gcc/tree-optimize.c

   1 /* Top-level control of tree optimizations.
   2    Copyright 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
   3    Contributed by Diego Novillo <dnovillo@redhat.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "tree.h"
  27 #include "rtl.h"
  28 #include "tm_p.h"
  29 #include "hard-reg-set.h"
  30 #include "basic-block.h"
  31 #include "output.h"
  32 #include "expr.h"
  33 #include "diagnostic.h"
  34 #include "basic-block.h"
  35 #include "flags.h"
  36 #include "tree-flow.h"
  37 #include "tree-dump.h"
  38 #include "timevar.h"
  39 #include "function.h"
  40 #include "langhooks.h"
  41 #include "toplev.h"
  42 #include "flags.h"
  43 #include "cgraph.h"
  44 #include "tree-inline.h"
  45 #include "tree-mudflap.h"
  46 #include "tree-pass.h"
  47 #include "ggc.h"
  48 #include "cgraph.h"
  49 #include "graph.h"
  50 #include "cfgloop.h"
  51 #include "except.h"
  52
  53 /* Global variables used to communicate with passes.  */
  54 int dump_flags;
  55 bool in_gimple_form;
  56
  57 /* The root of the compilation pass tree, once constructed.  */
  58 static struct tree_opt_pass *all_passes, *all_ipa_passes, *all_lowering_passes;
  59
  60 /* Gate: execute, or not, all of the non-trivial optimizations.  */
  61
  62 static bool
  63 gate_all_optimizations (void)
  64 {
  65   return (optimize >= 1
  66           /* Don't bother doing anything if the program has errors.  */
  67           && !(errorcount || sorrycount));
  68 }
  69
  70 static struct tree_opt_pass pass_all_optimizations =
  71 {
  72   NULL,                                 /* name */
  73   gate_all_optimizations,               /* gate */
  74   NULL,                                 /* execute */
  75   NULL,                                 /* sub */
  76   NULL,                                 /* next */
  77   0,                                    /* static_pass_number */
  78   0,                                    /* tv_id */
  79   0,                                    /* properties_required */
  80   0,                                    /* properties_provided */
  81   0,                                    /* properties_destroyed */
  82   0,                                    /* todo_flags_start */
  83   0,                                    /* todo_flags_finish */
  84   0                                     /* letter */
  85 };
  86
  87 static struct tree_opt_pass pass_early_local_passes =
  88 {
  89   NULL,                                 /* name */
  90   gate_all_optimizations,               /* gate */
  91   NULL,                                 /* execute */
  92   NULL,                                 /* sub */
  93   NULL,                                 /* next */
  94   0,                                    /* static_pass_number */
  95   0,                                    /* tv_id */
  96   0,                                    /* properties_required */
  97   0,                                    /* properties_provided */
  98   0,                                    /* properties_destroyed */
  99   0,                                    /* todo_flags_start */
 100   0,                                    /* todo_flags_finish */
 101   0                                     /* letter */
 102 };
 103
 104 /* Pass: cleanup the CFG just before expanding trees to RTL.
 105    This is just a round of label cleanups and case node grouping
 106    because after the tree optimizers have run such cleanups may
 107    be necessary.  */
 108
 109 static void
 110 execute_cleanup_cfg_pre_ipa (void)
 111 {
 112   cleanup_tree_cfg ();
 113 }
 114
 115 static struct tree_opt_pass pass_cleanup_cfg =
 116 {
 117   "cleanup_cfg",                        /* name */
 118   NULL,                                 /* gate */
 119   execute_cleanup_cfg_pre_ipa,          /* execute */
 120   NULL,                                 /* sub */
 121   NULL,                                 /* next */
 122   0,                                    /* static_pass_number */
 123   0,                                    /* tv_id */
 124   PROP_cfg,                             /* properties_required */
 125   0,                                    /* properties_provided */
 126   0,                                    /* properties_destroyed */
 127   0,                                    /* todo_flags_start */
 128   TODO_dump_func,                                       /* todo_flags_finish */
 129   0                                     /* letter */
 130 };
 131
 132
 133 /* Pass: cleanup the CFG just before expanding trees to RTL.
