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

   1 /*
   2  * Copyright (C) 1995-2011 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   Dataflow driven Load/Store optimizations, uses some ideas from
  23  *          VanDrunen's LEPRE
  24  * @author  Michael Beck
  25  * @version $Id$
  26  */
  27 #include "config.h"
  28
  29 #include "irnode_t.h"
  30 #include "irflag_t.h"
  31 #include "array_t.h"
  32 #include "ircons.h"
  33 #include "irdom.h"
  34 #include "irgmod.h"
  35 #include "irgwalk.h"
  36 #include "irouts.h"
  37 #include "irgraph.h"
  38 #include "irgopt.h"
  39 #include "iropt.h"
  40 #include "iroptimize.h"
  41 #include "irnodemap.h"
  42 #include "raw_bitset.h"
  43 #include "debug.h"
  44 #include "error.h"
  45 #include "irpass.h"
  46
  47 /* maximum number of output Proj's */
  48 #define MAX_PROJ ((long)pn_Load_max > (long)pn_Store_max ? (long)pn_Load_max : (long)pn_Store_max)
  49
  50 /**
  51  * Mapping an address to an dense ID.
  52  */
  53 typedef struct address_entry_t {
  54         unsigned id;          /**< The ID */
  55 } address_entry;
  56
  57 /**
  58  * Memop-flags.
  59  */
  60 enum memop_flags {
  61         FLAG_KILL_ALL    = 1, /**< KILL all addresses */
  62         FLAG_KILLED_NODE = 2, /**< this node was killed */
  63         FLAG_EXCEPTION   = 4, /**< this node has exception flow */
  64         FLAG_IGNORE      = 8, /**< ignore this node (volatile or other) */
  65 };
  66
  67 /**
  68  * A value: This represents a value stored at a given address in
  69  * memory. Do not confuse with values from value numbering.
  70  */
  71 typedef struct value_t value_t;
  72 struct value_t {
  73         ir_node  *address;    /**< the address of this value */
  74         ir_node  *value;      /**< the value itself */
  75         ir_mode  *mode;       /**< the mode of the value */
  76         unsigned id;          /**< address id */
  77 };
  78
  79 /**
  80  * A memop describes an memory-related operation.
  81  * These are Loads/Store and all other ops that might modify
  82  * memory (Calls, CopyB) or causing exceptions.
  83  */
  84 typedef struct memop_t memop_t;
  85 struct memop_t {
  86         value_t  value;      /**< the value of this memop: only defined for Load/Store */
  87         ir_node  *node;      /**< the memory op itself */
  88         ir_node  *mem;       /**< the memory FROM this node */
  89         ir_node  *replace;   /**< the replacement node if this memop is replaced */
  90         memop_t  *next;      /**< links to the next memory op in the block in forward order. */
  91         memop_t  *prev;      /**< links to the previous memory op in the block in forward order. */
  92         unsigned flags;      /**< memop flags */
  93         ir_node  *projs[MAX_PROJ]; /**< Projs of this memory op */
  94 };
  95
  96 /**
  97  * Additional data for every basic block.
  98  */
  99 typedef struct block_t block_t;
 100 struct block_t {
 101         memop_t  *memop_forward;     /**< topologically sorted list of memory ops in this block */
 102         memop_t  *memop_backward;    /**< last memop in the list */
 103         unsigned *avail_out;         /**< out-set of available addresses */
 104         memop_t  **id_2_memop_avail; /**< maps avail address ids to memops */
 105         unsigned *anticL_in;         /**< in-set of anticipated Load addresses */
 106         memop_t  **id_2_memop_antic; /**< maps anticipated address ids to memops */
 107         ir_node  *block;             /**< the associated block */
 108         block_t  *forward_next;      /**< next block entry for forward iteration */
 109         block_t  *backward_next;     /**< next block entry for backward iteration */
 110         memop_t  *avail;             /**< used locally for the avail map */
 111         memop_t  **trans_results;    /**< used to cached translated nodes due antic calculation. */
 112 };
 113
 114 /**
 115  * Metadata for this pass.
 116  */
 117 typedef struct ldst_env_t {
 118         struct obstack  obst;              /**< obstack for temporary data */
 119         ir_nodemap_t    adr_map;           /**< Map addresses to */
 120         block_t         *forward;          /**< Inverse post-order list of all blocks Start->End */
 121         block_t         *backward;         /**< Inverse post-order list of all blocks End->Start */
 122         ir_node         *start_bl;         /**< start block of the current graph */
 123         ir_node         *end_bl;           /**< end block of the current graph */
 124         unsigned        *curr_set;         /**< current set of addresses */
 125         memop_t         **curr_id_2_memop; /**< current map of address ids to memops */
 126         unsigned        curr_adr_id;       /**< number for address mapping */
 127         unsigned        n_mem_ops;         /**< number of memory operations (Loads/Stores) */
 128         size_t          rbs_size;          /**< size of all bitsets in bytes */
 129         int             max_cfg_preds;     /**< maximum number of block cfg predecessors */
 130         int             changed;           /**< Flags for changed graph state */
 131 #ifdef DEBUG_libfirm
 132         ir_node         **id_2_address;    /**< maps an id to the used address */
 133 #endif
 134 } ldst_env;
 135
 136 /* the one and only environment */
 137 static ldst_env env;
 138
 139 #ifdef DEBUG_libfirm
 140
 141 static firm_dbg_module_t *dbg;
 142
 143 /**
 144  * Dumps the block list.
 145  *
 146  * @param ldst environment
 147  */
 148 static void dump_block_list(ldst_env *env)
 149 {
 150         block_t *entry;
 151         memop_t *op;
 152         int     i;
 153
 154         for (entry = env->forward; entry != NULL; entry = entry->forward_next) {
 155                 DB((dbg, LEVEL_2, "%+F {", entry->block));
 156
 157                 i = 0;
 158                 for (op = entry->memop_forward; op != NULL; op = op->next) {
 159                         if (i == 0) {
 160                                 DB((dbg, LEVEL_2, "\n\t"));
 161                         }
 162                         DB((dbg, LEVEL_2, "%+F", op->node));
 163                         if ((op->flags & FLAG_KILL_ALL) == FLAG_KILL_ALL)
 164                                 DB((dbg, LEVEL_2, "X"));
 165                         else if (op->flags & FLAG_KILL_ALL)
 166                                 DB((dbg, LEVEL_2, "K"));
 167                         DB((dbg, LEVEL_2, ", "));
 168
 169                         i = (i + 1) & 3;
 170                 }
 171                 DB((dbg, LEVEL_2, "\n}\n\n"));
 172         }
 173 }  /* dump_block_list */
 174
 175 /**
 176  * Dumps the current set.
 177  *
 178  * @param bl   current block
 179  * @param s    name of the set
 180  */
 181 static void dump_curr(block_t *bl, const char *s)
 182 {
 183         size_t end = env.rbs_size - 1;
 184         size_t pos;
 185         int    i;
 186
 187         DB((dbg, LEVEL_2, "%s[%+F] = {", s, bl->block));
 188         i = 0;
 189         for (pos = rbitset_next(env.curr_set, 0, 1); pos < end; pos = rbitset_next(env.curr_set, pos + 1, 1)) {
 190                 memop_t *op = env.curr_id_2_memop[pos];
 191
 192                 if (i == 0) {
 193                         DB((dbg, LEVEL_2, "\n\t"));
 194                 }
 195
 196                 DB((dbg, LEVEL_2, "<%+F, %+F>, ", op->value.address, op->value.value));
 197                 i = (i + 1) & 3;
 198         }
 199         DB((dbg, LEVEL_2, "\n}\n"));
 200 }  /* dump_curr */
 201
 202 #else
 203 static void dump_block_list(ldst_env *env)
 204 {
 205         (void) env;
 206 }
 207 static void dump_curr(block_t *bl, const char *s)
 208 {
 209         (void) bl;
 210         (void) s;
 211 }
 212 #endif /* DEBUG_libfirm */
 213
 214 /** Get the block entry for a block node */
 215 static block_t *get_block_entry(const ir_node *block)
 216 {
 217         assert(is_Block(block));
 218
 219         return (block_t*)get_irn_link(block);
 220 }  /* get_block_entry */
 221
 222 /** Get the memop entry for a memory operation node */
 223 static memop_t *get_irn_memop(const ir_node *irn)
 224 {
 225         assert(! is_Block(irn));
 226         return (memop_t*)get_irn_link(irn);
 227 }  /* get_irn_memop */
 228
 229 /**
 230  * Walk over the memory edges from definition to users.
 231  * This ensures, that even operation without memory output are found.
 232  *
 233  * @param irn   start node
 234  * @param pre   pre walker function
 235  * @param post  post walker function
 236  * @param ctx   context parameter for the walker functions
 237  */
 238 static void walk_memory(ir_node *irn, irg_walk_func *pre, irg_walk_func *post, void *ctx)
 239 {
 240         int     i;
 241         ir_mode *mode;
 242
 243         mark_irn_visited(irn);
 244
 245         if (pre)
 246                 pre(irn, ctx);
 247
 248         mode = get_irn_mode(irn);
 249         if (mode == mode_M) {
 250                 /* every successor uses memory */
 251                 for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
 252                         ir_node *succ = get_irn_out(irn, i);
 253
 254                         if (! irn_visited(succ))
 255                                 walk_memory(succ, pre, post, ctx);
 256                 }
 257         } else if (mode == mode_T) {
 258                 /* only some Proj's uses memory */
 259                 for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
 260                         ir_node *proj = get_irn_out(irn, i);
 261
 262                         if (get_irn_mode(proj) == mode_M && ! irn_visited(proj))
 263                                 walk_memory(proj, pre, post, ctx);
 264                 }
 265         }
 266         if (post)
 267                 post(irn, ctx);
 268 }  /* walk_memory */
 269
 270 /**
 271  * Walks over all memory nodes of a graph.
 272  *
 273  * @param irg   a graph
 274  * @param pre   pre walker function
 275  * @param post  post walker function
 276  * @param ctx   context parameter for the walker functions
 277  */
 278 static void walk_memory_irg(ir_graph *irg, irg_walk_func pre, irg_walk_func post, void *ctx)
 279 {
 280         inc_irg_visited(irg);
 281
 282         ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
 283
 284         /*
 285          * there are two possible sources for memory: initial_mem and nomem
 286          * we ignore nomem as this should NOT change the memory
 287          */
 288         walk_memory(get_irg_initial_mem(irg), pre, post, ctx);
 289
 290         ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);
 291 }  /* walk_memory_irg */
 292
 293 /**
 294  * Register an address and allocate a (sparse, 0..n) ID for it.
 295  *
 296  * @param adr  the IR-node representing the address
 297  *
 298  * @return the allocated id
 299  */
 300 static unsigned register_address(ir_node *adr)
 301 {
 302         address_entry *entry;
 303
 304         /* skip Confirms and Casts */
 305 restart:
 306         if (is_Confirm(adr)) {
 307                 adr = get_Confirm_value(adr);
 308                 goto restart;
 309         }
 310         if (is_Cast(adr)) {
 311                 adr = get_Cast_op(adr);
 312                 goto restart;
 313         }
 314
 315         entry = (address_entry*)ir_nodemap_get(&env.adr_map, adr);
 316
 317         if (entry == NULL) {
 318                 /* new address */
 319                 entry = OALLOC(&env.obst, address_entry);
 320
 321                 entry->id = env.curr_adr_id++;
 322                 ir_nodemap_insert(&env.adr_map, adr, entry);
 323
 324                 DB((dbg, LEVEL_3, "ADDRESS %+F has ID %u\n", adr, entry->id));
 325 #ifdef DEBUG_libfirm
 326                 ARR_APP1(ir_node *, env.id_2_address, adr);
 327 #endif
 328         }
 329         return entry->id;
 330 }  /* register_address */
 331
 332
 333 /**
 334  * translate an address through a Phi node into a given predecessor
 335  * block.
