nsz Git - libfirm/blob - ir/be/bespillslots.c

   1 /*
   2  * Author:      Matthias Braun
   3  * Date:                26.7.06
   4  * Copyright:   (c) Universitaet Karlsruhe
   5  * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
   6  */
   7 #ifdef HAVE_CONFIG_H
   8 #include "config.h"
   9 #endif
  10
  11 #include <stdlib.h>
  12
  13 #include "set.h"
  14
  15 #include "irgwalk.h"
  16 #include "ircons.h"
  17 #include "irprintf.h"
  18 #include "execfreq.h"
  19 #include "unionfind.h"
  20 #include "type.h"
  21 #include "irdump_t.h"
  22
  23 #include "benode_t.h"
  24 #include "besched.h"
  25 #include "bespillslots.h"
  26 #include "bechordal_t.h"
  27 #include "bejavacoal.h"
  28
  29
  30 #define DBG_COALESCING          1
  31 #define DBG_INTERFERENCES       2
  32
  33 DEBUG_ONLY(
  34 static firm_dbg_module_t *dbg = NULL;
  35 )
  36
  37 typedef struct _spill_t {
  38         ir_node *spill;
  39         /** regclass of the spilled value */
  40         const arch_register_class_t *cls;
  41         /** index into spillslot_unionfind unionfind structure */
  42         int spillslot;
  43 } spill_t;
  44
  45 typedef struct _affinity_edge_t {
  46         double affinity;
  47         int slot1, slot2;
  48 } affinity_edge_t;
  49
  50 typedef struct _ss_env_t {
  51         struct obstack obst;
  52         const arch_env_t *arch_env;
  53         const be_chordal_env_t *chordal_env;
  54         set *spills;
  55         ir_node **reloads;
  56         affinity_edge_t **affinity_edges;
  57         set *memperms;
  58 } ss_env_t;
  59
  60 /** Compare 2 affinity edges (used in quicksort) */
  61 static int cmp_affinity(const void *d1, const void *d2) {
  62         const affinity_edge_t * const *e1 = d1;
  63         const affinity_edge_t * const *e2 = d2;
  64
  65         // sort in descending order
  66         return (*e1)->affinity < (*e2)->affinity ? 1 : -1;
  67 }
  68
  69 static int cmp_spill(const void* d1, const void* d2, size_t size) {
  70         const spill_t* s1 = d1;
  71         const spill_t* s2 = d2;
  72         return s1->spill != s2->spill;
  73 }
  74
  75 static spill_t *get_spill(ss_env_t *env, ir_node *node) {
  76         spill_t spill, *res;
  77         int hash = HASH_PTR(node);
  78
  79         spill.spill = node;
  80         res = set_find(env->spills, &spill, sizeof(spill), hash);
  81
  82         return res;
  83 }
  84
  85 /*
  86  *   ____      _ _           _     ____        _ _ _
  87  *  / ___|___ | | | ___  ___| |_  / ___| _ __ (_) | |___
  88  * | |   / _ \| | |/ _ \/ __| __| \___ \| '_ \| | | / __|
  89  * | |__| (_) | | |  __/ (__| |_   ___) | |_) | | | \__ \
  90  *  \____\___/|_|_|\___|\___|\__| |____/| .__/|_|_|_|___/
  91  *                                      |_|
  92  */
  93
  94 static ir_node *get_memory_edge(const ir_node *node) {
  95         int i, arity;
  96
  97         arity = get_irn_arity(node);
  98         for(i = arity - 1; i >= 0; --i) {
  99                 ir_node *arg = get_irn_n(node, i);
 100                 if(get_irn_mode(arg) == mode_M)
 101                         return arg;
 102         }
 103
 104         return NULL;
 105 }
 106
 107 static spill_t *collect_spill(ss_env_t *env, ir_node *node) {
 108         const arch_env_t *arch_env = env->arch_env;
 109         const arch_register_class_t *cls;
 110         spill_t spill, *res;
 111         int hash = HASH_PTR(node);
 112
 113         assert(arch_irn_class_is(arch_env, node, spill));
 114
 115         if(be_is_Spill(node)) {
 116                 cls = arch_get_irn_reg_class(arch_env, node, be_pos_Spill_val);
 117         } else {
 118                 // TODO add a way to detect the type of the spilled value
 119                 assert(0);
 120         }
 121
 122         spill.spill = node;
 123         res = set_find(env->spills, &spill, sizeof(spill), hash);
 124
 125         if(res == NULL) {
 126                 spill.spillslot = set_count(env->spills);
 127                 spill.cls = cls;
 128                 res = set_insert(env->spills, &spill, sizeof(spill), hash);
 129         }
 130
 131         return res;
 132 }
 133
 134 static spill_t *collect_memphi(ss_env_t *env, ir_node *node) {
 135         int i, arity;
 136         spill_t spill, *res;
 137         int hash = HASH_PTR(node);
 138
 139         assert(is_Phi(node));
 140
 141         spill.spill = node;
 142         res = set_find(env->spills, &spill, sizeof(spill), hash);
 143         if(res != NULL) {
 144                 return res;
 145         }
 146
 147         spill.spillslot = set_count(env->spills);
 148         spill.cls = NULL;
 149         res = set_insert(env->spills, &spill, sizeof(spill), hash);
 150
 151         // is 1 of the arguments a spill?
