gcc/cfgexpand.c

/* A pass for lowering trees to RTL.
   Copyright (C) 2004-2013 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 3, 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 COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "rtl.h"
#include "tm_p.h"
#include "basic-block.h"
#include "function.h"
#include "expr.h"
#include "langhooks.h"
#include "tree-flow.h"
#include "tree-pass.h"
#include "except.h"
#include "flags.h"
#include "diagnostic.h"
#include "gimple-pretty-print.h"
#include "toplev.h"
#include "debug.h"
#include "params.h"
#include "tree-inline.h"
#include "value-prof.h"
#include "target.h"
#include "ssaexpand.h"
#include "bitmap.h"
#include "sbitmap.h"
#include "cfgloop.h"
#include "regs.h" /* For reg_renumber.  */
#include "insn-attr.h" /* For INSN_SCHEDULING.  */
#include "asan.h"

/* This variable holds information helping the rewriting of SSA trees
   into RTL.  */
struct ssaexpand SA;

/* This variable holds the currently expanded gimple statement for purposes
   of comminucating the profile info to the builtin expanders.  */
gimple currently_expanding_gimple_stmt;

static rtx expand_debug_expr (tree);

/* Return an expression tree corresponding to the RHS of GIMPLE
   statement STMT.  */

tree
gimple_assign_rhs_to_tree (gimple stmt)
{
  tree t;
  enum gimple_rhs_class grhs_class;

  grhs_class = get_gimple_rhs_class (gimple_expr_code (stmt));

  if (grhs_class == GIMPLE_TERNARY_RHS)
    t = build3 (gimple_assign_rhs_code (stmt),
		TREE_TYPE (gimple_assign_lhs (stmt)),
		gimple_assign_rhs1 (stmt),
		gimple_assign_rhs2 (stmt),
		gimple_assign_rhs3 (stmt));
  else if (grhs_class == GIMPLE_BINARY_RHS)
    t = build2 (gimple_assign_rhs_code (stmt),
		TREE_TYPE (gimple_assign_lhs (stmt)),
		gimple_assign_rhs1 (stmt),
		gimple_assign_rhs2 (stmt));
  else if (grhs_class == GIMPLE_UNARY_RHS)
    t = build1 (gimple_assign_rhs_code (stmt),
		TREE_TYPE (gimple_assign_lhs (stmt)),
		gimple_assign_rhs1 (stmt));
  else if (grhs_class == GIMPLE_SINGLE_RHS)
    {
      t = gimple_assign_rhs1 (stmt);
      /* Avoid modifying this tree in place below.  */
      if ((gimple_has_location (stmt) && CAN_HAVE_LOCATION_P (t)
	   && gimple_location (stmt) != EXPR_LOCATION (t))
	  || (gimple_block (stmt)
	      && currently_expanding_to_rtl
	      && EXPR_P (t)))
	t = copy_node (t);
    }
  else
    gcc_unreachable ();

  if (gimple_has_location (stmt) && CAN_HAVE_LOCATION_P (t))
    SET_EXPR_LOCATION (t, gimple_location (stmt));

  return t;
}


#ifndef STACK_ALIGNMENT_NEEDED
#define STACK_ALIGNMENT_NEEDED 1
#endif

#define SSAVAR(x) (TREE_CODE (x) == SSA_NAME ? SSA_NAME_VAR (x) : x)

/* Associate declaration T with storage space X.  If T is no
   SSA name this is exactly SET_DECL_RTL, otherwise make the
   partition of T associated with X.  */
static inline void
set_rtl (tree t, rtx x)
{
  if (TREE_CODE (t) == SSA_NAME)
    {
      SA.partition_to_pseudo[var_to_partition (SA.map, t)] = x;
      if (x && !MEM_P (x))
	set_reg_attrs_for_decl_rtl (SSA_NAME_VAR (t), x);
      /* For the benefit of debug information at -O0 (where vartracking
         doesn't run) record the place also in the base DECL if it's
	 a normal variable (not a parameter).  */
      if (x && x != pc_rtx && TREE_CODE (SSA_NAME_VAR (t)) == VAR_DECL)
	{
	  tree var = SSA_NAME_VAR (t);
	  /* If we don't yet have something recorded, just record it now.  */
	  if (!DECL_RTL_SET_P (var))
	    SET_DECL_RTL (var, x);
	  /* If we have it set already to "multiple places" don't
	     change this.  */
	  else if (DECL_RTL (var) == pc_rtx)
	    ;
	  /* If we have something recorded and it's not the same place
	     as we want to record now, we have multiple partitions for the
	     same base variable, with different places.  We can't just
	     randomly chose one, hence we have to say that we don't know.
	     This only happens with optimization, and there var-tracking
	     will figure out the right thing.  */
	  else if (DECL_RTL (var) != x)
	    SET_DECL_RTL (var, pc_rtx);
	}
    }
  else
    SET_DECL_RTL (t, x);
}

/* This structure holds data relevant to one variable that will be
   placed in a stack slot.  */
struct stack_var
{
  /* The Variable.  */
  tree decl;

  /* Initially, the size of the variable.  Later, the size of the partition,
     if this variable becomes it's partition's representative.  */
  HOST_WIDE_INT size;

  /* The *byte* alignment required for this variable.  Or as, with the
     size, the alignment for this partition.  */
  unsigned int alignb;

  /* The partition representative.  */
  size_t representative;

  /* The next stack variable in the partition, or EOC.  */
  size_t next;

  /* The numbers of conflicting stack variables.  */
  bitmap conflicts;
};

#define EOC  ((size_t)-1)

/* We have an array of such objects while deciding allocation.  */
static struct stack_var *stack_vars;
static size_t stack_vars_alloc;
static size_t stack_vars_num;
static struct pointer_map_t *decl_to_stack_part;

/* Conflict bitmaps go on this obstack.  This allows us to destroy
   all of them in one big sweep.  */
static bitmap_obstack stack_var_bitmap_obstack;

/* An array of indices such that stack_vars[stack_vars_sorted[i]].size
   is non-decreasing.  */
static size_t *stack_vars_sorted;

/* The phase of the stack frame.  This is the known misalignment of
   virtual_stack_vars_rtx from PREFERRED_STACK_BOUNDARY.  That is,
   (frame_offset+frame_phase) % PREFERRED_STACK_BOUNDARY == 0.  */
static int frame_phase;

/* Used during expand_used_vars to remember if we saw any decls for
   which we'd like to enable stack smashing protection.  */
static bool has_protected_decls;

/* Used during expand_used_vars.  Remember if we say a character buffer
   smaller than our cutoff threshold.  Used for -Wstack-protector.  */
static bool has_short_buffer;

/* Compute the byte alignment to use for DECL.  Ignore alignment
   we can't do with expected alignment of the stack boundary.  */

static unsigned int
align_local_variable (tree decl)
{
  unsigned int align = LOCAL_DECL_ALIGNMENT (decl);
  DECL_ALIGN (decl) = align;
  return align / BITS_PER_UNIT;
}

/* Allocate SIZE bytes at byte alignment ALIGN from the stack frame.
   Return the frame offset.  */

static HOST_WIDE_INT
alloc_stack_frame_space (HOST_WIDE_INT size, unsigned HOST_WIDE_INT align)
{
  HOST_WIDE_INT offset, new_frame_offset;

  new_frame_offset = frame_offset;
  if (FRAME_GROWS_DOWNWARD)
    {
      new_frame_offset -= size + frame_phase;
      new_frame_offset &= -align;
      new_frame_offset += frame_phase;
      offset = new_frame_offset;
    }
  else
    {
      new_frame_offset -= frame_phase;
      new_frame_offset += align - 1;
      new_frame_offset &= -align;
      new_frame_offset += frame_phase;
      offset = new_frame_offset;
      new_frame_offset += size;
    }
  frame_offset = new_frame_offset;

  if (frame_offset_overflow (frame_offset, cfun->decl))
    frame_offset = offset = 0;

  return offset;
}

/* Accumulate DECL into STACK_VARS.  */

static void
add_stack_var (tree decl)
{
  struct stack_var *v;

  if (stack_vars_num >= stack_vars_alloc)
    {
      if (stack_vars_alloc)
	stack_vars_alloc = stack_vars_alloc * 3 / 2;
      else
	stack_vars_alloc = 32;
      stack_vars
	= XRESIZEVEC (struct stack_var, stack_vars, stack_vars_alloc);
    }
  if (!decl_to_stack_part)
    decl_to_stack_part = pointer_map_create ();

  v = &stack_vars[stack_vars_num];
  * (size_t *)pointer_map_insert (decl_to_stack_part, decl) = stack_vars_num;

  v->decl = decl;
  v->size = tree_low_cst (DECL_SIZE_UNIT (SSAVAR (decl)), 1);
  /* Ensure that all variables have size, so that &a != &b for any two
     variables that are simultaneously live.  */
  if (v->size == 0)
    v->size = 1;
  v->alignb = align_local_variable (SSAVAR (decl));
  /* An alignment of zero can mightily confuse us later.  */
  gcc_assert (v->alignb != 0);

  /* All variables are initially in their own partition.  */
  v->representative = stack_vars_num;
  v->next = EOC;

  /* All variables initially conflict with no other.  */
  v->conflicts = NULL;

  /* Ensure that this decl doesn't get put onto the list twice.  */
  set_rtl (decl, pc_rtx);

  stack_vars_num++;
}

/* Make the decls associated with luid's X and Y conflict.  */

static void
add_stack_var_conflict (size_t x, size_t y)
{
  struct stack_var *a = &stack_vars[x];
  struct stack_var *b = &stack_vars[y];
  if (!a->conflicts)
    a->conflicts = BITMAP_ALLOC (&stack_var_bitmap_obstack);
  if (!b->conflicts)
    b->conflicts = BITMAP_ALLOC (&stack_var_bitmap_obstack);
  bitmap_set_bit (a->conflicts, y);
  bitmap_set_bit (b->conflicts, x);
}

/* Check whether the decls associated with luid's X and Y conflict.  */

static bool
stack_var_conflict_p (size_t x, size_t y)
{
  struct stack_var *a = &stack_vars[x];
  struct stack_var *b = &stack_vars[y];
  if (x == y)
    return false;
  /* Partitions containing an SSA name result from gimple registers
     with things like unsupported modes.  They are top-level and
     hence conflict with everything else.  */
  if (TREE_CODE (a->decl) == SSA_NAME || TREE_CODE (b->decl) == SSA_NAME)
    return true;

  if (!a->conflicts || !b->conflicts)
    return false;
  return bitmap_bit_p (a->conflicts, y);
}

/* Callback for walk_stmt_ops.  If OP is a decl touched by add_stack_var
   enter its partition number into bitmap DATA.  */

static bool
visit_op (gimple, tree op, tree, void *data)
{
  bitmap active = (bitmap)data;
  op = get_base_address (op);
  if (op
      && DECL_P (op)
      && DECL_RTL_IF_SET (op) == pc_rtx)
    {
      size_t *v = (size_t *) pointer_map_contains (decl_to_stack_part, op);
      if (v)
	bitmap_set_bit (active, *v);
    }
  return false;
}

/* Callback for walk_stmt_ops.  If OP is a decl touched by add_stack_var
   record conflicts between it and all currently active other partitions
   from bitmap DATA.  */

static bool
visit_conflict (gimple, tree op, tree, void *data)
{
  bitmap active = (bitmap)data;
  op = get_base_address (op);
  if (op
      && DECL_P (op)
      && DECL_RTL_IF_SET (op) == pc_rtx)
    {
      size_t *v =
	(size_t *) pointer_map_contains (decl_to_stack_part, op);
      if (v && bitmap_set_bit (active, *v))
	{
	  size_t num = *v;
	  bitmap_iterator bi;
	  unsigned i;
	  gcc_assert (num < stack_vars_num);
	  EXECUTE_IF_SET_IN_BITMAP (active, 0, i, bi)
	    add_stack_var_conflict (num, i);
	}
    }
  return false;
}

/* Helper routine for add_scope_conflicts, calculating the active partitions
   at the end of BB, leaving the result in WORK.  We're called to generate
   conflicts when FOR_CONFLICT is true, otherwise we're just tracking
   liveness.  */

static void
add_scope_conflicts_1 (basic_block bb, bitmap work, bool for_conflict)
{
  edge e;
  edge_iterator ei;
  gimple_stmt_iterator gsi;
  walk_stmt_load_store_addr_fn visit;

  bitmap_clear (work);
  FOR_EACH_EDGE (e, ei, bb->preds)
    bitmap_ior_into (work, (bitmap)e->src->aux);

  visit = visit_op;

  for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
    {
      gimple stmt = gsi_stmt (gsi);
      walk_stmt_load_store_addr_ops (stmt, work, NULL, NULL, visit);
    }
  for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi))
    {
      gimple stmt = gsi_stmt (gsi);

      if (gimple_clobber_p (stmt))
	{
	  tree lhs = gimple_assign_lhs (stmt);
	  size_t *v;
	  /* Nested function lowering might introduce LHSs
	     that are COMPONENT_REFs.  */
	  if (TREE_CODE (lhs) != VAR_DECL)
	    continue;
	  if (DECL_RTL_IF_SET (lhs) == pc_rtx
	      && (v = (size_t *)
		  pointer_map_contains (decl_to_stack_part, lhs)))
	    bitmap_clear_bit (work, *v);
	}
      else if (!is_gimple_debug (stmt))
	{
	  if (for_conflict
	      && visit == visit_op)
	    {
	      /* If this is the first real instruction in this BB we need
	         to add conflicts for everything live at this point now.
		 Unlike classical liveness for named objects we can't
		 rely on seeing a def/use of the names we're interested in.
		 There might merely be indirect loads/stores.  We'd not add any
		 conflicts for such partitions.  */
	      bitmap_iterator bi;
	      unsigned i;
	      EXECUTE_IF_SET_IN_BITMAP (work, 0, i, bi)
		{
		  struct stack_var *a = &stack_vars[i];
		  if (!a->conflicts)
		    a->conflicts = BITMAP_ALLOC (&stack_var_bitmap_obstack);
		  bitmap_ior_into (a->conflicts, work);
		}
	      visit = visit_conflict;
	    }
	  walk_stmt_load_store_addr_ops (stmt, work, visit, visit, visit);
	}
    }
}

/* Generate stack partition conflicts between all partitions that are
   simultaneously live.  */

static void
add_scope_conflicts (void)
{
  basic_block bb;
  bool changed;
  bitmap work = BITMAP_ALLOC (NULL);
  int *rpo;
  int n_bbs;

  /* We approximate the live range of a stack variable by taking the first
     mention of its name as starting point(s), and by the end-of-scope
     death clobber added by gimplify as ending point(s) of the range.
     This overapproximates in the case we for instance moved an address-taken
     operation upward, without also moving a dereference to it upwards.
     But it's conservatively correct as a variable never can hold values
     before its name is mentioned at least once.

