gcc/tree-cfg.c

   1 /* Control flow functions for trees.
   2    Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
   3    2010, 2011  Free Software Foundation, Inc.
   4    Contributed by Diego Novillo <dnovillo@redhat.com>
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "tree.h"
  27 #include "tm_p.h"
  28 #include "basic-block.h"
  29 #include "output.h"
  30 #include "flags.h"
  31 #include "function.h"
  32 #include "ggc.h"
  33 #include "langhooks.h"
  34 #include "tree-pretty-print.h"
  35 #include "gimple-pretty-print.h"
  36 #include "tree-flow.h"
  37 #include "timevar.h"
  38 #include "tree-dump.h"
  39 #include "tree-pass.h"
  40 #include "diagnostic-core.h"
  41 #include "except.h"
  42 #include "cfgloop.h"
  43 #include "cfglayout.h"
  44 #include "tree-ssa-propagate.h"
  45 #include "value-prof.h"
  46 #include "pointer-set.h"
  47 #include "tree-inline.h"
  48
  49 /* This file contains functions for building the Control Flow Graph (CFG)
  50    for a function tree.  */
  51
  52 /* Local declarations.  */
  53
  54 /* Initial capacity for the basic block array.  */
  55 static const int initial_cfg_capacity = 20;
  56
  57 /* This hash table allows us to efficiently lookup all CASE_LABEL_EXPRs
  58    which use a particular edge.  The CASE_LABEL_EXPRs are chained together
  59    via their TREE_CHAIN field, which we clear after we're done with the
  60    hash table to prevent problems with duplication of GIMPLE_SWITCHes.
  61
  62    Access to this list of CASE_LABEL_EXPRs allows us to efficiently
  63    update the case vector in response to edge redirections.
  64
  65    Right now this table is set up and torn down at key points in the
  66    compilation process.  It would be nice if we could make the table
  67    more persistent.  The key is getting notification of changes to
  68    the CFG (particularly edge removal, creation and redirection).  */
  69
  70 static struct pointer_map_t *edge_to_cases;
  71
  72 /* If we record edge_to_cases, this bitmap will hold indexes
  73    of basic blocks that end in a GIMPLE_SWITCH which we touched
  74    due to edge manipulations.  */
  75
  76 static bitmap touched_switch_bbs;
  77
  78 /* CFG statistics.  */
  79 struct cfg_stats_d
  80 {
  81   long num_merged_labels;
  82 };
  83
  84 static struct cfg_stats_d cfg_stats;
  85
  86 /* Nonzero if we found a computed goto while building basic blocks.  */
  87 static bool found_computed_goto;
  88
  89 /* Hash table to store last discriminator assigned for each locus.  */
  90 struct locus_discrim_map
  91 {
  92   location_t locus;
  93   int discriminator;
  94 };
  95 static htab_t discriminator_per_locus;
  96
  97 /* Basic blocks and flowgraphs.  */
  98 static void make_blocks (gimple_seq);
  99 static void factor_computed_gotos (void);
 100
 101 /* Edges.  */
 102 static void make_edges (void);
 103 static void make_cond_expr_edges (basic_block);
 104 static void make_gimple_switch_edges (basic_block);
 105 static void make_goto_expr_edges (basic_block);
 106 static void make_gimple_asm_edges (basic_block);
 107 static unsigned int locus_map_hash (const void *);
 108 static int locus_map_eq (const void *, const void *);
 109 static void assign_discriminator (location_t, basic_block);
 110 static edge gimple_redirect_edge_and_branch (edge, basic_block);
 111 static edge gimple_try_redirect_by_replacing_jump (edge, basic_block);
 112 static unsigned int split_critical_edges (void);
 113
 114 /* Various helpers.  */
 115 static inline bool stmt_starts_bb_p (gimple, gimple);
 116 static int gimple_verify_flow_info (void);
 117 static void gimple_make_forwarder_block (edge);
 118 static void gimple_cfg2vcg (FILE *);
 119 static gimple first_non_label_stmt (basic_block);
 120
 121 /* Flowgraph optimization and cleanup.  */
 122 static void gimple_merge_blocks (basic_block, basic_block);
 123 static bool gimple_can_merge_blocks_p (basic_block, basic_block);
 124 static void remove_bb (basic_block);
 125 static edge find_taken_edge_computed_goto (basic_block, tree);
 126 static edge find_taken_edge_cond_expr (basic_block, tree);
 127 static edge find_taken_edge_switch_expr (basic_block, tree);
 128 static tree find_case_label_for_value (gimple, tree);
 129 static void group_case_labels_stmt (gimple);
 130
 131 void
 132 init_empty_tree_cfg_for_function (struct function *fn)
 133 {
 134   /* Initialize the basic block array.  */
 135   init_flow (fn);
 136   profile_status_for_function (fn) = PROFILE_ABSENT;
 137   n_basic_blocks_for_function (fn) = NUM_FIXED_BLOCKS;
 138   last_basic_block_for_function (fn) = NUM_FIXED_BLOCKS;
 139   basic_block_info_for_function (fn)
 140     = VEC_alloc (basic_block, gc, initial_cfg_capacity);
 141   VEC_safe_grow_cleared (basic_block, gc,
 142                          basic_block_info_for_function (fn),
 143                          initial_cfg_capacity);
 144
 145   /* Build a mapping of labels to their associated blocks.  */
 146   label_to_block_map_for_function (fn)
 147     = VEC_alloc (basic_block, gc, initial_cfg_capacity);
 148   VEC_safe_grow_cleared (basic_block, gc,
 149                          label_to_block_map_for_function (fn),
 150                          initial_cfg_capacity);
 151
 152   SET_BASIC_BLOCK_FOR_FUNCTION (fn, ENTRY_BLOCK,
 153                                 ENTRY_BLOCK_PTR_FOR_FUNCTION (fn));
 154   SET_BASIC_BLOCK_FOR_FUNCTION (fn, EXIT_BLOCK,
 155                    EXIT_BLOCK_PTR_FOR_FUNCTION (fn));
 156
 157   ENTRY_BLOCK_PTR_FOR_FUNCTION (fn)->next_bb
 158     = EXIT_BLOCK_PTR_FOR_FUNCTION (fn);
 159   EXIT_BLOCK_PTR_FOR_FUNCTION (fn)->prev_bb
 160     = ENTRY_BLOCK_PTR_FOR_FUNCTION (fn);
 161 }
 162
 163 void
 164 init_empty_tree_cfg (void)
 165 {
 166   init_empty_tree_cfg_for_function (cfun);
 167 }
 168
 169 /*---------------------------------------------------------------------------
 170                               Create basic blocks
 171 ---------------------------------------------------------------------------*/
 172
 173 /* Entry point to the CFG builder for trees.  SEQ is the sequence of
 174    statements to be added to the flowgraph.  */
 175
 176 static void
 177 build_gimple_cfg (gimple_seq seq)
 178 {
 179   /* Register specific gimple functions.  */
 180   gimple_register_cfg_hooks ();
 181
 182   memset ((void *) &cfg_stats, 0, sizeof (cfg_stats));
 183
 184   init_empty_tree_cfg ();
 185
 186   found_computed_goto = 0;
 187   make_blocks (seq);
 188
 189   /* Computed gotos are hell to deal with, especially if there are
 190      lots of them with a large number of destinations.  So we factor
 191      them to a common computed goto location before we build the
 192      edge list.  After we convert back to normal form, we will un-factor
 193      the computed gotos since factoring introduces an unwanted jump.  */
 194   if (found_computed_goto)
 195     factor_computed_gotos ();
 196
 197   /* Make sure there is always at least one block, even if it's empty.  */
 198   if (n_basic_blocks == NUM_FIXED_BLOCKS)
 199     create_empty_bb (ENTRY_BLOCK_PTR);
 200
 201   /* Adjust the size of the array.  */
 202   if (VEC_length (basic_block, basic_block_info) < (size_t) n_basic_blocks)
 203     VEC_safe_grow_cleared (basic_block, gc, basic_block_info, n_basic_blocks);
 204
 205   /* To speed up statement iterator walks, we first purge dead labels.  */
 206   cleanup_dead_labels ();
 207
 208   /* Group case nodes to reduce the number of edges.
 209      We do this after cleaning up dead labels because otherwise we miss
 210      a lot of obvious case merging opportunities.  */
 211   group_case_labels ();
 212
 213   /* Create the edges of the flowgraph.  */
 214   discriminator_per_locus = htab_create (13, locus_map_hash, locus_map_eq,
 215                                          free);
 216   make_edges ();
 217   cleanup_dead_labels ();
 218   htab_delete (discriminator_per_locus);
 219
 220   /* Debugging dumps.  */
 221
 222   /* Write the flowgraph to a VCG file.  */
 223   {
 224     int local_dump_flags;
 225     FILE *vcg_file = dump_begin (TDI_vcg, &local_dump_flags);
 226     if (vcg_file)
 227       {
 228         gimple_cfg2vcg (vcg_file);
 229         dump_end (TDI_vcg, vcg_file);
 230       }
 231   }
 232 }
 233
 234 static unsigned int
 235 execute_build_cfg (void)
 236 {
 237   gimple_seq body = gimple_body (current_function_decl);
 238
 239   build_gimple_cfg (body);
 240   gimple_set_body (current_function_decl, NULL);
 241   if (dump_file && (dump_flags & TDF_DETAILS))
 242     {
 243       fprintf (dump_file, "Scope blocks:\n");
 244       dump_scope_blocks (dump_file, dump_flags);
 245     }
 246   return 0;
 247 }
 248
 249 struct gimple_opt_pass pass_build_cfg =
 250 {
 251  {
 252   GIMPLE_PASS,
 253   "cfg",                                /* name */
 254   NULL,                                 /* gate */
 255   execute_build_cfg,                    /* execute */
 256   NULL,                                 /* sub */
 257   NULL,                                 /* next */
 258   0,                                    /* static_pass_number */
 259   TV_TREE_CFG,                          /* tv_id */
 260   PROP_gimple_leh,                      /* properties_required */
 261   PROP_cfg,                             /* properties_provided */
 262   0,                                    /* properties_destroyed */
 263   0,                                    /* todo_flags_start */
 264   TODO_verify_stmts | TODO_cleanup_cfg  /* todo_flags_finish */
 265  }
 266 };
 267
 268
 269 /* Return true if T is a computed goto.  */
 270
 271 static bool
 272 computed_goto_p (gimple t)
 273 {
 274   return (gimple_code (t) == GIMPLE_GOTO
 275           && TREE_CODE (gimple_goto_dest (t)) != LABEL_DECL);
 276 }
 277
 278
 279 /* Search the CFG for any computed gotos.  If found, factor them to a
 280    common computed goto site.  Also record the location of that site so
 281    that we can un-factor the gotos after we have converted back to
 282    normal form.  */
 283
 284 static void
 285 factor_computed_gotos (void)
 286 {
 287   basic_block bb;
 288   tree factored_label_decl = NULL;
 289   tree var = NULL;
 290   gimple factored_computed_goto_label = NULL;
 291   gimple factored_computed_goto = NULL;
 292
 293   /* We know there are one or more computed gotos in this function.
 294      Examine the last statement in each basic block to see if the block
 295      ends with a computed goto.  */
 296
 297   FOR_EACH_BB (bb)
 298     {
 299       gimple_stmt_iterator gsi = gsi_last_bb (bb);
 300       gimple last;
 301
 302       if (gsi_end_p (gsi))
 303         continue;
 304
 305       last = gsi_stmt (gsi);
 306
 307       /* Ignore the computed goto we create when we factor the original
 308          computed gotos.  */
 309       if (last == factored_computed_goto)
 310         continue;
 311
 312       /* If the last statement is a computed goto, factor it.  */
 313       if (computed_goto_p (last))
 314         {
 315           gimple assignment;
 316
 317           /* The first time we find a computed goto we need to create
 318              the factored goto block and the variable each original
 319              computed goto will use for their goto destination.  */
 320           if (!factored_computed_goto)
 321             {
 322               basic_block new_bb = create_empty_bb (bb);
 323               gimple_stmt_iterator new_gsi = gsi_start_bb (new_bb);
 324
 325               /* Create the destination of the factored goto.  Each original
 326                  computed goto will put its desired destination into this
 327                  variable and jump to the label we create immediately
 328                  below.  */
 329               var = create_tmp_var (ptr_type_node, "gotovar");
 330
 331               /* Build a label for the new block which will contain the
 332                  factored computed goto.  */
 333               factored_label_decl = create_artificial_label (UNKNOWN_LOCATION);
 334               factored_computed_goto_label
 335                 = gimple_build_label (factored_label_decl);
 336               gsi_insert_after (&new_gsi, factored_computed_goto_label,
 337                                 GSI_NEW_STMT);
 338
 339               /* Build our new computed goto.  */
 340               factored_computed_goto = gimple_build_goto (var);
 341               gsi_insert_after (&new_gsi, factored_computed_goto, GSI_NEW_STMT);
 342             }
 343
 344           /* Copy the original computed goto's destination into VAR.  */
 345           assignment = gimple_build_assign (var, gimple_goto_dest (last));
 346           gsi_insert_before (&gsi, assignment, GSI_SAME_STMT);
 347
 348           /* And re-vector the computed goto to the new destination.  */
 349           gimple_goto_set_dest (last, factored_label_decl);
 350         }
 351     }
 352 }
 353
 354
 355 /* Build a flowgraph for the sequence of stmts SEQ.  */
 356
 357 static void
 358 make_blocks (gimple_seq seq)
 359 {
 360   gimple_stmt_iterator i = gsi_start (seq);
 361   gimple stmt = NULL;
 362   bool start_new_block = true;
 363   bool first_stmt_of_seq = true;
 364   basic_block bb = ENTRY_BLOCK_PTR;
 365
 366   while (!gsi_end_p (i))
 367     {
 368       gimple prev_stmt;
 369
 370       prev_stmt = stmt;
 371       stmt = gsi_stmt (i);
 372
 373       /* If the statement starts a new basic block or if we have determined
 374          in a previous pass that we need to create a new block for STMT, do
 375          so now.  */
 376       if (start_new_block || stmt_starts_bb_p (stmt, prev_stmt))
 377         {
 378           if (!first_stmt_of_seq)
 379             seq = gsi_split_seq_before (&i);
 380           bb = create_basic_block (seq, NULL, bb);
 381           start_new_block = false;
 382         }
 383
 384       /* Now add STMT to BB and create the subgraphs for special statement
 385          codes.  */
 386       gimple_set_bb (stmt, bb);
 387
 388       if (computed_goto_p (stmt))
 389         found_computed_goto = true;
 390
 391       /* If STMT is a basic block terminator, set START_NEW_BLOCK for the
 392          next iteration.  */
 393       if (stmt_ends_bb_p (stmt))
 394         {
 395           /* If the stmt can make abnormal goto use a new temporary
 396              for the assignment to the LHS.  This makes sure the old value
 397              of the LHS is available on the abnormal edge.  Otherwise
 398              we will end up with overlapping life-ranges for abnormal
 399              SSA names.  */
 400           if (gimple_has_lhs (stmt)
 401               && stmt_can_make_abnormal_goto (stmt)
 402               && is_gimple_reg_type (TREE_TYPE (gimple_get_lhs (stmt))))
 403             {
 404               tree lhs = gimple_get_lhs (stmt);
 405               tree tmp = create_tmp_var (TREE_TYPE (lhs), NULL);
 406               gimple s = gimple_build_assign (lhs, tmp);
 407               gimple_set_location (s, gimple_location (stmt));
 408               gimple_set_block (s, gimple_block (stmt));
 409               gimple_set_lhs (stmt, tmp);
 410               if (TREE_CODE (TREE_TYPE (tmp)) == COMPLEX_TYPE
 411                   || TREE_CODE (TREE_TYPE (tmp)) == VECTOR_TYPE)
 412                 DECL_GIMPLE_REG_P (tmp) = 1;
 413               gsi_insert_after (&i, s, GSI_SAME_STMT);
 414             }
 415           start_new_block = true;
 416         }
 417
 418       gsi_next (&i);
 419       first_stmt_of_seq = false;
 420     }
 421 }
 422
 423
 424 /* Create and return a new empty basic block after bb AFTER.  */
 425
 426 static basic_block
 427 create_bb (void *h, void *e, basic_block after)
 428 {
 429   basic_block bb;
 430
 431   gcc_assert (!e);
 432
 433   /* Create and initialize a new basic block.  Since alloc_block uses
 434      GC allocation that clears memory to allocate a basic block, we do
 435      not have to clear the newly allocated basic block here.  */
 436   bb = alloc_block ();
 437
 438   bb->index = last_basic_block;
 439   bb->flags = BB_NEW;
 440   bb->il.gimple = ggc_alloc_cleared_gimple_bb_info ();
 441   set_bb_seq (bb, h ? (gimple_seq) h : gimple_seq_alloc ());
 442
 443   /* Add the new block to the linked list of blocks.  */
 444   link_block (bb, after);
 445
 446   /* Grow the basic block array if needed.  */
 447   if ((size_t) last_basic_block == VEC_length (basic_block, basic_block_info))
 448     {
 449       size_t new_size = last_basic_block + (last_basic_block + 3) / 4;
 450       VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size);
 451     }
 452
 453   /* Add the newly created block to the array.  */
 454   SET_BASIC_BLOCK (last_basic_block, bb);
 455
 456   n_basic_blocks++;
 457   last_basic_block++;
 458
 459   return bb;
 460 }
 461
 462
 463 /*---------------------------------------------------------------------------
 464                                  Edge creation
 465 ---------------------------------------------------------------------------*/
 466
 467 /* Fold COND_EXPR_COND of each COND_EXPR.  */
 468
 469 void
 470 fold_cond_expr_cond (void)
 471 {
 472   basic_block bb;
 473
 474   FOR_EACH_BB (bb)
 475     {
 476       gimple stmt = last_stmt (bb);
 477
 478       if (stmt && gimple_code (stmt) == GIMPLE_COND)
 479         {
 480           location_t loc = gimple_location (stmt);
 481           tree cond;
 482           bool zerop, onep;
 483
 484           fold_defer_overflow_warnings ();
 485           cond = fold_binary_loc (loc, gimple_cond_code (stmt), boolean_type_node,
 486                               gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
 487           if (cond)
 488             {
 489               zerop = integer_zerop (cond);
 490               onep = integer_onep (cond);
 491             }
 492           else
 493             zerop = onep = false;
 494
 495           fold_undefer_overflow_warnings (zerop || onep,
 496                                           stmt,
 497                                           WARN_STRICT_OVERFLOW_CONDITIONAL);
 498           if (zerop)
 499             gimple_cond_make_false (stmt);
 500           else if (onep)
 501             gimple_cond_make_true (stmt);
 502         }
 503     }
 504 }
 505
 506 /* Join all the blocks in the flowgraph.  */
 507
 508 static void
 509 make_edges (void)
 510 {
 511   basic_block bb;
 512   struct omp_region *cur_region = NULL;
 513
 514   /* Create an edge from entry to the first block with executable
 515      statements in it.  */
 516   make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (NUM_FIXED_BLOCKS), EDGE_FALLTHRU);
 517
 518   /* Traverse the basic block array placing edges.  */
 519   FOR_EACH_BB (bb)
 520     {
 521       gimple last = last_stmt (bb);
 522       bool fallthru;
 523
 524       if (last)
 525         {
 526           enum gimple_code code = gimple_code (last);
 527           switch (code)
 528             {
 529             case GIMPLE_GOTO:
 530               make_goto_expr_edges (bb);
 531               fallthru = false;
 532               break;
 533             case GIMPLE_RETURN:
 534               make_edge (bb, EXIT_BLOCK_PTR, 0);
 535               fallthru = false;
 536               break;
 537             case GIMPLE_COND:
 538               make_cond_expr_edges (bb);
 539               fallthru = false;
 540               break;
 541             case GIMPLE_SWITCH:
 542               make_gimple_switch_edges (bb);
 543               fallthru = false;
 544               break;
 545             case GIMPLE_RESX:
 546               make_eh_edges (last);
 547               fallthru = false;
 548               break;
 549             case GIMPLE_EH_DISPATCH:
 550               fallthru = make_eh_dispatch_edges (last);
 551               break;
 552
 553             case GIMPLE_CALL:
 554               /* If this function receives a nonlocal goto, then we need to
 555                  make edges from this call site to all the nonlocal goto
 556                  handlers.  */
 557               if (stmt_can_make_abnormal_goto (last))
 558                 make_abnormal_goto_edges (bb, true);
 559
 560               /* If this statement has reachable exception handlers, then
 561                  create abnormal edges to them.  */
 562               make_eh_edges (last);
 563
 564               /* BUILTIN_RETURN is really a return statement.  */
 565               if (gimple_call_builtin_p (last, BUILT_IN_RETURN))
 566                 make_edge (bb, EXIT_BLOCK_PTR, 0), fallthru = false;
 567               /* Some calls are known not to return.  */
 568               else
 569                 fallthru = !(gimple_call_flags (last) & ECF_NORETURN);
 570               break;
 571
 572             case GIMPLE_ASSIGN:
 573                /* A GIMPLE_ASSIGN may throw internally and thus be considered
 574                   control-altering. */
 575               if (is_ctrl_altering_stmt (last))
 576                 make_eh_edges (last);
 577               fallthru = true;
 578               break;
 579
 580             case GIMPLE_ASM:
 581               make_gimple_asm_edges (bb);
 582               fallthru = true;
 583               break;
 584
 585             case GIMPLE_OMP_PARALLEL:
 586             case GIMPLE_OMP_TASK:
 587             case GIMPLE_OMP_FOR:
 588             case GIMPLE_OMP_SINGLE:
 589             case GIMPLE_OMP_MASTER:
 590             case GIMPLE_OMP_ORDERED:
 591             case GIMPLE_OMP_CRITICAL:
 592             case GIMPLE_OMP_SECTION:
 593               cur_region = new_omp_region (bb, code, cur_region);
 594               fallthru = true;
 595               break;
 596
 597             case GIMPLE_OMP_SECTIONS:
 598               cur_region = new_omp_region (bb, code, cur_region);
 599               fallthru = true;
 600               break;
 601
 602             case GIMPLE_OMP_SECTIONS_SWITCH:
 603               fallthru = false;
 604               break;
 605
 606             case GIMPLE_OMP_ATOMIC_LOAD:
 607             case GIMPLE_OMP_ATOMIC_STORE:
 608                fallthru = true;
 609                break;
 610
 611             case GIMPLE_OMP_RETURN:
 612               /* In the case of a GIMPLE_OMP_SECTION, the edge will go
 613                  somewhere other than the next block.  This will be
 614                  created later.  */
 615               cur_region->exit = bb;
 616               fallthru = cur_region->type != GIMPLE_OMP_SECTION;
 617               cur_region = cur_region->outer;
 618               break;
 619
 620             case GIMPLE_OMP_CONTINUE:
 621               cur_region->cont = bb;
 622               switch (cur_region->type)
 623                 {
 624                 case GIMPLE_OMP_FOR:
 625                   /* Mark all GIMPLE_OMP_FOR and GIMPLE_OMP_CONTINUE
 626                      succs edges as abnormal to prevent splitting
 627                      them.  */
 628                   single_succ_edge (cur_region->entry)->flags |= EDGE_ABNORMAL;
 629                   /* Make the loopback edge.  */
 630                   make_edge (bb, single_succ (cur_region->entry),
 631                              EDGE_ABNORMAL);
 632
 633                   /* Create an edge from GIMPLE_OMP_FOR to exit, which
 634                      corresponds to the case that the body of the loop
 635                      is not executed at all.  */
 636                   make_edge (cur_region->entry, bb->next_bb, EDGE_ABNORMAL);
 637                   make_edge (bb, bb->next_bb, EDGE_FALLTHRU | EDGE_ABNORMAL);
 638                   fallthru = false;
 639                   break;
 640
 641                 case GIMPLE_OMP_SECTIONS:
 642                   /* Wire up the edges into and out of the nested sections.  */
 643                   {
 644                     basic_block switch_bb = single_succ (cur_region->entry);
 645
 646                     struct omp_region *i;
 647                     for (i = cur_region->inner; i ; i = i->next)
 648                       {
 649                         gcc_assert (i->type == GIMPLE_OMP_SECTION);
 650                         make_edge (switch_bb, i->entry, 0);
 651                         make_edge (i->exit, bb, EDGE_FALLTHRU);
 652                       }
 653
 654                     /* Make the loopback edge to the block with
 655                        GIMPLE_OMP_SECTIONS_SWITCH.  */
 656                     make_edge (bb, switch_bb, 0);
 657
 658                     /* Make the edge from the switch to exit.  */
 659                     make_edge (switch_bb, bb->next_bb, 0);
 660                     fallthru = false;
 661                   }
 662                   break;
 663
 664                 default:
 665                   gcc_unreachable ();
 666                 }
 667               break;
 668
 669             default:
 670               gcc_assert (!stmt_ends_bb_p (last));
 671               fallthru = true;
 672             }
 673         }
 674       else
 675         fallthru = true;
 676
 677       if (fallthru)
 678         {
 679           make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
 680           if (last)
 681             assign_discriminator (gimple_location (last), bb->next_bb);
 682         }
 683     }
 684
 685   if (root_omp_region)
 686     free_omp_regions ();
 687
 688   /* Fold COND_EXPR_COND of each COND_EXPR.  */
 689   fold_cond_expr_cond ();
 690 }
 691
 692 /* Trivial hash function for a location_t.  ITEM is a pointer to
 693    a hash table entry that maps a location_t to a discriminator.  */
 694
 695 static unsigned int
 696 locus_map_hash (const void *item)
 697 {
 698   return ((const struct locus_discrim_map *) item)->locus;
 699 }
 700
 701 /* Equality function for the locus-to-discriminator map.  VA and VB
 702    point to the two hash table entries to compare.  */
 703
 704 static int
 705 locus_map_eq (const void *va, const void *vb)
 706 {
 707   const struct locus_discrim_map *a = (const struct locus_discrim_map *) va;
 708   const struct locus_discrim_map *b = (const struct locus_discrim_map *) vb;
 709   return a->locus == b->locus;
 710 }
 711
 712 /* Find the next available discriminator value for LOCUS.  The
 713    discriminator distinguishes among several basic blocks that
 714    share a common locus, allowing for more accurate sample-based
 715    profiling.  */
 716
 717 static int
 718 next_discriminator_for_locus (location_t locus)
 719 {
 720   struct locus_discrim_map item;
 721   struct locus_discrim_map **slot;
 722
 723   item.locus = locus;
 724   item.discriminator = 0;
 725   slot = (struct locus_discrim_map **)
 726       htab_find_slot_with_hash (discriminator_per_locus, (void *) &item,
 727                                 (hashval_t) locus, INSERT);
 728   gcc_assert (slot);
 729   if (*slot == HTAB_EMPTY_ENTRY)
 730     {
 731       *slot = XNEW (struct locus_discrim_map);
 732       gcc_assert (*slot);
 733       (*slot)->locus = locus;
 734       (*slot)->discriminator = 0;
 735     }
 736   (*slot)->discriminator++;
 737   return (*slot)->discriminator;
 738 }
 739
 740 /* Return TRUE if LOCUS1 and LOCUS2 refer to the same source line.  */
 741
 742 static bool
 743 same_line_p (location_t locus1, location_t locus2)
 744 {
 745   expanded_location from, to;
 746
 747   if (locus1 == locus2)
 748     return true;
 749
 750   from = expand_location (locus1);
 751   to = expand_location (locus2);
 752
 753   if (from.line != to.line)
 754     return false;
 755   if (from.file == to.file)
 756     return true;
 757   return (from.file != NULL
 758           && to.file != NULL
 759           && filename_cmp (from.file, to.file) == 0);
 760 }
 761
 762 /* Assign a unique discriminator value to block BB if it begins at the same
 763    LOCUS as its predecessor block.  */
 764
 765 static void
 766 assign_discriminator (location_t locus, basic_block bb)
 767 {
 768   gimple first_in_to_bb, last_in_to_bb;
 769
 770   if (locus == 0 || bb->discriminator != 0)
 771     return;
 772
 773   first_in_to_bb = first_non_label_stmt (bb);
 774   last_in_to_bb = last_stmt (bb);
 775   if ((first_in_to_bb && same_line_p (locus, gimple_location (first_in_to_bb)))
 776       || (last_in_to_bb && same_line_p (locus, gimple_location (last_in_to_bb))))
 777     bb->discriminator = next_discriminator_for_locus (locus);
 778 }
 779
 780 /* Create the edges for a GIMPLE_COND starting at block BB.  */
 781
 782 static void
 783 make_cond_expr_edges (basic_block bb)
 784 {
 785   gimple entry = last_stmt (bb);
 786   gimple then_stmt, else_stmt;
 787   basic_block then_bb, else_bb;
 788   tree then_label, else_label;
 789   edge e;
 790   location_t entry_locus;
 791
 792   gcc_assert (entry);
 793   gcc_assert (gimple_code (entry) == GIMPLE_COND);
 794
 795   entry_locus = gimple_location (entry);
 796
 797   /* Entry basic blocks for each component.  */
 798   then_label = gimple_cond_true_label (entry);
 799   else_label = gimple_cond_false_label (entry);
 800   then_bb = label_to_block (then_label);
 801   else_bb = label_to_block (else_label);
 802   then_stmt = first_stmt (then_bb);
 803   else_stmt = first_stmt (else_bb);
 804
 805   e = make_edge (bb, then_bb, EDGE_TRUE_VALUE);
 806   assign_discriminator (entry_locus, then_bb);
 807   e->goto_locus = gimple_location (then_stmt);
 808   if (e->goto_locus)
 809     e->goto_block = gimple_block (then_stmt);
 810   e = make_edge (bb, else_bb, EDGE_FALSE_VALUE);
 811   if (e)
 812     {
 813       assign_discriminator (entry_locus, else_bb);
 814       e->goto_locus = gimple_location (else_stmt);
 815       if (e->goto_locus)
 816         e->goto_block = gimple_block (else_stmt);
 817     }
 818
 819   /* We do not need the labels anymore.  */
 820   gimple_cond_set_true_label (entry, NULL_TREE);
 821   gimple_cond_set_false_label (entry, NULL_TREE);
 822 }
 823
 824
 825 /* Called for each element in the hash table (P) as we delete the
 826    edge to cases hash table.
 827
 828    Clear all the TREE_CHAINs to prevent problems with copying of
 829    SWITCH_EXPRs and structure sharing rules, then free the hash table
 830    element.  */
 831
 832 static bool
 833 edge_to_cases_cleanup (const void *key ATTRIBUTE_UNUSED, void **value,
 834                        void *data ATTRIBUTE_UNUSED)
 835 {
 836   tree t, next;
 837
 838   for (t = (tree) *value; t; t = next)
 839     {
 840       next = CASE_CHAIN (t);
 841       CASE_CHAIN (t) = NULL;
 842     }
 843
 844   *value = NULL;
 845   return true;
 846 }
 847
 848 /* Start recording information mapping edges to case labels.  */
 849
 850 void
 851 start_recording_case_labels (void)
 852 {
 853   gcc_assert (edge_to_cases == NULL);
 854   edge_to_cases = pointer_map_create ();
 855   touched_switch_bbs = BITMAP_ALLOC (NULL);
 856 }
 857
 858 /* Return nonzero if we are recording information for case labels.  */
 859
 860 static bool
 861 recording_case_labels_p (void)
 862 {
 863   return (edge_to_cases != NULL);
 864 }
 865
 866 /* Stop recording information mapping edges to case labels and
 867    remove any information we have recorded.  */
 868 void
 869 end_recording_case_labels (void)
 870 {
 871   bitmap_iterator bi;
 872   unsigned i;
 873   pointer_map_traverse (edge_to_cases, edge_to_cases_cleanup, NULL);
 874   pointer_map_destroy (edge_to_cases);
 875   edge_to_cases = NULL;
 876   EXECUTE_IF_SET_IN_BITMAP (touched_switch_bbs, 0, i, bi)
 877     {
 878       basic_block bb = BASIC_BLOCK (i);
 879       if (bb)
 880         {
 881           gimple stmt = last_stmt (bb);
 882           if (stmt && gimple_code (stmt) == GIMPLE_SWITCH)
 883             group_case_labels_stmt (stmt);
 884         }
 885     }
 886   BITMAP_FREE (touched_switch_bbs);
 887 }
 888
 889 /* If we are inside a {start,end}_recording_cases block, then return
 890    a chain of CASE_LABEL_EXPRs from T which reference E.