 336  *
 337  * @param address  the address
 338  * @param block    the block
 339  * @param pos      the position of the predecessor in block
 340  */
 341 static ir_node *phi_translate(ir_node *address, const ir_node *block, int pos)
 342 {
 343         if (is_Phi(address) && get_nodes_block(address) == block)
 344                 address = get_Phi_pred(address, pos);
 345         return address;
 346 }  /* phi_translate */
 347
 348 /**
 349  * Walker: allocate an block entry for every block
 350  * and register all potential addresses.
 351  */
 352 static void prepare_blocks(ir_node *irn, void *ctx)
 353 {
 354         (void)ctx;
 355
 356         if (is_Block(irn)) {
 357                 block_t *entry = OALLOC(&env.obst, block_t);
 358                 int     n;
 359
 360                 entry->memop_forward    = NULL;
 361                 entry->memop_backward   = NULL;
 362                 entry->avail_out        = NULL;
 363                 entry->id_2_memop_avail = NULL;
 364                 entry->anticL_in        = NULL;
 365                 entry->id_2_memop_antic = NULL;
 366                 entry->block            = irn;
 367                 entry->forward_next     = NULL;
 368                 entry->backward_next    = NULL;
 369                 entry->avail            = NULL;
 370                 entry->trans_results    = NULL;
 371                 set_irn_link(irn, entry);
 372
 373                 set_Block_phis(irn, NULL);
 374
 375                 /* use block marks to track unreachable blocks */
 376                 set_Block_mark(irn, 0);
 377
 378                 n = get_Block_n_cfgpreds(irn);
 379                 if (n > env.max_cfg_preds)
 380                         env.max_cfg_preds = n;
 381         } else {
 382                 ir_mode *mode = get_irn_mode(irn);
 383
 384                 if (mode_is_reference(mode)) {
 385                         /*
 386                          * Register ALL possible addresses: this is overkill yet but
 387                          * simpler then doing it for all possible translated addresses
 388                          * (which would be sufficient in the moment.
 389                          */
 390                         (void)register_address(irn);
 391                 }
 392         }
 393 }  /* prepare_blocks */
 394
 395 /**
 396  * Post-Walker, link in all Phi's
 397  */
 398 static void link_phis(ir_node *irn, void *ctx)
 399 {
 400         (void)ctx;
 401
 402         if (is_Phi(irn)) {
 403                 ir_node *block = get_nodes_block(irn);
 404                 add_Block_phi(block, irn);
 405         }
 406 }  /* link_phis */
 407
 408 /**
 409  * Block walker: creates the inverse post-order list for the CFG.
 410  */
 411 static void inverse_post_order(ir_node *block, void *ctx)
 412 {
 413         block_t *entry = get_block_entry(block);
 414
 415         (void)ctx;
 416
 417         /* mark this block IS reachable from start */
 418         set_Block_mark(block, 1);
 419
 420         /* create the list in inverse order */
 421         entry->forward_next = env.forward;
 422         env.forward         = entry;
 423
 424         /* remember the first visited (last in list) entry, needed for later */
 425         if (env.backward == NULL)
 426                 env.backward = entry;
 427 }  /* inverse_post_order */
 428
 429 /**
 430  * Block walker: create backward links for the memops of a block.
 431  */
 432 static void collect_backward(ir_node *block, void *ctx)
 433 {
 434         block_t *entry = get_block_entry(block);
 435         memop_t *last, *op;
 436
 437         (void)ctx;
 438
 439         /*
 440          * Do NOT link in the end block yet. We want it to be
 441          * the first in the list. This is NOT guaranteed by the walker
 442          * if we have endless loops.
 443          */
 444         if (block != env.end_bl) {
 445                 entry->backward_next = env.backward;
 446
 447                 /* create the list in inverse order */
 448                 env.backward = entry;
 449         }
 450
 451         /* create backward links for all memory ops */
 452         last = NULL;
 453         for (op = entry->memop_forward; op != NULL; op = op->next) {
 454                 op->prev = last;
 455                 last     = op;
 456         }
 457         entry->memop_backward = last;
 458 }  /* collect_backward */
 459
 460 /**
 461  * Allocate a memop.
 462  *
 463  * @param irn  the IR-node representing the memop or NULL
 464  *             if this is a translated (virtual) memop
 465  *
 466  * @return the allocated memop
 467  */
 468 static memop_t *alloc_memop(ir_node *irn)
 469 {
 470         memop_t *m = OALLOC(&env.obst, memop_t);
 471
 472         m->value.address = NULL;
 473         m->value.value   = NULL;
 474         m->value.mode    = NULL;
 475
 476         m->node          = irn;
 477         m->mem           = NULL;
 478         m->replace       = NULL;
 479         m->next          = NULL;
 480         m->flags         = 0;
 481
 482         memset(m->projs, 0, sizeof(m->projs));
 483
 484         if (irn != NULL)
 485                 set_irn_link(irn, m);
 486         return m;
 487 }  /* alloc_memop */
 488
 489 /**
 490  * Create a memop for a Phi-replacement.
 491  *
 492  * @param op   the memop to clone
 493  * @param phi  the Phi-node representing the new value
 494  */
 495 static memop_t *clone_memop_phi(memop_t *op, ir_node *phi)
 496 {
 497         memop_t *m = OALLOC(&env.obst, memop_t);
 498
 499         m->value         = op->value;
 500         m->value.value   = phi;
 501
 502         m->node          = phi;
 503         m->replace       = NULL;
 504         m->next          = NULL;
 505         m->flags         = 0;
 506
 507         set_irn_link(phi, m);
 508         return m;
 509 }  /* clone_memop_phi */
 510
 511 /**
 512  * Return the memory properties of a call node.
 513  *
 514  * @param call  the call node
 515  *
 516  * return a bitset of mtp_property_const and mtp_property_pure
 517  */
 518 static unsigned get_Call_memory_properties(ir_node *call)
 519 {
 520         ir_type *call_tp = get_Call_type(call);
 521         unsigned prop = get_method_additional_properties(call_tp);
 522
 523         /* check first the call type */
 524         if ((prop & (mtp_property_const|mtp_property_pure)) == 0) {
 525                 /* try the called entity */
 526                 ir_node *ptr = get_Call_ptr(call);
 527
 528                 if (is_Global(ptr)) {
 529                         ir_entity *ent = get_Global_entity(ptr);
 530
 531                         prop = get_entity_additional_properties(ent);
 532                 }
 533         }
 534         return prop & (mtp_property_const|mtp_property_pure);
 535 }  /* get_Call_memory_properties */
 536
 537 /**
 538  * Returns an entity if the address ptr points to a constant one.
 539  *
 540  * @param ptr  the address
 541  *
 542  * @return an entity or NULL
 543  */
 544 static ir_entity *find_constant_entity(ir_node *ptr)
 545 {
 546         for (;;) {
 547                 if (is_SymConst(ptr) && get_SymConst_kind(ptr) == symconst_addr_ent) {
 548                         return get_SymConst_entity(ptr);
 549                 } else if (is_Sel(ptr)) {
 550                         ir_entity *ent = get_Sel_entity(ptr);
 551                         ir_type   *tp  = get_entity_owner(ent);
 552
 553                         /* Do not fiddle with polymorphism. */
 554                         if (is_Class_type(get_entity_owner(ent)) &&
 555                                 ((get_entity_n_overwrites(ent)    != 0) ||
 556                                 (get_entity_n_overwrittenby(ent) != 0)   ) )
 557                                 return NULL;
 558
 559                         if (is_Array_type(tp)) {
 560                                 /* check bounds */
 561                                 int i, n;
 562
 563                                 for (i = 0, n = get_Sel_n_indexs(ptr); i < n; ++i) {
 564                                         ir_node   *bound;
 565                                         ir_tarval *tlower, *tupper;
 566                                         ir_node   *index = get_Sel_index(ptr, i);
 567                                         ir_tarval *tv     = computed_value(index);
 568
 569                                         /* check if the index is constant */
 570                                         if (tv == tarval_bad)
 571                                                 return NULL;
 572
 573                                         bound  = get_array_lower_bound(tp, i);
 574                                         tlower = computed_value(bound);
 575                                         bound  = get_array_upper_bound(tp, i);
 576                                         tupper = computed_value(bound);
 577
 578                                         if (tlower == tarval_bad || tupper == tarval_bad)
 579                                                 return NULL;
 580
 581                                         if (tarval_cmp(tv, tlower) & pn_Cmp_Lt)
 582                                                 return NULL;
 583                                         if (tarval_cmp(tupper, tv) & pn_Cmp_Lt)
 584                                                 return NULL;
 585
 586                                         /* ok, bounds check finished */
 587                                 }
 588                         }
 589
 590                         if (get_entity_linkage(ent) == IR_LINKAGE_CONSTANT)
 591                                 return ent;
 592
 593                         /* try next */
 594                         ptr = get_Sel_ptr(ptr);
 595                 } else if (is_Add(ptr)) {
 596                         ir_node *l = get_Add_left(ptr);
 597                         ir_node *r = get_Add_right(ptr);
 598
 599                         if (get_irn_mode(l) == get_irn_mode(ptr) && is_Const(r))
 600                                 ptr = l;
 601                         else if (get_irn_mode(r) == get_irn_mode(ptr) && is_Const(l))
 602                                 ptr = r;
 603                         else
 604                                 return NULL;
 605
 606                         /* for now, we support only one addition, reassoc should fold all others */
 607                         if (! is_SymConst(ptr) && !is_Sel(ptr))
 608                                 return NULL;
 609                 } else if (is_Sub(ptr)) {
 610                         ir_node *l = get_Sub_left(ptr);
 611                         ir_node *r = get_Sub_right(ptr);
 612
 613                         if (get_irn_mode(l) == get_irn_mode(ptr) && is_Const(r))
 614                                 ptr = l;
 615                         else
 616                                 return NULL;
 617                         /* for now, we support only one subtraction, reassoc should fold all others */
 618                         if (! is_SymConst(ptr) && !is_Sel(ptr))
 619                                 return NULL;
 620                 } else
 621                         return NULL;
 622         }
 623 }  /* find_constant_entity */
 624
 625 /**
 626  * Return the Selection index of a Sel node from dimension n
 627  */
 628 static long get_Sel_array_index_long(ir_node *n, int dim)
 629 {
 630         ir_node *index = get_Sel_index(n, dim);
 631         assert(is_Const(index));
 632         return get_tarval_long(get_Const_tarval(index));
 633 }  /* get_Sel_array_index_long */
 634
 635 /**
 636  * Returns the accessed component graph path for an
 637  * node computing an address.
 638  *
 639  * @param ptr    the node computing the address
 640  * @param depth  current depth in steps upward from the root
 641  *               of the address
 642  */
 643 static compound_graph_path *rec_get_accessed_path(ir_node *ptr, int depth)
 644 {
 645         compound_graph_path *res = NULL;
 646         ir_entity           *root, *field, *ent;
 647         int                 path_len, pos, idx;
 648         ir_tarval           *tv;
 649         ir_type             *tp;
 650
 651         if (is_SymConst(ptr)) {
 652                 /* a SymConst. If the depth is 0, this is an access to a global
 653                  * entity and we don't need a component path, else we know
 654                  * at least its length.
