nsz Git - libfirm/blob - ir/opt/ldst2.c

   1 /*
   2  * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
   3  *
   4  * This file is part of libFirm.
   5  *
   6  * This file may be distributed and/or modified under the terms of the
   7  * GNU General Public License version 2 as published by the Free Software
   8  * Foundation and appearing in the file LICENSE.GPL included in the
   9  * packaging of this file.
  10  *
  11  * Licensees holding valid libFirm Professional Edition licenses may use
  12  * this file in accordance with the libFirm Commercial License.
  13  * Agreement provided with the Software.
  14  *
  15  * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
  16  * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE.
  18  */
  19
  20 /**
  21  * @file
  22  * @brief   parallelizing Load/Store optimisation
  23  * @author  Christoph Mallon
  24  * @version $Id: $
  25  */
  26 #ifdef HAVE_CONFIG_H
  27 #include "config.h"
  28 #endif
  29
  30 #include "iroptimize.h"
  31
  32 #include "array.h"
  33 #include "debug.h"
  34 #include "ircons.h"
  35 #include "irgraph.h"
  36 #include "irgmod.h"
  37 #include "irgopt.h"
  38 #include "irgwalk.h"
  39 #include "irmemory.h"
  40 #include "irnode.h"
  41 #include "irnodeset.h"
  42 #include "obst.h"
  43 #include "irdump.h"
  44 #include "irflag_t.h"
  45
  46 #define OPTIMISE_LOAD_AFTER_LOAD
  47
  48
  49 #define UNIMPLEMENTED abort();
  50
  51
  52 DEBUG_ONLY(static firm_dbg_module_t *dbg);
  53
  54
  55 static struct obstack obst;
  56 static size_t count_addrs;
  57 static ir_node** addrs;
  58
  59
  60 static void AddressCollector(ir_node* node, void* env)
  61 {
  62         ir_nodeset_t* addrs_set = env;
  63         ir_node* addr;
  64         if (is_Load(node)) {
  65                 addr = get_Load_ptr(node);
  66         } else if (is_Store(node)) {
  67                 addr = get_Store_ptr(node);
  68         } else {
  69                 return;
  70         }
  71         ir_nodeset_insert(addrs_set, addr);
  72 }
  73
  74
  75 /* Collects all unique addresses used by load and store nodes of a graph and
  76  * puts them into an array for later use */
  77 static void CollectAddresses(ir_graph* irg)
  78 {
  79         ir_nodeset_t addrs_set;
  80
  81         ir_nodeset_init(&addrs_set);
  82         irg_walk_graph(irg, AddressCollector, NULL, &addrs_set);
  83
  84         count_addrs = ir_nodeset_size(&addrs_set);
  85         DB((dbg, LEVEL_1, "===> %+F uses %u unique addresses\n", irg, (unsigned int)count_addrs));
  86         if (count_addrs != 0) {
  87                 ir_nodeset_iterator_t addr_iter;
  88                 size_t i;
  89
  90                 addrs = NEW_ARR_D(ir_node*, &obst, count_addrs);
  91                 ir_nodeset_iterator_init(&addr_iter, &addrs_set);
  92                 for (i = 0; i < count_addrs; i++) {
  93                         ir_node* addr = ir_nodeset_iterator_next(&addr_iter);
  94                         assert(addr != NULL);
  95                         set_irn_link(addr, (void *)i);
  96                         addrs[i] = addr;
  97                         DB((dbg, LEVEL_2, "===> Collected unique symbolic address %+F\n", addr));
  98                 }
  99         }
 100 }
 101
 102
 103 static void AliasSetAdder(ir_node* block, void* env)
 104 {
 105         ir_nodeset_t* alias_set;
 106         size_t i;
 107         (void) env;
 108
 109         alias_set = NEW_ARR_D(ir_nodeset_t, &obst, count_addrs);
 110         for (i = 0; i < count_addrs; i++) {
 111                 ir_nodeset_init(&alias_set[i]);
 112         }
 113         set_irn_link(block, alias_set);
 114 }
 115
 116
 117 static void SetStartAddressesTop(ir_graph* irg)
 118 {
 119         ir_node* initial_mem;
 120         ir_node* start_block;
 121         ir_nodeset_t* start_addrs;
 122         size_t i;
 123
 124         initial_mem = get_irg_initial_mem(irg);
 125         start_block = get_irg_start_block(irg);
 126         start_addrs = get_irn_link(start_block);
