text: /* A pass for lowering trees to RTL.
     Copyright (C) 2004-2017 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 "backend.h"
  #include "target.h"
  #include "rtl.h"
  #include "tree.h"
  #include "gimple.h"
  #include "cfghooks.h"
  #include "tree-pass.h"
  #include "memmodel.h"
  #include "tm_p.h"
  #include "ssa.h"
  #include "optabs.h"
  #include "regs.h" /* For reg_renumber.  */
  #include "emit-rtl.h"
  #include "recog.h"
  #include "cgraph.h"
  #include "diagnostic.h"
  #include "fold-const.h"
  #include "varasm.h"
  #include "stor-layout.h"
  #include "stmt.h"
  #include "print-tree.h"
  #include "cfgrtl.h"
  #include "cfganal.h"
  #include "cfgbuild.h"
  #include "cfgcleanup.h"
  #include "dojump.h"
  #include "explow.h"
  #include "calls.h"
  #include "expr.h"
  #include "internal-fn.h"
  #include "tree-eh.h"
  #include "gimple-iterator.h"
  #include "gimple-expr.h"
  #include "gimple-walk.h"
  #include "tree-cfg.h"
  #include "tree-dfa.h"
  #include "tree-ssa.h"
  #include "except.h"
  #include "gimple-pretty-print.h"
  #include "toplev.h"
  #include "debug.h"
  #include "params.h"
  #include "tree-inline.h"
  #include "value-prof.h"
  #include "tree-ssa-live.h"
  #include "tree-outof-ssa.h"
  #include "cfgloop.h"
  #include "insn-attr.h" /* For INSN_SCHEDULING.  */
  #include "asan.h"
  #include "tree-ssa-address.h"
  #include "output.h"
  #include "builtins.h"
  #include "tree-chkp.h"
  #include "rtl-chkp.h"
  
  /* Some systems use __main in a way incompatible with its use in gcc, in these
     cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
     give the same symbol without quotes for an alternative entry point.  You
     must define both, or neither.  */
  #ifndef NAME__MAIN
  #define NAME__MAIN "__main"
  #endif
  
  /* 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);
  
  static bool defer_stack_allocation (tree, bool);
  
  static void record_alignment_for_reg_var (unsigned int);
  
  /* 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)
  
  /* Choose either CUR or NEXT as the leader DECL for a partition.
     Prefer ignored decls, to simplify debug dumps and reduce ambiguity
     out of the same user variable being in multiple partitions (this is
     less likely for compiler-introduced temps).  */
  
  static tree
  leader_merge (tree cur, tree next)
  {
    if (cur == NULL || cur == next)
      return next;
  
    if (DECL_P (cur) && DECL_IGNORED_P (cur))
      return cur;
  
    if (DECL_P (next) && DECL_IGNORED_P (next))
      return next;
  
    return cur;
  }
  
  /* 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)
  {
    gcc_checking_assert (!x
  		       || !(TREE_CODE (t) == SSA_NAME || is_gimple_reg (t))
  		       || (use_register_for_decl (t)
  			   ? (REG_P (x)
  			      || (GET_CODE (x) == CONCAT
  				  && (REG_P (XEXP (x, 0))
  				      || SUBREG_P (XEXP (x, 0)))
  				  && (REG_P (XEXP (x, 1))
  				      || SUBREG_P (XEXP (x, 1))))
  			      /* We need to accept PARALLELs for RESUT_DECLs
  				 because of vector types with BLKmode returned
  				 in multiple registers, but they are supposed
  				 to be uncoalesced.  */
  			      || (GET_CODE (x) == PARALLEL
  				  && SSAVAR (t)
  				  && TREE_CODE (SSAVAR (t)) == RESULT_DECL
  				  && (GET_MODE (x) == BLKmode
  				      || !flag_tree_coalesce_vars)))
  			   : (MEM_P (x) || x == pc_rtx
  			      || (GET_CODE (x) == CONCAT
  				  && MEM_P (XEXP (x, 0))
  				  && MEM_P (XEXP (x, 1))))));
    /* Check that the RTL for SSA_NAMEs and gimple-reg PARM_DECLs and
       RESULT_DECLs has the expected mode.  For memory, we accept
       unpromoted modes, since that's what we're likely to get.  For
       PARM_DECLs and RESULT_DECLs, we'll have been called by
       set_parm_rtl, which will give us the default def, so we don't
       have to compute it ourselves.  For RESULT_DECLs, we accept mode
       mismatches too, as long as we have BLKmode or are not coalescing
       across variables, so that we don't reject BLKmode PARALLELs or
       unpromoted REGs.  */
    gcc_checking_assert (!x || x == pc_rtx || TREE_CODE (t) != SSA_NAME
  		       || (SSAVAR (t)
  			   && TREE_CODE (SSAVAR (t)) == RESULT_DECL
  			   && (promote_ssa_mode (t, NULL) == BLKmode
  			       || !flag_tree_coalesce_vars))
  		       || !use_register_for_decl (t)
  		       || GET_MODE (x) == promote_ssa_mode (t, NULL));
  
    if (x)
      {
        bool skip = false;
        tree cur = NULL_TREE;
        rtx xm = x;
  
      retry:
        if (MEM_P (xm))
  	cur = MEM_EXPR (xm);
        else if (REG_P (xm))
  	cur = REG_EXPR (xm);
        else if (SUBREG_P (xm))
  	{
  	  gcc_assert (subreg_lowpart_p (xm));
  	  xm = SUBREG_REG (xm);
  	  goto retry;
  	}
        else if (GET_CODE (xm) == CONCAT)
  	{
  	  xm = XEXP (xm, 0);
  	  goto retry;
  	}
        else if (GET_CODE (xm) == PARALLEL)
  	{
  	  xm = XVECEXP (xm, 0, 0);
  	  gcc_assert (GET_CODE (xm) == EXPR_LIST);
  	  xm = XEXP (xm, 0);
  	  goto retry;
  	}
        else if (xm == pc_rtx)
  	skip = true;
        else
  	gcc_unreachable ();
  
        tree next = skip ? cur : leader_merge (cur, SSAVAR (t) ? SSAVAR (t) : t);
  
        if (cur != next)
  	{
  	  if (MEM_P (x))
  	    set_mem_attributes (x,
  				next && TREE_CODE (next) == SSA_NAME
  				? TREE_TYPE (next)
  				: next, true);
  	  else
  	    set_reg_attrs_for_decl_rtl (next, x);
  	}
      }
  
    if (TREE_CODE (t) == SSA_NAME)
      {
        int part = var_to_partition (SA.map, t);
        if (part != NO_PARTITION)
  	{
  	  if (SA.partition_to_pseudo[part])
  	    gcc_assert (SA.partition_to_pseudo[part] == x);
  	  else if (x != pc_rtx)
  	    SA.partition_to_pseudo[part] = x;
  	}
        /* For the benefit of debug information at -O0 (where
           vartracking doesn't run) record the place also in the base
           DECL.  For PARMs and RESULTs, do so only when setting the
           default def.  */
        if (x && x != pc_rtx && SSA_NAME_VAR (t)
  	  && (VAR_P (SSA_NAME_VAR (t))
  	      || SSA_NAME_IS_DEFAULT_DEF (t)))
  	{
  	  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 hash_map<tree, size_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;
  
    if (TREE_CODE (decl) == SSA_NAME)
      align = TYPE_ALIGN (TREE_TYPE (decl));
    else
      {
        align = LOCAL_DECL_ALIGNMENT (decl);
        SET_DECL_ALIGN (decl, align);
      }
    return align / BITS_PER_UNIT;
  }
  
  /* Align given offset BASE with ALIGN.  Truncate up if ALIGN_UP is true,
     down otherwise.  Return truncated BASE value.  */
  
  static inline unsigned HOST_WIDE_INT
  align_base (HOST_WIDE_INT base, unsigned HOST_WIDE_INT align, bool align_up)
  {
    return align_up ? (base + align - 1) & -align : base & -align;
  }
  
  /* 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;
  
    if (FRAME_GROWS_DOWNWARD)
      {
        new_frame_offset
  	= align_base (frame_offset - frame_phase - size,
  		      align, false) + frame_phase;
        offset = new_frame_offset;
      }
    else
      {
        new_frame_offset
  	= align_base (frame_offset - frame_phase, align, true) + 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 = new hash_map<tree, size_t>;
  
    v = &stack_vars[stack_vars_num];
    decl_to_stack_part->put (decl, stack_vars_num);
  
    v->decl = decl;
    tree size = TREE_CODE (decl) == SSA_NAME
      ? TYPE_SIZE_UNIT (TREE_TYPE (decl))
      : DECL_SIZE_UNIT (decl);
    v->size = tree_to_uhwi (size);
    /* 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 (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 = decl_to_stack_part->get (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 = decl_to_stack_part->get (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 (!VAR_P (lhs))
  	    continue;
  	  if (DECL_RTL_IF_SET (lhs) == pc_rtx
  	      && (v = decl_to_stack_part->get (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_FN (bb, cfun)
      bb->aux = BITMAP_ALLOC (&stack_var_bitmap_obstack);
  
    rpo = XNEWVEC (int, last_basic_block_for_fn (cfun));
    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_FOR_FN (cfun, rpo[i]);
  	  active = (bitmap)bb->aux;
  	  add_scope_conflicts_1 (bb, work, false);
  	  if (bitmap_ior_into (active, work))
  	    changed = true;
  	}
      }
  
    FOR_EACH_BB_FN (bb, cfun)
      add_scope_conflicts_1 (bb, work, true);
  
    free (rpo);
    BITMAP_FREE (work);
    FOR_ALL_BB_FN (bb, cfun)
      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;
  }
  
  struct part_traits : unbounded_int_hashmap_traits <size_t, bitmap> {};
  typedef hash_map<size_t, bitmap, part_traits> part_hashmap;
  
  /* 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,
  			       part_hashmap *decls_to_partitions,
  			       hash_set<bitmap> *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.  */
        || visited->add (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 = decls_to_partitions->get (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)
  {
    part_hashmap *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 = new part_hashmap;
  	  cfun->gimple_df->decls_to_pointers = new hash_map<tree, tree>;
  	}
  
        /* 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);
        name = make_ssa_name (var);
  
        /* 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);
  	  decls_to_partitions->put (uid, part);
  	  cfun->gimple_df->decls_to_pointers->put (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;
        tree name;
        hash_set<bitmap> visited;
        bitmap temp = BITMAP_ALLOC (&stack_var_bitmap_obstack);
  
        FOR_EACH_SSA_NAME (i, name, cfun)
  	{
  	  struct ptr_info_def *pi;
  
  	  if (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);
  
        delete 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 ((asan_sanitize_stack_p ())
  	      && 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 (TREE_CODE (decl) == SSA_NAME
  		   ? TYPE_MODE (TREE_TYPE (decl))
  		   : 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 = least_bit_hwi (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.  */
  
        SET_DECL_ALIGN (decl, align);
        DECL_USER_ALIGN (decl) = 0;
      }
  
    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.  */
    auto_vec<HOST_WIDE_INT> asan_vec;
  
    /* Vector of partition representative decls in between the paddings.  */
    auto_vec<tree> asan_decl_vec;
  
    /* Base pseudo register for Address Sanitizer protected automatic vars.  */
    rtx asan_base;
  
    /* Alignment needed for the Address Sanitizer protected automatic vars.  */
    unsigned int asan_alignb;
  };
  
  /* 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;
    bool large_allocation_done = false;
    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;
  
  	  /* All "large" alignment decls come before all "small" alignment
  	     decls, but "large" alignment decls are not sorted based on
  	     their alignment.  Increase large_align to track the largest
  	     required alignment.  */
  	  if ((alignb * BITS_PER_UNIT) > large_align)
  	    large_align = alignb * BITS_PER_UNIT;
  
  	  /* 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)] != NULL_RTX
  	      : DECL_RTL (decl) != pc_rtx)
  	    continue;
  
  	  large_size += alignb - 1;
  	  large_size &= -(HOST_WIDE_INT)alignb;
  	  large_size += stack_vars[i].size;
  	}
      }
  
    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)] != NULL_RTX
  	  : 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)
  	{
  	  base = virtual_stack_vars_rtx;
  	  if ((asan_sanitize_stack_p ())
  	      && pred)
  	    {
  	      HOST_WIDE_INT prev_offset
  		= align_base (frame_offset,
  			      MAX (alignb, ASAN_RED_ZONE_SIZE),
  			      !FRAME_GROWS_DOWNWARD);
  	      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);
  	      data->asan_alignb = MAX (data->asan_alignb, alignb);
  	      if (data->asan_base == NULL)
  		data->asan_base = gen_reg_rtx (Pmode);
  	      base = data->asan_base;
  
  	      if (!STRICT_ALIGNMENT)
  		base_align = crtl->max_used_stack_slot_alignment;
  	      else
  		base_align = MAX (crtl->max_used_stack_slot_alignment,
  				  GET_MODE_ALIGNMENT (SImode)
  				  << ASAN_SHADOW_SHIFT);
  	    }
  	  else
  	    {
  	      offset = alloc_stack_frame_space (stack_vars[i].size, alignb);
  	      base_align = crtl->max_used_stack_slot_alignment;
  	    }
  	}
        else
  	{
  	  /* Large alignment is only processed in the last pass.  */
  	  if (pred)
  	    continue;
  
  	  /* If there were any variables requiring "large" alignment, allocate
  	     space.  */
  	  if (large_size > 0 && ! large_allocation_done)
  	    {
  	      HOST_WIDE_INT loffset;
  	      rtx large_allocsize;
  
  	      large_allocsize = GEN_INT (large_size);
  	      get_dynamic_stack_size (&large_allocsize, 0, large_align, NULL);
  	      loffset = alloc_stack_frame_space
  		(INTVAL (large_allocsize),
  		 PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT);
  	      large_base = get_dynamic_stack_base (loffset, large_align);
  	      large_allocation_done = true;
  	    }
  	  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;
  }
  
  /* Record the RTL assignment X for the default def of PARM.  */
  
  extern void
  set_parm_rtl (tree parm, rtx x)
  {
    gcc_assert (TREE_CODE (parm) == PARM_DECL
  	      || TREE_CODE (parm) == RESULT_DECL);
  
    if (x && !MEM_P (x))
      {
        unsigned int align = MINIMUM_ALIGNMENT (TREE_TYPE (parm),
  					      TYPE_MODE (TREE_TYPE (parm)),
  					      TYPE_ALIGN (TREE_TYPE (parm)));
  
        /* If the variable alignment is very large we'll dynamicaly
  	 allocate it, which means that in-frame portion is just a
  	 pointer.  ??? We've got a pseudo for sure here, do we
  	 actually dynamically allocate its spilling area if needed?
  	 ??? Isn't it a problem when POINTER_SIZE also exceeds
  	 MAX_SUPPORTED_STACK_ALIGNMENT, as on cris and lm32?  */
        if (align > MAX_SUPPORTED_STACK_ALIGNMENT)
  	align = POINTER_SIZE;
  
        record_alignment_for_reg_var (align);
      }
  
    tree ssa = ssa_default_def (cfun, parm);
    if (!ssa)
      return set_rtl (parm, x);
  
    int part = var_to_partition (SA.map, ssa);
    gcc_assert (part != NO_PARTITION);
  
    bool changed = bitmap_bit_p (SA.partitions_for_parm_default_defs, part);
    gcc_assert (changed);
  
    set_rtl (ssa, x);
    gcc_assert (DECL_RTL (parm) == x);
  }
  
  /* 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_1 (tree var)
  {
    HOST_WIDE_INT size, offset;
    unsigned byte_align;
  
    if (TREE_CODE (var) == SSA_NAME)
      {
        tree type = TREE_TYPE (var);
        size = tree_to_uhwi (TYPE_SIZE_UNIT (type));
        byte_align = TYPE_ALIGN_UNIT (type);
      }
    else
      {
        size = tree_to_uhwi (DECL_SIZE_UNIT (var));
        byte_align = align_local_variable (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);
  }
  
  /* Wrapper for expand_one_stack_var_1 that checks SSA_NAMEs are
     already assigned some MEM.  */
  
  static void
  expand_one_stack_var (tree var)
  {
    if (TREE_CODE (var) == SSA_NAME)
      {
        int part = var_to_partition (SA.map, var);
        if (part != NO_PARTITION)
  	{
  	  rtx x = SA.partition_to_pseudo[part];
  	  gcc_assert (x);
  	  gcc_assert (MEM_P (x));
  	  return;
  	}
      }
  
    return expand_one_stack_var_1 (var);
  }
  
  /* 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);
  }
  
  /* Record the alignment requirements of some variable assigned to a
     pseudo.  */
  
  static void
  record_alignment_for_reg_var (unsigned int align)
  {
    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;
  }
  
