gcc/tree-ssa-operands.c

   1 /* SSA operands management for trees.
   2    Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "tm.h"
  25 #include "tree.h"
  26 #include "flags.h"
  27 #include "function.h"
  28 #include "diagnostic.h"
  29 #include "tree-flow.h"
  30 #include "tree-inline.h"
  31 #include "tree-pass.h"
  32 #include "ggc.h"
  33 #include "timevar.h"
  34 #include "toplev.h"
  35 #include "langhooks.h"
  36 #include "ipa-reference.h"
  37
  38 /* This file contains the code required to manage the operands cache of the
  39    SSA optimizer.  For every stmt, we maintain an operand cache in the stmt
  40    annotation.  This cache contains operands that will be of interest to
  41    optimizers and other passes wishing to manipulate the IL.
  42
  43    The operand type are broken up into REAL and VIRTUAL operands.  The real
  44    operands are represented as pointers into the stmt's operand tree.  Thus
  45    any manipulation of the real operands will be reflected in the actual tree.
  46    Virtual operands are represented solely in the cache, although the base
  47    variable for the SSA_NAME may, or may not occur in the stmt's tree.
  48    Manipulation of the virtual operands will not be reflected in the stmt tree.
  49
  50    The routines in this file are concerned with creating this operand cache
  51    from a stmt tree.
  52
  53    The operand tree is the parsed by the various get_* routines which look
  54    through the stmt tree for the occurrence of operands which may be of
  55    interest, and calls are made to the append_* routines whenever one is
  56    found.  There are 4 of these routines, each representing one of the
  57    4 types of operands. Defs, Uses, Virtual Uses, and Virtual May Defs.
  58
  59    The append_* routines check for duplication, and simply keep a list of
  60    unique objects for each operand type in the build_* extendable vectors.
  61
  62    Once the stmt tree is completely parsed, the finalize_ssa_operands()
  63    routine is called, which proceeds to perform the finalization routine
  64    on each of the 4 operand vectors which have been built up.
  65
  66    If the stmt had a previous operand cache, the finalization routines
  67    attempt to match up the new operands with the old ones.  If it's a perfect
  68    match, the old vector is simply reused.  If it isn't a perfect match, then
  69    a new vector is created and the new operands are placed there.  For
  70    virtual operands, if the previous cache had SSA_NAME version of a
  71    variable, and that same variable occurs in the same operands cache, then
  72    the new cache vector will also get the same SSA_NAME.
  73
  74    i.e., if a stmt had a VUSE of 'a_5', and 'a' occurs in the new
  75    operand vector for VUSE, then the new vector will also be modified
  76    such that it contains 'a_5' rather than 'a'.  */
  77
  78 /* Structure storing statistics on how many call clobbers we have, and
  79    how many where avoided.  */
  80
  81 static struct
  82 {
  83   /* Number of call-clobbered ops we attempt to add to calls in
  84      add_call_clobbered_mem_symbols.  */
  85   unsigned int clobbered_vars;
  86
  87   /* Number of write-clobbers (VDEFs) avoided by using
  88      not_written information.  */
  89   unsigned int static_write_clobbers_avoided;
  90
  91   /* Number of reads (VUSEs) avoided by using not_read information.  */
  92   unsigned int static_read_clobbers_avoided;
  93
  94   /* Number of write-clobbers avoided because the variable can't escape to
  95      this call.  */
  96   unsigned int unescapable_clobbers_avoided;
  97
  98   /* Number of read-only uses we attempt to add to calls in
  99      add_call_read_mem_symbols.  */
 100   unsigned int readonly_clobbers;
 101
 102   /* Number of read-only uses we avoid using not_read information.  */
 103   unsigned int static_readonly_clobbers_avoided;
 104 } clobber_stats;
 105
 106
 107 /* Flags to describe operand properties in helpers.  */
 108
 109 /* By default, operands are loaded.  */
 110 #define opf_use         0
 111
 112 /* Operand is the target of an assignment expression or a
 113    call-clobbered variable.  */
 114 #define opf_def         (1 << 0)
 115
 116 /* No virtual operands should be created in the expression.  This is used
 117    when traversing ADDR_EXPR nodes which have different semantics than
 118    other expressions.  Inside an ADDR_EXPR node, the only operands that we
 119    need to consider are indices into arrays.  For instance, &a.b[i] should
 120    generate a USE of 'i' but it should not generate a VUSE for 'a' nor a
 121    VUSE for 'b'.  */
 122 #define opf_no_vops     (1 << 1)
 123
 124 /* Operand is an implicit reference.  This is used to distinguish
 125    explicit assignments in the form of MODIFY_EXPR from
 126    clobbering sites like function calls or ASM_EXPRs.  */
 127 #define opf_implicit    (1 << 2)
 128
 129 /* Array for building all the def operands.  */
 130 static VEC(tree,heap) *build_defs;
 131
 132 /* Array for building all the use operands.  */
 133 static VEC(tree,heap) *build_uses;
 134
 135 /* The built VDEF operand.  */
 136 static tree build_vdef;
 137
 138 /* The built VUSE operand.  */
 139 static tree build_vuse;
 140
 141 /* Bitmap obstack for our datastructures that needs to survive across
 142    compilations of multiple functions.  */
 143 static bitmap_obstack operands_bitmap_obstack;
 144
 145 static void get_expr_operands (gimple, tree *, int);
 146
 147 /* Number of functions with initialized ssa_operands.  */
 148 static int n_initialized = 0;
 149
 150 /* Return the DECL_UID of the base variable of T.  */
 151
 152 static inline unsigned
 153 get_name_decl (const_tree t)
 154 {
 155   if (TREE_CODE (t) != SSA_NAME)
 156     return DECL_UID (t);
 157   else
 158     return DECL_UID (SSA_NAME_VAR (t));
 159 }
 160
 161
 162 /*  Return true if the SSA operands cache is active.  */
 163
 164 bool
 165 ssa_operands_active (void)
 166 {
 167   /* This function may be invoked from contexts where CFUN is NULL
 168      (IPA passes), return false for now.  FIXME: operands may be
 169      active in each individual function, maybe this function should
 170      take CFUN as a parameter.  */
 171   if (cfun == NULL)
 172     return false;
 173
 174   return cfun->gimple_df && gimple_ssa_operands (cfun)->ops_active;
 175 }
 176
 177
 178 /* Create the VOP variable, an artificial global variable to act as a
 179    representative of all of the virtual operands FUD chain.  */
 180
 181 static void
 182 create_vop_var (void)
 183 {
 184   tree global_var;
 185
 186   gcc_assert (cfun->gimple_df->vop == NULL_TREE);
 187
 188   global_var = build_decl (BUILTINS_LOCATION, VAR_DECL,
 189                            get_identifier (".MEM"),
 190                            void_type_node);
 191   DECL_ARTIFICIAL (global_var) = 1;
 192   TREE_READONLY (global_var) = 0;
 193   DECL_EXTERNAL (global_var) = 1;
 194   TREE_STATIC (global_var) = 1;
 195   TREE_USED (global_var) = 1;
 196   DECL_CONTEXT (global_var) = NULL_TREE;
 197   TREE_THIS_VOLATILE (global_var) = 0;
 198   TREE_ADDRESSABLE (global_var) = 0;
 199
 200   create_var_ann (global_var);
 201   add_referenced_var (global_var);
 202   cfun->gimple_df->vop = global_var;
 203 }
 204
 205 /* These are the sizes of the operand memory buffer in bytes which gets
 206    allocated each time more operands space is required.  The final value is
 207    the amount that is allocated every time after that.