 127         for (i = 0; i < count_addrs; i++) {
 128                 ir_nodeset_insert(&start_addrs[i], initial_mem);
 129         }
 130         mark_Block_block_visited(start_block);
 131 }
 132
 133
 134 static void AliasSetDestroyer(ir_node* block, void* env)
 135 {
 136         ir_nodeset_t* alias_set = get_irn_link(block);
 137         size_t i;
 138         (void) env;
 139
 140         for (i = 0; i < count_addrs; i++) {
 141                 ir_nodeset_destroy(&alias_set[i]);
 142         }
 143 }
 144
 145
 146 static ir_alias_relation AliasTest(ir_graph* irg, ir_node* addr, ir_mode* mode, ir_node* other)
 147 {
 148         ir_node* other_addr;
 149         ir_mode* other_mode;
 150
 151         if (is_Proj(other)) other = get_Proj_pred(other);
 152
 153         if (is_Load(other)) {
 154                 other_addr = get_Load_ptr(other);
 155         } else if (is_Store(other)) {
 156                 other_addr = get_Store_ptr(other);
 157         } else {
 158                 return may_alias;
 159         }
 160
 161         other_mode = get_irn_mode(other);
 162         return get_alias_relation(irg, addr, mode, other_addr, other_mode);
 163 }
 164
 165
 166 static ir_node* GenerateSync(ir_graph* irg, ir_node* block, ir_nodeset_t* after_set)
 167 {
 168         size_t set_size = ir_nodeset_size(after_set);
 169         ir_nodeset_iterator_t iter;
 170
 171         assert(set_size != 0);
 172
 173         ir_nodeset_iterator_init(&iter, after_set);
 174         if (set_size == 1) {
 175                 return ir_nodeset_iterator_next(&iter);
 176         } else {
 177                 ir_node** in;
 178                 size_t i;
 179
 180                 NEW_ARR_A(ir_node*, in, set_size);
 181                 for (i = 0; i < set_size; i++) {
 182                         in[i] = ir_nodeset_iterator_next(&iter);
 183                 }
 184                 return new_r_Sync(irg, block, set_size, in);
 185         }
 186 }
 187
 188
 189 static ir_node** unfinished_phis;
 190
 191
 192 static void PlaceMemPhis(ir_graph* irg, ir_node* block, ir_node* phi)
 193 {
 194         int unfinished = 0;
 195         size_t block_n_preds = get_Block_n_cfgpreds(block);
 196         ir_nodeset_t* thissets;
 197         ir_node** in;
 198         size_t i;
 199         size_t j;
 200
 201         thissets = get_irn_link(block);
 202         NEW_ARR_A(ir_node*, in, block_n_preds);
 203         for (j = 0; j < count_addrs; j++) {
 204                 ir_node* new_phi;
 205
 206                 for (i = 0; i < block_n_preds; i++) {
 207                         ir_node* pred_block = get_nodes_block(get_Phi_pred(phi, i)); // TODO get_Block_cfgpred_block(block, i);
 208                         ir_nodeset_t* predsets = get_irn_link(pred_block);
 209                         size_t predset_size = ir_nodeset_size(&predsets[j]);
 210
 211                         if (predset_size == 0) {
 212                                 in[i] = new_r_Unknown(irg, mode_M);
 213                                 unfinished = 1;
 214                         } else {
 215                                 in[i] = GenerateSync(irg, pred_block, &predsets[j]);
 216                         }
 217                 }
 218                 new_phi = new_r_Phi(irg, block, block_n_preds, in, mode_M);
 219                 if (unfinished) {
 220                         set_irn_link(new_phi, unfinished_phis[j]);
 221                         unfinished_phis[j] = new_phi;
 222                 }
 223                 ir_nodeset_insert(&thissets[j], new_phi);
 224         }
 225 }
 226
 227
 228 static int WalkMem(ir_graph* irg, ir_node* node, ir_node* last_block);
 229
 230
 231 static void WalkMemPhi(ir_graph* irg, ir_node* block, ir_node* phi)
 232 {
 233         size_t n = get_Phi_n_preds(phi);
 234         size_t i;
 235
 236         for (i = 0; i < n; i++) {
 237                 WalkMem(irg, get_Phi_pred(phi, i), block);
 238         }
 239
 240         PlaceMemPhis(irg, block, phi);
 241         exchange(phi, new_Bad());
 242 }
 243
