osprey-gcc-4.2.0/gcc/passes.c

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/*
 * Copyright (C) 2007. QLogic Corporation. All Rights Reserved.
 */
/* Top level of GCC compilers (cc1, cc1plus, etc.)
   Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING.  If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA.  */

/* This is the top level of cc1/c++.
   It parses command args, opens files, invokes the various passes
   in the proper order, and counts the time used by each.
   Error messages and low-level interface to malloc also handled here.  */

#include "config.h"
#undef FLOAT /* This is for hpux. They should change hpux.  */
#undef FFS  /* Some systems define this in param.h.  */
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include <signal.h>

#ifdef HAVE_SYS_RESOURCE_H
# include <sys/resource.h>
#endif

#ifdef HAVE_SYS_TIMES_H
# include <sys/times.h>
#endif

#include "line-map.h"
#include "input.h"
#include "tree.h"
#include "rtl.h"
#include "tm_p.h"
#include "flags.h"
#include "insn-attr.h"
#include "insn-config.h"
#include "insn-flags.h"
#include "hard-reg-set.h"
#include "recog.h"
#include "output.h"
#include "except.h"
#include "function.h"
#include "toplev.h"
#include "expr.h"
#include "basic-block.h"
#include "intl.h"
#include "ggc.h"
#include "graph.h"
#include "regs.h"
#include "timevar.h"
#include "diagnostic.h"
#include "params.h"
#include "reload.h"
#include "dwarf2asm.h"
#include "integrate.h"
#include "real.h"
#include "debug.h"
#include "target.h"
#include "langhooks.h"
#include "cfglayout.h"
#include "cfgloop.h"
#include "hosthooks.h"
#include "cgraph.h"
#include "opts.h"
#include "coverage.h"
#include "value-prof.h"
#include "tree-inline.h"
#include "tree-flow.h"
#include "tree-pass.h"
#include "tree-dump.h"

#if defined (DWARF2_UNWIND_INFO) || defined (DWARF2_DEBUGGING_INFO)
#include "dwarf2out.h"
#endif

#if defined (DBX_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
#include "dbxout.h"
#endif

#ifdef SDB_DEBUGGING_INFO
#include "sdbout.h"
#endif

#ifdef XCOFF_DEBUGGING_INFO
#include "xcoffout.h"   /* Needed for external data
           declarations for e.g. AIX 4.x.  */
#endif

#ifdef KEY
extern void gspin_gxx_emits_decl (tree);
#endif

/* Global variables used to communicate with passes.  */
int dump_flags;
bool in_gimple_form;


/* This is called from various places for FUNCTION_DECL, VAR_DECL,
   and TYPE_DECL nodes.

   This does nothing for local (non-static) variables, unless the
   variable is a register variable with DECL_ASSEMBLER_NAME set.  In
   that case, or if the variable is not an automatic, it sets up the
   RTL and outputs any assembler code (label definition, storage
   allocation and initialization).

   DECL is the declaration.  TOP_LEVEL is nonzero
   if this declaration is not within a function.  */

void
rest_of_decl_compilation (tree decl,
        int top_level,
        int at_end)
{
  /* We deferred calling assemble_alias so that we could collect
     other attributes such as visibility.  Emit the alias now.  */
  {
    tree alias;
    alias = lookup_attribute ("alias", DECL_ATTRIBUTES (decl));
    if (alias)
      {
  alias = TREE_VALUE (TREE_VALUE (alias));
  alias = get_identifier (TREE_STRING_POINTER (alias));
  assemble_alias (decl, alias);
#ifdef KEY
  // Put aliases into the list of decls emitted by g++ so that we can
  // iterate through the list when expanding aliases to WHIRL.  An alias
  // can be expanded only if its target, which can be another alias, is
  // expanded.  Bug 4393.
  if (flag_spin_file)
    gspin_gxx_emits_decl(decl);
#endif
      }
  }

  /* Can't defer this, because it needs to happen before any
     later function definitions are processed.  */
  if (DECL_ASSEMBLER_NAME_SET_P (decl) && DECL_REGISTER (decl))
    make_decl_rtl (decl);

  /* Forward declarations for nested functions are not "external",
     but we need to treat them as if they were.  */
  if (TREE_STATIC (decl) || DECL_EXTERNAL (decl)
      || TREE_CODE (decl) == FUNCTION_DECL)
    {
      timevar_push (TV_VARCONST);

      /* Don't output anything when a tentative file-scope definition
   is seen.  But at end of compilation, do output code for them.