     We then do a mostly classical bitmap liveness algorithm.  */

  FOR_ALL_BB (bb)
    bb->aux = BITMAP_ALLOC (&stack_var_bitmap_obstack);

  rpo = XNEWVEC (int, last_basic_block);
  n_bbs = pre_and_rev_post_order_compute (NULL, rpo, false);

  changed = true;
  while (changed)
    {
      int i;
      changed = false;
      for (i = 0; i < n_bbs; i++)
	{
	  bitmap active;
	  bb = BASIC_BLOCK (rpo[i]);
	  active = (bitmap)bb->aux;
	  add_scope_conflicts_1 (bb, work, false);
	  if (bitmap_ior_into (active, work))
	    changed = true;
	}
    }

  FOR_EACH_BB (bb)
    add_scope_conflicts_1 (bb, work, true);

  free (rpo);
  BITMAP_FREE (work);
  FOR_ALL_BB (bb)
    BITMAP_FREE (bb->aux);
}

/* A subroutine of partition_stack_vars.  A comparison function for qsort,
   sorting an array of indices by the properties of the object.  */

static int
stack_var_cmp (const void *a, const void *b)
{
  size_t ia = *(const size_t *)a;
  size_t ib = *(const size_t *)b;
  unsigned int aligna = stack_vars[ia].alignb;
  unsigned int alignb = stack_vars[ib].alignb;
  HOST_WIDE_INT sizea = stack_vars[ia].size;
  HOST_WIDE_INT sizeb = stack_vars[ib].size;
  tree decla = stack_vars[ia].decl;
  tree declb = stack_vars[ib].decl;
  bool largea, largeb;
  unsigned int uida, uidb;

  /* Primary compare on "large" alignment.  Large comes first.  */
  largea = (aligna * BITS_PER_UNIT > MAX_SUPPORTED_STACK_ALIGNMENT);
  largeb = (alignb * BITS_PER_UNIT > MAX_SUPPORTED_STACK_ALIGNMENT);
  if (largea != largeb)
    return (int)largeb - (int)largea;

  /* Secondary compare on size, decreasing  */
  if (sizea > sizeb)
    return -1;
  if (sizea < sizeb)
    return 1;

  /* Tertiary compare on true alignment, decreasing.  */
  if (aligna < alignb)
    return -1;
  if (aligna > alignb)
    return 1;

  /* Final compare on ID for sort stability, increasing.
     Two SSA names are compared by their version, SSA names come before
     non-SSA names, and two normal decls are compared by their DECL_UID.  */
  if (TREE_CODE (decla) == SSA_NAME)
    {
      if (TREE_CODE (declb) == SSA_NAME)
	uida = SSA_NAME_VERSION (decla), uidb = SSA_NAME_VERSION (declb);
      else
	return -1;
    }
  else if (TREE_CODE (declb) == SSA_NAME)
    return 1;
  else
    uida = DECL_UID (decla), uidb = DECL_UID (declb);
  if (uida < uidb)
    return 1;
  if (uida > uidb)
    return -1;
  return 0;
}


/* If the points-to solution *PI points to variables that are in a partition
   together with other variables add all partition members to the pointed-to
   variables bitmap.  */

static void
add_partitioned_vars_to_ptset (struct pt_solution *pt,
			       struct pointer_map_t *decls_to_partitions,
			       struct pointer_set_t *visited, bitmap temp)
{
  bitmap_iterator bi;
  unsigned i;
  bitmap *part;

  if (pt->anything
      || pt->vars == NULL
      /* The pointed-to vars bitmap is shared, it is enough to
	 visit it once.  */
      || pointer_set_insert(visited, pt->vars))
    return;

  bitmap_clear (temp);

  /* By using a temporary bitmap to store all members of the partitions
     we have to add we make sure to visit each of the partitions only
     once.  */
  EXECUTE_IF_SET_IN_BITMAP (pt->vars, 0, i, bi)
    if ((!temp
	 || !bitmap_bit_p (temp, i))
	&& (part = (bitmap *) pointer_map_contains (decls_to_partitions,
						    (void *)(size_t) i)))
      bitmap_ior_into (temp, *part);
  if (!bitmap_empty_p (temp))
    bitmap_ior_into (pt->vars, temp);
}

/* Update points-to sets based on partition info, so we can use them on RTL.
   The bitmaps representing stack partitions will be saved until expand,
   where partitioned decls used as bases in memory expressions will be
   rewritten.  */

static void
update_alias_info_with_stack_vars (void)
{
  struct pointer_map_t *decls_to_partitions = NULL;
  size_t i, j;
  tree var = NULL_TREE;

  for (i = 0; i < stack_vars_num; i++)
    {
      bitmap part = NULL;
      tree name;
      struct ptr_info_def *pi;

      /* Not interested in partitions with single variable.  */
      if (stack_vars[i].representative != i
          || stack_vars[i].next == EOC)
        continue;

      if (!decls_to_partitions)
	{
	  decls_to_partitions = pointer_map_create ();
	  cfun->gimple_df->decls_to_pointers = pointer_map_create ();
	}

      /* Create an SSA_NAME that points to the partition for use
         as base during alias-oracle queries on RTL for bases that
	 have been partitioned.  */
      if (var == NULL_TREE)
	var = create_tmp_var (ptr_type_node, NULL);
      name = make_ssa_name (var, NULL);

      /* Create bitmaps representing partitions.  They will be used for
         points-to sets later, so use GGC alloc.  */
      part = BITMAP_GGC_ALLOC ();
      for (j = i; j != EOC; j = stack_vars[j].next)
	{
	  tree decl = stack_vars[j].decl;
	  unsigned int uid = DECL_PT_UID (decl);
	  bitmap_set_bit (part, uid);
	  *((bitmap *) pointer_map_insert (decls_to_partitions,
					   (void *)(size_t) uid)) = part;
	  *((tree *) pointer_map_insert (cfun->gimple_df->decls_to_pointers,
					 decl)) = name;
	  if (TREE_ADDRESSABLE (decl))
	    TREE_ADDRESSABLE (name) = 1;
	}

      /* Make the SSA name point to all partition members.  */
      pi = get_ptr_info (name);
      pt_solution_set (&pi->pt, part, false);
    }

  /* Make all points-to sets that contain one member of a partition
     contain all members of the partition.  */
  if (decls_to_partitions)
    {
      unsigned i;
      struct pointer_set_t *visited = pointer_set_create ();
      bitmap temp = BITMAP_ALLOC (&stack_var_bitmap_obstack);

      for (i = 1; i < num_ssa_names; i++)
	{
	  tree name = ssa_name (i);
	  struct ptr_info_def *pi;

	  if (name
	      && POINTER_TYPE_P (TREE_TYPE (name))
	      && ((pi = SSA_NAME_PTR_INFO (name)) != NULL))
	    add_partitioned_vars_to_ptset (&pi->pt, decls_to_partitions,
					   visited, temp);
	}

      add_partitioned_vars_to_ptset (&cfun->gimple_df->escaped,
				     decls_to_partitions, visited, temp);

      pointer_set_destroy (visited);
      pointer_map_destroy (decls_to_partitions);
      BITMAP_FREE (temp);
    }
}

/* A subroutine of partition_stack_vars.  The UNION portion of a UNION/FIND
   partitioning algorithm.  Partitions A and B are known to be non-conflicting.
   Merge them into a single partition A.  */

static void
union_stack_vars (size_t a, size_t b)
{
  struct stack_var *vb = &stack_vars[b];
  bitmap_iterator bi;
  unsigned u;

  gcc_assert (stack_vars[b].next == EOC);
   /* Add B to A's partition.  */
  stack_vars[b].next = stack_vars[a].next;
  stack_vars[b].representative = a;
  stack_vars[a].next = b;

  /* Update the required alignment of partition A to account for B.  */
  if (stack_vars[a].alignb < stack_vars[b].alignb)
    stack_vars[a].alignb = stack_vars[b].alignb;

  /* Update the interference graph and merge the conflicts.  */
  if (vb->conflicts)
    {
      EXECUTE_IF_SET_IN_BITMAP (vb->conflicts, 0, u, bi)
	add_stack_var_conflict (a, stack_vars[u].representative);
      BITMAP_FREE (vb->conflicts);
    }
}

/* A subroutine of expand_used_vars.  Binpack the variables into
   partitions constrained by the interference graph.  The overall
   algorithm used is as follows:

	Sort the objects by size in descending order.
	For each object A {
	  S = size(A)
	  O = 0
	  loop {
	    Look for the largest non-conflicting object B with size <= S.
	    UNION (A, B)
	  }
	}
*/

static void
partition_stack_vars (void)
{
  size_t si, sj, n = stack_vars_num;

  stack_vars_sorted = XNEWVEC (size_t, stack_vars_num);
  for (si = 0; si < n; ++si)
    stack_vars_sorted[si] = si;

  if (n == 1)
    return;

  qsort (stack_vars_sorted, n, sizeof (size_t), stack_var_cmp);

  for (si = 0; si < n; ++si)
    {
      size_t i = stack_vars_sorted[si];
      unsigned int ialign = stack_vars[i].alignb;
      HOST_WIDE_INT isize = stack_vars[i].size;

      /* Ignore objects that aren't partition representatives. If we
         see a var that is not a partition representative, it must
         have been merged earlier.  */
      if (stack_vars[i].representative != i)
        continue;

      for (sj = si + 1; sj < n; ++sj)
	{
	  size_t j = stack_vars_sorted[sj];
	  unsigned int jalign = stack_vars[j].alignb;
	  HOST_WIDE_INT jsize = stack_vars[j].size;

	  /* Ignore objects that aren't partition representatives.  */
	  if (stack_vars[j].representative != j)
	    continue;

	  /* Do not mix objects of "small" (supported) alignment
	     and "large" (unsupported) alignment.  */
	  if ((ialign * BITS_PER_UNIT <= MAX_SUPPORTED_STACK_ALIGNMENT)
	      != (jalign * BITS_PER_UNIT <= MAX_SUPPORTED_STACK_ALIGNMENT))
	    break;

	  /* For Address Sanitizer do not mix objects with different
	     sizes, as the shorter vars wouldn't be adequately protected.
	     Don't do that for "large" (unsupported) alignment objects,
	     those aren't protected anyway.  */
	  if (flag_asan && isize != jsize
	      && ialign * BITS_PER_UNIT <= MAX_SUPPORTED_STACK_ALIGNMENT)
	    break;

	  /* Ignore conflicting objects.  */
	  if (stack_var_conflict_p (i, j))
	    continue;

	  /* UNION the objects, placing J at OFFSET.  */
	  union_stack_vars (i, j);
	}
    }

  update_alias_info_with_stack_vars ();
}

/* A debugging aid for expand_used_vars.  Dump the generated partitions.  */

static void
dump_stack_var_partition (void)
{
  size_t si, i, j, n = stack_vars_num;

  for (si = 0; si < n; ++si)
    {
      i = stack_vars_sorted[si];

      /* Skip variables that aren't partition representatives, for now.  */
      if (stack_vars[i].representative != i)
	continue;

      fprintf (dump_file, "Partition %lu: size " HOST_WIDE_INT_PRINT_DEC
	       " align %u\n", (unsigned long) i, stack_vars[i].size,
	       stack_vars[i].alignb);

      for (j = i; j != EOC; j = stack_vars[j].next)
	{
	  fputc ('\t', dump_file);
	  print_generic_expr (dump_file, stack_vars[j].decl, dump_flags);
	}
      fputc ('\n', dump_file);
    }
}

/* Assign rtl to DECL at BASE + OFFSET.  */

static void
expand_one_stack_var_at (tree decl, rtx base, unsigned base_align,
			 HOST_WIDE_INT offset)
{
  unsigned align;
  rtx x;

  /* If this fails, we've overflowed the stack frame.  Error nicely?  */
  gcc_assert (offset == trunc_int_for_mode (offset, Pmode));

  x = plus_constant (Pmode, base, offset);
  x = gen_rtx_MEM (DECL_MODE (SSAVAR (decl)), x);

  if (TREE_CODE (decl) != SSA_NAME)
    {
      /* Set alignment we actually gave this decl if it isn't an SSA name.
         If it is we generate stack slots only accidentally so it isn't as
	 important, we'll simply use the alignment that is already set.  */
      if (base == virtual_stack_vars_rtx)
	offset -= frame_phase;
      align = offset & -offset;
      align *= BITS_PER_UNIT;
      if (align == 0 || align > base_align)
	align = base_align;

      /* One would think that we could assert that we're not decreasing
	 alignment here, but (at least) the i386 port does exactly this
	 via the MINIMUM_ALIGNMENT hook.  */