 244
 245 static void PlaceLoad(ir_graph* irg, ir_node* block, ir_node* load, ir_node* memory)
 246 {
 247         ir_node* addr = get_Load_ptr(load);
 248         size_t addr_idx = (size_t)get_irn_link(addr);
 249         ir_nodeset_t* interfere_sets = get_irn_link(block);
 250         ir_nodeset_t* interfere_set = &interfere_sets[addr_idx];
 251         size_t size = ir_nodeset_size(interfere_set);
 252         ir_nodeset_iterator_t interfere_iter;
 253         size_t i;
 254
 255         assert(size > 0);
 256         ir_nodeset_iterator_init(&interfere_iter, interfere_set);
 257         if (size == 1) {
 258                 ir_node* after = ir_nodeset_iterator_next(&interfere_iter);
 259                 assert(!is_Proj(after) || !is_Load(get_Proj_pred(after)));
 260                 DB((dbg, LEVEL_3, "===> %+F must be executed after %+F\n", load, after));
 261                 set_Load_mem(load, after);
 262         } else {
 263                 ir_node** after_set;
 264                 ir_node* after;
 265                 ir_node* mem;
 266                 size_t i;
 267
 268                 NEW_ARR_A(ir_node*, after_set, size);
 269                 i = 0;
 270                 while ((mem = ir_nodeset_iterator_next(&interfere_iter)) != NULL) {
 271                         if (is_Proj(mem)) {
 272                                 ir_node* pred = get_Proj_pred(mem);
 273                                 if (is_Load(pred)) {
 274 #ifdef OPTIMISE_LOAD_AFTER_LOAD
 275                                         if (get_Load_ptr(pred) == addr && get_Load_mode(pred) == get_Load_mode(load)) {
 276                                                 exchange(load, pred);
 277                                                 return;
 278                                         }
 279 #endif
 280                                         continue;
 281                                 }
 282                         }
 283                         DB((dbg, LEVEL_3, "===> %+F must be executed after %+F\n", load, mem));
 284                         after_set[i++] = mem;
 285                 }
 286                 assert(i != 0);
 287                 if (i == 1) {
 288                         after = after_set[0];
 289                 } else {
 290                         after = new_r_Sync(irg, block, i, after_set);
 291                 }
 292                 set_Load_mem(load, after);
 293         }
 294
 295         for (i = 0; i < count_addrs; i++) {
 296                 ir_mode* mode = get_Load_mode(load);
 297                 ir_node* other_addr = addrs[i];
 298                 ir_mode* other_mode = mode; // XXX second mode is nonsense
 299                 ir_alias_relation rel = get_alias_relation(irg, addr, mode, other_addr, other_mode);
 300
 301                 DB((dbg, LEVEL_3, "===> Testing for alias between %+F and %+F. Relation is %d\n", addr, other_addr, rel));
 302                 if (rel == no_alias) {
 303                         continue;
 304                 }
 305                 DB((dbg, LEVEL_3, "===> %+F potentially aliases address %+F\n", load, other_addr));
 306
 307                 ir_nodeset_insert(&interfere_sets[i], memory);
 308         }
 309 }
 310
 311
 312 static void PlaceStore(ir_graph* irg, ir_node* block, ir_node* store, ir_node* memory)
 313 {
 314         ir_node* addr = get_Store_ptr(store);
 315         size_t addr_idx = (size_t)get_irn_link(addr);
 316         ir_nodeset_t* interfere_sets = get_irn_link(block);
 317         ir_nodeset_t* interfere_set = &interfere_sets[addr_idx];
 318         ir_node* after;
 319         size_t i;
 320
 321         after = GenerateSync(irg, block, interfere_set);
 322         set_Store_mem(store, after);
 323
 324         for (i = 0; i < count_addrs; i++) {
 325                 ir_nodeset_iterator_t interfere_iter;
 326                 ir_mode* mode = get_irn_mode(get_Store_value(store));
 327                 ir_node* other_addr = addrs[i];
 328                 ir_mode* other_mode = mode; // XXX second mode is nonsense