 208    In 1k we can fit 25 use operands (or 63 def operands) on a host with
 209    8 byte pointers, that would be 10 statements each with 1 def and 2
 210    uses.  */
 211
 212 #define OP_SIZE_INIT    0
 213 #define OP_SIZE_1       (1024 - sizeof (void *))
 214 #define OP_SIZE_2       (1024 * 4 - sizeof (void *))
 215 #define OP_SIZE_3       (1024 * 16 - sizeof (void *))
 216
 217 /* Initialize the operand cache routines.  */
 218
 219 void
 220 init_ssa_operands (void)
 221 {
 222   if (!n_initialized++)
 223     {
 224       build_defs = VEC_alloc (tree, heap, 5);
 225       build_uses = VEC_alloc (tree, heap, 10);
 226       build_vuse = NULL_TREE;
 227       build_vdef = NULL_TREE;
 228       bitmap_obstack_initialize (&operands_bitmap_obstack);
 229     }
 230
 231   gcc_assert (gimple_ssa_operands (cfun)->operand_memory == NULL);
 232   gimple_ssa_operands (cfun)->operand_memory_index
 233      = gimple_ssa_operands (cfun)->ssa_operand_mem_size;
 234   gimple_ssa_operands (cfun)->ops_active = true;
 235   memset (&clobber_stats, 0, sizeof (clobber_stats));
 236   gimple_ssa_operands (cfun)->ssa_operand_mem_size = OP_SIZE_INIT;
 237   create_vop_var ();
 238 }
 239
 240
 241 /* Dispose of anything required by the operand routines.  */
 242
 243 void
 244 fini_ssa_operands (void)
 245 {
 246   struct ssa_operand_memory_d *ptr;
 247
 248   if (!--n_initialized)
 249     {
 250       VEC_free (tree, heap, build_defs);
 251       VEC_free (tree, heap, build_uses);
 252       build_vdef = NULL_TREE;
 253       build_vuse = NULL_TREE;
 254     }
 255
 256   gimple_ssa_operands (cfun)->free_defs = NULL;
 257   gimple_ssa_operands (cfun)->free_uses = NULL;
 258
 259   while ((ptr = gimple_ssa_operands (cfun)->operand_memory) != NULL)
 260     {
 261       gimple_ssa_operands (cfun)->operand_memory
 262         = gimple_ssa_operands (cfun)->operand_memory->next;
 263       ggc_free (ptr);
 264     }
 265
 266   gimple_ssa_operands (cfun)->ops_active = false;
 267
 268   if (!n_initialized)
 269     bitmap_obstack_release (&operands_bitmap_obstack);
 270
 271   cfun->gimple_df->vop = NULL_TREE;
 272
 273   if (dump_file && (dump_flags & TDF_STATS))
 274     {
 275       fprintf (dump_file, "Original clobbered vars:           %d\n",
 276                clobber_stats.clobbered_vars);
 277       fprintf (dump_file, "Static write clobbers avoided:     %d\n",
 278                clobber_stats.static_write_clobbers_avoided);
 279       fprintf (dump_file, "Static read clobbers avoided:      %d\n",
 280                clobber_stats.static_read_clobbers_avoided);
 281       fprintf (dump_file, "Unescapable clobbers avoided:      %d\n",
 282                clobber_stats.unescapable_clobbers_avoided);
 283       fprintf (dump_file, "Original read-only clobbers:       %d\n",
 284                clobber_stats.readonly_clobbers);
 285       fprintf (dump_file, "Static read-only clobbers avoided: %d\n",
 286                clobber_stats.static_readonly_clobbers_avoided);
 287     }
 288 }
 289
 290
 291 /* Return memory for an operand of size SIZE.  */
 292
 293 static inline void *
 294 ssa_operand_alloc (unsigned size)
 295 {
 296   char *ptr;
 297
 298   gcc_assert (size == sizeof (struct use_optype_d)
 299               || size == sizeof (struct def_optype_d));
 300
 301   if (gimple_ssa_operands (cfun)->operand_memory_index + size
 302       >= gimple_ssa_operands (cfun)->ssa_operand_mem_size)
 303     {
 304       struct ssa_operand_memory_d *ptr;
 305
 306       switch (gimple_ssa_operands (cfun)->ssa_operand_mem_size)
 307         {
 308         case OP_SIZE_INIT:
 309           gimple_ssa_operands (cfun)->ssa_operand_mem_size = OP_SIZE_1;
 310           break;
 311         case OP_SIZE_1:
 312           gimple_ssa_operands (cfun)->ssa_operand_mem_size = OP_SIZE_2;
 313           break;
 314         case OP_SIZE_2:
 315         case OP_SIZE_3:
 316           gimple_ssa_operands (cfun)->ssa_operand_mem_size = OP_SIZE_3;
 317           break;
 318         default:
 319           gcc_unreachable ();
 320         }
 321
 322       ptr = (struct ssa_operand_memory_d *)
 323               ggc_alloc (sizeof (void *)
 324                          + gimple_ssa_operands (cfun)->ssa_operand_mem_size);
 325       ptr->next = gimple_ssa_operands (cfun)->operand_memory;
 326       gimple_ssa_operands (cfun)->operand_memory = ptr;
 327       gimple_ssa_operands (cfun)->operand_memory_index = 0;
 328     }
 329
 330   ptr = &(gimple_ssa_operands (cfun)->operand_memory
 331           ->mem[gimple_ssa_operands (cfun)->operand_memory_index]);