 134    This is just a round of label cleanups and case node grouping
 135    because after the tree optimizers have run such cleanups may
 136    be necessary.  */
 137
 138 static void
 139 execute_cleanup_cfg_post_optimizing (void)
 140 {
 141   cleanup_tree_cfg ();
 142   cleanup_dead_labels ();
 143   group_case_labels ();
 144 }
 145
 146 static struct tree_opt_pass pass_cleanup_cfg_post_optimizing =
 147 {
 148   "final_cleanup",                      /* name */
 149   NULL,                                 /* gate */
 150   execute_cleanup_cfg_post_optimizing,  /* execute */
 151   NULL,                                 /* sub */
 152   NULL,                                 /* next */
 153   0,                                    /* static_pass_number */
 154   0,                                    /* tv_id */
 155   PROP_cfg,                             /* properties_required */
 156   0,                                    /* properties_provided */
 157   0,                                    /* properties_destroyed */
 158   0,                                    /* todo_flags_start */
 159   TODO_dump_func,                                       /* todo_flags_finish */
 160   0                                     /* letter */
 161 };
 162
 163 /* Pass: do the actions required to finish with tree-ssa optimization
 164    passes.  */
 165
 166 static void
 167 execute_free_datastructures (void)
 168 {
 169   /* ??? This isn't the right place for this.  Worse, it got computed
 170      more or less at random in various passes.  */
 171   free_dominance_info (CDI_DOMINATORS);
 172   free_dominance_info (CDI_POST_DOMINATORS);
 173
 174   /* Remove the ssa structures.  Do it here since this includes statement
 175      annotations that need to be intact during disband_implicit_edges.  */
 176   delete_tree_ssa ();
 177 }
 178
 179 static struct tree_opt_pass pass_free_datastructures =
 180 {
 181   NULL,                                 /* name */
 182   NULL,                                 /* gate */
 183   execute_free_datastructures,                  /* execute */
 184   NULL,                                 /* sub */
 185   NULL,                                 /* next */
 186   0,                                    /* static_pass_number */
 187   0,                                    /* tv_id */
 188   PROP_cfg,                             /* properties_required */
 189   0,                                    /* properties_provided */
 190   0,                                    /* properties_destroyed */
 191   0,                                    /* todo_flags_start */
 192   0,                                    /* todo_flags_finish */
 193   0                                     /* letter */
 194 };
 195 /* Pass: free cfg annotations.  */
 196
 197 static void
 198 execute_free_cfg_annotations (void)
 199 {
 200   basic_block bb;
 201   block_stmt_iterator bsi;
 202
 203   /* Emit gotos for implicit jumps.  */
 204   disband_implicit_edges ();
 205
 206   /* Remove annotations from every tree in the function.  */
 207   FOR_EACH_BB (bb)
 208     for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
 209       {
 210         tree stmt = bsi_stmt (bsi);
 211         ggc_free (stmt->common.ann);
 212         stmt->common.ann = NULL;
 213       }
 214
 215   /* And get rid of annotations we no longer need.  */
 216   delete_tree_cfg_annotations ();
 217 }
 218
 219 static struct tree_opt_pass pass_free_cfg_annotations =
 220 {
 221   NULL,                                 /* name */
 222   NULL,                                 /* gate */
 223   execute_free_cfg_annotations,         /* execute */
 224   NULL,                                 /* sub */
 225   NULL,                                 /* next */
 226   0,                                    /* static_pass_number */
 227   0,                                    /* tv_id */
 228   PROP_cfg,                             /* properties_required */
 229   0,                                    /* properties_provided */
 230   0,                                    /* properties_destroyed */
 231   0,                                    /* todo_flags_start */
 232   0,                                    /* todo_flags_finish */
 233   0                                     /* letter */
 234 };
 235 /* Pass: fixup_cfg - IPA passes or compilation of earlier functions might've
 236    changed some properties - such as marked functions nothrow.  Remove now
 237    redundant edges and basic blocks.  */
 238
 239 static void
 240 execute_fixup_cfg (void)
 241 {
 242   basic_block bb;
 243   block_stmt_iterator bsi;
 244
 245   if (cfun->eh)
 246     FOR_EACH_BB (bb)
 247       {
 248         for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
 249           {
 250             tree stmt = bsi_stmt (bsi);
 251             tree call = get_call_expr_in (stmt);
 252
 253             if (call && call_expr_flags (call) & (ECF_CONST | ECF_PURE))
 254               TREE_SIDE_EFFECTS (call) = 0;
 255             if (!tree_could_throw_p (stmt) && lookup_stmt_eh_region (stmt))
 256               remove_stmt_from_eh_region (stmt);
 257           }
 258         tree_purge_dead_eh_edges (bb);
 259       }
 260
 261   cleanup_tree_cfg ();
 262 }
 263
 264 static struct tree_opt_pass pass_fixup_cfg =
 265 {
 266   NULL,                                 /* name */
 267   NULL,                                 /* gate */
 268   execute_fixup_cfg,                    /* execute */
