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, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, 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 /* Pass: cleanup the CFG just before expanding trees to RTL.
  88    This is just a round of label cleanups and case node grouping
  89    because after the tree optimizers have run such cleanups may
  90    be necessary.  */
  91
  92 static void
  93 execute_cleanup_cfg_post_optimizing (void)
  94 {
  95   cleanup_tree_cfg ();
  96   cleanup_dead_labels ();
  97   group_case_labels ();
  98 }
  99
 100 static struct tree_opt_pass pass_cleanup_cfg_post_optimizing =
 101 {
 102   "final_cleanup",                      /* name */
 103   NULL,                                 /* gate */
 104   execute_cleanup_cfg_post_optimizing,  /* execute */
 105   NULL,                                 /* sub */
 106   NULL,                                 /* next */
 107   0,                                    /* static_pass_number */
 108   0,                                    /* tv_id */
 109   PROP_cfg,                             /* properties_required */
 110   0,                                    /* properties_provided */
 111   0,                                    /* properties_destroyed */
 112   0,                                    /* todo_flags_start */
 113   TODO_dump_func,                                       /* todo_flags_finish */
 114   0                                     /* letter */
 115 };
 116
 117 /* Pass: do the actions required to finish with tree-ssa optimization
 118    passes.  */
 119
 120 static void
 121 execute_free_datastructures (void)
 122 {
 123   tree *chain;
 124
 125   /* ??? This isn't the right place for this.  Worse, it got computed
 126      more or less at random in various passes.  */
 127   free_dominance_info (CDI_DOMINATORS);
 128
 129   /* Emit gotos for implicit jumps.  */
 130   disband_implicit_edges ();
 131
 132   /* Remove the ssa structures.  Do it here since this includes statement
 133      annotations that need to be intact during disband_implicit_edges.  */
 134   delete_tree_ssa ();
 135
 136   /* Re-chain the statements from the blocks.  */
 137   chain = &DECL_SAVED_TREE (current_function_decl);
 138   *chain = alloc_stmt_list ();
 139
 140   /* And get rid of annotations we no longer need.  */
 141   delete_tree_cfg_annotations ();
 142 }
 143
 144 static struct tree_opt_pass pass_free_datastructures =
 145 {
 146   NULL,                                 /* name */
 147   NULL,                                 /* gate */
 148   execute_free_datastructures,                  /* execute */
 149   NULL,                                 /* sub */
 150   NULL,                                 /* next */
 151   0,                                    /* static_pass_number */
 152   0,                                    /* tv_id */
 153   PROP_cfg,                             /* properties_required */
 154   0,                                    /* properties_provided */
 155   0,                                    /* properties_destroyed */
 156   0,                                    /* todo_flags_start */
 157   0,                                    /* todo_flags_finish */
 158   0                                     /* letter */
 159 };
 160
 161 /* Pass: fixup_cfg - IPA passes or compilation of earlier functions might've
 162    changed some properties - such as marked functions nothrow.  Remove now
 163    redundant edges and basic blocks.  */
 164
 165 static void
 166 execute_fixup_cfg (void)
 167 {
 168   basic_block bb;
 169   block_stmt_iterator bsi;
 170
 171   if (cfun->eh)
 172     FOR_EACH_BB (bb)
 173       {
 174         for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
 175           {
 176             tree stmt = bsi_stmt (bsi);
 177             tree call = get_call_expr_in (stmt);
 178
 179             if (call && call_expr_flags (call) & (ECF_CONST | ECF_PURE))
 180               TREE_SIDE_EFFECTS (call) = 0;
 181             if (!tree_could_throw_p (stmt) && lookup_stmt_eh_region (stmt))
 182               remove_stmt_from_eh_region (stmt);
 183           }
 184         tree_purge_dead_eh_edges (bb);
 185       }
 186
 187   cleanup_tree_cfg ();
 188 }
 189
 190 static struct tree_opt_pass pass_fixup_cfg =
 191 {
 192   NULL,                                 /* name */
 193   NULL,                                 /* gate */
 194   execute_fixup_cfg,                    /* execute */
 195   NULL,                                 /* sub */
 196   NULL,                                 /* next */
 197   0,                                    /* static_pass_number */
 198   0,                                    /* tv_id */
 199   PROP_cfg,                             /* properties_required */
 200   0,                                    /* properties_provided */
 201   0,                                    /* properties_destroyed */
 202   0,                                    /* todo_flags_start */