 332   gimple_ssa_operands (cfun)->operand_memory_index += size;
 333   return ptr;
 334 }
 335
 336
 337 /* Allocate a DEF operand.  */
 338
 339 static inline struct def_optype_d *
 340 alloc_def (void)
 341 {
 342   struct def_optype_d *ret;
 343   if (gimple_ssa_operands (cfun)->free_defs)
 344     {
 345       ret = gimple_ssa_operands (cfun)->free_defs;
 346       gimple_ssa_operands (cfun)->free_defs
 347         = gimple_ssa_operands (cfun)->free_defs->next;
 348     }
 349   else
 350     ret = (struct def_optype_d *)
 351           ssa_operand_alloc (sizeof (struct def_optype_d));
 352   return ret;
 353 }
 354
 355
 356 /* Allocate a USE operand.  */
 357
 358 static inline struct use_optype_d *
 359 alloc_use (void)
 360 {
 361   struct use_optype_d *ret;
 362   if (gimple_ssa_operands (cfun)->free_uses)
 363     {
 364       ret = gimple_ssa_operands (cfun)->free_uses;
 365       gimple_ssa_operands (cfun)->free_uses
 366         = gimple_ssa_operands (cfun)->free_uses->next;
 367     }
 368   else
 369     ret = (struct use_optype_d *)
 370           ssa_operand_alloc (sizeof (struct use_optype_d));
 371   return ret;
 372 }
 373
 374
 375 /* Adds OP to the list of defs after LAST.  */
 376
 377 static inline def_optype_p
 378 add_def_op (tree *op, def_optype_p last)
 379 {
 380   def_optype_p new_def;
 381
 382   new_def = alloc_def ();
 383   DEF_OP_PTR (new_def) = op;
 384   last->next = new_def;
 385   new_def->next = NULL;
 386   return new_def;
 387 }
 388
 389
 390 /* Adds OP to the list of uses of statement STMT after LAST.  */
 391
 392 static inline use_optype_p
 393 add_use_op (gimple stmt, tree *op, use_optype_p last)
 394 {
 395   use_optype_p new_use;
 396
 397   new_use = alloc_use ();
 398   USE_OP_PTR (new_use)->use = op;
 399   link_imm_use_stmt (USE_OP_PTR (new_use), *op, stmt);
 400   last->next = new_use;
 401   new_use->next = NULL;
 402   return new_use;
 403 }
 404
 405
 406
 407 /* Takes elements from build_defs and turns them into def operands of STMT.
 408    TODO -- Make build_defs VEC of tree *.  */
 409
 410 static inline void
 411 finalize_ssa_defs (gimple stmt)
 412 {
 413   unsigned new_i;
 414   struct def_optype_d new_list;
 415   def_optype_p old_ops, last;
 416   unsigned int num = VEC_length (tree, build_defs);
 417
 418   /* There should only be a single real definition per assignment.  */
 419   gcc_assert ((stmt && gimple_code (stmt) != GIMPLE_ASSIGN) || num <= 1);
 420
 421   /* Pre-pend the vdef we may have built.  */
 422   if (build_vdef != NULL_TREE)
 423     {
 424       tree oldvdef = gimple_vdef (stmt);
 425       if (oldvdef
 426           && TREE_CODE (oldvdef) == SSA_NAME)
 427         oldvdef = SSA_NAME_VAR (oldvdef);
 428       if (oldvdef != build_vdef)
 429         gimple_set_vdef (stmt, build_vdef);
 430       VEC_safe_insert (tree, heap, build_defs, 0, (tree)gimple_vdef_ptr (stmt));
 431       ++num;
 432     }
 433
 434   new_list.next = NULL;
 435   last = &new_list;
 436
 437   old_ops = gimple_def_ops (stmt);
 438
 439   new_i = 0;
 440
 441   /* Clear and unlink a no longer necessary VDEF.  */
 442   if (build_vdef == NULL_TREE
 443       && gimple_vdef (stmt) != NULL_TREE)
 444     {
 445       if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME)
 446         {
 447           unlink_stmt_vdef (stmt);
 448           release_ssa_name (gimple_vdef (stmt));
 449         }
 450       gimple_set_vdef (stmt, NULL_TREE);
 451     }
 452
 453   /* If we have a non-SSA_NAME VDEF, mark it for renaming.  */
 454   if (gimple_vdef (stmt)
 455       && TREE_CODE (gimple_vdef (stmt)) != SSA_NAME)
 456     mark_sym_for_renaming (gimple_vdef (stmt));
 457
 458   /* Check for the common case of 1 def that hasn't changed.  */
 459   if (old_ops && old_ops->next == NULL && num == 1
 460       && (tree *) VEC_index (tree, build_defs, 0) == DEF_OP_PTR (old_ops))
 461     return;
 462
 463   /* If there is anything in the old list, free it.  */
 464   if (old_ops)
 465     {
 466       old_ops->next = gimple_ssa_operands (cfun)->free_defs;
 467       gimple_ssa_operands (cfun)->free_defs = old_ops;
 468     }
 469
 470   /* If there is anything remaining in the build_defs list, simply emit it.  */
 471   for ( ; new_i < num; new_i++)
 472     last = add_def_op ((tree *) VEC_index (tree, build_defs, new_i), last);
 473
 474   /* Now set the stmt's operands.  */
 475   gimple_set_def_ops (stmt, new_list.next);
 476 }
 477
 478
 479 /* Takes elements from build_uses and turns them into use operands of STMT.
