Mercurial > hg > CbC > CbC_gcc
annotate gcc/tree-loop-distribution.c @ 136:4627f235cf2a
fix c-next example
| author | Shinji KONO <kono@ie.u-ryukyu.ac.jp> |
|---|---|
| date | Thu, 08 Nov 2018 14:11:56 +0900 |
| parents | 84e7813d76e9 |
| children | 1830386684a0 |
| rev | line source |
|---|---|
| 0 | 1 /* Loop distribution. |
| 131 | 2 Copyright (C) 2006-2018 Free Software Foundation, Inc. |
| 0 | 3 Contributed by Georges-Andre Silber <Georges-Andre.Silber@ensmp.fr> |
| 4 and Sebastian Pop <sebastian.pop@amd.com>. | |
| 5 | |
| 6 This file is part of GCC. | |
|
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7 |
| 0 | 8 GCC is free software; you can redistribute it and/or modify it |
| 9 under the terms of the GNU General Public License as published by the | |
| 10 Free Software Foundation; either version 3, or (at your option) any | |
| 11 later version. | |
|
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12 |
| 0 | 13 GCC is distributed in the hope that it will be useful, but WITHOUT |
| 14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 16 for more details. | |
|
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17 |
| 0 | 18 You should have received a copy of the GNU General Public License |
| 19 along with GCC; see the file COPYING3. If not see | |
| 20 <http://www.gnu.org/licenses/>. */ | |
| 21 | |
| 22 /* This pass performs loop distribution: for example, the loop | |
| 23 | |
| 24 |DO I = 2, N | |
| 25 | A(I) = B(I) + C | |
| 26 | D(I) = A(I-1)*E | |
| 27 |ENDDO | |
| 28 | |
|
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changeset
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29 is transformed to |
| 0 | 30 |
| 31 |DOALL I = 2, N | |
| 32 | A(I) = B(I) + C | |
| 33 |ENDDO | |
| 34 | | |
| 35 |DOALL I = 2, N | |
| 36 | D(I) = A(I-1)*E | |
| 37 |ENDDO | |
| 38 | |
| 111 | 39 Loop distribution is the dual of loop fusion. It separates statements |
| 40 of a loop (or loop nest) into multiple loops (or loop nests) with the | |
| 41 same loop header. The major goal is to separate statements which may | |
| 42 be vectorized from those that can't. This pass implements distribution | |
| 43 in the following steps: | |
| 44 | |
| 45 1) Seed partitions with specific type statements. For now we support | |
| 46 two types seed statements: statement defining variable used outside | |
| 47 of loop; statement storing to memory. | |
| 48 2) Build reduced dependence graph (RDG) for loop to be distributed. | |
| 49 The vertices (RDG:V) model all statements in the loop and the edges | |
| 50 (RDG:E) model flow and control dependencies between statements. | |
| 51 3) Apart from RDG, compute data dependencies between memory references. | |
| 52 4) Starting from seed statement, build up partition by adding depended | |
| 53 statements according to RDG's dependence information. Partition is | |
| 54 classified as parallel type if it can be executed paralleled; or as | |
| 55 sequential type if it can't. Parallel type partition is further | |
| 56 classified as different builtin kinds if it can be implemented as | |
| 57 builtin function calls. | |
| 58 5) Build partition dependence graph (PG) based on data dependencies. | |
| 59 The vertices (PG:V) model all partitions and the edges (PG:E) model | |
| 60 all data dependencies between every partitions pair. In general, | |
| 61 data dependence is either compilation time known or unknown. In C | |
| 62 family languages, there exists quite amount compilation time unknown | |
| 63 dependencies because of possible alias relation of data references. | |
| 64 We categorize PG's edge to two types: "true" edge that represents | |
| 65 compilation time known data dependencies; "alias" edge for all other | |
| 66 data dependencies. | |
| 67 6) Traverse subgraph of PG as if all "alias" edges don't exist. Merge | |
| 68 partitions in each strong connected component (SCC) correspondingly. | |
| 69 Build new PG for merged partitions. | |
| 70 7) Traverse PG again and this time with both "true" and "alias" edges | |
| 71 included. We try to break SCCs by removing some edges. Because | |
| 72 SCCs by "true" edges are all fused in step 6), we can break SCCs | |
| 73 by removing some "alias" edges. It's NP-hard to choose optimal | |
| 74 edge set, fortunately simple approximation is good enough for us | |
| 75 given the small problem scale. | |
| 76 8) Collect all data dependencies of the removed "alias" edges. Create | |
| 77 runtime alias checks for collected data dependencies. | |
| 78 9) Version loop under the condition of runtime alias checks. Given | |
| 79 loop distribution generally introduces additional overhead, it is | |
| 80 only useful if vectorization is achieved in distributed loop. We | |
| 81 version loop with internal function call IFN_LOOP_DIST_ALIAS. If | |
| 82 no distributed loop can be vectorized, we simply remove distributed | |
| 83 loops and recover to the original one. | |
| 84 | |
| 85 TODO: | |
| 86 1) We only distribute innermost two-level loop nest now. We should | |
| 87 extend it for arbitrary loop nests in the future. | |
| 88 2) We only fuse partitions in SCC now. A better fusion algorithm is | |
| 89 desired to minimize loop overhead, maximize parallelism and maximize | |
| 90 data reuse. */ | |
| 0 | 91 |
| 92 #include "config.h" | |
| 93 #include "system.h" | |
| 94 #include "coretypes.h" | |
| 111 | 95 #include "backend.h" |
| 96 #include "tree.h" | |
| 97 #include "gimple.h" | |
| 98 #include "cfghooks.h" | |
| 0 | 99 #include "tree-pass.h" |
| 111 | 100 #include "ssa.h" |
| 101 #include "gimple-pretty-print.h" | |
| 102 #include "fold-const.h" | |
| 103 #include "cfganal.h" | |
| 104 #include "gimple-iterator.h" | |
| 105 #include "gimplify-me.h" | |
| 106 #include "stor-layout.h" | |
| 107 #include "tree-cfg.h" | |
| 108 #include "tree-ssa-loop-manip.h" | |
| 109 #include "tree-ssa-loop-ivopts.h" | |
| 110 #include "tree-ssa-loop.h" | |
| 111 #include "tree-into-ssa.h" | |
| 112 #include "tree-ssa.h" | |
| 113 #include "cfgloop.h" | |
| 114 #include "tree-scalar-evolution.h" | |
| 115 #include "params.h" | |
| 116 #include "tree-vectorizer.h" | |
| 117 | |
| 118 | |
| 119 #define MAX_DATAREFS_NUM \ | |
| 120 ((unsigned) PARAM_VALUE (PARAM_LOOP_MAX_DATAREFS_FOR_DATADEPS)) | |
| 121 | |
| 122 /* Threshold controlling number of distributed partitions. Given it may | |
| 123 be unnecessary if a memory stream cost model is invented in the future, | |
| 124 we define it as a temporary macro, rather than a parameter. */ | |
| 125 #define NUM_PARTITION_THRESHOLD (4) | |
| 126 | |
| 127 /* Hashtable helpers. */ | |
| 128 | |
| 129 struct ddr_hasher : nofree_ptr_hash <struct data_dependence_relation> | |
| 130 { | |
| 131 static inline hashval_t hash (const data_dependence_relation *); | |
| 132 static inline bool equal (const data_dependence_relation *, | |
| 133 const data_dependence_relation *); | |
| 134 }; | |
| 135 | |
| 136 /* Hash function for data dependence. */ | |
| 137 | |
| 138 inline hashval_t | |
| 139 ddr_hasher::hash (const data_dependence_relation *ddr) | |
| 140 { | |
| 141 inchash::hash h; | |
| 142 h.add_ptr (DDR_A (ddr)); | |
| 143 h.add_ptr (DDR_B (ddr)); | |
| 144 return h.end (); | |
| 145 } | |
| 146 | |
| 147 /* Hash table equality function for data dependence. */ | |
| 148 | |
| 149 inline bool | |
| 150 ddr_hasher::equal (const data_dependence_relation *ddr1, | |
| 151 const data_dependence_relation *ddr2) | |
| 152 { | |
| 153 return (DDR_A (ddr1) == DDR_A (ddr2) && DDR_B (ddr1) == DDR_B (ddr2)); | |
| 154 } | |
| 155 | |
| 156 /* The loop (nest) to be distributed. */ | |
| 157 static vec<loop_p> loop_nest; | |
| 158 | |
| 159 /* Vector of data references in the loop to be distributed. */ | |
| 160 static vec<data_reference_p> datarefs_vec; | |
| 161 | |
| 162 /* Store index of data reference in aux field. */ | |
| 163 #define DR_INDEX(dr) ((uintptr_t) (dr)->aux) | |
| 164 | |
| 165 /* Hash table for data dependence relation in the loop to be distributed. */ | |
| 166 static hash_table<ddr_hasher> *ddrs_table; | |
| 167 | |
| 168 /* A Reduced Dependence Graph (RDG) vertex representing a statement. */ | |
| 169 struct rdg_vertex | |
| 170 { | |
| 171 /* The statement represented by this vertex. */ | |
| 172 gimple *stmt; | |
| 173 | |
| 174 /* Vector of data-references in this statement. */ | |
| 175 vec<data_reference_p> datarefs; | |
| 176 | |
| 177 /* True when the statement contains a write to memory. */ | |
| 178 bool has_mem_write; | |
| 179 | |
| 180 /* True when the statement contains a read from memory. */ | |
| 181 bool has_mem_reads; | |
| 182 }; | |
| 183 | |
| 184 #define RDGV_STMT(V) ((struct rdg_vertex *) ((V)->data))->stmt | |
| 185 #define RDGV_DATAREFS(V) ((struct rdg_vertex *) ((V)->data))->datarefs | |
| 186 #define RDGV_HAS_MEM_WRITE(V) ((struct rdg_vertex *) ((V)->data))->has_mem_write | |
| 187 #define RDGV_HAS_MEM_READS(V) ((struct rdg_vertex *) ((V)->data))->has_mem_reads | |
| 188 #define RDG_STMT(RDG, I) RDGV_STMT (&(RDG->vertices[I])) | |
| 189 #define RDG_DATAREFS(RDG, I) RDGV_DATAREFS (&(RDG->vertices[I])) | |
| 190 #define RDG_MEM_WRITE_STMT(RDG, I) RDGV_HAS_MEM_WRITE (&(RDG->vertices[I])) | |
| 191 #define RDG_MEM_READS_STMT(RDG, I) RDGV_HAS_MEM_READS (&(RDG->vertices[I])) | |
| 192 | |
| 193 /* Data dependence type. */ | |
| 194 | |
| 195 enum rdg_dep_type | |
| 196 { | |
| 197 /* Read After Write (RAW). */ | |
| 198 flow_dd = 'f', | |
| 199 | |
| 200 /* Control dependence (execute conditional on). */ | |
| 201 control_dd = 'c' | |
| 202 }; | |
| 203 | |
| 204 /* Dependence information attached to an edge of the RDG. */ | |
| 205 | |
| 206 struct rdg_edge | |
| 207 { | |
| 208 /* Type of the dependence. */ | |
| 209 enum rdg_dep_type type; | |
| 210 }; | |
| 211 | |
| 212 #define RDGE_TYPE(E) ((struct rdg_edge *) ((E)->data))->type | |
| 213 | |
| 214 /* Dump vertex I in RDG to FILE. */ | |
| 215 | |
| 216 static void | |
| 217 dump_rdg_vertex (FILE *file, struct graph *rdg, int i) | |
| 218 { | |
| 219 struct vertex *v = &(rdg->vertices[i]); | |
| 220 struct graph_edge *e; | |
| 221 | |
| 222 fprintf (file, "(vertex %d: (%s%s) (in:", i, | |
| 223 RDG_MEM_WRITE_STMT (rdg, i) ? "w" : "", | |
| 224 RDG_MEM_READS_STMT (rdg, i) ? "r" : ""); | |
| 225 | |
| 226 if (v->pred) | |
| 227 for (e = v->pred; e; e = e->pred_next) | |
| 228 fprintf (file, " %d", e->src); | |
| 229 | |
| 230 fprintf (file, ") (out:"); | |
| 231 | |
| 232 if (v->succ) | |
| 233 for (e = v->succ; e; e = e->succ_next) | |
| 234 fprintf (file, " %d", e->dest); | |
| 235 | |
| 236 fprintf (file, ")\n"); | |
| 237 print_gimple_stmt (file, RDGV_STMT (v), 0, TDF_VOPS|TDF_MEMSYMS); | |
| 238 fprintf (file, ")\n"); | |
| 239 } | |
| 240 | |
| 241 /* Call dump_rdg_vertex on stderr. */ | |
| 242 | |
| 243 DEBUG_FUNCTION void | |
| 244 debug_rdg_vertex (struct graph *rdg, int i) | |
| 245 { | |
| 246 dump_rdg_vertex (stderr, rdg, i); | |
| 247 } | |
| 248 | |
| 249 /* Dump the reduced dependence graph RDG to FILE. */ | |
| 250 | |
| 251 static void | |
| 252 dump_rdg (FILE *file, struct graph *rdg) | |
| 253 { | |
| 254 fprintf (file, "(rdg\n"); | |
| 255 for (int i = 0; i < rdg->n_vertices; i++) | |
| 256 dump_rdg_vertex (file, rdg, i); | |
| 257 fprintf (file, ")\n"); | |
| 258 } | |
| 259 | |
| 260 /* Call dump_rdg on stderr. */ | |
| 261 | |
| 262 DEBUG_FUNCTION void | |
| 263 debug_rdg (struct graph *rdg) | |
| 264 { | |
| 265 dump_rdg (stderr, rdg); | |
| 266 } | |
| 267 | |
| 268 static void | |
| 269 dot_rdg_1 (FILE *file, struct graph *rdg) | |
| 270 { | |
| 271 int i; | |
| 272 pretty_printer buffer; | |
| 273 pp_needs_newline (&buffer) = false; | |
| 274 buffer.buffer->stream = file; | |
| 275 | |
| 276 fprintf (file, "digraph RDG {\n"); | |
| 277 | |
| 278 for (i = 0; i < rdg->n_vertices; i++) | |
| 279 { | |
| 280 struct vertex *v = &(rdg->vertices[i]); | |
| 281 struct graph_edge *e; | |
| 282 | |
| 283 fprintf (file, "%d [label=\"[%d] ", i, i); | |
| 284 pp_gimple_stmt_1 (&buffer, RDGV_STMT (v), 0, TDF_SLIM); | |
| 285 pp_flush (&buffer); | |
| 286 fprintf (file, "\"]\n"); | |
| 287 | |
| 288 /* Highlight reads from memory. */ | |
| 289 if (RDG_MEM_READS_STMT (rdg, i)) | |
| 290 fprintf (file, "%d [style=filled, fillcolor=green]\n", i); | |
| 291 | |
| 292 /* Highlight stores to memory. */ | |
| 293 if (RDG_MEM_WRITE_STMT (rdg, i)) | |
| 294 fprintf (file, "%d [style=filled, fillcolor=red]\n", i); | |
| 295 | |
| 296 if (v->succ) | |
| 297 for (e = v->succ; e; e = e->succ_next) | |
| 298 switch (RDGE_TYPE (e)) | |
| 299 { | |
| 300 case flow_dd: | |
| 301 /* These are the most common dependences: don't print these. */ | |
| 302 fprintf (file, "%d -> %d \n", i, e->dest); | |
| 303 break; | |
| 304 | |
| 305 case control_dd: | |
| 306 fprintf (file, "%d -> %d [label=control] \n", i, e->dest); | |
| 307 break; | |
| 308 | |
| 309 default: | |
| 310 gcc_unreachable (); | |
| 311 } | |
| 312 } | |
| 313 | |
| 314 fprintf (file, "}\n\n"); | |
| 315 } | |
| 316 | |
| 317 /* Display the Reduced Dependence Graph using dotty. */ | |
| 318 | |
| 319 DEBUG_FUNCTION void | |
| 320 dot_rdg (struct graph *rdg) | |
| 321 { | |
| 322 /* When debugging, you may want to enable the following code. */ | |
| 323 #ifdef HAVE_POPEN | |
| 324 FILE *file = popen ("dot -Tx11", "w"); | |
| 325 if (!file) | |
| 326 return; | |
| 327 dot_rdg_1 (file, rdg); | |
| 328 fflush (file); | |
| 329 close (fileno (file)); | |
| 330 pclose (file); | |
| 331 #else | |
| 332 dot_rdg_1 (stderr, rdg); | |
| 333 #endif | |
| 334 } | |
| 335 | |
| 336 /* Returns the index of STMT in RDG. */ | |
| 337 | |
| 338 static int | |
| 339 rdg_vertex_for_stmt (struct graph *rdg ATTRIBUTE_UNUSED, gimple *stmt) | |
| 340 { | |
| 341 int index = gimple_uid (stmt); | |
| 342 gcc_checking_assert (index == -1 || RDG_STMT (rdg, index) == stmt); | |
| 343 return index; | |
| 344 } | |
| 345 | |
| 346 /* Creates dependence edges in RDG for all the uses of DEF. IDEF is | |
| 347 the index of DEF in RDG. */ | |
| 348 | |
| 349 static void | |
| 350 create_rdg_edges_for_scalar (struct graph *rdg, tree def, int idef) | |
| 351 { | |
| 352 use_operand_p imm_use_p; | |
| 353 imm_use_iterator iterator; | |
| 354 | |
| 355 FOR_EACH_IMM_USE_FAST (imm_use_p, iterator, def) | |
| 356 { | |
| 357 struct graph_edge *e; | |
| 358 int use = rdg_vertex_for_stmt (rdg, USE_STMT (imm_use_p)); | |
| 359 | |
| 360 if (use < 0) | |
| 361 continue; | |
| 362 | |
| 363 e = add_edge (rdg, idef, use); | |
| 364 e->data = XNEW (struct rdg_edge); | |
| 365 RDGE_TYPE (e) = flow_dd; | |
| 366 } | |
| 367 } | |
| 368 | |
| 369 /* Creates an edge for the control dependences of BB to the vertex V. */ | |
| 370 | |
| 371 static void | |
| 372 create_edge_for_control_dependence (struct graph *rdg, basic_block bb, | |
| 373 int v, control_dependences *cd) | |
| 374 { | |
| 375 bitmap_iterator bi; | |
| 376 unsigned edge_n; | |
| 377 EXECUTE_IF_SET_IN_BITMAP (cd->get_edges_dependent_on (bb->index), | |
| 378 0, edge_n, bi) | |
| 379 { | |
| 380 basic_block cond_bb = cd->get_edge_src (edge_n); | |
| 381 gimple *stmt = last_stmt (cond_bb); | |
| 382 if (stmt && is_ctrl_stmt (stmt)) | |
| 383 { | |
| 384 struct graph_edge *e; | |
| 385 int c = rdg_vertex_for_stmt (rdg, stmt); | |
| 386 if (c < 0) | |
| 387 continue; | |
| 388 | |
| 389 e = add_edge (rdg, c, v); | |
| 390 e->data = XNEW (struct rdg_edge); | |
| 391 RDGE_TYPE (e) = control_dd; | |
| 392 } | |
| 393 } | |
| 394 } | |
| 395 | |
