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           gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
1570           size_t i;
1571
1572           fold_stmt (&gsi);
1573           stmt = gsi_stmt (gsi);
1574           if (cfgcleanup_altered_bbs && !is_gimple_debug (stmt))
1575             bitmap_set_bit (cfgcleanup_altered_bbs, gimple_bb (stmt)->index);
1576
1577           /* FIXME.  This should go in update_stmt.  */
1578           for (i = 0; i < gimple_num_ops (stmt); i++)
1579             {
1580               tree op = gimple_op (stmt, i);
1581               /* Operands may be empty here.  For example, the labels
1582                  of a GIMPLE_COND are nulled out following the creation
1583                  of the corresponding CFG edges.  */
1584               if (op && TREE_CODE (op) == ADDR_EXPR)
1585                 recompute_tree_invariant_for_addr_expr (op);
1586             }
1587
1588           maybe_clean_or_replace_eh_stmt (stmt, stmt);
1589           update_stmt (stmt);
1590         }
1591     }
1592
1593   gcc_assert (has_zero_uses (name));
1594
1595   /* Also update the trees stored in loop structures.  */
1596   if (current_loops)
1597     {
1598       struct loop *loop;
1599       loop_iterator li;
1600
1601       FOR_EACH_LOOP (li, loop, 0)
1602         {
1603           substitute_in_loop_info (loop, name, val);
1604         }
1605     }
1606 }
1607
1608 /* Merge block B into block A.  */
1609
1610 static void
1611 gimple_merge_blocks (basic_block a, basic_block b)
1612 {
1613   gimple_stmt_iterator last, gsi, psi;
1614   gimple_seq phis = phi_nodes (b);
1615
1616   if (dump_file)
1617     fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index);
1618
1619   /* Remove all single-valued PHI nodes from block B of the form
1620      V_i = PHI <V_j> by propagating V_j to all the uses of V_i.  */
1621   gsi = gsi_last_bb (a);
1622   for (psi = gsi_start (phis); !gsi_end_p (psi); )
1623     {
1624       gimple phi = gsi_stmt (psi);
1625       tree def = gimple_phi_result (phi), use = gimple_phi_arg_def (phi, 0);
1626       gimple copy;
1627       bool may_replace_uses = !is_gimple_reg (def)
1628                               || may_propagate_copy (def, use);
1629
1630       /* In case we maintain loop closed ssa form, do not propagate arguments
1631          of loop exit phi nodes.  */
1632       if (current_loops
1633           && loops_state_satisfies_p (LOOP_CLOSED_SSA)
1634           && is_gimple_reg (def)
1635           && TREE_CODE (use) == SSA_NAME
1636           && a->loop_father != b->loop_father)
1637         may_replace_uses = false;
1638
1639       if (!may_replace_uses)
1640         {
1641           gcc_assert (is_gimple_reg (def));
1642
1643           /* Note that just emitting the copies is fine -- there is no problem
1644              with ordering of phi nodes.  This is because A is the single
1645              predecessor of B, therefore results of the phi nodes cannot
1646              appear as arguments of the phi nodes.  */
1647           copy = gimple_build_assign (def, use);
1648           gsi_insert_after (&gsi, copy, GSI_NEW_STMT);
1649           remove_phi_node (&psi, false);
1650         }
1651       else
1652         {
1653           /* If we deal with a PHI for virtual operands, we can simply
1654              propagate these without fussing with folding or updating
1655              the stmt.  */
1656           if (!is_gimple_reg (def))
1657             {
1658               imm_use_iterator iter;
1659               use_operand_p use_p;
1660               gimple stmt;
1661
1662               FOR_EACH_IMM_USE_STMT (stmt, iter, def)
1663                 FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
1664                   SET_USE (use_p, use);
1665
1666               if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (def))
1667                 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (use) = 1;
1668             }
1669           else
1670             replace_uses_by (def, use);
1671
1672           remove_phi_node (&psi, true);
1673         }
1674     }
1675
1676   /* Ensure that B follows A.  */
1677   move_block_after (b, a);
1678
1679   gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU);
1680   gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a)));
1681
1682   /* Remove labels from B and set gimple_bb to A for other statements.  */
1683   for (gsi = gsi_start_bb (b); !gsi_end_p (gsi);)
1684     {
1685       gimple stmt = gsi_stmt (gsi);
1686       if (gimple_code (stmt) == GIMPLE_LABEL)
1687         {
1688           tree label = gimple_label_label (stmt);
1689           int lp_nr;
1690
1691           gsi_remove (&gsi, false);
1692
1693           /* Now that we can thread computed gotos, we might have
1694              a situation where we have a forced label in block B
1695              However, the label at the start of block B might still be
1696              used in other ways (think about the runtime checking for
1697              Fortran assigned gotos).  So we can not just delete the
1698              label.  Instead we move the label to the start of block A.  */
1699           if (FORCED_LABEL (label))
1700             {
1701               gimple_stmt_iterator dest_gsi = gsi_start_bb (a);
1702               gsi_insert_before (&dest_gsi, stmt, GSI_NEW_STMT);
1703             }
1704
1705           lp_nr = EH_LANDING_PAD_NR (label);
1706           if (lp_nr)
1707             {
1708               eh_landing_pad lp = get_eh_landing_pad_from_number (lp_nr);
1709               lp->post_landing_pad = NULL;
1710             }
1711         }
1712       else
1713         {
1714           gimple_set_bb (stmt, a);
1715           gsi_next (&gsi);
1716         }
1717     }
1718
1719   /* Merge the sequences.  */
1720   last = gsi_last_bb (a);
1721   gsi_insert_seq_after (&last, bb_seq (b), GSI_NEW_STMT);
1722   set_bb_seq (b, NULL);
1723
1724   if (cfgcleanup_altered_bbs)
1725     bitmap_set_bit (cfgcleanup_altered_bbs, a->index);
1726 }
1727
1728
1729 /* Return the one of two successors of BB that is not reachable by a
1730    complex edge, if there is one.  Else, return BB.  We use
1731    this in optimizations that use post-dominators for their heuristics,
1732    to catch the cases in C++ where function calls are involved.  */
1733
1734 basic_block
1735 single_noncomplex_succ (basic_block bb)
1736 {
1737   edge e0, e1;
1738   if (EDGE_COUNT (bb->succs) != 2)
1739     return bb;
1740
1741   e0 = EDGE_SUCC (bb, 0);
1742   e1 = EDGE_SUCC (bb, 1);
1743   if (e0->flags & EDGE_COMPLEX)
1744     return e1->dest;
1745   if (e1->flags & EDGE_COMPLEX)
1746     return e0->dest;
1747
1748   return bb;
1749 }
1750
1751 /* T is CALL_EXPR.  Set current_function_calls_* flags.  */
1752
1753 void
1754 notice_special_calls (gimple call)
1755 {
1756   int flags = gimple_call_flags (call);
1757
1758   if (flags & ECF_MAY_BE_ALLOCA)
1759     cfun->calls_alloca = true;
1760   if (flags & ECF_RETURNS_TWICE)
1761     cfun->calls_setjmp = true;
1762 }
1763
1764
1765 /* Clear flags set by notice_special_calls.  Used by dead code removal
1766    to update the flags.  */
1767
1768 void
1769 clear_special_calls (void)
1770 {
1771   cfun->calls_alloca = false;
1772   cfun->calls_setjmp = false;
1773 }
1774
1775 /* Remove PHI nodes associated with basic block BB and all edges out of BB.  */
1776
1777 static void
1778 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb)
1779 {
1780   /* Since this block is no longer reachable, we can just delete all
1781      of its PHI nodes.  */
1782   remove_phi_nodes (bb);
1783
1784   /* Remove edges to BB's successors.  */
1785   while (EDGE_COUNT (bb->succs) > 0)
1786     remove_edge (EDGE_SUCC (bb, 0));
1787 }
1788
1789
1790 /* Remove statements of basic block BB.  */
1791
1792 static void
1793 remove_bb (basic_block bb)
1794 {
1795   gimple_stmt_iterator i;
1796
1797   if (dump_file)
1798     {
1799       fprintf (dump_file, "Removing basic block %d\n", bb->index);
1800       if (dump_flags & TDF_DETAILS)
1801         {
1802           dump_bb (bb, dump_file, 0);
1803           fprintf (dump_file, "\n");
1804         }
1805     }
1806
1807   if (current_loops)
1808     {
1809       struct loop *loop = bb->loop_father;
1810
1811       /* If a loop gets removed, clean up the information associated
1812          with it.  */
1813       if (loop->latch == bb
1814           || loop->header == bb)
1815         free_numbers_of_iterations_estimates_loop (loop);
1816     }
1817
1818   /* Remove all the instructions in the block.  */
1819   if (bb_seq (bb) != NULL)
1820     {
1821       /* Walk backwards so as to get a chance to substitute all
1822          released DEFs into debug stmts.  See
1823          eliminate_unnecessary_stmts() in tree-ssa-dce.c for more
1824          details.  */
1825       for (i = gsi_last_bb (bb); !gsi_end_p (i);)
1826         {
1827           gimple stmt = gsi_stmt (i);
1828           if (gimple_code (stmt) == GIMPLE_LABEL
1829               && (FORCED_LABEL (gimple_label_label (stmt))
1830                   || DECL_NONLOCAL (gimple_label_label (stmt))))
1831             {
1832               basic_block new_bb;
1833               gimple_stmt_iterator new_gsi;
1834
1835               /* A non-reachable non-local label may still be referenced.
1836                  But it no longer needs to carry the extra semantics of
1837                  non-locality.  */
1838               if (DECL_NONLOCAL (gimple_label_label (stmt)))
1839                 {
1840                   DECL_NONLOCAL (gimple_label_label (stmt)) = 0;
1841                   FORCED_LABEL (gimple_label_label (stmt)) = 1;
1842                 }
1843
1844               new_bb = bb->prev_bb;
1845               new_gsi = gsi_start_bb (new_bb);
1846               gsi_remove (&i, false);
1847               gsi_insert_before (&new_gsi, stmt, GSI_NEW_STMT);
1848             }
1849           else
1850             {
1851               /* Release SSA definitions if we are in SSA.  Note that we
1852                  may be called when not in SSA.  For example,
1853                  final_cleanup calls this function via
1854                  cleanup_tree_cfg.  */
1855               if (gimple_in_ssa_p (cfun))
1856                 release_defs (stmt);
1857
1858               gsi_remove (&i, true);
1859             }
1860
1861           if (gsi_end_p (i))
1862             i = gsi_last_bb (bb);
1863           else
1864             gsi_prev (&i);
1865         }
1866     }
1867
1868   remove_phi_nodes_and_edges_for_unreachable_block (bb);
1869   bb->il.gimple = NULL;
1870 }
1871
1872
1873 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
1874    predicate VAL, return the edge that will be taken out of the block.
1875    If VAL does not match a unique edge, NULL is returned.  */
1876
1877 edge
1878 find_taken_edge (basic_block bb, tree val)
1879 {
1880   gimple stmt;
1881
1882   stmt = last_stmt (bb);
1883
1884   gcc_assert (stmt);
1885   gcc_assert (is_ctrl_stmt (stmt));
1886
1887   if (val == NULL)
1888     return NULL;
1889
1890   if (!is_gimple_min_invariant (val))
1891     return NULL;
1892
1893   if (gimple_code (stmt) == GIMPLE_COND)
1894     return find_taken_edge_cond_expr (bb, val);
1895
1896   if (gimple_code (stmt) == GIMPLE_SWITCH)
1897     return find_taken_edge_switch_expr (bb, val);
1898
1899   if (computed_goto_p (stmt))
1900     {
1901       /* Only optimize if the argument is a label, if the argument is
1902          not a label then we can not construct a proper CFG.
1903
1904          It may be the case that we only need to allow the LABEL_REF to
1905          appear inside an ADDR_EXPR, but we also allow the LABEL_REF to
1906          appear inside a LABEL_EXPR just to be safe.  */
1907       if ((TREE_CODE (val) == ADDR_EXPR || TREE_CODE (val) == LABEL_EXPR)
1908           && TREE_CODE (TREE_OPERAND (val, 0)) == LABEL_DECL)
1909         return find_taken_edge_computed_goto (bb, TREE_OPERAND (val, 0));
1910       return NULL;
1911     }
1912
1913   gcc_unreachable ();
1914 }
1915
1916 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
1917    statement, determine which of the outgoing edges will be taken out of the
1918    block.  Return NULL if either edge may be taken.  */
1919
1920 static edge
1921 find_taken_edge_computed_goto (basic_block bb, tree val)
1922 {
1923   basic_block dest;
1924   edge e = NULL;
1925
1926   dest = label_to_block (val);
1927   if (dest)
1928     {
1929       e = find_edge (bb, dest);
1930       gcc_assert (e != NULL);
1931     }
1932
1933   return e;
1934 }
1935
1936 /* Given a constant value VAL and the entry block BB to a COND_EXPR
1937    statement, determine which of the two edges will be taken out of the
1938    block.  Return NULL if either edge may be taken.  */
1939
1940 static edge
1941 find_taken_edge_cond_expr (basic_block bb, tree val)
1942 {
1943   edge true_edge, false_edge;
1944
1945   extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
1946
1947   gcc_assert (TREE_CODE (val) == INTEGER_CST);
1948   return (integer_zerop (val) ? false_edge : true_edge);
1949 }
1950
1951 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
1952    statement, determine which edge will be taken out of the block.  Return
1953    NULL if any edge may be taken.  */
1954
1955 static edge
1956 find_taken_edge_switch_expr (basic_block bb, tree val)
1957 {
1958   basic_block dest_bb;
1959   edge e;
1960   gimple switch_stmt;
1961   tree taken_case;
1962
1963   switch_stmt = last_stmt (bb);
1964   taken_case = find_case_label_for_value (switch_stmt, val);
1965   dest_bb = label_to_block (CASE_LABEL (taken_case));
1966
1967   e = find_edge (bb, dest_bb);
1968   gcc_assert (e);
1969   return e;
1970 }
1971
1972
1973 /* Return the CASE_LABEL_EXPR that SWITCH_STMT will take for VAL.
1974    We can make optimal use here of the fact that the case labels are
1975    sorted: We can do a binary search for a case matching VAL.  */
1976
1977 static tree
1978 find_case_label_for_value (gimple switch_stmt, tree val)
1979 {
1980   size_t low, high, n = gimple_switch_num_labels (switch_stmt);
1981   tree default_case = gimple_switch_default_label (switch_stmt);
1982
1983   for (low = 0, high = n; high - low > 1; )
1984     {
1985       size_t i = (high + low) / 2;
1986       tree t = gimple_switch_label (switch_stmt, i);
1987       int cmp;
1988
1989       /* Cache the result of comparing CASE_LOW and val.  */
1990       cmp = tree_int_cst_compare (CASE_LOW (t), val);
1991
1992       if (cmp > 0)
1993         high = i;
1994       else
1995         low = i;
1996
1997       if (CASE_HIGH (t) == NULL)
1998         {
1999           /* A singe-valued case label.  */
2000           if (cmp == 0)
2001             return t;
2002         }
2003       else
2004         {
2005           /* A case range.  We can only handle integer ranges.  */
2006           if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
2007             return t;
2008         }
2009     }
2010
2011   return default_case;
2012 }
2013
2014
2015 /* Dump a basic block on stderr.  */
2016
2017 void
2018 gimple_debug_bb (basic_block bb)
2019 {
2020   gimple_dump_bb (bb, stderr, 0, TDF_VOPS|TDF_MEMSYMS);
2021 }
2022
2023
2024 /* Dump basic block with index N on stderr.  */
2025
2026 basic_block
2027 gimple_debug_bb_n (int n)
2028 {
2029   gimple_debug_bb (BASIC_BLOCK (n));
2030   return BASIC_BLOCK (n);
2031 }
2032
2033
2034 /* Dump the CFG on stderr.
2035
2036    FLAGS are the same used by the tree dumping functions
2037    (see TDF_* in tree-pass.h).  */
2038
2039 void
2040 gimple_debug_cfg (int flags)
2041 {
2042   gimple_dump_cfg (stderr, flags);
2043 }
2044
2045
2046 /* Dump the program showing basic block boundaries on the given FILE.
2047
2048    FLAGS are the same used by the tree dumping functions (see TDF_* in
2049    tree.h).  */
2050
2051 void
2052 gimple_dump_cfg (FILE *file, int flags)
2053 {
2054   if (flags & TDF_DETAILS)
2055     {
2056       dump_function_header (file, current_function_decl, flags);
2057       fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2058                n_basic_blocks, n_edges, last_basic_block);
2059
2060       brief_dump_cfg (file);
2061       fprintf (file, "\n");
2062     }
2063
2064   if (flags & TDF_STATS)
2065     dump_cfg_stats (file);
2066
2067   dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS);
2068 }
2069
2070
2071 /* Dump CFG statistics on FILE.  */
2072
2073 void
2074 dump_cfg_stats (FILE *file)
2075 {
2076   static long max_num_merged_labels = 0;
2077   unsigned long size, total = 0;
2078   long num_edges;
2079   basic_block bb;
2080   const char * const fmt_str   = "%-30s%-13s%12s\n";
2081   const char * const fmt_str_1 = "%-30s%13d%11lu%c\n";
2082   const char * const fmt_str_2 = "%-30s%13ld%11lu%c\n";
2083   const char * const fmt_str_3 = "%-43s%11lu%c\n";
2084   const char *funcname
2085     = lang_hooks.decl_printable_name (current_function_decl, 2);
2086
2087
2088   fprintf (file, "\nCFG Statistics for %s\n\n", funcname);
2089
2090   fprintf (file, "---------------------------------------------------------\n");
2091   fprintf (file, fmt_str, "", "  Number of  ", "Memory");
2092   fprintf (file, fmt_str, "", "  instances  ", "used ");
2093   fprintf (file, "---------------------------------------------------------\n");
2094
2095   size = n_basic_blocks * sizeof (struct basic_block_def);
2096   total += size;
2097   fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks,
2098            SCALE (size), LABEL (size));
2099
2100   num_edges = 0;
2101   FOR_EACH_BB (bb)
2102     num_edges += EDGE_COUNT (bb->succs);
2103   size = num_edges * sizeof (struct edge_def);
2104   total += size;
2105   fprintf (file, fmt_str_2, "Edges", num_edges, SCALE (size), LABEL (size));
2106
2107   fprintf (file, "---------------------------------------------------------\n");
2108   fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total),
2109            LABEL (total));
2110   fprintf (file, "---------------------------------------------------------\n");
2111   fprintf (file, "\n");
2112
2113   if (cfg_stats.num_merged_labels > max_num_merged_labels)
2114     max_num_merged_labels = cfg_stats.num_merged_labels;
2115
2116   fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2117            cfg_stats.num_merged_labels, max_num_merged_labels);
2118
2119   fprintf (file, "\n");
2120 }
2121
2122
2123 /* Dump CFG statistics on stderr.  Keep extern so that it's always
2124    linked in the final executable.  */
2125
2126 DEBUG_FUNCTION void
2127 debug_cfg_stats (void)
2128 {
2129   dump_cfg_stats (stderr);
2130 }
2131
2132
2133 /* Dump the flowgraph to a .vcg FILE.  */
2134
2135 static void
2136 gimple_cfg2vcg (FILE *file)
2137 {
2138   edge e;
2139   edge_iterator ei;
2140   basic_block bb;
2141   const char *funcname
2142     = lang_hooks.decl_printable_name (current_function_decl, 2);
2143
2144   /* Write the file header.  */
2145   fprintf (file, "graph: { title: \"%s\"\n", funcname);
2146   fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2147   fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2148
2149   /* Write blocks and edges.  */
2150   FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
2151     {
2152       fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2153                e->dest->index);
2154
2155       if (e->flags & EDGE_FAKE)
2156         fprintf (file, " linestyle: dotted priority: 10");
2157       else
2158         fprintf (file, " linestyle: solid priority: 100");
2159
2160       fprintf (file, " }\n");
2161     }
2162   fputc ('\n', file);
2163
2164   FOR_EACH_BB (bb)
2165     {
2166       enum gimple_code head_code, end_code;
2167       const char *head_name, *end_name;
2168       int head_line = 0;
2169       int end_line = 0;
2170       gimple first = first_stmt (bb);
2171       gimple last = last_stmt (bb);
2172
2173       if (first)
2174         {
2175           head_code = gimple_code (first);
2176           head_name = gimple_code_name[head_code];
2177           head_line = get_lineno (first);
2178         }
2179       else
2180         head_name = "no-statement";
2181
2182       if (last)
2183         {
2184           end_code = gimple_code (last);
2185           end_name = gimple_code_name[end_code];
2186           end_line = get_lineno (last);
2187         }
2188       else
2189         end_name = "no-statement";
2190
2191       fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2192                bb->index, bb->index, head_name, head_line, end_name,
2193                end_line);
2194
2195       FOR_EACH_EDGE (e, ei, bb->succs)
2196         {
2197           if (e->dest == EXIT_BLOCK_PTR)
2198             fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index);
2199           else
2200             fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index);
2201
2202           if (e->flags & EDGE_FAKE)
2203             fprintf (file, " priority: 10 linestyle: dotted");
2204           else
2205             fprintf (file, " priority: 100 linestyle: solid");
2206
2207           fprintf (file, " }\n");
2208         }
2209
2210       if (bb->next_bb != EXIT_BLOCK_PTR)
2211         fputc ('\n', file);
2212     }
2213
2214   fputs ("}\n\n", file);
2215 }
2216
2217
2218
2219 /*---------------------------------------------------------------------------
2220                              Miscellaneous helpers
2221 ---------------------------------------------------------------------------*/
2222
2223 /* Return true if T represents a stmt that always transfers control.  */
2224
2225 bool
2226 is_ctrl_stmt (gimple t)
2227 {
2228   switch (gimple_code (t))
2229     {
2230     case GIMPLE_COND:
2231     case GIMPLE_SWITCH:
2232     case GIMPLE_GOTO:
2233     case GIMPLE_RETURN:
2234     case GIMPLE_RESX:
2235       return true;
2236     default:
2237       return false;
2238     }
2239 }
2240
2241
2242 /* Return true if T is a statement that may alter the flow of control
2243    (e.g., a call to a non-returning function).  */
2244
2245 bool
2246 is_ctrl_altering_stmt (gimple t)
2247 {
2248   gcc_assert (t);
2249
2250   switch (gimple_code (t))
2251     {
2252     case GIMPLE_CALL:
2253       {
2254         int flags = gimple_call_flags (t);
2255
2256         /* A non-pure/const call alters flow control if the current
2257            function has nonlocal labels.  */
2258         if (!(flags & (ECF_CONST | ECF_PURE | ECF_LEAF))
2259             && cfun->has_nonlocal_label)
2260           return true;
2261
2262         /* A call also alters control flow if it does not return.  */
2263         if (flags & ECF_NORETURN)
2264           return true;
2265
2266         /* BUILT_IN_RETURN call is same as return statement.  */
2267         if (gimple_call_builtin_p (t, BUILT_IN_RETURN))
2268           return true;
2269       }
2270       break;
2271
2272     case GIMPLE_EH_DISPATCH:
2273       /* EH_DISPATCH branches to the individual catch handlers at
2274          this level of a try or allowed-exceptions region.  It can
2275          fallthru to the next statement as well.  */
2276       return true;
2277
2278     case GIMPLE_ASM:
2279       if (gimple_asm_nlabels (t) > 0)
2280         return true;
2281       break;
2282
2283     CASE_GIMPLE_OMP:
2284       /* OpenMP directives alter control flow.  */
2285       return true;
2286
2287     default:
2288       break;
2289     }
2290
2291   /* If a statement can throw, it alters control flow.  */
2292   return stmt_can_throw_internal (t);
2293 }
2294
2295
2296 /* Return true if T is a simple local goto.  */
2297
2298 bool
2299 simple_goto_p (gimple t)
2300 {
2301   return (gimple_code (t) == GIMPLE_GOTO
2302           && TREE_CODE (gimple_goto_dest (t)) == LABEL_DECL);
2303 }
2304
2305
2306 /* Return true if T can make an abnormal transfer of control flow.
