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annotate gcc/tree-predcom.c @ 158:494b0b89df80 default tip
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| author | Shinji KONO <kono@ie.u-ryukyu.ac.jp> |
|---|---|
| date | Mon, 25 May 2020 18:13:55 +0900 |
| parents | 1830386684a0 |
| children |
| rev | line source |
|---|---|
| 0 | 1 /* Predictive commoning. |
| 145 | 2 Copyright (C) 2005-2020 Free Software Foundation, Inc. |
|
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3 |
| 0 | 4 This file is part of GCC. |
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5 |
| 0 | 6 GCC is free software; you can redistribute it and/or modify it |
| 7 under the terms of the GNU General Public License as published by the | |
| 8 Free Software Foundation; either version 3, or (at your option) any | |
| 9 later version. | |
|
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10 |
| 0 | 11 GCC is distributed in the hope that it will be useful, but WITHOUT |
| 12 ANY 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. | |
|
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15 |
| 0 | 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 /* This file implements the predictive commoning optimization. Predictive | |
| 21 commoning can be viewed as CSE around a loop, and with some improvements, | |
| 22 as generalized strength reduction-- i.e., reusing values computed in | |
| 23 earlier iterations of a loop in the later ones. So far, the pass only | |
| 24 handles the most useful case, that is, reusing values of memory references. | |
| 25 If you think this is all just a special case of PRE, you are sort of right; | |
| 26 however, concentrating on loops is simpler, and makes it possible to | |
| 27 incorporate data dependence analysis to detect the opportunities, perform | |
| 28 loop unrolling to avoid copies together with renaming immediately, | |
| 29 and if needed, we could also take register pressure into account. | |
| 30 | |
| 31 Let us demonstrate what is done on an example: | |
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32 |
| 0 | 33 for (i = 0; i < 100; i++) |
| 34 { | |
| 35 a[i+2] = a[i] + a[i+1]; | |
| 36 b[10] = b[10] + i; | |
| 37 c[i] = c[99 - i]; | |
| 38 d[i] = d[i + 1]; | |
| 39 } | |
| 40 | |
| 41 1) We find data references in the loop, and split them to mutually | |
| 42 independent groups (i.e., we find components of a data dependence | |
| 43 graph). We ignore read-read dependences whose distance is not constant. | |
| 44 (TODO -- we could also ignore antidependences). In this example, we | |
| 45 find the following groups: | |
| 46 | |
| 47 a[i]{read}, a[i+1]{read}, a[i+2]{write} | |
| 48 b[10]{read}, b[10]{write} | |
| 49 c[99 - i]{read}, c[i]{write} | |
| 50 d[i + 1]{read}, d[i]{write} | |
| 51 | |
| 52 2) Inside each of the group, we verify several conditions: | |
| 53 a) all the references must differ in indices only, and the indices | |
| 54 must all have the same step | |
| 55 b) the references must dominate loop latch (and thus, they must be | |
| 56 ordered by dominance relation). | |
| 57 c) the distance of the indices must be a small multiple of the step | |
| 58 We are then able to compute the difference of the references (# of | |
| 59 iterations before they point to the same place as the first of them). | |
| 60 Also, in case there are writes in the loop, we split the groups into | |
| 61 chains whose head is the write whose values are used by the reads in | |
| 62 the same chain. The chains are then processed independently, | |
| 63 making the further transformations simpler. Also, the shorter chains | |
| 64 need the same number of registers, but may require lower unrolling | |
| 65 factor in order to get rid of the copies on the loop latch. | |
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66 |
| 0 | 67 In our example, we get the following chains (the chain for c is invalid). |
| 68 | |
| 69 a[i]{read,+0}, a[i+1]{read,-1}, a[i+2]{write,-2} | |
| 70 b[10]{read,+0}, b[10]{write,+0} | |
| 71 d[i + 1]{read,+0}, d[i]{write,+1} | |
| 72 | |
| 73 3) For each read, we determine the read or write whose value it reuses, | |
| 74 together with the distance of this reuse. I.e. we take the last | |
| 75 reference before it with distance 0, or the last of the references | |
| 76 with the smallest positive distance to the read. Then, we remove | |
| 77 the references that are not used in any of these chains, discard the | |
| 78 empty groups, and propagate all the links so that they point to the | |
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79 single root reference of the chain (adjusting their distance |
| 0 | 80 appropriately). Some extra care needs to be taken for references with |
| 81 step 0. In our example (the numbers indicate the distance of the | |
| 82 reuse), | |
| 83 | |
| 84 a[i] --> (*) 2, a[i+1] --> (*) 1, a[i+2] (*) | |
| 85 b[10] --> (*) 1, b[10] (*) | |
| 86 | |
| 87 4) The chains are combined together if possible. If the corresponding | |
| 88 elements of two chains are always combined together with the same | |
| 89 operator, we remember just the result of this combination, instead | |
| 90 of remembering the values separately. We may need to perform | |
| 91 reassociation to enable combining, for example | |
| 92 | |
| 93 e[i] + f[i+1] + e[i+1] + f[i] | |
| 94 | |
| 95 can be reassociated as | |
| 96 | |
| 97 (e[i] + f[i]) + (e[i+1] + f[i+1]) | |
| 98 | |
| 99 and we can combine the chains for e and f into one chain. | |
| 100 | |
| 101 5) For each root reference (end of the chain) R, let N be maximum distance | |
| 111 | 102 of a reference reusing its value. Variables R0 up to RN are created, |
| 0 | 103 together with phi nodes that transfer values from R1 .. RN to |
| 104 R0 .. R(N-1). | |
| 105 Initial values are loaded to R0..R(N-1) (in case not all references | |
| 106 must necessarily be accessed and they may trap, we may fail here; | |
| 107 TODO sometimes, the loads could be guarded by a check for the number | |
| 108 of iterations). Values loaded/stored in roots are also copied to | |
| 109 RN. Other reads are replaced with the appropriate variable Ri. | |
| 110 Everything is put to SSA form. | |
| 111 | |
| 112 As a small improvement, if R0 is dead after the root (i.e., all uses of | |
| 113 the value with the maximum distance dominate the root), we can avoid | |
| 114 creating RN and use R0 instead of it. | |
| 115 | |
| 116 In our example, we get (only the parts concerning a and b are shown): | |
| 117 for (i = 0; i < 100; i++) | |
| 118 { | |
| 119 f = phi (a[0], s); | |
| 120 s = phi (a[1], f); | |
| 121 x = phi (b[10], x); | |
| 122 | |
| 123 f = f + s; | |
| 124 a[i+2] = f; | |
| 125 x = x + i; | |
| 126 b[10] = x; | |
| 127 } | |
| 128 | |
| 129 6) Factor F for unrolling is determined as the smallest common multiple of | |
| 130 (N + 1) for each root reference (N for references for that we avoided | |
| 131 creating RN). If F and the loop is small enough, loop is unrolled F | |
| 132 times. The stores to RN (R0) in the copies of the loop body are | |
| 133 periodically replaced with R0, R1, ... (R1, R2, ...), so that they can | |
| 134 be coalesced and the copies can be eliminated. | |
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135 |
| 0 | 136 TODO -- copy propagation and other optimizations may change the live |
| 137 ranges of the temporary registers and prevent them from being coalesced; | |
| 138 this may increase the register pressure. | |
| 139 | |
| 140 In our case, F = 2 and the (main loop of the) result is | |
| 141 | |
| 142 for (i = 0; i < ...; i += 2) | |
| 143 { | |
| 144 f = phi (a[0], f); | |
| 145 s = phi (a[1], s); | |
| 146 x = phi (b[10], x); | |
| 147 | |
| 148 f = f + s; | |
| 149 a[i+2] = f; | |
| 150 x = x + i; | |
| 151 b[10] = x; | |
| 152 | |
| 153 s = s + f; | |
| 154 a[i+3] = s; | |
| 155 x = x + i; | |
| 156 b[10] = x; | |
| 157 } | |
| 158 | |
| 111 | 159 Apart from predictive commoning on Load-Load and Store-Load chains, we |
| 160 also support Store-Store chains -- stores killed by other store can be | |
| 161 eliminated. Given below example: | |
| 162 | |
| 163 for (i = 0; i < n; i++) | |
| 164 { | |
| 165 a[i] = 1; | |
| 166 a[i+2] = 2; | |
| 167 } | |
| 168 | |
| 169 It can be replaced with: | |
| 170 | |
| 171 t0 = a[0]; | |
| 172 t1 = a[1]; | |
| 173 for (i = 0; i < n; i++) | |
| 174 { | |
| 175 a[i] = 1; | |
| 176 t2 = 2; | |
| 177 t0 = t1; | |
| 178 t1 = t2; | |
| 179 } | |
| 180 a[n] = t0; | |
| 181 a[n+1] = t1; | |
| 182 | |
| 183 If the loop runs more than 1 iterations, it can be further simplified into: | |
| 184 | |
| 185 for (i = 0; i < n; i++) | |
| 186 { | |
| 187 a[i] = 1; | |
| 188 } | |
| 189 a[n] = 2; | |
| 190 a[n+1] = 2; | |
| 191 | |
| 192 The interesting part is this can be viewed either as general store motion | |
| 193 or general dead store elimination in either intra/inter-iterations way. | |
| 194 | |
| 131 | 195 With trivial effort, we also support load inside Store-Store chains if the |
| 196 load is dominated by a store statement in the same iteration of loop. You | |
| 197 can see this as a restricted Store-Mixed-Load-Store chain. | |
| 198 | |
| 111 | 199 TODO: For now, we don't support store-store chains in multi-exit loops. We |
| 200 force to not unroll in case of store-store chain even if other chains might | |
| 201 ask for unroll. | |
| 0 | 202 |
| 203 Predictive commoning can be generalized for arbitrary computations (not | |
| 204 just memory loads), and also nontrivial transfer functions (e.g., replacing | |
| 205 i * i with ii_last + 2 * i + 1), to generalize strength reduction. */ | |
| 206 | |
| 207 #include "config.h" | |
| 208 #include "system.h" | |
| 209 #include "coretypes.h" | |
| 111 | 210 #include "backend.h" |
| 211 #include "rtl.h" | |
| 0 | 212 #include "tree.h" |
| 111 | 213 #include "gimple.h" |
| 214 #include "predict.h" | |
| 215 #include "tree-pass.h" | |
| 216 #include "ssa.h" | |
| 217 #include "gimple-pretty-print.h" | |
| 218 #include "alias.h" | |
| 219 #include "fold-const.h" | |
| 0 | 220 #include "cfgloop.h" |
| 111 | 221 #include "tree-eh.h" |
| 222 #include "gimplify.h" | |
| 223 #include "gimple-iterator.h" | |
| 224 #include "gimplify-me.h" | |
| 225 #include "tree-ssa-loop-ivopts.h" | |
| 226 #include "tree-ssa-loop-manip.h" | |
| 227 #include "tree-ssa-loop-niter.h" | |
| 228 #include "tree-ssa-loop.h" | |
| 229 #include "tree-into-ssa.h" | |
| 230 #include "tree-dfa.h" | |
| 231 #include "tree-ssa.h" | |
| 0 | 232 #include "tree-data-ref.h" |
| 233 #include "tree-scalar-evolution.h" | |
| 234 #include "tree-affine.h" | |
| 111 | 235 #include "builtins.h" |
| 0 | 236 |
| 237 /* The maximum number of iterations between the considered memory | |
| 238 references. */ | |
| 239 | |
| 240 #define MAX_DISTANCE (target_avail_regs < 16 ? 4 : 8) | |
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241 |
| 0 | 242 /* Data references (or phi nodes that carry data reference values across |
| 243 loop iterations). */ | |
| 244 | |
| 145 | 245 typedef class dref_d |
| 0 | 246 { |
| 145 | 247 public: |
| 0 | 248 /* The reference itself. */ |
| 249 struct data_reference *ref; | |
| 250 | |
| 251 /* The statement in that the reference appears. */ | |
| 111 | 252 gimple *stmt; |
| 0 | 253 |
| 254 /* In case that STMT is a phi node, this field is set to the SSA name | |
| 255 defined by it in replace_phis_by_defined_names (in order to avoid | |
| 256 pointing to phi node that got reallocated in the meantime). */ | |
| 257 tree name_defined_by_phi; | |
| 258 | |
| 259 /* Distance of the reference from the root of the chain (in number of | |
| 260 iterations of the loop). */ | |
| 261 unsigned distance; | |
| 262 | |
| 263 /* Number of iterations offset from the first reference in the component. */ | |
| 111 | 264 widest_int offset; |
| 0 | 265 |
| 266 /* Number of the reference in a component, in dominance ordering. */ | |
| 267 unsigned pos; | |
| 268 | |
| 269 /* True if the memory reference is always accessed when the loop is | |
| 270 entered. */ | |
| 271 unsigned always_accessed : 1; | |
| 272 } *dref; | |
| 273 | |
| 274 | |
| 275 /* Type of the chain of the references. */ | |
| 276 | |
| 277 enum chain_type | |
| 278 { | |
| 279 /* The addresses of the references in the chain are constant. */ | |
| 280 CT_INVARIANT, | |
| 281 | |
| 282 /* There are only loads in the chain. */ | |
| 283 CT_LOAD, | |
| 284 | |
| 285 /* Root of the chain is store, the rest are loads. */ | |
| 286 CT_STORE_LOAD, | |
| 287 | |
| 111 | 288 /* There are only stores in the chain. */ |
| 289 CT_STORE_STORE, | |
| 290 | |
| 0 | 291 /* A combination of two chains. */ |
| 292 CT_COMBINATION | |
| 293 }; | |
| 294 | |
| 295 /* Chains of data references. */ | |
| 296 | |
| 297 typedef struct chain | |
| 298 { | |
| 299 /* Type of the chain. */ | |
| 300 enum chain_type type; | |
| 301 | |
| 302 /* For combination chains, the operator and the two chains that are | |
| 303 combined, and the type of the result. */ | |
| 304 enum tree_code op; | |
| 305 tree rslt_type; | |
| 306 struct chain *ch1, *ch2; | |
| 307 | |
| 308 /* The references in the chain. */ | |
| 111 | 309 vec<dref> refs; |
| 0 | 310 |
| 311 /* The maximum distance of the reference in the chain from the root. */ | |
| 312 unsigned length; | |
| 313 | |
| 314 /* The variables used to copy the value throughout iterations. */ | |
| 111 | 315 vec<tree> vars; |
| 0 | 316 |
| 317 /* Initializers for the variables. */ | |
| 111 | 318 vec<tree> inits; |
| 319 | |
| 320 /* Finalizers for the eliminated stores. */ | |
| 321 vec<tree> finis; | |
| 322 | |
| 323 /* gimple stmts intializing the initial variables of the chain. */ | |
| 324 gimple_seq init_seq; | |
| 325 | |
| 326 /* gimple stmts finalizing the eliminated stores of the chain. */ | |
| 327 gimple_seq fini_seq; | |
| 0 | 328 |
| 329 /* True if there is a use of a variable with the maximal distance | |
| 330 that comes after the root in the loop. */ | |
| 331 unsigned has_max_use_after : 1; | |
| 332 | |
| 333 /* True if all the memory references in the chain are always accessed. */ | |
| 334 unsigned all_always_accessed : 1; | |
| 335 | |
| 336 /* True if this chain was combined together with some other chain. */ | |
| 337 unsigned combined : 1; | |
| 111 | 338 |
| 339 /* True if this is store elimination chain and eliminated stores store | |
| 340 loop invariant value into memory. */ | |
| 341 unsigned inv_store_elimination : 1; | |
| 0 | 342 } *chain_p; |
| 343 | |
| 344 | |
| 345 /* Describes the knowledge about the step of the memory references in | |
| 346 the component. */ | |
| 347 | |
| 348 enum ref_step_type | |
| 349 { | |
| 350 /* The step is zero. */ | |
| 351 RS_INVARIANT, | |
| 352 | |
| 353 /* The step is nonzero. */ | |
| 354 RS_NONZERO, | |
| 355 | |
| 356 /* The step may or may not be nonzero. */ | |
| 357 RS_ANY | |
| 358 }; | |
| 359 | |
| 360 /* Components of the data dependence graph. */ | |
| 361 | |
| 362 struct component | |
| 363 { | |
| 364 /* The references in the component. */ | |
| 111 | 365 vec<dref> refs; |
| 0 | 366 |
| 367 /* What we know about the step of the references in the component. */ | |
| 368 enum ref_step_type comp_step; | |
| 369 | |
| 111 | 370 /* True if all references in component are stores and we try to do |
| 371 intra/inter loop iteration dead store elimination. */ | |
| 372 bool eliminate_store_p; | |