| 396 /* Creates the edges of the reduced dependence graph RDG. */ | |
| 0 | 397 |
| 398 static void | |
| 111 | 399 create_rdg_flow_edges (struct graph *rdg) |
| 0 | 400 { |
| 111 | 401 int i; |
| 402 def_operand_p def_p; | |
| 403 ssa_op_iter iter; | |
| 404 | |
| 405 for (i = 0; i < rdg->n_vertices; i++) | |
| 406 FOR_EACH_PHI_OR_STMT_DEF (def_p, RDG_STMT (rdg, i), | |
| 407 iter, SSA_OP_DEF) | |
| 408 create_rdg_edges_for_scalar (rdg, DEF_FROM_PTR (def_p), i); | |
| 409 } | |
| 410 | |
| 411 /* Creates the edges of the reduced dependence graph RDG. */ | |
| 412 | |
| 413 static void | |
| 414 create_rdg_cd_edges (struct graph *rdg, control_dependences *cd, loop_p loop) | |
| 415 { | |
| 416 int i; | |
| 417 | |
| 418 for (i = 0; i < rdg->n_vertices; i++) | |
| 0 | 419 { |
| 111 | 420 gimple *stmt = RDG_STMT (rdg, i); |
| 421 if (gimple_code (stmt) == GIMPLE_PHI) | |
| 0 | 422 { |
| 111 | 423 edge_iterator ei; |
| 424 edge e; | |
| 425 FOR_EACH_EDGE (e, ei, gimple_bb (stmt)->preds) | |
| 426 if (flow_bb_inside_loop_p (loop, e->src)) | |
| 427 create_edge_for_control_dependence (rdg, e->src, i, cd); | |
| 0 | 428 } |
| 429 else | |
| 111 | 430 create_edge_for_control_dependence (rdg, gimple_bb (stmt), i, cd); |
| 431 } | |
| 432 } | |
| 433 | |
| 434 /* Build the vertices of the reduced dependence graph RDG. Return false | |
| 435 if that failed. */ | |
| 436 | |
| 437 static bool | |
| 438 create_rdg_vertices (struct graph *rdg, vec<gimple *> stmts, loop_p loop) | |
| 439 { | |
| 440 int i; | |
| 441 gimple *stmt; | |
| 442 | |
| 443 FOR_EACH_VEC_ELT (stmts, i, stmt) | |
| 444 { | |
| 445 struct vertex *v = &(rdg->vertices[i]); | |
| 446 | |
| 447 /* Record statement to vertex mapping. */ | |
| 448 gimple_set_uid (stmt, i); | |
| 449 | |
| 450 v->data = XNEW (struct rdg_vertex); | |
| 451 RDGV_STMT (v) = stmt; | |
| 452 RDGV_DATAREFS (v).create (0); | |
| 453 RDGV_HAS_MEM_WRITE (v) = false; | |
| 454 RDGV_HAS_MEM_READS (v) = false; | |
| 455 if (gimple_code (stmt) == GIMPLE_PHI) | |
| 456 continue; | |
| 457 | |
| 458 unsigned drp = datarefs_vec.length (); | |
| 459 if (!find_data_references_in_stmt (loop, stmt, &datarefs_vec)) | |
| 460 return false; | |
| 461 for (unsigned j = drp; j < datarefs_vec.length (); ++j) | |
| 462 { | |
| 463 data_reference_p dr = datarefs_vec[j]; | |
| 464 if (DR_IS_READ (dr)) | |
| 465 RDGV_HAS_MEM_READS (v) = true; | |
| 466 else | |
| 467 RDGV_HAS_MEM_WRITE (v) = true; | |
| 468 RDGV_DATAREFS (v).safe_push (dr); | |
| 469 } | |
| 470 } | |
| 471 return true; | |
| 472 } | |
| 473 | |
| 474 /* Array mapping basic block's index to its topological order. */ | |
| 475 static int *bb_top_order_index; | |
| 476 /* And size of the array. */ | |
| 477 static int bb_top_order_index_size; | |
| 478 | |
| 479 /* If X has a smaller topological sort number than Y, returns -1; | |
| 480 if greater, returns 1. */ | |
| 481 | |
| 482 static int | |
| 483 bb_top_order_cmp (const void *x, const void *y) | |
| 484 { | |
| 485 basic_block bb1 = *(const basic_block *) x; | |
| 486 basic_block bb2 = *(const basic_block *) y; | |
| 487 | |
| 488 gcc_assert (bb1->index < bb_top_order_index_size | |
| 489 && bb2->index < bb_top_order_index_size); | |
| 490 gcc_assert (bb1 == bb2 | |
| 491 || bb_top_order_index[bb1->index] | |
| 492 != bb_top_order_index[bb2->index]); | |
| 493 | |
| 494 return (bb_top_order_index[bb1->index] - bb_top_order_index[bb2->index]); | |
| 495 } | |
| 496 | |
| 497 /* Initialize STMTS with all the statements of LOOP. We use topological | |
| 498 order to discover all statements. The order is important because | |
| 499 generate_loops_for_partition is using the same traversal for identifying | |
| 500 statements in loop copies. */ | |
| 501 | |
| 502 static void | |
| 503 stmts_from_loop (struct loop *loop, vec<gimple *> *stmts) | |
| 504 { | |
| 505 unsigned int i; | |
| 506 basic_block *bbs = get_loop_body_in_custom_order (loop, bb_top_order_cmp); | |
| 507 | |
| 508 for (i = 0; i < loop->num_nodes; i++) | |
| 509 { | |
| 510 basic_block bb = bbs[i]; | |
| 511 | |
| 512 for (gphi_iterator bsi = gsi_start_phis (bb); !gsi_end_p (bsi); | |
| 513 gsi_next (&bsi)) | |
| 514 if (!virtual_operand_p (gimple_phi_result (bsi.phi ()))) | |
| 515 stmts->safe_push (bsi.phi ()); | |
| 516 | |
| 517 for (gimple_stmt_iterator bsi = gsi_start_bb (bb); !gsi_end_p (bsi); | |
| 518 gsi_next (&bsi)) | |
| 519 { | |
| 520 gimple *stmt = gsi_stmt (bsi); | |
| 521 if (gimple_code (stmt) != GIMPLE_LABEL && !is_gimple_debug (stmt)) | |
| 522 stmts->safe_push (stmt); | |
| 523 } | |
| 524 } | |
| 525 | |
| 526 free (bbs); | |
| 527 } | |
| 528 | |
| 529 /* Free the reduced dependence graph RDG. */ | |
| 530 | |
| 531 static void | |
| 532 free_rdg (struct graph *rdg) | |
| 533 { | |
| 534 int i; | |
| 535 | |
| 536 for (i = 0; i < rdg->n_vertices; i++) | |
| 537 { | |
| 538 struct vertex *v = &(rdg->vertices[i]); | |
| 539 struct graph_edge *e; | |
| 540 | |
| 541 for (e = v->succ; e; e = e->succ_next) | |
| 542 free (e->data); | |
| 543 | |
| 544 if (v->data) | |
| 545 { | |
| 546 gimple_set_uid (RDGV_STMT (v), -1); | |
| 547 (RDGV_DATAREFS (v)).release (); | |
| 548 free (v->data); | |
| 549 } | |
| 550 } | |
| 551 | |
| 552 free_graph (rdg); | |
| 553 } | |
| 554 | |
| 555 /* Build the Reduced Dependence Graph (RDG) with one vertex per statement of | |
| 556 LOOP, and one edge per flow dependence or control dependence from control | |
| 557 dependence CD. During visiting each statement, data references are also | |
| 558 collected and recorded in global data DATAREFS_VEC. */ | |
| 559 | |
| 560 static struct graph * | |
| 561 build_rdg (struct loop *loop, control_dependences *cd) | |
| 562 { | |
| 563 struct graph *rdg; | |
| 564 | |
| 565 /* Create the RDG vertices from the stmts of the loop nest. */ | |
| 566 auto_vec<gimple *, 10> stmts; | |
| 567 stmts_from_loop (loop, &stmts); | |
| 568 rdg = new_graph (stmts.length ()); | |
| 569 if (!create_rdg_vertices (rdg, stmts, loop)) | |
| 570 { | |
| 571 free_rdg (rdg); | |
| 572 return NULL; | |
| 0 | 573 } |
| 111 | 574 stmts.release (); |
| 575 | |
| 576 create_rdg_flow_edges (rdg); | |
| 577 if (cd) | |
| 578 create_rdg_cd_edges (rdg, cd, loop); | |
| 579 | |
| 580 return rdg; | |
| 581 } | |
| 582 | |
| 583 | |
| 584 /* Kind of distributed loop. */ | |
| 585 enum partition_kind { | |
| 131 | 586 PKIND_NORMAL, |
| 587 /* Partial memset stands for a paritition can be distributed into a loop | |
| 588 of memset calls, rather than a single memset call. It's handled just | |
| 589 like a normal parition, i.e, distributed as separate loop, no memset | |
| 590 call is generated. | |
| 591 | |
| 592 Note: This is a hacking fix trying to distribute ZERO-ing stmt in a | |
| 593 loop nest as deep as possible. As a result, parloop achieves better | |
| 594 parallelization by parallelizing deeper loop nest. This hack should | |
| 595 be unnecessary and removed once distributed memset can be understood | |
| 596 and analyzed in data reference analysis. See PR82604 for more. */ | |
| 597 PKIND_PARTIAL_MEMSET, | |
| 598 PKIND_MEMSET, PKIND_MEMCPY, PKIND_MEMMOVE | |
| 111 | 599 }; |
| 600 | |
| 601 /* Type of distributed loop. */ | |
| 602 enum partition_type { | |
| 603 /* The distributed loop can be executed parallelly. */ | |
| 604 PTYPE_PARALLEL = 0, | |
| 605 /* The distributed loop has to be executed sequentially. */ | |
| 606 PTYPE_SEQUENTIAL | |
| 607 }; | |
| 608 | |
| 609 /* Builtin info for loop distribution. */ | |
| 610 struct builtin_info | |
| 611 { | |
| 612 /* data-references a kind != PKIND_NORMAL partition is about. */ | |
| 613 data_reference_p dst_dr; | |
| 614 data_reference_p src_dr; | |
| 615 /* Base address and size of memory objects operated by the builtin. Note | |
| 616 both dest and source memory objects must have the same size. */ | |
| 617 tree dst_base; | |
| 618 tree src_base; | |
| 619 tree size; | |
| 620 /* Base and offset part of dst_base after stripping constant offset. This | |
| 621 is only used in memset builtin distribution for now. */ | |
| 622 tree dst_base_base; | |
| 623 unsigned HOST_WIDE_INT dst_base_offset; | |
| 624 }; | |
| 625 | |
| 626 /* Partition for loop distribution. */ | |
| 627 struct partition | |
| 628 { | |
| 629 /* Statements of the partition. */ | |
| 630 bitmap stmts; | |
| 631 /* True if the partition defines variable which is used outside of loop. */ | |
| 632 bool reduction_p; | |
| 633 enum partition_kind kind; | |
| 634 enum partition_type type; | |
| 635 /* Data references in the partition. */ | |
| 636 bitmap datarefs; | |
| 637 /* Information of builtin parition. */ | |
| 638 struct builtin_info *builtin; | |
| 639 }; | |
| 640 | |
| 641 | |
| 642 /* Allocate and initialize a partition from BITMAP. */ | |
| 643 | |
| 644 static partition * | |
| 645 partition_alloc (void) | |
| 646 { | |
| 647 partition *partition = XCNEW (struct partition); | |
| 648 partition->stmts = BITMAP_ALLOC (NULL); | |
| 649 partition->reduction_p = false; | |
| 650 partition->kind = PKIND_NORMAL; | |
| 651 partition->datarefs = BITMAP_ALLOC (NULL); | |
| 652 return partition; | |
| 653 } | |
| 654 | |
| 655 /* Free PARTITION. */ | |
| 656 | |
| 657 static void | |
| 658 partition_free (partition *partition) | |
| 659 { | |
| 660 BITMAP_FREE (partition->stmts); | |
| 661 BITMAP_FREE (partition->datarefs); | |
| 662 if (partition->builtin) | |
| 663 free (partition->builtin); | |
| 664 | |
| 665 free (partition); | |
| 666 } | |
| 667 | |
| 668 /* Returns true if the partition can be generated as a builtin. */ | |
| 669 | |
| 670 static bool | |
| 671 partition_builtin_p (partition *partition) | |
| 672 { | |
| 131 | 673 return partition->kind > PKIND_PARTIAL_MEMSET; |
| 111 | 674 } |
| 675 | |
| 676 /* Returns true if the partition contains a reduction. */ | |
| 677 | |
| 678 static bool | |
| 679 partition_reduction_p (partition *partition) | |
| 680 { | |
| 681 return partition->reduction_p; | |
| 682 } | |
| 683 | |
| 684 /* Partitions are fused because of different reasons. */ | |
| 685 enum fuse_type | |
| 686 { | |
| 687 FUSE_NON_BUILTIN = 0, | |
| 688 FUSE_REDUCTION = 1, | |
| 689 FUSE_SHARE_REF = 2, | |
| 690 FUSE_SAME_SCC = 3, | |
| 691 FUSE_FINALIZE = 4 | |
| 692 }; | |
| 693 | |
| 694 /* Description on different fusing reason. */ | |
| 695 static const char *fuse_message[] = { | |
| 696 "they are non-builtins", | |
| 697 "they have reductions", | |
| 698 "they have shared memory refs", | |
| 699 "they are in the same dependence scc", | |
| 700 "there is no point to distribute loop"}; | |
| 701 | |
| 702 static void | |
| 703 update_type_for_merge (struct graph *, partition *, partition *); | |
| 704 | |
| 705 /* Merge PARTITION into the partition DEST. RDG is the reduced dependence | |
| 706 graph and we update type for result partition if it is non-NULL. */ | |
| 707 | |
| 708 static void | |
| 709 partition_merge_into (struct graph *rdg, partition *dest, | |
| 710 partition *partition, enum fuse_type ft) | |
| 711 { | |
| 712 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 713 { | |
| 714 fprintf (dump_file, "Fuse partitions because %s:\n", fuse_message[ft]); | |
| 715 fprintf (dump_file, " Part 1: "); | |
| 716 dump_bitmap (dump_file, dest->stmts); | |
| 717 fprintf (dump_file, " Part 2: "); | |
| 718 dump_bitmap (dump_file, partition->stmts); | |
| 719 } | |
| 720 | |
| 721 dest->kind = PKIND_NORMAL; | |
| 722 if (dest->type == PTYPE_PARALLEL) | |
| 723 dest->type = partition->type; | |
| 724 | |
| 725 bitmap_ior_into (dest->stmts, partition->stmts); | |
| 726 if (partition_reduction_p (partition)) | |
| 727 dest->reduction_p = true; | |
| 728 | |
| 729 /* Further check if any data dependence prevents us from executing the | |
| 730 new partition parallelly. */ | |
| 731 if (dest->type == PTYPE_PARALLEL && rdg != NULL) | |
| 732 update_type_for_merge (rdg, dest, partition); | |
| 733 | |
| 734 bitmap_ior_into (dest->datarefs, partition->datarefs); | |
| 735 } | |
| 736 | |
| 737 | |
| 738 /* Returns true when DEF is an SSA_NAME defined in LOOP and used after | |
| 739 the LOOP. */ | |
| 740 | |
| 741 static bool | |
| 742 ssa_name_has_uses_outside_loop_p (tree def, loop_p loop) | |
| 743 { | |
| 744 imm_use_iterator imm_iter; | |
| 745 use_operand_p use_p; | |
| 746 | |
| 747 FOR_EACH_IMM_USE_FAST (use_p, imm_iter, def) | |
| 748 { | |
| 749 if (is_gimple_debug (USE_STMT (use_p))) | |
| 750 continue; | |
| 751 | |
| 752 basic_block use_bb = gimple_bb (USE_STMT (use_p)); | |
| 753 if (!flow_bb_inside_loop_p (loop, use_bb)) | |
| 754 return true; | |
| 755 } | |
| 756 | |
| 757 return false; | |
| 758 } | |
| 759 | |
| 760 /* Returns true when STMT defines a scalar variable used after the | |
| 761 loop LOOP. */ | |
| 762 | |
| 763 static bool | |
| 764 stmt_has_scalar_dependences_outside_loop (loop_p loop, gimple *stmt) | |
| 765 { | |
| 766 def_operand_p def_p; | |
| 767 ssa_op_iter op_iter; | |
| 768 | |
| 769 if (gimple_code (stmt) == GIMPLE_PHI) | |
| 770 return ssa_name_has_uses_outside_loop_p (gimple_phi_result (stmt), loop); | |
| 771 | |
| 772 FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, op_iter, SSA_OP_DEF) | |
| 773 if (ssa_name_has_uses_outside_loop_p (DEF_FROM_PTR (def_p), loop)) | |
| 774 return true; | |
| 775 | |
| 776 return false; | |
| 0 | 777 } |
| 778 | |
| 779 /* Return a copy of LOOP placed before LOOP. */ | |
| 780 | |
| 781 static struct loop * | |
| 782 copy_loop_before (struct loop *loop) | |
| 783 { | |
| 784 struct loop *res; | |
| 785 edge preheader = loop_preheader_edge (loop); | |
| 786 | |
| 787 initialize_original_copy_tables (); | |
| 111 | 788 res = slpeel_tree_duplicate_loop_to_edge_cfg (loop, NULL, preheader); |
| 789 gcc_assert (res != NULL); | |
| 0 | 790 free_original_copy_tables (); |
| 111 | 791 delete_update_ssa (); |
| 0 | 792 |
| 793 return res; | |
| 794 } | |
| 795 | |
| 796 /* Creates an empty basic block after LOOP. */ | |
| 797 | |
| 798 static void | |
| 799 create_bb_after_loop (struct loop *loop) | |
| 800 { | |
| 801 edge exit = single_exit (loop); | |
| 802 | |
| 803 if (!exit) | |
| 804 return; | |
| 805 | |
| 806 split_edge (exit); | |
| 807 } | |
| 808 | |
| 809 /* Generate code for PARTITION from the code in LOOP. The loop is | |
| 810 copied when COPY_P is true. All the statements not flagged in the | |
| 811 PARTITION bitmap are removed from the loop or from its copy. The | |
| 812 statements are indexed in sequence inside a basic block, and the | |
| 111 | 813 basic blocks of a loop are taken in dom order. */ |
| 814 | |
| 815 static void | |
| 816 generate_loops_for_partition (struct loop *loop, partition *partition, | |
| 817 bool copy_p) | |
| 0 | 818 { |
| 111 | 819 unsigned i; |
| 0 | 820 basic_block *bbs; |
| 821 | |
| 822 if (copy_p) | |
| 823 { | |
| 111 | 824 int orig_loop_num = loop->orig_loop_num; |
| 0 | 825 loop = copy_loop_before (loop); |
| 111 | 826 gcc_assert (loop != NULL); |
| 827 loop->orig_loop_num = orig_loop_num; | |
| 0 | 828 create_preheader (loop, CP_SIMPLE_PREHEADERS); |
| 829 create_bb_after_loop (loop); | |
| 830 } | |
| 111 | 831 else |
| 0 | 832 { |
| 111 | 833 /* Origin number is set to the new versioned loop's num. */ |
| 834 gcc_assert (loop->orig_loop_num != loop->num); | |
| 0 | 835 } |
| 836 | |
| 111 | 837 /* Remove stmts not in the PARTITION bitmap. */ |
| 0 | 838 bbs = get_loop_body_in_dom_order (loop); |
| 839 | |
| 131 | 840 if (MAY_HAVE_DEBUG_BIND_STMTS) |
| 111 | 841 for (i = 0; i < loop->num_nodes; i++) |
| 842 { | |