 655                  */
 656                 assert(get_SymConst_kind(ptr) == symconst_addr_ent);
 657                 root = get_SymConst_entity(ptr);
 658                 res = (depth == 0) ? NULL : new_compound_graph_path(get_entity_type(root), depth);
 659         } else if (is_Sel(ptr)) {
 660                 /* it's a Sel, go up until we find the root */
 661                 res = rec_get_accessed_path(get_Sel_ptr(ptr), depth+1);
 662                 if (res == NULL)
 663                         return NULL;
 664
 665                 /* fill up the step in the path at the current position */
 666                 field    = get_Sel_entity(ptr);
 667                 path_len = get_compound_graph_path_length(res);
 668                 pos      = path_len - depth - 1;
 669                 set_compound_graph_path_node(res, pos, field);
 670
 671                 if (is_Array_type(get_entity_owner(field))) {
 672                         assert(get_Sel_n_indexs(ptr) == 1 && "multi dim arrays not implemented");
 673                         set_compound_graph_path_array_index(res, pos, get_Sel_array_index_long(ptr, 0));
 674                 }
 675         } else if (is_Add(ptr)) {
 676                 ir_mode   *mode;
 677                 ir_tarval *tmp;
 678
 679                 {
 680                         ir_node *l = get_Add_left(ptr);
 681                         ir_node *r = get_Add_right(ptr);
 682                         if (is_Const(r) && get_irn_mode(l) == get_irn_mode(ptr)) {
 683                                 ptr = l;
 684                                 tv  = get_Const_tarval(r);
 685                         } else {
 686                                 ptr = r;
 687                                 tv  = get_Const_tarval(l);
 688                         }
 689                 }
 690 ptr_arith:
 691                 mode = get_tarval_mode(tv);
 692                 tmp  = tv;
 693
 694                 /* ptr must be a Sel or a SymConst, this was checked in find_constant_entity() */
 695                 if (is_Sel(ptr)) {
 696                         field = get_Sel_entity(ptr);
 697                 } else {
 698                         field = get_SymConst_entity(ptr);
 699                 }
 700                 idx = 0;
 701                 for (ent = field;;) {
 702                         unsigned  size;
 703                         ir_tarval *sz, *tv_index, *tlower, *tupper;
 704                         ir_node   *bound;
 705
 706                         tp = get_entity_type(ent);
 707                         if (! is_Array_type(tp))
 708                                 break;
 709                         ent = get_array_element_entity(tp);
 710                         size = get_type_size_bytes(get_entity_type(ent));
 711                         sz   = new_tarval_from_long(size, mode);
 712
 713                         tv_index = tarval_div(tmp, sz);
 714                         tmp      = tarval_mod(tmp, sz);
 715
 716                         if (tv_index == tarval_bad || tmp == tarval_bad)
 717                                 return NULL;
 718
 719                         assert(get_array_n_dimensions(tp) == 1 && "multiarrays not implemented");
 720                         bound  = get_array_lower_bound(tp, 0);
 721                         tlower = computed_value(bound);
 722                         bound  = get_array_upper_bound(tp, 0);
 723                         tupper = computed_value(bound);
 724
 725                         if (tlower == tarval_bad || tupper == tarval_bad)
 726                                 return NULL;
 727
 728                         if (tarval_cmp(tv_index, tlower) & pn_Cmp_Lt)
 729                                 return NULL;
 730                         if (tarval_cmp(tupper, tv_index) & pn_Cmp_Lt)
 731                                 return NULL;
 732
 733                         /* ok, bounds check finished */
 734                         ++idx;
 735                 }
 736                 if (! tarval_is_null(tmp)) {
 737                         /* access to some struct/union member */
 738                         return NULL;
 739                 }
 740
 741                 /* should be at least ONE array */
 742                 if (idx == 0)
 743                         return NULL;
 744
 745                 res = rec_get_accessed_path(ptr, depth + idx);
 746                 if (res == NULL)
 747                         return NULL;
 748
 749                 path_len = get_compound_graph_path_length(res);
 750                 pos      = path_len - depth - idx;
 751
 752                 for (ent = field;;) {
 753                         unsigned   size;
 754                         ir_tarval *sz, *tv_index;
 755                         long       index;
 756
 757                         tp = get_entity_type(ent);
 758                         if (! is_Array_type(tp))
 759                                 break;
 760                         ent = get_array_element_entity(tp);
 761                         set_compound_graph_path_node(res, pos, ent);
 762
 763                         size = get_type_size_bytes(get_entity_type(ent));
 764                         sz   = new_tarval_from_long(size, mode);
 765
 766                         tv_index = tarval_div(tv, sz);
 767                         tv       = tarval_mod(tv, sz);
 768
 769                         /* worked above, should work again */
 770                         assert(tv_index != tarval_bad && tv != tarval_bad);
 771
 772                         /* bounds already checked above */
 773                         index = get_tarval_long(tv_index);
 774                         set_compound_graph_path_array_index(res, pos, index);
 775                         ++pos;
 776                 }
 777         } else if (is_Sub(ptr)) {
 778                 ir_node *l = get_Sub_left(ptr);
 779                 ir_node *r = get_Sub_right(ptr);
 780
 781                 ptr = l;
 782                 tv  = get_Const_tarval(r);
 783                 tv  = tarval_neg(tv);
 784                 goto ptr_arith;
 785         }
 786         return res;
 787 }  /* rec_get_accessed_path */
 788
 789 /**
 790  * Returns an access path or NULL.  The access path is only
 791  * valid, if the graph is in phase_high and _no_ address computation is used.
 792  */
 793 static compound_graph_path *get_accessed_path(ir_node *ptr)
 794 {
 795         compound_graph_path *gr = rec_get_accessed_path(ptr, 0);
 796         return gr;
 797 }  /* get_accessed_path */
 798
 799 typedef struct path_entry {
 800         ir_entity         *ent;
 801         struct path_entry *next;
 802         long              index;
 803 } path_entry;
 804
 805 static ir_node *rec_find_compound_ent_value(ir_node *ptr, path_entry *next)
 806 {
 807         path_entry       entry, *p;
 808         ir_entity        *ent, *field;
 809         ir_initializer_t *initializer;
 810         ir_tarval        *tv;
 811         ir_type          *tp;
 812         unsigned         n;
 813
 814         entry.next = next;
 815         if (is_SymConst(ptr)) {
 816                 /* found the root */
 817                 ent         = get_SymConst_entity(ptr);
 818                 initializer = get_entity_initializer(ent);
 819                 for (p = next; p != NULL;) {
 820                         if (initializer->kind != IR_INITIALIZER_COMPOUND)
 821                                 return NULL;
 822                         n  = get_initializer_compound_n_entries(initializer);
 823                         tp = get_entity_type(ent);
 824
 825                         if (is_Array_type(tp)) {
 826                                 ent = get_array_element_entity(tp);
 827                                 if (ent != p->ent) {
 828                                         /* a missing [0] */
 829                                         if (0 >= n)
 830                                                 return NULL;
 831                                         initializer = get_initializer_compound_value(initializer, 0);
 832                                         continue;
 833                                 }
 834                         }
 835                         if (p->index >= (int) n)
 836                                 return NULL;
 837                         initializer = get_initializer_compound_value(initializer, p->index);
 838
 839                         ent = p->ent;
 840                         p   = p->next;
 841                 }
 842                 tp = get_entity_type(ent);
 843                 while (is_Array_type(tp)) {
 844                         ent = get_array_element_entity(tp);
 845                         tp = get_entity_type(ent);
 846                         /* a missing [0] */
 847                         n  = get_initializer_compound_n_entries(initializer);
 848                         if (0 >= n)
 849                                 return NULL;
 850                         initializer = get_initializer_compound_value(initializer, 0);
 851                 }
 852
 853                 switch (initializer->kind) {
 854                 case IR_INITIALIZER_CONST:
 855                         return get_initializer_const_value(initializer);
 856                 case IR_INITIALIZER_TARVAL:
 857                 case IR_INITIALIZER_NULL:
 858                 default:
 859                         return NULL;
 860                 }
 861         } else if (is_Sel(ptr)) {
 862                 entry.ent = field = get_Sel_entity(ptr);
 863                 tp = get_entity_owner(field);
 864                 if (is_Array_type(tp)) {
 865                         assert(get_Sel_n_indexs(ptr) == 1 && "multi dim arrays not implemented");
 866                         entry.index = get_Sel_array_index_long(ptr, 0) - get_array_lower_bound_int(tp, 0);
 867                 } else {
 868                         int i, n_members = get_compound_n_members(tp);
 869                         for (i = 0; i < n_members; ++i) {
 870                                 if (get_compound_member(tp, i) == field)
 871                                         break;
 872                         }
 873                         if (i >= n_members) {
 874                                 /* not found: should NOT happen */
 875                                 return NULL;
 876                         }
 877                         entry.index = i;
 878                 }
 879                 return rec_find_compound_ent_value(get_Sel_ptr(ptr), &entry);
 880         }  else if (is_Add(ptr)) {
 881                 ir_mode *mode;
 882                 unsigned pos;
 883
 884                 {
 885                         ir_node *l = get_Add_left(ptr);
 886                         ir_node *r = get_Add_right(ptr);
 887                         if (is_Const(r)) {
 888                                 ptr = l;
 889                                 tv  = get_Const_tarval(r);
 890                         } else {
 891                                 ptr = r;
 892                                 tv  = get_Const_tarval(l);
 893                         }
 894                 }
 895 ptr_arith:
 896                 mode = get_tarval_mode(tv);
 897
 898                 /* ptr must be a Sel or a SymConst, this was checked in find_constant_entity() */
 899                 if (is_Sel(ptr)) {
 900                         field = get_Sel_entity(ptr);
 901                 } else {
 902                         field = get_SymConst_entity(ptr);
 903                 }
 904
 905                 /* count needed entries */
 906                 pos = 0;
 907                 for (ent = field;;) {
 908                         tp = get_entity_type(ent);
 909                         if (! is_Array_type(tp))
 910                                 break;
 911                         ent = get_array_element_entity(tp);
 912                         ++pos;
 913                 }
 914                 /* should be at least ONE entry */
 915                 if (pos == 0)
 916                         return NULL;
 917
 918                 /* allocate the right number of entries */
 919                 NEW_ARR_A(path_entry, p, pos);
 920
 921                 /* fill them up */
 922                 pos = 0;
 923                 for (ent = field;;) {
 924                         unsigned  size;
 925                         ir_tarval *sz, *tv_index, *tlower, *tupper;
 926                         long      index;
 927                         ir_node   *bound;
 928
 929                         tp = get_entity_type(ent);
 930                         if (! is_Array_type(tp))
 931                                 break;
 932                         ent = get_array_element_entity(tp);
 933                         p[pos].ent  = ent;
 934                         p[pos].next = &p[pos + 1];
 935
 936                         size = get_type_size_bytes(get_entity_type(ent));
 937                         sz   = new_tarval_from_long(size, mode);
 938
 939                         tv_index = tarval_div(tv, sz);
 940                         tv       = tarval_mod(tv, sz);
 941
 942                         if (tv_index == tarval_bad || tv == tarval_bad)
 943                                 return NULL;
 944
 945                         assert(get_array_n_dimensions(tp) == 1 && "multiarrays not implemented");
 946                         bound  = get_array_lower_bound(tp, 0);
 947                         tlower = computed_value(bound);
 948                         bound  = get_array_upper_bound(tp, 0);
 949                         tupper = computed_value(bound);
 950
 951                         if (tlower == tarval_bad || tupper == tarval_bad)
 952                                 return NULL;
 953
 954                         if (tarval_cmp(tv_index, tlower) & pn_Cmp_Lt)
 955                                 return NULL;
 956                         if (tarval_cmp(tupper, tv_index) & pn_Cmp_Lt)
 957                                 return NULL;
 958
 959                         /* ok, bounds check finished */
 960                         index = get_tarval_long(tv_index);
 961                         p[pos].index = index;
 962                         ++pos;
 963                 }
 964                 if (! tarval_is_null(tv)) {
 965                         /* hmm, wrong access */
 966                         return NULL;
 967                 }
 968                 p[pos - 1].next = next;
 969                 return rec_find_compound_ent_value(ptr, p);
 970         } else if (is_Sub(ptr)) {
 971                 ir_node *l = get_Sub_left(ptr);
 972                 ir_node *r = get_Sub_right(ptr);
 973
 974                 ptr = l;
 975                 tv  = get_Const_tarval(r);
 976                 tv  = tarval_neg(tv);
 977                 goto ptr_arith;
 978         }
 979         return NULL;
 980 }  /* rec_find_compound_ent_value */
 981
 982 static ir_node *find_compound_ent_value(ir_node *ptr)
 983 {
 984         return rec_find_compound_ent_value(ptr, NULL);
 985 }  /* find_compound_ent_value */
 986
 987 /**
 988  * Mark a Load memop to be replace by a definition
 989  *
 990  * @param op  the Load memop
 991  */
 992 static void mark_replace_load(memop_t *op, ir_node *def)
 993 {
 994         op->replace = def;
 995         op->flags |= FLAG_KILLED_NODE;
 996         env.changed = 1;
 997 }  /* mark_replace_load */
 998
 999 /**
1000  * Mark a Store memop to be removed.