 480    TODO -- Make build_uses VEC of tree *.  */
 481
 482 static inline void
 483 finalize_ssa_uses (gimple stmt)
 484 {
 485   unsigned new_i;
 486   struct use_optype_d new_list;
 487   use_optype_p old_ops, ptr, last;
 488
 489   /* Pre-pend the VUSE we may have built.  */
 490   if (build_vuse != NULL_TREE)
 491     {
 492       tree oldvuse = gimple_vuse (stmt);
 493       if (oldvuse
 494           && TREE_CODE (oldvuse) == SSA_NAME)
 495         oldvuse = SSA_NAME_VAR (oldvuse);
 496       if (oldvuse != (build_vuse != NULL_TREE
 497                       ? build_vuse : build_vdef))
 498         gimple_set_vuse (stmt, NULL_TREE);
 499       VEC_safe_insert (tree, heap, build_uses, 0, (tree)gimple_vuse_ptr (stmt));
 500     }
 501
 502   new_list.next = NULL;
 503   last = &new_list;
 504
 505   old_ops = gimple_use_ops (stmt);
 506
 507   /* Clear a no longer necessary VUSE.  */
 508   if (build_vuse == NULL_TREE
 509       && gimple_vuse (stmt) != NULL_TREE)
 510     gimple_set_vuse (stmt, NULL_TREE);
 511
 512   /* If there is anything in the old list, free it.  */
 513   if (old_ops)
 514     {
 515       for (ptr = old_ops; ptr; ptr = ptr->next)
 516         delink_imm_use (USE_OP_PTR (ptr));
 517       old_ops->next = gimple_ssa_operands (cfun)->free_uses;
 518       gimple_ssa_operands (cfun)->free_uses = old_ops;
 519     }
 520
 521   /* If we added a VUSE, make sure to set the operand if it is not already
 522      present and mark it for renaming.  */
 523   if (build_vuse != NULL_TREE
 524       && gimple_vuse (stmt) == NULL_TREE)
 525     {
 526       gimple_set_vuse (stmt, gimple_vop (cfun));
 527       mark_sym_for_renaming (gimple_vop (cfun));
 528     }
 529
 530   /* Now create nodes for all the new nodes.  */
 531   for (new_i = 0; new_i < VEC_length (tree, build_uses); new_i++)
 532     last = add_use_op (stmt,
 533                        (tree *) VEC_index (tree, build_uses, new_i),
 534                        last);
 535
 536   /* Now set the stmt's operands.  */
 537   gimple_set_use_ops (stmt, new_list.next);
 538 }
 539
 540
 541 /* Clear the in_list bits and empty the build array for VDEFs and
 542    VUSEs.  */
 543
 544 static inline void
 545 cleanup_build_arrays (void)
 546 {
 547   build_vdef = NULL_TREE;
 548   build_vuse = NULL_TREE;
 549   VEC_truncate (tree, build_defs, 0);
 550   VEC_truncate (tree, build_uses, 0);
 551 }
 552
 553
 554 /* Finalize all the build vectors, fill the new ones into INFO.  */
 555
 556 static inline void
 557 finalize_ssa_stmt_operands (gimple stmt)
 558 {
 559   finalize_ssa_defs (stmt);
 560   finalize_ssa_uses (stmt);
 561   cleanup_build_arrays ();
 562 }
 563
 564
 565 /* Start the process of building up operands vectors in INFO.  */
 566
 567 static inline void
 568 start_ssa_stmt_operands (void)
 569 {
 570   gcc_assert (VEC_length (tree, build_defs) == 0);
 571   gcc_assert (VEC_length (tree, build_uses) == 0);
 572   gcc_assert (build_vuse == NULL_TREE);
 573   gcc_assert (build_vdef == NULL_TREE);
 574 }
 575
 576
 577 /* Add DEF_P to the list of pointers to operands.  */
 578
 579 static inline void
 580 append_def (tree *def_p)
 581 {
 582   VEC_safe_push (tree, heap, build_defs, (tree) def_p);
 583 }
 584
 585
 586 /* Add USE_P to the list of pointers to operands.  */
 587
 588 static inline void
 589 append_use (tree *use_p)
 590 {
 591   VEC_safe_push (tree, heap, build_uses, (tree) use_p);
 592 }
 593
 594
 595 /* Add VAR to the set of variables that require a VDEF operator.  */
 596
 597 static inline void
 598 append_vdef (tree var)
 599 {
 600   if (!optimize)
 601     return;
 602
 603   gcc_assert ((build_vdef == NULL_TREE
 604                || build_vdef == var)
 605               && (build_vuse == NULL_TREE
 606                   || build_vuse == var));
 607
 608   build_vdef = var;
 609   build_vuse = var;
 610 }
 611
 612
 613 /* Add VAR to the set of variables that require a VUSE operator.  */
 614
 615 static inline void
 616 append_vuse (tree var)
 617 {
 618   if (!optimize)
 619     return;
 620
 621   gcc_assert (build_vuse == NULL_TREE
 622               || build_vuse == var);
 623
 624   build_vuse = var;
 625 }
 626
 627 /* Add virtual operands for STMT.  FLAGS is as in get_expr_operands.  */
 628
 629 static void
 630 add_virtual_operand (gimple stmt ATTRIBUTE_UNUSED, int flags)
 631 {
 632   /* Add virtual operands to the stmt, unless the caller has specifically
 633      requested not to do that (used when adding operands inside an
 634      ADDR_EXPR expression).  */
 635   if (flags & opf_no_vops)
 636     return;
 637
 638   gcc_assert (!is_gimple_debug (stmt));
 639
 640   if (flags & opf_def)
 641     append_vdef (gimple_vop (cfun));
 642   else
 643     append_vuse (gimple_vop (cfun));
 644 }
 645
 646
 647 /* Add *VAR_P to the appropriate operand array for statement STMT.