| 843 basic_block bb = bbs[i]; | |
| 844 | |
| 845 for (gphi_iterator bsi = gsi_start_phis (bb); !gsi_end_p (bsi); | |
| 846 gsi_next (&bsi)) | |
| 847 { | |
| 848 gphi *phi = bsi.phi (); | |
| 849 if (!virtual_operand_p (gimple_phi_result (phi)) | |
| 850 && !bitmap_bit_p (partition->stmts, gimple_uid (phi))) | |
| 851 reset_debug_uses (phi); | |
| 852 } | |
| 853 | |
| 854 for (gimple_stmt_iterator bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) | |
| 855 { | |
| 856 gimple *stmt = gsi_stmt (bsi); | |
| 857 if (gimple_code (stmt) != GIMPLE_LABEL | |
| 858 && !is_gimple_debug (stmt) | |
| 859 && !bitmap_bit_p (partition->stmts, gimple_uid (stmt))) | |
| 860 reset_debug_uses (stmt); | |
| 861 } | |
| 862 } | |
| 863 | |
| 0 | 864 for (i = 0; i < loop->num_nodes; i++) |
| 865 { | |
| 866 basic_block bb = bbs[i]; | |
| 111 | 867 edge inner_exit = NULL; |
| 868 | |
| 869 if (loop != bb->loop_father) | |
| 870 inner_exit = single_exit (bb->loop_father); | |
| 871 | |
| 872 for (gphi_iterator bsi = gsi_start_phis (bb); !gsi_end_p (bsi);) | |
| 873 { | |
| 874 gphi *phi = bsi.phi (); | |
| 875 if (!virtual_operand_p (gimple_phi_result (phi)) | |
| 876 && !bitmap_bit_p (partition->stmts, gimple_uid (phi))) | |
| 877 remove_phi_node (&bsi, true); | |
| 878 else | |
| 879 gsi_next (&bsi); | |
| 880 } | |
| 881 | |
| 882 for (gimple_stmt_iterator bsi = gsi_start_bb (bb); !gsi_end_p (bsi);) | |
| 0 | 883 { |
| 111 | 884 gimple *stmt = gsi_stmt (bsi); |
| 885 if (gimple_code (stmt) != GIMPLE_LABEL | |
| 886 && !is_gimple_debug (stmt) | |
| 887 && !bitmap_bit_p (partition->stmts, gimple_uid (stmt))) | |
| 0 | 888 { |
| 111 | 889 /* In distribution of loop nest, if bb is inner loop's exit_bb, |
| 890 we choose its exit edge/path in order to avoid generating | |
| 891 infinite loop. For all other cases, we choose an arbitrary | |
| 892 path through the empty CFG part that this unnecessary | |
| 893 control stmt controls. */ | |
| 894 if (gcond *cond_stmt = dyn_cast <gcond *> (stmt)) | |
| 895 { | |
| 896 if (inner_exit && inner_exit->flags & EDGE_TRUE_VALUE) | |
| 897 gimple_cond_make_true (cond_stmt); | |
| 898 else | |
| 899 gimple_cond_make_false (cond_stmt); | |
| 900 update_stmt (stmt); | |
| 901 } | |
| 902 else if (gimple_code (stmt) == GIMPLE_SWITCH) | |
| 903 { | |
| 904 gswitch *switch_stmt = as_a <gswitch *> (stmt); | |
| 905 gimple_switch_set_index | |
| 906 (switch_stmt, CASE_LOW (gimple_switch_label (switch_stmt, 1))); | |
| 907 update_stmt (stmt); | |
| 908 } | |
| 909 else | |
| 910 { | |
| 911 unlink_stmt_vdef (stmt); | |
| 912 gsi_remove (&bsi, true); | |
| 913 release_defs (stmt); | |
| 914 continue; | |
| 915 } | |
| 0 | 916 } |
| 111 | 917 gsi_next (&bsi); |
| 0 | 918 } |
| 919 } | |
| 920 | |
| 111 | 921 free (bbs); |
| 922 } | |
| 923 | |
| 924 /* If VAL memory representation contains the same value in all bytes, | |
| 925 return that value, otherwise return -1. | |
| 926 E.g. for 0x24242424 return 0x24, for IEEE double | |
| 927 747708026454360457216.0 return 0x44, etc. */ | |
| 928 | |
| 929 static int | |
| 930 const_with_all_bytes_same (tree val) | |
| 931 { | |
| 932 unsigned char buf[64]; | |
| 933 int i, len; | |
| 934 | |
| 935 if (integer_zerop (val) | |
| 936 || (TREE_CODE (val) == CONSTRUCTOR | |
| 937 && !TREE_CLOBBER_P (val) | |
| 938 && CONSTRUCTOR_NELTS (val) == 0)) | |
| 939 return 0; | |
| 940 | |
| 941 if (real_zerop (val)) | |
| 942 { | |
| 943 /* Only return 0 for +0.0, not for -0.0, which doesn't have | |
| 944 an all bytes same memory representation. Don't transform | |
| 945 -0.0 stores into +0.0 even for !HONOR_SIGNED_ZEROS. */ | |
| 946 switch (TREE_CODE (val)) | |
| 947 { | |
| 948 case REAL_CST: | |
| 949 if (!real_isneg (TREE_REAL_CST_PTR (val))) | |
| 950 return 0; | |
| 951 break; | |
| 952 case COMPLEX_CST: | |
| 953 if (!const_with_all_bytes_same (TREE_REALPART (val)) | |
| 954 && !const_with_all_bytes_same (TREE_IMAGPART (val))) | |
| 955 return 0; | |
| 956 break; | |
| 957 case VECTOR_CST: | |
| 131 | 958 { |
| 959 unsigned int count = vector_cst_encoded_nelts (val); | |
| 960 unsigned int j; | |
| 961 for (j = 0; j < count; ++j) | |
| 962 if (const_with_all_bytes_same (VECTOR_CST_ENCODED_ELT (val, j))) | |
| 963 break; | |
| 964 if (j == count) | |
| 965 return 0; | |
| 966 break; | |
| 967 } | |
| 111 | 968 default: |
| 969 break; | |
| 970 } | |
| 971 } | |
| 972 | |
| 973 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8) | |
| 974 return -1; | |
| 975 | |
| 976 len = native_encode_expr (val, buf, sizeof (buf)); | |
| 977 if (len == 0) | |
| 978 return -1; | |
| 979 for (i = 1; i < len; i++) | |
| 980 if (buf[i] != buf[0]) | |
| 981 return -1; | |
| 982 return buf[0]; | |
| 983 } | |
| 984 | |
| 985 /* Generate a call to memset for PARTITION in LOOP. */ | |
| 986 | |
| 987 static void | |
| 988 generate_memset_builtin (struct loop *loop, partition *partition) | |
| 989 { | |
| 990 gimple_stmt_iterator gsi; | |
| 991 tree mem, fn, nb_bytes; | |
| 992 tree val; | |
| 993 struct builtin_info *builtin = partition->builtin; | |
| 994 gimple *fn_call; | |
| 0 | 995 |
| 996 /* The new statements will be placed before LOOP. */ | |
| 111 | 997 gsi = gsi_last_bb (loop_preheader_edge (loop)->src); |
| 998 | |
| 999 nb_bytes = builtin->size; | |
| 1000 nb_bytes = force_gimple_operand_gsi (&gsi, nb_bytes, true, NULL_TREE, | |
| 1001 false, GSI_CONTINUE_LINKING); | |
| 1002 mem = builtin->dst_base; | |
| 1003 mem = force_gimple_operand_gsi (&gsi, mem, true, NULL_TREE, | |
| 1004 false, GSI_CONTINUE_LINKING); | |
| 1005 | |
| 1006 /* This exactly matches the pattern recognition in classify_partition. */ | |
| 1007 val = gimple_assign_rhs1 (DR_STMT (builtin->dst_dr)); | |
| 1008 /* Handle constants like 0x15151515 and similarly | |
| 1009 floating point constants etc. where all bytes are the same. */ | |
| 1010 int bytev = const_with_all_bytes_same (val); | |
| 1011 if (bytev != -1) | |
| 1012 val = build_int_cst (integer_type_node, bytev); | |
| 1013 else if (TREE_CODE (val) == INTEGER_CST) | |
| 1014 val = fold_convert (integer_type_node, val); | |
| 1015 else if (!useless_type_conversion_p (integer_type_node, TREE_TYPE (val))) | |
| 1016 { | |
| 1017 tree tem = make_ssa_name (integer_type_node); | |
| 1018 gimple *cstmt = gimple_build_assign (tem, NOP_EXPR, val); | |
| 1019 gsi_insert_after (&gsi, cstmt, GSI_CONTINUE_LINKING); | |
| 1020 val = tem; | |
| 1021 } | |
| 1022 | |
| 1023 fn = build_fold_addr_expr (builtin_decl_implicit (BUILT_IN_MEMSET)); | |
| 1024 fn_call = gimple_build_call (fn, 3, mem, val, nb_bytes); | |
| 1025 gsi_insert_after (&gsi, fn_call, GSI_CONTINUE_LINKING); | |
| 1026 | |
| 1027 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 0 | 1028 { |
| 111 | 1029 fprintf (dump_file, "generated memset"); |
| 1030 if (bytev == 0) | |
| 1031 fprintf (dump_file, " zero\n"); | |
| 1032 else | |
| 1033 fprintf (dump_file, "\n"); | |
| 1034 } | |
| 1035 } | |
| 1036 | |
| 1037 /* Generate a call to memcpy for PARTITION in LOOP. */ | |
| 1038 | |
| 1039 static void | |
| 1040 generate_memcpy_builtin (struct loop *loop, partition *partition) | |
| 1041 { | |
| 1042 gimple_stmt_iterator gsi; | |
| 1043 gimple *fn_call; | |
| 1044 tree dest, src, fn, nb_bytes; | |
| 1045 enum built_in_function kind; | |
| 1046 struct builtin_info *builtin = partition->builtin; | |
| 1047 | |
| 1048 /* The new statements will be placed before LOOP. */ | |
| 1049 gsi = gsi_last_bb (loop_preheader_edge (loop)->src); | |
| 1050 | |
| 1051 nb_bytes = builtin->size; | |
| 1052 nb_bytes = force_gimple_operand_gsi (&gsi, nb_bytes, true, NULL_TREE, | |
| 1053 false, GSI_CONTINUE_LINKING); | |
| 1054 dest = builtin->dst_base; | |
| 1055 src = builtin->src_base; | |
| 1056 if (partition->kind == PKIND_MEMCPY | |
| 1057 || ! ptr_derefs_may_alias_p (dest, src)) | |
| 1058 kind = BUILT_IN_MEMCPY; | |
| 1059 else | |
| 1060 kind = BUILT_IN_MEMMOVE; | |
| 1061 | |
| 1062 dest = force_gimple_operand_gsi (&gsi, dest, true, NULL_TREE, | |
| 1063 false, GSI_CONTINUE_LINKING); | |
| 1064 src = force_gimple_operand_gsi (&gsi, src, true, NULL_TREE, | |
| 1065 false, GSI_CONTINUE_LINKING); | |
| 1066 fn = build_fold_addr_expr (builtin_decl_implicit (kind)); | |
| 1067 fn_call = gimple_build_call (fn, 3, dest, src, nb_bytes); | |
| 1068 gsi_insert_after (&gsi, fn_call, GSI_CONTINUE_LINKING); | |
| 1069 | |
| 1070 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 1071 { | |
| 1072 if (kind == BUILT_IN_MEMCPY) | |
| 1073 fprintf (dump_file, "generated memcpy\n"); | |
| 1074 else | |
| 1075 fprintf (dump_file, "generated memmove\n"); | |
| 0 | 1076 } |
| 1077 } | |
| 1078 | |
| 111 | 1079 /* Remove and destroy the loop LOOP. */ |
| 1080 | |
| 1081 static void | |
| 1082 destroy_loop (struct loop *loop) | |
| 0 | 1083 { |
| 111 | 1084 unsigned nbbs = loop->num_nodes; |
| 1085 edge exit = single_exit (loop); | |
| 1086 basic_block src = loop_preheader_edge (loop)->src, dest = exit->dest; | |
| 1087 basic_block *bbs; | |
| 1088 unsigned i; | |
| 1089 | |
| 1090 bbs = get_loop_body_in_dom_order (loop); | |
| 1091 | |
| 1092 redirect_edge_pred (exit, src); | |
| 1093 exit->flags &= ~(EDGE_TRUE_VALUE|EDGE_FALSE_VALUE); | |
| 1094 exit->flags |= EDGE_FALLTHRU; | |
| 1095 cancel_loop_tree (loop); | |
| 1096 rescan_loop_exit (exit, false, true); | |
| 1097 | |
| 1098 i = nbbs; | |
| 1099 do | |
| 1100 { | |
| 1101 /* We have made sure to not leave any dangling uses of SSA | |
| 1102 names defined in the loop. With the exception of virtuals. | |
| 1103 Make sure we replace all uses of virtual defs that will remain | |
| 1104 outside of the loop with the bare symbol as delete_basic_block | |
| 1105 will release them. */ | |
| 1106 --i; | |
| 1107 for (gphi_iterator gsi = gsi_start_phis (bbs[i]); !gsi_end_p (gsi); | |
| 1108 gsi_next (&gsi)) | |
| 1109 { | |
| 1110 gphi *phi = gsi.phi (); | |
| 1111 if (virtual_operand_p (gimple_phi_result (phi))) | |
| 1112 mark_virtual_phi_result_for_renaming (phi); | |
| 1113 } | |
| 1114 for (gimple_stmt_iterator gsi = gsi_start_bb (bbs[i]); !gsi_end_p (gsi); | |
| 1115 gsi_next (&gsi)) | |
| 1116 { | |
| 1117 gimple *stmt = gsi_stmt (gsi); | |
| 1118 tree vdef = gimple_vdef (stmt); | |
| 1119 if (vdef && TREE_CODE (vdef) == SSA_NAME) | |
| 1120 mark_virtual_operand_for_renaming (vdef); | |
| 1121 } | |
| 1122 delete_basic_block (bbs[i]); | |
| 1123 } | |
| 1124 while (i != 0); | |
| 1125 | |
| 1126 free (bbs); | |
| 1127 | |
| 1128 set_immediate_dominator (CDI_DOMINATORS, dest, | |
| 1129 recompute_dominator (CDI_DOMINATORS, dest)); | |
| 1130 } | |
| 1131 | |
| 1132 /* Generates code for PARTITION. Return whether LOOP needs to be destroyed. */ | |
| 1133 | |
| 1134 static bool | |
| 1135 generate_code_for_partition (struct loop *loop, | |
| 1136 partition *partition, bool copy_p) | |
| 1137 { | |
| 1138 switch (partition->kind) | |
| 1139 { | |
| 1140 case PKIND_NORMAL: | |
| 131 | 1141 case PKIND_PARTIAL_MEMSET: |
| 111 | 1142 /* Reductions all have to be in the last partition. */ |
| 1143 gcc_assert (!partition_reduction_p (partition) | |
| 1144 || !copy_p); | |
| 1145 generate_loops_for_partition (loop, partition, copy_p); | |
| 1146 return false; | |
| 1147 | |
| 1148 case PKIND_MEMSET: | |
| 1149 generate_memset_builtin (loop, partition); | |
| 1150 break; | |
| 1151 | |
| 1152 case PKIND_MEMCPY: | |
| 1153 case PKIND_MEMMOVE: | |
| 1154 generate_memcpy_builtin (loop, partition); | |
| 1155 break; | |
| 1156 | |
| 1157 default: | |
| 1158 gcc_unreachable (); | |
| 1159 } | |
| 1160 | |
| 1161 /* Common tail for partitions we turn into a call. If this was the last | |
| 1162 partition for which we generate code, we have to destroy the loop. */ | |
| 1163 if (!copy_p) | |
| 0 | 1164 return true; |
| 1165 return false; | |
| 1166 } | |
| 1167 | |
| 111 | 1168 /* Return data dependence relation for data references A and B. The two |
| 1169 data references must be in lexicographic order wrto reduced dependence | |
| 1170 graph RDG. We firstly try to find ddr from global ddr hash table. If | |
| 1171 it doesn't exist, compute the ddr and cache it. */ | |
| 1172 | |
| 1173 static data_dependence_relation * | |
| 1174 get_data_dependence (struct graph *rdg, data_reference_p a, data_reference_p b) | |
| 0 | 1175 { |
| 111 | 1176 struct data_dependence_relation ent, **slot; |
| 1177 struct data_dependence_relation *ddr; | |
| 1178 | |
| 1179 gcc_assert (DR_IS_WRITE (a) || DR_IS_WRITE (b)); | |
| 1180 gcc_assert (rdg_vertex_for_stmt (rdg, DR_STMT (a)) | |
| 1181 <= rdg_vertex_for_stmt (rdg, DR_STMT (b))); | |
| 1182 ent.a = a; | |
| 1183 ent.b = b; | |
| 1184 slot = ddrs_table->find_slot (&ent, INSERT); | |
| 1185 if (*slot == NULL) | |
| 1186 { | |
| 1187 ddr = initialize_data_dependence_relation (a, b, loop_nest); | |
| 1188 compute_affine_dependence (ddr, loop_nest[0]); | |
| 1189 *slot = ddr; | |
| 1190 } | |
| 1191 | |
| 1192 return *slot; | |
| 0 | 1193 } |
| 1194 | |
| 111 | 1195 /* In reduced dependence graph RDG for loop distribution, return true if |
| 1196 dependence between references DR1 and DR2 leads to a dependence cycle | |
| 1197 and such dependence cycle can't be resolved by runtime alias check. */ | |
| 0 | 1198 |
| 1199 static bool | |
| 111 | 1200 data_dep_in_cycle_p (struct graph *rdg, |
| 1201 data_reference_p dr1, data_reference_p dr2) | |
| 0 | 1202 { |
| 111 | 1203 struct data_dependence_relation *ddr; |
| 1204 | |
| 1205 /* Re-shuffle data-refs to be in topological order. */ | |
| 1206 if (rdg_vertex_for_stmt (rdg, DR_STMT (dr1)) | |
| 1207 > rdg_vertex_for_stmt (rdg, DR_STMT (dr2))) | |
| 1208 std::swap (dr1, dr2); | |
| 1209 | |
| 1210 ddr = get_data_dependence (rdg, dr1, dr2); | |
| 1211 | |
| 1212 /* In case of no data dependence. */ | |
| 1213 if (DDR_ARE_DEPENDENT (ddr) == chrec_known) | |
| 1214 return false; | |
| 1215 /* For unknown data dependence or known data dependence which can't be | |
| 1216 expressed in classic distance vector, we check if it can be resolved | |
| 1217 by runtime alias check. If yes, we still consider data dependence | |
| 1218 as won't introduce data dependence cycle. */ | |
| 1219 else if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know | |
| 1220 || DDR_NUM_DIST_VECTS (ddr) == 0) | |
| 1221 return !runtime_alias_check_p (ddr, NULL, true); | |
| 1222 else if (DDR_NUM_DIST_VECTS (ddr) > 1) | |
| 1223 return true; | |
| 1224 else if (DDR_REVERSED_P (ddr) | |
| 1225 || lambda_vector_zerop (DDR_DIST_VECT (ddr, 0), 1)) | |
| 1226 return false; | |
| 1227 | |
| 1228 return true; | |
| 0 | 1229 } |
| 1230 | |
| 111 | 1231 /* Given reduced dependence graph RDG, PARTITION1 and PARTITION2, update |
| 1232 PARTITION1's type after merging PARTITION2 into PARTITION1. */ | |
| 0 | 1233 |
| 1234 static void | |
| 111 | 1235 update_type_for_merge (struct graph *rdg, |
| 1236 partition *partition1, partition *partition2) | |
| 0 | 1237 { |
| 111 | 1238 unsigned i, j; |
| 1239 bitmap_iterator bi, bj; | |
| 1240 data_reference_p dr1, dr2; | |
| 1241 | |
| 1242 EXECUTE_IF_SET_IN_BITMAP (partition1->datarefs, 0, i, bi) | |
| 0 | 1243 { |
| 111 | 1244 unsigned start = (partition1 == partition2) ? i + 1 : 0; |
| 1245 | |
| 1246 dr1 = datarefs_vec[i]; | |
| 1247 EXECUTE_IF_SET_IN_BITMAP (partition2->datarefs, start, j, bj) | |
| 0 | 1248 { |
| 111 | 1249 dr2 = datarefs_vec[j]; |
| 1250 if (DR_IS_READ (dr1) && DR_IS_READ (dr2)) | |
| 1251 continue; | |
| 1252 | |
| 1253 /* Partition can only be executed sequentially if there is any | |
| 1254 data dependence cycle. */ | |