1001  *
1002  * @param op  the Store memop
1003  */
1004 static void mark_remove_store(memop_t *op)
1005 {
1006         op->flags |= FLAG_KILLED_NODE;
1007         env.changed = 1;
1008 }  /* mark_remove_store */
1009
1010 /**
1011  * Update a memop for a Load.
1012  *
1013  * @param m  the memop
1014  */
1015 static void update_Load_memop(memop_t *m)
1016 {
1017         int       i;
1018         ir_node   *load = m->node;
1019         ir_node   *ptr;
1020         ir_entity *ent;
1021
1022         if (get_Load_volatility(load) == volatility_is_volatile)
1023                 m->flags |= FLAG_IGNORE;
1024
1025         ptr = get_Load_ptr(load);
1026
1027         m->value.address = ptr;
1028
1029         for (i = get_irn_n_outs(load) - 1; i >= 0; --i) {
1030                 ir_node *proj = get_irn_out(load, i);
1031                 long    pn;
1032
1033                 /* beware of keep edges */
1034                 if (is_End(proj))
1035                         continue;
1036
1037                 pn = get_Proj_proj(proj);
1038                 m->projs[pn] = proj;
1039                 switch (pn) {
1040                 case pn_Load_res:
1041                         m->value.value = proj;
1042                         m->value.mode  = get_irn_mode(proj);
1043                         break;
1044                 case pn_Load_X_except:
1045                         m->flags |= FLAG_EXCEPTION;
1046                         break;
1047                 case pn_Load_M:
1048                         m->mem = proj;
1049                         break;
1050                 case pn_Load_X_regular:
1051                         break;
1052                 default:
1053                         panic("Unsupported Proj from Load %+F", proj);
1054                 }
1055         }
1056
1057         /* check if we can determine the entity that will be loaded */
1058         ent = find_constant_entity(ptr);
1059
1060         if (ent != NULL && get_entity_visibility(ent) != ir_visibility_external) {
1061                 /* a static allocation that is not external: there should be NO exception
1062                  * when loading even if we cannot replace the load itself. */
1063                 ir_node *value = NULL;
1064
1065                 /* no exception, clear the m fields as it might be checked later again */
1066                 if (m->projs[pn_Load_X_except]) {
1067                         ir_graph *irg = get_irn_irg(ptr);
1068                         exchange(m->projs[pn_Load_X_except], new_r_Bad(irg));
1069                         m->projs[pn_Load_X_except] = NULL;
1070                         m->flags &= ~FLAG_EXCEPTION;
1071                         env.changed = 1;
1072                 }
1073                 if (m->projs[pn_Load_X_regular]) {
1074                         exchange(m->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
1075                         m->projs[pn_Load_X_regular] = NULL;
1076                         env.changed = 1;
1077                 }
1078
1079                 if (get_entity_linkage(ent) & IR_LINKAGE_CONSTANT) {
1080                         if (ent->initializer) {
1081                                 /* new style initializer */
1082                                 value = find_compound_ent_value(ptr);
1083                         } else if (entity_has_compound_ent_values(ent)) {
1084                                 /* old style initializer */
1085                                 compound_graph_path *path = get_accessed_path(ptr);
1086
1087                                 if (path != NULL) {
1088                                         assert(is_proper_compound_graph_path(path, get_compound_graph_path_length(path)-1));
1089
1090                                         value = get_compound_ent_value_by_path(ent, path);
1091                                         DB((dbg, LEVEL_1, "  Constant access at %F%F resulted in %+F\n", ent, path, value));
1092                                         free_compound_graph_path(path);
1093                                 }
1094                         }
1095                         if (value != NULL)
1096                                 value = can_replace_load_by_const(load, value);
1097                 }
1098
1099                 if (value != NULL) {
1100                         /* we completely replace the load by this value */
1101                         DB((dbg, LEVEL_1, "Replacing Load %+F by constant %+F\n", m->node, value));
1102                         mark_replace_load(m, value);
1103                         return;
1104                 }
1105         }
1106
1107         if (m->value.value != NULL && !(m->flags & FLAG_IGNORE)) {
1108                 /* only create an address if this node is NOT killed immediately or ignored */
1109                 m->value.id = register_address(ptr);
1110                 ++env.n_mem_ops;
1111         } else {
1112                 /* no user, KILL it */
1113                 mark_replace_load(m, NULL);
1114         }
1115 }  /* update_Load_memop */
1116
1117 /**
1118  * Update a memop for a Store.
1119  *
1120  * @param m  the memop
1121  */
1122 static void update_Store_memop(memop_t *m)
1123 {
1124         int     i;
1125         ir_node *store = m->node;
1126         ir_node *adr   = get_Store_ptr(store);
1127
1128         if (get_Store_volatility(store) == volatility_is_volatile) {
1129                 m->flags |= FLAG_IGNORE;
1130         } else {
1131                 /* only create an address if this node is NOT ignored */
1132                 m->value.id = register_address(adr);
1133                 ++env.n_mem_ops;
1134         }
1135
1136         m->value.address = adr;
1137
1138         for (i = get_irn_n_outs(store) - 1; i >= 0; --i) {
1139                 ir_node *proj = get_irn_out(store, i);
1140                 long    pn;
1141
1142                 /* beware of keep edges */
1143                 if (is_End(proj))
1144                         continue;
1145
1146                 pn = get_Proj_proj(proj);
1147                 m->projs[pn] = proj;
1148                 switch (pn) {
1149                 case pn_Store_X_except:
1150                         m->flags |= FLAG_EXCEPTION;
1151                         break;
1152                 case pn_Store_M:
1153                         m->mem = proj;
1154                         break;
1155                 case pn_Store_X_regular:
1156                         break;
1157                 default:
1158                         panic("Unsupported Proj from Store %+F", proj);
1159                 }
1160         }
1161         m->value.value = get_Store_value(store);
1162         m->value.mode  = get_irn_mode(m->value.value);
1163 }  /* update_Store_memop */
1164
1165 /**
1166  * Update a memop for a Call.
1167  *
1168  * @param m  the memop
1169  */
1170 static void update_Call_memop(memop_t *m)
1171 {
1172         ir_node  *call = m->node;
1173         unsigned prop  = get_Call_memory_properties(call);
1174         int      i;
1175
1176         if (prop & mtp_property_const) {
1177                 /* A constant call did NOT use memory at all, we
1178                    can kick it from the list. */
1179         } else if (prop & mtp_property_pure) {
1180                 /* pure calls READ memory */
1181                 m->flags = 0;
1182         } else
1183                 m->flags = FLAG_KILL_ALL;
1184
1185         for (i = get_irn_n_outs(call) - 1; i >= 0; --i) {
1186                 ir_node *proj = get_irn_out(call, i);
1187
1188                 /* beware of keep edges */
1189                 if (is_End(proj))
1190                         continue;
1191
1192                 switch (get_Proj_proj(proj)) {
1193                 case pn_Call_X_except:
1194                         m->flags |= FLAG_EXCEPTION;
1195                         break;
1196                 case pn_Call_M:
1197                         m->mem = proj;
1198                         break;
1199                 }
1200         }
1201 }  /* update_Call_memop */
1202
1203 /**
1204  * Update a memop for a Div/Mod/Quot.
1205  *
1206  * @param m  the memop
1207  */
1208 static void update_DivOp_memop(memop_t *m)
1209 {
1210         ir_node *div = m->node;
1211         int     i;
1212
1213         for (i = get_irn_n_outs(div) - 1; i >= 0; --i) {
1214                 ir_node *proj = get_irn_out(div, i);
1215
1216                 /* beware of keep edges */
1217                 if (is_End(proj))
1218                         continue;
1219
1220                 switch (get_Proj_proj(proj)) {
1221                 case pn_Generic_X_except:
1222                         m->flags |= FLAG_EXCEPTION;
1223                         break;
1224                 case pn_Generic_M:
1225                         m->mem = proj;
1226                         break;
1227                 }
1228         }
1229 }  /* update_DivOp_memop */
1230
1231 /**
1232  * Update a memop for a Phi.
1233  *
1234  * @param m  the memop
1235  */
1236 static void update_Phi_memop(memop_t *m)
1237 {
1238         /* the Phi is it's own mem */
1239         m->mem = m->node;
1240 }  /* update_Phi_memop */
1241
1242 /**
1243  * Memory walker: collect all memory ops and build topological lists.