 269   NULL,                                 /* sub */
 270   NULL,                                 /* next */
 271   0,                                    /* static_pass_number */
 272   0,                                    /* tv_id */
 273   PROP_cfg,                             /* properties_required */
 274   0,                                    /* properties_provided */
 275   0,                                    /* properties_destroyed */
 276   0,                                    /* todo_flags_start */
 277   0,                                    /* todo_flags_finish */
 278   0                                     /* letter */
 279 };
 280
 281 /* Do the actions required to initialize internal data structures used
 282    in tree-ssa optimization passes.  */
 283
 284 static void
 285 execute_init_datastructures (void)
 286 {
 287   /* Allocate hash tables, arrays and other structures.  */
 288   init_tree_ssa ();
 289 }
 290
 291 static struct tree_opt_pass pass_init_datastructures =
 292 {
 293   NULL,                                 /* name */
 294   NULL,                                 /* gate */
 295   execute_init_datastructures,          /* execute */
 296   NULL,                                 /* sub */
 297   NULL,                                 /* next */
 298   0,                                    /* static_pass_number */
 299   0,                                    /* tv_id */
 300   PROP_cfg,                             /* properties_required */
 301   0,                                    /* properties_provided */
 302   0,                                    /* properties_destroyed */
 303   0,                                    /* todo_flags_start */
 304   0,                                    /* todo_flags_finish */
 305   0                                     /* letter */
 306 };
 307
 308 /* Iterate over the pass tree allocating dump file numbers.  We want
 309    to do this depth first, and independent of whether the pass is
 310    enabled or not.  */
 311
 312 static void
 313 register_one_dump_file (struct tree_opt_pass *pass, bool ipa, int n)
 314 {
 315   char *dot_name, *flag_name, *glob_name;
 316   char num[10];
 317
 318   /* See below in next_pass_1.  */
 319   num[0] = '\0';
 320   if (pass->static_pass_number != -1)
 321     sprintf (num, "%d", ((int) pass->static_pass_number < 0
 322                          ? 1 : pass->static_pass_number));
 323
 324   dot_name = concat (".", pass->name, num, NULL);
 325   if (ipa)
 326     {
 327       flag_name = concat ("ipa-", pass->name, num, NULL);
 328       glob_name = concat ("ipa-", pass->name, NULL);
 329       /* First IPA dump is cgraph that is dumped via separate channels.  */
 330       pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,
 331                                                 TDF_IPA, n + 1, 0);
 332     }
 333   else if (pass->properties_provided & PROP_trees)
 334     {
 335       flag_name = concat ("tree-", pass->name, num, NULL);
 336       glob_name = concat ("tree-", pass->name, NULL);
 337       pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,
 338                                                 TDF_TREE, n + TDI_tree_all, 0);
 339     }
 340   else
 341     {
 342       flag_name = concat ("rtl-", pass->name, num, NULL);
 343       glob_name = concat ("rtl-", pass->name, NULL);
 344       pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,
 345                                                 TDF_RTL, n, pass->letter);
 346     }
 347 }
 348
 349 static int
 350 register_dump_files (struct tree_opt_pass *pass, bool ipa, int properties)
 351 {
 352   static int n = 0;
 353   do
 354     {
 355       int new_properties;
 356       int pass_number;
 357
 358       pass->properties_required = properties;
 359       new_properties =
 360         (properties | pass->properties_provided) & ~pass->properties_destroyed;
 361
 362       /* Reset the counter when we reach RTL-based passes.  */
 363       if ((pass->properties_provided ^ pass->properties_required) & PROP_rtl)
 364         n = 0;
 365
 366       pass_number = n;
 367       if (pass->name)
 368         n++;
 369
 370       if (pass->sub)
 371         new_properties = register_dump_files (pass->sub, false, new_properties);
 372
 373       /* If we have a gate, combine the properties that we could have with
 374          and without the pass being examined.  */
 375       if (pass->gate)
 376         properties &= new_properties;
 377       else
 378         properties = new_properties;
 379
 380       pass->properties_provided = properties;
 381       if (pass->name)
 382         register_one_dump_file (pass, ipa, pass_number);
 383
 384       pass = pass->next;
 385     }
 386   while (pass);
 387
 388   return properties;
 389 }
 390
 391 /* Add a pass to the pass list. Duplicate the pass if it's already
 392    in the list.  */
 393
 394 static struct tree_opt_pass **
 395 next_pass_1 (struct tree_opt_pass **list, struct tree_opt_pass *pass)
 396 {
 397
 398   /* A nonzero static_pass_number indicates that the
 399      pass is already in the list.  */
 400   if (pass->static_pass_number)
 401     {
 402       struct tree_opt_pass *new;
 403
 404       new = xmalloc (sizeof (*new));
 405       memcpy (new, pass, sizeof (*new));
 406
 407       /* Indicate to register_dump_files that this pass has duplicates,
 408          and so it should rename the dump file.  The first instance will
 409          be -1, and be number of duplicates = -static_pass_number - 1.