 329                 ir_alias_relation rel = get_alias_relation(irg, addr, mode, other_addr, other_mode);
 330                 ir_node* other_node;
 331
 332                 DB((dbg, LEVEL_3, "===> Testing for alias between %+F and %+F. Relation is %d\n", addr, other_addr, rel));
 333                 if (rel == no_alias) {
 334                         continue;
 335                 }
 336                 DB((dbg, LEVEL_3, "===> %+F potentially aliases address %+F\n", store, other_addr));
 337
 338                 ir_nodeset_iterator_init(&interfere_iter, &interfere_sets[i]);
 339                 while ((other_node = ir_nodeset_iterator_next(&interfere_iter)) != NULL) {
 340                         if (AliasTest(irg, addr, mode, other_node) != no_alias) {
 341                                 DB((dbg, LEVEL_3, "===> Removing %+F from execute-after set of %+F due to %+F\n", other_node, addrs[i], store));
 342                                 ir_nodeset_remove_iterator(&interfere_sets[i], &interfere_iter);
 343                         }
 344                 }
 345
 346                 ir_nodeset_insert(&interfere_sets[i], memory);
 347         }
 348 }
 349
 350
 351 static int WalkMem(ir_graph* irg, ir_node* node, ir_node* last_block)
 352 {
 353         int block_change = 0;
 354         ir_node* block = get_nodes_block(node);
 355         ir_node* pred;
 356         ir_node* memory = node;
 357         ir_nodeset_t* addr_sets;
 358
 359         if (block != last_block) {
 360                 DB((dbg, LEVEL_3, "===> Changing block from %+F to %+F\n", last_block, block));
 361                 block_change = 1;
 362                 if (Block_not_block_visited(block)) {
 363                         mark_Block_block_visited(block);
 364                 } else {
 365                         DB((dbg, LEVEL_2, "===> Hit already visited block at %+F\n", node));
 366                         return block_change;
 367                 }
 368         }
 369
 370         // Skip projs
 371         if (is_Proj(node)) node = get_Proj_pred(node);
 372
 373         if (is_Phi(node)) {
 374                 WalkMemPhi(irg, block, node);
 375                 return block_change;
 376         } else if (is_Sync(node)) {
 377                 UNIMPLEMENTED
 378         } else if (is_Return(node)) {
 379                 pred = get_Return_mem(node);
 380         } else {
 381                 pred = get_fragile_op_mem(node);
 382         }
 383
 384         if (WalkMem(irg, pred, block)) {
 385                 // There was a block change
 386                 size_t block_arity = get_Block_n_cfgpreds(block);
 387
 388                 DB((dbg, LEVEL_3, "===> There is a block change before %+F\n", node));
 389                 if (block_arity == 1) {
 390                         // Just one predecessor, inherit its alias sets
 391                         ir_node* pred_block = get_nodes_block(pred);
 392                         ir_nodeset_t* predsets = get_irn_link(pred_block);
 393                         ir_nodeset_t* thissets = get_irn_link(block);
 394                         size_t i;
 395
 396                         DB((dbg, LEVEL_3, "===> Copying the only predecessor's address sets\n"));
 397
 398                         if (ir_nodeset_size(&predsets[0]) == 0) {
 399                                 ir_node* unknown;
 400
 401                                 DB((dbg, LEVEL_3, "===> The predecessor was not finished yet\n"));
 402                                 assert(!Block_not_block_visited(pred_block));
 403
 404                                 unknown = new_r_Unknown(irg, mode_M);
 405                                 for (i = 0; i < count_addrs; i++) {
 406                                         ir_node* phi_unk = new_r_Phi(irg, block, 1, &unknown, mode_M);
 407                                         DB((dbg, LEVEL_3, "===> Placing unfinished %+F for %+F in %+F\n", phi_unk, addrs[i], block));
 408                                         set_irn_link(phi_unk, unfinished_phis[i]);