 648    FLAGS is as in get_expr_operands.  If *VAR_P is a GIMPLE register,
 649    it will be added to the statement's real operands, otherwise it is
 650    added to virtual operands.  */
 651
 652 static void
 653 add_stmt_operand (tree *var_p, gimple stmt, int flags)
 654 {
 655   tree var, sym;
 656   var_ann_t v_ann;
 657
 658   gcc_assert (SSA_VAR_P (*var_p));
 659
 660   var = *var_p;
 661   sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var);
 662   v_ann = var_ann (sym);
 663
 664   /* Mark statements with volatile operands.  */
 665   if (TREE_THIS_VOLATILE (sym))
 666     gimple_set_has_volatile_ops (stmt, true);
 667
 668   if (is_gimple_reg (sym))
 669     {
 670       /* The variable is a GIMPLE register.  Add it to real operands.  */
 671       if (flags & opf_def)
 672         append_def (var_p);
 673       else
 674         append_use (var_p);
 675     }
 676   else
 677     add_virtual_operand (stmt, flags);
 678 }
 679
 680 /* Mark the base address of REF as having its address taken.
 681    REF may be a single variable whose address has been taken or any
 682    other valid GIMPLE memory reference (structure reference, array,
 683    etc).  */
 684
 685 static void
 686 mark_address_taken (tree ref)
 687 {
 688   tree var;
 689
 690   /* Note that it is *NOT OKAY* to use the target of a COMPONENT_REF
 691      as the only thing we take the address of.  If VAR is a structure,
 692      taking the address of a field means that the whole structure may
 693      be referenced using pointer arithmetic.  See PR 21407 and the
 694      ensuing mailing list discussion.  */
 695   var = get_base_address (ref);
 696   if (var && DECL_P (var))
 697     TREE_ADDRESSABLE (var) = 1;
 698 }
 699
 700
 701 /* A subroutine of get_expr_operands to handle INDIRECT_REF,
 702    ALIGN_INDIRECT_REF and MISALIGNED_INDIRECT_REF.
 703
 704    STMT is the statement being processed, EXPR is the INDIRECT_REF
 705       that got us here.
 706
 707    FLAGS is as in get_expr_operands.
 708
 709    RECURSE_ON_BASE should be set to true if we want to continue
 710       calling get_expr_operands on the base pointer, and false if
 711       something else will do it for us.  */
 712
 713 static void
 714 get_indirect_ref_operands (gimple stmt, tree expr, int flags,
 715                            bool recurse_on_base)
 716 {
 717   tree *pptr = &TREE_OPERAND (expr, 0);
 718
 719   if (TREE_THIS_VOLATILE (expr))
 720     gimple_set_has_volatile_ops (stmt, true);
 721
 722   /* Add the VOP.  */
 723   add_virtual_operand (stmt, flags);
 724
 725   /* If requested, add a USE operand for the base pointer.  */
 726   if (recurse_on_base)
 727     get_expr_operands (stmt, pptr,
 728                        opf_use | (flags & opf_no_vops));
 729 }
 730
 731
 732 /* A subroutine of get_expr_operands to handle TARGET_MEM_REF.  */
 733
 734 static void
 735 get_tmr_operands (gimple stmt, tree expr, int flags)
 736 {
 737   /* First record the real operands.  */
 738   get_expr_operands (stmt, &TMR_BASE (expr), opf_use | (flags & opf_no_vops));
 739   get_expr_operands (stmt, &TMR_INDEX (expr), opf_use | (flags & opf_no_vops));
 740
 741   if (TMR_SYMBOL (expr))
 742     mark_address_taken (TMR_SYMBOL (expr));
 743
 744   add_virtual_operand (stmt, flags);
 745 }
 746
 747
 748 /* If STMT is a call that may clobber globals and other symbols that
 749    escape, add them to the VDEF/VUSE lists for it.  */
 750
 751 static void
 752 maybe_add_call_vops (gimple stmt)
 753 {
 754   int call_flags = gimple_call_flags (stmt);
 755
 756   /* If aliases have been computed already, add VDEF or VUSE
 757      operands for all the symbols that have been found to be
 758      call-clobbered.  */
 759   if (!(call_flags & ECF_NOVOPS))
 760     {
 761       /* A 'pure' or a 'const' function never call-clobbers anything.
 762          A 'noreturn' function might, but since we don't return anyway
 763          there is no point in recording that.  */
 764       if (!(call_flags & (ECF_PURE | ECF_CONST | ECF_NORETURN)))
 765         add_virtual_operand (stmt, opf_def);
 766       else if (!(call_flags & ECF_CONST))
 767         add_virtual_operand (stmt, opf_use);
 768     }
 769 }
 770
 771
 772 /* Scan operands in the ASM_EXPR stmt referred to in INFO.  */
 773
 774 static void
 775 get_asm_expr_operands (gimple stmt)
 776 {
 777   size_t i, noutputs;
 778   const char **oconstraints;
 779   const char *constraint;
 780   bool allows_mem, allows_reg, is_inout;
 781
 782   noutputs = gimple_asm_noutputs (stmt);
 783   oconstraints = (const char **) alloca ((noutputs) * sizeof (const char *));
 784
 785   /* Gather all output operands.  */
 786   for (i = 0; i < gimple_asm_noutputs (stmt); i++)
 787     {
 788       tree link = gimple_asm_output_op (stmt, i);
 789       constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
 790       oconstraints[i] = constraint;
 791       parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
 792                                &allows_reg, &is_inout);
 793
 794       /* This should have been split in gimplify_asm_expr.  */
 795       gcc_assert (!allows_reg || !is_inout);
 796
 797       /* Memory operands are addressable.  Note that STMT needs the
 798          address of this operand.  */
 799       if (!allows_reg && allows_mem)
 800         {
 801           tree t = get_base_address (TREE_VALUE (link));
 802           if (t && DECL_P (t))
 803             mark_address_taken (t);
 804         }
 805
 806       get_expr_operands (stmt, &TREE_VALUE (link), opf_def);
 807     }
 808
 809   /* Gather all input operands.  */
 810   for (i = 0; i < gimple_asm_ninputs (stmt); i++)
 811     {
 812       tree link = gimple_asm_input_op (stmt, i);
 813       constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
 814       parse_input_constraint (&constraint, 0, 0, noutputs, 0, oconstraints,
 815                               &allows_mem, &allows_reg);
 816
 817       /* Memory operands are addressable.  Note that STMT needs the