 203   0,                                    /* todo_flags_finish */
 204   0                                     /* letter */
 205 };
 206
 207 /* Do the actions required to initialize internal data structures used
 208    in tree-ssa optimization passes.  */
 209
 210 static void
 211 execute_init_datastructures (void)
 212 {
 213   /* Allocate hash tables, arrays and other structures.  */
 214   init_tree_ssa ();
 215 }
 216
 217 static struct tree_opt_pass pass_init_datastructures =
 218 {
 219   NULL,                                 /* name */
 220   NULL,                                 /* gate */
 221   execute_init_datastructures,          /* execute */
 222   NULL,                                 /* sub */
 223   NULL,                                 /* next */
 224   0,                                    /* static_pass_number */
 225   0,                                    /* tv_id */
 226   PROP_cfg,                             /* properties_required */
 227   0,                                    /* properties_provided */
 228   0,                                    /* properties_destroyed */
 229   0,                                    /* todo_flags_start */
 230   0,                                    /* todo_flags_finish */
 231   0                                     /* letter */
 232 };
 233
 234 /* Iterate over the pass tree allocating dump file numbers.  We want
 235    to do this depth first, and independent of whether the pass is
 236    enabled or not.  */
 237
 238 static void
 239 register_one_dump_file (struct tree_opt_pass *pass, bool ipa, int n)
 240 {
 241   char *dot_name, *flag_name, *glob_name;
 242   char num[10];
 243
 244   /* See below in next_pass_1.  */
 245   num[0] = '\0';
 246   if (pass->static_pass_number != -1)
 247     sprintf (num, "%d", ((int) pass->static_pass_number < 0
 248                          ? 1 : pass->static_pass_number));
 249
 250   dot_name = concat (".", pass->name, num, NULL);
 251   if (ipa)
 252     {
 253       flag_name = concat ("ipa-", pass->name, num, NULL);
 254       glob_name = concat ("ipa-", pass->name, NULL);
 255       /* First IPA dump is cgraph that is dumped via separate channels.  */
 256       pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,
 257                                                 TDF_IPA, n + 1, 0);
 258     }
 259   else if (pass->properties_provided & PROP_trees)
 260     {
 261       flag_name = concat ("tree-", pass->name, num, NULL);
 262       glob_name = concat ("tree-", pass->name, NULL);
 263       pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,
 264                                                 TDF_TREE, n + TDI_tree_all, 0);
 265     }
 266   else
 267     {
 268       flag_name = concat ("rtl-", pass->name, num, NULL);
 269       glob_name = concat ("rtl-", pass->name, NULL);
 270       pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,
 271                                                 TDF_RTL, n, pass->letter);
 272     }
 273 }
 274
 275 static int
 276 register_dump_files (struct tree_opt_pass *pass, bool ipa, int properties)
 277 {
 278   static int n = 0;
 279   do
 280     {
 281       int new_properties;
 282       int pass_number;
 283
 284       pass->properties_required = properties;
 285       new_properties =
 286         (properties | pass->properties_provided) & ~pass->properties_destroyed;
 287
 288       /* Reset the counter when we reach RTL-based passes.  */
 289       if ((pass->properties_provided ^ pass->properties_required) & PROP_rtl)
 290         n = 0;
 291
 292       pass_number = n;
 293       if (pass->name)
 294         n++;
 295
 296       if (pass->sub)
 297         new_properties = register_dump_files (pass->sub, ipa, new_properties);
 298
 299       /* If we have a gate, combine the properties that we could have with
 300          and without the pass being examined.  */
 301       if (pass->gate)
 302         properties &= new_properties;
 303       else
 304         properties = new_properties;
 305
 306       pass->properties_provided = properties;
 307       if (pass->name)
 308         register_one_dump_file (pass, ipa, pass_number);
 309
 310       pass = pass->next;
 311     }
 312   while (pass);
 313
 314   return properties;
 315 }
 316
 317 /* Add a pass to the pass list. Duplicate the pass if it's already
 318    in the list.  */
 319
 320 static struct tree_opt_pass **
 321 next_pass_1 (struct tree_opt_pass **list, struct tree_opt_pass *pass)
 322 {
 323
 324   /* A nonzero static_pass_number indicates that the
 325      pass is already in the list.  */
 326   if (pass->static_pass_number)
 327     {
 328       struct tree_opt_pass *new;
 329
 330       new = xmalloc (sizeof (*new));
 331       memcpy (new, pass, sizeof (*new));
 332
 333       /* Indicate to register_dump_files that this pass has duplicates,
 334          and so it should rename the dump file.  The first instance will
 335          be -1, and be number of duplicates = -static_pass_number - 1.