 891
 892    Otherwise return NULL.  */
 893
 894 static tree
 895 get_cases_for_edge (edge e, gimple t)
 896 {
 897   void **slot;
 898   size_t i, n;
 899
 900   /* If we are not recording cases, then we do not have CASE_LABEL_EXPR
 901      chains available.  Return NULL so the caller can detect this case.  */
 902   if (!recording_case_labels_p ())
 903     return NULL;
 904
 905   slot = pointer_map_contains (edge_to_cases, e);
 906   if (slot)
 907     return (tree) *slot;
 908
 909   /* If we did not find E in the hash table, then this must be the first
 910      time we have been queried for information about E & T.  Add all the
 911      elements from T to the hash table then perform the query again.  */
 912
 913   n = gimple_switch_num_labels (t);
 914   for (i = 0; i < n; i++)
 915     {
 916       tree elt = gimple_switch_label (t, i);
 917       tree lab = CASE_LABEL (elt);
 918       basic_block label_bb = label_to_block (lab);
 919       edge this_edge = find_edge (e->src, label_bb);
 920
 921       /* Add it to the chain of CASE_LABEL_EXPRs referencing E, or create
 922          a new chain.  */
 923       slot = pointer_map_insert (edge_to_cases, this_edge);
 924       CASE_CHAIN (elt) = (tree) *slot;
 925       *slot = elt;
 926     }
 927
 928   return (tree) *pointer_map_contains (edge_to_cases, e);
 929 }
 930
 931 /* Create the edges for a GIMPLE_SWITCH starting at block BB.  */
 932
 933 static void
 934 make_gimple_switch_edges (basic_block bb)
 935 {
 936   gimple entry = last_stmt (bb);
 937   location_t entry_locus;
 938   size_t i, n;
 939
 940   entry_locus = gimple_location (entry);
 941
 942   n = gimple_switch_num_labels (entry);
 943
 944   for (i = 0; i < n; ++i)
 945     {
 946       tree lab = CASE_LABEL (gimple_switch_label (entry, i));
 947       basic_block label_bb = label_to_block (lab);
 948       make_edge (bb, label_bb, 0);
 949       assign_discriminator (entry_locus, label_bb);
 950     }
 951 }
 952
 953
 954 /* Return the basic block holding label DEST.  */
 955
 956 basic_block
 957 label_to_block_fn (struct function *ifun, tree dest)
 958 {
 959   int uid = LABEL_DECL_UID (dest);
 960
 961   /* We would die hard when faced by an undefined label.  Emit a label to
 962      the very first basic block.  This will hopefully make even the dataflow
 963      and undefined variable warnings quite right.  */
 964   if (seen_error () && uid < 0)
 965     {
 966       gimple_stmt_iterator gsi = gsi_start_bb (BASIC_BLOCK (NUM_FIXED_BLOCKS));
 967       gimple stmt;
 968
 969       stmt = gimple_build_label (dest);
 970       gsi_insert_before (&gsi, stmt, GSI_NEW_STMT);
 971       uid = LABEL_DECL_UID (dest);
 972     }
 973   if (VEC_length (basic_block, ifun->cfg->x_label_to_block_map)
 974       <= (unsigned int) uid)
 975     return NULL;
 976   return VEC_index (basic_block, ifun->cfg->x_label_to_block_map, uid);
 977 }
 978
 979 /* Create edges for an abnormal goto statement at block BB.  If FOR_CALL
 980    is true, the source statement is a CALL_EXPR instead of a GOTO_EXPR.  */
 981
 982 void
 983 make_abnormal_goto_edges (basic_block bb, bool for_call)
 984 {
 985   basic_block target_bb;
 986   gimple_stmt_iterator gsi;
 987
 988   FOR_EACH_BB (target_bb)
 989     for (gsi = gsi_start_bb (target_bb); !gsi_end_p (gsi); gsi_next (&gsi))
 990       {
 991         gimple label_stmt = gsi_stmt (gsi);
 992         tree target;
 993
 994         if (gimple_code (label_stmt) != GIMPLE_LABEL)
 995           break;
 996
 997         target = gimple_label_label (label_stmt);
 998
 999         /* Make an edge to every label block that has been marked as a
1000            potential target for a computed goto or a non-local goto.  */
1001         if ((FORCED_LABEL (target) && !for_call)
1002             || (DECL_NONLOCAL (target) && for_call))
1003           {
1004             make_edge (bb, target_bb, EDGE_ABNORMAL);
1005             break;
1006           }
1007       }
1008 }
1009
1010 /* Create edges for a goto statement at block BB.  */
1011
1012 static void
1013 make_goto_expr_edges (basic_block bb)
1014 {
1015   gimple_stmt_iterator last = gsi_last_bb (bb);
1016   gimple goto_t = gsi_stmt (last);
1017
1018   /* A simple GOTO creates normal edges.  */
1019   if (simple_goto_p (goto_t))
1020     {
1021       tree dest = gimple_goto_dest (goto_t);
1022       basic_block label_bb = label_to_block (dest);
1023       edge e = make_edge (bb, label_bb, EDGE_FALLTHRU);
1024       e->goto_locus = gimple_location (goto_t);
1025       assign_discriminator (e->goto_locus, label_bb);
1026       if (e->goto_locus)
1027         e->goto_block = gimple_block (goto_t);
1028       gsi_remove (&last, true);
1029       return;
1030     }
1031
1032   /* A computed GOTO creates abnormal edges.  */
1033   make_abnormal_goto_edges (bb, false);
1034 }
1035
1036 /* Create edges for an asm statement with labels at block BB.  */
1037
1038 static void
1039 make_gimple_asm_edges (basic_block bb)
1040 {
1041   gimple stmt = last_stmt (bb);
1042   location_t stmt_loc = gimple_location (stmt);
1043   int i, n = gimple_asm_nlabels (stmt);
1044
1045   for (i = 0; i < n; ++i)
1046     {
1047       tree label = TREE_VALUE (gimple_asm_label_op (stmt, i));
1048       basic_block label_bb = label_to_block (label);
1049       make_edge (bb, label_bb, 0);
1050       assign_discriminator (stmt_loc, label_bb);
1051     }
1052 }
1053
1054 /*---------------------------------------------------------------------------
1055                                Flowgraph analysis
1056 ---------------------------------------------------------------------------*/
1057
1058 /* Cleanup useless labels in basic blocks.  This is something we wish
1059    to do early because it allows us to group case labels before creating
1060    the edges for the CFG, and it speeds up block statement iterators in
1061    all passes later on.
1062    We rerun this pass after CFG is created, to get rid of the labels that
1063    are no longer referenced.  After then we do not run it any more, since
1064    (almost) no new labels should be created.  */
1065
1066 /* A map from basic block index to the leading label of that block.  */
1067 static struct label_record
1068 {
1069   /* The label.  */
1070   tree label;
1071
1072   /* True if the label is referenced from somewhere.  */
1073   bool used;
1074 } *label_for_bb;
1075
1076 /* Given LABEL return the first label in the same basic block.  */
1077
1078 static tree
1079 main_block_label (tree label)
1080 {
1081   basic_block bb = label_to_block (label);
1082   tree main_label = label_for_bb[bb->index].label;
1083
1084   /* label_to_block possibly inserted undefined label into the chain.  */
1085   if (!main_label)
1086     {
1087       label_for_bb[bb->index].label = label;
1088       main_label = label;
1089     }
1090
1091   label_for_bb[bb->index].used = true;
1092   return main_label;
1093 }
1094
1095 /* Clean up redundant labels within the exception tree.  */
1096
1097 static void
1098 cleanup_dead_labels_eh (void)
1099 {
1100   eh_landing_pad lp;
1101   eh_region r;
1102   tree lab;
1103   int i;
1104
1105   if (cfun->eh == NULL)
1106     return;
1107
1108   for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i)
1109     if (lp && lp->post_landing_pad)
1110       {
1111         lab = main_block_label (lp->post_landing_pad);
1112         if (lab != lp->post_landing_pad)
1113           {
1114             EH_LANDING_PAD_NR (lp->post_landing_pad) = 0;
1115             EH_LANDING_PAD_NR (lab) = lp->index;
1116           }
1117       }
1118
1119   FOR_ALL_EH_REGION (r)
1120     switch (r->type)
1121       {
1122       case ERT_CLEANUP:
1123       case ERT_MUST_NOT_THROW:
1124         break;
1125
1126       case ERT_TRY:
1127         {
1128           eh_catch c;
1129           for (c = r->u.eh_try.first_catch; c ; c = c->next_catch)
1130             {
1131               lab = c->label;
1132               if (lab)
1133                 c->label = main_block_label (lab);
1134             }
1135         }
1136         break;
1137
1138       case ERT_ALLOWED_EXCEPTIONS:
1139         lab = r->u.allowed.label;
1140         if (lab)
1141           r->u.allowed.label = main_block_label (lab);
1142         break;
1143       }
1144 }
1145
1146
1147 /* Cleanup redundant labels.  This is a three-step process:
1148      1) Find the leading label for each block.
1149      2) Redirect all references to labels to the leading labels.
1150      3) Cleanup all useless labels.  */
1151
1152 void
1153 cleanup_dead_labels (void)
1154 {
1155   basic_block bb;
1156   label_for_bb = XCNEWVEC (struct label_record, last_basic_block);
1157
1158   /* Find a suitable label for each block.  We use the first user-defined
1159      label if there is one, or otherwise just the first label we see.  */
1160   FOR_EACH_BB (bb)
1161     {
1162       gimple_stmt_iterator i;
1163
1164       for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i))
1165         {
1166           tree label;
1167           gimple stmt = gsi_stmt (i);
1168
1169           if (gimple_code (stmt) != GIMPLE_LABEL)
1170             break;
1171
1172           label = gimple_label_label (stmt);
1173
1174           /* If we have not yet seen a label for the current block,
1175              remember this one and see if there are more labels.  */
1176           if (!label_for_bb[bb->index].label)
1177             {
1178               label_for_bb[bb->index].label = label;
1179               continue;
1180             }
1181
1182           /* If we did see a label for the current block already, but it
1183              is an artificially created label, replace it if the current
1184              label is a user defined label.  */
1185           if (!DECL_ARTIFICIAL (label)
1186               && DECL_ARTIFICIAL (label_for_bb[bb->index].label))
1187             {
1188               label_for_bb[bb->index].label = label;
1189               break;
1190             }
1191         }
1192     }
1193
1194   /* Now redirect all jumps/branches to the selected label.
1195      First do so for each block ending in a control statement.  */
1196   FOR_EACH_BB (bb)
1197     {
1198       gimple stmt = last_stmt (bb);
1199       if (!stmt)
1200         continue;
1201
1202       switch (gimple_code (stmt))
1203         {
1204         case GIMPLE_COND:
1205           {
1206             tree true_label = gimple_cond_true_label (stmt);
1207             tree false_label = gimple_cond_false_label (stmt);
1208
1209             if (true_label)
1210               gimple_cond_set_true_label (stmt, main_block_label (true_label));
1211             if (false_label)
1212               gimple_cond_set_false_label (stmt, main_block_label (false_label));
1213             break;
1214           }
1215
1216         case GIMPLE_SWITCH:
1217           {
1218             size_t i, n = gimple_switch_num_labels (stmt);
1219
1220             /* Replace all destination labels.  */
1221             for (i = 0; i < n; ++i)
1222               {
1223                 tree case_label = gimple_switch_label (stmt, i);
1224                 tree label = main_block_label (CASE_LABEL (case_label));
1225                 CASE_LABEL (case_label) = label;
1226               }
1227             break;
1228           }
1229
1230         case GIMPLE_ASM:
1231           {
1232             int i, n = gimple_asm_nlabels (stmt);
1233
1234             for (i = 0; i < n; ++i)
1235               {
1236                 tree cons = gimple_asm_label_op (stmt, i);
1237                 tree label = main_block_label (TREE_VALUE (cons));
1238                 TREE_VALUE (cons) = label;
1239               }
1240             break;
1241           }
1242
1243         /* We have to handle gotos until they're removed, and we don't
1244            remove them until after we've created the CFG edges.  */
1245         case GIMPLE_GOTO:
1246           if (!computed_goto_p (stmt))
1247             {
1248               tree new_dest = main_block_label (gimple_goto_dest (stmt));
1249               gimple_goto_set_dest (stmt, new_dest);
1250             }
1251           break;
1252
1253         default:
1254           break;
1255       }
1256     }
1257
1258   /* Do the same for the exception region tree labels.  */
1259   cleanup_dead_labels_eh ();
1260
1261   /* Finally, purge dead labels.  All user-defined labels and labels that
1262      can be the target of non-local gotos and labels which have their
1263      address taken are preserved.  */
1264   FOR_EACH_BB (bb)
1265     {
1266       gimple_stmt_iterator i;
1267       tree label_for_this_bb = label_for_bb[bb->index].label;
1268
1269       if (!label_for_this_bb)
1270         continue;
1271
1272       /* If the main label of the block is unused, we may still remove it.  */
1273       if (!label_for_bb[bb->index].used)
1274         label_for_this_bb = NULL;
1275
1276       for (i = gsi_start_bb (bb); !gsi_end_p (i); )
1277         {
1278           tree label;
1279           gimple stmt = gsi_stmt (i);
1280
1281           if (gimple_code (stmt) != GIMPLE_LABEL)
1282             break;
1283
1284           label = gimple_label_label (stmt);
1285
1286           if (label == label_for_this_bb
1287               || !DECL_ARTIFICIAL (label)
1288               || DECL_NONLOCAL (label)
1289               || FORCED_LABEL (label))
1290             gsi_next (&i);
1291           else
1292             gsi_remove (&i, true);
1293         }
1294     }
1295
1296   free (label_for_bb);
1297 }
1298
1299 /* Scan the sorted vector of cases in STMT (a GIMPLE_SWITCH) and combine
1300    the ones jumping to the same label.
1301    Eg. three separate entries 1: 2: 3: become one entry 1..3:  */
1302
1303 static void
1304 group_case_labels_stmt (gimple stmt)
1305 {
1306   int old_size = gimple_switch_num_labels (stmt);
1307   int i, j, new_size = old_size;
1308   tree default_case = NULL_TREE;
1309   tree default_label = NULL_TREE;
1310   bool has_default;
1311
1312   /* The default label is always the first case in a switch
1313      statement after gimplification if it was not optimized
1314      away */
1315   if (!CASE_LOW (gimple_switch_default_label (stmt))
1316       && !CASE_HIGH (gimple_switch_default_label (stmt)))
1317     {
1318       default_case = gimple_switch_default_label (stmt);
1319       default_label = CASE_LABEL (default_case);
1320       has_default = true;
1321     }
1322   else
1323     has_default = false;
1324
1325   /* Look for possible opportunities to merge cases.  */
1326   if (has_default)
1327     i = 1;
1328   else
1329     i = 0;
1330   while (i < old_size)
1331     {
1332       tree base_case, base_label, base_high;
1333       base_case = gimple_switch_label (stmt, i);
1334
1335       gcc_assert (base_case);
1336       base_label = CASE_LABEL (base_case);
1337
1338       /* Discard cases that have the same destination as the
1339          default case.  */
1340       if (base_label == default_label)
1341         {
1342           gimple_switch_set_label (stmt, i, NULL_TREE);
1343           i++;
1344           new_size--;
1345           continue;
1346         }
1347
1348       base_high = CASE_HIGH (base_case)
1349           ? CASE_HIGH (base_case)
1350           : CASE_LOW (base_case);
1351       i++;
1352
1353       /* Try to merge case labels.  Break out when we reach the end
1354          of the label vector or when we cannot merge the next case
1355          label with the current one.  */
1356       while (i < old_size)
1357         {
1358           tree merge_case = gimple_switch_label (stmt, i);
1359           tree merge_label = CASE_LABEL (merge_case);
1360           double_int bhp1 = double_int_add (tree_to_double_int (base_high),
1361                                             double_int_one);
1362
1363           /* Merge the cases if they jump to the same place,
1364              and their ranges are consecutive.  */
1365           if (merge_label == base_label
1366               && double_int_equal_p (tree_to_double_int (CASE_LOW (merge_case)),
1367                                      bhp1))
1368             {
1369               base_high = CASE_HIGH (merge_case) ?
1370                   CASE_HIGH (merge_case) : CASE_LOW (merge_case);
1371               CASE_HIGH (base_case) = base_high;
1372               gimple_switch_set_label (stmt, i, NULL_TREE);
1373               new_size--;
1374               i++;
1375             }
1376           else
1377             break;
1378         }
1379     }
1380
1381   /* Compress the case labels in the label vector, and adjust the
1382      length of the vector.  */
1383   for (i = 0, j = 0; i < new_size; i++)
1384     {
1385       while (! gimple_switch_label (stmt, j))
1386         j++;
1387       gimple_switch_set_label (stmt, i,
1388                                gimple_switch_label (stmt, j++));
1389     }
1390
1391   gcc_assert (new_size <= old_size);
1392   gimple_switch_set_num_labels (stmt, new_size);
1393 }
1394
1395 /* Look for blocks ending in a multiway branch (a GIMPLE_SWITCH),
1396    and scan the sorted vector of cases.  Combine the ones jumping to the
1397    same label.  */
1398
1399 void
1400 group_case_labels (void)
1401 {
1402   basic_block bb;
1403
1404   FOR_EACH_BB (bb)
1405     {
1406       gimple stmt = last_stmt (bb);
1407       if (stmt && gimple_code (stmt) == GIMPLE_SWITCH)
1408         group_case_labels_stmt (stmt);
1409     }
1410 }
1411
1412 /* Checks whether we can merge block B into block A.  */
1413
1414 static bool
1415 gimple_can_merge_blocks_p (basic_block a, basic_block b)
1416 {
1417   gimple stmt;
1418   gimple_stmt_iterator gsi;
1419   gimple_seq phis;
1420
1421   if (!single_succ_p (a))
1422     return false;
1423
1424   if (single_succ_edge (a)->flags & (EDGE_ABNORMAL | EDGE_EH | EDGE_PRESERVE))
1425     return false;
1426
1427   if (single_succ (a) != b)
1428     return false;
1429
1430   if (!single_pred_p (b))
1431     return false;
1432
1433   if (b == EXIT_BLOCK_PTR)
1434     return false;
1435
1436   /* If A ends by a statement causing exceptions or something similar, we
1437      cannot merge the blocks.  */
1438   stmt = last_stmt (a);
1439   if (stmt && stmt_ends_bb_p (stmt))
1440     return false;
1441
1442   /* Do not allow a block with only a non-local label to be merged.  */
1443   if (stmt
1444       && gimple_code (stmt) == GIMPLE_LABEL
1445       && DECL_NONLOCAL (gimple_label_label (stmt)))
1446     return false;
1447
1448   /* Examine the labels at the beginning of B.  */
1449   for (gsi = gsi_start_bb (b); !gsi_end_p (gsi); gsi_next (&gsi))
1450     {
1451       tree lab;
1452       stmt = gsi_stmt (gsi);
1453       if (gimple_code (stmt) != GIMPLE_LABEL)
1454         break;
1455       lab = gimple_label_label (stmt);
1456
1457       /* Do not remove user labels.  */
1458       if (!DECL_ARTIFICIAL (lab))
1459         return false;
1460     }
1461
1462   /* Protect the loop latches.  */
1463   if (current_loops && b->loop_father->latch == b)
1464     return false;
1465
1466   /* It must be possible to eliminate all phi nodes in B.  If ssa form
1467      is not up-to-date and a name-mapping is registered, we cannot eliminate
1468      any phis.  Symbols marked for renaming are never a problem though.  */
1469   phis = phi_nodes (b);
1470   if (!gimple_seq_empty_p (phis)
1471       && name_mappings_registered_p ())
1472     return false;
1473
1474   /* When not optimizing, don't merge if we'd lose goto_locus.  */
1475   if (!optimize
1476       && single_succ_edge (a)->goto_locus != UNKNOWN_LOCATION)
1477     {
1478       location_t goto_locus = single_succ_edge (a)->goto_locus;
1479       gimple_stmt_iterator prev, next;
1480       prev = gsi_last_nondebug_bb (a);
1481       next = gsi_after_labels (b);
1482       if (!gsi_end_p (next) && is_gimple_debug (gsi_stmt (next)))
1483         gsi_next_nondebug (&next);
1484       if ((gsi_end_p (prev)
1485            || gimple_location (gsi_stmt (prev)) != goto_locus)
1486           && (gsi_end_p (next)
1487               || gimple_location (gsi_stmt (next)) != goto_locus))
1488         return false;
1489     }
1490
1491   return true;
1492 }
1493
1494 /* Return true if the var whose chain of uses starts at PTR has no
1495    nondebug uses.  */
1496 bool
1497 has_zero_uses_1 (const ssa_use_operand_t *head)
1498 {
1499   const ssa_use_operand_t *ptr;
1500
1501   for (ptr = head->next; ptr != head; ptr = ptr->next)
1502     if (!is_gimple_debug (USE_STMT (ptr)))
1503       return false;
1504
1505   return true;
1506 }
1507
1508 /* Return true if the var whose chain of uses starts at PTR has a
1509    single nondebug use.  Set USE_P and STMT to that single nondebug
1510    use, if so, or to NULL otherwise.  */
1511 bool
1512 single_imm_use_1 (const ssa_use_operand_t *head,
1513                   use_operand_p *use_p, gimple *stmt)
1514 {
1515   ssa_use_operand_t *ptr, *single_use = 0;
1516
1517   for (ptr = head->next; ptr != head; ptr = ptr->next)
1518     if (!is_gimple_debug (USE_STMT (ptr)))
1519       {
1520         if (single_use)
1521           {
1522             single_use = NULL;
1523             break;
1524           }
1525         single_use = ptr;
1526       }
1527
1528   if (use_p)
1529     *use_p = single_use;
1530
1531   if (stmt)
1532     *stmt = single_use ? single_use->loc.stmt : NULL;
1533
1534   return !!single_use;
1535 }
1536
1537 /* Replaces all uses of NAME by VAL.  */
1538
1539 void
1540 replace_uses_by (tree name, tree val)
1541 {
1542   imm_use_iterator imm_iter;
1543   use_operand_p use;
1544   gimple stmt;
1545   edge e;
1546
1547   FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name)
1548     {
1549       FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
1550         {
1551           replace_exp (use, val);
1552
1553           if (gimple_code (stmt) == GIMPLE_PHI)
1554             {
1555               e = gimple_phi_arg_edge (stmt, PHI_ARG_INDEX_FROM_USE (use));
1556               if (e->flags & EDGE_ABNORMAL)
1557                 {
1558                   /* This can only occur for virtual operands, since
1559                      for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
1560                      would prevent replacement.  */
1561                   gcc_assert (!is_gimple_reg (name));
1562                   SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val) = 1;
1563                 }
1564             }
1565         }
1566
1567       if (gimple_code (stmt) != GIMPLE_PHI)
1568         {
1569           size_t i;
1570
1571           fold_stmt_inplace (stmt);
1572           if (cfgcleanup_altered_bbs && !is_gimple_debug (stmt))
1573             bitmap_set_bit (cfgcleanup_altered_bbs, gimple_bb (stmt)->index);
1574
1575           /* FIXME.  This should go in update_stmt.  */
1576           for (i = 0; i < gimple_num_ops (stmt); i++)
1577             {
1578               tree op = gimple_op (stmt, i);
1579               /* Operands may be empty here.  For example, the labels
1580                  of a GIMPLE_COND are nulled out following the creation
1581                  of the corresponding CFG edges.  */
1582               if (op && TREE_CODE (op) == ADDR_EXPR)
1583                 recompute_tree_invariant_for_addr_expr (op);
1584             }
1585
1586           maybe_clean_or_replace_eh_stmt (stmt, stmt);
1587           update_stmt (stmt);
1588         }
1589     }
1590
1591   gcc_assert (has_zero_uses (name));
1592
1593   /* Also update the trees stored in loop structures.  */
1594   if (current_loops)
1595     {
1596       struct loop *loop;
1597       loop_iterator li;
1598
1599       FOR_EACH_LOOP (li, loop, 0)
1600         {
1601           substitute_in_loop_info (loop, name, val);
1602         }
1603     }
1604 }
1605
1606 /* Merge block B into block A.  */
1607
1608 static void
1609 gimple_merge_blocks (basic_block a, basic_block b)
1610 {
1611   gimple_stmt_iterator last, gsi, psi;
1612   gimple_seq phis = phi_nodes (b);
1613
1614   if (dump_file)
1615     fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index);
1616
1617   /* Remove all single-valued PHI nodes from block B of the form
1618      V_i = PHI <V_j> by propagating V_j to all the uses of V_i.  */
1619   gsi = gsi_last_bb (a);
1620   for (psi = gsi_start (phis); !gsi_end_p (psi); )
1621     {
1622       gimple phi = gsi_stmt (psi);
1623       tree def = gimple_phi_result (phi), use = gimple_phi_arg_def (phi, 0);
1624       gimple copy;
1625       bool may_replace_uses = !is_gimple_reg (def)
1626                               || may_propagate_copy (def, use);
1627
1628       /* In case we maintain loop closed ssa form, do not propagate arguments
1629          of loop exit phi nodes.  */
1630       if (current_loops
1631           && loops_state_satisfies_p (LOOP_CLOSED_SSA)
1632           && is_gimple_reg (def)
1633           && TREE_CODE (use) == SSA_NAME
1634           && a->loop_father != b->loop_father)
1635         may_replace_uses = false;
1636
1637       if (!may_replace_uses)
1638         {
1639           gcc_assert (is_gimple_reg (def));
1640
1641           /* Note that just emitting the copies is fine -- there is no problem
1642              with ordering of phi nodes.  This is because A is the single
1643              predecessor of B, therefore results of the phi nodes cannot
1644              appear as arguments of the phi nodes.  */
1645           copy = gimple_build_assign (def, use);
1646           gsi_insert_after (&gsi, copy, GSI_NEW_STMT);
1647           remove_phi_node (&psi, false);
1648         }
1649       else
1650         {
1651           /* If we deal with a PHI for virtual operands, we can simply
1652              propagate these without fussing with folding or updating
1653              the stmt.  */
1654           if (!is_gimple_reg (def))
1655             {
1656               imm_use_iterator iter;
1657               use_operand_p use_p;
1658               gimple stmt;
1659
1660               FOR_EACH_IMM_USE_STMT (stmt, iter, def)
1661                 FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
1662                   SET_USE (use_p, use);
1663
1664               if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (def))
1665                 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (use) = 1;
1666             }
1667           else
1668             replace_uses_by (def, use);
1669
1670           remove_phi_node (&psi, true);
1671         }
1672     }
1673
1674   /* Ensure that B follows A.  */
1675   move_block_after (b, a);
1676
1677   gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU);
1678   gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a)));
1679
1680   /* Remove labels from B and set gimple_bb to A for other statements.  */
1681   for (gsi = gsi_start_bb (b); !gsi_end_p (gsi);)
1682     {
1683       gimple stmt = gsi_stmt (gsi);
1684       if (gimple_code (stmt) == GIMPLE_LABEL)
1685         {
1686           tree label = gimple_label_label (stmt);
1687           int lp_nr;
1688
1689           gsi_remove (&gsi, false);
1690
1691           /* Now that we can thread computed gotos, we might have
1692              a situation where we have a forced label in block B
1693              However, the label at the start of block B might still be
1694              used in other ways (think about the runtime checking for
1695              Fortran assigned gotos).  So we can not just delete the
1696              label.  Instead we move the label to the start of block A.  */
1697           if (FORCED_LABEL (label))
1698             {
1699               gimple_stmt_iterator dest_gsi = gsi_start_bb (a);
1700               gsi_insert_before (&dest_gsi, stmt, GSI_NEW_STMT);
1701             }
1702
1703           lp_nr = EH_LANDING_PAD_NR (label);
1704           if (lp_nr)
1705             {
1706               eh_landing_pad lp = get_eh_landing_pad_from_number (lp_nr);
1707               lp->post_landing_pad = NULL;
1708             }
1709         }
1710       else
1711         {
1712           gimple_set_bb (stmt, a);
1713           gsi_next (&gsi);
1714         }
1715     }
1716
1717   /* Merge the sequences.  */
1718   last = gsi_last_bb (a);
1719   gsi_insert_seq_after (&last, bb_seq (b), GSI_NEW_STMT);
1720   set_bb_seq (b, NULL);
1721
1722   if (cfgcleanup_altered_bbs)
1723     bitmap_set_bit (cfgcleanup_altered_bbs, a->index);
1724 }
1725
1726
1727 /* Return the one of two successors of BB that is not reachable by a
1728    complex edge, if there is one.  Else, return BB.  We use
1729    this in optimizations that use post-dominators for their heuristics,
1730    to catch the cases in C++ where function calls are involved.  */
1731
1732 basic_block
1733 single_noncomplex_succ (basic_block bb)
1734 {
1735   edge e0, e1;
1736   if (EDGE_COUNT (bb->succs) != 2)
1737     return bb;
1738
1739   e0 = EDGE_SUCC (bb, 0);
1740   e1 = EDGE_SUCC (bb, 1);
1741   if (e0->flags & EDGE_COMPLEX)
1742     return e1->dest;
1743   if (e1->flags & EDGE_COMPLEX)
1744     return e0->dest;
1745
1746   return bb;
1747 }
1748
1749 /* T is CALL_EXPR.  Set current_function_calls_* flags.  */
1750
1751 void
1752 notice_special_calls (gimple call)
1753 {
1754   int flags = gimple_call_flags (call);
1755
1756   if (flags & ECF_MAY_BE_ALLOCA)
1757     cfun->calls_alloca = true;
1758   if (flags & ECF_RETURNS_TWICE)
1759     cfun->calls_setjmp = true;
1760 }
1761
1762
1763 /* Clear flags set by notice_special_calls.  Used by dead code removal
1764    to update the flags.  */
1765
1766 void
1767 clear_special_calls (void)
1768 {
1769   cfun->calls_alloca = false;
1770   cfun->calls_setjmp = false;
1771 }
1772
1773 /* Remove PHI nodes associated with basic block BB and all edges out of BB.  */
1774
1775 static void
1776 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb)
1777 {
1778   /* Since this block is no longer reachable, we can just delete all
1779      of its PHI nodes.  */
1780   remove_phi_nodes (bb);
1781
1782   /* Remove edges to BB's successors.  */
1783   while (EDGE_COUNT (bb->succs) > 0)
1784     remove_edge (EDGE_SUCC (bb, 0));
1785 }
1786
1787
1788 /* Remove statements of basic block BB.  */
1789
1790 static void
1791 remove_bb (basic_block bb)
1792 {
1793   gimple_stmt_iterator i;
1794
1795   if (dump_file)
1796     {
1797       fprintf (dump_file, "Removing basic block %d\n", bb->index);
1798       if (dump_flags & TDF_DETAILS)
1799         {
1800           dump_bb (bb, dump_file, 0);
1801           fprintf (dump_file, "\n");
1802         }
1803     }
1804
1805   if (current_loops)
1806     {
1807       struct loop *loop = bb->loop_father;
1808
1809       /* If a loop gets removed, clean up the information associated
1810          with it.  */
1811       if (loop->latch == bb
1812           || loop->header == bb)
1813         free_numbers_of_iterations_estimates_loop (loop);
1814     }
1815
1816   /* Remove all the instructions in the block.  */
1817   if (bb_seq (bb) != NULL)
1818     {
1819       /* Walk backwards so as to get a chance to substitute all
1820          released DEFs into debug stmts.  See
1821          eliminate_unnecessary_stmts() in tree-ssa-dce.c for more
1822          details.  */
1823       for (i = gsi_last_bb (bb); !gsi_end_p (i);)
1824         {
1825           gimple stmt = gsi_stmt (i);
1826           if (gimple_code (stmt) == GIMPLE_LABEL
1827               && (FORCED_LABEL (gimple_label_label (stmt))
1828                   || DECL_NONLOCAL (gimple_label_label (stmt))))
1829             {
1830               basic_block new_bb;
1831               gimple_stmt_iterator new_gsi;
1832
1833               /* A non-reachable non-local label may still be referenced.
1834                  But it no longer needs to carry the extra semantics of
1835                  non-locality.  */
1836               if (DECL_NONLOCAL (gimple_label_label (stmt)))
1837                 {
1838                   DECL_NONLOCAL (gimple_label_label (stmt)) = 0;
1839                   FORCED_LABEL (gimple_label_label (stmt)) = 1;
1840                 }
1841
1842               new_bb = bb->prev_bb;
1843               new_gsi = gsi_start_bb (new_bb);
1844               gsi_remove (&i, false);
1845               gsi_insert_before (&new_gsi, stmt, GSI_NEW_STMT);
1846             }
1847           else
1848             {
1849               /* Release SSA definitions if we are in SSA.  Note that we
1850                  may be called when not in SSA.  For example,
1851                  final_cleanup calls this function via
1852                  cleanup_tree_cfg.  */
1853               if (gimple_in_ssa_p (cfun))
1854                 release_defs (stmt);
1855
1856               gsi_remove (&i, true);
1857             }
1858
1859           if (gsi_end_p (i))
1860             i = gsi_last_bb (bb);
1861           else
1862             gsi_prev (&i);
1863         }
1864     }
1865
1866   remove_phi_nodes_and_edges_for_unreachable_block (bb);
1867   bb->il.gimple = NULL;
1868 }
1869
1870
1871 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
1872    predicate VAL, return the edge that will be taken out of the block.