 409                                         unfinished_phis[i] = phi_unk;
 410                                         ir_nodeset_insert(&thissets[i], phi_unk);
 411                                 }
 412                         } else {
 413                                 for (i = 0; i < count_addrs; i++) {
 414                                         ir_nodeset_iterator_t prediter;
 415                                         ir_node* addr;
 416
 417                                         ir_nodeset_iterator_init(&prediter, &predsets[i]);
 418                                         while ((addr = ir_nodeset_iterator_next(&prediter)) != NULL) {
 419                                                 ir_nodeset_insert(&thissets[i], addr);
 420                                         }
 421                                 }
 422                         }
 423                 }
 424         }
 425
 426         DB((dbg, LEVEL_3, "===> Detotalising %+F\n", node));
 427
 428         addr_sets = get_irn_link(block);
 429
 430         if (is_Load(node)) {
 431                 PlaceLoad(irg, block, node, memory);
 432         } else if (is_Store(node)) {
 433                 PlaceStore(irg, block, node, memory);
 434         } else {
 435                 ir_nodeset_t sync_set;
 436                 size_t i;
 437                 ir_node* after;
 438
 439                 DB((dbg, LEVEL_3, "===> Fallback: %+F aliases everything\n", node));
 440
 441                 ir_nodeset_init(&sync_set);
 442                 for (i = 0; i < count_addrs; i++) {
 443                         ir_nodeset_iterator_t iter;
 444                         ir_node* mem;
 445
 446                         ir_nodeset_iterator_init(&iter, &addr_sets[i]);
 447                         while ((mem = ir_nodeset_iterator_next(&iter)) != NULL) {
 448                                 ir_nodeset_insert(&sync_set, mem);
 449                         }
 450                 }
 451
 452                 after = GenerateSync(irg, block, &sync_set);
 453                 set_irn_n(node, 0, after); // XXX unnice way to set the memory input
 454
 455                 for (i = 0; i < count_addrs; i++) {
 456                         ir_nodeset_iterator_t iter;
 457                         ir_nodeset_iterator_init(&iter, &addr_sets[i]);
 458                         while (ir_nodeset_iterator_next(&iter) != NULL) {
 459                                 ir_nodeset_remove_iterator(&addr_sets[i], &iter);
 460                         }
 461                         ir_nodeset_insert(&addr_sets[i], memory);
 462                 }
 463         }
 464
 465         return block_change;
 466 }
 467
 468
 469 static void FinalisePhis(ir_graph* irg)
 470 {
 471         size_t i;
 472
 473         for (i = 0; i < count_addrs; i++) {
 474                 ir_node* next_phi;
 475                 ir_node* phi;
 476
 477                 for (phi = unfinished_phis[i]; phi != NULL; phi = next_phi) {
 478                         ir_node* block = get_nodes_block(phi);
 479                         size_t block_n_preds = get_Block_n_cfgpreds(block);
 480
 481                         next_phi = get_irn_link(phi);
 482
 483                         DB((dbg, LEVEL_4, "===> Finialising phi %+F in %+F\n", phi, block));
 484
 485                         if (block_n_preds == 1) {
 486                                 ir_node* pred_block = get_Block_cfgpred_block(block, 0);
 487                                 ir_nodeset_t* pred_sets = get_irn_link(pred_block);
 488                                 ir_node* after = GenerateSync(irg, pred_block, &pred_sets[i]);
 489
 490                                 assert(is_Unknown(get_Phi_pred(phi, 0)));
 491                                 exchange(phi, after);
 492                         } else {
 493                                 ir_node** in;
 494                                 size_t j;
 495
 496                                 NEW_ARR_A(ir_node*, in, block_n_preds);
 497                                 for (j = 0; j < block_n_preds; j++) {