 152         for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
 153                 affinity_edge_t *affinty_edge;
 154                 ir_node* arg = get_irn_n(node, i);
 155                 spill_t* arg_spill;
 156
 157                 if(be_is_Spill(arg)) {
 158                         arg_spill = collect_spill(env, arg);
 159                 } else {
 160                         // if it wasn't a spill then it must be a Mem-Phi
 161                         assert(is_Phi(arg));
 162                         arg_spill = collect_memphi(env, arg);
 163                 }
 164
 165                 if(res->cls == NULL) {
 166                         res->cls = arg_spill->cls;
 167                 } else {
 168                         assert(arg_spill->cls == NULL || res->cls == arg_spill->cls);
 169                 }
 170
 171                 // add an affinity edge
 172                 affinty_edge = obstack_alloc(&env->obst, sizeof(affinty_edge[0]));
 173                 affinty_edge->affinity = get_block_execfreq(env->chordal_env->exec_freq, get_nodes_block(arg));
 174                 affinty_edge->slot1 = res->spillslot;
 175                 affinty_edge->slot2 = arg_spill->spillslot;
 176                 ARR_APP1(affinity_edge_t*, env->affinity_edges, affinty_edge);
 177         }
 178
 179         return res;
 180 }
 181
 182 /**
 183  * This walker function searches for reloads and collects all the spills
 184  * and memphis attached to them.
 185  */
 186 static void collect_spills_walker(ir_node *node, void *data) {
 187         ss_env_t *env = data;
 188         const arch_env_t *arch_env = env->arch_env;
 189
 190         // @@@ ia32 classify returns classification of the irn the proj is attached
 191         // too, why oh why?...
 192         if(is_Proj(node))
 193                 return;
 194
 195         if(arch_irn_class_is(arch_env, node, reload)) {
 196                 ir_node *spillnode = get_memory_edge(node);
 197                 spill_t *spill;
 198
 199                 assert(spillnode != NULL);
 200
 201                 if(is_Phi(spillnode)) {
 202                         spill = collect_memphi(env, spillnode);
 203                 } else {
 204                         spill = collect_spill(env, spillnode);
 205                 }
 206
 207                 assert(!be_is_Reload(node) || spill->cls == arch_get_irn_reg_class(arch_env, node, -1));
 208                 ARR_APP1(ir_node*, env->reloads, node);
 209         }
 210 }
 211
 212 /*
 213  *   ____            _                      ____  _       _
 214  *  / ___|___   __ _| | ___  ___  ___ ___  / ___|| | ___ | |_ ___
 215  * | |   / _ \ / _` | |/ _ \/ __|/ __/ _ \ \___ \| |/ _ \| __/ __|
 216  * | |__| (_) | (_| | |  __/\__ \ (_|  __/  ___) | | (_) | |_\__ \
 217  *  \____\___/ \__,_|_|\___||___/\___\___| |____/|_|\___/ \__|___/
 218  */
 219
 220 static int merge_interferences(ss_env_t *env, bitset_t** interferences, int* spillslot_unionfind, int s1, int s2)
 221 {
 222         int res;
 223         int i;
 224         int spillcount;
 225
 226         // merge spillslots and interferences
 227         res = uf_union(spillslot_unionfind, s1, s2);
 228         // we assume that we always merge s2 to s1 so swap s1, s2 if necessary
 229         if(res != 0) {
 230                 int t = s1;
 231                 s1 = s2;
 232                 s2 = t;
 233         }
 234
 235         bitset_or(interferences[s1], interferences[s2]);
 236
 237         // update other interferences
 238         spillcount = set_count(env->spills);
 239         for(i = 0; i < spillcount; ++i) {
 240                 bitset_t *intfs = interferences[i];
 241                 if(bitset_is_set(intfs, s2))
 242                         bitset_set(intfs, s1);
 243         }
 244
 245         return res;
 246 }
 247
 248 #if 0
 249
 250 static void dump_interference_graph(ss_env_t *env, bitset_t **interferences, const char* suffix) {