 818          address of this operand.  */
 819       if (!allows_reg && allows_mem)
 820         {
 821           tree t = get_base_address (TREE_VALUE (link));
 822           if (t && DECL_P (t))
 823             mark_address_taken (t);
 824         }
 825
 826       get_expr_operands (stmt, &TREE_VALUE (link), 0);
 827     }
 828
 829   /* Clobber all memory and addressable symbols for asm ("" : : : "memory");  */
 830   for (i = 0; i < gimple_asm_nclobbers (stmt); i++)
 831     {
 832       tree link = gimple_asm_clobber_op (stmt, i);
 833       if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0)
 834         {
 835           add_virtual_operand (stmt, opf_def);
 836           break;
 837         }
 838     }
 839 }
 840
 841
 842 /* Recursively scan the expression pointed to by EXPR_P in statement
 843    STMT.  FLAGS is one of the OPF_* constants modifying how to
 844    interpret the operands found.  */
 845
 846 static void
 847 get_expr_operands (gimple stmt, tree *expr_p, int flags)
 848 {
 849   enum tree_code code;
 850   enum tree_code_class codeclass;
 851   tree expr = *expr_p;
 852   int uflags = opf_use;
 853
 854   if (expr == NULL)
 855     return;
 856
 857   if (is_gimple_debug (stmt))
 858     uflags |= (flags & opf_no_vops);
 859
 860   code = TREE_CODE (expr);
 861   codeclass = TREE_CODE_CLASS (code);
 862
 863   switch (code)
 864     {
 865     case ADDR_EXPR:
 866       /* Taking the address of a variable does not represent a
 867          reference to it, but the fact that the statement takes its
 868          address will be of interest to some passes (e.g. alias
 869          resolution).  */
 870       if (!is_gimple_debug (stmt))
 871         mark_address_taken (TREE_OPERAND (expr, 0));
 872
 873       /* If the address is invariant, there may be no interesting
 874          variable references inside.  */
 875       if (is_gimple_min_invariant (expr))
 876         return;
 877
 878       /* Otherwise, there may be variables referenced inside but there
 879          should be no VUSEs created, since the referenced objects are
 880          not really accessed.  The only operands that we should find
 881          here are ARRAY_REF indices which will always be real operands
 882          (GIMPLE does not allow non-registers as array indices).  */
 883       flags |= opf_no_vops;
 884       get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
 885       return;
 886
 887     case SSA_NAME:
 888      add_stmt_operand (expr_p, stmt, flags);
 889      return;
 890
 891     case VAR_DECL:
 892     case PARM_DECL:
 893     case RESULT_DECL:
 894       add_stmt_operand (expr_p, stmt, flags);
 895       return;
 896
 897     case DEBUG_EXPR_DECL:
 898       gcc_assert (gimple_debug_bind_p (stmt));
 899       return;
 900
 901     case MISALIGNED_INDIRECT_REF:
 902       get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
 903       /* fall through */
 904
 905     case ALIGN_INDIRECT_REF:
 906     case INDIRECT_REF:
 907       get_indirect_ref_operands (stmt, expr, flags, true);
 908       return;
 909
 910     case TARGET_MEM_REF:
 911       get_tmr_operands (stmt, expr, flags);
 912       return;
 913
 914     case ARRAY_REF:
 915     case ARRAY_RANGE_REF:
 916     case COMPONENT_REF:
 917     case REALPART_EXPR:
 918     case IMAGPART_EXPR:
 919       {
 920         if (TREE_THIS_VOLATILE (expr))
 921           gimple_set_has_volatile_ops (stmt, true);
 922
 923         get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
 924
 925         if (code == COMPONENT_REF)
 926           {
 927             if (TREE_THIS_VOLATILE (TREE_OPERAND (expr, 1)))
 928               gimple_set_has_volatile_ops (stmt, true);
 929             get_expr_operands (stmt, &TREE_OPERAND (expr, 2), uflags);
 930           }
 931         else if (code == ARRAY_REF || code == ARRAY_RANGE_REF)
 932           {
 933             get_expr_operands (stmt, &TREE_OPERAND (expr, 1), uflags);
 934             get_expr_operands (stmt, &TREE_OPERAND (expr, 2), uflags);
 935             get_expr_operands (stmt, &TREE_OPERAND (expr, 3), uflags);
 936           }
 937
 938         return;
 939       }
 940
 941     case WITH_SIZE_EXPR:
 942       /* WITH_SIZE_EXPR is a pass-through reference to its first argument,
 943          and an rvalue reference to its second argument.  */
 944       get_expr_operands (stmt, &TREE_OPERAND (expr, 1), uflags);
 945       get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
 946       return;
 947
 948     case COND_EXPR:
 949     case VEC_COND_EXPR:
 950       get_expr_operands (stmt, &TREE_OPERAND (expr, 0), uflags);
 951       get_expr_operands (stmt, &TREE_OPERAND (expr, 1), uflags);
 952       get_expr_operands (stmt, &TREE_OPERAND (expr, 2), uflags);
 953       return;
 954
 955     case CONSTRUCTOR:
 956       {
 957         /* General aggregate CONSTRUCTORs have been decomposed, but they
 958            are still in use as the COMPLEX_EXPR equivalent for vectors.  */
 959         constructor_elt *ce;
 960         unsigned HOST_WIDE_INT idx;
 961
 962         for (idx = 0;
 963              VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (expr), idx, ce);
 964              idx++)
 965           get_expr_operands (stmt, &ce->value, uflags);
 966
 967         return;
 968       }
 969
 970     case BIT_FIELD_REF:
 971       if (TREE_THIS_VOLATILE (expr))
 972         gimple_set_has_volatile_ops (stmt, true);
 973       /* FALLTHRU */
 974
 975     case TRUTH_NOT_EXPR:
 976     case VIEW_CONVERT_EXPR:
 977     do_unary:
 978       get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
 979       return;
 980
 981     case TRUTH_AND_EXPR:
 982     case TRUTH_OR_EXPR:
 983     case TRUTH_XOR_EXPR:
 984     case COMPOUND_EXPR:
 985     case OBJ_TYPE_REF:
 986     case ASSERT_EXPR:
 987     do_binary:
 988       {
 989         get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