  /* Create RTL for an SSA partition.  */
  
  static void
  expand_one_ssa_partition (tree var)
  {
    int part = var_to_partition (SA.map, var);
    gcc_assert (part != NO_PARTITION);
  
    if (SA.partition_to_pseudo[part])
      return;
  
    unsigned int align = MINIMUM_ALIGNMENT (TREE_TYPE (var),
  					  TYPE_MODE (TREE_TYPE (var)),
  					  TYPE_ALIGN (TREE_TYPE (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;
  
    record_alignment_for_reg_var (align);
  
    if (!use_register_for_decl (var))
      {
        if (defer_stack_allocation (var, true))
  	add_stack_var (var);
        else
  	expand_one_stack_var_1 (var);
        return;
      }
  
    machine_mode reg_mode = promote_ssa_mode (var, NULL);
  
    rtx x = gen_reg_rtx (reg_mode);
  
    set_rtl (var, x);
  }
  
  /* Record the association between the RTL generated for partition PART
     and the underlying variable of the SSA_NAME VAR.  */
  
  static void
  adjust_one_expanded_partition_var (tree var)
  {
    if (!var)
      return;
  
    tree decl = SSA_NAME_VAR (var);
  
    int part = var_to_partition (SA.map, var);
    if (part == NO_PARTITION)
      return;
  
    rtx x = SA.partition_to_pseudo[part];
  
    gcc_assert (x);
  
    set_rtl (var, x);
  
    if (!REG_P (x))
      return;
  
    /* Note if the object is a user variable.  */
    if (decl && !DECL_ARTIFICIAL (decl))
      mark_user_reg (x);
  
    if (POINTER_TYPE_P (decl ? TREE_TYPE (decl) : TREE_TYPE (var)))
      mark_reg_pointer (x, get_pointer_alignment (var));
  }
  
  /* 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)
  {
    if (TREE_CODE (var) == SSA_NAME)
      {
        int part = var_to_partition (SA.map, var);
        if (part != NO_PARTITION)
  	{
  	  rtx x = SA.partition_to_pseudo[part];
  	  gcc_assert (x);
  	  gcc_assert (REG_P (x));
  	  return;
  	}
        gcc_unreachable ();
      }
  
    tree decl = var;
    tree type = TREE_TYPE (decl);
    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)
  {
    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)
  {
    tree size_unit = TREE_CODE (var) == SSA_NAME
      ? TYPE_SIZE_UNIT (TREE_TYPE (var))
      : DECL_SIZE_UNIT (var);
  
    /* Whether the variable is small enough for immediate allocation not to be
       a problem with regard to the frame size.  */
    bool smallish
      = ((HOST_WIDE_INT) tree_to_uhwi (size_unit)
         < PARAM_VALUE (PARAM_MIN_SIZE_FOR_STACK_SHARING));
  
    /* 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 || asan_sanitize_stack_p ())
      return true;
  
    unsigned int align = TREE_CODE (var) == SSA_NAME
      ? TYPE_ALIGN (TREE_TYPE (var))
      : DECL_ALIGN (var);
  
    /* We handle "large" alignment via dynamic allocation.  We want to handle
       this extra complication in only one place, so defer them.  */
    if (align > MAX_SUPPORTED_STACK_ALIGNMENT)
      return true;
  
    bool ignored = TREE_CODE (var) == SSA_NAME
      ? !SSAVAR (var) || DECL_IGNORED_P (SSA_NAME_VAR (var))
      : DECL_IGNORED_P (var);
  
    /* When optimization is enabled, DECL_IGNORED_P variables originally scoped
       might be detached from their block and appear at toplevel when we reach
       here.  We want to coalesce them with variables from other blocks when
       the immediate contribution to the frame size would be noticeable.  */
    if (toplevel && optimize > 0 && ignored && !smallish)
      return true;
  
    /* Variables declared 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 && smallish)
      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 && VAR_P (var))
      {
        if (is_global_var (var))
  	return 0;
  
        /* 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.  Similarly for
  	 SSA_NAMEs for which use_register_for_decl returns true.  */
        if (TREE_STATIC (var)
  	  || DECL_EXTERNAL (var)
  	  || (TREE_CODE (origvar) == SSA_NAME && use_register_for_decl (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;
      }
  
    record_alignment_for_reg_var (align);
  
    if (TREE_CODE (origvar) == SSA_NAME)
      {
        gcc_assert (!VAR_P (var)
  		  || (!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 (!VAR_P (var) && 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 (VAR_P (var) && DECL_HARD_REGISTER (var))
      {
        if (really_expand)
  	{
  	  expand_one_hard_reg_var (var);
  	  if (!DECL_HARD_REGISTER (var))
  	    /* Invalid register specification.  */
  	    expand_one_error_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)
          {
            if (lookup_attribute ("naked",
                                  DECL_ATTRIBUTES (current_function_decl)))
              error ("cannot allocate stack for variable %q+D, naked function.",
                     var);
  
            expand_one_stack_var (origvar);
          }
  
  
        return tree_to_uhwi (DECL_SIZE_UNIT (var));
      }
    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)
          && ((!VAR_P (t) && 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 ((!VAR_P (t) && 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);
  }
  
  enum {
    SPCT_FLAG_DEFAULT = 1,
    SPCT_FLAG_ALL = 2,
    SPCT_FLAG_STRONG = 3,
    SPCT_FLAG_EXPLICIT = 4
  };
  
  /* 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)
  	      || !tree_fits_uhwi_p (TYPE_SIZE_UNIT (type)))
  	    len = max;
  	  else
  	    len = tree_to_uhwi (TYPE_SIZE_UNIT (type));
  
  	  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 == SPCT_FLAG_ALL
        || flag_stack_protect == SPCT_FLAG_STRONG
        || (flag_stack_protect == SPCT_FLAG_EXPLICIT
  	  && lookup_attribute ("stack_protect",
  			       DECL_ATTRIBUTES (current_function_decl))))
      {
        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 = new hash_map<tree, size_t>;
  
    /* 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;
    delete 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->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;
  }
  
  /* Helper routine to check if a record or union contains an array field. */
  
  static int
  record_or_union_type_has_array_p (const_tree tree_type)
  {
    tree fields = TYPE_FIELDS (tree_type);
    tree f;
  
    for (f = fields; f; f = DECL_CHAIN (f))
      if (TREE_CODE (f) == FIELD_DECL)
        {
  	tree field_type = TREE_TYPE (f);
  	if (RECORD_OR_UNION_TYPE_P (field_type)
  	    && record_or_union_type_has_array_p (field_type))
  	  return 1;
  	if (TREE_CODE (field_type) == ARRAY_TYPE)
  	  return 1;
        }
    return 0;
  }
  
  /* Check if the current function has local referenced variables that
     have their addresses taken, contain an array, or are arrays.  */
  
  static bool
  stack_protect_decl_p ()
  {
    unsigned i;
    tree var;
  
    FOR_EACH_LOCAL_DECL (cfun, i, var)
      if (!is_global_var (var))
        {
  	tree var_type = TREE_TYPE (var);
  	if (VAR_P (var)
  	    && (TREE_CODE (var_type) == ARRAY_TYPE
  		|| TREE_ADDRESSABLE (var)
  		|| (RECORD_OR_UNION_TYPE_P (var_type)
  		    && record_or_union_type_has_array_p (var_type))))
  	  return true;
        }
    return false;
  }
  
  /* Check if the current function has calls that use a return slot.  */
  
  static bool
  stack_protect_return_slot_p ()
  {
    basic_block bb;
    
    FOR_ALL_BB_FN (bb, cfun)
      for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
  	 !gsi_end_p (gsi); gsi_next (&gsi))
        {
  	gimple *stmt = gsi_stmt (gsi);
  	/* This assumes that calls to internal-only functions never
  	   use a return slot.  */
  	if (is_gimple_call (stmt)
  	    && !gimple_call_internal_p (stmt)
  	    && aggregate_value_p (TREE_TYPE (gimple_call_fntype (stmt)),
  				  gimple_call_fndecl (stmt)))
  	  return true;
        }
    return false;
  }
  
  /* Expand all variables used in the function.  */
  
  static rtx_insn *
  expand_used_vars (void)
  {
    tree var, outer_block = DECL_INITIAL (current_function_decl);
    auto_vec<tree> maybe_local_decls;
    rtx_insn *var_end_seq = NULL;
    unsigned i;
    unsigned len;
    bool gen_stack_protect_signal = false;
  
    /* 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 ();
  
    if (targetm.use_pseudo_pic_reg ())
      pic_offset_table_rtx = gen_reg_rtx (Pmode);
  
    for (i = 0; i < SA.map->num_partitions; i++)
      {
        if (bitmap_bit_p (SA.partitions_for_parm_default_defs, i))
  	continue;
  
        tree var = partition_to_var (SA.map, i);
  
        gcc_assert (!virtual_operand_p (var));
  
        expand_one_ssa_partition (var);
      }
  
    if (flag_stack_protect == SPCT_FLAG_STRONG)
        gen_stack_protect_signal
  	= stack_protect_decl_p () || stack_protect_return_slot_p ();
  
    /* 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;
  
        /* Expand variables not associated with any block now.  Those created by
  	 the optimizers could be live anywhere in the function.  Those that
  	 could possibly have been scoped originally and detached from their
  	 block will have their allocation deferred so we coalesce them with
  	 others when optimization is enabled.  */
        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 != 0
  	  && (flag_stack_protect != SPCT_FLAG_EXPLICIT
  	      || (flag_stack_protect == SPCT_FLAG_EXPLICIT
  		  && lookup_attribute ("stack_protect",
  				       DECL_ATTRIBUTES (current_function_decl)))))
  	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 ();
      }
  
    switch (flag_stack_protect)
      {
      case SPCT_FLAG_ALL:
        create_stack_guard ();
        break;
  
      case SPCT_FLAG_STRONG:
        if (gen_stack_protect_signal
  	  || cfun->calls_alloca || has_protected_decls
  	  || lookup_attribute ("stack_protect",
  			       DECL_ATTRIBUTES (current_function_decl)))
  	create_stack_guard ();
        break;
  
      case SPCT_FLAG_DEFAULT:
        if (cfun->calls_alloca || has_protected_decls
  	  || lookup_attribute ("stack_protect",
  			       DECL_ATTRIBUTES (current_function_decl)))
  	create_stack_guard ();
        break;
  
      case SPCT_FLAG_EXPLICIT:
        if (lookup_attribute ("stack_protect",
  			    DECL_ATTRIBUTES (current_function_decl)))
  	create_stack_guard ();
        break;
      default:
        ;
      }
  
    /* Assign rtl to each variable based on these partitions.  */
    if (stack_vars_num > 0)
      {
        struct stack_vars_data data;
  
        data.asan_base = NULL_RTX;
        data.asan_alignb = 0;
  
        /* 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 == SPCT_FLAG_ALL
  	      || flag_stack_protect == SPCT_FLAG_STRONG
  	      || (flag_stack_protect == SPCT_FLAG_EXPLICIT
  		  && lookup_attribute ("stack_protect",
  				       DECL_ATTRIBUTES (current_function_decl))))
  	    expand_stack_vars (stack_protect_decl_phase_2, &data);
  	}
  
        if (asan_sanitize_stack_p ())
  	/* 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, sz, redzonesz;
  	  redzonesz = ASAN_RED_ZONE_SIZE;
  	  sz = data.asan_vec[0] - prev_offset;
  	  if (data.asan_alignb > ASAN_RED_ZONE_SIZE
  	      && data.asan_alignb <= 4096
  	      && sz + ASAN_RED_ZONE_SIZE >= (int) data.asan_alignb)
  	    redzonesz = ((sz + ASAN_RED_ZONE_SIZE + data.asan_alignb - 1)
  			 & ~(data.asan_alignb - HOST_WIDE_INT_1)) - sz;
  	  offset
  	    = alloc_stack_frame_space (redzonesz, ASAN_RED_ZONE_SIZE);
  	  data.asan_vec.safe_push (prev_offset);
  	  data.asan_vec.safe_push (offset);
  	  /* Leave space for alignment if STRICT_ALIGNMENT.  */
  	  if (STRICT_ALIGNMENT)
  	    alloc_stack_frame_space ((GET_MODE_ALIGNMENT (SImode)
  				      << ASAN_SHADOW_SHIFT)
  				     / BITS_PER_UNIT, 1);
  
  	  var_end_seq
  	    = asan_emit_stack_protection (virtual_stack_vars_rtx,
  					  data.asan_base,
  					  data.asan_alignb,
  					  data.asan_vec.address (),
  					  data.asan_decl_vec.address (),
  					  data.asan_vec.length ());
  	}
  
        expand_stack_vars (NULL, &data);
      }
  
    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);
      }
  
    /* 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_insn *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 hash_map<basic_block, rtx_code_label *> *lab_rtx_for_bb;
  
  /* Returns the label_rtx expression for a label starting basic block BB.  */
  
  static rtx_code_label *
  label_rtx_for_bb (basic_block bb ATTRIBUTE_UNUSED)
  {
    gimple_stmt_iterator gsi;
    tree lab;
  
    if (bb->flags & BB_RTL)
      return block_label (bb);
  
    rtx_code_label **elt = lab_rtx_for_bb->get (bb);
    if (elt)
      return *elt;
  
    /* Find the tree label if it is present.  */
  
    for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
      {
        glabel *lab_stmt;
  
        lab_stmt = dyn_cast <glabel *> (gsi_stmt (gsi));
        if (!lab_stmt)
  	break;
  
        lab = gimple_label_label (lab_stmt);
        if (DECL_NONLOCAL (lab))
  	break;
  
        return jump_target_rtx (lab);
      }
  
    rtx_code_label *l = gen_label_rtx ();
    lab_rtx_for_bb->put (bb, l);
    return l;
  }
  
  
  /* 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_insn *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 *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, gcond *stmt)
  {
    basic_block new_bb, dest;
    edge new_edge;
    edge true_edge;
    edge false_edge;
    rtx_insn *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 (SA.values
        && TREE_CODE (op0) == SSA_NAME
        && TREE_CODE (TREE_TYPE (op0)) == BOOLEAN_TYPE
        && TREE_CODE (op1) == INTEGER_CST
        && ((gimple_cond_code (stmt) == NE_EXPR
  	   && integer_zerop (op1))
  	  || (gimple_cond_code (stmt) == EQ_EXPR
  	      && integer_onep (op1)))
        && 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 and the target does not support conditional
  	     compare, turn some more codes into jumpy sequences.  */
  	  else if (BRANCH_COST (optimize_insn_for_speed_p (), false) < 4
  		   && targetm.gen_ccmp_first == NULL)
  	    {
  	      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);
    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;
    tm_restart_node **slot;
  
    if (!cfun->gimple_df->tm_restart)
      return;
  
    dummy.stmt = stmt;
    slot = cfun->gimple_df->tm_restart->find_slot (&dummy, NO_INSERT);
    if (slot)
      {
        struct tm_restart_node *n = *slot;
        tree list = n->label_or_list;
        rtx_insn *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 (gcall *stmt)
  {
    tree exp, decl, lhs;
    bool builtin_p;
    size_t i;
  
    if (gimple_call_internal_p (stmt))
      {
        expand_internal_call (stmt);
        return;
      }
  
    /* If this is a call to a built-in function and it has no effect other
       than setting the lhs, try to implement it using an internal function
       instead.  */
    decl = gimple_call_fndecl (stmt);
    if (gimple_call_lhs (stmt)
        && !gimple_has_side_effects (stmt)
        && (optimize || (decl && called_as_built_in (decl))))
      {
        internal_fn ifn = replacement_internal_fn (stmt);
        if (ifn != IFN_LAST)
  	{
  	  expand_internal_call (ifn, stmt);
  	  return;
  	}
      }
  
    exp = build_vl_exp (CALL_EXPR, gimple_call_num_args (stmt) + 3);
  
    CALL_EXPR_FN (exp) = gimple_call_fn (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_MUST_TAIL_CALL (exp) = gimple_call_must_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);
    CALL_EXPR_BY_DESCRIPTOR (exp) = gimple_call_by_descriptor_p (stmt);
    SET_EXPR_LOCATION (exp, gimple_location (stmt));
    CALL_WITH_BOUNDS_P (exp) = gimple_call_with_bounds_p (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);
  }
  
  
  /* Generate RTL for an asm statement (explicit assembler code).
     STRING is a STRING_CST node containing the assembler code text,
     or an ADDR_EXPR containing a STRING_CST.  VOL nonzero means the
     insn is volatile; don't optimize it.  */
  
  static void
  expand_asm_loc (tree string, int vol, location_t locus)
  {
    rtx body;
  
    body = gen_rtx_ASM_INPUT_loc (VOIDmode,
  				ggc_strdup (TREE_STRING_POINTER (string)),
  				locus);
  
    MEM_VOLATILE_P (body) = vol;
  
    /* Non-empty basic ASM implicitly clobbers memory.  */
    if (TREE_STRING_LENGTH (string) != 0)
      {
        rtx asm_op, clob;
        unsigned i, nclobbers;
        auto_vec<rtx> input_rvec, output_rvec;
        auto_vec<const char *> constraints;
        auto_vec<rtx> clobber_rvec;
        HARD_REG_SET clobbered_regs;
        CLEAR_HARD_REG_SET (clobbered_regs);
  
        clob = gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode));
        clobber_rvec.safe_push (clob);
  
        if (targetm.md_asm_adjust)
  	targetm.md_asm_adjust (output_rvec, input_rvec,
  			       constraints, clobber_rvec,
  			       clobbered_regs);
  
        asm_op = body;
        nclobbers = clobber_rvec.length ();
        body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (1 + nclobbers));
  
        XVECEXP (body, 0, 0) = asm_op;
        for (i = 0; i < nclobbers; i++)
  	XVECEXP (body, 0, i + 1) = gen_rtx_CLOBBER (VOIDmode, clobber_rvec[i]);
      }
  
    emit_insn (body);
  }
  
  /* Return the number of times character C occurs in string S.  */
  static int
  n_occurrences (int c, const char *s)
  {
    int n = 0;
    while (*s)
      n += (*s++ == c);
    return n;
  }
  
  /* A subroutine of expand_asm_operands.  Check that all operands have
     the same number of alternatives.  Return true if so.  */
  
  static bool
  check_operand_nalternatives (const vec<const char *> &constraints)
  {
    unsigned len = constraints.length();
    if (len > 0)
      {
        int nalternatives = n_occurrences (',', constraints[0]);
  
        if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
  	{
  	  error ("too many alternatives in %<asm%>");
  	  return false;
  	}
  
        for (unsigned i = 1; i < len; ++i)
  	if (n_occurrences (',', constraints[i]) != nalternatives)
  	  {
  	    error ("operand constraints for %<asm%> differ "
  		   "in number of alternatives");
  	    return false;
  	  }
      }
    return true;
  }
  
  /* Check for overlap between registers marked in CLOBBERED_REGS and
     anything inappropriate in T.  Emit error and return the register
     variable definition for error, NULL_TREE for ok.  */
  
  static bool
  tree_conflicts_with_clobbers_p (tree t, HARD_REG_SET *clobbered_regs)
  {
    /* Conflicts between asm-declared register variables and the clobber
       list are not allowed.  */
    tree overlap = tree_overlaps_hard_reg_set (t, clobbered_regs);
  
    if (overlap)
      {
        error ("asm-specifier for variable %qE conflicts with asm clobber list",
  	     DECL_NAME (overlap));
  
        /* Reset registerness to stop multiple errors emitted for a single
  	 variable.  */
        DECL_REGISTER (overlap) = 0;
        return true;
      }
  
    return false;
  }
  
  /* Generate RTL for an asm statement with arguments.
     STRING is the instruction template.
     OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
     Each output or input has an expression in the TREE_VALUE and
     a tree list in TREE_PURPOSE which in turn contains a constraint
     name in TREE_VALUE (or NULL_TREE) and a constraint string
     in TREE_PURPOSE.
     CLOBBERS is a list of STRING_CST nodes each naming a hard register
     that is clobbered by this insn.
  