| 1255 if (data_dep_in_cycle_p (rdg, dr1, dr2)) | |
| 0 | 1256 { |
| 111 | 1257 partition1->type = PTYPE_SEQUENTIAL; |
| 1258 return; | |
| 0 | 1259 } |
| 1260 } | |
| 1261 } | |
| 1262 } | |
| 1263 | |
| 111 | 1264 /* Returns a partition with all the statements needed for computing |
| 1265 the vertex V of the RDG, also including the loop exit conditions. */ | |
| 1266 | |
| 1267 static partition * | |
| 1268 build_rdg_partition_for_vertex (struct graph *rdg, int v) | |
| 0 | 1269 { |
| 111 | 1270 partition *partition = partition_alloc (); |
| 1271 auto_vec<int, 3> nodes; | |
| 1272 unsigned i, j; | |
| 0 | 1273 int x; |
| 111 | 1274 data_reference_p dr; |
| 1275 | |
| 1276 graphds_dfs (rdg, &v, 1, &nodes, false, NULL); | |
| 1277 | |
| 1278 FOR_EACH_VEC_ELT (nodes, i, x) | |
| 1279 { | |
| 1280 bitmap_set_bit (partition->stmts, x); | |
| 1281 | |
| 1282 for (j = 0; RDG_DATAREFS (rdg, x).iterate (j, &dr); ++j) | |
| 1283 { | |
| 1284 unsigned idx = (unsigned) DR_INDEX (dr); | |
| 1285 gcc_assert (idx < datarefs_vec.length ()); | |
| 1286 | |
| 1287 /* Partition can only be executed sequentially if there is any | |
| 1288 unknown data reference. */ | |
| 1289 if (!DR_BASE_ADDRESS (dr) || !DR_OFFSET (dr) | |
| 1290 || !DR_INIT (dr) || !DR_STEP (dr)) | |
| 1291 partition->type = PTYPE_SEQUENTIAL; | |
| 1292 | |
| 1293 bitmap_set_bit (partition->datarefs, idx); | |
| 1294 } | |
| 1295 } | |
| 1296 | |
| 1297 if (partition->type == PTYPE_SEQUENTIAL) | |
| 1298 return partition; | |
| 1299 | |
| 1300 /* Further check if any data dependence prevents us from executing the | |
| 1301 partition parallelly. */ | |
| 1302 update_type_for_merge (rdg, partition, partition); | |
| 1303 | |
| 1304 return partition; | |
| 0 | 1305 } |
| 1306 | |
| 111 | 1307 /* Given PARTITION of LOOP and RDG, record single load/store data references |
| 1308 for builtin partition in SRC_DR/DST_DR, return false if there is no such | |
| 1309 data references. */ | |
| 1310 | |
| 1311 static bool | |
| 1312 find_single_drs (struct loop *loop, struct graph *rdg, partition *partition, | |
| 1313 data_reference_p *dst_dr, data_reference_p *src_dr) | |
| 0 | 1314 { |
| 1315 unsigned i; | |
| 111 | 1316 data_reference_p single_ld = NULL, single_st = NULL; |
| 0 | 1317 bitmap_iterator bi; |
| 111 | 1318 |
| 1319 EXECUTE_IF_SET_IN_BITMAP (partition->stmts, 0, i, bi) | |
| 0 | 1320 { |
| 111 | 1321 gimple *stmt = RDG_STMT (rdg, i); |
| 1322 data_reference_p dr; | |
| 1323 | |
| 1324 if (gimple_code (stmt) == GIMPLE_PHI) | |
| 1325 continue; | |
| 1326 | |
| 1327 /* Any scalar stmts are ok. */ | |
| 1328 if (!gimple_vuse (stmt)) | |
| 1329 continue; | |
| 1330 | |
| 1331 /* Otherwise just regular loads/stores. */ | |
| 1332 if (!gimple_assign_single_p (stmt)) | |
| 1333 return false; | |
| 1334 | |
| 1335 /* But exactly one store and/or load. */ | |
| 1336 for (unsigned j = 0; RDG_DATAREFS (rdg, i).iterate (j, &dr); ++j) | |
| 1337 { | |
| 1338 tree type = TREE_TYPE (DR_REF (dr)); | |
| 1339 | |
| 1340 /* The memset, memcpy and memmove library calls are only | |
| 1341 able to deal with generic address space. */ | |
| 1342 if (!ADDR_SPACE_GENERIC_P (TYPE_ADDR_SPACE (type))) | |
| 1343 return false; | |
| 1344 | |
| 1345 if (DR_IS_READ (dr)) | |
| 1346 { | |
| 1347 if (single_ld != NULL) | |
| 1348 return false; | |
| 1349 single_ld = dr; | |
| 1350 } | |
| 1351 else | |
| 1352 { | |
| 1353 if (single_st != NULL) | |
| 1354 return false; | |
| 1355 single_st = dr; | |
| 1356 } | |
| 1357 } | |
| 0 | 1358 } |
| 1359 | |
| 111 | 1360 if (!single_st) |
| 1361 return false; | |
| 1362 | |
| 1363 /* Bail out if this is a bitfield memory reference. */ | |
| 1364 if (TREE_CODE (DR_REF (single_st)) == COMPONENT_REF | |
| 1365 && DECL_BIT_FIELD (TREE_OPERAND (DR_REF (single_st), 1))) | |
| 1366 return false; | |
| 1367 | |
| 1368 /* Data reference must be executed exactly once per iteration of each | |
| 1369 loop in the loop nest. We only need to check dominance information | |
| 1370 against the outermost one in a perfect loop nest because a bb can't | |
| 1371 dominate outermost loop's latch without dominating inner loop's. */ | |
| 1372 basic_block bb_st = gimple_bb (DR_STMT (single_st)); | |
| 1373 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb_st)) | |
| 1374 return false; | |
| 1375 | |
| 1376 if (single_ld) | |
| 1377 { | |
| 1378 gimple *store = DR_STMT (single_st), *load = DR_STMT (single_ld); | |
| 1379 /* Direct aggregate copy or via an SSA name temporary. */ | |
| 1380 if (load != store | |
| 1381 && gimple_assign_lhs (load) != gimple_assign_rhs1 (store)) | |
| 1382 return false; | |
| 1383 | |
| 1384 /* Bail out if this is a bitfield memory reference. */ | |
| 1385 if (TREE_CODE (DR_REF (single_ld)) == COMPONENT_REF | |
| 1386 && DECL_BIT_FIELD (TREE_OPERAND (DR_REF (single_ld), 1))) | |
| 1387 return false; | |
| 1388 | |
| 1389 /* Load and store must be in the same loop nest. */ | |
| 1390 basic_block bb_ld = gimple_bb (DR_STMT (single_ld)); | |
| 1391 if (bb_st->loop_father != bb_ld->loop_father) | |
| 1392 return false; | |
| 1393 | |
| 1394 /* Data reference must be executed exactly once per iteration. | |
| 1395 Same as single_st, we only need to check against the outermost | |
| 1396 loop. */ | |
| 1397 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb_ld)) | |
| 1398 return false; | |
| 1399 | |
| 1400 edge e = single_exit (bb_st->loop_father); | |
| 1401 bool dom_ld = dominated_by_p (CDI_DOMINATORS, e->src, bb_ld); | |
| 1402 bool dom_st = dominated_by_p (CDI_DOMINATORS, e->src, bb_st); | |
| 1403 if (dom_ld != dom_st) | |
| 1404 return false; | |
| 1405 } | |
| 1406 | |
| 1407 *src_dr = single_ld; | |
| 1408 *dst_dr = single_st; | |
| 1409 return true; | |
| 0 | 1410 } |
| 1411 | |
| 111 | 1412 /* Given data reference DR in LOOP_NEST, this function checks the enclosing |
| 1413 loops from inner to outer to see if loop's step equals to access size at | |
| 131 | 1414 each level of loop. Return 2 if we can prove this at all level loops; |
| 1415 record access base and size in BASE and SIZE; save loop's step at each | |
| 1416 level of loop in STEPS if it is not null. For example: | |
| 111 | 1417 |
| 1418 int arr[100][100][100]; | |
| 1419 for (i = 0; i < 100; i++) ;steps[2] = 40000 | |
| 1420 for (j = 100; j > 0; j--) ;steps[1] = -400 | |
| 1421 for (k = 0; k < 100; k++) ;steps[0] = 4 | |
| 131 | 1422 arr[i][j - 1][k] = 0; ;base = &arr, size = 4000000 |
| 1423 | |
| 1424 Return 1 if we can prove the equality at the innermost loop, but not all | |
| 1425 level loops. In this case, no information is recorded. | |
| 1426 | |
| 1427 Return 0 if no equality can be proven at any level loops. */ | |
| 1428 | |
| 1429 static int | |
| 111 | 1430 compute_access_range (loop_p loop_nest, data_reference_p dr, tree *base, |
| 1431 tree *size, vec<tree> *steps = NULL) | |
| 0 | 1432 { |
| 111 | 1433 location_t loc = gimple_location (DR_STMT (dr)); |
| 1434 basic_block bb = gimple_bb (DR_STMT (dr)); | |
| 1435 struct loop *loop = bb->loop_father; | |
| 1436 tree ref = DR_REF (dr); | |
| 1437 tree access_base = build_fold_addr_expr (ref); | |
| 1438 tree access_size = TYPE_SIZE_UNIT (TREE_TYPE (ref)); | |
| 131 | 1439 int res = 0; |
| 111 | 1440 |
| 1441 do { | |
| 1442 tree scev_fn = analyze_scalar_evolution (loop, access_base); | |
| 1443 if (TREE_CODE (scev_fn) != POLYNOMIAL_CHREC) | |
| 131 | 1444 return res; |
| 111 | 1445 |
| 1446 access_base = CHREC_LEFT (scev_fn); | |
| 1447 if (tree_contains_chrecs (access_base, NULL)) | |
| 131 | 1448 return res; |
| 111 | 1449 |
| 1450 tree scev_step = CHREC_RIGHT (scev_fn); | |
| 1451 /* Only support constant steps. */ | |
| 1452 if (TREE_CODE (scev_step) != INTEGER_CST) | |
| 131 | 1453 return res; |
| 111 | 1454 |
| 1455 enum ev_direction access_dir = scev_direction (scev_fn); | |
| 1456 if (access_dir == EV_DIR_UNKNOWN) | |
| 131 | 1457 return res; |
| 111 | 1458 |
| 1459 if (steps != NULL) | |
| 1460 steps->safe_push (scev_step); | |
| 1461 | |
| 1462 scev_step = fold_convert_loc (loc, sizetype, scev_step); | |
| 1463 /* Compute absolute value of scev step. */ | |
| 1464 if (access_dir == EV_DIR_DECREASES) | |
| 1465 scev_step = fold_build1_loc (loc, NEGATE_EXPR, sizetype, scev_step); | |
| 1466 | |
| 1467 /* At each level of loop, scev step must equal to access size. In other | |
| 1468 words, DR must access consecutive memory between loop iterations. */ | |
| 1469 if (!operand_equal_p (scev_step, access_size, 0)) | |
| 131 | 1470 return res; |
| 1471 | |
| 1472 /* Access stride can be computed for data reference at least for the | |
| 1473 innermost loop. */ | |
| 1474 res = 1; | |
| 111 | 1475 |
| 1476 /* Compute DR's execution times in loop. */ | |
| 1477 tree niters = number_of_latch_executions (loop); | |
| 1478 niters = fold_convert_loc (loc, sizetype, niters); | |
| 1479 if (dominated_by_p (CDI_DOMINATORS, single_exit (loop)->src, bb)) | |
| 1480 niters = size_binop_loc (loc, PLUS_EXPR, niters, size_one_node); | |
| 1481 | |
| 1482 /* Compute DR's overall access size in loop. */ | |
| 1483 access_size = fold_build2_loc (loc, MULT_EXPR, sizetype, | |
| 1484 niters, scev_step); | |
| 1485 /* Adjust base address in case of negative step. */ | |
| 1486 if (access_dir == EV_DIR_DECREASES) | |
| 1487 { | |
| 1488 tree adj = fold_build2_loc (loc, MINUS_EXPR, sizetype, | |
| 1489 scev_step, access_size); | |
| 1490 access_base = fold_build_pointer_plus_loc (loc, access_base, adj); | |
| 1491 } | |
| 1492 } while (loop != loop_nest && (loop = loop_outer (loop)) != NULL); | |
| 1493 | |
| 1494 *base = access_base; | |
| 1495 *size = access_size; | |
| 131 | 1496 /* Access stride can be computed for data reference at each level loop. */ |
| 1497 return 2; | |
| 0 | 1498 } |
| 1499 | |
| 111 | 1500 /* Allocate and return builtin struct. Record information like DST_DR, |
| 1501 SRC_DR, DST_BASE, SRC_BASE and SIZE in the allocated struct. */ | |
| 1502 | |
| 1503 static struct builtin_info * | |
| 1504 alloc_builtin (data_reference_p dst_dr, data_reference_p src_dr, | |
| 1505 tree dst_base, tree src_base, tree size) | |
| 1506 { | |
| 1507 struct builtin_info *builtin = XNEW (struct builtin_info); | |
| 1508 builtin->dst_dr = dst_dr; | |
| 1509 builtin->src_dr = src_dr; | |
| 1510 builtin->dst_base = dst_base; | |
| 1511 builtin->src_base = src_base; | |
| 1512 builtin->size = size; | |
| 1513 return builtin; | |
| 1514 } | |
| 1515 | |
| 1516 /* Given data reference DR in loop nest LOOP, classify if it forms builtin | |
| 1517 memset call. */ | |
| 0 | 1518 |
| 1519 static void | |
| 111 | 1520 classify_builtin_st (loop_p loop, partition *partition, data_reference_p dr) |
| 0 | 1521 { |
| 111 | 1522 gimple *stmt = DR_STMT (dr); |
| 1523 tree base, size, rhs = gimple_assign_rhs1 (stmt); | |
| 1524 | |
| 1525 if (const_with_all_bytes_same (rhs) == -1 | |
| 1526 && (!INTEGRAL_TYPE_P (TREE_TYPE (rhs)) | |
| 1527 || (TYPE_MODE (TREE_TYPE (rhs)) | |
| 1528 != TYPE_MODE (unsigned_char_type_node)))) | |
| 1529 return; | |
| 1530 | |
| 1531 if (TREE_CODE (rhs) == SSA_NAME | |
| 1532 && !SSA_NAME_IS_DEFAULT_DEF (rhs) | |
| 1533 && flow_bb_inside_loop_p (loop, gimple_bb (SSA_NAME_DEF_STMT (rhs)))) | |
| 1534 return; | |
| 1535 | |
| 131 | 1536 int res = compute_access_range (loop, dr, &base, &size); |
| 1537 if (res == 0) | |
| 1538 return; | |
| 1539 if (res == 1) | |
| 1540 { | |
| 1541 partition->kind = PKIND_PARTIAL_MEMSET; | |
| 1542 return; | |
| 1543 } | |
| 1544 | |
| 1545 poly_uint64 base_offset; | |
| 1546 unsigned HOST_WIDE_INT const_base_offset; | |
| 1547 tree base_base = strip_offset (base, &base_offset); | |
| 1548 if (!base_offset.is_constant (&const_base_offset)) | |
| 111 | 1549 return; |
| 1550 | |
| 1551 struct builtin_info *builtin; | |
| 1552 builtin = alloc_builtin (dr, NULL, base, NULL_TREE, size); | |
| 131 | 1553 builtin->dst_base_base = base_base; |
| 1554 builtin->dst_base_offset = const_base_offset; | |
| 111 | 1555 partition->builtin = builtin; |
| 1556 partition->kind = PKIND_MEMSET; | |
| 0 | 1557 } |
| 1558 | |
| 111 | 1559 /* Given data references DST_DR and SRC_DR in loop nest LOOP and RDG, classify |
| 1560 if it forms builtin memcpy or memmove call. */ | |
| 0 | 1561 |
| 1562 static void | |
| 111 | 1563 classify_builtin_ldst (loop_p loop, struct graph *rdg, partition *partition, |
| 1564 data_reference_p dst_dr, data_reference_p src_dr) | |
| 0 | 1565 { |
| 111 | 1566 tree base, size, src_base, src_size; |
| 1567 auto_vec<tree> dst_steps, src_steps; | |
| 1568 | |
| 131 | 1569 /* Compute access range of both load and store. */ |
| 1570 int res = compute_access_range (loop, dst_dr, &base, &size, &dst_steps); | |
| 1571 if (res != 2) | |
| 1572 return; | |
| 1573 res = compute_access_range (loop, src_dr, &src_base, &src_size, &src_steps); | |
| 1574 if (res != 2) | |
| 1575 return; | |
| 1576 | |
| 1577 /* They much have the same access size. */ | |
| 1578 if (!operand_equal_p (size, src_size, 0)) | |
| 111 | 1579 return; |
| 1580 | |
| 1581 /* Load and store in loop nest must access memory in the same way, i.e, | |
| 1582 their must have the same steps in each loop of the nest. */ | |
| 1583 if (dst_steps.length () != src_steps.length ()) | |
| 1584 return; | |
| 1585 for (unsigned i = 0; i < dst_steps.length (); ++i) | |
| 1586 if (!operand_equal_p (dst_steps[i], src_steps[i], 0)) | |
| 1587 return; | |
| 1588 | |
| 1589 /* Now check that if there is a dependence. */ | |
| 1590 ddr_p ddr = get_data_dependence (rdg, src_dr, dst_dr); | |
| 1591 | |
| 1592 /* Classify as memcpy if no dependence between load and store. */ | |
| 1593 if (DDR_ARE_DEPENDENT (ddr) == chrec_known) | |
| 1594 { | |
| 1595 partition->builtin = alloc_builtin (dst_dr, src_dr, base, src_base, size); | |
| 1596 partition->kind = PKIND_MEMCPY; | |
| 1597 return; | |
| 1598 } | |
| 1599 | |
| 1600 /* Can't do memmove in case of unknown dependence or dependence without | |
| 1601 classical distance vector. */ | |
| 1602 if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know | |
| 1603 || DDR_NUM_DIST_VECTS (ddr) == 0) | |
| 1604 return; | |
| 1605 | |
| 1606 unsigned i; | |
| 1607 lambda_vector dist_v; | |
| 1608 int num_lev = (DDR_LOOP_NEST (ddr)).length (); | |
| 1609 FOR_EACH_VEC_ELT (DDR_DIST_VECTS (ddr), i, dist_v) | |
| 0 | 1610 { |
| 111 | 1611 unsigned dep_lev = dependence_level (dist_v, num_lev); |
| 1612 /* Can't do memmove if load depends on store. */ | |
| 1613 if (dep_lev > 0 && dist_v[dep_lev - 1] > 0 && !DDR_REVERSED_P (ddr)) | |
| 1614 return; | |
| 1615 } | |
| 1616 | |
| 1617 partition->builtin = alloc_builtin (dst_dr, src_dr, base, src_base, size); | |
| 1618 partition->kind = PKIND_MEMMOVE; | |
| 1619 return; | |
| 1620 } | |
| 1621 | |
| 1622 /* Classifies the builtin kind we can generate for PARTITION of RDG and LOOP. | |
| 1623 For the moment we detect memset, memcpy and memmove patterns. Bitmap | |
| 1624 STMT_IN_ALL_PARTITIONS contains statements belonging to all partitions. */ | |
| 1625 | |
| 1626 static void | |
| 1627 classify_partition (loop_p loop, struct graph *rdg, partition *partition, | |
| 1628 bitmap stmt_in_all_partitions) | |
| 1629 { | |
| 1630 bitmap_iterator bi; | |
| 1631 unsigned i; | |
| 1632 data_reference_p single_ld = NULL, single_st = NULL; | |
| 1633 bool volatiles_p = false, has_reduction = false; | |
| 1634 | |
| 1635 EXECUTE_IF_SET_IN_BITMAP (partition->stmts, 0, i, bi) | |
| 1636 { | |
| 1637 gimple *stmt = RDG_STMT (rdg, i); | |
| 1638 | |