2307    Transfers of control flow associated with EH are excluded.  */
2308
2309 bool
2310 stmt_can_make_abnormal_goto (gimple t)
2311 {
2312   if (computed_goto_p (t))
2313     return true;
2314   if (is_gimple_call (t))
2315     return (gimple_has_side_effects (t) && cfun->has_nonlocal_label
2316             && !(gimple_call_flags (t) & ECF_LEAF));
2317   return false;
2318 }
2319
2320
2321 /* Return true if STMT should start a new basic block.  PREV_STMT is
2322    the statement preceding STMT.  It is used when STMT is a label or a
2323    case label.  Labels should only start a new basic block if their
2324    previous statement wasn't a label.  Otherwise, sequence of labels
2325    would generate unnecessary basic blocks that only contain a single
2326    label.  */
2327
2328 static inline bool
2329 stmt_starts_bb_p (gimple stmt, gimple prev_stmt)
2330 {
2331   if (stmt == NULL)
2332     return false;
2333
2334   /* Labels start a new basic block only if the preceding statement
2335      wasn't a label of the same type.  This prevents the creation of
2336      consecutive blocks that have nothing but a single label.  */
2337   if (gimple_code (stmt) == GIMPLE_LABEL)
2338     {
2339       /* Nonlocal and computed GOTO targets always start a new block.  */
2340       if (DECL_NONLOCAL (gimple_label_label (stmt))
2341           || FORCED_LABEL (gimple_label_label (stmt)))
2342         return true;
2343
2344       if (prev_stmt && gimple_code (prev_stmt) == GIMPLE_LABEL)
2345         {
2346           if (DECL_NONLOCAL (gimple_label_label (prev_stmt)))
2347             return true;
2348
2349           cfg_stats.num_merged_labels++;
2350           return false;
2351         }
2352       else
2353         return true;
2354     }
2355
2356   return false;
2357 }
2358
2359
2360 /* Return true if T should end a basic block.  */
2361
2362 bool
2363 stmt_ends_bb_p (gimple t)
2364 {
2365   return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t);
2366 }
2367
2368 /* Remove block annotations and other data structures.  */
2369
2370 void
2371 delete_tree_cfg_annotations (void)
2372 {
2373   label_to_block_map = NULL;
2374 }
2375
2376
2377 /* Return the first statement in basic block BB.  */
2378
2379 gimple
2380 first_stmt (basic_block bb)
2381 {
2382   gimple_stmt_iterator i = gsi_start_bb (bb);
2383   gimple stmt = NULL;
2384
2385   while (!gsi_end_p (i) && is_gimple_debug ((stmt = gsi_stmt (i))))
2386     {
2387       gsi_next (&i);
2388       stmt = NULL;
2389     }
2390   return stmt;
2391 }
2392
2393 /* Return the first non-label statement in basic block BB.  */
2394
2395 static gimple
2396 first_non_label_stmt (basic_block bb)
2397 {
2398   gimple_stmt_iterator i = gsi_start_bb (bb);
2399   while (!gsi_end_p (i) && gimple_code (gsi_stmt (i)) == GIMPLE_LABEL)
2400     gsi_next (&i);
2401   return !gsi_end_p (i) ? gsi_stmt (i) : NULL;
2402 }
2403
2404 /* Return the last statement in basic block BB.  */
2405
2406 gimple
2407 last_stmt (basic_block bb)
2408 {
2409   gimple_stmt_iterator i = gsi_last_bb (bb);
2410   gimple stmt = NULL;
2411
2412   while (!gsi_end_p (i) && is_gimple_debug ((stmt = gsi_stmt (i))))
2413     {
2414       gsi_prev (&i);
2415       stmt = NULL;
2416     }
2417   return stmt;
2418 }
2419
2420 /* Return the last statement of an otherwise empty block.  Return NULL
2421    if the block is totally empty, or if it contains more than one
2422    statement.  */
2423
2424 gimple
2425 last_and_only_stmt (basic_block bb)
2426 {
2427   gimple_stmt_iterator i = gsi_last_nondebug_bb (bb);
2428   gimple last, prev;
2429
2430   if (gsi_end_p (i))
2431     return NULL;
2432
2433   last = gsi_stmt (i);
2434   gsi_prev_nondebug (&i);
2435   if (gsi_end_p (i))
2436     return last;
2437
2438   /* Empty statements should no longer appear in the instruction stream.
2439      Everything that might have appeared before should be deleted by
2440      remove_useless_stmts, and the optimizers should just gsi_remove
2441      instead of smashing with build_empty_stmt.
2442
2443      Thus the only thing that should appear here in a block containing
2444      one executable statement is a label.  */
2445   prev = gsi_stmt (i);
2446   if (gimple_code (prev) == GIMPLE_LABEL)
2447     return last;
2448   else
2449     return NULL;
2450 }
2451
2452 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE.  */
2453
2454 static void
2455 reinstall_phi_args (edge new_edge, edge old_edge)
2456 {
2457   edge_var_map_vector v;
2458   edge_var_map *vm;
2459   int i;
2460   gimple_stmt_iterator phis;
2461
2462   v = redirect_edge_var_map_vector (old_edge);
2463   if (!v)
2464     return;
2465
2466   for (i = 0, phis = gsi_start_phis (new_edge->dest);
2467        VEC_iterate (edge_var_map, v, i, vm) && !gsi_end_p (phis);
2468        i++, gsi_next (&phis))
2469     {
2470       gimple phi = gsi_stmt (phis);
2471       tree result = redirect_edge_var_map_result (vm);
2472       tree arg = redirect_edge_var_map_def (vm);
2473
2474       gcc_assert (result == gimple_phi_result (phi));
2475
2476       add_phi_arg (phi, arg, new_edge, redirect_edge_var_map_location (vm));
2477     }
2478
2479   redirect_edge_var_map_clear (old_edge);
2480 }
2481
2482 /* Returns the basic block after which the new basic block created
2483    by splitting edge EDGE_IN should be placed.  Tries to keep the new block
2484    near its "logical" location.  This is of most help to humans looking
2485    at debugging dumps.  */
2486
2487 static basic_block
2488 split_edge_bb_loc (edge edge_in)
2489 {
2490   basic_block dest = edge_in->dest;
2491   basic_block dest_prev = dest->prev_bb;
2492
2493   if (dest_prev)
2494     {
2495       edge e = find_edge (dest_prev, dest);
2496       if (e && !(e->flags & EDGE_COMPLEX))
2497         return edge_in->src;
2498     }
2499   return dest_prev;
2500 }
2501
2502 /* Split a (typically critical) edge EDGE_IN.  Return the new block.
2503    Abort on abnormal edges.  */
2504
2505 static basic_block
2506 gimple_split_edge (edge edge_in)
2507 {
2508   basic_block new_bb, after_bb, dest;
2509   edge new_edge, e;
2510
2511   /* Abnormal edges cannot be split.  */
2512   gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
2513
2514   dest = edge_in->dest;
2515
2516   after_bb = split_edge_bb_loc (edge_in);
2517
2518   new_bb = create_empty_bb (after_bb);
2519   new_bb->frequency = EDGE_FREQUENCY (edge_in);
2520   new_bb->count = edge_in->count;
2521   new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU);
2522   new_edge->probability = REG_BR_PROB_BASE;
2523   new_edge->count = edge_in->count;
2524
2525   e = redirect_edge_and_branch (edge_in, new_bb);
2526   gcc_assert (e == edge_in);
2527   reinstall_phi_args (new_edge, e);
2528
2529   return new_bb;
2530 }
2531
2532
2533 /* Verify properties of the address expression T with base object BASE.  */
2534
2535 static tree
2536 verify_address (tree t, tree base)
2537 {
2538   bool old_constant;
2539   bool old_side_effects;
2540   bool new_constant;
2541   bool new_side_effects;
2542
2543   old_constant = TREE_CONSTANT (t);
2544   old_side_effects = TREE_SIDE_EFFECTS (t);
2545
2546   recompute_tree_invariant_for_addr_expr (t);
2547   new_side_effects = TREE_SIDE_EFFECTS (t);
2548   new_constant = TREE_CONSTANT (t);
2549
2550   if (old_constant != new_constant)
2551     {
2552       error ("constant not recomputed when ADDR_EXPR changed");
2553       return t;
2554     }
2555   if (old_side_effects != new_side_effects)
2556     {
2557       error ("side effects not recomputed when ADDR_EXPR changed");
2558       return t;
2559     }
2560
2561   if (!(TREE_CODE (base) == VAR_DECL
2562         || TREE_CODE (base) == PARM_DECL
2563         || TREE_CODE (base) == RESULT_DECL))
2564     return NULL_TREE;
2565
2566   if (DECL_GIMPLE_REG_P (base))
2567     {
2568       error ("DECL_GIMPLE_REG_P set on a variable with address taken");
2569       return base;
2570     }
2571
2572   return NULL_TREE;
2573 }
2574
2575 /* Callback for walk_tree, check that all elements with address taken are
2576    properly noticed as such.  The DATA is an int* that is 1 if TP was seen
2577    inside a PHI node.  */
2578
2579 static tree
2580 verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
2581 {
2582   tree t = *tp, x;
2583
2584   if (TYPE_P (t))
2585     *walk_subtrees = 0;
2586
2587   /* Check operand N for being valid GIMPLE and give error MSG if not.  */
2588 #define CHECK_OP(N, MSG) \
2589   do { if (!is_gimple_val (TREE_OPERAND (t, N)))                \
2590        { error (MSG); return TREE_OPERAND (t, N); }} while (0)
2591
2592   switch (TREE_CODE (t))
2593     {
2594     case SSA_NAME:
2595       if (SSA_NAME_IN_FREE_LIST (t))
2596         {
2597           error ("SSA name in freelist but still referenced");
2598           return *tp;
2599         }
2600       break;
2601
2602     case INDIRECT_REF:
2603       error ("INDIRECT_REF in gimple IL");
2604       return t;
2605
2606     case MEM_REF:
2607       x = TREE_OPERAND (t, 0);
2608       if (!POINTER_TYPE_P (TREE_TYPE (x))
2609           || !is_gimple_mem_ref_addr (x))
2610         {
2611           error ("invalid first operand of MEM_REF");
2612           return x;
2613         }
2614       if (TREE_CODE (TREE_OPERAND (t, 1)) != INTEGER_CST
2615           || !POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 1))))
2616         {
2617           error ("invalid offset operand of MEM_REF");
2618           return TREE_OPERAND (t, 1);
2619         }
2620       if (TREE_CODE (x) == ADDR_EXPR
2621           && (x = verify_address (x, TREE_OPERAND (x, 0))))
2622         return x;
2623       *walk_subtrees = 0;
2624       break;
2625
2626     case ASSERT_EXPR:
2627       x = fold (ASSERT_EXPR_COND (t));
2628       if (x == boolean_false_node)
2629         {
2630           error ("ASSERT_EXPR with an always-false condition");
2631           return *tp;
2632         }
2633       break;
2634
2635     case MODIFY_EXPR:
2636       error ("MODIFY_EXPR not expected while having tuples");
2637       return *tp;
2638
2639     case ADDR_EXPR:
2640       {
2641         tree tem;
2642
2643         gcc_assert (is_gimple_address (t));
2644
2645         /* Skip any references (they will be checked when we recurse down the
2646            tree) and ensure that any variable used as a prefix is marked
2647            addressable.  */
2648         for (x = TREE_OPERAND (t, 0);
2649              handled_component_p (x);
2650              x = TREE_OPERAND (x, 0))
2651           ;
2652
2653         if ((tem = verify_address (t, x)))
2654           return tem;
2655
2656         if (!(TREE_CODE (x) == VAR_DECL
2657               || TREE_CODE (x) == PARM_DECL
2658               || TREE_CODE (x) == RESULT_DECL))
2659           return NULL;
2660
2661         if (!TREE_ADDRESSABLE (x))
2662           {
2663             error ("address taken, but ADDRESSABLE bit not set");
2664             return x;
2665           }
2666
2667         break;
2668       }
2669
2670     case COND_EXPR:
2671       x = COND_EXPR_COND (t);
2672       if (!INTEGRAL_TYPE_P (TREE_TYPE (x)))
2673         {
2674           error ("non-integral used in condition");
2675           return x;
2676         }
2677       if (!is_gimple_condexpr (x))
2678         {
2679           error ("invalid conditional operand");
2680           return x;
2681         }
2682       break;
2683
2684     case NON_LVALUE_EXPR:
2685     case TRUTH_NOT_EXPR:
2686       gcc_unreachable ();
2687
2688     CASE_CONVERT:
2689     case FIX_TRUNC_EXPR:
2690     case FLOAT_EXPR:
2691     case NEGATE_EXPR:
2692     case ABS_EXPR:
2693     case BIT_NOT_EXPR:
2694       CHECK_OP (0, "invalid operand to unary operator");
2695       break;
2696
2697     case REALPART_EXPR:
2698     case IMAGPART_EXPR:
2699     case COMPONENT_REF:
2700     case ARRAY_REF:
2701     case ARRAY_RANGE_REF:
2702     case BIT_FIELD_REF:
2703     case VIEW_CONVERT_EXPR:
2704       /* We have a nest of references.  Verify that each of the operands
2705          that determine where to reference is either a constant or a variable,
2706          verify that the base is valid, and then show we've already checked
2707          the subtrees.  */
2708       while (handled_component_p (t))
2709         {
2710           if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2))
2711             CHECK_OP (2, "invalid COMPONENT_REF offset operator");
2712           else if (TREE_CODE (t) == ARRAY_REF
2713                    || TREE_CODE (t) == ARRAY_RANGE_REF)
2714             {
2715               CHECK_OP (1, "invalid array index");
2716               if (TREE_OPERAND (t, 2))
2717                 CHECK_OP (2, "invalid array lower bound");
2718               if (TREE_OPERAND (t, 3))
2719                 CHECK_OP (3, "invalid array stride");
2720             }
2721           else if (TREE_CODE (t) == BIT_FIELD_REF)
2722             {
2723               if (!host_integerp (TREE_OPERAND (t, 1), 1)
2724                   || !host_integerp (TREE_OPERAND (t, 2), 1))
2725                 {
2726                   error ("invalid position or size operand to BIT_FIELD_REF");
2727                   return t;
2728                 }
2729               else if (INTEGRAL_TYPE_P (TREE_TYPE (t))
2730                        && (TYPE_PRECISION (TREE_TYPE (t))
2731                            != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
2732                 {
2733                   error ("integral result type precision does not match "
2734                          "field size of BIT_FIELD_REF");
2735                   return t;
2736                 }
2737               if (!INTEGRAL_TYPE_P (TREE_TYPE (t))
2738                   && (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (t)))
2739                       != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
2740                 {
2741                   error ("mode precision of non-integral result does not "
2742                          "match field size of BIT_FIELD_REF");
2743                   return t;
2744                 }
2745             }
2746
2747           t = TREE_OPERAND (t, 0);
2748         }
2749
2750       if (!is_gimple_min_invariant (t) && !is_gimple_lvalue (t))
2751         {
2752           error ("invalid reference prefix");
2753           return t;
2754         }
2755       *walk_subtrees = 0;
2756       break;
2757     case PLUS_EXPR:
2758     case MINUS_EXPR:
2759       /* PLUS_EXPR and MINUS_EXPR don't work on pointers, they should be done using
2760          POINTER_PLUS_EXPR. */
2761       if (POINTER_TYPE_P (TREE_TYPE (t)))
2762         {
2763           error ("invalid operand to plus/minus, type is a pointer");
2764           return t;
2765         }
2766       CHECK_OP (0, "invalid operand to binary operator");
2767       CHECK_OP (1, "invalid operand to binary operator");
2768       break;
2769
2770     case POINTER_PLUS_EXPR:
2771       /* Check to make sure the first operand is a pointer or reference type. */
2772       if (!POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
2773         {
2774           error ("invalid operand to pointer plus, first operand is not a pointer");
2775           return t;
2776         }
2777       /* Check to make sure the second operand is a ptrofftype.  */
2778       if (!ptrofftype_p (TREE_TYPE (TREE_OPERAND (t, 1))))
2779         {
2780           error ("invalid operand to pointer plus, second operand is not an "
2781                  "integer type of appropriate width");
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      Because we special-case pointers to void we allow
3199      comparisons of pointers with the same mode as well.  */
3200   if (!useless_type_conversion_p (op0_type, op1_type)
3201       && !useless_type_conversion_p (op1_type, op0_type)
3202       && (!POINTER_TYPE_P (op0_type)
3203           || !POINTER_TYPE_P (op1_type)
3204           || TYPE_MODE (op0_type) != TYPE_MODE (op1_type)))
3205     {
3206       error ("mismatching comparison operand types");
3207       debug_generic_expr (op0_type);
3208       debug_generic_expr (op1_type);
3209       return true;
3210     }
3211
3212   /* The resulting type of a comparison may be an effective boolean type.  */
3213   if (INTEGRAL_TYPE_P (type)
3214       && (TREE_CODE (type) == BOOLEAN_TYPE
3215           || TYPE_PRECISION (type) == 1))
3216     ;
3217   /* Or an integer vector type with the same size and element count
3218      as the comparison operand types.  */
3219   else if (TREE_CODE (type) == VECTOR_TYPE
3220            && TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE)
3221     {
3222       if (TREE_CODE (op0_type) != VECTOR_TYPE
3223           || TREE_CODE (op1_type) != VECTOR_TYPE)
3224         {
3225           error ("non-vector operands in vector comparison");
3226           debug_generic_expr (op0_type);
3227           debug_generic_expr (op1_type);
3228           return true;
3229         }
3230
3231       if (TYPE_VECTOR_SUBPARTS (type) != TYPE_VECTOR_SUBPARTS (op0_type)
3232           || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (type)))
3233               != GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0_type)))))
3234         {
3235           error ("invalid vector comparison resulting type");
3236           debug_generic_expr (type);
3237           return true;
3238         }
3239     }
3240   else
3241     {
3242       error ("bogus comparison result type");
3243       debug_generic_expr (type);
3244       return true;
3245     }
3246
3247   return false;
3248 }
3249
3250 /* Verify a gimple assignment statement STMT with an unary rhs.
3251    Returns true if anything is wrong.  */
3252
3253 static bool
3254 verify_gimple_assign_unary (gimple stmt)
3255 {
3256   enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3257   tree lhs = gimple_assign_lhs (stmt);
3258   tree lhs_type = TREE_TYPE (lhs);
3259   tree rhs1 = gimple_assign_rhs1 (stmt);
3260   tree rhs1_type = TREE_TYPE (rhs1);
3261
3262   if (!is_gimple_reg (lhs))
3263     {
3264       error ("non-register as LHS of unary operation");
3265       return true;
3266     }
3267
3268   if (!is_gimple_val (rhs1))
3269     {
3270       error ("invalid operand in unary operation");
3271       return true;
3272     }
3273
3274   /* First handle conversions.  */
3275   switch (rhs_code)
3276     {
3277     CASE_CONVERT:
3278       {
3279         /* Allow conversions between integral types and pointers only if
3280            there is no sign or zero extension involved.
3281            For targets were the precision of ptrofftype doesn't match that
3282            of pointers we need to allow arbitrary conversions from and
3283            to ptrofftype.  */
3284         if ((POINTER_TYPE_P (lhs_type)
3285              && INTEGRAL_TYPE_P (rhs1_type)
3286              && (TYPE_PRECISION (lhs_type) >= TYPE_PRECISION (rhs1_type)
3287                  || ptrofftype_p (rhs1_type)))
3288             || (POINTER_TYPE_P (rhs1_type)
3289                 && INTEGRAL_TYPE_P (lhs_type)
3290                 && (TYPE_PRECISION (rhs1_type) >= TYPE_PRECISION (lhs_type)
3291                     || ptrofftype_p (sizetype))))
3292           return false;
3293
3294         /* Allow conversion from integer to offset type and vice versa.  */
3295         if ((TREE_CODE (lhs_type) == OFFSET_TYPE
3296              && TREE_CODE (rhs1_type) == INTEGER_TYPE)
3297             || (TREE_CODE (lhs_type) == INTEGER_TYPE
3298                 && TREE_CODE (rhs1_type) == OFFSET_TYPE))
3299           return false;
3300
3301         /* Otherwise assert we are converting between types of the
3302            same kind.  */
3303         if (INTEGRAL_TYPE_P (lhs_type) != INTEGRAL_TYPE_P (rhs1_type))
3304           {
3305             error ("invalid types in nop conversion");
3306             debug_generic_expr (lhs_type);
3307             debug_generic_expr (rhs1_type);
3308             return true;
3309           }
3310
3311         return false;
3312       }
3313
3314     case ADDR_SPACE_CONVERT_EXPR:
3315       {
3316         if (!POINTER_TYPE_P (rhs1_type) || !POINTER_TYPE_P (lhs_type)
3317             || (TYPE_ADDR_SPACE (TREE_TYPE (rhs1_type))
3318                 == TYPE_ADDR_SPACE (TREE_TYPE (lhs_type))))
3319           {
3320             error ("invalid types in address space conversion");
3321             debug_generic_expr (lhs_type);
3322             debug_generic_expr (rhs1_type);
3323             return true;
3324           }
3325
3326         return false;
3327       }
3328
3329     case FIXED_CONVERT_EXPR:
3330       {
3331         if (!valid_fixed_convert_types_p (lhs_type, rhs1_type)
3332             && !valid_fixed_convert_types_p (rhs1_type, lhs_type))
3333           {
3334             error ("invalid types in fixed-point conversion");
3335             debug_generic_expr (lhs_type);
3336             debug_generic_expr (rhs1_type);
3337             return true;
3338           }
3339
3340         return false;
3341       }
3342
3343     case FLOAT_EXPR:
3344       {
3345         if (!INTEGRAL_TYPE_P (rhs1_type) || !SCALAR_FLOAT_TYPE_P (lhs_type))
3346           {
3347             error ("invalid types in conversion to floating point");
3348             debug_generic_expr (lhs_type);
3349             debug_generic_expr (rhs1_type);
3350             return true;
3351           }
3352
3353         return false;
3354       }
3355
3356     case FIX_TRUNC_EXPR:
3357       {
3358         if (!INTEGRAL_TYPE_P (lhs_type) || !SCALAR_FLOAT_TYPE_P (rhs1_type))
3359           {
3360             error ("invalid types in conversion to integer");
3361             debug_generic_expr (lhs_type);
3362             debug_generic_expr (rhs1_type);
3363             return true;
3364           }
3365
3366         return false;
3367       }
3368
3369     case VEC_UNPACK_HI_EXPR:
3370     case VEC_UNPACK_LO_EXPR:
3371     case REDUC_MAX_EXPR:
3372     case REDUC_MIN_EXPR:
3373     case REDUC_PLUS_EXPR:
3374     case VEC_UNPACK_FLOAT_HI_EXPR:
3375     case VEC_UNPACK_FLOAT_LO_EXPR:
3376       /* FIXME.  */
3377       return false;
3378
3379     case NEGATE_EXPR:
3380     case ABS_EXPR:
3381     case BIT_NOT_EXPR:
3382     case PAREN_EXPR:
3383     case NON_LVALUE_EXPR:
3384     case CONJ_EXPR:
3385       break;
3386
3387     default:
3388       gcc_unreachable ();
3389     }
3390
3391   /* For the remaining codes assert there is no conversion involved.  */
3392   if (!useless_type_conversion_p (lhs_type, rhs1_type))
3393     {
3394       error ("non-trivial conversion in unary operation");
3395       debug_generic_expr (lhs_type);
3396       debug_generic_expr (rhs1_type);
3397       return true;
3398     }
3399
3400   return false;
3401 }
3402
3403 /* Verify a gimple assignment statement STMT with a binary rhs.