1244  */
1245 static void collect_memops(ir_node *irn, void *ctx)
1246 {
1247         memop_t  *op;
1248         ir_node  *block;
1249         block_t  *entry;
1250
1251         (void) ctx;
1252         if (is_Proj(irn)) {
1253                 /* we can safely ignore ProjM's except the initial memory */
1254                 ir_graph *irg = get_irn_irg(irn);
1255                 if (irn != get_irg_initial_mem(irg))
1256                         return;
1257         }
1258
1259         op    = alloc_memop(irn);
1260         block = get_nodes_block(irn);
1261         entry = get_block_entry(block);
1262
1263         if (is_Phi(irn)) {
1264                 update_Phi_memop(op);
1265                 /* Phis must be always placed first */
1266                 op->next = entry->memop_forward;
1267                 entry->memop_forward = op;
1268                 if (entry->memop_backward == NULL)
1269                         entry->memop_backward = op;
1270         } else {
1271                 switch (get_irn_opcode(irn)) {
1272                 case iro_Load:
1273                         update_Load_memop(op);
1274                         break;
1275                 case iro_Store:
1276                         update_Store_memop(op);
1277                         break;
1278                 case iro_Call:
1279                         update_Call_memop(op);
1280                         break;
1281                 case iro_Sync:
1282                 case iro_Pin:
1283                         op->mem = irn;
1284                         break;
1285                 case iro_Proj:
1286                         /* initial memory */
1287                         op->mem = irn;
1288                         break;
1289                 case iro_Return:
1290                 case iro_End:
1291                         /* we can those to find the memory edge */
1292                         break;
1293                 case iro_Div:
1294                 case iro_Quot:
1295                 case iro_Mod:
1296                         update_DivOp_memop(op);
1297                         break;
1298
1299                 case iro_Builtin:
1300                         /* TODO: handle some builtins */
1301                 default:
1302                         /* unsupported operation */
1303                         op->flags = FLAG_KILL_ALL;
1304                 }
1305
1306
1307                 /* all other should be placed last */
1308                 if (entry->memop_backward == NULL) {
1309                         entry->memop_forward = entry->memop_backward = op;
1310                 } else {
1311                         entry->memop_backward->next = op;
1312                         entry->memop_backward       = op;
1313                 }
1314         }
1315 }  /* collect_memops */
1316
1317 /**
1318  * Find an address in the current set.
1319  *
1320  * @param value  the value to be searched for
1321  *
1322  * @return a memop for the value or NULL if the value does
1323  *         not exists in the set or cannot be converted into
1324  *         the requested mode
1325  */
1326 static memop_t *find_address(const value_t *value)
1327 {
1328         if (rbitset_is_set(env.curr_set, value->id)) {
1329                 memop_t *res = env.curr_id_2_memop[value->id];
1330
1331                 if (res->value.mode == value->mode)
1332                         return res;
1333                 /* allow hidden casts */
1334                 if (get_mode_arithmetic(res->value.mode) == irma_twos_complement &&
1335                     get_mode_arithmetic(value->mode) == irma_twos_complement &&
1336                     get_mode_size_bits(res->value.mode) == get_mode_size_bits(value->mode))
1337                         return res;
1338         }
1339         return NULL;
1340 }  /* find_address */
1341
1342 /**
1343  * Find an address in the avail_out set.
1344  *
1345  * @param bl     the block
1346  */
1347 static memop_t *find_address_avail(const block_t *bl, unsigned id, const ir_mode *mode)
1348 {
1349         if (rbitset_is_set(bl->avail_out, id)) {
1350                 memop_t *res = bl->id_2_memop_avail[id];
1351
1352                 if (res->value.mode == mode)
1353                         return res;
1354                 /* allow hidden casts */
1355                 if (get_mode_arithmetic(res->value.mode) == irma_twos_complement &&
1356                     get_mode_arithmetic(mode) == irma_twos_complement &&
1357                     get_mode_size_bits(res->value.mode) == get_mode_size_bits(mode))
1358                         return res;
1359         }
1360         return NULL;
1361 }  /* find_address_avail */
1362
1363 /**
1364  * Kill all addresses from the current set.
1365  */
1366 static void kill_all(void)
1367 {
1368         rbitset_clear_all(env.curr_set, env.rbs_size);
1369
1370         /* set sentinel */
1371         rbitset_set(env.curr_set, env.rbs_size - 1);
1372 }  /* kill_all */
1373
1374 /**
1375  * Kill memops that are not alias free due to a Store value from the current set.
1376  *
1377  * @param value  the Store value
1378  */
1379 static void kill_memops(const value_t *value)
1380 {
1381         size_t end = env.rbs_size - 1;
1382         size_t pos;
1383
1384         for (pos = rbitset_next(env.curr_set, 0, 1); pos < end; pos = rbitset_next(env.curr_set, pos + 1, 1)) {
1385                 memop_t *op = env.curr_id_2_memop[pos];
1386
1387                 if (ir_no_alias != get_alias_relation(value->address, value->mode,
1388                                                           op->value.address, op->value.mode)) {
1389                         rbitset_clear(env.curr_set, pos);
1390                         env.curr_id_2_memop[pos] = NULL;
1391                         DB((dbg, LEVEL_2, "KILLING %+F because of possible alias address %+F\n", op->node, value->address));
1392                 }
1393         }
1394 }  /* kill_memops */
1395
1396 /**
1397  * Add the value of a memop to the current set.
1398  *
1399  * @param op  the memory op
1400  */
1401 static void add_memop(memop_t *op)
1402 {
1403         rbitset_set(env.curr_set, op->value.id);
1404         env.curr_id_2_memop[op->value.id] = op;
1405 }  /* add_memop */
1406
1407 /**
1408  * Add the value of a memop to the avail_out set.
1409  *
1410  * @param bl  the block
1411  * @param op  the memory op
1412  */
1413 static void add_memop_avail(block_t *bl, memop_t *op)
1414 {
1415         rbitset_set(bl->avail_out, op->value.id);
1416         bl->id_2_memop_avail[op->value.id] = op;
1417 }  /* add_memop_avail */
1418
1419 /**
1420  * Check, if we can convert a value of one mode to another mode
1421  * without changing the representation of bits.
1422  *
1423  * @param from  the original mode
1424  * @param to    the destination mode
1425  */
1426 static int can_convert_to(const ir_mode *from, const ir_mode *to)
1427 {
1428         if (get_mode_arithmetic(from) == irma_twos_complement &&
1429             get_mode_arithmetic(to) == irma_twos_complement &&
1430             get_mode_size_bits(from) == get_mode_size_bits(to))
1431                 return 1;
1432         return 0;
1433 }  /* can_convert_to */
1434
1435 /**
1436  * Add a Conv to the requested mode if needed.
1437  *
1438  * @param irn   the IR-node to convert
1439  * @param mode  the destination mode
1440  *
1441  * @return the possible converted node or NULL
1442  *         if the conversion is not possible
1443  */
1444 static ir_node *conv_to(ir_node *irn, ir_mode *mode)
1445 {
1446         ir_mode *other = get_irn_mode(irn);
1447         if (other != mode) {
1448                 /* different modes: check if conversion is possible without changing the bits */
1449                 if (can_convert_to(other, mode)) {
1450                         ir_node *block = get_nodes_block(irn);
1451                         return new_r_Conv(block, irn, mode);
1452                 }
1453                 /* otherwise not possible ... yet */
1454                 return NULL;
1455         }
1456         return irn;
1457 }  /* conv_to */
1458
1459 /**
1460  * Update the address of an value if this address was a load result
1461  * and the load is killed now.
1462  *
1463  * @param value  the value whose address is updated
1464  */
1465 static void update_address(value_t *value)
1466 {
1467         if (is_Proj(value->address)) {
1468                 ir_node *load = get_Proj_pred(value->address);
1469
1470                 if (is_Load(load)) {
1471                         const memop_t *op = get_irn_memop(load);
1472
1473                         if (op->flags & FLAG_KILLED_NODE)
1474                                 value->address = op->replace;
1475                 }
1476         }
1477 }  /* update_address */
1478
1479 /**
1480  * Do forward dataflow analysis on the given block and calculate the
1481  * GEN and KILL in the current (avail) set.
1482  *
1483  * @param bl  the block
1484  */
1485 static void calc_gen_kill_avail(block_t *bl)
1486 {
1487         memop_t *op;
1488         ir_node *def;
1489
1490         for (op = bl->memop_forward; op != NULL; op = op->next) {
1491                 switch (get_irn_opcode(op->node)) {
1492                 case iro_Phi:
1493                         /* meet */
1494                         break;
1495                 case iro_Sync:
1496                         /* join */
1497                         break;
1498                 case iro_Load:
1499                         if (! (op->flags & (FLAG_KILLED_NODE|FLAG_IGNORE))) {
1500                                 /* do we have this already? */
1501                                 memop_t *other;
1502
1503                                 update_address(&op->value);
1504                                 other = find_address(&op->value);
1505                                 if (other != NULL && other != op) {
1506                                         def = conv_to(other->value.value, op->value.mode);
1507                                         if (def != NULL) {
1508 #ifdef DEBUG_libfirm
1509                                                 if (is_Store(other->node)) {
1510                                                         /* RAW */
1511                                                         DB((dbg, LEVEL_1, "RAW %+F <- %+F(%+F)\n", op->node, def, other->node));
1512                                                 } else {
1513                                                         /* RAR */
1514                                                         DB((dbg, LEVEL_1, "RAR %+F <- %+F(%+F)\n", op->node, def, other->node));
1515                                                 }
1516 #endif
1517                                                 mark_replace_load(op, def);
1518                                                 /* do NOT change the memop table */
1519                                                 continue;
1520                                         }
1521                                 }
1522                                 /* add this value */
1523                                 add_memop(op);
1524                         }
1525                         break;
1526                 case iro_Store:
1527                         if (! (op->flags & FLAG_KILLED_NODE)) {
1528                                 /* do we have this store already */
1529                                 memop_t *other;
1530
1531                                 update_address(&op->value);
1532                                 other = find_address(&op->value);
1533                                 if (other != NULL) {
1534                                         if (is_Store(other->node)) {
1535                                                 if (op != other && !(other->flags & FLAG_IGNORE) &&
1536                                                     get_nodes_block(other->node) == get_nodes_block(op->node)) {
1537                                                         /*
1538                                                          * A WAW in the same block we can kick the first store.
1539                                                          * This is a shortcut: we know that the second Store will be anticipated
1540                                                          * then in an case.
1541                                                          */
1542                                                         DB((dbg, LEVEL_1, "WAW %+F <- %+F\n", other->node, op->node));
1543                                                         mark_remove_store(other);
1544                                                         /* FIXME: a Load might be get freed due to this killed store */
1545                                                 }
1546                                         } else if (other->value.value == op->value.value && !(op->flags & FLAG_IGNORE)) {
1547                                                 /* WAR */
1548                                                 DB((dbg, LEVEL_1, "WAR %+F <- %+F\n", op->node, other->node));
1549                                                 mark_remove_store(op);
1550                                                 /* do NOT change the memop table */
1551                                                 continue;
1552                                         }
1553                                 }
1554                                 /* KILL all possible aliases */
1555                                 kill_memops(&op->value);
1556                                 /* add this value */
1557                                 add_memop(op);
1558                         }
1559                         break;
1560                 default:
1561                         if (op->flags & FLAG_KILL_ALL)
1562                                 kill_all();
1563                 }
1564         }
1565 }  /* calc_gen_kill_avail */
1566
1567 #define BYTE_SIZE(x)  (((x) + 7) >> 3)
1568
1569 /**
1570  * Do forward dataflow analysis on a given block to calculate the avail_out set
1571  * for this block only.
1572  *
1573  * @param block  the block
1574  */
1575 static void forward_avail(block_t *bl)
1576 {
1577         /* fill the data from the current block */
1578         env.curr_id_2_memop = bl->id_2_memop_avail;
1579         env.curr_set        = bl->avail_out;
1580
1581         calc_gen_kill_avail(bl);
1582         dump_curr(bl, "Avail_out");
1583 }  /* forward_avail */
1584
1585 /**
1586  * Do backward dataflow analysis on a given block to calculate the antic set
1587  * of Loaded addresses.