| 1639 if (gimple_has_volatile_ops (stmt)) | |
| 1640 volatiles_p = true; | |
| 1641 | |
| 1642 /* If the stmt is not included by all partitions and there is uses | |
| 1643 outside of the loop, then mark the partition as reduction. */ | |
| 1644 if (stmt_has_scalar_dependences_outside_loop (loop, stmt)) | |
| 0 | 1645 { |
| 111 | 1646 /* Due to limitation in the transform phase we have to fuse all |
| 1647 reduction partitions. As a result, this could cancel valid | |
| 1648 loop distribution especially for loop that induction variable | |
| 1649 is used outside of loop. To workaround this issue, we skip | |
| 1650 marking partition as reudction if the reduction stmt belongs | |
| 1651 to all partitions. In such case, reduction will be computed | |
| 1652 correctly no matter how partitions are fused/distributed. */ | |
| 1653 if (!bitmap_bit_p (stmt_in_all_partitions, i)) | |
| 1654 { | |
| 1655 partition->reduction_p = true; | |
| 1656 return; | |
| 1657 } | |
| 1658 has_reduction = true; | |
| 0 | 1659 } |
| 1660 } | |
| 1661 | |
| 111 | 1662 /* Perform general partition disqualification for builtins. */ |
| 1663 if (volatiles_p | |
| 1664 /* Simple workaround to prevent classifying the partition as builtin | |
| 1665 if it contains any use outside of loop. */ | |
| 1666 || has_reduction | |
| 1667 || !flag_tree_loop_distribute_patterns) | |
| 1668 return; | |
| 1669 | |
| 1670 /* Find single load/store data references for builtin partition. */ | |
| 1671 if (!find_single_drs (loop, rdg, partition, &single_st, &single_ld)) | |
| 1672 return; | |
| 1673 | |
| 1674 /* Classify the builtin kind. */ | |
| 1675 if (single_ld == NULL) | |
| 1676 classify_builtin_st (loop, partition, single_st); | |
| 1677 else | |
| 1678 classify_builtin_ldst (loop, rdg, partition, single_st, single_ld); | |
| 0 | 1679 } |
| 1680 | |
| 111 | 1681 /* Returns true when PARTITION1 and PARTITION2 access the same memory |
| 1682 object in RDG. */ | |
|
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1683 |
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1684 static bool |
| 111 | 1685 share_memory_accesses (struct graph *rdg, |
| 1686 partition *partition1, partition *partition2) | |
|
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1687 { |
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1688 unsigned i, j; |
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1689 bitmap_iterator bi, bj; |
| 111 | 1690 data_reference_p dr1, dr2; |
| 1691 | |
| 1692 /* First check whether in the intersection of the two partitions are | |
| 1693 any loads or stores. Common loads are the situation that happens | |
| 1694 most often. */ | |
| 1695 EXECUTE_IF_AND_IN_BITMAP (partition1->stmts, partition2->stmts, 0, i, bi) | |
|
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1696 if (RDG_MEM_WRITE_STMT (rdg, i) |
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1697 || RDG_MEM_READS_STMT (rdg, i)) |
| 111 | 1698 return true; |
| 1699 | |
| 1700 /* Then check whether the two partitions access the same memory object. */ | |
| 1701 EXECUTE_IF_SET_IN_BITMAP (partition1->datarefs, 0, i, bi) | |
| 1702 { | |
| 1703 dr1 = datarefs_vec[i]; | |
| 1704 | |
| 1705 if (!DR_BASE_ADDRESS (dr1) | |
| 1706 || !DR_OFFSET (dr1) || !DR_INIT (dr1) || !DR_STEP (dr1)) | |
| 1707 continue; | |
| 1708 | |
| 1709 EXECUTE_IF_SET_IN_BITMAP (partition2->datarefs, 0, j, bj) | |
| 1710 { | |
| 1711 dr2 = datarefs_vec[j]; | |
| 1712 | |
| 1713 if (!DR_BASE_ADDRESS (dr2) | |
| 1714 || !DR_OFFSET (dr2) || !DR_INIT (dr2) || !DR_STEP (dr2)) | |
| 1715 continue; | |
| 1716 | |
| 1717 if (operand_equal_p (DR_BASE_ADDRESS (dr1), DR_BASE_ADDRESS (dr2), 0) | |
| 1718 && operand_equal_p (DR_OFFSET (dr1), DR_OFFSET (dr2), 0) | |
| 1719 && operand_equal_p (DR_INIT (dr1), DR_INIT (dr2), 0) | |
| 1720 && operand_equal_p (DR_STEP (dr1), DR_STEP (dr2), 0)) | |
|
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1721 return true; |
| 111 | 1722 } |
|
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1723 } |
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1724 |
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1725 return false; |
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1726 } |
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1727 |
| 111 | 1728 /* For each seed statement in STARTING_STMTS, this function builds |
| 1729 partition for it by adding depended statements according to RDG. | |
| 1730 All partitions are recorded in PARTITIONS. */ | |
|
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1731 |
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1732 static void |
| 111 | 1733 rdg_build_partitions (struct graph *rdg, |
| 1734 vec<gimple *> starting_stmts, | |
| 1735 vec<partition *> *partitions) | |
|
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1736 { |
| 111 | 1737 auto_bitmap processed; |
| 0 | 1738 int i; |
| 111 | 1739 gimple *stmt; |
| 1740 | |
| 1741 FOR_EACH_VEC_ELT (starting_stmts, i, stmt) | |
| 0 | 1742 { |
| 111 | 1743 int v = rdg_vertex_for_stmt (rdg, stmt); |
| 1744 | |
| 1745 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 1746 fprintf (dump_file, | |
| 1747 "ldist asked to generate code for vertex %d\n", v); | |
| 1748 | |
| 1749 /* If the vertex is already contained in another partition so | |
| 1750 is the partition rooted at it. */ | |
| 0 | 1751 if (bitmap_bit_p (processed, v)) |
| 1752 continue; | |
|
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1753 |
| 111 | 1754 partition *partition = build_rdg_partition_for_vertex (rdg, v); |
| 1755 bitmap_ior_into (processed, partition->stmts); | |
| 1756 | |
| 1757 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 0 | 1758 { |
| 111 | 1759 fprintf (dump_file, "ldist creates useful %s partition:\n", |
| 1760 partition->type == PTYPE_PARALLEL ? "parallel" : "sequent"); | |
| 1761 bitmap_print (dump_file, partition->stmts, " ", "\n"); | |
| 0 | 1762 } |
| 111 | 1763 |
| 1764 partitions->safe_push (partition); | |
| 0 | 1765 } |
| 1766 | |
| 111 | 1767 /* All vertices should have been assigned to at least one partition now, |
| 1768 other than vertices belonging to dead code. */ | |
| 0 | 1769 } |
| 1770 | |
| 1771 /* Dump to FILE the PARTITIONS. */ | |
| 1772 | |
| 1773 static void | |
| 111 | 1774 dump_rdg_partitions (FILE *file, vec<partition *> partitions) |
| 0 | 1775 { |
| 1776 int i; | |
| 111 | 1777 partition *partition; |
| 1778 | |
| 1779 FOR_EACH_VEC_ELT (partitions, i, partition) | |
| 1780 debug_bitmap_file (file, partition->stmts); | |
| 0 | 1781 } |
| 1782 | |
| 1783 /* Debug PARTITIONS. */ | |
| 111 | 1784 extern void debug_rdg_partitions (vec<partition *> ); |
| 0 | 1785 |
|
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1786 DEBUG_FUNCTION void |
| 111 | 1787 debug_rdg_partitions (vec<partition *> partitions) |
| 0 | 1788 { |
| 1789 dump_rdg_partitions (stderr, partitions); | |
| 1790 } | |
| 1791 | |
| 1792 /* Returns the number of read and write operations in the RDG. */ | |
| 1793 | |
| 1794 static int | |
| 1795 number_of_rw_in_rdg (struct graph *rdg) | |
| 1796 { | |
| 1797 int i, res = 0; | |
| 1798 | |
| 1799 for (i = 0; i < rdg->n_vertices; i++) | |
| 1800 { | |
| 1801 if (RDG_MEM_WRITE_STMT (rdg, i)) | |
| 1802 ++res; | |
| 1803 | |
| 1804 if (RDG_MEM_READS_STMT (rdg, i)) | |
| 1805 ++res; | |
| 1806 } | |
| 1807 | |
| 1808 return res; | |
| 1809 } | |
| 1810 | |
| 1811 /* Returns the number of read and write operations in a PARTITION of | |
| 1812 the RDG. */ | |
| 1813 | |
| 1814 static int | |
| 111 | 1815 number_of_rw_in_partition (struct graph *rdg, partition *partition) |
| 0 | 1816 { |
| 1817 int res = 0; | |
| 1818 unsigned i; | |
| 1819 bitmap_iterator ii; | |
| 1820 | |
| 111 | 1821 EXECUTE_IF_SET_IN_BITMAP (partition->stmts, 0, i, ii) |
| 0 | 1822 { |
| 1823 if (RDG_MEM_WRITE_STMT (rdg, i)) | |
| 1824 ++res; | |
| 1825 | |
| 1826 if (RDG_MEM_READS_STMT (rdg, i)) | |
| 1827 ++res; | |
| 1828 } | |
| 1829 | |
| 1830 return res; | |
| 1831 } | |
| 1832 | |
| 1833 /* Returns true when one of the PARTITIONS contains all the read or | |
| 1834 write operations of RDG. */ | |
| 1835 | |
| 1836 static bool | |
| 111 | 1837 partition_contains_all_rw (struct graph *rdg, |
| 1838 vec<partition *> partitions) | |
| 0 | 1839 { |
| 1840 int i; | |
| 111 | 1841 partition *partition; |
| 0 | 1842 int nrw = number_of_rw_in_rdg (rdg); |
| 1843 | |
| 111 | 1844 FOR_EACH_VEC_ELT (partitions, i, partition) |
| 0 | 1845 if (nrw == number_of_rw_in_partition (rdg, partition)) |
| 1846 return true; | |
| 1847 | |
| 1848 return false; | |
| 1849 } | |
| 1850 | |
| 111 | 1851 /* Compute partition dependence created by the data references in DRS1 |
| 1852 and DRS2, modify and return DIR according to that. IF ALIAS_DDR is | |
| 1853 not NULL, we record dependence introduced by possible alias between | |
| 1854 two data references in ALIAS_DDRS; otherwise, we simply ignore such | |
| 1855 dependence as if it doesn't exist at all. */ | |
| 1856 | |
| 1857 static int | |
| 1858 pg_add_dependence_edges (struct graph *rdg, int dir, | |
| 1859 bitmap drs1, bitmap drs2, vec<ddr_p> *alias_ddrs) | |
| 1860 { | |
| 1861 unsigned i, j; | |
| 1862 bitmap_iterator bi, bj; | |
| 1863 data_reference_p dr1, dr2, saved_dr1; | |
| 1864 | |
| 1865 /* dependence direction - 0 is no dependence, -1 is back, | |
| 1866 1 is forth, 2 is both (we can stop then, merging will occur). */ | |
| 1867 EXECUTE_IF_SET_IN_BITMAP (drs1, 0, i, bi) | |
| 1868 { | |
| 1869 dr1 = datarefs_vec[i]; | |
| 1870 | |
| 1871 EXECUTE_IF_SET_IN_BITMAP (drs2, 0, j, bj) | |
| 1872 { | |
| 1873 int res, this_dir = 1; | |
| 1874 ddr_p ddr; | |
| 1875 | |
| 1876 dr2 = datarefs_vec[j]; | |
| 1877 | |
| 1878 /* Skip all <read, read> data dependence. */ | |
| 1879 if (DR_IS_READ (dr1) && DR_IS_READ (dr2)) | |
| 1880 continue; | |
| 1881 | |
| 1882 saved_dr1 = dr1; | |
| 1883 /* Re-shuffle data-refs to be in topological order. */ | |
| 1884 if (rdg_vertex_for_stmt (rdg, DR_STMT (dr1)) | |
| 1885 > rdg_vertex_for_stmt (rdg, DR_STMT (dr2))) | |
| 1886 { | |
| 1887 std::swap (dr1, dr2); | |
| 1888 this_dir = -this_dir; | |
| 1889 } | |
| 1890 ddr = get_data_dependence (rdg, dr1, dr2); | |
| 1891 if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) | |
| 1892 { | |
| 1893 this_dir = 0; | |
| 1894 res = data_ref_compare_tree (DR_BASE_ADDRESS (dr1), | |
| 1895 DR_BASE_ADDRESS (dr2)); | |
| 1896 /* Be conservative. If data references are not well analyzed, | |
| 1897 or the two data references have the same base address and | |
| 1898 offset, add dependence and consider it alias to each other. | |
| 1899 In other words, the dependence can not be resolved by | |
| 1900 runtime alias check. */ | |
| 1901 if (!DR_BASE_ADDRESS (dr1) || !DR_BASE_ADDRESS (dr2) | |
| 1902 || !DR_OFFSET (dr1) || !DR_OFFSET (dr2) | |
| 1903 || !DR_INIT (dr1) || !DR_INIT (dr2) | |
| 1904 || !DR_STEP (dr1) || !tree_fits_uhwi_p (DR_STEP (dr1)) | |
| 1905 || !DR_STEP (dr2) || !tree_fits_uhwi_p (DR_STEP (dr2)) | |
| 1906 || res == 0) | |
| 1907 this_dir = 2; | |
| 1908 /* Data dependence could be resolved by runtime alias check, | |
| 1909 record it in ALIAS_DDRS. */ | |
| 1910 else if (alias_ddrs != NULL) | |
| 1911 alias_ddrs->safe_push (ddr); | |
| 1912 /* Or simply ignore it. */ | |
| 1913 } | |
| 1914 else if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE) | |
| 1915 { | |
| 1916 if (DDR_REVERSED_P (ddr)) | |
| 1917 this_dir = -this_dir; | |
| 1918 | |
| 1919 /* Known dependences can still be unordered througout the | |
| 1920 iteration space, see gcc.dg/tree-ssa/ldist-16.c. */ | |
| 1921 if (DDR_NUM_DIST_VECTS (ddr) != 1) | |
| 1922 this_dir = 2; | |
| 1923 /* If the overlap is exact preserve stmt order. */ | |
| 131 | 1924 else if (lambda_vector_zerop (DDR_DIST_VECT (ddr, 0), |
| 1925 DDR_NB_LOOPS (ddr))) | |
| 111 | 1926 ; |
| 1927 /* Else as the distance vector is lexicographic positive swap | |
| 1928 the dependence direction. */ | |
| 1929 else | |
| 1930 this_dir = -this_dir; | |
| 1931 } | |
| 1932 else | |
| 1933 this_dir = 0; | |
| 1934 if (this_dir == 2) | |
| 1935 return 2; | |
| 1936 else if (dir == 0) | |
| 1937 dir = this_dir; | |
| 1938 else if (this_dir != 0 && dir != this_dir) | |
| 1939 return 2; | |
| 1940 /* Shuffle "back" dr1. */ | |
| 1941 dr1 = saved_dr1; | |
| 1942 } | |
| 1943 } | |
| 1944 return dir; | |
| 1945 } | |
| 1946 | |
| 1947 /* Compare postorder number of the partition graph vertices V1 and V2. */ | |
| 0 | 1948 |
| 1949 static int | |
| 111 | 1950 pgcmp (const void *v1_, const void *v2_) |
| 1951 { | |
| 1952 const vertex *v1 = (const vertex *)v1_; | |
| 1953 const vertex *v2 = (const vertex *)v2_; | |
| 1954 return v2->post - v1->post; | |
| 1955 } | |
| 1956 | |
| 1957 /* Data attached to vertices of partition dependence graph. */ | |
| 1958 struct pg_vdata | |
| 1959 { | |
| 1960 /* ID of the corresponding partition. */ | |
| 1961 int id; | |
| 1962 /* The partition. */ | |
| 1963 struct partition *partition; | |
| 1964 }; | |
| 1965 | |
| 1966 /* Data attached to edges of partition dependence graph. */ | |
| 1967 struct pg_edata | |
| 1968 { | |
| 1969 /* If the dependence edge can be resolved by runtime alias check, | |
| 1970 this vector contains data dependence relations for runtime alias | |
| 1971 check. On the other hand, if the dependence edge is introduced | |
| 1972 because of compilation time known data dependence, this vector | |
| 1973 contains nothing. */ | |
| 1974 vec<ddr_p> alias_ddrs; | |
| 1975 }; | |
| 1976 | |
| 1977 /* Callback data for traversing edges in graph. */ | |
| 1978 struct pg_edge_callback_data | |
| 0 | 1979 { |
| 111 | 1980 /* Bitmap contains strong connected components should be merged. */ |
| 1981 bitmap sccs_to_merge; | |
| 1982 /* Array constains component information for all vertices. */ | |
| 1983 int *vertices_component; | |
| 1984 /* Vector to record all data dependence relations which are needed | |
| 1985 to break strong connected components by runtime alias checks. */ | |
| 1986 vec<ddr_p> *alias_ddrs; | |
| 1987 }; | |
| 1988 | |
| 1989 /* Initialize vertice's data for partition dependence graph PG with | |
| 1990 PARTITIONS. */ | |
| 1991 | |
| 1992 static void | |
| 1993 init_partition_graph_vertices (struct graph *pg, | |
| 1994 vec<struct partition *> *partitions) | |
| 1995 { | |
| 1996 int i; | |
| 1997 partition *partition; | |
| 1998 struct pg_vdata *data; | |
| 1999 | |
| 2000 for (i = 0; partitions->iterate (i, &partition); ++i) | |
| 2001 { | |
| 2002 data = new pg_vdata; | |
| 2003 pg->vertices[i].data = data; | |
| 2004 data->id = i; | |
| 2005 data->partition = partition; | |
| 2006 } | |
| 2007 } | |
| 2008 | |
| 2009 /* Add edge <I, J> to partition dependence graph PG. Attach vector of data | |
| 2010 dependence relations to the EDGE if DDRS isn't NULL. */ | |
| 2011 | |
| 2012 static void | |
| 2013 add_partition_graph_edge (struct graph *pg, int i, int j, vec<ddr_p> *ddrs) | |
| 2014 { | |
| 2015 struct graph_edge *e = add_edge (pg, i, j); | |
| 2016 | |
| 2017 /* If the edge is attached with data dependence relations, it means this | |
| 2018 dependence edge can be resolved by runtime alias checks. */ | |
| 2019 if (ddrs != NULL) | |
| 0 | 2020 { |
| 111 | 2021 struct pg_edata *data = new pg_edata; |
| 2022 | |
| 2023 gcc_assert (ddrs->length () > 0); | |
| 2024 e->data = data; | |
| 2025 data->alias_ddrs = vNULL; | |
| 2026 data->alias_ddrs.safe_splice (*ddrs); | |
| 2027 } | |
| 2028 } | |
| 2029 | |
| 2030 /* Callback function for graph travesal algorithm. It returns true | |