     LABELS is a list of labels, and if LABELS is non-NULL, FALLTHRU_BB
     should be the fallthru basic block of the asm goto.
  
     Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
     Some elements of OUTPUTS may be replaced with trees representing temporary
     values.  The caller should copy those temporary values to the originally
     specified lvalues.
  
     VOL nonzero means the insn is volatile; don't optimize it.  */
  
  static void
  expand_asm_stmt (gasm *stmt)
  {
    class save_input_location
    {
      location_t old;
  
    public:
      explicit save_input_location(location_t where)
      {
        old = input_location;
        input_location = where;
      }
  
      ~save_input_location()
      {
        input_location = old;
      }
    };
  
    location_t locus = gimple_location (stmt);
  
    if (gimple_asm_input_p (stmt))
      {
        const char *s = gimple_asm_string (stmt);
        tree string = build_string (strlen (s), s);
        expand_asm_loc (string, gimple_asm_volatile_p (stmt), locus);
        return;
      }
  
    /* There are some legacy diagnostics in here, and also avoids a
       sixth parameger to targetm.md_asm_adjust.  */
    save_input_location s_i_l(locus);
  
    unsigned noutputs = gimple_asm_noutputs (stmt);
    unsigned ninputs = gimple_asm_ninputs (stmt);
    unsigned nlabels = gimple_asm_nlabels (stmt);
    unsigned i;
  
    /* ??? Diagnose during gimplification?  */
    if (ninputs + noutputs + nlabels > MAX_RECOG_OPERANDS)
      {
        error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS);
        return;
      }
  
    auto_vec<tree, MAX_RECOG_OPERANDS> output_tvec;
    auto_vec<tree, MAX_RECOG_OPERANDS> input_tvec;
    auto_vec<const char *, MAX_RECOG_OPERANDS> constraints;
  
    /* Copy the gimple vectors into new vectors that we can manipulate.  */
  
    output_tvec.safe_grow (noutputs);
    input_tvec.safe_grow (ninputs);
    constraints.safe_grow (noutputs + ninputs);
  
    for (i = 0; i < noutputs; ++i)
      {
        tree t = gimple_asm_output_op (stmt, i);
        output_tvec[i] = TREE_VALUE (t);
        constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
      }
    for (i = 0; i < ninputs; i++)
      {
        tree t = gimple_asm_input_op (stmt, i);
        input_tvec[i] = TREE_VALUE (t);
        constraints[i + noutputs]
  	= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
      }
  
    /* ??? Diagnose during gimplification?  */
    if (! check_operand_nalternatives (constraints))
      return;
  
    /* Count the number of meaningful clobbered registers, ignoring what
       we would ignore later.  */
    auto_vec<rtx> clobber_rvec;
    HARD_REG_SET clobbered_regs;
    CLEAR_HARD_REG_SET (clobbered_regs);
  
    if (unsigned n = gimple_asm_nclobbers (stmt))
      {
        clobber_rvec.reserve (n);
        for (i = 0; i < n; i++)
  	{
  	  tree t = gimple_asm_clobber_op (stmt, i);
            const char *regname = TREE_STRING_POINTER (TREE_VALUE (t));
  	  int nregs, j;
  
  	  j = decode_reg_name_and_count (regname, &nregs);
  	  if (j < 0)
  	    {
  	      if (j == -2)
  		{
  		  /* ??? Diagnose during gimplification?  */
  		  error ("unknown register name %qs in %<asm%>", regname);
  		}
  	      else if (j == -4)
  		{
  		  rtx x = gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode));
  		  clobber_rvec.safe_push (x);
  		}
  	      else
  		{
  		  /* Otherwise we should have -1 == empty string
  		     or -3 == cc, which is not a register.  */
  		  gcc_assert (j == -1 || j == -3);
  		}
  	    }
  	  else
  	    for (int reg = j; reg < j + nregs; reg++)
  	      {
  		/* Clobbering the PIC register is an error.  */
  		if (reg == (int) PIC_OFFSET_TABLE_REGNUM)
  		  {
  		    /* ??? Diagnose during gimplification?  */
  		    error ("PIC register clobbered by %qs in %<asm%>",
  			   regname);
  		    return;
  		  }
  
  	        SET_HARD_REG_BIT (clobbered_regs, reg);
  	        rtx x = gen_rtx_REG (reg_raw_mode[reg], reg);
  		clobber_rvec.safe_push (x);
  	      }
  	}
      }
    unsigned nclobbers = clobber_rvec.length();
  
    /* First pass over inputs and outputs checks validity and sets
       mark_addressable if needed.  */
    /* ??? Diagnose during gimplification?  */
  
    for (i = 0; i < noutputs; ++i)
      {
        tree val = output_tvec[i];
        tree type = TREE_TYPE (val);
        const char *constraint;
        bool is_inout;
        bool allows_reg;
        bool allows_mem;
  
        /* Try to parse the output constraint.  If that fails, there's
  	 no point in going further.  */
        constraint = constraints[i];
        if (!parse_output_constraint (&constraint, i, ninputs, noutputs,
  				    &allows_mem, &allows_reg, &is_inout))
  	return;
  
        if (! allows_reg
  	  && (allows_mem
  	      || is_inout
  	      || (DECL_P (val)
  		  && REG_P (DECL_RTL (val))
  		  && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))))
  	mark_addressable (val);
      }
  
    for (i = 0; i < ninputs; ++i)
      {
        bool allows_reg, allows_mem;
        const char *constraint;
  
        constraint = constraints[i + noutputs];
        if (! parse_input_constraint (&constraint, i, ninputs, noutputs, 0,
  				    constraints.address (),
  				    &allows_mem, &allows_reg))
  	return;
  
        if (! allows_reg && allows_mem)
  	mark_addressable (input_tvec[i]);
      }
  
    /* Second pass evaluates arguments.  */
  
    /* Make sure stack is consistent for asm goto.  */
    if (nlabels > 0)
      do_pending_stack_adjust ();
    int old_generating_concat_p = generating_concat_p;
  
    /* Vector of RTX's of evaluated output operands.  */
    auto_vec<rtx, MAX_RECOG_OPERANDS> output_rvec;
    auto_vec<int, MAX_RECOG_OPERANDS> inout_opnum;
    rtx_insn *after_rtl_seq = NULL, *after_rtl_end = NULL;
  
    output_rvec.safe_grow (noutputs);
  
    for (i = 0; i < noutputs; ++i)
      {
        tree val = output_tvec[i];
        tree type = TREE_TYPE (val);
        bool is_inout, allows_reg, allows_mem, ok;
        rtx op;
  
        ok = parse_output_constraint (&constraints[i], i, ninputs,
  				    noutputs, &allows_mem, &allows_reg,
  				    &is_inout);
        gcc_assert (ok);
  
        /* If an output operand is not a decl or indirect ref and our constraint
  	 allows a register, make a temporary to act as an intermediate.
  	 Make the asm insn write into that, then we will copy it to
  	 the real output operand.  Likewise for promoted variables.  */
  
        generating_concat_p = 0;
  
        if ((TREE_CODE (val) == INDIRECT_REF
  	   && allows_mem)
  	  || (DECL_P (val)
  	      && (allows_mem || REG_P (DECL_RTL (val)))
  	      && ! (REG_P (DECL_RTL (val))
  		    && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
  	  || ! allows_reg
  	  || is_inout)
  	{
  	  op = expand_expr (val, NULL_RTX, VOIDmode,
  			    !allows_reg ? EXPAND_MEMORY : EXPAND_WRITE);
  	  if (MEM_P (op))
  	    op = validize_mem (op);
  
  	  if (! allows_reg && !MEM_P (op))
  	    error ("output number %d not directly addressable", i);
  	  if ((! allows_mem && MEM_P (op))
  	      || GET_CODE (op) == CONCAT)
  	    {
  	      rtx old_op = op;
  	      op = gen_reg_rtx (GET_MODE (op));
  
  	      generating_concat_p = old_generating_concat_p;
  
  	      if (is_inout)
  		emit_move_insn (op, old_op);
  
  	      push_to_sequence2 (after_rtl_seq, after_rtl_end);
  	      emit_move_insn (old_op, op);
  	      after_rtl_seq = get_insns ();
  	      after_rtl_end = get_last_insn ();
  	      end_sequence ();
  	    }
  	}
        else
  	{
  	  op = assign_temp (type, 0, 1);
  	  op = validize_mem (op);
  	  if (!MEM_P (op) && TREE_CODE (val) == SSA_NAME)
  	    set_reg_attrs_for_decl_rtl (SSA_NAME_VAR (val), op);
  
  	  generating_concat_p = old_generating_concat_p;
  
  	  push_to_sequence2 (after_rtl_seq, after_rtl_end);
  	  expand_assignment (val, make_tree (type, op), false);
  	  after_rtl_seq = get_insns ();
  	  after_rtl_end = get_last_insn ();
  	  end_sequence ();
  	}
        output_rvec[i] = op;
  
        if (is_inout)
  	inout_opnum.safe_push (i);
      }
  
    auto_vec<rtx, MAX_RECOG_OPERANDS> input_rvec;
    auto_vec<machine_mode, MAX_RECOG_OPERANDS> input_mode;
  
    input_rvec.safe_grow (ninputs);
    input_mode.safe_grow (ninputs);
  
    generating_concat_p = 0;
  
    for (i = 0; i < ninputs; ++i)
      {
        tree val = input_tvec[i];
        tree type = TREE_TYPE (val);
        bool allows_reg, allows_mem, ok;
        const char *constraint;
        rtx op;
  
        constraint = constraints[i + noutputs];
        ok = parse_input_constraint (&constraint, i, ninputs, noutputs, 0,
  				   constraints.address (),
  				   &allows_mem, &allows_reg);
        gcc_assert (ok);
  
        /* EXPAND_INITIALIZER will not generate code for valid initializer
  	 constants, but will still generate code for other types of operand.
  	 This is the behavior we want for constant constraints.  */
        op = expand_expr (val, NULL_RTX, VOIDmode,
  			allows_reg ? EXPAND_NORMAL
  			: allows_mem ? EXPAND_MEMORY
  			: EXPAND_INITIALIZER);
  
        /* Never pass a CONCAT to an ASM.  */
        if (GET_CODE (op) == CONCAT)
  	op = force_reg (GET_MODE (op), op);
        else if (MEM_P (op))
  	op = validize_mem (op);
  
        if (asm_operand_ok (op, constraint, NULL) <= 0)
  	{
  	  if (allows_reg && TYPE_MODE (type) != BLKmode)
  	    op = force_reg (TYPE_MODE (type), op);
  	  else if (!allows_mem)
  	    warning (0, "asm operand %d probably doesn%'t match constraints",
  		     i + noutputs);
  	  else if (MEM_P (op))
  	    {
  	      /* We won't recognize either volatile memory or memory
  		 with a queued address as available a memory_operand
  		 at this point.  Ignore it: clearly this *is* a memory.  */
  	    }
  	  else
  	    gcc_unreachable ();
  	}
        input_rvec[i] = op;
        input_mode[i] = TYPE_MODE (type);
      }
  
    /* For in-out operands, copy output rtx to input rtx.  */
    unsigned ninout = inout_opnum.length();
    for (i = 0; i < ninout; i++)
      {
        int j = inout_opnum[i];
        rtx o = output_rvec[j];
  
        input_rvec.safe_push (o);
        input_mode.safe_push (GET_MODE (o));
  
        char buffer[16];
        sprintf (buffer, "%d", j);
        constraints.safe_push (ggc_strdup (buffer));
      }
    ninputs += ninout;
  
    /* Sometimes we wish to automatically clobber registers across an asm.
       Case in point is when the i386 backend moved from cc0 to a hard reg --
       maintaining source-level compatibility means automatically clobbering
       the flags register.  */
    rtx_insn *after_md_seq = NULL;
    if (targetm.md_asm_adjust)
      after_md_seq = targetm.md_asm_adjust (output_rvec, input_rvec,
  					  constraints, clobber_rvec,
  					  clobbered_regs);
  
    /* Do not allow the hook to change the output and input count,
       lest it mess up the operand numbering.  */
    gcc_assert (output_rvec.length() == noutputs);
    gcc_assert (input_rvec.length() == ninputs);
    gcc_assert (constraints.length() == noutputs + ninputs);
  
    /* But it certainly can adjust the clobbers.  */
    nclobbers = clobber_rvec.length();
  
    /* Third pass checks for easy conflicts.  */
    /* ??? Why are we doing this on trees instead of rtx.  */
  
    bool clobber_conflict_found = 0;
    for (i = 0; i < noutputs; ++i)
      if (tree_conflicts_with_clobbers_p (output_tvec[i], &clobbered_regs))
  	clobber_conflict_found = 1;
    for (i = 0; i < ninputs - ninout; ++i)
      if (tree_conflicts_with_clobbers_p (input_tvec[i], &clobbered_regs))
  	clobber_conflict_found = 1;
  
    /* Make vectors for the expression-rtx, constraint strings,
       and named operands.  */
  
    rtvec argvec = rtvec_alloc (ninputs);
    rtvec constraintvec = rtvec_alloc (ninputs);
    rtvec labelvec = rtvec_alloc (nlabels);
  
    rtx body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
  				    : GET_MODE (output_rvec[0])),
  				   ggc_strdup (gimple_asm_string (stmt)),
  				   empty_string, 0, argvec, constraintvec,
  				   labelvec, locus);
    MEM_VOLATILE_P (body) = gimple_asm_volatile_p (stmt);
  
    for (i = 0; i < ninputs; ++i)
      {
        ASM_OPERANDS_INPUT (body, i) = input_rvec[i];
        ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
  	= gen_rtx_ASM_INPUT_loc (input_mode[i],
  				 constraints[i + noutputs],
  				 locus);
      }
  
    /* Copy labels to the vector.  */
    rtx_code_label *fallthru_label = NULL;
    if (nlabels > 0)
      {
        basic_block fallthru_bb = NULL;
        edge fallthru = find_fallthru_edge (gimple_bb (stmt)->succs);
        if (fallthru)
  	fallthru_bb = fallthru->dest;
  
        for (i = 0; i < nlabels; ++i)
  	{
  	  tree label = TREE_VALUE (gimple_asm_label_op (stmt, i));
  	  rtx_insn *r;
  	  /* If asm goto has any labels in the fallthru basic block, use
  	     a label that we emit immediately after the asm goto.  Expansion
  	     may insert further instructions into the same basic block after
  	     asm goto and if we don't do this, insertion of instructions on
  	     the fallthru edge might misbehave.  See PR58670.  */
  	  if (fallthru_bb && label_to_block_fn (cfun, label) == fallthru_bb)
  	    {
  	      if (fallthru_label == NULL_RTX)
  	        fallthru_label = gen_label_rtx ();
  	      r = fallthru_label;
  	    }
  	  else
  	    r = label_rtx (label);
  	  ASM_OPERANDS_LABEL (body, i) = gen_rtx_LABEL_REF (Pmode, r);
  	}
      }
  