 336          Subsequent instances will be > 0 and just the duplicate number.  */
 337       if (pass->name)
 338         {
 339           pass->static_pass_number -= 1;
 340           new->static_pass_number = -pass->static_pass_number;
 341         }
 342
 343       *list = new;
 344     }
 345   else
 346     {
 347       pass->static_pass_number = -1;
 348       *list = pass;
 349     }
 350
 351   return &(*list)->next;
 352
 353 }
 354
 355 /* Construct the pass tree.  */
 356
 357 void
 358 init_tree_optimization_passes (void)
 359 {
 360   struct tree_opt_pass **p;
 361
 362 #define NEXT_PASS(PASS)  (p = next_pass_1 (p, &PASS))
 363   /* Intraprocedural optimization passes.  */
 364   p = &all_ipa_passes;
 365   NEXT_PASS (pass_ipa_inline);
 366   *p = NULL;
 367
 368   /* All passes needed to lower the function into shape optimizers can operate
 369      on.  These passes are performed before interprocedural passes, unlike rest
 370      of local passes (all_passes).  */
 371   p = &all_lowering_passes;
 372   NEXT_PASS (pass_remove_useless_stmts);
 373   NEXT_PASS (pass_mudflap_1);
 374   NEXT_PASS (pass_lower_cf);
 375   NEXT_PASS (pass_lower_eh);
 376   NEXT_PASS (pass_build_cfg);
 377   NEXT_PASS (pass_lower_complex_O0);
 378   NEXT_PASS (pass_lower_vector);
 379   NEXT_PASS (pass_warn_function_return);
 380   NEXT_PASS (pass_tree_profile);
 381   *p = NULL;
 382
 383   p = &all_passes;
 384   NEXT_PASS (pass_fixup_cfg);
 385   NEXT_PASS (pass_init_datastructures);
 386   NEXT_PASS (pass_all_optimizations);
 387   NEXT_PASS (pass_warn_function_noreturn);
 388   NEXT_PASS (pass_mudflap_2);
 389   NEXT_PASS (pass_free_datastructures);
 390   NEXT_PASS (pass_expand);
 391   NEXT_PASS (pass_rest_of_compilation);
 392   *p = NULL;
 393
 394   p = &pass_all_optimizations.sub;
 395   NEXT_PASS (pass_referenced_vars);
 396   NEXT_PASS (pass_create_structure_vars);
 397   NEXT_PASS (pass_build_ssa);
 398   NEXT_PASS (pass_build_pta);
 399   NEXT_PASS (pass_may_alias);
 400   NEXT_PASS (pass_return_slot);
 401   NEXT_PASS (pass_del_pta);
 402   NEXT_PASS (pass_rename_ssa_copies);
 403   NEXT_PASS (pass_early_warn_uninitialized);
 404
 405   /* Initial scalar cleanups.  */
 406   NEXT_PASS (pass_ccp);
 407   NEXT_PASS (pass_fre);
 408   NEXT_PASS (pass_dce);
 409   NEXT_PASS (pass_forwprop);
 410   NEXT_PASS (pass_vrp);
 411   NEXT_PASS (pass_copy_prop);
 412   NEXT_PASS (pass_dce);
 413   NEXT_PASS (pass_merge_phi);
 414   NEXT_PASS (pass_dominator);
 415
 416   NEXT_PASS (pass_phiopt);
 417   NEXT_PASS (pass_build_pta);
 418   NEXT_PASS (pass_may_alias);
 419   NEXT_PASS (pass_del_pta);
 420   NEXT_PASS (pass_tail_recursion);
 421   NEXT_PASS (pass_profile);
 422   NEXT_PASS (pass_ch);
 423   NEXT_PASS (pass_stdarg);
 424   NEXT_PASS (pass_lower_complex);
 425   NEXT_PASS (pass_sra);
 426   /* FIXME: SRA may generate arbitrary gimple code, exposing new