 251         char name[256];
 252         int i;
 253         int spillcount;
 254         spill_t *spill;
 255         FILE *f;
 256         static int cnt = 0;
 257
 258         snprintf(name, sizeof(name), "%d-%s-spillslots-%s.vcg", cnt++, get_irg_dump_name(env->chordal_env->birg->irg), suffix);
 259
 260         f = fopen(name, "w");
 261         assert(f != NULL);
 262
 263         fprintf(f, "graph: {\n");
 264
 265         spillcount = set_count(env->spills);
 266         for(spill = set_first(env->spills), i = 0; spill != NULL; spill = set_next(env->spills), ++i) {
 267                 int slotid = spill->spillslot;
 268                 fprintf(f, "\tnode: { title: \"n%d\" label: \"%d\" }\n", i, slotid);
 269         }
 270
 271         for(i = 0; i < ARR_LEN(env->affinity_edges); ++i) {
 272                 affinity_edge_t *edge = env->affinity_edges[i];
 273                 fprintf(f, "\tedge: { sourcename: \"n%d\" targetname: \"n%d\" color: green }\n", edge->slot1, edge->slot2);
 274         }
 275
 276         for(i = 0; i < spillcount; ++i) {
 277                 int i2;
 278                 for(i2 = 0; i2 < spillcount; ++i2) {
 279                         if(bitset_is_set(interferences[i], i2)) {
 280                                 fprintf(f, "\tedge: { sourcename: \"n%d\" targetname: \"n%d\" color: red }\n", i, i2);
 281                         }
 282                 }
 283         }
 284
 285         fprintf(f, "}\n");
 286         fclose(f);
 287 }
 288
 289 static void show_stats(ss_env_t *env) {
 290         int spillcount;
 291         int slotcount;
 292         int *slotused;
 293         spill_t *spill;
 294
 295         spillcount = set_count(env->spills);
 296         fprintf(stderr, "%s: Collected %d spills\n", get_irg_dump_name(env->chordal_env->birg->irg), spillcount);
 297
 298         slotused = alloca(spillcount * sizeof(slotused[0]));
 299         memset(slotused, 0, spillcount * sizeof(slotused[0]));
 300
 301         slotcount = 0;
 302         for(spill = set_first(env->spills); spill != NULL; spill = set_next(env->spills)) {
 303                 int slot = spill->spillslot;
 304                 if(slotused[slot] == 0) {
 305                         slotused[slot] = 1;
 306                         slotcount++;
 307                 }
 308         }
 309
 310         fprintf(stderr, "%s: Coalesced to %d spillslots\n", get_irg_dump_name(env->chordal_env->birg->irg), slotcount);
 311 }
 312
 313 #endif
 314
 315 static void assign_spillslots(ss_env_t *env);
 316
 317 /**
 318  * A greedy coalescing algorithm for spillslots:
 319  *  1. Sort the list of affinity edges
 320  *  2. Try to merge slots with affinity edges (most expensive slots first)
 321  *  3. Try to merge everything else that is possible
 322  */
 323 static void do_greedy_coalescing(ss_env_t *env)
 324 {
 325         int spillcount;
 326         spill_t **spilllist;
 327         spill_t *spill;
 328         int i, i2;
 329         int affinity_edge_count;
 330         bitset_t **interferences;
 331         int* spillslot_unionfind;
 332
 333         spillcount = set_count(env->spills);
 334         if(spillcount == 0)
 335                 return;
 336
 337         DBG((dbg, DBG_COALESCING, "Coalescing %d spillslots\n", spillcount));
 338
 339         interferences = alloca(spillcount * sizeof(interferences[0]));
 340         spillslot_unionfind = alloca(spillcount * sizeof(spillslot_unionfind[0]));
 341         spilllist = alloca(spillcount * sizeof(spilllist[0]));
 342
 343         uf_init(spillslot_unionfind, 0, spillcount);
 344
 345         DEBUG_ONLY(
 346                 memset(spilllist, 0, spillcount * sizeof(spilllist[0]));
 347         );
 348
 349         for(spill = set_first(env->spills), i = 0; spill != NULL; spill = set_next(env->spills), ++i) {
 350                 assert(spill->spillslot < spillcount);