| 373 | |
| 0 | 374 /* Next component in the list. */ |
| 375 struct component *next; | |
| 376 }; | |
| 377 | |
| 378 /* Bitmap of ssa names defined by looparound phi nodes covered by chains. */ | |
| 379 | |
| 380 static bitmap looparound_phis; | |
| 381 | |
| 382 /* Cache used by tree_to_aff_combination_expand. */ | |
| 383 | |
| 111 | 384 static hash_map<tree, name_expansion *> *name_expansions; |
| 0 | 385 |
| 386 /* Dumps data reference REF to FILE. */ | |
| 387 | |
| 388 extern void dump_dref (FILE *, dref); | |
| 389 void | |
| 390 dump_dref (FILE *file, dref ref) | |
| 391 { | |
| 392 if (ref->ref) | |
| 393 { | |
| 394 fprintf (file, " "); | |
| 395 print_generic_expr (file, DR_REF (ref->ref), TDF_SLIM); | |
| 396 fprintf (file, " (id %u%s)\n", ref->pos, | |
| 397 DR_IS_READ (ref->ref) ? "" : ", write"); | |
| 398 | |
| 399 fprintf (file, " offset "); | |
| 111 | 400 print_decs (ref->offset, file); |
| 0 | 401 fprintf (file, "\n"); |
| 402 | |
| 403 fprintf (file, " distance %u\n", ref->distance); | |
| 404 } | |
| 405 else | |
| 406 { | |
| 407 if (gimple_code (ref->stmt) == GIMPLE_PHI) | |
| 408 fprintf (file, " looparound ref\n"); | |
| 409 else | |
| 410 fprintf (file, " combination ref\n"); | |
| 411 fprintf (file, " in statement "); | |
| 412 print_gimple_stmt (file, ref->stmt, 0, TDF_SLIM); | |
| 413 fprintf (file, "\n"); | |
| 414 fprintf (file, " distance %u\n", ref->distance); | |
| 415 } | |
| 416 | |
| 417 } | |
| 418 | |
| 419 /* Dumps CHAIN to FILE. */ | |
| 420 | |
| 421 extern void dump_chain (FILE *, chain_p); | |
| 422 void | |
| 423 dump_chain (FILE *file, chain_p chain) | |
| 424 { | |
| 425 dref a; | |
| 426 const char *chain_type; | |
| 427 unsigned i; | |
| 428 tree var; | |
| 429 | |
| 430 switch (chain->type) | |
| 431 { | |
| 432 case CT_INVARIANT: | |
| 433 chain_type = "Load motion"; | |
| 434 break; | |
| 435 | |
| 436 case CT_LOAD: | |
| 437 chain_type = "Loads-only"; | |
| 438 break; | |
| 439 | |
| 440 case CT_STORE_LOAD: | |
| 441 chain_type = "Store-loads"; | |
| 442 break; | |
| 443 | |
| 111 | 444 case CT_STORE_STORE: |
| 445 chain_type = "Store-stores"; | |
| 446 break; | |
| 447 | |
| 0 | 448 case CT_COMBINATION: |
| 449 chain_type = "Combination"; | |
| 450 break; | |
| 451 | |
| 452 default: | |
| 453 gcc_unreachable (); | |
| 454 } | |
| 455 | |
| 456 fprintf (file, "%s chain %p%s\n", chain_type, (void *) chain, | |
| 457 chain->combined ? " (combined)" : ""); | |
| 458 if (chain->type != CT_INVARIANT) | |
| 459 fprintf (file, " max distance %u%s\n", chain->length, | |
| 460 chain->has_max_use_after ? "" : ", may reuse first"); | |
| 461 | |
| 462 if (chain->type == CT_COMBINATION) | |
| 463 { | |
| 464 fprintf (file, " equal to %p %s %p in type ", | |
| 465 (void *) chain->ch1, op_symbol_code (chain->op), | |
| 466 (void *) chain->ch2); | |
| 467 print_generic_expr (file, chain->rslt_type, TDF_SLIM); | |
| 468 fprintf (file, "\n"); | |
| 469 } | |
| 470 | |
| 111 | 471 if (chain->vars.exists ()) |
| 0 | 472 { |
| 473 fprintf (file, " vars"); | |
| 111 | 474 FOR_EACH_VEC_ELT (chain->vars, i, var) |
| 0 | 475 { |
| 476 fprintf (file, " "); | |
| 477 print_generic_expr (file, var, TDF_SLIM); | |
| 478 } | |
| 479 fprintf (file, "\n"); | |
| 480 } | |
| 481 | |
| 111 | 482 if (chain->inits.exists ()) |
| 0 | 483 { |
| 484 fprintf (file, " inits"); | |
| 111 | 485 FOR_EACH_VEC_ELT (chain->inits, i, var) |
| 0 | 486 { |
| 487 fprintf (file, " "); | |
| 488 print_generic_expr (file, var, TDF_SLIM); | |
| 489 } | |
| 490 fprintf (file, "\n"); | |
| 491 } | |
| 492 | |
| 493 fprintf (file, " references:\n"); | |
| 111 | 494 FOR_EACH_VEC_ELT (chain->refs, i, a) |
| 0 | 495 dump_dref (file, a); |
| 496 | |
| 497 fprintf (file, "\n"); | |
| 498 } | |
| 499 | |
| 500 /* Dumps CHAINS to FILE. */ | |
| 501 | |
| 111 | 502 extern void dump_chains (FILE *, vec<chain_p> ); |
| 0 | 503 void |
| 111 | 504 dump_chains (FILE *file, vec<chain_p> chains) |
| 0 | 505 { |
| 506 chain_p chain; | |
| 507 unsigned i; | |
| 508 | |
| 111 | 509 FOR_EACH_VEC_ELT (chains, i, chain) |
| 0 | 510 dump_chain (file, chain); |
| 511 } | |
| 512 | |
| 513 /* Dumps COMP to FILE. */ | |
| 514 | |
| 515 extern void dump_component (FILE *, struct component *); | |
| 516 void | |
| 517 dump_component (FILE *file, struct component *comp) | |
| 518 { | |
| 519 dref a; | |
| 520 unsigned i; | |
| 521 | |
| 522 fprintf (file, "Component%s:\n", | |
| 523 comp->comp_step == RS_INVARIANT ? " (invariant)" : ""); | |
| 111 | 524 FOR_EACH_VEC_ELT (comp->refs, i, a) |
| 0 | 525 dump_dref (file, a); |
| 526 fprintf (file, "\n"); | |
| 527 } | |
| 528 | |
| 529 /* Dumps COMPS to FILE. */ | |
| 530 | |
| 531 extern void dump_components (FILE *, struct component *); | |
| 532 void | |
| 533 dump_components (FILE *file, struct component *comps) | |
| 534 { | |
| 535 struct component *comp; | |
| 536 | |
| 537 for (comp = comps; comp; comp = comp->next) | |
| 538 dump_component (file, comp); | |
| 539 } | |
| 540 | |
| 541 /* Frees a chain CHAIN. */ | |
| 542 | |
| 543 static void | |
| 544 release_chain (chain_p chain) | |
| 545 { | |
| 546 dref ref; | |
| 547 unsigned i; | |
| 548 | |
| 549 if (chain == NULL) | |
| 550 return; | |
| 551 | |
| 111 | 552 FOR_EACH_VEC_ELT (chain->refs, i, ref) |
| 0 | 553 free (ref); |
| 554 | |
| 111 | 555 chain->refs.release (); |
| 556 chain->vars.release (); | |
| 557 chain->inits.release (); | |
| 558 if (chain->init_seq) | |
| 559 gimple_seq_discard (chain->init_seq); | |
| 560 | |
| 561 chain->finis.release (); | |
| 562 if (chain->fini_seq) | |
| 563 gimple_seq_discard (chain->fini_seq); | |
| 0 | 564 |
| 565 free (chain); | |
| 566 } | |
| 567 | |
| 568 /* Frees CHAINS. */ | |
| 569 | |
| 570 static void | |
| 111 | 571 release_chains (vec<chain_p> chains) |
| 0 | 572 { |
| 573 unsigned i; | |
| 574 chain_p chain; | |
| 575 | |
| 111 | 576 FOR_EACH_VEC_ELT (chains, i, chain) |
| 0 | 577 release_chain (chain); |
| 111 | 578 chains.release (); |
| 0 | 579 } |
| 580 | |
| 581 /* Frees a component COMP. */ | |
| 582 | |
| 583 static void | |
| 584 release_component (struct component *comp) | |
| 585 { | |
| 111 | 586 comp->refs.release (); |
| 0 | 587 free (comp); |
| 588 } | |
| 589 | |
| 590 /* Frees list of components COMPS. */ | |
| 591 | |
| 592 static void | |
| 593 release_components (struct component *comps) | |
| 594 { | |
| 595 struct component *act, *next; | |
| 596 | |
| 597 for (act = comps; act; act = next) | |
| 598 { | |
| 599 next = act->next; | |
| 600 release_component (act); | |
| 601 } | |
| 602 } | |
| 603 | |
| 604 /* Finds a root of tree given by FATHERS containing A, and performs path | |
| 605 shortening. */ | |
| 606 | |
| 607 static unsigned | |
| 608 component_of (unsigned fathers[], unsigned a) | |
| 609 { | |
| 610 unsigned root, n; | |
| 611 | |
| 612 for (root = a; root != fathers[root]; root = fathers[root]) | |
| 613 continue; | |
| 614 | |
| 615 for (; a != root; a = n) | |
| 616 { | |
| 617 n = fathers[a]; | |
| 618 fathers[a] = root; | |
| 619 } | |
| 620 | |
| 621 return root; | |
| 622 } | |
| 623 | |
| 624 /* Join operation for DFU. FATHERS gives the tree, SIZES are sizes of the | |
| 625 components, A and B are components to merge. */ | |
| 626 | |
| 627 static void | |
| 628 merge_comps (unsigned fathers[], unsigned sizes[], unsigned a, unsigned b) | |
| 629 { | |
| 630 unsigned ca = component_of (fathers, a); | |
| 631 unsigned cb = component_of (fathers, b); | |
| 632 | |
| 633 if (ca == cb) | |
| 634 return; | |
| 635 | |
| 636 if (sizes[ca] < sizes[cb]) | |
| 637 { | |
| 638 sizes[cb] += sizes[ca]; | |
| 639 fathers[ca] = cb; | |
| 640 } | |
| 641 else | |
| 642 { | |
| 643 sizes[ca] += sizes[cb]; | |
| 644 fathers[cb] = ca; | |
| 645 } | |
| 646 } | |
| 647 | |
| 648 /* Returns true if A is a reference that is suitable for predictive commoning | |
| 649 in the innermost loop that contains it. REF_STEP is set according to the | |
| 650 step of the reference A. */ | |
| 651 | |
| 652 static bool | |
| 653 suitable_reference_p (struct data_reference *a, enum ref_step_type *ref_step) | |
| 654 { | |
| 655 tree ref = DR_REF (a), step = DR_STEP (a); | |
| 656 | |
| 657 if (!step | |
| 111 | 658 || TREE_THIS_VOLATILE (ref) |
| 0 | 659 || !is_gimple_reg_type (TREE_TYPE (ref)) |
| 660 || tree_could_throw_p (ref)) | |
| 661 return false; | |
| 662 | |
| 663 if (integer_zerop (step)) | |
| 664 *ref_step = RS_INVARIANT; | |
| 665 else if (integer_nonzerop (step)) | |
| 666 *ref_step = RS_NONZERO; | |
| 667 else | |
| 668 *ref_step = RS_ANY; | |
| 669 | |
| 670 return true; | |
| 671 } | |
| 672 | |
| 673 /* Stores DR_OFFSET (DR) + DR_INIT (DR) to OFFSET. */ | |
| 674 | |
| 675 static void | |
| 676 aff_combination_dr_offset (struct data_reference *dr, aff_tree *offset) | |
| 677 { | |
| 111 | 678 tree type = TREE_TYPE (DR_OFFSET (dr)); |
| 0 | 679 aff_tree delta; |
| 680 | |
| 111 | 681 tree_to_aff_combination_expand (DR_OFFSET (dr), type, offset, |
| 0 | 682 &name_expansions); |
| 131 | 683 aff_combination_const (&delta, type, wi::to_poly_widest (DR_INIT (dr))); |
| 0 | 684 aff_combination_add (offset, &delta); |
| 685 } | |
| 686 | |
| 687 /* Determines number of iterations of the innermost enclosing loop before B | |
| 688 refers to exactly the same location as A and stores it to OFF. If A and | |
| 689 B do not have the same step, they never meet, or anything else fails, | |
| 690 returns false, otherwise returns true. Both A and B are assumed to | |
| 691 satisfy suitable_reference_p. */ | |
| 692 | |
| 693 static bool | |
| 694 determine_offset (struct data_reference *a, struct data_reference *b, | |
| 131 | 695 poly_widest_int *off) |
| 0 | 696 { |
| 697 aff_tree diff, baseb, step; | |
| 698 tree typea, typeb; | |
| 699 | |
| 700 /* Check that both the references access the location in the same type. */ | |
| 701 typea = TREE_TYPE (DR_REF (a)); | |
| 702 typeb = TREE_TYPE (DR_REF (b)); | |
| 703 if (!useless_type_conversion_p (typeb, typea)) | |
| 704 return false; | |
| 705 | |
| 706 /* Check whether the base address and the step of both references is the | |
| 707 same. */ | |
| 708 if (!operand_equal_p (DR_STEP (a), DR_STEP (b), 0) | |
| 709 || !operand_equal_p (DR_BASE_ADDRESS (a), DR_BASE_ADDRESS (b), 0)) | |
| 710 return false; | |
| 711 | |
| 712 if (integer_zerop (DR_STEP (a))) | |
| 713 { | |
| 714 /* If the references have loop invariant address, check that they access | |
| 715 exactly the same location. */ | |
| 111 | 716 *off = 0; |
| 0 | 717 return (operand_equal_p (DR_OFFSET (a), DR_OFFSET (b), 0) |
| 718 && operand_equal_p (DR_INIT (a), DR_INIT (b), 0)); | |
| 719 } | |
| 720 | |
| 721 /* Compare the offsets of the addresses, and check whether the difference | |
| 722 is a multiple of step. */ | |
| 723 aff_combination_dr_offset (a, &diff); | |
| 724 aff_combination_dr_offset (b, &baseb); | |
| 111 | 725 aff_combination_scale (&baseb, -1); |
| 0 | 726 aff_combination_add (&diff, &baseb); |
| 727 | |
| 111 | 728 tree_to_aff_combination_expand (DR_STEP (a), TREE_TYPE (DR_STEP (a)), |
| 0 | 729 &step, &name_expansions); |
| 730 return aff_combination_constant_multiple_p (&diff, &step, off); | |
| 731 } | |
| 732 | |
| 733 /* Returns the last basic block in LOOP for that we are sure that | |
| 734 it is executed whenever the loop is entered. */ | |
| 735 | |
| 736 static basic_block | |
| 145 | 737 last_always_executed_block (class loop *loop) |
| 0 | 738 { |
| 739 unsigned i; | |
| 111 | 740 vec<edge> exits = get_loop_exit_edges (loop); |
| 0 | 741 edge ex; |
| 742 basic_block last = loop->latch; | |
| 743 | |
| 111 | 744 FOR_EACH_VEC_ELT (exits, i, ex) |
| 0 | 745 last = nearest_common_dominator (CDI_DOMINATORS, last, ex->src); |
| 111 | 746 exits.release (); |
| 0 | 747 |
| 748 return last; | |
| 749 } | |
| 750 | |
| 751 /* Splits dependence graph on DATAREFS described by DEPENDS to components. */ | |
| 752 | |
| 753 static struct component * | |
| 145 | 754 split_data_refs_to_components (class loop *loop, |
| 111 | 755 vec<data_reference_p> datarefs, |
| 756 vec<ddr_p> depends) | |
| 0 | 757 { |
| 111 | 758 unsigned i, n = datarefs.length (); |
| 0 | 759 unsigned ca, ia, ib, bad; |
| 760 unsigned *comp_father = XNEWVEC (unsigned, n + 1); | |
| 761 unsigned *comp_size = XNEWVEC (unsigned, n + 1); | |
| 762 struct component **comps; | |
| 763 struct data_reference *dr, *dra, *drb; | |
| 764 struct data_dependence_relation *ddr; | |
| 765 struct component *comp_list = NULL, *comp; | |
| 766 dref dataref; | |
| 111 | 767 /* Don't do store elimination if loop has multiple exit edges. */ |
| 768 bool eliminate_store_p = single_exit (loop) != NULL; | |
| 0 | 769 basic_block last_always_executed = last_always_executed_block (loop); |
| 145 | 770 auto_bitmap no_store_store_comps; |
|
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|
771 |
| 111 | 772 FOR_EACH_VEC_ELT (datarefs, i, dr) |
| 0 | 773 { |
| 774 if (!DR_REF (dr)) | |
| 775 { | |
| 776 /* A fake reference for call or asm_expr that may clobber memory; | |
| 777 just fail. */ | |
| 778 goto end; | |
| 779 } | |
| 111 | 780 /* predcom pass isn't prepared to handle calls with data references. */ |
| 781 if (is_gimple_call (DR_STMT (dr))) | |
| 782 goto end; | |
| 0 | 783 dr->aux = (void *) (size_t) i; |
| 784 comp_father[i] = i; | |
| 785 comp_size[i] = 1; | |
| 786 } | |
| 787 | |
| 788 /* A component reserved for the "bad" data references. */ | |
| 789 comp_father[n] = n; | |
| 790 comp_size[n] = 1; | |
| 791 | |
| 111 | 792 FOR_EACH_VEC_ELT (datarefs, i, dr) |
| 0 | 793 { |
| 794 enum ref_step_type dummy; | |
| 795 | |
| 796 if (!suitable_reference_p (dr, &dummy)) | |
| 797 { | |
| 798 ia = (unsigned) (size_t) dr->aux; | |
| 799 merge_comps (comp_father, comp_size, n, ia); | |
| 800 } | |
| 801 } | |
| 802 | |
| 111 | 803 FOR_EACH_VEC_ELT (depends, i, ddr) |
| 0 | 804 { |
| 131 | 805 poly_widest_int dummy_off; |
| 0 | 806 |
| 807 if (DDR_ARE_DEPENDENT (ddr) == chrec_known) | |
| 808 continue; | |
| 809 | |
| 810 dra = DDR_A (ddr); | |
| 811 drb = DDR_B (ddr); | |
| 111 | 812 |
| 813 /* Don't do store elimination if there is any unknown dependence for | |
| 814 any store data reference. */ | |
| 815 if ((DR_IS_WRITE (dra) || DR_IS_WRITE (drb)) | |
| 816 && (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know | |
| 817 || DDR_NUM_DIST_VECTS (ddr) == 0)) | |
| 818 eliminate_store_p = false; | |
| 819 | |
| 0 | 820 ia = component_of (comp_father, (unsigned) (size_t) dra->aux); |
| 821 ib = component_of (comp_father, (unsigned) (size_t) drb->aux); | |
| 822 if (ia == ib) | |
| 823 continue; | |
| 824 | |
| 825 bad = component_of (comp_father, n); | |
| 826 | |
| 827 /* If both A and B are reads, we may ignore unsuitable dependences. */ | |
| 111 | 828 if (DR_IS_READ (dra) && DR_IS_READ (drb)) |
| 829 { | |
| 830 if (ia == bad || ib == bad | |
| 831 || !determine_offset (dra, drb, &dummy_off)) | |
| 832 continue; | |
| 833 } | |
| 834 /* If A is read and B write or vice versa and there is unsuitable | |
| 835 dependence, instead of merging both components into a component | |
| 836 that will certainly not pass suitable_component_p, just put the | |
| 837 read into bad component, perhaps at least the write together with | |
| 838 all the other data refs in it's component will be optimizable. */ | |
| 839 else if (DR_IS_READ (dra) && ib != bad) | |
| 840 { | |
| 841 if (ia == bad) | |