3404    Returns true if anything is wrong.  */
3405
3406 static bool
3407 verify_gimple_assign_binary (gimple stmt)
3408 {
3409   enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3410   tree lhs = gimple_assign_lhs (stmt);
3411   tree lhs_type = TREE_TYPE (lhs);
3412   tree rhs1 = gimple_assign_rhs1 (stmt);
3413   tree rhs1_type = TREE_TYPE (rhs1);
3414   tree rhs2 = gimple_assign_rhs2 (stmt);
3415   tree rhs2_type = TREE_TYPE (rhs2);
3416
3417   if (!is_gimple_reg (lhs))
3418     {
3419       error ("non-register as LHS of binary operation");
3420       return true;
3421     }
3422
3423   if (!is_gimple_val (rhs1)
3424       || !is_gimple_val (rhs2))
3425     {
3426       error ("invalid operands in binary operation");
3427       return true;
3428     }
3429
3430   /* First handle operations that involve different types.  */
3431   switch (rhs_code)
3432     {
3433     case COMPLEX_EXPR:
3434       {
3435         if (TREE_CODE (lhs_type) != COMPLEX_TYPE
3436             || !(INTEGRAL_TYPE_P (rhs1_type)
3437                  || SCALAR_FLOAT_TYPE_P (rhs1_type))
3438             || !(INTEGRAL_TYPE_P (rhs2_type)
3439                  || SCALAR_FLOAT_TYPE_P (rhs2_type)))
3440           {
3441             error ("type mismatch in complex expression");
3442             debug_generic_expr (lhs_type);
3443             debug_generic_expr (rhs1_type);
3444             debug_generic_expr (rhs2_type);
3445             return true;
3446           }
3447
3448         return false;
3449       }
3450
3451     case LSHIFT_EXPR:
3452     case RSHIFT_EXPR:
3453     case LROTATE_EXPR:
3454     case RROTATE_EXPR:
3455       {
3456         /* Shifts and rotates are ok on integral types, fixed point
3457            types and integer vector types.  */
3458         if ((!INTEGRAL_TYPE_P (rhs1_type)
3459              && !FIXED_POINT_TYPE_P (rhs1_type)
3460              && !(TREE_CODE (rhs1_type) == VECTOR_TYPE
3461                   && INTEGRAL_TYPE_P (TREE_TYPE (rhs1_type))))
3462             || (!INTEGRAL_TYPE_P (rhs2_type)
3463                 /* Vector shifts of vectors are also ok.  */
3464                 && !(TREE_CODE (rhs1_type) == VECTOR_TYPE
3465                      && INTEGRAL_TYPE_P (TREE_TYPE (rhs1_type))
3466                      && TREE_CODE (rhs2_type) == VECTOR_TYPE
3467                      && INTEGRAL_TYPE_P (TREE_TYPE (rhs2_type))))
3468             || !useless_type_conversion_p (lhs_type, rhs1_type))
3469           {
3470             error ("type mismatch in shift expression");
3471             debug_generic_expr (lhs_type);
3472             debug_generic_expr (rhs1_type);
3473             debug_generic_expr (rhs2_type);
3474             return true;
3475           }
3476
3477         return false;
3478       }
3479
3480     case VEC_LSHIFT_EXPR:
3481     case VEC_RSHIFT_EXPR:
3482       {
3483         if (TREE_CODE (rhs1_type) != VECTOR_TYPE
3484             || !(INTEGRAL_TYPE_P (TREE_TYPE (rhs1_type))
3485                  || POINTER_TYPE_P (TREE_TYPE (rhs1_type))
3486                  || FIXED_POINT_TYPE_P (TREE_TYPE (rhs1_type))
3487                  || SCALAR_FLOAT_TYPE_P (TREE_TYPE (rhs1_type)))
3488             || (!INTEGRAL_TYPE_P (rhs2_type)
3489                 && (TREE_CODE (rhs2_type) != VECTOR_TYPE
3490                     || !INTEGRAL_TYPE_P (TREE_TYPE (rhs2_type))))
3491             || !useless_type_conversion_p (lhs_type, rhs1_type))
3492           {
3493             error ("type mismatch in vector shift expression");
3494             debug_generic_expr (lhs_type);
3495             debug_generic_expr (rhs1_type);
3496             debug_generic_expr (rhs2_type);
3497             return true;
3498           }
3499         /* For shifting a vector of non-integral components we
3500            only allow shifting by a constant multiple of the element size.  */
3501         if (!INTEGRAL_TYPE_P (TREE_TYPE (rhs1_type))
3502             && (TREE_CODE (rhs2) != INTEGER_CST
3503                 || !div_if_zero_remainder (EXACT_DIV_EXPR, rhs2,
3504                                            TYPE_SIZE (TREE_TYPE (rhs1_type)))))
3505           {
3506             error ("non-element sized vector shift of floating point vector");
3507             return true;
3508           }
3509
3510         return false;
3511       }
3512
3513     case WIDEN_LSHIFT_EXPR:
3514       {
3515         if (!INTEGRAL_TYPE_P (lhs_type)
3516             || !INTEGRAL_TYPE_P (rhs1_type)
3517             || TREE_CODE (rhs2) != INTEGER_CST
3518             || (2 * TYPE_PRECISION (rhs1_type) > TYPE_PRECISION (lhs_type)))
3519           {
3520             error ("type mismatch in widening vector shift expression");
3521             debug_generic_expr (lhs_type);
3522             debug_generic_expr (rhs1_type);
3523             debug_generic_expr (rhs2_type);
3524             return true;
3525           }
3526
3527         return false;
3528       }
3529
3530     case VEC_WIDEN_LSHIFT_HI_EXPR:
3531     case VEC_WIDEN_LSHIFT_LO_EXPR:
3532       {
3533         if (TREE_CODE (rhs1_type) != VECTOR_TYPE
3534             || TREE_CODE (lhs_type) != VECTOR_TYPE
3535             || !INTEGRAL_TYPE_P (TREE_TYPE (rhs1_type))
3536             || !INTEGRAL_TYPE_P (TREE_TYPE (lhs_type))
3537             || TREE_CODE (rhs2) != INTEGER_CST
3538             || (2 * TYPE_PRECISION (TREE_TYPE (rhs1_type))
3539                 > TYPE_PRECISION (TREE_TYPE (lhs_type))))
3540           {
3541             error ("type mismatch in widening vector shift expression");
3542             debug_generic_expr (lhs_type);
3543             debug_generic_expr (rhs1_type);
3544             debug_generic_expr (rhs2_type);
3545             return true;
3546           }
3547
3548         return false;
3549       }
3550
3551     case PLUS_EXPR:
3552     case MINUS_EXPR:
3553       {
3554         /* We use regular PLUS_EXPR and MINUS_EXPR for vectors.
3555            ???  This just makes the checker happy and may not be what is
3556            intended.  */
3557         if (TREE_CODE (lhs_type) == VECTOR_TYPE
3558             && POINTER_TYPE_P (TREE_TYPE (lhs_type)))
3559           {
3560             if (TREE_CODE (rhs1_type) != VECTOR_TYPE
3561                 || TREE_CODE (rhs2_type) != VECTOR_TYPE)
3562               {
3563                 error ("invalid non-vector operands to vector valued plus");
3564                 return true;
3565               }
3566             lhs_type = TREE_TYPE (lhs_type);
3567             rhs1_type = TREE_TYPE (rhs1_type);
3568             rhs2_type = TREE_TYPE (rhs2_type);
3569             /* PLUS_EXPR is commutative, so we might end up canonicalizing
3570                the pointer to 2nd place.  */
3571             if (POINTER_TYPE_P (rhs2_type))
3572               {
3573                 tree tem = rhs1_type;
3574                 rhs1_type = rhs2_type;
3575                 rhs2_type = tem;
3576               }
3577             goto do_pointer_plus_expr_check;
3578           }
3579         if (POINTER_TYPE_P (lhs_type)
3580             || POINTER_TYPE_P (rhs1_type)
3581             || POINTER_TYPE_P (rhs2_type))
3582           {
3583             error ("invalid (pointer) operands to plus/minus");
3584             return true;
3585           }
3586
3587         /* Continue with generic binary expression handling.  */
3588         break;
3589       }
3590
3591     case POINTER_PLUS_EXPR:
3592       {
3593 do_pointer_plus_expr_check:
3594         if (!POINTER_TYPE_P (rhs1_type)
3595             || !useless_type_conversion_p (lhs_type, rhs1_type)
3596             || !ptrofftype_p (rhs2_type))
3597           {
3598             error ("type mismatch in pointer plus expression");
3599             debug_generic_stmt (lhs_type);
3600             debug_generic_stmt (rhs1_type);
3601             debug_generic_stmt (rhs2_type);
3602             return true;
3603           }
3604
3605         return false;
3606       }
3607
3608     case TRUTH_ANDIF_EXPR:
3609     case TRUTH_ORIF_EXPR:
3610     case TRUTH_AND_EXPR:
3611     case TRUTH_OR_EXPR:
3612     case TRUTH_XOR_EXPR:
3613
3614       gcc_unreachable ();
3615
3616     case LT_EXPR:
3617     case LE_EXPR:
3618     case GT_EXPR:
3619     case GE_EXPR:
3620     case EQ_EXPR:
3621     case NE_EXPR:
3622     case UNORDERED_EXPR:
3623     case ORDERED_EXPR:
3624     case UNLT_EXPR:
3625     case UNLE_EXPR:
3626     case UNGT_EXPR:
3627     case UNGE_EXPR:
3628     case UNEQ_EXPR:
3629     case LTGT_EXPR:
3630       /* Comparisons are also binary, but the result type is not
3631          connected to the operand types.  */
3632       return verify_gimple_comparison (lhs_type, rhs1, rhs2);
3633
3634     case WIDEN_MULT_EXPR:
3635       if (TREE_CODE (lhs_type) != INTEGER_TYPE)
3636         return true;
3637       return ((2 * TYPE_PRECISION (rhs1_type) > TYPE_PRECISION (lhs_type))
3638               || (TYPE_PRECISION (rhs1_type) != TYPE_PRECISION (rhs2_type)));
3639
3640     case WIDEN_SUM_EXPR:
3641     case VEC_WIDEN_MULT_HI_EXPR:
3642     case VEC_WIDEN_MULT_LO_EXPR:
3643     case VEC_PACK_TRUNC_EXPR:
3644     case VEC_PACK_SAT_EXPR:
3645     case VEC_PACK_FIX_TRUNC_EXPR:
3646     case VEC_EXTRACT_EVEN_EXPR:
3647     case VEC_EXTRACT_ODD_EXPR:
3648     case VEC_INTERLEAVE_HIGH_EXPR:
3649     case VEC_INTERLEAVE_LOW_EXPR:
3650       /* FIXME.  */
3651       return false;
3652
3653     case MULT_EXPR:
3654     case TRUNC_DIV_EXPR:
3655     case CEIL_DIV_EXPR:
3656     case FLOOR_DIV_EXPR:
3657     case ROUND_DIV_EXPR:
3658     case TRUNC_MOD_EXPR:
3659     case CEIL_MOD_EXPR:
3660     case FLOOR_MOD_EXPR:
3661     case ROUND_MOD_EXPR:
3662     case RDIV_EXPR:
3663     case EXACT_DIV_EXPR:
3664     case MIN_EXPR:
3665     case MAX_EXPR:
3666     case BIT_IOR_EXPR:
3667     case BIT_XOR_EXPR:
3668     case BIT_AND_EXPR:
3669       /* Continue with generic binary expression handling.  */
3670       break;
3671
3672     default:
3673       gcc_unreachable ();
3674     }
3675
3676   if (!useless_type_conversion_p (lhs_type, rhs1_type)
3677       || !useless_type_conversion_p (lhs_type, rhs2_type))
3678     {
3679       error ("type mismatch in binary expression");
3680       debug_generic_stmt (lhs_type);
3681       debug_generic_stmt (rhs1_type);
3682       debug_generic_stmt (rhs2_type);
3683       return true;
3684     }
3685
3686   return false;
3687 }
3688
3689 /* Verify a gimple assignment statement STMT with a ternary rhs.
3690    Returns true if anything is wrong.  */
3691
3692 static bool
3693 verify_gimple_assign_ternary (gimple stmt)
3694 {
3695   enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3696   tree lhs = gimple_assign_lhs (stmt);
3697   tree lhs_type = TREE_TYPE (lhs);
3698   tree rhs1 = gimple_assign_rhs1 (stmt);
3699   tree rhs1_type = TREE_TYPE (rhs1);
3700   tree rhs2 = gimple_assign_rhs2 (stmt);
3701   tree rhs2_type = TREE_TYPE (rhs2);
3702   tree rhs3 = gimple_assign_rhs3 (stmt);
3703   tree rhs3_type = TREE_TYPE (rhs3);
3704
3705   if (!is_gimple_reg (lhs))
3706     {
3707       error ("non-register as LHS of ternary operation");
3708       return true;
3709     }
3710
3711   if (((rhs_code == VEC_COND_EXPR || rhs_code == COND_EXPR)
3712        ? !is_gimple_condexpr (rhs1) : !is_gimple_val (rhs1))
3713       || !is_gimple_val (rhs2)
3714       || !is_gimple_val (rhs3))
3715     {
3716       error ("invalid operands in ternary operation");
3717       return true;
3718     }
3719
3720   /* First handle operations that involve different types.  */
3721   switch (rhs_code)
3722     {
3723     case WIDEN_MULT_PLUS_EXPR:
3724     case WIDEN_MULT_MINUS_EXPR:
3725       if ((!INTEGRAL_TYPE_P (rhs1_type)
3726            && !FIXED_POINT_TYPE_P (rhs1_type))
3727           || !useless_type_conversion_p (rhs1_type, rhs2_type)
3728           || !useless_type_conversion_p (lhs_type, rhs3_type)
3729           || 2 * TYPE_PRECISION (rhs1_type) > TYPE_PRECISION (lhs_type)
3730           || TYPE_PRECISION (rhs1_type) != TYPE_PRECISION (rhs2_type))
3731         {
3732           error ("type mismatch in widening multiply-accumulate expression");
3733           debug_generic_expr (lhs_type);
3734           debug_generic_expr (rhs1_type);
3735           debug_generic_expr (rhs2_type);
3736           debug_generic_expr (rhs3_type);
3737           return true;
3738         }
3739       break;
3740
3741     case FMA_EXPR:
3742       if (!useless_type_conversion_p (lhs_type, rhs1_type)
3743           || !useless_type_conversion_p (lhs_type, rhs2_type)
3744           || !useless_type_conversion_p (lhs_type, rhs3_type))
3745         {
3746           error ("type mismatch in fused multiply-add expression");
3747           debug_generic_expr (lhs_type);
3748           debug_generic_expr (rhs1_type);
3749           debug_generic_expr (rhs2_type);
3750           debug_generic_expr (rhs3_type);
3751           return true;
3752         }
3753       break;
3754
3755     case COND_EXPR:
3756     case VEC_COND_EXPR:
3757       if (!useless_type_conversion_p (lhs_type, rhs2_type)
3758           || !useless_type_conversion_p (lhs_type, rhs3_type))
3759         {
3760           error ("type mismatch in conditional expression");
3761           debug_generic_expr (lhs_type);
3762           debug_generic_expr (rhs2_type);
3763           debug_generic_expr (rhs3_type);
3764           return true;
3765         }
3766       break;
3767
3768     case VEC_PERM_EXPR:
3769       if (!useless_type_conversion_p (lhs_type, rhs1_type)
3770           || !useless_type_conversion_p (lhs_type, rhs2_type))
3771         {
3772           error ("type mismatch in vector permute expression");
3773           debug_generic_expr (lhs_type);
3774           debug_generic_expr (rhs1_type);
3775           debug_generic_expr (rhs2_type);
3776           debug_generic_expr (rhs3_type);
3777           return true;
3778         }
3779
3780       if (TREE_CODE (rhs1_type) != VECTOR_TYPE
3781           || TREE_CODE (rhs2_type) != VECTOR_TYPE
3782           || TREE_CODE (rhs3_type) != VECTOR_TYPE)
3783         {
3784           error ("vector types expected in vector permute expression");
3785           debug_generic_expr (lhs_type);
3786           debug_generic_expr (rhs1_type);
3787           debug_generic_expr (rhs2_type);
3788           debug_generic_expr (rhs3_type);
3789           return true;
3790         }
3791
3792       if (TYPE_VECTOR_SUBPARTS (rhs1_type) != TYPE_VECTOR_SUBPARTS (rhs2_type)
3793           || TYPE_VECTOR_SUBPARTS (rhs2_type)
3794              != TYPE_VECTOR_SUBPARTS (rhs3_type)
3795           || TYPE_VECTOR_SUBPARTS (rhs3_type)
3796              != TYPE_VECTOR_SUBPARTS (lhs_type))
3797         {
3798           error ("vectors with different element number found "
3799                  "in vector permute expression");
3800           debug_generic_expr (lhs_type);
3801           debug_generic_expr (rhs1_type);
3802           debug_generic_expr (rhs2_type);
3803           debug_generic_expr (rhs3_type);
3804           return true;
3805         }
3806
3807       if (TREE_CODE (TREE_TYPE (rhs3_type)) != INTEGER_TYPE
3808           || GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (rhs3_type)))
3809              != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (rhs1_type))))
3810         {
3811           error ("invalid mask type in vector permute expression");
3812           debug_generic_expr (lhs_type);
3813           debug_generic_expr (rhs1_type);
3814           debug_generic_expr (rhs2_type);
3815           debug_generic_expr (rhs3_type);
3816           return true;
3817         }
3818
3819       return false;
3820
3821     case DOT_PROD_EXPR:
3822     case REALIGN_LOAD_EXPR:
3823       /* FIXME.  */
3824       return false;
3825
3826     default:
3827       gcc_unreachable ();
3828     }
3829   return false;
3830 }
3831
3832 /* Verify a gimple assignment statement STMT with a single rhs.
3833    Returns true if anything is wrong.  */
3834
3835 static bool
3836 verify_gimple_assign_single (gimple stmt)
3837 {
3838   enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3839   tree lhs = gimple_assign_lhs (stmt);
3840   tree lhs_type = TREE_TYPE (lhs);
3841   tree rhs1 = gimple_assign_rhs1 (stmt);
3842   tree rhs1_type = TREE_TYPE (rhs1);
3843   bool res = false;
3844
3845   if (!useless_type_conversion_p (lhs_type, rhs1_type))
3846     {
3847       error ("non-trivial conversion at assignment");
3848       debug_generic_expr (lhs_type);
3849       debug_generic_expr (rhs1_type);
3850       return true;
3851     }
3852
3853   if (handled_component_p (lhs))
3854     res |= verify_types_in_gimple_reference (lhs, true);
3855
3856   /* Special codes we cannot handle via their class.  */
3857   switch (rhs_code)
3858     {
3859     case ADDR_EXPR:
3860       {
3861         tree op = TREE_OPERAND (rhs1, 0);
3862         if (!is_gimple_addressable (op))
3863           {
3864             error ("invalid operand in unary expression");
3865             return true;
3866           }
3867
3868         /* Technically there is no longer a need for matching types, but
3869            gimple hygiene asks for this check.  In LTO we can end up
3870            combining incompatible units and thus end up with addresses
3871            of globals that change their type to a common one.  */
3872         if (!in_lto_p
3873             && !types_compatible_p (TREE_TYPE (op),
3874                                     TREE_TYPE (TREE_TYPE (rhs1)))
3875             && !one_pointer_to_useless_type_conversion_p (TREE_TYPE (rhs1),
3876                                                           TREE_TYPE (op)))
3877           {
3878             error ("type mismatch in address expression");
3879             debug_generic_stmt (TREE_TYPE (rhs1));
3880             debug_generic_stmt (TREE_TYPE (op));
3881             return true;
3882           }
3883
3884         return verify_types_in_gimple_reference (op, true);
3885       }
3886
3887     /* tcc_reference  */
3888     case INDIRECT_REF:
3889       error ("INDIRECT_REF in gimple IL");
3890       return true;
3891
3892     case COMPONENT_REF:
3893     case BIT_FIELD_REF:
3894     case ARRAY_REF:
3895     case ARRAY_RANGE_REF:
3896     case VIEW_CONVERT_EXPR:
3897     case REALPART_EXPR:
3898     case IMAGPART_EXPR:
3899     case TARGET_MEM_REF:
3900     case MEM_REF:
3901       if (!is_gimple_reg (lhs)
3902           && is_gimple_reg_type (TREE_TYPE (lhs)))
3903         {
3904           error ("invalid rhs for gimple memory store");
3905           debug_generic_stmt (lhs);
3906           debug_generic_stmt (rhs1);
3907           return true;
3908         }
3909       return res || verify_types_in_gimple_reference (rhs1, false);
3910
3911     /* tcc_constant  */
3912     case SSA_NAME:
3913     case INTEGER_CST:
3914     case REAL_CST:
3915     case FIXED_CST:
3916     case COMPLEX_CST:
3917     case VECTOR_CST:
3918     case STRING_CST:
3919       return res;
3920
3921     /* tcc_declaration  */
3922     case CONST_DECL:
3923       return res;
3924     case VAR_DECL:
3925     case PARM_DECL:
3926       if (!is_gimple_reg (lhs)
3927           && !is_gimple_reg (rhs1)
3928           && is_gimple_reg_type (TREE_TYPE (lhs)))
3929         {
3930           error ("invalid rhs for gimple memory store");
3931           debug_generic_stmt (lhs);
3932           debug_generic_stmt (rhs1);
3933           return true;
3934         }
3935       return res;
3936
3937     case CONSTRUCTOR:
3938     case OBJ_TYPE_REF:
3939     case ASSERT_EXPR:
3940     case WITH_SIZE_EXPR:
3941       /* FIXME.  */
3942       return res;
3943
3944     default:;
3945     }
3946
3947   return res;
3948 }
3949
3950 /* Verify the contents of a GIMPLE_ASSIGN STMT.  Returns true when there
3951    is a problem, otherwise false.  */
3952
3953 static bool
3954 verify_gimple_assign (gimple stmt)
3955 {
3956   switch (gimple_assign_rhs_class (stmt))
3957     {
3958     case GIMPLE_SINGLE_RHS:
3959       return verify_gimple_assign_single (stmt);
3960
3961     case GIMPLE_UNARY_RHS:
3962       return verify_gimple_assign_unary (stmt);
3963
3964     case GIMPLE_BINARY_RHS:
3965       return verify_gimple_assign_binary (stmt);
3966
3967     case GIMPLE_TERNARY_RHS:
3968       return verify_gimple_assign_ternary (stmt);
3969
3970     default:
3971       gcc_unreachable ();
3972     }
3973 }
3974
3975 /* Verify the contents of a GIMPLE_RETURN STMT.  Returns true when there
3976    is a problem, otherwise false.  */
3977
3978 static bool
3979 verify_gimple_return (gimple stmt)
3980 {
3981   tree op = gimple_return_retval (stmt);
3982   tree restype = TREE_TYPE (TREE_TYPE (cfun->decl));
3983
3984   /* We cannot test for present return values as we do not fix up missing
3985      return values from the original source.  */
3986   if (op == NULL)
3987     return false;
3988
3989   if (!is_gimple_val (op)
3990       && TREE_CODE (op) != RESULT_DECL)
3991     {
3992       error ("invalid operand in return statement");
3993       debug_generic_stmt (op);
3994       return true;
3995     }
3996
3997   if ((TREE_CODE (op) == RESULT_DECL
3998        && DECL_BY_REFERENCE (op))
3999       || (TREE_CODE (op) == SSA_NAME
4000           && TREE_CODE (SSA_NAME_VAR (op)) == RESULT_DECL
4001           && DECL_BY_REFERENCE (SSA_NAME_VAR (op))))
4002     op = TREE_TYPE (op);
4003
4004   if (!useless_type_conversion_p (restype, TREE_TYPE (op)))
4005     {
4006       error ("invalid conversion in return statement");
4007       debug_generic_stmt (restype);
4008       debug_generic_stmt (TREE_TYPE (op));
4009       return true;
4010     }
4011
4012   return false;
4013 }
4014
4015
4016 /* Verify the contents of a GIMPLE_GOTO STMT.  Returns true when there
4017    is a problem, otherwise false.  */
4018
4019 static bool
4020 verify_gimple_goto (gimple stmt)
4021 {
4022   tree dest = gimple_goto_dest (stmt);
4023
4024   /* ???  We have two canonical forms of direct goto destinations, a
4025      bare LABEL_DECL and an ADDR_EXPR of a LABEL_DECL.  */
4026   if (TREE_CODE (dest) != LABEL_DECL
4027       && (!is_gimple_val (dest)
4028           || !POINTER_TYPE_P (TREE_TYPE (dest))))
4029     {
4030       error ("goto destination is neither a label nor a pointer");
4031       return true;
4032     }
4033
4034   return false;
4035 }
4036
4037 /* Verify the contents of a GIMPLE_SWITCH STMT.  Returns true when there
4038    is a problem, otherwise false.  */
4039
4040 static bool
4041 verify_gimple_switch (gimple stmt)
4042 {
4043   if (!is_gimple_val (gimple_switch_index (stmt)))
4044     {
4045       error ("invalid operand to switch statement");
4046       debug_generic_stmt (gimple_switch_index (stmt));
4047       return true;
4048     }
4049
4050   return false;
4051 }
4052
4053
4054 /* Verify a gimple debug statement STMT.
4055    Returns true if anything is wrong.  */
4056
4057 static bool
4058 verify_gimple_debug (gimple stmt ATTRIBUTE_UNUSED)
4059 {
4060   /* There isn't much that could be wrong in a gimple debug stmt.  A
4061      gimple debug bind stmt, for example, maps a tree, that's usually
4062      a VAR_DECL or a PARM_DECL, but that could also be some scalarized
4063      component or member of an aggregate type, to another tree, that
4064      can be an arbitrary expression.  These stmts expand into debug
4065      insns, and are converted to debug notes by var-tracking.c.  */
4066   return false;
4067 }
4068
4069 /* Verify a gimple label statement STMT.