 427      aliased and call-clobbered variables.  As mentioned below,
 428      pass_may_alias should be a TODO item.  */
 429   NEXT_PASS (pass_may_alias);
 430   NEXT_PASS (pass_rename_ssa_copies);
 431   NEXT_PASS (pass_dominator);
 432   NEXT_PASS (pass_copy_prop);
 433   NEXT_PASS (pass_dce);
 434   NEXT_PASS (pass_dse);
 435   NEXT_PASS (pass_may_alias);
 436   NEXT_PASS (pass_forwprop);
 437   NEXT_PASS (pass_phiopt);
 438   NEXT_PASS (pass_store_ccp);
 439   NEXT_PASS (pass_store_copy_prop);
 440   NEXT_PASS (pass_fold_builtins);
 441   /* FIXME: May alias should a TODO but for 4.0.0,
 442      we add may_alias right after fold builtins
 443      which can create arbitrary GIMPLE.  */
 444   NEXT_PASS (pass_may_alias);
 445   NEXT_PASS (pass_cse_reciprocals);
 446   NEXT_PASS (pass_split_crit_edges);
 447   NEXT_PASS (pass_reassoc);
 448   NEXT_PASS (pass_pre);
 449   NEXT_PASS (pass_sink_code);
 450   NEXT_PASS (pass_loop);
 451   NEXT_PASS (pass_dominator);
 452   NEXT_PASS (pass_copy_prop);
 453   NEXT_PASS (pass_cd_dce);
 454   /* FIXME: If DCE is not run before checking for uninitialized uses,
 455      we may get false warnings (e.g., testsuite/gcc.dg/uninit-5.c).
 456      However, this also causes us to misdiagnose cases that should be
 457      real warnings (e.g., testsuite/gcc.dg/pr18501.c).
 458
 459      To fix the false positives in uninit-5.c, we would have to
 460      account for the predicates protecting the set and the use of each
 461      variable.  Using a representation like Gated Single Assignment
 462      may help.  */
 463   NEXT_PASS (pass_late_warn_uninitialized);
 464   NEXT_PASS (pass_dse);
 465   NEXT_PASS (pass_forwprop);
 466   NEXT_PASS (pass_phiopt);
 467   NEXT_PASS (pass_tail_calls);
 468   NEXT_PASS (pass_rename_ssa_copies);
 469   NEXT_PASS (pass_uncprop);
 470   NEXT_PASS (pass_del_ssa);
 471   NEXT_PASS (pass_nrv);
 472   NEXT_PASS (pass_remove_useless_vars);
 473   NEXT_PASS (pass_mark_used_blocks);
 474   NEXT_PASS (pass_cleanup_cfg_post_optimizing);
 475   *p = NULL;
 476
 477   p = &pass_loop.sub;
 478   NEXT_PASS (pass_loop_init);
 479   NEXT_PASS (pass_copy_prop);
 480   NEXT_PASS (pass_lim);
 481   NEXT_PASS (pass_unswitch);
 482   NEXT_PASS (pass_scev_cprop);
 483   NEXT_PASS (pass_record_bounds);
 484   NEXT_PASS (pass_linear_transform);
 485   NEXT_PASS (pass_iv_canon);
 486   NEXT_PASS (pass_if_conversion);
 487   NEXT_PASS (pass_vectorize);
 488   /* NEXT_PASS (pass_may_alias) cannot be done again because the
 489      vectorizer creates alias relations that are not supported by
 490      pass_may_alias.  */
 491   NEXT_PASS (pass_lower_vector_ssa);
 492   NEXT_PASS (pass_complete_unroll);
 493   NEXT_PASS (pass_iv_optimize);
 494   NEXT_PASS (pass_loop_done);
 495   *p = NULL;
 496
 497 #undef NEXT_PASS
 498
 499   register_dump_files (all_lowering_passes, false, PROP_gimple_any);
 500   register_dump_files (all_passes, false, PROP_gimple_any