1588  *
1589  * @param bl  the block
1590  *
1591  * @return non-zero if the set has changed since last iteration
1592  */
1593 static int backward_antic(block_t *bl)
1594 {
1595         memop_t *op;
1596         ir_node *block = bl->block;
1597         int     n = get_Block_n_cfg_outs(block);
1598
1599         if (n == 1) {
1600                 ir_node  *succ    = get_Block_cfg_out(block, 0);
1601                 block_t  *succ_bl = get_block_entry(succ);
1602                 int      pred_pos = get_Block_cfgpred_pos(succ, block);
1603                 size_t   end      = env.rbs_size - 1;
1604                 size_t   pos;
1605
1606                 kill_all();
1607
1608                 if (bl->trans_results == NULL) {
1609                         /* allocate the translate cache */
1610                         bl->trans_results = OALLOCNZ(&env.obst, memop_t*, env.curr_adr_id);
1611                 }
1612
1613                 /* check for partly redundant values */
1614                 for (pos = rbitset_next(succ_bl->anticL_in, 0, 1);
1615                      pos < end;
1616                      pos = rbitset_next(succ_bl->anticL_in, pos + 1, 1)) {
1617                         /*
1618                          * do Phi-translation here: Note that at this point the nodes are
1619                          * not changed, so we can safely cache the results.
1620                          * However: Loads of Load results ARE bad, because we have no way
1621                           to translate them yet ...
1622                          */
1623                         memop_t *op = bl->trans_results[pos];
1624                         if (op == NULL) {
1625                                 /* not yet translated */
1626                                 ir_node *adr, *trans_adr;
1627
1628                                 op  = succ_bl->id_2_memop_antic[pos];
1629                                 adr = op->value.address;
1630
1631                                 trans_adr = phi_translate(adr, succ, pred_pos);
1632                                 if (trans_adr != adr) {
1633                                         /* create a new entry for the translated one */
1634                                         memop_t *new_op;
1635
1636                                         new_op = alloc_memop(NULL);
1637                                         new_op->value.address = trans_adr;
1638                                         new_op->value.id      = register_address(trans_adr);
1639                                         new_op->value.mode    = op->value.mode;
1640                                         new_op->node          = op->node; /* we need the node to decide if Load/Store */
1641                                         new_op->flags         = op->flags;
1642
1643                                         bl->trans_results[pos] = new_op;
1644                                         op = new_op;
1645                                 }
1646                         }
1647                         env.curr_id_2_memop[op->value.id] = op;
1648                         rbitset_set(env.curr_set, op->value.id);
1649                 }
1650         } else if (n > 1) {
1651                 ir_node *succ    = get_Block_cfg_out(block, 0);
1652                 block_t *succ_bl = get_block_entry(succ);
1653                 int i;
1654
1655                 rbitset_copy(env.curr_set, succ_bl->anticL_in, env.rbs_size);
1656                 memcpy(env.curr_id_2_memop, succ_bl->id_2_memop_antic, env.rbs_size * sizeof(env.curr_id_2_memop[0]));
1657
1658                 /* Hmm: probably we want kill merges of Loads ans Stores here */
1659                 for (i = n - 1; i > 0; --i) {
1660                         ir_node *succ    = get_Block_cfg_out(bl->block, i);
1661                         block_t *succ_bl = get_block_entry(succ);
1662
1663                         rbitset_and(env.curr_set, succ_bl->anticL_in, env.rbs_size);
1664                 }
1665         } else {
1666                 /* block ends with a noreturn call */
1667                 kill_all();
1668         }
1669
1670         dump_curr(bl, "AnticL_out");
1671
1672         for (op = bl->memop_backward; op != NULL; op = op->prev) {
1673                 switch (get_irn_opcode(op->node)) {
1674                 case iro_Phi:
1675                         /* meet */
1676                         break;
1677                 case iro_Sync:
1678                         /* join */
1679                         break;
1680                 case iro_Load:
1681                         if (! (op->flags & (FLAG_KILLED_NODE|FLAG_IGNORE))) {
1682                                 /* always add it */
1683                                 add_memop(op);
1684                         }
1685                         break;
1686                 case iro_Store:
1687                         if (! (op->flags & FLAG_KILLED_NODE)) {
1688                                 /* a Store: check which memops must be killed */
1689                                 kill_memops(&op->value);
1690                         }
1691                         break;
1692                 default:
1693                         if (op->flags & FLAG_KILL_ALL)
1694                                 kill_all();
1695                 }
1696         }
1697
1698         memcpy(bl->id_2_memop_antic, env.curr_id_2_memop, env.rbs_size * sizeof(env.curr_id_2_memop[0]));
1699         if (! rbitsets_equal(bl->anticL_in, env.curr_set, env.rbs_size)) {
1700                 /* changed */
1701                 rbitset_copy(bl->anticL_in, env.curr_set, env.rbs_size);
1702                 dump_curr(bl, "AnticL_in*");
1703                 return 1;
1704         }
1705         dump_curr(bl, "AnticL_in");
1706         return 0;
1707 }  /* backward_antic */
1708
1709 /**
1710  * Replace a Load memop by a already known value.
1711  *
1712  * @param op  the Load memop
1713  */
1714 static void replace_load(memop_t *op)
1715 {
1716         ir_node *load = op->node;
1717         ir_node *def  = skip_Id(op->replace);
1718         ir_node *proj;
1719         ir_mode *mode;
1720
1721         if (def != NULL)
1722                 DB((dbg, LEVEL_1, "Replacing %+F by definition %+F\n", load, is_Proj(def) ? get_Proj_pred(def) : def));
1723         else {
1724                 if (op->flags & FLAG_EXCEPTION) {
1725                         /* bad: this node is unused and executed for exception only */
1726                         DB((dbg, LEVEL_1, "Unused %+F executed for exception only ...\n", load));
1727                         return;
1728                 }
1729                 DB((dbg, LEVEL_1, "Killing unused %+F\n", load));
1730         }
1731
1732         if (op->mem != NULL) {
1733                 /* in rare cases a Load might have NO memory */
1734                 exchange(op->mem, get_Load_mem(load));
1735         }
1736         proj = op->projs[pn_Load_res];
1737         if (proj != NULL) {
1738                 mode = get_irn_mode(proj);
1739                 if (get_irn_mode(def) != mode) {
1740                         /* a hidden cast */
1741                         dbg_info *db    = get_irn_dbg_info(load);
1742                         ir_node  *block = get_nodes_block(proj);
1743                         def = new_rd_Conv(db, block, def, mode);
1744                 }
1745                 exchange(proj, def);
1746         }
1747         proj = op->projs[pn_Load_X_except];
1748         if (proj != NULL) {
1749                 ir_graph *irg = get_irn_irg(load);
1750                 exchange(proj, new_r_Bad(irg));
1751         }
1752         proj = op->projs[pn_Load_X_regular];
1753         if (proj != NULL) {
1754                 exchange(proj, new_r_Jmp(get_nodes_block(load)));
1755         }
1756 }  /* replace_load */
1757
1758 /**
1759  * Remove a Store memop.
1760  *
1761  * @param op  the Store memop
1762  */
1763 static void remove_store(memop_t *op)
1764 {
1765         ir_node *store = op->node;
1766         ir_node *proj;
1767
1768         DB((dbg, LEVEL_1, "Removing %+F\n", store));
1769
1770         if (op->mem != NULL) {
1771                 /* in rare cases a Store might have no memory */
1772                 exchange(op->mem, get_Store_mem(store));
1773         }
1774         proj = op->projs[pn_Store_X_except];
1775         if (proj != NULL) {
1776                 ir_graph *irg = get_irn_irg(store);
1777                 exchange(proj, new_r_Bad(irg));
1778         }
1779         proj = op->projs[pn_Store_X_regular];
1780         if (proj != NULL) {
1781                 exchange(proj, new_r_Jmp(get_nodes_block(store)));
1782         }
1783 }  /* remove_store */
1784
1785
1786 /**
1787  * Do all necessary replacements for a given block.
1788  *
1789  * @param bl  the block
1790  */
1791 static void do_replacements(block_t *bl)
1792 {
1793         memop_t *op;
1794
1795         for (op = bl->memop_forward; op != NULL; op = op->next) {
1796                 if (op->flags & FLAG_KILLED_NODE) {
1797                         switch (get_irn_opcode(op->node)) {
1798                         case iro_Load:
1799                                 replace_load(op);
1800                                 break;
1801                         case iro_Store:
1802                                 remove_store(op);
1803                                 break;
1804                         }
1805                 }
1806         }
1807 }  /* do_replacements */
1808
1809 /**
1810  * Calculate the Avail_out sets for all basic blocks.
1811  */
1812 static void calcAvail(void)
1813 {
1814         memop_t  **tmp_memop = env.curr_id_2_memop;
1815         unsigned *tmp_set    = env.curr_set;
1816         block_t  *bl;
1817
1818         /* calculate avail_out */
1819         DB((dbg, LEVEL_2, "Calculate Avail_out\n"));
1820
1821         /* iterate over all blocks in in any order, skip the start block */
1822         for (bl = env.forward->forward_next; bl != NULL; bl = bl->forward_next) {
1823                 forward_avail(bl);
1824         }
1825
1826         /* restore the current sets */
1827         env.curr_id_2_memop = tmp_memop;
1828         env.curr_set        = tmp_set;
1829 }  /* calcAvail */
1830
1831 /**
1832  * Calculate the Antic_in sets for all basic blocks.
1833  */
1834 static void calcAntic(void)
1835 {
1836         int i, need_iter;
1837
1838         /* calculate antic_out */
1839         DB((dbg, LEVEL_2, "Calculate Antic_in\n"));
1840         i = 0;
1841         do {
1842                 block_t *bl;
1843
1844                 DB((dbg, LEVEL_2, "Iteration %d:\n=========\n", i));
1845
1846                 need_iter = 0;
1847
1848                 /* over all blocks in reverse post order */
1849                 for (bl = env.backward->backward_next; bl != NULL; bl = bl->backward_next) {
1850                         need_iter |= backward_antic(bl);
1851                 }
1852                 ++i;
1853         } while (need_iter);
1854         DB((dbg, LEVEL_2, "Get anticipated Load set after %d iterations\n", i));
1855 }  /* calcAntic */
1856
1857 /**
1858  * Return the node representing the last memory in a block.
1859  *
1860  * @param bl  the block
1861  */
1862 static ir_node *find_last_memory(block_t *bl)
1863 {
1864         for (;;) {
1865                 if (bl->memop_backward != NULL) {
1866                         return bl->memop_backward->mem;
1867                 }
1868                 /* if there is NO memory in this block, go to the dominator */
1869                 bl = get_block_entry(get_Block_idom(bl->block));
1870         }
1871 }  /* find_last_memory */
1872
1873 /**
1874  * Reroute all memory users of old memory
1875  * to a new memory IR-node.
1876  *
1877  * @param omem  the old memory IR-node
1878  * @param nmem  the new memory IR-node
1879  */
1880 static void reroute_all_mem_users(ir_node *omem, ir_node *nmem)
1881 {
1882         int i;
1883
1884         for (i = get_irn_n_outs(omem) - 1; i >= 0; --i) {
1885                 int     n_pos;
1886                 ir_node *user = get_irn_out_ex(omem, i, &n_pos);
1887
1888                 set_irn_n(user, n_pos, nmem);
1889         }
1890
1891         /* all edges previously point to omem now point to nmem */
1892         nmem->out = omem->out;
1893 }  /* reroute_all_mem_users */
1894
1895 /**
1896  * Reroute memory users of old memory that are dominated by a given block
1897  * to a new memory IR-node.