 990         get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
 991         return;
 992       }
 993
 994     case DOT_PROD_EXPR:
 995     case REALIGN_LOAD_EXPR:
 996       {
 997         get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
 998         get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
 999         get_expr_operands (stmt, &TREE_OPERAND (expr, 2), flags);
1000         return;
1001       }
1002
1003     case FUNCTION_DECL:
1004     case LABEL_DECL:
1005     case CONST_DECL:
1006     case CASE_LABEL_EXPR:
1007       /* Expressions that make no memory references.  */
1008       return;
1009
1010     default:
1011       if (codeclass == tcc_unary)
1012         goto do_unary;
1013       if (codeclass == tcc_binary || codeclass == tcc_comparison)
1014         goto do_binary;
1015       if (codeclass == tcc_constant || codeclass == tcc_type)
1016         return;
1017     }
1018
1019   /* If we get here, something has gone wrong.  */
1020 #ifdef ENABLE_CHECKING
1021   fprintf (stderr, "unhandled expression in get_expr_operands():\n");
1022   debug_tree (expr);
1023   fputs ("\n", stderr);
1024 #endif
1025   gcc_unreachable ();
1026 }
1027
1028
1029 /* Parse STMT looking for operands.  When finished, the various
1030    build_* operand vectors will have potential operands in them.  */
1031
1032 static void
1033 parse_ssa_operands (gimple stmt)
1034 {
1035   enum gimple_code code = gimple_code (stmt);
1036
1037   if (code == GIMPLE_ASM)
1038     get_asm_expr_operands (stmt);
1039   else if (is_gimple_debug (stmt))
1040     {
1041       if (gimple_debug_bind_p (stmt)
1042           && gimple_debug_bind_has_value_p (stmt))
1043         get_expr_operands (stmt, gimple_debug_bind_get_value_ptr (stmt),
1044                            opf_use | opf_no_vops);
1045     }
1046   else
1047     {
1048       size_t i, start = 0;
1049
1050       if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
1051         {
1052           get_expr_operands (stmt, gimple_op_ptr (stmt, 0), opf_def);
1053           start = 1;
1054         }
1055
1056       for (i = start; i < gimple_num_ops (stmt); i++)
1057         get_expr_operands (stmt, gimple_op_ptr (stmt, i), opf_use);
1058
1059       /* Add call-clobbered operands, if needed.  */
1060       if (code == GIMPLE_CALL)
1061         maybe_add_call_vops (stmt);
1062     }
1063 }
1064
1065
1066 /* Create an operands cache for STMT.  */
1067
1068 static void
1069 build_ssa_operands (gimple stmt)
1070 {
1071   /* Initially assume that the statement has no volatile operands.  */
1072   gimple_set_has_volatile_ops (stmt, false);
1073
1074   start_ssa_stmt_operands ();
1075   parse_ssa_operands (stmt);
1076   finalize_ssa_stmt_operands (stmt);
1077 }
1078
1079
1080 /* Releases the operands of STMT back to their freelists, and clears
1081    the stmt operand lists.  */
1082
1083 void
1084 free_stmt_operands (gimple stmt)
1085 {
1086   def_optype_p defs = gimple_def_ops (stmt), last_def;
1087   use_optype_p uses = gimple_use_ops (stmt), last_use;
1088
1089   if (defs)
1090     {
1091       for (last_def = defs; last_def->next; last_def = last_def->next)
1092         continue;
1093       last_def->next = gimple_ssa_operands (cfun)->free_defs;
1094       gimple_ssa_operands (cfun)->free_defs = defs;
1095       gimple_set_def_ops (stmt, NULL);
1096     }
1097
1098   if (uses)
1099     {
1100       for (last_use = uses; last_use->next; last_use = last_use->next)
1101         delink_imm_use (USE_OP_PTR (last_use));
1102       delink_imm_use (USE_OP_PTR (last_use));
1103       last_use->next = gimple_ssa_operands (cfun)->free_uses;
1104       gimple_ssa_operands (cfun)->free_uses = uses;
1105       gimple_set_use_ops (stmt, NULL);
1106     }
1107
1108   if (gimple_has_mem_ops (stmt))
1109     {
1110       gimple_set_vuse (stmt, NULL_TREE);
1111       gimple_set_vdef (stmt, NULL_TREE);
1112     }
1113 }
1114
1115
1116 /* Get the operands of statement STMT.  */
1117
1118 void
1119 update_stmt_operands (gimple stmt)
1120 {
1121   /* If update_stmt_operands is called before SSA is initialized, do
1122      nothing.  */
1123   if (!ssa_operands_active ())
1124     return;
1125
1126   timevar_push (TV_TREE_OPS);
1127
1128   gcc_assert (gimple_modified_p (stmt));
1129   build_ssa_operands (stmt);
1130   gimple_set_modified (stmt, false);
1131
1132   timevar_pop (TV_TREE_OPS);
1133 }
1134
1135
1136 /* Swap operands EXP0 and EXP1 in statement STMT.  No attempt is done
1137    to test the validity of the swap operation.  */
1138
1139 void
1140 swap_tree_operands (gimple stmt, tree *exp0, tree *exp1)
1141 {
1142   tree op0, op1;
1143   op0 = *exp0;
1144   op1 = *exp1;
1145
1146   /* If the operand cache is active, attempt to preserve the relative
1147      positions of these two operands in their respective immediate use
1148      lists.  */
1149   if (ssa_operands_active () && op0 != op1)
1150     {
1151       use_optype_p use0, use1, ptr;
1152       use0 = use1 = NULL;
1153
1154       /* Find the 2 operands in the cache, if they are there.  */
1155       for (ptr = gimple_use_ops (stmt); ptr; ptr = ptr->next)
1156         if (USE_OP_PTR (ptr)->use == exp0)
1157           {
1158             use0 = ptr;
1159             break;
1160           }
1161
1162       for (ptr = gimple_use_ops (stmt); ptr; ptr = ptr->next)
1163         if (USE_OP_PTR (ptr)->use == exp1)
1164           {
1165             use1 = ptr;
1166             break;
1167           }
1168
1169       /* If both uses don't have operand entries, there isn't much we can do
1170          at this point.  Presumably we don't need to worry about it.  */
1171       if (use0 && use1)
1172         {
1173           tree *tmp = USE_OP_PTR (use1)->use;
1174           USE_OP_PTR (use1)->use = USE_OP_PTR (use0)->use;
1175           USE_OP_PTR (use0)->use = tmp;
1176         }
1177     }
1178
1179   /* Now swap the data.  */
1180   *exp0 = op1;
1181   *exp1 = op0;
1182 }
1183
1184
1185 /* Scan the immediate_use list for VAR making sure its linked properly.
