osprey/kg++fe/gnu/expr.c

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/*
 * Copyright 2003, 2004, 2005, 2006 PathScale, Inc.  All Rights Reserved.
 */

/* Convert tree expression to rtl instructions, for GNU compiler.
   Copyright (C) 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   2000, 2001, 2002, 2003 Free Software Foundation, Inc.

This file is part of GCC.

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

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

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.  */

#include "config.h"
#include "system.h"
#include "machmode.h"
#include "real.h"
#include "rtl.h"
#include "tree.h"
#include "flags.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "except.h"
#include "function.h"
#include "insn-config.h"
#include "insn-attr.h"
#ifdef SGI_MONGOOSE
// To get HAVE_tablejump
#include "insn-flags.h"
#endif /* SGI_MONGOOSE */
/* Include expr.h after insn-config.h so we get HAVE_conditional_move.  */
#include "expr.h"
#include "optabs.h"
#include "libfuncs.h"
#include "recog.h"
#include "reload.h"
#include "output.h"
#include "typeclass.h"
#include "toplev.h"
#include "ggc.h"
#include "langhooks.h"
#include "intl.h"
#include "tm_p.h"
#ifdef SGI_MONGOOSE
// To get FUNCTION_ARG_REG_LITTLE_ENDIAN, etc.
#include "defaults.h"
#endif /* SGI_MONGOOSE */

/* Decide whether a function's arguments should be processed
   from first to last or from last to first.

   They should if the stack and args grow in opposite directions, but
   only if we have push insns.  */

#ifdef PUSH_ROUNDING

#ifndef PUSH_ARGS_REVERSED
#if defined (STACK_GROWS_DOWNWARD) != defined (ARGS_GROW_DOWNWARD)
#define PUSH_ARGS_REVERSED  /* If it's last to first.  */
#endif
#endif

#endif

#ifndef STACK_PUSH_CODE
#ifdef STACK_GROWS_DOWNWARD
#define STACK_PUSH_CODE PRE_DEC
#else
#define STACK_PUSH_CODE PRE_INC
#endif
#endif

/* Assume that case vectors are not pc-relative.  */
#ifndef CASE_VECTOR_PC_RELATIVE
#define CASE_VECTOR_PC_RELATIVE 0
#endif

/* Convert defined/undefined to boolean.  */
#ifdef TARGET_MEM_FUNCTIONS
#undef TARGET_MEM_FUNCTIONS
#define TARGET_MEM_FUNCTIONS 1
#else
#define TARGET_MEM_FUNCTIONS 0
#endif


/* If this is nonzero, we do not bother generating VOLATILE
   around volatile memory references, and we are willing to
   output indirect addresses.  If cse is to follow, we reject
   indirect addresses so a useful potential cse is generated;
   if it is used only once, instruction combination will produce
   the same indirect address eventually.  */
int cse_not_expected;

/* Chain of pending expressions for PLACEHOLDER_EXPR to replace.  */
static tree placeholder_list = 0;

/* This structure is used by move_by_pieces to describe the move to
   be performed.  */
struct move_by_pieces
{
  rtx to;
  rtx to_addr;
  int autinc_to;
  int explicit_inc_to;
  rtx from;
  rtx from_addr;
  int autinc_from;
  int explicit_inc_from;
  unsigned HOST_WIDE_INT len;
  HOST_WIDE_INT offset;
  int reverse;
};

/* This structure is used by store_by_pieces to describe the clear to
   be performed.  */

struct store_by_pieces
{
  rtx to;
  rtx to_addr;
  int autinc_to;
  int explicit_inc_to;
  unsigned HOST_WIDE_INT len;
  HOST_WIDE_INT offset;
  rtx (*constfun) PARAMS ((PTR, HOST_WIDE_INT, enum machine_mode));
  PTR constfundata;
  int reverse;
};

static rtx enqueue_insn   PARAMS ((rtx, rtx));
static unsigned HOST_WIDE_INT move_by_pieces_ninsns
        PARAMS ((unsigned HOST_WIDE_INT,
           unsigned int));
static void move_by_pieces_1  PARAMS ((rtx (*) (rtx, ...), enum machine_mode,
           struct move_by_pieces *));
static bool block_move_libcall_safe_for_call_parm PARAMS ((void));
static bool emit_block_move_via_movstr PARAMS ((rtx, rtx, rtx, unsigned));
static rtx emit_block_move_via_libcall PARAMS ((rtx, rtx, rtx));
static tree emit_block_move_libcall_fn PARAMS ((int));
static void emit_block_move_via_loop PARAMS ((rtx, rtx, rtx, unsigned));
static rtx clear_by_pieces_1  PARAMS ((PTR, HOST_WIDE_INT,
           enum machine_mode));
static void clear_by_pieces PARAMS ((rtx, unsigned HOST_WIDE_INT,
           unsigned int));
static void store_by_pieces_1 PARAMS ((struct store_by_pieces *,
           unsigned int));
static void store_by_pieces_2 PARAMS ((rtx (*) (rtx, ...),
           enum machine_mode,
           struct store_by_pieces *));
static bool clear_storage_via_clrstr PARAMS ((rtx, rtx, unsigned));
static rtx clear_storage_via_libcall PARAMS ((rtx, rtx));
static tree clear_storage_libcall_fn PARAMS ((int));
static rtx compress_float_constant PARAMS ((rtx, rtx));
static rtx get_subtarget  PARAMS ((rtx));
static int is_zeros_p         PARAMS ((tree));
static int mostly_zeros_p PARAMS ((tree));
static void store_constructor_field PARAMS ((rtx, unsigned HOST_WIDE_INT,
               HOST_WIDE_INT, enum machine_mode,
               tree, tree, int, int));
static void store_constructor PARAMS ((tree, rtx, int, HOST_WIDE_INT));
static rtx store_field    PARAMS ((rtx, HOST_WIDE_INT,
           HOST_WIDE_INT, enum machine_mode,
           tree, enum machine_mode, int, tree,
           int));
static rtx var_rtx    PARAMS ((tree));
static HOST_WIDE_INT highest_pow2_factor PARAMS ((tree));
static HOST_WIDE_INT highest_pow2_factor_for_type PARAMS ((tree, tree));
static int is_aligning_offset PARAMS ((tree, tree));
static rtx expand_increment PARAMS ((tree, int, int));
static void do_jump_by_parts_greater PARAMS ((tree, int, rtx, rtx));
static void do_jump_by_parts_equality PARAMS ((tree, rtx, rtx));
static void do_compare_and_jump PARAMS ((tree, enum rtx_code, enum rtx_code,
           rtx, rtx));
static rtx do_store_flag  PARAMS ((tree, rtx, enum machine_mode, int));
#ifdef PUSH_ROUNDING
static void emit_single_push_insn PARAMS ((enum machine_mode, rtx, tree));
#endif
static void do_tablejump PARAMS ((rtx, enum machine_mode, rtx, rtx, rtx));
static rtx const_vector_from_tree PARAMS ((tree));

/* Record for each mode whether we can move a register directly to or
   from an object of that mode in memory.  If we can't, we won't try
   to use that mode directly when accessing a field of that mode.  */

static char direct_load[NUM_MACHINE_MODES];
static char direct_store[NUM_MACHINE_MODES];

/* Record for each mode whether we can float-extend from memory.  */

static bool float_extend_from_mem[NUM_MACHINE_MODES][NUM_MACHINE_MODES];

/* If a memory-to-memory move would take MOVE_RATIO or more simple
   move-instruction sequences, we will do a movstr or libcall instead.  */

#ifndef MOVE_RATIO
#if defined (HAVE_movstrqi) || defined (HAVE_movstrhi) || defined (HAVE_movstrsi) || defined (HAVE_movstrdi) || defined (HAVE_movstrti)
#define MOVE_RATIO 2
#else
/* If we are optimizing for space (-Os), cut down the default move ratio.  */
#define MOVE_RATIO (optimize_size ? 3 : 15)
#endif
#endif

/* This macro is used to determine whether move_by_pieces should be called
   to perform a structure copy.  */
#ifndef MOVE_BY_PIECES_P
#define MOVE_BY_PIECES_P(SIZE, ALIGN) \
  (move_by_pieces_ninsns (SIZE, ALIGN) < (unsigned int) MOVE_RATIO)
#endif

/* If a clear memory operation would take CLEAR_RATIO or more simple
   move-instruction sequences, we will do a clrstr or libcall instead.  */

#ifndef CLEAR_RATIO
#if defined (HAVE_clrstrqi) || defined (HAVE_clrstrhi) || defined (HAVE_clrstrsi) || defined (HAVE_clrstrdi) || defined (HAVE_clrstrti)
#define CLEAR_RATIO 2
#else
/* If we are optimizing for space, cut down the default clear ratio.  */
#define CLEAR_RATIO (optimize_size ? 3 : 15)
#endif
#endif

/* This macro is used to determine whether clear_by_pieces should be
   called to clear storage.  */
#ifndef CLEAR_BY_PIECES_P
#define CLEAR_BY_PIECES_P(SIZE, ALIGN) \
  (move_by_pieces_ninsns (SIZE, ALIGN) < (unsigned int) CLEAR_RATIO)
#endif

/* This array records the insn_code of insns to perform block moves.  */
enum insn_code movstr_optab[NUM_MACHINE_MODES];

/* This array records the insn_code of insns to perform block clears.  */
enum insn_code clrstr_optab[NUM_MACHINE_MODES];

/* SLOW_UNALIGNED_ACCESS is nonzero if unaligned accesses are very slow.  */

#ifndef SLOW_UNALIGNED_ACCESS
#define SLOW_UNALIGNED_ACCESS(MODE, ALIGN) STRICT_ALIGNMENT
#endif

/* This is run once per compilation to set up which modes can be used
   directly in memory and to initialize the block move optab.  */

void
init_expr_once ()
{
  rtx insn, pat;
  enum machine_mode mode;
  int num_clobbers;
  rtx mem, mem1;
  rtx reg;

  /* Try indexing by frame ptr and try by stack ptr.
     It is known that on the Convex the stack ptr isn't a valid index.
     With luck, one or the other is valid on any machine.  */
  mem = gen_rtx_MEM (VOIDmode, stack_pointer_rtx);
  mem1 = gen_rtx_MEM (VOIDmode, frame_pointer_rtx);

  /* A scratch register we can modify in-place below to avoid
     useless RTL allocations.  */
  reg = gen_rtx_REG (VOIDmode, -1);

  insn = rtx_alloc (INSN);
  pat = gen_rtx_SET (0, NULL_RTX, NULL_RTX);
  PATTERN (insn) = pat;

  for (mode = VOIDmode; (int) mode < NUM_MACHINE_MODES;
       mode = (enum machine_mode) ((int) mode + 1))
    {
      int regno;

      direct_load[(int) mode] = direct_store[(int) mode] = 0;
      PUT_MODE (mem, mode);
      PUT_MODE (mem1, mode);
      PUT_MODE (reg, mode);

      /* See if there is some register that can be used in this mode and
   directly loaded or stored from memory.  */

      if (mode != VOIDmode && mode != BLKmode)
  for (regno = 0; regno < FIRST_PSEUDO_REGISTER
       && (direct_load[(int) mode] == 0 || direct_store[(int) mode] == 0);
       regno++)
    {
      if (! HARD_REGNO_MODE_OK (regno, mode))
        continue;

      REGNO (reg) = regno;

      SET_SRC (pat) = mem;
      SET_DEST (pat) = reg;
      if (recog (pat, insn, &num_clobbers) >= 0)
        direct_load[(int) mode] = 1;

      SET_SRC (pat) = mem1;
      SET_DEST (pat) = reg;
      if (recog (pat, insn, &num_clobbers) >= 0)
        direct_load[(int) mode] = 1;

      SET_SRC (pat) = reg;
      SET_DEST (pat) = mem;
      if (recog (pat, insn, &num_clobbers) >= 0)
        direct_store[(int) mode] = 1;

      SET_SRC (pat) = reg;
      SET_DEST (pat) = mem1;
      if (recog (pat, insn, &num_clobbers) >= 0)
        direct_store[(int) mode] = 1;
    }
    }

  mem = gen_rtx_MEM (VOIDmode, gen_rtx_raw_REG (Pmode, 10000));

  for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
       mode = GET_MODE_WIDER_MODE (mode))
    {
      enum machine_mode srcmode;
      for (srcmode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); srcmode != mode;
     srcmode = GET_MODE_WIDER_MODE (srcmode))
  {
    enum insn_code ic;

    ic = can_extend_p (mode, srcmode, 0);
    if (ic == CODE_FOR_nothing)
      continue;

    PUT_MODE (mem, srcmode);

    if ((*insn_data[ic].operand[1].predicate) (mem, srcmode))
      float_extend_from_mem[mode][srcmode] = true;
  }
    }
}

/* This is run at the start of compiling a function.  */

void
init_expr ()
{
  cfun->expr = (struct expr_status *) ggc_alloc (sizeof (struct expr_status));

  pending_chain = 0;
  pending_stack_adjust = 0;
  stack_pointer_delta = 0;
  inhibit_defer_pop = 0;
  saveregs_value = 0;
  apply_args_value = 0;
  forced_labels = 0;
}

/* Small sanity check that the queue is empty at the end of a function.  */

void
finish_expr_for_function ()
{
  if (pending_chain)
    abort ();
}

/* Manage the queue of increment instructions to be output
   for POSTINCREMENT_EXPR expressions, etc.  */

/* Queue up to increment (or change) VAR later.  BODY says how:
   BODY should be the same thing you would pass to emit_insn
   to increment right away.  It will go to emit_insn later on.