      DECL_ALIGN (decl) = align;
      DECL_USER_ALIGN (decl) = 0;
    }

  set_mem_attributes (x, SSAVAR (decl), true);
  set_rtl (decl, x);
}

struct stack_vars_data
{
  /* Vector of offset pairs, always end of some padding followed
     by start of the padding that needs Address Sanitizer protection.
     The vector is in reversed, highest offset pairs come first.  */
  vec<HOST_WIDE_INT> asan_vec;

  /* Vector of partition representative decls in between the paddings.  */
  vec<tree> asan_decl_vec;
};

/* A subroutine of expand_used_vars.  Give each partition representative
   a unique location within the stack frame.  Update each partition member
   with that location.  */

static void
expand_stack_vars (bool (*pred) (size_t), struct stack_vars_data *data)
{
  size_t si, i, j, n = stack_vars_num;
  HOST_WIDE_INT large_size = 0, large_alloc = 0;
  rtx large_base = NULL;
  unsigned large_align = 0;
  tree decl;

  /* Determine if there are any variables requiring "large" alignment.
     Since these are dynamically allocated, we only process these if
     no predicate involved.  */
  large_align = stack_vars[stack_vars_sorted[0]].alignb * BITS_PER_UNIT;
  if (pred == NULL && large_align > MAX_SUPPORTED_STACK_ALIGNMENT)
    {
      /* Find the total size of these variables.  */
      for (si = 0; si < n; ++si)
	{
	  unsigned alignb;

	  i = stack_vars_sorted[si];
	  alignb = stack_vars[i].alignb;

	  /* Stop when we get to the first decl with "small" alignment.  */
	  if (alignb * BITS_PER_UNIT <= MAX_SUPPORTED_STACK_ALIGNMENT)
	    break;

	  /* Skip variables that aren't partition representatives.  */
	  if (stack_vars[i].representative != i)
	    continue;

	  /* Skip variables that have already had rtl assigned.  See also
	     add_stack_var where we perpetrate this pc_rtx hack.  */
	  decl = stack_vars[i].decl;
	  if ((TREE_CODE (decl) == SSA_NAME
	      ? SA.partition_to_pseudo[var_to_partition (SA.map, decl)]
	      : DECL_RTL (decl)) != pc_rtx)
	    continue;

	  large_size += alignb - 1;
	  large_size &= -(HOST_WIDE_INT)alignb;
	  large_size += stack_vars[i].size;
	}

      /* If there were any, allocate space.  */
      if (large_size > 0)
	large_base = allocate_dynamic_stack_space (GEN_INT (large_size), 0,
						   large_align, true);
    }

  for (si = 0; si < n; ++si)
    {
      rtx base;
      unsigned base_align, alignb;
      HOST_WIDE_INT offset;

      i = stack_vars_sorted[si];

      /* Skip variables that aren't partition representatives, for now.  */
      if (stack_vars[i].representative != i)
	continue;

      /* Skip variables that have already had rtl assigned.  See also
	 add_stack_var where we perpetrate this pc_rtx hack.  */
      decl = stack_vars[i].decl;
      if ((TREE_CODE (decl) == SSA_NAME
	   ? SA.partition_to_pseudo[var_to_partition (SA.map, decl)]
	   : DECL_RTL (decl)) != pc_rtx)
	continue;

      /* Check the predicate to see whether this variable should be
	 allocated in this pass.  */
      if (pred && !pred (i))
	continue;

      alignb = stack_vars[i].alignb;
      if (alignb * BITS_PER_UNIT <= MAX_SUPPORTED_STACK_ALIGNMENT)
	{
	  if (flag_asan && pred)
	    {
	      HOST_WIDE_INT prev_offset = frame_offset;
	      tree repr_decl = NULL_TREE;

	      offset
		= alloc_stack_frame_space (stack_vars[i].size
					   + ASAN_RED_ZONE_SIZE,
					   MAX (alignb, ASAN_RED_ZONE_SIZE));
	      data->asan_vec.safe_push (prev_offset);
	      data->asan_vec.safe_push (offset + stack_vars[i].size);
	      /* Find best representative of the partition.
		 Prefer those with DECL_NAME, even better
		 satisfying asan_protect_stack_decl predicate.  */
	      for (j = i; j != EOC; j = stack_vars[j].next)
		if (asan_protect_stack_decl (stack_vars[j].decl)
		    && DECL_NAME (stack_vars[j].decl))
		  {
		    repr_decl = stack_vars[j].decl;
		    break;
		  }
		else if (repr_decl == NULL_TREE
			 && DECL_P (stack_vars[j].decl)
			 && DECL_NAME (stack_vars[j].decl))
		  repr_decl = stack_vars[j].decl;
	      if (repr_decl == NULL_TREE)
		repr_decl = stack_vars[i].decl;
	      data->asan_decl_vec.safe_push (repr_decl);
	    }
	  else
	    offset = alloc_stack_frame_space (stack_vars[i].size, alignb);
	  base = virtual_stack_vars_rtx;
	  base_align = crtl->max_used_stack_slot_alignment;
	}
      else
	{
	  /* Large alignment is only processed in the last pass.  */
	  if (pred)
	    continue;
	  gcc_assert (large_base != NULL);

	  large_alloc += alignb - 1;
	  large_alloc &= -(HOST_WIDE_INT)alignb;
	  offset = large_alloc;
	  large_alloc += stack_vars[i].size;

	  base = large_base;
	  base_align = large_align;
	}

      /* Create rtl for each variable based on their location within the
	 partition.  */
      for (j = i; j != EOC; j = stack_vars[j].next)
	{
	  expand_one_stack_var_at (stack_vars[j].decl,
				   base, base_align,
				   offset);
	}
    }

  gcc_assert (large_alloc == large_size);
}

/* Take into account all sizes of partitions and reset DECL_RTLs.  */
static HOST_WIDE_INT
account_stack_vars (void)
{
  size_t si, j, i, n = stack_vars_num;
  HOST_WIDE_INT size = 0;

  for (si = 0; si < n; ++si)
    {
      i = stack_vars_sorted[si];

      /* Skip variables that aren't partition representatives, for now.  */
      if (stack_vars[i].representative != i)
	continue;

      size += stack_vars[i].size;
      for (j = i; j != EOC; j = stack_vars[j].next)
	set_rtl (stack_vars[j].decl, NULL);
    }
  return size;
}

/* A subroutine of expand_one_var.  Called to immediately assign rtl
   to a variable to be allocated in the stack frame.  */

static void
expand_one_stack_var (tree var)
{
  HOST_WIDE_INT size, offset;
  unsigned byte_align;

  size = tree_low_cst (DECL_SIZE_UNIT (SSAVAR (var)), 1);
  byte_align = align_local_variable (SSAVAR (var));

  /* We handle highly aligned variables in expand_stack_vars.  */
  gcc_assert (byte_align * BITS_PER_UNIT <= MAX_SUPPORTED_STACK_ALIGNMENT);

  offset = alloc_stack_frame_space (size, byte_align);

  expand_one_stack_var_at (var, virtual_stack_vars_rtx,
			   crtl->max_used_stack_slot_alignment, offset);
}

/* A subroutine of expand_one_var.  Called to assign rtl to a VAR_DECL
   that will reside in a hard register.  */

static void
expand_one_hard_reg_var (tree var)
{
  rest_of_decl_compilation (var, 0, 0);
}

/* A subroutine of expand_one_var.  Called to assign rtl to a VAR_DECL
   that will reside in a pseudo register.  */

static void
expand_one_register_var (tree var)
{
  tree decl = SSAVAR (var);
  tree type = TREE_TYPE (decl);
  enum machine_mode reg_mode = promote_decl_mode (decl, NULL);
  rtx x = gen_reg_rtx (reg_mode);

  set_rtl (var, x);

  /* Note if the object is a user variable.  */
  if (!DECL_ARTIFICIAL (decl))
    mark_user_reg (x);

  if (POINTER_TYPE_P (type))
    mark_reg_pointer (x, get_pointer_alignment (var));
}

/* A subroutine of expand_one_var.  Called to assign rtl to a VAR_DECL that
   has some associated error, e.g. its type is error-mark.  We just need
   to pick something that won't crash the rest of the compiler.  */

static void
expand_one_error_var (tree var)
{
  enum machine_mode mode = DECL_MODE (var);
  rtx x;

  if (mode == BLKmode)
    x = gen_rtx_MEM (BLKmode, const0_rtx);
  else if (mode == VOIDmode)
    x = const0_rtx;
  else
    x = gen_reg_rtx (mode);

  SET_DECL_RTL (var, x);
}

/* A subroutine of expand_one_var.  VAR is a variable that will be
   allocated to the local stack frame.  Return true if we wish to
   add VAR to STACK_VARS so that it will be coalesced with other
   variables.  Return false to allocate VAR immediately.

   This function is used to reduce the number of variables considered
   for coalescing, which reduces the size of the quadratic problem.  */

static bool
defer_stack_allocation (tree var, bool toplevel)
{
  /* If stack protection is enabled, *all* stack variables must be deferred,
     so that we can re-order the strings to the top of the frame.
     Similarly for Address Sanitizer.  */
  if (flag_stack_protect || flag_asan)
    return true;

  /* We handle "large" alignment via dynamic allocation.  We want to handle
     this extra complication in only one place, so defer them.  */
  if (DECL_ALIGN (var) > MAX_SUPPORTED_STACK_ALIGNMENT)
    return true;

  /* Variables in the outermost scope automatically conflict with
     every other variable.  The only reason to want to defer them
     at all is that, after sorting, we can more efficiently pack
     small variables in the stack frame.  Continue to defer at -O2.  */
  if (toplevel && optimize < 2)
    return false;

  /* Without optimization, *most* variables are allocated from the
     stack, which makes the quadratic problem large exactly when we
     want compilation to proceed as quickly as possible.  On the
     other hand, we don't want the function's stack frame size to
     get completely out of hand.  So we avoid adding scalars and
     "small" aggregates to the list at all.  */
  if (optimize == 0 && tree_low_cst (DECL_SIZE_UNIT (var), 1) < 32)
    return false;

  return true;
}

/* A subroutine of expand_used_vars.  Expand one variable according to
   its flavor.  Variables to be placed on the stack are not actually
   expanded yet, merely recorded.
   When REALLY_EXPAND is false, only add stack values to be allocated.
   Return stack usage this variable is supposed to take.
*/

static HOST_WIDE_INT
expand_one_var (tree var, bool toplevel, bool really_expand)
{
  unsigned int align = BITS_PER_UNIT;
  tree origvar = var;

  var = SSAVAR (var);

  if (TREE_TYPE (var) != error_mark_node && TREE_CODE (var) == VAR_DECL)
    {
      /* Because we don't know if VAR will be in register or on stack,
	 we conservatively assume it will be on stack even if VAR is
	 eventually put into register after RA pass.  For non-automatic
	 variables, which won't be on stack, we collect alignment of
	 type and ignore user specified alignment.  */
      if (TREE_STATIC (var) || DECL_EXTERNAL (var))
	align = MINIMUM_ALIGNMENT (TREE_TYPE (var),
				   TYPE_MODE (TREE_TYPE (var)),
				   TYPE_ALIGN (TREE_TYPE (var)));
      else if (DECL_HAS_VALUE_EXPR_P (var)
	       || (DECL_RTL_SET_P (var) && MEM_P (DECL_RTL (var))))
	/* Don't consider debug only variables with DECL_HAS_VALUE_EXPR_P set
	   or variables which were assigned a stack slot already by
	   expand_one_stack_var_at - in the latter case DECL_ALIGN has been
	   changed from the offset chosen to it.  */
	align = crtl->stack_alignment_estimated;
      else
	align = MINIMUM_ALIGNMENT (var, DECL_MODE (var), DECL_ALIGN (var));

      /* If the variable alignment is very large we'll dynamicaly allocate
	 it, which means that in-frame portion is just a pointer.  */
      if (align > MAX_SUPPORTED_STACK_ALIGNMENT)
	align = POINTER_SIZE;
    }

  if (SUPPORTS_STACK_ALIGNMENT
      && crtl->stack_alignment_estimated < align)
    {
      /* stack_alignment_estimated shouldn't change after stack
         realign decision made */
      gcc_assert(!crtl->stack_realign_processed);
      crtl->stack_alignment_estimated = align;
    }

  /* stack_alignment_needed > PREFERRED_STACK_BOUNDARY is permitted.
     So here we only make sure stack_alignment_needed >= align.  */
  if (crtl->stack_alignment_needed < align)
    crtl->stack_alignment_needed = align;
  if (crtl->max_used_stack_slot_alignment < align)
    crtl->max_used_stack_slot_alignment = align;

  if (TREE_CODE (origvar) == SSA_NAME)
    {
      gcc_assert (TREE_CODE (var) != VAR_DECL
		  || (!DECL_EXTERNAL (var)
		      && !DECL_HAS_VALUE_EXPR_P (var)
		      && !TREE_STATIC (var)
		      && TREE_TYPE (var) != error_mark_node
		      && !DECL_HARD_REGISTER (var)
		      && really_expand));
    }
  if (TREE_CODE (var) != VAR_DECL && TREE_CODE (origvar) != SSA_NAME)
    ;
  else if (DECL_EXTERNAL (var))
    ;
  else if (DECL_HAS_VALUE_EXPR_P (var))
    ;
  else if (TREE_STATIC (var))
    ;
  else if (TREE_CODE (origvar) != SSA_NAME && DECL_RTL_SET_P (var))
    ;
  else if (TREE_TYPE (var) == error_mark_node)
    {
      if (really_expand)
        expand_one_error_var (var);
    }
  else if (TREE_CODE (var) == VAR_DECL && DECL_HARD_REGISTER (var))
    {
      if (really_expand)
        expand_one_hard_reg_var (var);
    }
  else if (use_register_for_decl (var))
    {
      if (really_expand)
        expand_one_register_var (origvar);
    }
  else if (! valid_constant_size_p (DECL_SIZE_UNIT (var)))
    {
      /* Reject variables which cover more than half of the address-space.  */
      if (really_expand)
	{
	  error ("size of variable %q+D is too large", var);
	  expand_one_error_var (var);
	}
    }
  else if (defer_stack_allocation (var, toplevel))
    add_stack_var (origvar);
  else
    {
      if (really_expand)
        expand_one_stack_var (origvar);
      return tree_low_cst (DECL_SIZE_UNIT (var), 1);
    }
  return 0;
}

/* A subroutine of expand_used_vars.  Walk down through the BLOCK tree
   expanding variables.  Those variables that can be put into registers
   are allocated pseudos; those that can't are put on the stack.