 501                                           | PROP_gimple_lcf
 502                                           | PROP_gimple_leh
 503                                           | PROP_cfg);
 504   register_dump_files (all_ipa_passes, true, PROP_gimple_any
 505                                              | PROP_gimple_lcf
 506                                              | PROP_gimple_leh
 507                                              | PROP_cfg);
 508 }
 509
 510 static unsigned int last_verified;
 511
 512 static void
 513 execute_todo (struct tree_opt_pass *pass, unsigned int flags, bool use_required)
 514 {
 515   int properties
 516     = use_required ? pass->properties_required : pass->properties_provided;
 517
 518 #if defined ENABLE_CHECKING
 519   if (need_ssa_update_p ())
 520     gcc_assert (flags & TODO_update_ssa_any);
 521 #endif
 522
 523   if (flags & TODO_update_ssa_any)
 524     {
 525       unsigned update_flags = flags & TODO_update_ssa_any;
 526       update_ssa (update_flags);
 527     }
 528
 529   if (flags & TODO_cleanup_cfg)
 530     {
 531       if (current_loops)
 532         cleanup_tree_cfg_loop ();
 533       else
 534         cleanup_tree_cfg ();
 535     }
 536
 537   if ((flags & TODO_dump_func)
 538       && dump_file && current_function_decl)
 539     {
 540       if (properties & PROP_trees)
 541         dump_function_to_file (current_function_decl,
 542                                dump_file, dump_flags);
 543       else if (properties & PROP_cfg)
 544         print_rtl_with_bb (dump_file, get_insns ());
 545       else
 546         print_rtl (dump_file, get_insns ());
 547
 548       /* Flush the file.  If verification fails, we won't be able to
 549          close the file before dieing.  */
 550       fflush (dump_file);
 551     }
 552   if ((flags & TODO_dump_cgraph)
 553       && dump_file && !current_function_decl)
 554     {
 555       dump_cgraph (dump_file);
 556       /* Flush the file.  If verification fails, we won't be able to
 557          close the file before aborting.  */
 558       fflush (dump_file);
 559     }
 560
 561   if (flags & TODO_ggc_collect)
 562     {
 563       ggc_collect ();
 564     }
 565
 566 #if defined ENABLE_CHECKING
 567   if ((pass->properties_required & PROP_ssa)
 568       && !(pass->properties_destroyed & PROP_ssa))
 569     verify_ssa (true);
 570   if (flags & TODO_verify_flow)
 571     verify_flow_info ();
 572   if (flags & TODO_verify_stmts)
 573     verify_stmts ();
 574   if (flags & TODO_verify_loops)
 575     verify_loop_closed_ssa ();
 576 #endif
 577 }
 578
 579 static bool
 580 execute_one_pass (struct tree_opt_pass *pass)
 581 {
 582   unsigned int todo;
 583
 584   /* See if we're supposed to run this pass.  */
 585   if (pass->gate && !pass->gate ())
 586     return false;
 587
 588   /* Note that the folders should only create gimple expressions.