    /* Now, for each output, construct an rtx
       (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
  			       ARGVEC CONSTRAINTS OPNAMES))
       If there is more than one, put them inside a PARALLEL.  */
  
    if (nlabels > 0 && nclobbers == 0)
      {
        gcc_assert (noutputs == 0);
        emit_jump_insn (body);
      }
    else if (noutputs == 0 && nclobbers == 0)
      {
        /* No output operands: put in a raw ASM_OPERANDS rtx.  */
        emit_insn (body);
      }
    else if (noutputs == 1 && nclobbers == 0)
      {
        ASM_OPERANDS_OUTPUT_CONSTRAINT (body) = constraints[0];
        emit_insn (gen_rtx_SET (output_rvec[0], body));
      }
    else
      {
        rtx obody = body;
        int num = noutputs;
  
        if (num == 0)
  	num = 1;
  
        body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
  
        /* For each output operand, store a SET.  */
        for (i = 0; i < noutputs; ++i)
  	{
  	  rtx src, o = output_rvec[i];
  	  if (i == 0)
  	    {
  	      ASM_OPERANDS_OUTPUT_CONSTRAINT (obody) = constraints[0];
  	      src = obody;
  	    }
  	  else
  	    {
  	      src = gen_rtx_ASM_OPERANDS (GET_MODE (o),
  					  ASM_OPERANDS_TEMPLATE (obody),
  					  constraints[i], i, argvec,
  					  constraintvec, labelvec, locus);
  	      MEM_VOLATILE_P (src) = gimple_asm_volatile_p (stmt);
  	    }
  	  XVECEXP (body, 0, i) = gen_rtx_SET (o, src);
  	}
  
        /* If there are no outputs (but there are some clobbers)
  	 store the bare ASM_OPERANDS into the PARALLEL.  */
        if (i == 0)
  	XVECEXP (body, 0, i++) = obody;
  
        /* Store (clobber REG) for each clobbered register specified.  */
        for (unsigned j = 0; j < nclobbers; ++j)
  	{
  	  rtx clobbered_reg = clobber_rvec[j];
  
  	  /* Do sanity check for overlap between clobbers and respectively
  	     input and outputs that hasn't been handled.  Such overlap
  	     should have been detected and reported above.  */
  	  if (!clobber_conflict_found && REG_P (clobbered_reg))
  	    {
  	      /* We test the old body (obody) contents to avoid
  		 tripping over the under-construction body.  */
  	      for (unsigned k = 0; k < noutputs; ++k)
  		if (reg_overlap_mentioned_p (clobbered_reg, output_rvec[k]))
  		  internal_error ("asm clobber conflict with output operand");
  
  	      for (unsigned k = 0; k < ninputs - ninout; ++k)
  		if (reg_overlap_mentioned_p (clobbered_reg, input_rvec[k]))
  		  internal_error ("asm clobber conflict with input operand");
  	    }
  
  	  XVECEXP (body, 0, i++) = gen_rtx_CLOBBER (VOIDmode, clobbered_reg);
  	}
  
        if (nlabels > 0)
  	emit_jump_insn (body);
        else
  	emit_insn (body);
      }
  
    generating_concat_p = old_generating_concat_p;
  
    if (fallthru_label)
      emit_label (fallthru_label);
  
    if (after_md_seq)
      emit_insn (after_md_seq);
    if (after_rtl_seq)
      emit_insn (after_rtl_seq);
  
    free_temp_slots ();
    crtl->has_asm_statement = 1;
  }
  
  /* Emit code to jump to the address
     specified by the pointer expression EXP.  */
  
  static void
  expand_computed_goto (tree exp)
  {
    rtx x = expand_normal (exp);
  
    do_pending_stack_adjust ();
    emit_indirect_jump (x);
  }
  
  /* Generate RTL code for a `goto' statement with target label LABEL.
     LABEL should be a LABEL_DECL tree node that was or will later be
     defined with `expand_label'.  */
  
  static void
  expand_goto (tree label)
  {
    if (flag_checking)
      {
        /* Check for a nonlocal goto to a containing function.  Should have
  	 gotten translated to __builtin_nonlocal_goto.  */
        tree context = decl_function_context (label);
        gcc_assert (!context || context == current_function_decl);
      }
  
    emit_jump (jump_target_rtx (label));
  }
  
  /* Output a return with no value.  */
  
  static void
  expand_null_return_1 (void)
  {
    clear_pending_stack_adjust ();
    do_pending_stack_adjust ();
    emit_jump (return_label);
  }
  
  /* Generate RTL to return from the current function, with no value.
     (That is, we do not do anything about returning any value.)  */
  
  void
  expand_null_return (void)
  {
    /* If this function was declared to return a value, but we
       didn't, clobber the return registers so that they are not
       propagated live to the rest of the function.  */
    clobber_return_register ();
  
    expand_null_return_1 ();
  }
  
  /* Generate RTL to return from the current function, with value VAL.  */
  
  static void
  expand_value_return (rtx val)
  {
    /* Copy the value to the return location unless it's already there.  */
  
    tree decl = DECL_RESULT (current_function_decl);
    rtx return_reg = DECL_RTL (decl);
    if (return_reg != val)
      {
        tree funtype = TREE_TYPE (current_function_decl);
        tree type = TREE_TYPE (decl);
        int unsignedp = TYPE_UNSIGNED (type);
        machine_mode old_mode = DECL_MODE (decl);
        machine_mode mode;
        if (DECL_BY_REFERENCE (decl))
          mode = promote_function_mode (type, old_mode, &unsignedp, funtype, 2);
        else
          mode = promote_function_mode (type, old_mode, &unsignedp, funtype, 1);
  
        if (mode != old_mode)
  	val = convert_modes (mode, old_mode, val, unsignedp);
  
        if (GET_CODE (return_reg) == PARALLEL)
  	emit_group_load (return_reg, val, type, int_size_in_bytes (type));
        else
  	emit_move_insn (return_reg, val);
      }
  
    expand_null_return_1 ();
  }
  
  /* Generate RTL to evaluate the expression RETVAL and return it
     from the current function.  */
  
  static void
  expand_return (tree retval, tree bounds)
  {
    rtx result_rtl;
    rtx val = 0;
    tree retval_rhs;
    rtx bounds_rtl;
  
    /* If function wants no value, give it none.  */
    if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
      {
        expand_normal (retval);
        expand_null_return ();
        return;
      }
  
    if (retval == error_mark_node)
      {
        /* Treat this like a return of no value from a function that
  	 returns a value.  */
        expand_null_return ();
        return;
      }
    else if ((TREE_CODE (retval) == MODIFY_EXPR
  	    || TREE_CODE (retval) == INIT_EXPR)
  	   && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
      retval_rhs = TREE_OPERAND (retval, 1);
    else
      retval_rhs = retval;
  
    result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
  
    /* Put returned bounds to the right place.  */
    bounds_rtl = DECL_BOUNDS_RTL (DECL_RESULT (current_function_decl));
    if (bounds_rtl)
      {
        rtx addr = NULL;
        rtx bnd = NULL;
  
        if (bounds && bounds != error_mark_node)
  	{
  	  bnd = expand_normal (bounds);
  	  targetm.calls.store_returned_bounds (bounds_rtl, bnd);
  	}
        else if (REG_P (bounds_rtl))
  	{
  	  if (bounds)
  	    bnd = chkp_expand_zero_bounds ();
  	  else
  	    {
  	      addr = expand_normal (build_fold_addr_expr (retval_rhs));
  	      addr = gen_rtx_MEM (Pmode, addr);
  	      bnd = targetm.calls.load_bounds_for_arg (addr, NULL, NULL);
  	    }
  
  	  targetm.calls.store_returned_bounds (bounds_rtl, bnd);
  	}
        else
  	{
  	  int n;
  
  	  gcc_assert (GET_CODE (bounds_rtl) == PARALLEL);
  
  	  if (bounds)
  	    bnd = chkp_expand_zero_bounds ();
  	  else
  	    {
  	      addr = expand_normal (build_fold_addr_expr (retval_rhs));
  	      addr = gen_rtx_MEM (Pmode, addr);
  	    }
  
  	  for (n = 0; n < XVECLEN (bounds_rtl, 0); n++)
  	    {
  	      rtx slot = XEXP (XVECEXP (bounds_rtl, 0, n), 0);
  	      if (!bounds)
  		{
  		  rtx offs = XEXP (XVECEXP (bounds_rtl, 0, n), 1);
  		  rtx from = adjust_address (addr, Pmode, INTVAL (offs));
  		  bnd = targetm.calls.load_bounds_for_arg (from, NULL, NULL);
  		}
  	      targetm.calls.store_returned_bounds (slot, bnd);
  	    }
  	}
      }
    else if (chkp_function_instrumented_p (current_function_decl)
  	   && !BOUNDED_P (retval_rhs)
  	   && chkp_type_has_pointer (TREE_TYPE (retval_rhs))
  	   && TREE_CODE (retval_rhs) != RESULT_DECL)
      {
        rtx addr = expand_normal (build_fold_addr_expr (retval_rhs));
        addr = gen_rtx_MEM (Pmode, addr);
  
        gcc_assert (MEM_P (result_rtl));
  
        chkp_copy_bounds_for_stack_parm (result_rtl, addr, TREE_TYPE (retval_rhs));
      }
  
    /* If we are returning the RESULT_DECL, then the value has already
       been stored into it, so we don't have to do anything special.  */
    if (TREE_CODE (retval_rhs) == RESULT_DECL)
      expand_value_return (result_rtl);
  
    /* If the result is an aggregate that is being returned in one (or more)
       registers, load the registers here.  */
  
    else if (retval_rhs != 0
  	   && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
  	   && REG_P (result_rtl))
      {
        val = copy_blkmode_to_reg (GET_MODE (result_rtl), retval_rhs);
        if (val)
  	{
  	  /* Use the mode of the result value on the return register.  */
  	  PUT_MODE (result_rtl, GET_MODE (val));
  	  expand_value_return (val);
  	}
        else
  	expand_null_return ();
      }
    else if (retval_rhs != 0
  	   && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
  	   && (REG_P (result_rtl)
  	       || (GET_CODE (result_rtl) == PARALLEL)))
      {
        /* Compute the return value into a temporary (usually a pseudo reg).  */
        val
  	= assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)), 0, 1);
        val = expand_expr (retval_rhs, val, GET_MODE (val), EXPAND_NORMAL);
        val = force_not_mem (val);
        expand_value_return (val);
      }
    else
      {
        /* No hard reg used; calculate value into hard return reg.  */
        expand_expr (retval, const0_rtx, VOIDmode, EXPAND_NORMAL);
        expand_value_return (result_rtl);
      }
  }
  
  /* 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 (as_a <glabel *> (stmt)));
        break;
      case GIMPLE_NOP:
      case GIMPLE_PREDICT:
        break;
      case GIMPLE_SWITCH:
        expand_case (as_a <gswitch *> (stmt));
        break;
      case GIMPLE_ASM:
        expand_asm_stmt (as_a <gasm *> (stmt));
        break;
      case GIMPLE_CALL:
        expand_call_stmt (as_a <gcall *> (stmt));
        break;
  
      case GIMPLE_RETURN:
        {
  	tree bnd = gimple_return_retbnd (as_a <greturn *> (stmt));
  	op0 = gimple_return_retval (as_a <greturn *> (stmt));
  
  	if (op0 && op0 != error_mark_node)
  	  {
  	    tree result = DECL_RESULT (current_function_decl);
  
  	    /* Mark we have return statement with missing bounds.  */
  	    if (!bnd
  		&& chkp_function_instrumented_p (cfun->decl)
  		&& !DECL_P (op0))
  	      bnd = error_mark_node;
  
  	    /* 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, bnd);
        }
        break;
  
      case GIMPLE_ASSIGN:
        {
  	gassign *assign_stmt = as_a <gassign *> (stmt);
  	tree lhs = gimple_assign_lhs (assign_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 (assign_stmt);
  	    gcc_assert (get_gimple_rhs_class (gimple_expr_code (stmt))
  			== GIMPLE_SINGLE_RHS);
  	    if (gimple_has_location (stmt) && CAN_HAVE_LOCATION_P (rhs)
  		/* Do not put locations on possibly shared trees.  */
  		&& !is_gimple_min_invariant (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 (
  				   assign_stmt));
  	  }
  	else
  	  {
  	    rtx target, temp;
  	    bool nontemporal = gimple_assign_nontemporal_move_p (assign_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 (assign_stmt);
  	    ops.type = TREE_TYPE (lhs);
  	    switch (get_gimple_rhs_class (ops.code))
  	      {
  		case GIMPLE_TERNARY_RHS:
  		  ops.op2 = gimple_assign_rhs3 (assign_stmt);
  		  /* Fallthru */
  		case GIMPLE_BINARY_RHS:
  		  ops.op1 = gimple_assign_rhs2 (assign_stmt);
  		  /* Fallthru */
  		case GIMPLE_UNARY_RHS:
  		  ops.op0 = gimple_assign_rhs1 (assign_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_SIGN (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_insn *
  expand_gimple_stmt (gimple *stmt)
  {
    location_t saved_location = input_location;
    rtx_insn *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 *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, gcall *stmt, bool *can_fallthru)
  {
    rtx_insn *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_FOR_FN (cfun))
  	    {
  	      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_FOR_FN (cfun), 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 (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 (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 (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 (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 (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 (machine_mode mode, rtx x,
  			      addr_space_t as)
  {
    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 = lowpart_subreg (mode, x, 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, label_ref_label (x));
  	  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;
  }
  
  /* Map from SSA_NAMEs to corresponding DEBUG_EXPR_DECLs created
     by avoid_deep_ter_for_debug.  */
  
  static hash_map<tree, tree> *deep_ter_debug_map;
  
  /* Split too deep TER chains for debug stmts using debug temporaries.  */
  
  static void
  avoid_deep_ter_for_debug (gimple *stmt, int depth)
  {
    use_operand_p use_p;
    ssa_op_iter iter;
    FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE)
      {
        tree use = USE_FROM_PTR (use_p);
        if (TREE_CODE (use) != SSA_NAME || SSA_NAME_IS_DEFAULT_DEF (use))
  	continue;
        gimple *g = get_gimple_for_ssa_name (use);
        if (g == NULL)
  	continue;
        if (depth > 6 && !stmt_ends_bb_p (g))
  	{
  	  if (deep_ter_debug_map == NULL)
  	    deep_ter_debug_map = new hash_map<tree, tree>;
  
  	  tree &vexpr = deep_ter_debug_map->get_or_insert (use);
  	  if (vexpr != NULL)
  	    continue;
  	  vexpr = make_node (DEBUG_EXPR_DECL);
  	  gimple *def_temp = gimple_build_debug_bind (vexpr, use, g);
  	  DECL_ARTIFICIAL (vexpr) = 1;
  	  TREE_TYPE (vexpr) = TREE_TYPE (use);
  	  SET_DECL_MODE (vexpr, TYPE_MODE (TREE_TYPE (use)));
  	  gimple_stmt_iterator gsi = gsi_for_stmt (g);
  	  gsi_insert_after (&gsi, def_temp, GSI_NEW_STMT);
  	  avoid_deep_ter_for_debug (def_temp, 0);
  	}
        else
  	avoid_deep_ter_for_debug (g, depth + 1);
      }
  }
  
  /* 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;
    machine_mode mode = TYPE_MODE (TREE_TYPE (exp));
    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 SAD_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:
        op1 = expand_debug_expr (TREE_OPERAND (exp, 1));
        if (!op1)
  	return NULL_RTX;
        switch (TREE_CODE (exp))
  	{
  	case LSHIFT_EXPR:
  	case RSHIFT_EXPR:
  	case LROTATE_EXPR:
  	case RROTATE_EXPR:
  	case WIDEN_LSHIFT_EXPR:
  	  /* Ensure second operand isn't wider than the first one.  */
  	  inner_mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 1)));
  	  if (SCALAR_INT_MODE_P (inner_mode))
  	    {
  	      machine_mode opmode = mode;
  	      if (VECTOR_MODE_P (mode))
  		opmode = GET_MODE_INNER (mode);
  	      if (SCALAR_INT_MODE_P (opmode)
  		  && (GET_MODE_PRECISION (opmode)
  		      < GET_MODE_PRECISION (inner_mode)))
  		op1 = lowpart_subreg (opmode, op1, inner_mode);
  	    }
  	  break;
  	default:
  	  break;
  	}
        /* 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_comparison:
        unsignedp = TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (exp, 0)));
        goto binary;
  
      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 (!VAR_P (exp)
  	      || 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 mode 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_CONVERT:
        {
  	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 = lowpart_subreg (mode, op0, inner_mode);
  	else if (UNARY_CLASS_P (exp)
  		 ? 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));
  	}
  
        as = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))));
  