   We do output all variables when unit-at-a-time is active and rely on
   callgraph code to defer them except for forward declarations
   (see gcc.c-torture/compile/920624-1.c) */
      if ((at_end
     || !DECL_DEFER_OUTPUT (decl)
     || DECL_INITIAL (decl))
    && !DECL_EXTERNAL (decl))
  {
    if (TREE_CODE (decl) != FUNCTION_DECL)
      cgraph_varpool_finalize_decl (decl);
    else
      assemble_variable (decl, top_level, at_end, 0);
  }

#ifdef ASM_FINISH_DECLARE_OBJECT
      if (decl == last_assemble_variable_decl)
  {
    ASM_FINISH_DECLARE_OBJECT (asm_out_file, decl,
             top_level, at_end);
  }
#endif

      timevar_pop (TV_VARCONST);
    }
  else if (TREE_CODE (decl) == TYPE_DECL
     /* Like in rest_of_type_compilation, avoid confusing the debug
        information machinery when there are errors.  */
     && !(sorrycount || errorcount))
    {
      timevar_push (TV_SYMOUT);
      debug_hooks->type_decl (decl, !top_level);
      timevar_pop (TV_SYMOUT);
    }

  /* Let cgraph know about the existence of variables.  */
  if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
    cgraph_varpool_node (decl);
}

/* Called after finishing a record, union or enumeral type.  */

void
rest_of_type_compilation (tree type, int toplev)
{
  /* Avoid confusing the debug information machinery when there are
     errors.  */
  if (errorcount != 0 || sorrycount != 0)
    return;

  timevar_push (TV_SYMOUT);
  debug_hooks->type_decl (TYPE_STUB_DECL (type), !toplev);
  timevar_pop (TV_SYMOUT);
}



void
finish_optimization_passes (void)
{
  enum tree_dump_index i;
  struct dump_file_info *dfi;
  char *name;

  timevar_push (TV_DUMP);
  if (profile_arc_flag || flag_test_coverage || flag_branch_probabilities)
    {
      dump_file = dump_begin (pass_profile.static_pass_number, NULL);
      end_branch_prob ();
      if (dump_file)
  dump_end (pass_profile.static_pass_number, dump_file);
    }

  if (optimize > 0)
    {
      dump_file = dump_begin (pass_combine.static_pass_number, NULL);
      if (dump_file)
  {
    dump_combine_total_stats (dump_file);
          dump_end (pass_combine.static_pass_number, dump_file);
  }
    }

  /* Do whatever is necessary to finish printing the graphs.  */
  if (graph_dump_format != no_graph)
    for (i = TDI_end; (dfi = get_dump_file_info (i)) != NULL; ++i)
      if (dump_initialized_p (i)
    && (dfi->flags & TDF_GRAPH) != 0
    && (name = get_dump_file_name (i)) != NULL)
  {
    finish_graph_dump_file (name);
    free (name);
  }

  timevar_pop (TV_DUMP);
}

static bool
gate_rest_of_compilation (void)
{
#ifdef KEY
  if (flag_spin_file)
    gspin_gxx_emits_decl(current_function_decl);
#endif
  /* Early return if there were errors.  We can run afoul of our
     consistency checks, and there's not really much point in fixing them.  */
  return !(rtl_dump_and_exit || flag_syntax_only || errorcount || sorrycount);
}

struct tree_opt_pass pass_rest_of_compilation =
{
  NULL,                                 /* name */
  gate_rest_of_compilation,             /* gate */
  NULL,                                 /* execute */
  NULL,                                 /* sub */
  NULL,                                 /* next */
  0,                                    /* static_pass_number */
  TV_REST_OF_COMPILATION,               /* tv_id */
  PROP_rtl,                             /* properties_required */
  0,                                    /* properties_provided */
  0,                                    /* properties_destroyed */
  0,                                    /* todo_flags_start */
  TODO_ggc_collect,                     /* todo_flags_finish */
  0                                     /* letter */
};