 410          Subsequent instances will be > 0 and just the duplicate number.  */
 411       if (pass->name)
 412         {
 413           pass->static_pass_number -= 1;
 414           new->static_pass_number = -pass->static_pass_number;
 415         }
 416
 417       *list = new;
 418     }
 419   else
 420     {
 421       pass->static_pass_number = -1;
 422       *list = pass;
 423     }
 424
 425   return &(*list)->next;
 426
 427 }
 428
 429 /* Construct the pass tree.  */
 430
 431 void
 432 init_tree_optimization_passes (void)
 433 {
 434   struct tree_opt_pass **p;
 435
 436 #define NEXT_PASS(PASS)  (p = next_pass_1 (p, &PASS))
 437   /* Interprocedural optimization passes.  */
 438   p = &all_ipa_passes;
 439   NEXT_PASS (pass_early_ipa_inline);
 440   NEXT_PASS (pass_early_local_passes);
 441   NEXT_PASS (pass_ipa_inline);
 442   *p = NULL;
 443
 444   /* All passes needed to lower the function into shape optimizers can operate
 445      on.  These passes are performed before interprocedural passes, unlike rest
 446      of local passes (all_passes).  */
 447   p = &all_lowering_passes;
 448   NEXT_PASS (pass_remove_useless_stmts);
 449   NEXT_PASS (pass_mudflap_1);
 450   NEXT_PASS (pass_lower_cf);
 451   NEXT_PASS (pass_lower_eh);
 452   NEXT_PASS (pass_build_cfg);
 453   NEXT_PASS (pass_lower_complex_O0);
 454   NEXT_PASS (pass_lower_vector);
 455   NEXT_PASS (pass_warn_function_return);
 456   NEXT_PASS (pass_early_tree_profile);
 457   *p = NULL;
 458
 459   p = &pass_early_local_passes.sub;
 460   NEXT_PASS (pass_tree_profile);
 461   NEXT_PASS (pass_cleanup_cfg);
 462   NEXT_PASS (pass_rebuild_cgraph_edges);
 463   *p = NULL;
 464
 465   p = &all_passes;
 466   NEXT_PASS (pass_fixup_cfg);
 467   NEXT_PASS (pass_init_datastructures);
 468   NEXT_PASS (pass_all_optimizations);
 469   NEXT_PASS (pass_warn_function_noreturn);
 470   NEXT_PASS (pass_mudflap_2);
 471   NEXT_PASS (pass_free_datastructures);
 472   NEXT_PASS (pass_free_cfg_annotations);
 473   NEXT_PASS (pass_expand);
 474   NEXT_PASS (pass_rest_of_compilation);
 475   *p = NULL;
 476
 477   p = &pass_all_optimizations.sub;
 478   NEXT_PASS (pass_referenced_vars);
 479   NEXT_PASS (pass_create_structure_vars);
 480   NEXT_PASS (pass_build_ssa);
 481   NEXT_PASS (pass_build_pta);
 482   NEXT_PASS (pass_may_alias);
 483   NEXT_PASS (pass_return_slot);
 484   NEXT_PASS (pass_del_pta);
 485   NEXT_PASS (pass_rename_ssa_copies);
 486   NEXT_PASS (pass_early_warn_uninitialized);
 487
 488   /* Initial scalar cleanups.  */
 489   NEXT_PASS (pass_ccp);
 490   NEXT_PASS (pass_fre);
 491   NEXT_PASS (pass_dce);
 492   NEXT_PASS (pass_forwprop);
 493   NEXT_PASS (pass_copy_prop);
 494   NEXT_PASS (pass_vrp);
 495   NEXT_PASS (pass_dce);
 496   NEXT_PASS (pass_merge_phi);
 497   NEXT_PASS (pass_dominator);
 498
 499   NEXT_PASS (pass_phiopt);
 500   NEXT_PASS (pass_build_pta);
 501   NEXT_PASS (pass_may_alias);
 502   NEXT_PASS (pass_del_pta);
 503   NEXT_PASS (pass_tail_recursion);
 504   NEXT_PASS (pass_profile);
 505   NEXT_PASS (pass_ch);
 506   NEXT_PASS (pass_stdarg);
 507   NEXT_PASS (pass_lower_complex);
 508   NEXT_PASS (pass_sra);
 509   /* FIXME: SRA may generate arbitrary gimple code, exposing new
 510      aliased and call-clobbered variables.  As mentioned below,
 511      pass_may_alias should be a TODO item.  */
 512   NEXT_PASS (pass_may_alias);
 513   NEXT_PASS (pass_rename_ssa_copies);
 514   NEXT_PASS (pass_dominator);
 515   NEXT_PASS (pass_copy_prop);
 516   NEXT_PASS (pass_dce);
 517   NEXT_PASS (pass_dse);
 518   NEXT_PASS (pass_may_alias);
 519   NEXT_PASS (pass_forwprop);
 520   NEXT_PASS (pass_phiopt);
 521   NEXT_PASS (pass_object_sizes);
 522   NEXT_PASS (pass_store_ccp);
 523   NEXT_PASS (pass_store_copy_prop);
 524   NEXT_PASS (pass_fold_builtins);
 525   /* FIXME: May alias should a TODO but for 4.0.0,
 526      we add may_alias right after fold builtins
 527      which can create arbitrary GIMPLE.  */
 528   NEXT_PASS (pass_may_alias);
 529   NEXT_PASS (pass_cse_reciprocals);
 530   NEXT_PASS (pass_split_crit_edges);
 531   NEXT_PASS (pass_reassoc);
 532   NEXT_PASS (pass_pre);
 533   NEXT_PASS (pass_sink_code);
 534   NEXT_PASS (pass_loop);
 535   NEXT_PASS (pass_dominator);
 536   NEXT_PASS (pass_copy_prop);
 537   NEXT_PASS (pass_cd_dce);
 538   /* FIXME: If DCE is not run before checking for uninitialized uses,
 539      we may get false warnings (e.g., testsuite/gcc.dg/uninit-5.c).
