | |
| 1160 TODO_ggc_collect /* todo_flags_finish */ | |
| 1161 } | |
| 1162 }; |