   TOPLEVEL is true if this is the outermost BLOCK.  */

static void
expand_used_vars_for_block (tree block, bool toplevel)
{
  tree t;

  /* Expand all variables at this level.  */
  for (t = BLOCK_VARS (block); t ; t = DECL_CHAIN (t))
    if (TREE_USED (t)
        && ((TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != RESULT_DECL)
	    || !DECL_NONSHAREABLE (t)))
      expand_one_var (t, toplevel, true);

  /* Expand all variables at containing levels.  */
  for (t = BLOCK_SUBBLOCKS (block); t ; t = BLOCK_CHAIN (t))
    expand_used_vars_for_block (t, false);
}

/* A subroutine of expand_used_vars.  Walk down through the BLOCK tree
   and clear TREE_USED on all local variables.  */

static void
clear_tree_used (tree block)
{
  tree t;

  for (t = BLOCK_VARS (block); t ; t = DECL_CHAIN (t))
    /* if (!TREE_STATIC (t) && !DECL_EXTERNAL (t)) */
    if ((TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != RESULT_DECL)
	|| !DECL_NONSHAREABLE (t))
      TREE_USED (t) = 0;

  for (t = BLOCK_SUBBLOCKS (block); t ; t = BLOCK_CHAIN (t))
    clear_tree_used (t);
}

/* Examine TYPE and determine a bit mask of the following features.  */

#define SPCT_HAS_LARGE_CHAR_ARRAY	1
#define SPCT_HAS_SMALL_CHAR_ARRAY	2
#define SPCT_HAS_ARRAY			4
#define SPCT_HAS_AGGREGATE		8

static unsigned int
stack_protect_classify_type (tree type)
{
  unsigned int ret = 0;
  tree t;

  switch (TREE_CODE (type))
    {
    case ARRAY_TYPE:
      t = TYPE_MAIN_VARIANT (TREE_TYPE (type));
      if (t == char_type_node
	  || t == signed_char_type_node
	  || t == unsigned_char_type_node)
	{
	  unsigned HOST_WIDE_INT max = PARAM_VALUE (PARAM_SSP_BUFFER_SIZE);
	  unsigned HOST_WIDE_INT len;

	  if (!TYPE_SIZE_UNIT (type)
	      || !host_integerp (TYPE_SIZE_UNIT (type), 1))
	    len = max;
	  else
	    len = tree_low_cst (TYPE_SIZE_UNIT (type), 1);

	  if (len < max)
	    ret = SPCT_HAS_SMALL_CHAR_ARRAY | SPCT_HAS_ARRAY;
	  else
	    ret = SPCT_HAS_LARGE_CHAR_ARRAY | SPCT_HAS_ARRAY;
	}
      else
	ret = SPCT_HAS_ARRAY;
      break;

    case UNION_TYPE:
    case QUAL_UNION_TYPE:
    case RECORD_TYPE:
      ret = SPCT_HAS_AGGREGATE;
      for (t = TYPE_FIELDS (type); t ; t = TREE_CHAIN (t))
	if (TREE_CODE (t) == FIELD_DECL)
	  ret |= stack_protect_classify_type (TREE_TYPE (t));
      break;

    default:
      break;
    }

  return ret;
}

/* Return nonzero if DECL should be segregated into the "vulnerable" upper
   part of the local stack frame.  Remember if we ever return nonzero for
   any variable in this function.  The return value is the phase number in
   which the variable should be allocated.  */

static int
stack_protect_decl_phase (tree decl)
{
  unsigned int bits = stack_protect_classify_type (TREE_TYPE (decl));
  int ret = 0;

  if (bits & SPCT_HAS_SMALL_CHAR_ARRAY)
    has_short_buffer = true;

  if (flag_stack_protect == 2)
    {
      if ((bits & (SPCT_HAS_SMALL_CHAR_ARRAY | SPCT_HAS_LARGE_CHAR_ARRAY))
	  && !(bits & SPCT_HAS_AGGREGATE))
	ret = 1;
      else if (bits & SPCT_HAS_ARRAY)
	ret = 2;
    }
  else
    ret = (bits & SPCT_HAS_LARGE_CHAR_ARRAY) != 0;

  if (ret)
    has_protected_decls = true;

  return ret;
}

/* Two helper routines that check for phase 1 and phase 2.  These are used
   as callbacks for expand_stack_vars.  */

static bool
stack_protect_decl_phase_1 (size_t i)
{
  return stack_protect_decl_phase (stack_vars[i].decl) == 1;
}

static bool
stack_protect_decl_phase_2 (size_t i)
{
  return stack_protect_decl_phase (stack_vars[i].decl) == 2;
}

/* And helper function that checks for asan phase (with stack protector
   it is phase 3).  This is used as callback for expand_stack_vars.
   Returns true if any of the vars in the partition need to be protected.  */

static bool
asan_decl_phase_3 (size_t i)
{
  while (i != EOC)
    {
      if (asan_protect_stack_decl (stack_vars[i].decl))
	return true;
      i = stack_vars[i].next;
    }
  return false;
}

/* Ensure that variables in different stack protection phases conflict
   so that they are not merged and share the same stack slot.  */

static void
add_stack_protection_conflicts (void)
{
  size_t i, j, n = stack_vars_num;
  unsigned char *phase;

  phase = XNEWVEC (unsigned char, n);
  for (i = 0; i < n; ++i)
    phase[i] = stack_protect_decl_phase (stack_vars[i].decl);

  for (i = 0; i < n; ++i)
    {
      unsigned char ph_i = phase[i];
      for (j = i + 1; j < n; ++j)
	if (ph_i != phase[j])
	  add_stack_var_conflict (i, j);
    }

  XDELETEVEC (phase);
}

/* Create a decl for the guard at the top of the stack frame.  */

static void
create_stack_guard (void)
{
  tree guard = build_decl (DECL_SOURCE_LOCATION (current_function_decl),
			   VAR_DECL, NULL, ptr_type_node);
  TREE_THIS_VOLATILE (guard) = 1;
  TREE_USED (guard) = 1;
  expand_one_stack_var (guard);
  crtl->stack_protect_guard = guard;
}

/* Prepare for expanding variables.  */
static void
init_vars_expansion (void)
{
  /* Conflict bitmaps, and a few related temporary bitmaps, go here.  */
  bitmap_obstack_initialize (&stack_var_bitmap_obstack);

  /* A map from decl to stack partition.  */
  decl_to_stack_part = pointer_map_create ();

  /* Initialize local stack smashing state.  */
  has_protected_decls = false;
  has_short_buffer = false;
}

/* Free up stack variable graph data.  */
static void
fini_vars_expansion (void)
{
  bitmap_obstack_release (&stack_var_bitmap_obstack);
  if (stack_vars)
    XDELETEVEC (stack_vars);
  if (stack_vars_sorted)
    XDELETEVEC (stack_vars_sorted);
  stack_vars = NULL;
  stack_vars_sorted = NULL;
  stack_vars_alloc = stack_vars_num = 0;
  pointer_map_destroy (decl_to_stack_part);
  decl_to_stack_part = NULL;
}

/* Make a fair guess for the size of the stack frame of the function
   in NODE.  This doesn't have to be exact, the result is only used in
   the inline heuristics.  So we don't want to run the full stack var
   packing algorithm (which is quadratic in the number of stack vars).
   Instead, we calculate the total size of all stack vars.  This turns
   out to be a pretty fair estimate -- packing of stack vars doesn't
   happen very often.  */

HOST_WIDE_INT
estimated_stack_frame_size (struct cgraph_node *node)
{
  HOST_WIDE_INT size = 0;
  size_t i;
  tree var;
  struct function *fn = DECL_STRUCT_FUNCTION (node->symbol.decl);

  push_cfun (fn);

  init_vars_expansion ();

  FOR_EACH_LOCAL_DECL (fn, i, var)
    if (auto_var_in_fn_p (var, fn->decl))
      size += expand_one_var (var, true, false);

  if (stack_vars_num > 0)
    {
      /* Fake sorting the stack vars for account_stack_vars ().  */
      stack_vars_sorted = XNEWVEC (size_t, stack_vars_num);
      for (i = 0; i < stack_vars_num; ++i)
	stack_vars_sorted[i] = i;
      size += account_stack_vars ();
    }

  fini_vars_expansion ();
  pop_cfun ();
  return size;
}

/* Expand all variables used in the function.  */

static rtx
expand_used_vars (void)
{
  tree var, outer_block = DECL_INITIAL (current_function_decl);
  vec<tree> maybe_local_decls = vNULL;
  rtx var_end_seq = NULL_RTX;
  struct pointer_map_t *ssa_name_decls;
  unsigned i;
  unsigned len;

  /* Compute the phase of the stack frame for this function.  */
  {
    int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
    int off = STARTING_FRAME_OFFSET % align;
    frame_phase = off ? align - off : 0;
  }

  /* Set TREE_USED on all variables in the local_decls.  */
  FOR_EACH_LOCAL_DECL (cfun, i, var)
    TREE_USED (var) = 1;
  /* Clear TREE_USED on all variables associated with a block scope.  */
  clear_tree_used (DECL_INITIAL (current_function_decl));

  init_vars_expansion ();

  ssa_name_decls = pointer_map_create ();
  for (i = 0; i < SA.map->num_partitions; i++)
    {
      tree var = partition_to_var (SA.map, i);

      gcc_assert (!virtual_operand_p (var));

      /* Assign decls to each SSA name partition, share decls for partitions
         we could have coalesced (those with the same type).  */
      if (SSA_NAME_VAR (var) == NULL_TREE)
	{
	  void **slot = pointer_map_insert (ssa_name_decls, TREE_TYPE (var));
	  if (!*slot)
	    *slot = (void *) create_tmp_reg (TREE_TYPE (var), NULL);
	  replace_ssa_name_symbol (var, (tree) *slot);
	}

      if (TREE_CODE (SSA_NAME_VAR (var)) == VAR_DECL)
	expand_one_var (var, true, true);
      else
	{
	  /* This is a PARM_DECL or RESULT_DECL.  For those partitions that
	     contain the default def (representing the parm or result itself)
	     we don't do anything here.  But those which don't contain the
	     default def (representing a temporary based on the parm/result)
	     we need to allocate space just like for normal VAR_DECLs.  */
	  if (!bitmap_bit_p (SA.partition_has_default_def, i))
	    {
	      expand_one_var (var, true, true);
	      gcc_assert (SA.partition_to_pseudo[i]);
	    }
	}
    }
  pointer_map_destroy (ssa_name_decls);

  /* At this point all variables on the local_decls with TREE_USED
     set are not associated with any block scope.  Lay them out.  */

  len = vec_safe_length (cfun->local_decls);
  FOR_EACH_LOCAL_DECL (cfun, i, var)
    {
      bool expand_now = false;

      /* Expanded above already.  */
      if (is_gimple_reg (var))
	{
	  TREE_USED (var) = 0;
	  goto next;
	}
      /* We didn't set a block for static or extern because it's hard
	 to tell the difference between a global variable (re)declared
	 in a local scope, and one that's really declared there to
	 begin with.  And it doesn't really matter much, since we're
	 not giving them stack space.  Expand them now.  */
      else if (TREE_STATIC (var) || DECL_EXTERNAL (var))
	expand_now = true;

      /* If the variable is not associated with any block, then it
	 was created by the optimizers, and could be live anywhere
	 in the function.  */
      else if (TREE_USED (var))
	expand_now = true;

      /* Finally, mark all variables on the list as used.  We'll use
	 this in a moment when we expand those associated with scopes.  */
      TREE_USED (var) = 1;

      if (expand_now)
	expand_one_var (var, true, true);

    next:
      if (DECL_ARTIFICIAL (var) && !DECL_IGNORED_P (var))
	{
	  rtx rtl = DECL_RTL_IF_SET (var);

	  /* Keep artificial non-ignored vars in cfun->local_decls
	     chain until instantiate_decls.  */
	  if (rtl && (MEM_P (rtl) || GET_CODE (rtl) == CONCAT))
	    add_local_decl (cfun, var);
	  else if (rtl == NULL_RTX)
	    /* If rtl isn't set yet, which can happen e.g. with
	       -fstack-protector, retry before returning from this
	       function.  */
	    maybe_local_decls.safe_push (var);
	}
    }

  /* We duplicated some of the decls in CFUN->LOCAL_DECLS.

     +-----------------+-----------------+
     | ...processed... | ...duplicates...|
     +-----------------+-----------------+
                       ^
		       +-- LEN points here.