 540      However, this also causes us to misdiagnose cases that should be
 541      real warnings (e.g., testsuite/gcc.dg/pr18501.c).
 542
 543      To fix the false positives in uninit-5.c, we would have to
 544      account for the predicates protecting the set and the use of each
 545      variable.  Using a representation like Gated Single Assignment
 546      may help.  */
 547   NEXT_PASS (pass_late_warn_uninitialized);
 548   NEXT_PASS (pass_dse);
 549   NEXT_PASS (pass_forwprop);
 550   NEXT_PASS (pass_phiopt);
 551   NEXT_PASS (pass_tail_calls);
 552   NEXT_PASS (pass_rename_ssa_copies);
 553   NEXT_PASS (pass_uncprop);
 554   NEXT_PASS (pass_del_ssa);
 555   NEXT_PASS (pass_nrv);
 556   NEXT_PASS (pass_remove_useless_vars);
 557   NEXT_PASS (pass_mark_used_blocks);
 558   NEXT_PASS (pass_cleanup_cfg_post_optimizing);
 559   *p = NULL;
 560
 561   p = &pass_loop.sub;
 562   NEXT_PASS (pass_loop_init);
 563   NEXT_PASS (pass_copy_prop);
 564   NEXT_PASS (pass_lim);
 565   NEXT_PASS (pass_unswitch);
 566   NEXT_PASS (pass_scev_cprop);
 567   NEXT_PASS (pass_record_bounds);
 568   NEXT_PASS (pass_linear_transform);
 569   NEXT_PASS (pass_iv_canon);
 570   NEXT_PASS (pass_if_conversion);
 571   NEXT_PASS (pass_vectorize);
 572   /* NEXT_PASS (pass_may_alias) cannot be done again because the
 573      vectorizer creates alias relations that are not supported by
 574      pass_may_alias.  */
 575   NEXT_PASS (pass_lower_vector_ssa);
 576   NEXT_PASS (pass_complete_unroll);
 577   NEXT_PASS (pass_iv_optimize);
 578   NEXT_PASS (pass_loop_done);
 579   *p = NULL;
 580
 581 #undef NEXT_PASS
 582
 583   register_dump_files (all_lowering_passes, false, PROP_gimple_any);
 584   register_dump_files (all_passes, false, PROP_gimple_any
 585                                           | PROP_gimple_lcf
 586                                           | PROP_gimple_leh
 587                                           | PROP_cfg);
 588   register_dump_files (all_ipa_passes, true, PROP_gimple_any
 589                                              | PROP_gimple_lcf
 590                                              | PROP_gimple_leh
 591                                              | PROP_cfg);
 592 }
 593
 594 static unsigned int last_verified;
 595
 596 static void
 597 execute_todo (struct tree_opt_pass *pass, unsigned int flags, bool use_required)
 598 {
 599   int properties
 600     = use_required ? pass->properties_required : pass->properties_provided;
 601
 602 #if defined ENABLE_CHECKING
 603   if (need_ssa_update_p ())
 604     gcc_assert (flags & TODO_update_ssa_any);
 605 #endif
 606
 607   if (flags & TODO_update_ssa_any)
 608     {
 609       unsigned update_flags = flags & TODO_update_ssa_any;
 610       update_ssa (update_flags);
 611     }
 612
 613   if (flags & TODO_cleanup_cfg)
 614     {
 615       if (current_loops)
 616         cleanup_tree_cfg_loop ();
 617       else
 618         cleanup_tree_cfg ();
 619     }
 620
 621   if ((flags & TODO_dump_func)
 622       && dump_file && current_function_decl)
 623     {
 624       if (properties & PROP_trees)
 625         dump_function_to_file (current_function_decl,
 626                                dump_file, dump_flags);
 627       else if (properties & PROP_cfg)
 628         print_rtl_with_bb (dump_file, get_insns ());
 629       else
 630         print_rtl (dump_file, get_insns ());
 631
 632       /* Flush the file.  If verification fails, we won't be able to
 633          close the file before dieing.  */
 634       fflush (dump_file);
 635     }
 636   if ((flags & TODO_dump_cgraph)
 637       && dump_file && !current_function_decl)
 638     {
 639       dump_cgraph (dump_file);
 640       /* Flush the file.  If verification fails, we won't be able to
 641          close the file before aborting.  */
 642       fflush (dump_file);
 643     }
 644
 645   if (flags & TODO_ggc_collect)
 646     {
 647       ggc_collect ();
 648     }
 649
 650 #if defined ENABLE_CHECKING
 651   if ((pass->properties_required & PROP_ssa)