1873    If VAL does not match a unique edge, NULL is returned.  */
1874
1875 edge
1876 find_taken_edge (basic_block bb, tree val)
1877 {
1878   gimple stmt;
1879
1880   stmt = last_stmt (bb);
1881
1882   gcc_assert (stmt);
1883   gcc_assert (is_ctrl_stmt (stmt));
1884
1885   if (val == NULL)
1886     return NULL;
1887
1888   if (!is_gimple_min_invariant (val))
1889     return NULL;
1890
1891   if (gimple_code (stmt) == GIMPLE_COND)
1892     return find_taken_edge_cond_expr (bb, val);
1893
1894   if (gimple_code (stmt) == GIMPLE_SWITCH)
1895     return find_taken_edge_switch_expr (bb, val);
1896
1897   if (computed_goto_p (stmt))
1898     {
1899       /* Only optimize if the argument is a label, if the argument is
1900          not a label then we can not construct a proper CFG.
1901
1902          It may be the case that we only need to allow the LABEL_REF to
1903          appear inside an ADDR_EXPR, but we also allow the LABEL_REF to
1904          appear inside a LABEL_EXPR just to be safe.  */
1905       if ((TREE_CODE (val) == ADDR_EXPR || TREE_CODE (val) == LABEL_EXPR)
1906           && TREE_CODE (TREE_OPERAND (val, 0)) == LABEL_DECL)
1907         return find_taken_edge_computed_goto (bb, TREE_OPERAND (val, 0));
1908       return NULL;
1909     }
1910
1911   gcc_unreachable ();
1912 }
1913
1914 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
1915    statement, determine which of the outgoing edges will be taken out of the
1916    block.  Return NULL if either edge may be taken.  */
1917
1918 static edge
1919 find_taken_edge_computed_goto (basic_block bb, tree val)
1920 {
1921   basic_block dest;
1922   edge e = NULL;
1923
1924   dest = label_to_block (val);
1925   if (dest)
1926     {
1927       e = find_edge (bb, dest);
1928       gcc_assert (e != NULL);
1929     }
1930
1931   return e;
1932 }
1933
1934 /* Given a constant value VAL and the entry block BB to a COND_EXPR
1935    statement, determine which of the two edges will be taken out of the
1936    block.  Return NULL if either edge may be taken.  */
1937
1938 static edge
1939 find_taken_edge_cond_expr (basic_block bb, tree val)
1940 {
1941   edge true_edge, false_edge;
1942
1943   extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
1944
1945   gcc_assert (TREE_CODE (val) == INTEGER_CST);
1946   return (integer_zerop (val) ? false_edge : true_edge);
1947 }
1948
1949 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
1950    statement, determine which edge will be taken out of the block.  Return
1951    NULL if any edge may be taken.  */
1952
1953 static edge
1954 find_taken_edge_switch_expr (basic_block bb, tree val)
1955 {
1956   basic_block dest_bb;
1957   edge e;
1958   gimple switch_stmt;
1959   tree taken_case;
1960
1961   switch_stmt = last_stmt (bb);
1962   taken_case = find_case_label_for_value (switch_stmt, val);
1963   dest_bb = label_to_block (CASE_LABEL (taken_case));
1964
1965   e = find_edge (bb, dest_bb);
1966   gcc_assert (e);
1967   return e;
1968 }
1969
1970
1971 /* Return the CASE_LABEL_EXPR that SWITCH_STMT will take for VAL.
1972    We can make optimal use here of the fact that the case labels are
1973    sorted: We can do a binary search for a case matching VAL.  */
1974
1975 static tree
1976 find_case_label_for_value (gimple switch_stmt, tree val)
1977 {
1978   size_t low, high, n = gimple_switch_num_labels (switch_stmt);
1979   tree default_case = gimple_switch_default_label (switch_stmt);
1980
1981   for (low = 0, high = n; high - low > 1; )
1982     {
1983       size_t i = (high + low) / 2;
1984       tree t = gimple_switch_label (switch_stmt, i);
1985       int cmp;
1986
1987       /* Cache the result of comparing CASE_LOW and val.  */
1988       cmp = tree_int_cst_compare (CASE_LOW (t), val);
1989
1990       if (cmp > 0)
1991         high = i;
1992       else
1993         low = i;
1994
1995       if (CASE_HIGH (t) == NULL)
1996         {
1997           /* A singe-valued case label.  */
1998           if (cmp == 0)
1999             return t;
2000         }
2001       else
2002         {
2003           /* A case range.  We can only handle integer ranges.  */
2004           if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
2005             return t;
2006         }
2007     }
2008
2009   return default_case;
2010 }
2011
2012
2013 /* Dump a basic block on stderr.  */
2014
2015 void
2016 gimple_debug_bb (basic_block bb)
2017 {
2018   gimple_dump_bb (bb, stderr, 0, TDF_VOPS|TDF_MEMSYMS);
2019 }
2020
2021
2022 /* Dump basic block with index N on stderr.  */
2023
2024 basic_block
2025 gimple_debug_bb_n (int n)
2026 {
2027   gimple_debug_bb (BASIC_BLOCK (n));
2028   return BASIC_BLOCK (n);
2029 }
2030
2031
2032 /* Dump the CFG on stderr.
2033
2034    FLAGS are the same used by the tree dumping functions
2035    (see TDF_* in tree-pass.h).  */
2036
2037 void
2038 gimple_debug_cfg (int flags)
2039 {
2040   gimple_dump_cfg (stderr, flags);
2041 }
2042
2043
2044 /* Dump the program showing basic block boundaries on the given FILE.
2045
2046    FLAGS are the same used by the tree dumping functions (see TDF_* in
2047    tree.h).  */
2048
2049 void
2050 gimple_dump_cfg (FILE *file, int flags)
2051 {
2052   if (flags & TDF_DETAILS)
2053     {
2054       dump_function_header (file, current_function_decl, flags);
2055       fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2056                n_basic_blocks, n_edges, last_basic_block);
2057
2058       brief_dump_cfg (file);
2059       fprintf (file, "\n");
2060     }
2061
2062   if (flags & TDF_STATS)
2063     dump_cfg_stats (file);
2064
2065   dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS);
2066 }
2067
2068
2069 /* Dump CFG statistics on FILE.  */
2070
2071 void
2072 dump_cfg_stats (FILE *file)
2073 {
2074   static long max_num_merged_labels = 0;
2075   unsigned long size, total = 0;
2076   long num_edges;
2077   basic_block bb;
2078   const char * const fmt_str   = "%-30s%-13s%12s\n";
2079   const char * const fmt_str_1 = "%-30s%13d%11lu%c\n";
2080   const char * const fmt_str_2 = "%-30s%13ld%11lu%c\n";
2081   const char * const fmt_str_3 = "%-43s%11lu%c\n";
2082   const char *funcname
2083     = lang_hooks.decl_printable_name (current_function_decl, 2);
2084
2085
2086   fprintf (file, "\nCFG Statistics for %s\n\n", funcname);
2087
2088   fprintf (file, "---------------------------------------------------------\n");
2089   fprintf (file, fmt_str, "", "  Number of  ", "Memory");
2090   fprintf (file, fmt_str, "", "  instances  ", "used ");
2091   fprintf (file, "---------------------------------------------------------\n");
2092
2093   size = n_basic_blocks * sizeof (struct basic_block_def);
2094   total += size;
2095   fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks,
2096            SCALE (size), LABEL (size));
2097
2098   num_edges = 0;
2099   FOR_EACH_BB (bb)
2100     num_edges += EDGE_COUNT (bb->succs);
2101   size = num_edges * sizeof (struct edge_def);
2102   total += size;
2103   fprintf (file, fmt_str_2, "Edges", num_edges, SCALE (size), LABEL (size));
2104
2105   fprintf (file, "---------------------------------------------------------\n");
2106   fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total),
2107            LABEL (total));
2108   fprintf (file, "---------------------------------------------------------\n");
2109   fprintf (file, "\n");
2110
2111   if (cfg_stats.num_merged_labels > max_num_merged_labels)
2112     max_num_merged_labels = cfg_stats.num_merged_labels;
2113
2114   fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2115            cfg_stats.num_merged_labels, max_num_merged_labels);
2116
2117   fprintf (file, "\n");
2118 }
2119
2120
2121 /* Dump CFG statistics on stderr.  Keep extern so that it's always
2122    linked in the final executable.  */
2123
2124 DEBUG_FUNCTION void
2125 debug_cfg_stats (void)
2126 {
2127   dump_cfg_stats (stderr);
2128 }
2129
2130
2131 /* Dump the flowgraph to a .vcg FILE.  */
2132
2133 static void
2134 gimple_cfg2vcg (FILE *file)
2135 {
2136   edge e;
2137   edge_iterator ei;
2138   basic_block bb;
2139   const char *funcname
2140     = lang_hooks.decl_printable_name (current_function_decl, 2);
2141
2142   /* Write the file header.  */
2143   fprintf (file, "graph: { title: \"%s\"\n", funcname);
2144   fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2145   fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2146
2147   /* Write blocks and edges.  */
2148   FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
2149     {
2150       fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2151                e->dest->index);
2152
2153       if (e->flags & EDGE_FAKE)
2154         fprintf (file, " linestyle: dotted priority: 10");
2155       else
2156         fprintf (file, " linestyle: solid priority: 100");
2157
2158       fprintf (file, " }\n");
2159     }
2160   fputc ('\n', file);
2161
2162   FOR_EACH_BB (bb)
2163     {
2164       enum gimple_code head_code, end_code;
2165       const char *head_name, *end_name;
2166       int head_line = 0;
2167       int end_line = 0;
2168       gimple first = first_stmt (bb);
2169       gimple last = last_stmt (bb);
2170
2171       if (first)
2172         {
2173           head_code = gimple_code (first);
2174           head_name = gimple_code_name[head_code];
2175           head_line = get_lineno (first);
2176         }
2177       else
2178         head_name = "no-statement";
2179
2180       if (last)
2181         {
2182           end_code = gimple_code (last);
2183           end_name = gimple_code_name[end_code];
2184           end_line = get_lineno (last);
2185         }
2186       else
2187         end_name = "no-statement";
2188
2189       fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2190                bb->index, bb->index, head_name, head_line, end_name,
2191                end_line);
2192
2193       FOR_EACH_EDGE (e, ei, bb->succs)
2194         {
2195           if (e->dest == EXIT_BLOCK_PTR)
2196             fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index);
2197           else
2198             fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index);
2199
2200           if (e->flags & EDGE_FAKE)
2201             fprintf (file, " priority: 10 linestyle: dotted");
2202           else
2203             fprintf (file, " priority: 100 linestyle: solid");
2204
2205           fprintf (file, " }\n");
2206         }
2207
2208       if (bb->next_bb != EXIT_BLOCK_PTR)
2209         fputc ('\n', file);
2210     }
2211
2212   fputs ("}\n\n", file);
2213 }
2214
2215
2216
2217 /*---------------------------------------------------------------------------
2218                              Miscellaneous helpers
2219 ---------------------------------------------------------------------------*/
2220
2221 /* Return true if T represents a stmt that always transfers control.  */
2222
2223 bool
2224 is_ctrl_stmt (gimple t)
2225 {
2226   switch (gimple_code (t))
2227     {
2228     case GIMPLE_COND:
2229     case GIMPLE_SWITCH:
2230     case GIMPLE_GOTO:
2231     case GIMPLE_RETURN:
2232     case GIMPLE_RESX:
2233       return true;
2234     default:
2235       return false;
2236     }
2237 }
2238
2239
2240 /* Return true if T is a statement that may alter the flow of control
2241    (e.g., a call to a non-returning function).  */
2242
2243 bool
2244 is_ctrl_altering_stmt (gimple t)
2245 {
2246   gcc_assert (t);
2247
2248   switch (gimple_code (t))
2249     {
2250     case GIMPLE_CALL:
2251       {
2252         int flags = gimple_call_flags (t);
2253
2254         /* A non-pure/const call alters flow control if the current
2255            function has nonlocal labels.  */
2256         if (!(flags & (ECF_CONST | ECF_PURE | ECF_LEAF))
2257             && cfun->has_nonlocal_label)
2258           return true;
2259
2260         /* A call also alters control flow if it does not return.  */
2261         if (flags & ECF_NORETURN)
2262           return true;
2263
2264         /* BUILT_IN_RETURN call is same as return statement.  */
2265         if (gimple_call_builtin_p (t, BUILT_IN_RETURN))
2266           return true;
2267       }
2268       break;
2269
2270     case GIMPLE_EH_DISPATCH:
2271       /* EH_DISPATCH branches to the individual catch handlers at
2272          this level of a try or allowed-exceptions region.  It can
2273          fallthru to the next statement as well.  */
2274       return true;
2275
2276     case GIMPLE_ASM:
2277       if (gimple_asm_nlabels (t) > 0)
2278         return true;
2279       break;
2280
2281     CASE_GIMPLE_OMP:
2282       /* OpenMP directives alter control flow.  */
2283       return true;
2284
2285     default:
2286       break;
2287     }
2288
2289   /* If a statement can throw, it alters control flow.  */
2290   return stmt_can_throw_internal (t);
2291 }
2292
2293
2294 /* Return true if T is a simple local goto.  */
2295
2296 bool
2297 simple_goto_p (gimple t)
2298 {
2299   return (gimple_code (t) == GIMPLE_GOTO
2300           && TREE_CODE (gimple_goto_dest (t)) == LABEL_DECL);
2301 }
2302
2303
2304 /* Return true if T can make an abnormal transfer of control flow.
2305    Transfers of control flow associated with EH are excluded.  */
2306
2307 bool
2308 stmt_can_make_abnormal_goto (gimple t)
2309 {
2310   if (computed_goto_p (t))
2311     return true;
2312   if (is_gimple_call (t))
2313     return (gimple_has_side_effects (t) && cfun->has_nonlocal_label
2314             && !(gimple_call_flags (t) & ECF_LEAF));
2315   return false;
2316 }
2317
2318
2319 /* Return true if STMT should start a new basic block.  PREV_STMT is
2320    the statement preceding STMT.  It is used when STMT is a label or a
2321    case label.  Labels should only start a new basic block if their
2322    previous statement wasn't a label.  Otherwise, sequence of labels
2323    would generate unnecessary basic blocks that only contain a single
2324    label.  */
2325
2326 static inline bool
2327 stmt_starts_bb_p (gimple stmt, gimple prev_stmt)
2328 {
2329   if (stmt == NULL)
2330     return false;
2331
2332   /* Labels start a new basic block only if the preceding statement
2333      wasn't a label of the same type.  This prevents the creation of
2334      consecutive blocks that have nothing but a single label.  */
2335   if (gimple_code (stmt) == GIMPLE_LABEL)
2336     {
2337       /* Nonlocal and computed GOTO targets always start a new block.  */
2338       if (DECL_NONLOCAL (gimple_label_label (stmt))
2339           || FORCED_LABEL (gimple_label_label (stmt)))
2340         return true;
2341
2342       if (prev_stmt && gimple_code (prev_stmt) == GIMPLE_LABEL)
2343         {
2344           if (DECL_NONLOCAL (gimple_label_label (prev_stmt)))
2345             return true;
2346
2347           cfg_stats.num_merged_labels++;
2348           return false;
2349         }
2350       else
2351         return true;
2352     }
2353
2354   return false;
2355 }
2356
2357
2358 /* Return true if T should end a basic block.  */
2359
2360 bool
2361 stmt_ends_bb_p (gimple t)
2362 {
2363   return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t);
2364 }
2365
2366 /* Remove block annotations and other data structures.  */
2367
2368 void
2369 delete_tree_cfg_annotations (void)
2370 {
2371   label_to_block_map = NULL;
2372 }
2373
2374
2375 /* Return the first statement in basic block BB.  */
2376
2377 gimple
2378 first_stmt (basic_block bb)
2379 {
2380   gimple_stmt_iterator i = gsi_start_bb (bb);
2381   gimple stmt = NULL;
2382
2383   while (!gsi_end_p (i) && is_gimple_debug ((stmt = gsi_stmt (i))))
2384     {
2385       gsi_next (&i);
2386       stmt = NULL;
2387     }
2388   return stmt;
2389 }
2390
2391 /* Return the first non-label statement in basic block BB.  */
2392
2393 static gimple
2394 first_non_label_stmt (basic_block bb)
2395 {
2396   gimple_stmt_iterator i = gsi_start_bb (bb);
2397   while (!gsi_end_p (i) && gimple_code (gsi_stmt (i)) == GIMPLE_LABEL)
2398     gsi_next (&i);
2399   return !gsi_end_p (i) ? gsi_stmt (i) : NULL;
2400 }
2401
2402 /* Return the last statement in basic block BB.  */
2403
2404 gimple
2405 last_stmt (basic_block bb)
2406 {
2407   gimple_stmt_iterator i = gsi_last_bb (bb);
2408   gimple stmt = NULL;
2409
2410   while (!gsi_end_p (i) && is_gimple_debug ((stmt = gsi_stmt (i))))
2411     {
2412       gsi_prev (&i);
2413       stmt = NULL;
2414     }
2415   return stmt;
2416 }
2417
2418 /* Return the last statement of an otherwise empty block.  Return NULL
2419    if the block is totally empty, or if it contains more than one
2420    statement.  */
2421
2422 gimple
2423 last_and_only_stmt (basic_block bb)
2424 {
2425   gimple_stmt_iterator i = gsi_last_nondebug_bb (bb);
2426   gimple last, prev;
2427
2428   if (gsi_end_p (i))
2429     return NULL;
2430
2431   last = gsi_stmt (i);
2432   gsi_prev_nondebug (&i);
2433   if (gsi_end_p (i))
2434     return last;
2435
2436   /* Empty statements should no longer appear in the instruction stream.
2437      Everything that might have appeared before should be deleted by
2438      remove_useless_stmts, and the optimizers should just gsi_remove
2439      instead of smashing with build_empty_stmt.
2440
2441      Thus the only thing that should appear here in a block containing
2442      one executable statement is a label.  */
2443   prev = gsi_stmt (i);
2444   if (gimple_code (prev) == GIMPLE_LABEL)
2445     return last;
2446   else
2447     return NULL;
2448 }
2449
2450 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE.  */
2451
2452 static void
2453 reinstall_phi_args (edge new_edge, edge old_edge)
2454 {
2455   edge_var_map_vector v;
2456   edge_var_map *vm;
2457   int i;
2458   gimple_stmt_iterator phis;
2459
2460   v = redirect_edge_var_map_vector (old_edge);
2461   if (!v)
2462     return;
2463
2464   for (i = 0, phis = gsi_start_phis (new_edge->dest);
2465        VEC_iterate (edge_var_map, v, i, vm) && !gsi_end_p (phis);
2466        i++, gsi_next (&phis))
2467     {
2468       gimple phi = gsi_stmt (phis);
2469       tree result = redirect_edge_var_map_result (vm);
2470       tree arg = redirect_edge_var_map_def (vm);
2471
2472       gcc_assert (result == gimple_phi_result (phi));
2473
2474       add_phi_arg (phi, arg, new_edge, redirect_edge_var_map_location (vm));
2475     }
2476
2477   redirect_edge_var_map_clear (old_edge);
2478 }
2479
2480 /* Returns the basic block after which the new basic block created
2481    by splitting edge EDGE_IN should be placed.  Tries to keep the new block
2482    near its "logical" location.  This is of most help to humans looking
2483    at debugging dumps.  */
2484
2485 static basic_block
2486 split_edge_bb_loc (edge edge_in)
2487 {
2488   basic_block dest = edge_in->dest;
2489   basic_block dest_prev = dest->prev_bb;
2490
2491   if (dest_prev)
2492     {
2493       edge e = find_edge (dest_prev, dest);
2494       if (e && !(e->flags & EDGE_COMPLEX))
2495         return edge_in->src;
2496     }
2497   return dest_prev;
2498 }
2499
2500 /* Split a (typically critical) edge EDGE_IN.  Return the new block.
2501    Abort on abnormal edges.  */
2502
2503 static basic_block
2504 gimple_split_edge (edge edge_in)
2505 {
2506   basic_block new_bb, after_bb, dest;
2507   edge new_edge, e;
2508
2509   /* Abnormal edges cannot be split.  */
2510   gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
2511
2512   dest = edge_in->dest;
2513
2514   after_bb = split_edge_bb_loc (edge_in);
2515
2516   new_bb = create_empty_bb (after_bb);
2517   new_bb->frequency = EDGE_FREQUENCY (edge_in);
2518   new_bb->count = edge_in->count;
2519   new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU);
2520   new_edge->probability = REG_BR_PROB_BASE;
2521   new_edge->count = edge_in->count;
2522
2523   e = redirect_edge_and_branch (edge_in, new_bb);
2524   gcc_assert (e == edge_in);
2525   reinstall_phi_args (new_edge, e);
2526
2527   return new_bb;
2528 }
2529
2530
2531 /* Verify properties of the address expression T with base object BASE.  */
2532
2533 static tree
2534 verify_address (tree t, tree base)
2535 {
2536   bool old_constant;
2537   bool old_side_effects;
2538   bool new_constant;
2539   bool new_side_effects;
2540
2541   old_constant = TREE_CONSTANT (t);
2542   old_side_effects = TREE_SIDE_EFFECTS (t);
2543
2544   recompute_tree_invariant_for_addr_expr (t);
2545   new_side_effects = TREE_SIDE_EFFECTS (t);
2546   new_constant = TREE_CONSTANT (t);
2547
2548   if (old_constant != new_constant)
2549     {
2550       error ("constant not recomputed when ADDR_EXPR changed");
2551       return t;
2552     }
2553   if (old_side_effects != new_side_effects)
2554     {
2555       error ("side effects not recomputed when ADDR_EXPR changed");
2556       return t;
2557     }
2558
2559   if (!(TREE_CODE (base) == VAR_DECL
2560         || TREE_CODE (base) == PARM_DECL
2561         || TREE_CODE (base) == RESULT_DECL))
2562     return NULL_TREE;
2563
2564   if (DECL_GIMPLE_REG_P (base))
2565     {
2566       error ("DECL_GIMPLE_REG_P set on a variable with address taken");
2567       return base;
2568     }
2569
2570   return NULL_TREE;
2571 }
2572
2573 /* Callback for walk_tree, check that all elements with address taken are
2574    properly noticed as such.  The DATA is an int* that is 1 if TP was seen
2575    inside a PHI node.  */
2576
2577 static tree
2578 verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
2579 {
2580   tree t = *tp, x;
2581
2582   if (TYPE_P (t))
2583     *walk_subtrees = 0;
2584
2585   /* Check operand N for being valid GIMPLE and give error MSG if not.  */
2586 #define CHECK_OP(N, MSG) \
2587   do { if (!is_gimple_val (TREE_OPERAND (t, N)))                \
2588        { error (MSG); return TREE_OPERAND (t, N); }} while (0)
2589
2590   switch (TREE_CODE (t))
2591     {
2592     case SSA_NAME:
2593       if (SSA_NAME_IN_FREE_LIST (t))
2594         {
2595           error ("SSA name in freelist but still referenced");
2596           return *tp;
2597         }
2598       break;
2599
2600     case INDIRECT_REF:
2601       error ("INDIRECT_REF in gimple IL");
2602       return t;
2603
2604     case MEM_REF:
2605       x = TREE_OPERAND (t, 0);
2606       if (!POINTER_TYPE_P (TREE_TYPE (x))
2607           || !is_gimple_mem_ref_addr (x))
2608         {
2609           error ("invalid first operand of MEM_REF");
2610           return x;
2611         }
2612       if (TREE_CODE (TREE_OPERAND (t, 1)) != INTEGER_CST
2613           || !POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 1))))
2614         {
2615           error ("invalid offset operand of MEM_REF");
2616           return TREE_OPERAND (t, 1);
2617         }
2618       if (TREE_CODE (x) == ADDR_EXPR
2619           && (x = verify_address (x, TREE_OPERAND (x, 0))))
2620         return x;
2621       *walk_subtrees = 0;
2622       break;
2623
2624     case ASSERT_EXPR:
2625       x = fold (ASSERT_EXPR_COND (t));
2626       if (x == boolean_false_node)
2627         {
2628           error ("ASSERT_EXPR with an always-false condition");
2629           return *tp;
2630         }
2631       break;
2632
2633     case MODIFY_EXPR:
2634       error ("MODIFY_EXPR not expected while having tuples");
2635       return *tp;
2636
2637     case ADDR_EXPR:
2638       {
2639         tree tem;
2640
2641         gcc_assert (is_gimple_address (t));
2642
2643         /* Skip any references (they will be checked when we recurse down the
2644            tree) and ensure that any variable used as a prefix is marked
2645            addressable.  */
2646         for (x = TREE_OPERAND (t, 0);
2647              handled_component_p (x);
2648              x = TREE_OPERAND (x, 0))
2649           ;
2650
2651         if ((tem = verify_address (t, x)))
2652           return tem;
2653
2654         if (!(TREE_CODE (x) == VAR_DECL
2655               || TREE_CODE (x) == PARM_DECL
2656               || TREE_CODE (x) == RESULT_DECL))
2657           return NULL;
2658
2659         if (!TREE_ADDRESSABLE (x))
2660           {
2661             error ("address taken, but ADDRESSABLE bit not set");
2662             return x;
2663           }
2664
2665         break;
2666       }
2667
2668     case COND_EXPR:
2669       x = COND_EXPR_COND (t);
2670       if (!INTEGRAL_TYPE_P (TREE_TYPE (x)))
2671         {
2672           error ("non-integral used in condition");
2673           return x;
2674         }
2675       if (!is_gimple_condexpr (x))
2676         {
2677           error ("invalid conditional operand");
2678           return x;
2679         }
2680       break;
2681
2682     case NON_LVALUE_EXPR:
2683     case TRUTH_NOT_EXPR:
2684       gcc_unreachable ();
2685
2686     CASE_CONVERT:
2687     case FIX_TRUNC_EXPR:
2688     case FLOAT_EXPR:
2689     case NEGATE_EXPR:
2690     case ABS_EXPR:
2691     case BIT_NOT_EXPR:
2692       CHECK_OP (0, "invalid operand to unary operator");
2693       break;
2694
2695     case REALPART_EXPR:
2696     case IMAGPART_EXPR:
2697     case COMPONENT_REF:
2698     case ARRAY_REF:
2699     case ARRAY_RANGE_REF:
2700     case BIT_FIELD_REF:
2701     case VIEW_CONVERT_EXPR:
2702       /* We have a nest of references.  Verify that each of the operands
2703          that determine where to reference is either a constant or a variable,
2704          verify that the base is valid, and then show we've already checked
2705          the subtrees.  */
2706       while (handled_component_p (t))
2707         {
2708           if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2))
2709             CHECK_OP (2, "invalid COMPONENT_REF offset operator");
2710           else if (TREE_CODE (t) == ARRAY_REF
2711                    || TREE_CODE (t) == ARRAY_RANGE_REF)
2712             {
2713               CHECK_OP (1, "invalid array index");
2714               if (TREE_OPERAND (t, 2))
2715                 CHECK_OP (2, "invalid array lower bound");
2716               if (TREE_OPERAND (t, 3))
2717                 CHECK_OP (3, "invalid array stride");
2718             }
2719           else if (TREE_CODE (t) == BIT_FIELD_REF)
2720             {
2721               if (!host_integerp (TREE_OPERAND (t, 1), 1)
2722                   || !host_integerp (TREE_OPERAND (t, 2), 1))
2723                 {
2724                   error ("invalid position or size operand to BIT_FIELD_REF");
2725                   return t;
2726                 }
2727               else if (INTEGRAL_TYPE_P (TREE_TYPE (t))
2728                        && (TYPE_PRECISION (TREE_TYPE (t))
2729                            != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
2730                 {
2731                   error ("integral result type precision does not match "
2732                          "field size of BIT_FIELD_REF");
2733                   return t;
2734                 }
2735               if (!INTEGRAL_TYPE_P (TREE_TYPE (t))
2736                   && (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (t)))
2737                       != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
2738                 {
2739                   error ("mode precision of non-integral result does not "
2740                          "match field size of BIT_FIELD_REF");
2741                   return t;
2742                 }
2743             }
2744
2745           t = TREE_OPERAND (t, 0);
2746         }
2747
2748       if (!is_gimple_min_invariant (t) && !is_gimple_lvalue (t))
2749         {
2750           error ("invalid reference prefix");
2751           return t;
2752         }
2753       *walk_subtrees = 0;
2754       break;
2755     case PLUS_EXPR:
2756     case MINUS_EXPR:
2757       /* PLUS_EXPR and MINUS_EXPR don't work on pointers, they should be done using
2758          POINTER_PLUS_EXPR. */
2759       if (POINTER_TYPE_P (TREE_TYPE (t)))
2760         {
2761           error ("invalid operand to plus/minus, type is a pointer");
2762           return t;
2763         }
2764       CHECK_OP (0, "invalid operand to binary operator");
2765       CHECK_OP (1, "invalid operand to binary operator");
2766       break;
2767
2768     case POINTER_PLUS_EXPR:
2769       /* Check to make sure the first operand is a pointer or reference type. */
2770       if (!POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
2771         {
2772           error ("invalid operand to pointer plus, first operand is not a pointer");
2773           return t;
2774         }
2775       /* Check to make sure the second operand is an integer with type of
2776          sizetype.  */
2777       if (!useless_type_conversion_p (sizetype,
2778                                      TREE_TYPE (TREE_OPERAND (t, 1))))
2779         {
2780           error ("invalid operand to pointer plus, second operand is not an "
2781                  "integer with type of sizetype");
2782           return t;
2783         }
2784       /* FALLTHROUGH */
2785     case LT_EXPR:
2786     case LE_EXPR:
2787     case GT_EXPR:
2788     case GE_EXPR:
2789     case EQ_EXPR:
2790     case NE_EXPR:
2791     case UNORDERED_EXPR:
2792     case ORDERED_EXPR:
2793     case UNLT_EXPR:
2794     case UNLE_EXPR:
2795     case UNGT_EXPR:
2796     case UNGE_EXPR:
2797     case UNEQ_EXPR:
2798     case LTGT_EXPR:
2799     case MULT_EXPR:
2800     case TRUNC_DIV_EXPR:
2801     case CEIL_DIV_EXPR:
2802     case FLOOR_DIV_EXPR:
2803     case ROUND_DIV_EXPR:
2804     case TRUNC_MOD_EXPR:
2805     case CEIL_MOD_EXPR:
2806     case FLOOR_MOD_EXPR:
2807     case ROUND_MOD_EXPR:
2808     case RDIV_EXPR:
2809     case EXACT_DIV_EXPR:
2810     case MIN_EXPR:
2811     case MAX_EXPR:
2812     case LSHIFT_EXPR:
2813     case RSHIFT_EXPR:
2814     case LROTATE_EXPR:
2815     case RROTATE_EXPR:
2816     case BIT_IOR_EXPR:
2817     case BIT_XOR_EXPR:
2818     case BIT_AND_EXPR:
2819       CHECK_OP (0, "invalid operand to binary operator");
2820       CHECK_OP (1, "invalid operand to binary operator");
2821       break;
2822
2823     case CONSTRUCTOR:
2824       if (TREE_CONSTANT (t) && TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
2825         *walk_subtrees = 0;
2826       break;
2827
2828     case CASE_LABEL_EXPR:
2829       if (CASE_CHAIN (t))
2830         {
2831           error ("invalid CASE_CHAIN");
2832           return t;
2833         }
2834       break;
2835
2836     default:
2837       break;
2838     }
2839   return NULL;
2840
2841 #undef CHECK_OP
2842 }
2843
2844
2845 /* Verify if EXPR is either a GIMPLE ID or a GIMPLE indirect reference.