   The value is a QUEUED expression to be used in place of VAR
   where you want to guarantee the pre-incrementation value of VAR.  */

static rtx
enqueue_insn (var, body)
     rtx var, body;
{
  pending_chain = gen_rtx_QUEUED (GET_MODE (var), var, NULL_RTX, NULL_RTX,
          body, pending_chain);
  return pending_chain;
}

/* Use protect_from_queue to convert a QUEUED expression
   into something that you can put immediately into an instruction.
   If the queued incrementation has not happened yet,
   protect_from_queue returns the variable itself.
   If the incrementation has happened, protect_from_queue returns a temp
   that contains a copy of the old value of the variable.

   Any time an rtx which might possibly be a QUEUED is to be put
   into an instruction, it must be passed through protect_from_queue first.
   QUEUED expressions are not meaningful in instructions.

   Do not pass a value through protect_from_queue and then hold
   on to it for a while before putting it in an instruction!
   If the queue is flushed in between, incorrect code will result.  */

rtx
protect_from_queue (x, modify)
     rtx x;
     int modify;
{
  RTX_CODE code = GET_CODE (x);

#if 0  /* A QUEUED can hang around after the queue is forced out.  */
  /* Shortcut for most common case.  */
  if (pending_chain == 0)
    return x;
#endif

  if (code != QUEUED)
    {
      /* A special hack for read access to (MEM (QUEUED ...)) to facilitate
   use of autoincrement.  Make a copy of the contents of the memory
   location rather than a copy of the address, but not if the value is
   of mode BLKmode.  Don't modify X in place since it might be
   shared.  */
      if (code == MEM && GET_MODE (x) != BLKmode
    && GET_CODE (XEXP (x, 0)) == QUEUED && !modify)
  {
    rtx y = XEXP (x, 0);
    rtx new = replace_equiv_address_nv (x, QUEUED_VAR (y));

    if (QUEUED_INSN (y))
      {
        rtx temp = gen_reg_rtx (GET_MODE (x));

        emit_insn_before (gen_move_insn (temp, new),
        QUEUED_INSN (y));
        return temp;
      }

    /* Copy the address into a pseudo, so that the returned value
       remains correct across calls to emit_queue.  */
    return replace_equiv_address (new, copy_to_reg (XEXP (new, 0)));
  }

      /* Otherwise, recursively protect the subexpressions of all
   the kinds of rtx's that can contain a QUEUED.  */
      if (code == MEM)
  {
    rtx tem = protect_from_queue (XEXP (x, 0), 0);
    if (tem != XEXP (x, 0))
      {
        x = copy_rtx (x);
        XEXP (x, 0) = tem;
      }
  }
      else if (code == PLUS || code == MULT)
  {
    rtx new0 = protect_from_queue (XEXP (x, 0), 0);
    rtx new1 = protect_from_queue (XEXP (x, 1), 0);
    if (new0 != XEXP (x, 0) || new1 != XEXP (x, 1))
      {
        x = copy_rtx (x);
        XEXP (x, 0) = new0;
        XEXP (x, 1) = new1;
      }
  }
      return x;
    }
  /* If the increment has not happened, use the variable itself.  Copy it
     into a new pseudo so that the value remains correct across calls to
     emit_queue.  */
  if (QUEUED_INSN (x) == 0)
    return copy_to_reg (QUEUED_VAR (x));
  /* If the increment has happened and a pre-increment copy exists,
     use that copy.  */
  if (QUEUED_COPY (x) != 0)
    return QUEUED_COPY (x);
  /* The increment has happened but we haven't set up a pre-increment copy.
     Set one up now, and use it.  */
  QUEUED_COPY (x) = gen_reg_rtx (GET_MODE (QUEUED_VAR (x)));
  emit_insn_before (gen_move_insn (QUEUED_COPY (x), QUEUED_VAR (x)),
        QUEUED_INSN (x));
  return QUEUED_COPY (x);
}

/* Return nonzero if X contains a QUEUED expression:
   if it contains anything that will be altered by a queued increment.
   We handle only combinations of MEM, PLUS, MINUS and MULT operators
   since memory addresses generally contain only those.  */

int
queued_subexp_p (x)
     rtx x;
{
  enum rtx_code code = GET_CODE (x);
  switch (code)
    {
    case QUEUED:
      return 1;
    case MEM:
      return queued_subexp_p (XEXP (x, 0));
    case MULT:
    case PLUS:
    case MINUS:
      return (queued_subexp_p (XEXP (x, 0))
        || queued_subexp_p (XEXP (x, 1)));
    default:
      return 0;
    }
}

/* Perform all the pending incrementations.  */

void
emit_queue ()
{
  rtx p;
  while ((p = pending_chain))
    {
      rtx body = QUEUED_BODY (p);

      switch (GET_CODE (body))
  {
  case INSN:
  case JUMP_INSN:
  case CALL_INSN:
  case CODE_LABEL:
  case BARRIER:
  case NOTE:
    QUEUED_INSN (p) = body;
    emit_insn (body);
    break;

#ifdef ENABLE_CHECKING
  case SEQUENCE:
    abort ();
    break;
#endif

  default:
    QUEUED_INSN (p) = emit_insn (body);
    break;
  }

      pending_chain = QUEUED_NEXT (p);
    }
}

/* Copy data from FROM to TO, where the machine modes are not the same.
   Both modes may be integer, or both may be floating.
   UNSIGNEDP should be nonzero if FROM is an unsigned type.
   This causes zero-extension instead of sign-extension.  */

void
convert_move (to, from, unsignedp)
     rtx to, from;
     int unsignedp;
{
  enum machine_mode to_mode = GET_MODE (to);
  enum machine_mode from_mode = GET_MODE (from);
  int to_real = GET_MODE_CLASS (to_mode) == MODE_FLOAT;
  int from_real = GET_MODE_CLASS (from_mode) == MODE_FLOAT;
  enum insn_code code;
  rtx libcall;

  /* rtx code for making an equivalent value.  */
  enum rtx_code equiv_code = (unsignedp < 0 ? UNKNOWN
            : (unsignedp ? ZERO_EXTEND : SIGN_EXTEND));

  to = protect_from_queue (to, 1);
  from = protect_from_queue (from, 0);

  if (to_real != from_real)
    abort ();

  /* If FROM is a SUBREG that indicates that we have already done at least
     the required extension, strip it.  We don't handle such SUBREGs as
     TO here.  */

  if (GET_CODE (from) == SUBREG && SUBREG_PROMOTED_VAR_P (from)
      && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (from)))
    >= GET_MODE_SIZE (to_mode))
      && SUBREG_PROMOTED_UNSIGNED_P (from) == unsignedp)
    from = gen_lowpart (to_mode, from), from_mode = to_mode;

  if (GET_CODE (to) == SUBREG && SUBREG_PROMOTED_VAR_P (to))
    abort ();

  if (to_mode == from_mode
      || (from_mode == VOIDmode && CONSTANT_P (from)))
    {
      emit_move_insn (to, from);
      return;
    }

  if (VECTOR_MODE_P (to_mode) || VECTOR_MODE_P (from_mode))
    {
      if (GET_MODE_BITSIZE (from_mode) != GET_MODE_BITSIZE (to_mode))
  abort ();

      if (VECTOR_MODE_P (to_mode))
  from = simplify_gen_subreg (to_mode, from, GET_MODE (from), 0);
      else
  to = simplify_gen_subreg (from_mode, to, GET_MODE (to), 0);

      emit_move_insn (to, from);
      return;
    }

  if (to_real != from_real)
    abort ();

  if (to_real)
    {
      rtx value, insns;

      if (GET_MODE_BITSIZE (from_mode) < GET_MODE_BITSIZE (to_mode))
  {
    /* Try converting directly if the insn is supported.  */
    if ((code = can_extend_p (to_mode, from_mode, 0))
        != CODE_FOR_nothing)
      {
        emit_unop_insn (code, to, from, UNKNOWN);
        return;
      }
  }

#ifdef HAVE_trunchfqf2
      if (HAVE_trunchfqf2 && from_mode == HFmode && to_mode == QFmode)
  {
    emit_unop_insn (CODE_FOR_trunchfqf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_trunctqfqf2
      if (HAVE_trunctqfqf2 && from_mode == TQFmode && to_mode == QFmode)
  {
    emit_unop_insn (CODE_FOR_trunctqfqf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_truncsfqf2
      if (HAVE_truncsfqf2 && from_mode == SFmode && to_mode == QFmode)
  {
    emit_unop_insn (CODE_FOR_truncsfqf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_truncdfqf2
      if (HAVE_truncdfqf2 && from_mode == DFmode && to_mode == QFmode)
  {
    emit_unop_insn (CODE_FOR_truncdfqf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_truncxfqf2
      if (HAVE_truncxfqf2 && from_mode == XFmode && to_mode == QFmode)
  {
    emit_unop_insn (CODE_FOR_truncxfqf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_trunctfqf2
      if (HAVE_trunctfqf2 && from_mode == TFmode && to_mode == QFmode)
  {
    emit_unop_insn (CODE_FOR_trunctfqf2, to, from, UNKNOWN);
    return;
  }
#endif

#ifdef HAVE_trunctqfhf2
      if (HAVE_trunctqfhf2 && from_mode == TQFmode && to_mode == HFmode)
  {
    emit_unop_insn (CODE_FOR_trunctqfhf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_truncsfhf2
      if (HAVE_truncsfhf2 && from_mode == SFmode && to_mode == HFmode)
  {
    emit_unop_insn (CODE_FOR_truncsfhf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_truncdfhf2
      if (HAVE_truncdfhf2 && from_mode == DFmode && to_mode == HFmode)
  {
    emit_unop_insn (CODE_FOR_truncdfhf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_truncxfhf2
      if (HAVE_truncxfhf2 && from_mode == XFmode && to_mode == HFmode)
  {
    emit_unop_insn (CODE_FOR_truncxfhf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_trunctfhf2
      if (HAVE_trunctfhf2 && from_mode == TFmode && to_mode == HFmode)
  {
    emit_unop_insn (CODE_FOR_trunctfhf2, to, from, UNKNOWN);
    return;
  }
#endif

#ifdef HAVE_truncsftqf2
      if (HAVE_truncsftqf2 && from_mode == SFmode && to_mode == TQFmode)
  {
    emit_unop_insn (CODE_FOR_truncsftqf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_truncdftqf2
      if (HAVE_truncdftqf2 && from_mode == DFmode && to_mode == TQFmode)
  {
    emit_unop_insn (CODE_FOR_truncdftqf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_truncxftqf2
      if (HAVE_truncxftqf2 && from_mode == XFmode && to_mode == TQFmode)
  {
    emit_unop_insn (CODE_FOR_truncxftqf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_trunctftqf2
      if (HAVE_trunctftqf2 && from_mode == TFmode && to_mode == TQFmode)
  {
    emit_unop_insn (CODE_FOR_trunctftqf2, to, from, UNKNOWN);
    return;
  }
#endif