1898  *
1899  * @param omem     the old memory IR-node
1900  * @param nmem     the new memory IR-node
1901  * @param pass_bl  the block the memory must pass
1902  */
1903 static void reroute_mem_through(ir_node *omem, ir_node *nmem, ir_node *pass_bl)
1904 {
1905         int             i, j, n = get_irn_n_outs(omem);
1906         ir_def_use_edge *edges = NEW_ARR_D(ir_def_use_edge, &env.obst, n + 1);
1907
1908         for (i = j = 0; i < n; ++i) {
1909                 int     n_pos;
1910                 ir_node *user   = get_irn_out_ex(omem, i, &n_pos);
1911                 ir_node *use_bl = get_nodes_block(user);
1912
1913
1914                 if (is_Phi(user)) {
1915                         use_bl = get_Block_cfgpred_block(use_bl, n_pos);
1916                 }
1917                 if (block_dominates(pass_bl, use_bl)) {
1918                         /* found an user that is dominated */
1919                         ++j;
1920                         edges[j].pos = n_pos;
1921                         edges[j].use = user;
1922
1923                         set_irn_n(user, n_pos, nmem);
1924                 }
1925         }
1926
1927         /* Modify the out structure: we create a new out edge array on our
1928            temporary obstack here. This should be no problem, as we invalidate the edges
1929            at the end either. */
1930         /* first entry is used for the length */
1931         edges[0].pos = j;
1932         nmem->out = edges;
1933 }  /* reroute_mem_through */
1934
1935 /**
1936  * insert Loads, making partly redundant Loads fully redundant
1937  */
1938 static int insert_Load(block_t *bl)
1939 {
1940         ir_node  *block = bl->block;
1941         int      i, n = get_Block_n_cfgpreds(block);
1942         size_t   end = env.rbs_size - 1;
1943
1944         DB((dbg, LEVEL_3, "processing %+F\n", block));
1945
1946         if (n == 0) {
1947                 /* might still happen for an unreachable block (end for instance) */
1948                 return 0;
1949         }
1950
1951         if (n > 1) {
1952                 ir_node **ins;
1953                 size_t    pos;
1954
1955                 NEW_ARR_A(ir_node *, ins, n);
1956
1957                 rbitset_set_all(env.curr_set, env.rbs_size);
1958
1959                 /* More than one predecessors, calculate the join for all avail_outs ignoring unevaluated
1960                    Blocks. These put in Top anyway. */
1961                 for (i = n - 1; i >= 0; --i) {
1962                         ir_node *pred = skip_Proj(get_Block_cfgpred(block, i));
1963                         ir_node *blk  = get_nodes_block(pred);
1964                         block_t *pred_bl;
1965
1966                         pred_bl = get_block_entry(blk);
1967                         rbitset_and(env.curr_set, pred_bl->avail_out, env.rbs_size);
1968
1969                         if (is_Load(pred) || is_Store(pred)) {
1970                                 /* We reached this block by an exception from a Load or Store:
1971                                  * the memop creating the exception was NOT completed than, kill it
1972                                  */
1973                                 memop_t *exc_op = get_irn_memop(pred);
1974                                 rbitset_clear(env.curr_set, exc_op->value.id);
1975                         }
1976
1977                 }
1978                 /*
1979                  * Ensure that all values are in the map: build Phi's if necessary:
1980                  * Note: the last bit is the sentinel and ALWAYS set, so end with -2.
1981                  */
1982                 for (pos = 0; pos < env.rbs_size - 1; ++pos) {
1983                         if (! rbitset_is_set(env.curr_set, pos))
1984                                 env.curr_id_2_memop[pos] = NULL;
1985                         else {
1986                                 ir_node *pred    = get_Block_cfgpred_block(bl->block, 0);
1987                                 block_t *pred_bl = get_block_entry(pred);
1988                                 int     need_phi = 0;
1989                                 memop_t *first   = NULL;
1990                                 ir_mode *mode    = NULL;
1991
1992                                 for (i = 0; i < n; ++i) {
1993                                         memop_t *mop;
1994
1995                                         pred    = get_Block_cfgpred_block(bl->block, i);
1996                                         pred_bl = get_block_entry(pred);
1997
1998                                         mop = pred_bl->id_2_memop_avail[pos];
1999                                         if (first == NULL) {
2000                                                 first = mop;
2001                                                 ins[0] = first->value.value;
2002                                                 mode = get_irn_mode(ins[0]);
2003
2004                                                 /* no Phi needed so far */
2005                                                 env.curr_id_2_memop[pos] = first;
2006                                         } else {
2007                                                 ins[i] = conv_to(mop->value.value, mode);
2008                                                 if (ins[i] != ins[0]) {
2009                                                         if (ins[i] == NULL) {
2010                                                                 /* conversion failed */
2011                                                                 env.curr_id_2_memop[pos] = NULL;
2012                                                                 rbitset_clear(env.curr_set, pos);
2013                                                                 break;
2014                                                         }
2015                                                         need_phi = 1;
2016                                                 }
2017                                         }
2018                                 }
2019                                 if (need_phi) {
2020                                         /* build a Phi  */
2021                                         ir_node *phi = new_r_Phi(bl->block, n, ins, mode);
2022                                         memop_t *phiop = alloc_memop(phi);
2023
2024                                         phiop->value = first->value;
2025                                         phiop->value.value = phi;
2026
2027                                         /* no need to link it in, as it is a DATA phi */
2028
2029                                         env.curr_id_2_memop[pos] = phiop;
2030
2031                                         DB((dbg, LEVEL_3, "Created new %+F on merging value for address %+F\n", phi, first->value.address));
2032                                 }
2033                         }
2034                 }
2035         } else {
2036                 /* only one predecessor, simply copy the map */
2037                 ir_node *pred    = get_Block_cfgpred_block(bl->block, 0);
2038                 block_t *pred_bl = get_block_entry(pred);
2039
2040                 rbitset_copy(env.curr_set, pred_bl->avail_out, env.rbs_size);
2041
2042                 memcpy(env.curr_id_2_memop, pred_bl->id_2_memop_avail, env.rbs_size * sizeof(bl->id_2_memop_avail[0]));
2043         }
2044
2045         if (n > 1) {
2046                 size_t pos;
2047
2048                 /* check for partly redundant values */
2049                 for (pos = rbitset_next(bl->anticL_in, 0, 1);
2050                      pos < end;
2051                      pos = rbitset_next(bl->anticL_in, pos + 1, 1)) {
2052                         memop_t *op = bl->id_2_memop_antic[pos];
2053                         int     have_some, all_same;
2054                         ir_node *first;
2055
2056                         if (rbitset_is_set(env.curr_set, pos)) {
2057                                 /* already avail */
2058                                 continue;
2059                         }
2060
2061                         assert(is_Load(op->node));
2062
2063                         DB((dbg, LEVEL_3, "anticipated %+F\n", op->node));
2064
2065                         have_some  = 0;
2066                         all_same   = 1;
2067                         first      = 0;
2068                         for (i = n - 1; i >= 0; --i) {
2069                                 ir_node *pred    = get_Block_cfgpred_block(block, i);
2070                                 block_t *pred_bl = get_block_entry(pred);
2071                                 ir_mode *mode    = op->value.mode;
2072                                 memop_t *e;
2073                                 ir_node *adr;
2074
2075                                 adr = phi_translate(op->value.address, block, i);
2076                                 DB((dbg, LEVEL_3, ".. using address %+F in pred %d\n", adr, i));
2077                                 e   = find_address_avail(pred_bl, register_address(adr), mode);
2078                                 if (e == NULL) {
2079                                         ir_node *ef_block = get_nodes_block(adr);
2080                                         if (! block_dominates(ef_block, pred)) {
2081                                                 /* cannot place a copy here */
2082                                                 have_some = 0;
2083                                                 DB((dbg, LEVEL_3, "%+F cannot be moved into predecessor %+F\n", op->node, pred));
2084                                                 break;
2085                                         }
2086                                         DB((dbg, LEVEL_3, "%+F is not available in predecessor %+F\n", op->node, pred));
2087                                         pred_bl->avail = NULL;
2088                                         all_same       = 0;
2089                                 } else {
2090                                         if (e->value.mode != mode && !can_convert_to(e->value.mode, mode)) {
2091                                                 /* cannot create a Phi due to different modes */
2092                                                 have_some = 0;
2093                                                 break;
2094                                         }
2095                                         pred_bl->avail = e;
2096                                         have_some      = 1;
2097                                         DB((dbg, LEVEL_3, "%+F is available for %+F in predecessor %+F\n", e->node, op->node, pred));
2098                                         if (first == NULL)
2099                                                 first = e->node;
2100                                         else if (first != e->node)
2101                                                 all_same = 0;
2102                                 }
2103                         }
2104                         if (have_some && !all_same) {
2105                                 ir_mode *mode = op->value.mode;
2106                                 ir_node **in, *phi;
2107                                 memop_t *phi_op;
2108
2109                                 NEW_ARR_A(ir_node *, in, n);
2110
2111                                 for (i = n - 1; i >= 0; --i) {
2112                                         ir_node *pred    = get_Block_cfgpred_block(block, i);
2113                                         block_t *pred_bl = get_block_entry(pred);
2114
2115                                         if (pred_bl->avail == NULL) {
2116                                                 /* create a new Load here and make to make it fully redundant */
2117                                                 dbg_info *db       = get_irn_dbg_info(op->node);
2118                                                 ir_node  *last_mem = find_last_memory(pred_bl);
2119                                                 ir_node  *load, *def, *adr;
2120                                                 memop_t  *new_op;
2121
2122                                                 assert(last_mem != NULL);
2123                                                 adr  = phi_translate(op->value.address, block, i);
2124                                                 load = new_rd_Load(db, pred, last_mem, adr, mode, cons_none);
2125                                                 def  = new_r_Proj(load, mode, pn_Load_res);
2126                                                 DB((dbg, LEVEL_1, "Created new %+F in %+F for party redundant %+F\n", load, pred, op->node));
2127
2128                                                 new_op                = alloc_memop(load);
2129                                                 new_op->mem           = new_r_Proj(load, mode_M, pn_Load_M);
2130                                                 new_op->value.address = adr;
2131                                                 new_op->value.id      = op->value.id;
2132                                                 new_op->value.mode    = mode;
2133                                                 new_op->value.value   = def;
2134
2135                                                 new_op->projs[pn_Load_M]   = new_op->mem;
2136                                                 new_op->projs[pn_Load_res] = def;
2137
2138                                                 new_op->prev = pred_bl->memop_backward;
2139                                                 if (pred_bl->memop_backward != NULL)
2140                                                         pred_bl->memop_backward->next = new_op;
2141
2142                                                 pred_bl->memop_backward = new_op;
2143
2144                                                 if (pred_bl->memop_forward == NULL)
2145                                                         pred_bl->memop_forward = new_op;
2146
2147                                                 if (get_nodes_block(last_mem) == pred) {
2148                                                         /* We have add a new last memory op in pred block.