        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;
  
        as = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))));
        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:
        {
  	machine_mode mode1;
  	HOST_WIDE_INT bitsize, bitpos;
  	tree offset;
  	int reversep, volatilep = 0;
  	tree tem
  	  = get_inner_reference (exp, &bitsize, &bitpos, &offset, &mode1,
  				 &unsignedp, &reversep, &volatilep);
  	rtx orig_op0;
  
  	if (bitsize == 0)
  	  return NULL;
  
  	orig_op0 = op0 = expand_debug_expr (tem);
  
  	if (!op0)
  	  return NULL;
  
  	if (offset)
  	  {
  	    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 = lowpart_subreg (addrmode, op1, 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))
  	  {
  	    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))
  	      /* If OP0 is a partial mode, then we must truncate, even if it has
  		 the same bitsize as OP1 as GCC's representation of partial modes
  		 is opaque.  */
  	      || (GET_MODE_CLASS (GET_MODE (op0)) == MODE_PARTIAL_INT
  		  && 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);
  	  adj = simplify_gen_unary (NEG, mode,
  				    simplify_gen_binary (MULT, mode, adj, op1),
  				    mode);
  	  return simplify_gen_binary (PLUS, mode, mod, adj);
  	}
  
      case ROUND_DIV_EXPR:
        if (unsignedp)
  	{
  	  rtx div = simplify_gen_binary (UDIV, mode, op0, op1);
  	  rtx mod = simplify_gen_binary (UMOD, mode, op0, op1);
  	  rtx adj = round_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 = round_sdiv_adjust (mode, mod, op1);
  	  return simplify_gen_binary (PLUS, mode, div, adj);
  	}
  
      case ROUND_MOD_EXPR:
        if (unsignedp)
  	{
  	  rtx mod = simplify_gen_binary (UMOD, mode, op0, op1);
  	  rtx adj = round_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 = round_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 LSHIFT_EXPR:
        return simplify_gen_binary (ASHIFT, mode, op0, op1);
  
      case RSHIFT_EXPR:
        if (unsignedp)
  	return simplify_gen_binary (LSHIFTRT, mode, op0, op1);
        else
  	return simplify_gen_binary (ASHIFTRT, mode, op0, op1);
  
      case LROTATE_EXPR:
        return simplify_gen_binary (ROTATE, mode, op0, op1);
  
      case RROTATE_EXPR:
        return simplify_gen_binary (ROTATERT, mode, op0, op1);
  
      case MIN_EXPR:
        return simplify_gen_binary (unsignedp ? UMIN : SMIN, mode, op0, op1);
  
      case MAX_EXPR:
        return simplify_gen_binary (unsignedp ? UMAX : SMAX, mode, op0, op1);
  
      case BIT_AND_EXPR:
      case TRUTH_AND_EXPR:
        return simplify_gen_binary (AND, mode, op0, op1);
  
      case BIT_IOR_EXPR:
      case TRUTH_OR_EXPR:
        return simplify_gen_binary (IOR, mode, op0, op1);
  
      case BIT_XOR_EXPR:
      case TRUTH_XOR_EXPR:
        return simplify_gen_binary (XOR, mode, op0, op1);
  
      case TRUTH_ANDIF_EXPR:
        return gen_rtx_IF_THEN_ELSE (mode, op0, op1, const0_rtx);
  
      case TRUTH_ORIF_EXPR:
        return gen_rtx_IF_THEN_ELSE (mode, op0, const_true_rtx, op1);
  
      case TRUTH_NOT_EXPR:
        return simplify_gen_relational (EQ, mode, inner_mode, op0, const0_rtx);
  
      case LT_EXPR:
        return simplify_gen_relational (unsignedp ? LTU : LT, mode, inner_mode,
  				      op0, op1);
  
      case LE_EXPR:
        return simplify_gen_relational (unsignedp ? LEU : LE, mode, inner_mode,
  				      op0, op1);
  
      case GT_EXPR:
        return simplify_gen_relational (unsignedp ? GTU : GT, mode, inner_mode,
  				      op0, op1);
  
      case GE_EXPR:
        return simplify_gen_relational (unsignedp ? GEU : GE, mode, inner_mode,
  				      op0, op1);
  
      case EQ_EXPR:
        return simplify_gen_relational (EQ, mode, inner_mode, op0, op1);
  
      case NE_EXPR:
        return simplify_gen_relational (NE, mode, inner_mode, op0, op1);
  
      case UNORDERED_EXPR:
        return simplify_gen_relational (UNORDERED, mode, inner_mode, op0, op1);
  
      case ORDERED_EXPR:
        return simplify_gen_relational (ORDERED, mode, inner_mode, op0, op1);
  
      case UNLT_EXPR:
        return simplify_gen_relational (UNLT, mode, inner_mode, op0, op1);
  
      case UNLE_EXPR:
        return simplify_gen_relational (UNLE, mode, inner_mode, op0, op1);
  
      case UNGT_EXPR:
        return simplify_gen_relational (UNGT, mode, inner_mode, op0, op1);
  
      case UNGE_EXPR:
        return simplify_gen_relational (UNGE, mode, inner_mode, op0, op1);
  
      case UNEQ_EXPR:
        return simplify_gen_relational (UNEQ, mode, inner_mode, op0, op1);
  
      case LTGT_EXPR:
        return simplify_gen_relational (LTGT, mode, inner_mode, op0, op1);
  
      case COND_EXPR:
        return gen_rtx_IF_THEN_ELSE (mode, op0, op1, op2);
  
      case COMPLEX_EXPR:
        gcc_assert (COMPLEX_MODE_P (mode));
        if (GET_MODE (op0) == VOIDmode)
  	op0 = gen_rtx_CONST (GET_MODE_INNER (mode), op0);
        if (GET_MODE (op1) == VOIDmode)
  	op1 = gen_rtx_CONST (GET_MODE_INNER (mode), op1);
        return gen_rtx_CONCAT (mode, op0, op1);
  
      case CONJ_EXPR:
        if (GET_CODE (op0) == CONCAT)
  	return gen_rtx_CONCAT (mode, XEXP (op0, 0),
  			       simplify_gen_unary (NEG, GET_MODE_INNER (mode),
  						   XEXP (op0, 1),
  						   GET_MODE_INNER (mode)));
        else
  	{
  	  machine_mode imode = GET_MODE_INNER (mode);
  	  rtx re, im;
  
  	  if (MEM_P (op0))
  	    {
  	      re = adjust_address_nv (op0, imode, 0);
  	      im = adjust_address_nv (op0, imode, GET_MODE_SIZE (imode));
  	    }
  	  else
  	    {
  	      machine_mode ifmode = int_mode_for_mode (mode);
  	      machine_mode ihmode = int_mode_for_mode (imode);
  	      rtx halfsize;
  	      if (ifmode == BLKmode || ihmode == BLKmode)
  		return NULL;
  	      halfsize = GEN_INT (GET_MODE_BITSIZE (ihmode));
  	      re = op0;
  	      if (mode != ifmode)
  		re = gen_rtx_SUBREG (ifmode, re, 0);
  	      re = gen_rtx_ZERO_EXTRACT (ihmode, re, halfsize, const0_rtx);
  	      if (imode != ihmode)
  		re = gen_rtx_SUBREG (imode, re, 0);
  	      im = copy_rtx (op0);
  	      if (mode != ifmode)
  		im = gen_rtx_SUBREG (ifmode, im, 0);
  	      im = gen_rtx_ZERO_EXTRACT (ihmode, im, halfsize, halfsize);
  	      if (imode != ihmode)
  		im = gen_rtx_SUBREG (imode, im, 0);
  	    }
  	  im = gen_rtx_NEG (imode, im);
  	  return gen_rtx_CONCAT (mode, re, im);
  	}
  
      case ADDR_EXPR:
        op0 = expand_debug_expr (TREE_OPERAND (exp, 0));
        if (!op0 || !MEM_P (op0))
  	{
  	  if ((TREE_CODE (TREE_OPERAND (exp, 0)) == VAR_DECL
  	       || TREE_CODE (TREE_OPERAND (exp, 0)) == PARM_DECL
  	       || TREE_CODE (TREE_OPERAND (exp, 0)) == RESULT_DECL)
  	      && (!TREE_ADDRESSABLE (TREE_OPERAND (exp, 0))
  		  || target_for_debug_bind (TREE_OPERAND (exp, 0))))
  	    return gen_rtx_DEBUG_IMPLICIT_PTR (mode, TREE_OPERAND (exp, 0));
  
  	  if (handled_component_p (TREE_OPERAND (exp, 0)))
  	    {
  	      HOST_WIDE_INT bitoffset, bitsize, maxsize;
  	      bool reverse;
  	      tree decl
  		= get_ref_base_and_extent (TREE_OPERAND (exp, 0), &bitoffset,
  					   &bitsize, &maxsize, &reverse);
  	      if ((VAR_P (decl)
  		   || TREE_CODE (decl) == PARM_DECL
  		   || TREE_CODE (decl) == RESULT_DECL)
  		  && (!TREE_ADDRESSABLE (decl)
  		      || target_for_debug_bind (decl))
  		  && (bitoffset % BITS_PER_UNIT) == 0
  		  && bitsize > 0
  		  && bitsize == maxsize)
  		{
  		  rtx base = gen_rtx_DEBUG_IMPLICIT_PTR (mode, decl);
  		  return plus_constant (mode, base, bitoffset / BITS_PER_UNIT);
  		}
  	    }
  
  	  if (TREE_CODE (TREE_OPERAND (exp, 0)) == MEM_REF
  	      && TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
  		 == ADDR_EXPR)
  	    {
  	      op0 = expand_debug_expr (TREE_OPERAND (TREE_OPERAND (exp, 0),
  						     0));
  	      if (op0 != NULL
  		  && (GET_CODE (op0) == DEBUG_IMPLICIT_PTR
  		      || (GET_CODE (op0) == PLUS
  			  && GET_CODE (XEXP (op0, 0)) == DEBUG_IMPLICIT_PTR
  			  && CONST_INT_P (XEXP (op0, 1)))))
  		{
  		  op1 = expand_debug_expr (TREE_OPERAND (TREE_OPERAND (exp, 0),
  							 1));
  		  if (!op1 || !CONST_INT_P (op1))
  		    return NULL;
  
  		  return plus_constant (mode, op0, INTVAL (op1));
  		}
  	    }
  
  	  return NULL;
  	}
  
        as = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (exp)));
        op0 = convert_debug_memory_address (mode, XEXP (op0, 0), as);
  
        return op0;
  
      case VECTOR_CST:
        {
  	unsigned i;
  
  	op0 = gen_rtx_CONCATN
  	  (mode, rtvec_alloc (TYPE_VECTOR_SUBPARTS (TREE_TYPE (exp))));
  
  	for (i = 0; i < VECTOR_CST_NELTS (exp); ++i)
  	  {
  	    op1 = expand_debug_expr (VECTOR_CST_ELT (exp, i));
  	    if (!op1)
  	      return NULL;
  	    XVECEXP (op0, 0, i) = op1;
  	  }
  
  	return op0;
        }
  
      case CONSTRUCTOR:
        if (TREE_CLOBBER_P (exp))
  	return NULL;
        else if (TREE_CODE (TREE_TYPE (exp)) == VECTOR_TYPE)
  	{
  	  unsigned i;
  	  tree val;
  
  	  op0 = gen_rtx_CONCATN
  	    (mode, rtvec_alloc (TYPE_VECTOR_SUBPARTS (TREE_TYPE (exp))));
  
  	  FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), i, val)
  	    {
  	      op1 = expand_debug_expr (val);
  	      if (!op1)
  		return NULL;
  	      XVECEXP (op0, 0, i) = op1;
  	    }
  
  	  if (i < TYPE_VECTOR_SUBPARTS (TREE_TYPE (exp)))
  	    {
  	      op1 = expand_debug_expr
  		(build_zero_cst (TREE_TYPE (TREE_TYPE (exp))));
  
  	      if (!op1)
  		return NULL;
  
  	      for (; i < TYPE_VECTOR_SUBPARTS (TREE_TYPE (exp)); i++)
  		XVECEXP (op0, 0, i) = op1;
  	    }
  
  	  return op0;
  	}
        else
  	goto flag_unsupported;
  
      case CALL_EXPR:
        /* ??? Maybe handle some builtins?  */
        return NULL;
  
      case SSA_NAME:
        {
  	gimple *g = get_gimple_for_ssa_name (exp);
  	if (g)
  	  {
  	    tree t = NULL_TREE;
  	    if (deep_ter_debug_map)
  	      {
  		tree *slot = deep_ter_debug_map->get (exp);
  		if (slot)
  		  t = *slot;
  	      }
  	    if (t == NULL_TREE)
  	      t = gimple_assign_rhs_to_tree (g);
  	    op0 = expand_debug_expr (t);
  	    if (!op0)
  	      return NULL;
  	  }
  	else
  	  {
  	    /* If this is a reference to an incoming value of
  	       parameter that is never used in the code or where the
  	       incoming value is never used in the code, use
  	       PARM_DECL's DECL_RTL if set.  */
  	    if (SSA_NAME_IS_DEFAULT_DEF (exp)
  		&& SSA_NAME_VAR (exp)
  		&& TREE_CODE (SSA_NAME_VAR (exp)) == PARM_DECL
  		&& has_zero_uses (exp))
  	      {
  		op0 = expand_debug_parm_decl (SSA_NAME_VAR (exp));
  		if (op0)
  		  goto adjust_mode;
  		op0 = expand_debug_expr (SSA_NAME_VAR (exp));
  		if (op0)
  		  goto adjust_mode;
  	      }
  
  	    int part = var_to_partition (SA.map, exp);
  
  	    if (part == NO_PARTITION)
  	      return NULL;
  
  	    gcc_assert (part >= 0 && (unsigned)part < SA.map->num_partitions);
  
  	    op0 = copy_rtx (SA.partition_to_pseudo[part]);
  	  }
  	goto adjust_mode;
        }
  
      case ERROR_MARK:
        return NULL;
  
      /* Vector stuff.  For most of the codes we don't have rtl codes.  */
      case REALIGN_LOAD_EXPR:
      case REDUC_MAX_EXPR:
      case REDUC_MIN_EXPR:
      case REDUC_PLUS_EXPR:
      case VEC_COND_EXPR:
      case VEC_PACK_FIX_TRUNC_EXPR:
      case VEC_PACK_SAT_EXPR:
      case VEC_PACK_TRUNC_EXPR:
      case VEC_UNPACK_FLOAT_HI_EXPR:
      case VEC_UNPACK_FLOAT_LO_EXPR:
      case VEC_UNPACK_HI_EXPR:
      case VEC_UNPACK_LO_EXPR:
      case VEC_WIDEN_MULT_HI_EXPR:
      case VEC_WIDEN_MULT_LO_EXPR:
      case VEC_WIDEN_MULT_EVEN_EXPR:
      case VEC_WIDEN_MULT_ODD_EXPR:
      case VEC_WIDEN_LSHIFT_HI_EXPR:
      case VEC_WIDEN_LSHIFT_LO_EXPR:
      case VEC_PERM_EXPR:
        return NULL;
  
      /* Misc codes.  */
      case ADDR_SPACE_CONVERT_EXPR:
      case FIXED_CONVERT_EXPR:
      case OBJ_TYPE_REF:
      case WITH_SIZE_EXPR:
      case BIT_INSERT_EXPR:
        return NULL;
  
      case DOT_PROD_EXPR:
        if (SCALAR_INT_MODE_P (GET_MODE (op0))
  	  && SCALAR_INT_MODE_P (mode))
  	{
  	  op0
  	    = simplify_gen_unary (TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (exp,
  									  0)))
  				  ? ZERO_EXTEND : SIGN_EXTEND, mode, op0,
  				  inner_mode);
  	  op1
  	    = simplify_gen_unary (TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (exp,
  									  1)))
  				  ? ZERO_EXTEND : SIGN_EXTEND, mode, op1,
  				  inner_mode);
  	  op0 = simplify_gen_binary (MULT, mode, op0, op1);
  	  return simplify_gen_binary (PLUS, mode, op0, op2);
  	}
        return NULL;
  
      case WIDEN_MULT_EXPR:
      case WIDEN_MULT_PLUS_EXPR:
      case WIDEN_MULT_MINUS_EXPR:
        if (SCALAR_INT_MODE_P (GET_MODE (op0))
  	  && SCALAR_INT_MODE_P (mode))
  	{
  	  inner_mode = GET_MODE (op0);
  	  if (TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (exp, 0))))
  	    op0 = simplify_gen_unary (ZERO_EXTEND, mode, op0, inner_mode);
  	  else
  	    op0 = simplify_gen_unary (SIGN_EXTEND, mode, op0, inner_mode);
  	  if (TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (exp, 1))))
  	    op1 = simplify_gen_unary (ZERO_EXTEND, mode, op1, inner_mode);
  	  else
  	    op1 = simplify_gen_unary (SIGN_EXTEND, mode, op1, inner_mode);
  	  op0 = simplify_gen_binary (MULT, mode, op0, op1);
  	  if (TREE_CODE (exp) == WIDEN_MULT_EXPR)
  	    return op0;
  	  else if (TREE_CODE (exp) == WIDEN_MULT_PLUS_EXPR)
  	    return simplify_gen_binary (PLUS, mode, op0, op2);
  	  else
  	    return simplify_gen_binary (MINUS, mode, op2, op0);
  	}
        return NULL;
  
      case MULT_HIGHPART_EXPR:
        /* ??? Similar to the above.  */
        return NULL;
  
      case WIDEN_SUM_EXPR:
      case WIDEN_LSHIFT_EXPR:
        if (SCALAR_INT_MODE_P (GET_MODE (op0))
  	  && SCALAR_INT_MODE_P (mode))
  	{
  	  op0
  	    = simplify_gen_unary (TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (exp,
  									  0)))
  				  ? ZERO_EXTEND : SIGN_EXTEND, mode, op0,
  				  inner_mode);
  	  return simplify_gen_binary (TREE_CODE (exp) == WIDEN_LSHIFT_EXPR
  				      ? ASHIFT : PLUS, mode, op0, op1);
  	}
        return NULL;
  
      case FMA_EXPR:
        return simplify_gen_ternary (FMA, mode, inner_mode, op0, op1, op2);
  
      default:
      flag_unsupported:
        if (flag_checking)
  	{
  	  debug_tree (exp);
  	  gcc_unreachable ();
  	}
        return NULL;
      }
  }
  