#ifdef HAVE_truncdfsf2
      if (HAVE_truncdfsf2 && from_mode == DFmode && to_mode == SFmode)
  {
    emit_unop_insn (CODE_FOR_truncdfsf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_truncxfsf2
      if (HAVE_truncxfsf2 && from_mode == XFmode && to_mode == SFmode)
  {
    emit_unop_insn (CODE_FOR_truncxfsf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_trunctfsf2
      if (HAVE_trunctfsf2 && from_mode == TFmode && to_mode == SFmode)
  {
    emit_unop_insn (CODE_FOR_trunctfsf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_truncxfdf2
      if (HAVE_truncxfdf2 && from_mode == XFmode && to_mode == DFmode)
  {
    emit_unop_insn (CODE_FOR_truncxfdf2, to, from, UNKNOWN);
    return;
  }
#endif
#ifdef HAVE_trunctfdf2
      if (HAVE_trunctfdf2 && from_mode == TFmode && to_mode == DFmode)
  {
    emit_unop_insn (CODE_FOR_trunctfdf2, to, from, UNKNOWN);
    return;
  }
#endif

      libcall = (rtx) 0;
      switch (from_mode)
  {
  case SFmode:
    switch (to_mode)
      {
      case DFmode:
        libcall = extendsfdf2_libfunc;
        break;

      case XFmode:
        libcall = extendsfxf2_libfunc;
        break;

      case TFmode:
        libcall = extendsftf2_libfunc;
        break;

      default:
        break;
      }
    break;

  case DFmode:
    switch (to_mode)
      {
      case SFmode:
        libcall = truncdfsf2_libfunc;
        break;

      case XFmode:
        libcall = extenddfxf2_libfunc;
        break;

      case TFmode:
        libcall = extenddftf2_libfunc;
        break;

      default:
        break;
      }
    break;

  case XFmode:
    switch (to_mode)
      {
      case SFmode:
        libcall = truncxfsf2_libfunc;
        break;

      case DFmode:
        libcall = truncxfdf2_libfunc;
        break;

      default:
        break;
      }
    break;

  case TFmode:
    switch (to_mode)
      {
      case SFmode:
        libcall = trunctfsf2_libfunc;
        break;

      case DFmode:
        libcall = trunctfdf2_libfunc;
        break;

      default:
        break;
      }
    break;

  default:
    break;
  }

      if (libcall == (rtx) 0)
  /* This conversion is not implemented yet.  */
  abort ();

      start_sequence ();
      value = emit_library_call_value (libcall, NULL_RTX, LCT_CONST, to_mode,
               1, from, from_mode);
      insns = get_insns ();
      end_sequence ();
      emit_libcall_block (insns, to, value, gen_rtx_FLOAT_TRUNCATE (to_mode,
                    from));
      return;
    }

  /* Now both modes are integers.  */

  /* Handle expanding beyond a word.  */
  if (GET_MODE_BITSIZE (from_mode) < GET_MODE_BITSIZE (to_mode)
      && GET_MODE_BITSIZE (to_mode) > BITS_PER_WORD)
    {
      rtx insns;
      rtx lowpart;
      rtx fill_value;
      rtx lowfrom;
      int i;
      enum machine_mode lowpart_mode;
      int nwords = CEIL (GET_MODE_SIZE (to_mode), UNITS_PER_WORD);

      /* Try converting directly if the insn is supported.  */
      if ((code = can_extend_p (to_mode, from_mode, unsignedp))
    != CODE_FOR_nothing)
  {
    /* If FROM is a SUBREG, put it into a register.  Do this
       so that we always generate the same set of insns for
       better cse'ing; if an intermediate assignment occurred,
       we won't be doing the operation directly on the SUBREG.  */
    if (optimize > 0 && GET_CODE (from) == SUBREG)
      from = force_reg (from_mode, from);
    emit_unop_insn (code, to, from, equiv_code);
    return;
  }
      /* Next, try converting via full word.  */
      else if (GET_MODE_BITSIZE (from_mode) < BITS_PER_WORD
         && ((code = can_extend_p (to_mode, word_mode, unsignedp))
       != CODE_FOR_nothing))
  {
    if (GET_CODE (to) == REG)
      emit_insn (gen_rtx_CLOBBER (VOIDmode, to));
    convert_move (gen_lowpart (word_mode, to), from, unsignedp);
    emit_unop_insn (code, to,
        gen_lowpart (word_mode, to), equiv_code);
    return;
  }

      /* No special multiword conversion insn; do it by hand.  */
      start_sequence ();

      /* Since we will turn this into a no conflict block, we must ensure
   that the source does not overlap the target.  */

      if (reg_overlap_mentioned_p (to, from))
  from = force_reg (from_mode, from);

      /* Get a copy of FROM widened to a word, if necessary.  */
      if (GET_MODE_BITSIZE (from_mode) < BITS_PER_WORD)
  lowpart_mode = word_mode;
      else
  lowpart_mode = from_mode;

      lowfrom = convert_to_mode (lowpart_mode, from, unsignedp);

      lowpart = gen_lowpart (lowpart_mode, to);
      emit_move_insn (lowpart, lowfrom);

      /* Compute the value to put in each remaining word.  */
      if (unsignedp)
  fill_value = const0_rtx;
      else
  {
#ifdef HAVE_slt
    if (HAVE_slt
        && insn_data[(int) CODE_FOR_slt].operand[0].mode == word_mode
        && STORE_FLAG_VALUE == -1)
      {
        emit_cmp_insn (lowfrom, const0_rtx, NE, NULL_RTX,
           lowpart_mode, 0);
        fill_value = gen_reg_rtx (word_mode);
        emit_insn (gen_slt (fill_value));
      }
    else
#endif
      {
        fill_value
    = expand_shift (RSHIFT_EXPR, lowpart_mode, lowfrom,
        size_int (GET_MODE_BITSIZE (lowpart_mode) - 1),
        NULL_RTX, 0);
        fill_value = convert_to_mode (word_mode, fill_value, 1);
      }
  }

      /* Fill the remaining words.  */
      for (i = GET_MODE_SIZE (lowpart_mode) / UNITS_PER_WORD; i < nwords; i++)
  {
    int index = (WORDS_BIG_ENDIAN ? nwords - i - 1 : i);
    rtx subword = operand_subword (to, index, 1, to_mode);

    if (subword == 0)
      abort ();

    if (fill_value != subword)
      emit_move_insn (subword, fill_value);
  }

      insns = get_insns ();
      end_sequence ();

      emit_no_conflict_block (insns, to, from, NULL_RTX,
            gen_rtx_fmt_e (equiv_code, to_mode, copy_rtx (from)));
      return;
    }

  /* Truncating multi-word to a word or less.  */
  if (GET_MODE_BITSIZE (from_mode) > BITS_PER_WORD
      && GET_MODE_BITSIZE (to_mode) <= BITS_PER_WORD)
    {
      if (!((GET_CODE (from) == MEM
       && ! MEM_VOLATILE_P (from)
       && direct_load[(int) to_mode]
       && ! mode_dependent_address_p (XEXP (from, 0)))
      || GET_CODE (from) == REG
      || GET_CODE (from) == SUBREG))
  from = force_reg (from_mode, from);
      convert_move (to, gen_lowpart (word_mode, from), 0);
      return;
    }

  /* Handle pointer conversion.  */     /* SPEE 900220.  */
  if (to_mode == PQImode)
    {
      if (from_mode != QImode)
  from = convert_to_mode (QImode, from, unsignedp);

#ifdef HAVE_truncqipqi2
      if (HAVE_truncqipqi2)
  {
    emit_unop_insn (CODE_FOR_truncqipqi2, to, from, UNKNOWN);
    return;
  }
#endif /* HAVE_truncqipqi2 */
      abort ();
    }

  if (from_mode == PQImode)
    {
      if (to_mode != QImode)
  {
    from = convert_to_mode (QImode, from, unsignedp);
    from_mode = QImode;
  }
      else
  {
#ifdef HAVE_extendpqiqi2
    if (HAVE_extendpqiqi2)
      {
        emit_unop_insn (CODE_FOR_extendpqiqi2, to, from, UNKNOWN);
        return;
      }
#endif /* HAVE_extendpqiqi2 */
    abort ();
  }
    }

  if (to_mode == PSImode)
    {
      if (from_mode != SImode)
  from = convert_to_mode (SImode, from, unsignedp);

#ifdef HAVE_truncsipsi2
      if (HAVE_truncsipsi2)
  {
    emit_unop_insn (CODE_FOR_truncsipsi2, to, from, UNKNOWN);
    return;
  }
#endif /* HAVE_truncsipsi2 */
      abort ();
    }

  if (from_mode == PSImode)
    {
      if (to_mode != SImode)
  {
    from = convert_to_mode (SImode, from, unsignedp);
    from_mode = SImode;
  }
      else
  {
#ifdef HAVE_extendpsisi2
    if (! unsignedp && HAVE_extendpsisi2)
      {
        emit_unop_insn (CODE_FOR_extendpsisi2, to, from, UNKNOWN);
        return;
      }
#endif /* HAVE_extendpsisi2 */
#ifdef HAVE_zero_extendpsisi2
    if (unsignedp && HAVE_zero_extendpsisi2)
      {
        emit_unop_insn (CODE_FOR_zero_extendpsisi2, to, from, UNKNOWN);
        return;
      }
#endif /* HAVE_zero_extendpsisi2 */
    abort ();
  }
    }

  if (to_mode == PDImode)
    {
      if (from_mode != DImode)
  from = convert_to_mode (DImode, from, unsignedp);

#ifdef HAVE_truncdipdi2
      if (HAVE_truncdipdi2)
  {
    emit_unop_insn (CODE_FOR_truncdipdi2, to, from, UNKNOWN);
    return;
  }
#endif /* HAVE_truncdipdi2 */
      abort ();
    }

  if (from_mode == PDImode)
    {
      if (to_mode != DImode)
  {
    from = convert_to_mode (DImode, from, unsignedp);
    from_mode = DImode;
  }
      else
  {
#ifdef HAVE_extendpdidi2
    if (HAVE_extendpdidi2)
      {
        emit_unop_insn (CODE_FOR_extendpdidi2, to, from, UNKNOWN);
        return;
      }
#endif /* HAVE_extendpdidi2 */
    abort ();
  }
    }

  /* Now follow all the conversions between integers
     no more than a word long.  */

  /* For truncation, usually we can just refer to FROM in a narrower mode.  */
  if (GET_MODE_BITSIZE (to_mode) < GET_MODE_BITSIZE (from_mode)
      && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (to_mode),
        GET_MODE_BITSIZE (from_mode)))
    {
      if (!((GET_CODE (from) == MEM
       && ! MEM_VOLATILE_P (from)
       && direct_load[(int) to_mode]
       && ! mode_dependent_address_p (XEXP (from, 0)))
      || GET_CODE (from) == REG
      || GET_CODE (from) == SUBREG))
  from = force_reg (from_mode, from);
      if (GET_CODE (from) == REG && REGNO (from) < FIRST_PSEUDO_REGISTER
    && ! HARD_REGNO_MODE_OK (REGNO (from), to_mode))
  from = copy_to_reg (from);
      emit_move_insn (to, gen_lowpart (to_mode, from));
      return;
    }

  /* Handle extension.  */
  if (GET_MODE_BITSIZE (to_mode) > GET_MODE_BITSIZE (from_mode))
    {
      /* Convert directly if that works.  */
      if ((code = can_extend_p (to_mode, from_mode, unsignedp))
    != CODE_FOR_nothing)
  {
    if (flag_force_mem)
      from = force_not_mem (from);

    emit_unop_insn (code, to, from, equiv_code);
    return;
  }
      else
  {
    enum machine_mode intermediate;
    rtx tmp;
    tree shift_amount;

    /* Search for a mode to convert via.  */
    for (intermediate = from_mode; intermediate != VOIDmode;
         intermediate = GET_MODE_WIDER_MODE (intermediate))
      if (((can_extend_p (to_mode, intermediate, unsignedp)
      != CODE_FOR_nothing)
     || (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (intermediate)
         && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (to_mode),
                 GET_MODE_BITSIZE (intermediate))))
    && (can_extend_p (intermediate, from_mode, unsignedp)
        != CODE_FOR_nothing))
        {
    convert_move (to, convert_to_mode (intermediate, from,
               unsignedp), unsignedp);
    return;
        }