 589      This is a hack until the new folder is ready.  */
 590   in_gimple_form = (pass->properties_provided & PROP_trees) != 0;
 591
 592   /* Run pre-pass verification.  */
 593   todo = pass->todo_flags_start & ~last_verified;
 594   if (todo)
 595     execute_todo (pass, todo, true);
 596
 597   /* If a dump file name is present, open it if enabled.  */
 598   if (pass->static_pass_number != -1)
 599     {
 600       bool initializing_dump = !dump_initialized_p (pass->static_pass_number);
 601       dump_file_name = get_dump_file_name (pass->static_pass_number);
 602       dump_file = dump_begin (pass->static_pass_number, &dump_flags);
 603       if (dump_file && current_function_decl)
 604         {
 605           const char *dname, *aname;
 606           dname = lang_hooks.decl_printable_name (current_function_decl, 2);
 607           aname = (IDENTIFIER_POINTER
 608                    (DECL_ASSEMBLER_NAME (current_function_decl)));
 609           fprintf (dump_file, "\n;; Function %s (%s)%s\n\n", dname, aname,
 610              cfun->function_frequency == FUNCTION_FREQUENCY_HOT
 611              ? " (hot)"
 612              : cfun->function_frequency == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED
 613              ? " (unlikely executed)"
 614              : "");
 615         }
 616
 617       if (initializing_dump
 618           && graph_dump_format != no_graph
 619           && (pass->properties_provided & (PROP_cfg | PROP_rtl))
 620               == (PROP_cfg | PROP_rtl))
 621         clean_graph_dump_file (dump_file_name);
 622     }
 623
 624   /* If a timevar is present, start it.  */
 625   if (pass->tv_id)
 626     timevar_push (pass->tv_id);
 627
 628   /* Do it!  */
 629   if (pass->execute)
 630     pass->execute ();
 631
 632   /* Stop timevar.  */
 633   if (pass->tv_id)
 634     timevar_pop (pass->tv_id);
 635
 636   if (dump_file
 637       && (pass->properties_provided & (PROP_cfg | PROP_rtl))
 638           == (PROP_cfg | PROP_rtl))
 639     print_rtl_with_bb (dump_file, get_insns ());
 640
 641   /* Run post-pass cleanup and verification.  */
 642   todo = pass->todo_flags_finish;
 643   last_verified = todo & TODO_verify_all;
 644   if (todo)
 645     execute_todo (pass, todo, false);
 646
 647   /* Flush and close dump file.  */
 648   if (dump_file_name)
 649     {
 650       free ((char *) dump_file_name);
 651       dump_file_name = NULL;
 652     }
 653   if (dump_file)
 654     {
 655       dump_end (pass->static_pass_number, dump_file);
 656       dump_file = NULL;
 657     }
 658
 659   return true;
 660 }
 661
 662 static void
 663 execute_pass_list (struct tree_opt_pass *pass)
 664 {
 665   do
 666     {
 667       if (execute_one_pass (pass) && pass->sub)
 668         execute_pass_list (pass->sub);
 669       pass = pass->next;
 670     }
 671   while (pass);
 672 }
 673
 674 /* Same as execute_pass_list but assume that subpasses of IPA passes
 675    are local passes.  */
 676 static void
 677 execute_ipa_pass_list (struct tree_opt_pass *pass)
 678 {
 679   do
 680     {
 681       if (execute_one_pass (pass) && pass->sub)
 682         {
 683           struct cgraph_node *node;
 684           for (node = cgraph_nodes; node; node = node->next)
 685             if (node->analyzed)
 686               {
 687                 push_cfun (DECL_STRUCT_FUNCTION (node->decl));
 688                 current_function_decl = node->decl;
 689                 execute_pass_list (pass);
 690                 free_dominance_info (CDI_DOMINATORS);
 691                 free_dominance_info (CDI_POST_DOMINATORS);
 692                 current_function_decl = NULL;
 693                 pop_cfun ();
 694                 ggc_collect ();
 695               }
 696         }
 697       pass = pass->next;
 698     }
 699   while (pass);
 700 }