  /* Return an RTX equivalent to the source bind value of the tree expression
     EXP.  */
  
  static rtx
  expand_debug_source_expr (tree exp)
  {
    rtx op0 = NULL_RTX;
    machine_mode mode = VOIDmode, inner_mode;
  
    switch (TREE_CODE (exp))
      {
      case PARM_DECL:
        {
  	mode = DECL_MODE (exp);
  	op0 = expand_debug_parm_decl (exp);
  	if (op0)
  	   break;
  	/* See if this isn't an argument that has been completely
  	   optimized out.  */
  	if (!DECL_RTL_SET_P (exp)
  	    && !DECL_INCOMING_RTL (exp)
  	    && DECL_ABSTRACT_ORIGIN (current_function_decl))
  	  {
  	    tree aexp = DECL_ORIGIN (exp);
  	    if (DECL_CONTEXT (aexp)
  		== DECL_ABSTRACT_ORIGIN (current_function_decl))
  	      {
  		vec<tree, va_gc> **debug_args;
  		unsigned int ix;
  		tree ddecl;
  		debug_args = decl_debug_args_lookup (current_function_decl);
  		if (debug_args != NULL)
  		  {
  		    for (ix = 0; vec_safe_iterate (*debug_args, ix, &ddecl);
  			 ix += 2)
  		      if (ddecl == aexp)
  			return gen_rtx_DEBUG_PARAMETER_REF (mode, aexp);
  		  }
  	      }
  	  }
  	break;
        }
      default:
        break;
      }
  
    if (op0 == NULL_RTX)
      return NULL_RTX;
  
    inner_mode = GET_MODE (op0);
    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_unreachable ();
    else if (FLOAT_MODE_P (inner_mode))
      {
        if (TYPE_UNSIGNED (TREE_TYPE (exp)))
  	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_BITSIZE (mode) <= GET_MODE_BITSIZE (inner_mode))
      op0 = lowpart_subreg (mode, op0, inner_mode);
    else if (TYPE_UNSIGNED (TREE_TYPE (exp)))
      op0 = simplify_gen_unary (ZERO_EXTEND, mode, op0, inner_mode);
    else
      op0 = simplify_gen_unary (SIGN_EXTEND, mode, op0, inner_mode);
  
    return op0;
  }
  
  /* Ensure INSN_VAR_LOCATION_LOC (insn) doesn't have unbound complexity.
     Allow 4 levels of rtl nesting for most rtl codes, and if we see anything
     deeper than that, create DEBUG_EXPRs and emit DEBUG_INSNs before INSN.  */
  
  static void
  avoid_complex_debug_insns (rtx_insn *insn, rtx *exp_p, int depth)
  {
    rtx exp = *exp_p;
  
    if (exp == NULL_RTX)
      return;
  
    if ((OBJECT_P (exp) && !MEM_P (exp)) || GET_CODE (exp) == CLOBBER)
      return;
  
    if (depth == 4)
      {
        /* Create DEBUG_EXPR (and DEBUG_EXPR_DECL).  */
        rtx dval = make_debug_expr_from_rtl (exp);
  
        /* Emit a debug bind insn before INSN.  */
        rtx bind = gen_rtx_VAR_LOCATION (GET_MODE (exp),
  				       DEBUG_EXPR_TREE_DECL (dval), exp,
  				       VAR_INIT_STATUS_INITIALIZED);
  
        emit_debug_insn_before (bind, insn);
        *exp_p = dval;
        return;
      }
  
    const char *format_ptr = GET_RTX_FORMAT (GET_CODE (exp));
    int i, j;
    for (i = 0; i < GET_RTX_LENGTH (GET_CODE (exp)); i++)
      switch (*format_ptr++)
        {
        case 'e':
  	avoid_complex_debug_insns (insn, &XEXP (exp, i), depth + 1);
  	break;
  
        case 'E':
        case 'V':
  	for (j = 0; j < XVECLEN (exp, i); j++)
  	  avoid_complex_debug_insns (insn, &XVECEXP (exp, i, j), depth + 1);
  	break;
  
        default:
  	break;
        }
  }
  
  /* Expand the _LOCs in debug insns.  We run this after expanding all
     regular insns, so that any variables referenced in the function
     will have their DECL_RTLs set.  */
  
  static void
  expand_debug_locations (void)
  {
    rtx_insn *insn;
    rtx_insn *last = get_last_insn ();
    int save_strict_alias = flag_strict_aliasing;
  
    /* New alias sets while setting up memory attributes cause
       -fcompare-debug failures, even though it doesn't bring about any
       codegen changes.  */
    flag_strict_aliasing = 0;
  
    for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
      if (DEBUG_INSN_P (insn))
        {
  	tree value = (tree)INSN_VAR_LOCATION_LOC (insn);
  	rtx val;
  	rtx_insn *prev_insn, *insn2;
  	machine_mode mode;
  
  	if (value == NULL_TREE)
  	  val = NULL_RTX;
  	else
  	  {
  	    if (INSN_VAR_LOCATION_STATUS (insn)
  		== VAR_INIT_STATUS_UNINITIALIZED)
  	      val = expand_debug_source_expr (value);
  	    /* The avoid_deep_ter_for_debug function inserts
  	       debug bind stmts after SSA_NAME definition, with the
  	       SSA_NAME as the whole bind location.  Disable temporarily
  	       expansion of that SSA_NAME into the DEBUG_EXPR_DECL
  	       being defined in this DEBUG_INSN.  */
  	    else if (deep_ter_debug_map && TREE_CODE (value) == SSA_NAME)
  	      {
  		tree *slot = deep_ter_debug_map->get (value);
  		if (slot)
  		  {
  		    if (*slot == INSN_VAR_LOCATION_DECL (insn))
  		      *slot = NULL_TREE;
  		    else
  		      slot = NULL;
  		  }
  		val = expand_debug_expr (value);
  		if (slot)
  		  *slot = INSN_VAR_LOCATION_DECL (insn);
  	      }
  	    else
  	      val = expand_debug_expr (value);
  	    gcc_assert (last == get_last_insn ());
  	  }
  
  	if (!val)
  	  val = gen_rtx_UNKNOWN_VAR_LOC ();
  	else
  	  {
  	    mode = GET_MODE (INSN_VAR_LOCATION (insn));
  
  	    gcc_assert (mode == GET_MODE (val)
  			|| (GET_MODE (val) == VOIDmode
  			    && (CONST_SCALAR_INT_P (val)
  				|| GET_CODE (val) == CONST_FIXED
  				|| GET_CODE (val) == LABEL_REF)));
  	  }
  
  	INSN_VAR_LOCATION_LOC (insn) = val;
  	prev_insn = PREV_INSN (insn);
  	for (insn2 = insn; insn2 != prev_insn; insn2 = PREV_INSN (insn2))
  	  avoid_complex_debug_insns (insn2, &INSN_VAR_LOCATION_LOC (insn2), 0);
        }
  
    flag_strict_aliasing = save_strict_alias;
  }
  
  /* Performs swapping operands of commutative operations to expand
     the expensive one first.  */
  
  static void
  reorder_operands (basic_block bb)
  {
    unsigned int *lattice;  /* Hold cost of each statement.  */
    unsigned int i = 0, n = 0;
    gimple_stmt_iterator gsi;
    gimple_seq stmts;
    gimple *stmt;
    bool swap;
    tree op0, op1;
    ssa_op_iter iter;
    use_operand_p use_p;
    gimple *def0, *def1;
  
    /* Compute cost of each statement using estimate_num_insns.  */
    stmts = bb_seq (bb);
    for (gsi = gsi_start (stmts); !gsi_end_p (gsi); gsi_next (&gsi))
      {
        stmt = gsi_stmt (gsi);
        if (!is_gimple_debug (stmt))
          gimple_set_uid (stmt, n++);
      }
    lattice = XNEWVEC (unsigned int, n);
    for (gsi = gsi_start (stmts); !gsi_end_p (gsi); gsi_next (&gsi))
      {
        unsigned cost;
        stmt = gsi_stmt (gsi);
        if (is_gimple_debug (stmt))
  	continue;
        cost = estimate_num_insns (stmt, &eni_size_weights);
        lattice[i] = cost;
        FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE)
  	{
  	  tree use = USE_FROM_PTR (use_p);
  	  gimple *def_stmt;
  	  if (TREE_CODE (use) != SSA_NAME)
  	    continue;
  	  def_stmt = get_gimple_for_ssa_name (use);
  	  if (!def_stmt)
  	    continue;
  	  lattice[i] += lattice[gimple_uid (def_stmt)];
  	}
        i++;
        if (!is_gimple_assign (stmt)
  	  || !commutative_tree_code (gimple_assign_rhs_code (stmt)))
  	continue;
        op0 = gimple_op (stmt, 1);
        op1 = gimple_op (stmt, 2);
        if (TREE_CODE (op0) != SSA_NAME
  	  || TREE_CODE (op1) != SSA_NAME)
  	continue;
        /* Swap operands if the second one is more expensive.  */
        def0 = get_gimple_for_ssa_name (op0);
        def1 = get_gimple_for_ssa_name (op1);
        if (!def1)
  	continue;
        swap = false;
        if (!def0 || lattice[gimple_uid (def1)] > lattice[gimple_uid (def0)])
  	swap = true;
        if (swap)
  	{
  	  if (dump_file && (dump_flags & TDF_DETAILS))
  	    {
  	      fprintf (dump_file, "Swap operands in stmt:\n");
  	      print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
  	      fprintf (dump_file, "Cost left opnd=%d, right opnd=%d\n",
  		       def0 ? lattice[gimple_uid (def0)] : 0,
  		       lattice[gimple_uid (def1)]);
  	    }
  	  swap_ssa_operands (stmt, gimple_assign_rhs1_ptr (stmt),
  			     gimple_assign_rhs2_ptr (stmt));
  	}
      }
    XDELETE (lattice);
  }
  
  /* Expand basic block BB from GIMPLE trees to RTL.  */
  
  static basic_block
  expand_gimple_basic_block (basic_block bb, bool disable_tail_calls)
  {
    gimple_stmt_iterator gsi;
    gimple_seq stmts;
    gimple *stmt = NULL;
    rtx_note *note;
    rtx_insn *last;
    edge e;
    edge_iterator ei;
  
    if (dump_file)
      fprintf (dump_file, "\n;; Generating RTL for gimple basic block %d\n",
  	     bb->index);
  
    /* Note that since we are now transitioning from GIMPLE to RTL, we
       cannot use the gsi_*_bb() routines because they expect the basic
       block to be in GIMPLE, instead of RTL.  Therefore, we need to
       access the BB sequence directly.  */
    if (optimize)
      reorder_operands (bb);
    stmts = bb_seq (bb);
    bb->il.gimple.seq = NULL;
    bb->il.gimple.phi_nodes = NULL;
    rtl_profile_for_bb (bb);
    init_rtl_bb_info (bb);
    bb->flags |= BB_RTL;
  
    /* Remove the RETURN_EXPR if we may fall though to the exit
       instead.  */
    gsi = gsi_last (stmts);
    if (!gsi_end_p (gsi)
        && gimple_code (gsi_stmt (gsi)) == GIMPLE_RETURN)
      {
        greturn *ret_stmt = as_a <greturn *> (gsi_stmt (gsi));
  
        gcc_assert (single_succ_p (bb));
        gcc_assert (single_succ (bb) == EXIT_BLOCK_PTR_FOR_FN (cfun));
  
        if (bb->next_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)
  	  && !gimple_return_retval (ret_stmt))
  	{
  	  gsi_remove (&gsi, false);
  	  single_succ_edge (bb)->flags |= EDGE_FALLTHRU;
  	}
      }
  
    gsi = gsi_start (stmts);
    if (!gsi_end_p (gsi))
      {
        stmt = gsi_stmt (gsi);
        if (gimple_code (stmt) != GIMPLE_LABEL)
  	stmt = NULL;
      }
  
    rtx_code_label **elt = lab_rtx_for_bb->get (bb);
  
    if (stmt || elt)
      {
        last = get_last_insn ();
  
        if (stmt)
  	{
  	  expand_gimple_stmt (stmt);
  	  gsi_next (&gsi);
  	}
  
        if (elt)
  	emit_label (*elt);
  
        /* Java emits line number notes in the top of labels.
  	 ??? Make this go away once line number notes are obsoleted.  */
        BB_HEAD (bb) = NEXT_INSN (last);
        if (NOTE_P (BB_HEAD (bb)))
  	BB_HEAD (bb) = NEXT_INSN (BB_HEAD (bb));
        note = emit_note_after (NOTE_INSN_BASIC_BLOCK, BB_HEAD (bb));
  
        maybe_dump_rtl_for_gimple_stmt (stmt, last);
      }
    else
      BB_HEAD (bb) = note = emit_note (NOTE_INSN_BASIC_BLOCK);
  
    NOTE_BASIC_BLOCK (note) = bb;
  
    for (; !gsi_end_p (gsi); gsi_next (&gsi))
      {
        basic_block new_bb;
  
        stmt = gsi_stmt (gsi);
  
        /* If this statement is a non-debug one, and we generate debug
  	 insns, then this one might be the last real use of a TERed
  	 SSA_NAME, but where there are still some debug uses further
  	 down.  Expanding the current SSA name in such further debug
  	 uses by their RHS might lead to wrong debug info, as coalescing
  	 might make the operands of such RHS be placed into the same
  	 pseudo as something else.  Like so:
  	   a_1 = a_0 + 1;   // Assume a_1 is TERed and a_0 is dead
  	   use(a_1);
  	   a_2 = ...
             #DEBUG ... => a_1
  	 As a_0 and a_2 don't overlap in lifetime, assume they are coalesced.
  	 If we now would expand a_1 by it's RHS (a_0 + 1) in the debug use,
  	 the write to a_2 would actually have clobbered the place which
  	 formerly held a_0.
  