     We just want the duplicates, as those are the artificial
     non-ignored vars that we want to keep until instantiate_decls.
     Move them down and truncate the array.  */
  if (!vec_safe_is_empty (cfun->local_decls))
    cfun->local_decls->block_remove (0, len);

  /* At this point, all variables within the block tree with TREE_USED
     set are actually used by the optimized function.  Lay them out.  */
  expand_used_vars_for_block (outer_block, true);

  if (stack_vars_num > 0)
    {
      add_scope_conflicts ();

      /* If stack protection is enabled, we don't share space between
	 vulnerable data and non-vulnerable data.  */
      if (flag_stack_protect)
	add_stack_protection_conflicts ();

      /* Now that we have collected all stack variables, and have computed a
	 minimal interference graph, attempt to save some stack space.  */
      partition_stack_vars ();
      if (dump_file)
	dump_stack_var_partition ();
    }

  /* There are several conditions under which we should create a
     stack guard: protect-all, alloca used, protected decls present.  */
  if (flag_stack_protect == 2
      || (flag_stack_protect
	  && (cfun->calls_alloca || has_protected_decls)))
    create_stack_guard ();

  /* Assign rtl to each variable based on these partitions.  */
  if (stack_vars_num > 0)
    {
      struct stack_vars_data data;

      data.asan_vec = vNULL;
      data.asan_decl_vec = vNULL;

      /* Reorder decls to be protected by iterating over the variables
	 array multiple times, and allocating out of each phase in turn.  */
      /* ??? We could probably integrate this into the qsort we did
	 earlier, such that we naturally see these variables first,
	 and thus naturally allocate things in the right order.  */
      if (has_protected_decls)
	{
	  /* Phase 1 contains only character arrays.  */
	  expand_stack_vars (stack_protect_decl_phase_1, &data);

	  /* Phase 2 contains other kinds of arrays.  */
	  if (flag_stack_protect == 2)
	    expand_stack_vars (stack_protect_decl_phase_2, &data);
	}

      if (flag_asan)
	/* Phase 3, any partitions that need asan protection
	   in addition to phase 1 and 2.  */
	expand_stack_vars (asan_decl_phase_3, &data);

      if (!data.asan_vec.is_empty ())
	{
	  HOST_WIDE_INT prev_offset = frame_offset;
	  HOST_WIDE_INT offset
	    = alloc_stack_frame_space (ASAN_RED_ZONE_SIZE,
				       ASAN_RED_ZONE_SIZE);
	  data.asan_vec.safe_push (prev_offset);
	  data.asan_vec.safe_push (offset);

	  var_end_seq
	    = asan_emit_stack_protection (virtual_stack_vars_rtx,
					  data.asan_vec.address (),
					  data.asan_decl_vec. address(),
					  data.asan_vec.length ());
	}

      expand_stack_vars (NULL, &data);

      data.asan_vec.release ();
      data.asan_decl_vec.release ();
    }

  fini_vars_expansion ();

  /* If there were any artificial non-ignored vars without rtl
     found earlier, see if deferred stack allocation hasn't assigned
     rtl to them.  */
  FOR_EACH_VEC_ELT_REVERSE (maybe_local_decls, i, var)
    {
      rtx rtl = DECL_RTL_IF_SET (var);

      /* Keep artificial non-ignored vars in cfun->local_decls
	 chain until instantiate_decls.  */
      if (rtl && (MEM_P (rtl) || GET_CODE (rtl) == CONCAT))
	add_local_decl (cfun, var);
    }
  maybe_local_decls.release ();

  /* If the target requires that FRAME_OFFSET be aligned, do it.  */
  if (STACK_ALIGNMENT_NEEDED)
    {
      HOST_WIDE_INT align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
      if (!FRAME_GROWS_DOWNWARD)
	frame_offset += align - 1;
      frame_offset &= -align;
    }

  return var_end_seq;
}


/* If we need to produce a detailed dump, print the tree representation
   for STMT to the dump file.  SINCE is the last RTX after which the RTL
   generated for STMT should have been appended.  */

static void
maybe_dump_rtl_for_gimple_stmt (gimple stmt, rtx since)
{
  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "\n;; ");
      print_gimple_stmt (dump_file, stmt, 0,
			 TDF_SLIM | (dump_flags & TDF_LINENO));
      fprintf (dump_file, "\n");

      print_rtl (dump_file, since ? NEXT_INSN (since) : since);
    }
}

/* Maps the blocks that do not contain tree labels to rtx labels.  */

static struct pointer_map_t *lab_rtx_for_bb;

/* Returns the label_rtx expression for a label starting basic block BB.  */

static rtx
label_rtx_for_bb (basic_block bb ATTRIBUTE_UNUSED)
{
  gimple_stmt_iterator gsi;
  tree lab;
  gimple lab_stmt;
  void **elt;

  if (bb->flags & BB_RTL)
    return block_label (bb);

  elt = pointer_map_contains (lab_rtx_for_bb, bb);
  if (elt)
    return (rtx) *elt;

  /* Find the tree label if it is present.  */

  for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
    {
      lab_stmt = gsi_stmt (gsi);
      if (gimple_code (lab_stmt) != GIMPLE_LABEL)
	break;

      lab = gimple_label_label (lab_stmt);
      if (DECL_NONLOCAL (lab))
	break;

      return label_rtx (lab);
    }

  elt = pointer_map_insert (lab_rtx_for_bb, bb);
  *elt = gen_label_rtx ();
  return (rtx) *elt;
}


/* A subroutine of expand_gimple_cond.  Given E, a fallthrough edge
   of a basic block where we just expanded the conditional at the end,
   possibly clean up the CFG and instruction sequence.  LAST is the
   last instruction before the just emitted jump sequence.  */

static void
maybe_cleanup_end_of_block (edge e, rtx last)
{
  /* Special case: when jumpif decides that the condition is
     trivial it emits an unconditional jump (and the necessary
     barrier).  But we still have two edges, the fallthru one is
     wrong.  purge_dead_edges would clean this up later.  Unfortunately
     we have to insert insns (and split edges) before
     find_many_sub_basic_blocks and hence before purge_dead_edges.
     But splitting edges might create new blocks which depend on the
     fact that if there are two edges there's no barrier.  So the
     barrier would get lost and verify_flow_info would ICE.  Instead
     of auditing all edge splitters to care for the barrier (which
     normally isn't there in a cleaned CFG), fix it here.  */
  if (BARRIER_P (get_last_insn ()))
    {
      rtx insn;
      remove_edge (e);
      /* Now, we have a single successor block, if we have insns to
	 insert on the remaining edge we potentially will insert
	 it at the end of this block (if the dest block isn't feasible)
	 in order to avoid splitting the edge.  This insertion will take
	 place in front of the last jump.  But we might have emitted
	 multiple jumps (conditional and one unconditional) to the
	 same destination.  Inserting in front of the last one then
	 is a problem.  See PR 40021.  We fix this by deleting all
	 jumps except the last unconditional one.  */
      insn = PREV_INSN (get_last_insn ());
      /* Make sure we have an unconditional jump.  Otherwise we're
	 confused.  */
      gcc_assert (JUMP_P (insn) && !any_condjump_p (insn));
      for (insn = PREV_INSN (insn); insn != last;)
	{
	  insn = PREV_INSN (insn);
	  if (JUMP_P (NEXT_INSN (insn)))
	    {
	      if (!any_condjump_p (NEXT_INSN (insn)))
		{
		  gcc_assert (BARRIER_P (NEXT_INSN (NEXT_INSN (insn))));
		  delete_insn (NEXT_INSN (NEXT_INSN (insn)));
		}
	      delete_insn (NEXT_INSN (insn));
	    }
	}
    }
}

/* A subroutine of expand_gimple_basic_block.  Expand one GIMPLE_COND.
   Returns a new basic block if we've terminated the current basic
   block and created a new one.  */

static basic_block
expand_gimple_cond (basic_block bb, gimple stmt)
{
  basic_block new_bb, dest;
  edge new_edge;
  edge true_edge;
  edge false_edge;
  rtx last2, last;
  enum tree_code code;
  tree op0, op1;

  code = gimple_cond_code (stmt);
  op0 = gimple_cond_lhs (stmt);
  op1 = gimple_cond_rhs (stmt);
  /* We're sometimes presented with such code:
       D.123_1 = x < y;
       if (D.123_1 != 0)
         ...
     This would expand to two comparisons which then later might
     be cleaned up by combine.  But some pattern matchers like if-conversion
     work better when there's only one compare, so make up for this
     here as special exception if TER would have made the same change.  */
  if (gimple_cond_single_var_p (stmt)
      && SA.values
      && TREE_CODE (op0) == SSA_NAME
      && bitmap_bit_p (SA.values, SSA_NAME_VERSION (op0)))
    {
      gimple second = SSA_NAME_DEF_STMT (op0);
      if (gimple_code (second) == GIMPLE_ASSIGN)
	{
	  enum tree_code code2 = gimple_assign_rhs_code (second);
	  if (TREE_CODE_CLASS (code2) == tcc_comparison)
	    {
	      code = code2;
	      op0 = gimple_assign_rhs1 (second);
	      op1 = gimple_assign_rhs2 (second);
	    }
	  /* If jumps are cheap turn some more codes into
	     jumpy sequences.  */
	  else if (BRANCH_COST (optimize_insn_for_speed_p (), false) < 4)
	    {
	      if ((code2 == BIT_AND_EXPR
		   && TYPE_PRECISION (TREE_TYPE (op0)) == 1
		   && TREE_CODE (gimple_assign_rhs2 (second)) != INTEGER_CST)
		  || code2 == TRUTH_AND_EXPR)
		{
		  code = TRUTH_ANDIF_EXPR;
		  op0 = gimple_assign_rhs1 (second);
		  op1 = gimple_assign_rhs2 (second);
		}
	      else if (code2 == BIT_IOR_EXPR || code2 == TRUTH_OR_EXPR)
		{
		  code = TRUTH_ORIF_EXPR;
		  op0 = gimple_assign_rhs1 (second);
		  op1 = gimple_assign_rhs2 (second);
		}
	    }
	}
    }

  last2 = last = get_last_insn ();

  extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
  set_curr_insn_location (gimple_location (stmt));

  /* These flags have no purpose in RTL land.  */
  true_edge->flags &= ~EDGE_TRUE_VALUE;
  false_edge->flags &= ~EDGE_FALSE_VALUE;

  /* We can either have a pure conditional jump with one fallthru edge or
     two-way jump that needs to be decomposed into two basic blocks.  */
  if (false_edge->dest == bb->next_bb)
    {
      jumpif_1 (code, op0, op1, label_rtx_for_bb (true_edge->dest),
		true_edge->probability);
      maybe_dump_rtl_for_gimple_stmt (stmt, last);
      if (true_edge->goto_locus != UNKNOWN_LOCATION)
	set_curr_insn_location (true_edge->goto_locus);
      false_edge->flags |= EDGE_FALLTHRU;
      maybe_cleanup_end_of_block (false_edge, last);
      return NULL;
    }
  if (true_edge->dest == bb->next_bb)
    {
      jumpifnot_1 (code, op0, op1, label_rtx_for_bb (false_edge->dest),
		   false_edge->probability);
      maybe_dump_rtl_for_gimple_stmt (stmt, last);
      if (false_edge->goto_locus != UNKNOWN_LOCATION)
	set_curr_insn_location (false_edge->goto_locus);
      true_edge->flags |= EDGE_FALLTHRU;
      maybe_cleanup_end_of_block (true_edge, last);
      return NULL;
    }

  jumpif_1 (code, op0, op1, label_rtx_for_bb (true_edge->dest),
	    true_edge->probability);
  last = get_last_insn ();
  if (false_edge->goto_locus != UNKNOWN_LOCATION)
    set_curr_insn_location (false_edge->goto_locus);
  emit_jump (label_rtx_for_bb (false_edge->dest));

  BB_END (bb) = last;
  if (BARRIER_P (BB_END (bb)))
    BB_END (bb) = PREV_INSN (BB_END (bb));
  update_bb_for_insn (bb);

  new_bb = create_basic_block (NEXT_INSN (last), get_last_insn (), bb);
  dest = false_edge->dest;
  redirect_edge_succ (false_edge, new_bb);
  false_edge->flags |= EDGE_FALLTHRU;
  new_bb->count = false_edge->count;
  new_bb->frequency = EDGE_FREQUENCY (false_edge);
  if (current_loops && bb->loop_father)
    add_bb_to_loop (new_bb, bb->loop_father);
  new_edge = make_edge (new_bb, dest, 0);
  new_edge->probability = REG_BR_PROB_BASE;
  new_edge->count = new_bb->count;
  if (BARRIER_P (BB_END (new_bb)))
    BB_END (new_bb) = PREV_INSN (BB_END (new_bb));
  update_bb_for_insn (new_bb);

  maybe_dump_rtl_for_gimple_stmt (stmt, last2);

  if (true_edge->goto_locus != UNKNOWN_LOCATION)
    {
      set_curr_insn_location (true_edge->goto_locus);
      true_edge->goto_locus = curr_insn_location ();
    }

  return new_bb;
}

/* Mark all calls that can have a transaction restart.  */

static void
mark_transaction_restart_calls (gimple stmt)
{
  struct tm_restart_node dummy;
  void **slot;

  if (!cfun->gimple_df->tm_restart)
    return;

  dummy.stmt = stmt;
  slot = htab_find_slot (cfun->gimple_df->tm_restart, &dummy, NO_INSERT);
  if (slot)
    {
      struct tm_restart_node *n = (struct tm_restart_node *) *slot;
      tree list = n->label_or_list;
      rtx insn;

      for (insn = next_real_insn (get_last_insn ());
	   !CALL_P (insn);
	   insn = next_real_insn (insn))
	continue;

      if (TREE_CODE (list) == LABEL_DECL)
	add_reg_note (insn, REG_TM, label_rtx (list));
      else
	for (; list ; list = TREE_CHAIN (list))
	  add_reg_note (insn, REG_TM, label_rtx (TREE_VALUE (list)));
    }
}