static bool
gate_postreload (void)
{
  return reload_completed;
}

struct tree_opt_pass pass_postreload =
{
  NULL,                                 /* name */
  gate_postreload,                      /* gate */
  NULL,                                 /* execute */
  NULL,                                 /* sub */
  NULL,                                 /* next */
  0,                                    /* static_pass_number */
  0,                                    /* tv_id */
  PROP_rtl,                             /* properties_required */
  0,                                    /* properties_provided */
  0,                                    /* properties_destroyed */
  0,                                    /* todo_flags_start */
  TODO_ggc_collect,                     /* todo_flags_finish */
  0         /* letter */
};



/* The root of the compilation pass tree, once constructed.  */
struct tree_opt_pass *all_passes, *all_ipa_passes, *all_lowering_passes;

/* Iterate over the pass tree allocating dump file numbers.  We want
   to do this depth first, and independent of whether the pass is
   enabled or not.  */

static void
register_one_dump_file (struct tree_opt_pass *pass, bool ipa, int properties)
{
  char *dot_name, *flag_name, *glob_name;
  const char *prefix;
  char num[10];
  int flags;

  /* See below in next_pass_1.  */
  num[0] = '\0';
  if (pass->static_pass_number != -1)
    sprintf (num, "%d", ((int) pass->static_pass_number < 0
       ? 1 : pass->static_pass_number));

  dot_name = concat (".", pass->name, num, NULL);
  if (ipa)
    prefix = "ipa-", flags = TDF_IPA;
  else if (properties & PROP_trees)
    prefix = "tree-", flags = TDF_TREE;
  else
    prefix = "rtl-", flags = TDF_RTL;

  flag_name = concat (prefix, pass->name, num, NULL);
  glob_name = concat (prefix, pass->name, NULL);
  pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,
                                            flags, pass->letter);
}

/* Recursive worker function for register_dump_files.  */

static int 
register_dump_files_1 (struct tree_opt_pass *pass, bool ipa, int properties)
{
  do
    {
      int new_properties = (properties | pass->properties_provided)
         & ~pass->properties_destroyed;

      if (pass->name)
        register_one_dump_file (pass, ipa, new_properties);

      if (pass->sub)
        new_properties = register_dump_files_1 (pass->sub, false,
            new_properties);

      /* If we have a gate, combine the properties that we could have with
         and without the pass being examined.  */
      if (pass->gate)
        properties &= new_properties;
      else
        properties = new_properties;

      pass = pass->next;
    }
  while (pass);

  return properties;
}

/* Register the dump files for the pipeline starting at PASS.  IPA is
   true if the pass is inter-procedural, and PROPERTIES reflects the
   properties that are guaranteed to be available at the beginning of
   the pipeline.  */

static void 
register_dump_files (struct tree_opt_pass *pass, bool ipa, int properties)
{
  pass->properties_required |= properties;
  pass->todo_flags_start |= TODO_set_props;
  register_dump_files_1 (pass, ipa, properties);
}

/* Add a pass to the pass list. Duplicate the pass if it's already
   in the list.  */

static struct tree_opt_pass **
next_pass_1 (struct tree_opt_pass **list, struct tree_opt_pass *pass)
{
  /* A nonzero static_pass_number indicates that the
     pass is already in the list.  */
  if (pass->static_pass_number)
    {
      struct tree_opt_pass *new;

      new = xmalloc (sizeof (*new));
      memcpy (new, pass, sizeof (*new));

      /* Indicate to register_dump_files that this pass has duplicates,
         and so it should rename the dump file.  The first instance will
         be -1, and be number of duplicates = -static_pass_number - 1.
         Subsequent instances will be > 0 and just the duplicate number.  */
      if (pass->name)
        {
          pass->static_pass_number -= 1;
          new->static_pass_number = -pass->static_pass_number;
  }
      
      *list = new;
    }
  else
    {
      pass->static_pass_number = -1;
      *list = pass;
    }  
  
  return &(*list)->next;
          