    /* No suitable intermediate mode.
       Generate what we need with shifts.  */
    shift_amount = build_int_2 (GET_MODE_BITSIZE (to_mode)
              - GET_MODE_BITSIZE (from_mode), 0);
    from = gen_lowpart (to_mode, force_reg (from_mode, from));
    tmp = expand_shift (LSHIFT_EXPR, to_mode, from, shift_amount,
            to, unsignedp);
    tmp = expand_shift (RSHIFT_EXPR, to_mode, tmp, shift_amount,
            to, unsignedp);
    if (tmp != to)
      emit_move_insn (to, tmp);
    return;
  }
    }

  /* Support special truncate insns for certain modes.  */

  if (from_mode == DImode && to_mode == SImode)
    {
#ifdef HAVE_truncdisi2
      if (HAVE_truncdisi2)
  {
    emit_unop_insn (CODE_FOR_truncdisi2, to, from, UNKNOWN);
    return;
  }
#endif
      convert_move (to, force_reg (from_mode, from), unsignedp);
      return;
    }

  if (from_mode == DImode && to_mode == HImode)
    {
#ifdef HAVE_truncdihi2
      if (HAVE_truncdihi2)
  {
    emit_unop_insn (CODE_FOR_truncdihi2, to, from, UNKNOWN);
    return;
  }
#endif
      convert_move (to, force_reg (from_mode, from), unsignedp);
      return;
    }

  if (from_mode == DImode && to_mode == QImode)
    {
#ifdef HAVE_truncdiqi2
      if (HAVE_truncdiqi2)
  {
    emit_unop_insn (CODE_FOR_truncdiqi2, to, from, UNKNOWN);
    return;
  }
#endif
      convert_move (to, force_reg (from_mode, from), unsignedp);
      return;
    }

  if (from_mode == SImode && to_mode == HImode)
    {
#ifdef HAVE_truncsihi2
      if (HAVE_truncsihi2)
  {
    emit_unop_insn (CODE_FOR_truncsihi2, to, from, UNKNOWN);
    return;
  }
#endif
      convert_move (to, force_reg (from_mode, from), unsignedp);
      return;
    }

  if (from_mode == SImode && to_mode == QImode)
    {
#ifdef HAVE_truncsiqi2
      if (HAVE_truncsiqi2)
  {
    emit_unop_insn (CODE_FOR_truncsiqi2, to, from, UNKNOWN);
    return;
  }
#endif
      convert_move (to, force_reg (from_mode, from), unsignedp);
      return;
    }

  if (from_mode == HImode && to_mode == QImode)
    {
#ifdef HAVE_trunchiqi2
      if (HAVE_trunchiqi2)
  {
    emit_unop_insn (CODE_FOR_trunchiqi2, to, from, UNKNOWN);
    return;
  }
#endif
      convert_move (to, force_reg (from_mode, from), unsignedp);
      return;
    }

  if (from_mode == TImode && to_mode == DImode)
    {
#ifdef HAVE_trunctidi2
      if (HAVE_trunctidi2)
  {
    emit_unop_insn (CODE_FOR_trunctidi2, to, from, UNKNOWN);
    return;
  }
#endif
      convert_move (to, force_reg (from_mode, from), unsignedp);
      return;
    }

  if (from_mode == TImode && to_mode == SImode)
    {
#ifdef HAVE_trunctisi2
      if (HAVE_trunctisi2)
  {
    emit_unop_insn (CODE_FOR_trunctisi2, to, from, UNKNOWN);
    return;
  }
#endif
      convert_move (to, force_reg (from_mode, from), unsignedp);
      return;
    }

  if (from_mode == TImode && to_mode == HImode)
    {
#ifdef HAVE_trunctihi2
      if (HAVE_trunctihi2)
  {
    emit_unop_insn (CODE_FOR_trunctihi2, to, from, UNKNOWN);
    return;
  }
#endif
      convert_move (to, force_reg (from_mode, from), unsignedp);
      return;
    }

  if (from_mode == TImode && to_mode == QImode)
    {
#ifdef HAVE_trunctiqi2
      if (HAVE_trunctiqi2)
  {
    emit_unop_insn (CODE_FOR_trunctiqi2, to, from, UNKNOWN);
    return;
  }
#endif
      convert_move (to, force_reg (from_mode, from), unsignedp);
      return;
    }

  /* Handle truncation of volatile memrefs, and so on;
     the things that couldn't be truncated directly,
     and for which there was no special instruction.  */
  if (GET_MODE_BITSIZE (to_mode) < GET_MODE_BITSIZE (from_mode))
    {
      rtx temp = force_reg (to_mode, gen_lowpart (to_mode, from));
      emit_move_insn (to, temp);
      return;
    }

  /* Mode combination is not recognized.  */
  abort ();
}

/* Return an rtx for a value that would result
   from converting X to mode MODE.
   Both X and MODE may be floating, or both integer.
   UNSIGNEDP is nonzero if X is an unsigned value.
   This can be done by referring to a part of X in place
   or by copying to a new temporary with conversion.

   This function *must not* call protect_from_queue
   except when putting X into an insn (in which case convert_move does it).  */

rtx
convert_to_mode (mode, x, unsignedp)
     enum machine_mode mode;
     rtx x;
     int unsignedp;
{
  return convert_modes (mode, VOIDmode, x, unsignedp);
}

/* Return an rtx for a value that would result
   from converting X from mode OLDMODE to mode MODE.
   Both modes may be floating, or both integer.
   UNSIGNEDP is nonzero if X is an unsigned value.

   This can be done by referring to a part of X in place
   or by copying to a new temporary with conversion.

   You can give VOIDmode for OLDMODE, if you are sure X has a nonvoid mode.

   This function *must not* call protect_from_queue
   except when putting X into an insn (in which case convert_move does it).  */

rtx
convert_modes (mode, oldmode, x, unsignedp)
     enum machine_mode mode, oldmode;
     rtx x;
     int unsignedp;
{
  rtx temp;

  /* If FROM is a SUBREG that indicates that we have already done at least
     the required extension, strip it.  */

  if (GET_CODE (x) == SUBREG && SUBREG_PROMOTED_VAR_P (x)
      && GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))) >= GET_MODE_SIZE (mode)
      && SUBREG_PROMOTED_UNSIGNED_P (x) == unsignedp)
    x = gen_lowpart (mode, x);

  if (GET_MODE (x) != VOIDmode)
    oldmode = GET_MODE (x);

  if (mode == oldmode)
    return x;

  /* There is one case that we must handle specially: If we are converting
     a CONST_INT into a mode whose size is twice HOST_BITS_PER_WIDE_INT and
     we are to interpret the constant as unsigned, gen_lowpart will do
     the wrong if the constant appears negative.  What we want to do is
     make the high-order word of the constant zero, not all ones.  */

  if (unsignedp && GET_MODE_CLASS (mode) == MODE_INT
      && GET_MODE_BITSIZE (mode) == 2 * HOST_BITS_PER_WIDE_INT
      && GET_CODE (x) == CONST_INT && INTVAL (x) < 0)
    {
      HOST_WIDE_INT val = INTVAL (x);

      if (oldmode != VOIDmode
    && HOST_BITS_PER_WIDE_INT > GET_MODE_BITSIZE (oldmode))
  {
    int width = GET_MODE_BITSIZE (oldmode);

    /* We need to zero extend VAL.  */
    val &= ((HOST_WIDE_INT) 1 << width) - 1;
  }

      return immed_double_const (val, (HOST_WIDE_INT) 0, mode);
    }

  /* We can do this with a gen_lowpart if both desired and current modes
     are integer, and this is either a constant integer, a register, or a
     non-volatile MEM.  Except for the constant case where MODE is no
     wider than HOST_BITS_PER_WIDE_INT, we must be narrowing the operand.  */

  if ((GET_CODE (x) == CONST_INT
       && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT)
      || (GET_MODE_CLASS (mode) == MODE_INT
    && GET_MODE_CLASS (oldmode) == MODE_INT
    && (GET_CODE (x) == CONST_DOUBLE
        || (GET_MODE_SIZE (mode) <= GET_MODE_SIZE (oldmode)
      && ((GET_CODE (x) == MEM && ! MEM_VOLATILE_P (x)
           && direct_load[(int) mode])
          || (GET_CODE (x) == REG
        && (! HARD_REGISTER_P (x)
            || HARD_REGNO_MODE_OK (REGNO (x), mode))
        && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode),
                GET_MODE_BITSIZE (GET_MODE (x)))))))))
    {
      /* ?? If we don't know OLDMODE, we have to assume here that
   X does not need sign- or zero-extension.   This may not be
   the case, but it's the best we can do.  */
      if (GET_CODE (x) == CONST_INT && oldmode != VOIDmode
    && GET_MODE_SIZE (mode) > GET_MODE_SIZE (oldmode))
  {
    HOST_WIDE_INT val = INTVAL (x);
    int width = GET_MODE_BITSIZE (oldmode);

    /* We must sign or zero-extend in this case.  Start by
       zero-extending, then sign extend if we need to.  */
    val &= ((HOST_WIDE_INT) 1 << width) - 1;
    if (! unsignedp
        && (val & ((HOST_WIDE_INT) 1 << (width - 1))))
      val |= (HOST_WIDE_INT) (-1) << width;

    return gen_int_mode (val, mode);
  }

      return gen_lowpart (mode, x);
    }

  /* Converting from integer constant into mode is always equivalent to an
     subreg operation.  */
  if (VECTOR_MODE_P (mode) && GET_MODE (x) == VOIDmode)
    {
      if (GET_MODE_BITSIZE (mode) != GET_MODE_BITSIZE (oldmode))
  abort ();
      return simplify_gen_subreg (mode, x, oldmode, 0);
    }

  temp = gen_reg_rtx (mode);
  convert_move (temp, x, unsignedp);
  return temp;
}

/* This macro is used to determine what the largest unit size that
   move_by_pieces can use is.  */

/* MOVE_MAX_PIECES is the number of bytes at a time which we can
   move efficiently, as opposed to  MOVE_MAX which is the maximum
   number of bytes we can move with a single instruction.  */

#ifndef MOVE_MAX_PIECES
#define MOVE_MAX_PIECES   MOVE_MAX
#endif

/* STORE_MAX_PIECES is the number of bytes at a time that we can
   store efficiently.  Due to internal GCC limitations, this is
   MOVE_MAX_PIECES limited by the number of bytes GCC can represent
   for an immediate constant.  */

#define STORE_MAX_PIECES  MIN (MOVE_MAX_PIECES, 2 * sizeof (HOST_WIDE_INT))

/* Determine whether the LEN bytes can be moved by using several move
   instructions.  Return nonzero if a call to move_by_pieces should
   succeed.  */

int
can_move_by_pieces (len, align)
     unsigned HOST_WIDE_INT len;
     unsigned int align;
{
  return MOVE_BY_PIECES_P (len, align);
}

/* Generate several move instructions to copy LEN bytes from block FROM to
   block TO.  (These are MEM rtx's with BLKmode).  The caller must pass FROM
   and TO through protect_from_queue before calling.

   If PUSH_ROUNDING is defined and TO is NULL, emit_single_push_insn is
   used to push FROM to the stack.

   ALIGN is maximum alignment we can assume.