| 145 | 842 { |
| 843 bitmap_set_bit (no_store_store_comps, ib); | |
| 844 continue; | |
| 845 } | |
| 111 | 846 else if (!determine_offset (dra, drb, &dummy_off)) |
| 847 { | |
| 145 | 848 bitmap_set_bit (no_store_store_comps, ib); |
| 111 | 849 merge_comps (comp_father, comp_size, bad, ia); |
| 850 continue; | |
| 851 } | |
| 852 } | |
| 853 else if (DR_IS_READ (drb) && ia != bad) | |
| 854 { | |
| 855 if (ib == bad) | |
| 145 | 856 { |
| 857 bitmap_set_bit (no_store_store_comps, ia); | |
| 858 continue; | |
| 859 } | |
| 111 | 860 else if (!determine_offset (dra, drb, &dummy_off)) |
| 861 { | |
| 145 | 862 bitmap_set_bit (no_store_store_comps, ia); |
| 111 | 863 merge_comps (comp_father, comp_size, bad, ib); |
| 864 continue; | |
| 865 } | |
| 866 } | |
| 867 else if (DR_IS_WRITE (dra) && DR_IS_WRITE (drb) | |
| 868 && ia != bad && ib != bad | |
| 869 && !determine_offset (dra, drb, &dummy_off)) | |
| 870 { | |
| 871 merge_comps (comp_father, comp_size, bad, ia); | |
| 872 merge_comps (comp_father, comp_size, bad, ib); | |
| 873 continue; | |
| 874 } | |
|
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parents:
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|
875 |
| 0 | 876 merge_comps (comp_father, comp_size, ia, ib); |
| 877 } | |
| 878 | |
| 111 | 879 if (eliminate_store_p) |
| 880 { | |
| 881 tree niters = number_of_latch_executions (loop); | |
| 882 | |
| 883 /* Don't do store elimination if niters info is unknown because stores | |
| 884 in the last iteration can't be eliminated and we need to recover it | |
| 885 after loop. */ | |
| 886 eliminate_store_p = (niters != NULL_TREE && niters != chrec_dont_know); | |
| 887 } | |
| 888 | |
| 0 | 889 comps = XCNEWVEC (struct component *, n); |
| 890 bad = component_of (comp_father, n); | |
| 111 | 891 FOR_EACH_VEC_ELT (datarefs, i, dr) |
| 0 | 892 { |
| 893 ia = (unsigned) (size_t) dr->aux; | |
| 894 ca = component_of (comp_father, ia); | |
| 895 if (ca == bad) | |
| 896 continue; | |
| 897 | |
| 898 comp = comps[ca]; | |
| 899 if (!comp) | |
| 900 { | |
| 901 comp = XCNEW (struct component); | |
| 111 | 902 comp->refs.create (comp_size[ca]); |
| 903 comp->eliminate_store_p = eliminate_store_p; | |
| 0 | 904 comps[ca] = comp; |
| 905 } | |
| 906 | |
| 145 | 907 dataref = XCNEW (class dref_d); |
| 0 | 908 dataref->ref = dr; |
| 909 dataref->stmt = DR_STMT (dr); | |
| 111 | 910 dataref->offset = 0; |
| 0 | 911 dataref->distance = 0; |
| 912 | |
| 913 dataref->always_accessed | |
| 914 = dominated_by_p (CDI_DOMINATORS, last_always_executed, | |
| 915 gimple_bb (dataref->stmt)); | |
| 111 | 916 dataref->pos = comp->refs.length (); |
| 917 comp->refs.quick_push (dataref); | |
| 0 | 918 } |
| 919 | |
| 145 | 920 if (eliminate_store_p) |
| 921 { | |
| 922 bitmap_iterator bi; | |
| 923 EXECUTE_IF_SET_IN_BITMAP (no_store_store_comps, 0, ia, bi) | |
| 924 { | |
| 925 ca = component_of (comp_father, ia); | |
| 926 if (ca != bad) | |
| 927 comps[ca]->eliminate_store_p = false; | |
| 928 } | |
| 929 } | |
| 930 | |
| 0 | 931 for (i = 0; i < n; i++) |
| 932 { | |
| 933 comp = comps[i]; | |
| 934 if (comp) | |
| 935 { | |
| 936 comp->next = comp_list; | |
| 937 comp_list = comp; | |
| 938 } | |
| 939 } | |
| 940 free (comps); | |
| 941 | |
| 942 end: | |
| 943 free (comp_father); | |
| 944 free (comp_size); | |
| 945 return comp_list; | |
| 946 } | |
| 947 | |
| 948 /* Returns true if the component COMP satisfies the conditions | |
| 949 described in 2) at the beginning of this file. LOOP is the current | |
| 950 loop. */ | |
|
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|
951 |
| 0 | 952 static bool |
| 145 | 953 suitable_component_p (class loop *loop, struct component *comp) |
| 0 | 954 { |
| 955 unsigned i; | |
| 956 dref a, first; | |
| 957 basic_block ba, bp = loop->header; | |
| 958 bool ok, has_write = false; | |
| 959 | |
| 111 | 960 FOR_EACH_VEC_ELT (comp->refs, i, a) |
| 0 | 961 { |
| 962 ba = gimple_bb (a->stmt); | |
| 963 | |
| 964 if (!just_once_each_iteration_p (loop, ba)) | |
| 965 return false; | |
| 966 | |
| 967 gcc_assert (dominated_by_p (CDI_DOMINATORS, ba, bp)); | |
| 968 bp = ba; | |
| 969 | |
|
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diff
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|
970 if (DR_IS_WRITE (a->ref)) |
| 0 | 971 has_write = true; |
| 972 } | |
| 973 | |
| 111 | 974 first = comp->refs[0]; |
| 0 | 975 ok = suitable_reference_p (first->ref, &comp->comp_step); |
| 976 gcc_assert (ok); | |
| 111 | 977 first->offset = 0; |
| 978 | |
| 979 for (i = 1; comp->refs.iterate (i, &a); i++) | |
| 0 | 980 { |
| 131 | 981 /* Polynomial offsets are no use, since we need to know the |
| 982 gap between iteration numbers at compile time. */ | |
| 983 poly_widest_int offset; | |
| 984 if (!determine_offset (first->ref, a->ref, &offset) | |
| 985 || !offset.is_constant (&a->offset)) | |
| 0 | 986 return false; |
| 987 | |
| 111 | 988 enum ref_step_type a_step; |
| 989 gcc_checking_assert (suitable_reference_p (a->ref, &a_step) | |
| 990 && a_step == comp->comp_step); | |
| 0 | 991 } |
| 992 | |
| 993 /* If there is a write inside the component, we must know whether the | |
| 994 step is nonzero or not -- we would not otherwise be able to recognize | |
| 995 whether the value accessed by reads comes from the OFFSET-th iteration | |
| 996 or the previous one. */ | |
| 997 if (has_write && comp->comp_step == RS_ANY) | |
| 998 return false; | |
| 999 | |
| 1000 return true; | |
| 1001 } | |
|
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diff
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|
1002 |
| 0 | 1003 /* Check the conditions on references inside each of components COMPS, |
| 1004 and remove the unsuitable components from the list. The new list | |
| 1005 of components is returned. The conditions are described in 2) at | |
| 1006 the beginning of this file. LOOP is the current loop. */ | |
| 1007 | |
| 1008 static struct component * | |
| 145 | 1009 filter_suitable_components (class loop *loop, struct component *comps) |
| 0 | 1010 { |
| 1011 struct component **comp, *act; | |
| 1012 | |
| 1013 for (comp = &comps; *comp; ) | |
| 1014 { | |
| 1015 act = *comp; | |
| 1016 if (suitable_component_p (loop, act)) | |
| 1017 comp = &act->next; | |
| 1018 else | |
| 1019 { | |
| 1020 dref ref; | |
| 1021 unsigned i; | |
| 1022 | |
| 1023 *comp = act->next; | |
| 111 | 1024 FOR_EACH_VEC_ELT (act->refs, i, ref) |
| 0 | 1025 free (ref); |
| 1026 release_component (act); | |
| 1027 } | |
| 1028 } | |
| 1029 | |
| 1030 return comps; | |
| 1031 } | |
| 1032 | |
| 1033 /* Compares two drefs A and B by their offset and position. Callback for | |
| 1034 qsort. */ | |
| 1035 | |
| 1036 static int | |
| 1037 order_drefs (const void *a, const void *b) | |
| 1038 { | |
| 1039 const dref *const da = (const dref *) a; | |
| 1040 const dref *const db = (const dref *) b; | |
| 111 | 1041 int offcmp = wi::cmps ((*da)->offset, (*db)->offset); |
| 0 | 1042 |
| 1043 if (offcmp != 0) | |
| 1044 return offcmp; | |
| 1045 | |
| 1046 return (*da)->pos - (*db)->pos; | |
| 1047 } | |
| 1048 | |
| 131 | 1049 /* Compares two drefs A and B by their position. Callback for qsort. */ |
| 1050 | |
| 1051 static int | |
| 1052 order_drefs_by_pos (const void *a, const void *b) | |
| 1053 { | |
| 1054 const dref *const da = (const dref *) a; | |
| 1055 const dref *const db = (const dref *) b; | |
| 1056 | |
| 1057 return (*da)->pos - (*db)->pos; | |
| 1058 } | |
| 1059 | |
| 0 | 1060 /* Returns root of the CHAIN. */ |
| 1061 | |
| 1062 static inline dref | |
| 1063 get_chain_root (chain_p chain) | |
| 1064 { | |
| 111 | 1065 return chain->refs[0]; |
| 1066 } | |
| 1067 | |
| 131 | 1068 /* Given CHAIN, returns the last write ref at DISTANCE, or NULL if it doesn't |
| 111 | 1069 exist. */ |
| 1070 | |
| 1071 static inline dref | |
| 131 | 1072 get_chain_last_write_at (chain_p chain, unsigned distance) |
| 111 | 1073 { |
| 131 | 1074 for (unsigned i = chain->refs.length (); i > 0; i--) |
| 1075 if (DR_IS_WRITE (chain->refs[i - 1]->ref) | |
| 1076 && distance == chain->refs[i - 1]->distance) | |
| 1077 return chain->refs[i - 1]; | |
| 1078 | |
| 1079 return NULL; | |
| 1080 } | |
| 1081 | |
| 1082 /* Given CHAIN, returns the last write ref with the same distance before load | |
| 1083 at index LOAD_IDX, or NULL if it doesn't exist. */ | |
| 1084 | |
| 1085 static inline dref | |
| 1086 get_chain_last_write_before_load (chain_p chain, unsigned load_idx) | |
| 1087 { | |
| 1088 gcc_assert (load_idx < chain->refs.length ()); | |
| 1089 | |
| 1090 unsigned distance = chain->refs[load_idx]->distance; | |
| 1091 | |
| 1092 for (unsigned i = load_idx; i > 0; i--) | |
| 1093 if (DR_IS_WRITE (chain->refs[i - 1]->ref) | |
| 1094 && distance == chain->refs[i - 1]->distance) | |
| 1095 return chain->refs[i - 1]; | |
| 1096 | |
| 1097 return NULL; | |
| 0 | 1098 } |
| 1099 | |
| 1100 /* Adds REF to the chain CHAIN. */ | |
| 1101 | |
| 1102 static void | |
| 1103 add_ref_to_chain (chain_p chain, dref ref) | |
| 1104 { | |
| 1105 dref root = get_chain_root (chain); | |
| 111 | 1106 |
| 1107 gcc_assert (wi::les_p (root->offset, ref->offset)); | |
| 1108 widest_int dist = ref->offset - root->offset; | |
| 1109 gcc_assert (wi::fits_uhwi_p (dist)); | |
| 1110 | |
| 1111 chain->refs.safe_push (ref); | |
| 1112 | |
| 1113 ref->distance = dist.to_uhwi (); | |
| 0 | 1114 |
| 1115 if (ref->distance >= chain->length) | |
| 1116 { | |
| 1117 chain->length = ref->distance; | |
| 1118 chain->has_max_use_after = false; | |
| 1119 } | |
| 1120 | |
| 131 | 1121 /* Promote this chain to CT_STORE_STORE if it has multiple stores. */ |
| 1122 if (DR_IS_WRITE (ref->ref)) | |
| 1123 chain->type = CT_STORE_STORE; | |
| 1124 | |
| 111 | 1125 /* Don't set the flag for store-store chain since there is no use. */ |
| 1126 if (chain->type != CT_STORE_STORE | |
| 1127 && ref->distance == chain->length | |
| 0 | 1128 && ref->pos > root->pos) |
| 1129 chain->has_max_use_after = true; | |
| 1130 | |
| 1131 chain->all_always_accessed &= ref->always_accessed; | |
| 1132 } | |
| 1133 | |
| 1134 /* Returns the chain for invariant component COMP. */ | |
| 1135 | |
| 1136 static chain_p | |
| 1137 make_invariant_chain (struct component *comp) | |
| 1138 { | |
| 1139 chain_p chain = XCNEW (struct chain); | |
| 1140 unsigned i; | |
| 1141 dref ref; | |
| 1142 | |
| 1143 chain->type = CT_INVARIANT; | |
| 1144 | |
| 1145 chain->all_always_accessed = true; | |
| 1146 | |
| 111 | 1147 FOR_EACH_VEC_ELT (comp->refs, i, ref) |
| 0 | 1148 { |
| 111 | 1149 chain->refs.safe_push (ref); |
| 0 | 1150 chain->all_always_accessed &= ref->always_accessed; |
| 1151 } | |
| 1152 | |
| 111 | 1153 chain->inits = vNULL; |
| 1154 chain->finis = vNULL; | |
| 1155 | |
| 0 | 1156 return chain; |
| 1157 } | |
| 1158 | |
| 111 | 1159 /* Make a new chain of type TYPE rooted at REF. */ |
| 0 | 1160 |
| 1161 static chain_p | |
| 111 | 1162 make_rooted_chain (dref ref, enum chain_type type) |
| 0 | 1163 { |
| 1164 chain_p chain = XCNEW (struct chain); | |
| 1165 | |
| 111 | 1166 chain->type = type; |
| 1167 chain->refs.safe_push (ref); | |
| 0 | 1168 chain->all_always_accessed = ref->always_accessed; |
| 1169 ref->distance = 0; | |
| 1170 | |
| 111 | 1171 chain->inits = vNULL; |
| 1172 chain->finis = vNULL; | |
| 1173 | |
| 0 | 1174 return chain; |
| 1175 } | |
| 1176 | |
| 1177 /* Returns true if CHAIN is not trivial. */ | |
| 1178 | |
| 1179 static bool | |
| 1180 nontrivial_chain_p (chain_p chain) | |
| 1181 { | |
| 111 | 1182 return chain != NULL && chain->refs.length () > 1; |
| 0 | 1183 } |
| 1184 | |
| 1185 /* Returns the ssa name that contains the value of REF, or NULL_TREE if there | |
| 1186 is no such name. */ | |
| 1187 | |
| 1188 static tree | |
| 1189 name_for_ref (dref ref) | |
| 1190 { | |
| 1191 tree name; | |
| 1192 | |
| 1193 if (is_gimple_assign (ref->stmt)) | |
| 1194 { | |
| 1195 if (!ref->ref || DR_IS_READ (ref->ref)) | |
| 1196 name = gimple_assign_lhs (ref->stmt); | |
| 1197 else | |
| 1198 name = gimple_assign_rhs1 (ref->stmt); | |
| 1199 } | |
| 1200 else | |
| 1201 name = PHI_RESULT (ref->stmt); | |
| 1202 | |
| 1203 return (TREE_CODE (name) == SSA_NAME ? name : NULL_TREE); | |
| 1204 } | |
| 1205 | |
| 1206 /* Returns true if REF is a valid initializer for ROOT with given DISTANCE (in | |
| 1207 iterations of the innermost enclosing loop). */ | |
| 1208 | |
| 1209 static bool | |
| 1210 valid_initializer_p (struct data_reference *ref, | |
| 1211 unsigned distance, struct data_reference *root) | |
| 1212 { | |
| 1213 aff_tree diff, base, step; | |
| 131 | 1214 poly_widest_int off; |
| 0 | 1215 |
| 1216 /* Both REF and ROOT must be accessing the same object. */ | |
| 1217 if (!operand_equal_p (DR_BASE_ADDRESS (ref), DR_BASE_ADDRESS (root), 0)) | |
| 1218 return false; | |
| 1219 | |
| 1220 /* The initializer is defined outside of loop, hence its address must be | |
| 1221 invariant inside the loop. */ | |
| 1222 gcc_assert (integer_zerop (DR_STEP (ref))); | |
| 1223 | |
| 1224 /* If the address of the reference is invariant, initializer must access | |
| 1225 exactly the same location. */ | |
| 1226 if (integer_zerop (DR_STEP (root))) | |
| 1227 return (operand_equal_p (DR_OFFSET (ref), DR_OFFSET (root), 0) | |
| 1228 && operand_equal_p (DR_INIT (ref), DR_INIT (root), 0)); | |
| 1229 | |
| 1230 /* Verify that this index of REF is equal to the root's index at | |
| 1231 -DISTANCE-th iteration. */ | |
| 1232 aff_combination_dr_offset (root, &diff); | |
| 1233 aff_combination_dr_offset (ref, &base); | |
| 111 | 1234 aff_combination_scale (&base, -1); |
| 0 | 1235 aff_combination_add (&diff, &base); |
| 1236 | |
| 111 | 1237 tree_to_aff_combination_expand (DR_STEP (root), TREE_TYPE (DR_STEP (root)), |
| 1238 &step, &name_expansions); | |
| 0 | 1239 if (!aff_combination_constant_multiple_p (&diff, &step, &off)) |
| 1240 return false; | |
| 1241 | |
| 131 | 1242 if (maybe_ne (off, distance)) |
| 0 | 1243 return false; |
| 1244 | |
| 1245 return true; | |
| 1246 } | |
| 1247 | |
| 1248 /* Finds looparound phi node of LOOP that copies the value of REF, and if its | |
| 1249 initial value is correct (equal to initial value of REF shifted by one | |
| 1250 iteration), returns the phi node. Otherwise, NULL_TREE is returned. ROOT | |
| 1251 is the root of the current chain. */ | |
| 1252 | |
| 111 | 1253 static gphi * |
| 145 | 1254 find_looparound_phi (class loop *loop, dref ref, dref root) |
| 0 | 1255 { |
| 1256 tree name, init, init_ref; | |
| 111 | 1257 gphi *phi = NULL; |
| 1258 gimple *init_stmt; | |
| 0 | 1259 edge latch = loop_latch_edge (loop); |
| 1260 struct data_reference init_dr; | |
| 111 | 1261 gphi_iterator psi; |
| 0 | 1262 |
| 1263 if (is_gimple_assign (ref->stmt)) | |
| 1264 { | |
| 1265 if (DR_IS_READ (ref->ref)) | |
| 1266 name = gimple_assign_lhs (ref->stmt); | |
| 1267 else | |
| 1268 name = gimple_assign_rhs1 (ref->stmt); | |
| 1269 } | |
| 1270 else | |
| 1271 name = PHI_RESULT (ref->stmt); | |
| 1272 if (!name) | |
| 1273 return NULL; | |
| 1274 | |
| 1275 for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) | |
| 1276 { | |
| 111 | 1277 phi = psi.phi (); |
| 0 | 1278 if (PHI_ARG_DEF_FROM_EDGE (phi, latch) == name) |
| 1279 break; | |
| 1280 } | |
| 1281 | |
| 1282 if (gsi_end_p (psi)) | |
| 1283 return NULL; | |
| 1284 | |
| 1285 init = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop)); | |