1186    Return TRUE if there is a problem and emit an error message to F.  */
1187
1188 bool
1189 verify_imm_links (FILE *f, tree var)
1190 {
1191   use_operand_p ptr, prev, list;
1192   int count;
1193
1194   gcc_assert (TREE_CODE (var) == SSA_NAME);
1195
1196   list = &(SSA_NAME_IMM_USE_NODE (var));
1197   gcc_assert (list->use == NULL);
1198
1199   if (list->prev == NULL)
1200     {
1201       gcc_assert (list->next == NULL);
1202       return false;
1203     }
1204
1205   prev = list;
1206   count = 0;
1207   for (ptr = list->next; ptr != list; )
1208     {
1209       if (prev != ptr->prev)
1210         goto error;
1211
1212       if (ptr->use == NULL)
1213         goto error; /* 2 roots, or SAFE guard node.  */
1214       else if (*(ptr->use) != var)
1215         goto error;
1216
1217       prev = ptr;
1218       ptr = ptr->next;
1219
1220       /* Avoid infinite loops.  50,000,000 uses probably indicates a
1221          problem.  */
1222       if (count++ > 50000000)
1223         goto error;
1224     }
1225
1226   /* Verify list in the other direction.  */
1227   prev = list;
1228   for (ptr = list->prev; ptr != list; )
1229     {
1230       if (prev != ptr->next)
1231         goto error;
1232       prev = ptr;
1233       ptr = ptr->prev;
1234       if (count-- < 0)
1235         goto error;
1236     }
1237
1238   if (count != 0)
1239     goto error;
1240
1241   return false;
1242
1243  error:
1244   if (ptr->loc.stmt && gimple_modified_p (ptr->loc.stmt))
1245     {
1246       fprintf (f, " STMT MODIFIED. - <%p> ", (void *)ptr->loc.stmt);
1247       print_gimple_stmt (f, ptr->loc.stmt, 0, TDF_SLIM);
1248     }
1249   fprintf (f, " IMM ERROR : (use_p : tree - %p:%p)", (void *)ptr,
1250            (void *)ptr->use);
1251   print_generic_expr (f, USE_FROM_PTR (ptr), TDF_SLIM);
1252   fprintf(f, "\n");
1253   return true;
1254 }
1255
1256
1257 /* Dump all the immediate uses to FILE.  */
1258
1259 void
1260 dump_immediate_uses_for (FILE *file, tree var)
1261 {
1262   imm_use_iterator iter;
1263   use_operand_p use_p;
1264
1265   gcc_assert (var && TREE_CODE (var) == SSA_NAME);
1266
1267   print_generic_expr (file, var, TDF_SLIM);
1268   fprintf (file, " : -->");
1269   if (has_zero_uses (var))
1270     fprintf (file, " no uses.\n");
1271   else
1272     if (has_single_use (var))
1273       fprintf (file, " single use.\n");
1274     else
1275       fprintf (file, "%d uses.\n", num_imm_uses (var));
1276
1277   FOR_EACH_IMM_USE_FAST (use_p, iter, var)
1278     {
1279       if (use_p->loc.stmt == NULL && use_p->use == NULL)
1280         fprintf (file, "***end of stmt iterator marker***\n");
1281       else
1282         if (!is_gimple_reg (USE_FROM_PTR (use_p)))
1283           print_gimple_stmt (file, USE_STMT (use_p), 0, TDF_VOPS|TDF_MEMSYMS);
1284         else
1285           print_gimple_stmt (file, USE_STMT (use_p), 0, TDF_SLIM);
1286     }
1287   fprintf(file, "\n");
1288 }
1289
1290
1291 /* Dump all the immediate uses to FILE.  */
1292
1293 void
1294 dump_immediate_uses (FILE *file)
1295 {
1296   tree var;
1297   unsigned int x;
1298
1299   fprintf (file, "Immediate_uses: \n\n");
1300   for (x = 1; x < num_ssa_names; x++)
1301     {
1302       var = ssa_name(x);
1303       if (!var)
1304         continue;
1305       dump_immediate_uses_for (file, var);
1306     }
1307 }
1308
1309
1310 /* Dump def-use edges on stderr.  */
1311
1312 void
1313 debug_immediate_uses (void)
1314 {
1315   dump_immediate_uses (stderr);
1316 }
1317
1318
1319 /* Dump def-use edges on stderr.  */
1320
1321 void
1322 debug_immediate_uses_for (tree var)
1323 {
1324   dump_immediate_uses_for (stderr, var);
1325 }
1326
1327
1328 /* Unlink STMTs virtual definition from the IL by propagating its use.  */
1329
1330 void
1331 unlink_stmt_vdef (gimple stmt)
1332 {
1333   use_operand_p use_p;
1334   imm_use_iterator iter;
1335   gimple use_stmt;
1336   tree vdef = gimple_vdef (stmt);
1337
1338   if (!vdef
1339       || TREE_CODE (vdef) != SSA_NAME)
1340     return;
1341
1342   FOR_EACH_IMM_USE_STMT (use_stmt, iter, gimple_vdef (stmt))
1343     {
1344       FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
1345         SET_USE (use_p, gimple_vuse (stmt));
1346     }
1347
1348   if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_vdef (stmt)))
1349     SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_vuse (stmt)) = 1;
1350 }
1351