   If ENDP is 0 return to, if ENDP is 1 return memory at the end ala
   mempcpy, and if ENDP is 2 return memory the end minus one byte ala
   stpcpy.  */

rtx
move_by_pieces (to, from, len, align, endp)
     rtx to, from;
     unsigned HOST_WIDE_INT len;
     unsigned int align;
     int endp;
{
  struct move_by_pieces data;
  rtx to_addr, from_addr = XEXP (from, 0);
  unsigned int max_size = MOVE_MAX_PIECES + 1;
  enum machine_mode mode = VOIDmode, tmode;
  enum insn_code icode;

  data.offset = 0;
  data.from_addr = from_addr;
  if (to)
    {
      to_addr = XEXP (to, 0);
      data.to = to;
      data.autinc_to
  = (GET_CODE (to_addr) == PRE_INC || GET_CODE (to_addr) == PRE_DEC
     || GET_CODE (to_addr) == POST_INC || GET_CODE (to_addr) == POST_DEC);
      data.reverse
  = (GET_CODE (to_addr) == PRE_DEC || GET_CODE (to_addr) == POST_DEC);
    }
  else
    {
      to_addr = NULL_RTX;
      data.to = NULL_RTX;
      data.autinc_to = 1;
#ifdef STACK_GROWS_DOWNWARD
      data.reverse = 1;
#else
      data.reverse = 0;
#endif
    }
  data.to_addr = to_addr;
  data.from = from;
  data.autinc_from
    = (GET_CODE (from_addr) == PRE_INC || GET_CODE (from_addr) == PRE_DEC
       || GET_CODE (from_addr) == POST_INC
       || GET_CODE (from_addr) == POST_DEC);

  data.explicit_inc_from = 0;
  data.explicit_inc_to = 0;
  if (data.reverse) data.offset = len;
  data.len = len;

  /* If copying requires more than two move insns,
     copy addresses to registers (to make displacements shorter)
     and use post-increment if available.  */
  if (!(data.autinc_from && data.autinc_to)
      && move_by_pieces_ninsns (len, align) > 2)
    {
      /* Find the mode of the largest move...  */
      for (tmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
     tmode != VOIDmode; tmode = GET_MODE_WIDER_MODE (tmode))
  if (GET_MODE_SIZE (tmode) < max_size)
    mode = tmode;

      if (USE_LOAD_PRE_DECREMENT (mode) && data.reverse && ! data.autinc_from)
  {
    data.from_addr = copy_addr_to_reg (plus_constant (from_addr, len));
    data.autinc_from = 1;
    data.explicit_inc_from = -1;
  }
      if (USE_LOAD_POST_INCREMENT (mode) && ! data.autinc_from)
  {
    data.from_addr = copy_addr_to_reg (from_addr);
    data.autinc_from = 1;
    data.explicit_inc_from = 1;
  }
      if (!data.autinc_from && CONSTANT_P (from_addr))
  data.from_addr = copy_addr_to_reg (from_addr);
      if (USE_STORE_PRE_DECREMENT (mode) && data.reverse && ! data.autinc_to)
  {
    data.to_addr = copy_addr_to_reg (plus_constant (to_addr, len));
    data.autinc_to = 1;
    data.explicit_inc_to = -1;
  }
      if (USE_STORE_POST_INCREMENT (mode) && ! data.reverse && ! data.autinc_to)
  {
    data.to_addr = copy_addr_to_reg (to_addr);
    data.autinc_to = 1;
    data.explicit_inc_to = 1;
  }
      if (!data.autinc_to && CONSTANT_P (to_addr))
  data.to_addr = copy_addr_to_reg (to_addr);
    }

  if (! SLOW_UNALIGNED_ACCESS (word_mode, align)
      || align > MOVE_MAX * BITS_PER_UNIT || align >= BIGGEST_ALIGNMENT)
    align = MOVE_MAX * BITS_PER_UNIT;

  /* First move what we can in the largest integer mode, then go to
     successively smaller modes.  */

  while (max_size > 1)
    {
      for (tmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
     tmode != VOIDmode; tmode = GET_MODE_WIDER_MODE (tmode))
  if (GET_MODE_SIZE (tmode) < max_size)
    mode = tmode;

      if (mode == VOIDmode)
  break;

      icode = mov_optab->handlers[(int) mode].insn_code;
      if (icode != CODE_FOR_nothing && align >= GET_MODE_ALIGNMENT (mode))
  move_by_pieces_1 (GEN_FCN (icode), mode, &data);

      max_size = GET_MODE_SIZE (mode);
    }

  /* The code above should have handled everything.  */
  if (data.len > 0)
    abort ();

  if (endp)
    {
      rtx to1;

      if (data.reverse)
  abort ();
      if (data.autinc_to)
  {
    if (endp == 2)
      {
        if (HAVE_POST_INCREMENT && data.explicit_inc_to > 0)
    emit_insn (gen_add2_insn (data.to_addr, constm1_rtx));
        else
    data.to_addr = copy_addr_to_reg (plus_constant (data.to_addr,
                -1));
      }
    to1 = adjust_automodify_address (data.to, QImode, data.to_addr,
             data.offset);
  }
      else
  {
    if (endp == 2)
      --data.offset;
    to1 = adjust_address (data.to, QImode, data.offset);
  }
      return to1;
    }
  else
    return data.to;
}

/* Return number of insns required to move L bytes by pieces.
   ALIGN (in bits) is maximum alignment we can assume.  */

static unsigned HOST_WIDE_INT
move_by_pieces_ninsns (l, align)
     unsigned HOST_WIDE_INT l;
     unsigned int align;
{
  unsigned HOST_WIDE_INT n_insns = 0;
  unsigned HOST_WIDE_INT max_size = MOVE_MAX + 1;

  if (! SLOW_UNALIGNED_ACCESS (word_mode, align)
      || align > MOVE_MAX * BITS_PER_UNIT || align >= BIGGEST_ALIGNMENT)
    align = MOVE_MAX * BITS_PER_UNIT;

  while (max_size > 1)
    {
      enum machine_mode mode = VOIDmode, tmode;
      enum insn_code icode;

      for (tmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
     tmode != VOIDmode; tmode = GET_MODE_WIDER_MODE (tmode))
  if (GET_MODE_SIZE (tmode) < max_size)
    mode = tmode;

      if (mode == VOIDmode)
  break;

      icode = mov_optab->handlers[(int) mode].insn_code;
      if (icode != CODE_FOR_nothing && align >= GET_MODE_ALIGNMENT (mode))
  n_insns += l / GET_MODE_SIZE (mode), l %= GET_MODE_SIZE (mode);

      max_size = GET_MODE_SIZE (mode);
    }

  if (l)
    abort ();
  return n_insns;
}

/* Subroutine of move_by_pieces.  Move as many bytes as appropriate
   with move instructions for mode MODE.  GENFUN is the gen_... function
   to make a move insn for that mode.  DATA has all the other info.  */

static void
move_by_pieces_1 (genfun, mode, data)
     rtx (*genfun) PARAMS ((rtx, ...));
     enum machine_mode mode;
     struct move_by_pieces *data;
{
  unsigned int size = GET_MODE_SIZE (mode);
  rtx to1 = NULL_RTX, from1;

  while (data->len >= size)
    {
      if (data->reverse)
  data->offset -= size;

      if (data->to)
  {
    if (data->autinc_to)
      to1 = adjust_automodify_address (data->to, mode, data->to_addr,
               data->offset);
    else
      to1 = adjust_address (data->to, mode, data->offset);
  }

      if (data->autinc_from)
  from1 = adjust_automodify_address (data->from, mode, data->from_addr,
             data->offset);
      else
  from1 = adjust_address (data->from, mode, data->offset);

      if (HAVE_PRE_DECREMENT && data->explicit_inc_to < 0)
  emit_insn (gen_add2_insn (data->to_addr,
          GEN_INT (-(HOST_WIDE_INT)size)));
      if (HAVE_PRE_DECREMENT && data->explicit_inc_from < 0)
  emit_insn (gen_add2_insn (data->from_addr,
          GEN_INT (-(HOST_WIDE_INT)size)));

      if (data->to)
  emit_insn ((*genfun) (to1, from1));
      else
  {
#ifdef PUSH_ROUNDING
    emit_single_push_insn (mode, from1, NULL);
#else
    abort ();
#endif
  }

      if (HAVE_POST_INCREMENT && data->explicit_inc_to > 0)
  emit_insn (gen_add2_insn (data->to_addr, GEN_INT (size)));
      if (HAVE_POST_INCREMENT && data->explicit_inc_from > 0)
  emit_insn (gen_add2_insn (data->from_addr, GEN_INT (size)));

      if (! data->reverse)
  data->offset += size;

      data->len -= size;
    }
}

/* Emit code to move a block Y to a block X.  This may be done with
   string-move instructions, with multiple scalar move instructions,
   or with a library call.

   Both X and Y must be MEM rtx's (perhaps inside VOLATILE) with mode BLKmode.
   SIZE is an rtx that says how long they are.
   ALIGN is the maximum alignment we can assume they have.
   METHOD describes what kind of copy this is, and what mechanisms may be used.

   Return the address of the new block, if memcpy is called and returns it,
   0 otherwise.  */

rtx
emit_block_move (x, y, size, method)
     rtx x, y, size;
     enum block_op_methods method;
{
  bool may_use_call;
  rtx retval = 0;
  unsigned int align;

  switch (method)
    {
    case BLOCK_OP_NORMAL:
      may_use_call = true;
      break;

    case BLOCK_OP_CALL_PARM:
      may_use_call = block_move_libcall_safe_for_call_parm ();

      /* Make inhibit_defer_pop nonzero around the library call
   to force it to pop the arguments right away.  */
      NO_DEFER_POP;
      break;

    case BLOCK_OP_NO_LIBCALL:
      may_use_call = false;
      break;

    default:
      abort ();
    }

  align = MIN (MEM_ALIGN (x), MEM_ALIGN (y));

  if (GET_MODE (x) != BLKmode)
    abort ();
  if (GET_MODE (y) != BLKmode)
    abort ();

  x = protect_from_queue (x, 1);
  y = protect_from_queue (y, 0);
  size = protect_from_queue (size, 0);

  if (GET_CODE (x) != MEM)
    abort ();
  if (GET_CODE (y) != MEM)
    abort ();
  if (size == 0)
    abort ();

  /* Set MEM_SIZE as appropriate for this block copy.  The main place this
     can be incorrect is coming from __builtin_memcpy.  */
  if (GET_CODE (size) == CONST_INT)
    {
      x = shallow_copy_rtx (x);
      y = shallow_copy_rtx (y);
      set_mem_size (x, size);
      set_mem_size (y, size);
    }

  if (size == const0_rtx)
    ;
  else if (GET_CODE (size) == CONST_INT
     && MOVE_BY_PIECES_P (INTVAL (size), align))
    move_by_pieces (x, y, INTVAL (size), align, 0);
  else if (emit_block_move_via_movstr (x, y, size, align))
    ;
  else if (may_use_call)
    retval = emit_block_move_via_libcall (x, y, size);
  else
    emit_block_move_via_loop (x, y, size, align);

  if (method == BLOCK_OP_CALL_PARM)
    OK_DEFER_POP;

  return retval;
}

/* A subroutine of emit_block_move.  Returns true if calling the 
   block move libcall will not clobber any parameters which may have
   already been placed on the stack.  */

static bool
block_move_libcall_safe_for_call_parm ()
{
  if (PUSH_ARGS)
    return true;
  else
    {
      /* Check to see whether memcpy takes all register arguments.  */
      static enum {
  takes_regs_uninit, takes_regs_no, takes_regs_yes
      } takes_regs = takes_regs_uninit;

      switch (takes_regs)
  {
  case takes_regs_uninit:
    {
      CUMULATIVE_ARGS args_so_far;
      tree fn, arg;

      fn = emit_block_move_libcall_fn (false);
      INIT_CUMULATIVE_ARGS (args_so_far, TREE_TYPE (fn), NULL_RTX, 0);

      arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
      for ( ; arg != void_list_node ; arg = TREE_CHAIN (arg))
        {
    enum machine_mode mode = TYPE_MODE (TREE_VALUE (arg));
    rtx tmp = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
    if (!tmp || !REG_P (tmp))
      goto fail_takes_regs;
#ifdef FUNCTION_ARG_PARTIAL_NREGS
    if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode,
            NULL_TREE, 1))
      goto fail_takes_regs;
#endif
    FUNCTION_ARG_ADVANCE (args_so_far, mode, NULL_TREE, 1);
        }
    }
    takes_regs = takes_regs_yes;
    /* FALLTHRU */

  case takes_regs_yes:
    return true;

  fail_takes_regs:
    takes_regs = takes_regs_no;
    /* FALLTHRU */
  case takes_regs_no:
    return false;

  default:
    abort ();
  }
    }
}

/* A subroutine of emit_block_move.  Expand a movstr pattern; 
   return true if successful.  */

static bool
emit_block_move_via_movstr (x, y, size, align)
     rtx x, y, size;
     unsigned int align;
{
  /* Try the most limited insn first, because there's no point
     including more than one in the machine description unless
     the more limited one has some advantage.  */

  rtx opalign = GEN_INT (align / BITS_PER_UNIT);
  enum machine_mode mode;