| 2031 if edge E should skipped when traversing the graph. */ | |
| 2032 | |
| 2033 static bool | |
| 2034 pg_skip_alias_edge (struct graph_edge *e) | |
| 2035 { | |
| 2036 struct pg_edata *data = (struct pg_edata *)e->data; | |
| 2037 return (data != NULL && data->alias_ddrs.length () > 0); | |
| 2038 } | |
| 2039 | |
| 2040 /* Callback function freeing data attached to edge E of graph. */ | |
| 2041 | |
| 2042 static void | |
| 2043 free_partition_graph_edata_cb (struct graph *, struct graph_edge *e, void *) | |
| 2044 { | |
| 2045 if (e->data != NULL) | |
| 2046 { | |
| 2047 struct pg_edata *data = (struct pg_edata *)e->data; | |
| 2048 data->alias_ddrs.release (); | |
| 2049 delete data; | |
| 2050 } | |
| 2051 } | |
| 2052 | |
| 2053 /* Free data attached to vertice of partition dependence graph PG. */ | |
| 2054 | |
| 2055 static void | |
| 2056 free_partition_graph_vdata (struct graph *pg) | |
| 2057 { | |
| 2058 int i; | |
| 2059 struct pg_vdata *data; | |
| 2060 | |
| 2061 for (i = 0; i < pg->n_vertices; ++i) | |
| 2062 { | |
| 2063 data = (struct pg_vdata *)pg->vertices[i].data; | |
| 2064 delete data; | |
| 2065 } | |
| 2066 } | |
| 2067 | |
| 2068 /* Build and return partition dependence graph for PARTITIONS. RDG is | |
| 2069 reduced dependence graph for the loop to be distributed. If IGNORE_ALIAS_P | |
| 2070 is true, data dependence caused by possible alias between references | |
| 2071 is ignored, as if it doesn't exist at all; otherwise all depdendences | |
| 2072 are considered. */ | |
| 2073 | |
| 2074 static struct graph * | |
| 2075 build_partition_graph (struct graph *rdg, | |
| 2076 vec<struct partition *> *partitions, | |
| 2077 bool ignore_alias_p) | |
| 2078 { | |
| 2079 int i, j; | |
| 2080 struct partition *partition1, *partition2; | |
| 2081 graph *pg = new_graph (partitions->length ()); | |
| 2082 auto_vec<ddr_p> alias_ddrs, *alias_ddrs_p; | |
| 2083 | |
| 2084 alias_ddrs_p = ignore_alias_p ? NULL : &alias_ddrs; | |
| 2085 | |
| 2086 init_partition_graph_vertices (pg, partitions); | |
| 2087 | |
| 2088 for (i = 0; partitions->iterate (i, &partition1); ++i) | |
| 2089 { | |
| 2090 for (j = i + 1; partitions->iterate (j, &partition2); ++j) | |
| 0 | 2091 { |
| 111 | 2092 /* dependence direction - 0 is no dependence, -1 is back, |
| 2093 1 is forth, 2 is both (we can stop then, merging will occur). */ | |
| 2094 int dir = 0; | |
| 2095 | |
| 2096 /* If the first partition has reduction, add back edge; if the | |
| 2097 second partition has reduction, add forth edge. This makes | |
| 2098 sure that reduction partition will be sorted as the last one. */ | |
| 2099 if (partition_reduction_p (partition1)) | |
| 2100 dir = -1; | |
| 2101 else if (partition_reduction_p (partition2)) | |
| 2102 dir = 1; | |
| 2103 | |
| 2104 /* Cleanup the temporary vector. */ | |
| 2105 alias_ddrs.truncate (0); | |
| 2106 | |
| 2107 dir = pg_add_dependence_edges (rdg, dir, partition1->datarefs, | |
| 2108 partition2->datarefs, alias_ddrs_p); | |
| 2109 | |
| 2110 /* Add edge to partition graph if there exists dependence. There | |
| 2111 are two types of edges. One type edge is caused by compilation | |
| 2112 time known dependence, this type can not be resolved by runtime | |
| 2113 alias check. The other type can be resolved by runtime alias | |
| 2114 check. */ | |
| 2115 if (dir == 1 || dir == 2 | |
| 2116 || alias_ddrs.length () > 0) | |
| 2117 { | |
| 2118 /* Attach data dependence relations to edge that can be resolved | |
| 2119 by runtime alias check. */ | |
| 2120 bool alias_edge_p = (dir != 1 && dir != 2); | |
| 2121 add_partition_graph_edge (pg, i, j, | |
| 2122 (alias_edge_p) ? &alias_ddrs : NULL); | |
| 2123 } | |
| 2124 if (dir == -1 || dir == 2 | |
| 2125 || alias_ddrs.length () > 0) | |
| 2126 { | |
| 2127 /* Attach data dependence relations to edge that can be resolved | |
| 2128 by runtime alias check. */ | |
| 2129 bool alias_edge_p = (dir != -1 && dir != 2); | |
| 2130 add_partition_graph_edge (pg, j, i, | |
| 2131 (alias_edge_p) ? &alias_ddrs : NULL); | |
| 2132 } | |
| 0 | 2133 } |
| 2134 } | |
| 111 | 2135 return pg; |
| 2136 } | |
| 2137 | |
| 2138 /* Sort partitions in PG in descending post order and store them in | |
| 2139 PARTITIONS. */ | |
| 2140 | |
| 2141 static void | |
| 2142 sort_partitions_by_post_order (struct graph *pg, | |
| 2143 vec<struct partition *> *partitions) | |
| 2144 { | |
| 2145 int i; | |
| 2146 struct pg_vdata *data; | |
| 2147 | |
| 2148 /* Now order the remaining nodes in descending postorder. */ | |
| 2149 qsort (pg->vertices, pg->n_vertices, sizeof (vertex), pgcmp); | |
| 2150 partitions->truncate (0); | |
| 2151 for (i = 0; i < pg->n_vertices; ++i) | |
| 2152 { | |
| 2153 data = (struct pg_vdata *)pg->vertices[i].data; | |
| 2154 if (data->partition) | |
| 2155 partitions->safe_push (data->partition); | |
| 2156 } | |
| 2157 } | |
| 2158 | |
| 2159 /* Given reduced dependence graph RDG merge strong connected components | |
| 2160 of PARTITIONS. If IGNORE_ALIAS_P is true, data dependence caused by | |
| 2161 possible alias between references is ignored, as if it doesn't exist | |
| 2162 at all; otherwise all depdendences are considered. */ | |
| 2163 | |
| 2164 static void | |
| 2165 merge_dep_scc_partitions (struct graph *rdg, | |
| 2166 vec<struct partition *> *partitions, | |
| 2167 bool ignore_alias_p) | |
| 2168 { | |
| 2169 struct partition *partition1, *partition2; | |
| 2170 struct pg_vdata *data; | |
| 2171 graph *pg = build_partition_graph (rdg, partitions, ignore_alias_p); | |
| 2172 int i, j, num_sccs = graphds_scc (pg, NULL); | |
| 2173 | |
| 2174 /* Strong connected compoenent means dependence cycle, we cannot distribute | |
| 2175 them. So fuse them together. */ | |
| 2176 if ((unsigned) num_sccs < partitions->length ()) | |
| 2177 { | |
| 2178 for (i = 0; i < num_sccs; ++i) | |
| 2179 { | |
| 2180 for (j = 0; partitions->iterate (j, &partition1); ++j) | |
| 2181 if (pg->vertices[j].component == i) | |
| 2182 break; | |
| 2183 for (j = j + 1; partitions->iterate (j, &partition2); ++j) | |
| 2184 if (pg->vertices[j].component == i) | |
| 2185 { | |
| 2186 partition_merge_into (NULL, partition1, | |
| 2187 partition2, FUSE_SAME_SCC); | |
| 2188 partition1->type = PTYPE_SEQUENTIAL; | |
| 2189 (*partitions)[j] = NULL; | |
| 2190 partition_free (partition2); | |
| 2191 data = (struct pg_vdata *)pg->vertices[j].data; | |
| 2192 data->partition = NULL; | |
| 2193 } | |
| 2194 } | |
| 2195 } | |
| 2196 | |
| 2197 sort_partitions_by_post_order (pg, partitions); | |
| 2198 gcc_assert (partitions->length () == (unsigned)num_sccs); | |
| 2199 free_partition_graph_vdata (pg); | |
| 2200 free_graph (pg); | |
| 2201 } | |
| 2202 | |
| 2203 /* Callback function for traversing edge E in graph G. DATA is private | |
| 2204 callback data. */ | |
| 2205 | |
| 2206 static void | |
| 2207 pg_collect_alias_ddrs (struct graph *g, struct graph_edge *e, void *data) | |
| 2208 { | |
| 2209 int i, j, component; | |
| 2210 struct pg_edge_callback_data *cbdata; | |
| 2211 struct pg_edata *edata = (struct pg_edata *) e->data; | |
| 2212 | |
| 2213 /* If the edge doesn't have attached data dependence, it represents | |
| 2214 compilation time known dependences. This type dependence cannot | |
| 2215 be resolved by runtime alias check. */ | |
| 2216 if (edata == NULL || edata->alias_ddrs.length () == 0) | |
| 2217 return; | |
| 2218 | |
| 2219 cbdata = (struct pg_edge_callback_data *) data; | |
| 2220 i = e->src; | |
| 2221 j = e->dest; | |
| 2222 component = cbdata->vertices_component[i]; | |
| 2223 /* Vertices are topologically sorted according to compilation time | |
| 2224 known dependences, so we can break strong connected components | |
| 2225 by removing edges of the opposite direction, i.e, edges pointing | |
| 2226 from vertice with smaller post number to vertice with bigger post | |
| 2227 number. */ | |
| 2228 if (g->vertices[i].post < g->vertices[j].post | |
| 2229 /* We only need to remove edges connecting vertices in the same | |
| 2230 strong connected component to break it. */ | |
| 2231 && component == cbdata->vertices_component[j] | |
| 2232 /* Check if we want to break the strong connected component or not. */ | |
| 2233 && !bitmap_bit_p (cbdata->sccs_to_merge, component)) | |
| 2234 cbdata->alias_ddrs->safe_splice (edata->alias_ddrs); | |
| 2235 } | |
| 2236 | |
| 2237 /* This is the main function breaking strong conected components in | |
| 2238 PARTITIONS giving reduced depdendence graph RDG. Store data dependence | |
| 2239 relations for runtime alias check in ALIAS_DDRS. */ | |
| 2240 | |
| 2241 static void | |
| 2242 break_alias_scc_partitions (struct graph *rdg, | |
| 2243 vec<struct partition *> *partitions, | |
| 2244 vec<ddr_p> *alias_ddrs) | |
| 2245 { | |
| 2246 int i, j, k, num_sccs, num_sccs_no_alias; | |
| 2247 /* Build partition dependence graph. */ | |
| 2248 graph *pg = build_partition_graph (rdg, partitions, false); | |
| 2249 | |
| 2250 alias_ddrs->truncate (0); | |
| 2251 /* Find strong connected components in the graph, with all dependence edges | |
| 2252 considered. */ | |
| 2253 num_sccs = graphds_scc (pg, NULL); | |
| 2254 /* All SCCs now can be broken by runtime alias checks because SCCs caused by | |
| 2255 compilation time known dependences are merged before this function. */ | |
| 2256 if ((unsigned) num_sccs < partitions->length ()) | |
| 2257 { | |
| 2258 struct pg_edge_callback_data cbdata; | |
| 2259 auto_bitmap sccs_to_merge; | |
| 2260 auto_vec<enum partition_type> scc_types; | |
| 2261 struct partition *partition, *first; | |
| 2262 | |
| 2263 /* If all partitions in a SCC have the same type, we can simply merge the | |
| 2264 SCC. This loop finds out such SCCS and record them in bitmap. */ | |
| 2265 bitmap_set_range (sccs_to_merge, 0, (unsigned) num_sccs); | |
| 2266 for (i = 0; i < num_sccs; ++i) | |
| 2267 { | |
| 2268 for (j = 0; partitions->iterate (j, &first); ++j) | |
| 2269 if (pg->vertices[j].component == i) | |
| 2270 break; | |
| 131 | 2271 |
| 2272 bool same_type = true, all_builtins = partition_builtin_p (first); | |
| 111 | 2273 for (++j; partitions->iterate (j, &partition); ++j) |
| 2274 { | |
| 2275 if (pg->vertices[j].component != i) | |
| 2276 continue; | |
| 2277 | |
| 2278 if (first->type != partition->type) | |
| 2279 { | |
| 131 | 2280 same_type = false; |
| 111 | 2281 break; |
| 2282 } | |
| 131 | 2283 all_builtins &= partition_builtin_p (partition); |
| 111 | 2284 } |
| 131 | 2285 /* Merge SCC if all partitions in SCC have the same type, though the |
| 2286 result partition is sequential, because vectorizer can do better | |
| 2287 runtime alias check. One expecption is all partitions in SCC are | |
| 2288 builtins. */ | |
| 2289 if (!same_type || all_builtins) | |
| 2290 bitmap_clear_bit (sccs_to_merge, i); | |
| 111 | 2291 } |
| 2292 | |
| 2293 /* Initialize callback data for traversing. */ | |
| 2294 cbdata.sccs_to_merge = sccs_to_merge; | |
| 2295 cbdata.alias_ddrs = alias_ddrs; | |
| 2296 cbdata.vertices_component = XNEWVEC (int, pg->n_vertices); | |
| 2297 /* Record the component information which will be corrupted by next | |
| 2298 graph scc finding call. */ | |
| 2299 for (i = 0; i < pg->n_vertices; ++i) | |
| 2300 cbdata.vertices_component[i] = pg->vertices[i].component; | |
| 2301 | |
| 2302 /* Collect data dependences for runtime alias checks to break SCCs. */ | |
| 2303 if (bitmap_count_bits (sccs_to_merge) != (unsigned) num_sccs) | |
| 2304 { | |
| 2305 /* Run SCC finding algorithm again, with alias dependence edges | |
| 2306 skipped. This is to topologically sort partitions according to | |
| 2307 compilation time known dependence. Note the topological order | |
| 2308 is stored in the form of pg's post order number. */ | |
| 2309 num_sccs_no_alias = graphds_scc (pg, NULL, pg_skip_alias_edge); | |
| 2310 gcc_assert (partitions->length () == (unsigned) num_sccs_no_alias); | |
| 2311 /* With topological order, we can construct two subgraphs L and R. | |
| 2312 L contains edge <x, y> where x < y in terms of post order, while | |
| 2313 R contains edge <x, y> where x > y. Edges for compilation time | |
| 2314 known dependence all fall in R, so we break SCCs by removing all | |
| 2315 (alias) edges of in subgraph L. */ | |
| 2316 for_each_edge (pg, pg_collect_alias_ddrs, &cbdata); | |
| 2317 } | |
| 2318 | |
| 2319 /* For SCC that doesn't need to be broken, merge it. */ | |
| 2320 for (i = 0; i < num_sccs; ++i) | |
| 2321 { | |
| 2322 if (!bitmap_bit_p (sccs_to_merge, i)) | |
| 2323 continue; | |
| 2324 | |
| 2325 for (j = 0; partitions->iterate (j, &first); ++j) | |
| 2326 if (cbdata.vertices_component[j] == i) | |
| 2327 break; | |
| 2328 for (k = j + 1; partitions->iterate (k, &partition); ++k) | |
| 2329 { | |
| 2330 struct pg_vdata *data; | |
| 2331 | |
| 2332 if (cbdata.vertices_component[k] != i) | |
| 2333 continue; | |
| 2334 | |
| 2335 /* Update postorder number so that merged reduction partition is | |
| 2336 sorted after other partitions. */ | |
| 2337 if (!partition_reduction_p (first) | |
| 2338 && partition_reduction_p (partition)) | |
| 2339 { | |
| 2340 gcc_assert (pg->vertices[k].post < pg->vertices[j].post); | |
| 2341 pg->vertices[j].post = pg->vertices[k].post; | |
| 2342 } | |
| 2343 partition_merge_into (NULL, first, partition, FUSE_SAME_SCC); | |
| 2344 (*partitions)[k] = NULL; | |
| 2345 partition_free (partition); | |
| 2346 data = (struct pg_vdata *)pg->vertices[k].data; | |
| 2347 gcc_assert (data->id == k); | |
| 2348 data->partition = NULL; | |
| 2349 /* The result partition of merged SCC must be sequential. */ | |
| 2350 first->type = PTYPE_SEQUENTIAL; | |
| 2351 } | |
| 2352 } | |
| 2353 } | |
| 2354 | |
| 2355 sort_partitions_by_post_order (pg, partitions); | |
| 2356 free_partition_graph_vdata (pg); | |
| 2357 for_each_edge (pg, free_partition_graph_edata_cb, NULL); | |
| 2358 free_graph (pg); | |
| 0 | 2359 |
| 2360 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 111 | 2361 { |
| 2362 fprintf (dump_file, "Possible alias data dependence to break:\n"); | |
| 2363 dump_data_dependence_relations (dump_file, *alias_ddrs); | |
| 2364 } | |
| 2365 } | |
| 2366 | |
| 2367 /* Compute and return an expression whose value is the segment length which | |
| 2368 will be accessed by DR in NITERS iterations. */ | |
| 2369 | |
| 2370 static tree | |
| 2371 data_ref_segment_size (struct data_reference *dr, tree niters) | |
| 2372 { | |
| 131 | 2373 niters = size_binop (MINUS_EXPR, |
| 2374 fold_convert (sizetype, niters), | |
| 2375 size_one_node); | |
| 2376 return size_binop (MULT_EXPR, | |
| 2377 fold_convert (sizetype, DR_STEP (dr)), | |
| 2378 fold_convert (sizetype, niters)); | |
| 111 | 2379 } |
| 2380 | |
| 2381 /* Return true if LOOP's latch is dominated by statement for data reference | |
| 2382 DR. */ | |
| 2383 | |
| 2384 static inline bool | |
| 2385 latch_dominated_by_data_ref (struct loop *loop, data_reference *dr) | |
| 2386 { | |
| 2387 return dominated_by_p (CDI_DOMINATORS, single_exit (loop)->src, | |
| 2388 gimple_bb (DR_STMT (dr))); | |
| 2389 } | |
| 2390 | |
| 2391 /* Compute alias check pairs and store them in COMP_ALIAS_PAIRS for LOOP's | |
| 2392 data dependence relations ALIAS_DDRS. */ | |
| 2393 | |
| 2394 static void | |
| 2395 compute_alias_check_pairs (struct loop *loop, vec<ddr_p> *alias_ddrs, | |
| 2396 vec<dr_with_seg_len_pair_t> *comp_alias_pairs) | |
| 2397 { | |
| 2398 unsigned int i; | |
