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