  /* Since this is a move insn, we don't care about volatility.  */
  volatile_ok = 1;

  for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode;
       mode = GET_MODE_WIDER_MODE (mode))
    {
      enum insn_code code = movstr_optab[(int) mode];
      insn_operand_predicate_fn pred;

      if (code != CODE_FOR_nothing
    /* We don't need MODE to be narrower than BITS_PER_HOST_WIDE_INT
       here because if SIZE is less than the mode mask, as it is
       returned by the macro, it will definitely be less than the
       actual mode mask.  */
    && ((GET_CODE (size) == CONST_INT
         && ((unsigned HOST_WIDE_INT) INTVAL (size)
       <= (GET_MODE_MASK (mode) >> 1)))
        || GET_MODE_BITSIZE (mode) >= BITS_PER_WORD)
    && ((pred = insn_data[(int) code].operand[0].predicate) == 0
        || (*pred) (x, BLKmode))
    && ((pred = insn_data[(int) code].operand[1].predicate) == 0
        || (*pred) (y, BLKmode))
    && ((pred = insn_data[(int) code].operand[3].predicate) == 0
        || (*pred) (opalign, VOIDmode)))
  {
    rtx op2;
    rtx last = get_last_insn ();
    rtx pat;

    op2 = convert_to_mode (mode, size, 1);
    pred = insn_data[(int) code].operand[2].predicate;
    if (pred != 0 && ! (*pred) (op2, mode))
      op2 = copy_to_mode_reg (mode, op2);

    /* ??? When called via emit_block_move_for_call, it'd be
       nice if there were some way to inform the backend, so
       that it doesn't fail the expansion because it thinks
       emitting the libcall would be more efficient.  */

    pat = GEN_FCN ((int) code) (x, y, op2, opalign);
    if (pat)
      {
        emit_insn (pat);
        volatile_ok = 0;
        return true;
      }
    else
      delete_insns_since (last);
  }
    }

  volatile_ok = 0;
  return false;
}

/* A subroutine of emit_block_move.  Expand a call to memcpy or bcopy.
   Return the return value from memcpy, 0 otherwise.  */

static rtx
emit_block_move_via_libcall (dst, src, size)
     rtx dst, src, size;
{
  tree call_expr, arg_list, fn, src_tree, dst_tree, size_tree;
  enum machine_mode size_mode;
  rtx retval;

  /* DST, SRC, or SIZE may have been passed through protect_from_queue.

     It is unsafe to save the value generated by protect_from_queue
     and reuse it later.  Consider what happens if emit_queue is
     called before the return value from protect_from_queue is used.

     Expansion of the CALL_EXPR below will call emit_queue before
     we are finished emitting RTL for argument setup.  So if we are
     not careful we could get the wrong value for an argument.

     To avoid this problem we go ahead and emit code to copy X, Y &
     SIZE into new pseudos.  We can then place those new pseudos
     into an RTL_EXPR and use them later, even after a call to
     emit_queue.

     Note this is not strictly needed for library calls since they
     do not call emit_queue before loading their arguments.  However,
     we may need to have library calls call emit_queue in the future
     since failing to do so could cause problems for targets which
     define SMALL_REGISTER_CLASSES and pass arguments in registers.  */

  dst = copy_to_mode_reg (Pmode, XEXP (dst, 0));
  src = copy_to_mode_reg (Pmode, XEXP (src, 0));

  if (TARGET_MEM_FUNCTIONS)
    size_mode = TYPE_MODE (sizetype);
  else
    size_mode = TYPE_MODE (unsigned_type_node);
  size = convert_to_mode (size_mode, size, 1);
  size = copy_to_mode_reg (size_mode, size);

  /* It is incorrect to use the libcall calling conventions to call
     memcpy in this context.  This could be a user call to memcpy and
     the user may wish to examine the return value from memcpy.  For
     targets where libcalls and normal calls have different conventions
     for returning pointers, we could end up generating incorrect code.

     For convenience, we generate the call to bcopy this way as well.  */

  dst_tree = make_tree (ptr_type_node, dst);
  src_tree = make_tree (ptr_type_node, src);
  if (TARGET_MEM_FUNCTIONS)
    size_tree = make_tree (sizetype, size);
  else
    size_tree = make_tree (unsigned_type_node, size);

  fn = emit_block_move_libcall_fn (true);
  arg_list = tree_cons (NULL_TREE, size_tree, NULL_TREE);
  if (TARGET_MEM_FUNCTIONS)
    {
      arg_list = tree_cons (NULL_TREE, src_tree, arg_list);
      arg_list = tree_cons (NULL_TREE, dst_tree, arg_list);
    }
  else
    {
      arg_list = tree_cons (NULL_TREE, dst_tree, arg_list);
      arg_list = tree_cons (NULL_TREE, src_tree, arg_list);
    }

  /* Now we have to build up the CALL_EXPR itself.  */
  call_expr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (fn)), fn);
  call_expr = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (fn)),
         call_expr, arg_list, NULL_TREE);
  TREE_SIDE_EFFECTS (call_expr) = 1;

  retval = expand_expr (call_expr, NULL_RTX, VOIDmode, 0);

  /* If we are initializing a readonly value, show the above call
     clobbered it.  Otherwise, a load from it may erroneously be
     hoisted from a loop.  */
  if (RTX_UNCHANGING_P (dst))
    emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));

  return (TARGET_MEM_FUNCTIONS ? retval : NULL_RTX);
}

/* A subroutine of emit_block_move_via_libcall.  Create the tree node
   for the function we use for block copies.  The first time FOR_CALL
   is true, we call assemble_external.  */

static GTY(()) tree block_move_fn;

void
init_block_move_fn (asmspec)
     const char *asmspec;
{
  if (!block_move_fn)
    {
      tree args, fn;

      if (TARGET_MEM_FUNCTIONS)
  {
    fn = get_identifier ("memcpy");
    args = build_function_type_list (ptr_type_node, ptr_type_node,
             const_ptr_type_node, sizetype,
             NULL_TREE);
  }
      else
  {
    fn = get_identifier ("bcopy");
    args = build_function_type_list (void_type_node, const_ptr_type_node,
             ptr_type_node, unsigned_type_node,
             NULL_TREE);
  }

      fn = build_decl (FUNCTION_DECL, fn, args);
      DECL_EXTERNAL (fn) = 1;
      TREE_PUBLIC (fn) = 1;
      DECL_ARTIFICIAL (fn) = 1;
      TREE_NOTHROW (fn) = 1;

      block_move_fn = fn;
    }

  if (asmspec)
    {
      SET_DECL_RTL (block_move_fn, NULL_RTX);
      SET_DECL_ASSEMBLER_NAME (block_move_fn, get_identifier (asmspec));
    }
}

static tree
emit_block_move_libcall_fn (for_call)
     int for_call;
{
  static bool emitted_extern;

  if (!block_move_fn)
    init_block_move_fn (NULL);

  if (for_call && !emitted_extern)
    {
      emitted_extern = true;
      make_decl_rtl (block_move_fn, NULL);
      assemble_external (block_move_fn);
    }

  return block_move_fn;
}

/* A subroutine of emit_block_move.  Copy the data via an explicit
   loop.  This is used only when libcalls are forbidden.  */
/* ??? It'd be nice to copy in hunks larger than QImode.  */

static void
emit_block_move_via_loop (x, y, size, align)
     rtx x, y, size;
     unsigned int align ATTRIBUTE_UNUSED;
{
  rtx cmp_label, top_label, iter, x_addr, y_addr, tmp;
  enum machine_mode iter_mode;

  iter_mode = GET_MODE (size);
  if (iter_mode == VOIDmode)
    iter_mode = word_mode;

  top_label = gen_label_rtx ();
  cmp_label = gen_label_rtx ();
  iter = gen_reg_rtx (iter_mode);

  emit_move_insn (iter, const0_rtx);

  x_addr = force_operand (XEXP (x, 0), NULL_RTX);
  y_addr = force_operand (XEXP (y, 0), NULL_RTX);
  do_pending_stack_adjust ();

  emit_note (NULL, NOTE_INSN_LOOP_BEG);

  emit_jump (cmp_label);
  emit_label (top_label);

  tmp = convert_modes (Pmode, iter_mode, iter, true);
  x_addr = gen_rtx_PLUS (Pmode, x_addr, tmp);
  y_addr = gen_rtx_PLUS (Pmode, y_addr, tmp);
  x = change_address (x, QImode, x_addr);
  y = change_address (y, QImode, y_addr);

  emit_move_insn (x, y);

  tmp = expand_simple_binop (iter_mode, PLUS, iter, const1_rtx, iter,
           true, OPTAB_LIB_WIDEN);
  if (tmp != iter)
    emit_move_insn (iter, tmp);

  emit_note (NULL, NOTE_INSN_LOOP_CONT);
  emit_label (cmp_label);

  emit_cmp_and_jump_insns (iter, size, LT, NULL_RTX, iter_mode,
         true, top_label);

  emit_note (NULL, NOTE_INSN_LOOP_END);
}

/* Copy all or part of a value X into registers starting at REGNO.
   The number of registers to be filled is NREGS.  */

void
move_block_to_reg (regno, x, nregs, mode)
     int regno;
     rtx x;
     int nregs;
     enum machine_mode mode;
{
  int i;
#ifdef HAVE_load_multiple
  rtx pat;
  rtx last;
#endif

  if (nregs == 0)
    return;

  if (CONSTANT_P (x) && ! LEGITIMATE_CONSTANT_P (x))
    x = validize_mem (force_const_mem (mode, x));

  /* See if the machine can do this with a load multiple insn.  */
#ifdef HAVE_load_multiple
  if (HAVE_load_multiple)
    {
      last = get_last_insn ();
      pat = gen_load_multiple (gen_rtx_REG (word_mode, regno), x,
             GEN_INT (nregs));
      if (pat)
  {
    emit_insn (pat);
    return;
  }
      else
  delete_insns_since (last);
    }
#endif

  for (i = 0; i < nregs; i++)
    emit_move_insn (gen_rtx_REG (word_mode, regno + i),
        operand_subword_force (x, i, mode));
}

/* Copy all or part of a BLKmode value X out of registers starting at REGNO.
   The number of registers to be filled is NREGS.  SIZE indicates the number
   of bytes in the object X.  */

void
move_block_from_reg (regno, x, nregs, size)
     int regno;
     rtx x;
     int nregs;
     int size;
{
  int i;
#ifdef HAVE_store_multiple
  rtx pat;
  rtx last;
#endif
  enum machine_mode mode;

  if (nregs == 0)
    return;

  /* If SIZE is that of a mode no bigger than a word, just use that
     mode's store operation.  */
  if (size <= UNITS_PER_WORD
      && (mode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0)) != BLKmode)
    {
      emit_move_insn (adjust_address (x, mode, 0), gen_rtx_REG (mode, regno));
      return;
    }

  /* Blocks smaller than a word on a BYTES_BIG_ENDIAN machine must be aligned
     to the left before storing to memory.  Note that the previous test
     doesn't handle all cases (e.g. SIZE == 3).  */
  if (size < UNITS_PER_WORD && BYTES_BIG_ENDIAN)
    {
      rtx tem = operand_subword (x, 0, 1, BLKmode);
      rtx shift;

      if (tem == 0)
  abort ();

      shift = expand_shift (LSHIFT_EXPR, word_mode,
          gen_rtx_REG (word_mode, regno),
          build_int_2 ((UNITS_PER_WORD - size)
           * BITS_PER_UNIT, 0), NULL_RTX, 0);
      emit_move_insn (tem, shift);
      return;
    }

  /* See if the machine can do this with a store multiple insn.  */
#ifdef HAVE_store_multiple
  if (HAVE_store_multiple)
    {
      last = get_last_insn ();
      pat = gen_store_multiple (x, gen_rtx_REG (word_mode, regno),
        GEN_INT (nregs));
      if (pat)
  {
    emit_insn (pat);
    return;
  }
      else
  delete_insns_since (last);
    }
#endif

  for (i = 0; i < nregs; i++)
    {
      rtx tem = operand_subword (x, i, 1, BLKmode);

      if (tem == 0)
  abort ();

      emit_move_insn (tem, gen_rtx_REG (word_mode, regno + i));
    }
}

/* Generate a PARALLEL rtx for a new non-consecutive group of registers from
   ORIG, where ORIG is a non-consecutive group of registers represented by
   a PARALLEL.  The clone is identical to the original except in that the
   original set of registers is replaced by a new set of pseudo registers.
   The new set has the same modes as the original set.  */

rtx
gen_group_rtx (orig)
     rtx orig;
{
  int i, length;
  rtx *tmps;

  if (GET_CODE (orig) != PARALLEL)
    abort ();

  length = XVECLEN (orig, 0);
  tmps = (rtx *) alloca (sizeof (rtx) * length);