/* A subroutine of expand_gimple_stmt_1, expanding one GIMPLE_CALL
   statement STMT.  */

static void
expand_call_stmt (gimple stmt)
{
  tree exp, decl, lhs;
  bool builtin_p;
  size_t i;

  if (gimple_call_internal_p (stmt))
    {
      expand_internal_call (stmt);
      return;
    }

  exp = build_vl_exp (CALL_EXPR, gimple_call_num_args (stmt) + 3);

  CALL_EXPR_FN (exp) = gimple_call_fn (stmt);
  decl = gimple_call_fndecl (stmt);
  builtin_p = decl && DECL_BUILT_IN (decl);

  /* If this is not a builtin function, the function type through which the
     call is made may be different from the type of the function.  */
  if (!builtin_p)
    CALL_EXPR_FN (exp)
      = fold_convert (build_pointer_type (gimple_call_fntype (stmt)),
		      CALL_EXPR_FN (exp));

  TREE_TYPE (exp) = gimple_call_return_type (stmt);
  CALL_EXPR_STATIC_CHAIN (exp) = gimple_call_chain (stmt);

  for (i = 0; i < gimple_call_num_args (stmt); i++)
    {
      tree arg = gimple_call_arg (stmt, i);
      gimple def;
      /* TER addresses into arguments of builtin functions so we have a
	 chance to infer more correct alignment information.  See PR39954.  */
      if (builtin_p
	  && TREE_CODE (arg) == SSA_NAME
	  && (def = get_gimple_for_ssa_name (arg))
	  && gimple_assign_rhs_code (def) == ADDR_EXPR)
	arg = gimple_assign_rhs1 (def);
      CALL_EXPR_ARG (exp, i) = arg;
    }

  if (gimple_has_side_effects (stmt))
    TREE_SIDE_EFFECTS (exp) = 1;

  if (gimple_call_nothrow_p (stmt))
    TREE_NOTHROW (exp) = 1;

  CALL_EXPR_TAILCALL (exp) = gimple_call_tail_p (stmt);
  CALL_EXPR_RETURN_SLOT_OPT (exp) = gimple_call_return_slot_opt_p (stmt);
  if (decl
      && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
      && (DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA
	  || DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA_WITH_ALIGN))
    CALL_ALLOCA_FOR_VAR_P (exp) = gimple_call_alloca_for_var_p (stmt);
  else
    CALL_FROM_THUNK_P (exp) = gimple_call_from_thunk_p (stmt);
  CALL_EXPR_VA_ARG_PACK (exp) = gimple_call_va_arg_pack_p (stmt);
  SET_EXPR_LOCATION (exp, gimple_location (stmt));

  /* Ensure RTL is created for debug args.  */
  if (decl && DECL_HAS_DEBUG_ARGS_P (decl))
    {
      vec<tree, va_gc> **debug_args = decl_debug_args_lookup (decl);
      unsigned int ix;
      tree dtemp;

      if (debug_args)
	for (ix = 1; (*debug_args)->iterate (ix, &dtemp); ix += 2)
	  {
	    gcc_assert (TREE_CODE (dtemp) == DEBUG_EXPR_DECL);
	    expand_debug_expr (dtemp);
	  }
    }

  lhs = gimple_call_lhs (stmt);
  if (lhs)
    expand_assignment (lhs, exp, false);
  else
    expand_expr (exp, const0_rtx, VOIDmode, EXPAND_NORMAL);

  mark_transaction_restart_calls (stmt);
}

/* A subroutine of expand_gimple_stmt, expanding one gimple statement
   STMT that doesn't require special handling for outgoing edges.  That
   is no tailcalls and no GIMPLE_COND.  */

static void
expand_gimple_stmt_1 (gimple stmt)
{
  tree op0;

  set_curr_insn_location (gimple_location (stmt));

  switch (gimple_code (stmt))
    {
    case GIMPLE_GOTO:
      op0 = gimple_goto_dest (stmt);
      if (TREE_CODE (op0) == LABEL_DECL)
	expand_goto (op0);
      else
	expand_computed_goto (op0);
      break;
    case GIMPLE_LABEL:
      expand_label (gimple_label_label (stmt));
      break;
    case GIMPLE_NOP:
    case GIMPLE_PREDICT:
      break;
    case GIMPLE_SWITCH:
      expand_case (stmt);
      break;
    case GIMPLE_ASM:
      expand_asm_stmt (stmt);
      break;
    case GIMPLE_CALL:
      expand_call_stmt (stmt);
      break;

    case GIMPLE_RETURN:
      op0 = gimple_return_retval (stmt);

      if (op0 && op0 != error_mark_node)
	{
	  tree result = DECL_RESULT (current_function_decl);

	  /* If we are not returning the current function's RESULT_DECL,
	     build an assignment to it.  */
	  if (op0 != result)
	    {
	      /* I believe that a function's RESULT_DECL is unique.  */
	      gcc_assert (TREE_CODE (op0) != RESULT_DECL);

	      /* ??? We'd like to use simply expand_assignment here,
	         but this fails if the value is of BLKmode but the return
		 decl is a register.  expand_return has special handling
		 for this combination, which eventually should move
		 to common code.  See comments there.  Until then, let's
		 build a modify expression :-/  */
	      op0 = build2 (MODIFY_EXPR, TREE_TYPE (result),
			    result, op0);
	    }
	}
      if (!op0)
	expand_null_return ();
      else
	expand_return (op0);
      break;

    case GIMPLE_ASSIGN:
      {
	tree lhs = gimple_assign_lhs (stmt);

	/* Tree expand used to fiddle with |= and &= of two bitfield
	   COMPONENT_REFs here.  This can't happen with gimple, the LHS
	   of binary assigns must be a gimple reg.  */

	if (TREE_CODE (lhs) != SSA_NAME
	    || get_gimple_rhs_class (gimple_expr_code (stmt))
	       == GIMPLE_SINGLE_RHS)
	  {
	    tree rhs = gimple_assign_rhs1 (stmt);
	    gcc_assert (get_gimple_rhs_class (gimple_expr_code (stmt))
			== GIMPLE_SINGLE_RHS);
	    if (gimple_has_location (stmt) && CAN_HAVE_LOCATION_P (rhs))
	      SET_EXPR_LOCATION (rhs, gimple_location (stmt));
	    if (TREE_CLOBBER_P (rhs))
	      /* This is a clobber to mark the going out of scope for
		 this LHS.  */
	      ;
	    else
	      expand_assignment (lhs, rhs,
				 gimple_assign_nontemporal_move_p (stmt));
	  }
	else
	  {
	    rtx target, temp;
	    bool nontemporal = gimple_assign_nontemporal_move_p (stmt);
	    struct separate_ops ops;
	    bool promoted = false;

	    target = expand_expr (lhs, NULL_RTX, VOIDmode, EXPAND_WRITE);
	    if (GET_CODE (target) == SUBREG && SUBREG_PROMOTED_VAR_P (target))
	      promoted = true;

	    ops.code = gimple_assign_rhs_code (stmt);
	    ops.type = TREE_TYPE (lhs);
	    switch (get_gimple_rhs_class (gimple_expr_code (stmt)))
	      {
		case GIMPLE_TERNARY_RHS:
		  ops.op2 = gimple_assign_rhs3 (stmt);
		  /* Fallthru */
		case GIMPLE_BINARY_RHS:
		  ops.op1 = gimple_assign_rhs2 (stmt);
		  /* Fallthru */
		case GIMPLE_UNARY_RHS:
		  ops.op0 = gimple_assign_rhs1 (stmt);
		  break;
		default:
		  gcc_unreachable ();
	      }
	    ops.location = gimple_location (stmt);

	    /* If we want to use a nontemporal store, force the value to
	       register first.  If we store into a promoted register,
	       don't directly expand to target.  */
	    temp = nontemporal || promoted ? NULL_RTX : target;
	    temp = expand_expr_real_2 (&ops, temp, GET_MODE (target),
				       EXPAND_NORMAL);

	    if (temp == target)
	      ;
	    else if (promoted)
	      {
		int unsignedp = SUBREG_PROMOTED_UNSIGNED_P (target);
		/* If TEMP is a VOIDmode constant, use convert_modes to make
		   sure that we properly convert it.  */
		if (CONSTANT_P (temp) && GET_MODE (temp) == VOIDmode)
		  {
		    temp = convert_modes (GET_MODE (target),
					  TYPE_MODE (ops.type),
					  temp, unsignedp);
		    temp = convert_modes (GET_MODE (SUBREG_REG (target)),
					  GET_MODE (target), temp, unsignedp);
		  }

		convert_move (SUBREG_REG (target), temp, unsignedp);
	      }
	    else if (nontemporal && emit_storent_insn (target, temp))
	      ;
	    else
	      {
		temp = force_operand (temp, target);
		if (temp != target)
		  emit_move_insn (target, temp);
	      }
	  }
      }
      break;

    default:
      gcc_unreachable ();
    }
}

/* Expand one gimple statement STMT and return the last RTL instruction
   before any of the newly generated ones.

   In addition to generating the necessary RTL instructions this also
   sets REG_EH_REGION notes if necessary and sets the current source
   location for diagnostics.  */

static rtx
expand_gimple_stmt (gimple stmt)
{
  location_t saved_location = input_location;
  rtx last = get_last_insn ();
  int lp_nr;

  gcc_assert (cfun);

  /* We need to save and restore the current source location so that errors
     discovered during expansion are emitted with the right location.  But
     it would be better if the diagnostic routines used the source location
     embedded in the tree nodes rather than globals.  */
  if (gimple_has_location (stmt))
    input_location = gimple_location (stmt);

  expand_gimple_stmt_1 (stmt);

  /* Free any temporaries used to evaluate this statement.  */
  free_temp_slots ();

  input_location = saved_location;

  /* Mark all insns that may trap.  */
  lp_nr = lookup_stmt_eh_lp (stmt);
  if (lp_nr)
    {
      rtx insn;
      for (insn = next_real_insn (last); insn;
	   insn = next_real_insn (insn))
	{
	  if (! find_reg_note (insn, REG_EH_REGION, NULL_RTX)
	      /* If we want exceptions for non-call insns, any
		 may_trap_p instruction may throw.  */
	      && GET_CODE (PATTERN (insn)) != CLOBBER
	      && GET_CODE (PATTERN (insn)) != USE
	      && insn_could_throw_p (insn))
	    make_reg_eh_region_note (insn, 0, lp_nr);
	}
    }

  return last;
}

/* A subroutine of expand_gimple_basic_block.  Expand one GIMPLE_CALL
   that has CALL_EXPR_TAILCALL set.  Returns non-null if we actually
   generated a tail call (something that might be denied by the ABI
   rules governing the call; see calls.c).

   Sets CAN_FALLTHRU if we generated a *conditional* tail call, and
   can still reach the rest of BB.  The case here is __builtin_sqrt,
   where the NaN result goes through the external function (with a
   tailcall) and the normal result happens via a sqrt instruction.  */

static basic_block
expand_gimple_tailcall (basic_block bb, gimple stmt, bool *can_fallthru)
{
  rtx last2, last;
  edge e;
  edge_iterator ei;
  int probability;
  gcov_type count;

  last2 = last = expand_gimple_stmt (stmt);

  for (last = NEXT_INSN (last); last; last = NEXT_INSN (last))
    if (CALL_P (last) && SIBLING_CALL_P (last))
      goto found;

  maybe_dump_rtl_for_gimple_stmt (stmt, last2);

  *can_fallthru = true;
  return NULL;

 found:
  /* ??? Wouldn't it be better to just reset any pending stack adjust?
     Any instructions emitted here are about to be deleted.  */
  do_pending_stack_adjust ();

  /* Remove any non-eh, non-abnormal edges that don't go to exit.  */
  /* ??? I.e. the fallthrough edge.  HOWEVER!  If there were to be
     EH or abnormal edges, we shouldn't have created a tail call in
     the first place.  So it seems to me we should just be removing
     all edges here, or redirecting the existing fallthru edge to
     the exit block.  */

  probability = 0;
  count = 0;

  for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
    {
      if (!(e->flags & (EDGE_ABNORMAL | EDGE_EH)))
	{
	  if (e->dest != EXIT_BLOCK_PTR)
	    {
	      e->dest->count -= e->count;
	      e->dest->frequency -= EDGE_FREQUENCY (e);
	      if (e->dest->count < 0)
		e->dest->count = 0;
	      if (e->dest->frequency < 0)
		e->dest->frequency = 0;
	    }
	  count += e->count;
	  probability += e->probability;
	  remove_edge (e);
	}
      else
	ei_next (&ei);
    }

  /* This is somewhat ugly: the call_expr expander often emits instructions
     after the sibcall (to perform the function return).  These confuse the
     find_many_sub_basic_blocks code, so we need to get rid of these.  */
  last = NEXT_INSN (last);
  gcc_assert (BARRIER_P (last));

  *can_fallthru = false;
  while (NEXT_INSN (last))
    {
      /* For instance an sqrt builtin expander expands if with
	 sibcall in the then and label for `else`.  */
      if (LABEL_P (NEXT_INSN (last)))
	{
	  *can_fallthru = true;
	  break;
	}
      delete_insn (NEXT_INSN (last));
    }

  e = make_edge (bb, EXIT_BLOCK_PTR, EDGE_ABNORMAL | EDGE_SIBCALL);
  e->probability += probability;
  e->count += count;
  BB_END (bb) = last;
  update_bb_for_insn (bb);

  if (NEXT_INSN (last))
    {
      bb = create_basic_block (NEXT_INSN (last), get_last_insn (), bb);

      last = BB_END (bb);
      if (BARRIER_P (last))
	BB_END (bb) = PREV_INSN (last);
    }

  maybe_dump_rtl_for_gimple_stmt (stmt, last2);

  return bb;
}

/* Return the difference between the floor and the truncated result of
   a signed division by OP1 with remainder MOD.  */
static rtx
floor_sdiv_adjust (enum machine_mode mode, rtx mod, rtx op1)
{
  /* (mod != 0 ? (op1 / mod < 0 ? -1 : 0) : 0) */
  return gen_rtx_IF_THEN_ELSE
    (mode, gen_rtx_NE (BImode, mod, const0_rtx),
     gen_rtx_IF_THEN_ELSE
     (mode, gen_rtx_LT (BImode,
			gen_rtx_DIV (mode, op1, mod),
			const0_rtx),
      constm1_rtx, const0_rtx),
     const0_rtx);
}