2846    Returns true if there is an error, otherwise false.  */
2847
2848 static bool
2849 verify_types_in_gimple_min_lval (tree expr)
2850 {
2851   tree op;
2852
2853   if (is_gimple_id (expr))
2854     return false;
2855
2856   if (TREE_CODE (expr) != TARGET_MEM_REF
2857       && TREE_CODE (expr) != MEM_REF)
2858     {
2859       error ("invalid expression for min lvalue");
2860       return true;
2861     }
2862
2863   /* TARGET_MEM_REFs are strange beasts.  */
2864   if (TREE_CODE (expr) == TARGET_MEM_REF)
2865     return false;
2866
2867   op = TREE_OPERAND (expr, 0);
2868   if (!is_gimple_val (op))
2869     {
2870       error ("invalid operand in indirect reference");
2871       debug_generic_stmt (op);
2872       return true;
2873     }
2874   /* Memory references now generally can involve a value conversion.  */
2875
2876   return false;
2877 }
2878
2879 /* Verify if EXPR is a valid GIMPLE reference expression.  If
2880    REQUIRE_LVALUE is true verifies it is an lvalue.  Returns true
2881    if there is an error, otherwise false.  */
2882
2883 static bool
2884 verify_types_in_gimple_reference (tree expr, bool require_lvalue)
2885 {
2886   while (handled_component_p (expr))
2887     {
2888       tree op = TREE_OPERAND (expr, 0);
2889
2890       if (TREE_CODE (expr) == ARRAY_REF
2891           || TREE_CODE (expr) == ARRAY_RANGE_REF)
2892         {
2893           if (!is_gimple_val (TREE_OPERAND (expr, 1))
2894               || (TREE_OPERAND (expr, 2)
2895                   && !is_gimple_val (TREE_OPERAND (expr, 2)))
2896               || (TREE_OPERAND (expr, 3)
2897                   && !is_gimple_val (TREE_OPERAND (expr, 3))))
2898             {
2899               error ("invalid operands to array reference");
2900               debug_generic_stmt (expr);
2901               return true;
2902             }
2903         }
2904
2905       /* Verify if the reference array element types are compatible.  */
2906       if (TREE_CODE (expr) == ARRAY_REF
2907           && !useless_type_conversion_p (TREE_TYPE (expr),
2908                                          TREE_TYPE (TREE_TYPE (op))))
2909         {
2910           error ("type mismatch in array reference");
2911           debug_generic_stmt (TREE_TYPE (expr));
2912           debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
2913           return true;
2914         }
2915       if (TREE_CODE (expr) == ARRAY_RANGE_REF
2916           && !useless_type_conversion_p (TREE_TYPE (TREE_TYPE (expr)),
2917                                          TREE_TYPE (TREE_TYPE (op))))
2918         {
2919           error ("type mismatch in array range reference");
2920           debug_generic_stmt (TREE_TYPE (TREE_TYPE (expr)));
2921           debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
2922           return true;
2923         }
2924
2925       if ((TREE_CODE (expr) == REALPART_EXPR
2926            || TREE_CODE (expr) == IMAGPART_EXPR)
2927           && !useless_type_conversion_p (TREE_TYPE (expr),
2928                                          TREE_TYPE (TREE_TYPE (op))))
2929         {
2930           error ("type mismatch in real/imagpart reference");
2931           debug_generic_stmt (TREE_TYPE (expr));
2932           debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
2933           return true;
2934         }
2935
2936       if (TREE_CODE (expr) == COMPONENT_REF
2937           && !useless_type_conversion_p (TREE_TYPE (expr),
2938                                          TREE_TYPE (TREE_OPERAND (expr, 1))))
2939         {
2940           error ("type mismatch in component reference");
2941           debug_generic_stmt (TREE_TYPE (expr));
2942           debug_generic_stmt (TREE_TYPE (TREE_OPERAND (expr, 1)));
2943           return true;
2944         }
2945
2946       if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
2947         {
2948           /* For VIEW_CONVERT_EXPRs which are allowed here too, we only check
2949              that their operand is not an SSA name or an invariant when
2950              requiring an lvalue (this usually means there is a SRA or IPA-SRA
2951              bug).  Otherwise there is nothing to verify, gross mismatches at
2952              most invoke undefined behavior.  */
2953           if (require_lvalue
2954               && (TREE_CODE (op) == SSA_NAME
2955                   || is_gimple_min_invariant (op)))
2956             {
2957               error ("conversion of an SSA_NAME on the left hand side");
2958               debug_generic_stmt (expr);
2959               return true;
2960             }
2961           else if (TREE_CODE (op) == SSA_NAME
2962                    && TYPE_SIZE (TREE_TYPE (expr)) != TYPE_SIZE (TREE_TYPE (op)))
2963             {
2964               error ("conversion of register to a different size");
2965               debug_generic_stmt (expr);
2966               return true;
2967             }
2968           else if (!handled_component_p (op))
2969             return false;
2970         }
2971
2972       expr = op;
2973     }
2974
2975   if (TREE_CODE (expr) == MEM_REF)
2976     {
2977       if (!is_gimple_mem_ref_addr (TREE_OPERAND (expr, 0)))
2978         {
2979           error ("invalid address operand in MEM_REF");
2980           debug_generic_stmt (expr);
2981           return true;
2982         }
2983       if (TREE_CODE (TREE_OPERAND (expr, 1)) != INTEGER_CST
2984           || !POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 1))))
2985         {
2986           error ("invalid offset operand in MEM_REF");
2987           debug_generic_stmt (expr);
2988           return true;
2989         }
2990     }
2991   else if (TREE_CODE (expr) == TARGET_MEM_REF)
2992     {
2993       if (!TMR_BASE (expr)
2994           || !is_gimple_mem_ref_addr (TMR_BASE (expr)))
2995         {
2996           error ("invalid address operand in TARGET_MEM_REF");
2997           return true;
2998         }
2999       if (!TMR_OFFSET (expr)
3000           || TREE_CODE (TMR_OFFSET (expr)) != INTEGER_CST
3001           || !POINTER_TYPE_P (TREE_TYPE (TMR_OFFSET (expr))))
3002         {
3003           error ("invalid offset operand in TARGET_MEM_REF");
3004           debug_generic_stmt (expr);
3005           return true;
3006         }
3007     }
3008
3009   return ((require_lvalue || !is_gimple_min_invariant (expr))
3010           && verify_types_in_gimple_min_lval (expr));
3011 }
3012
3013 /* Returns true if there is one pointer type in TYPE_POINTER_TO (SRC_OBJ)
3014    list of pointer-to types that is trivially convertible to DEST.  */
3015
3016 static bool
3017 one_pointer_to_useless_type_conversion_p (tree dest, tree src_obj)
3018 {
3019   tree src;
3020
3021   if (!TYPE_POINTER_TO (src_obj))
3022     return true;
3023
3024   for (src = TYPE_POINTER_TO (src_obj); src; src = TYPE_NEXT_PTR_TO (src))
3025     if (useless_type_conversion_p (dest, src))
3026       return true;
3027
3028   return false;
3029 }
3030
3031 /* Return true if TYPE1 is a fixed-point type and if conversions to and
3032    from TYPE2 can be handled by FIXED_CONVERT_EXPR.  */
3033
3034 static bool
3035 valid_fixed_convert_types_p (tree type1, tree type2)
3036 {
3037   return (FIXED_POINT_TYPE_P (type1)
3038           && (INTEGRAL_TYPE_P (type2)
3039               || SCALAR_FLOAT_TYPE_P (type2)
3040               || FIXED_POINT_TYPE_P (type2)));
3041 }
3042
3043 /* Verify the contents of a GIMPLE_CALL STMT.  Returns true when there
3044    is a problem, otherwise false.  */
3045
3046 static bool
3047 verify_gimple_call (gimple stmt)
3048 {
3049   tree fn = gimple_call_fn (stmt);
3050   tree fntype, fndecl;
3051   unsigned i;
3052
3053   if (gimple_call_internal_p (stmt))
3054     {
3055       if (fn)
3056         {
3057           error ("gimple call has two targets");
3058           debug_generic_stmt (fn);
3059           return true;
3060         }
3061     }
3062   else
3063     {
3064       if (!fn)
3065         {
3066           error ("gimple call has no target");
3067           return true;
3068         }
3069     }
3070
3071   if (fn && !is_gimple_call_addr (fn))
3072     {
3073       error ("invalid function in gimple call");
3074       debug_generic_stmt (fn);
3075       return true;
3076     }
3077
3078   if (fn
3079       && (!POINTER_TYPE_P (TREE_TYPE (fn))
3080           || (TREE_CODE (TREE_TYPE (TREE_TYPE (fn))) != FUNCTION_TYPE
3081               && TREE_CODE (TREE_TYPE (TREE_TYPE (fn))) != METHOD_TYPE)))
3082     {
3083       error ("non-function in gimple call");
3084       return true;
3085     }
3086
3087    fndecl = gimple_call_fndecl (stmt);
3088    if (fndecl
3089        && TREE_CODE (fndecl) == FUNCTION_DECL
3090        && DECL_LOOPING_CONST_OR_PURE_P (fndecl)
3091        && !DECL_PURE_P (fndecl)
3092        && !TREE_READONLY (fndecl))
3093      {
3094        error ("invalid pure const state for function");
3095        return true;
3096      }
3097
3098   if (gimple_call_lhs (stmt)
3099       && (!is_gimple_lvalue (gimple_call_lhs (stmt))
3100           || verify_types_in_gimple_reference (gimple_call_lhs (stmt), true)))
3101     {
3102       error ("invalid LHS in gimple call");
3103       return true;
3104     }
3105
3106   if (gimple_call_lhs (stmt) && gimple_call_noreturn_p (stmt))
3107     {
3108       error ("LHS in noreturn call");
3109       return true;
3110     }
3111
3112   fntype = gimple_call_fntype (stmt);
3113   if (fntype
3114       && gimple_call_lhs (stmt)
3115       && !useless_type_conversion_p (TREE_TYPE (gimple_call_lhs (stmt)),
3116                                      TREE_TYPE (fntype))
3117       /* ???  At least C++ misses conversions at assignments from
3118          void * call results.
3119          ???  Java is completely off.  Especially with functions
3120          returning java.lang.Object.
3121          For now simply allow arbitrary pointer type conversions.  */
3122       && !(POINTER_TYPE_P (TREE_TYPE (gimple_call_lhs (stmt)))
3123            && POINTER_TYPE_P (TREE_TYPE (fntype))))
3124     {
3125       error ("invalid conversion in gimple call");
3126       debug_generic_stmt (TREE_TYPE (gimple_call_lhs (stmt)));
3127       debug_generic_stmt (TREE_TYPE (fntype));
3128       return true;
3129     }
3130
3131   if (gimple_call_chain (stmt)
3132       && !is_gimple_val (gimple_call_chain (stmt)))
3133     {
3134       error ("invalid static chain in gimple call");
3135       debug_generic_stmt (gimple_call_chain (stmt));
3136       return true;
3137     }
3138
3139   /* If there is a static chain argument, this should not be an indirect
3140      call, and the decl should have DECL_STATIC_CHAIN set.  */
3141   if (gimple_call_chain (stmt))
3142     {
3143       if (!gimple_call_fndecl (stmt))
3144         {
3145           error ("static chain in indirect gimple call");
3146           return true;
3147         }
3148       fn = TREE_OPERAND (fn, 0);
3149
3150       if (!DECL_STATIC_CHAIN (fn))
3151         {
3152           error ("static chain with function that doesn%'t use one");
3153           return true;
3154         }
3155     }
3156
3157   /* ???  The C frontend passes unpromoted arguments in case it
3158      didn't see a function declaration before the call.  So for now
3159      leave the call arguments mostly unverified.  Once we gimplify
3160      unit-at-a-time we have a chance to fix this.  */
3161
3162   for (i = 0; i < gimple_call_num_args (stmt); ++i)
3163     {
3164       tree arg = gimple_call_arg (stmt, i);
3165       if ((is_gimple_reg_type (TREE_TYPE (arg))
3166            && !is_gimple_val (arg))
3167           || (!is_gimple_reg_type (TREE_TYPE (arg))
3168               && !is_gimple_lvalue (arg)))
3169         {
3170           error ("invalid argument to gimple call");
3171           debug_generic_expr (arg);
3172           return true;
3173         }
3174     }
3175
3176   return false;
3177 }
3178
3179 /* Verifies the gimple comparison with the result type TYPE and
3180    the operands OP0 and OP1.  */
3181
3182 static bool
3183 verify_gimple_comparison (tree type, tree op0, tree op1)
3184 {
3185   tree op0_type = TREE_TYPE (op0);
3186   tree op1_type = TREE_TYPE (op1);
3187
3188   if (!is_gimple_val (op0) || !is_gimple_val (op1))
3189     {
3190       error ("invalid operands in gimple comparison");
3191       return true;
3192     }
3193
3194   /* For comparisons we do not have the operations type as the
3195      effective type the comparison is carried out in.  Instead
3196      we require that either the first operand is trivially
3197      convertible into the second, or the other way around.
3198      The resulting type of a comparison may be any integral type.
3199      Because we special-case pointers to void we allow
3200      comparisons of pointers with the same mode as well.  */
3201   if ((!useless_type_conversion_p (op0_type, op1_type)
3202        && !useless_type_conversion_p (op1_type, op0_type)
3203        && (!POINTER_TYPE_P (op0_type)
3204            || !POINTER_TYPE_P (op1_type)
3205            || TYPE_MODE (op0_type) != TYPE_MODE (op1_type)))
3206       || !INTEGRAL_TYPE_P (type)
3207       || (TREE_CODE (type) != BOOLEAN_TYPE
3208           && TYPE_PRECISION (type) != 1))
3209     {
3210       error ("type mismatch in comparison expression");
3211       debug_generic_expr (type);
3212       debug_generic_expr (op0_type);
3213       debug_generic_expr (op1_type);
3214       return true;
3215     }
3216
3217   return false;
3218 }
3219
3220 /* Verify a gimple assignment statement STMT with an unary rhs.
3221    Returns true if anything is wrong.  */
3222
3223 static bool
3224 verify_gimple_assign_unary (gimple stmt)
3225 {
3226   enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3227   tree lhs = gimple_assign_lhs (stmt);
3228   tree lhs_type = TREE_TYPE (lhs);
3229   tree rhs1 = gimple_assign_rhs1 (stmt);
3230   tree rhs1_type = TREE_TYPE (rhs1);
3231
3232   if (!is_gimple_reg (lhs))
3233     {
3234       error ("non-register as LHS of unary operation");
3235       return true;
3236     }
3237
3238   if (!is_gimple_val (rhs1))
3239     {
3240       error ("invalid operand in unary operation");
3241       return true;
3242     }
3243
3244   /* First handle conversions.  */
3245   switch (rhs_code)
3246     {
3247     CASE_CONVERT:
3248       {
3249         /* Allow conversions between integral types and pointers only if
3250            there is no sign or zero extension involved.
3251            For targets were the precision of sizetype doesn't match that
3252            of pointers we need to allow arbitrary conversions from and
3253            to sizetype.  */
3254         if ((POINTER_TYPE_P (lhs_type)
3255              && INTEGRAL_TYPE_P (rhs1_type)
3256              && (TYPE_PRECISION (lhs_type) >= TYPE_PRECISION (rhs1_type)
3257                  || rhs1_type == sizetype))
3258             || (POINTER_TYPE_P (rhs1_type)
3259                 && INTEGRAL_TYPE_P (lhs_type)
3260                 && (TYPE_PRECISION (rhs1_type) >= TYPE_PRECISION (lhs_type)
3261                     || lhs_type == sizetype)))
3262           return false;
3263
3264         /* Allow conversion from integer to offset type and vice versa.  */
3265         if ((TREE_CODE (lhs_type) == OFFSET_TYPE
3266              && TREE_CODE (rhs1_type) == INTEGER_TYPE)
3267             || (TREE_CODE (lhs_type) == INTEGER_TYPE
3268                 && TREE_CODE (rhs1_type) == OFFSET_TYPE))
3269           return false;
3270
3271         /* Otherwise assert we are converting between types of the
3272            same kind.  */
3273         if (INTEGRAL_TYPE_P (lhs_type) != INTEGRAL_TYPE_P (rhs1_type))
3274           {
3275             error ("invalid types in nop conversion");
3276             debug_generic_expr (lhs_type);
3277             debug_generic_expr (rhs1_type);
3278             return true;
3279           }
3280
3281         return false;
3282       }
3283
3284     case ADDR_SPACE_CONVERT_EXPR:
3285       {
3286         if (!POINTER_TYPE_P (rhs1_type) || !POINTER_TYPE_P (lhs_type)
3287             || (TYPE_ADDR_SPACE (TREE_TYPE (rhs1_type))
3288                 == TYPE_ADDR_SPACE (TREE_TYPE (lhs_type))))
3289           {
3290             error ("invalid types in address space conversion");
3291             debug_generic_expr (lhs_type);
3292             debug_generic_expr (rhs1_type);
3293             return true;
3294           }
3295
3296         return false;
3297       }
3298
3299     case FIXED_CONVERT_EXPR:
3300       {
3301         if (!valid_fixed_convert_types_p (lhs_type, rhs1_type)
3302             && !valid_fixed_convert_types_p (rhs1_type, lhs_type))
3303           {
3304             error ("invalid types in fixed-point conversion");
3305             debug_generic_expr (lhs_type);
3306             debug_generic_expr (rhs1_type);
3307             return true;
3308           }
3309
3310         return false;
3311       }
3312
3313     case FLOAT_EXPR:
3314       {
3315         if (!INTEGRAL_TYPE_P (rhs1_type) || !SCALAR_FLOAT_TYPE_P (lhs_type))
3316           {
3317             error ("invalid types in conversion to floating point");
3318             debug_generic_expr (lhs_type);
3319             debug_generic_expr (rhs1_type);
3320             return true;
3321           }
3322
3323         return false;
3324       }
3325
3326     case FIX_TRUNC_EXPR:
3327       {
3328         if (!INTEGRAL_TYPE_P (lhs_type) || !SCALAR_FLOAT_TYPE_P (rhs1_type))
3329           {
3330             error ("invalid types in conversion to integer");
3331             debug_generic_expr (lhs_type);
3332             debug_generic_expr (rhs1_type);
3333             return true;
3334           }
3335
3336         return false;
3337       }
3338
3339     case VEC_UNPACK_HI_EXPR:
3340     case VEC_UNPACK_LO_EXPR:
3341     case REDUC_MAX_EXPR:
3342     case REDUC_MIN_EXPR:
3343     case REDUC_PLUS_EXPR:
3344     case VEC_UNPACK_FLOAT_HI_EXPR:
3345     case VEC_UNPACK_FLOAT_LO_EXPR:
3346       /* FIXME.  */
3347       return false;
3348
3349     case NEGATE_EXPR:
3350     case ABS_EXPR:
3351     case BIT_NOT_EXPR:
3352     case PAREN_EXPR:
3353     case NON_LVALUE_EXPR:
3354     case CONJ_EXPR:
3355       break;
3356
3357     default:
3358       gcc_unreachable ();
3359     }
3360
3361   /* For the remaining codes assert there is no conversion involved.  */
3362   if (!useless_type_conversion_p (lhs_type, rhs1_type))
3363     {
3364       error ("non-trivial conversion in unary operation");
3365       debug_generic_expr (lhs_type);
3366       debug_generic_expr (rhs1_type);
3367       return true;
3368     }
3369
3370   return false;
3371 }
3372
3373 /* Verify a gimple assignment statement STMT with a binary rhs.
3374    Returns true if anything is wrong.  */
3375
3376 static bool
3377 verify_gimple_assign_binary (gimple stmt)
3378 {
3379   enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3380   tree lhs = gimple_assign_lhs (stmt);
3381   tree lhs_type = TREE_TYPE (lhs);
3382   tree rhs1 = gimple_assign_rhs1 (stmt);
3383   tree rhs1_type = TREE_TYPE (rhs1);
3384   tree rhs2 = gimple_assign_rhs2 (stmt);
3385   tree rhs2_type = TREE_TYPE (rhs2);
3386
3387   if (!is_gimple_reg (lhs))
3388     {
3389       error ("non-register as LHS of binary operation");
3390       return true;
3391     }
3392
3393   if (!is_gimple_val (rhs1)
3394       || !is_gimple_val (rhs2))
3395     {
3396       error ("invalid operands in binary operation");
3397       return true;
3398     }
3399
3400   /* First handle operations that involve different types.  */
3401   switch (rhs_code)
3402     {
3403     case COMPLEX_EXPR:
3404       {
3405         if (TREE_CODE (lhs_type) != COMPLEX_TYPE
3406             || !(INTEGRAL_TYPE_P (rhs1_type)
3407                  || SCALAR_FLOAT_TYPE_P (rhs1_type))
3408             || !(INTEGRAL_TYPE_P (rhs2_type)
3409                  || SCALAR_FLOAT_TYPE_P (rhs2_type)))
3410           {
3411             error ("type mismatch in complex expression");
3412             debug_generic_expr (lhs_type);
3413             debug_generic_expr (rhs1_type);
3414             debug_generic_expr (rhs2_type);
3415             return true;
3416           }
3417
3418         return false;
3419       }
3420
3421     case LSHIFT_EXPR:
3422     case RSHIFT_EXPR:
3423     case LROTATE_EXPR:
3424     case RROTATE_EXPR:
3425       {
3426         /* Shifts and rotates are ok on integral types, fixed point
3427            types and integer vector types.  */
3428         if ((!INTEGRAL_TYPE_P (rhs1_type)
3429              && !FIXED_POINT_TYPE_P (rhs1_type)
3430              && !(TREE_CODE (rhs1_type) == VECTOR_TYPE
3431                   && INTEGRAL_TYPE_P (TREE_TYPE (rhs1_type))))
3432             || (!INTEGRAL_TYPE_P (rhs2_type)
3433                 /* Vector shifts of vectors are also ok.  */
3434                 && !(TREE_CODE (rhs1_type) == VECTOR_TYPE
3435                      && INTEGRAL_TYPE_P (TREE_TYPE (rhs1_type))
3436                      && TREE_CODE (rhs2_type) == VECTOR_TYPE
3437                      && INTEGRAL_TYPE_P (TREE_TYPE (rhs2_type))))
3438             || !useless_type_conversion_p (lhs_type, rhs1_type))
3439           {
3440             error ("type mismatch in shift expression");
3441             debug_generic_expr (lhs_type);
3442             debug_generic_expr (rhs1_type);
3443             debug_generic_expr (rhs2_type);
3444             return true;
3445           }
3446
3447         return false;
3448       }
3449
3450     case VEC_LSHIFT_EXPR:
3451     case VEC_RSHIFT_EXPR:
3452       {
3453         if (TREE_CODE (rhs1_type) != VECTOR_TYPE
3454             || !(INTEGRAL_TYPE_P (TREE_TYPE (rhs1_type))
3455                  || POINTER_TYPE_P (TREE_TYPE (rhs1_type))
3456                  || FIXED_POINT_TYPE_P (TREE_TYPE (rhs1_type))
3457                  || SCALAR_FLOAT_TYPE_P (TREE_TYPE (rhs1_type)))
3458             || (!INTEGRAL_TYPE_P (rhs2_type)
3459                 && (TREE_CODE (rhs2_type) != VECTOR_TYPE
3460                     || !INTEGRAL_TYPE_P (TREE_TYPE (rhs2_type))))
3461             || !useless_type_conversion_p (lhs_type, rhs1_type))
3462           {
3463             error ("type mismatch in vector shift expression");
3464             debug_generic_expr (lhs_type);
3465             debug_generic_expr (rhs1_type);
3466             debug_generic_expr (rhs2_type);
3467             return true;
3468           }
3469         /* For shifting a vector of non-integral components we
3470            only allow shifting by a constant multiple of the element size.  */
3471         if (!INTEGRAL_TYPE_P (TREE_TYPE (rhs1_type))
3472             && (TREE_CODE (rhs2) != INTEGER_CST
3473                 || !div_if_zero_remainder (EXACT_DIV_EXPR, rhs2,
3474                                            TYPE_SIZE (TREE_TYPE (rhs1_type)))))
3475           {
3476             error ("non-element sized vector shift of floating point vector");
3477             return true;
3478           }
3479
3480         return false;
3481       }
3482
3483     case PLUS_EXPR:
3484     case MINUS_EXPR:
3485       {
3486         /* We use regular PLUS_EXPR and MINUS_EXPR for vectors.
3487            ???  This just makes the checker happy and may not be what is
3488            intended.  */
3489         if (TREE_CODE (lhs_type) == VECTOR_TYPE
3490             && POINTER_TYPE_P (TREE_TYPE (lhs_type)))
3491           {
3492             if (TREE_CODE (rhs1_type) != VECTOR_TYPE
3493                 || TREE_CODE (rhs2_type) != VECTOR_TYPE)
3494               {
3495                 error ("invalid non-vector operands to vector valued plus");
3496                 return true;
3497               }
3498             lhs_type = TREE_TYPE (lhs_type);
3499             rhs1_type = TREE_TYPE (rhs1_type);
3500             rhs2_type = TREE_TYPE (rhs2_type);
3501             /* PLUS_EXPR is commutative, so we might end up canonicalizing
3502                the pointer to 2nd place.  */
3503             if (POINTER_TYPE_P (rhs2_type))
3504               {
3505                 tree tem = rhs1_type;
3506                 rhs1_type = rhs2_type;
3507                 rhs2_type = tem;
3508               }
3509             goto do_pointer_plus_expr_check;
3510           }
3511         if (POINTER_TYPE_P (lhs_type)
3512             || POINTER_TYPE_P (rhs1_type)
3513             || POINTER_TYPE_P (rhs2_type))
3514           {
3515             error ("invalid (pointer) operands to plus/minus");
3516             return true;
3517           }
3518
3519         /* Continue with generic binary expression handling.  */
3520         break;
3521       }
3522
3523     case POINTER_PLUS_EXPR:
3524       {
3525 do_pointer_plus_expr_check:
3526         if (!POINTER_TYPE_P (rhs1_type)
3527             || !useless_type_conversion_p (lhs_type, rhs1_type)
3528             || !useless_type_conversion_p (sizetype, rhs2_type))
3529           {
3530             error ("type mismatch in pointer plus expression");
3531             debug_generic_stmt (lhs_type);
3532             debug_generic_stmt (rhs1_type);
3533             debug_generic_stmt (rhs2_type);
3534             return true;
3535           }
3536
3537         return false;
3538       }
3539
3540     case TRUTH_ANDIF_EXPR:
3541     case TRUTH_ORIF_EXPR:
3542     case TRUTH_AND_EXPR:
3543     case TRUTH_OR_EXPR:
3544     case TRUTH_XOR_EXPR:
3545
3546       gcc_unreachable ();
3547
3548     case LT_EXPR:
3549     case LE_EXPR:
3550     case GT_EXPR:
3551     case GE_EXPR:
3552     case EQ_EXPR:
3553     case NE_EXPR:
3554     case UNORDERED_EXPR:
3555     case ORDERED_EXPR:
3556     case UNLT_EXPR:
3557     case UNLE_EXPR:
3558     case UNGT_EXPR:
3559     case UNGE_EXPR:
3560     case UNEQ_EXPR:
3561     case LTGT_EXPR:
3562       /* Comparisons are also binary, but the result type is not
3563          connected to the operand types.  */
3564       return verify_gimple_comparison (lhs_type, rhs1, rhs2);
3565
3566     case WIDEN_MULT_EXPR:
3567       if (TREE_CODE (lhs_type) != INTEGER_TYPE)
3568         return true;
3569       return ((2 * TYPE_PRECISION (rhs1_type) != TYPE_PRECISION (lhs_type))
3570               || (TYPE_PRECISION (rhs1_type) != TYPE_PRECISION (rhs2_type)));
3571
3572     case WIDEN_SUM_EXPR:
3573     case VEC_WIDEN_MULT_HI_EXPR:
3574     case VEC_WIDEN_MULT_LO_EXPR:
3575     case VEC_PACK_TRUNC_EXPR:
3576     case VEC_PACK_SAT_EXPR:
3577     case VEC_PACK_FIX_TRUNC_EXPR:
3578     case VEC_EXTRACT_EVEN_EXPR:
3579     case VEC_EXTRACT_ODD_EXPR:
3580     case VEC_INTERLEAVE_HIGH_EXPR:
3581     case VEC_INTERLEAVE_LOW_EXPR:
3582       /* FIXME.  */
3583       return false;
3584
3585     case MULT_EXPR:
3586     case TRUNC_DIV_EXPR:
3587     case CEIL_DIV_EXPR:
3588     case FLOOR_DIV_EXPR:
3589     case ROUND_DIV_EXPR:
3590     case TRUNC_MOD_EXPR:
3591     case CEIL_MOD_EXPR:
3592     case FLOOR_MOD_EXPR:
3593     case ROUND_MOD_EXPR:
3594     case RDIV_EXPR:
3595     case EXACT_DIV_EXPR:
3596     case MIN_EXPR:
3597     case MAX_EXPR:
3598     case BIT_IOR_EXPR:
3599     case BIT_XOR_EXPR:
3600     case BIT_AND_EXPR:
3601       /* Continue with generic binary expression handling.  */
3602       break;
3603
3604     default:
3605       gcc_unreachable ();
3606     }
3607
3608   if (!useless_type_conversion_p (lhs_type, rhs1_type)
3609       || !useless_type_conversion_p (lhs_type, rhs2_type))
3610     {
3611       error ("type mismatch in binary expression");
3612       debug_generic_stmt (lhs_type);
3613       debug_generic_stmt (rhs1_type);
3614       debug_generic_stmt (rhs2_type);
3615       return true;
3616     }
3617
3618   return false;
3619 }
3620
3621 /* Verify a gimple assignment statement STMT with a ternary rhs.
3622    Returns true if anything is wrong.  */
3623
3624 static bool
3625 verify_gimple_assign_ternary (gimple stmt)
3626 {
3627   enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3628   tree lhs = gimple_assign_lhs (stmt);
3629   tree lhs_type = TREE_TYPE (lhs);
3630   tree rhs1 = gimple_assign_rhs1 (stmt);
3631   tree rhs1_type = TREE_TYPE (rhs1);
3632   tree rhs2 = gimple_assign_rhs2 (stmt);
3633   tree rhs2_type = TREE_TYPE (rhs2);
3634   tree rhs3 = gimple_assign_rhs3 (stmt);
3635   tree rhs3_type = TREE_TYPE (rhs3);
3636
3637   if (!is_gimple_reg (lhs))
3638     {
3639       error ("non-register as LHS of ternary operation");
3640       return true;
3641     }
3642
3643   if (!is_gimple_val (rhs1)
3644       || !is_gimple_val (rhs2)
3645       || !is_gimple_val (rhs3))
3646     {
3647       error ("invalid operands in ternary operation");
3648       return true;
3649     }
3650
3651   /* First handle operations that involve different types.  */
3652   switch (rhs_code)
3653     {
3654     case WIDEN_MULT_PLUS_EXPR:
3655     case WIDEN_MULT_MINUS_EXPR:
3656       if ((!INTEGRAL_TYPE_P (rhs1_type)
3657            && !FIXED_POINT_TYPE_P (rhs1_type))
3658           || !useless_type_conversion_p (rhs1_type, rhs2_type)
3659           || !useless_type_conversion_p (lhs_type, rhs3_type)
3660           || 2 * TYPE_PRECISION (rhs1_type) != TYPE_PRECISION (lhs_type)
3661           || TYPE_PRECISION (rhs1_type) != TYPE_PRECISION (rhs2_type))
3662         {
3663           error ("type mismatch in widening multiply-accumulate expression");
3664           debug_generic_expr (lhs_type);
3665           debug_generic_expr (rhs1_type);
3666           debug_generic_expr (rhs2_type);
3667           debug_generic_expr (rhs3_type);
3668           return true;
3669         }
3670       break;
3671
3672     case FMA_EXPR:
3673       if (!useless_type_conversion_p (lhs_type, rhs1_type)
3674           || !useless_type_conversion_p (lhs_type, rhs2_type)
3675           || !useless_type_conversion_p (lhs_type, rhs3_type))
3676         {
3677           error ("type mismatch in fused multiply-add expression");
3678           debug_generic_expr (lhs_type);
3679           debug_generic_expr (rhs1_type);
3680           debug_generic_expr (rhs2_type);
3681           debug_generic_expr (rhs3_type);
3682           return true;
3683         }
3684       break;
3685
3686     case DOT_PROD_EXPR:
3687     case REALIGN_LOAD_EXPR:
3688       /* FIXME.  */
3689       return false;
3690
3691     default:
3692       gcc_unreachable ();
3693     }
3694   return false;
3695 }
3696
3697 /* Verify a gimple assignment statement STMT with a single rhs.