| 1286 if (TREE_CODE (init) != SSA_NAME) | |
| 1287 return NULL; | |
| 1288 init_stmt = SSA_NAME_DEF_STMT (init); | |
| 1289 if (gimple_code (init_stmt) != GIMPLE_ASSIGN) | |
| 1290 return NULL; | |
| 1291 gcc_assert (gimple_assign_lhs (init_stmt) == init); | |
| 1292 | |
| 1293 init_ref = gimple_assign_rhs1 (init_stmt); | |
| 1294 if (!REFERENCE_CLASS_P (init_ref) | |
| 1295 && !DECL_P (init_ref)) | |
| 1296 return NULL; | |
| 1297 | |
| 1298 /* Analyze the behavior of INIT_REF with respect to LOOP (innermost | |
| 1299 loop enclosing PHI). */ | |
| 1300 memset (&init_dr, 0, sizeof (struct data_reference)); | |
| 1301 DR_REF (&init_dr) = init_ref; | |
| 1302 DR_STMT (&init_dr) = phi; | |
| 131 | 1303 if (!dr_analyze_innermost (&DR_INNERMOST (&init_dr), init_ref, loop, |
| 1304 init_stmt)) | |
| 0 | 1305 return NULL; |
| 1306 | |
| 1307 if (!valid_initializer_p (&init_dr, ref->distance + 1, root->ref)) | |
| 1308 return NULL; | |
| 1309 | |
| 1310 return phi; | |
| 1311 } | |
| 1312 | |
| 1313 /* Adds a reference for the looparound copy of REF in PHI to CHAIN. */ | |
| 1314 | |
| 1315 static void | |
| 111 | 1316 insert_looparound_copy (chain_p chain, dref ref, gphi *phi) |
| 0 | 1317 { |
| 145 | 1318 dref nw = XCNEW (class dref_d), aref; |
| 0 | 1319 unsigned i; |
| 1320 | |
| 1321 nw->stmt = phi; | |
| 1322 nw->distance = ref->distance + 1; | |
| 1323 nw->always_accessed = 1; | |
| 1324 | |
| 111 | 1325 FOR_EACH_VEC_ELT (chain->refs, i, aref) |
| 0 | 1326 if (aref->distance >= nw->distance) |
| 1327 break; | |
| 111 | 1328 chain->refs.safe_insert (i, nw); |
| 0 | 1329 |
| 1330 if (nw->distance > chain->length) | |
| 1331 { | |
| 1332 chain->length = nw->distance; | |
| 1333 chain->has_max_use_after = false; | |
| 1334 } | |
| 1335 } | |
| 1336 | |
| 1337 /* For references in CHAIN that are copied around the LOOP (created previously | |
| 1338 by PRE, or by user), add the results of such copies to the chain. This | |
| 1339 enables us to remove the copies by unrolling, and may need less registers | |
| 1340 (also, it may allow us to combine chains together). */ | |
| 1341 | |
| 1342 static void | |
| 145 | 1343 add_looparound_copies (class loop *loop, chain_p chain) |
| 0 | 1344 { |
| 1345 unsigned i; | |
| 1346 dref ref, root = get_chain_root (chain); | |
| 111 | 1347 gphi *phi; |
| 1348 | |
| 1349 if (chain->type == CT_STORE_STORE) | |
| 1350 return; | |
| 1351 | |
| 1352 FOR_EACH_VEC_ELT (chain->refs, i, ref) | |
| 0 | 1353 { |
| 1354 phi = find_looparound_phi (loop, ref, root); | |
| 1355 if (!phi) | |
| 1356 continue; | |
| 1357 | |
| 1358 bitmap_set_bit (looparound_phis, SSA_NAME_VERSION (PHI_RESULT (phi))); | |
| 1359 insert_looparound_copy (chain, ref, phi); | |
| 1360 } | |
| 1361 } | |
| 1362 | |
| 1363 /* Find roots of the values and determine distances in the component COMP. | |
| 1364 The references are redistributed into CHAINS. LOOP is the current | |
| 1365 loop. */ | |
| 1366 | |
| 1367 static void | |
| 145 | 1368 determine_roots_comp (class loop *loop, |
| 0 | 1369 struct component *comp, |
| 111 | 1370 vec<chain_p> *chains) |
| 0 | 1371 { |
| 1372 unsigned i; | |
| 1373 dref a; | |
| 1374 chain_p chain = NULL; | |
| 111 | 1375 widest_int last_ofs = 0; |
| 1376 enum chain_type type; | |
| 0 | 1377 |
| 1378 /* Invariants are handled specially. */ | |
| 1379 if (comp->comp_step == RS_INVARIANT) | |
| 1380 { | |
| 1381 chain = make_invariant_chain (comp); | |
| 111 | 1382 chains->safe_push (chain); |
| 0 | 1383 return; |
| 1384 } | |
| 1385 | |
| 111 | 1386 /* Trivial component. */ |
| 1387 if (comp->refs.length () <= 1) | |
| 131 | 1388 { |
| 1389 if (comp->refs.length () == 1) | |
| 1390 { | |
| 1391 free (comp->refs[0]); | |
| 1392 comp->refs.truncate (0); | |
| 1393 } | |
| 1394 return; | |
| 1395 } | |
| 111 | 1396 |
| 1397 comp->refs.qsort (order_drefs); | |
| 131 | 1398 |
| 1399 /* For Store-Store chain, we only support load if it is dominated by a | |
| 1400 store statement in the same iteration of loop. */ | |
| 1401 if (comp->eliminate_store_p) | |
| 1402 for (a = NULL, i = 0; i < comp->refs.length (); i++) | |
| 1403 { | |
| 1404 if (DR_IS_WRITE (comp->refs[i]->ref)) | |
| 1405 a = comp->refs[i]; | |
| 1406 else if (a == NULL || a->offset != comp->refs[i]->offset) | |
| 1407 { | |
| 1408 /* If there is load that is not dominated by a store in the | |
| 1409 same iteration of loop, clear the flag so no Store-Store | |
| 1410 chain is generated for this component. */ | |
| 1411 comp->eliminate_store_p = false; | |
| 1412 break; | |
| 1413 } | |
| 1414 } | |
| 1415 | |
| 1416 /* Determine roots and create chains for components. */ | |
| 111 | 1417 FOR_EACH_VEC_ELT (comp->refs, i, a) |
| 0 | 1418 { |
| 111 | 1419 if (!chain |
| 131 | 1420 || (chain->type == CT_LOAD && DR_IS_WRITE (a->ref)) |
| 111 | 1421 || (!comp->eliminate_store_p && DR_IS_WRITE (a->ref)) |
| 1422 || wi::leu_p (MAX_DISTANCE, a->offset - last_ofs)) | |
| 0 | 1423 { |
| 1424 if (nontrivial_chain_p (chain)) | |
|
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1425 { |
|
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1426 add_looparound_copies (loop, chain); |
| 111 | 1427 chains->safe_push (chain); |
|
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1428 } |
| 0 | 1429 else |
| 1430 release_chain (chain); | |
| 111 | 1431 |
| 131 | 1432 /* Determine type of the chain. If the root reference is a load, |
| 1433 this can only be a CT_LOAD chain; other chains are intialized | |
| 1434 to CT_STORE_LOAD and might be promoted to CT_STORE_STORE when | |
| 1435 new reference is added. */ | |
| 1436 type = DR_IS_READ (a->ref) ? CT_LOAD : CT_STORE_LOAD; | |
| 111 | 1437 chain = make_rooted_chain (a, type); |
|
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1438 last_ofs = a->offset; |
| 0 | 1439 continue; |
| 1440 } | |
| 1441 | |
| 1442 add_ref_to_chain (chain, a); | |
| 1443 } | |
| 1444 | |
| 1445 if (nontrivial_chain_p (chain)) | |
| 1446 { | |
| 1447 add_looparound_copies (loop, chain); | |
| 111 | 1448 chains->safe_push (chain); |
| 0 | 1449 } |
| 1450 else | |
| 1451 release_chain (chain); | |
| 1452 } | |
| 1453 | |
| 1454 /* Find roots of the values and determine distances in components COMPS, and | |
| 1455 separates the references to CHAINS. LOOP is the current loop. */ | |
| 1456 | |
| 1457 static void | |
| 145 | 1458 determine_roots (class loop *loop, |
| 111 | 1459 struct component *comps, vec<chain_p> *chains) |
| 0 | 1460 { |
| 1461 struct component *comp; | |
| 1462 | |
| 1463 for (comp = comps; comp; comp = comp->next) | |
| 1464 determine_roots_comp (loop, comp, chains); | |
| 1465 } | |
| 1466 | |
| 1467 /* Replace the reference in statement STMT with temporary variable | |
| 1468 NEW_TREE. If SET is true, NEW_TREE is instead initialized to the value of | |
| 1469 the reference in the statement. IN_LHS is true if the reference | |
| 1470 is in the lhs of STMT, false if it is in rhs. */ | |
| 1471 | |
| 1472 static void | |
| 111 | 1473 replace_ref_with (gimple *stmt, tree new_tree, bool set, bool in_lhs) |
| 0 | 1474 { |
| 1475 tree val; | |
| 111 | 1476 gassign *new_stmt; |
| 0 | 1477 gimple_stmt_iterator bsi, psi; |
| 1478 | |
| 1479 if (gimple_code (stmt) == GIMPLE_PHI) | |
| 1480 { | |
| 1481 gcc_assert (!in_lhs && !set); | |
| 1482 | |
| 1483 val = PHI_RESULT (stmt); | |
| 1484 bsi = gsi_after_labels (gimple_bb (stmt)); | |
| 1485 psi = gsi_for_stmt (stmt); | |
| 1486 remove_phi_node (&psi, false); | |
| 1487 | |
| 1488 /* Turn the phi node into GIMPLE_ASSIGN. */ | |
| 1489 new_stmt = gimple_build_assign (val, new_tree); | |
| 1490 gsi_insert_before (&bsi, new_stmt, GSI_NEW_STMT); | |
| 1491 return; | |
| 1492 } | |
|
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1493 |
| 0 | 1494 /* Since the reference is of gimple_reg type, it should only |
| 1495 appear as lhs or rhs of modify statement. */ | |
| 1496 gcc_assert (is_gimple_assign (stmt)); | |
| 1497 | |
| 1498 bsi = gsi_for_stmt (stmt); | |
| 1499 | |
| 1500 /* If we do not need to initialize NEW_TREE, just replace the use of OLD. */ | |
| 1501 if (!set) | |
| 1502 { | |
| 1503 gcc_assert (!in_lhs); | |
| 1504 gimple_assign_set_rhs_from_tree (&bsi, new_tree); | |
| 1505 stmt = gsi_stmt (bsi); | |
| 1506 update_stmt (stmt); | |
| 1507 return; | |
| 1508 } | |
| 1509 | |
| 1510 if (in_lhs) | |
| 1511 { | |
| 1512 /* We have statement | |
|
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1513 |
| 0 | 1514 OLD = VAL |
| 1515 | |
| 1516 If OLD is a memory reference, then VAL is gimple_val, and we transform | |
| 1517 this to | |
| 1518 | |
| 1519 OLD = VAL | |
| 1520 NEW = VAL | |
| 1521 | |
|
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1522 Otherwise, we are replacing a combination chain, |
| 0 | 1523 VAL is the expression that performs the combination, and OLD is an |
| 1524 SSA name. In this case, we transform the assignment to | |
| 1525 | |
| 1526 OLD = VAL | |
| 1527 NEW = OLD | |
| 1528 | |
| 1529 */ | |
| 1530 | |
| 1531 val = gimple_assign_lhs (stmt); | |
| 1532 if (TREE_CODE (val) != SSA_NAME) | |
| 1533 { | |
| 1534 val = gimple_assign_rhs1 (stmt); | |
| 111 | 1535 gcc_assert (gimple_assign_single_p (stmt)); |
| 1536 if (TREE_CLOBBER_P (val)) | |
| 1537 val = get_or_create_ssa_default_def (cfun, SSA_NAME_VAR (new_tree)); | |
| 1538 else | |
| 1539 gcc_assert (gimple_assign_copy_p (stmt)); | |
| 0 | 1540 } |
| 1541 } | |
| 1542 else | |
| 1543 { | |
| 1544 /* VAL = OLD | |
| 1545 | |
| 1546 is transformed to | |
| 1547 | |
| 1548 VAL = OLD | |
| 1549 NEW = VAL */ | |
| 1550 | |
| 1551 val = gimple_assign_lhs (stmt); | |
| 1552 } | |
| 1553 | |
| 1554 new_stmt = gimple_build_assign (new_tree, unshare_expr (val)); | |
| 1555 gsi_insert_after (&bsi, new_stmt, GSI_NEW_STMT); | |
| 1556 } | |
| 1557 | |
| 111 | 1558 /* Returns a memory reference to DR in the (NITERS + ITER)-th iteration |
| 1559 of the loop it was analyzed in. Append init stmts to STMTS. */ | |
| 0 | 1560 |
| 1561 static tree | |
| 111 | 1562 ref_at_iteration (data_reference_p dr, int iter, |
| 1563 gimple_seq *stmts, tree niters = NULL_TREE) | |
| 0 | 1564 { |
| 111 | 1565 tree off = DR_OFFSET (dr); |
| 1566 tree coff = DR_INIT (dr); | |
| 1567 tree ref = DR_REF (dr); | |
| 1568 enum tree_code ref_code = ERROR_MARK; | |
| 1569 tree ref_type = NULL_TREE; | |
| 1570 tree ref_op1 = NULL_TREE; | |
| 1571 tree ref_op2 = NULL_TREE; | |
| 1572 tree new_offset; | |
| 1573 | |
| 1574 if (iter != 0) | |
| 0 | 1575 { |
| 111 | 1576 new_offset = size_binop (MULT_EXPR, DR_STEP (dr), ssize_int (iter)); |
| 1577 if (TREE_CODE (new_offset) == INTEGER_CST) | |
| 1578 coff = size_binop (PLUS_EXPR, coff, new_offset); | |
| 1579 else | |
| 1580 off = size_binop (PLUS_EXPR, off, new_offset); | |
| 0 | 1581 } |
| 111 | 1582 |
| 1583 if (niters != NULL_TREE) | |
| 0 | 1584 { |
| 111 | 1585 niters = fold_convert (ssizetype, niters); |
| 1586 new_offset = size_binop (MULT_EXPR, DR_STEP (dr), niters); | |
| 1587 if (TREE_CODE (niters) == INTEGER_CST) | |
| 1588 coff = size_binop (PLUS_EXPR, coff, new_offset); | |
| 1589 else | |
| 1590 off = size_binop (PLUS_EXPR, off, new_offset); | |
| 0 | 1591 } |
| 111 | 1592 |
| 1593 /* While data-ref analysis punts on bit offsets it still handles | |
| 1594 bitfield accesses at byte boundaries. Cope with that. Note that | |
| 1595 if the bitfield object also starts at a byte-boundary we can simply | |
| 1596 replicate the COMPONENT_REF, but we have to subtract the component's | |
| 1597 byte-offset from the MEM_REF address first. | |
| 1598 Otherwise we simply build a BIT_FIELD_REF knowing that the bits | |
| 1599 start at offset zero. */ | |
| 1600 if (TREE_CODE (ref) == COMPONENT_REF | |
| 1601 && DECL_BIT_FIELD (TREE_OPERAND (ref, 1))) | |
| 0 | 1602 { |
| 111 | 1603 unsigned HOST_WIDE_INT boff; |
| 1604 tree field = TREE_OPERAND (ref, 1); | |
| 1605 tree offset = component_ref_field_offset (ref); | |
| 1606 ref_type = TREE_TYPE (ref); | |
| 1607 boff = tree_to_uhwi (DECL_FIELD_BIT_OFFSET (field)); | |
| 1608 /* This can occur in Ada. See the comment in get_bit_range. */ | |
| 1609 if (boff % BITS_PER_UNIT != 0 | |
| 1610 || !tree_fits_uhwi_p (offset)) | |
| 0 | 1611 { |
| 111 | 1612 ref_code = BIT_FIELD_REF; |
| 1613 ref_op1 = DECL_SIZE (field); | |
| 1614 ref_op2 = bitsize_zero_node; | |
| 0 | 1615 } |
| 1616 else | |
| 1617 { | |
| 111 | 1618 boff >>= LOG2_BITS_PER_UNIT; |
| 1619 boff += tree_to_uhwi (offset); | |
| 1620 coff = size_binop (MINUS_EXPR, coff, ssize_int (boff)); | |
| 1621 ref_code = COMPONENT_REF; | |
| 1622 ref_op1 = field; | |
| 1623 ref_op2 = TREE_OPERAND (ref, 2); | |
| 1624 ref = TREE_OPERAND (ref, 0); | |
| 0 | 1625 } |
| 1626 } | |
| 111 | 1627 tree addr = fold_build_pointer_plus (DR_BASE_ADDRESS (dr), off); |
| 1628 addr = force_gimple_operand_1 (unshare_expr (addr), stmts, | |
| 1629 is_gimple_mem_ref_addr, NULL_TREE); | |
| 1630 tree alias_ptr = fold_convert (reference_alias_ptr_type (ref), coff); | |
| 1631 tree type = build_aligned_type (TREE_TYPE (ref), | |
| 1632 get_object_alignment (ref)); | |
| 1633 ref = build2 (MEM_REF, type, addr, alias_ptr); | |
| 1634 if (ref_type) | |
| 1635 ref = build3 (ref_code, ref_type, ref, ref_op1, ref_op2); | |
| 1636 return ref; | |
| 0 | 1637 } |
| 1638 | |
| 1639 /* Get the initialization expression for the INDEX-th temporary variable | |
| 1640 of CHAIN. */ | |
| 1641 | |
| 1642 static tree | |
| 1643 get_init_expr (chain_p chain, unsigned index) | |
| 1644 { | |
| 1645 if (chain->type == CT_COMBINATION) | |
| 1646 { | |
| 1647 tree e1 = get_init_expr (chain->ch1, index); | |
| 1648 tree e2 = get_init_expr (chain->ch2, index); | |
| 1649 | |
| 1650 return fold_build2 (chain->op, chain->rslt_type, e1, e2); | |
| 1651 } | |
| 1652 else | |
| 111 | 1653 return chain->inits[index]; |
| 0 | 1654 } |
| 1655 | |
| 1656 /* Returns a new temporary variable used for the I-th variable carrying | |
| 1657 value of REF. The variable's uid is marked in TMP_VARS. */ | |
| 1658 | |
| 1659 static tree | |
| 1660 predcom_tmp_var (tree ref, unsigned i, bitmap tmp_vars) | |
| 1661 { | |
| 1662 tree type = TREE_TYPE (ref); | |
| 1663 /* We never access the components of the temporary variable in predictive | |
| 1664 commoning. */ | |
|
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1665 tree var = create_tmp_reg (type, get_lsm_tmp_name (ref, i)); |
| 0 | 1666 bitmap_set_bit (tmp_vars, DECL_UID (var)); |
| 1667 return var; | |
| 1668 } | |
| 1669 | |
| 1670 /* Creates the variables for CHAIN, as well as phi nodes for them and | |
| 1671 initialization on entry to LOOP. Uids of the newly created | |
| 1672 temporary variables are marked in TMP_VARS. */ | |
| 1673 | |
| 1674 static void | |
| 145 | 1675 initialize_root_vars (class loop *loop, chain_p chain, bitmap tmp_vars) |
| 0 | 1676 { |
| 1677 unsigned i; | |
| 1678 unsigned n = chain->length; | |
| 1679 dref root = get_chain_root (chain); | |
| 1680 bool reuse_first = !chain->has_max_use_after; | |
| 1681 tree ref, init, var, next; | |
| 111 | 1682 gphi *phi; |
| 0 | 1683 gimple_seq stmts; |
| 1684 edge entry = loop_preheader_edge (loop), latch = loop_latch_edge (loop); | |
| 1685 | |
| 1686 /* If N == 0, then all the references are within the single iteration. And | |
| 1687 since this is an nonempty chain, reuse_first cannot be true. */ | |
| 1688 gcc_assert (n > 0 || !reuse_first); | |
| 1689 | |
| 111 | 1690 chain->vars.create (n + 1); |