 652       && !(pass->properties_destroyed & PROP_ssa))
 653     verify_ssa (true);
 654   if (flags & TODO_verify_flow)
 655     verify_flow_info ();
 656   if (flags & TODO_verify_stmts)
 657     verify_stmts ();
 658   if (flags & TODO_verify_loops)
 659     verify_loop_closed_ssa ();
 660 #endif
 661 }
 662
 663 static bool
 664 execute_one_pass (struct tree_opt_pass *pass)
 665 {
 666   unsigned int todo;
 667
 668   /* See if we're supposed to run this pass.  */
 669   if (pass->gate && !pass->gate ())
 670     return false;
 671
 672   /* Note that the folders should only create gimple expressions.
 673      This is a hack until the new folder is ready.  */
 674   in_gimple_form = (pass->properties_provided & PROP_trees) != 0;
 675
 676   /* Run pre-pass verification.  */
 677   todo = pass->todo_flags_start & ~last_verified;
 678   if (todo)
 679     execute_todo (pass, todo, true);
 680
 681   /* If a dump file name is present, open it if enabled.  */
 682   if (pass->static_pass_number != -1)
 683     {
 684       bool initializing_dump = !dump_initialized_p (pass->static_pass_number);
 685       dump_file_name = get_dump_file_name (pass->static_pass_number);
 686       dump_file = dump_begin (pass->static_pass_number, &dump_flags);
 687       if (dump_file && current_function_decl)
 688         {
 689           const char *dname, *aname;
 690           dname = lang_hooks.decl_printable_name (current_function_decl, 2);
 691           aname = (IDENTIFIER_POINTER
 692                    (DECL_ASSEMBLER_NAME (current_function_decl)));
 693           fprintf (dump_file, "\n;; Function %s (%s)%s\n\n", dname, aname,
 694              cfun->function_frequency == FUNCTION_FREQUENCY_HOT
 695              ? " (hot)"
 696              : cfun->function_frequency == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED
 697              ? " (unlikely executed)"
 698              : "");
 699         }
 700
 701       if (initializing_dump
 702           && graph_dump_format != no_graph
 703           && (pass->properties_provided & (PROP_cfg | PROP_rtl))
 704               == (PROP_cfg | PROP_rtl))
 705         clean_graph_dump_file (dump_file_name);
 706     }
 707
 708   /* If a timevar is present, start it.  */
 709   if (pass->tv_id)
 710     timevar_push (pass->tv_id);
 711
 712   /* Do it!  */
 713   if (pass->execute)
 714     pass->execute ();
 715
 716   /* Stop timevar.  */
 717   if (pass->tv_id)
 718     timevar_pop (pass->tv_id);
 719
 720   if (dump_file
 721       && (pass->properties_provided & (PROP_cfg | PROP_rtl))
 722           == (PROP_cfg | PROP_rtl))
 723     print_rtl_with_bb (dump_file, get_insns ());
 724
 725   /* Run post-pass cleanup and verification.  */
 726   todo = pass->todo_flags_finish;
 727   last_verified = todo & TODO_verify_all;
 728   if (todo)
 729     execute_todo (pass, todo, false);
 730
 731   /* Flush and close dump file.  */
 732   if (dump_file_name)
 733     {
 734       free ((char *) dump_file_name);
 735       dump_file_name = NULL;
 736     }
 737   if (dump_file)
 738     {
 739       dump_end (pass->static_pass_number, dump_file);
 740       dump_file = NULL;
 741     }
 742
 743   return true;
 744 }
 745
 746 static void
 747 execute_pass_list (struct tree_opt_pass *pass)
 748 {
 749   do
 750     {
 751       if (execute_one_pass (pass) && pass->sub)
 752         execute_pass_list (pass->sub);
 753       pass = pass->next;
 754     }
 755   while (pass);
 756 }
 757
 758 /* Same as execute_pass_list but assume that subpasses of IPA passes
 759    are local passes.  */
 760 static void
 761 execute_ipa_pass_list (struct tree_opt_pass *pass)
 762 {
 763   do
 764     {
 765       if (execute_one_pass (pass) && pass->sub)
 766         {
 767           struct cgraph_node *node;
 768           for (node = cgraph_nodes; node; node = node->next)
 769             if (node->analyzed)
 770               {
 771                 push_cfun (DECL_STRUCT_FUNCTION (node->decl));
 772                 current_function_decl = node->decl;