4070    Returns true if anything is wrong.  */
4071
4072 static bool
4073 verify_gimple_label (gimple stmt)
4074 {
4075   tree decl = gimple_label_label (stmt);
4076   int uid;
4077   bool err = false;
4078
4079   if (TREE_CODE (decl) != LABEL_DECL)
4080     return true;
4081
4082   uid = LABEL_DECL_UID (decl);
4083   if (cfun->cfg
4084       && (uid == -1
4085           || VEC_index (basic_block,
4086                         label_to_block_map, uid) != gimple_bb (stmt)))
4087     {
4088       error ("incorrect entry in label_to_block_map");
4089       err |= true;
4090     }
4091
4092   uid = EH_LANDING_PAD_NR (decl);
4093   if (uid)
4094     {
4095       eh_landing_pad lp = get_eh_landing_pad_from_number (uid);
4096       if (decl != lp->post_landing_pad)
4097         {
4098           error ("incorrect setting of landing pad number");
4099           err |= true;
4100         }
4101     }
4102
4103   return err;
4104 }
4105
4106 /* Verify the GIMPLE statement STMT.  Returns true if there is an
4107    error, otherwise false.  */
4108
4109 static bool
4110 verify_gimple_stmt (gimple stmt)
4111 {
4112   switch (gimple_code (stmt))
4113     {
4114     case GIMPLE_ASSIGN:
4115       return verify_gimple_assign (stmt);
4116
4117     case GIMPLE_LABEL:
4118       return verify_gimple_label (stmt);
4119
4120     case GIMPLE_CALL:
4121       return verify_gimple_call (stmt);
4122
4123     case GIMPLE_COND:
4124       if (TREE_CODE_CLASS (gimple_cond_code (stmt)) != tcc_comparison)
4125         {
4126           error ("invalid comparison code in gimple cond");
4127           return true;
4128         }
4129       if (!(!gimple_cond_true_label (stmt)
4130             || TREE_CODE (gimple_cond_true_label (stmt)) == LABEL_DECL)
4131           || !(!gimple_cond_false_label (stmt)
4132                || TREE_CODE (gimple_cond_false_label (stmt)) == LABEL_DECL))
4133         {
4134           error ("invalid labels in gimple cond");
4135           return true;
4136         }
4137
4138       return verify_gimple_comparison (boolean_type_node,
4139                                        gimple_cond_lhs (stmt),
4140                                        gimple_cond_rhs (stmt));
4141
4142     case GIMPLE_GOTO:
4143       return verify_gimple_goto (stmt);
4144
4145     case GIMPLE_SWITCH:
4146       return verify_gimple_switch (stmt);
4147
4148     case GIMPLE_RETURN:
4149       return verify_gimple_return (stmt);
4150
4151     case GIMPLE_ASM:
4152       return false;
4153
4154     /* Tuples that do not have tree operands.  */
4155     case GIMPLE_NOP:
4156     case GIMPLE_PREDICT:
4157     case GIMPLE_RESX:
4158     case GIMPLE_EH_DISPATCH:
4159     case GIMPLE_EH_MUST_NOT_THROW:
4160       return false;
4161
4162     CASE_GIMPLE_OMP:
4163       /* OpenMP directives are validated by the FE and never operated
4164          on by the optimizers.  Furthermore, GIMPLE_OMP_FOR may contain
4165          non-gimple expressions when the main index variable has had
4166          its address taken.  This does not affect the loop itself
4167          because the header of an GIMPLE_OMP_FOR is merely used to determine
4168          how to setup the parallel iteration.  */
4169       return false;
4170
4171     case GIMPLE_DEBUG:
4172       return verify_gimple_debug (stmt);
4173
4174     default:
4175       gcc_unreachable ();
4176     }
4177 }
4178
4179 /* Verify the contents of a GIMPLE_PHI.  Returns true if there is a problem,
4180    and false otherwise.  */
4181
4182 static bool
4183 verify_gimple_phi (gimple phi)
4184 {
4185   bool err = false;
4186   unsigned i;
4187   tree phi_result = gimple_phi_result (phi);
4188   bool virtual_p;
4189
4190   if (!phi_result)
4191     {
4192       error ("invalid PHI result");
4193       return true;
4194     }
4195
4196   virtual_p = !is_gimple_reg (phi_result);
4197   if (TREE_CODE (phi_result) != SSA_NAME
4198       || (virtual_p
4199           && SSA_NAME_VAR (phi_result) != gimple_vop (cfun)))
4200     {
4201       error ("invalid PHI result");
4202       err = true;
4203     }
4204
4205   for (i = 0; i < gimple_phi_num_args (phi); i++)
4206     {
4207       tree t = gimple_phi_arg_def (phi, i);
4208
4209       if (!t)
4210         {
4211           error ("missing PHI def");
4212           err |= true;
4213           continue;
4214         }
4215       /* Addressable variables do have SSA_NAMEs but they
4216          are not considered gimple values.  */
4217       else if ((TREE_CODE (t) == SSA_NAME
4218                 && virtual_p != !is_gimple_reg (t))
4219                || (virtual_p
4220                    && (TREE_CODE (t) != SSA_NAME
4221                        || SSA_NAME_VAR (t) != gimple_vop (cfun)))
4222                || (!virtual_p
4223                    && !is_gimple_val (t)))
4224         {
4225           error ("invalid PHI argument");
4226           debug_generic_expr (t);
4227           err |= true;
4228         }
4229 #ifdef ENABLE_TYPES_CHECKING
4230       if (!useless_type_conversion_p (TREE_TYPE (phi_result), TREE_TYPE (t)))
4231         {
4232           error ("incompatible types in PHI argument %u", i);
4233           debug_generic_stmt (TREE_TYPE (phi_result));
4234           debug_generic_stmt (TREE_TYPE (t));
4235           err |= true;
4236         }
4237 #endif
4238     }
4239
4240   return err;
4241 }
4242
4243 /* Verify the GIMPLE statements inside the sequence STMTS.  */
4244
4245 static bool
4246 verify_gimple_in_seq_2 (gimple_seq stmts)
4247 {
4248   gimple_stmt_iterator ittr;
4249   bool err = false;
4250
4251   for (ittr = gsi_start (stmts); !gsi_end_p (ittr); gsi_next (&ittr))
4252     {
4253       gimple stmt = gsi_stmt (ittr);
4254
4255       switch (gimple_code (stmt))
4256         {
4257         case GIMPLE_BIND:
4258           err |= verify_gimple_in_seq_2 (gimple_bind_body (stmt));
4259           break;
4260
4261         case GIMPLE_TRY:
4262           err |= verify_gimple_in_seq_2 (gimple_try_eval (stmt));
4263           err |= verify_gimple_in_seq_2 (gimple_try_cleanup (stmt));
4264           break;
4265
4266         case GIMPLE_EH_FILTER:
4267           err |= verify_gimple_in_seq_2 (gimple_eh_filter_failure (stmt));
4268           break;
4269
4270         case GIMPLE_CATCH:
4271           err |= verify_gimple_in_seq_2 (gimple_catch_handler (stmt));
4272           break;
4273
4274         default:
4275           {
4276             bool err2 = verify_gimple_stmt (stmt);
4277             if (err2)
4278               debug_gimple_stmt (stmt);
4279             err |= err2;
4280           }
4281         }
4282     }
4283
4284   return err;
4285 }
4286
4287
4288 /* Verify the GIMPLE statements inside the statement list STMTS.  */
4289
4290 DEBUG_FUNCTION void
4291 verify_gimple_in_seq (gimple_seq stmts)
4292 {
4293   timevar_push (TV_TREE_STMT_VERIFY);
4294   if (verify_gimple_in_seq_2 (stmts))
4295     internal_error ("verify_gimple failed");
4296   timevar_pop (TV_TREE_STMT_VERIFY);
4297 }
4298
4299 /* Return true when the T can be shared.  */
4300
4301 bool
4302 tree_node_can_be_shared (tree t)
4303 {
4304   if (IS_TYPE_OR_DECL_P (t)
4305       || is_gimple_min_invariant (t)
4306       || TREE_CODE (t) == SSA_NAME
4307       || t == error_mark_node
4308       || TREE_CODE (t) == IDENTIFIER_NODE)
4309     return true;
4310
4311   if (TREE_CODE (t) == CASE_LABEL_EXPR)
4312     return true;
4313
4314   while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
4315            && is_gimple_min_invariant (TREE_OPERAND (t, 1)))
4316          || TREE_CODE (t) == COMPONENT_REF
4317          || TREE_CODE (t) == REALPART_EXPR
4318          || TREE_CODE (t) == IMAGPART_EXPR)
4319     t = TREE_OPERAND (t, 0);
4320
4321   if (DECL_P (t))
4322     return true;
4323
4324   return false;
4325 }
4326
4327 /* Called via walk_gimple_stmt.  Verify tree sharing.  */
4328
4329 static tree
4330 verify_node_sharing (tree *tp, int *walk_subtrees, void *data)
4331 {
4332   struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
4333   struct pointer_set_t *visited = (struct pointer_set_t *) wi->info;
4334
4335   if (tree_node_can_be_shared (*tp))
4336     {
4337       *walk_subtrees = false;
4338       return NULL;
4339     }
4340
4341   if (pointer_set_insert (visited, *tp))
4342     return *tp;
4343
4344   return NULL;
4345 }
4346
4347 static bool eh_error_found;
4348 static int
4349 verify_eh_throw_stmt_node (void **slot, void *data)
4350 {
4351   struct throw_stmt_node *node = (struct throw_stmt_node *)*slot;
4352   struct pointer_set_t *visited = (struct pointer_set_t *) data;
4353
4354   if (!pointer_set_contains (visited, node->stmt))
4355     {
4356       error ("dead STMT in EH table");
4357       debug_gimple_stmt (node->stmt);
4358       eh_error_found = true;
4359     }
4360   return 1;
4361 }
4362
4363 /* Verify the GIMPLE statements in the CFG of FN.  */
4364
4365 DEBUG_FUNCTION void
4366 verify_gimple_in_cfg (struct function *fn)
4367 {
4368   basic_block bb;
4369   bool err = false;
4370   struct pointer_set_t *visited, *visited_stmts;
4371
4372   timevar_push (TV_TREE_STMT_VERIFY);
4373   visited = pointer_set_create ();
4374   visited_stmts = pointer_set_create ();
4375
4376   FOR_EACH_BB_FN (bb, fn)
4377     {
4378       gimple_stmt_iterator gsi;
4379
4380       for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4381         {
4382           gimple phi = gsi_stmt (gsi);
4383           bool err2 = false;
4384           unsigned i;
4385
4386           pointer_set_insert (visited_stmts, phi);
4387
4388           if (gimple_bb (phi) != bb)
4389             {
4390               error ("gimple_bb (phi) is set to a wrong basic block");
4391               err2 = true;
4392             }
4393
4394           err2 |= verify_gimple_phi (phi);
4395
4396           for (i = 0; i < gimple_phi_num_args (phi); i++)
4397             {
4398               tree arg = gimple_phi_arg_def (phi, i);
4399               tree addr = walk_tree (&arg, verify_node_sharing, visited, NULL);
4400               if (addr)
4401                 {
4402                   error ("incorrect sharing of tree nodes");
4403                   debug_generic_expr (addr);
4404                   err2 |= true;
4405                 }
4406             }
4407
4408           if (err2)
4409             debug_gimple_stmt (phi);
4410           err |= err2;
4411         }
4412
4413       for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4414         {
4415           gimple stmt = gsi_stmt (gsi);
4416           bool err2 = false;
4417           struct walk_stmt_info wi;
4418           tree addr;
4419           int lp_nr;
4420
4421           pointer_set_insert (visited_stmts, stmt);
4422
4423           if (gimple_bb (stmt) != bb)
4424             {
4425               error ("gimple_bb (stmt) is set to a wrong basic block");
4426               err2 = true;
4427             }
4428
4429           err2 |= verify_gimple_stmt (stmt);
4430
4431           memset (&wi, 0, sizeof (wi));
4432           wi.info = (void *) visited;
4433           addr = walk_gimple_op (stmt, verify_node_sharing, &wi);
4434           if (addr)
4435             {
4436               error ("incorrect sharing of tree nodes");
4437               debug_generic_expr (addr);
4438               err2 |= true;
4439             }
4440
4441           /* ???  Instead of not checking these stmts at all the walker
4442              should know its context via wi.  */
4443           if (!is_gimple_debug (stmt)
4444               && !is_gimple_omp (stmt))
4445             {
4446               memset (&wi, 0, sizeof (wi));
4447               addr = walk_gimple_op (stmt, verify_expr, &wi);
4448               if (addr)
4449                 {
4450                   debug_generic_expr (addr);
4451                   inform (gimple_location (stmt), "in statement");
4452                   err2 |= true;
4453                 }
4454             }
4455
4456           /* If the statement is marked as part of an EH region, then it is
4457              expected that the statement could throw.  Verify that when we
4458              have optimizations that simplify statements such that we prove
4459              that they cannot throw, that we update other data structures
4460              to match.  */
4461           lp_nr = lookup_stmt_eh_lp (stmt);
4462           if (lp_nr != 0)
4463             {
4464               if (!stmt_could_throw_p (stmt))
4465                 {
4466                   error ("statement marked for throw, but doesn%'t");
4467                   err2 |= true;
4468                 }
4469               else if (lp_nr > 0
4470                        && !gsi_one_before_end_p (gsi)
4471                        && stmt_can_throw_internal (stmt))
4472                 {
4473                   error ("statement marked for throw in middle of block");
4474                   err2 |= true;
4475                 }
4476             }
4477
4478           if (err2)
4479             debug_gimple_stmt (stmt);
4480           err |= err2;
4481         }
4482     }
4483
4484   eh_error_found = false;
4485   if (get_eh_throw_stmt_table (cfun))
4486     htab_traverse (get_eh_throw_stmt_table (cfun),
4487                    verify_eh_throw_stmt_node,
4488                    visited_stmts);
4489
4490   if (err || eh_error_found)
4491     internal_error ("verify_gimple failed");
4492
4493   pointer_set_destroy (visited);
4494   pointer_set_destroy (visited_stmts);
4495   verify_histograms ();
4496   timevar_pop (TV_TREE_STMT_VERIFY);
4497 }
4498
4499
4500 /* Verifies that the flow information is OK.  */
4501
4502 static int
4503 gimple_verify_flow_info (void)
4504 {
4505   int err = 0;
4506   basic_block bb;
4507   gimple_stmt_iterator gsi;
4508   gimple stmt;
4509   edge e;
4510   edge_iterator ei;
4511
4512   if (ENTRY_BLOCK_PTR->il.gimple)
4513     {
4514       error ("ENTRY_BLOCK has IL associated with it");
4515       err = 1;
4516     }
4517
4518   if (EXIT_BLOCK_PTR->il.gimple)
4519     {
4520       error ("EXIT_BLOCK has IL associated with it");
4521       err = 1;
4522     }
4523
4524   FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4525     if (e->flags & EDGE_FALLTHRU)
4526       {
4527         error ("fallthru to exit from bb %d", e->src->index);
4528         err = 1;
4529       }
4530
4531   FOR_EACH_BB (bb)
4532     {
4533       bool found_ctrl_stmt = false;
4534
4535       stmt = NULL;
4536
4537       /* Skip labels on the start of basic block.  */
4538       for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4539         {
4540           tree label;
4541           gimple prev_stmt = stmt;
4542
4543           stmt = gsi_stmt (gsi);
4544
4545           if (gimple_code (stmt) != GIMPLE_LABEL)
4546             break;
4547
4548           label = gimple_label_label (stmt);
4549           if (prev_stmt && DECL_NONLOCAL (label))
4550             {
4551               error ("nonlocal label ");
4552               print_generic_expr (stderr, label, 0);
4553               fprintf (stderr, " is not first in a sequence of labels in bb %d",
4554                        bb->index);
4555               err = 1;
4556             }
4557
4558           if (prev_stmt && EH_LANDING_PAD_NR (label) != 0)
4559             {
4560               error ("EH landing pad label ");
4561               print_generic_expr (stderr, label, 0);
4562               fprintf (stderr, " is not first in a sequence of labels in bb %d",
4563                        bb->index);
4564               err = 1;
4565             }
4566
4567           if (label_to_block (label) != bb)
4568             {
4569               error ("label ");
4570               print_generic_expr (stderr, label, 0);
4571               fprintf (stderr, " to block does not match in bb %d",
4572                        bb->index);
4573               err = 1;
4574             }
4575
4576           if (decl_function_context (label) != current_function_decl)
4577             {
4578               error ("label ");
4579               print_generic_expr (stderr, label, 0);
4580               fprintf (stderr, " has incorrect context in bb %d",
4581                        bb->index);
4582               err = 1;
4583             }
4584         }
4585
4586       /* Verify that body of basic block BB is free of control flow.  */
4587       for (; !gsi_end_p (gsi); gsi_next (&gsi))
4588         {
4589           gimple stmt = gsi_stmt (gsi);
4590
4591           if (found_ctrl_stmt)
4592             {
4593               error ("control flow in the middle of basic block %d",
4594                      bb->index);
4595               err = 1;
4596             }
4597
4598           if (stmt_ends_bb_p (stmt))
4599             found_ctrl_stmt = true;
4600
4601           if (gimple_code (stmt) == GIMPLE_LABEL)
4602             {
4603               error ("label ");
4604               print_generic_expr (stderr, gimple_label_label (stmt), 0);
4605               fprintf (stderr, " in the middle of basic block %d", bb->index);
4606               err = 1;
4607             }
4608         }
4609
4610       gsi = gsi_last_bb (bb);
4611       if (gsi_end_p (gsi))
4612         continue;
4613
4614       stmt = gsi_stmt (gsi);
4615
4616       if (gimple_code (stmt) == GIMPLE_LABEL)
4617         continue;
4618
4619       err |= verify_eh_edges (stmt);
4620
4621       if (is_ctrl_stmt (stmt))
4622         {
4623           FOR_EACH_EDGE (e, ei, bb->succs)
4624             if (e->flags & EDGE_FALLTHRU)
4625               {
4626                 error ("fallthru edge after a control statement in bb %d",
4627                        bb->index);
4628                 err = 1;
4629               }
4630         }
4631
4632       if (gimple_code (stmt) != GIMPLE_COND)
4633         {
4634           /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4635              after anything else but if statement.  */
4636           FOR_EACH_EDGE (e, ei, bb->succs)
4637             if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
4638               {
4639                 error ("true/false edge after a non-GIMPLE_COND in bb %d",
4640                        bb->index);
4641                 err = 1;
4642               }
4643         }
4644
4645       switch (gimple_code (stmt))
4646         {
4647         case GIMPLE_COND:
4648           {
4649             edge true_edge;
4650             edge false_edge;
4651
4652             extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
4653
4654             if (!true_edge
4655                 || !false_edge
4656                 || !(true_edge->flags & EDGE_TRUE_VALUE)
4657                 || !(false_edge->flags & EDGE_FALSE_VALUE)
4658                 || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4659                 || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4660                 || EDGE_COUNT (bb->succs) >= 3)
4661               {
4662                 error ("wrong outgoing edge flags at end of bb %d",
4663                        bb->index);
4664                 err = 1;
4665               }
4666           }
4667           break;
4668
4669         case GIMPLE_GOTO:
4670           if (simple_goto_p (stmt))
4671             {
4672               error ("explicit goto at end of bb %d", bb->index);
4673               err = 1;
4674             }
4675           else
4676             {
4677               /* FIXME.  We should double check that the labels in the
4678                  destination blocks have their address taken.  */
4679               FOR_EACH_EDGE (e, ei, bb->succs)
4680                 if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE
4681                                  | EDGE_FALSE_VALUE))
4682                     || !(e->flags & EDGE_ABNORMAL))
4683                   {
4684                     error ("wrong outgoing edge flags at end of bb %d",
4685                            bb->index);
4686                     err = 1;
4687                   }
4688             }
4689           break;
4690
4691         case GIMPLE_CALL:
4692           if (!gimple_call_builtin_p (stmt, BUILT_IN_RETURN))
4693             break;
4694           /* ... fallthru ... */
4695         case GIMPLE_RETURN:
4696           if (!single_succ_p (bb)
4697               || (single_succ_edge (bb)->flags
4698                   & (EDGE_FALLTHRU | EDGE_ABNORMAL
4699                      | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4700             {
4701               error ("wrong outgoing edge flags at end of bb %d", bb->index);
4702               err = 1;
4703             }
4704           if (single_succ (bb) != EXIT_BLOCK_PTR)
4705             {
4706               error ("return edge does not point to exit in bb %d",
4707                      bb->index);
4708               err = 1;
4709             }
4710           break;
4711
4712         case GIMPLE_SWITCH:
4713           {
4714             tree prev;
4715             edge e;
4716             size_t i, n;
4717
4718             n = gimple_switch_num_labels (stmt);
4719
4720             /* Mark all the destination basic blocks.  */
4721             for (i = 0; i < n; ++i)
4722               {
4723                 tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
4724                 basic_block label_bb = label_to_block (lab);
4725                 gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
4726                 label_bb->aux = (void *)1;
4727               }
4728
4729             /* Verify that the case labels are sorted.  */
4730             prev = gimple_switch_label (stmt, 0);
4731             for (i = 1; i < n; ++i)
4732               {
4733                 tree c = gimple_switch_label (stmt, i);
4734                 if (!CASE_LOW (c))
4735                   {
4736                     error ("found default case not at the start of "
4737                            "case vector");
4738                     err = 1;
4739                     continue;
4740                   }
4741                 if (CASE_LOW (prev)
4742                     && !tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c)))
4743                   {
4744                     error ("case labels not sorted: ");
4745                     print_generic_expr (stderr, prev, 0);
4746                     fprintf (stderr," is greater than ");
4747                     print_generic_expr (stderr, c, 0);
4748                     fprintf (stderr," but comes before it.\n");
4749                     err = 1;
4750                   }
4751                 prev = c;
4752               }
4753             /* VRP will remove the default case if it can prove it will
4754                never be executed.  So do not verify there always exists
4755                a default case here.  */
4756
4757             FOR_EACH_EDGE (e, ei, bb->succs)
4758               {
4759                 if (!e->dest->aux)
4760                   {
4761                     error ("extra outgoing edge %d->%d",
4762                            bb->index, e->dest->index);
4763                     err = 1;
4764                   }
4765
4766                 e->dest->aux = (void *)2;
4767                 if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL
4768                                  | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4769                   {
4770                     error ("wrong outgoing edge flags at end of bb %d",
4771                            bb->index);
4772                     err = 1;
4773                   }
4774               }
4775
4776             /* Check that we have all of them.  */
4777             for (i = 0; i < n; ++i)
4778               {
4779                 tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
4780                 basic_block label_bb = label_to_block (lab);
4781
4782                 if (label_bb->aux != (void *)2)
4783                   {
4784                     error ("missing edge %i->%i", bb->index, label_bb->index);
4785                     err = 1;
4786                   }
4787               }
4788
4789             FOR_EACH_EDGE (e, ei, bb->succs)
4790               e->dest->aux = (void *)0;
4791           }
4792           break;
4793
4794         case GIMPLE_EH_DISPATCH:
4795           err |= verify_eh_dispatch_edge (stmt);
4796           break;
4797
4798         default:
4799           break;
4800         }
4801     }
4802
4803   if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
4804     verify_dominators (CDI_DOMINATORS);
4805
4806   return err;
4807 }
4808
4809
4810 /* Updates phi nodes after creating a forwarder block joined
4811    by edge FALLTHRU.  */
4812
4813 static void
4814 gimple_make_forwarder_block (edge fallthru)
4815 {
4816   edge e;
4817   edge_iterator ei;
4818   basic_block dummy, bb;
4819   tree var;
4820   gimple_stmt_iterator gsi;
4821
4822   dummy = fallthru->src;
4823   bb = fallthru->dest;
4824
4825   if (single_pred_p (bb))
4826     return;
4827
4828   /* If we redirected a branch we must create new PHI nodes at the
4829      start of BB.  */
4830   for (gsi = gsi_start_phis (dummy); !gsi_end_p (gsi); gsi_next (&gsi))
4831     {
4832       gimple phi, new_phi;
4833
4834       phi = gsi_stmt (gsi);
4835       var = gimple_phi_result (phi);
4836       new_phi = create_phi_node (var, bb);
4837       SSA_NAME_DEF_STMT (var) = new_phi;
4838       gimple_phi_set_result (phi, make_ssa_name (SSA_NAME_VAR (var), phi));
4839       add_phi_arg (new_phi, gimple_phi_result (phi), fallthru,
4840                    UNKNOWN_LOCATION);
4841     }
4842
4843   /* Add the arguments we have stored on edges.  */
4844   FOR_EACH_EDGE (e, ei, bb->preds)
4845     {
4846       if (e == fallthru)
4847         continue;
4848
4849       flush_pending_stmts (e);
4850     }
4851 }
4852
4853
4854 /* Return a non-special label in the head of basic block BLOCK.