 498                                         ir_node* pred_block = get_Block_cfgpred_block(block, j);
 499                                         ir_nodeset_t* pred_sets = get_irn_link(pred_block);
 500
 501                                         if (is_Unknown(get_Phi_pred(phi, j))) {
 502                                                 set_Phi_pred(phi, j, GenerateSync(irg, pred_block, &pred_sets[i]));
 503                                         }
 504                                 }
 505                         }
 506                 }
 507         }
 508 }
 509
 510
 511 static void Detotalise(ir_graph* irg)
 512 {
 513         ir_node* end_block = get_irg_end_block(irg);
 514         size_t npreds = get_Block_n_cfgpreds(end_block);
 515         size_t i;
 516
 517         unfinished_phis = xmalloc(sizeof(*unfinished_phis) * count_addrs);
 518         for (i = 0; i < count_addrs; i++) {
 519                 unfinished_phis[i] = NULL;
 520         }
 521
 522         for (i = 0; i < npreds; i++) {
 523                 ir_node* pred = get_Block_cfgpred(end_block, i);
 524                 assert(is_Return(pred));
 525                 DB((dbg, LEVEL_2, "===> Starting memory walk at %+F\n", pred));
 526                 WalkMem(irg, pred, NULL);
 527         }
 528
 529         FinalisePhis(irg);
 530         xfree(unfinished_phis);
 531 }
 532
 533
 534 static void AddSyncPreds(ir_nodeset_t* preds, ir_node* sync)
 535 {
 536         size_t n = get_Sync_n_preds(sync);
 537         size_t i;
 538
 539         for (i = 0; i < n; i++) {
 540                 ir_node* pred = get_Sync_pred(sync, i);
 541                 if (is_Sync(pred)) {
 542                         AddSyncPreds(preds, pred);
 543                 } else {
 544                         ir_nodeset_insert(preds, pred);
 545                 }
 546         }
 547 }
 548
 549
 550 static void NormaliseSync(ir_node* node, void* env)
 551 {
 552         ir_nodeset_t preds;
 553         ir_nodeset_iterator_t iter;
 554         ir_node** in;
 555         size_t count_preds;
 556         size_t i;
 557         (void) env;
 558
 559         if (!is_Sync(node)) return;
 560
 561         ir_nodeset_init(&preds);
 562         AddSyncPreds(&preds, node);
 563
 564         count_preds = ir_nodeset_size(&preds);
 565         if (count_preds != (unsigned)get_Sync_n_preds(node)) {
 566                 NEW_ARR_A(ir_node*, in, count_preds);
 567                 ir_nodeset_iterator_init(&iter, &preds);
 568                 for (i = 0; i < count_preds; i++) {
 569                         ir_node* pred = ir_nodeset_iterator_next(&iter);
 570                         assert(pred != NULL);
 571                         in[i] = pred;
 572                 }
 573                 set_irn_in(node, count_preds, in);
 574         }
 575
 576         ir_nodeset_destroy(&preds);
 577 }
 578
 579
 580 void opt_ldst2(ir_graph* irg)
 581 {
 582         FIRM_DBG_REGISTER(dbg, "firm.opt.ldst2");
 583         DB((dbg, LEVEL_1, "===> Performing load/store optimisation on %+F\n", irg));
 584
 585         normalize_one_return(irg);
 586         dump_ir_block_graph(irg, "-prefluffig");
 587
 588         obstack_init(&obst);
 589
 590         if (1 /* XXX */ || get_opt_alias_analysis()) {
 591                 assure_irg_address_taken_computed(irg);
 592                 assure_irp_globals_address_taken_computed();
 593         }
 594
 595
 596         CollectAddresses(irg);
 597         if (count_addrs == 0) return;
 598
 599         irg_block_walk_graph(irg, AliasSetAdder, NULL, NULL);
 600         inc_irg_block_visited(irg);
 601         SetStartAddressesTop(irg);
 602         Detotalise(irg);
 603         dump_ir_block_graph(irg, "-fluffig");
 604
 605         irg_block_walk_graph(irg, AliasSetDestroyer, NULL, NULL);
 606         obstack_free(&obst, NULL);
 607
 608         irg_walk_graph(irg, NormaliseSync, NULL, NULL);
 609         optimize_graph_df(irg);
 610         irg_walk_graph(irg, NormaliseSync, NULL, NULL);
 611         dump_ir_block_graph(irg, "-postfluffig");
 612 }