 701
 702 void
 703 tree_lowering_passes (tree fn)
 704 {
 705   tree saved_current_function_decl = current_function_decl;
 706
 707   current_function_decl = fn;
 708   push_cfun (DECL_STRUCT_FUNCTION (fn));
 709   tree_register_cfg_hooks ();
 710   bitmap_obstack_initialize (NULL);
 711   execute_pass_list (all_lowering_passes);
 712   free_dominance_info (CDI_POST_DOMINATORS);
 713   compact_blocks ();
 714   current_function_decl = saved_current_function_decl;
 715   bitmap_obstack_release (NULL);
 716   pop_cfun ();
 717 }
 718
 719 /* Execute all IPA passes.  */
 720 void
 721 ipa_passes (void)
 722 {
 723   cfun = NULL;
 724   tree_register_cfg_hooks ();
 725   bitmap_obstack_initialize (NULL);
 726   execute_ipa_pass_list (all_ipa_passes);
 727   bitmap_obstack_release (NULL);
 728 }
 729 \f
 730
 731 /* Update recursively all inlined_to pointers of functions
 732    inlined into NODE to INLINED_TO.  */
 733 static void
 734 update_inlined_to_pointers (struct cgraph_node *node,
 735                             struct cgraph_node *inlined_to)
 736 {
 737   struct cgraph_edge *e;
 738   for (e = node->callees; e; e = e->next_callee)
 739     {
 740       if (e->callee->global.inlined_to)
 741         {
 742           e->callee->global.inlined_to = inlined_to;
 743           update_inlined_to_pointers (e->callee, inlined_to);
 744         }
 745     }
 746 }
 747
 748 \f
 749 /* For functions-as-trees languages, this performs all optimization and
 750    compilation for FNDECL.  */
 751
 752 void
 753 tree_rest_of_compilation (tree fndecl)
 754 {
 755   location_t saved_loc;
 756   struct cgraph_node *saved_node = NULL, *node;
 757
 758   timevar_push (TV_EXPAND);
 759
 760   gcc_assert (!flag_unit_at_a_time || cgraph_global_info_ready);
 761
 762   /* Initialize the RTL code for the function.  */
 763   current_function_decl = fndecl;
 764   saved_loc = input_location;
 765   input_location = DECL_SOURCE_LOCATION (fndecl);
 766   init_function_start (fndecl);
 767
 768   /* Even though we're inside a function body, we still don't want to
 769      call expand_expr to calculate the size of a variable-sized array.
 770      We haven't necessarily assigned RTL to all variables yet, so it's
 771      not safe to try to expand expressions involving them.  */
 772   cfun->x_dont_save_pending_sizes_p = 1;
 773   cfun->after_inlining = true;
 774
 775   node = cgraph_node (fndecl);
 776
 777   /* We might need the body of this function so that we can expand
 778      it inline somewhere else.  This means not lowering some constructs
 779      such as exception handling.  */
 780   if (cgraph_preserve_function_body_p (fndecl))
 781     {
 782       if (!flag_unit_at_a_time)
 783         {
 784           struct cgraph_edge *e;
 785
 786           saved_node = cgraph_clone_node (node, node->count, 1);
 787           for (e = saved_node->callees; e; e = e->next_callee)
 788             if (!e->inline_failed)
 789               cgraph_clone_inlined_nodes (e, true);
 790         }
 791       cfun->saved_static_chain_decl = cfun->static_chain_decl;
 792       save_body (fndecl, &cfun->saved_args, &cfun->saved_static_chain_decl);
 793     }
 794
 795   if (flag_inline_trees)
 796     {
 797       struct cgraph_edge *e;
 798       for (e = node->callees; e; e = e->next_callee)
 799         if (!e->inline_failed || warn_inline)
 800           break;
 801       if (e)
 802         {
 803           timevar_push (TV_INTEGRATION);
 804           optimize_inline_calls (fndecl);
 805           timevar_pop (TV_INTEGRATION);
 806         }
 807     }
 808   /* We are not going to maintain the cgraph edges up to date.
 809      Kill it so it won't confuse us.  */
 810   while (node->callees)
 811     {
 812       /* In non-unit-at-a-time we must mark all referenced functions as needed.