3698    Returns true if anything is wrong.  */
3699
3700 static bool
3701 verify_gimple_assign_single (gimple stmt)
3702 {
3703   enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3704   tree lhs = gimple_assign_lhs (stmt);
3705   tree lhs_type = TREE_TYPE (lhs);
3706   tree rhs1 = gimple_assign_rhs1 (stmt);
3707   tree rhs1_type = TREE_TYPE (rhs1);
3708   bool res = false;
3709
3710   if (!useless_type_conversion_p (lhs_type, rhs1_type))
3711     {
3712       error ("non-trivial conversion at assignment");
3713       debug_generic_expr (lhs_type);
3714       debug_generic_expr (rhs1_type);
3715       return true;
3716     }
3717
3718   if (handled_component_p (lhs))
3719     res |= verify_types_in_gimple_reference (lhs, true);
3720
3721   /* Special codes we cannot handle via their class.  */
3722   switch (rhs_code)
3723     {
3724     case ADDR_EXPR:
3725       {
3726         tree op = TREE_OPERAND (rhs1, 0);
3727         if (!is_gimple_addressable (op))
3728           {
3729             error ("invalid operand in unary expression");
3730             return true;
3731           }
3732
3733         /* Technically there is no longer a need for matching types, but
3734            gimple hygiene asks for this check.  In LTO we can end up
3735            combining incompatible units and thus end up with addresses
3736            of globals that change their type to a common one.  */
3737         if (!in_lto_p
3738             && !types_compatible_p (TREE_TYPE (op),
3739                                     TREE_TYPE (TREE_TYPE (rhs1)))
3740             && !one_pointer_to_useless_type_conversion_p (TREE_TYPE (rhs1),
3741                                                           TREE_TYPE (op)))
3742           {
3743             error ("type mismatch in address expression");
3744             debug_generic_stmt (TREE_TYPE (rhs1));
3745             debug_generic_stmt (TREE_TYPE (op));
3746             return true;
3747           }
3748
3749         return verify_types_in_gimple_reference (op, true);
3750       }
3751
3752     /* tcc_reference  */
3753     case INDIRECT_REF:
3754       error ("INDIRECT_REF in gimple IL");
3755       return true;
3756
3757     case COMPONENT_REF:
3758     case BIT_FIELD_REF:
3759     case ARRAY_REF:
3760     case ARRAY_RANGE_REF:
3761     case VIEW_CONVERT_EXPR:
3762     case REALPART_EXPR:
3763     case IMAGPART_EXPR:
3764     case TARGET_MEM_REF:
3765     case MEM_REF:
3766       if (!is_gimple_reg (lhs)
3767           && is_gimple_reg_type (TREE_TYPE (lhs)))
3768         {
3769           error ("invalid rhs for gimple memory store");
3770           debug_generic_stmt (lhs);
3771           debug_generic_stmt (rhs1);
3772           return true;
3773         }
3774       return res || verify_types_in_gimple_reference (rhs1, false);
3775
3776     /* tcc_constant  */
3777     case SSA_NAME:
3778     case INTEGER_CST:
3779     case REAL_CST:
3780     case FIXED_CST:
3781     case COMPLEX_CST:
3782     case VECTOR_CST:
3783     case STRING_CST:
3784       return res;
3785
3786     /* tcc_declaration  */
3787     case CONST_DECL:
3788       return res;
3789     case VAR_DECL:
3790     case PARM_DECL:
3791       if (!is_gimple_reg (lhs)
3792           && !is_gimple_reg (rhs1)
3793           && is_gimple_reg_type (TREE_TYPE (lhs)))
3794         {
3795           error ("invalid rhs for gimple memory store");
3796           debug_generic_stmt (lhs);
3797           debug_generic_stmt (rhs1);
3798           return true;
3799         }
3800       return res;
3801
3802     case COND_EXPR:
3803       if (!is_gimple_reg (lhs)
3804           || (!is_gimple_reg (TREE_OPERAND (rhs1, 0))
3805               && !COMPARISON_CLASS_P (TREE_OPERAND (rhs1, 0)))
3806           || (!is_gimple_reg (TREE_OPERAND (rhs1, 1))
3807               && !is_gimple_min_invariant (TREE_OPERAND (rhs1, 1)))
3808           || (!is_gimple_reg (TREE_OPERAND (rhs1, 2))
3809               && !is_gimple_min_invariant (TREE_OPERAND (rhs1, 2))))
3810         {
3811           error ("invalid COND_EXPR in gimple assignment");
3812           debug_generic_stmt (rhs1);
3813           return true;
3814         }
3815       return res;
3816
3817     case CONSTRUCTOR:
3818     case OBJ_TYPE_REF:
3819     case ASSERT_EXPR:
3820     case WITH_SIZE_EXPR:
3821     case VEC_COND_EXPR:
3822       /* FIXME.  */
3823       return res;
3824
3825     default:;
3826     }
3827
3828   return res;
3829 }
3830
3831 /* Verify the contents of a GIMPLE_ASSIGN STMT.  Returns true when there
3832    is a problem, otherwise false.  */
3833
3834 static bool
3835 verify_gimple_assign (gimple stmt)
3836 {
3837   switch (gimple_assign_rhs_class (stmt))
3838     {
3839     case GIMPLE_SINGLE_RHS:
3840       return verify_gimple_assign_single (stmt);
3841
3842     case GIMPLE_UNARY_RHS:
3843       return verify_gimple_assign_unary (stmt);
3844
3845     case GIMPLE_BINARY_RHS:
3846       return verify_gimple_assign_binary (stmt);
3847
3848     case GIMPLE_TERNARY_RHS:
3849       return verify_gimple_assign_ternary (stmt);
3850
3851     default:
3852       gcc_unreachable ();
3853     }
3854 }
3855
3856 /* Verify the contents of a GIMPLE_RETURN STMT.  Returns true when there
3857    is a problem, otherwise false.  */
3858
3859 static bool
3860 verify_gimple_return (gimple stmt)
3861 {
3862   tree op = gimple_return_retval (stmt);
3863   tree restype = TREE_TYPE (TREE_TYPE (cfun->decl));
3864
3865   /* We cannot test for present return values as we do not fix up missing
3866      return values from the original source.  */
3867   if (op == NULL)
3868     return false;
3869
3870   if (!is_gimple_val (op)
3871       && TREE_CODE (op) != RESULT_DECL)
3872     {
3873       error ("invalid operand in return statement");
3874       debug_generic_stmt (op);
3875       return true;
3876     }
3877
3878   if ((TREE_CODE (op) == RESULT_DECL
3879        && DECL_BY_REFERENCE (op))
3880       || (TREE_CODE (op) == SSA_NAME
3881           && TREE_CODE (SSA_NAME_VAR (op)) == RESULT_DECL
3882           && DECL_BY_REFERENCE (SSA_NAME_VAR (op))))
3883     op = TREE_TYPE (op);
3884
3885   if (!useless_type_conversion_p (restype, TREE_TYPE (op)))
3886     {
3887       error ("invalid conversion in return statement");
3888       debug_generic_stmt (restype);
3889       debug_generic_stmt (TREE_TYPE (op));
3890       return true;
3891     }
3892
3893   return false;
3894 }
3895
3896
3897 /* Verify the contents of a GIMPLE_GOTO STMT.  Returns true when there
3898    is a problem, otherwise false.  */
3899
3900 static bool
3901 verify_gimple_goto (gimple stmt)
3902 {
3903   tree dest = gimple_goto_dest (stmt);
3904
3905   /* ???  We have two canonical forms of direct goto destinations, a
3906      bare LABEL_DECL and an ADDR_EXPR of a LABEL_DECL.  */
3907   if (TREE_CODE (dest) != LABEL_DECL
3908       && (!is_gimple_val (dest)
3909           || !POINTER_TYPE_P (TREE_TYPE (dest))))
3910     {
3911       error ("goto destination is neither a label nor a pointer");
3912       return true;
3913     }
3914
3915   return false;
3916 }
3917
3918 /* Verify the contents of a GIMPLE_SWITCH STMT.  Returns true when there
3919    is a problem, otherwise false.  */
3920
3921 static bool
3922 verify_gimple_switch (gimple stmt)
3923 {
3924   if (!is_gimple_val (gimple_switch_index (stmt)))
3925     {
3926       error ("invalid operand to switch statement");
3927       debug_generic_stmt (gimple_switch_index (stmt));
3928       return true;
3929     }
3930
3931   return false;
3932 }
3933
3934
3935 /* Verify a gimple debug statement STMT.
3936    Returns true if anything is wrong.  */
3937
3938 static bool
3939 verify_gimple_debug (gimple stmt ATTRIBUTE_UNUSED)
3940 {
3941   /* There isn't much that could be wrong in a gimple debug stmt.  A
3942      gimple debug bind stmt, for example, maps a tree, that's usually
3943      a VAR_DECL or a PARM_DECL, but that could also be some scalarized
3944      component or member of an aggregate type, to another tree, that
3945      can be an arbitrary expression.  These stmts expand into debug
3946      insns, and are converted to debug notes by var-tracking.c.  */
3947   return false;
3948 }
3949
3950 /* Verify a gimple label statement STMT.
3951    Returns true if anything is wrong.  */
3952
3953 static bool
3954 verify_gimple_label (gimple stmt)
3955 {
3956   tree decl = gimple_label_label (stmt);
3957   int uid;
3958   bool err = false;
3959
3960   if (TREE_CODE (decl) != LABEL_DECL)
3961     return true;
3962
3963   uid = LABEL_DECL_UID (decl);
3964   if (cfun->cfg
3965       && (uid == -1
3966           || VEC_index (basic_block,
3967                         label_to_block_map, uid) != gimple_bb (stmt)))
3968     {
3969       error ("incorrect entry in label_to_block_map");
3970       err |= true;
3971     }
3972
3973   uid = EH_LANDING_PAD_NR (decl);
3974   if (uid)
3975     {
3976       eh_landing_pad lp = get_eh_landing_pad_from_number (uid);
3977       if (decl != lp->post_landing_pad)
3978         {
3979           error ("incorrect setting of landing pad number");
3980           err |= true;
3981         }
3982     }
3983
3984   return err;
3985 }
3986
3987 /* Verify the GIMPLE statement STMT.  Returns true if there is an
3988    error, otherwise false.  */
3989
3990 static bool
3991 verify_gimple_stmt (gimple stmt)
3992 {
3993   switch (gimple_code (stmt))
3994     {
3995     case GIMPLE_ASSIGN:
3996       return verify_gimple_assign (stmt);
3997
3998     case GIMPLE_LABEL:
3999       return verify_gimple_label (stmt);
4000
4001     case GIMPLE_CALL:
4002       return verify_gimple_call (stmt);
4003
4004     case GIMPLE_COND:
4005       if (TREE_CODE_CLASS (gimple_cond_code (stmt)) != tcc_comparison)
4006         {
4007           error ("invalid comparison code in gimple cond");
4008           return true;
4009         }
4010       if (!(!gimple_cond_true_label (stmt)
4011             || TREE_CODE (gimple_cond_true_label (stmt)) == LABEL_DECL)
4012           || !(!gimple_cond_false_label (stmt)
4013                || TREE_CODE (gimple_cond_false_label (stmt)) == LABEL_DECL))
4014         {
4015           error ("invalid labels in gimple cond");
4016           return true;
4017         }
4018
4019       return verify_gimple_comparison (boolean_type_node,
4020                                        gimple_cond_lhs (stmt),
4021                                        gimple_cond_rhs (stmt));
4022
4023     case GIMPLE_GOTO:
4024       return verify_gimple_goto (stmt);
4025
4026     case GIMPLE_SWITCH:
4027       return verify_gimple_switch (stmt);
4028
4029     case GIMPLE_RETURN:
4030       return verify_gimple_return (stmt);
4031
4032     case GIMPLE_ASM:
4033       return false;
4034
4035     /* Tuples that do not have tree operands.  */
4036     case GIMPLE_NOP:
4037     case GIMPLE_PREDICT:
4038     case GIMPLE_RESX:
4039     case GIMPLE_EH_DISPATCH:
4040     case GIMPLE_EH_MUST_NOT_THROW:
4041       return false;
4042
4043     CASE_GIMPLE_OMP:
4044       /* OpenMP directives are validated by the FE and never operated
4045          on by the optimizers.  Furthermore, GIMPLE_OMP_FOR may contain
4046          non-gimple expressions when the main index variable has had
4047          its address taken.  This does not affect the loop itself
4048          because the header of an GIMPLE_OMP_FOR is merely used to determine
4049          how to setup the parallel iteration.  */
4050       return false;
4051
4052     case GIMPLE_DEBUG:
4053       return verify_gimple_debug (stmt);
4054
4055     default:
4056       gcc_unreachable ();
4057     }
4058 }
4059
4060 /* Verify the contents of a GIMPLE_PHI.  Returns true if there is a problem,
4061    and false otherwise.  */
4062
4063 static bool
4064 verify_gimple_phi (gimple phi)
4065 {
4066   bool err = false;
4067   unsigned i;
4068   tree phi_result = gimple_phi_result (phi);
4069   bool virtual_p;
4070
4071   if (!phi_result)
4072     {
4073       error ("invalid PHI result");
4074       return true;
4075     }
4076
4077   virtual_p = !is_gimple_reg (phi_result);
4078   if (TREE_CODE (phi_result) != SSA_NAME
4079       || (virtual_p
4080           && SSA_NAME_VAR (phi_result) != gimple_vop (cfun)))
4081     {
4082       error ("invalid PHI result");
4083       err = true;
4084     }
4085
4086   for (i = 0; i < gimple_phi_num_args (phi); i++)
4087     {
4088       tree t = gimple_phi_arg_def (phi, i);
4089
4090       if (!t)
4091         {
4092           error ("missing PHI def");
4093           err |= true;
4094           continue;
4095         }
4096       /* Addressable variables do have SSA_NAMEs but they
4097          are not considered gimple values.  */
4098       else if ((TREE_CODE (t) == SSA_NAME
4099                 && virtual_p != !is_gimple_reg (t))
4100                || (virtual_p
4101                    && (TREE_CODE (t) != SSA_NAME
4102                        || SSA_NAME_VAR (t) != gimple_vop (cfun)))
4103                || (!virtual_p
4104                    && !is_gimple_val (t)))
4105         {
4106           error ("invalid PHI argument");
4107           debug_generic_expr (t);
4108           err |= true;
4109         }
4110 #ifdef ENABLE_TYPES_CHECKING
4111       if (!useless_type_conversion_p (TREE_TYPE (phi_result), TREE_TYPE (t)))
4112         {
4113           error ("incompatible types in PHI argument %u", i);
4114           debug_generic_stmt (TREE_TYPE (phi_result));
4115           debug_generic_stmt (TREE_TYPE (t));
4116           err |= true;
4117         }
4118 #endif
4119     }
4120
4121   return err;
4122 }
4123
4124 /* Verify the GIMPLE statements inside the sequence STMTS.  */
4125
4126 static bool
4127 verify_gimple_in_seq_2 (gimple_seq stmts)
4128 {
4129   gimple_stmt_iterator ittr;
4130   bool err = false;
4131
4132   for (ittr = gsi_start (stmts); !gsi_end_p (ittr); gsi_next (&ittr))
4133     {
4134       gimple stmt = gsi_stmt (ittr);
4135
4136       switch (gimple_code (stmt))
4137         {
4138         case GIMPLE_BIND:
4139           err |= verify_gimple_in_seq_2 (gimple_bind_body (stmt));
4140           break;
4141
4142         case GIMPLE_TRY:
4143           err |= verify_gimple_in_seq_2 (gimple_try_eval (stmt));
4144           err |= verify_gimple_in_seq_2 (gimple_try_cleanup (stmt));
4145           break;
4146
4147         case GIMPLE_EH_FILTER:
4148           err |= verify_gimple_in_seq_2 (gimple_eh_filter_failure (stmt));
4149           break;
4150
4151         case GIMPLE_CATCH:
4152           err |= verify_gimple_in_seq_2 (gimple_catch_handler (stmt));
4153           break;
4154
4155         default:
4156           {
4157             bool err2 = verify_gimple_stmt (stmt);
4158             if (err2)
4159               debug_gimple_stmt (stmt);
4160             err |= err2;
4161           }
4162         }
4163     }
4164
4165   return err;
4166 }
4167
4168
4169 /* Verify the GIMPLE statements inside the statement list STMTS.  */
4170
4171 DEBUG_FUNCTION void
4172 verify_gimple_in_seq (gimple_seq stmts)
4173 {
4174   timevar_push (TV_TREE_STMT_VERIFY);
4175   if (verify_gimple_in_seq_2 (stmts))
4176     internal_error ("verify_gimple failed");
4177   timevar_pop (TV_TREE_STMT_VERIFY);
4178 }
4179
4180 /* Return true when the T can be shared.  */
4181
4182 bool
4183 tree_node_can_be_shared (tree t)
4184 {
4185   if (IS_TYPE_OR_DECL_P (t)
4186       || is_gimple_min_invariant (t)
4187       || TREE_CODE (t) == SSA_NAME
4188       || t == error_mark_node
4189       || TREE_CODE (t) == IDENTIFIER_NODE)
4190     return true;
4191
4192   if (TREE_CODE (t) == CASE_LABEL_EXPR)
4193     return true;
4194
4195   while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
4196            && is_gimple_min_invariant (TREE_OPERAND (t, 1)))
4197          || TREE_CODE (t) == COMPONENT_REF
4198          || TREE_CODE (t) == REALPART_EXPR
4199          || TREE_CODE (t) == IMAGPART_EXPR)
4200     t = TREE_OPERAND (t, 0);
4201
4202   if (DECL_P (t))
4203     return true;
4204
4205   return false;
4206 }
4207
4208 /* Called via walk_gimple_stmt.  Verify tree sharing.  */
4209
4210 static tree
4211 verify_node_sharing (tree *tp, int *walk_subtrees, void *data)
4212 {
4213   struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
4214   struct pointer_set_t *visited = (struct pointer_set_t *) wi->info;
4215
4216   if (tree_node_can_be_shared (*tp))
4217     {
4218       *walk_subtrees = false;
4219       return NULL;
4220     }
4221
4222   if (pointer_set_insert (visited, *tp))
4223     return *tp;
4224
4225   return NULL;
4226 }
4227
4228 static bool eh_error_found;
4229 static int
4230 verify_eh_throw_stmt_node (void **slot, void *data)
4231 {
4232   struct throw_stmt_node *node = (struct throw_stmt_node *)*slot;
4233   struct pointer_set_t *visited = (struct pointer_set_t *) data;
4234
4235   if (!pointer_set_contains (visited, node->stmt))
4236     {
4237       error ("dead STMT in EH table");
4238       debug_gimple_stmt (node->stmt);
4239       eh_error_found = true;
4240     }
4241   return 1;
4242 }
4243
4244 /* Verify the GIMPLE statements in the CFG of FN.  */
4245
4246 DEBUG_FUNCTION void
4247 verify_gimple_in_cfg (struct function *fn)
4248 {
4249   basic_block bb;
4250   bool err = false;
4251   struct pointer_set_t *visited, *visited_stmts;
4252
4253   timevar_push (TV_TREE_STMT_VERIFY);
4254   visited = pointer_set_create ();
4255   visited_stmts = pointer_set_create ();
4256
4257   FOR_EACH_BB_FN (bb, fn)
4258     {
4259       gimple_stmt_iterator gsi;
4260
4261       for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4262         {
4263           gimple phi = gsi_stmt (gsi);
4264           bool err2 = false;
4265           unsigned i;
4266
4267           pointer_set_insert (visited_stmts, phi);
4268
4269           if (gimple_bb (phi) != bb)
4270             {
4271               error ("gimple_bb (phi) is set to a wrong basic block");
4272               err2 = true;
4273             }
4274
4275           err2 |= verify_gimple_phi (phi);
4276
4277           for (i = 0; i < gimple_phi_num_args (phi); i++)
4278             {
4279               tree arg = gimple_phi_arg_def (phi, i);
4280               tree addr = walk_tree (&arg, verify_node_sharing, visited, NULL);
4281               if (addr)
4282                 {
4283                   error ("incorrect sharing of tree nodes");
4284                   debug_generic_expr (addr);
4285                   err2 |= true;
4286                 }
4287             }
4288
4289           if (err2)
4290             debug_gimple_stmt (phi);
4291           err |= err2;
4292         }
4293
4294       for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4295         {
4296           gimple stmt = gsi_stmt (gsi);
4297           bool err2 = false;
4298           struct walk_stmt_info wi;
4299           tree addr;
4300           int lp_nr;
4301
4302           pointer_set_insert (visited_stmts, stmt);
4303
4304           if (gimple_bb (stmt) != bb)
4305             {
4306               error ("gimple_bb (stmt) is set to a wrong basic block");
4307               err2 = true;
4308             }
4309
4310           err2 |= verify_gimple_stmt (stmt);
4311
4312           memset (&wi, 0, sizeof (wi));
4313           wi.info = (void *) visited;
4314           addr = walk_gimple_op (stmt, verify_node_sharing, &wi);
4315           if (addr)
4316             {
4317               error ("incorrect sharing of tree nodes");
4318               debug_generic_expr (addr);
4319               err2 |= true;
4320             }
4321
4322           /* ???  Instead of not checking these stmts at all the walker
4323              should know its context via wi.  */
4324           if (!is_gimple_debug (stmt)
4325               && !is_gimple_omp (stmt))
4326             {
4327               memset (&wi, 0, sizeof (wi));
4328               addr = walk_gimple_op (stmt, verify_expr, &wi);
4329               if (addr)
4330                 {
4331                   debug_generic_expr (addr);
4332                   inform (gimple_location (stmt), "in statement");
4333                   err2 |= true;
4334                 }
4335             }
4336
4337           /* If the statement is marked as part of an EH region, then it is
4338              expected that the statement could throw.  Verify that when we
4339              have optimizations that simplify statements such that we prove
4340              that they cannot throw, that we update other data structures
4341              to match.  */
4342           lp_nr = lookup_stmt_eh_lp (stmt);
4343           if (lp_nr != 0)
4344             {
4345               if (!stmt_could_throw_p (stmt))
4346                 {
4347                   error ("statement marked for throw, but doesn%'t");
4348                   err2 |= true;
4349                 }
4350               else if (lp_nr > 0
4351                        && !gsi_one_before_end_p (gsi)
4352                        && stmt_can_throw_internal (stmt))
4353                 {
4354                   error ("statement marked for throw in middle of block");
4355                   err2 |= true;
4356                 }
4357             }
4358
4359           if (err2)
4360             debug_gimple_stmt (stmt);
4361           err |= err2;
4362         }
4363     }
4364
4365   eh_error_found = false;
4366   if (get_eh_throw_stmt_table (cfun))
4367     htab_traverse (get_eh_throw_stmt_table (cfun),
4368                    verify_eh_throw_stmt_node,
4369                    visited_stmts);
4370
4371   if (err || eh_error_found)
4372     internal_error ("verify_gimple failed");
4373
4374   pointer_set_destroy (visited);
4375   pointer_set_destroy (visited_stmts);
4376   verify_histograms ();
4377   timevar_pop (TV_TREE_STMT_VERIFY);
4378 }
4379
4380
4381 /* Verifies that the flow information is OK.  */
4382
4383 static int
4384 gimple_verify_flow_info (void)
4385 {
4386   int err = 0;
4387   basic_block bb;
4388   gimple_stmt_iterator gsi;
4389   gimple stmt;
4390   edge e;
4391   edge_iterator ei;
4392
4393   if (ENTRY_BLOCK_PTR->il.gimple)
4394     {
4395       error ("ENTRY_BLOCK has IL associated with it");
4396       err = 1;
4397     }
4398
4399   if (EXIT_BLOCK_PTR->il.gimple)
4400     {
4401       error ("EXIT_BLOCK has IL associated with it");
4402       err = 1;
4403     }
4404
4405   FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4406     if (e->flags & EDGE_FALLTHRU)
4407       {
4408         error ("fallthru to exit from bb %d", e->src->index);
4409         err = 1;
4410       }
4411
4412   FOR_EACH_BB (bb)
4413     {
4414       bool found_ctrl_stmt = false;
4415
4416       stmt = NULL;
4417
4418       /* Skip labels on the start of basic block.  */
4419       for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4420         {
4421           tree label;
4422           gimple prev_stmt = stmt;
4423
4424           stmt = gsi_stmt (gsi);
4425
4426           if (gimple_code (stmt) != GIMPLE_LABEL)
4427             break;
4428
4429           label = gimple_label_label (stmt);
4430           if (prev_stmt && DECL_NONLOCAL (label))
4431             {
4432               error ("nonlocal label ");
4433               print_generic_expr (stderr, label, 0);
4434               fprintf (stderr, " is not first in a sequence of labels in bb %d",
4435                        bb->index);
4436               err = 1;
4437             }
4438
4439           if (prev_stmt && EH_LANDING_PAD_NR (label) != 0)
4440             {
4441               error ("EH landing pad label ");
4442               print_generic_expr (stderr, label, 0);
4443               fprintf (stderr, " is not first in a sequence of labels in bb %d",
4444                        bb->index);
4445               err = 1;
4446             }
4447
4448           if (label_to_block (label) != bb)
4449             {
4450               error ("label ");
4451               print_generic_expr (stderr, label, 0);
4452               fprintf (stderr, " to block does not match in bb %d",
4453                        bb->index);
4454               err = 1;
4455             }
4456
4457           if (decl_function_context (label) != current_function_decl)
4458             {
4459               error ("label ");
4460               print_generic_expr (stderr, label, 0);
4461               fprintf (stderr, " has incorrect context in bb %d",
4462                        bb->index);
4463               err = 1;
4464             }
4465         }
4466
4467       /* Verify that body of basic block BB is free of control flow.  */
4468       for (; !gsi_end_p (gsi); gsi_next (&gsi))
4469         {
4470           gimple stmt = gsi_stmt (gsi);
4471
4472           if (found_ctrl_stmt)
4473             {
4474               error ("control flow in the middle of basic block %d",
4475                      bb->index);
4476               err = 1;
4477             }
4478
4479           if (stmt_ends_bb_p (stmt))
4480             found_ctrl_stmt = true;
4481
4482           if (gimple_code (stmt) == GIMPLE_LABEL)
4483             {
4484               error ("label ");
4485               print_generic_expr (stderr, gimple_label_label (stmt), 0);
4486               fprintf (stderr, " in the middle of basic block %d", bb->index);
4487               err = 1;
4488             }
4489         }
4490
4491       gsi = gsi_last_bb (bb);
4492       if (gsi_end_p (gsi))
4493         continue;
4494
4495       stmt = gsi_stmt (gsi);
4496
4497       if (gimple_code (stmt) == GIMPLE_LABEL)
4498         continue;
4499
4500       err |= verify_eh_edges (stmt);
4501
4502       if (is_ctrl_stmt (stmt))
4503         {
4504           FOR_EACH_EDGE (e, ei, bb->succs)
4505             if (e->flags & EDGE_FALLTHRU)
4506               {
4507                 error ("fallthru edge after a control statement in bb %d",
4508                        bb->index);
4509                 err = 1;
4510               }
4511         }
4512
4513       if (gimple_code (stmt) != GIMPLE_COND)
4514         {
4515           /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4516              after anything else but if statement.  */
4517           FOR_EACH_EDGE (e, ei, bb->succs)
4518             if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
4519               {
4520                 error ("true/false edge after a non-GIMPLE_COND in bb %d",
4521                        bb->index);
4522                 err = 1;
4523               }
4524         }
4525
4526       switch (gimple_code (stmt))
4527         {
4528         case GIMPLE_COND:
4529           {
4530             edge true_edge;
4531             edge false_edge;
4532
4533             extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
4534
4535             if (!true_edge
4536                 || !false_edge
4537                 || !(true_edge->flags & EDGE_TRUE_VALUE)
4538                 || !(false_edge->flags & EDGE_FALSE_VALUE)
4539                 || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4540                 || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4541                 || EDGE_COUNT (bb->succs) >= 3)
4542               {
4543                 error ("wrong outgoing edge flags at end of bb %d",
4544                        bb->index);
4545                 err = 1;
4546               }
4547           }
4548           break;
4549
4550         case GIMPLE_GOTO:
4551           if (simple_goto_p (stmt))
4552             {
4553               error ("explicit goto at end of bb %d", bb->index);
4554               err = 1;
4555             }
4556           else
4557             {
4558               /* FIXME.  We should double check that the labels in the
4559                  destination blocks have their address taken.  */
4560               FOR_EACH_EDGE (e, ei, bb->succs)
4561                 if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE
4562                                  | EDGE_FALSE_VALUE))
4563                     || !(e->flags & EDGE_ABNORMAL))
4564                   {
4565                     error ("wrong outgoing edge flags at end of bb %d",
4566                            bb->index);
4567                     err = 1;
4568                   }
4569             }
4570           break;
4571
4572         case GIMPLE_CALL:
4573           if (!gimple_call_builtin_p (stmt, BUILT_IN_RETURN))
4574             break;
4575           /* ... fallthru ... */
4576         case GIMPLE_RETURN:
4577           if (!single_succ_p (bb)
4578               || (single_succ_edge (bb)->flags
4579                   & (EDGE_FALLTHRU | EDGE_ABNORMAL
4580                      | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4581             {
4582               error ("wrong outgoing edge flags at end of bb %d", bb->index);
4583               err = 1;
4584             }
4585           if (single_succ (bb) != EXIT_BLOCK_PTR)
4586             {
4587               error ("return edge does not point to exit in bb %d",
4588                      bb->index);
4589               err = 1;
4590             }
4591           break;
4592
4593         case GIMPLE_SWITCH:
4594           {
4595             tree prev;
4596             edge e;
4597             size_t i, n;
4598
4599             n = gimple_switch_num_labels (stmt);
4600
4601             /* Mark all the destination basic blocks.  */
4602             for (i = 0; i < n; ++i)
4603               {
4604                 tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
4605                 basic_block label_bb = label_to_block (lab);
4606                 gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
4607                 label_bb->aux = (void *)1;
4608               }
4609
4610             /* Verify that the case labels are sorted.  */
4611             prev = gimple_switch_label (stmt, 0);
4612             for (i = 1; i < n; ++i)
4613               {
4614                 tree c = gimple_switch_label (stmt, i);
4615                 if (!CASE_LOW (c))
4616                   {
4617                     error ("found default case not at the start of "
4618                            "case vector");
4619                     err = 1;
4620                     continue;
4621                   }
4622                 if (CASE_LOW (prev)
4623                     && !tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c)))
4624                   {
4625                     error ("case labels not sorted: ");
4626                     print_generic_expr (stderr, prev, 0);
4627                     fprintf (stderr," is greater than ");
4628                     print_generic_expr (stderr, c, 0);
4629                     fprintf (stderr," but comes before it.\n");
4630                     err = 1;
4631                   }
4632                 prev = c;
4633               }
4634             /* VRP will remove the default case if it can prove it will
4635                never be executed.  So do not verify there always exists
4636                a default case here.  */
4637
4638             FOR_EACH_EDGE (e, ei, bb->succs)
4639               {
4640                 if (!e->dest->aux)
4641                   {
4642                     error ("extra outgoing edge %d->%d",
4643                            bb->index, e->dest->index);
4644                     err = 1;
4645                   }
4646
4647                 e->dest->aux = (void *)2;
4648                 if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL
4649                                  | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4650                   {
4651                     error ("wrong outgoing edge flags at end of bb %d",
4652                            bb->index);
4653                     err = 1;
4654                   }
4655               }
4656
4657             /* Check that we have all of them.  */
4658             for (i = 0; i < n; ++i)
4659               {
4660                 tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
4661                 basic_block label_bb = label_to_block (lab);
4662
4663                 if (label_bb->aux != (void *)2)
4664                   {
4665                     error ("missing edge %i->%i", bb->index, label_bb->index);
4666                     err = 1;
4667                   }
4668               }
4669
4670             FOR_EACH_EDGE (e, ei, bb->succs)
4671               e->dest->aux = (void *)0;
4672           }
4673           break;
4674
4675         case GIMPLE_EH_DISPATCH:
4676           err |= verify_eh_dispatch_edge (stmt);
4677           break;
4678
4679         default:
4680           break;
4681         }
4682     }
4683
4684   if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
4685     verify_dominators (CDI_DOMINATORS);
4686
4687   return err;
4688 }
4689
4690
4691 /* Updates phi nodes after creating a forwarder block joined
4692    by edge FALLTHRU.  */
4693
4694 static void
4695 gimple_make_forwarder_block (edge fallthru)
4696 {
4697   edge e;
4698   edge_iterator ei;
4699   basic_block dummy, bb;
4700   tree var;
4701   gimple_stmt_iterator gsi;
4702
4703   dummy = fallthru->src;
4704   bb = fallthru->dest;
4705
4706   if (single_pred_p (bb))
4707     return;
4708
4709   /* If we redirected a branch we must create new PHI nodes at the
4710      start of BB.  */
4711   for (gsi = gsi_start_phis (dummy); !gsi_end_p (gsi); gsi_next (&gsi))
4712     {
4713       gimple phi, new_phi;
4714
4715       phi = gsi_stmt (gsi);
4716       var = gimple_phi_result (phi);
4717       new_phi = create_phi_node (var, bb);
4718       SSA_NAME_DEF_STMT (var) = new_phi;
4719       gimple_phi_set_result (phi, make_ssa_name (SSA_NAME_VAR (var), phi));
4720       add_phi_arg (new_phi, gimple_phi_result (phi), fallthru,
4721                    UNKNOWN_LOCATION);
4722     }
4723
4724   /* Add the arguments we have stored on edges.  */
4725   FOR_EACH_EDGE (e, ei, bb->preds)
4726     {
4727       if (e == fallthru)
4728         continue;
4729
4730       flush_pending_stmts (e);
4731     }
4732 }
4733
4734
4735 /* Return a non-special label in the head of basic block BLOCK.