 351                 spilllist[spill->spillslot] = spill;
 352         }
 353
 354         for(i = 0; i < spillcount; ++i) {
 355                 interferences[i] = bitset_alloca(spillcount);
 356         }
 357
 358         // construct interferences
 359         for(i = 0; i < spillcount; ++i) {
 360                 for(i2 = i+1; i2 < spillcount; ++i2) {
 361                         if(values_interfere(env->chordal_env->lv, spilllist[i]->spill, spilllist[i2]->spill)) {
 362                                 DBG((dbg, DBG_INTERFERENCES, "Slot %d and %d interfere\n", i, i2));
 363                                 bitset_set(interferences[i], i2);
 364                                 bitset_set(interferences[i2], i);
 365                         }
 366                 }
 367         }
 368
 369         // sort affinity edges
 370         affinity_edge_count = ARR_LEN(env->affinity_edges);
 371         qsort(env->affinity_edges, affinity_edge_count, sizeof(env->affinity_edges[0]), cmp_affinity);
 372
 373         //dump_interference_graph(env, interferences, "before");
 374
 375         // try to merge affine nodes
 376         for(i = 0; i < affinity_edge_count; ++i) {
 377                 const affinity_edge_t *edge = env->affinity_edges[i];
 378                 int s1 = uf_find(spillslot_unionfind, edge->slot1);
 379                 int s2 = uf_find(spillslot_unionfind, edge->slot2);
 380
 381                 /* test if values interfere */
 382                 if(bitset_is_set(interferences[s1], s2)) {
 383                         assert(bitset_is_set(interferences[s2], s1));
 384                         continue;
 385                 }
 386
 387                 DBG((dbg, DBG_COALESCING, "Merging %d and %d because of affinity edge\n", s1, s2));
 388
 389                 merge_interferences(env, interferences, spillslot_unionfind, s1, s2);
 390         }
 391
 392         // try to merge as much remaining spillslots as possible
 393         for(i = 0; i < spillcount; ++i) {
 394                 int s1 = uf_find(spillslot_unionfind, i);
 395                 if(s1 != i)
 396                         continue;
 397
 398                 for(i2 = i+1; i2 < spillcount; ++i2) {
 399                         int s2 = uf_find(spillslot_unionfind, i2);
 400                         if(s2 != i2)
 401                                 continue;
 402
 403                         /* test if values interfere
 404                          * we have to test n1-n2 and n2-n1, because only 1 side gets updated
 405                          * when node merging occurs
 406                          */
 407                         if(bitset_is_set(interferences[s1], s2)) {
 408                                 assert(bitset_is_set(interferences[s2], s1));
 409                                 continue;
 410                         }
 411
 412                         DBG((dbg, DBG_COALESCING, "Merging %d and %d because it is possible\n", s1, s2));
 413
 414                         if(merge_interferences(env, interferences, spillslot_unionfind, s1, s2) != 0) {
 415                                 // we can break the loop here, because s2 is the new supernode now
 416                                 // and we'll test s2 again later anyway
 417                                 break;
 418                         }
 419                 }
 420         }
 421
 422         // assign spillslots to spills
 423         for(i = 0; i < spillcount; ++i) {
 424                 spill_t *spill = spilllist[i];
 425
 426                 spill->spillslot = uf_find(spillslot_unionfind, i);
 427         }
 428
 429         //dump_interference_graph(env, interferences, "after");
 430 }
 431
 432 #if 0
 433 static void do_java_coalescing(ss_env_t *env)
 434 {
 435         int spillcount;
 436         spill_t **spilllist;
 437         spill_t *spill;
 438         int i, i2;
 439         be_java_coal_t *coal;
 440