  /* Skip a NULL entry in first slot.  */
  i = XEXP (XVECEXP (orig, 0, 0), 0) ? 0 : 1;

  if (i)
    tmps[0] = 0;

  for (; i < length; i++)
    {
      enum machine_mode mode = GET_MODE (XEXP (XVECEXP (orig, 0, i), 0));
      rtx offset = XEXP (XVECEXP (orig, 0, i), 1);

      tmps[i] = gen_rtx_EXPR_LIST (VOIDmode, gen_reg_rtx (mode), offset);
    }

  return gen_rtx_PARALLEL (GET_MODE (orig), gen_rtvec_v (length, tmps));
}

/* Emit code to move a block SRC to a block DST, where DST is non-consecutive
   registers represented by a PARALLEL.  SSIZE represents the total size of
   block SRC in bytes, or -1 if not known.  */
/* ??? If SSIZE % UNITS_PER_WORD != 0, we make the blatant assumption that
   the balance will be in what would be the low-order memory addresses, i.e.
   left justified for big endian, right justified for little endian.  This
   happens to be true for the targets currently using this support.  If this
   ever changes, a new target macro along the lines of FUNCTION_ARG_PADDING
   would be needed.  */

void
emit_group_load (dst, orig_src, ssize)
     rtx dst, orig_src;
     int ssize;
{
  rtx *tmps, src;
  int start, i;

  if (GET_CODE (dst) != PARALLEL)
    abort ();

  /* Check for a NULL entry, used to indicate that the parameter goes
     both on the stack and in registers.  */
  if (XEXP (XVECEXP (dst, 0, 0), 0))
    start = 0;
  else
    start = 1;

  tmps = (rtx *) alloca (sizeof (rtx) * XVECLEN (dst, 0));

  /* Process the pieces.  */
  for (i = start; i < XVECLEN (dst, 0); i++)
    {
      enum machine_mode mode = GET_MODE (XEXP (XVECEXP (dst, 0, i), 0));
      HOST_WIDE_INT bytepos = INTVAL (XEXP (XVECEXP (dst, 0, i), 1));
      unsigned int bytelen = GET_MODE_SIZE (mode);
      int shift = 0;

      /* Handle trailing fragments that run over the size of the struct.  */
      if (ssize >= 0 && bytepos + (HOST_WIDE_INT) bytelen > ssize)
  {
    shift = (bytelen - (ssize - bytepos)) * BITS_PER_UNIT;
    bytelen = ssize - bytepos;
    if (bytelen <= 0)
      abort ();
  }

      /* If we won't be loading directly from memory, protect the real source
   from strange tricks we might play; but make sure that the source can
   be loaded directly into the destination.  */
      src = orig_src;
      if (GET_CODE (orig_src) != MEM
    && (!CONSTANT_P (orig_src)
        || (GET_MODE (orig_src) != mode
      && GET_MODE (orig_src) != VOIDmode)))
  {
    if (GET_MODE (orig_src) == VOIDmode)
      src = gen_reg_rtx (mode);
    else
      src = gen_reg_rtx (GET_MODE (orig_src));

    emit_move_insn (src, orig_src);
  }

      /* Optimize the access just a bit.  */
      if (GET_CODE (src) == MEM
    && MEM_ALIGN (src) >= GET_MODE_ALIGNMENT (mode)
    && bytepos * BITS_PER_UNIT % GET_MODE_ALIGNMENT (mode) == 0
    && bytelen == GET_MODE_SIZE (mode))
  {
    tmps[i] = gen_reg_rtx (mode);
    emit_move_insn (tmps[i], adjust_address (src, mode, bytepos));
  }
      else if (GET_CODE (src) == CONCAT)
  {
    unsigned int slen = GET_MODE_SIZE (GET_MODE (src));
    unsigned int slen0 = GET_MODE_SIZE (GET_MODE (XEXP (src, 0)));

    if ((bytepos == 0 && bytelen == slen0)
        || (bytepos != 0 && bytepos + bytelen <= slen))
      {
        /* The following assumes that the concatenated objects all
     have the same size.  In this case, a simple calculation
     can be used to determine the object and the bit field
     to be extracted.  */
        tmps[i] = XEXP (src, bytepos / slen0);
        if (! CONSTANT_P (tmps[i])
      && (GET_CODE (tmps[i]) != REG || GET_MODE (tmps[i]) != mode))
    tmps[i] = extract_bit_field (tmps[i], bytelen * BITS_PER_UNIT,
               (bytepos % slen0) * BITS_PER_UNIT,
               1, NULL_RTX, mode, mode, ssize);
      }
    else if (bytepos == 0)
      {
        rtx mem = assign_stack_temp (GET_MODE (src), slen, 0);
        emit_move_insn (mem, src);
        tmps[i] = adjust_address (mem, mode, 0);
      }
    else
      abort ();
  }
      else if (CONSTANT_P (src)
         || (GET_CODE (src) == REG && GET_MODE (src) == mode))
  tmps[i] = src;
      else
  tmps[i] = extract_bit_field (src, bytelen * BITS_PER_UNIT,
             bytepos * BITS_PER_UNIT, 1, NULL_RTX,
             mode, mode, ssize);

      if (BYTES_BIG_ENDIAN && shift)
  expand_binop (mode, ashl_optab, tmps[i], GEN_INT (shift),
          tmps[i], 0, OPTAB_WIDEN);
    }

  emit_queue ();

  /* Copy the extracted pieces into the proper (probable) hard regs.  */
  for (i = start; i < XVECLEN (dst, 0); i++)
    emit_move_insn (XEXP (XVECEXP (dst, 0, i), 0), tmps[i]);
}

/* Emit code to move a block SRC to block DST, where SRC and DST are
   non-consecutive groups of registers, each represented by a PARALLEL.  */

void
emit_group_move (dst, src)
     rtx dst, src;
{
  int i;

  if (GET_CODE (src) != PARALLEL
      || GET_CODE (dst) != PARALLEL
      || XVECLEN (src, 0) != XVECLEN (dst, 0))
    abort ();

  /* Skip first entry if NULL.  */
  for (i = XEXP (XVECEXP (src, 0, 0), 0) ? 0 : 1; i < XVECLEN (src, 0); i++)
    emit_move_insn (XEXP (XVECEXP (dst, 0, i), 0),
        XEXP (XVECEXP (src, 0, i), 0));
}

/* Emit code to move a block SRC to a block DST, where SRC is non-consecutive
   registers represented by a PARALLEL.  SSIZE represents the total size of
   block DST, or -1 if not known.  */

void
emit_group_store (orig_dst, src, ssize)
     rtx orig_dst, src;
     int ssize;
{
  rtx *tmps, dst;
  int start, i;

  if (GET_CODE (src) != PARALLEL)
    abort ();

  /* Check for a NULL entry, used to indicate that the parameter goes
     both on the stack and in registers.  */
  if (XEXP (XVECEXP (src, 0, 0), 0))
    start = 0;
  else
    start = 1;

  tmps = (rtx *) alloca (sizeof (rtx) * XVECLEN (src, 0));

  /* Copy the (probable) hard regs into pseudos.  */
  for (i = start; i < XVECLEN (src, 0); i++)
    {
      rtx reg = XEXP (XVECEXP (src, 0, i), 0);
      tmps[i] = gen_reg_rtx (GET_MODE (reg));
      emit_move_insn (tmps[i], reg);
    }
  emit_queue ();

  /* If we won't be storing directly into memory, protect the real destination
     from strange tricks we might play.  */
  dst = orig_dst;
  if (GET_CODE (dst) == PARALLEL)
    {
      rtx temp;

      /* We can get a PARALLEL dst if there is a conditional expression in
   a return statement.  In that case, the dst and src are the same,
   so no action is necessary.  */
      if (rtx_equal_p (dst, src))
  return;

      /* It is unclear if we can ever reach here, but we may as well handle
   it.  Allocate a temporary, and split this into a store/load to/from
   the temporary.  */

      temp = assign_stack_temp (GET_MODE (dst), ssize, 0);
      emit_group_store (temp, src, ssize);
      emit_group_load (dst, temp, ssize);
      return;
    }
  else if (GET_CODE (dst) != MEM && GET_CODE (dst) != CONCAT)
    {
      dst = gen_reg_rtx (GET_MODE (orig_dst));
      /* Make life a bit easier for combine.  */
      emit_move_insn (dst, CONST0_RTX (GET_MODE (orig_dst)));
    }

  /* Process the pieces.  */
  for (i = start; i < XVECLEN (src, 0); i++)
    {
      HOST_WIDE_INT bytepos = INTVAL (XEXP (XVECEXP (src, 0, i), 1));
      enum machine_mode mode = GET_MODE (tmps[i]);
      unsigned int bytelen = GET_MODE_SIZE (mode);
      rtx dest = dst;

      /* Handle trailing fragments that run over the size of the struct.  */
      if (ssize >= 0 && bytepos + (HOST_WIDE_INT) bytelen > ssize)
  {
    if (BYTES_BIG_ENDIAN)
      {
        int shift = (bytelen - (ssize - bytepos)) * BITS_PER_UNIT;
        expand_binop (mode, ashr_optab, tmps[i], GEN_INT (shift),
          tmps[i], 0, OPTAB_WIDEN);
      }
    bytelen = ssize - bytepos;
  }

      if (GET_CODE (dst) == CONCAT)
  {
    if (bytepos + bytelen <= GET_MODE_SIZE (GET_MODE (XEXP (dst, 0))))
      dest = XEXP (dst, 0);
    else if (bytepos >= GET_MODE_SIZE (GET_MODE (XEXP (dst, 0))))
      {
        bytepos -= GET_MODE_SIZE (GET_MODE (XEXP (dst, 0)));
        dest = XEXP (dst, 1);
      }
    else if (bytepos == 0 && XVECLEN (src, 0))
      {
        dest = assign_stack_temp (GET_MODE (dest),
                GET_MODE_SIZE (GET_MODE (dest)), 0);
        emit_move_insn (adjust_address (dest, GET_MODE (tmps[i]), bytepos),
            tmps[i]);
        dst = dest;
        break;
      }
    else
      abort ();
  }

      /* Optimize the access just a bit.  */
      if (GET_CODE (dest) == MEM
    && MEM_ALIGN (dest) >= GET_MODE_ALIGNMENT (mode)
    && bytepos * BITS_PER_UNIT % GET_MODE_ALIGNMENT (mode) == 0
    && bytelen == GET_MODE_SIZE (mode))
  emit_move_insn (adjust_address (dest, mode, bytepos), tmps[i]);
      else
  store_bit_field (dest, bytelen * BITS_PER_UNIT, bytepos * BITS_PER_UNIT,
       mode, tmps[i], ssize);
    }

  emit_queue ();

  /* Copy from the pseudo into the (probable) hard reg.  */
  if (orig_dst != dst)
    emit_move_insn (orig_dst, dst);
}

/* Generate code to copy a BLKmode object of TYPE out of a
   set of registers starting with SRCREG into TGTBLK.  If TGTBLK
   is null, a stack temporary is created.  TGTBLK is returned.

   The primary purpose of this routine is to handle functions
   that return BLKmode structures in registers.  Some machines
   (the PA for example) want to return all small structures
   in registers regardless of the structure's alignment.  */

rtx
copy_blkmode_from_reg (tgtblk, srcreg, type)
     rtx tgtblk;
     rtx srcreg;
     tree type;
{
  unsigned HOST_WIDE_INT bytes = int_size_in_bytes (type);
  rtx src = NULL, dst = NULL;
  unsigned HOST_WIDE_INT bitsize = MIN (TYPE_ALIGN (type), BITS_PER_WORD);
  unsigned HOST_WIDE_INT bitpos, xbitpos, big_endian_correction = 0;

  if (tgtblk == 0)
    {
      tgtblk = assign_temp (build_qualified_type (type,
              (TYPE_QUALS (type)
               | TYPE_QUAL_CONST)),
          0, 1, 1);
      preserve_temp_slots (tgtblk);
    }

  /* This code assumes srcreg is at least a full word.  If it isn't, copy it
     into a new pseudo which is a full word.  */

  if (GET_MODE (srcreg) != BLKmode
      && GET_MODE_SIZE (GET_MODE (srcreg)) < UNITS_PER_WORD)
    srcreg = convert_to_mode (word_mode, srcreg, TREE_UNSIGNED (type));

  /* Structures whose size is not a multiple of a word are aligned
     to the least significant byte (to the right).  On a BYTES_BIG_ENDIAN
     machine, this means we must skip the empty high order bytes when
     calculating the bit offset.  */
  if (BYTES_BIG_ENDIAN
      && bytes % UNITS_PER_WORD)
    big_endian_correction
      = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD) * BITS_PER_UNIT));

  /* Copy the structure BITSIZE bites at a time.