}

/* Construct the pass tree.  The sequencing of passes is driven by
   the cgraph routines:

   cgraph_finalize_compilation_unit ()
       for each node N in the cgraph
     cgraph_analyze_function (N)
         cgraph_lower_function (N) -> all_lowering_passes

   If we are optimizing, cgraph_optimize is then invoked:

   cgraph_optimize ()
       ipa_passes ()      -> all_ipa_passes
       cgraph_expand_all_functions ()
           for each node N in the cgraph
         cgraph_expand_function (N)
             cgraph_lower_function (N)  -> Now a NOP.
       lang_hooks.callgraph.expand_function (DECL (N))
        tree_rest_of_compilation (DECL (N))  -> all_passes
*/

void
init_optimization_passes (void)
{
  struct tree_opt_pass **p;

#define NEXT_PASS(PASS)  (p = next_pass_1 (p, &PASS))
  /* Interprocedural optimization passes.  */
  p = &all_ipa_passes;
  NEXT_PASS (pass_early_ipa_inline);
  NEXT_PASS (pass_early_local_passes);
  NEXT_PASS (pass_ipa_cp);
  NEXT_PASS (pass_ipa_inline);
  NEXT_PASS (pass_ipa_reference);
  NEXT_PASS (pass_ipa_pure_const); 
  NEXT_PASS (pass_ipa_type_escape);
  NEXT_PASS (pass_ipa_pta);
  *p = NULL;

  /* All passes needed to lower the function into shape optimizers can
     operate on.  */
  p = &all_lowering_passes;
  NEXT_PASS (pass_remove_useless_stmts);
  NEXT_PASS (pass_mudflap_1);
  NEXT_PASS (pass_lower_omp);
  NEXT_PASS (pass_lower_cf);
  NEXT_PASS (pass_lower_eh);
  NEXT_PASS (pass_build_cfg);
  NEXT_PASS (pass_lower_complex_O0);
  NEXT_PASS (pass_lower_vector);
  NEXT_PASS (pass_warn_function_return);
  NEXT_PASS (pass_early_tree_profile);
  *p = NULL;

  p = &pass_early_local_passes.sub;
  NEXT_PASS (pass_tree_profile);
  NEXT_PASS (pass_cleanup_cfg);
  NEXT_PASS (pass_rebuild_cgraph_edges);
  *p = NULL;

  p = &all_passes;
  NEXT_PASS (pass_fixup_cfg);
  NEXT_PASS (pass_init_datastructures);
  NEXT_PASS (pass_expand_omp);
  NEXT_PASS (pass_all_optimizations);
  NEXT_PASS (pass_warn_function_noreturn);
  NEXT_PASS (pass_mudflap_2);
  NEXT_PASS (pass_free_datastructures);
  NEXT_PASS (pass_free_cfg_annotations);
  NEXT_PASS (pass_expand);
  NEXT_PASS (pass_rest_of_compilation);
  NEXT_PASS (pass_clean_state);
  *p = NULL;

  p = &pass_all_optimizations.sub;
  NEXT_PASS (pass_referenced_vars);
  NEXT_PASS (pass_reset_cc_flags);
  NEXT_PASS (pass_create_structure_vars);
  NEXT_PASS (pass_build_ssa);
  NEXT_PASS (pass_may_alias);
  NEXT_PASS (pass_return_slot);
  NEXT_PASS (pass_rename_ssa_copies);
  NEXT_PASS (pass_early_warn_uninitialized);

  /* Initial scalar cleanups.  */
  NEXT_PASS (pass_ccp);
  NEXT_PASS (pass_fre);
  NEXT_PASS (pass_dce);
  NEXT_PASS (pass_forwprop);
  NEXT_PASS (pass_copy_prop);
  NEXT_PASS (pass_merge_phi);
  NEXT_PASS (pass_vrp);
  NEXT_PASS (pass_dce);
  NEXT_PASS (pass_dominator);

  /* The only const/copy propagation opportunities left after
     DOM should be due to degenerate PHI nodes.  So rather than
     run the full propagators, run a specialized pass which
     only examines PHIs to discover const/copy propagation
     opportunities.  */
  NEXT_PASS (pass_phi_only_cprop);