2149                                                            If pred had already a last mem, reroute all memory
2150                                                            users. */
2151                                                         reroute_all_mem_users(last_mem, new_op->mem);
2152                                                 } else {
2153                                                         /* reroute only those memory going through the pre block */
2154                                                         reroute_mem_through(last_mem, new_op->mem, pred);
2155                                                 }
2156
2157                                                 /* we added this load at the end, so it will be avail anyway */
2158                                                 add_memop_avail(pred_bl, new_op);
2159                                                 pred_bl->avail = new_op;
2160                                         }
2161                                         in[i] = conv_to(pred_bl->avail->value.value, mode);
2162                                 }
2163                                 phi = new_r_Phi(block, n, in, mode);
2164                                 DB((dbg, LEVEL_1, "Created new %+F in %+F for now redundant %+F\n", phi, block, op->node));
2165
2166                                 phi_op = clone_memop_phi(op, phi);
2167                                 add_memop(phi_op);
2168                         }
2169                 }
2170         }
2171
2172         /* recalculate avail by gen and kill */
2173         calc_gen_kill_avail(bl);
2174
2175         /* always update the map after gen/kill, as values might have been changed due to RAR/WAR/WAW */
2176         memcpy(bl->id_2_memop_avail, env.curr_id_2_memop, env.rbs_size * sizeof(env.curr_id_2_memop[0]));
2177
2178         if (!rbitsets_equal(bl->avail_out, env.curr_set, env.rbs_size)) {
2179                 /* the avail set has changed */
2180                 rbitset_copy(bl->avail_out, env.curr_set, env.rbs_size);
2181                 dump_curr(bl, "Avail_out*");
2182                 return 1;
2183         }
2184         dump_curr(bl, "Avail_out");
2185         return 0;
2186 }  /* insert_Load */
2187
2188 /**
2189  * Insert Loads upwards.
2190  */
2191 static void insert_Loads_upwards(void)
2192 {
2193         int i, need_iter;
2194         block_t *bl;
2195
2196         /* recalculate antic_out and insert Loads */
2197         DB((dbg, LEVEL_2, "Inserting Loads\n"));
2198
2199         i = 0;
2200         do {
2201                 DB((dbg, LEVEL_2, "Iteration %d:\n=========\n", i));
2202
2203                 need_iter = 0;
2204
2205                 /* over all blocks in reverse post order, skip the start block */
2206                 for (bl = env.forward->forward_next; bl != NULL; bl = bl->forward_next) {
2207                         need_iter |= insert_Load(bl);
2208                 }
2209                 ++i;
2210         } while (need_iter);
2211
2212         DB((dbg, LEVEL_2, "Finished Load inserting after %d iterations\n", i));
2213 }  /* insert_Loads_upwards */
2214
2215 /**
2216  * Kill unreachable control flow.
2217  *
2218  * @param irg  the graph to operate on
2219  */
2220 static void kill_unreachable_blocks(ir_graph *irg)
2221 {
2222         block_t *bl;
2223         ir_node **ins;
2224         int     changed = 0;
2225
2226         NEW_ARR_A(ir_node *, ins, env.max_cfg_preds);
2227
2228         for (bl = env.forward; bl != NULL; bl = bl->forward_next) {
2229                 ir_node *block = bl->block;
2230                 int     i, j, k, n;
2231
2232                 assert(get_Block_mark(block));
2233
2234                 n = get_Block_n_cfgpreds(block);
2235
2236                 for (i = j = 0; i < n; ++i) {
2237                         ir_node *pred = get_Block_cfgpred(block, i);
2238                         ir_node *pred_bl;
2239
2240                         if (is_Bad(pred))
2241                                 continue;
2242
2243                         pred_bl = get_nodes_block(skip_Proj(pred));
2244                         if (! get_Block_mark(pred_bl))
2245                                 continue;
2246
2247                         ins[j++] = pred;
2248                 }
2249                 if (j != n) {
2250                         ir_node *phi, *next;
2251
2252                         /* some unreachable blocks detected */
2253                         changed = 1;
2254
2255                         DB((dbg, LEVEL_1, "Killing dead block predecessors on %+F\n", block));
2256
2257                         set_irn_in(block, j, ins);
2258
2259                         /* shorten all Phi nodes */
2260                         for (phi = get_Block_phis(block); phi != NULL; phi = next) {
2261                                 next = get_Phi_next(phi);
2262
2263                                 for (i = k = 0; i < n; ++i) {
2264                                         ir_node *pred = get_Block_cfgpred_block(block, i);
2265
2266                                         if (is_Bad(pred))
2267                                                 continue;
2268
2269                                         if (! get_Block_mark(pred))
2270                                                 continue;
2271
2272                                         ins[k++] = get_Phi_pred(phi, i);
2273                                 }
2274                                 if (k == 1)
2275                                         exchange(phi, ins[0]);
2276                                 else
2277                                         set_irn_in(phi, k, ins);
2278                         }
2279                 }
2280
2281         }
2282
2283         if (changed) {
2284                 /* kick keep alives */
2285                 ir_node *end = get_irg_end(irg);
2286                 int     i, j, n = get_End_n_keepalives(end);
2287
2288                 NEW_ARR_A(ir_node *, ins, n);
2289
2290                 for (i = j = 0; i < n; ++i) {
2291                         ir_node *ka = get_End_keepalive(end, i);
2292                         ir_node *ka_bl;
2293
2294                         if (is_Bad(ka))
2295                                 continue;
2296                         if (is_Block(ka))
2297                                 ka_bl = ka;
2298                         else
2299                                 ka_bl = get_nodes_block(skip_Proj(ka));
2300                         if (get_Block_mark(ka_bl))
2301                                 ins[j++] = ka;
2302                 }
2303                 if (j != n)
2304                         set_End_keepalives(end, j, ins);
2305
2306                 free_irg_outs(irg);
2307
2308                 /* this transformation do NOT invalidate the dominance */
2309         }
2310 }  /* kill_unreachable_blocks */
2311
2312 int opt_ldst(ir_graph *irg)
2313 {
2314         block_t *bl;
2315
2316         FIRM_DBG_REGISTER(dbg, "firm.opt.ldst");
2317
2318         DB((dbg, LEVEL_1, "\nDoing Load/Store optimization on %+F\n", irg));
2319
2320         /* we need landing pads */
2321         remove_critical_cf_edges(irg);
2322
2323         if (get_opt_alias_analysis()) {
2324                 assure_irg_entity_usage_computed(irg);
2325                 assure_irp_globals_entity_usage_computed();
2326         }
2327
2328         obstack_init(&env.obst);
2329         ir_nodemap_init(&env.adr_map);
2330
2331         env.forward       = NULL;
2332         env.backward      = NULL;
2333         env.curr_adr_id   = 0;
2334         env.n_mem_ops     = 0;
2335         env.max_cfg_preds = 0;
2336         env.changed       = 0;
2337         env.start_bl      = get_irg_start_block(irg);
2338         env.end_bl        = get_irg_end_block(irg);
2339 #ifdef DEBUG_libfirm
2340         env.id_2_address  = NEW_ARR_F(ir_node *, 0);
2341 #endif
2342
2343         assure_irg_outs(irg);
2344
2345         ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_BLOCK_MARK);
2346
2347         /* first step: allocate block entries. Note that some blocks might be
2348            unreachable here. Using the normal walk ensures that ALL blocks are initialized. */
2349         irg_walk_graph(irg, prepare_blocks, link_phis, NULL);
2350
2351         /* produce an inverse post-order list for the CFG: this links only reachable
2352            blocks */
2353         irg_out_block_walk(get_irg_start_block(irg), NULL, inverse_post_order, NULL);
2354
2355         if (! get_Block_mark(env.end_bl)) {
2356                 /*
2357                  * The end block is NOT reachable due to endless loops
2358                  * or no_return calls.
2359                  * Place the end block last.
2360                  * env.backward points to the last block in the list for this purpose.
2361                  */
2362                 env.backward->forward_next = get_block_entry(env.end_bl);
2363
2364                 set_Block_mark(env.end_bl, 1);
2365         }
2366
2367         /* KILL unreachable blocks: these disturb the data flow analysis */
2368         kill_unreachable_blocks(irg);
2369
2370         assure_doms(irg);
2371
2372         /* second step: find and sort all memory ops */
2373         walk_memory_irg(irg, collect_memops, NULL, NULL);
2374
2375 #ifdef DEBUG_libfirm
2376         /* check that the backward map is correct */
2377         assert((unsigned)ARR_LEN(env.id_2_address) == env.curr_adr_id);
2378 #endif
2379
2380         if (env.n_mem_ops == 0) {
2381                 /* no memory ops */
2382                 goto end;
2383         }
2384
2385         /* create the backward links. */
2386         env.backward = NULL;
2387         irg_block_walk_graph(irg, NULL, collect_backward, NULL);
2388
2389         /* link the end block in */
2390         bl = get_block_entry(env.end_bl);
2391         bl->backward_next = env.backward;
2392         env.backward      = bl;
2393
2394         /* check that we really start with the start / end block */
2395         assert(env.forward->block  == env.start_bl);
2396         assert(env.backward->block == env.end_bl);
2397
2398         /* create address sets: for now, only the existing addresses are allowed plus one
2399            needed for the sentinel */
2400         env.rbs_size = env.curr_adr_id + 1;
2401
2402         /* create the current set */
2403         env.curr_set = rbitset_obstack_alloc(&env.obst, env.rbs_size);
2404         rbitset_set(env.curr_set, env.rbs_size - 1);
2405         env.curr_id_2_memop = NEW_ARR_D(memop_t *, &env.obst, env.rbs_size);
2406         memset(env.curr_id_2_memop, 0, env.rbs_size * sizeof(env.curr_id_2_memop[0]));
2407
2408         for (bl = env.forward; bl != NULL; bl = bl->forward_next) {
2409                 /* set sentinel bits */
2410                 bl->avail_out  = rbitset_obstack_alloc(&env.obst, env.rbs_size);
2411                 rbitset_set(bl->avail_out, env.rbs_size - 1);
2412
2413                 bl->id_2_memop_avail = NEW_ARR_D(memop_t *, &env.obst, env.rbs_size);
2414                 memset(bl->id_2_memop_avail, 0, env.rbs_size * sizeof(bl->id_2_memop_avail[0]));
2415
2416                 bl->anticL_in  = rbitset_obstack_alloc(&env.obst, env.rbs_size);
2417                 rbitset_set(bl->anticL_in, env.rbs_size - 1);
2418
2419                 bl->id_2_memop_antic = NEW_ARR_D(memop_t *, &env.obst, env.rbs_size);
2420                 memset(bl->id_2_memop_antic, 0, env.rbs_size * sizeof(bl->id_2_memop_antic[0]));
2421         }
2422
2423         (void) dump_block_list;
2424
2425         calcAvail();
2426         calcAntic();
2427
2428         insert_Loads_upwards();
2429
2430         if (env.changed) {
2431                 /* over all blocks in reverse post order */
2432                 for (bl = env.forward; bl != NULL; bl = bl->forward_next) {
2433                         do_replacements(bl);
2434                 }
2435
2436                 /* not only invalidate but free them. We might allocate new out arrays
2437                    on our obstack which will be deleted yet. */
2438                 free_irg_outs(irg);
2439                 set_irg_entity_usage_state(irg, ir_entity_usage_not_computed);
2440         }
2441 end:
2442
2443         ir_free_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_BLOCK_MARK);
2444         ir_nodemap_destroy(&env.adr_map);
2445         obstack_free(&env.obst, NULL);
2446
2447 #ifdef DEBUG_libfirm
2448         DEL_ARR_F(env.id_2_address);
2449 #endif
2450
2451         return env.changed != 0;
2452 }  /* opt_ldst */
2453
2454 ir_graph_pass_t *opt_ldst_pass(const char *name)
2455 {
2456         return def_graph_pass_ret(name ? name : "ldst_df", opt_ldst);
2457 }  /* opt_ldst_pass */