/* Return the difference between the ceil and the truncated result of
   a signed division by OP1 with remainder MOD.  */
static rtx
ceil_sdiv_adjust (enum machine_mode mode, rtx mod, rtx op1)
{
  /* (mod != 0 ? (op1 / mod > 0 ? 1 : 0) : 0) */
  return gen_rtx_IF_THEN_ELSE
    (mode, gen_rtx_NE (BImode, mod, const0_rtx),
     gen_rtx_IF_THEN_ELSE
     (mode, gen_rtx_GT (BImode,
			gen_rtx_DIV (mode, op1, mod),
			const0_rtx),
      const1_rtx, const0_rtx),
     const0_rtx);
}

/* Return the difference between the ceil and the truncated result of
   an unsigned division by OP1 with remainder MOD.  */
static rtx
ceil_udiv_adjust (enum machine_mode mode, rtx mod, rtx op1 ATTRIBUTE_UNUSED)
{
  /* (mod != 0 ? 1 : 0) */
  return gen_rtx_IF_THEN_ELSE
    (mode, gen_rtx_NE (BImode, mod, const0_rtx),
     const1_rtx, const0_rtx);
}

/* Return the difference between the rounded and the truncated result
   of a signed division by OP1 with remainder MOD.  Halfway cases are
   rounded away from zero, rather than to the nearest even number.  */
static rtx
round_sdiv_adjust (enum machine_mode mode, rtx mod, rtx op1)
{
  /* (abs (mod) >= abs (op1) - abs (mod)
      ? (op1 / mod > 0 ? 1 : -1)
      : 0) */
  return gen_rtx_IF_THEN_ELSE
    (mode, gen_rtx_GE (BImode, gen_rtx_ABS (mode, mod),
		       gen_rtx_MINUS (mode,
				      gen_rtx_ABS (mode, op1),
				      gen_rtx_ABS (mode, mod))),
     gen_rtx_IF_THEN_ELSE
     (mode, gen_rtx_GT (BImode,
			gen_rtx_DIV (mode, op1, mod),
			const0_rtx),
      const1_rtx, constm1_rtx),
     const0_rtx);
}

/* Return the difference between the rounded and the truncated result
   of a unsigned division by OP1 with remainder MOD.  Halfway cases
   are rounded away from zero, rather than to the nearest even
   number.  */
static rtx
round_udiv_adjust (enum machine_mode mode, rtx mod, rtx op1)
{
  /* (mod >= op1 - mod ? 1 : 0) */
  return gen_rtx_IF_THEN_ELSE
    (mode, gen_rtx_GE (BImode, mod,
		       gen_rtx_MINUS (mode, op1, mod)),
     const1_rtx, const0_rtx);
}

/* Convert X to MODE, that must be Pmode or ptr_mode, without emitting
   any rtl.  */

static rtx
convert_debug_memory_address (enum machine_mode mode, rtx x,
			      addr_space_t as)
{
  enum machine_mode xmode = GET_MODE (x);

#ifndef POINTERS_EXTEND_UNSIGNED
  gcc_assert (mode == Pmode
	      || mode == targetm.addr_space.address_mode (as));
  gcc_assert (xmode == mode || xmode == VOIDmode);
#else
  rtx temp;

  gcc_assert (targetm.addr_space.valid_pointer_mode (mode, as));

  if (GET_MODE (x) == mode || GET_MODE (x) == VOIDmode)
    return x;

  if (GET_MODE_PRECISION (mode) < GET_MODE_PRECISION (xmode))
    x = simplify_gen_subreg (mode, x, xmode,
			     subreg_lowpart_offset
			     (mode, xmode));
  else if (POINTERS_EXTEND_UNSIGNED > 0)
    x = gen_rtx_ZERO_EXTEND (mode, x);
  else if (!POINTERS_EXTEND_UNSIGNED)
    x = gen_rtx_SIGN_EXTEND (mode, x);
  else
    {
      switch (GET_CODE (x))
	{
	case SUBREG:
	  if ((SUBREG_PROMOTED_VAR_P (x)
	       || (REG_P (SUBREG_REG (x)) && REG_POINTER (SUBREG_REG (x)))
	       || (GET_CODE (SUBREG_REG (x)) == PLUS
		   && REG_P (XEXP (SUBREG_REG (x), 0))
		   && REG_POINTER (XEXP (SUBREG_REG (x), 0))
		   && CONST_INT_P (XEXP (SUBREG_REG (x), 1))))
	      && GET_MODE (SUBREG_REG (x)) == mode)
	    return SUBREG_REG (x);
	  break;
	case LABEL_REF:
	  temp = gen_rtx_LABEL_REF (mode, XEXP (x, 0));
	  LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x);
	  return temp;
	case SYMBOL_REF:
	  temp = shallow_copy_rtx (x);
	  PUT_MODE (temp, mode);
	  return temp;
	case CONST:
	  temp = convert_debug_memory_address (mode, XEXP (x, 0), as);
	  if (temp)
	    temp = gen_rtx_CONST (mode, temp);
	  return temp;
	case PLUS:
	case MINUS:
	  if (CONST_INT_P (XEXP (x, 1)))
	    {
	      temp = convert_debug_memory_address (mode, XEXP (x, 0), as);
	      if (temp)
		return gen_rtx_fmt_ee (GET_CODE (x), mode, temp, XEXP (x, 1));
	    }
	  break;
	default:
	  break;
	}
      /* Don't know how to express ptr_extend as operation in debug info.  */
      return NULL;
    }
#endif /* POINTERS_EXTEND_UNSIGNED */

  return x;
}

/* Return an RTX equivalent to the value of the parameter DECL.  */

static rtx
expand_debug_parm_decl (tree decl)
{
  rtx incoming = DECL_INCOMING_RTL (decl);

  if (incoming
      && GET_MODE (incoming) != BLKmode
      && ((REG_P (incoming) && HARD_REGISTER_P (incoming))
	  || (MEM_P (incoming)
	      && REG_P (XEXP (incoming, 0))
	      && HARD_REGISTER_P (XEXP (incoming, 0)))))
    {
      rtx rtl = gen_rtx_ENTRY_VALUE (GET_MODE (incoming));

#ifdef HAVE_window_save
      /* DECL_INCOMING_RTL uses the INCOMING_REGNO of parameter registers.
	 If the target machine has an explicit window save instruction, the
	 actual entry value is the corresponding OUTGOING_REGNO instead.  */
      if (REG_P (incoming)
	  && OUTGOING_REGNO (REGNO (incoming)) != REGNO (incoming))
	incoming
	  = gen_rtx_REG_offset (incoming, GET_MODE (incoming),
				OUTGOING_REGNO (REGNO (incoming)), 0);
      else if (MEM_P (incoming))
	{
	  rtx reg = XEXP (incoming, 0);
	  if (OUTGOING_REGNO (REGNO (reg)) != REGNO (reg))
	    {
	      reg = gen_raw_REG (GET_MODE (reg), OUTGOING_REGNO (REGNO (reg)));
	      incoming = replace_equiv_address_nv (incoming, reg);
	    }
	  else
	    incoming = copy_rtx (incoming);
	}
#endif

      ENTRY_VALUE_EXP (rtl) = incoming;
      return rtl;
    }

  if (incoming
      && GET_MODE (incoming) != BLKmode
      && !TREE_ADDRESSABLE (decl)
      && MEM_P (incoming)
      && (XEXP (incoming, 0) == virtual_incoming_args_rtx
	  || (GET_CODE (XEXP (incoming, 0)) == PLUS
	      && XEXP (XEXP (incoming, 0), 0) == virtual_incoming_args_rtx
	      && CONST_INT_P (XEXP (XEXP (incoming, 0), 1)))))
    return copy_rtx (incoming);

  return NULL_RTX;
}

/* Return an RTX equivalent to the value of the tree expression EXP.  */

static rtx
expand_debug_expr (tree exp)
{
  rtx op0 = NULL_RTX, op1 = NULL_RTX, op2 = NULL_RTX;
  enum machine_mode mode = TYPE_MODE (TREE_TYPE (exp));
  enum machine_mode inner_mode = VOIDmode;
  int unsignedp = TYPE_UNSIGNED (TREE_TYPE (exp));
  addr_space_t as;

  switch (TREE_CODE_CLASS (TREE_CODE (exp)))
    {
    case tcc_expression:
      switch (TREE_CODE (exp))
	{
	case COND_EXPR:
	case DOT_PROD_EXPR:
	case WIDEN_MULT_PLUS_EXPR:
	case WIDEN_MULT_MINUS_EXPR:
	case FMA_EXPR:
	  goto ternary;

	case TRUTH_ANDIF_EXPR:
	case TRUTH_ORIF_EXPR:
	case TRUTH_AND_EXPR:
	case TRUTH_OR_EXPR:
	case TRUTH_XOR_EXPR:
	  goto binary;

	case TRUTH_NOT_EXPR:
	  goto unary;

	default:
	  break;
	}
      break;

    ternary:
      op2 = expand_debug_expr (TREE_OPERAND (exp, 2));
      if (!op2)
	return NULL_RTX;
      /* Fall through.  */

    binary:
    case tcc_binary:
    case tcc_comparison:
      op1 = expand_debug_expr (TREE_OPERAND (exp, 1));
      if (!op1)
	return NULL_RTX;
      /* Fall through.  */

    unary:
    case tcc_unary:
      inner_mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
      op0 = expand_debug_expr (TREE_OPERAND (exp, 0));
      if (!op0)
	return NULL_RTX;
      break;

    case tcc_type:
    case tcc_statement:
      gcc_unreachable ();

    case tcc_constant:
    case tcc_exceptional:
    case tcc_declaration:
    case tcc_reference:
    case tcc_vl_exp:
      break;
    }

  switch (TREE_CODE (exp))
    {
    case STRING_CST:
      if (!lookup_constant_def (exp))
	{
	  if (strlen (TREE_STRING_POINTER (exp)) + 1
	      != (size_t) TREE_STRING_LENGTH (exp))
	    return NULL_RTX;
	  op0 = gen_rtx_CONST_STRING (Pmode, TREE_STRING_POINTER (exp));
	  op0 = gen_rtx_MEM (BLKmode, op0);
	  set_mem_attributes (op0, exp, 0);
	  return op0;
	}
      /* Fall through...  */

    case INTEGER_CST:
    case REAL_CST:
    case FIXED_CST:
      op0 = expand_expr (exp, NULL_RTX, mode, EXPAND_INITIALIZER);
      return op0;

    case COMPLEX_CST:
      gcc_assert (COMPLEX_MODE_P (mode));
      op0 = expand_debug_expr (TREE_REALPART (exp));
      op1 = expand_debug_expr (TREE_IMAGPART (exp));
      return gen_rtx_CONCAT (mode, op0, op1);

    case DEBUG_EXPR_DECL:
      op0 = DECL_RTL_IF_SET (exp);

      if (op0)
	return op0;

      op0 = gen_rtx_DEBUG_EXPR (mode);
      DEBUG_EXPR_TREE_DECL (op0) = exp;
      SET_DECL_RTL (exp, op0);

      return op0;

    case VAR_DECL:
    case PARM_DECL:
    case FUNCTION_DECL:
    case LABEL_DECL:
    case CONST_DECL:
    case RESULT_DECL:
      op0 = DECL_RTL_IF_SET (exp);

      /* This decl was probably optimized away.  */
      if (!op0)
	{
	  if (TREE_CODE (exp) != VAR_DECL
	      || DECL_EXTERNAL (exp)
	      || !TREE_STATIC (exp)
	      || !DECL_NAME (exp)
	      || DECL_HARD_REGISTER (exp)
	      || DECL_IN_CONSTANT_POOL (exp)
	      || mode == VOIDmode)
	    return NULL;

	  op0 = make_decl_rtl_for_debug (exp);
	  if (!MEM_P (op0)
	      || GET_CODE (XEXP (op0, 0)) != SYMBOL_REF
	      || SYMBOL_REF_DECL (XEXP (op0, 0)) != exp)
	    return NULL;
	}
      else
	op0 = copy_rtx (op0);

      if (GET_MODE (op0) == BLKmode
	  /* If op0 is not BLKmode, but BLKmode is, adjust_mode
	     below would ICE.  While it is likely a FE bug,
	     try to be robust here.  See PR43166.  */
	  || mode == BLKmode
	  || (mode == VOIDmode && GET_MODE (op0) != VOIDmode))
	{
	  gcc_assert (MEM_P (op0));
	  op0 = adjust_address_nv (op0, mode, 0);
	  return op0;
	}