4855    Create one if it doesn't exist.  */
4856
4857 tree
4858 gimple_block_label (basic_block bb)
4859 {
4860   gimple_stmt_iterator i, s = gsi_start_bb (bb);
4861   bool first = true;
4862   tree label;
4863   gimple stmt;
4864
4865   for (i = s; !gsi_end_p (i); first = false, gsi_next (&i))
4866     {
4867       stmt = gsi_stmt (i);
4868       if (gimple_code (stmt) != GIMPLE_LABEL)
4869         break;
4870       label = gimple_label_label (stmt);
4871       if (!DECL_NONLOCAL (label))
4872         {
4873           if (!first)
4874             gsi_move_before (&i, &s);
4875           return label;
4876         }
4877     }
4878
4879   label = create_artificial_label (UNKNOWN_LOCATION);
4880   stmt = gimple_build_label (label);
4881   gsi_insert_before (&s, stmt, GSI_NEW_STMT);
4882   return label;
4883 }
4884
4885
4886 /* Attempt to perform edge redirection by replacing a possibly complex
4887    jump instruction by a goto or by removing the jump completely.
4888    This can apply only if all edges now point to the same block.  The
4889    parameters and return values are equivalent to
4890    redirect_edge_and_branch.  */
4891
4892 static edge
4893 gimple_try_redirect_by_replacing_jump (edge e, basic_block target)
4894 {
4895   basic_block src = e->src;
4896   gimple_stmt_iterator i;
4897   gimple stmt;
4898
4899   /* We can replace or remove a complex jump only when we have exactly
4900      two edges.  */
4901   if (EDGE_COUNT (src->succs) != 2
4902       /* Verify that all targets will be TARGET.  Specifically, the
4903          edge that is not E must also go to TARGET.  */
4904       || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)
4905     return NULL;
4906
4907   i = gsi_last_bb (src);
4908   if (gsi_end_p (i))
4909     return NULL;
4910
4911   stmt = gsi_stmt (i);
4912
4913   if (gimple_code (stmt) == GIMPLE_COND || gimple_code (stmt) == GIMPLE_SWITCH)
4914     {
4915       gsi_remove (&i, true);
4916       e = ssa_redirect_edge (e, target);
4917       e->flags = EDGE_FALLTHRU;
4918       return e;
4919     }
4920
4921   return NULL;
4922 }
4923
4924
4925 /* Redirect E to DEST.  Return NULL on failure.  Otherwise, return the
4926    edge representing the redirected branch.  */
4927
4928 static edge
4929 gimple_redirect_edge_and_branch (edge e, basic_block dest)
4930 {
4931   basic_block bb = e->src;
4932   gimple_stmt_iterator gsi;
4933   edge ret;
4934   gimple stmt;
4935
4936   if (e->flags & EDGE_ABNORMAL)
4937     return NULL;
4938
4939   if (e->dest == dest)
4940     return NULL;
4941
4942   if (e->flags & EDGE_EH)
4943     return redirect_eh_edge (e, dest);
4944
4945   if (e->src != ENTRY_BLOCK_PTR)
4946     {
4947       ret = gimple_try_redirect_by_replacing_jump (e, dest);
4948       if (ret)
4949         return ret;
4950     }
4951
4952   gsi = gsi_last_bb (bb);
4953   stmt = gsi_end_p (gsi) ? NULL : gsi_stmt (gsi);
4954
4955   switch (stmt ? gimple_code (stmt) : GIMPLE_ERROR_MARK)
4956     {
4957     case GIMPLE_COND:
4958       /* For COND_EXPR, we only need to redirect the edge.  */
4959       break;
4960
4961     case GIMPLE_GOTO:
4962       /* No non-abnormal edges should lead from a non-simple goto, and
4963          simple ones should be represented implicitly.  */
4964       gcc_unreachable ();
4965
4966     case GIMPLE_SWITCH:
4967       {
4968         tree label = gimple_block_label (dest);
4969         tree cases = get_cases_for_edge (e, stmt);
4970
4971         /* If we have a list of cases associated with E, then use it
4972            as it's a lot faster than walking the entire case vector.  */
4973         if (cases)
4974           {
4975             edge e2 = find_edge (e->src, dest);
4976             tree last, first;
4977
4978             first = cases;
4979             while (cases)
4980               {
4981                 last = cases;
4982                 CASE_LABEL (cases) = label;
4983                 cases = CASE_CHAIN (cases);
4984               }
4985
4986             /* If there was already an edge in the CFG, then we need
4987                to move all the cases associated with E to E2.  */
4988             if (e2)
4989               {
4990                 tree cases2 = get_cases_for_edge (e2, stmt);
4991
4992                 CASE_CHAIN (last) = CASE_CHAIN (cases2);
4993                 CASE_CHAIN (cases2) = first;
4994               }
4995             bitmap_set_bit (touched_switch_bbs, gimple_bb (stmt)->index);
4996           }
4997         else
4998           {
4999             size_t i, n = gimple_switch_num_labels (stmt);
5000
5001             for (i = 0; i < n; i++)
5002               {
5003                 tree elt = gimple_switch_label (stmt, i);
5004                 if (label_to_block (CASE_LABEL (elt)) == e->dest)
5005                   CASE_LABEL (elt) = label;
5006               }
5007           }
5008       }
5009       break;
5010
5011     case GIMPLE_ASM:
5012       {
5013         int i, n = gimple_asm_nlabels (stmt);
5014         tree label = NULL;
5015
5016         for (i = 0; i < n; ++i)
5017           {
5018             tree cons = gimple_asm_label_op (stmt, i);
5019             if (label_to_block (TREE_VALUE (cons)) == e->dest)
5020               {
5021                 if (!label)
5022                   label = gimple_block_label (dest);
5023                 TREE_VALUE (cons) = label;
5024               }
5025           }
5026
5027         /* If we didn't find any label matching the former edge in the
5028            asm labels, we must be redirecting the fallthrough
5029            edge.  */
5030         gcc_assert (label || (e->flags & EDGE_FALLTHRU));
5031       }
5032       break;
5033
5034     case GIMPLE_RETURN:
5035       gsi_remove (&gsi, true);
5036       e->flags |= EDGE_FALLTHRU;
5037       break;
5038
5039     case GIMPLE_OMP_RETURN:
5040     case GIMPLE_OMP_CONTINUE:
5041     case GIMPLE_OMP_SECTIONS_SWITCH:
5042     case GIMPLE_OMP_FOR:
5043       /* The edges from OMP constructs can be simply redirected.  */
5044       break;
5045
5046     case GIMPLE_EH_DISPATCH:
5047       if (!(e->flags & EDGE_FALLTHRU))
5048         redirect_eh_dispatch_edge (stmt, e, dest);
5049       break;
5050
5051     default:
5052       /* Otherwise it must be a fallthru edge, and we don't need to
5053          do anything besides redirecting it.  */
5054       gcc_assert (e->flags & EDGE_FALLTHRU);
5055       break;
5056     }
5057
5058   /* Update/insert PHI nodes as necessary.  */
5059
5060   /* Now update the edges in the CFG.  */
5061   e = ssa_redirect_edge (e, dest);
5062
5063   return e;
5064 }
5065
5066 /* Returns true if it is possible to remove edge E by redirecting
5067    it to the destination of the other edge from E->src.  */
5068
5069 static bool
5070 gimple_can_remove_branch_p (const_edge e)
5071 {
5072   if (e->flags & (EDGE_ABNORMAL | EDGE_EH))
5073     return false;
5074
5075   return true;
5076 }
5077
5078 /* Simple wrapper, as we can always redirect fallthru edges.  */
5079
5080 static basic_block
5081 gimple_redirect_edge_and_branch_force (edge e, basic_block dest)
5082 {
5083   e = gimple_redirect_edge_and_branch (e, dest);
5084   gcc_assert (e);
5085
5086   return NULL;
5087 }
5088
5089
5090 /* Splits basic block BB after statement STMT (but at least after the
5091    labels).  If STMT is NULL, BB is split just after the labels.  */
5092
5093 static basic_block
5094 gimple_split_block (basic_block bb, void *stmt)
5095 {
5096   gimple_stmt_iterator gsi;
5097   gimple_stmt_iterator gsi_tgt;
5098   gimple act;
5099   gimple_seq list;
5100   basic_block new_bb;
5101   edge e;
5102   edge_iterator ei;
5103
5104   new_bb = create_empty_bb (bb);
5105
5106   /* Redirect the outgoing edges.  */
5107   new_bb->succs = bb->succs;
5108   bb->succs = NULL;
5109   FOR_EACH_EDGE (e, ei, new_bb->succs)
5110     e->src = new_bb;
5111
5112   if (stmt && gimple_code ((gimple) stmt) == GIMPLE_LABEL)
5113     stmt = NULL;
5114
5115   /* Move everything from GSI to the new basic block.  */
5116   for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
5117     {
5118       act = gsi_stmt (gsi);
5119       if (gimple_code (act) == GIMPLE_LABEL)
5120         continue;
5121
5122       if (!stmt)
5123         break;
5124
5125       if (stmt == act)
5126         {
5127           gsi_next (&gsi);
5128           break;
5129         }
5130     }
5131
5132   if (gsi_end_p (gsi))
5133     return new_bb;
5134
5135   /* Split the statement list - avoid re-creating new containers as this
5136      brings ugly quadratic memory consumption in the inliner.
5137      (We are still quadratic since we need to update stmt BB pointers,
5138      sadly.)  */
5139   list = gsi_split_seq_before (&gsi);
5140   set_bb_seq (new_bb, list);
5141   for (gsi_tgt = gsi_start (list);
5142        !gsi_end_p (gsi_tgt); gsi_next (&gsi_tgt))
5143     gimple_set_bb (gsi_stmt (gsi_tgt), new_bb);
5144
5145   return new_bb;
5146 }
5147
5148
5149 /* Moves basic block BB after block AFTER.  */
5150
5151 static bool
5152 gimple_move_block_after (basic_block bb, basic_block after)
5153 {
5154   if (bb->prev_bb == after)
5155     return true;
5156
5157   unlink_block (bb);
5158   link_block (bb, after);
5159
5160   return true;
5161 }
5162
5163
5164 /* Return true if basic_block can be duplicated.  */
5165
5166 static bool
5167 gimple_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED)
5168 {
5169   return true;
5170 }
5171
5172 /* Create a duplicate of the basic block BB.  NOTE: This does not
5173    preserve SSA form.  */
5174
5175 static basic_block
5176 gimple_duplicate_bb (basic_block bb)
5177 {
5178   basic_block new_bb;
5179   gimple_stmt_iterator gsi, gsi_tgt;
5180   gimple_seq phis = phi_nodes (bb);
5181   gimple phi, stmt, copy;
5182
5183   new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb);
5184
5185   /* Copy the PHI nodes.  We ignore PHI node arguments here because
5186      the incoming edges have not been setup yet.  */
5187   for (gsi = gsi_start (phis); !gsi_end_p (gsi); gsi_next (&gsi))
5188     {
5189       phi = gsi_stmt (gsi);
5190       copy = create_phi_node (gimple_phi_result (phi), new_bb);
5191       create_new_def_for (gimple_phi_result (copy), copy,
5192                           gimple_phi_result_ptr (copy));
5193     }
5194
5195   gsi_tgt = gsi_start_bb (new_bb);
5196   for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
5197     {
5198       def_operand_p def_p;
5199       ssa_op_iter op_iter;
5200       tree lhs;
5201
5202       stmt = gsi_stmt (gsi);
5203       if (gimple_code (stmt) == GIMPLE_LABEL)
5204         continue;
5205
5206       /* Create a new copy of STMT and duplicate STMT's virtual
5207          operands.  */
5208       copy = gimple_copy (stmt);
5209       gsi_insert_after (&gsi_tgt, copy, GSI_NEW_STMT);
5210
5211       maybe_duplicate_eh_stmt (copy, stmt);
5212       gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
5213
5214       /* When copying around a stmt writing into a local non-user
5215          aggregate, make sure it won't share stack slot with other
5216          vars.  */
5217       lhs = gimple_get_lhs (stmt);
5218       if (lhs && TREE_CODE (lhs) != SSA_NAME)
5219         {
5220           tree base = get_base_address (lhs);
5221           if (base
5222               && (TREE_CODE (base) == VAR_DECL
5223                   || TREE_CODE (base) == RESULT_DECL)
5224               && DECL_IGNORED_P (base)
5225               && !TREE_STATIC (base)
5226               && !DECL_EXTERNAL (base)
5227               && (TREE_CODE (base) != VAR_DECL
5228                   || !DECL_HAS_VALUE_EXPR_P (base)))
5229             DECL_NONSHAREABLE (base) = 1;
5230         }
5231
5232       /* Create new names for all the definitions created by COPY and
5233          add replacement mappings for each new name.  */
5234       FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
5235         create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p);
5236     }
5237
5238   return new_bb;
5239 }
5240
5241 /* Adds phi node arguments for edge E_COPY after basic block duplication.  */
5242
5243 static void
5244 add_phi_args_after_copy_edge (edge e_copy)
5245 {
5246   basic_block bb, bb_copy = e_copy->src, dest;
5247   edge e;
5248   edge_iterator ei;
5249   gimple phi, phi_copy;
5250   tree def;
5251   gimple_stmt_iterator psi, psi_copy;
5252
5253   if (gimple_seq_empty_p (phi_nodes (e_copy->dest)))
5254     return;
5255
5256   bb = bb_copy->flags & BB_DUPLICATED ? get_bb_original (bb_copy) : bb_copy;
5257
5258   if (e_copy->dest->flags & BB_DUPLICATED)
5259     dest = get_bb_original (e_copy->dest);
5260   else
5261     dest = e_copy->dest;
5262
5263   e = find_edge (bb, dest);
5264   if (!e)
5265     {
5266       /* During loop unrolling the target of the latch edge is copied.
5267          In this case we are not looking for edge to dest, but to
5268          duplicated block whose original was dest.  */
5269       FOR_EACH_EDGE (e, ei, bb->succs)
5270         {
5271           if ((e->dest->flags & BB_DUPLICATED)
5272               && get_bb_original (e->dest) == dest)
5273             break;
5274         }
5275
5276       gcc_assert (e != NULL);
5277     }
5278
5279   for (psi = gsi_start_phis (e->dest),
5280        psi_copy = gsi_start_phis (e_copy->dest);
5281        !gsi_end_p (psi);
5282        gsi_next (&psi), gsi_next (&psi_copy))
5283     {
5284       phi = gsi_stmt (psi);
5285       phi_copy = gsi_stmt (psi_copy);
5286       def = PHI_ARG_DEF_FROM_EDGE (phi, e);
5287       add_phi_arg (phi_copy, def, e_copy,
5288                    gimple_phi_arg_location_from_edge (phi, e));
5289     }
5290 }
5291
5292
5293 /* Basic block BB_COPY was created by code duplication.  Add phi node
5294    arguments for edges going out of BB_COPY.  The blocks that were
5295    duplicated have BB_DUPLICATED set.  */
5296
5297 void
5298 add_phi_args_after_copy_bb (basic_block bb_copy)
5299 {
5300   edge e_copy;
5301   edge_iterator ei;
5302
5303   FOR_EACH_EDGE (e_copy, ei, bb_copy->succs)
5304     {
5305       add_phi_args_after_copy_edge (e_copy);
5306     }
5307 }
5308
5309 /* Blocks in REGION_COPY array of length N_REGION were created by
5310    duplication of basic blocks.  Add phi node arguments for edges
5311    going from these blocks.  If E_COPY is not NULL, also add
5312    phi node arguments for its destination.*/
5313
5314 void
5315 add_phi_args_after_copy (basic_block *region_copy, unsigned n_region,
5316                          edge e_copy)
5317 {
5318   unsigned i;
5319
5320   for (i = 0; i < n_region; i++)
5321     region_copy[i]->flags |= BB_DUPLICATED;
5322
5323   for (i = 0; i < n_region; i++)
5324     add_phi_args_after_copy_bb (region_copy[i]);
5325   if (e_copy)
5326     add_phi_args_after_copy_edge (e_copy);
5327
5328   for (i = 0; i < n_region; i++)
5329     region_copy[i]->flags &= ~BB_DUPLICATED;
5330 }
5331
5332 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
5333    important exit edge EXIT.  By important we mean that no SSA name defined
5334    inside region is live over the other exit edges of the region.  All entry
5335    edges to the region must go to ENTRY->dest.  The edge ENTRY is redirected
5336    to the duplicate of the region.  SSA form, dominance and loop information
5337    is updated.  The new basic blocks are stored to REGION_COPY in the same
5338    order as they had in REGION, provided that REGION_COPY is not NULL.
5339    The function returns false if it is unable to copy the region,
5340    true otherwise.  */
5341
5342 bool
5343 gimple_duplicate_sese_region (edge entry, edge exit,
5344                             basic_block *region, unsigned n_region,
5345                             basic_block *region_copy)
5346 {
5347   unsigned i;
5348   bool free_region_copy = false, copying_header = false;
5349   struct loop *loop = entry->dest->loop_father;
5350   edge exit_copy;
5351   VEC (basic_block, heap) *doms;
5352   edge redirected;
5353   int total_freq = 0, entry_freq = 0;
5354   gcov_type total_count = 0, entry_count = 0;
5355
5356   if (!can_copy_bbs_p (region, n_region))
5357     return false;
5358
5359   /* Some sanity checking.  Note that we do not check for all possible
5360      missuses of the functions.  I.e. if you ask to copy something weird,
5361      it will work, but the state of structures probably will not be
5362      correct.  */
5363   for (i = 0; i < n_region; i++)
5364     {
5365       /* We do not handle subloops, i.e. all the blocks must belong to the
5366          same loop.  */
5367       if (region[i]->loop_father != loop)
5368         return false;
5369
5370       if (region[i] != entry->dest
5371           && region[i] == loop->header)
5372         return false;
5373     }
5374
5375   set_loop_copy (loop, loop);
5376
5377   /* In case the function is used for loop header copying (which is the primary
5378      use), ensure that EXIT and its copy will be new latch and entry edges.  */
5379   if (loop->header == entry->dest)
5380     {
5381       copying_header = true;
5382       set_loop_copy (loop, loop_outer (loop));
5383
5384       if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src))
5385         return false;
5386
5387       for (i = 0; i < n_region; i++)
5388         if (region[i] != exit->src
5389             && dominated_by_p (CDI_DOMINATORS, region[i], exit->src))
5390           return false;
5391     }
5392
5393   if (!region_copy)
5394     {
5395       region_copy = XNEWVEC (basic_block, n_region);
5396       free_region_copy = true;
5397     }
5398
5399   gcc_assert (!need_ssa_update_p (cfun));
5400
5401   /* Record blocks outside the region that are dominated by something
5402      inside.  */
5403   doms = NULL;
5404   initialize_original_copy_tables ();
5405
5406   doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5407
5408   if (entry->dest->count)
5409     {
5410       total_count = entry->dest->count;
5411       entry_count = entry->count;
5412       /* Fix up corner cases, to avoid division by zero or creation of negative
5413          frequencies.  */
5414       if (entry_count > total_count)
5415         entry_count = total_count;
5416     }
5417   else
5418     {
5419       total_freq = entry->dest->frequency;
5420       entry_freq = EDGE_FREQUENCY (entry);
5421       /* Fix up corner cases, to avoid division by zero or creation of negative
5422          frequencies.  */
5423       if (total_freq == 0)
5424         total_freq = 1;
5425       else if (entry_freq > total_freq)
5426         entry_freq = total_freq;
5427     }
5428
5429   copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
5430             split_edge_bb_loc (entry));
5431   if (total_count)
5432     {
5433       scale_bbs_frequencies_gcov_type (region, n_region,
5434                                        total_count - entry_count,
5435                                        total_count);
5436       scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count,
5437                                        total_count);
5438     }
5439   else
5440     {
5441       scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq,
5442                                  total_freq);
5443       scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq);
5444     }
5445
5446   if (copying_header)
5447     {
5448       loop->header = exit->dest;
5449       loop->latch = exit->src;
5450     }
5451
5452   /* Redirect the entry and add the phi node arguments.  */
5453   redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest));
5454   gcc_assert (redirected != NULL);
5455   flush_pending_stmts (entry);
5456
5457   /* Concerning updating of dominators:  We must recount dominators
5458      for entry block and its copy.  Anything that is outside of the
5459      region, but was dominated by something inside needs recounting as
5460      well.  */
5461   set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src);
5462   VEC_safe_push (basic_block, heap, doms, get_bb_original (entry->dest));
5463   iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5464   VEC_free (basic_block, heap, doms);
5465
5466   /* Add the other PHI node arguments.  */
5467   add_phi_args_after_copy (region_copy, n_region, NULL);
5468
5469   /* Update the SSA web.  */
5470   update_ssa (TODO_update_ssa);
5471
5472   if (free_region_copy)
5473     free (region_copy);
5474
5475   free_original_copy_tables ();
5476   return true;
5477 }
5478
5479 /* Duplicates REGION consisting of N_REGION blocks.  The new blocks
5480    are stored to REGION_COPY in the same order in that they appear
5481    in REGION, if REGION_COPY is not NULL.  ENTRY is the entry to
5482    the region, EXIT an exit from it.  The condition guarding EXIT
5483    is moved to ENTRY.  Returns true if duplication succeeds, false
5484    otherwise.