  NEXT_PASS (pass_phiopt);
  NEXT_PASS (pass_may_alias);
  NEXT_PASS (pass_tail_recursion);
  NEXT_PASS (pass_profile);
  NEXT_PASS (pass_ch);
  NEXT_PASS (pass_stdarg);
  NEXT_PASS (pass_lower_complex);
  NEXT_PASS (pass_sra);
  /* FIXME: SRA may generate arbitrary gimple code, exposing new
     aliased and call-clobbered variables.  As mentioned below,
     pass_may_alias should be a TODO item.  */
  NEXT_PASS (pass_may_alias);
  NEXT_PASS (pass_rename_ssa_copies);
  NEXT_PASS (pass_dominator);

  /* The only const/copy propagation opportunities left after
     DOM should be due to degenerate PHI nodes.  So rather than
     run the full propagators, run a specialized pass which
     only examines PHIs to discover const/copy propagation
     opportunities.  */
  NEXT_PASS (pass_phi_only_cprop);

  NEXT_PASS (pass_reassoc);
  NEXT_PASS (pass_dce);
  NEXT_PASS (pass_dse);
  NEXT_PASS (pass_may_alias);
  NEXT_PASS (pass_forwprop);
  NEXT_PASS (pass_phiopt);
  NEXT_PASS (pass_object_sizes);
  NEXT_PASS (pass_store_ccp);
  NEXT_PASS (pass_store_copy_prop);
  NEXT_PASS (pass_fold_builtins);
  /* FIXME: May alias should a TODO but for 4.0.0,
     we add may_alias right after fold builtins
     which can create arbitrary GIMPLE.  */
  NEXT_PASS (pass_may_alias);
  NEXT_PASS (pass_split_crit_edges);
  NEXT_PASS (pass_pre);
  NEXT_PASS (pass_may_alias);
  NEXT_PASS (pass_sink_code);
  NEXT_PASS (pass_tree_loop);
  NEXT_PASS (pass_cse_reciprocals);
  NEXT_PASS (pass_reassoc);
  NEXT_PASS (pass_vrp);
  NEXT_PASS (pass_dominator);

  /* The only const/copy propagation opportunities left after
     DOM should be due to degenerate PHI nodes.  So rather than
     run the full propagators, run a specialized pass which
     only examines PHIs to discover const/copy propagation
     opportunities.  */
  NEXT_PASS (pass_phi_only_cprop);

  NEXT_PASS (pass_cd_dce);

  /* FIXME: If DCE is not run before checking for uninitialized uses,
     we may get false warnings (e.g., testsuite/gcc.dg/uninit-5.c).
     However, this also causes us to misdiagnose cases that should be
     real warnings (e.g., testsuite/gcc.dg/pr18501.c).
     
     To fix the false positives in uninit-5.c, we would have to
     account for the predicates protecting the set and the use of each
     variable.  Using a representation like Gated Single Assignment
     may help.  */
  NEXT_PASS (pass_late_warn_uninitialized);
  NEXT_PASS (pass_dse);
  NEXT_PASS (pass_forwprop);
  NEXT_PASS (pass_phiopt);
  NEXT_PASS (pass_tail_calls);
  NEXT_PASS (pass_rename_ssa_copies);
  NEXT_PASS (pass_uncprop);
  NEXT_PASS (pass_del_ssa);
  NEXT_PASS (pass_nrv);
  NEXT_PASS (pass_mark_used_blocks);
  NEXT_PASS (pass_cleanup_cfg_post_optimizing);
  *p = NULL;

  p = &pass_tree_loop.sub;
  NEXT_PASS (pass_tree_loop_init);
  NEXT_PASS (pass_copy_prop);
  NEXT_PASS (pass_lim);
  NEXT_PASS (pass_tree_unswitch);
  NEXT_PASS (pass_scev_cprop);
  NEXT_PASS (pass_empty_loop);
  NEXT_PASS (pass_record_bounds);
  NEXT_PASS (pass_linear_transform);
  NEXT_PASS (pass_iv_canon);
  NEXT_PASS (pass_if_conversion);
  NEXT_PASS (pass_vectorize);
  /* NEXT_PASS (pass_may_alias) cannot be done again because the
     vectorizer creates alias relations that are not supported by
     pass_may_alias.  */
  NEXT_PASS (pass_complete_unroll);
  NEXT_PASS (pass_loop_prefetch);
  NEXT_PASS (pass_iv_optimize);
  NEXT_PASS (pass_tree_loop_done);
  *p = NULL;