4736    Create one if it doesn't exist.  */
4737
4738 tree
4739 gimple_block_label (basic_block bb)
4740 {
4741   gimple_stmt_iterator i, s = gsi_start_bb (bb);
4742   bool first = true;
4743   tree label;
4744   gimple stmt;
4745
4746   for (i = s; !gsi_end_p (i); first = false, gsi_next (&i))
4747     {
4748       stmt = gsi_stmt (i);
4749       if (gimple_code (stmt) != GIMPLE_LABEL)
4750         break;
4751       label = gimple_label_label (stmt);
4752       if (!DECL_NONLOCAL (label))
4753         {
4754           if (!first)
4755             gsi_move_before (&i, &s);
4756           return label;
4757         }
4758     }
4759
4760   label = create_artificial_label (UNKNOWN_LOCATION);
4761   stmt = gimple_build_label (label);
4762   gsi_insert_before (&s, stmt, GSI_NEW_STMT);
4763   return label;
4764 }
4765
4766
4767 /* Attempt to perform edge redirection by replacing a possibly complex
4768    jump instruction by a goto or by removing the jump completely.
4769    This can apply only if all edges now point to the same block.  The
4770    parameters and return values are equivalent to
4771    redirect_edge_and_branch.  */
4772
4773 static edge
4774 gimple_try_redirect_by_replacing_jump (edge e, basic_block target)
4775 {
4776   basic_block src = e->src;
4777   gimple_stmt_iterator i;
4778   gimple stmt;
4779
4780   /* We can replace or remove a complex jump only when we have exactly
4781      two edges.  */
4782   if (EDGE_COUNT (src->succs) != 2
4783       /* Verify that all targets will be TARGET.  Specifically, the
4784          edge that is not E must also go to TARGET.  */
4785       || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)
4786     return NULL;
4787
4788   i = gsi_last_bb (src);
4789   if (gsi_end_p (i))
4790     return NULL;
4791
4792   stmt = gsi_stmt (i);
4793
4794   if (gimple_code (stmt) == GIMPLE_COND || gimple_code (stmt) == GIMPLE_SWITCH)
4795     {
4796       gsi_remove (&i, true);
4797       e = ssa_redirect_edge (e, target);
4798       e->flags = EDGE_FALLTHRU;
4799       return e;
4800     }
4801
4802   return NULL;
4803 }
4804
4805
4806 /* Redirect E to DEST.  Return NULL on failure.  Otherwise, return the
4807    edge representing the redirected branch.  */
4808
4809 static edge
4810 gimple_redirect_edge_and_branch (edge e, basic_block dest)
4811 {
4812   basic_block bb = e->src;
4813   gimple_stmt_iterator gsi;
4814   edge ret;
4815   gimple stmt;
4816
4817   if (e->flags & EDGE_ABNORMAL)
4818     return NULL;
4819
4820   if (e->dest == dest)
4821     return NULL;
4822
4823   if (e->flags & EDGE_EH)
4824     return redirect_eh_edge (e, dest);
4825
4826   if (e->src != ENTRY_BLOCK_PTR)
4827     {
4828       ret = gimple_try_redirect_by_replacing_jump (e, dest);
4829       if (ret)
4830         return ret;
4831     }
4832
4833   gsi = gsi_last_bb (bb);
4834   stmt = gsi_end_p (gsi) ? NULL : gsi_stmt (gsi);
4835
4836   switch (stmt ? gimple_code (stmt) : GIMPLE_ERROR_MARK)
4837     {
4838     case GIMPLE_COND:
4839       /* For COND_EXPR, we only need to redirect the edge.  */
4840       break;
4841
4842     case GIMPLE_GOTO:
4843       /* No non-abnormal edges should lead from a non-simple goto, and
4844          simple ones should be represented implicitly.  */
4845       gcc_unreachable ();
4846
4847     case GIMPLE_SWITCH:
4848       {
4849         tree label = gimple_block_label (dest);
4850         tree cases = get_cases_for_edge (e, stmt);
4851
4852         /* If we have a list of cases associated with E, then use it
4853            as it's a lot faster than walking the entire case vector.  */
4854         if (cases)
4855           {
4856             edge e2 = find_edge (e->src, dest);
4857             tree last, first;
4858
4859             first = cases;
4860             while (cases)
4861               {
4862                 last = cases;
4863                 CASE_LABEL (cases) = label;
4864                 cases = CASE_CHAIN (cases);
4865               }
4866
4867             /* If there was already an edge in the CFG, then we need
4868                to move all the cases associated with E to E2.  */
4869             if (e2)
4870               {
4871                 tree cases2 = get_cases_for_edge (e2, stmt);
4872
4873                 CASE_CHAIN (last) = CASE_CHAIN (cases2);
4874                 CASE_CHAIN (cases2) = first;
4875               }
4876             bitmap_set_bit (touched_switch_bbs, gimple_bb (stmt)->index);
4877           }
4878         else
4879           {
4880             size_t i, n = gimple_switch_num_labels (stmt);
4881
4882             for (i = 0; i < n; i++)
4883               {
4884                 tree elt = gimple_switch_label (stmt, i);
4885                 if (label_to_block (CASE_LABEL (elt)) == e->dest)
4886                   CASE_LABEL (elt) = label;
4887               }
4888           }
4889       }
4890       break;
4891
4892     case GIMPLE_ASM:
4893       {
4894         int i, n = gimple_asm_nlabels (stmt);
4895         tree label = NULL;
4896
4897         for (i = 0; i < n; ++i)
4898           {
4899             tree cons = gimple_asm_label_op (stmt, i);
4900             if (label_to_block (TREE_VALUE (cons)) == e->dest)
4901               {
4902                 if (!label)
4903                   label = gimple_block_label (dest);
4904                 TREE_VALUE (cons) = label;
4905               }
4906           }
4907
4908         /* If we didn't find any label matching the former edge in the
4909            asm labels, we must be redirecting the fallthrough
4910            edge.  */
4911         gcc_assert (label || (e->flags & EDGE_FALLTHRU));
4912       }
4913       break;
4914
4915     case GIMPLE_RETURN:
4916       gsi_remove (&gsi, true);
4917       e->flags |= EDGE_FALLTHRU;
4918       break;
4919
4920     case GIMPLE_OMP_RETURN:
4921     case GIMPLE_OMP_CONTINUE:
4922     case GIMPLE_OMP_SECTIONS_SWITCH:
4923     case GIMPLE_OMP_FOR:
4924       /* The edges from OMP constructs can be simply redirected.  */
4925       break;
4926
4927     case GIMPLE_EH_DISPATCH:
4928       if (!(e->flags & EDGE_FALLTHRU))
4929         redirect_eh_dispatch_edge (stmt, e, dest);
4930       break;
4931
4932     default:
4933       /* Otherwise it must be a fallthru edge, and we don't need to
4934          do anything besides redirecting it.  */
4935       gcc_assert (e->flags & EDGE_FALLTHRU);
4936       break;
4937     }
4938
4939   /* Update/insert PHI nodes as necessary.  */
4940
4941   /* Now update the edges in the CFG.  */
4942   e = ssa_redirect_edge (e, dest);
4943
4944   return e;
4945 }
4946
4947 /* Returns true if it is possible to remove edge E by redirecting
4948    it to the destination of the other edge from E->src.  */
4949
4950 static bool
4951 gimple_can_remove_branch_p (const_edge e)
4952 {
4953   if (e->flags & (EDGE_ABNORMAL | EDGE_EH))
4954     return false;
4955
4956   return true;
4957 }
4958
4959 /* Simple wrapper, as we can always redirect fallthru edges.  */
4960
4961 static basic_block
4962 gimple_redirect_edge_and_branch_force (edge e, basic_block dest)
4963 {
4964   e = gimple_redirect_edge_and_branch (e, dest);
4965   gcc_assert (e);
4966
4967   return NULL;
4968 }
4969
4970
4971 /* Splits basic block BB after statement STMT (but at least after the
4972    labels).  If STMT is NULL, BB is split just after the labels.  */
4973
4974 static basic_block
4975 gimple_split_block (basic_block bb, void *stmt)
4976 {
4977   gimple_stmt_iterator gsi;
4978   gimple_stmt_iterator gsi_tgt;
4979   gimple act;
4980   gimple_seq list;
4981   basic_block new_bb;
4982   edge e;
4983   edge_iterator ei;
4984
4985   new_bb = create_empty_bb (bb);
4986
4987   /* Redirect the outgoing edges.  */
4988   new_bb->succs = bb->succs;
4989   bb->succs = NULL;
4990   FOR_EACH_EDGE (e, ei, new_bb->succs)
4991     e->src = new_bb;
4992
4993   if (stmt && gimple_code ((gimple) stmt) == GIMPLE_LABEL)
4994     stmt = NULL;
4995
4996   /* Move everything from GSI to the new basic block.  */
4997   for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4998     {
4999       act = gsi_stmt (gsi);
5000       if (gimple_code (act) == GIMPLE_LABEL)
5001         continue;
5002
5003       if (!stmt)
5004         break;
5005
5006       if (stmt == act)
5007         {
5008           gsi_next (&gsi);
5009           break;
5010         }
5011     }
5012
5013   if (gsi_end_p (gsi))
5014     return new_bb;
5015
5016   /* Split the statement list - avoid re-creating new containers as this
5017      brings ugly quadratic memory consumption in the inliner.
5018      (We are still quadratic since we need to update stmt BB pointers,
5019      sadly.)  */
5020   list = gsi_split_seq_before (&gsi);
5021   set_bb_seq (new_bb, list);
5022   for (gsi_tgt = gsi_start (list);
5023        !gsi_end_p (gsi_tgt); gsi_next (&gsi_tgt))
5024     gimple_set_bb (gsi_stmt (gsi_tgt), new_bb);
5025
5026   return new_bb;
5027 }
5028
5029
5030 /* Moves basic block BB after block AFTER.  */
5031
5032 static bool
5033 gimple_move_block_after (basic_block bb, basic_block after)
5034 {
5035   if (bb->prev_bb == after)
5036     return true;
5037
5038   unlink_block (bb);
5039   link_block (bb, after);
5040
5041   return true;
5042 }
5043
5044
5045 /* Return true if basic_block can be duplicated.  */
5046
5047 static bool
5048 gimple_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED)
5049 {
5050   return true;
5051 }
5052
5053 /* Create a duplicate of the basic block BB.  NOTE: This does not
5054    preserve SSA form.  */
5055
5056 static basic_block
5057 gimple_duplicate_bb (basic_block bb)
5058 {
5059   basic_block new_bb;
5060   gimple_stmt_iterator gsi, gsi_tgt;
5061   gimple_seq phis = phi_nodes (bb);
5062   gimple phi, stmt, copy;
5063
5064   new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb);
5065
5066   /* Copy the PHI nodes.  We ignore PHI node arguments here because
5067      the incoming edges have not been setup yet.  */
5068   for (gsi = gsi_start (phis); !gsi_end_p (gsi); gsi_next (&gsi))
5069     {
5070       phi = gsi_stmt (gsi);
5071       copy = create_phi_node (gimple_phi_result (phi), new_bb);
5072       create_new_def_for (gimple_phi_result (copy), copy,
5073                           gimple_phi_result_ptr (copy));
5074     }
5075
5076   gsi_tgt = gsi_start_bb (new_bb);
5077   for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
5078     {
5079       def_operand_p def_p;
5080       ssa_op_iter op_iter;
5081       tree lhs;
5082
5083       stmt = gsi_stmt (gsi);
5084       if (gimple_code (stmt) == GIMPLE_LABEL)
5085         continue;
5086
5087       /* Create a new copy of STMT and duplicate STMT's virtual
5088          operands.  */
5089       copy = gimple_copy (stmt);
5090       gsi_insert_after (&gsi_tgt, copy, GSI_NEW_STMT);
5091
5092       maybe_duplicate_eh_stmt (copy, stmt);
5093       gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
5094
5095       /* When copying around a stmt writing into a local non-user
5096          aggregate, make sure it won't share stack slot with other
5097          vars.  */
5098       lhs = gimple_get_lhs (stmt);
5099       if (lhs && TREE_CODE (lhs) != SSA_NAME)
5100         {
5101           tree base = get_base_address (lhs);
5102           if (base
5103               && (TREE_CODE (base) == VAR_DECL
5104                   || TREE_CODE (base) == RESULT_DECL)
5105               && DECL_IGNORED_P (base)
5106               && !TREE_STATIC (base)
5107               && !DECL_EXTERNAL (base)
5108               && (TREE_CODE (base) != VAR_DECL
5109                   || !DECL_HAS_VALUE_EXPR_P (base)))
5110             DECL_NONSHAREABLE (base) = 1;
5111         }
5112
5113       /* Create new names for all the definitions created by COPY and
5114          add replacement mappings for each new name.  */
5115       FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
5116         create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p);
5117     }
5118
5119   return new_bb;
5120 }
5121
5122 /* Adds phi node arguments for edge E_COPY after basic block duplication.  */
5123
5124 static void
5125 add_phi_args_after_copy_edge (edge e_copy)
5126 {
5127   basic_block bb, bb_copy = e_copy->src, dest;
5128   edge e;
5129   edge_iterator ei;
5130   gimple phi, phi_copy;
5131   tree def;
5132   gimple_stmt_iterator psi, psi_copy;
5133
5134   if (gimple_seq_empty_p (phi_nodes (e_copy->dest)))
5135     return;
5136
5137   bb = bb_copy->flags & BB_DUPLICATED ? get_bb_original (bb_copy) : bb_copy;
5138
5139   if (e_copy->dest->flags & BB_DUPLICATED)
5140     dest = get_bb_original (e_copy->dest);
5141   else
5142     dest = e_copy->dest;
5143
5144   e = find_edge (bb, dest);
5145   if (!e)
5146     {
5147       /* During loop unrolling the target of the latch edge is copied.
5148          In this case we are not looking for edge to dest, but to
5149          duplicated block whose original was dest.  */
5150       FOR_EACH_EDGE (e, ei, bb->succs)
5151         {
5152           if ((e->dest->flags & BB_DUPLICATED)
5153               && get_bb_original (e->dest) == dest)
5154             break;
5155         }
5156
5157       gcc_assert (e != NULL);
5158     }
5159
5160   for (psi = gsi_start_phis (e->dest),
5161        psi_copy = gsi_start_phis (e_copy->dest);
5162        !gsi_end_p (psi);
5163        gsi_next (&psi), gsi_next (&psi_copy))
5164     {
5165       phi = gsi_stmt (psi);
5166       phi_copy = gsi_stmt (psi_copy);
5167       def = PHI_ARG_DEF_FROM_EDGE (phi, e);
5168       add_phi_arg (phi_copy, def, e_copy,
5169                    gimple_phi_arg_location_from_edge (phi, e));
5170     }
5171 }
5172
5173
5174 /* Basic block BB_COPY was created by code duplication.  Add phi node
5175    arguments for edges going out of BB_COPY.  The blocks that were
5176    duplicated have BB_DUPLICATED set.  */
5177
5178 void
5179 add_phi_args_after_copy_bb (basic_block bb_copy)
5180 {
5181   edge e_copy;
5182   edge_iterator ei;
5183
5184   FOR_EACH_EDGE (e_copy, ei, bb_copy->succs)
5185     {
5186       add_phi_args_after_copy_edge (e_copy);
5187     }
5188 }
5189
5190 /* Blocks in REGION_COPY array of length N_REGION were created by
5191    duplication of basic blocks.  Add phi node arguments for edges
5192    going from these blocks.  If E_COPY is not NULL, also add
5193    phi node arguments for its destination.*/
5194
5195 void
5196 add_phi_args_after_copy (basic_block *region_copy, unsigned n_region,
5197                          edge e_copy)
5198 {
5199   unsigned i;
5200
5201   for (i = 0; i < n_region; i++)
5202     region_copy[i]->flags |= BB_DUPLICATED;
5203
5204   for (i = 0; i < n_region; i++)
5205     add_phi_args_after_copy_bb (region_copy[i]);
5206   if (e_copy)
5207     add_phi_args_after_copy_edge (e_copy);
5208
5209   for (i = 0; i < n_region; i++)
5210     region_copy[i]->flags &= ~BB_DUPLICATED;
5211 }
5212
5213 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
5214    important exit edge EXIT.  By important we mean that no SSA name defined
5215    inside region is live over the other exit edges of the region.  All entry
5216    edges to the region must go to ENTRY->dest.  The edge ENTRY is redirected
5217    to the duplicate of the region.  SSA form, dominance and loop information
5218    is updated.  The new basic blocks are stored to REGION_COPY in the same
5219    order as they had in REGION, provided that REGION_COPY is not NULL.
5220    The function returns false if it is unable to copy the region,
5221    true otherwise.  */
5222
5223 bool
5224 gimple_duplicate_sese_region (edge entry, edge exit,
5225                             basic_block *region, unsigned n_region,
5226                             basic_block *region_copy)
5227 {
5228   unsigned i;
5229   bool free_region_copy = false, copying_header = false;
5230   struct loop *loop = entry->dest->loop_father;
5231   edge exit_copy;
5232   VEC (basic_block, heap) *doms;
5233   edge redirected;
5234   int total_freq = 0, entry_freq = 0;
5235   gcov_type total_count = 0, entry_count = 0;
5236
5237   if (!can_copy_bbs_p (region, n_region))
5238     return false;
5239
5240   /* Some sanity checking.  Note that we do not check for all possible
5241      missuses of the functions.  I.e. if you ask to copy something weird,
5242      it will work, but the state of structures probably will not be
5243      correct.  */
5244   for (i = 0; i < n_region; i++)
5245     {
5246       /* We do not handle subloops, i.e. all the blocks must belong to the
5247          same loop.  */
5248       if (region[i]->loop_father != loop)
5249         return false;
5250
5251       if (region[i] != entry->dest
5252           && region[i] == loop->header)
5253         return false;
5254     }
5255
5256   set_loop_copy (loop, loop);
5257
5258   /* In case the function is used for loop header copying (which is the primary
5259      use), ensure that EXIT and its copy will be new latch and entry edges.  */
5260   if (loop->header == entry->dest)
5261     {
5262       copying_header = true;
5263       set_loop_copy (loop, loop_outer (loop));
5264
5265       if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src))
5266         return false;
5267
5268       for (i = 0; i < n_region; i++)
5269         if (region[i] != exit->src
5270             && dominated_by_p (CDI_DOMINATORS, region[i], exit->src))
5271           return false;
5272     }
5273
5274   if (!region_copy)
5275     {
5276       region_copy = XNEWVEC (basic_block, n_region);
5277       free_region_copy = true;
5278     }
5279
5280   gcc_assert (!need_ssa_update_p (cfun));
5281
5282   /* Record blocks outside the region that are dominated by something
5283      inside.  */
5284   doms = NULL;
5285   initialize_original_copy_tables ();
5286
5287   doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5288
5289   if (entry->dest->count)
5290     {
5291       total_count = entry->dest->count;
5292       entry_count = entry->count;
5293       /* Fix up corner cases, to avoid division by zero or creation of negative
5294          frequencies.  */
5295       if (entry_count > total_count)
5296         entry_count = total_count;
5297     }
5298   else
5299     {
5300       total_freq = entry->dest->frequency;
5301       entry_freq = EDGE_FREQUENCY (entry);
5302       /* Fix up corner cases, to avoid division by zero or creation of negative
5303          frequencies.  */
5304       if (total_freq == 0)
5305         total_freq = 1;
5306       else if (entry_freq > total_freq)
5307         entry_freq = total_freq;
5308     }
5309
5310   copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
5311             split_edge_bb_loc (entry));
5312   if (total_count)
5313     {
5314       scale_bbs_frequencies_gcov_type (region, n_region,
5315                                        total_count - entry_count,
5316                                        total_count);
5317       scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count,
5318                                        total_count);
5319     }
5320   else
5321     {
5322       scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq,
5323                                  total_freq);
5324       scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq);
5325     }
5326
5327   if (copying_header)
5328     {
5329       loop->header = exit->dest;
5330       loop->latch = exit->src;
5331     }
5332
5333   /* Redirect the entry and add the phi node arguments.  */
5334   redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest));
5335   gcc_assert (redirected != NULL);
5336   flush_pending_stmts (entry);
5337
5338   /* Concerning updating of dominators:  We must recount dominators
5339      for entry block and its copy.  Anything that is outside of the
5340      region, but was dominated by something inside needs recounting as
5341      well.  */
5342   set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src);
5343   VEC_safe_push (basic_block, heap, doms, get_bb_original (entry->dest));
5344   iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5345   VEC_free (basic_block, heap, doms);
5346
5347   /* Add the other PHI node arguments.  */
5348   add_phi_args_after_copy (region_copy, n_region, NULL);
5349
5350   /* Update the SSA web.  */
5351   update_ssa (TODO_update_ssa);
5352
5353   if (free_region_copy)
5354     free (region_copy);
5355
5356   free_original_copy_tables ();
5357   return true;
5358 }
5359
5360 /* Duplicates REGION consisting of N_REGION blocks.  The new blocks
5361    are stored to REGION_COPY in the same order in that they appear
5362    in REGION, if REGION_COPY is not NULL.  ENTRY is the entry to
5363    the region, EXIT an exit from it.  The condition guarding EXIT
5364    is moved to ENTRY.  Returns true if duplication succeeds, false
5365    otherwise.
5366
5367    For example,
5368
5369    some_code;
5370    if (cond)
5371      A;
5372    else
5373      B;
5374
5375    is transformed to
5376
5377    if (cond)
5378      {
5379        some_code;
5380        A;
5381      }
5382    else
5383      {
5384        some_code;
5385        B;
5386      }
5387 */
5388
5389 bool
5390 gimple_duplicate_sese_tail (edge entry ATTRIBUTE_UNUSED, edge exit ATTRIBUTE_UNUSED,
5391                           basic_block *region ATTRIBUTE_UNUSED, unsigned n_region ATTRIBUTE_UNUSED,
5392                           basic_block *region_copy ATTRIBUTE_UNUSED)
5393 {
5394   unsigned i;
5395   bool free_region_copy = false;
5396   struct loop *loop = exit->dest->loop_father;
5397   struct loop *orig_loop = entry->dest->loop_father;
5398   basic_block switch_bb, entry_bb, nentry_bb;
5399   VEC (basic_block, heap) *doms;
5400   int total_freq = 0, exit_freq = 0;
5401   gcov_type total_count = 0, exit_count = 0;
5402   edge exits[2], nexits[2], e;
5403   gimple_stmt_iterator gsi;
5404   gimple cond_stmt;
5405   edge sorig, snew;
5406   basic_block exit_bb;
5407   gimple_stmt_iterator psi;
5408   gimple phi;
5409   tree def;
5410
5411   gcc_assert (EDGE_COUNT (exit->src->succs) == 2);
5412   exits[0] = exit;
5413   exits[1] = EDGE_SUCC (exit->src, EDGE_SUCC (exit->src, 0) == exit);
5414
5415   if (!can_copy_bbs_p (region, n_region))
5416     return false;
5417
5418   initialize_original_copy_tables ();
5419   set_loop_copy (orig_loop, loop);
5420   duplicate_subloops (orig_loop, loop);
5421
5422   if (!region_copy)
5423     {
5424       region_copy = XNEWVEC (basic_block, n_region);
5425       free_region_copy = true;
5426     }
5427
5428   gcc_assert (!need_ssa_update_p (cfun));
5429
5430   /* Record blocks outside the region that are dominated by something
5431      inside.  */
5432   doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5433
5434   if (exit->src->count)
5435     {
5436       total_count = exit->src->count;
5437       exit_count = exit->count;
5438       /* Fix up corner cases, to avoid division by zero or creation of negative
5439          frequencies.  */
5440       if (exit_count > total_count)
5441         exit_count = total_count;
5442     }
5443   else
5444     {
5445       total_freq = exit->src->frequency;
5446       exit_freq = EDGE_FREQUENCY (exit);
5447       /* Fix up corner cases, to avoid division by zero or creation of negative
5448          frequencies.  */
5449       if (total_freq == 0)
5450         total_freq = 1;
5451       if (exit_freq > total_freq)
5452         exit_freq = total_freq;
5453     }
5454
5455   copy_bbs (region, n_region, region_copy, exits, 2, nexits, orig_loop,
5456             split_edge_bb_loc (exit));
5457   if (total_count)
5458     {
5459       scale_bbs_frequencies_gcov_type (region, n_region,
5460                                        total_count - exit_count,
5461                                        total_count);
5462       scale_bbs_frequencies_gcov_type (region_copy, n_region, exit_count,
5463                                        total_count);
5464     }
5465   else
5466     {
5467       scale_bbs_frequencies_int (region, n_region, total_freq - exit_freq,
5468                                  total_freq);
5469       scale_bbs_frequencies_int (region_copy, n_region, exit_freq, total_freq);
5470     }
5471
5472   /* Create the switch block, and put the exit condition to it.  */
5473   entry_bb = entry->dest;
5474   nentry_bb = get_bb_copy (entry_bb);
5475   if (!last_stmt (entry->src)
5476       || !stmt_ends_bb_p (last_stmt (entry->src)))
5477     switch_bb = entry->src;
5478   else
5479     switch_bb = split_edge (entry);
5480   set_immediate_dominator (CDI_DOMINATORS, nentry_bb, switch_bb);
5481
5482   gsi = gsi_last_bb (switch_bb);
5483   cond_stmt = last_stmt (exit->src);
5484   gcc_assert (gimple_code (cond_stmt) == GIMPLE_COND);
5485   cond_stmt = gimple_copy (cond_stmt);
5486
5487   gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT);
5488
5489   sorig = single_succ_edge (switch_bb);
5490   sorig->flags = exits[1]->flags;
5491   snew = make_edge (switch_bb, nentry_bb, exits[0]->flags);
5492
5493   /* Register the new edge from SWITCH_BB in loop exit lists.  */
5494   rescan_loop_exit (snew, true, false);
5495
5496   /* Add the PHI node arguments.  */
5497   add_phi_args_after_copy (region_copy, n_region, snew);
5498
5499   /* Get rid of now superfluous conditions and associated edges (and phi node
5500      arguments).  */
5501   exit_bb = exit->dest;
5502
5503   e = redirect_edge_and_branch (exits[0], exits[1]->dest);
5504   PENDING_STMT (e) = NULL;
5505
5506   /* The latch of ORIG_LOOP was copied, and so was the backedge
5507      to the original header.  We redirect this backedge to EXIT_BB.  */
5508   for (i = 0; i < n_region; i++)
5509     if (get_bb_original (region_copy[i]) == orig_loop->latch)
5510       {
5511         gcc_assert (single_succ_edge (region_copy[i]));
5512         e = redirect_edge_and_branch (single_succ_edge (region_copy[i]), exit_bb);
5513         PENDING_STMT (e) = NULL;
5514         for (psi = gsi_start_phis (exit_bb);
5515              !gsi_end_p (psi);
5516              gsi_next (&psi))
5517           {
5518             phi = gsi_stmt (psi);
5519             def = PHI_ARG_DEF (phi, nexits[0]->dest_idx);
5520             add_phi_arg (phi, def, e, gimple_phi_arg_location_from_edge (phi, e));
5521           }
5522       }
5523   e = redirect_edge_and_branch (nexits[0], nexits[1]->dest);
5524   PENDING_STMT (e) = NULL;
5525
5526   /* Anything that is outside of the region, but was dominated by something
5527      inside needs to update dominance info.  */
5528   iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5529   VEC_free (basic_block, heap, doms);
5530   /* Update the SSA web.  */
5531   update_ssa (TODO_update_ssa);
5532
5533   if (free_region_copy)
5534     free (region_copy);
5535
5536   free_original_copy_tables ();
5537   return true;
5538 }
5539
5540 /* Add all the blocks dominated by ENTRY to the array BBS_P.  Stop
5541    adding blocks when the dominator traversal reaches EXIT.  This
5542    function silently assumes that ENTRY strictly dominates EXIT.  */
5543
5544 void
5545 gather_blocks_in_sese_region (basic_block entry, basic_block exit,
5546                               VEC(basic_block,heap) **bbs_p)
5547 {
5548   basic_block son;
5549
5550   for (son = first_dom_son (CDI_DOMINATORS, entry);
5551        son;
5552        son = next_dom_son (CDI_DOMINATORS, son))
5553     {
5554       VEC_safe_push (basic_block, heap, *bbs_p, son);
5555       if (son != exit)
5556         gather_blocks_in_sese_region (son, exit, bbs_p);
5557     }
5558 }
5559
5560 /* Replaces *TP with a duplicate (belonging to function TO_CONTEXT).
5561    The duplicates are recorded in VARS_MAP.  */
5562
5563 static void
5564 replace_by_duplicate_decl (tree *tp, struct pointer_map_t *vars_map,
5565                            tree to_context)
5566 {
5567   tree t = *tp, new_t;
5568   struct function *f = DECL_STRUCT_FUNCTION (to_context);
5569   void **loc;
5570
5571   if (DECL_CONTEXT (t) == to_context)
5572     return;
5573
5574   loc = pointer_map_contains (vars_map, t);
5575
5576   if (!loc)
5577     {
5578       loc = pointer_map_insert (vars_map, t);
5579
5580       if (SSA_VAR_P (t))
5581         {
5582           new_t = copy_var_decl (t, DECL_NAME (t), TREE_TYPE (t));
5583           add_local_decl (f, new_t);
5584         }
5585       else
5586         {
5587           gcc_assert (TREE_CODE (t) == CONST_DECL);
5588           new_t = copy_node (t);
5589         }
5590       DECL_CONTEXT (new_t) = to_context;
5591
5592       *loc = new_t;
5593     }
5594   else
5595     new_t = (tree) *loc;
5596
5597   *tp = new_t;
5598 }
5599
5600
5601 /* Creates an ssa name in TO_CONTEXT equivalent to NAME.