 813          */
 814       if (node->callees->callee->analyzed && !flag_unit_at_a_time)
 815         cgraph_mark_needed_node (node->callees->callee);
 816       cgraph_remove_edge (node->callees);
 817     }
 818
 819   /* We are not going to maintain the cgraph edges up to date.
 820      Kill it so it won't confuse us.  */
 821   cgraph_node_remove_callees (node);
 822
 823
 824   /* Initialize the default bitmap obstack.  */
 825   bitmap_obstack_initialize (NULL);
 826   bitmap_obstack_initialize (&reg_obstack); /* FIXME, only at RTL generation*/
 827
 828   tree_register_cfg_hooks ();
 829   /* Perform all tree transforms and optimizations.  */
 830   execute_pass_list (all_passes);
 831
 832   bitmap_obstack_release (&reg_obstack);
 833
 834   /* Release the default bitmap obstack.  */
 835   bitmap_obstack_release (NULL);
 836
 837   /* Restore original body if still needed.  */
 838   if (cfun->saved_cfg)
 839     {
 840       DECL_ARGUMENTS (fndecl) = cfun->saved_args;
 841       cfun->cfg = cfun->saved_cfg;
 842       cfun->eh = cfun->saved_eh;
 843       cfun->saved_cfg = NULL;
 844       cfun->saved_eh = NULL;
 845       cfun->saved_args = NULL_TREE;
 846       cfun->static_chain_decl = cfun->saved_static_chain_decl;
 847       cfun->saved_static_chain_decl = NULL;
 848       /* When not in unit-at-a-time mode, we must preserve out of line copy
 849          representing node before inlining.  Restore original outgoing edges
 850          using clone we created earlier.  */
 851       if (!flag_unit_at_a_time)
 852         {
 853           struct cgraph_edge *e;
 854
 855           node = cgraph_node (current_function_decl);
 856           cgraph_node_remove_callees (node);
 857           node->callees = saved_node->callees;
 858           saved_node->callees = NULL;
 859           update_inlined_to_pointers (node, node);
 860           for (e = node->callees; e; e = e->next_callee)
 861             e->caller = node;
 862           cgraph_remove_node (saved_node);
 863         }
 864     }
 865   else
 866     DECL_SAVED_TREE (fndecl) = NULL;
 867   cfun = 0;
 868
 869   /* If requested, warn about function definitions where the function will
 870      return a value (usually of some struct or union type) which itself will
 871      take up a lot of stack space.  */
 872   if (warn_larger_than && !DECL_EXTERNAL (fndecl) && TREE_TYPE (fndecl))
 873     {
 874       tree ret_type = TREE_TYPE (TREE_TYPE (fndecl));
 875
 876       if (ret_type && TYPE_SIZE_UNIT (ret_type)
 877           && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
 878           && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
 879                                    larger_than_size))
 880         {
 881           unsigned int size_as_int
 882             = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
 883
 884           if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
 885             warning (0, "%Jsize of return value of %qD is %u bytes",
 886                      fndecl, fndecl, size_as_int);
 887           else
 888             warning (0, "%Jsize of return value of %qD is larger than %wd bytes",
 889                      fndecl, fndecl, larger_than_size);
 890         }
 891     }
 892
 893   if (!flag_inline_trees)
 894     {
 895       DECL_SAVED_TREE (fndecl) = NULL;
 896       if (DECL_STRUCT_FUNCTION (fndecl) == 0
 897           && !cgraph_node (fndecl)->origin)
 898         {
 899           /* Stop pointing to the local nodes about to be freed.
 900              But DECL_INITIAL must remain nonzero so we know this
 901              was an actual function definition.
 902              For a nested function, this is done in c_pop_function_context.
 903              If rest_of_compilation set this to 0, leave it 0.  */
 904           if (DECL_INITIAL (fndecl) != 0)
 905             DECL_INITIAL (fndecl) = error_mark_node;
 906         }
 907     }
 908
 909   input_location = saved_loc;
 910
 911   ggc_collect ();
 912   timevar_pop (TV_EXPAND);
 913 }