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/* 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 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

/* 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);

      }

  }

  /* 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_branch_prob.static_pass_number, NULL);

      end_branch_prob ();

      if (dump_file)

        dump_end (pass_branch_prob.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)

{

  /* 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 */

};

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 */

};

/* 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 n)

{

  char *dot_name, *flag_name, *glob_name;

  char num[10];

  /* 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)

    {

      flag_name = concat ("ipa-", pass->name, num, NULL);

      glob_name = concat ("ipa-", pass->name, NULL);

      /* First IPA dump is cgraph that is dumped via separate channels.  */

      pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,

                                                TDF_IPA, n + 1, 0);

    }

  else if (pass->properties_provided & PROP_trees)

    {

      flag_name = concat ("tree-", pass->name, num, NULL);

      glob_name = concat ("tree-", pass->name, NULL);

      pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,

                                                TDF_TREE, n + TDI_tree_all, 0);

    }

  else

    {

      flag_name = concat ("rtl-", pass->name, num, NULL);

      glob_name = concat ("rtl-", pass->name, NULL);

      pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,

                                                TDF_RTL, n, pass->letter);

    }

}

static int

register_dump_files (struct tree_opt_pass *pass, bool ipa, int properties)

{

  static int n = 0;

  do

    {

      int new_properties;

      int pass_number;

      pass->properties_required = properties;

      new_properties =

        (properties | pass->properties_provided) & ~pass->properties_destroyed;

      /* Reset the counter when we reach RTL-based passes.  */

      if ((new_properties ^ pass->properties_required) & PROP_rtl)

        n = 0;

      pass_number = n;

      if (pass->name)

        n++;

      if (pass->sub)

        new_properties = register_dump_files (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->properties_provided = properties;

      if (pass->name)

        register_one_dump_file (pass, ipa, pass_number);

      pass = pass->next;

    }

  while (pass);

  return 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.  */

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);

  *p = NULL;

  /* All passes needed to lower the function into shape optimizers can operate

     on.  These passes are performed before interprocedural passes, unlike rest

     of local passes (all_passes).  */

  p = &all_lowering_passes;

  NEXT_PASS (pass_remove_useless_stmts);

  NEXT_PASS (pass_mudflap_1);

  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_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_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);

  NEXT_PASS (pass_eliminate_useless_stores);

  /* 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_vrp);

  NEXT_PASS (pass_dce);

  NEXT_PASS (pass_merge_phi);

  NEXT_PASS (pass_dominator);

  /* The only copy propagation opportunities left after DOM

     should be due to degenerate PHI nodes.  So rather than

     run the full copy propagator, just discover and copy

     propagate away the degenerate PHI nodes.  */

  NEXT_PASS (pass_phi_only_copy_prop);

  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 copy propagation opportunities left after DOM

     should be due to degenerate PHI nodes.  So rather than

     run the full copy propagator, just discover and copy

     propagate away the degenerate PHI nodes.  */

  NEXT_PASS (pass_phi_only_copy_prop);

  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_reassoc);

  NEXT_PASS (pass_pre);

  NEXT_PASS (pass_sink_code);

  NEXT_PASS (pass_tree_loop);

  NEXT_PASS (pass_cse_reciprocals);

  NEXT_PASS (pass_dominator);

  /* The only copy propagation opportunities left after DOM

     should be due to degenerate PHI nodes.  So rather than

     run the full copy propagator, just discover and copy

     propagate away the degenerate PHI nodes.  */

  NEXT_PASS (pass_phi_only_copy_prop);

  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_remove_useless_vars);

  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_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_remove_unnecessary_notes);

  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_loop_optimize);

  NEXT_PASS (pass_jump_bypass);

  NEXT_PASS (pass_cfg);

  NEXT_PASS (pass_branch_prob);

  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_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_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_leh | PROP_cfg);

  register_dump_files (all_lowering_passes, false, PROP_gimple_any);

  register_dump_files (all_passes, false, PROP_gimple_leh | PROP_cfg);

}

static unsigned int last_verified;

static void

execute_todo (struct tree_opt_pass *pass, unsigned int flags, bool use_required)

{

  int properties

    = use_required ? pass->properties_required : pass->properties_provided;

#if defined ENABLE_CHECKING

  if (need_ssa_update_p ())

    gcc_assert (flags & TODO_update_ssa_any);

#endif

  /* Always cleanup the CFG before doing anything else.  */

  if (flags & TODO_cleanup_cfg)

    {

      if (current_loops)

        cleanup_tree_cfg_loop ();

      else

        cleanup_tree_cfg ();

      /* 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)

    {