 441         spillcount = set_count(env->spills);
 442         if(spillcount == 0)
 443                 return;
 444
 445         spilllist = alloca(spillcount * sizeof(spilllist[0]));
 446
 447         DEBUG_ONLY(
 448                 memset(spilllist, 0, spillcount * sizeof(spilllist[0]));
 449         );
 450
 451         coal = be_java_coal_init("spillslot coalescing", spillcount, spillcount, 1);
 452
 453         for(spill = set_first(env->spills), i = 0; spill != NULL; spill = set_next(env->spills), ++i) {
 454                 assert(spill->spillslot < spillcount);
 455                 DEBUG_ONLY(assert(spilllist[spill->spillslot] == NULL));
 456                 spilllist[spill->spillslot] = spill;
 457
 458                 be_java_coal_set_color(coal, spill->spillslot, spill->spillslot);
 459         }
 460
 461         // construct interferences
 462         for(i = 0; i < spillcount; ++i) {
 463                 for(i2 = i+1; i2 < spillcount; ++i2) {
 464                         if(values_interfere(env->chordal_env->lv, spilllist[i]->spill, spilllist[i2]->spill)) {
 465                                 be_java_coal_add_int_edge(coal, i, i2);
 466                         }
 467                 }
 468         }
 469
 470         for(i = 0; i < ARR_LEN(env->affinity_edges); ++i) {
 471                 const affinity_edge_t *edge = env->affinity_edges[i];
 472                 int n = edge->slot1;
 473                 int m = edge->slot2;
 474                 int costs = (int) (edge->affinity * 10000);
 475                 be_java_coal_add_aff_edge(coal, n, m, costs);
 476         }
 477
 478         be_java_coal_coalesce(coal);
 479
 480         // construct spillslots
 481         for(i = 0; i < spillcount; ++i) {
 482                 spill_t *spill = spilllist[i];
 483                 spill->spillslot = be_java_coal_get_color(coal, i);
 484         }
 485         be_java_coal_destroy(coal);
 486 }
 487 #endif
 488
 489 /*
 490  *     _            _               _____       _   _ _   _
 491  *    / \   ___ ___(_) __ _ _ __   | ____|_ __ | |_(_) |_(_) ___  ___
 492  *   / _ \ / __/ __| |/ _` | '_ \  |  _| | '_ \| __| | __| |/ _ \/ __|
 493  *  / ___ \\__ \__ \ | (_| | | | | | |___| | | | |_| | |_| |  __/\__ \
 494  * /_/   \_\___/___/_|\__, |_| |_| |_____|_| |_|\__|_|\__|_|\___||___/
 495  *                    |___/
 496  */
 497
 498 typedef struct _spill_slot_t {
 499         int size;
 500         int align;
 501         entity   *entity;
 502 } spill_slot_t;
 503
 504 typedef struct _memperm_entry_t {
 505         ir_node* node;
 506         int pos;
 507         entity *in;
 508         entity *out;
 509         struct _memperm_entry_t *next;
 510 } memperm_entry_t;
 511
 512 typedef struct _memperm_t {
 513         ir_node *block;
 514         int entrycount;
 515         memperm_entry_t *entries;
 516 } memperm_t;
 517
 518 static int cmp_memperm(const void* d1, const void* d2, size_t size) {
 519         const memperm_t* e1 = d1;
 520         const memperm_t* e2 = d2;
 521         return e1->block != e2->block;
 522 }
 523
 524 static memperm_t *get_memperm(ss_env_t *env, ir_node *block) {
 525         memperm_t entry, *res;
 526         int hash;
 527
 528         entry.block = block;
 529         hash = HASH_PTR(block);
 530
 531         res = set_find(env->memperms, &entry, sizeof(entry), hash);
 532
 533         if(res == NULL) {
 534                 entry.entrycount = 0;
 535                 entry.entries = NULL;
 536                 res = set_insert(env->memperms, &entry, sizeof(entry), hash);
 537         }
 538
 539         return res;
 540 }
 541
 542 static entity* create_stack_entity(ss_env_t *env, spill_slot_t *slot) {
 543         ir_type* frame = get_irg_frame_type(env->chordal_env->irg);
 544         entity* res = frame_alloc_area(frame, slot->size, slot->align, 0);
 545
 546         // adjust size of the entity type...