  p = &pass_vectorize.sub;
  NEXT_PASS (pass_lower_vector_ssa);
  NEXT_PASS (pass_dce_loop);
  *p = NULL;

  p = &pass_loop2.sub;
  NEXT_PASS (pass_rtl_loop_init);
  NEXT_PASS (pass_rtl_move_loop_invariants);
  NEXT_PASS (pass_rtl_unswitch);
  NEXT_PASS (pass_rtl_unroll_and_peel_loops);
  NEXT_PASS (pass_rtl_doloop);
  NEXT_PASS (pass_rtl_loop_done);
  *p = NULL;
  
  p = &pass_rest_of_compilation.sub;
  NEXT_PASS (pass_init_function);
  NEXT_PASS (pass_jump);
  NEXT_PASS (pass_insn_locators_initialize);
  NEXT_PASS (pass_rtl_eh);
  NEXT_PASS (pass_initial_value_sets);
  NEXT_PASS (pass_unshare_all_rtl);
  NEXT_PASS (pass_instantiate_virtual_regs);
  NEXT_PASS (pass_jump2);
  NEXT_PASS (pass_cse);
  NEXT_PASS (pass_gcse);
  NEXT_PASS (pass_jump_bypass);
  NEXT_PASS (pass_rtl_ifcvt);
  NEXT_PASS (pass_tracer);
  /* Perform loop optimizations.  It might be better to do them a bit
     sooner, but we want the profile feedback to work more
     efficiently.  */
  NEXT_PASS (pass_loop2);
  NEXT_PASS (pass_web);
  NEXT_PASS (pass_cse2);
  NEXT_PASS (pass_life);
  NEXT_PASS (pass_combine);
  NEXT_PASS (pass_if_after_combine);
  NEXT_PASS (pass_partition_blocks);
  NEXT_PASS (pass_regmove);
  NEXT_PASS (pass_split_all_insns);
  NEXT_PASS (pass_mode_switching);
  NEXT_PASS (pass_see);
  NEXT_PASS (pass_recompute_reg_usage);
  NEXT_PASS (pass_sms);
  NEXT_PASS (pass_sched);
  NEXT_PASS (pass_local_alloc);
  NEXT_PASS (pass_global_alloc);
  NEXT_PASS (pass_postreload);
  *p = NULL;

  p = &pass_postreload.sub;
  NEXT_PASS (pass_postreload_cse);
  NEXT_PASS (pass_gcse2);
  NEXT_PASS (pass_flow2);
  NEXT_PASS (pass_rtl_seqabstr);
  NEXT_PASS (pass_stack_adjustments);
  NEXT_PASS (pass_peephole2);
  NEXT_PASS (pass_if_after_reload);
  NEXT_PASS (pass_regrename);
  NEXT_PASS (pass_reorder_blocks);
  NEXT_PASS (pass_branch_target_load_optimize);
  NEXT_PASS (pass_leaf_regs);
  NEXT_PASS (pass_sched2);
  NEXT_PASS (pass_split_before_regstack);
  NEXT_PASS (pass_stack_regs);
  NEXT_PASS (pass_compute_alignments);
  NEXT_PASS (pass_duplicate_computed_gotos);
  NEXT_PASS (pass_variable_tracking);
  NEXT_PASS (pass_free_cfg);
  NEXT_PASS (pass_machine_reorg);
  NEXT_PASS (pass_purge_lineno_notes);
  NEXT_PASS (pass_cleanup_barriers);
  NEXT_PASS (pass_delay_slots);
  NEXT_PASS (pass_split_for_shorten_branches);
  NEXT_PASS (pass_convert_to_eh_region_ranges);
  NEXT_PASS (pass_shorten_branches);
  NEXT_PASS (pass_set_nothrow_function_flags);
  NEXT_PASS (pass_final);
  *p = NULL;

