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