5602    VARS_MAP maps old ssa names and var_decls to the new ones.  */
5603
5604 static tree
5605 replace_ssa_name (tree name, struct pointer_map_t *vars_map,
5606                   tree to_context)
5607 {
5608   void **loc;
5609   tree new_name, decl = SSA_NAME_VAR (name);
5610
5611   gcc_assert (is_gimple_reg (name));
5612
5613   loc = pointer_map_contains (vars_map, name);
5614
5615   if (!loc)
5616     {
5617       replace_by_duplicate_decl (&decl, vars_map, to_context);
5618
5619       push_cfun (DECL_STRUCT_FUNCTION (to_context));
5620       if (gimple_in_ssa_p (cfun))
5621         add_referenced_var (decl);
5622
5623       new_name = make_ssa_name (decl, SSA_NAME_DEF_STMT (name));
5624       if (SSA_NAME_IS_DEFAULT_DEF (name))
5625         set_default_def (decl, new_name);
5626       pop_cfun ();
5627
5628       loc = pointer_map_insert (vars_map, name);
5629       *loc = new_name;
5630     }
5631   else
5632     new_name = (tree) *loc;
5633
5634   return new_name;
5635 }
5636
5637 struct move_stmt_d
5638 {
5639   tree orig_block;
5640   tree new_block;
5641   tree from_context;
5642   tree to_context;
5643   struct pointer_map_t *vars_map;
5644   htab_t new_label_map;
5645   struct pointer_map_t *eh_map;
5646   bool remap_decls_p;
5647 };
5648
5649 /* Helper for move_block_to_fn.  Set TREE_BLOCK in every expression
5650    contained in *TP if it has been ORIG_BLOCK previously and change the
5651    DECL_CONTEXT of every local variable referenced in *TP.  */
5652
5653 static tree
5654 move_stmt_op (tree *tp, int *walk_subtrees, void *data)
5655 {
5656   struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
5657   struct move_stmt_d *p = (struct move_stmt_d *) wi->info;
5658   tree t = *tp;
5659
5660   if (EXPR_P (t))
5661     /* We should never have TREE_BLOCK set on non-statements.  */
5662     gcc_assert (!TREE_BLOCK (t));
5663
5664   else if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
5665     {
5666       if (TREE_CODE (t) == SSA_NAME)
5667         *tp = replace_ssa_name (t, p->vars_map, p->to_context);
5668       else if (TREE_CODE (t) == LABEL_DECL)
5669         {
5670           if (p->new_label_map)
5671             {
5672               struct tree_map in, *out;
5673               in.base.from = t;
5674               out = (struct tree_map *)
5675                 htab_find_with_hash (p->new_label_map, &in, DECL_UID (t));
5676               if (out)
5677                 *tp = t = out->to;
5678             }
5679
5680           DECL_CONTEXT (t) = p->to_context;
5681         }
5682       else if (p->remap_decls_p)
5683         {
5684           /* Replace T with its duplicate.  T should no longer appear in the
5685              parent function, so this looks wasteful; however, it may appear
5686              in referenced_vars, and more importantly, as virtual operands of
5687              statements, and in alias lists of other variables.  It would be
5688              quite difficult to expunge it from all those places.  ??? It might
5689              suffice to do this for addressable variables.  */
5690           if ((TREE_CODE (t) == VAR_DECL
5691                && !is_global_var (t))
5692               || TREE_CODE (t) == CONST_DECL)
5693             replace_by_duplicate_decl (tp, p->vars_map, p->to_context);
5694
5695           if (SSA_VAR_P (t)
5696               && gimple_in_ssa_p (cfun))
5697             {
5698               push_cfun (DECL_STRUCT_FUNCTION (p->to_context));
5699               add_referenced_var (*tp);
5700               pop_cfun ();
5701             }
5702         }
5703       *walk_subtrees = 0;
5704     }
5705   else if (TYPE_P (t))
5706     *walk_subtrees = 0;
5707
5708   return NULL_TREE;
5709 }
5710
5711 /* Helper for move_stmt_r.  Given an EH region number for the source
5712    function, map that to the duplicate EH regio number in the dest.  */
5713
5714 static int
5715 move_stmt_eh_region_nr (int old_nr, struct move_stmt_d *p)
5716 {
5717   eh_region old_r, new_r;
5718   void **slot;
5719
5720   old_r = get_eh_region_from_number (old_nr);
5721   slot = pointer_map_contains (p->eh_map, old_r);
5722   new_r = (eh_region) *slot;
5723
5724   return new_r->index;
5725 }
5726
5727 /* Similar, but operate on INTEGER_CSTs.  */
5728
5729 static tree
5730 move_stmt_eh_region_tree_nr (tree old_t_nr, struct move_stmt_d *p)
5731 {
5732   int old_nr, new_nr;
5733
5734   old_nr = tree_low_cst (old_t_nr, 0);
5735   new_nr = move_stmt_eh_region_nr (old_nr, p);
5736
5737   return build_int_cst (integer_type_node, new_nr);
5738 }
5739
5740 /* Like move_stmt_op, but for gimple statements.
5741
5742    Helper for move_block_to_fn.  Set GIMPLE_BLOCK in every expression
5743    contained in the current statement in *GSI_P and change the
5744    DECL_CONTEXT of every local variable referenced in the current
5745    statement.  */
5746
5747 static tree
5748 move_stmt_r (gimple_stmt_iterator *gsi_p, bool *handled_ops_p,
5749              struct walk_stmt_info *wi)
5750 {
5751   struct move_stmt_d *p = (struct move_stmt_d *) wi->info;
5752   gimple stmt = gsi_stmt (*gsi_p);
5753   tree block = gimple_block (stmt);
5754
5755   if (p->orig_block == NULL_TREE
5756       || block == p->orig_block
5757       || block == NULL_TREE)
5758     gimple_set_block (stmt, p->new_block);
5759 #ifdef ENABLE_CHECKING
5760   else if (block != p->new_block)
5761     {
5762       while (block && block != p->orig_block)
5763         block = BLOCK_SUPERCONTEXT (block);
5764       gcc_assert (block);
5765     }
5766 #endif
5767
5768   switch (gimple_code (stmt))
5769     {
5770     case GIMPLE_CALL:
5771       /* Remap the region numbers for __builtin_eh_{pointer,filter}.  */
5772       {
5773         tree r, fndecl = gimple_call_fndecl (stmt);
5774         if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
5775           switch (DECL_FUNCTION_CODE (fndecl))
5776             {
5777             case BUILT_IN_EH_COPY_VALUES:
5778               r = gimple_call_arg (stmt, 1);
5779               r = move_stmt_eh_region_tree_nr (r, p);
5780               gimple_call_set_arg (stmt, 1, r);
5781               /* FALLTHRU */
5782
5783             case BUILT_IN_EH_POINTER:
5784             case BUILT_IN_EH_FILTER:
5785               r = gimple_call_arg (stmt, 0);
5786               r = move_stmt_eh_region_tree_nr (r, p);
5787               gimple_call_set_arg (stmt, 0, r);
5788               break;
5789
5790             default:
5791               break;
5792             }
5793       }
5794       break;
5795
5796     case GIMPLE_RESX:
5797       {
5798         int r = gimple_resx_region (stmt);
5799         r = move_stmt_eh_region_nr (r, p);
5800         gimple_resx_set_region (stmt, r);
5801       }
5802       break;
5803
5804     case GIMPLE_EH_DISPATCH:
5805       {
5806         int r = gimple_eh_dispatch_region (stmt);
5807         r = move_stmt_eh_region_nr (r, p);
5808         gimple_eh_dispatch_set_region (stmt, r);
5809       }
5810       break;
5811
5812     case GIMPLE_OMP_RETURN:
5813     case GIMPLE_OMP_CONTINUE:
5814       break;
5815     default:
5816       if (is_gimple_omp (stmt))
5817         {
5818           /* Do not remap variables inside OMP directives.  Variables
5819              referenced in clauses and directive header belong to the
5820              parent function and should not be moved into the child
5821              function.  */
5822           bool save_remap_decls_p = p->remap_decls_p;
5823           p->remap_decls_p = false;
5824           *handled_ops_p = true;
5825
5826           walk_gimple_seq (gimple_omp_body (stmt), move_stmt_r,
5827                            move_stmt_op, wi);
5828
5829           p->remap_decls_p = save_remap_decls_p;
5830         }
5831       break;
5832     }
5833
5834   return NULL_TREE;
5835 }
5836
5837 /* Move basic block BB from function CFUN to function DEST_FN.  The
5838    block is moved out of the original linked list and placed after
5839    block AFTER in the new list.  Also, the block is removed from the
5840    original array of blocks and placed in DEST_FN's array of blocks.
5841    If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5842    updated to reflect the moved edges.
5843
5844    The local variables are remapped to new instances, VARS_MAP is used
5845    to record the mapping.  */
5846
5847 static void
5848 move_block_to_fn (struct function *dest_cfun, basic_block bb,
5849                   basic_block after, bool update_edge_count_p,
5850                   struct move_stmt_d *d)
5851 {
5852   struct control_flow_graph *cfg;
5853   edge_iterator ei;
5854   edge e;
5855   gimple_stmt_iterator si;
5856   unsigned old_len, new_len;
5857
5858   /* Remove BB from dominance structures.  */
5859   delete_from_dominance_info (CDI_DOMINATORS, bb);
5860   if (current_loops)
5861     remove_bb_from_loops (bb);
5862
5863   /* Link BB to the new linked list.  */
5864   move_block_after (bb, after);
5865
5866   /* Update the edge count in the corresponding flowgraphs.  */
5867   if (update_edge_count_p)
5868     FOR_EACH_EDGE (e, ei, bb->succs)
5869       {
5870         cfun->cfg->x_n_edges--;
5871         dest_cfun->cfg->x_n_edges++;
5872       }
5873
5874   /* Remove BB from the original basic block array.  */
5875   VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL);
5876   cfun->cfg->x_n_basic_blocks--;
5877
5878   /* Grow DEST_CFUN's basic block array if needed.  */
5879   cfg = dest_cfun->cfg;
5880   cfg->x_n_basic_blocks++;
5881   if (bb->index >= cfg->x_last_basic_block)
5882     cfg->x_last_basic_block = bb->index + 1;
5883
5884   old_len = VEC_length (basic_block, cfg->x_basic_block_info);
5885   if ((unsigned) cfg->x_last_basic_block >= old_len)
5886     {
5887       new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4;
5888       VEC_safe_grow_cleared (basic_block, gc, cfg->x_basic_block_info,
5889                              new_len);
5890     }
5891
5892   VEC_replace (basic_block, cfg->x_basic_block_info,
5893                bb->index, bb);
5894
5895   /* Remap the variables in phi nodes.  */
5896   for (si = gsi_start_phis (bb); !gsi_end_p (si); )
5897     {
5898       gimple phi = gsi_stmt (si);
5899       use_operand_p use;
5900       tree op = PHI_RESULT (phi);
5901       ssa_op_iter oi;
5902
5903       if (!is_gimple_reg (op))
5904         {
5905           /* Remove the phi nodes for virtual operands (alias analysis will be
5906              run for the new function, anyway).  */
5907           remove_phi_node (&si, true);
5908           continue;
5909         }
5910
5911       SET_PHI_RESULT (phi,
5912                       replace_ssa_name (op, d->vars_map, dest_cfun->decl));
5913       FOR_EACH_PHI_ARG (use, phi, oi, SSA_OP_USE)
5914         {
5915           op = USE_FROM_PTR (use);
5916           if (TREE_CODE (op) == SSA_NAME)
5917             SET_USE (use, replace_ssa_name (op, d->vars_map, dest_cfun->decl));
5918         }
5919
5920       gsi_next (&si);
5921     }
5922
5923   for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
5924     {
5925       gimple stmt = gsi_stmt (si);
5926       struct walk_stmt_info wi;
5927
5928       memset (&wi, 0, sizeof (wi));
5929       wi.info = d;
5930       walk_gimple_stmt (&si, move_stmt_r, move_stmt_op, &wi);
5931
5932       if (gimple_code (stmt) == GIMPLE_LABEL)
5933         {
5934           tree label = gimple_label_label (stmt);
5935           int uid = LABEL_DECL_UID (label);
5936
5937           gcc_assert (uid > -1);
5938
5939           old_len = VEC_length (basic_block, cfg->x_label_to_block_map);
5940           if (old_len <= (unsigned) uid)
5941             {
5942               new_len = 3 * uid / 2 + 1;
5943               VEC_safe_grow_cleared (basic_block, gc,
5944                                      cfg->x_label_to_block_map, new_len);
5945             }
5946
5947           VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb);
5948           VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL);
5949
5950           gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl);
5951
5952           if (uid >= dest_cfun->cfg->last_label_uid)
5953             dest_cfun->cfg->last_label_uid = uid + 1;
5954         }
5955
5956       maybe_duplicate_eh_stmt_fn (dest_cfun, stmt, cfun, stmt, d->eh_map, 0);
5957       remove_stmt_from_eh_lp_fn (cfun, stmt);
5958
5959       gimple_duplicate_stmt_histograms (dest_cfun, stmt, cfun, stmt);
5960       gimple_remove_stmt_histograms (cfun, stmt);
5961
5962       /* We cannot leave any operands allocated from the operand caches of
5963          the current function.  */
5964       free_stmt_operands (stmt);
5965       push_cfun (dest_cfun);
5966       update_stmt (stmt);
5967       pop_cfun ();
5968     }
5969
5970   FOR_EACH_EDGE (e, ei, bb->succs)
5971     if (e->goto_locus)
5972       {
5973         tree block = e->goto_block;
5974         if (d->orig_block == NULL_TREE
5975             || block == d->orig_block)
5976           e->goto_block = d->new_block;
5977 #ifdef ENABLE_CHECKING
5978         else if (block != d->new_block)
5979           {
5980             while (block && block != d->orig_block)
5981               block = BLOCK_SUPERCONTEXT (block);
5982             gcc_assert (block);
5983           }
5984 #endif
5985       }
5986 }
5987
5988 /* Examine the statements in BB (which is in SRC_CFUN); find and return
5989    the outermost EH region.  Use REGION as the incoming base EH region.  */
5990
5991 static eh_region
5992 find_outermost_region_in_block (struct function *src_cfun,
5993                                 basic_block bb, eh_region region)
5994 {
5995   gimple_stmt_iterator si;
5996
5997   for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
5998     {
5999       gimple stmt = gsi_stmt (si);
6000       eh_region stmt_region;
6001       int lp_nr;
6002
6003       lp_nr = lookup_stmt_eh_lp_fn (src_cfun, stmt);
6004       stmt_region = get_eh_region_from_lp_number_fn (src_cfun, lp_nr);
6005       if (stmt_region)
6006         {
6007           if (region == NULL)
6008             region = stmt_region;
6009           else if (stmt_region != region)
6010             {
6011               region = eh_region_outermost (src_cfun, stmt_region, region);
6012               gcc_assert (region != NULL);
6013             }
6014         }
6015     }
6016
6017   return region;
6018 }
6019
6020 static tree
6021 new_label_mapper (tree decl, void *data)
6022 {
6023   htab_t hash = (htab_t) data;
6024   struct tree_map *m;
6025   void **slot;
6026
6027   gcc_assert (TREE_CODE (decl) == LABEL_DECL);
6028
6029   m = XNEW (struct tree_map);
6030   m->hash = DECL_UID (decl);
6031   m->base.from = decl;
6032   m->to = create_artificial_label (UNKNOWN_LOCATION);
6033   LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl);
6034   if (LABEL_DECL_UID (m->to) >= cfun->cfg->last_label_uid)
6035     cfun->cfg->last_label_uid = LABEL_DECL_UID (m->to) + 1;
6036
6037   slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT);
6038   gcc_assert (*slot == NULL);
6039
6040   *slot = m;
6041
6042   return m->to;
6043 }
6044
6045 /* Change DECL_CONTEXT of all BLOCK_VARS in block, including
6046    subblocks.  */
6047
6048 static void
6049 replace_block_vars_by_duplicates (tree block, struct pointer_map_t *vars_map,
6050                                   tree to_context)
6051 {
6052   tree *tp, t;
6053
6054   for (tp = &BLOCK_VARS (block); *tp; tp = &DECL_CHAIN (*tp))
6055     {
6056       t = *tp;
6057       if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != CONST_DECL)
6058         continue;
6059       replace_by_duplicate_decl (&t, vars_map, to_context);
6060       if (t != *tp)
6061         {
6062           if (TREE_CODE (*tp) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (*tp))
6063             {
6064               SET_DECL_VALUE_EXPR (t, DECL_VALUE_EXPR (*tp));
6065               DECL_HAS_VALUE_EXPR_P (t) = 1;
6066             }
6067           DECL_CHAIN (t) = DECL_CHAIN (*tp);
6068           *tp = t;
6069         }
6070     }
6071
6072   for (block = BLOCK_SUBBLOCKS (block); block; block = BLOCK_CHAIN (block))
6073     replace_block_vars_by_duplicates (block, vars_map, to_context);
6074 }
6075
6076 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
6077    EXIT_BB to function DEST_CFUN.  The whole region is replaced by a
6078    single basic block in the original CFG and the new basic block is
6079    returned.  DEST_CFUN must not have a CFG yet.
6080
6081    Note that the region need not be a pure SESE region.  Blocks inside
6082    the region may contain calls to abort/exit.  The only restriction
6083    is that ENTRY_BB should be the only entry point and it must
6084    dominate EXIT_BB.
6085
6086    Change TREE_BLOCK of all statements in ORIG_BLOCK to the new
6087    functions outermost BLOCK, move all subblocks of ORIG_BLOCK
6088    to the new function.
6089
6090    All local variables referenced in the region are assumed to be in
6091    the corresponding BLOCK_VARS and unexpanded variable lists
6092    associated with DEST_CFUN.  */
6093
6094 basic_block
6095 move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
6096                         basic_block exit_bb, tree orig_block)
6097 {
6098   VEC(basic_block,heap) *bbs, *dom_bbs;
6099   basic_block dom_entry = get_immediate_dominator (CDI_DOMINATORS, entry_bb);
6100   basic_block after, bb, *entry_pred, *exit_succ, abb;
6101   struct function *saved_cfun = cfun;
6102   int *entry_flag, *exit_flag;
6103   unsigned *entry_prob, *exit_prob;
6104   unsigned i, num_entry_edges, num_exit_edges;
6105   edge e;
6106   edge_iterator ei;
6107   htab_t new_label_map;
6108   struct pointer_map_t *vars_map, *eh_map;
6109   struct loop *loop = entry_bb->loop_father;
6110   struct move_stmt_d d;
6111
6112   /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
6113      region.  */
6114   gcc_assert (entry_bb != exit_bb
6115               && (!exit_bb
6116                   || dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)));
6117
6118   /* Collect all the blocks in the region.  Manually add ENTRY_BB
6119      because it won't be added by dfs_enumerate_from.  */
6120   bbs = NULL;
6121   VEC_safe_push (basic_block, heap, bbs, entry_bb);
6122   gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs);
6123
6124   /* The blocks that used to be dominated by something in BBS will now be
6125      dominated by the new block.  */
6126   dom_bbs = get_dominated_by_region (CDI_DOMINATORS,
6127                                      VEC_address (basic_block, bbs),
6128                                      VEC_length (basic_block, bbs));
6129
6130   /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG.  We need to remember
6131      the predecessor edges to ENTRY_BB and the successor edges to
6132      EXIT_BB so that we can re-attach them to the new basic block that
6133      will replace the region.  */
6134   num_entry_edges = EDGE_COUNT (entry_bb->preds);
6135   entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
6136   entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
6137   entry_prob = XNEWVEC (unsigned, num_entry_edges);
6138   i = 0;
6139   for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
6140     {
6141       entry_prob[i] = e->probability;
6142       entry_flag[i] = e->flags;
6143       entry_pred[i++] = e->src;
6144       remove_edge (e);
6145     }
6146
6147   if (exit_bb)
6148     {
6149       num_exit_edges = EDGE_COUNT (exit_bb->succs);
6150       exit_succ = (basic_block *) xcalloc (num_exit_edges,
6151                                            sizeof (basic_block));
6152       exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
6153       exit_prob = XNEWVEC (unsigned, num_exit_edges);
6154       i = 0;
6155       for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)
6156         {
6157           exit_prob[i] = e->probability;
6158           exit_flag[i] = e->flags;
6159           exit_succ[i++] = e->dest;
6160           remove_edge (e);
6161         }
6162     }
6163   else
6164     {
6165       num_exit_edges = 0;
6166       exit_succ = NULL;
6167       exit_flag = NULL;
6168       exit_prob = NULL;
6169     }
6170
6171   /* Switch context to the child function to initialize DEST_FN's CFG.  */
6172   gcc_assert (dest_cfun->cfg == NULL);
6173   push_cfun (dest_cfun);
6174
6175   init_empty_tree_cfg ();
6176
6177   /* Initialize EH information for the new function.  */
6178   eh_map = NULL;
6179   new_label_map = NULL;
6180   if (saved_cfun->eh)
6181     {
6182       eh_region region = NULL;
6183
6184       FOR_EACH_VEC_ELT (basic_block, bbs, i, bb)
6185         region = find_outermost_region_in_block (saved_cfun, bb, region);
6186
6187       init_eh_for_function ();
6188       if (region != NULL)
6189         {
6190           new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free);
6191           eh_map = duplicate_eh_regions (saved_cfun, region, 0,
6192                                          new_label_mapper, new_label_map);
6193         }
6194     }
6195
6196   pop_cfun ();
6197
6198   /* Move blocks from BBS into DEST_CFUN.  */
6199   gcc_assert (VEC_length (basic_block, bbs) >= 2);
6200   after = dest_cfun->cfg->x_entry_block_ptr;
6201   vars_map = pointer_map_create ();
6202
6203   memset (&d, 0, sizeof (d));
6204   d.orig_block = orig_block;
6205   d.new_block = DECL_INITIAL (dest_cfun->decl);
6206   d.from_context = cfun->decl;
6207   d.to_context = dest_cfun->decl;
6208   d.vars_map = vars_map;
6209   d.new_label_map = new_label_map;
6210   d.eh_map = eh_map;
6211   d.remap_decls_p = true;
6212
6213   FOR_EACH_VEC_ELT (basic_block, bbs, i, bb)
6214     {
6215       /* No need to update edge counts on the last block.  It has
6216          already been updated earlier when we detached the region from
6217          the original CFG.  */
6218       move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, &d);
6219       after = bb;
6220     }
6221
6222   /* Rewire BLOCK_SUBBLOCKS of orig_block.  */
6223   if (orig_block)
6224     {
6225       tree block;
6226       gcc_assert (BLOCK_SUBBLOCKS (DECL_INITIAL (dest_cfun->decl))
6227                   == NULL_TREE);
6228       BLOCK_SUBBLOCKS (DECL_INITIAL (dest_cfun->decl))
6229         = BLOCK_SUBBLOCKS (orig_block);
6230       for (block = BLOCK_SUBBLOCKS (orig_block);
6231            block; block = BLOCK_CHAIN (block))
6232         BLOCK_SUPERCONTEXT (block) = DECL_INITIAL (dest_cfun->decl);
6233       BLOCK_SUBBLOCKS (orig_block) = NULL_TREE;
6234     }
6235
6236   replace_block_vars_by_duplicates (DECL_INITIAL (dest_cfun->decl),
6237                                     vars_map, dest_cfun->decl);
6238
6239   if (new_label_map)
6240     htab_delete (new_label_map);
6241   if (eh_map)
6242     pointer_map_destroy (eh_map);
6243   pointer_map_destroy (vars_map);
6244
6245   /* Rewire the entry and exit blocks.  The successor to the entry
6246      block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
6247      the child function.  Similarly, the predecessor of DEST_FN's
6248      EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR.  We
6249      need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
6250      various CFG manipulation function get to the right CFG.
6251
6252      FIXME, this is silly.  The CFG ought to become a parameter to
6253      these helpers.  */
6254   push_cfun (dest_cfun);
6255   make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU);
6256   if (exit_bb)
6257     make_edge (exit_bb,  EXIT_BLOCK_PTR, 0);
6258   pop_cfun ();
6259
6260   /* Back in the original function, the SESE region has disappeared,
6261      create a new basic block in its place.  */
6262   bb = create_empty_bb (entry_pred[0]);
6263   if (current_loops)
6264     add_bb_to_loop (bb, loop);
6265   for (i = 0; i < num_entry_edges; i++)
6266     {
6267       e = make_edge (entry_pred[i], bb, entry_flag[i]);
6268       e->probability = entry_prob[i];
6269     }
6270
6271   for (i = 0; i < num_exit_edges; i++)
6272     {
6273       e = make_edge (bb, exit_succ[i], exit_flag[i]);
6274       e->probability = exit_prob[i];
6275     }
6276
6277   set_immediate_dominator (CDI_DOMINATORS, bb, dom_entry);
6278   FOR_EACH_VEC_ELT (basic_block, dom_bbs, i, abb)
6279     set_immediate_dominator (CDI_DOMINATORS, abb, bb);
6280   VEC_free (basic_block, heap, dom_bbs);
6281
6282   if (exit_bb)
6283     {
6284       free (exit_prob);
6285       free (exit_flag);
6286       free (exit_succ);
6287     }
6288   free (entry_prob);
6289   free (entry_flag);
6290   free (entry_pred);
6291   VEC_free (basic_block, heap, bbs);
6292
6293   return bb;
6294 }
6295
6296
6297 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree-pass.h)
6298    */
6299
6300 void
6301 dump_function_to_file (tree fn, FILE *file, int flags)
6302 {
6303   tree arg, var;
6304   struct function *dsf;
6305   bool ignore_topmost_bind = false, any_var = false;
6306   basic_block bb;
6307   tree chain;
6308
6309   fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2));
6310
6311   arg = DECL_ARGUMENTS (fn);
6312   while (arg)
6313     {
6314       print_generic_expr (file, TREE_TYPE (arg), dump_flags);
6315       fprintf (file, " ");
6316       print_generic_expr (file, arg, dump_flags);
6317       if (flags & TDF_VERBOSE)
6318         print_node (file, "", arg, 4);
6319       if (DECL_CHAIN (arg))
6320         fprintf (file, ", ");
6321       arg = DECL_CHAIN (arg);
6322     }
6323   fprintf (file, ")\n");
6324
6325   if (flags & TDF_VERBOSE)
6326     print_node (file, "", fn, 2);
6327
6328   dsf = DECL_STRUCT_FUNCTION (fn);
6329   if (dsf && (flags & TDF_EH))
6330     dump_eh_tree (file, dsf);
6331
6332   if (flags & TDF_RAW && !gimple_has_body_p (fn))
6333     {
6334       dump_node (fn, TDF_SLIM | flags, file);
6335       return;
6336     }
6337
6338   /* Switch CFUN to point to FN.  */
6339   push_cfun (DECL_STRUCT_FUNCTION (fn));
6340
6341   /* When GIMPLE is lowered, the variables are no longer available in
6342      BIND_EXPRs, so display them separately.  */
6343   if (cfun && cfun->decl == fn && !VEC_empty (tree, cfun->local_decls))
6344     {
6345       unsigned ix;
6346       ignore_topmost_bind = true;
6347
6348       fprintf (file, "{\n");
6349       FOR_EACH_LOCAL_DECL (cfun, ix, var)
6350         {
6351           print_generic_decl (file, var, flags);
6352           if (flags & TDF_VERBOSE)
6353             print_node (file, "", var, 4);
6354           fprintf (file, "\n");
6355
6356           any_var = true;
6357         }
6358     }
6359
6360   if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info)
6361     {
6362       /* If the CFG has been built, emit a CFG-based dump.  */
6363       check_bb_profile (ENTRY_BLOCK_PTR, file);
6364       if (!ignore_topmost_bind)
6365         fprintf (file, "{\n");
6366
6367       if (any_var && n_basic_blocks)
6368         fprintf (file, "\n");
6369
6370       FOR_EACH_BB (bb)
6371         gimple_dump_bb (bb, file, 2, flags);
6372
6373       fprintf (file, "}\n");
6374       check_bb_profile (EXIT_BLOCK_PTR, file);
6375     }
6376   else if (DECL_SAVED_TREE (fn) == NULL)
6377     {
6378       /* The function is now in GIMPLE form but the CFG has not been
6379          built yet.  Emit the single sequence of GIMPLE statements
6380          that make up its body.  */
6381       gimple_seq body = gimple_body (fn);
6382
6383       if (gimple_seq_first_stmt (body)
6384           && gimple_seq_first_stmt (body) == gimple_seq_last_stmt (body)
6385           && gimple_code (gimple_seq_first_stmt (body)) == GIMPLE_BIND)
6386         print_gimple_seq (file, body, 0, flags);
6387       else
6388         {
6389           if (!ignore_topmost_bind)
6390             fprintf (file, "{\n");
6391
6392           if (any_var)
6393             fprintf (file, "\n");
6394
6395           print_gimple_seq (file, body, 2, flags);
6396           fprintf (file, "}\n");
6397         }
6398     }
6399   else
6400     {
6401       int indent;
6402
6403       /* Make a tree based dump.  */
6404       chain = DECL_SAVED_TREE (fn);
6405
6406       if (chain && TREE_CODE (chain) == BIND_EXPR)
6407         {
6408           if (ignore_topmost_bind)
6409             {
6410               chain = BIND_EXPR_BODY (chain);
6411               indent = 2;
6412             }
6413           else
6414             indent = 0;
6415         }
6416       else
6417         {
6418           if (!ignore_topmost_bind)
6419             fprintf (file, "{\n");
6420           indent = 2;
6421         }
6422
6423       if (any_var)
6424         fprintf (file, "\n");
6425
6426       print_generic_stmt_indented (file, chain, flags, indent);
6427       if (ignore_topmost_bind)
6428         fprintf (file, "}\n");
6429     }
6430
6431   if (flags & TDF_ENUMERATE_LOCALS)
6432     dump_enumerated_decls (file, flags);
6433   fprintf (file, "\n\n");
6434
6435   /* Restore CFUN.  */
6436   pop_cfun ();
6437 }
6438
6439
6440 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h)  */
6441
6442 DEBUG_FUNCTION void
6443 debug_function (tree fn, int flags)
6444 {
6445   dump_function_to_file (fn, stderr, flags);
6446 }
6447
6448
6449 /* Print on FILE the indexes for the predecessors of basic_block BB.  */
6450
6451 static void
6452 print_pred_bbs (FILE *file, basic_block bb)
6453 {
6454   edge e;
6455   edge_iterator ei;
6456
6457   FOR_EACH_EDGE (e, ei, bb->preds)
6458     fprintf (file, "bb_%d ", e->src->index);
6459 }
6460
6461
6462 /* Print on FILE the indexes for the successors of basic_block BB.  */
6463
6464 static void
6465 print_succ_bbs (FILE *file, basic_block bb)
6466 {
6467   edge e;
6468   edge_iterator ei;
6469
6470   FOR_EACH_EDGE (e, ei, bb->succs)
6471     fprintf (file, "bb_%d ", e->dest->index);
6472 }
6473
6474 /* Print to FILE the basic block BB following the VERBOSITY level.  */
6475
6476 void
6477 print_loops_bb (FILE *file, basic_block bb, int indent, int verbosity)
6478 {
6479   char *s_indent = (char *) alloca ((size_t) indent + 1);
6480   memset ((void *) s_indent, ' ', (size_t) indent);
6481   s_indent[indent] = '\0';
6482
6483   /* Print basic_block's header.  */
6484   if (verbosity >= 2)
6485     {
6486       fprintf (file, "%s  bb_%d (preds = {", s_indent, bb->index);
6487       print_pred_bbs (file, bb);
6488       fprintf (file, "}, succs = {");
6489       print_succ_bbs (file, bb);
6490       fprintf (file, "})\n");
6491     }
6492
6493   /* Print basic_block's body.  */
6494   if (verbosity >= 3)
6495     {
6496       fprintf (file, "%s  {\n", s_indent);
6497       gimple_dump_bb (bb, file, indent + 4, TDF_VOPS|TDF_MEMSYMS);
6498       fprintf (file, "%s  }\n", s_indent);
6499     }
6500 }
6501
6502 static void print_loop_and_siblings (FILE *, struct loop *, int, int);
6503
6504 /* Pretty print LOOP on FILE, indented INDENT spaces.  Following
6505    VERBOSITY level this outputs the contents of the loop, or just its
6506    structure.  */
6507
6508 static void
6509 print_loop (FILE *file, struct loop *loop, int indent, int verbosity)
6510 {
6511   char *s_indent;
6512   basic_block bb;
6513
6514   if (loop == NULL)
6515     return;
6516
6517   s_indent = (char *) alloca ((size_t) indent + 1);
6518   memset ((void *) s_indent, ' ', (size_t) indent);
6519   s_indent[indent] = '\0';
6520
6521   /* Print loop's header.  */
6522   fprintf (file, "%sloop_%d (header = %d, latch = %d", s_indent,
6523            loop->num, loop->header->index, loop->latch->index);
6524   fprintf (file, ", niter = ");
6525   print_generic_expr (file, loop->nb_iterations, 0);
6526
6527   if (loop->any_upper_bound)
6528     {
6529       fprintf (file, ", upper_bound = ");
6530       dump_double_int (file, loop->nb_iterations_upper_bound, true);
6531     }
6532
6533   if (loop->any_estimate)
6534     {
6535       fprintf (file, ", estimate = ");
6536       dump_double_int (file, loop->nb_iterations_estimate, true);
6537     }
6538   fprintf (file, ")\n");
6539
6540   /* Print loop's body.  */
6541   if (verbosity >= 1)
6542     {
6543       fprintf (file, "%s{\n", s_indent);
6544       FOR_EACH_BB (bb)
6545         if (bb->loop_father == loop)
6546           print_loops_bb (file, bb, indent, verbosity);
6547
6548       print_loop_and_siblings (file, loop->inner, indent + 2, verbosity);
6549       fprintf (file, "%s}\n", s_indent);
6550     }
6551 }
6552
6553 /* Print the LOOP and its sibling loops on FILE, indented INDENT
6554    spaces.  Following VERBOSITY level this outputs the contents of the
6555    loop, or just its structure.  */
6556
6557 static void
6558 print_loop_and_siblings (FILE *file, struct loop *loop, int indent, int verbosity)
6559 {
6560   if (loop == NULL)
6561     return;
6562
6563   print_loop (file, loop, indent, verbosity);
6564   print_loop_and_siblings (file, loop->next, indent, verbosity);
6565 }
6566
6567 /* Follow a CFG edge from the entry point of the program, and on entry
6568    of a loop, pretty print the loop structure on FILE.  */
6569
6570 void
6571 print_loops (FILE *file, int verbosity)
6572 {
6573   basic_block bb;
6574
6575   bb = ENTRY_BLOCK_PTR;
6576   if (bb && bb->loop_father)
6577     print_loop_and_siblings (file, bb->loop_father, 0, verbosity);
6578 }
6579
6580
6581 /* Debugging loops structure at tree level, at some VERBOSITY level.  */
6582
6583 DEBUG_FUNCTION void
6584 debug_loops (int verbosity)
6585 {
6586   print_loops (stderr, verbosity);
6587 }
6588
6589 /* Print on stderr the code of LOOP, at some VERBOSITY level.  */
6590
6591 DEBUG_FUNCTION void
6592 debug_loop (struct loop *loop, int verbosity)
6593 {
6594   print_loop (stderr, loop, 0, verbosity);
6595 }
6596
6597 /* Print on stderr the code of loop number NUM, at some VERBOSITY
6598    level.  */
6599
6600 DEBUG_FUNCTION void
6601 debug_loop_num (unsigned num, int verbosity)
6602 {
6603   debug_loop (get_loop (num), verbosity);
6604 }
6605
6606 /* Return true if BB ends with a call, possibly followed by some
6607    instructions that must stay with the call.  Return false,
6608    otherwise.  */
6609
6610 static bool
6611 gimple_block_ends_with_call_p (basic_block bb)
6612 {
6613   gimple_stmt_iterator gsi = gsi_last_nondebug_bb (bb);
6614   return !gsi_end_p (gsi) && is_gimple_call (gsi_stmt (gsi));
6615 }
6616
6617
6618 /* Return true if BB ends with a conditional branch.  Return false,
6619    otherwise.  */
6620
6621 static bool
6622 gimple_block_ends_with_condjump_p (const_basic_block bb)
6623 {
6624   gimple stmt = last_stmt (CONST_CAST_BB (bb));
6625   return (stmt && gimple_code (stmt) == GIMPLE_COND);
6626 }
6627
6628
6629 /* Return true if we need to add fake edge to exit at statement T.