| 2399 unsigned HOST_WIDE_INT factor = 1; | |
| 2400 tree niters_plus_one, niters = number_of_latch_executions (loop); | |
| 2401 | |
| 2402 gcc_assert (niters != NULL_TREE && niters != chrec_dont_know); | |
| 2403 niters = fold_convert (sizetype, niters); | |
| 2404 niters_plus_one = size_binop (PLUS_EXPR, niters, size_one_node); | |
| 2405 | |
| 2406 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 2407 fprintf (dump_file, "Creating alias check pairs:\n"); | |
| 2408 | |
| 2409 /* Iterate all data dependence relations and compute alias check pairs. */ | |
| 2410 for (i = 0; i < alias_ddrs->length (); i++) | |
| 2411 { | |
| 2412 ddr_p ddr = (*alias_ddrs)[i]; | |
| 2413 struct data_reference *dr_a = DDR_A (ddr); | |
| 2414 struct data_reference *dr_b = DDR_B (ddr); | |
| 2415 tree seg_length_a, seg_length_b; | |
| 2416 int comp_res = data_ref_compare_tree (DR_BASE_ADDRESS (dr_a), | |
| 2417 DR_BASE_ADDRESS (dr_b)); | |
| 2418 | |
| 2419 if (comp_res == 0) | |
| 2420 comp_res = data_ref_compare_tree (DR_OFFSET (dr_a), DR_OFFSET (dr_b)); | |
| 2421 gcc_assert (comp_res != 0); | |
| 2422 | |
| 2423 if (latch_dominated_by_data_ref (loop, dr_a)) | |
| 2424 seg_length_a = data_ref_segment_size (dr_a, niters_plus_one); | |
| 2425 else | |
| 2426 seg_length_a = data_ref_segment_size (dr_a, niters); | |
| 2427 | |
| 2428 if (latch_dominated_by_data_ref (loop, dr_b)) | |
| 2429 seg_length_b = data_ref_segment_size (dr_b, niters_plus_one); | |
| 2430 else | |
| 2431 seg_length_b = data_ref_segment_size (dr_b, niters); | |
| 2432 | |
| 131 | 2433 unsigned HOST_WIDE_INT access_size_a |
| 2434 = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr_a)))); | |
| 2435 unsigned HOST_WIDE_INT access_size_b | |
| 2436 = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr_b)))); | |
| 2437 unsigned int align_a = TYPE_ALIGN_UNIT (TREE_TYPE (DR_REF (dr_a))); | |
| 2438 unsigned int align_b = TYPE_ALIGN_UNIT (TREE_TYPE (DR_REF (dr_b))); | |
| 2439 | |
| 111 | 2440 dr_with_seg_len_pair_t dr_with_seg_len_pair |
| 131 | 2441 (dr_with_seg_len (dr_a, seg_length_a, access_size_a, align_a), |
| 2442 dr_with_seg_len (dr_b, seg_length_b, access_size_b, align_b)); | |
| 111 | 2443 |
| 2444 /* Canonicalize pairs by sorting the two DR members. */ | |
| 2445 if (comp_res > 0) | |
| 2446 std::swap (dr_with_seg_len_pair.first, dr_with_seg_len_pair.second); | |
| 2447 | |
| 2448 comp_alias_pairs->safe_push (dr_with_seg_len_pair); | |
| 2449 } | |
| 2450 | |
| 2451 if (tree_fits_uhwi_p (niters)) | |
| 2452 factor = tree_to_uhwi (niters); | |
| 2453 | |
| 2454 /* Prune alias check pairs. */ | |
| 2455 prune_runtime_alias_test_list (comp_alias_pairs, factor); | |
| 2456 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 2457 fprintf (dump_file, | |
| 2458 "Improved number of alias checks from %d to %d\n", | |
| 2459 alias_ddrs->length (), comp_alias_pairs->length ()); | |
| 2460 } | |
| 2461 | |
| 2462 /* Given data dependence relations in ALIAS_DDRS, generate runtime alias | |
| 2463 checks and version LOOP under condition of these runtime alias checks. */ | |
| 2464 | |
| 2465 static void | |
| 131 | 2466 version_loop_by_alias_check (vec<struct partition *> *partitions, |
| 2467 struct loop *loop, vec<ddr_p> *alias_ddrs) | |
| 111 | 2468 { |
| 2469 profile_probability prob; | |
| 2470 basic_block cond_bb; | |
| 2471 struct loop *nloop; | |
| 2472 tree lhs, arg0, cond_expr = NULL_TREE; | |
| 2473 gimple_seq cond_stmts = NULL; | |
| 2474 gimple *call_stmt = NULL; | |
| 2475 auto_vec<dr_with_seg_len_pair_t> comp_alias_pairs; | |
| 2476 | |
| 2477 /* Generate code for runtime alias checks if necessary. */ | |
| 2478 gcc_assert (alias_ddrs->length () > 0); | |
| 2479 | |
| 2480 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 2481 fprintf (dump_file, | |
| 2482 "Version loop <%d> with runtime alias check\n", loop->num); | |
| 2483 | |
| 2484 compute_alias_check_pairs (loop, alias_ddrs, &comp_alias_pairs); | |
| 2485 create_runtime_alias_checks (loop, &comp_alias_pairs, &cond_expr); | |
| 2486 cond_expr = force_gimple_operand_1 (cond_expr, &cond_stmts, | |
| 2487 is_gimple_val, NULL_TREE); | |
| 2488 | |
| 2489 /* Depend on vectorizer to fold IFN_LOOP_DIST_ALIAS. */ | |
| 131 | 2490 bool cancelable_p = flag_tree_loop_vectorize; |
| 2491 if (cancelable_p) | |
| 111 | 2492 { |
| 131 | 2493 unsigned i = 0; |
| 2494 struct partition *partition; | |
| 2495 for (; partitions->iterate (i, &partition); ++i) | |
| 2496 if (!partition_builtin_p (partition)) | |
| 2497 break; | |
| 2498 | |
| 2499 /* If all partitions are builtins, distributing it would be profitable and | |
| 2500 we don't want to cancel the runtime alias checks. */ | |
| 2501 if (i == partitions->length ()) | |
| 2502 cancelable_p = false; | |
| 2503 } | |
| 2504 | |
| 2505 /* Generate internal function call for loop distribution alias check if the | |
| 2506 runtime alias check should be cancelable. */ | |
| 2507 if (cancelable_p) | |
| 2508 { | |
| 111 | 2509 call_stmt = gimple_build_call_internal (IFN_LOOP_DIST_ALIAS, |
| 2510 2, NULL_TREE, cond_expr); | |
| 2511 lhs = make_ssa_name (boolean_type_node); | |
| 2512 gimple_call_set_lhs (call_stmt, lhs); | |
| 2513 } | |
| 2514 else | |
| 2515 lhs = cond_expr; | |
| 2516 | |
| 2517 prob = profile_probability::guessed_always ().apply_scale (9, 10); | |
| 2518 initialize_original_copy_tables (); | |
| 2519 nloop = loop_version (loop, lhs, &cond_bb, prob, prob.invert (), | |
| 2520 prob, prob.invert (), true); | |
| 2521 free_original_copy_tables (); | |
| 2522 /* Record the original loop number in newly generated loops. In case of | |
| 2523 distribution, the original loop will be distributed and the new loop | |
| 2524 is kept. */ | |
| 2525 loop->orig_loop_num = nloop->num; | |
| 2526 nloop->orig_loop_num = nloop->num; | |
| 2527 nloop->dont_vectorize = true; | |
| 2528 nloop->force_vectorize = false; | |
| 2529 | |
| 2530 if (call_stmt) | |
| 2531 { | |
| 2532 /* Record new loop's num in IFN_LOOP_DIST_ALIAS because the original | |
| 2533 loop could be destroyed. */ | |
| 2534 arg0 = build_int_cst (integer_type_node, loop->orig_loop_num); | |
| 2535 gimple_call_set_arg (call_stmt, 0, arg0); | |
| 2536 gimple_seq_add_stmt_without_update (&cond_stmts, call_stmt); | |
| 2537 } | |
| 2538 | |
| 2539 if (cond_stmts) | |
| 2540 { | |
| 2541 gimple_stmt_iterator cond_gsi = gsi_last_bb (cond_bb); | |
| 2542 gsi_insert_seq_before (&cond_gsi, cond_stmts, GSI_SAME_STMT); | |
| 2543 } | |
| 2544 update_ssa (TODO_update_ssa); | |
| 0 | 2545 } |
| 2546 | |
| 111 | 2547 /* Return true if loop versioning is needed to distrubute PARTITIONS. |
| 2548 ALIAS_DDRS are data dependence relations for runtime alias check. */ | |
| 2549 | |
| 2550 static inline bool | |
| 2551 version_for_distribution_p (vec<struct partition *> *partitions, | |
| 2552 vec<ddr_p> *alias_ddrs) | |
| 2553 { | |
| 2554 /* No need to version loop if we have only one partition. */ | |
| 2555 if (partitions->length () == 1) | |
| 2556 return false; | |
| 2557 | |
| 2558 /* Need to version loop if runtime alias check is necessary. */ | |
| 2559 return (alias_ddrs->length () > 0); | |
| 2560 } | |
| 2561 | |
| 2562 /* Compare base offset of builtin mem* partitions P1 and P2. */ | |
| 2563 | |
| 131 | 2564 static int |
| 2565 offset_cmp (const void *vp1, const void *vp2) | |
| 111 | 2566 { |
| 131 | 2567 struct partition *p1 = *(struct partition *const *) vp1; |
| 2568 struct partition *p2 = *(struct partition *const *) vp2; | |
| 2569 unsigned HOST_WIDE_INT o1 = p1->builtin->dst_base_offset; | |
| 2570 unsigned HOST_WIDE_INT o2 = p2->builtin->dst_base_offset; | |
| 2571 return (o2 < o1) - (o1 < o2); | |
| 111 | 2572 } |
| 2573 | |
| 2574 /* Fuse adjacent memset builtin PARTITIONS if possible. This is a special | |
| 2575 case optimization transforming below code: | |
| 2576 | |
| 2577 __builtin_memset (&obj, 0, 100); | |
| 2578 _1 = &obj + 100; | |
| 2579 __builtin_memset (_1, 0, 200); | |
| 2580 _2 = &obj + 300; | |
| 2581 __builtin_memset (_2, 0, 100); | |
| 2582 | |
| 2583 into: | |
| 2584 | |
| 2585 __builtin_memset (&obj, 0, 400); | |
| 2586 | |
| 2587 Note we don't have dependence information between different partitions | |
| 2588 at this point, as a result, we can't handle nonadjacent memset builtin | |
| 2589 partitions since dependence might be broken. */ | |
| 2590 | |
| 2591 static void | |
| 2592 fuse_memset_builtins (vec<struct partition *> *partitions) | |
| 2593 { | |
| 2594 unsigned i, j; | |
| 2595 struct partition *part1, *part2; | |
| 131 | 2596 tree rhs1, rhs2; |
| 111 | 2597 |
| 2598 for (i = 0; partitions->iterate (i, &part1);) | |
| 2599 { | |
| 2600 if (part1->kind != PKIND_MEMSET) | |
| 2601 { | |
| 2602 i++; | |
| 2603 continue; | |
| 2604 } | |
| 2605 | |
| 2606 /* Find sub-array of memset builtins of the same base. Index range | |
| 2607 of the sub-array is [i, j) with "j > i". */ | |
| 2608 for (j = i + 1; partitions->iterate (j, &part2); ++j) | |
| 2609 { | |
| 2610 if (part2->kind != PKIND_MEMSET | |
| 2611 || !operand_equal_p (part1->builtin->dst_base_base, | |
| 2612 part2->builtin->dst_base_base, 0)) | |
| 2613 break; | |
| 131 | 2614 |
| 2615 /* Memset calls setting different values can't be merged. */ | |
| 2616 rhs1 = gimple_assign_rhs1 (DR_STMT (part1->builtin->dst_dr)); | |
| 2617 rhs2 = gimple_assign_rhs1 (DR_STMT (part2->builtin->dst_dr)); | |
| 2618 if (!operand_equal_p (rhs1, rhs2, 0)) | |
| 2619 break; | |
| 111 | 2620 } |
| 2621 | |
| 2622 /* Stable sort is required in order to avoid breaking dependence. */ | |
| 131 | 2623 gcc_stablesort (&(*partitions)[i], j - i, sizeof (*partitions)[i], |
| 2624 offset_cmp); | |
| 111 | 2625 /* Continue with next partition. */ |
| 2626 i = j; | |
| 2627 } | |
| 2628 | |
| 2629 /* Merge all consecutive memset builtin partitions. */ | |
| 2630 for (i = 0; i < partitions->length () - 1;) | |
| 2631 { | |
| 2632 part1 = (*partitions)[i]; | |
| 2633 if (part1->kind != PKIND_MEMSET) | |
| 2634 { | |
| 2635 i++; | |
| 2636 continue; | |
| 2637 } | |
| 2638 | |
| 2639 part2 = (*partitions)[i + 1]; | |
| 2640 /* Only merge memset partitions of the same base and with constant | |
| 2641 access sizes. */ | |
| 2642 if (part2->kind != PKIND_MEMSET | |
| 2643 || TREE_CODE (part1->builtin->size) != INTEGER_CST | |
| 2644 || TREE_CODE (part2->builtin->size) != INTEGER_CST | |
| 2645 || !operand_equal_p (part1->builtin->dst_base_base, | |
| 2646 part2->builtin->dst_base_base, 0)) | |
| 2647 { | |
| 2648 i++; | |
| 2649 continue; | |
| 2650 } | |
| 131 | 2651 rhs1 = gimple_assign_rhs1 (DR_STMT (part1->builtin->dst_dr)); |
| 2652 rhs2 = gimple_assign_rhs1 (DR_STMT (part2->builtin->dst_dr)); | |
| 111 | 2653 int bytev1 = const_with_all_bytes_same (rhs1); |
| 2654 int bytev2 = const_with_all_bytes_same (rhs2); | |
| 2655 /* Only merge memset partitions of the same value. */ | |
| 2656 if (bytev1 != bytev2 || bytev1 == -1) | |
| 2657 { | |
| 2658 i++; | |
| 2659 continue; | |
| 2660 } | |
| 2661 wide_int end1 = wi::add (part1->builtin->dst_base_offset, | |
| 2662 wi::to_wide (part1->builtin->size)); | |
| 2663 /* Only merge adjacent memset partitions. */ | |
| 2664 if (wi::ne_p (end1, part2->builtin->dst_base_offset)) | |
| 2665 { | |
| 2666 i++; | |
| 2667 continue; | |
| 2668 } | |
| 2669 /* Merge partitions[i] and partitions[i+1]. */ | |
| 2670 part1->builtin->size = fold_build2 (PLUS_EXPR, sizetype, | |
| 2671 part1->builtin->size, | |
| 2672 part2->builtin->size); | |
| 2673 partition_free (part2); | |
| 2674 partitions->ordered_remove (i + 1); | |
| 2675 } | |
| 2676 } | |
| 2677 | |
| 2678 /* Fuse PARTITIONS of LOOP if necessary before finalizing distribution. | |
| 2679 ALIAS_DDRS contains ddrs which need runtime alias check. */ | |
| 2680 | |
| 2681 static void | |
| 2682 finalize_partitions (struct loop *loop, vec<struct partition *> *partitions, | |
| 2683 vec<ddr_p> *alias_ddrs) | |
| 2684 { | |
| 2685 unsigned i; | |
| 2686 struct partition *partition, *a; | |
| 2687 | |
| 2688 if (partitions->length () == 1 | |
| 2689 || alias_ddrs->length () > 0) | |
| 2690 return; | |
| 2691 | |
| 131 | 2692 unsigned num_builtin = 0, num_normal = 0, num_partial_memset = 0; |
| 111 | 2693 bool same_type_p = true; |
| 2694 enum partition_type type = ((*partitions)[0])->type; | |
| 2695 for (i = 0; partitions->iterate (i, &partition); ++i) | |
| 2696 { | |
| 2697 same_type_p &= (type == partition->type); | |
| 131 | 2698 if (partition_builtin_p (partition)) |
| 2699 { | |
| 2700 num_builtin++; | |
| 2701 continue; | |
| 2702 } | |
| 2703 num_normal++; | |
| 2704 if (partition->kind == PKIND_PARTIAL_MEMSET) | |
| 2705 num_partial_memset++; | |
| 111 | 2706 } |
| 2707 | |
| 2708 /* Don't distribute current loop into too many loops given we don't have | |
| 2709 memory stream cost model. Be even more conservative in case of loop | |
| 2710 nest distribution. */ | |
| 131 | 2711 if ((same_type_p && num_builtin == 0 |
| 2712 && (loop->inner == NULL || num_normal != 2 || num_partial_memset != 1)) | |
| 111 | 2713 || (loop->inner != NULL |
| 2714 && i >= NUM_PARTITION_THRESHOLD && num_normal > 1) | |
| 2715 || (loop->inner == NULL | |
| 2716 && i >= NUM_PARTITION_THRESHOLD && num_normal > num_builtin)) | |
| 2717 { | |
| 2718 a = (*partitions)[0]; | |
| 2719 for (i = 1; partitions->iterate (i, &partition); ++i) | |
| 2720 { | |
| 2721 partition_merge_into (NULL, a, partition, FUSE_FINALIZE); | |
| 2722 partition_free (partition); | |
| 2723 } | |
| 2724 partitions->truncate (1); | |
| 2725 } | |
| 2726 | |
| 2727 /* Fuse memset builtins if possible. */ | |
| 2728 if (partitions->length () > 1) | |
| 2729 fuse_memset_builtins (partitions); | |
| 2730 } | |
| 2731 | |
| 2732 /* Distributes the code from LOOP in such a way that producer statements | |
| 2733 are placed before consumer statements. Tries to separate only the | |
| 2734 statements from STMTS into separate loops. Returns the number of | |
| 2735 distributed loops. Set NB_CALLS to number of generated builtin calls. | |
| 2736 Set *DESTROY_P to whether LOOP needs to be destroyed. */ | |
| 0 | 2737 |
| 2738 static int | |
| 111 | 2739 distribute_loop (struct loop *loop, vec<gimple *> stmts, |
| 2740 control_dependences *cd, int *nb_calls, bool *destroy_p) | |
| 0 | 2741 { |
| 111 | 2742 ddrs_table = new hash_table<ddr_hasher> (389); |
| 0 | 2743 struct graph *rdg; |
| 111 | 2744 partition *partition; |
| 2745 bool any_builtin; | |
| 2746 int i, nbp; | |
| 2747 | |
| 2748 *destroy_p = false; | |
| 2749 *nb_calls = 0; | |
| 2750 loop_nest.create (0); | |
| 2751 if (!find_loop_nest (loop, &loop_nest)) | |
| 0 | 2752 { |
| 111 | 2753 loop_nest.release (); |
| 2754 delete ddrs_table; | |
| 2755 return 0; | |
| 0 | 2756 } |
| 2757 | |
| 111 | 2758 datarefs_vec.create (20); |
| 2759 rdg = build_rdg (loop, cd); | |
| 0 | 2760 if (!rdg) |
| 2761 { | |
| 2762 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 2763 fprintf (dump_file, | |
| 111 | 2764 "Loop %d not distributed: failed to build the RDG.\n", |
| 0 | 2765 loop->num); |
| 2766 | |
| 111 | 2767 loop_nest.release (); |
| 2768 free_data_refs (datarefs_vec); | |
| 2769 delete ddrs_table; | |
| 2770 return 0; | |
| 0 | 2771 } |
| 2772 | |
| 111 | 2773 if (datarefs_vec.length () > MAX_DATAREFS_NUM) |
| 2774 { | |
| 2775 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 2776 fprintf (dump_file, | |
| 2777 "Loop %d not distributed: too many memory references.\n", | |
| 2778 loop->num); | |
| 2779 | |
| 2780 free_rdg (rdg); | |
| 2781 loop_nest.release (); | |