5485
5486    For example,
5487
5488    some_code;
5489    if (cond)
5490      A;
5491    else
5492      B;
5493
5494    is transformed to
5495
5496    if (cond)
5497      {
5498        some_code;
5499        A;
5500      }
5501    else
5502      {
5503        some_code;
5504        B;
5505      }
5506 */
5507
5508 bool
5509 gimple_duplicate_sese_tail (edge entry ATTRIBUTE_UNUSED, edge exit ATTRIBUTE_UNUSED,
5510                           basic_block *region ATTRIBUTE_UNUSED, unsigned n_region ATTRIBUTE_UNUSED,
5511                           basic_block *region_copy ATTRIBUTE_UNUSED)
5512 {
5513   unsigned i;
5514   bool free_region_copy = false;
5515   struct loop *loop = exit->dest->loop_father;
5516   struct loop *orig_loop = entry->dest->loop_father;
5517   basic_block switch_bb, entry_bb, nentry_bb;
5518   VEC (basic_block, heap) *doms;
5519   int total_freq = 0, exit_freq = 0;
5520   gcov_type total_count = 0, exit_count = 0;
5521   edge exits[2], nexits[2], e;
5522   gimple_stmt_iterator gsi;
5523   gimple cond_stmt;
5524   edge sorig, snew;
5525   basic_block exit_bb;
5526   gimple_stmt_iterator psi;
5527   gimple phi;
5528   tree def;
5529
5530   gcc_assert (EDGE_COUNT (exit->src->succs) == 2);
5531   exits[0] = exit;
5532   exits[1] = EDGE_SUCC (exit->src, EDGE_SUCC (exit->src, 0) == exit);
5533
5534   if (!can_copy_bbs_p (region, n_region))
5535     return false;
5536
5537   initialize_original_copy_tables ();
5538   set_loop_copy (orig_loop, loop);
5539   duplicate_subloops (orig_loop, loop);
5540
5541   if (!region_copy)
5542     {
5543       region_copy = XNEWVEC (basic_block, n_region);
5544       free_region_copy = true;
5545     }
5546
5547   gcc_assert (!need_ssa_update_p (cfun));
5548
5549   /* Record blocks outside the region that are dominated by something
5550      inside.  */
5551   doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5552
5553   if (exit->src->count)
5554     {
5555       total_count = exit->src->count;
5556       exit_count = exit->count;
5557       /* Fix up corner cases, to avoid division by zero or creation of negative
5558          frequencies.  */
5559       if (exit_count > total_count)
5560         exit_count = total_count;
5561     }
5562   else
5563     {
5564       total_freq = exit->src->frequency;
5565       exit_freq = EDGE_FREQUENCY (exit);
5566       /* Fix up corner cases, to avoid division by zero or creation of negative
5567          frequencies.  */
5568       if (total_freq == 0)
5569         total_freq = 1;
5570       if (exit_freq > total_freq)
5571         exit_freq = total_freq;
5572     }
5573
5574   copy_bbs (region, n_region, region_copy, exits, 2, nexits, orig_loop,
5575             split_edge_bb_loc (exit));
5576   if (total_count)
5577     {
5578       scale_bbs_frequencies_gcov_type (region, n_region,
5579                                        total_count - exit_count,
5580                                        total_count);
5581       scale_bbs_frequencies_gcov_type (region_copy, n_region, exit_count,
5582                                        total_count);
5583     }
5584   else
5585     {
5586       scale_bbs_frequencies_int (region, n_region, total_freq - exit_freq,
5587                                  total_freq);
5588       scale_bbs_frequencies_int (region_copy, n_region, exit_freq, total_freq);
5589     }
5590
5591   /* Create the switch block, and put the exit condition to it.  */
5592   entry_bb = entry->dest;
5593   nentry_bb = get_bb_copy (entry_bb);
5594   if (!last_stmt (entry->src)
5595       || !stmt_ends_bb_p (last_stmt (entry->src)))
5596     switch_bb = entry->src;
5597   else
5598     switch_bb = split_edge (entry);
5599   set_immediate_dominator (CDI_DOMINATORS, nentry_bb, switch_bb);
5600
5601   gsi = gsi_last_bb (switch_bb);
5602   cond_stmt = last_stmt (exit->src);
5603   gcc_assert (gimple_code (cond_stmt) == GIMPLE_COND);
5604   cond_stmt = gimple_copy (cond_stmt);
5605
5606   gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT);
5607
5608   sorig = single_succ_edge (switch_bb);
5609   sorig->flags = exits[1]->flags;
5610   snew = make_edge (switch_bb, nentry_bb, exits[0]->flags);
5611
5612   /* Register the new edge from SWITCH_BB in loop exit lists.  */
5613   rescan_loop_exit (snew, true, false);
5614
5615   /* Add the PHI node arguments.  */
5616   add_phi_args_after_copy (region_copy, n_region, snew);
5617
5618   /* Get rid of now superfluous conditions and associated edges (and phi node
5619      arguments).  */
5620   exit_bb = exit->dest;
5621
5622   e = redirect_edge_and_branch (exits[0], exits[1]->dest);
5623   PENDING_STMT (e) = NULL;
5624
5625   /* The latch of ORIG_LOOP was copied, and so was the backedge
5626      to the original header.  We redirect this backedge to EXIT_BB.  */
5627   for (i = 0; i < n_region; i++)
5628     if (get_bb_original (region_copy[i]) == orig_loop->latch)
5629       {
5630         gcc_assert (single_succ_edge (region_copy[i]));
5631         e = redirect_edge_and_branch (single_succ_edge (region_copy[i]), exit_bb);
5632         PENDING_STMT (e) = NULL;
5633         for (psi = gsi_start_phis (exit_bb);
5634              !gsi_end_p (psi);
5635              gsi_next (&psi))
5636           {
5637             phi = gsi_stmt (psi);
5638             def = PHI_ARG_DEF (phi, nexits[0]->dest_idx);
5639             add_phi_arg (phi, def, e, gimple_phi_arg_location_from_edge (phi, e));
5640           }
5641       }
5642   e = redirect_edge_and_branch (nexits[0], nexits[1]->dest);
5643   PENDING_STMT (e) = NULL;
5644
5645   /* Anything that is outside of the region, but was dominated by something
5646      inside needs to update dominance info.  */
5647   iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5648   VEC_free (basic_block, heap, doms);
5649   /* Update the SSA web.  */
5650   update_ssa (TODO_update_ssa);
5651
5652   if (free_region_copy)
5653     free (region_copy);
5654
5655   free_original_copy_tables ();
5656   return true;
5657 }
5658
5659 /* Add all the blocks dominated by ENTRY to the array BBS_P.  Stop
5660    adding blocks when the dominator traversal reaches EXIT.  This
5661    function silently assumes that ENTRY strictly dominates EXIT.  */
5662
5663 void
5664 gather_blocks_in_sese_region (basic_block entry, basic_block exit,
5665                               VEC(basic_block,heap) **bbs_p)
5666 {
5667   basic_block son;
5668
5669   for (son = first_dom_son (CDI_DOMINATORS, entry);
5670        son;
5671        son = next_dom_son (CDI_DOMINATORS, son))
5672     {
5673       VEC_safe_push (basic_block, heap, *bbs_p, son);
5674       if (son != exit)
5675         gather_blocks_in_sese_region (son, exit, bbs_p);
5676     }
5677 }
5678
5679 /* Replaces *TP with a duplicate (belonging to function TO_CONTEXT).
5680    The duplicates are recorded in VARS_MAP.  */
5681
5682 static void
5683 replace_by_duplicate_decl (tree *tp, struct pointer_map_t *vars_map,
5684                            tree to_context)
5685 {
5686   tree t = *tp, new_t;
5687   struct function *f = DECL_STRUCT_FUNCTION (to_context);
5688   void **loc;
5689
5690   if (DECL_CONTEXT (t) == to_context)
5691     return;
5692
5693   loc = pointer_map_contains (vars_map, t);
5694
5695   if (!loc)
5696     {
5697       loc = pointer_map_insert (vars_map, t);
5698
5699       if (SSA_VAR_P (t))
5700         {
5701           new_t = copy_var_decl (t, DECL_NAME (t), TREE_TYPE (t));
5702           add_local_decl (f, new_t);
5703         }
5704       else
5705         {
5706           gcc_assert (TREE_CODE (t) == CONST_DECL);
5707           new_t = copy_node (t);
5708         }
5709       DECL_CONTEXT (new_t) = to_context;
5710
5711       *loc = new_t;
5712     }
5713   else
5714     new_t = (tree) *loc;
5715
5716   *tp = new_t;
5717 }
5718
5719
5720 /* Creates an ssa name in TO_CONTEXT equivalent to NAME.
5721    VARS_MAP maps old ssa names and var_decls to the new ones.  */
5722
5723 static tree
5724 replace_ssa_name (tree name, struct pointer_map_t *vars_map,
5725                   tree to_context)
5726 {
5727   void **loc;
5728   tree new_name, decl = SSA_NAME_VAR (name);
5729
5730   gcc_assert (is_gimple_reg (name));
5731
5732   loc = pointer_map_contains (vars_map, name);
5733
5734   if (!loc)
5735     {
5736       replace_by_duplicate_decl (&decl, vars_map, to_context);
5737
5738       push_cfun (DECL_STRUCT_FUNCTION (to_context));
5739       if (gimple_in_ssa_p (cfun))
5740         add_referenced_var (decl);
5741
5742       new_name = make_ssa_name (decl, SSA_NAME_DEF_STMT (name));
5743       if (SSA_NAME_IS_DEFAULT_DEF (name))
5744         set_default_def (decl, new_name);
5745       pop_cfun ();
5746
5747       loc = pointer_map_insert (vars_map, name);
5748       *loc = new_name;
5749     }
5750   else
5751     new_name = (tree) *loc;
5752
5753   return new_name;
5754 }
5755
5756 struct move_stmt_d
5757 {
5758   tree orig_block;
5759   tree new_block;
5760   tree from_context;
5761   tree to_context;
5762   struct pointer_map_t *vars_map;
5763   htab_t new_label_map;
5764   struct pointer_map_t *eh_map;
5765   bool remap_decls_p;
5766 };
5767
5768 /* Helper for move_block_to_fn.  Set TREE_BLOCK in every expression
5769    contained in *TP if it has been ORIG_BLOCK previously and change the
5770    DECL_CONTEXT of every local variable referenced in *TP.  */
5771
5772 static tree
5773 move_stmt_op (tree *tp, int *walk_subtrees, void *data)
5774 {
5775   struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
5776   struct move_stmt_d *p = (struct move_stmt_d *) wi->info;
5777   tree t = *tp;
5778
5779   if (EXPR_P (t))
5780     /* We should never have TREE_BLOCK set on non-statements.  */
5781     gcc_assert (!TREE_BLOCK (t));
5782
5783   else if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
5784     {
5785       if (TREE_CODE (t) == SSA_NAME)
5786         *tp = replace_ssa_name (t, p->vars_map, p->to_context);
5787       else if (TREE_CODE (t) == LABEL_DECL)
5788         {
5789           if (p->new_label_map)
5790             {
5791               struct tree_map in, *out;
5792               in.base.from = t;
5793               out = (struct tree_map *)
5794                 htab_find_with_hash (p->new_label_map, &in, DECL_UID (t));
5795               if (out)
5796                 *tp = t = out->to;
5797             }
5798
5799           DECL_CONTEXT (t) = p->to_context;
5800         }
5801       else if (p->remap_decls_p)
5802         {
5803           /* Replace T with its duplicate.  T should no longer appear in the
5804              parent function, so this looks wasteful; however, it may appear
5805              in referenced_vars, and more importantly, as virtual operands of
5806              statements, and in alias lists of other variables.  It would be
5807              quite difficult to expunge it from all those places.  ??? It might
5808              suffice to do this for addressable variables.  */
5809           if ((TREE_CODE (t) == VAR_DECL
5810                && !is_global_var (t))
5811               || TREE_CODE (t) == CONST_DECL)
5812             replace_by_duplicate_decl (tp, p->vars_map, p->to_context);
5813
5814           if (SSA_VAR_P (t)
5815               && gimple_in_ssa_p (cfun))
5816             {
5817               push_cfun (DECL_STRUCT_FUNCTION (p->to_context));
5818               add_referenced_var (*tp);
5819               pop_cfun ();
5820             }
5821         }
5822       *walk_subtrees = 0;
5823     }
5824   else if (TYPE_P (t))
5825     *walk_subtrees = 0;
5826
5827   return NULL_TREE;
5828 }
5829
5830 /* Helper for move_stmt_r.  Given an EH region number for the source
5831    function, map that to the duplicate EH regio number in the dest.  */
5832
5833 static int
5834 move_stmt_eh_region_nr (int old_nr, struct move_stmt_d *p)
5835 {
5836   eh_region old_r, new_r;
5837   void **slot;
5838
5839   old_r = get_eh_region_from_number (old_nr);
5840   slot = pointer_map_contains (p->eh_map, old_r);
5841   new_r = (eh_region) *slot;
5842
5843   return new_r->index;
5844 }
5845
5846 /* Similar, but operate on INTEGER_CSTs.  */
5847
5848 static tree
5849 move_stmt_eh_region_tree_nr (tree old_t_nr, struct move_stmt_d *p)
5850 {
5851   int old_nr, new_nr;
5852
5853   old_nr = tree_low_cst (old_t_nr, 0);
5854   new_nr = move_stmt_eh_region_nr (old_nr, p);
5855
5856   return build_int_cst (integer_type_node, new_nr);
5857 }
5858
5859 /* Like move_stmt_op, but for gimple statements.
5860
5861    Helper for move_block_to_fn.  Set GIMPLE_BLOCK in every expression
5862    contained in the current statement in *GSI_P and change the
5863    DECL_CONTEXT of every local variable referenced in the current
5864    statement.  */
5865
5866 static tree
5867 move_stmt_r (gimple_stmt_iterator *gsi_p, bool *handled_ops_p,
5868              struct walk_stmt_info *wi)
5869 {
5870   struct move_stmt_d *p = (struct move_stmt_d *) wi->info;
5871   gimple stmt = gsi_stmt (*gsi_p);
5872   tree block = gimple_block (stmt);
5873
5874   if (p->orig_block == NULL_TREE
5875       || block == p->orig_block
5876       || block == NULL_TREE)
5877     gimple_set_block (stmt, p->new_block);
5878 #ifdef ENABLE_CHECKING
5879   else if (block != p->new_block)
5880     {
5881       while (block && block != p->orig_block)
5882         block = BLOCK_SUPERCONTEXT (block);
5883       gcc_assert (block);
5884     }
5885 #endif
5886
5887   switch (gimple_code (stmt))
5888     {
5889     case GIMPLE_CALL:
5890       /* Remap the region numbers for __builtin_eh_{pointer,filter}.  */
5891       {
5892         tree r, fndecl = gimple_call_fndecl (stmt);
5893         if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
5894           switch (DECL_FUNCTION_CODE (fndecl))
5895             {
5896             case BUILT_IN_EH_COPY_VALUES:
5897               r = gimple_call_arg (stmt, 1);
5898               r = move_stmt_eh_region_tree_nr (r, p);
5899               gimple_call_set_arg (stmt, 1, r);
5900               /* FALLTHRU */
5901
5902             case BUILT_IN_EH_POINTER:
5903             case BUILT_IN_EH_FILTER:
5904               r = gimple_call_arg (stmt, 0);
5905               r = move_stmt_eh_region_tree_nr (r, p);
5906               gimple_call_set_arg (stmt, 0, r);
5907               break;
5908
5909             default:
5910               break;
5911             }
5912       }
5913       break;
5914
5915     case GIMPLE_RESX:
5916       {
5917         int r = gimple_resx_region (stmt);
5918         r = move_stmt_eh_region_nr (r, p);
5919         gimple_resx_set_region (stmt, r);
5920       }
5921       break;
5922
5923     case GIMPLE_EH_DISPATCH:
5924       {
5925         int r = gimple_eh_dispatch_region (stmt);
5926         r = move_stmt_eh_region_nr (r, p);
5927         gimple_eh_dispatch_set_region (stmt, r);
5928       }
5929       break;
5930
5931     case GIMPLE_OMP_RETURN:
5932     case GIMPLE_OMP_CONTINUE:
5933       break;
5934     default:
5935       if (is_gimple_omp (stmt))
5936         {
5937           /* Do not remap variables inside OMP directives.  Variables
5938              referenced in clauses and directive header belong to the
5939              parent function and should not be moved into the child
5940              function.  */
5941           bool save_remap_decls_p = p->remap_decls_p;
5942           p->remap_decls_p = false;
5943           *handled_ops_p = true;
5944
5945           walk_gimple_seq (gimple_omp_body (stmt), move_stmt_r,
5946                            move_stmt_op, wi);
5947
5948           p->remap_decls_p = save_remap_decls_p;
5949         }
5950       break;
5951     }
5952
5953   return NULL_TREE;
5954 }
5955
5956 /* Move basic block BB from function CFUN to function DEST_FN.  The
5957    block is moved out of the original linked list and placed after
5958    block AFTER in the new list.  Also, the block is removed from the
5959    original array of blocks and placed in DEST_FN's array of blocks.
5960    If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5961    updated to reflect the moved edges.
5962
5963    The local variables are remapped to new instances, VARS_MAP is used
5964    to record the mapping.  */
5965
5966 static void
5967 move_block_to_fn (struct function *dest_cfun, basic_block bb,
5968                   basic_block after, bool update_edge_count_p,
5969                   struct move_stmt_d *d)
5970 {
5971   struct control_flow_graph *cfg;
5972   edge_iterator ei;
5973   edge e;
5974   gimple_stmt_iterator si;
5975   unsigned old_len, new_len;
5976
5977   /* Remove BB from dominance structures.  */
5978   delete_from_dominance_info (CDI_DOMINATORS, bb);
5979   if (current_loops)
5980     remove_bb_from_loops (bb);
5981
5982   /* Link BB to the new linked list.  */
5983   move_block_after (bb, after);
5984
5985   /* Update the edge count in the corresponding flowgraphs.  */
5986   if (update_edge_count_p)
5987     FOR_EACH_EDGE (e, ei, bb->succs)
5988       {
5989         cfun->cfg->x_n_edges--;
5990         dest_cfun->cfg->x_n_edges++;
5991       }
5992
5993   /* Remove BB from the original basic block array.  */
5994   VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL);
5995   cfun->cfg->x_n_basic_blocks--;
5996
5997   /* Grow DEST_CFUN's basic block array if needed.  */
5998   cfg = dest_cfun->cfg;
5999   cfg->x_n_basic_blocks++;
6000   if (bb->index >= cfg->x_last_basic_block)
6001     cfg->x_last_basic_block = bb->index + 1;
6002
6003   old_len = VEC_length (basic_block, cfg->x_basic_block_info);
6004   if ((unsigned) cfg->x_last_basic_block >= old_len)
6005     {
6006       new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4;
6007       VEC_safe_grow_cleared (basic_block, gc, cfg->x_basic_block_info,
6008                              new_len);
6009     }
6010
6011   VEC_replace (basic_block, cfg->x_basic_block_info,
6012                bb->index, bb);
6013
6014   /* Remap the variables in phi nodes.  */
6015   for (si = gsi_start_phis (bb); !gsi_end_p (si); )
6016     {
6017       gimple phi = gsi_stmt (si);
6018       use_operand_p use;
6019       tree op = PHI_RESULT (phi);
6020       ssa_op_iter oi;
6021
6022       if (!is_gimple_reg (op))
6023         {
6024           /* Remove the phi nodes for virtual operands (alias analysis will be
6025              run for the new function, anyway).  */
6026           remove_phi_node (&si, true);
6027           continue;
6028         }
6029
6030       SET_PHI_RESULT (phi,
6031                       replace_ssa_name (op, d->vars_map, dest_cfun->decl));
6032       FOR_EACH_PHI_ARG (use, phi, oi, SSA_OP_USE)
6033         {
6034           op = USE_FROM_PTR (use);
6035           if (TREE_CODE (op) == SSA_NAME)
6036             SET_USE (use, replace_ssa_name (op, d->vars_map, dest_cfun->decl));
6037         }
6038
6039       gsi_next (&si);
6040     }
6041
6042   for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
6043     {
6044       gimple stmt = gsi_stmt (si);
6045       struct walk_stmt_info wi;
6046
6047       memset (&wi, 0, sizeof (wi));
6048       wi.info = d;
6049       walk_gimple_stmt (&si, move_stmt_r, move_stmt_op, &wi);
6050
6051       if (gimple_code (stmt) == GIMPLE_LABEL)
6052         {
6053           tree label = gimple_label_label (stmt);
6054           int uid = LABEL_DECL_UID (label);
6055
6056           gcc_assert (uid > -1);
6057
6058           old_len = VEC_length (basic_block, cfg->x_label_to_block_map);
6059           if (old_len <= (unsigned) uid)
6060             {
6061               new_len = 3 * uid / 2 + 1;
6062               VEC_safe_grow_cleared (basic_block, gc,
6063                                      cfg->x_label_to_block_map, new_len);
6064             }
6065
6066           VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb);
6067           VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL);
6068
6069           gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl);
6070
6071           if (uid >= dest_cfun->cfg->last_label_uid)
6072             dest_cfun->cfg->last_label_uid = uid + 1;
6073         }
6074
6075       maybe_duplicate_eh_stmt_fn (dest_cfun, stmt, cfun, stmt, d->eh_map, 0);
6076       remove_stmt_from_eh_lp_fn (cfun, stmt);
6077
6078       gimple_duplicate_stmt_histograms (dest_cfun, stmt, cfun, stmt);
6079       gimple_remove_stmt_histograms (cfun, stmt);
6080
6081       /* We cannot leave any operands allocated from the operand caches of
6082          the current function.  */
6083       free_stmt_operands (stmt);
6084       push_cfun (dest_cfun);
6085       update_stmt (stmt);
6086       pop_cfun ();
6087     }
6088
6089   FOR_EACH_EDGE (e, ei, bb->succs)
6090     if (e->goto_locus)
6091       {
6092         tree block = e->goto_block;
6093         if (d->orig_block == NULL_TREE
6094             || block == d->orig_block)
6095           e->goto_block = d->new_block;
6096 #ifdef ENABLE_CHECKING
6097         else if (block != d->new_block)
6098           {
6099             while (block && block != d->orig_block)
6100               block = BLOCK_SUPERCONTEXT (block);
6101             gcc_assert (block);
6102           }
6103 #endif
6104       }
6105 }
6106
6107 /* Examine the statements in BB (which is in SRC_CFUN); find and return
6108    the outermost EH region.  Use REGION as the incoming base EH region.  */
6109
6110 static eh_region
6111 find_outermost_region_in_block (struct function *src_cfun,
6112                                 basic_block bb, eh_region region)
6113 {
6114   gimple_stmt_iterator si;
6115
6116   for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
6117     {
6118       gimple stmt = gsi_stmt (si);
6119       eh_region stmt_region;
6120       int lp_nr;
6121
6122       lp_nr = lookup_stmt_eh_lp_fn (src_cfun, stmt);
6123       stmt_region = get_eh_region_from_lp_number_fn (src_cfun, lp_nr);
6124       if (stmt_region)
6125         {
6126           if (region == NULL)
6127             region = stmt_region;
6128           else if (stmt_region != region)
6129             {
6130               region = eh_region_outermost (src_cfun, stmt_region, region);
6131               gcc_assert (region != NULL);
6132             }
6133         }
6134     }
6135
6136   return region;
6137 }
6138
6139 static tree
6140 new_label_mapper (tree decl, void *data)
6141 {
6142   htab_t hash = (htab_t) data;
6143   struct tree_map *m;
6144   void **slot;
6145
6146   gcc_assert (TREE_CODE (decl) == LABEL_DECL);
6147
6148   m = XNEW (struct tree_map);
6149   m->hash = DECL_UID (decl);
6150   m->base.from = decl;
6151   m->to = create_artificial_label (UNKNOWN_LOCATION);
6152   LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl);
6153   if (LABEL_DECL_UID (m->to) >= cfun->cfg->last_label_uid)
6154     cfun->cfg->last_label_uid = LABEL_DECL_UID (m->to) + 1;
6155
6156   slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT);
6157   gcc_assert (*slot == NULL);
6158
6159   *slot = m;
6160
6161   return m->to;
6162 }
6163
6164 /* Change DECL_CONTEXT of all BLOCK_VARS in block, including
6165    subblocks.  */
6166
6167 static void
6168 replace_block_vars_by_duplicates (tree block, struct pointer_map_t *vars_map,
6169                                   tree to_context)
6170 {
6171   tree *tp, t;
6172
6173   for (tp = &BLOCK_VARS (block); *tp; tp = &DECL_CHAIN (*tp))
6174     {
6175       t = *tp;
6176       if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != CONST_DECL)
6177         continue;
6178       replace_by_duplicate_decl (&t, vars_map, to_context);
6179       if (t != *tp)
6180         {
6181           if (TREE_CODE (*tp) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (*tp))
6182             {
6183               SET_DECL_VALUE_EXPR (t, DECL_VALUE_EXPR (*tp));
6184               DECL_HAS_VALUE_EXPR_P (t) = 1;
6185             }
6186           DECL_CHAIN (t) = DECL_CHAIN (*tp);
6187           *tp = t;
6188         }
6189     }
6190
6191   for (block = BLOCK_SUBBLOCKS (block); block; block = BLOCK_CHAIN (block))
6192     replace_block_vars_by_duplicates (block, vars_map, to_context);
6193 }
6194
6195 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
6196    EXIT_BB to function DEST_CFUN.  The whole region is replaced by a
6197    single basic block in the original CFG and the new basic block is
6198    returned.  DEST_CFUN must not have a CFG yet.
6199
6200    Note that the region need not be a pure SESE region.  Blocks inside
6201    the region may contain calls to abort/exit.  The only restriction
6202    is that ENTRY_BB should be the only entry point and it must
6203    dominate EXIT_BB.
6204
6205    Change TREE_BLOCK of all statements in ORIG_BLOCK to the new
6206    functions outermost BLOCK, move all subblocks of ORIG_BLOCK
6207    to the new function.