  	 So, instead of that, we recognize the situation, and generate
  	 debug temporaries at the last real use of TERed SSA names:
  	   a_1 = a_0 + 1;
             #DEBUG #D1 => a_1
  	   use(a_1);
  	   a_2 = ...
             #DEBUG ... => #D1
  	 */
        if (MAY_HAVE_DEBUG_INSNS
  	  && SA.values
  	  && !is_gimple_debug (stmt))
  	{
  	  ssa_op_iter iter;
  	  tree op;
  	  gimple *def;
  
  	  location_t sloc = curr_insn_location ();
  
  	  /* Look for SSA names that have their last use here (TERed
  	     names always have only one real use).  */
  	  FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE)
  	    if ((def = get_gimple_for_ssa_name (op)))
  	      {
  		imm_use_iterator imm_iter;
  		use_operand_p use_p;
  		bool have_debug_uses = false;
  
  		FOR_EACH_IMM_USE_FAST (use_p, imm_iter, op)
  		  {
  		    if (gimple_debug_bind_p (USE_STMT (use_p)))
  		      {
  			have_debug_uses = true;
  			break;
  		      }
  		  }
  
  		if (have_debug_uses)
  		  {
  		    /* OP is a TERed SSA name, with DEF its defining
  		       statement, and where OP is used in further debug
  		       instructions.  Generate a debug temporary, and
  		       replace all uses of OP in debug insns with that
  		       temporary.  */
  		    gimple *debugstmt;
  		    tree value = gimple_assign_rhs_to_tree (def);
  		    tree vexpr = make_node (DEBUG_EXPR_DECL);
  		    rtx val;
  		    machine_mode mode;
  
  		    set_curr_insn_location (gimple_location (def));
  
  		    DECL_ARTIFICIAL (vexpr) = 1;
  		    TREE_TYPE (vexpr) = TREE_TYPE (value);
  		    if (DECL_P (value))
  		      mode = DECL_MODE (value);
  		    else
  		      mode = TYPE_MODE (TREE_TYPE (value));
  		    SET_DECL_MODE (vexpr, mode);
  
  		    val = gen_rtx_VAR_LOCATION
  			(mode, vexpr, (rtx)value, VAR_INIT_STATUS_INITIALIZED);
  
  		    emit_debug_insn (val);
  
  		    FOR_EACH_IMM_USE_STMT (debugstmt, imm_iter, op)
  		      {
  			if (!gimple_debug_bind_p (debugstmt))
  			  continue;
  
  			FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
  			  SET_USE (use_p, vexpr);
  
  			update_stmt (debugstmt);
  		      }
  		  }
  	      }
  	  set_curr_insn_location (sloc);
  	}
  
        currently_expanding_gimple_stmt = stmt;
  
        /* Expand this statement, then evaluate the resulting RTL and
  	 fixup the CFG accordingly.  */
        if (gimple_code (stmt) == GIMPLE_COND)
  	{
  	  new_bb = expand_gimple_cond (bb, as_a <gcond *> (stmt));
  	  if (new_bb)
  	    return new_bb;
  	}
        else if (gimple_debug_bind_p (stmt))
  	{
  	  location_t sloc = curr_insn_location ();
  	  gimple_stmt_iterator nsi = gsi;
  
  	  for (;;)
  	    {
  	      tree var = gimple_debug_bind_get_var (stmt);
  	      tree value;
  	      rtx val;
  	      machine_mode mode;
  
  	      if (TREE_CODE (var) != DEBUG_EXPR_DECL
  		  && TREE_CODE (var) != LABEL_DECL
  		  && !target_for_debug_bind (var))
  		goto delink_debug_stmt;
  
  	      if (gimple_debug_bind_has_value_p (stmt))
  		value = gimple_debug_bind_get_value (stmt);
  	      else
  		value = NULL_TREE;
  
  	      last = get_last_insn ();
  
  	      set_curr_insn_location (gimple_location (stmt));
  
  	      if (DECL_P (var))
  		mode = DECL_MODE (var);
  	      else
  		mode = TYPE_MODE (TREE_TYPE (var));
  
  	      val = gen_rtx_VAR_LOCATION
  		(mode, var, (rtx)value, VAR_INIT_STATUS_INITIALIZED);
  
  	      emit_debug_insn (val);
  
  	      if (dump_file && (dump_flags & TDF_DETAILS))
  		{
  		  /* We can't dump the insn with a TREE where an RTX
  		     is expected.  */
  		  PAT_VAR_LOCATION_LOC (val) = const0_rtx;
  		  maybe_dump_rtl_for_gimple_stmt (stmt, last);
  		  PAT_VAR_LOCATION_LOC (val) = (rtx)value;
  		}
  
  	    delink_debug_stmt:
  	      /* In order not to generate too many debug temporaries,
  	         we delink all uses of debug statements we already expanded.
  		 Therefore debug statements between definition and real
  		 use of TERed SSA names will continue to use the SSA name,
  		 and not be replaced with debug temps.  */
  	      delink_stmt_imm_use (stmt);
  
  	      gsi = nsi;
  	      gsi_next (&nsi);
  	      if (gsi_end_p (nsi))
  		break;
  	      stmt = gsi_stmt (nsi);
  	      if (!gimple_debug_bind_p (stmt))
  		break;
  	    }
  
  	  set_curr_insn_location (sloc);
  	}
        else if (gimple_debug_source_bind_p (stmt))
  	{
  	  location_t sloc = curr_insn_location ();
  	  tree var = gimple_debug_source_bind_get_var (stmt);
  	  tree value = gimple_debug_source_bind_get_value (stmt);
  	  rtx val;
  	  machine_mode mode;
  
  	  last = get_last_insn ();
  
  	  set_curr_insn_location (gimple_location (stmt));
  
  	  mode = DECL_MODE (var);
  
  	  val = gen_rtx_VAR_LOCATION (mode, var, (rtx)value,
  				      VAR_INIT_STATUS_UNINITIALIZED);
  
  	  emit_debug_insn (val);
  
  	  if (dump_file && (dump_flags & TDF_DETAILS))
  	    {
  	      /* We can't dump the insn with a TREE where an RTX
  		 is expected.  */
  	      PAT_VAR_LOCATION_LOC (val) = const0_rtx;
  	      maybe_dump_rtl_for_gimple_stmt (stmt, last);
  	      PAT_VAR_LOCATION_LOC (val) = (rtx)value;
  	    }
  
  	  set_curr_insn_location (sloc);
  	}
        else
  	{
  	  gcall *call_stmt = dyn_cast <gcall *> (stmt);
  	  if (call_stmt
  	      && gimple_call_tail_p (call_stmt)
  	      && disable_tail_calls)
  	    gimple_call_set_tail (call_stmt, false);
  
  	  if (call_stmt && gimple_call_tail_p (call_stmt))
  	    {
  	      bool can_fallthru;
  	      new_bb = expand_gimple_tailcall (bb, call_stmt, &can_fallthru);
  	      if (new_bb)
  		{
  		  if (can_fallthru)
  		    bb = new_bb;
  		  else
  		    return new_bb;
  		}
  	    }
  	  else
  	    {
  	      def_operand_p def_p;
  	      def_p = SINGLE_SSA_DEF_OPERAND (stmt, SSA_OP_DEF);
  
  	      if (def_p != NULL)
  		{
  		  /* Ignore this stmt if it is in the list of
  		     replaceable expressions.  */
  		  if (SA.values
  		      && bitmap_bit_p (SA.values,
  				       SSA_NAME_VERSION (DEF_FROM_PTR (def_p))))
  		    continue;
  		}
  	      last = expand_gimple_stmt (stmt);
  	      maybe_dump_rtl_for_gimple_stmt (stmt, last);
  	    }
  	}
      }
  
    currently_expanding_gimple_stmt = NULL;
  
    /* Expand implicit goto and convert goto_locus.  */
    FOR_EACH_EDGE (e, ei, bb->succs)
      {
        if (e->goto_locus != UNKNOWN_LOCATION)
  	set_curr_insn_location (e->goto_locus);
        if ((e->flags & EDGE_FALLTHRU) && e->dest != bb->next_bb)
  	{
  	  emit_jump (label_rtx_for_bb (e->dest));
  	  e->flags &= ~EDGE_FALLTHRU;
  	}
      }
  
    /* Expanded RTL can create a jump in the last instruction of block.
       This later might be assumed to be a jump to successor and break edge insertion.
       We need to insert dummy move to prevent this. PR41440. */
    if (single_succ_p (bb)
        && (single_succ_edge (bb)->flags & EDGE_FALLTHRU)
        && (last = get_last_insn ())
        && (JUMP_P (last)
  	  || (DEBUG_INSN_P (last)
  	      && JUMP_P (prev_nondebug_insn (last)))))
      {
        rtx dummy = gen_reg_rtx (SImode);
        emit_insn_after_noloc (gen_move_insn (dummy, dummy), last, NULL);
      }
  
    do_pending_stack_adjust ();
  
    /* Find the block tail.  The last insn in the block is the insn
       before a barrier and/or table jump insn.  */
    last = get_last_insn ();
    if (BARRIER_P (last))
      last = PREV_INSN (last);
    if (JUMP_TABLE_DATA_P (last))
      last = PREV_INSN (PREV_INSN (last));
    BB_END (bb) = last;
  
    update_bb_for_insn (bb);
  
    return bb;
  }
  
  
  /* Create a basic block for initialization code.  */
  
  static basic_block
  construct_init_block (void)
  {
    basic_block init_block, first_block;
    edge e = NULL;
    int flags;
  
    /* Multiple entry points not supported yet.  */
    gcc_assert (EDGE_COUNT (ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs) == 1);
    init_rtl_bb_info (ENTRY_BLOCK_PTR_FOR_FN (cfun));
    init_rtl_bb_info (EXIT_BLOCK_PTR_FOR_FN (cfun));
    ENTRY_BLOCK_PTR_FOR_FN (cfun)->flags |= BB_RTL;
    EXIT_BLOCK_PTR_FOR_FN (cfun)->flags |= BB_RTL;
  
    e = EDGE_SUCC (ENTRY_BLOCK_PTR_FOR_FN (cfun), 0);
  
    /* When entry edge points to first basic block, we don't need jump,
       otherwise we have to jump into proper target.  */
    if (e && e->dest != ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb)
      {
        tree label = gimple_block_label (e->dest);
  
        emit_jump (jump_target_rtx (label));
        flags = 0;
      }
    else
      flags = EDGE_FALLTHRU;
  
    init_block = create_basic_block (NEXT_INSN (get_insns ()),
  				   get_last_insn (),
  				   ENTRY_BLOCK_PTR_FOR_FN (cfun));
    init_block->frequency = ENTRY_BLOCK_PTR_FOR_FN (cfun)->frequency;
    init_block->count = ENTRY_BLOCK_PTR_FOR_FN (cfun)->count;
    add_bb_to_loop (init_block, ENTRY_BLOCK_PTR_FOR_FN (cfun)->loop_father);
    if (e)
      {
        first_block = e->dest;
        redirect_edge_succ (e, init_block);
        e = make_edge (init_block, first_block, flags);
      }
    else
      e = make_edge (init_block, EXIT_BLOCK_PTR_FOR_FN (cfun), EDGE_FALLTHRU);
    e->probability = REG_BR_PROB_BASE;
    e->count = ENTRY_BLOCK_PTR_FOR_FN (cfun)->count;
  
    update_bb_for_insn (init_block);
    return init_block;
  }
  
  /* For each lexical block, set BLOCK_NUMBER to the depth at which it is
     found in the block tree.  */
  
  static void
  set_block_levels (tree block, int level)
  {
    while (block)
      {
        BLOCK_NUMBER (block) = level;
        set_block_levels (BLOCK_SUBBLOCKS (block), level + 1);
        block = BLOCK_CHAIN (block);
      }
  }
  
  /* Create a block containing landing pads and similar stuff.  */
  
  static void
  construct_exit_block (void)
  {
    rtx_insn *head = get_last_insn ();
    rtx_insn *end;
    basic_block exit_block;
    edge e, e2;
    unsigned ix;
    edge_iterator ei;
    basic_block prev_bb = EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb;
    rtx_insn *orig_end = BB_END (prev_bb);
  
    rtl_profile_for_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
  
    /* Make sure the locus is set to the end of the function, so that
       epilogue line numbers and warnings are set properly.  */
    if (LOCATION_LOCUS (cfun->function_end_locus) != UNKNOWN_LOCATION)
      input_location = cfun->function_end_locus;
  
    /* Generate rtl for function exit.  */
    expand_function_end ();
  
    end = get_last_insn ();
    if (head == end)
      return;
    /* While emitting the function end we could move end of the last basic
       block.  */
    BB_END (prev_bb) = orig_end;
    while (NEXT_INSN (head) && NOTE_P (NEXT_INSN (head)))
      head = NEXT_INSN (head);
    /* But make sure exit_block starts with RETURN_LABEL, otherwise the
       bb frequency counting will be confused.  Any instructions before that
       label are emitted for the case where PREV_BB falls through into the
       exit block, so append those instructions to prev_bb in that case.  */
    if (NEXT_INSN (head) != return_label)
      {
        while (NEXT_INSN (head) != return_label)
  	{
  	  if (!NOTE_P (NEXT_INSN (head)))
  	    BB_END (prev_bb) = NEXT_INSN (head);
  	  head = NEXT_INSN (head);
  	}
      }
    exit_block = create_basic_block (NEXT_INSN (head), end, prev_bb);
    exit_block->frequency = EXIT_BLOCK_PTR_FOR_FN (cfun)->frequency;
    exit_block->count = EXIT_BLOCK_PTR_FOR_FN (cfun)->count;
    add_bb_to_loop (exit_block, EXIT_BLOCK_PTR_FOR_FN (cfun)->loop_father);
  
    ix = 0;
    while (ix < EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds))
      {
        e = EDGE_PRED (EXIT_BLOCK_PTR_FOR_FN (cfun), ix);
        if (!(e->flags & EDGE_ABNORMAL))
  	redirect_edge_succ (e, exit_block);
        else
  	ix++;
      }
  
    e = make_edge (exit_block, EXIT_BLOCK_PTR_FOR_FN (cfun), EDGE_FALLTHRU);
    e->probability = REG_BR_PROB_BASE;
    e->count = EXIT_BLOCK_PTR_FOR_FN (cfun)->count;
    FOR_EACH_EDGE (e2, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
      if (e2 != e)
        {
  	e->count -= e2->count;
  	exit_block->count -= e2->count;
  	exit_block->frequency -= EDGE_FREQUENCY (e2);
        }
    if (e->count < 0)
      e->count = 0;
    if (exit_block->count < 0)
      exit_block->count = 0;
    if (exit_block->frequency < 0)
      exit_block->frequency = 0;
    update_bb_for_insn (exit_block);
  }
  
  /* Helper function for discover_nonconstant_array_refs.
     Look for ARRAY_REF nodes with non-constant indexes and mark them
     addressable.  */
  
  static tree
  discover_nonconstant_array_refs_r (tree * tp, int *walk_subtrees,
  				   void *data ATTRIBUTE_UNUSED)
  {
    tree t = *tp;
  
    if (IS_TYPE_OR_DECL_P (t))
      *walk_subtrees = 0;
    else if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
      {
        while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
  	      && is_gimple_min_invariant (TREE_OPERAND (t, 1))
  	      && (!TREE_OPERAND (t, 2)
  		  || is_gimple_min_invariant (TREE_OPERAND (t, 2))))
  	     || (TREE_CODE (t) == COMPONENT_REF
  		 && (!TREE_OPERAND (t,2)
  		     || is_gimple_min_invariant (TREE_OPERAND (t, 2))))
  	     || TREE_CODE (t) == BIT_FIELD_REF
  	     || TREE_CODE (t) == REALPART_EXPR
  	     || TREE_CODE (t) == IMAGPART_EXPR
  	     || TREE_CODE (t) == VIEW_CONVERT_EXPR
  	     || CONVERT_EXPR_P (t))
  	t = TREE_OPERAND (t, 0);
  
        if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
  	{
  	  t = get_base_address (t);
  	  if (t && DECL_P (t)
                && DECL_MODE (t) != BLKmode)
  	    TREE_ADDRESSABLE (t) = 1;
  	}
  
        *walk_subtrees = 0;
      }
  
    return NULL_TREE;
  }
  
  /* RTL expansion is not able to compile array references with variable
     offsets for arrays stored in single register.  Discover such
     expressions and mark variables as addressable to avoid this
     scenario.  */
  
  static void
  discover_nonconstant_array_refs (void)
  {
    basic_block bb;
    gimple_stmt_iterator gsi;
  
    FOR_EACH_BB_FN (bb, cfun)
      for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
        {
  	gimple *stmt = gsi_stmt (gsi);
  	if (!is_gimple_debug (stmt))
  	  walk_gimple_op (stmt, discover_nonconstant_array_refs_r, NULL);
        }
  }
  
  /* This function sets crtl->args.internal_arg_pointer to a virtual
     register if DRAP is needed.  Local register allocator will replace
     virtual_incoming_args_rtx with the virtual register.  */
  
  static void
  expand_stack_alignment (void)
  {
    rtx drap_rtx;
    unsigned int preferred_stack_boundary;
  
    if (! SUPPORTS_STACK_ALIGNMENT)
      return;
  
    if (cfun->calls_alloca
        || cfun->has_nonlocal_label
        || crtl->has_nonlocal_goto)
      crtl->need_drap = true;
  
    /* Call update_stack_boundary here again to update incoming stack
       boundary.  It may set incoming stack alignment to a different
       value after RTL expansion.  TARGET_FUNCTION_OK_FOR_SIBCALL may
       use the minimum incoming stack alignment to check if it is OK
       to perform sibcall optimization since sibcall optimization will
       only align the outgoing stack to incoming stack boundary.  */
    if (targetm.calls.update_stack_boundary)
      targetm.calls.update_stack_boundary ();
  
    /* The incoming stack frame has to be aligned at least at
       parm_stack_boundary.  */
    gcc_assert (crtl->parm_stack_boundary <= INCOMING_STACK_BOUNDARY);
  
    /* Update crtl->stack_alignment_estimated and use it later to align
       stack.  We check PREFERRED_STACK_BOUNDARY if there may be non-call
       exceptions since callgraph doesn't collect incoming stack alignment
       in this case.  */
    if (cfun->can_throw_non_call_exceptions
        && PREFERRED_STACK_BOUNDARY > crtl->preferred_stack_boundary)
      preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
    else
      preferred_stack_boundary = crtl->preferred_stack_boundary;
    if (preferred_stack_boundary > crtl->stack_alignment_estimated)
      crtl->stack_alignment_estimated = preferred_stack_boundary;
    if (preferred_stack_boundary > crtl->stack_alignment_needed)
      crtl->stack_alignment_needed = preferred_stack_boundary;
  
    gcc_assert (crtl->stack_alignment_needed
  	      <= crtl->stack_alignment_estimated);
  
    crtl->stack_realign_needed
      = INCOMING_STACK_BOUNDARY < crtl->stack_alignment_estimated;
    crtl->stack_realign_tried = crtl->stack_realign_needed;
  
    crtl->stack_realign_processed = true;
  
    /* Target has to redefine TARGET_GET_DRAP_RTX to support stack
       alignment.  */
    gcc_assert (targetm.calls.get_drap_rtx != NULL);
    drap_rtx = targetm.calls.get_drap_rtx ();
  
    /* stack_realign_drap and drap_rtx must match.  */
    gcc_assert ((stack_realign_drap != 0) == (drap_rtx != NULL));
  
    /* Do nothing if NULL is returned, which means DRAP is not needed.  */
    if (NULL != drap_rtx)
      {
        crtl->args.internal_arg_pointer = drap_rtx;
  
        /* Call fixup_tail_calls to clean up REG_EQUIV note if DRAP is
           needed. */
        fixup_tail_calls ();
      }
  }
  
  
  static void
  expand_main_function (void)
  {
  #if (defined(INVOKE__main)				\
       || (!defined(HAS_INIT_SECTION)			\
  	 && !defined(INIT_SECTION_ASM_OP)		\
  	 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
    emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
  #endif
  }
  
  
  /* Expand code to initialize the stack_protect_guard.  This is invoked at
     the beginning of a function to be protected.  */
  
  static void
  stack_protect_prologue (void)
  {
    tree guard_decl = targetm.stack_protect_guard ();
    rtx x, y;
  
    x = expand_normal (crtl->stack_protect_guard);
    if (guard_decl)
      y = expand_normal (guard_decl);
    else
      y = const0_rtx;
  
    /* Allow the target to copy from Y to X without leaking Y into a
       register.  */
    if (targetm.have_stack_protect_set ())
      if (rtx_insn *insn = targetm.gen_stack_protect_set (x, y))
        {
  	emit_insn (insn);
  	return;
        }
  
    /* Otherwise do a straight move.  */
    emit_move_insn (x, y);
  }
  
  /* Translate the intermediate representation contained in the CFG
     from GIMPLE trees to RTL.
  