| 2782 free_data_refs (datarefs_vec); | |
| 2783 delete ddrs_table; | |
| 2784 return 0; | |
| 2785 } | |
| 2786 | |
| 2787 data_reference_p dref; | |
| 2788 for (i = 0; datarefs_vec.iterate (i, &dref); ++i) | |
| 2789 dref->aux = (void *) (uintptr_t) i; | |
| 0 | 2790 |
| 2791 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 2792 dump_rdg (dump_file, rdg); | |
| 2793 | |
| 111 | 2794 auto_vec<struct partition *, 3> partitions; |
| 2795 rdg_build_partitions (rdg, stmts, &partitions); | |
| 2796 | |
| 2797 auto_vec<ddr_p> alias_ddrs; | |
| 2798 | |
| 2799 auto_bitmap stmt_in_all_partitions; | |
| 2800 bitmap_copy (stmt_in_all_partitions, partitions[0]->stmts); | |
| 2801 for (i = 1; partitions.iterate (i, &partition); ++i) | |
| 2802 bitmap_and_into (stmt_in_all_partitions, partitions[i]->stmts); | |
| 2803 | |
| 2804 any_builtin = false; | |
| 2805 FOR_EACH_VEC_ELT (partitions, i, partition) | |
| 2806 { | |
| 2807 classify_partition (loop, rdg, partition, stmt_in_all_partitions); | |
| 2808 any_builtin |= partition_builtin_p (partition); | |
| 2809 } | |
| 2810 | |
| 2811 /* If we are only distributing patterns but did not detect any, | |
| 2812 simply bail out. */ | |
| 2813 if (!flag_tree_loop_distribution | |
| 2814 && !any_builtin) | |
| 2815 { | |
| 2816 nbp = 0; | |
| 2817 goto ldist_done; | |
| 2818 } | |
| 2819 | |
| 2820 /* If we are only distributing patterns fuse all partitions that | |
| 2821 were not classified as builtins. This also avoids chopping | |
| 2822 a loop into pieces, separated by builtin calls. That is, we | |
| 2823 only want no or a single loop body remaining. */ | |
| 2824 struct partition *into; | |
| 2825 if (!flag_tree_loop_distribution) | |
| 0 | 2826 { |
| 111 | 2827 for (i = 0; partitions.iterate (i, &into); ++i) |
| 2828 if (!partition_builtin_p (into)) | |
| 2829 break; | |
| 2830 for (++i; partitions.iterate (i, &partition); ++i) | |
| 2831 if (!partition_builtin_p (partition)) | |
| 2832 { | |
| 2833 partition_merge_into (NULL, into, partition, FUSE_NON_BUILTIN); | |
| 2834 partitions.unordered_remove (i); | |
| 2835 partition_free (partition); | |
| 2836 i--; | |
| 2837 } | |
| 2838 } | |
| 2839 | |
| 2840 /* Due to limitations in the transform phase we have to fuse all | |
| 2841 reduction partitions into the last partition so the existing | |
| 2842 loop will contain all loop-closed PHI nodes. */ | |
| 2843 for (i = 0; partitions.iterate (i, &into); ++i) | |
| 2844 if (partition_reduction_p (into)) | |
| 2845 break; | |
| 2846 for (i = i + 1; partitions.iterate (i, &partition); ++i) | |
| 2847 if (partition_reduction_p (partition)) | |
| 2848 { | |
| 2849 partition_merge_into (rdg, into, partition, FUSE_REDUCTION); | |
| 2850 partitions.unordered_remove (i); | |
| 2851 partition_free (partition); | |
| 2852 i--; | |
| 2853 } | |
| 2854 | |
| 2855 /* Apply our simple cost model - fuse partitions with similar | |
| 2856 memory accesses. */ | |
| 2857 for (i = 0; partitions.iterate (i, &into); ++i) | |
| 2858 { | |
| 2859 bool changed = false; | |
| 131 | 2860 if (partition_builtin_p (into) || into->kind == PKIND_PARTIAL_MEMSET) |
| 111 | 2861 continue; |
| 2862 for (int j = i + 1; | |
| 2863 partitions.iterate (j, &partition); ++j) | |
| 0 | 2864 { |
| 111 | 2865 if (share_memory_accesses (rdg, into, partition)) |
| 2866 { | |
| 2867 partition_merge_into (rdg, into, partition, FUSE_SHARE_REF); | |
| 2868 partitions.unordered_remove (j); | |
| 2869 partition_free (partition); | |
| 2870 j--; | |
| 2871 changed = true; | |
| 2872 } | |
| 2873 } | |
| 2874 /* If we fused 0 1 2 in step 1 to 0,2 1 as 0 and 2 have similar | |
| 2875 accesses when 1 and 2 have similar accesses but not 0 and 1 | |
| 2876 then in the next iteration we will fail to consider merging | |
| 2877 1 into 0,2. So try again if we did any merging into 0. */ | |
| 2878 if (changed) | |
| 2879 i--; | |
| 2880 } | |
| 2881 | |
| 2882 /* Build the partition dependency graph and fuse partitions in strong | |
| 2883 connected component. */ | |
| 2884 if (partitions.length () > 1) | |
| 2885 { | |
| 2886 /* Don't support loop nest distribution under runtime alias check | |
| 2887 since it's not likely to enable many vectorization opportunities. */ | |
| 2888 if (loop->inner) | |
| 2889 merge_dep_scc_partitions (rdg, &partitions, false); | |
| 2890 else | |
| 2891 { | |
| 2892 merge_dep_scc_partitions (rdg, &partitions, true); | |
| 2893 if (partitions.length () > 1) | |
| 2894 break_alias_scc_partitions (rdg, &partitions, &alias_ddrs); | |
| 0 | 2895 } |
| 2896 } | |
| 2897 | |
| 111 | 2898 finalize_partitions (loop, &partitions, &alias_ddrs); |
| 2899 | |
| 2900 nbp = partitions.length (); | |
| 2901 if (nbp == 0 | |
| 2902 || (nbp == 1 && !partition_builtin_p (partitions[0])) | |
| 2903 || (nbp > 1 && partition_contains_all_rw (rdg, partitions))) | |
| 2904 { | |
| 2905 nbp = 0; | |
| 2906 goto ldist_done; | |
| 2907 } | |
| 2908 | |
| 2909 if (version_for_distribution_p (&partitions, &alias_ddrs)) | |
| 131 | 2910 version_loop_by_alias_check (&partitions, loop, &alias_ddrs); |
| 111 | 2911 |
| 2912 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 2913 { | |
| 2914 fprintf (dump_file, | |
| 2915 "distribute loop <%d> into partitions:\n", loop->num); | |
| 2916 dump_rdg_partitions (dump_file, partitions); | |
| 2917 } | |
| 2918 | |
| 2919 FOR_EACH_VEC_ELT (partitions, i, partition) | |
| 2920 { | |
| 2921 if (partition_builtin_p (partition)) | |
| 2922 (*nb_calls)++; | |
| 2923 *destroy_p |= generate_code_for_partition (loop, partition, i < nbp - 1); | |
| 2924 } | |
| 2925 | |
| 2926 ldist_done: | |
| 2927 loop_nest.release (); | |
| 2928 free_data_refs (datarefs_vec); | |
| 2929 for (hash_table<ddr_hasher>::iterator iter = ddrs_table->begin (); | |
| 2930 iter != ddrs_table->end (); ++iter) | |
| 2931 { | |
| 2932 free_dependence_relation (*iter); | |
| 2933 *iter = NULL; | |
| 2934 } | |
| 2935 delete ddrs_table; | |
| 2936 | |
| 2937 FOR_EACH_VEC_ELT (partitions, i, partition) | |
| 2938 partition_free (partition); | |
| 2939 | |
| 0 | 2940 free_rdg (rdg); |
| 111 | 2941 return nbp - *nb_calls; |
| 0 | 2942 } |
| 2943 | |
| 2944 /* Distribute all loops in the current function. */ | |
| 2945 | |
| 111 | 2946 namespace { |
| 2947 | |
| 2948 const pass_data pass_data_loop_distribution = | |
| 2949 { | |
| 2950 GIMPLE_PASS, /* type */ | |
| 2951 "ldist", /* name */ | |
| 2952 OPTGROUP_LOOP, /* optinfo_flags */ | |
| 2953 TV_TREE_LOOP_DISTRIBUTION, /* tv_id */ | |
| 2954 ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
| 2955 0, /* properties_provided */ | |
| 2956 0, /* properties_destroyed */ | |
| 2957 0, /* todo_flags_start */ | |
| 2958 0, /* todo_flags_finish */ | |
| 2959 }; | |
| 2960 | |
| 2961 class pass_loop_distribution : public gimple_opt_pass | |
| 2962 { | |
| 2963 public: | |
| 2964 pass_loop_distribution (gcc::context *ctxt) | |
| 2965 : gimple_opt_pass (pass_data_loop_distribution, ctxt) | |
| 2966 {} | |
| 2967 | |
| 2968 /* opt_pass methods: */ | |
| 2969 virtual bool gate (function *) | |
| 2970 { | |
| 2971 return flag_tree_loop_distribution | |
| 2972 || flag_tree_loop_distribute_patterns; | |
| 2973 } | |
| 2974 | |
| 2975 virtual unsigned int execute (function *); | |
| 2976 | |
| 2977 }; // class pass_loop_distribution | |
| 2978 | |
| 2979 | |
| 2980 /* Given LOOP, this function records seed statements for distribution in | |
| 2981 WORK_LIST. Return false if there is nothing for distribution. */ | |
| 2982 | |
| 2983 static bool | |
| 2984 find_seed_stmts_for_distribution (struct loop *loop, vec<gimple *> *work_list) | |
| 2985 { | |
| 2986 basic_block *bbs = get_loop_body_in_dom_order (loop); | |
| 2987 | |
| 2988 /* Initialize the worklist with stmts we seed the partitions with. */ | |
| 2989 for (unsigned i = 0; i < loop->num_nodes; ++i) | |
| 2990 { | |
| 2991 for (gphi_iterator gsi = gsi_start_phis (bbs[i]); | |
| 2992 !gsi_end_p (gsi); gsi_next (&gsi)) | |
| 2993 { | |
| 2994 gphi *phi = gsi.phi (); | |
| 2995 if (virtual_operand_p (gimple_phi_result (phi))) | |
| 2996 continue; | |
| 2997 /* Distribute stmts which have defs that are used outside of | |
| 2998 the loop. */ | |
| 2999 if (!stmt_has_scalar_dependences_outside_loop (loop, phi)) | |
| 3000 continue; | |
| 3001 work_list->safe_push (phi); | |
| 3002 } | |
| 3003 for (gimple_stmt_iterator gsi = gsi_start_bb (bbs[i]); | |
| 3004 !gsi_end_p (gsi); gsi_next (&gsi)) | |
| 3005 { | |
| 3006 gimple *stmt = gsi_stmt (gsi); | |
| 3007 | |
| 3008 /* If there is a stmt with side-effects bail out - we | |
| 3009 cannot and should not distribute this loop. */ | |
| 3010 if (gimple_has_side_effects (stmt)) | |
| 3011 { | |
| 3012 free (bbs); | |
| 3013 return false; | |
| 3014 } | |
| 3015 | |
| 3016 /* Distribute stmts which have defs that are used outside of | |
| 3017 the loop. */ | |
| 3018 if (stmt_has_scalar_dependences_outside_loop (loop, stmt)) | |
| 3019 ; | |
| 3020 /* Otherwise only distribute stores for now. */ | |
| 3021 else if (!gimple_vdef (stmt)) | |
| 3022 continue; | |
| 3023 | |
| 3024 work_list->safe_push (stmt); | |
| 3025 } | |
| 3026 } | |
| 3027 free (bbs); | |
| 3028 return work_list->length () > 0; | |
| 3029 } | |
| 3030 | |
| 3031 /* Given innermost LOOP, return the outermost enclosing loop that forms a | |
| 3032 perfect loop nest. */ | |
| 3033 | |
| 3034 static struct loop * | |
| 3035 prepare_perfect_loop_nest (struct loop *loop) | |
| 3036 { | |
| 3037 struct loop *outer = loop_outer (loop); | |
| 3038 tree niters = number_of_latch_executions (loop); | |
| 3039 | |
| 131 | 3040 /* TODO: We only support the innermost 3-level loop nest distribution |
| 111 | 3041 because of compilation time issue for now. This should be relaxed |
| 131 | 3042 in the future. Note we only allow 3-level loop nest distribution |
| 3043 when parallelizing loops. */ | |
| 3044 while ((loop->inner == NULL | |
| 3045 || (loop->inner->inner == NULL && flag_tree_parallelize_loops > 1)) | |
| 111 | 3046 && loop_outer (outer) |
| 3047 && outer->inner == loop && loop->next == NULL | |
| 3048 && single_exit (outer) | |
| 3049 && optimize_loop_for_speed_p (outer) | |
| 3050 && !chrec_contains_symbols_defined_in_loop (niters, outer->num) | |
| 3051 && (niters = number_of_latch_executions (outer)) != NULL_TREE | |
| 3052 && niters != chrec_dont_know) | |
| 3053 { | |
| 3054 loop = outer; | |
| 3055 outer = loop_outer (loop); | |
| 3056 } | |
| 3057 | |
| 3058 return loop; | |
| 3059 } | |
| 3060 | |
| 3061 unsigned int | |
| 3062 pass_loop_distribution::execute (function *fun) | |
| 0 | 3063 { |
| 3064 struct loop *loop; | |
| 111 | 3065 bool changed = false; |
| 3066 basic_block bb; | |
| 3067 control_dependences *cd = NULL; | |
| 3068 auto_vec<loop_p> loops_to_be_destroyed; | |
| 3069 | |
| 3070 if (number_of_loops (fun) <= 1) | |
| 3071 return 0; | |
| 3072 | |
| 3073 /* Compute topological order for basic blocks. Topological order is | |
| 3074 needed because data dependence is computed for data references in | |
| 3075 lexicographical order. */ | |
| 3076 if (bb_top_order_index == NULL) | |
| 0 | 3077 { |
| 111 | 3078 int rpo_num; |
| 3079 int *rpo = XNEWVEC (int, last_basic_block_for_fn (cfun)); | |
| 3080 | |
| 3081 bb_top_order_index = XNEWVEC (int, last_basic_block_for_fn (cfun)); | |
| 3082 bb_top_order_index_size = last_basic_block_for_fn (cfun); | |
| 3083 rpo_num = pre_and_rev_post_order_compute_fn (cfun, NULL, rpo, true); | |
| 3084 for (int i = 0; i < rpo_num; i++) | |
| 3085 bb_top_order_index[rpo[i]] = i; | |
| 3086 | |
| 3087 free (rpo); | |
| 3088 } | |
| 3089 | |
| 3090 FOR_ALL_BB_FN (bb, fun) | |
| 3091 { | |
| 3092 gimple_stmt_iterator gsi; | |
| 3093 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
| 3094 gimple_set_uid (gsi_stmt (gsi), -1); | |
| 3095 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
| 3096 gimple_set_uid (gsi_stmt (gsi), -1); | |
| 3097 } | |
| 3098 | |
| 3099 /* We can at the moment only distribute non-nested loops, thus restrict | |
| 3100 walking to innermost loops. */ | |
| 3101 FOR_EACH_LOOP (loop, LI_ONLY_INNERMOST) | |
| 3102 { | |
| 3103 /* Don't distribute multiple exit edges loop, or cold loop. */ | |
| 3104 if (!single_exit (loop) | |
| 3105 || !optimize_loop_for_speed_p (loop)) | |
|
67
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
63
diff
changeset
|
3106 continue; |
| 0 | 3107 |
| 111 | 3108 /* Don't distribute loop if niters is unknown. */ |
| 3109 tree niters = number_of_latch_executions (loop); | |
| 3110 if (niters == NULL_TREE || niters == chrec_dont_know) | |
| 3111 continue; | |
| 3112 | |
| 3113 /* Get the perfect loop nest for distribution. */ | |
| 3114 loop = prepare_perfect_loop_nest (loop); | |
| 3115 for (; loop; loop = loop->inner) | |
|
67
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
63
diff
changeset
|
3116 { |
| 111 | 3117 auto_vec<gimple *> work_list; |
| 3118 if (!find_seed_stmts_for_distribution (loop, &work_list)) | |
| 3119 break; | |
| 3120 | |
| 3121 const char *str = loop->inner ? " nest" : ""; | |
| 131 | 3122 dump_user_location_t loc = find_loop_location (loop); |
| 111 | 3123 if (!cd) |
| 3124 { | |
| 3125 calculate_dominance_info (CDI_DOMINATORS); | |
| 3126 calculate_dominance_info (CDI_POST_DOMINATORS); | |
| 3127 cd = new control_dependences (); | |
| 3128 free_dominance_info (CDI_POST_DOMINATORS); | |
| 3129 } | |
| 3130 | |
| 3131 bool destroy_p; | |
| 3132 int nb_generated_loops, nb_generated_calls; | |
| 3133 nb_generated_loops = distribute_loop (loop, work_list, cd, | |
| 3134 &nb_generated_calls, | |
| 3135 &destroy_p); | |
| 3136 if (destroy_p) | |
| 3137 loops_to_be_destroyed.safe_push (loop); | |
| 3138 | |
| 3139 if (nb_generated_loops + nb_generated_calls > 0) | |
| 3140 { | |
| 3141 changed = true; | |
| 3142 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, | |
| 3143 loc, "Loop%s %d distributed: split to %d loops " | |
| 3144 "and %d library calls.\n", str, loop->num, | |
| 3145 nb_generated_loops, nb_generated_calls); | |
| 3146 | |
| 3147 break; | |
| 3148 } | |
| 3149 | |
| 3150 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 3151 fprintf (dump_file, "Loop%s %d not distributed.\n", str, loop->num); | |
|
67
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
63
diff
changeset
|
3152 } |
| 111 | 3153 } |
| 3154 | |
| 3155 if (cd) | |
| 3156 delete cd; | |
| 3157 | |
| 3158 if (bb_top_order_index != NULL) | |
| 3159 { | |
| 3160 free (bb_top_order_index); | |
| 3161 bb_top_order_index = NULL; | |
| 3162 bb_top_order_index_size = 0; | |
| 0 | 3163 } |
| 3164 | |
| 111 | 3165 if (changed) |
| 3166 { | |
| 3167 /* Destroy loop bodies that could not be reused. Do this late as we | |
| 3168 otherwise can end up refering to stale data in control dependences. */ | |
| 3169 unsigned i; | |
| 3170 FOR_EACH_VEC_ELT (loops_to_be_destroyed, i, loop) | |
| 3171 destroy_loop (loop); | |
| 3172 | |
| 3173 /* Cached scalar evolutions now may refer to wrong or non-existing | |
| 3174 loops. */ | |
| 3175 scev_reset_htab (); | |
| 3176 mark_virtual_operands_for_renaming (fun); | |
| 3177 rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa); | |
| 3178 } | |
| 3179 | |
| 3180 checking_verify_loop_structure (); | |
| 3181 | |
| 131 | 3182 return changed ? TODO_cleanup_cfg : 0; |
| 0 | 3183 } |
| 3184 | |
| 111 | 3185 } // anon namespace |
| 3186 | |
| 3187 gimple_opt_pass * | |
| 3188 make_pass_loop_distribution (gcc::context *ctxt) | |
| 0 | 3189 { |
| 111 | 3190 return new pass_loop_distribution (ctxt); |
| 3191 } |