 773                 execute_pass_list (pass->sub);
 774                 free_dominance_info (CDI_DOMINATORS);
 775                 free_dominance_info (CDI_POST_DOMINATORS);
 776                 current_function_decl = NULL;
 777                 pop_cfun ();
 778                 ggc_collect ();
 779               }
 780         }
 781       pass = pass->next;
 782     }
 783   while (pass);
 784 }
 785
 786 void
 787 tree_lowering_passes (tree fn)
 788 {
 789   tree saved_current_function_decl = current_function_decl;
 790
 791   current_function_decl = fn;
 792   push_cfun (DECL_STRUCT_FUNCTION (fn));
 793   tree_register_cfg_hooks ();
 794   bitmap_obstack_initialize (NULL);
 795   execute_pass_list (all_lowering_passes);
 796   free_dominance_info (CDI_POST_DOMINATORS);
 797   compact_blocks ();
 798   current_function_decl = saved_current_function_decl;
 799   bitmap_obstack_release (NULL);
 800   pop_cfun ();
 801 }
 802
 803 /* Execute all IPA passes.  */
 804 void
 805 ipa_passes (void)
 806 {
 807   cfun = NULL;
 808   tree_register_cfg_hooks ();
 809   bitmap_obstack_initialize (NULL);
 810   execute_ipa_pass_list (all_ipa_passes);
 811   bitmap_obstack_release (NULL);
 812 }
 813 \f
 814
 815 /* Update recursively all inlined_to pointers of functions
 816    inlined into NODE to INLINED_TO.  */
 817 static void
 818 update_inlined_to_pointers (struct cgraph_node *node,
 819                             struct cgraph_node *inlined_to)
 820 {
 821   struct cgraph_edge *e;
 822   for (e = node->callees; e; e = e->next_callee)
 823     {
 824       if (e->callee->global.inlined_to)
 825         {
 826           e->callee->global.inlined_to = inlined_to;
 827           update_inlined_to_pointers (e->callee, inlined_to);
 828         }
 829     }
 830 }
 831
 832 \f
 833 /* For functions-as-trees languages, this performs all optimization and
 834    compilation for FNDECL.  */
 835
 836 void
 837 tree_rest_of_compilation (tree fndecl)
 838 {
 839   location_t saved_loc;
 840   struct cgraph_node *saved_node = NULL, *node;
 841
 842   timevar_push (TV_EXPAND);
 843
 844   gcc_assert (!flag_unit_at_a_time || cgraph_global_info_ready);
 845
 846   /* Initialize the RTL code for the function.  */
 847   current_function_decl = fndecl;
 848   saved_loc = input_location;
 849   input_location = DECL_SOURCE_LOCATION (fndecl);
 850   init_function_start (fndecl);
 851
 852   /* Even though we're inside a function body, we still don't want to
 853      call expand_expr to calculate the size of a variable-sized array.
 854      We haven't necessarily assigned RTL to all variables yet, so it's
 855      not safe to try to expand expressions involving them.  */
 856   cfun->x_dont_save_pending_sizes_p = 1;
 857   cfun->after_inlining = true;
 858
 859   node = cgraph_node (fndecl);
 860
 861   /* We might need the body of this function so that we can expand
 862      it inline somewhere else.  This means not lowering some constructs
 863      such as exception handling.  */
 864   if (cgraph_preserve_function_body_p (fndecl))
 865     {
 866       if (!flag_unit_at_a_time)
 867         {
 868           struct cgraph_edge *e;
 869
 870           saved_node = cgraph_clone_node (node, node->count, 1);
 871           for (e = saved_node->callees; e; e = e->next_callee)
 872             if (!e->inline_failed)
 873               cgraph_clone_inlined_nodes (e, true);
 874         }
 875       cfun->saved_static_chain_decl = cfun->static_chain_decl;
 876       save_body (fndecl, &cfun->saved_args, &cfun->saved_static_chain_decl);
 877     }
 878
 879   if (flag_inline_trees)
 880     {
 881       struct cgraph_edge *e;
 882       for (e = node->callees; e; e = e->next_callee)
 883         if (!e->inline_failed || warn_inline)
 884           break;
 885       if (e)
 886         {
 887           timevar_push (TV_INTEGRATION);
 888           optimize_inline_calls (fndecl);
 889           timevar_pop (TV_INTEGRATION);
 890         }
 891     }
 892   /* We are not going to maintain the cgraph edges up to date.