 547         ir_type *enttype = get_entity_type(res);
 548         set_type_size_bytes(enttype, slot->size);
 549
 550         slot->entity = res;
 551
 552         return res;
 553 }
 554
 555 static int get_spillslotsize_for_spill(ss_env_t *env, spill_t *spill) {
 556         const ir_mode *mode = arch_register_class_mode(spill->cls);
 557
 558         return get_mode_size_bytes(mode);
 559 }
 560
 561 static int get_spillslotalign_for_spill(ss_env_t *env, spill_t *spill) {
 562         const arch_isa_t *isa = env->chordal_env->birg->main_env->arch_env->isa;
 563
 564         return arch_isa_get_reg_class_alignment(isa, spill->cls);
 565 }
 566
 567 /**
 568  * Enlarges a spillslot (if necessary) so that it can carry a value of size
 569  * @p othersize and alignment @p otheralign.
 570  */
 571 static void enlarge_spillslot(spill_slot_t *slot, int otheralign, int othersize) {
 572         if(othersize > slot->size) {
 573                 slot->size = othersize;
 574         }
 575         if(otheralign > slot->align) {
 576                 if(otheralign % slot->align != 0)
 577                         slot->align *= otheralign;
 578                 else
 579                         slot->align = otheralign;
 580         } else if(slot->align % otheralign != 0) {
 581                 slot->align *= otheralign;
 582         }
 583 }
 584
 585 /**
 586  * Create stack entities for the spillslots and assign them to the spill and
 587  * reload nodes.
 588  */
 589 static void assign_spillslots(ss_env_t *env) {
 590         const arch_env_t *arch_env = env->arch_env;
 591         int i;
 592         int spillcount;
 593         spill_t *spill;
 594         spill_slot_t* spillslots;
 595
 596         spillcount = set_count(env->spills);
 597         spillslots = alloca(spillcount * sizeof(spillslots[0]));
 598
 599         memset(spillslots, 0, spillcount * sizeof(spillslots[0]));
 600
 601         // construct spillslots
 602         for(spill = set_first(env->spills); spill != NULL; spill = set_next(env->spills)) {
 603                 int slotid = spill->spillslot;
 604                 spill_slot_t *slot = & (spillslots[slotid]);
 605                 int align = get_spillslotalign_for_spill(env, spill);
 606                 int size = get_spillslotsize_for_spill(env, spill);
 607
 608                 if(slot->align == 0 && slot->size == 0) {
 609                         slot->align = align;
 610                         slot->size = size;
 611                 } else {
 612                         enlarge_spillslot(slot, align, size);
 613                 }
 614         }
 615
 616         for(spill = set_first(env->spills); spill != NULL; spill = set_next(env->spills)) {
 617                 spill_slot_t *slot;
 618                 ir_node *node = spill->spill;
 619                 int slotid = spill->spillslot;
 620
 621                 slot = &spillslots[slotid];
 622                 if(slot->entity == NULL) {
 623                         create_stack_entity(env, slot);
 624                 }
 625
 626                 if(is_Phi(node)) {
 627                         int i, arity;
 628                         ir_node *block = get_nodes_block(node);
 629
 630                         // should be a PhiM
 631                         assert(is_Phi(node));
 632
 633                         for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
 634                                 ir_node *arg = get_irn_n(node, i);
 635                                 ir_node *predblock = get_Block_cfgpred_block(block, i);
 636                                 spill_t *argspill;
 637                                 int argslotid;
 638
 639                                 argspill = get_spill(env, arg);
 640                                 assert(argspill != NULL);
 641
 642                                 argslotid = argspill->spillslot;
 643                                 if(slotid != argslotid) {
 644                                         memperm_t *memperm;
 645                                         memperm_entry_t *entry;
 646                                         spill_slot_t *argslot = &spillslots[argslotid];
 647                                         if(argslot->entity == NULL) {
 648                                                 create_stack_entity(env, argslot);
 649                                         }
 650
 651                                         memperm = get_memperm(env, predblock);
 652
 653                                         entry = obstack_alloc(&env->obst, sizeof(entry[0]));
 654                                         entry->node = node;
 655                                         entry->pos = i;
 656                                         entry->in = argslot->entity;