| 0 | 1691 |
| 1692 if (chain->type == CT_COMBINATION) | |
| 1693 ref = gimple_assign_lhs (root->stmt); | |
| 1694 else | |
| 1695 ref = DR_REF (root->ref); | |
| 1696 | |
| 1697 for (i = 0; i < n + (reuse_first ? 0 : 1); i++) | |
| 1698 { | |
| 1699 var = predcom_tmp_var (ref, i, tmp_vars); | |
| 111 | 1700 chain->vars.quick_push (var); |
| 0 | 1701 } |
| 1702 if (reuse_first) | |
| 111 | 1703 chain->vars.quick_push (chain->vars[0]); |
| 1704 | |
| 1705 FOR_EACH_VEC_ELT (chain->vars, i, var) | |
| 1706 chain->vars[i] = make_ssa_name (var); | |
| 0 | 1707 |
| 1708 for (i = 0; i < n; i++) | |
| 1709 { | |
| 111 | 1710 var = chain->vars[i]; |
| 1711 next = chain->vars[i + 1]; | |
| 0 | 1712 init = get_init_expr (chain, i); |
| 1713 | |
| 1714 init = force_gimple_operand (init, &stmts, true, NULL_TREE); | |
| 1715 if (stmts) | |
|
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1716 gsi_insert_seq_on_edge_immediate (entry, stmts); |
| 0 | 1717 |
| 1718 phi = create_phi_node (var, loop->header); | |
|
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1719 add_phi_arg (phi, init, entry, UNKNOWN_LOCATION); |
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1720 add_phi_arg (phi, next, latch, UNKNOWN_LOCATION); |
| 0 | 1721 } |
| 1722 } | |
| 1723 | |
| 111 | 1724 /* For inter-iteration store elimination CHAIN in LOOP, returns true if |
| 1725 all stores to be eliminated store loop invariant values into memory. | |
| 1726 In this case, we can use these invariant values directly after LOOP. */ | |
| 1727 | |
| 1728 static bool | |
| 145 | 1729 is_inv_store_elimination_chain (class loop *loop, chain_p chain) |
| 111 | 1730 { |
| 1731 if (chain->length == 0 || chain->type != CT_STORE_STORE) | |
| 1732 return false; | |
| 1733 | |
| 1734 gcc_assert (!chain->has_max_use_after); | |
| 1735 | |
| 145 | 1736 /* If loop iterates for unknown times or fewer times than chain->length, |
| 111 | 1737 we still need to setup root variable and propagate it with PHI node. */ |
| 1738 tree niters = number_of_latch_executions (loop); | |
| 1739 if (TREE_CODE (niters) != INTEGER_CST | |
| 1740 || wi::leu_p (wi::to_wide (niters), chain->length)) | |
| 1741 return false; | |
| 1742 | |
| 1743 /* Check stores in chain for elimination if they only store loop invariant | |
| 1744 values. */ | |
| 1745 for (unsigned i = 0; i < chain->length; i++) | |
| 1746 { | |
| 131 | 1747 dref a = get_chain_last_write_at (chain, i); |
| 111 | 1748 if (a == NULL) |
| 1749 continue; | |
| 1750 | |
| 1751 gimple *def_stmt, *stmt = a->stmt; | |
| 1752 if (!gimple_assign_single_p (stmt)) | |
| 1753 return false; | |
| 1754 | |
| 1755 tree val = gimple_assign_rhs1 (stmt); | |
| 1756 if (TREE_CLOBBER_P (val)) | |
| 1757 return false; | |
| 1758 | |
| 1759 if (CONSTANT_CLASS_P (val)) | |
| 1760 continue; | |
| 1761 | |
| 1762 if (TREE_CODE (val) != SSA_NAME) | |
| 1763 return false; | |
| 1764 | |
| 1765 def_stmt = SSA_NAME_DEF_STMT (val); | |
| 1766 if (gimple_nop_p (def_stmt)) | |
| 1767 continue; | |
| 1768 | |
| 1769 if (flow_bb_inside_loop_p (loop, gimple_bb (def_stmt))) | |
| 1770 return false; | |
| 1771 } | |
| 1772 return true; | |
| 1773 } | |
| 1774 | |
| 1775 /* Creates root variables for store elimination CHAIN in which stores for | |
| 1776 elimination only store loop invariant values. In this case, we neither | |
| 1777 need to load root variables before loop nor propagate it with PHI nodes. */ | |
| 1778 | |
| 1779 static void | |
| 1780 initialize_root_vars_store_elim_1 (chain_p chain) | |
| 1781 { | |
| 1782 tree var; | |
| 1783 unsigned i, n = chain->length; | |
| 1784 | |
| 1785 chain->vars.create (n); | |
| 1786 chain->vars.safe_grow_cleared (n); | |
| 1787 | |
| 1788 /* Initialize root value for eliminated stores at each distance. */ | |
| 1789 for (i = 0; i < n; i++) | |
| 1790 { | |
| 131 | 1791 dref a = get_chain_last_write_at (chain, i); |
| 111 | 1792 if (a == NULL) |
| 1793 continue; | |
| 1794 | |
| 1795 var = gimple_assign_rhs1 (a->stmt); | |
| 1796 chain->vars[a->distance] = var; | |
| 1797 } | |
| 1798 | |
| 1799 /* We don't propagate values with PHI nodes, so manually propagate value | |
| 1800 to bubble positions. */ | |
| 1801 var = chain->vars[0]; | |
| 1802 for (i = 1; i < n; i++) | |
| 1803 { | |
| 1804 if (chain->vars[i] != NULL_TREE) | |
| 1805 { | |
| 1806 var = chain->vars[i]; | |
| 1807 continue; | |
| 1808 } | |
| 1809 chain->vars[i] = var; | |
| 1810 } | |
| 1811 | |
| 1812 /* Revert the vector. */ | |
| 1813 for (i = 0; i < n / 2; i++) | |
| 1814 std::swap (chain->vars[i], chain->vars[n - i - 1]); | |
| 1815 } | |
| 1816 | |
| 1817 /* Creates root variables for store elimination CHAIN in which stores for | |
| 1818 elimination store loop variant values. In this case, we may need to | |
| 1819 load root variables before LOOP and propagate it with PHI nodes. Uids | |
| 1820 of the newly created root variables are marked in TMP_VARS. */ | |
| 0 | 1821 |
| 1822 static void | |
| 145 | 1823 initialize_root_vars_store_elim_2 (class loop *loop, |
| 111 | 1824 chain_p chain, bitmap tmp_vars) |
| 0 | 1825 { |
| 111 | 1826 unsigned i, n = chain->length; |
| 1827 tree ref, init, var, next, val, phi_result; | |
| 1828 gimple *stmt; | |
| 1829 gimple_seq stmts; | |
| 1830 | |
| 1831 chain->vars.create (n); | |
| 1832 | |
| 1833 ref = DR_REF (get_chain_root (chain)->ref); | |
| 1834 for (i = 0; i < n; i++) | |
| 1835 { | |
| 1836 var = predcom_tmp_var (ref, i, tmp_vars); | |
| 1837 chain->vars.quick_push (var); | |
| 1838 } | |
| 1839 | |
| 1840 FOR_EACH_VEC_ELT (chain->vars, i, var) | |
| 1841 chain->vars[i] = make_ssa_name (var); | |
| 1842 | |
| 1843 /* Root values are either rhs operand of stores to be eliminated, or | |
| 1844 loaded from memory before loop. */ | |
| 1845 auto_vec<tree> vtemps; | |
| 1846 vtemps.safe_grow_cleared (n); | |
| 1847 for (i = 0; i < n; i++) | |
| 1848 { | |
| 1849 init = get_init_expr (chain, i); | |
| 1850 if (init == NULL_TREE) | |
| 1851 { | |
| 1852 /* Root value is rhs operand of the store to be eliminated if | |
| 1853 it isn't loaded from memory before loop. */ | |
| 131 | 1854 dref a = get_chain_last_write_at (chain, i); |
| 111 | 1855 val = gimple_assign_rhs1 (a->stmt); |
| 1856 if (TREE_CLOBBER_P (val)) | |
| 131 | 1857 { |
| 1858 val = get_or_create_ssa_default_def (cfun, SSA_NAME_VAR (var)); | |
| 1859 gimple_assign_set_rhs1 (a->stmt, val); | |
| 1860 } | |
| 111 | 1861 |
| 1862 vtemps[n - i - 1] = val; | |
| 1863 } | |
| 1864 else | |
| 1865 { | |
| 1866 edge latch = loop_latch_edge (loop); | |
| 1867 edge entry = loop_preheader_edge (loop); | |
| 1868 | |
| 1869 /* Root value is loaded from memory before loop, we also need | |
| 1870 to add PHI nodes to propagate the value across iterations. */ | |
| 1871 init = force_gimple_operand (init, &stmts, true, NULL_TREE); | |
| 1872 if (stmts) | |
| 1873 gsi_insert_seq_on_edge_immediate (entry, stmts); | |
| 1874 | |
| 1875 next = chain->vars[n - i]; | |
| 1876 phi_result = copy_ssa_name (next); | |
| 1877 gphi *phi = create_phi_node (phi_result, loop->header); | |
| 1878 add_phi_arg (phi, init, entry, UNKNOWN_LOCATION); | |
| 1879 add_phi_arg (phi, next, latch, UNKNOWN_LOCATION); | |
| 1880 vtemps[n - i - 1] = phi_result; | |
| 1881 } | |
| 1882 } | |
| 1883 | |
| 1884 /* Find the insertion position. */ | |
| 1885 dref last = get_chain_root (chain); | |
| 1886 for (i = 0; i < chain->refs.length (); i++) | |
| 1887 { | |
| 1888 if (chain->refs[i]->pos > last->pos) | |
| 1889 last = chain->refs[i]; | |
| 1890 } | |
| 1891 | |
| 1892 gimple_stmt_iterator gsi = gsi_for_stmt (last->stmt); | |
| 1893 | |
| 1894 /* Insert statements copying root value to root variable. */ | |
| 1895 for (i = 0; i < n; i++) | |
| 1896 { | |
| 1897 var = chain->vars[i]; | |
| 1898 val = vtemps[i]; | |
| 1899 stmt = gimple_build_assign (var, val); | |
| 1900 gsi_insert_after (&gsi, stmt, GSI_NEW_STMT); | |
| 1901 } | |
| 1902 } | |
| 1903 | |
| 1904 /* Generates stores for CHAIN's eliminated stores in LOOP's last | |
| 1905 (CHAIN->length - 1) iterations. */ | |
| 1906 | |
| 1907 static void | |
| 145 | 1908 finalize_eliminated_stores (class loop *loop, chain_p chain) |
| 111 | 1909 { |
| 1910 unsigned i, n = chain->length; | |
| 1911 | |
| 1912 for (i = 0; i < n; i++) | |
| 1913 { | |
| 1914 tree var = chain->vars[i]; | |
| 1915 tree fini = chain->finis[n - i - 1]; | |
| 1916 gimple *stmt = gimple_build_assign (fini, var); | |
| 1917 | |
| 1918 gimple_seq_add_stmt_without_update (&chain->fini_seq, stmt); | |
| 1919 } | |
| 1920 | |
| 1921 if (chain->fini_seq) | |
| 1922 { | |
| 1923 gsi_insert_seq_on_edge_immediate (single_exit (loop), chain->fini_seq); | |
| 1924 chain->fini_seq = NULL; | |
| 1925 } | |
| 0 | 1926 } |
| 1927 | |
| 1928 /* Initializes a variable for load motion for ROOT and prepares phi nodes and | |
| 1929 initialization on entry to LOOP if necessary. The ssa name for the variable | |
| 1930 is stored in VARS. If WRITTEN is true, also a phi node to copy its value | |
| 1931 around the loop is created. Uid of the newly created temporary variable | |
| 1932 is marked in TMP_VARS. INITS is the list containing the (single) | |
| 1933 initializer. */ | |
| 1934 | |
| 1935 static void | |
| 145 | 1936 initialize_root_vars_lm (class loop *loop, dref root, bool written, |
| 111 | 1937 vec<tree> *vars, vec<tree> inits, |
| 0 | 1938 bitmap tmp_vars) |
| 1939 { | |
| 1940 unsigned i; | |
| 1941 tree ref = DR_REF (root->ref), init, var, next; | |
| 1942 gimple_seq stmts; | |
| 111 | 1943 gphi *phi; |
| 0 | 1944 edge entry = loop_preheader_edge (loop), latch = loop_latch_edge (loop); |
| 1945 | |
| 1946 /* Find the initializer for the variable, and check that it cannot | |
| 1947 trap. */ | |
| 111 | 1948 init = inits[0]; |
| 1949 | |
| 1950 vars->create (written ? 2 : 1); | |
| 0 | 1951 var = predcom_tmp_var (ref, 0, tmp_vars); |
| 111 | 1952 vars->quick_push (var); |
| 0 | 1953 if (written) |
| 111 | 1954 vars->quick_push ((*vars)[0]); |
| 1955 | |
| 1956 FOR_EACH_VEC_ELT (*vars, i, var) | |
| 1957 (*vars)[i] = make_ssa_name (var); | |
| 1958 | |
| 1959 var = (*vars)[0]; | |
|
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1960 |
| 0 | 1961 init = force_gimple_operand (init, &stmts, written, NULL_TREE); |
| 1962 if (stmts) | |
|
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1963 gsi_insert_seq_on_edge_immediate (entry, stmts); |
| 0 | 1964 |
| 1965 if (written) | |
| 1966 { | |
| 111 | 1967 next = (*vars)[1]; |
| 0 | 1968 phi = create_phi_node (var, loop->header); |
|
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1969 add_phi_arg (phi, init, entry, UNKNOWN_LOCATION); |
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1970 add_phi_arg (phi, next, latch, UNKNOWN_LOCATION); |
| 0 | 1971 } |
| 1972 else | |
| 1973 { | |
| 111 | 1974 gassign *init_stmt = gimple_build_assign (var, init); |
| 0 | 1975 gsi_insert_on_edge_immediate (entry, init_stmt); |
| 1976 } | |
| 1977 } | |
| 1978 | |
| 1979 | |
| 1980 /* Execute load motion for references in chain CHAIN. Uids of the newly | |
| 1981 created temporary variables are marked in TMP_VARS. */ | |
| 1982 | |
| 1983 static void | |
| 145 | 1984 execute_load_motion (class loop *loop, chain_p chain, bitmap tmp_vars) |
| 0 | 1985 { |
| 111 | 1986 auto_vec<tree> vars; |
| 0 | 1987 dref a; |
| 1988 unsigned n_writes = 0, ridx, i; | |
| 1989 tree var; | |
| 1990 | |
| 1991 gcc_assert (chain->type == CT_INVARIANT); | |
| 1992 gcc_assert (!chain->combined); | |
| 111 | 1993 FOR_EACH_VEC_ELT (chain->refs, i, a) |
|
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1994 if (DR_IS_WRITE (a->ref)) |
| 0 | 1995 n_writes++; |
|
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1996 |
| 0 | 1997 /* If there are no reads in the loop, there is nothing to do. */ |
| 111 | 1998 if (n_writes == chain->refs.length ()) |
| 0 | 1999 return; |
| 2000 | |
| 2001 initialize_root_vars_lm (loop, get_chain_root (chain), n_writes > 0, | |
| 2002 &vars, chain->inits, tmp_vars); | |
| 2003 | |
| 2004 ridx = 0; | |
| 111 | 2005 FOR_EACH_VEC_ELT (chain->refs, i, a) |
| 0 | 2006 { |
| 2007 bool is_read = DR_IS_READ (a->ref); | |
| 2008 | |
|
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2009 if (DR_IS_WRITE (a->ref)) |
| 0 | 2010 { |
| 2011 n_writes--; | |
| 2012 if (n_writes) | |
| 2013 { | |
| 111 | 2014 var = vars[0]; |
| 2015 var = make_ssa_name (SSA_NAME_VAR (var)); | |
| 2016 vars[0] = var; | |
| 0 | 2017 } |
| 2018 else | |
| 2019 ridx = 1; | |
| 2020 } | |
|
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2021 |
| 111 | 2022 replace_ref_with (a->stmt, vars[ridx], |
| 0 | 2023 !is_read, !is_read); |
| 2024 } | |
| 2025 } | |
| 2026 | |
| 2027 /* Returns the single statement in that NAME is used, excepting | |
| 2028 the looparound phi nodes contained in one of the chains. If there is no | |
| 2029 such statement, or more statements, NULL is returned. */ | |
| 2030 | |
| 111 | 2031 static gimple * |
| 0 | 2032 single_nonlooparound_use (tree name) |
| 2033 { | |
| 2034 use_operand_p use; | |
| 2035 imm_use_iterator it; | |
| 111 | 2036 gimple *stmt, *ret = NULL; |
| 0 | 2037 |
| 2038 FOR_EACH_IMM_USE_FAST (use, it, name) | |
| 2039 { | |
| 2040 stmt = USE_STMT (use); | |
| 2041 | |
| 2042 if (gimple_code (stmt) == GIMPLE_PHI) | |
| 2043 { | |
| 2044 /* Ignore uses in looparound phi nodes. Uses in other phi nodes | |
| 2045 could not be processed anyway, so just fail for them. */ | |
| 2046 if (bitmap_bit_p (looparound_phis, | |
| 2047 SSA_NAME_VERSION (PHI_RESULT (stmt)))) | |
| 2048 continue; | |
| 2049 | |
| 2050 return NULL; | |
| 2051 } | |
|
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2052 else if (is_gimple_debug (stmt)) |
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2053 continue; |
| 0 | 2054 else if (ret != NULL) |
| 2055 return NULL; | |
| 2056 else | |
| 2057 ret = stmt; | |
| 2058 } | |
| 2059 | |
| 2060 return ret; | |
| 2061 } | |
| 2062 | |
| 2063 /* Remove statement STMT, as well as the chain of assignments in that it is | |
| 2064 used. */ | |
| 2065 | |
| 2066 static void | |
| 111 | 2067 remove_stmt (gimple *stmt) |
| 0 | 2068 { |
| 2069 tree name; | |
| 111 | 2070 gimple *next; |
| 0 | 2071 gimple_stmt_iterator psi; |
| 2072 | |
| 2073 if (gimple_code (stmt) == GIMPLE_PHI) | |
| 2074 { | |
| 2075 name = PHI_RESULT (stmt); | |
| 2076 next = single_nonlooparound_use (name); | |
| 111 | 2077 reset_debug_uses (stmt); |
| 0 | 2078 psi = gsi_for_stmt (stmt); |
| 2079 remove_phi_node (&psi, true); | |
| 2080 | |
| 2081 if (!next | |
| 2082 || !gimple_assign_ssa_name_copy_p (next) | |
| 2083 || gimple_assign_rhs1 (next) != name) | |
| 2084 return; | |
| 2085 | |
| 2086 stmt = next; | |
| 2087 } | |
| 2088 | |
| 2089 while (1) | |
| 2090 { | |
| 2091 gimple_stmt_iterator bsi; | |
|
55
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ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
2092 |
| 0 | 2093 bsi = gsi_for_stmt (stmt); |
| 2094 | |
| 2095 name = gimple_assign_lhs (stmt); | |
| 111 | 2096 if (TREE_CODE (name) == SSA_NAME) |
| 2097 { | |
| 2098 next = single_nonlooparound_use (name); | |
| 2099 reset_debug_uses (stmt); | |
| 2100 } | |
| 2101 else | |
| 2102 { | |
| 2103 /* This is a store to be eliminated. */ | |
| 2104 gcc_assert (gimple_vdef (stmt) != NULL); | |
| 2105 next = NULL; | |
| 2106 } | |
| 2107 | |
| 2108 unlink_stmt_vdef (stmt); | |
| 0 | 2109 gsi_remove (&bsi, true); |