 893      Kill it so it won't confuse us.  */
 894   while (node->callees)
 895     {
 896       /* In non-unit-at-a-time we must mark all referenced functions as needed.
 897          */
 898       if (node->callees->callee->analyzed && !flag_unit_at_a_time)
 899         cgraph_mark_needed_node (node->callees->callee);
 900       cgraph_remove_edge (node->callees);
 901     }
 902
 903   /* We are not going to maintain the cgraph edges up to date.
 904      Kill it so it won't confuse us.  */
 905   cgraph_node_remove_callees (node);
 906
 907
 908   /* Initialize the default bitmap obstack.  */
 909   bitmap_obstack_initialize (NULL);
 910   bitmap_obstack_initialize (&reg_obstack); /* FIXME, only at RTL generation*/
 911
 912   tree_register_cfg_hooks ();
 913   /* Perform all tree transforms and optimizations.  */
 914   execute_pass_list (all_passes);
 915
 916   bitmap_obstack_release (&reg_obstack);
 917
 918   /* Release the default bitmap obstack.  */
 919   bitmap_obstack_release (NULL);
 920
 921   /* Restore original body if still needed.  */
 922   if (cfun->saved_cfg)
 923     {
 924       DECL_ARGUMENTS (fndecl) = cfun->saved_args;
 925       cfun->cfg = cfun->saved_cfg;
 926       cfun->eh = cfun->saved_eh;
 927       DECL_INITIAL (fndecl) = cfun->saved_blocks;
 928       cfun->unexpanded_var_list = cfun->saved_unexpanded_var_list;
 929       cfun->saved_cfg = NULL;
 930       cfun->saved_eh = NULL;
 931       cfun->saved_args = NULL_TREE;
 932       cfun->saved_blocks = NULL_TREE;
 933       cfun->saved_unexpanded_var_list = NULL_TREE;
 934       cfun->static_chain_decl = cfun->saved_static_chain_decl;
 935       cfun->saved_static_chain_decl = NULL;
 936       /* When not in unit-at-a-time mode, we must preserve out of line copy
 937          representing node before inlining.  Restore original outgoing edges
 938          using clone we created earlier.  */
 939       if (!flag_unit_at_a_time)
 940         {
 941           struct cgraph_edge *e;
 942
 943           node = cgraph_node (current_function_decl);
 944           cgraph_node_remove_callees (node);
 945           node->callees = saved_node->callees;
 946           saved_node->callees = NULL;
 947           update_inlined_to_pointers (node, node);
 948           for (e = node->callees; e; e = e->next_callee)
 949             e->caller = node;
 950           cgraph_remove_node (saved_node);
 951         }
 952     }
 953   else
 954     DECL_SAVED_TREE (fndecl) = NULL;
 955   cfun = 0;
 956
 957   /* If requested, warn about function definitions where the function will
 958      return a value (usually of some struct or union type) which itself will
 959      take up a lot of stack space.  */
 960   if (warn_larger_than && !DECL_EXTERNAL (fndecl) && TREE_TYPE (fndecl))
 961     {
 962       tree ret_type = TREE_TYPE (TREE_TYPE (fndecl));
 963
 964       if (ret_type && TYPE_SIZE_UNIT (ret_type)
 965           && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
 966           && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
 967                                    larger_than_size))
 968         {
 969           unsigned int size_as_int
 970             = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
 971
 972           if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
 973             warning (0, "%Jsize of return value of %qD is %u bytes",
 974                      fndecl, fndecl, size_as_int);
 975           else
 976             warning (0, "%Jsize of return value of %qD is larger than %wd bytes",
 977                      fndecl, fndecl, larger_than_size);
 978         }
 979     }
 980
 981   if (!flag_inline_trees)
 982     {
 983       DECL_SAVED_TREE (fndecl) = NULL;
 984       if (DECL_STRUCT_FUNCTION (fndecl) == 0
 985           && !cgraph_node (fndecl)->origin)
 986         {
 987           /* Stop pointing to the local nodes about to be freed.
 988              But DECL_INITIAL must remain nonzero so we know this
 989              was an actual function definition.
 990              For a nested function, this is done in c_pop_function_context.
 991              If rest_of_compilation set this to 0, leave it 0.  */
 992           if (DECL_INITIAL (fndecl) != 0)
 993             DECL_INITIAL (fndecl) = error_mark_node;
 994         }
 995     }
 996
 997   input_location = saved_loc;
 998
 999   ggc_collect ();
1000   timevar_pop (TV_EXPAND);
1001 }