6208
6209    All local variables referenced in the region are assumed to be in
6210    the corresponding BLOCK_VARS and unexpanded variable lists
6211    associated with DEST_CFUN.  */
6212
6213 basic_block
6214 move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
6215                         basic_block exit_bb, tree orig_block)
6216 {
6217   VEC(basic_block,heap) *bbs, *dom_bbs;
6218   basic_block dom_entry = get_immediate_dominator (CDI_DOMINATORS, entry_bb);
6219   basic_block after, bb, *entry_pred, *exit_succ, abb;
6220   struct function *saved_cfun = cfun;
6221   int *entry_flag, *exit_flag;
6222   unsigned *entry_prob, *exit_prob;
6223   unsigned i, num_entry_edges, num_exit_edges;
6224   edge e;
6225   edge_iterator ei;
6226   htab_t new_label_map;
6227   struct pointer_map_t *vars_map, *eh_map;
6228   struct loop *loop = entry_bb->loop_father;
6229   struct move_stmt_d d;
6230
6231   /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
6232      region.  */
6233   gcc_assert (entry_bb != exit_bb
6234               && (!exit_bb
6235                   || dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)));
6236
6237   /* Collect all the blocks in the region.  Manually add ENTRY_BB
6238      because it won't be added by dfs_enumerate_from.  */
6239   bbs = NULL;
6240   VEC_safe_push (basic_block, heap, bbs, entry_bb);
6241   gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs);
6242
6243   /* The blocks that used to be dominated by something in BBS will now be
6244      dominated by the new block.  */
6245   dom_bbs = get_dominated_by_region (CDI_DOMINATORS,
6246                                      VEC_address (basic_block, bbs),
6247                                      VEC_length (basic_block, bbs));
6248
6249   /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG.  We need to remember
6250      the predecessor edges to ENTRY_BB and the successor edges to
6251      EXIT_BB so that we can re-attach them to the new basic block that
6252      will replace the region.  */
6253   num_entry_edges = EDGE_COUNT (entry_bb->preds);
6254   entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
6255   entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
6256   entry_prob = XNEWVEC (unsigned, num_entry_edges);
6257   i = 0;
6258   for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
6259     {
6260       entry_prob[i] = e->probability;
6261       entry_flag[i] = e->flags;
6262       entry_pred[i++] = e->src;
6263       remove_edge (e);
6264     }
6265
6266   if (exit_bb)
6267     {
6268       num_exit_edges = EDGE_COUNT (exit_bb->succs);
6269       exit_succ = (basic_block *) xcalloc (num_exit_edges,
6270                                            sizeof (basic_block));
6271       exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
6272       exit_prob = XNEWVEC (unsigned, num_exit_edges);
6273       i = 0;
6274       for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)
6275         {
6276           exit_prob[i] = e->probability;
6277           exit_flag[i] = e->flags;
6278           exit_succ[i++] = e->dest;
6279           remove_edge (e);
6280         }
6281     }
6282   else
6283     {
6284       num_exit_edges = 0;
6285       exit_succ = NULL;
6286       exit_flag = NULL;
6287       exit_prob = NULL;
6288     }
6289
6290   /* Switch context to the child function to initialize DEST_FN's CFG.  */
6291   gcc_assert (dest_cfun->cfg == NULL);
6292   push_cfun (dest_cfun);
6293
6294   init_empty_tree_cfg ();
6295
6296   /* Initialize EH information for the new function.  */
6297   eh_map = NULL;
6298   new_label_map = NULL;
6299   if (saved_cfun->eh)
6300     {
6301       eh_region region = NULL;
6302
6303       FOR_EACH_VEC_ELT (basic_block, bbs, i, bb)
6304         region = find_outermost_region_in_block (saved_cfun, bb, region);
6305
6306       init_eh_for_function ();
6307       if (region != NULL)
6308         {
6309           new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free);
6310           eh_map = duplicate_eh_regions (saved_cfun, region, 0,
6311                                          new_label_mapper, new_label_map);
6312         }
6313     }
6314
6315   pop_cfun ();
6316
6317   /* Move blocks from BBS into DEST_CFUN.  */
6318   gcc_assert (VEC_length (basic_block, bbs) >= 2);
6319   after = dest_cfun->cfg->x_entry_block_ptr;
6320   vars_map = pointer_map_create ();
6321
6322   memset (&d, 0, sizeof (d));
6323   d.orig_block = orig_block;
6324   d.new_block = DECL_INITIAL (dest_cfun->decl);
6325   d.from_context = cfun->decl;
6326   d.to_context = dest_cfun->decl;
6327   d.vars_map = vars_map;
6328   d.new_label_map = new_label_map;
6329   d.eh_map = eh_map;
6330   d.remap_decls_p = true;
6331
6332   FOR_EACH_VEC_ELT (basic_block, bbs, i, bb)
6333     {
6334       /* No need to update edge counts on the last block.  It has
6335          already been updated earlier when we detached the region from
6336          the original CFG.  */
6337       move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, &d);
6338       after = bb;
6339     }
6340
6341   /* Rewire BLOCK_SUBBLOCKS of orig_block.  */
6342   if (orig_block)
6343     {
6344       tree block;
6345       gcc_assert (BLOCK_SUBBLOCKS (DECL_INITIAL (dest_cfun->decl))
6346                   == NULL_TREE);
6347       BLOCK_SUBBLOCKS (DECL_INITIAL (dest_cfun->decl))
6348         = BLOCK_SUBBLOCKS (orig_block);
6349       for (block = BLOCK_SUBBLOCKS (orig_block);
6350            block; block = BLOCK_CHAIN (block))
6351         BLOCK_SUPERCONTEXT (block) = DECL_INITIAL (dest_cfun->decl);
6352       BLOCK_SUBBLOCKS (orig_block) = NULL_TREE;
6353     }
6354
6355   replace_block_vars_by_duplicates (DECL_INITIAL (dest_cfun->decl),
6356                                     vars_map, dest_cfun->decl);
6357
6358   if (new_label_map)
6359     htab_delete (new_label_map);
6360   if (eh_map)
6361     pointer_map_destroy (eh_map);
6362   pointer_map_destroy (vars_map);
6363
6364   /* Rewire the entry and exit blocks.  The successor to the entry
6365      block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
6366      the child function.  Similarly, the predecessor of DEST_FN's
6367      EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR.  We
6368      need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
6369      various CFG manipulation function get to the right CFG.
6370
6371      FIXME, this is silly.  The CFG ought to become a parameter to
6372      these helpers.  */
6373   push_cfun (dest_cfun);
6374   make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU);
6375   if (exit_bb)
6376     make_edge (exit_bb,  EXIT_BLOCK_PTR, 0);
6377   pop_cfun ();
6378
6379   /* Back in the original function, the SESE region has disappeared,
6380      create a new basic block in its place.  */
6381   bb = create_empty_bb (entry_pred[0]);
6382   if (current_loops)
6383     add_bb_to_loop (bb, loop);
6384   for (i = 0; i < num_entry_edges; i++)
6385     {
6386       e = make_edge (entry_pred[i], bb, entry_flag[i]);
6387       e->probability = entry_prob[i];
6388     }
6389
6390   for (i = 0; i < num_exit_edges; i++)
6391     {
6392       e = make_edge (bb, exit_succ[i], exit_flag[i]);
6393       e->probability = exit_prob[i];
6394     }
6395
6396   set_immediate_dominator (CDI_DOMINATORS, bb, dom_entry);
6397   FOR_EACH_VEC_ELT (basic_block, dom_bbs, i, abb)
6398     set_immediate_dominator (CDI_DOMINATORS, abb, bb);
6399   VEC_free (basic_block, heap, dom_bbs);
6400
6401   if (exit_bb)
6402     {
6403       free (exit_prob);
6404       free (exit_flag);
6405       free (exit_succ);
6406     }
6407   free (entry_prob);
6408   free (entry_flag);
6409   free (entry_pred);
6410   VEC_free (basic_block, heap, bbs);
6411
6412   return bb;
6413 }
6414
6415
6416 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree-pass.h)
6417    */
6418
6419 void
6420 dump_function_to_file (tree fn, FILE *file, int flags)
6421 {
6422   tree arg, var;
6423   struct function *dsf;
6424   bool ignore_topmost_bind = false, any_var = false;
6425   basic_block bb;
6426   tree chain;
6427
6428   fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2));
6429
6430   arg = DECL_ARGUMENTS (fn);
6431   while (arg)
6432     {
6433       print_generic_expr (file, TREE_TYPE (arg), dump_flags);
6434       fprintf (file, " ");
6435       print_generic_expr (file, arg, dump_flags);
6436       if (flags & TDF_VERBOSE)
6437         print_node (file, "", arg, 4);
6438       if (DECL_CHAIN (arg))
6439         fprintf (file, ", ");
6440       arg = DECL_CHAIN (arg);
6441     }
6442   fprintf (file, ")\n");
6443
6444   if (flags & TDF_VERBOSE)
6445     print_node (file, "", fn, 2);
6446
6447   dsf = DECL_STRUCT_FUNCTION (fn);
6448   if (dsf && (flags & TDF_EH))
6449     dump_eh_tree (file, dsf);
6450
6451   if (flags & TDF_RAW && !gimple_has_body_p (fn))
6452     {
6453       dump_node (fn, TDF_SLIM | flags, file);
6454       return;
6455     }
6456
6457   /* Switch CFUN to point to FN.  */
6458   push_cfun (DECL_STRUCT_FUNCTION (fn));
6459
6460   /* When GIMPLE is lowered, the variables are no longer available in
6461      BIND_EXPRs, so display them separately.  */
6462   if (cfun && cfun->decl == fn && !VEC_empty (tree, cfun->local_decls))
6463     {
6464       unsigned ix;
6465       ignore_topmost_bind = true;
6466
6467       fprintf (file, "{\n");
6468       FOR_EACH_LOCAL_DECL (cfun, ix, var)
6469         {
6470           print_generic_decl (file, var, flags);
6471           if (flags & TDF_VERBOSE)
6472             print_node (file, "", var, 4);
6473           fprintf (file, "\n");
6474
6475           any_var = true;
6476         }
6477     }
6478
6479   if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info)
6480     {
6481       /* If the CFG has been built, emit a CFG-based dump.  */
6482       check_bb_profile (ENTRY_BLOCK_PTR, file);
6483       if (!ignore_topmost_bind)
6484         fprintf (file, "{\n");
6485
6486       if (any_var && n_basic_blocks)
6487         fprintf (file, "\n");
6488
6489       FOR_EACH_BB (bb)
6490         gimple_dump_bb (bb, file, 2, flags);
6491
6492       fprintf (file, "}\n");
6493       check_bb_profile (EXIT_BLOCK_PTR, file);
6494     }
6495   else if (DECL_SAVED_TREE (fn) == NULL)
6496     {
6497       /* The function is now in GIMPLE form but the CFG has not been
6498          built yet.  Emit the single sequence of GIMPLE statements
6499          that make up its body.  */
6500       gimple_seq body = gimple_body (fn);
6501
6502       if (gimple_seq_first_stmt (body)
6503           && gimple_seq_first_stmt (body) == gimple_seq_last_stmt (body)
6504           && gimple_code (gimple_seq_first_stmt (body)) == GIMPLE_BIND)
6505         print_gimple_seq (file, body, 0, flags);
6506       else
6507         {
6508           if (!ignore_topmost_bind)
6509             fprintf (file, "{\n");
6510
6511           if (any_var)
6512             fprintf (file, "\n");
6513
6514           print_gimple_seq (file, body, 2, flags);
6515           fprintf (file, "}\n");
6516         }
6517     }
6518   else
6519     {
6520       int indent;
6521
6522       /* Make a tree based dump.  */
6523       chain = DECL_SAVED_TREE (fn);
6524
6525       if (chain && TREE_CODE (chain) == BIND_EXPR)
6526         {
6527           if (ignore_topmost_bind)
6528             {
6529               chain = BIND_EXPR_BODY (chain);
6530               indent = 2;
6531             }
6532           else
6533             indent = 0;
6534         }
6535       else
6536         {
6537           if (!ignore_topmost_bind)
6538             fprintf (file, "{\n");
6539           indent = 2;
6540         }
6541
6542       if (any_var)
6543         fprintf (file, "\n");
6544
6545       print_generic_stmt_indented (file, chain, flags, indent);
6546       if (ignore_topmost_bind)
6547         fprintf (file, "}\n");
6548     }
6549
6550   if (flags & TDF_ENUMERATE_LOCALS)
6551     dump_enumerated_decls (file, flags);
6552   fprintf (file, "\n\n");
6553
6554   /* Restore CFUN.  */
6555   pop_cfun ();
6556 }
6557
6558
6559 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h)  */
6560
6561 DEBUG_FUNCTION void
6562 debug_function (tree fn, int flags)
6563 {
6564   dump_function_to_file (fn, stderr, flags);
6565 }
6566
6567
6568 /* Print on FILE the indexes for the predecessors of basic_block BB.  */
6569
6570 static void
6571 print_pred_bbs (FILE *file, basic_block bb)
6572 {
6573   edge e;
6574   edge_iterator ei;
6575
6576   FOR_EACH_EDGE (e, ei, bb->preds)
6577     fprintf (file, "bb_%d ", e->src->index);
6578 }
6579
6580
6581 /* Print on FILE the indexes for the successors of basic_block BB.  */
6582
6583 static void
6584 print_succ_bbs (FILE *file, basic_block bb)
6585 {
6586   edge e;
6587   edge_iterator ei;
6588
6589   FOR_EACH_EDGE (e, ei, bb->succs)
6590     fprintf (file, "bb_%d ", e->dest->index);
6591 }
6592
6593 /* Print to FILE the basic block BB following the VERBOSITY level.  */
6594
6595 void
6596 print_loops_bb (FILE *file, basic_block bb, int indent, int verbosity)
6597 {
6598   char *s_indent = (char *) alloca ((size_t) indent + 1);
6599   memset ((void *) s_indent, ' ', (size_t) indent);
6600   s_indent[indent] = '\0';
6601
6602   /* Print basic_block's header.  */
6603   if (verbosity >= 2)
6604     {
6605       fprintf (file, "%s  bb_%d (preds = {", s_indent, bb->index);
6606       print_pred_bbs (file, bb);
6607       fprintf (file, "}, succs = {");
6608       print_succ_bbs (file, bb);
6609       fprintf (file, "})\n");
6610     }
6611
6612   /* Print basic_block's body.  */
6613   if (verbosity >= 3)
6614     {
6615       fprintf (file, "%s  {\n", s_indent);
6616       gimple_dump_bb (bb, file, indent + 4, TDF_VOPS|TDF_MEMSYMS);
6617       fprintf (file, "%s  }\n", s_indent);
6618     }
6619 }
6620
6621 static void print_loop_and_siblings (FILE *, struct loop *, int, int);
6622
6623 /* Pretty print LOOP on FILE, indented INDENT spaces.  Following
6624    VERBOSITY level this outputs the contents of the loop, or just its
6625    structure.  */
6626
6627 static void
6628 print_loop (FILE *file, struct loop *loop, int indent, int verbosity)
6629 {
6630   char *s_indent;
6631   basic_block bb;
6632
6633   if (loop == NULL)
6634     return;
6635
6636   s_indent = (char *) alloca ((size_t) indent + 1);
6637   memset ((void *) s_indent, ' ', (size_t) indent);
6638   s_indent[indent] = '\0';
6639
6640   /* Print loop's header.  */
6641   fprintf (file, "%sloop_%d (header = %d, latch = %d", s_indent,
6642            loop->num, loop->header->index, loop->latch->index);
6643   fprintf (file, ", niter = ");
6644   print_generic_expr (file, loop->nb_iterations, 0);
6645
6646   if (loop->any_upper_bound)
6647     {
6648       fprintf (file, ", upper_bound = ");
6649       dump_double_int (file, loop->nb_iterations_upper_bound, true);
6650     }
6651
6652   if (loop->any_estimate)
6653     {
6654       fprintf (file, ", estimate = ");
6655       dump_double_int (file, loop->nb_iterations_estimate, true);
6656     }
6657   fprintf (file, ")\n");
6658
6659   /* Print loop's body.  */
6660   if (verbosity >= 1)
6661     {
6662       fprintf (file, "%s{\n", s_indent);
6663       FOR_EACH_BB (bb)
6664         if (bb->loop_father == loop)
6665           print_loops_bb (file, bb, indent, verbosity);
6666
6667       print_loop_and_siblings (file, loop->inner, indent + 2, verbosity);
6668       fprintf (file, "%s}\n", s_indent);
6669     }
6670 }
6671
6672 /* Print the LOOP and its sibling loops on FILE, indented INDENT
6673    spaces.  Following VERBOSITY level this outputs the contents of the
6674    loop, or just its structure.  */
6675
6676 static void
6677 print_loop_and_siblings (FILE *file, struct loop *loop, int indent, int verbosity)
6678 {
6679   if (loop == NULL)
6680     return;
6681
6682   print_loop (file, loop, indent, verbosity);
6683   print_loop_and_siblings (file, loop->next, indent, verbosity);
6684 }
6685
6686 /* Follow a CFG edge from the entry point of the program, and on entry
6687    of a loop, pretty print the loop structure on FILE.  */
6688
6689 void
6690 print_loops (FILE *file, int verbosity)
6691 {
6692   basic_block bb;
6693
6694   bb = ENTRY_BLOCK_PTR;
6695   if (bb && bb->loop_father)
6696     print_loop_and_siblings (file, bb->loop_father, 0, verbosity);
6697 }
6698
6699
6700 /* Debugging loops structure at tree level, at some VERBOSITY level.  */
6701
6702 DEBUG_FUNCTION void
6703 debug_loops (int verbosity)
6704 {
6705   print_loops (stderr, verbosity);
6706 }
6707
6708 /* Print on stderr the code of LOOP, at some VERBOSITY level.  */
6709
6710 DEBUG_FUNCTION void
6711 debug_loop (struct loop *loop, int verbosity)
6712 {
6713   print_loop (stderr, loop, 0, verbosity);
6714 }
6715
6716 /* Print on stderr the code of loop number NUM, at some VERBOSITY
6717    level.  */
6718
6719 DEBUG_FUNCTION void
6720 debug_loop_num (unsigned num, int verbosity)
6721 {
6722   debug_loop (get_loop (num), verbosity);
6723 }
6724
6725 /* Return true if BB ends with a call, possibly followed by some
6726    instructions that must stay with the call.  Return false,
6727    otherwise.  */
6728
6729 static bool
6730 gimple_block_ends_with_call_p (basic_block bb)
6731 {
6732   gimple_stmt_iterator gsi = gsi_last_nondebug_bb (bb);
6733   return !gsi_end_p (gsi) && is_gimple_call (gsi_stmt (gsi));
6734 }
6735
6736
6737 /* Return true if BB ends with a conditional branch.  Return false,
6738    otherwise.  */
6739
6740 static bool
6741 gimple_block_ends_with_condjump_p (const_basic_block bb)
6742 {
6743   gimple stmt = last_stmt (CONST_CAST_BB (bb));
6744   return (stmt && gimple_code (stmt) == GIMPLE_COND);
6745 }
6746
6747
6748 /* Return true if we need to add fake edge to exit at statement T.
6749    Helper function for gimple_flow_call_edges_add.  */
6750
6751 static bool
6752 need_fake_edge_p (gimple t)
6753 {
6754   tree fndecl = NULL_TREE;
6755   int call_flags = 0;
6756
6757   /* NORETURN and LONGJMP calls already have an edge to exit.
6758      CONST and PURE calls do not need one.
6759      We don't currently check for CONST and PURE here, although
6760      it would be a good idea, because those attributes are
6761      figured out from the RTL in mark_constant_function, and
6762      the counter incrementation code from -fprofile-arcs
6763      leads to different results from -fbranch-probabilities.  */
6764   if (is_gimple_call (t))
6765     {
6766       fndecl = gimple_call_fndecl (t);
6767       call_flags = gimple_call_flags (t);
6768     }
6769
6770   if (is_gimple_call (t)
6771       && fndecl
6772       && DECL_BUILT_IN (fndecl)
6773       && (call_flags & ECF_NOTHROW)
6774       && !(call_flags & ECF_RETURNS_TWICE)
6775       /* fork() doesn't really return twice, but the effect of
6776          wrapping it in __gcov_fork() which calls __gcov_flush()
6777          and clears the counters before forking has the same
6778          effect as returning twice.  Force a fake edge.  */
6779       && !(DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
6780            && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_FORK))
6781     return false;
6782
6783   if (is_gimple_call (t)
6784       && !(call_flags & ECF_NORETURN))
6785     return true;
6786
6787   if (gimple_code (t) == GIMPLE_ASM
6788        && (gimple_asm_volatile_p (t) || gimple_asm_input_p (t)))
6789     return true;
6790
6791   return false;
6792 }
6793
6794
6795 /* Add fake edges to the function exit for any non constant and non
6796    noreturn calls, volatile inline assembly in the bitmap of blocks
6797    specified by BLOCKS or to the whole CFG if BLOCKS is zero.  Return
6798    the number of blocks that were split.
6799
6800    The goal is to expose cases in which entering a basic block does
6801    not imply that all subsequent instructions must be executed.  */
6802
6803 static int
6804 gimple_flow_call_edges_add (sbitmap blocks)
6805 {
6806   int i;
6807   int blocks_split = 0;
6808   int last_bb = last_basic_block;
6809   bool check_last_block = false;
6810
6811   if (n_basic_blocks == NUM_FIXED_BLOCKS)
6812     return 0;
6813
6814   if (! blocks)
6815     check_last_block = true;
6816   else
6817     check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
6818
6819   /* In the last basic block, before epilogue generation, there will be
6820      a fallthru edge to EXIT.  Special care is required if the last insn
6821      of the last basic block is a call because make_edge folds duplicate
6822      edges, which would result in the fallthru edge also being marked
6823      fake, which would result in the fallthru edge being removed by
6824      remove_fake_edges, which would result in an invalid CFG.
6825
6826      Moreover, we can't elide the outgoing fake edge, since the block
6827      profiler needs to take this into account in order to solve the minimal
6828      spanning tree in the case that the call doesn't return.
6829
6830      Handle this by adding a dummy instruction in a new last basic block.  */
6831   if (check_last_block)
6832     {
6833       basic_block bb = EXIT_BLOCK_PTR->prev_bb;
6834       gimple_stmt_iterator gsi = gsi_last_nondebug_bb (bb);
6835       gimple t = NULL;
6836
6837       if (!gsi_end_p (gsi))
6838         t = gsi_stmt (gsi);
6839
6840       if (t && need_fake_edge_p (t))
6841         {
6842           edge e;
6843
6844           e = find_edge (bb, EXIT_BLOCK_PTR);
6845           if (e)
6846             {
6847               gsi_insert_on_edge (e, gimple_build_nop ());
6848               gsi_commit_edge_inserts ();
6849             }
6850         }
6851     }
6852
6853   /* Now add fake edges to the function exit for any non constant
6854      calls since there is no way that we can determine if they will
6855      return or not...  */
6856   for (i = 0; i < last_bb; i++)
6857     {
6858       basic_block bb = BASIC_BLOCK (i);
6859       gimple_stmt_iterator gsi;
6860       gimple stmt, last_stmt;
6861
6862       if (!bb)
6863         continue;
6864
6865       if (blocks && !TEST_BIT (blocks, i))
6866         continue;
6867
6868       gsi = gsi_last_nondebug_bb (bb);
6869       if (!gsi_end_p (gsi))
6870         {
6871           last_stmt = gsi_stmt (gsi);
6872           do
6873             {
6874               stmt = gsi_stmt (gsi);
6875               if (need_fake_edge_p (stmt))
6876                 {
6877                   edge e;
6878
6879                   /* The handling above of the final block before the
6880                      epilogue should be enough to verify that there is
6881                      no edge to the exit block in CFG already.
6882                      Calling make_edge in such case would cause us to
6883                      mark that edge as fake and remove it later.  */
6884 #ifdef ENABLE_CHECKING
6885                   if (stmt == last_stmt)
6886                     {
6887                       e = find_edge (bb, EXIT_BLOCK_PTR);
6888                       gcc_assert (e == NULL);
6889                     }
6890 #endif
6891
6892                   /* Note that the following may create a new basic block
6893                      and renumber the existing basic blocks.  */
6894                   if (stmt != last_stmt)
6895                     {
6896                       e = split_block (bb, stmt);
6897                       if (e)
6898                         blocks_split++;
6899                     }
6900                   make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
6901                 }
6902               gsi_prev (&gsi);
6903             }
6904           while (!gsi_end_p (gsi));
6905         }
6906     }
6907
6908   if (blocks_split)
6909     verify_flow_info ();
6910
6911   return blocks_split;
6912 }
6913
6914 /* Removes edge E and all the blocks dominated by it, and updates dominance
6915    information.  The IL in E->src needs to be updated separately.
6916    If dominance info is not available, only the edge E is removed.*/
6917
6918 void
6919 remove_edge_and_dominated_blocks (edge e)
6920 {
6921   VEC (basic_block, heap) *bbs_to_remove = NULL;
6922   VEC (basic_block, heap) *bbs_to_fix_dom = NULL;
6923   bitmap df, df_idom;
6924   edge f;
6925   edge_iterator ei;
6926   bool none_removed = false;
6927   unsigned i;
6928   basic_block bb, dbb;
6929   bitmap_iterator bi;
6930
6931   if (!dom_info_available_p (CDI_DOMINATORS))
6932     {
6933       remove_edge (e);
6934       return;
6935     }
6936
6937   /* No updating is needed for edges to exit.  */
6938   if (e->dest == EXIT_BLOCK_PTR)
6939     {
6940       if (cfgcleanup_altered_bbs)
6941         bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6942       remove_edge (e);
6943       return;
6944     }
6945
6946   /* First, we find the basic blocks to remove.  If E->dest has a predecessor
6947      that is not dominated by E->dest, then this set is empty.  Otherwise,
6948      all the basic blocks dominated by E->dest are removed.