| 2110 release_defs (stmt); | |
| 2111 | |
| 2112 if (!next | |
| 2113 || !gimple_assign_ssa_name_copy_p (next) | |
| 2114 || gimple_assign_rhs1 (next) != name) | |
| 2115 return; | |
| 2116 | |
| 2117 stmt = next; | |
| 2118 } | |
| 2119 } | |
| 2120 | |
| 2121 /* Perform the predictive commoning optimization for a chain CHAIN. | |
| 2122 Uids of the newly created temporary variables are marked in TMP_VARS.*/ | |
| 2123 | |
| 2124 static void | |
| 145 | 2125 execute_pred_commoning_chain (class loop *loop, chain_p chain, |
| 111 | 2126 bitmap tmp_vars) |
| 0 | 2127 { |
| 131 | 2128 unsigned i; |
| 111 | 2129 dref a; |
| 0 | 2130 tree var; |
| 111 | 2131 bool in_lhs; |
| 0 | 2132 |
| 2133 if (chain->combined) | |
| 2134 { | |
| 2135 /* For combined chains, just remove the statements that are used to | |
| 111 | 2136 compute the values of the expression (except for the root one). |
| 2137 We delay this until after all chains are processed. */ | |
| 2138 } | |
| 2139 else if (chain->type == CT_STORE_STORE) | |
| 2140 { | |
| 2141 if (chain->length > 0) | |
| 2142 { | |
| 2143 if (chain->inv_store_elimination) | |
| 2144 { | |
| 2145 /* If dead stores in this chain only store loop invariant | |
| 2146 values, we can simply record the invariant value and use | |
| 2147 it directly after loop. */ | |
| 2148 initialize_root_vars_store_elim_1 (chain); | |
| 2149 } | |
| 2150 else | |
| 2151 { | |
| 2152 /* If dead stores in this chain store loop variant values, | |
| 2153 we need to set up the variables by loading from memory | |
| 2154 before loop and propagating it with PHI nodes. */ | |
| 2155 initialize_root_vars_store_elim_2 (loop, chain, tmp_vars); | |
| 2156 } | |
| 2157 | |
| 2158 /* For inter-iteration store elimination chain, stores at each | |
| 2159 distance in loop's last (chain->length - 1) iterations can't | |
| 2160 be eliminated, because there is no following killing store. | |
| 2161 We need to generate these stores after loop. */ | |
| 2162 finalize_eliminated_stores (loop, chain); | |
| 2163 } | |
| 2164 | |
| 131 | 2165 bool last_store_p = true; |
| 2166 for (i = chain->refs.length (); i > 0; i--) | |
| 2167 { | |
| 2168 a = chain->refs[i - 1]; | |
| 2169 /* Preserve the last store of the chain. Eliminate other stores | |
| 2170 which are killed by the last one. */ | |
| 2171 if (DR_IS_WRITE (a->ref)) | |
| 2172 { | |
| 2173 if (last_store_p) | |
| 2174 last_store_p = false; | |
| 2175 else | |
| 2176 remove_stmt (a->stmt); | |
| 2177 | |
| 2178 continue; | |
| 2179 } | |
| 2180 | |
| 2181 /* Any load in Store-Store chain must be dominated by a previous | |
| 2182 store, we replace the load reference with rhs of the store. */ | |
| 2183 dref b = get_chain_last_write_before_load (chain, i - 1); | |
| 2184 gcc_assert (b != NULL); | |
| 2185 var = gimple_assign_rhs1 (b->stmt); | |
| 2186 replace_ref_with (a->stmt, var, false, false); | |
| 2187 } | |
| 0 | 2188 } |
| 2189 else | |
| 2190 { | |
| 111 | 2191 /* For non-combined chains, set up the variables that hold its value. */ |
| 2192 initialize_root_vars (loop, chain, tmp_vars); | |
| 2193 a = get_chain_root (chain); | |
| 2194 in_lhs = (chain->type == CT_STORE_LOAD | |
| 2195 || chain->type == CT_COMBINATION); | |
| 2196 replace_ref_with (a->stmt, chain->vars[chain->length], true, in_lhs); | |
| 2197 | |
| 2198 /* Replace the uses of the original references by these variables. */ | |
| 2199 for (i = 1; chain->refs.iterate (i, &a); i++) | |
| 0 | 2200 { |
| 111 | 2201 var = chain->vars[chain->length - a->distance]; |
| 0 | 2202 replace_ref_with (a->stmt, var, false, false); |
| 2203 } | |
| 2204 } | |
| 2205 } | |
| 2206 | |
| 2207 /* Determines the unroll factor necessary to remove as many temporary variable | |
| 2208 copies as possible. CHAINS is the list of chains that will be | |
| 2209 optimized. */ | |
| 2210 | |
| 2211 static unsigned | |
| 111 | 2212 determine_unroll_factor (vec<chain_p> chains) |
| 0 | 2213 { |
| 2214 chain_p chain; | |
| 2215 unsigned factor = 1, af, nfactor, i; | |
| 145 | 2216 unsigned max = param_max_unroll_times; |
| 0 | 2217 |
| 111 | 2218 FOR_EACH_VEC_ELT (chains, i, chain) |
| 0 | 2219 { |
| 111 | 2220 if (chain->type == CT_INVARIANT) |
| 0 | 2221 continue; |
| 111 | 2222 /* For now we can't handle unrolling when eliminating stores. */ |
| 2223 else if (chain->type == CT_STORE_STORE) | |
| 2224 return 1; | |
| 2225 | |
| 2226 if (chain->combined) | |
| 2227 { | |
| 2228 /* For combined chains, we can't handle unrolling if we replace | |
| 2229 looparound PHIs. */ | |
| 2230 dref a; | |
| 2231 unsigned j; | |
| 2232 for (j = 1; chain->refs.iterate (j, &a); j++) | |
| 2233 if (gimple_code (a->stmt) == GIMPLE_PHI) | |
| 2234 return 1; | |
| 2235 continue; | |
| 2236 } | |
| 0 | 2237 |
| 2238 /* The best unroll factor for this chain is equal to the number of | |
| 2239 temporary variables that we create for it. */ | |
| 2240 af = chain->length; | |
| 2241 if (chain->has_max_use_after) | |
| 2242 af++; | |
| 2243 | |
| 2244 nfactor = factor * af / gcd (factor, af); | |
| 2245 if (nfactor <= max) | |
| 2246 factor = nfactor; | |
| 2247 } | |
| 2248 | |
| 2249 return factor; | |
| 2250 } | |
| 2251 | |
| 2252 /* Perform the predictive commoning optimization for CHAINS. | |
| 2253 Uids of the newly created temporary variables are marked in TMP_VARS. */ | |
| 2254 | |
| 2255 static void | |
| 145 | 2256 execute_pred_commoning (class loop *loop, vec<chain_p> chains, |
| 0 | 2257 bitmap tmp_vars) |
| 2258 { | |
| 2259 chain_p chain; | |
| 2260 unsigned i; | |
| 2261 | |
| 111 | 2262 FOR_EACH_VEC_ELT (chains, i, chain) |
| 0 | 2263 { |
| 2264 if (chain->type == CT_INVARIANT) | |
| 2265 execute_load_motion (loop, chain, tmp_vars); | |
| 2266 else | |
| 2267 execute_pred_commoning_chain (loop, chain, tmp_vars); | |
| 2268 } | |
|
55
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ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
2269 |
| 111 | 2270 FOR_EACH_VEC_ELT (chains, i, chain) |
| 2271 { | |
| 2272 if (chain->type == CT_INVARIANT) | |
| 2273 ; | |
| 2274 else if (chain->combined) | |
| 2275 { | |
| 2276 /* For combined chains, just remove the statements that are used to | |
| 2277 compute the values of the expression (except for the root one). */ | |
| 2278 dref a; | |
| 2279 unsigned j; | |
| 2280 for (j = 1; chain->refs.iterate (j, &a); j++) | |
| 2281 remove_stmt (a->stmt); | |
| 2282 } | |
| 2283 } | |
| 2284 | |
| 0 | 2285 update_ssa (TODO_update_ssa_only_virtuals); |
| 2286 } | |
| 2287 | |
| 2288 /* For each reference in CHAINS, if its defining statement is | |
| 2289 phi node, record the ssa name that is defined by it. */ | |
| 2290 | |
| 2291 static void | |
| 111 | 2292 replace_phis_by_defined_names (vec<chain_p> chains) |
| 0 | 2293 { |
| 2294 chain_p chain; | |
| 2295 dref a; | |
| 2296 unsigned i, j; | |
| 2297 | |
| 111 | 2298 FOR_EACH_VEC_ELT (chains, i, chain) |
| 2299 FOR_EACH_VEC_ELT (chain->refs, j, a) | |
| 0 | 2300 { |
| 2301 if (gimple_code (a->stmt) == GIMPLE_PHI) | |
| 2302 { | |
| 2303 a->name_defined_by_phi = PHI_RESULT (a->stmt); | |
| 2304 a->stmt = NULL; | |
| 2305 } | |
| 2306 } | |
| 2307 } | |
| 2308 | |
| 2309 /* For each reference in CHAINS, if name_defined_by_phi is not | |
| 2310 NULL, use it to set the stmt field. */ | |
| 2311 | |
| 2312 static void | |
| 111 | 2313 replace_names_by_phis (vec<chain_p> chains) |
| 0 | 2314 { |
| 2315 chain_p chain; | |
| 2316 dref a; | |
| 2317 unsigned i, j; | |
| 2318 | |
| 111 | 2319 FOR_EACH_VEC_ELT (chains, i, chain) |
| 2320 FOR_EACH_VEC_ELT (chain->refs, j, a) | |
| 0 | 2321 if (a->stmt == NULL) |
| 2322 { | |
| 2323 a->stmt = SSA_NAME_DEF_STMT (a->name_defined_by_phi); | |
| 2324 gcc_assert (gimple_code (a->stmt) == GIMPLE_PHI); | |
| 2325 a->name_defined_by_phi = NULL_TREE; | |
| 2326 } | |
| 2327 } | |
| 2328 | |
| 2329 /* Wrapper over execute_pred_commoning, to pass it as a callback | |
| 2330 to tree_transform_and_unroll_loop. */ | |
| 2331 | |
| 2332 struct epcc_data | |
| 2333 { | |
| 111 | 2334 vec<chain_p> chains; |
| 0 | 2335 bitmap tmp_vars; |
| 2336 }; | |
| 2337 | |
| 2338 static void | |
| 145 | 2339 execute_pred_commoning_cbck (class loop *loop, void *data) |
| 0 | 2340 { |
| 2341 struct epcc_data *const dta = (struct epcc_data *) data; | |
| 2342 | |
| 2343 /* Restore phi nodes that were replaced by ssa names before | |
| 2344 tree_transform_and_unroll_loop (see detailed description in | |
| 2345 tree_predictive_commoning_loop). */ | |
| 2346 replace_names_by_phis (dta->chains); | |
| 2347 execute_pred_commoning (loop, dta->chains, dta->tmp_vars); | |
| 2348 } | |
| 2349 | |
| 2350 /* Base NAME and all the names in the chain of phi nodes that use it | |
| 2351 on variable VAR. The phi nodes are recognized by being in the copies of | |
| 2352 the header of the LOOP. */ | |
| 2353 | |
| 2354 static void | |
| 145 | 2355 base_names_in_chain_on (class loop *loop, tree name, tree var) |
| 0 | 2356 { |
| 111 | 2357 gimple *stmt, *phi; |
| 0 | 2358 imm_use_iterator iter; |
| 2359 | |
| 111 | 2360 replace_ssa_name_symbol (name, var); |
| 0 | 2361 |
| 2362 while (1) | |
| 2363 { | |
| 2364 phi = NULL; | |
| 2365 FOR_EACH_IMM_USE_STMT (stmt, iter, name) | |
| 2366 { | |
| 2367 if (gimple_code (stmt) == GIMPLE_PHI | |
| 2368 && flow_bb_inside_loop_p (loop, gimple_bb (stmt))) | |
| 2369 { | |
| 2370 phi = stmt; | |
| 2371 BREAK_FROM_IMM_USE_STMT (iter); | |
| 2372 } | |
| 2373 } | |
| 2374 if (!phi) | |
| 2375 return; | |
| 2376 | |
| 2377 name = PHI_RESULT (phi); | |
| 111 | 2378 replace_ssa_name_symbol (name, var); |
| 0 | 2379 } |
| 2380 } | |
| 2381 | |
| 2382 /* Given an unrolled LOOP after predictive commoning, remove the | |
| 2383 register copies arising from phi nodes by changing the base | |
| 2384 variables of SSA names. TMP_VARS is the set of the temporary variables | |
| 2385 for those we want to perform this. */ | |
| 2386 | |
| 2387 static void | |
| 145 | 2388 eliminate_temp_copies (class loop *loop, bitmap tmp_vars) |
| 0 | 2389 { |
| 2390 edge e; | |
| 111 | 2391 gphi *phi; |
| 2392 gimple *stmt; | |
| 0 | 2393 tree name, use, var; |
| 111 | 2394 gphi_iterator psi; |
| 0 | 2395 |
| 2396 e = loop_latch_edge (loop); | |
| 2397 for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) | |
| 2398 { | |
| 111 | 2399 phi = psi.phi (); |
| 0 | 2400 name = PHI_RESULT (phi); |
| 2401 var = SSA_NAME_VAR (name); | |
| 111 | 2402 if (!var || !bitmap_bit_p (tmp_vars, DECL_UID (var))) |
| 0 | 2403 continue; |
| 2404 use = PHI_ARG_DEF_FROM_EDGE (phi, e); | |
| 2405 gcc_assert (TREE_CODE (use) == SSA_NAME); | |
| 2406 | |
| 2407 /* Base all the ssa names in the ud and du chain of NAME on VAR. */ | |
| 2408 stmt = SSA_NAME_DEF_STMT (use); | |
| 2409 while (gimple_code (stmt) == GIMPLE_PHI | |
| 2410 /* In case we could not unroll the loop enough to eliminate | |
| 2411 all copies, we may reach the loop header before the defining | |
| 2412 statement (in that case, some register copies will be present | |
| 2413 in loop latch in the final code, corresponding to the newly | |
| 2414 created looparound phi nodes). */ | |
| 2415 && gimple_bb (stmt) != loop->header) | |
| 2416 { | |
| 2417 gcc_assert (single_pred_p (gimple_bb (stmt))); | |
| 2418 use = PHI_ARG_DEF (stmt, 0); | |
| 2419 stmt = SSA_NAME_DEF_STMT (use); | |
| 2420 } | |
| 2421 | |
| 2422 base_names_in_chain_on (loop, use, var); | |
| 2423 } | |
| 2424 } | |
| 2425 | |
| 2426 /* Returns true if CHAIN is suitable to be combined. */ | |
| 2427 | |
| 2428 static bool | |
| 2429 chain_can_be_combined_p (chain_p chain) | |
| 2430 { | |
| 2431 return (!chain->combined | |
| 2432 && (chain->type == CT_LOAD || chain->type == CT_COMBINATION)); | |
| 2433 } | |
| 2434 | |
| 2435 /* Returns the modify statement that uses NAME. Skips over assignment | |
| 2436 statements, NAME is replaced with the actual name used in the returned | |
| 2437 statement. */ | |
| 2438 | |
| 111 | 2439 static gimple * |
| 0 | 2440 find_use_stmt (tree *name) |
| 2441 { | |
| 111 | 2442 gimple *stmt; |
| 0 | 2443 tree rhs, lhs; |
| 2444 | |
| 2445 /* Skip over assignments. */ | |
| 2446 while (1) | |
| 2447 { | |
| 2448 stmt = single_nonlooparound_use (*name); | |
| 2449 if (!stmt) | |
| 2450 return NULL; | |
| 2451 | |
| 2452 if (gimple_code (stmt) != GIMPLE_ASSIGN) | |
| 2453 return NULL; | |
| 2454 | |
| 2455 lhs = gimple_assign_lhs (stmt); | |
| 2456 if (TREE_CODE (lhs) != SSA_NAME) | |
| 2457 return NULL; | |
| 2458 | |
| 2459 if (gimple_assign_copy_p (stmt)) | |
| 2460 { | |
| 2461 rhs = gimple_assign_rhs1 (stmt); | |
| 2462 if (rhs != *name) | |
| 2463 return NULL; | |
| 2464 | |
| 2465 *name = lhs; | |
| 2466 } | |
| 2467 else if (get_gimple_rhs_class (gimple_assign_rhs_code (stmt)) | |
| 2468 == GIMPLE_BINARY_RHS) | |
| 2469 return stmt; | |
| 2470 else | |
| 2471 return NULL; | |
| 2472 } | |
| 2473 } | |
| 2474 | |
| 2475 /* Returns true if we may perform reassociation for operation CODE in TYPE. */ | |
| 2476 | |
| 2477 static bool | |
| 2478 may_reassociate_p (tree type, enum tree_code code) | |
| 2479 { | |
| 2480 if (FLOAT_TYPE_P (type) | |
| 2481 && !flag_unsafe_math_optimizations) | |
| 2482 return false; | |
| 2483 | |
| 2484 return (commutative_tree_code (code) | |
| 2485 && associative_tree_code (code)); | |
| 2486 } | |
| 2487 | |
| 2488 /* If the operation used in STMT is associative and commutative, go through the | |
| 2489 tree of the same operations and returns its root. Distance to the root | |
| 2490 is stored in DISTANCE. */ | |
| 2491 | |
| 111 | 2492 static gimple * |
| 2493 find_associative_operation_root (gimple *stmt, unsigned *distance) | |
| 0 | 2494 { |
| 2495 tree lhs; | |
| 111 | 2496 gimple *next; |
| 0 | 2497 enum tree_code code = gimple_assign_rhs_code (stmt); |
| 2498 tree type = TREE_TYPE (gimple_assign_lhs (stmt)); | |
| 2499 unsigned dist = 0; | |
| 2500 | |
| 2501 if (!may_reassociate_p (type, code)) | |
| 2502 return NULL; | |
| 2503 | |
| 2504 while (1) | |
| 2505 { | |
| 2506 lhs = gimple_assign_lhs (stmt); | |
| 2507 gcc_assert (TREE_CODE (lhs) == SSA_NAME); | |
| 2508 | |
| 2509 next = find_use_stmt (&lhs); | |
| 2510 if (!next | |
| 2511 || gimple_assign_rhs_code (next) != code) | |
| 2512 break; | |
| 2513 | |
| 2514 stmt = next; | |
| 2515 dist++; | |
| 2516 } | |
| 2517 | |
| 2518 if (distance) | |
| 2519 *distance = dist; | |
| 2520 return stmt; | |
| 2521 } | |
| 2522 | |
| 2523 /* Returns the common statement in that NAME1 and NAME2 have a use. If there | |
| 2524 is no such statement, returns NULL_TREE. In case the operation used on | |
| 2525 NAME1 and NAME2 is associative and commutative, returns the root of the | |
| 2526 tree formed by this operation instead of the statement that uses NAME1 or | |
| 2527 NAME2. */ | |
| 2528 | |
| 111 | 2529 static gimple * |
| 0 | 2530 find_common_use_stmt (tree *name1, tree *name2) |
| 2531 { | |
| 111 | 2532 gimple *stmt1, *stmt2; |
| 0 | 2533 |
| 2534 stmt1 = find_use_stmt (name1); | |
| 2535 if (!stmt1) | |
| 2536 return NULL; | |
| 2537 | |
| 2538 stmt2 = find_use_stmt (name2); | |
| 2539 if (!stmt2) | |
| 2540 return NULL; | |
| 2541 | |
| 2542 if (stmt1 == stmt2) | |
| 2543 return stmt1; | |
| 2544 | |
| 2545 stmt1 = find_associative_operation_root (stmt1, NULL); | |
| 2546 if (!stmt1) | |
| 2547 return NULL; | |
| 2548 stmt2 = find_associative_operation_root (stmt2, NULL); | |
| 2549 if (!stmt2) | |