     We do conversion per basic block and preserve/update the tree CFG.
     This implies we have to do some magic as the CFG can simultaneously
     consist of basic blocks containing RTL and GIMPLE trees.  This can
     confuse the CFG hooks, so be careful to not manipulate CFG during
     the expansion.  */
  
  namespace {
  
  const pass_data pass_data_expand =
  {
    RTL_PASS, /* type */
    "expand", /* name */
    OPTGROUP_NONE, /* optinfo_flags */
    TV_EXPAND, /* tv_id */
    ( PROP_ssa | PROP_gimple_leh | PROP_cfg
      | PROP_gimple_lcx
      | PROP_gimple_lvec
      | PROP_gimple_lva), /* properties_required */
    PROP_rtl, /* properties_provided */
    ( PROP_ssa | PROP_trees ), /* properties_destroyed */
    0, /* todo_flags_start */
    0, /* todo_flags_finish */
  };
  
  class pass_expand : public rtl_opt_pass
  {
  public:
    pass_expand (gcc::context *ctxt)
      : rtl_opt_pass (pass_data_expand, ctxt)
    {}
  
    /* opt_pass methods: */
    virtual unsigned int execute (function *);
  
  }; // class pass_expand
  
  unsigned int
  pass_expand::execute (function *fun)
  {
    basic_block bb, init_block;
    edge_iterator ei;
    edge e;
    rtx_insn *var_seq, *var_ret_seq;
    unsigned i;
  
    timevar_push (TV_OUT_OF_SSA);
    rewrite_out_of_ssa (&SA);
    timevar_pop (TV_OUT_OF_SSA);
    SA.partition_to_pseudo = XCNEWVEC (rtx, SA.map->num_partitions);
  
    if (MAY_HAVE_DEBUG_STMTS && flag_tree_ter)
      {
        gimple_stmt_iterator gsi;
        FOR_EACH_BB_FN (bb, cfun)
  	for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
  	  if (gimple_debug_bind_p (gsi_stmt (gsi)))
  	    avoid_deep_ter_for_debug (gsi_stmt (gsi), 0);
      }
  
    /* Make sure all values used by the optimization passes have sane
       defaults.  */
    reg_renumber = 0;
  
    /* Some backends want to know that we are expanding to RTL.  */
    currently_expanding_to_rtl = 1;
    /* Dominators are not kept up-to-date as we may create new basic-blocks.  */
    free_dominance_info (CDI_DOMINATORS);
  
    rtl_profile_for_bb (ENTRY_BLOCK_PTR_FOR_FN (fun));
  
    if (chkp_function_instrumented_p (current_function_decl))
      chkp_reset_rtl_bounds ();
  
    insn_locations_init ();
    if (!DECL_IS_BUILTIN (current_function_decl))
      {
        /* Eventually, all FEs should explicitly set function_start_locus.  */
        if (LOCATION_LOCUS (fun->function_start_locus) == UNKNOWN_LOCATION)
  	set_curr_insn_location
  	  (DECL_SOURCE_LOCATION (current_function_decl));
        else
  	set_curr_insn_location (fun->function_start_locus);
      }
    else
      set_curr_insn_location (UNKNOWN_LOCATION);
    prologue_location = curr_insn_location ();
  
  #ifdef INSN_SCHEDULING
    init_sched_attrs ();
  #endif
  
    /* Make sure first insn is a note even if we don't want linenums.
       This makes sure the first insn will never be deleted.
       Also, final expects a note to appear there.  */
    emit_note (NOTE_INSN_DELETED);
  
    /* Mark arrays indexed with non-constant indices with TREE_ADDRESSABLE.  */
    discover_nonconstant_array_refs ();
  
    targetm.expand_to_rtl_hook ();
    crtl->init_stack_alignment ();
    fun->cfg->max_jumptable_ents = 0;
  
    /* Resovle the function section.  Some targets, like ARM EABI rely on knowledge
       of the function section at exapnsion time to predict distance of calls.  */
    resolve_unique_section (current_function_decl, 0, flag_function_sections);
  
    /* Expand the variables recorded during gimple lowering.  */
    timevar_push (TV_VAR_EXPAND);
    start_sequence ();
  
    var_ret_seq = expand_used_vars ();
  
    var_seq = get_insns ();
    end_sequence ();
    timevar_pop (TV_VAR_EXPAND);
  
    /* Honor stack protection warnings.  */
    if (warn_stack_protect)
      {
        if (fun->calls_alloca)
  	warning (OPT_Wstack_protector,
  		 "stack protector not protecting local variables: "
  		 "variable length buffer");
        if (has_short_buffer && !crtl->stack_protect_guard)
  	warning (OPT_Wstack_protector,
  		 "stack protector not protecting function: "
  		 "all local arrays are less than %d bytes long",
  		 (int) PARAM_VALUE (PARAM_SSP_BUFFER_SIZE));
      }
  
    /* Set up parameters and prepare for return, for the function.  */
    expand_function_start (current_function_decl);
  
    /* If we emitted any instructions for setting up the variables,
       emit them before the FUNCTION_START note.  */
    if (var_seq)
      {
        emit_insn_before (var_seq, parm_birth_insn);
  
        /* In expand_function_end we'll insert the alloca save/restore
  	 before parm_birth_insn.  We've just insertted an alloca call.
  	 Adjust the pointer to match.  */
        parm_birth_insn = var_seq;
      }
  
    /* Now propagate the RTL assignment of each partition to the
       underlying var of each SSA_NAME.  */
    tree name;
  
    FOR_EACH_SSA_NAME (i, name, cfun)
      {
        /* We might have generated new SSA names in
  	 update_alias_info_with_stack_vars.  They will have a NULL
  	 defining statements, and won't be part of the partitioning,
  	 so ignore those.  */
        if (!SSA_NAME_DEF_STMT (name))
  	continue;
  
        adjust_one_expanded_partition_var (name);
      }
  
    /* Clean up RTL of variables that straddle across multiple
       partitions, and check that the rtl of any PARM_DECLs that are not
       cleaned up is that of their default defs.  */
    FOR_EACH_SSA_NAME (i, name, cfun)
      {
        int part;
  
        /* We might have generated new SSA names in
  	 update_alias_info_with_stack_vars.  They will have a NULL
  	 defining statements, and won't be part of the partitioning,
  	 so ignore those.  */
        if (!SSA_NAME_DEF_STMT (name))
  	continue;
        part = var_to_partition (SA.map, name);
        if (part == NO_PARTITION)
  	continue;
  
        /* If this decl was marked as living in multiple places, reset
  	 this now to NULL.  */
        tree var = SSA_NAME_VAR (name);
        if (var && DECL_RTL_IF_SET (var) == pc_rtx)
  	SET_DECL_RTL (var, NULL);
        /* Check that the pseudos chosen by assign_parms are those of
  	 the corresponding default defs.  */
        else if (SSA_NAME_IS_DEFAULT_DEF (name)
  	       && (TREE_CODE (var) == PARM_DECL
  		   || TREE_CODE (var) == RESULT_DECL))
  	{
  	  rtx in = DECL_RTL_IF_SET (var);
  	  gcc_assert (in);
  	  rtx out = SA.partition_to_pseudo[part];
  	  gcc_assert (in == out);
  
  	  /* Now reset VAR's RTL to IN, so that the _EXPR attrs match
  	     those expected by debug backends for each parm and for
  	     the result.  This is particularly important for stabs,
  	     whose register elimination from parm's DECL_RTL may cause
  	     -fcompare-debug differences as SET_DECL_RTL changes reg's
  	     attrs.  So, make sure the RTL already has the parm as the
  	     EXPR, so that it won't change.  */
  	  SET_DECL_RTL (var, NULL_RTX);
  	  if (MEM_P (in))
  	    set_mem_attributes (in, var, true);
  	  SET_DECL_RTL (var, in);
  	}
      }
  
    /* If this function is `main', emit a call to `__main'
       to run global initializers, etc.  */
    if (DECL_NAME (current_function_decl)
        && MAIN_NAME_P (DECL_NAME (current_function_decl))
        && DECL_FILE_SCOPE_P (current_function_decl))
      expand_main_function ();
  
    /* Initialize the stack_protect_guard field.  This must happen after the
       call to __main (if any) so that the external decl is initialized.  */
    if (crtl->stack_protect_guard && targetm.stack_protect_runtime_enabled_p ())
      stack_protect_prologue ();
  
    expand_phi_nodes (&SA);
  
    /* Release any stale SSA redirection data.  */
    redirect_edge_var_map_empty ();
  
    /* Register rtl specific functions for cfg.  */
    rtl_register_cfg_hooks ();
  
    init_block = construct_init_block ();
  
    /* Clear EDGE_EXECUTABLE on the entry edge(s).  It is cleaned from the
       remaining edges later.  */
    FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR_FOR_FN (fun)->succs)
      e->flags &= ~EDGE_EXECUTABLE;
  
    lab_rtx_for_bb = new hash_map<basic_block, rtx_code_label *>;
    FOR_BB_BETWEEN (bb, init_block->next_bb, EXIT_BLOCK_PTR_FOR_FN (fun),
  		  next_bb)
      bb = expand_gimple_basic_block (bb, var_ret_seq != NULL_RTX);
  
    if (MAY_HAVE_DEBUG_INSNS)
      expand_debug_locations ();
  
    if (deep_ter_debug_map)
      {
        delete deep_ter_debug_map;
        deep_ter_debug_map = NULL;
      }
  
    /* Free stuff we no longer need after GIMPLE optimizations.  */
    free_dominance_info (CDI_DOMINATORS);
    free_dominance_info (CDI_POST_DOMINATORS);
    delete_tree_cfg_annotations (fun);
  
    timevar_push (TV_OUT_OF_SSA);
    finish_out_of_ssa (&SA);
    timevar_pop (TV_OUT_OF_SSA);
  
    timevar_push (TV_POST_EXPAND);
    /* We are no longer in SSA form.  */
    fun->gimple_df->in_ssa_p = false;
    loops_state_clear (LOOP_CLOSED_SSA);
  
    /* Expansion is used by optimization passes too, set maybe_hot_insn_p
       conservatively to true until they are all profile aware.  */
    delete lab_rtx_for_bb;
    free_histograms (fun);
  
    construct_exit_block ();
    insn_locations_finalize ();
  
    if (var_ret_seq)
      {
        rtx_insn *after = return_label;
        rtx_insn *next = NEXT_INSN (after);
        if (next && NOTE_INSN_BASIC_BLOCK_P (next))
  	after = next;
        emit_insn_after (var_ret_seq, after);
      }
  
    /* Zap the tree EH table.  */
    set_eh_throw_stmt_table (fun, NULL);
  
    /* We need JUMP_LABEL be set in order to redirect jumps, and hence
       split edges which edge insertions might do.  */
    rebuild_jump_labels (get_insns ());
  
    FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (fun),
  		  EXIT_BLOCK_PTR_FOR_FN (fun), next_bb)
      {
        edge e;
        edge_iterator ei;
        for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
  	{
  	  if (e->insns.r)
  	    {
  	      rebuild_jump_labels_chain (e->insns.r);
  	      /* Put insns after parm birth, but before
  		 NOTE_INSNS_FUNCTION_BEG.  */
  	      if (e->src == ENTRY_BLOCK_PTR_FOR_FN (fun)
  		  && single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (fun)))
  		{
  		  rtx_insn *insns = e->insns.r;
  		  e->insns.r = NULL;
  		  if (NOTE_P (parm_birth_insn)
  		      && NOTE_KIND (parm_birth_insn) == NOTE_INSN_FUNCTION_BEG)
  		    emit_insn_before_noloc (insns, parm_birth_insn, e->dest);
  		  else
  		    emit_insn_after_noloc (insns, parm_birth_insn, e->dest);
  		}
  	      else
  		commit_one_edge_insertion (e);
  	    }
  	  else
  	    ei_next (&ei);
  	}
      }
  
    /* We're done expanding trees to RTL.  */
    currently_expanding_to_rtl = 0;
  
    flush_mark_addressable_queue ();
  
    FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (fun)->next_bb,
  		  EXIT_BLOCK_PTR_FOR_FN (fun), next_bb)
      {
        edge e;
        edge_iterator ei;
        for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
  	{
  	  /* Clear EDGE_EXECUTABLE.  This flag is never used in the backend.  */
  	  e->flags &= ~EDGE_EXECUTABLE;
  
  	  /* At the moment not all abnormal edges match the RTL
  	     representation.  It is safe to remove them here as
  	     find_many_sub_basic_blocks will rediscover them.
  	     In the future we should get this fixed properly.  */
  	  if ((e->flags & EDGE_ABNORMAL)
  	      && !(e->flags & EDGE_SIBCALL))
  	    remove_edge (e);
  	  else
  	    ei_next (&ei);
  	}
      }
  
    auto_sbitmap blocks (last_basic_block_for_fn (fun));
    bitmap_ones (blocks);
    find_many_sub_basic_blocks (blocks);
    purge_all_dead_edges ();
  
    expand_stack_alignment ();
  
    /* Fixup REG_EQUIV notes in the prologue if there are tailcalls in this
       function.  */
    if (crtl->tail_call_emit)
      fixup_tail_calls ();
  
    /* After initial rtl generation, call back to finish generating
       exception support code.  We need to do this before cleaning up
       the CFG as the code does not expect dead landing pads.  */
    if (fun->eh->region_tree != NULL)
      finish_eh_generation ();
  
    /* Remove unreachable blocks, otherwise we cannot compute dominators
       which are needed for loop state verification.  As a side-effect
       this also compacts blocks.
       ???  We cannot remove trivially dead insns here as for example
       the DRAP reg on i?86 is not magically live at this point.
       gcc.c-torture/execute/ipa-sra-2.c execution, -Os -m32 fails otherwise.  */
    cleanup_cfg (CLEANUP_NO_INSN_DEL);
  
    checking_verify_flow_info ();
  
    /* Initialize pseudos allocated for hard registers.  */
    emit_initial_value_sets ();
  
    /* And finally unshare all RTL.  */
    unshare_all_rtl ();
  
    /* There's no need to defer outputting this function any more; we
       know we want to output it.  */
    DECL_DEFER_OUTPUT (current_function_decl) = 0;
  
    /* Now that we're done expanding trees to RTL, we shouldn't have any
       more CONCATs anywhere.  */
    generating_concat_p = 0;
  
    if (dump_file)
      {
        fprintf (dump_file,
  	       "\n\n;;\n;; Full RTL generated for this function:\n;;\n");
        /* And the pass manager will dump RTL for us.  */
      }
  
    /* If we're emitting a nested function, make sure its parent gets
       emitted as well.  Doing otherwise confuses debug info.  */
      {
        tree parent;
        for (parent = DECL_CONTEXT (current_function_decl);
  	   parent != NULL_TREE;
  	   parent = get_containing_scope (parent))
  	if (TREE_CODE (parent) == FUNCTION_DECL)
  	  TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (parent)) = 1;
      }
  
    /* We are now committed to emitting code for this function.  Do any
       preparation, such as emitting abstract debug info for the inline
       before it gets mangled by optimization.  */
    if (cgraph_function_possibly_inlined_p (current_function_decl))
      (*debug_hooks->outlining_inline_function) (current_function_decl);
  
    TREE_ASM_WRITTEN (current_function_decl) = 1;
  
    /* After expanding, the return labels are no longer needed. */
    return_label = NULL;
    naked_return_label = NULL;
  
    /* After expanding, the tm_restart map is no longer needed.  */
    if (fun->gimple_df->tm_restart)
      fun->gimple_df->tm_restart = NULL;
  
    /* Tag the blocks with a depth number so that change_scope can find
       the common parent easily.  */
    set_block_levels (DECL_INITIAL (fun->decl), 0);
    default_rtl_profile ();
  
    timevar_pop (TV_POST_EXPAND);
  
    return 0;
  }
  
  } // anon namespace
  
  rtl_opt_pass *
  make_pass_expand (gcc::context *ctxt)
  {
    return new pass_expand (ctxt);
  }
  