#undef NEXT_PASS

  /* Register the passes with the tree dump code.  */
  register_dump_files (all_ipa_passes, true,
           PROP_gimple_any | PROP_gimple_lcf | PROP_gimple_leh
           | PROP_cfg);
  register_dump_files (all_lowering_passes, false, PROP_gimple_any);
  register_dump_files (all_passes, false,
           PROP_gimple_any | PROP_gimple_lcf | PROP_gimple_leh
           | PROP_cfg);
}

static unsigned int last_verified;
static unsigned int curr_properties;

static void
execute_todo (unsigned int flags)
{
#if defined ENABLE_CHECKING
  if (need_ssa_update_p ())
    gcc_assert (flags & TODO_update_ssa_any);
#endif

  if (curr_properties & PROP_ssa)
    flags |= TODO_verify_ssa;
  flags &= ~last_verified;
  if (!flags)
    return;
  
  /* Always recalculate SMT usage before doing anything else.  */
  if (flags & TODO_update_smt_usage)
    recalculate_used_alone ();

  /* Always cleanup the CFG before trying to update SSA .  */
  if (flags & TODO_cleanup_cfg)
    {
      /* CFG Cleanup can cause a constant to prop into an ARRAY_REF.  */
      updating_used_alone = true;

      if (current_loops)
  cleanup_tree_cfg_loop ();
      else
  cleanup_tree_cfg ();

      /* Update the used alone after cleanup cfg.  */
      recalculate_used_alone ();

      /* When cleanup_tree_cfg merges consecutive blocks, it may
   perform some simplistic propagation when removing single
   valued PHI nodes.  This propagation may, in turn, cause the
   SSA form to become out-of-date (see PR 22037).  So, even
   if the parent pass had not scheduled an SSA update, we may
   still need to do one.  */
      if (!(flags & TODO_update_ssa_any) && need_ssa_update_p ())
  flags |= TODO_update_ssa;
    }

  if (flags & TODO_update_ssa_any)
    {
      unsigned update_flags = flags & TODO_update_ssa_any;
      update_ssa (update_flags);
      last_verified &= ~TODO_verify_ssa;
    }

  if (flags & TODO_remove_unused_locals)
    remove_unused_locals ();

  if ((flags & TODO_dump_func)
      && dump_file && current_function_decl)
    {
      if (curr_properties & PROP_trees)
        dump_function_to_file (current_function_decl,
                               dump_file, dump_flags);
      else
  {
    if (dump_flags & TDF_SLIM)
      print_rtl_slim_with_bb (dump_file, get_insns (), dump_flags);
    else if ((curr_properties & PROP_cfg) && (dump_flags & TDF_BLOCKS))
      print_rtl_with_bb (dump_file, get_insns ());
          else
      print_rtl (dump_file, get_insns ());

    if (curr_properties & PROP_cfg
        && graph_dump_format != no_graph
        && (dump_flags & TDF_GRAPH))
      print_rtl_graph_with_bb (dump_file_name, get_insns ());
  }

      /* Flush the file.  If verification fails, we won't be able to
   close the file before aborting.  */
      fflush (dump_file);
    }
  if ((flags & TODO_dump_cgraph)
      && dump_file && !current_function_decl)
    {
      dump_cgraph (dump_file);
      /* Flush the file.  If verification fails, we won't be able to
   close the file before aborting.  */
      fflush (dump_file);
    }

  if (flags & TODO_ggc_collect)
    {
      ggc_collect ();
    }

#if defined ENABLE_CHECKING
  if (flags & TODO_verify_ssa)
    verify_ssa (true);
  if (flags & TODO_verify_flow)
    verify_flow_info ();
  if (flags & TODO_verify_stmts)
    verify_stmts ();
  if (flags & TODO_verify_loops)
    verify_loop_closed_ssa ();
#endif

  last_verified = flags & TODO_verify_all;
}

/* Verify invariants that should hold between passes.  This is a place
   to put simple sanity checks.  */

static void
verify_interpass_invariants (void)
{
#ifdef ENABLE_CHECKING
  gcc_assert (!fold_deferring_overflow_warnings_p ());
#endif
}

static bool
execute_one_pass (struct tree_opt_pass *pass)
{
  bool initializing_dump;
  unsigned int todo_after = 0;