| 2550 return NULL; | |
| 2551 | |
| 2552 return (stmt1 == stmt2 ? stmt1 : NULL); | |
| 2553 } | |
| 2554 | |
| 2555 /* Checks whether R1 and R2 are combined together using CODE, with the result | |
| 2556 in RSLT_TYPE, in order R1 CODE R2 if SWAP is false and in order R2 CODE R1 | |
| 2557 if it is true. If CODE is ERROR_MARK, set these values instead. */ | |
| 2558 | |
| 2559 static bool | |
| 2560 combinable_refs_p (dref r1, dref r2, | |
| 2561 enum tree_code *code, bool *swap, tree *rslt_type) | |
| 2562 { | |
| 2563 enum tree_code acode; | |
| 2564 bool aswap; | |
| 2565 tree atype; | |
| 2566 tree name1, name2; | |
| 111 | 2567 gimple *stmt; |
| 0 | 2568 |
| 2569 name1 = name_for_ref (r1); | |
| 2570 name2 = name_for_ref (r2); | |
| 2571 gcc_assert (name1 != NULL_TREE && name2 != NULL_TREE); | |
| 2572 | |
| 2573 stmt = find_common_use_stmt (&name1, &name2); | |
| 2574 | |
| 111 | 2575 if (!stmt |
| 2576 /* A simple post-dominance check - make sure the combination | |
| 2577 is executed under the same condition as the references. */ | |
| 2578 || (gimple_bb (stmt) != gimple_bb (r1->stmt) | |
| 2579 && gimple_bb (stmt) != gimple_bb (r2->stmt))) | |
| 0 | 2580 return false; |
| 2581 | |
| 2582 acode = gimple_assign_rhs_code (stmt); | |
| 2583 aswap = (!commutative_tree_code (acode) | |
| 2584 && gimple_assign_rhs1 (stmt) != name1); | |
| 2585 atype = TREE_TYPE (gimple_assign_lhs (stmt)); | |
| 2586 | |
| 2587 if (*code == ERROR_MARK) | |
| 2588 { | |
| 2589 *code = acode; | |
| 2590 *swap = aswap; | |
| 2591 *rslt_type = atype; | |
| 2592 return true; | |
| 2593 } | |
| 2594 | |
| 2595 return (*code == acode | |
| 2596 && *swap == aswap | |
| 2597 && *rslt_type == atype); | |
| 2598 } | |
| 2599 | |
| 2600 /* Remove OP from the operation on rhs of STMT, and replace STMT with | |
| 2601 an assignment of the remaining operand. */ | |
| 2602 | |
| 2603 static void | |
| 111 | 2604 remove_name_from_operation (gimple *stmt, tree op) |
| 0 | 2605 { |
| 2606 tree other_op; | |
| 2607 gimple_stmt_iterator si; | |
| 2608 | |
| 2609 gcc_assert (is_gimple_assign (stmt)); | |
| 2610 | |
| 2611 if (gimple_assign_rhs1 (stmt) == op) | |
| 2612 other_op = gimple_assign_rhs2 (stmt); | |
| 2613 else | |
| 2614 other_op = gimple_assign_rhs1 (stmt); | |
| 2615 | |
| 2616 si = gsi_for_stmt (stmt); | |
| 2617 gimple_assign_set_rhs_from_tree (&si, other_op); | |
| 2618 | |
| 2619 /* We should not have reallocated STMT. */ | |
| 2620 gcc_assert (gsi_stmt (si) == stmt); | |
| 2621 | |
| 2622 update_stmt (stmt); | |
| 2623 } | |
| 2624 | |
| 2625 /* Reassociates the expression in that NAME1 and NAME2 are used so that they | |
| 131 | 2626 are combined in a single statement, and returns this statement. */ |
| 111 | 2627 |
| 2628 static gimple * | |
| 131 | 2629 reassociate_to_the_same_stmt (tree name1, tree name2) |
| 0 | 2630 { |
| 111 | 2631 gimple *stmt1, *stmt2, *root1, *root2, *s1, *s2; |
| 2632 gassign *new_stmt, *tmp_stmt; | |
| 0 | 2633 tree new_name, tmp_name, var, r1, r2; |
| 2634 unsigned dist1, dist2; | |
| 2635 enum tree_code code; | |
| 2636 tree type = TREE_TYPE (name1); | |
| 2637 gimple_stmt_iterator bsi; | |
| 2638 | |
| 2639 stmt1 = find_use_stmt (&name1); | |
| 2640 stmt2 = find_use_stmt (&name2); | |
| 2641 root1 = find_associative_operation_root (stmt1, &dist1); | |
| 2642 root2 = find_associative_operation_root (stmt2, &dist2); | |
| 2643 code = gimple_assign_rhs_code (stmt1); | |
| 2644 | |
| 2645 gcc_assert (root1 && root2 && root1 == root2 | |
| 2646 && code == gimple_assign_rhs_code (stmt2)); | |
| 2647 | |
| 2648 /* Find the root of the nearest expression in that both NAME1 and NAME2 | |
| 2649 are used. */ | |
| 2650 r1 = name1; | |
| 2651 s1 = stmt1; | |
| 2652 r2 = name2; | |
| 2653 s2 = stmt2; | |
| 2654 | |
| 2655 while (dist1 > dist2) | |
| 2656 { | |
| 2657 s1 = find_use_stmt (&r1); | |
| 2658 r1 = gimple_assign_lhs (s1); | |
| 2659 dist1--; | |
| 2660 } | |
| 2661 while (dist2 > dist1) | |
| 2662 { | |
| 2663 s2 = find_use_stmt (&r2); | |
| 2664 r2 = gimple_assign_lhs (s2); | |
| 2665 dist2--; | |
| 2666 } | |
| 2667 | |
| 2668 while (s1 != s2) | |
| 2669 { | |
| 2670 s1 = find_use_stmt (&r1); | |
| 2671 r1 = gimple_assign_lhs (s1); | |
| 2672 s2 = find_use_stmt (&r2); | |
| 2673 r2 = gimple_assign_lhs (s2); | |
| 2674 } | |
| 2675 | |
| 2676 /* Remove NAME1 and NAME2 from the statements in that they are used | |
| 2677 currently. */ | |
| 2678 remove_name_from_operation (stmt1, name1); | |
| 2679 remove_name_from_operation (stmt2, name2); | |
| 2680 | |
| 2681 /* Insert the new statement combining NAME1 and NAME2 before S1, and | |
| 2682 combine it with the rhs of S1. */ | |
|
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2683 var = create_tmp_reg (type, "predreastmp"); |
| 111 | 2684 new_name = make_ssa_name (var); |
| 2685 new_stmt = gimple_build_assign (new_name, code, name1, name2); | |
| 0 | 2686 |
|
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|
2687 var = create_tmp_reg (type, "predreastmp"); |
| 111 | 2688 tmp_name = make_ssa_name (var); |
| 0 | 2689 |
| 2690 /* Rhs of S1 may now be either a binary expression with operation | |
| 2691 CODE, or gimple_val (in case that stmt1 == s1 or stmt2 == s1, | |
| 2692 so that name1 or name2 was removed from it). */ | |
| 111 | 2693 tmp_stmt = gimple_build_assign (tmp_name, gimple_assign_rhs_code (s1), |
| 2694 gimple_assign_rhs1 (s1), | |
| 2695 gimple_assign_rhs2 (s1)); | |
| 0 | 2696 |
| 2697 bsi = gsi_for_stmt (s1); | |
| 2698 gimple_assign_set_rhs_with_ops (&bsi, code, new_name, tmp_name); | |
| 2699 s1 = gsi_stmt (bsi); | |
| 2700 update_stmt (s1); | |
| 2701 | |
| 131 | 2702 gsi_insert_before (&bsi, new_stmt, GSI_SAME_STMT); |
| 0 | 2703 gsi_insert_before (&bsi, tmp_stmt, GSI_SAME_STMT); |
| 2704 | |
| 2705 return new_stmt; | |
| 2706 } | |
| 2707 | |
| 2708 /* Returns the statement that combines references R1 and R2. In case R1 | |
| 2709 and R2 are not used in the same statement, but they are used with an | |
| 2710 associative and commutative operation in the same expression, reassociate | |
| 131 | 2711 the expression so that they are used in the same statement. */ |
| 111 | 2712 |
| 2713 static gimple * | |
| 131 | 2714 stmt_combining_refs (dref r1, dref r2) |
| 0 | 2715 { |
| 111 | 2716 gimple *stmt1, *stmt2; |
| 0 | 2717 tree name1 = name_for_ref (r1); |
| 2718 tree name2 = name_for_ref (r2); | |
| 2719 | |
| 2720 stmt1 = find_use_stmt (&name1); | |
| 2721 stmt2 = find_use_stmt (&name2); | |
| 2722 if (stmt1 == stmt2) | |
| 2723 return stmt1; | |
| 2724 | |
| 131 | 2725 return reassociate_to_the_same_stmt (name1, name2); |
| 0 | 2726 } |
| 2727 | |
| 2728 /* Tries to combine chains CH1 and CH2 together. If this succeeds, the | |
| 2729 description of the new chain is returned, otherwise we return NULL. */ | |
| 2730 | |
| 2731 static chain_p | |
| 2732 combine_chains (chain_p ch1, chain_p ch2) | |
| 2733 { | |
| 2734 dref r1, r2, nw; | |
| 2735 enum tree_code op = ERROR_MARK; | |
| 2736 bool swap = false; | |
| 2737 chain_p new_chain; | |
| 131 | 2738 unsigned i; |
| 0 | 2739 tree rslt_type = NULL_TREE; |
| 2740 | |
| 2741 if (ch1 == ch2) | |
|
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|
2742 return NULL; |
| 0 | 2743 if (ch1->length != ch2->length) |
| 2744 return NULL; | |
| 2745 | |
| 111 | 2746 if (ch1->refs.length () != ch2->refs.length ()) |
| 0 | 2747 return NULL; |
| 2748 | |
| 111 | 2749 for (i = 0; (ch1->refs.iterate (i, &r1) |
| 2750 && ch2->refs.iterate (i, &r2)); i++) | |
| 0 | 2751 { |
| 2752 if (r1->distance != r2->distance) | |
| 2753 return NULL; | |
| 2754 | |
| 2755 if (!combinable_refs_p (r1, r2, &op, &swap, &rslt_type)) | |
| 2756 return NULL; | |
| 2757 } | |
| 2758 | |
| 2759 if (swap) | |
| 111 | 2760 std::swap (ch1, ch2); |
| 0 | 2761 |
| 2762 new_chain = XCNEW (struct chain); | |
| 2763 new_chain->type = CT_COMBINATION; | |
| 2764 new_chain->op = op; | |
| 2765 new_chain->ch1 = ch1; | |
| 2766 new_chain->ch2 = ch2; | |
| 2767 new_chain->rslt_type = rslt_type; | |
| 2768 new_chain->length = ch1->length; | |
| 2769 | |
| 131 | 2770 for (i = 0; (ch1->refs.iterate (i, &r1) |
| 2771 && ch2->refs.iterate (i, &r2)); i++) | |
| 0 | 2772 { |
| 145 | 2773 nw = XCNEW (class dref_d); |
| 131 | 2774 nw->stmt = stmt_combining_refs (r1, r2); |
| 0 | 2775 nw->distance = r1->distance; |
| 2776 | |
| 111 | 2777 new_chain->refs.safe_push (nw); |
| 2778 } | |
| 131 | 2779 |
| 2780 ch1->combined = true; | |
| 2781 ch2->combined = true; | |
| 0 | 2782 return new_chain; |
| 2783 } | |
| 2784 | |
| 131 | 2785 /* Recursively update position information of all offspring chains to ROOT |
| 2786 chain's position information. */ | |
| 0 | 2787 |
| 2788 static void | |
| 131 | 2789 update_pos_for_combined_chains (chain_p root) |
| 2790 { | |
| 2791 chain_p ch1 = root->ch1, ch2 = root->ch2; | |
| 2792 dref ref, ref1, ref2; | |
| 2793 for (unsigned j = 0; (root->refs.iterate (j, &ref) | |
| 2794 && ch1->refs.iterate (j, &ref1) | |
| 2795 && ch2->refs.iterate (j, &ref2)); ++j) | |
| 2796 ref1->pos = ref2->pos = ref->pos; | |
| 2797 | |
| 2798 if (ch1->type == CT_COMBINATION) | |
| 2799 update_pos_for_combined_chains (ch1); | |
| 2800 if (ch2->type == CT_COMBINATION) | |
| 2801 update_pos_for_combined_chains (ch2); | |
| 2802 } | |
| 2803 | |
| 2804 /* Returns true if statement S1 dominates statement S2. */ | |
| 2805 | |
| 2806 static bool | |
| 2807 pcom_stmt_dominates_stmt_p (gimple *s1, gimple *s2) | |
| 2808 { | |
| 2809 basic_block bb1 = gimple_bb (s1), bb2 = gimple_bb (s2); | |
| 2810 | |
| 2811 if (!bb1 || s1 == s2) | |
| 2812 return true; | |
| 2813 | |
| 2814 if (bb1 == bb2) | |
| 2815 return gimple_uid (s1) < gimple_uid (s2); | |
| 2816 | |
| 2817 return dominated_by_p (CDI_DOMINATORS, bb2, bb1); | |
| 2818 } | |
| 2819 | |
| 2820 /* Try to combine the CHAINS in LOOP. */ | |
| 2821 | |
| 2822 static void | |
| 145 | 2823 try_combine_chains (class loop *loop, vec<chain_p> *chains) |
| 0 | 2824 { |
| 2825 unsigned i, j; | |
| 2826 chain_p ch1, ch2, cch; | |
| 111 | 2827 auto_vec<chain_p> worklist; |
| 131 | 2828 bool combined_p = false; |
| 111 | 2829 |
| 2830 FOR_EACH_VEC_ELT (*chains, i, ch1) | |
| 0 | 2831 if (chain_can_be_combined_p (ch1)) |
| 111 | 2832 worklist.safe_push (ch1); |
| 2833 | |
| 2834 while (!worklist.is_empty ()) | |
| 0 | 2835 { |
| 111 | 2836 ch1 = worklist.pop (); |
| 0 | 2837 if (!chain_can_be_combined_p (ch1)) |
| 2838 continue; | |
| 2839 | |
| 111 | 2840 FOR_EACH_VEC_ELT (*chains, j, ch2) |
| 0 | 2841 { |
| 2842 if (!chain_can_be_combined_p (ch2)) | |
| 2843 continue; | |
| 2844 | |
| 2845 cch = combine_chains (ch1, ch2); | |
| 2846 if (cch) | |
| 2847 { | |
| 111 | 2848 worklist.safe_push (cch); |
| 2849 chains->safe_push (cch); | |
| 131 | 2850 combined_p = true; |
| 2851 break; | |
| 2852 } | |
| 2853 } | |
| 2854 } | |
| 2855 if (!combined_p) | |
| 2856 return; | |
| 2857 | |
| 2858 /* Setup UID for all statements in dominance order. */ | |
| 145 | 2859 basic_block *bbs = get_loop_body_in_dom_order (loop); |
| 131 | 2860 renumber_gimple_stmt_uids_in_blocks (bbs, loop->num_nodes); |
| 2861 free (bbs); | |
| 2862 | |
| 2863 /* Re-association in combined chains may generate statements different to | |
| 2864 order of references of the original chain. We need to keep references | |
| 2865 of combined chain in dominance order so that all uses will be inserted | |
| 2866 after definitions. Note: | |
| 2867 A) This is necessary for all combined chains. | |
| 2868 B) This is only necessary for ZERO distance references because other | |
| 2869 references inherit value from loop carried PHIs. | |
| 2870 | |
| 2871 We first update position information for all combined chains. */ | |
| 2872 dref ref; | |
| 2873 for (i = 0; chains->iterate (i, &ch1); ++i) | |
| 2874 { | |
| 2875 if (ch1->type != CT_COMBINATION || ch1->combined) | |
| 2876 continue; | |
| 2877 | |
| 2878 for (j = 0; ch1->refs.iterate (j, &ref); ++j) | |
| 2879 ref->pos = gimple_uid (ref->stmt); | |
| 2880 | |
| 2881 update_pos_for_combined_chains (ch1); | |
| 2882 } | |
| 2883 /* Then sort references according to newly updated position information. */ | |
| 2884 for (i = 0; chains->iterate (i, &ch1); ++i) | |
| 2885 { | |
| 2886 if (ch1->type != CT_COMBINATION && !ch1->combined) | |
| 2887 continue; | |
| 2888 | |
| 2889 /* Find the first reference with non-ZERO distance. */ | |
| 2890 if (ch1->length == 0) | |
| 2891 j = ch1->refs.length(); | |
| 2892 else | |
| 2893 { | |
| 2894 for (j = 0; ch1->refs.iterate (j, &ref); ++j) | |
| 2895 if (ref->distance != 0) | |
| 2896 break; | |
| 2897 } | |
| 2898 | |
| 2899 /* Sort all ZERO distance references by position. */ | |
| 2900 qsort (&ch1->refs[0], j, sizeof (ch1->refs[0]), order_drefs_by_pos); | |
| 2901 | |
| 2902 if (ch1->combined) | |
| 2903 continue; | |
| 2904 | |
| 2905 /* For ZERO length chain, has_max_use_after must be true since root | |
| 2906 combined stmt must dominates others. */ | |
| 2907 if (ch1->length == 0) | |
| 2908 { | |
| 2909 ch1->has_max_use_after = true; | |
| 2910 continue; | |
| 2911 } | |
| 2912 /* Check if there is use at max distance after root for combined chains | |
| 2913 and set flag accordingly. */ | |
| 2914 ch1->has_max_use_after = false; | |
| 2915 gimple *root_stmt = get_chain_root (ch1)->stmt; | |
| 2916 for (j = 1; ch1->refs.iterate (j, &ref); ++j) | |
| 2917 { | |
| 2918 if (ref->distance == ch1->length | |
| 2919 && !pcom_stmt_dominates_stmt_p (ref->stmt, root_stmt)) | |
| 2920 { | |
| 2921 ch1->has_max_use_after = true; | |
| 0 | 2922 break; |
| 2923 } | |
| 2924 } | |
| 2925 } | |
| 2926 } | |
| 2927 | |
| 111 | 2928 /* Prepare initializers for store elimination CHAIN in LOOP. Returns false |
| 2929 if this is impossible because one of these initializers may trap, true | |
| 2930 otherwise. */ | |
| 2931 | |
| 2932 static bool | |
| 145 | 2933 prepare_initializers_chain_store_elim (class loop *loop, chain_p chain) |
| 111 | 2934 { |
| 2935 unsigned i, n = chain->length; | |
| 2936 | |
| 2937 /* For now we can't eliminate stores if some of them are conditional | |
| 2938 executed. */ | |
| 2939 if (!chain->all_always_accessed) | |
| 2940 return false; | |
| 2941 | |
| 2942 /* Nothing to intialize for intra-iteration store elimination. */ | |
| 2943 if (n == 0 && chain->type == CT_STORE_STORE) | |
| 2944 return true; | |
| 2945 | |
| 2946 /* For store elimination chain, there is nothing to initialize if stores | |
| 2947 to be eliminated only store loop invariant values into memory. */ | |
| 2948 if (chain->type == CT_STORE_STORE | |
| 2949 && is_inv_store_elimination_chain (loop, chain)) | |
| 2950 { | |
| 2951 chain->inv_store_elimination = true; | |
| 2952 return true; | |
| 2953 } | |
| 2954 | |
| 2955 chain->inits.create (n); | |
| 2956 chain->inits.safe_grow_cleared (n); | |
| 2957 | |
| 2958 /* For store eliminatin chain like below: | |
| 2959 | |
| 2960 for (i = 0; i < len; i++) | |
| 2961 { | |
| 2962 a[i] = 1; | |
| 2963 // a[i + 1] = ... | |
| 2964 a[i + 2] = 3; | |
| 2965 } | |
| 2966 | |
| 2967 store to a[i + 1] is missed in loop body, it acts like bubbles. The | |
| 2968 content of a[i + 1] remain the same if the loop iterates fewer times | |
| 2969 than chain->length. We need to set up root variables for such stores | |
| 2970 by loading from memory before loop. Note we only need to load bubble | |
| 2971 elements because loop body is guaranteed to be executed at least once | |