6949
6950      Also, to DF_IDOM we store the immediate dominators of the blocks in
6951      the dominance frontier of E (i.e., of the successors of the
6952      removed blocks, if there are any, and of E->dest otherwise).  */
6953   FOR_EACH_EDGE (f, ei, e->dest->preds)
6954     {
6955       if (f == e)
6956         continue;
6957
6958       if (!dominated_by_p (CDI_DOMINATORS, f->src, e->dest))
6959         {
6960           none_removed = true;
6961           break;
6962         }
6963     }
6964
6965   df = BITMAP_ALLOC (NULL);
6966   df_idom = BITMAP_ALLOC (NULL);
6967
6968   if (none_removed)
6969     bitmap_set_bit (df_idom,
6970                     get_immediate_dominator (CDI_DOMINATORS, e->dest)->index);
6971   else
6972     {
6973       bbs_to_remove = get_all_dominated_blocks (CDI_DOMINATORS, e->dest);
6974       FOR_EACH_VEC_ELT (basic_block, bbs_to_remove, i, bb)
6975         {
6976           FOR_EACH_EDGE (f, ei, bb->succs)
6977             {
6978               if (f->dest != EXIT_BLOCK_PTR)
6979                 bitmap_set_bit (df, f->dest->index);
6980             }
6981         }
6982       FOR_EACH_VEC_ELT (basic_block, bbs_to_remove, i, bb)
6983         bitmap_clear_bit (df, bb->index);
6984
6985       EXECUTE_IF_SET_IN_BITMAP (df, 0, i, bi)
6986         {
6987           bb = BASIC_BLOCK (i);
6988           bitmap_set_bit (df_idom,
6989                           get_immediate_dominator (CDI_DOMINATORS, bb)->index);
6990         }
6991     }
6992
6993   if (cfgcleanup_altered_bbs)
6994     {
6995       /* Record the set of the altered basic blocks.  */
6996       bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6997       bitmap_ior_into (cfgcleanup_altered_bbs, df);
6998     }
6999
7000   /* Remove E and the cancelled blocks.  */
7001   if (none_removed)
7002     remove_edge (e);
7003   else
7004     {
7005       /* Walk backwards so as to get a chance to substitute all
7006          released DEFs into debug stmts.  See
7007          eliminate_unnecessary_stmts() in tree-ssa-dce.c for more
7008          details.  */
7009       for (i = VEC_length (basic_block, bbs_to_remove); i-- > 0; )
7010         delete_basic_block (VEC_index (basic_block, bbs_to_remove, i));
7011     }
7012
7013   /* Update the dominance information.  The immediate dominator may change only
7014      for blocks whose immediate dominator belongs to DF_IDOM:
7015
7016      Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
7017      removal.  Let Z the arbitrary block such that idom(Z) = Y and
7018      Z dominates X after the removal.  Before removal, there exists a path P
7019      from Y to X that avoids Z.  Let F be the last edge on P that is
7020      removed, and let W = F->dest.  Before removal, idom(W) = Y (since Y
7021      dominates W, and because of P, Z does not dominate W), and W belongs to
7022      the dominance frontier of E.  Therefore, Y belongs to DF_IDOM.  */
7023   EXECUTE_IF_SET_IN_BITMAP (df_idom, 0, i, bi)
7024     {
7025       bb = BASIC_BLOCK (i);
7026       for (dbb = first_dom_son (CDI_DOMINATORS, bb);
7027            dbb;
7028            dbb = next_dom_son (CDI_DOMINATORS, dbb))
7029         VEC_safe_push (basic_block, heap, bbs_to_fix_dom, dbb);
7030     }
7031
7032   iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true);
7033
7034   BITMAP_FREE (df);
7035   BITMAP_FREE (df_idom);
7036   VEC_free (basic_block, heap, bbs_to_remove);
7037   VEC_free (basic_block, heap, bbs_to_fix_dom);
7038 }
7039
7040 /* Purge dead EH edges from basic block BB.  */
7041
7042 bool
7043 gimple_purge_dead_eh_edges (basic_block bb)
7044 {
7045   bool changed = false;
7046   edge e;
7047   edge_iterator ei;
7048   gimple stmt = last_stmt (bb);
7049
7050   if (stmt && stmt_can_throw_internal (stmt))
7051     return false;
7052
7053   for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
7054     {
7055       if (e->flags & EDGE_EH)
7056         {
7057           remove_edge_and_dominated_blocks (e);
7058           changed = true;
7059         }
7060       else
7061         ei_next (&ei);
7062     }
7063
7064   return changed;
7065 }
7066
7067 /* Purge dead EH edges from basic block listed in BLOCKS.  */
7068
7069 bool
7070 gimple_purge_all_dead_eh_edges (const_bitmap blocks)
7071 {
7072   bool changed = false;
7073   unsigned i;
7074   bitmap_iterator bi;
7075
7076   EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
7077     {
7078       basic_block bb = BASIC_BLOCK (i);
7079
7080       /* Earlier gimple_purge_dead_eh_edges could have removed
7081          this basic block already.  */
7082       gcc_assert (bb || changed);
7083       if (bb != NULL)
7084         changed |= gimple_purge_dead_eh_edges (bb);
7085     }
7086
7087   return changed;
7088 }
7089
7090 /* Purge dead abnormal call edges from basic block BB.  */
7091
7092 bool
7093 gimple_purge_dead_abnormal_call_edges (basic_block bb)
7094 {
7095   bool changed = false;
7096   edge e;
7097   edge_iterator ei;
7098   gimple stmt = last_stmt (bb);
7099
7100   if (!cfun->has_nonlocal_label)
7101     return false;
7102
7103   if (stmt && stmt_can_make_abnormal_goto (stmt))
7104     return false;
7105
7106   for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
7107     {
7108       if (e->flags & EDGE_ABNORMAL)
7109         {
7110           remove_edge_and_dominated_blocks (e);
7111           changed = true;
7112         }
7113       else
7114         ei_next (&ei);
7115     }
7116
7117   return changed;
7118 }
7119
7120 /* Purge dead abnormal call edges from basic block listed in BLOCKS.  */
7121
7122 bool
7123 gimple_purge_all_dead_abnormal_call_edges (const_bitmap blocks)
7124 {
7125   bool changed = false;
7126   unsigned i;
7127   bitmap_iterator bi;
7128
7129   EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
7130     {
7131       basic_block bb = BASIC_BLOCK (i);
7132
7133       /* Earlier gimple_purge_dead_abnormal_call_edges could have removed
7134          this basic block already.  */
7135       gcc_assert (bb || changed);
7136       if (bb != NULL)
7137         changed |= gimple_purge_dead_abnormal_call_edges (bb);
7138     }
7139
7140   return changed;
7141 }
7142
7143 /* This function is called whenever a new edge is created or
7144    redirected.  */
7145
7146 static void
7147 gimple_execute_on_growing_pred (edge e)
7148 {
7149   basic_block bb = e->dest;
7150
7151   if (!gimple_seq_empty_p (phi_nodes (bb)))
7152     reserve_phi_args_for_new_edge (bb);
7153 }
7154
7155 /* This function is called immediately before edge E is removed from
7156    the edge vector E->dest->preds.  */
7157
7158 static void
7159 gimple_execute_on_shrinking_pred (edge e)
7160 {
7161   if (!gimple_seq_empty_p (phi_nodes (e->dest)))
7162     remove_phi_args (e);
7163 }
7164
7165 /*---------------------------------------------------------------------------
7166   Helper functions for Loop versioning
7167   ---------------------------------------------------------------------------*/
7168
7169 /* Adjust phi nodes for 'first' basic block.  'second' basic block is a copy
7170    of 'first'. Both of them are dominated by 'new_head' basic block. When
7171    'new_head' was created by 'second's incoming edge it received phi arguments
7172    on the edge by split_edge(). Later, additional edge 'e' was created to
7173    connect 'new_head' and 'first'. Now this routine adds phi args on this
7174    additional edge 'e' that new_head to second edge received as part of edge
7175    splitting.  */
7176
7177 static void
7178 gimple_lv_adjust_loop_header_phi (basic_block first, basic_block second,
7179                                   basic_block new_head, edge e)
7180 {
7181   gimple phi1, phi2;
7182   gimple_stmt_iterator psi1, psi2;
7183   tree def;
7184   edge e2 = find_edge (new_head, second);
7185
7186   /* Because NEW_HEAD has been created by splitting SECOND's incoming
7187      edge, we should always have an edge from NEW_HEAD to SECOND.  */
7188   gcc_assert (e2 != NULL);
7189
7190   /* Browse all 'second' basic block phi nodes and add phi args to
7191      edge 'e' for 'first' head. PHI args are always in correct order.  */
7192
7193   for (psi2 = gsi_start_phis (second),
7194        psi1 = gsi_start_phis (first);
7195        !gsi_end_p (psi2) && !gsi_end_p (psi1);
7196        gsi_next (&psi2),  gsi_next (&psi1))
7197     {
7198       phi1 = gsi_stmt (psi1);
7199       phi2 = gsi_stmt (psi2);
7200       def = PHI_ARG_DEF (phi2, e2->dest_idx);
7201       add_phi_arg (phi1, def, e, gimple_phi_arg_location_from_edge (phi2, e2));
7202     }
7203 }
7204
7205
7206 /* Adds a if else statement to COND_BB with condition COND_EXPR.
7207    SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
7208    the destination of the ELSE part.  */
7209
7210 static void
7211 gimple_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
7212                                basic_block second_head ATTRIBUTE_UNUSED,
7213                                basic_block cond_bb, void *cond_e)
7214 {
7215   gimple_stmt_iterator gsi;
7216   gimple new_cond_expr;
7217   tree cond_expr = (tree) cond_e;
7218   edge e0;
7219
7220   /* Build new conditional expr */
7221   new_cond_expr = gimple_build_cond_from_tree (cond_expr,
7222                                                NULL_TREE, NULL_TREE);
7223
7224   /* Add new cond in cond_bb.  */
7225   gsi = gsi_last_bb (cond_bb);
7226   gsi_insert_after (&gsi, new_cond_expr, GSI_NEW_STMT);
7227
7228   /* Adjust edges appropriately to connect new head with first head
7229      as well as second head.  */
7230   e0 = single_succ_edge (cond_bb);
7231   e0->flags &= ~EDGE_FALLTHRU;
7232   e0->flags |= EDGE_FALSE_VALUE;
7233 }
7234
7235 struct cfg_hooks gimple_cfg_hooks = {
7236   "gimple",
7237   gimple_verify_flow_info,
7238   gimple_dump_bb,               /* dump_bb  */
7239   create_bb,                    /* create_basic_block  */
7240   gimple_redirect_edge_and_branch, /* redirect_edge_and_branch  */
7241   gimple_redirect_edge_and_branch_force, /* redirect_edge_and_branch_force  */
7242   gimple_can_remove_branch_p,   /* can_remove_branch_p  */
7243   remove_bb,                    /* delete_basic_block  */
7244   gimple_split_block,           /* split_block  */
7245   gimple_move_block_after,      /* move_block_after  */
7246   gimple_can_merge_blocks_p,    /* can_merge_blocks_p  */
7247   gimple_merge_blocks,          /* merge_blocks  */
7248   gimple_predict_edge,          /* predict_edge  */
7249   gimple_predicted_by_p,        /* predicted_by_p  */
7250   gimple_can_duplicate_bb_p,    /* can_duplicate_block_p  */
7251   gimple_duplicate_bb,          /* duplicate_block  */
7252   gimple_split_edge,            /* split_edge  */
7253   gimple_make_forwarder_block,  /* make_forward_block  */
7254   NULL,                         /* tidy_fallthru_edge  */
7255   NULL,                         /* force_nonfallthru */
7256   gimple_block_ends_with_call_p,/* block_ends_with_call_p */
7257   gimple_block_ends_with_condjump_p, /* block_ends_with_condjump_p */
7258   gimple_flow_call_edges_add,   /* flow_call_edges_add */
7259   gimple_execute_on_growing_pred,       /* execute_on_growing_pred */
7260   gimple_execute_on_shrinking_pred, /* execute_on_shrinking_pred */
7261   gimple_duplicate_loop_to_header_edge, /* duplicate loop for trees */
7262   gimple_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
7263   gimple_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/
7264   extract_true_false_edges_from_block, /* extract_cond_bb_edges */
7265   flush_pending_stmts           /* flush_pending_stmts */
7266 };
7267
7268
7269 /* Split all critical edges.  */
7270
7271 static unsigned int
7272 split_critical_edges (void)
7273 {
7274   basic_block bb;
7275   edge e;
7276   edge_iterator ei;
7277
7278   /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
7279      expensive.  So we want to enable recording of edge to CASE_LABEL_EXPR
7280      mappings around the calls to split_edge.  */
7281   start_recording_case_labels ();
7282   FOR_ALL_BB (bb)
7283     {
7284       FOR_EACH_EDGE (e, ei, bb->succs)
7285         {
7286           if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL))
7287             split_edge (e);
7288           /* PRE inserts statements to edges and expects that
7289              since split_critical_edges was done beforehand, committing edge
7290              insertions will not split more edges.  In addition to critical
7291              edges we must split edges that have multiple successors and
7292              end by control flow statements, such as RESX.
7293              Go ahead and split them too.  This matches the logic in
7294              gimple_find_edge_insert_loc.  */
7295           else if ((!single_pred_p (e->dest)
7296                     || !gimple_seq_empty_p (phi_nodes (e->dest))
7297                     || e->dest == EXIT_BLOCK_PTR)
7298                    && e->src != ENTRY_BLOCK_PTR
7299                    && !(e->flags & EDGE_ABNORMAL))
7300             {
7301               gimple_stmt_iterator gsi;
7302
7303               gsi = gsi_last_bb (e->src);
7304               if (!gsi_end_p (gsi)
7305                   && stmt_ends_bb_p (gsi_stmt (gsi))
7306                   && (gimple_code (gsi_stmt (gsi)) != GIMPLE_RETURN
7307                       && !gimple_call_builtin_p (gsi_stmt (gsi),
7308                                                  BUILT_IN_RETURN)))
7309                 split_edge (e);
7310             }
7311         }
7312     }
7313   end_recording_case_labels ();
7314   return 0;
7315 }
7316
7317 struct gimple_opt_pass pass_split_crit_edges =
7318 {
7319  {
7320   GIMPLE_PASS,
7321   "crited",                          /* name */
7322   NULL,                          /* gate */
7323   split_critical_edges,          /* execute */
7324   NULL,                          /* sub */
7325   NULL,                          /* next */
7326   0,                             /* static_pass_number */
7327   TV_TREE_SPLIT_EDGES,           /* tv_id */
7328   PROP_cfg,                      /* properties required */
7329   PROP_no_crit_edges,            /* properties_provided */
7330   0,                             /* properties_destroyed */
7331   0,                             /* todo_flags_start */
7332   TODO_verify_flow               /* todo_flags_finish */
7333  }
7334 };
7335
7336
7337 /* Build a ternary operation and gimplify it.  Emit code before GSI.
7338    Return the gimple_val holding the result.  */
7339
7340 tree
7341 gimplify_build3 (gimple_stmt_iterator *gsi, enum tree_code code,
7342                  tree type, tree a, tree b, tree c)
7343 {
7344   tree ret;
7345   location_t loc = gimple_location (gsi_stmt (*gsi));
7346
7347   ret = fold_build3_loc (loc, code, type, a, b, c);
7348   STRIP_NOPS (ret);
7349
7350   return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
7351                                    GSI_SAME_STMT);
7352 }
7353
7354 /* Build a binary operation and gimplify it.  Emit code before GSI.
7355    Return the gimple_val holding the result.  */
7356
7357 tree
7358 gimplify_build2 (gimple_stmt_iterator *gsi, enum tree_code code,
7359                  tree type, tree a, tree b)
7360 {
7361   tree ret;
7362
7363   ret = fold_build2_loc (gimple_location (gsi_stmt (*gsi)), code, type, a, b);
7364   STRIP_NOPS (ret);
7365
7366   return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
7367                                    GSI_SAME_STMT);
7368 }
7369
7370 /* Build a unary operation and gimplify it.  Emit code before GSI.
7371    Return the gimple_val holding the result.  */
7372
7373 tree
7374 gimplify_build1 (gimple_stmt_iterator *gsi, enum tree_code code, tree type,
7375                  tree a)
7376 {
7377   tree ret;
7378
7379   ret = fold_build1_loc (gimple_location (gsi_stmt (*gsi)), code, type, a);
7380   STRIP_NOPS (ret);
7381
7382   return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
7383                                    GSI_SAME_STMT);
7384 }
7385
7386
7387 \f
7388 /* Emit return warnings.  */
7389
7390 static unsigned int
7391 execute_warn_function_return (void)
7392 {
7393   source_location location;
7394   gimple last;
7395   edge e;
7396   edge_iterator ei;
7397
7398   /* If we have a path to EXIT, then we do return.  */
7399   if (TREE_THIS_VOLATILE (cfun->decl)
7400       && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
7401     {
7402       location = UNKNOWN_LOCATION;
7403       FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7404         {
7405           last = last_stmt (e->src);
7406           if ((gimple_code (last) == GIMPLE_RETURN
7407                || gimple_call_builtin_p (last, BUILT_IN_RETURN))
7408               && (location = gimple_location (last)) != UNKNOWN_LOCATION)
7409             break;
7410         }
7411       if (location == UNKNOWN_LOCATION)
7412         location = cfun->function_end_locus;
7413       warning_at (location, 0, "%<noreturn%> function does return");
7414     }
7415
7416   /* If we see "return;" in some basic block, then we do reach the end
7417      without returning a value.  */
7418   else if (warn_return_type
7419            && !TREE_NO_WARNING (cfun->decl)
7420            && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0
7421            && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl))))
7422     {
7423       FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7424         {
7425           gimple last = last_stmt (e->src);
7426           if (gimple_code (last) == GIMPLE_RETURN
7427               && gimple_return_retval (last) == NULL
7428               && !gimple_no_warning_p (last))
7429             {
7430               location = gimple_location (last);
7431               if (location == UNKNOWN_LOCATION)
7432                   location = cfun->function_end_locus;
7433               warning_at (location, OPT_Wreturn_type, "control reaches end of non-void function");
7434               TREE_NO_WARNING (cfun->decl) = 1;
7435               break;
7436             }
7437         }
7438     }
7439   return 0;
7440 }
7441
7442
7443 /* Given a basic block B which ends with a conditional and has
7444    precisely two successors, determine which of the edges is taken if
7445    the conditional is true and which is taken if the conditional is
7446    false.  Set TRUE_EDGE and FALSE_EDGE appropriately.  */
7447
7448 void
7449 extract_true_false_edges_from_block (basic_block b,
7450                                      edge *true_edge,
7451                                      edge *false_edge)
7452 {
7453   edge e = EDGE_SUCC (b, 0);
7454
7455   if (e->flags & EDGE_TRUE_VALUE)
7456     {
7457       *true_edge = e;
7458       *false_edge = EDGE_SUCC (b, 1);
7459     }
7460   else
7461     {
7462       *false_edge = e;
7463       *true_edge = EDGE_SUCC (b, 1);
7464     }
7465 }
7466
7467 struct gimple_opt_pass pass_warn_function_return =
7468 {
7469  {
7470   GIMPLE_PASS,
7471   "*warn_function_return",              /* name */
7472   NULL,                                 /* gate */
7473   execute_warn_function_return,         /* execute */
7474   NULL,                                 /* sub */
7475   NULL,                                 /* next */
7476   0,                                    /* static_pass_number */
7477   TV_NONE,                              /* tv_id */
7478   PROP_cfg,                             /* properties_required */
7479   0,                                    /* properties_provided */
7480   0,                                    /* properties_destroyed */
7481   0,                                    /* todo_flags_start */
7482   0                                     /* todo_flags_finish */
7483  }
7484 };
7485
7486 /* Emit noreturn warnings.  */
7487
7488 static unsigned int
7489 execute_warn_function_noreturn (void)
7490 {
7491   if (!TREE_THIS_VOLATILE (current_function_decl)
7492       && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0)
7493     warn_function_noreturn (current_function_decl);
7494   return 0;
7495 }
7496
7497 static bool
7498 gate_warn_function_noreturn (void)
7499 {
7500   return warn_suggest_attribute_noreturn;
7501 }
7502
7503 struct gimple_opt_pass pass_warn_function_noreturn =
7504 {
7505  {
7506   GIMPLE_PASS,
7507   "*warn_function_noreturn",            /* name */
7508   gate_warn_function_noreturn,          /* gate */
7509   execute_warn_function_noreturn,       /* execute */
7510   NULL,                                 /* sub */
7511   NULL,                                 /* next */
7512   0,                                    /* static_pass_number */
7513   TV_NONE,                              /* tv_id */
7514   PROP_cfg,                             /* properties_required */
7515   0,                                    /* properties_provided */
7516   0,                                    /* properties_destroyed */
7517   0,                                    /* todo_flags_start */
7518   0                                     /* todo_flags_finish */
7519  }
7520 };
7521
7522
7523 /* Walk a gimplified function and warn for functions whose return value is
7524    ignored and attribute((warn_unused_result)) is set.  This is done before
7525    inlining, so we don't have to worry about that.  */
7526
7527 static void
7528 do_warn_unused_result (gimple_seq seq)
7529 {
7530   tree fdecl, ftype;
7531   gimple_stmt_iterator i;
7532
7533   for (i = gsi_start (seq); !gsi_end_p (i); gsi_next (&i))
7534     {
7535       gimple g = gsi_stmt (i);
7536
7537       switch (gimple_code (g))
7538         {
7539         case GIMPLE_BIND:
7540           do_warn_unused_result (gimple_bind_body (g));
7541           break;
7542         case GIMPLE_TRY:
7543           do_warn_unused_result (gimple_try_eval (g));
7544           do_warn_unused_result (gimple_try_cleanup (g));
7545           break;
7546         case GIMPLE_CATCH:
7547           do_warn_unused_result (gimple_catch_handler (g));
7548           break;
7549         case GIMPLE_EH_FILTER:
7550           do_warn_unused_result (gimple_eh_filter_failure (g));
7551           break;
7552
7553         case GIMPLE_CALL:
7554           if (gimple_call_lhs (g))
7555             break;
7556           if (gimple_call_internal_p (g))
7557             break;
7558
7559           /* This is a naked call, as opposed to a GIMPLE_CALL with an
7560              LHS.  All calls whose value is ignored should be
7561              represented like this.  Look for the attribute.  */
7562           fdecl = gimple_call_fndecl (g);
7563           ftype = gimple_call_fntype (g);
7564
7565           if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype)))
7566             {
7567               location_t loc = gimple_location (g);
7568
7569               if (fdecl)
7570                 warning_at (loc, OPT_Wunused_result,
7571                             "ignoring return value of %qD, "
7572                             "declared with attribute warn_unused_result",
7573                             fdecl);
7574               else
7575                 warning_at (loc, OPT_Wunused_result,
7576                             "ignoring return value of function "
7577                             "declared with attribute warn_unused_result");
7578             }
7579           break;
7580
7581         default:
7582           /* Not a container, not a call, or a call whose value is used.  */
7583           break;
7584         }
7585     }
7586 }
7587
7588 static unsigned int
7589 run_warn_unused_result (void)
7590 {
7591   do_warn_unused_result (gimple_body (current_function_decl));
7592   return 0;
7593 }
7594
7595 static bool
7596 gate_warn_unused_result (void)
7597 {
7598   return flag_warn_unused_result;
7599 }
7600
7601 struct gimple_opt_pass pass_warn_unused_result =
7602 {
7603   {
7604     GIMPLE_PASS,
7605     "*warn_unused_result",              /* name */
7606     gate_warn_unused_result,            /* gate */
7607     run_warn_unused_result,             /* execute */
7608     NULL,                               /* sub */
7609     NULL,                               /* next */
7610     0,                                  /* static_pass_number */
7611     TV_NONE,                            /* tv_id */
7612     PROP_gimple_any,                    /* properties_required */
7613     0,                                  /* properties_provided */
7614     0,                                  /* properties_destroyed */
7615     0,                                  /* todo_flags_start */
7616     0,                                  /* todo_flags_finish */
7617   }
7618 };