  /* See if we're supposed to run this pass.  */
  if (pass->gate && !pass->gate ())
    return false;

  if (pass->todo_flags_start & TODO_set_props)
    curr_properties = pass->properties_required;

  /* Note that the folders should only create gimple expressions.
     This is a hack until the new folder is ready.  */
  in_gimple_form = (curr_properties & PROP_trees) != 0;

  /* Run pre-pass verification.  */
  execute_todo (pass->todo_flags_start);

  gcc_assert ((curr_properties & pass->properties_required)
        == pass->properties_required);

  if (pass->properties_destroyed & PROP_smt_usage)
    updating_used_alone = true;

  /* If a dump file name is present, open it if enabled.  */
  if (pass->static_pass_number != -1)
    {
      initializing_dump = !dump_initialized_p (pass->static_pass_number);
      dump_file_name = get_dump_file_name (pass->static_pass_number);
      dump_file = dump_begin (pass->static_pass_number, &dump_flags);
      if (dump_file && current_function_decl)
  {
    const char *dname, *aname;
    dname = lang_hooks.decl_printable_name (current_function_decl, 2);
    aname = (IDENTIFIER_POINTER
       (DECL_ASSEMBLER_NAME (current_function_decl)));
    fprintf (dump_file, "\n;; Function %s (%s)%s\n\n", dname, aname,
       cfun->function_frequency == FUNCTION_FREQUENCY_HOT
       ? " (hot)"
       : cfun->function_frequency == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED
       ? " (unlikely executed)"
       : "");
  }
    }
  else
    initializing_dump = false;

  /* If a timevar is present, start it.  */
  if (pass->tv_id)
    timevar_push (pass->tv_id);

  /* Do it!  */
  if (pass->execute)
    {
      todo_after = pass->execute ();
      last_verified = 0;
    }

  /* Stop timevar.  */
  if (pass->tv_id)
    timevar_pop (pass->tv_id);

  curr_properties = (curr_properties | pass->properties_provided)
        & ~pass->properties_destroyed;

  if (initializing_dump
      && dump_file
      && graph_dump_format != no_graph
      && (curr_properties & (PROP_cfg | PROP_rtl)) == (PROP_cfg | PROP_rtl))
    {
      get_dump_file_info (pass->static_pass_number)->flags |= TDF_GRAPH;
      dump_flags |= TDF_GRAPH;
      clean_graph_dump_file (dump_file_name);
    }

  /* Run post-pass cleanup and verification.  */
  execute_todo (todo_after | pass->todo_flags_finish);
  verify_interpass_invariants ();

  /* Flush and close dump file.  */
  if (dump_file_name)
    {
      free ((char *) dump_file_name);
      dump_file_name = NULL;
    }
  if (dump_file)
    {
      dump_end (pass->static_pass_number, dump_file);
      dump_file = NULL;
    }

  if (pass->properties_destroyed & PROP_smt_usage)
    updating_used_alone = false;

  /* Reset in_gimple_form to not break non-unit-at-a-time mode.  */
  in_gimple_form = false;

  return true;
}

void
execute_pass_list (struct tree_opt_pass *pass)
{
  do
    {
      if (execute_one_pass (pass) && pass->sub)
        execute_pass_list (pass->sub);
      pass = pass->next;
    }
  while (pass);
}

/* Same as execute_pass_list but assume that subpasses of IPA passes
   are local passes.  */
void
execute_ipa_pass_list (struct tree_opt_pass *pass)
{
  do
    {
      if (execute_one_pass (pass) && pass->sub)
  {
    struct cgraph_node *node;
    for (node = cgraph_nodes; node; node = node->next)
      if (node->analyzed)
        {
    push_cfun (DECL_STRUCT_FUNCTION (node->decl));
    current_function_decl = node->decl;
    execute_pass_list (pass->sub);
    free_dominance_info (CDI_DOMINATORS);
    free_dominance_info (CDI_POST_DOMINATORS);
    current_function_decl = NULL;
    pop_cfun ();
    ggc_collect ();
        }
  }
      pass = pass->next;
    }
  while (pass);
}

---