| 2972 after loop's preheader edge. */ | |
| 2973 auto_vec<bool> bubbles; | |
| 2974 bubbles.safe_grow_cleared (n + 1); | |
| 2975 for (i = 0; i < chain->refs.length (); i++) | |
| 2976 bubbles[chain->refs[i]->distance] = true; | |
| 2977 | |
| 2978 struct data_reference *dr = get_chain_root (chain)->ref; | |
| 2979 for (i = 0; i < n; i++) | |
| 2980 { | |
| 2981 if (bubbles[i]) | |
| 2982 continue; | |
| 2983 | |
| 2984 gimple_seq stmts = NULL; | |
| 2985 | |
| 2986 tree init = ref_at_iteration (dr, (int) 0 - i, &stmts); | |
| 2987 if (stmts) | |
| 2988 gimple_seq_add_seq_without_update (&chain->init_seq, stmts); | |
| 2989 | |
| 2990 chain->inits[i] = init; | |
| 2991 } | |
| 2992 | |
| 2993 return true; | |
| 2994 } | |
| 2995 | |
| 0 | 2996 /* Prepare initializers for CHAIN in LOOP. Returns false if this is |
| 2997 impossible because one of these initializers may trap, true otherwise. */ | |
| 2998 | |
| 2999 static bool | |
| 145 | 3000 prepare_initializers_chain (class loop *loop, chain_p chain) |
| 0 | 3001 { |
| 3002 unsigned i, n = (chain->type == CT_INVARIANT) ? 1 : chain->length; | |
| 3003 struct data_reference *dr = get_chain_root (chain)->ref; | |
| 3004 tree init; | |
| 3005 dref laref; | |
| 3006 edge entry = loop_preheader_edge (loop); | |
| 3007 | |
| 111 | 3008 if (chain->type == CT_STORE_STORE) |
| 3009 return prepare_initializers_chain_store_elim (loop, chain); | |
| 3010 | |
| 0 | 3011 /* Find the initializers for the variables, and check that they cannot |
| 3012 trap. */ | |
| 111 | 3013 chain->inits.create (n); |
| 0 | 3014 for (i = 0; i < n; i++) |
| 111 | 3015 chain->inits.quick_push (NULL_TREE); |
| 0 | 3016 |
| 3017 /* If we have replaced some looparound phi nodes, use their initializers | |
| 3018 instead of creating our own. */ | |
| 111 | 3019 FOR_EACH_VEC_ELT (chain->refs, i, laref) |
| 0 | 3020 { |
| 3021 if (gimple_code (laref->stmt) != GIMPLE_PHI) | |
| 3022 continue; | |
| 3023 | |
| 3024 gcc_assert (laref->distance > 0); | |
| 111 | 3025 chain->inits[n - laref->distance] |
| 3026 = PHI_ARG_DEF_FROM_EDGE (laref->stmt, entry); | |
| 0 | 3027 } |
| 3028 | |
| 3029 for (i = 0; i < n; i++) | |
| 3030 { | |
| 111 | 3031 gimple_seq stmts = NULL; |
| 3032 | |
| 3033 if (chain->inits[i] != NULL_TREE) | |
| 0 | 3034 continue; |
| 3035 | |
| 111 | 3036 init = ref_at_iteration (dr, (int) i - n, &stmts); |
| 0 | 3037 if (!chain->all_always_accessed && tree_could_trap_p (init)) |
| 111 | 3038 { |
| 3039 gimple_seq_discard (stmts); | |
| 3040 return false; | |
| 3041 } | |
| 3042 | |
| 0 | 3043 if (stmts) |
| 111 | 3044 gimple_seq_add_seq_without_update (&chain->init_seq, stmts); |
| 3045 | |
| 3046 chain->inits[i] = init; | |
| 0 | 3047 } |
| 3048 | |
| 3049 return true; | |
| 3050 } | |
| 3051 | |
| 3052 /* Prepare initializers for CHAINS in LOOP, and free chains that cannot | |
| 3053 be used because the initializers might trap. */ | |
| 3054 | |
| 3055 static void | |
| 145 | 3056 prepare_initializers (class loop *loop, vec<chain_p> chains) |
| 0 | 3057 { |
| 3058 chain_p chain; | |
| 3059 unsigned i; | |
| 3060 | |
| 111 | 3061 for (i = 0; i < chains.length (); ) |
| 0 | 3062 { |
| 111 | 3063 chain = chains[i]; |
| 0 | 3064 if (prepare_initializers_chain (loop, chain)) |
| 3065 i++; | |
| 3066 else | |
| 3067 { | |
| 3068 release_chain (chain); | |
| 111 | 3069 chains.unordered_remove (i); |
| 0 | 3070 } |
| 3071 } | |
| 3072 } | |
| 3073 | |
| 111 | 3074 /* Generates finalizer memory references for CHAIN in LOOP. Returns true |
| 3075 if finalizer code for CHAIN can be generated, otherwise false. */ | |
| 3076 | |
| 3077 static bool | |
| 145 | 3078 prepare_finalizers_chain (class loop *loop, chain_p chain) |
| 111 | 3079 { |
| 3080 unsigned i, n = chain->length; | |
| 3081 struct data_reference *dr = get_chain_root (chain)->ref; | |
| 3082 tree fini, niters = number_of_latch_executions (loop); | |
| 3083 | |
| 3084 /* For now we can't eliminate stores if some of them are conditional | |
| 3085 executed. */ | |
| 3086 if (!chain->all_always_accessed) | |
| 3087 return false; | |
| 3088 | |
| 3089 chain->finis.create (n); | |
| 3090 for (i = 0; i < n; i++) | |
| 3091 chain->finis.quick_push (NULL_TREE); | |
| 3092 | |
| 3093 /* We never use looparound phi node for store elimination chains. */ | |
| 3094 | |
| 3095 /* Find the finalizers for the variables, and check that they cannot | |
| 3096 trap. */ | |
| 3097 for (i = 0; i < n; i++) | |
| 3098 { | |
| 3099 gimple_seq stmts = NULL; | |
| 3100 gcc_assert (chain->finis[i] == NULL_TREE); | |
| 3101 | |
| 3102 if (TREE_CODE (niters) != INTEGER_CST && TREE_CODE (niters) != SSA_NAME) | |
| 3103 { | |
| 3104 niters = unshare_expr (niters); | |
| 3105 niters = force_gimple_operand (niters, &stmts, true, NULL); | |
| 3106 if (stmts) | |
| 3107 { | |
| 3108 gimple_seq_add_seq_without_update (&chain->fini_seq, stmts); | |
| 3109 stmts = NULL; | |
| 3110 } | |
| 3111 } | |
| 3112 fini = ref_at_iteration (dr, (int) 0 - i, &stmts, niters); | |
| 3113 if (stmts) | |
| 3114 gimple_seq_add_seq_without_update (&chain->fini_seq, stmts); | |
| 3115 | |
| 3116 chain->finis[i] = fini; | |
| 3117 } | |
| 3118 | |
| 3119 return true; | |
| 3120 } | |
| 3121 | |
| 3122 /* Generates finalizer memory reference for CHAINS in LOOP. Returns true | |
| 3123 if finalizer code generation for CHAINS breaks loop closed ssa form. */ | |
| 0 | 3124 |
| 3125 static bool | |
| 145 | 3126 prepare_finalizers (class loop *loop, vec<chain_p> chains) |
| 111 | 3127 { |
| 3128 chain_p chain; | |
| 3129 unsigned i; | |
| 3130 bool loop_closed_ssa = false; | |
| 3131 | |
| 3132 for (i = 0; i < chains.length ();) | |
| 3133 { | |
| 3134 chain = chains[i]; | |
| 3135 | |
| 3136 /* Finalizer is only necessary for inter-iteration store elimination | |
| 3137 chains. */ | |
| 3138 if (chain->length == 0 || chain->type != CT_STORE_STORE) | |
| 3139 { | |
| 3140 i++; | |
| 3141 continue; | |
| 3142 } | |
| 3143 | |
| 3144 if (prepare_finalizers_chain (loop, chain)) | |
| 3145 { | |
| 3146 i++; | |
| 3147 /* Be conservative, assume loop closed ssa form is corrupted | |
| 3148 by store-store chain. Though it's not always the case if | |
| 3149 eliminated stores only store loop invariant values into | |
| 3150 memory. */ | |
| 3151 loop_closed_ssa = true; | |
| 3152 } | |
| 3153 else | |
| 3154 { | |
| 3155 release_chain (chain); | |
| 3156 chains.unordered_remove (i); | |
| 3157 } | |
| 3158 } | |
| 3159 return loop_closed_ssa; | |
| 3160 } | |
| 3161 | |
| 3162 /* Insert all initializing gimple stmts into loop's entry edge. */ | |
| 3163 | |
| 3164 static void | |
| 145 | 3165 insert_init_seqs (class loop *loop, vec<chain_p> chains) |
| 111 | 3166 { |
| 3167 unsigned i; | |
| 3168 edge entry = loop_preheader_edge (loop); | |
| 3169 | |
| 3170 for (i = 0; i < chains.length (); ++i) | |
| 3171 if (chains[i]->init_seq) | |
| 3172 { | |
| 3173 gsi_insert_seq_on_edge_immediate (entry, chains[i]->init_seq); | |
| 3174 chains[i]->init_seq = NULL; | |
| 3175 } | |
| 3176 } | |
| 3177 | |
| 3178 /* Performs predictive commoning for LOOP. Sets bit 1<<0 of return value | |
| 3179 if LOOP was unrolled; Sets bit 1<<1 of return value if loop closed ssa | |
| 3180 form was corrupted. */ | |
| 3181 | |
| 3182 static unsigned | |
| 145 | 3183 tree_predictive_commoning_loop (class loop *loop) |
| 0 | 3184 { |
| 111 | 3185 vec<data_reference_p> datarefs; |
| 3186 vec<ddr_p> dependences; | |
| 0 | 3187 struct component *components; |
| 111 | 3188 vec<chain_p> chains = vNULL; |
| 0 | 3189 unsigned unroll_factor; |
| 145 | 3190 class tree_niter_desc desc; |
| 111 | 3191 bool unroll = false, loop_closed_ssa = false; |
| 0 | 3192 edge exit; |
| 3193 | |
| 3194 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 3195 fprintf (dump_file, "Processing loop %d\n", loop->num); | |
| 3196 | |
| 111 | 3197 /* Nothing for predicitive commoning if loop only iterates 1 time. */ |
| 3198 if (get_max_loop_iterations_int (loop) == 0) | |
| 3199 { | |
| 3200 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 3201 fprintf (dump_file, "Loop iterates only 1 time, nothing to do.\n"); | |
| 3202 | |
| 3203 return 0; | |
| 3204 } | |
| 3205 | |
| 0 | 3206 /* Find the data references and split them into components according to their |
| 3207 dependence relations. */ | |
| 111 | 3208 auto_vec<loop_p, 3> loop_nest; |
| 3209 dependences.create (10); | |
| 3210 datarefs.create (10); | |
| 3211 if (! compute_data_dependences_for_loop (loop, true, &loop_nest, &datarefs, | |
| 3212 &dependences)) | |
| 3213 { | |
| 3214 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 3215 fprintf (dump_file, "Cannot analyze data dependencies\n"); | |
| 3216 free_data_refs (datarefs); | |
| 3217 free_dependence_relations (dependences); | |
| 3218 return 0; | |
| 3219 } | |
| 3220 | |
| 0 | 3221 if (dump_file && (dump_flags & TDF_DETAILS)) |
| 3222 dump_data_dependence_relations (dump_file, dependences); | |
| 3223 | |
| 3224 components = split_data_refs_to_components (loop, datarefs, dependences); | |
| 111 | 3225 loop_nest.release (); |
| 0 | 3226 free_dependence_relations (dependences); |
| 3227 if (!components) | |
| 3228 { | |
| 3229 free_data_refs (datarefs); | |
| 111 | 3230 free_affine_expand_cache (&name_expansions); |
| 3231 return 0; | |
| 0 | 3232 } |
| 3233 | |
| 3234 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 3235 { | |
| 3236 fprintf (dump_file, "Initial state:\n\n"); | |
| 3237 dump_components (dump_file, components); | |
| 3238 } | |
| 3239 | |
| 3240 /* Find the suitable components and split them into chains. */ | |
| 3241 components = filter_suitable_components (loop, components); | |
| 3242 | |
| 111 | 3243 auto_bitmap tmp_vars; |
| 0 | 3244 looparound_phis = BITMAP_ALLOC (NULL); |
| 3245 determine_roots (loop, components, &chains); | |
| 3246 release_components (components); | |
| 3247 | |
| 111 | 3248 if (!chains.exists ()) |
| 0 | 3249 { |
| 3250 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 3251 fprintf (dump_file, | |
| 3252 "Predictive commoning failed: no suitable chains\n"); | |
| 3253 goto end; | |
| 3254 } | |
| 3255 prepare_initializers (loop, chains); | |
| 111 | 3256 loop_closed_ssa = prepare_finalizers (loop, chains); |
| 0 | 3257 |
| 3258 /* Try to combine the chains that are always worked with together. */ | |
| 131 | 3259 try_combine_chains (loop, &chains); |
| 0 | 3260 |
| 111 | 3261 insert_init_seqs (loop, chains); |
| 3262 | |
| 0 | 3263 if (dump_file && (dump_flags & TDF_DETAILS)) |
| 3264 { | |
| 3265 fprintf (dump_file, "Before commoning:\n\n"); | |
| 3266 dump_chains (dump_file, chains); | |
| 3267 } | |
| 3268 | |
| 3269 /* Determine the unroll factor, and if the loop should be unrolled, ensure | |
| 3270 that its number of iterations is divisible by the factor. */ | |
| 3271 unroll_factor = determine_unroll_factor (chains); | |
| 3272 scev_reset (); | |
|
55
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update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
3273 unroll = (unroll_factor > 1 |
|
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
3274 && can_unroll_loop_p (loop, unroll_factor, &desc)); |
| 0 | 3275 exit = single_dom_exit (loop); |
| 3276 | |
| 3277 /* Execute the predictive commoning transformations, and possibly unroll the | |
| 3278 loop. */ | |
| 3279 if (unroll) | |
| 3280 { | |
| 3281 struct epcc_data dta; | |
| 3282 | |
| 3283 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 3284 fprintf (dump_file, "Unrolling %u times.\n", unroll_factor); | |
| 3285 | |
| 3286 dta.chains = chains; | |
| 3287 dta.tmp_vars = tmp_vars; | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
3288 |
| 0 | 3289 update_ssa (TODO_update_ssa_only_virtuals); |
| 3290 | |
| 3291 /* Cfg manipulations performed in tree_transform_and_unroll_loop before | |
| 3292 execute_pred_commoning_cbck is called may cause phi nodes to be | |
| 3293 reallocated, which is a problem since CHAINS may point to these | |
| 3294 statements. To fix this, we store the ssa names defined by the | |
| 3295 phi nodes here instead of the phi nodes themselves, and restore | |
| 3296 the phi nodes in execute_pred_commoning_cbck. A bit hacky. */ | |
| 3297 replace_phis_by_defined_names (chains); | |
| 3298 | |
| 3299 tree_transform_and_unroll_loop (loop, unroll_factor, exit, &desc, | |
| 3300 execute_pred_commoning_cbck, &dta); | |
| 3301 eliminate_temp_copies (loop, tmp_vars); | |
| 3302 } | |
| 3303 else | |
| 3304 { | |
| 3305 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 3306 fprintf (dump_file, | |
| 3307 "Executing predictive commoning without unrolling.\n"); | |
| 3308 execute_pred_commoning (loop, chains, tmp_vars); | |
| 3309 } | |
| 3310 | |
| 3311 end: ; | |
| 3312 release_chains (chains); | |
| 3313 free_data_refs (datarefs); | |
| 3314 BITMAP_FREE (looparound_phis); | |
| 3315 | |
| 3316 free_affine_expand_cache (&name_expansions); | |
| 3317 | |
| 111 | 3318 return (unroll ? 1 : 0) | (loop_closed_ssa ? 2 : 0); |
| 0 | 3319 } |
| 3320 | |
| 3321 /* Runs predictive commoning. */ | |
| 3322 | |
| 3323 unsigned | |
| 3324 tree_predictive_commoning (void) | |
| 3325 { | |
| 145 | 3326 class loop *loop; |
| 111 | 3327 unsigned ret = 0, changed = 0; |
| 0 | 3328 |
| 3329 initialize_original_copy_tables (); | |
| 111 | 3330 FOR_EACH_LOOP (loop, LI_ONLY_INNERMOST) |
| 0 | 3331 if (optimize_loop_for_speed_p (loop)) |
| 3332 { | |
| 111 | 3333 changed |= tree_predictive_commoning_loop (loop); |
| 0 | 3334 } |
| 111 | 3335 free_original_copy_tables (); |
| 3336 | |
| 3337 if (changed > 0) | |
| 0 | 3338 { |
| 3339 scev_reset (); | |
| 111 | 3340 |
| 3341 if (changed > 1) | |
| 3342 rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa); | |
| 3343 | |
| 0 | 3344 ret = TODO_cleanup_cfg; |
| 3345 } | |
| 3346 | |
| 3347 return ret; | |
| 3348 } | |
| 111 | 3349 |
| 3350 /* Predictive commoning Pass. */ | |
| 3351 | |
| 3352 static unsigned | |
| 3353 run_tree_predictive_commoning (struct function *fun) | |
| 3354 { | |
| 3355 if (number_of_loops (fun) <= 1) | |
| 3356 return 0; | |
| 3357 | |
| 3358 return tree_predictive_commoning (); | |
| 3359 } | |
| 3360 | |
| 3361 namespace { | |
| 3362 | |
| 3363 const pass_data pass_data_predcom = | |
| 3364 { | |
| 3365 GIMPLE_PASS, /* type */ | |
| 3366 "pcom", /* name */ | |
| 3367 OPTGROUP_LOOP, /* optinfo_flags */ | |
| 3368 TV_PREDCOM, /* tv_id */ | |
| 3369 PROP_cfg, /* properties_required */ | |
| 3370 0, /* properties_provided */ | |
| 3371 0, /* properties_destroyed */ | |
| 3372 0, /* todo_flags_start */ | |
| 3373 TODO_update_ssa_only_virtuals, /* todo_flags_finish */ | |
| 3374 }; | |
| 3375 | |
| 3376 class pass_predcom : public gimple_opt_pass | |
| 3377 { | |
| 3378 public: | |
| 3379 pass_predcom (gcc::context *ctxt) | |
| 3380 : gimple_opt_pass (pass_data_predcom, ctxt) | |
| 3381 {} | |
| 3382 | |
| 3383 /* opt_pass methods: */ | |
| 3384 virtual bool gate (function *) { return flag_predictive_commoning != 0; } | |
| 3385 virtual unsigned int execute (function *fun) | |
| 3386 { | |
| 3387 return run_tree_predictive_commoning (fun); | |
| 3388 } | |
| 3389 | |
| 3390 }; // class pass_predcom | |
| 3391 | |
| 3392 } // anon namespace | |
| 3393 | |
| 3394 gimple_opt_pass * | |
| 3395 make_pass_predcom (gcc::context *ctxt) | |
| 3396 { | |
| 3397 return new pass_predcom (ctxt); | |
| 3398 } | |
| 3399 | |
| 3400 |