6630    Helper function for gimple_flow_call_edges_add.  */
6631
6632 static bool
6633 need_fake_edge_p (gimple t)
6634 {
6635   tree fndecl = NULL_TREE;
6636   int call_flags = 0;
6637
6638   /* NORETURN and LONGJMP calls already have an edge to exit.
6639      CONST and PURE calls do not need one.
6640      We don't currently check for CONST and PURE here, although
6641      it would be a good idea, because those attributes are
6642      figured out from the RTL in mark_constant_function, and
6643      the counter incrementation code from -fprofile-arcs
6644      leads to different results from -fbranch-probabilities.  */
6645   if (is_gimple_call (t))
6646     {
6647       fndecl = gimple_call_fndecl (t);
6648       call_flags = gimple_call_flags (t);
6649     }
6650
6651   if (is_gimple_call (t)
6652       && fndecl
6653       && DECL_BUILT_IN (fndecl)
6654       && (call_flags & ECF_NOTHROW)
6655       && !(call_flags & ECF_RETURNS_TWICE)
6656       /* fork() doesn't really return twice, but the effect of
6657          wrapping it in __gcov_fork() which calls __gcov_flush()
6658          and clears the counters before forking has the same
6659          effect as returning twice.  Force a fake edge.  */
6660       && !(DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
6661            && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_FORK))
6662     return false;
6663
6664   if (is_gimple_call (t)
6665       && !(call_flags & ECF_NORETURN))
6666     return true;
6667
6668   if (gimple_code (t) == GIMPLE_ASM
6669        && (gimple_asm_volatile_p (t) || gimple_asm_input_p (t)))
6670     return true;
6671
6672   return false;
6673 }
6674
6675
6676 /* Add fake edges to the function exit for any non constant and non
6677    noreturn calls, volatile inline assembly in the bitmap of blocks
6678    specified by BLOCKS or to the whole CFG if BLOCKS is zero.  Return
6679    the number of blocks that were split.
6680
6681    The goal is to expose cases in which entering a basic block does
6682    not imply that all subsequent instructions must be executed.  */
6683
6684 static int
6685 gimple_flow_call_edges_add (sbitmap blocks)
6686 {
6687   int i;
6688   int blocks_split = 0;
6689   int last_bb = last_basic_block;
6690   bool check_last_block = false;
6691
6692   if (n_basic_blocks == NUM_FIXED_BLOCKS)
6693     return 0;
6694
6695   if (! blocks)
6696     check_last_block = true;
6697   else
6698     check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
6699
6700   /* In the last basic block, before epilogue generation, there will be
6701      a fallthru edge to EXIT.  Special care is required if the last insn
6702      of the last basic block is a call because make_edge folds duplicate
6703      edges, which would result in the fallthru edge also being marked
6704      fake, which would result in the fallthru edge being removed by
6705      remove_fake_edges, which would result in an invalid CFG.
6706
6707      Moreover, we can't elide the outgoing fake edge, since the block
6708      profiler needs to take this into account in order to solve the minimal
6709      spanning tree in the case that the call doesn't return.
6710
6711      Handle this by adding a dummy instruction in a new last basic block.  */
6712   if (check_last_block)
6713     {
6714       basic_block bb = EXIT_BLOCK_PTR->prev_bb;
6715       gimple_stmt_iterator gsi = gsi_last_nondebug_bb (bb);
6716       gimple t = NULL;
6717
6718       if (!gsi_end_p (gsi))
6719         t = gsi_stmt (gsi);
6720
6721       if (t && need_fake_edge_p (t))
6722         {
6723           edge e;
6724
6725           e = find_edge (bb, EXIT_BLOCK_PTR);
6726           if (e)
6727             {
6728               gsi_insert_on_edge (e, gimple_build_nop ());
6729               gsi_commit_edge_inserts ();
6730             }
6731         }
6732     }
6733
6734   /* Now add fake edges to the function exit for any non constant
6735      calls since there is no way that we can determine if they will
6736      return or not...  */
6737   for (i = 0; i < last_bb; i++)
6738     {
6739       basic_block bb = BASIC_BLOCK (i);
6740       gimple_stmt_iterator gsi;
6741       gimple stmt, last_stmt;
6742
6743       if (!bb)
6744         continue;
6745
6746       if (blocks && !TEST_BIT (blocks, i))
6747         continue;
6748
6749       gsi = gsi_last_nondebug_bb (bb);
6750       if (!gsi_end_p (gsi))
6751         {
6752           last_stmt = gsi_stmt (gsi);
6753           do
6754             {
6755               stmt = gsi_stmt (gsi);
6756               if (need_fake_edge_p (stmt))
6757                 {
6758                   edge e;
6759
6760                   /* The handling above of the final block before the
6761                      epilogue should be enough to verify that there is
6762                      no edge to the exit block in CFG already.
6763                      Calling make_edge in such case would cause us to
6764                      mark that edge as fake and remove it later.  */
6765 #ifdef ENABLE_CHECKING
6766                   if (stmt == last_stmt)
6767                     {
6768                       e = find_edge (bb, EXIT_BLOCK_PTR);
6769                       gcc_assert (e == NULL);
6770                     }
6771 #endif
6772
6773                   /* Note that the following may create a new basic block
6774                      and renumber the existing basic blocks.  */
6775                   if (stmt != last_stmt)
6776                     {
6777                       e = split_block (bb, stmt);
6778                       if (e)
6779                         blocks_split++;
6780                     }
6781                   make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
6782                 }
6783               gsi_prev (&gsi);
6784             }
6785           while (!gsi_end_p (gsi));
6786         }
6787     }
6788
6789   if (blocks_split)
6790     verify_flow_info ();
6791
6792   return blocks_split;
6793 }
6794
6795 /* Removes edge E and all the blocks dominated by it, and updates dominance
6796    information.  The IL in E->src needs to be updated separately.
6797    If dominance info is not available, only the edge E is removed.*/
6798
6799 void
6800 remove_edge_and_dominated_blocks (edge e)
6801 {
6802   VEC (basic_block, heap) *bbs_to_remove = NULL;
6803   VEC (basic_block, heap) *bbs_to_fix_dom = NULL;
6804   bitmap df, df_idom;
6805   edge f;
6806   edge_iterator ei;
6807   bool none_removed = false;
6808   unsigned i;
6809   basic_block bb, dbb;
6810   bitmap_iterator bi;
6811
6812   if (!dom_info_available_p (CDI_DOMINATORS))
6813     {
6814       remove_edge (e);
6815       return;
6816     }
6817
6818   /* No updating is needed for edges to exit.  */
6819   if (e->dest == EXIT_BLOCK_PTR)
6820     {
6821       if (cfgcleanup_altered_bbs)
6822         bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6823       remove_edge (e);
6824       return;
6825     }
6826
6827   /* First, we find the basic blocks to remove.  If E->dest has a predecessor
6828      that is not dominated by E->dest, then this set is empty.  Otherwise,
6829      all the basic blocks dominated by E->dest are removed.
6830
6831      Also, to DF_IDOM we store the immediate dominators of the blocks in
6832      the dominance frontier of E (i.e., of the successors of the
6833      removed blocks, if there are any, and of E->dest otherwise).  */
6834   FOR_EACH_EDGE (f, ei, e->dest->preds)
6835     {
6836       if (f == e)
6837         continue;
6838
6839       if (!dominated_by_p (CDI_DOMINATORS, f->src, e->dest))
6840         {
6841           none_removed = true;
6842           break;
6843         }
6844     }
6845
6846   df = BITMAP_ALLOC (NULL);
6847   df_idom = BITMAP_ALLOC (NULL);
6848
6849   if (none_removed)
6850     bitmap_set_bit (df_idom,
6851                     get_immediate_dominator (CDI_DOMINATORS, e->dest)->index);
6852   else
6853     {
6854       bbs_to_remove = get_all_dominated_blocks (CDI_DOMINATORS, e->dest);
6855       FOR_EACH_VEC_ELT (basic_block, bbs_to_remove, i, bb)
6856         {
6857           FOR_EACH_EDGE (f, ei, bb->succs)
6858             {
6859               if (f->dest != EXIT_BLOCK_PTR)
6860                 bitmap_set_bit (df, f->dest->index);
6861             }
6862         }
6863       FOR_EACH_VEC_ELT (basic_block, bbs_to_remove, i, bb)
6864         bitmap_clear_bit (df, bb->index);
6865
6866       EXECUTE_IF_SET_IN_BITMAP (df, 0, i, bi)
6867         {
6868           bb = BASIC_BLOCK (i);
6869           bitmap_set_bit (df_idom,
6870                           get_immediate_dominator (CDI_DOMINATORS, bb)->index);
6871         }
6872     }
6873
6874   if (cfgcleanup_altered_bbs)
6875     {
6876       /* Record the set of the altered basic blocks.  */
6877       bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6878       bitmap_ior_into (cfgcleanup_altered_bbs, df);
6879     }
6880
6881   /* Remove E and the cancelled blocks.  */
6882   if (none_removed)
6883     remove_edge (e);
6884   else
6885     {
6886       /* Walk backwards so as to get a chance to substitute all
6887          released DEFs into debug stmts.  See
6888          eliminate_unnecessary_stmts() in tree-ssa-dce.c for more
6889          details.  */
6890       for (i = VEC_length (basic_block, bbs_to_remove); i-- > 0; )
6891         delete_basic_block (VEC_index (basic_block, bbs_to_remove, i));
6892     }
6893
6894   /* Update the dominance information.  The immediate dominator may change only
6895      for blocks whose immediate dominator belongs to DF_IDOM:
6896
6897      Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
6898      removal.  Let Z the arbitrary block such that idom(Z) = Y and
6899      Z dominates X after the removal.  Before removal, there exists a path P
6900      from Y to X that avoids Z.  Let F be the last edge on P that is
6901      removed, and let W = F->dest.  Before removal, idom(W) = Y (since Y
6902      dominates W, and because of P, Z does not dominate W), and W belongs to
6903      the dominance frontier of E.  Therefore, Y belongs to DF_IDOM.  */
6904   EXECUTE_IF_SET_IN_BITMAP (df_idom, 0, i, bi)
6905     {
6906       bb = BASIC_BLOCK (i);
6907       for (dbb = first_dom_son (CDI_DOMINATORS, bb);
6908            dbb;
6909            dbb = next_dom_son (CDI_DOMINATORS, dbb))
6910         VEC_safe_push (basic_block, heap, bbs_to_fix_dom, dbb);
6911     }
6912
6913   iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true);
6914
6915   BITMAP_FREE (df);
6916   BITMAP_FREE (df_idom);
6917   VEC_free (basic_block, heap, bbs_to_remove);
6918   VEC_free (basic_block, heap, bbs_to_fix_dom);
6919 }
6920
6921 /* Purge dead EH edges from basic block BB.  */
6922
6923 bool
6924 gimple_purge_dead_eh_edges (basic_block bb)
6925 {
6926   bool changed = false;
6927   edge e;
6928   edge_iterator ei;
6929   gimple stmt = last_stmt (bb);
6930
6931   if (stmt && stmt_can_throw_internal (stmt))
6932     return false;
6933
6934   for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6935     {
6936       if (e->flags & EDGE_EH)
6937         {
6938           remove_edge_and_dominated_blocks (e);
6939           changed = true;
6940         }
6941       else
6942         ei_next (&ei);
6943     }
6944
6945   return changed;
6946 }
6947
6948 /* Purge dead EH edges from basic block listed in BLOCKS.  */
6949
6950 bool
6951 gimple_purge_all_dead_eh_edges (const_bitmap blocks)
6952 {
6953   bool changed = false;
6954   unsigned i;
6955   bitmap_iterator bi;
6956
6957   EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
6958     {
6959       basic_block bb = BASIC_BLOCK (i);
6960
6961       /* Earlier gimple_purge_dead_eh_edges could have removed
6962          this basic block already.  */
6963       gcc_assert (bb || changed);
6964       if (bb != NULL)
6965         changed |= gimple_purge_dead_eh_edges (bb);
6966     }
6967
6968   return changed;
6969 }
6970
6971 /* Purge dead abnormal call edges from basic block BB.  */
6972
6973 bool
6974 gimple_purge_dead_abnormal_call_edges (basic_block bb)
6975 {
6976   bool changed = false;
6977   edge e;
6978   edge_iterator ei;
6979   gimple stmt = last_stmt (bb);
6980
6981   if (!cfun->has_nonlocal_label)
6982     return false;
6983
6984   if (stmt && stmt_can_make_abnormal_goto (stmt))
6985     return false;
6986
6987   for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6988     {
6989       if (e->flags & EDGE_ABNORMAL)
6990         {
6991           remove_edge_and_dominated_blocks (e);
6992           changed = true;
6993         }
6994       else
6995         ei_next (&ei);
6996     }
6997
6998   return changed;
6999 }
7000
7001 /* Purge dead abnormal call edges from basic block listed in BLOCKS.  */
7002
7003 bool
7004 gimple_purge_all_dead_abnormal_call_edges (const_bitmap blocks)
7005 {
7006   bool changed = false;
7007   unsigned i;
7008   bitmap_iterator bi;
7009
7010   EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
7011     {
7012       basic_block bb = BASIC_BLOCK (i);
7013
7014       /* Earlier gimple_purge_dead_abnormal_call_edges could have removed
7015          this basic block already.  */
7016       gcc_assert (bb || changed);
7017       if (bb != NULL)
7018         changed |= gimple_purge_dead_abnormal_call_edges (bb);
7019     }
7020
7021   return changed;
7022 }
7023
7024 /* This function is called whenever a new edge is created or
7025    redirected.  */
7026
7027 static void
7028 gimple_execute_on_growing_pred (edge e)
7029 {
7030   basic_block bb = e->dest;
7031
7032   if (!gimple_seq_empty_p (phi_nodes (bb)))
7033     reserve_phi_args_for_new_edge (bb);
7034 }
7035
7036 /* This function is called immediately before edge E is removed from
7037    the edge vector E->dest->preds.  */
7038
7039 static void
7040 gimple_execute_on_shrinking_pred (edge e)
7041 {
7042   if (!gimple_seq_empty_p (phi_nodes (e->dest)))
7043     remove_phi_args (e);
7044 }
7045
7046 /*---------------------------------------------------------------------------
7047   Helper functions for Loop versioning
7048   ---------------------------------------------------------------------------*/
7049
7050 /* Adjust phi nodes for 'first' basic block.  'second' basic block is a copy
7051    of 'first'. Both of them are dominated by 'new_head' basic block. When
7052    'new_head' was created by 'second's incoming edge it received phi arguments
7053    on the edge by split_edge(). Later, additional edge 'e' was created to
7054    connect 'new_head' and 'first'. Now this routine adds phi args on this
7055    additional edge 'e' that new_head to second edge received as part of edge
7056    splitting.  */
7057
7058 static void
7059 gimple_lv_adjust_loop_header_phi (basic_block first, basic_block second,
7060                                   basic_block new_head, edge e)
7061 {
7062   gimple phi1, phi2;
7063   gimple_stmt_iterator psi1, psi2;
7064   tree def;
7065   edge e2 = find_edge (new_head, second);
7066
7067   /* Because NEW_HEAD has been created by splitting SECOND's incoming
7068      edge, we should always have an edge from NEW_HEAD to SECOND.  */
7069   gcc_assert (e2 != NULL);
7070
7071   /* Browse all 'second' basic block phi nodes and add phi args to
7072      edge 'e' for 'first' head. PHI args are always in correct order.  */
7073
7074   for (psi2 = gsi_start_phis (second),
7075        psi1 = gsi_start_phis (first);
7076        !gsi_end_p (psi2) && !gsi_end_p (psi1);
7077        gsi_next (&psi2),  gsi_next (&psi1))
7078     {
7079       phi1 = gsi_stmt (psi1);
7080       phi2 = gsi_stmt (psi2);
7081       def = PHI_ARG_DEF (phi2, e2->dest_idx);
7082       add_phi_arg (phi1, def, e, gimple_phi_arg_location_from_edge (phi2, e2));
7083     }
7084 }
7085
7086
7087 /* Adds a if else statement to COND_BB with condition COND_EXPR.
7088    SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
7089    the destination of the ELSE part.  */
7090
7091 static void
7092 gimple_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
7093                                basic_block second_head ATTRIBUTE_UNUSED,
7094                                basic_block cond_bb, void *cond_e)
7095 {
7096   gimple_stmt_iterator gsi;
7097   gimple new_cond_expr;
7098   tree cond_expr = (tree) cond_e;
7099   edge e0;
7100
7101   /* Build new conditional expr */
7102   new_cond_expr = gimple_build_cond_from_tree (cond_expr,
7103                                                NULL_TREE, NULL_TREE);
7104
7105   /* Add new cond in cond_bb.  */
7106   gsi = gsi_last_bb (cond_bb);
7107   gsi_insert_after (&gsi, new_cond_expr, GSI_NEW_STMT);
7108
7109   /* Adjust edges appropriately to connect new head with first head
7110      as well as second head.  */
7111   e0 = single_succ_edge (cond_bb);
7112   e0->flags &= ~EDGE_FALLTHRU;
7113   e0->flags |= EDGE_FALSE_VALUE;
7114 }
7115
7116 struct cfg_hooks gimple_cfg_hooks = {
7117   "gimple",
7118   gimple_verify_flow_info,
7119   gimple_dump_bb,               /* dump_bb  */
7120   create_bb,                    /* create_basic_block  */
7121   gimple_redirect_edge_and_branch, /* redirect_edge_and_branch  */
7122   gimple_redirect_edge_and_branch_force, /* redirect_edge_and_branch_force  */
7123   gimple_can_remove_branch_p,   /* can_remove_branch_p  */
7124   remove_bb,                    /* delete_basic_block  */
7125   gimple_split_block,           /* split_block  */
7126   gimple_move_block_after,      /* move_block_after  */
7127   gimple_can_merge_blocks_p,    /* can_merge_blocks_p  */
7128   gimple_merge_blocks,          /* merge_blocks  */
7129   gimple_predict_edge,          /* predict_edge  */
7130   gimple_predicted_by_p,        /* predicted_by_p  */
7131   gimple_can_duplicate_bb_p,    /* can_duplicate_block_p  */
7132   gimple_duplicate_bb,          /* duplicate_block  */
7133   gimple_split_edge,            /* split_edge  */
7134   gimple_make_forwarder_block,  /* make_forward_block  */
7135   NULL,                         /* tidy_fallthru_edge  */
7136   NULL,                         /* force_nonfallthru */
7137   gimple_block_ends_with_call_p,/* block_ends_with_call_p */
7138   gimple_block_ends_with_condjump_p, /* block_ends_with_condjump_p */
7139   gimple_flow_call_edges_add,   /* flow_call_edges_add */
7140   gimple_execute_on_growing_pred,       /* execute_on_growing_pred */
7141   gimple_execute_on_shrinking_pred, /* execute_on_shrinking_pred */
7142   gimple_duplicate_loop_to_header_edge, /* duplicate loop for trees */
7143   gimple_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
7144   gimple_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/
7145   extract_true_false_edges_from_block, /* extract_cond_bb_edges */
7146   flush_pending_stmts           /* flush_pending_stmts */
7147 };
7148
7149
7150 /* Split all critical edges.  */
7151
7152 static unsigned int
7153 split_critical_edges (void)
7154 {
7155   basic_block bb;
7156   edge e;
7157   edge_iterator ei;
7158
7159   /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
7160      expensive.  So we want to enable recording of edge to CASE_LABEL_EXPR
7161      mappings around the calls to split_edge.  */
7162   start_recording_case_labels ();
7163   FOR_ALL_BB (bb)
7164     {
7165       FOR_EACH_EDGE (e, ei, bb->succs)
7166         {
7167           if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL))
7168             split_edge (e);
7169           /* PRE inserts statements to edges and expects that
7170              since split_critical_edges was done beforehand, committing edge
7171              insertions will not split more edges.  In addition to critical
7172              edges we must split edges that have multiple successors and
7173              end by control flow statements, such as RESX.
7174              Go ahead and split them too.  This matches the logic in
7175              gimple_find_edge_insert_loc.  */
7176           else if ((!single_pred_p (e->dest)
7177                     || !gimple_seq_empty_p (phi_nodes (e->dest))
7178                     || e->dest == EXIT_BLOCK_PTR)
7179                    && e->src != ENTRY_BLOCK_PTR
7180                    && !(e->flags & EDGE_ABNORMAL))
7181             {
7182               gimple_stmt_iterator gsi;
7183
7184               gsi = gsi_last_bb (e->src);
7185               if (!gsi_end_p (gsi)
7186                   && stmt_ends_bb_p (gsi_stmt (gsi))
7187                   && (gimple_code (gsi_stmt (gsi)) != GIMPLE_RETURN
7188                       && !gimple_call_builtin_p (gsi_stmt (gsi),
7189                                                  BUILT_IN_RETURN)))
7190                 split_edge (e);
7191             }
7192         }
7193     }
7194   end_recording_case_labels ();
7195   return 0;
7196 }
7197
7198 struct gimple_opt_pass pass_split_crit_edges =
7199 {
7200  {
7201   GIMPLE_PASS,
7202   "crited",                          /* name */
7203   NULL,                          /* gate */
7204   split_critical_edges,          /* execute */
7205   NULL,                          /* sub */
7206   NULL,                          /* next */
7207   0,                             /* static_pass_number */
7208   TV_TREE_SPLIT_EDGES,           /* tv_id */
7209   PROP_cfg,                      /* properties required */
7210   PROP_no_crit_edges,            /* properties_provided */
7211   0,                             /* properties_destroyed */
7212   0,                             /* todo_flags_start */
7213   TODO_verify_flow               /* todo_flags_finish */
7214  }
7215 };
7216
7217
7218 /* Build a ternary operation and gimplify it.  Emit code before GSI.
7219    Return the gimple_val holding the result.  */
7220
7221 tree
7222 gimplify_build3 (gimple_stmt_iterator *gsi, enum tree_code code,
7223                  tree type, tree a, tree b, tree c)
7224 {
7225   tree ret;
7226   location_t loc = gimple_location (gsi_stmt (*gsi));
7227
7228   ret = fold_build3_loc (loc, code, type, a, b, c);
7229   STRIP_NOPS (ret);
7230
7231   return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
7232                                    GSI_SAME_STMT);
7233 }
7234
7235 /* Build a binary operation and gimplify it.  Emit code before GSI.
7236    Return the gimple_val holding the result.  */
7237
7238 tree
7239 gimplify_build2 (gimple_stmt_iterator *gsi, enum tree_code code,
7240                  tree type, tree a, tree b)
7241 {
7242   tree ret;
7243
7244   ret = fold_build2_loc (gimple_location (gsi_stmt (*gsi)), code, type, a, b);
7245   STRIP_NOPS (ret);
7246
7247   return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
7248                                    GSI_SAME_STMT);
7249 }
7250
7251 /* Build a unary operation and gimplify it.  Emit code before GSI.
7252    Return the gimple_val holding the result.  */
7253
7254 tree
7255 gimplify_build1 (gimple_stmt_iterator *gsi, enum tree_code code, tree type,
7256                  tree a)
7257 {
7258   tree ret;
7259
7260   ret = fold_build1_loc (gimple_location (gsi_stmt (*gsi)), code, type, a);
7261   STRIP_NOPS (ret);
7262
7263   return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
7264                                    GSI_SAME_STMT);
7265 }
7266
7267
7268 \f
7269 /* Emit return warnings.  */
7270
7271 static unsigned int
7272 execute_warn_function_return (void)
7273 {
7274   source_location location;
7275   gimple last;
7276   edge e;
7277   edge_iterator ei;
7278
7279   /* If we have a path to EXIT, then we do return.  */
7280   if (TREE_THIS_VOLATILE (cfun->decl)
7281       && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
7282     {
7283       location = UNKNOWN_LOCATION;
7284       FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7285         {
7286           last = last_stmt (e->src);
7287           if ((gimple_code (last) == GIMPLE_RETURN
7288                || gimple_call_builtin_p (last, BUILT_IN_RETURN))
7289               && (location = gimple_location (last)) != UNKNOWN_LOCATION)
7290             break;
7291         }
7292       if (location == UNKNOWN_LOCATION)
7293         location = cfun->function_end_locus;
7294       warning_at (location, 0, "%<noreturn%> function does return");
7295     }
7296
7297   /* If we see "return;" in some basic block, then we do reach the end
7298      without returning a value.  */
7299   else if (warn_return_type
7300            && !TREE_NO_WARNING (cfun->decl)
7301            && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0
7302            && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl))))
7303     {
7304       FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7305         {
7306           gimple last = last_stmt (e->src);
7307           if (gimple_code (last) == GIMPLE_RETURN
7308               && gimple_return_retval (last) == NULL
7309               && !gimple_no_warning_p (last))
7310             {
7311               location = gimple_location (last);
7312               if (location == UNKNOWN_LOCATION)
7313                   location = cfun->function_end_locus;
7314               warning_at (location, OPT_Wreturn_type, "control reaches end of non-void function");
7315               TREE_NO_WARNING (cfun->decl) = 1;
7316               break;
7317             }
7318         }
7319     }
7320   return 0;
7321 }
7322
7323
7324 /* Given a basic block B which ends with a conditional and has
7325    precisely two successors, determine which of the edges is taken if
7326    the conditional is true and which is taken if the conditional is
7327    false.  Set TRUE_EDGE and FALSE_EDGE appropriately.  */
7328
7329 void
7330 extract_true_false_edges_from_block (basic_block b,
7331                                      edge *true_edge,
7332                                      edge *false_edge)
7333 {
7334   edge e = EDGE_SUCC (b, 0);
7335
7336   if (e->flags & EDGE_TRUE_VALUE)
7337     {
7338       *true_edge = e;
7339       *false_edge = EDGE_SUCC (b, 1);
7340     }
7341   else
7342     {
7343       *false_edge = e;
7344       *true_edge = EDGE_SUCC (b, 1);
7345     }
7346 }
7347
7348 struct gimple_opt_pass pass_warn_function_return =
7349 {
7350  {
7351   GIMPLE_PASS,
7352   "*warn_function_return",              /* name */
7353   NULL,                                 /* gate */
7354   execute_warn_function_return,         /* execute */
7355   NULL,                                 /* sub */
7356   NULL,                                 /* next */
7357   0,                                    /* static_pass_number */
7358   TV_NONE,                              /* tv_id */
7359   PROP_cfg,                             /* properties_required */
7360   0,                                    /* properties_provided */
7361   0,                                    /* properties_destroyed */
7362   0,                                    /* todo_flags_start */
7363   0                                     /* todo_flags_finish */
7364  }
7365 };
7366
7367 /* Emit noreturn warnings.  */
7368
7369 static unsigned int
7370 execute_warn_function_noreturn (void)
7371 {
7372   if (!TREE_THIS_VOLATILE (current_function_decl)
7373       && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0)
7374     warn_function_noreturn (current_function_decl);
7375   return 0;
7376 }
7377
7378 static bool
7379 gate_warn_function_noreturn (void)
7380 {
7381   return warn_suggest_attribute_noreturn;
7382 }
7383
7384 struct gimple_opt_pass pass_warn_function_noreturn =
7385 {
7386  {
7387   GIMPLE_PASS,
7388   "*warn_function_noreturn",            /* name */
7389   gate_warn_function_noreturn,          /* gate */
7390   execute_warn_function_noreturn,       /* execute */
7391   NULL,                                 /* sub */
7392   NULL,                                 /* next */
7393   0,                                    /* static_pass_number */
7394   TV_NONE,                              /* tv_id */
7395   PROP_cfg,                             /* properties_required */
7396   0,                                    /* properties_provided */
7397   0,                                    /* properties_destroyed */
7398   0,                                    /* todo_flags_start */
7399   0                                     /* todo_flags_finish */
7400  }
7401 };
7402
7403
7404 /* Walk a gimplified function and warn for functions whose return value is
7405    ignored and attribute((warn_unused_result)) is set.  This is done before
7406    inlining, so we don't have to worry about that.  */
7407
7408 static void
7409 do_warn_unused_result (gimple_seq seq)
7410 {
7411   tree fdecl, ftype;
7412   gimple_stmt_iterator i;
7413
7414   for (i = gsi_start (seq); !gsi_end_p (i); gsi_next (&i))
7415     {
7416       gimple g = gsi_stmt (i);
7417
7418       switch (gimple_code (g))
7419         {
7420         case GIMPLE_BIND:
7421           do_warn_unused_result (gimple_bind_body (g));
7422           break;
7423         case GIMPLE_TRY:
7424           do_warn_unused_result (gimple_try_eval (g));
7425           do_warn_unused_result (gimple_try_cleanup (g));
7426           break;
7427         case GIMPLE_CATCH:
7428           do_warn_unused_result (gimple_catch_handler (g));
7429           break;
7430         case GIMPLE_EH_FILTER:
7431           do_warn_unused_result (gimple_eh_filter_failure (g));
7432           break;
7433
7434         case GIMPLE_CALL:
7435           if (gimple_call_lhs (g))
7436             break;
7437           if (gimple_call_internal_p (g))
7438             break;
7439
7440           /* This is a naked call, as opposed to a GIMPLE_CALL with an
7441              LHS.  All calls whose value is ignored should be
7442              represented like this.  Look for the attribute.  */
7443           fdecl = gimple_call_fndecl (g);
7444           ftype = gimple_call_fntype (g);
7445
7446           if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype)))
7447             {
7448               location_t loc = gimple_location (g);
7449
7450               if (fdecl)
7451                 warning_at (loc, OPT_Wunused_result,
7452                             "ignoring return value of %qD, "
7453                             "declared with attribute warn_unused_result",
7454                             fdecl);
7455               else
7456                 warning_at (loc, OPT_Wunused_result,
7457                             "ignoring return value of function "
7458                             "declared with attribute warn_unused_result");
7459             }
7460           break;
7461
7462         default:
7463           /* Not a container, not a call, or a call whose value is used.  */
7464           break;
7465         }
7466     }
7467 }
7468
7469 static unsigned int
7470 run_warn_unused_result (void)
7471 {
7472   do_warn_unused_result (gimple_body (current_function_decl));
7473   return 0;
7474 }
7475
7476 static bool
7477 gate_warn_unused_result (void)
7478 {
7479   return flag_warn_unused_result;
7480 }
7481
7482 struct gimple_opt_pass pass_warn_unused_result =
7483 {
7484   {
7485     GIMPLE_PASS,
7486     "*warn_unused_result",              /* name */
7487     gate_warn_unused_result,            /* gate */
7488     run_warn_unused_result,             /* execute */
7489     NULL,                               /* sub */
7490     NULL,                               /* next */
7491     0,                                  /* static_pass_number */
7492     TV_NONE,                            /* tv_id */
7493     PROP_gimple_any,                    /* properties_required */
7494     0,                                  /* properties_provided */
7495     0,                                  /* properties_destroyed */
7496     0,                                  /* todo_flags_start */
7497     0,                                  /* todo_flags_finish */
7498   }
7499 };