      /* Fall through.  */

    adjust_mode:
    case PAREN_EXPR:
    case NOP_EXPR:
    case CONVERT_EXPR:
      {
	inner_mode = GET_MODE (op0);

	if (mode == inner_mode)
	  return op0;

	if (inner_mode == VOIDmode)
	  {
	    if (TREE_CODE (exp) == SSA_NAME)
	      inner_mode = TYPE_MODE (TREE_TYPE (exp));
	    else
	      inner_mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
	    if (mode == inner_mode)
	      return op0;
	  }

	if (FLOAT_MODE_P (mode) && FLOAT_MODE_P (inner_mode))
	  {
	    if (GET_MODE_BITSIZE (mode) == GET_MODE_BITSIZE (inner_mode))
	      op0 = simplify_gen_subreg (mode, op0, inner_mode, 0);
	    else if (GET_MODE_BITSIZE (mode) < GET_MODE_BITSIZE (inner_mode))
	      op0 = simplify_gen_unary (FLOAT_TRUNCATE, mode, op0, inner_mode);
	    else
	      op0 = simplify_gen_unary (FLOAT_EXTEND, mode, op0, inner_mode);
	  }
	else if (FLOAT_MODE_P (mode))
	  {
	    gcc_assert (TREE_CODE (exp) != SSA_NAME);
	    if (TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (exp, 0))))
	      op0 = simplify_gen_unary (UNSIGNED_FLOAT, mode, op0, inner_mode);
	    else
	      op0 = simplify_gen_unary (FLOAT, mode, op0, inner_mode);
	  }
	else if (FLOAT_MODE_P (inner_mode))
	  {
	    if (unsignedp)
	      op0 = simplify_gen_unary (UNSIGNED_FIX, mode, op0, inner_mode);
	    else
	      op0 = simplify_gen_unary (FIX, mode, op0, inner_mode);
	  }
	else if (CONSTANT_P (op0)
		 || GET_MODE_PRECISION (mode) <= GET_MODE_PRECISION (inner_mode))
	  op0 = simplify_gen_subreg (mode, op0, inner_mode,
				     subreg_lowpart_offset (mode,
							    inner_mode));
	else if (TREE_CODE_CLASS (TREE_CODE (exp)) == tcc_unary
		 ? TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (exp, 0)))
		 : unsignedp)
	  op0 = simplify_gen_unary (ZERO_EXTEND, mode, op0, inner_mode);
	else
	  op0 = simplify_gen_unary (SIGN_EXTEND, mode, op0, inner_mode);

	return op0;
      }

    case MEM_REF:
      if (!is_gimple_mem_ref_addr (TREE_OPERAND (exp, 0)))
	{
	  tree newexp = fold_binary (MEM_REF, TREE_TYPE (exp),
				     TREE_OPERAND (exp, 0),
				     TREE_OPERAND (exp, 1));
	  if (newexp)
	    return expand_debug_expr (newexp);
	}
      /* FALLTHROUGH */
    case INDIRECT_REF:
      inner_mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
      op0 = expand_debug_expr (TREE_OPERAND (exp, 0));
      if (!op0)
	return NULL;

      if (TREE_CODE (exp) == MEM_REF)
	{
	  if (GET_CODE (op0) == DEBUG_IMPLICIT_PTR
	      || (GET_CODE (op0) == PLUS
		  && GET_CODE (XEXP (op0, 0)) == DEBUG_IMPLICIT_PTR))
	    /* (mem (debug_implicit_ptr)) might confuse aliasing.
	       Instead just use get_inner_reference.  */
	    goto component_ref;

	  op1 = expand_debug_expr (TREE_OPERAND (exp, 1));
	  if (!op1 || !CONST_INT_P (op1))
	    return NULL;

	  op0 = plus_constant (inner_mode, op0, INTVAL (op1));
	}

      if (POINTER_TYPE_P (TREE_TYPE (exp)))
	as = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (exp)));
      else
	as = ADDR_SPACE_GENERIC;

      op0 = convert_debug_memory_address (targetm.addr_space.address_mode (as),
					  op0, as);
      if (op0 == NULL_RTX)
	return NULL;

      op0 = gen_rtx_MEM (mode, op0);
      set_mem_attributes (op0, exp, 0);
      if (TREE_CODE (exp) == MEM_REF
	  && !is_gimple_mem_ref_addr (TREE_OPERAND (exp, 0)))
	set_mem_expr (op0, NULL_TREE);
      set_mem_addr_space (op0, as);

      return op0;

    case TARGET_MEM_REF:
      if (TREE_CODE (TMR_BASE (exp)) == ADDR_EXPR
	  && !DECL_RTL_SET_P (TREE_OPERAND (TMR_BASE (exp), 0)))
	return NULL;

      op0 = expand_debug_expr
	    (tree_mem_ref_addr (build_pointer_type (TREE_TYPE (exp)), exp));
      if (!op0)
	return NULL;

      if (POINTER_TYPE_P (TREE_TYPE (exp)))
	as = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (exp)));
      else
	as = ADDR_SPACE_GENERIC;

      op0 = convert_debug_memory_address (targetm.addr_space.address_mode (as),
					  op0, as);
      if (op0 == NULL_RTX)
	return NULL;

      op0 = gen_rtx_MEM (mode, op0);

      set_mem_attributes (op0, exp, 0);
      set_mem_addr_space (op0, as);

      return op0;

    component_ref:
    case ARRAY_REF:
    case ARRAY_RANGE_REF:
    case COMPONENT_REF:
    case BIT_FIELD_REF:
    case REALPART_EXPR:
    case IMAGPART_EXPR:
    case VIEW_CONVERT_EXPR:
      {
	enum machine_mode mode1;
	HOST_WIDE_INT bitsize, bitpos;
	tree offset;
	int volatilep = 0;
	tree tem = get_inner_reference (exp, &bitsize, &bitpos, &offset,
					&mode1, &unsignedp, &volatilep, false);
	rtx orig_op0;

	if (bitsize == 0)
	  return NULL;

	orig_op0 = op0 = expand_debug_expr (tem);

	if (!op0)
	  return NULL;

	if (offset)
	  {
	    enum machine_mode addrmode, offmode;

	    if (!MEM_P (op0))
	      return NULL;

	    op0 = XEXP (op0, 0);
	    addrmode = GET_MODE (op0);
	    if (addrmode == VOIDmode)
	      addrmode = Pmode;

	    op1 = expand_debug_expr (offset);
	    if (!op1)
	      return NULL;

	    offmode = GET_MODE (op1);
	    if (offmode == VOIDmode)
	      offmode = TYPE_MODE (TREE_TYPE (offset));

	    if (addrmode != offmode)
	      op1 = simplify_gen_subreg (addrmode, op1, offmode,
					 subreg_lowpart_offset (addrmode,
								offmode));

	    /* Don't use offset_address here, we don't need a
	       recognizable address, and we don't want to generate
	       code.  */
	    op0 = gen_rtx_MEM (mode, simplify_gen_binary (PLUS, addrmode,
							  op0, op1));
	  }

	if (MEM_P (op0))
	  {
	    if (mode1 == VOIDmode)
	      /* Bitfield.  */
	      mode1 = smallest_mode_for_size (bitsize, MODE_INT);
	    if (bitpos >= BITS_PER_UNIT)
	      {
		op0 = adjust_address_nv (op0, mode1, bitpos / BITS_PER_UNIT);
		bitpos %= BITS_PER_UNIT;
	      }
	    else if (bitpos < 0)
	      {
		HOST_WIDE_INT units
		  = (-bitpos + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
		op0 = adjust_address_nv (op0, mode1, units);
		bitpos += units * BITS_PER_UNIT;
	      }
	    else if (bitpos == 0 && bitsize == GET_MODE_BITSIZE (mode))
	      op0 = adjust_address_nv (op0, mode, 0);
	    else if (GET_MODE (op0) != mode1)
	      op0 = adjust_address_nv (op0, mode1, 0);
	    else
	      op0 = copy_rtx (op0);
	    if (op0 == orig_op0)
	      op0 = shallow_copy_rtx (op0);
	    set_mem_attributes (op0, exp, 0);
	  }

	if (bitpos == 0 && mode == GET_MODE (op0))
	  return op0;

        if (bitpos < 0)
          return NULL;

	if (GET_MODE (op0) == BLKmode)
	  return NULL;

	if ((bitpos % BITS_PER_UNIT) == 0
	    && bitsize == GET_MODE_BITSIZE (mode1))
	  {
	    enum machine_mode opmode = GET_MODE (op0);

	    if (opmode == VOIDmode)
	      opmode = TYPE_MODE (TREE_TYPE (tem));

	    /* This condition may hold if we're expanding the address
	       right past the end of an array that turned out not to
	       be addressable (i.e., the address was only computed in
	       debug stmts).  The gen_subreg below would rightfully
	       crash, and the address doesn't really exist, so just
	       drop it.  */
	    if (bitpos >= GET_MODE_BITSIZE (opmode))
	      return NULL;

	    if ((bitpos % GET_MODE_BITSIZE (mode)) == 0)
	      return simplify_gen_subreg (mode, op0, opmode,
					  bitpos / BITS_PER_UNIT);
	  }

	return simplify_gen_ternary (SCALAR_INT_MODE_P (GET_MODE (op0))
				     && TYPE_UNSIGNED (TREE_TYPE (exp))
				     ? SIGN_EXTRACT
				     : ZERO_EXTRACT, mode,
				     GET_MODE (op0) != VOIDmode
				     ? GET_MODE (op0)
				     : TYPE_MODE (TREE_TYPE (tem)),
				     op0, GEN_INT (bitsize), GEN_INT (bitpos));
      }

    case ABS_EXPR:
      return simplify_gen_unary (ABS, mode, op0, mode);

    case NEGATE_EXPR:
      return simplify_gen_unary (NEG, mode, op0, mode);

    case BIT_NOT_EXPR:
      return simplify_gen_unary (NOT, mode, op0, mode);

    case FLOAT_EXPR:
      return simplify_gen_unary (TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (exp,
									 0)))
				 ? UNSIGNED_FLOAT : FLOAT, mode, op0,
				 inner_mode);

    case FIX_TRUNC_EXPR:
      return simplify_gen_unary (unsignedp ? UNSIGNED_FIX : FIX, mode, op0,
				 inner_mode);

    case POINTER_PLUS_EXPR:
      /* For the rare target where pointers are not the same size as
	 size_t, we need to check for mis-matched modes and correct
	 the addend.  */
      if (op0 && op1
	  && GET_MODE (op0) != VOIDmode && GET_MODE (op1) != VOIDmode
	  && GET_MODE (op0) != GET_MODE (op1))
	{
	  if (GET_MODE_BITSIZE (GET_MODE (op0)) < GET_MODE_BITSIZE (GET_MODE (op1)))
	    op1 = simplify_gen_unary (TRUNCATE, GET_MODE (op0), op1,
				      GET_MODE (op1));
	  else
	    /* We always sign-extend, regardless of the signedness of
	       the operand, because the operand is always unsigned
	       here even if the original C expression is signed.  */
	    op1 = simplify_gen_unary (SIGN_EXTEND, GET_MODE (op0), op1,
				      GET_MODE (op1));
	}
      /* Fall through.  */
    case PLUS_EXPR:
      return simplify_gen_binary (PLUS, mode, op0, op1);

    case MINUS_EXPR:
      return simplify_gen_binary (MINUS, mode, op0, op1);

    case MULT_EXPR:
      return simplify_gen_binary (MULT, mode, op0, op1);

    case RDIV_EXPR:
    case TRUNC_DIV_EXPR:
    case EXACT_DIV_EXPR:
      if (unsignedp)
	return simplify_gen_binary (UDIV, mode, op0, op1);
      else
	return simplify_gen_binary (DIV, mode, op0, op1);

    case TRUNC_MOD_EXPR:
      return simplify_gen_binary (unsignedp ? UMOD : MOD, mode, op0, op1);

    case FLOOR_DIV_EXPR:
      if (unsignedp)
	return simplify_gen_binary (UDIV, mode, op0, op1);
      else
	{
	  rtx div = simplify_gen_binary (DIV, mode, op0, op1);
	  rtx mod = simplify_gen_binary (MOD, mode, op0, op1);
	  rtx adj = floor_sdiv_adjust (mode, mod, op1);
	  return simplify_gen_binary (PLUS, mode, div, adj);
	}

    case FLOOR_MOD_EXPR:
      if (unsignedp)
	return simplify_gen_binary (UMOD, mode, op0, op1);
      else
	{
	  rtx mod = simplify_gen_binary (MOD, mode, op0, op1);
	  rtx adj = floor_sdiv_adjust (mode, mod, op1);
	  adj = simplify_gen_unary (NEG, mode,
				    simplify_gen_binary (MULT, mode, adj, op1),
				    mode);
	  return simplify_gen_binary (PLUS, mode, mod, adj);
	}

    case CEIL_DIV_EXPR:
      if (unsignedp)
	{
	  rtx div = simplify_gen_binary (UDIV, mode, op0, op1);
	  rtx mod = simplify_gen_binary (UMOD, mode, op0, op1);
	  rtx adj = ceil_udiv_adjust (mode, mod, op1);
	  return simplify_gen_binary (PLUS, mode, div, adj);
	}
      else
	{
	  rtx div = simplify_gen_binary (DIV, mode, op0, op1);
	  rtx mod = simplify_gen_binary (MOD, mode, op0, op1);
	  rtx adj = ceil_sdiv_adjust (mode, mod, op1);
	  return simplify_gen_binary (PLUS, mode, div, adj);
	}

    case CEIL_MOD_EXPR:
      if (unsignedp)
	{
	  rtx mod = simplify_gen_binary (UMOD, mode, op0, op1);
	  rtx adj = ceil_udiv_adjust (mode, mod, op1);
	  adj = simplify_gen_unary (NEG, mode,
				    simplify_gen_binary (MULT, mode, adj, op1),
				    mode);
	  return simplify_gen_binary (PLUS, mode, mod, adj);
	}
      else
	{
	  rtx mod = simplify_gen_binary (MOD, mode, op0, op1);
	  rtx adj = ceil_sdiv_adjust (mode, mod, op1);