 657                                         entry->out = slot->entity;
 658                                         entry->next = memperm->entries;
 659                                         memperm->entrycount++;
 660                                         memperm->entries = entry;
 661                                 }
 662                         }
 663                 } else {
 664                         assert(arch_irn_class_is(arch_env, node, spill));
 665                         arch_set_frame_entity(arch_env, node, slot->entity);
 666                 }
 667         }
 668
 669         for(i = 0; i < ARR_LEN(env->reloads); ++i) {
 670                 ir_node* reload = env->reloads[i];
 671                 ir_node* spillnode = get_memory_edge(reload);
 672                 spill_t *spill = get_spill(env, spillnode);
 673                 const spill_slot_t *slot = & spillslots[spill->spillslot];
 674
 675                 assert(slot->entity != NULL);
 676
 677                 arch_set_frame_entity(arch_env, reload, slot->entity);
 678         }
 679 }
 680
 681 /**
 682  * Returns the last node in a block which is no control flow changing node
 683  */
 684 static ir_node *get_end_of_block_insertion_point(ir_node* block)
 685 {
 686         ir_node* ins = sched_last(block);
 687         while(is_Proj(ins) && get_irn_mode(ins) == mode_X) {
 688                 ins = sched_prev(ins);
 689                 assert(ins != NULL);
 690         }
 691
 692         if(is_cfop(ins)) {
 693                 while(1) {
 694                         ir_node *prev = sched_prev(ins);
 695                         if(!is_cfop(prev))
 696                                 break;
 697                         ins = prev;
 698                 }
 699         }
 700
 701         return ins;
 702 }
 703
 704 static void create_memperms(ss_env_t *env) {
 705         memperm_t *memperm;
 706
 707         for(memperm = set_first(env->memperms); memperm != NULL; memperm = set_next(env->memperms)) {
 708                 int i;
 709                 memperm_entry_t *entry;
 710                 ir_node *blockend;
 711                 ir_node** nodes = alloca(memperm->entrycount * sizeof(nodes[0]));
 712                 ir_node* mempermnode;
 713
 714                 assert(memperm->entrycount > 0);
 715
 716                 for(entry = memperm->entries, i = 0; entry != NULL; entry = entry->next, ++i) {
 717                         ir_node* arg = get_irn_n(entry->node, entry->pos);
 718                         nodes[i] = arg;
 719                 }
 720
 721                 mempermnode = be_new_MemPerm(env->chordal_env->birg->main_env->arch_env, env->chordal_env->irg, memperm->block,
 722                         memperm->entrycount, nodes);
 723
 724                 // insert node into schedule
 725                 blockend = get_end_of_block_insertion_point(memperm->block);
 726                 sched_add_before(blockend, mempermnode);
 727
 728                 for(entry = memperm->entries, i = 0; entry != NULL; entry = entry->next, ++i) {
 729                         ir_node *proj;
 730                         ir_node* arg = get_irn_n(entry->node, entry->pos);
 731
 732                         be_set_MemPerm_in_entity(mempermnode, i, entry->in);
 733                         be_set_MemPerm_out_entity(mempermnode, i, entry->out);
 734                         set_irg_current_block(env->chordal_env->irg, memperm->block);
 735                         proj = new_Proj(mempermnode, get_irn_mode(arg), i);
 736                         sched_add_before(blockend, proj);
 737
 738                         set_irn_n(entry->node, entry->pos, proj);
 739                 }
 740         }
 741 }
 742
 743 void be_coalesce_spillslots(const be_chordal_env_t *chordal_env) {
 744         ss_env_t env;
 745
 746         obstack_init(&env.obst);
 747         env.arch_env = chordal_env->birg->main_env->arch_env;
 748         env.chordal_env = chordal_env;
 749         env.spills = new_set(cmp_spill, 10);
 750         env.reloads = NEW_ARR_F(ir_node*, 0);
 751         env.affinity_edges = NEW_ARR_F(affinity_edge_t*, 0);
 752         env.memperms = new_set(cmp_memperm, 10);
 753         FIRM_DBG_REGISTER(dbg, "firm.be.spillslots");
 754         //firm_dbg_set_mask(dbg, DBG_COALESCING);
 755
 756         /* Get initial spill slots */
 757         irg_walk_graph(chordal_env->irg, NULL, collect_spills_walker, &env);
 758
 759         do_greedy_coalescing(&env);
 760
 761         assign_spillslots(&env);
 762
 763         create_memperms(&env);
 764
 765         //show_stats(&env);
 766
 767         del_set(env.memperms);
 768         DEL_ARR_F(env.reloads);
 769         DEL_ARR_F(env.affinity_edges);
 770         del_set(env.spills);
 771         obstack_free(&env.obst, NULL);
 772 }