     We could probably emit more efficient code for machines which do not use
     strict alignment, but it doesn't seem worth the effort at the current
     time.  */
  for (bitpos = 0, xbitpos = big_endian_correction;
       bitpos < bytes * BITS_PER_UNIT;
       bitpos += bitsize, xbitpos += bitsize)
    {
      /* We need a new source operand each time xbitpos is on a
   word boundary and when xbitpos == big_endian_correction
   (the first time through).  */
      if (xbitpos % BITS_PER_WORD == 0
    || xbitpos == big_endian_correction)
  src = operand_subword_force (srcreg, xbitpos / BITS_PER_WORD,
             GET_MODE (srcreg));

      /* We need a new destination operand each time bitpos is on
   a word boundary.  */
      if (bitpos % BITS_PER_WORD == 0)
  dst = operand_subword (tgtblk, bitpos / BITS_PER_WORD, 1, BLKmode);

      /* Use xbitpos for the source extraction (right justified) and
   xbitpos for the destination store (left justified).  */
      store_bit_field (dst, bitsize, bitpos % BITS_PER_WORD, word_mode,
           extract_bit_field (src, bitsize,
            xbitpos % BITS_PER_WORD, 1,
            NULL_RTX, word_mode, word_mode,
            BITS_PER_WORD),
           BITS_PER_WORD);
    }

  return tgtblk;
}

/* Add a USE expression for REG to the (possibly empty) list pointed
   to by CALL_FUSAGE.  REG must denote a hard register.  */

void
use_reg (call_fusage, reg)
     rtx *call_fusage, reg;
{
  if (GET_CODE (reg) != REG
      || REGNO (reg) >= FIRST_PSEUDO_REGISTER)
    abort ();

  *call_fusage
    = gen_rtx_EXPR_LIST (VOIDmode,
       gen_rtx_USE (VOIDmode, reg), *call_fusage);
}

/* Add USE expressions to *CALL_FUSAGE for each of NREGS consecutive regs,
   starting at REGNO.  All of these registers must be hard registers.  */

void
use_regs (call_fusage, regno, nregs)
     rtx *call_fusage;
     int regno;
     int nregs;
{
  int i;

  if (regno + nregs > FIRST_PSEUDO_REGISTER)
    abort ();

  for (i = 0; i < nregs; i++)
    use_reg (call_fusage, regno_reg_rtx[regno + i]);
}

/* Add USE expressions to *CALL_FUSAGE for each REG contained in the
   PARALLEL REGS.  This is for calls that pass values in multiple
   non-contiguous locations.  The Irix 6 ABI has examples of this.  */

void
use_group_regs (call_fusage, regs)
     rtx *call_fusage;
     rtx regs;
{
  int i;

  for (i = 0; i < XVECLEN (regs, 0); i++)
    {
      rtx reg = XEXP (XVECEXP (regs, 0, i), 0);

      /* A NULL entry means the parameter goes both on the stack and in
   registers.  This can also be a MEM for targets that pass values
   partially on the stack and partially in registers.  */
      if (reg != 0 && GET_CODE (reg) == REG)
  use_reg (call_fusage, reg);
    }
}


/* Determine whether the LEN bytes generated by CONSTFUN can be
   stored to memory using several move instructions.  CONSTFUNDATA is
   a pointer which will be passed as argument in every CONSTFUN call.
   ALIGN is maximum alignment we can assume.  Return nonzero if a
   call to store_by_pieces should succeed.  */

int
can_store_by_pieces (len, constfun, constfundata, align)
     unsigned HOST_WIDE_INT len;
     rtx (*constfun) PARAMS ((PTR, HOST_WIDE_INT, enum machine_mode));
     PTR constfundata;
     unsigned int align;
{
  unsigned HOST_WIDE_INT max_size, l;
  HOST_WIDE_INT offset = 0;
  enum machine_mode mode, tmode;
  enum insn_code icode;
  int reverse;
  rtx cst;

  if (len == 0)
    return 1;

  if (! MOVE_BY_PIECES_P (len, align))
    return 0;

  if (! SLOW_UNALIGNED_ACCESS (word_mode, align)
      || align > MOVE_MAX * BITS_PER_UNIT || align >= BIGGEST_ALIGNMENT)
    align = MOVE_MAX * BITS_PER_UNIT;

  /* We would first store what we can in the largest integer mode, then go to
     successively smaller modes.  */

  for (reverse = 0;
       reverse <= (HAVE_PRE_DECREMENT || HAVE_POST_DECREMENT);
       reverse++)
    {
      l = len;
      mode = VOIDmode;
      max_size = STORE_MAX_PIECES + 1;
      while (max_size > 1)
  {
    for (tmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
         tmode != VOIDmode; tmode = GET_MODE_WIDER_MODE (tmode))
      if (GET_MODE_SIZE (tmode) < max_size)
        mode = tmode;

    if (mode == VOIDmode)
      break;

    icode = mov_optab->handlers[(int) mode].insn_code;
    if (icode != CODE_FOR_nothing
        && align >= GET_MODE_ALIGNMENT (mode))
      {
        unsigned int size = GET_MODE_SIZE (mode);

        while (l >= size)
    {
      if (reverse)
        offset -= size;

      cst = (*constfun) (constfundata, offset, mode);
      if (!LEGITIMATE_CONSTANT_P (cst))
        return 0;

      if (!reverse)
        offset += size;

      l -= size;
    }
      }

    max_size = GET_MODE_SIZE (mode);
  }

      /* The code above should have handled everything.  */
      if (l != 0)
  abort ();
    }

  return 1;
}

/* Generate several move instructions to store LEN bytes generated by
   CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
   pointer which will be passed as argument in every CONSTFUN call.
   ALIGN is maximum alignment we can assume.
   If ENDP is 0 return to, if ENDP is 1 return memory at the end ala
   mempcpy, and if ENDP is 2 return memory the end minus one byte ala
   stpcpy.  */

rtx
store_by_pieces (to, len, constfun, constfundata, align, endp)
     rtx to;
     unsigned HOST_WIDE_INT len;
     rtx (*constfun) PARAMS ((PTR, HOST_WIDE_INT, enum machine_mode));
     PTR constfundata;
     unsigned int align;
     int endp;
{
  struct store_by_pieces data;

  if (len == 0)
    {
      if (endp == 2)
  abort ();
      return to;
    }

  if (! MOVE_BY_PIECES_P (len, align))
    abort ();
  to = protect_from_queue (to, 1);
  data.constfun = constfun;
  data.constfundata = constfundata;
  data.len = len;
  data.to = to;
  store_by_pieces_1 (&data, align);
  if (endp)
    {
      rtx to1;

      if (data.reverse)
  abort ();
      if (data.autinc_to)
  {
    if (endp == 2)
      {
        if (HAVE_POST_INCREMENT && data.explicit_inc_to > 0)
    emit_insn (gen_add2_insn (data.to_addr, constm1_rtx));
        else
    data.to_addr = copy_addr_to_reg (plus_constant (data.to_addr,
                -1));
      }
    to1 = adjust_automodify_address (data.to, QImode, data.to_addr,
             data.offset);
  }
      else
  {
    if (endp == 2)
      --data.offset;
    to1 = adjust_address (data.to, QImode, data.offset);
  }
      return to1;
    }
  else
    return data.to;
}

/* Generate several move instructions to clear LEN bytes of block TO.  (A MEM
   rtx with BLKmode).  The caller must pass TO through protect_from_queue
   before calling. ALIGN is maximum alignment we can assume.  */

static void
clear_by_pieces (to, len, align)
     rtx to;
     unsigned HOST_WIDE_INT len;
     unsigned int align;
{
  struct store_by_pieces data;

  if (len == 0)
    return;

  data.constfun = clear_by_pieces_1;
  data.constfundata = NULL;
  data.len = len;
  data.to = to;
  store_by_pieces_1 (&data, align);
}

/* Callback routine for clear_by_pieces.
   Return const0_rtx unconditionally.  */

static rtx
clear_by_pieces_1 (data, offset, mode)
     PTR data ATTRIBUTE_UNUSED;
     HOST_WIDE_INT offset ATTRIBUTE_UNUSED;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return const0_rtx;
}

/* Subroutine of clear_by_pieces and store_by_pieces.
   Generate several move instructions to store LEN bytes of block TO.  (A MEM
   rtx with BLKmode).  The caller must pass TO through protect_from_queue
   before calling.  ALIGN is maximum alignment we can assume.  */

static void
store_by_pieces_1 (data, align)
     struct store_by_pieces *data;
     unsigned int align;
{
  rtx to_addr = XEXP (data->to, 0);
  unsigned HOST_WIDE_INT max_size = STORE_MAX_PIECES + 1;
  enum machine_mode mode = VOIDmode, tmode;
  enum insn_code icode;

  data->offset = 0;
  data->to_addr = to_addr;
  data->autinc_to
    = (GET_CODE (to_addr) == PRE_INC || GET_CODE (to_addr) == PRE_DEC
       || GET_CODE (to_addr) == POST_INC || GET_CODE (to_addr) == POST_DEC);

  data->explicit_inc_to = 0;
  data->reverse
    = (GET_CODE (to_addr) == PRE_DEC || GET_CODE (to_addr) == POST_DEC);
  if (data->reverse)
    data->offset = data->len;

  /* If storing requires more than two move insns,
     copy addresses to registers (to make displacements shorter)
     and use post-increment if available.  */
  if (!data->autinc_to
      && move_by_pieces_ninsns (data->len, align) > 2)
    {
      /* Determine the main mode we'll be using.  */
      for (tmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
     tmode != VOIDmode; tmode = GET_MODE_WIDER_MODE (tmode))
  if (GET_MODE_SIZE (tmode) < max_size)
    mode = tmode;

      if (USE_STORE_PRE_DECREMENT (mode) && data->reverse && ! data->autinc_to)
  {
    data->to_addr = copy_addr_to_reg (plus_constant (to_addr, data->len));
    data->autinc_to = 1;
    data->explicit_inc_to = -1;
  }

      if (USE_STORE_POST_INCREMENT (mode) && ! data->reverse
    && ! data->autinc_to)
  {
    data->to_addr = copy_addr_to_reg (to_addr);
    data->autinc_to = 1;
    data->explicit_inc_to = 1;
  }

      if ( !data->autinc_to && CONSTANT_P (to_addr))
  data->to_addr = copy_addr_to_reg (to_addr);
    }

  if (! SLOW_UNALIGNED_ACCESS (word_mode, align)
      || align > MOVE_MAX * BITS_PER_UNIT || align >= BIGGEST_ALIGNMENT)
    align = MOVE_MAX * BITS_PER_UNIT;

  /* First store what we can in the largest integer mode, then go to
     successively smaller modes.  */

  while (max_size > 1)
    {
      for (tmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
     tmode != VOIDmode; tmode = GET_MODE_WIDER_MODE (tmode))
  if (GET_MODE_SIZE (tmode) < max_size)
    mode = tmode;

      if (mode == VOIDmode)
  break;

      icode = mov_optab->handlers[(int) mode].insn_code;
      if (icode != CODE_FOR_nothing && align >= GET_MODE_ALIGNMENT (mode))
  store_by_pieces_2 (GEN_FCN (icode), mode, data);

      max_size = GET_MODE_SIZE (mode);
    }

  /* The code above should have handled everything.  */
  if (data->len != 0)
    abort ();
}

/* Subroutine of store_by_pieces_1.  Store as many bytes as appropriate
   with move instructions for mode MODE.  GENFUN is the gen_... function
   to make a move insn for that mode.  DATA has all the other info.  */

static void
store_by_pieces_2 (genfun, mode, data)
     rtx (*genfun) PARAMS ((rtx, ...));
     enum machine_mode mode;
     struct store_by_pieces *data;
{
  unsigned int size = GET_MODE_SIZE (mode);
  rtx to1, cst;

  while (data->len >= size)
    {
      if (data->reverse)
  data->offset -= size;

      if (data->autinc_to)
  to1 = adjust_automodify_address (data->to, mode, data->to_addr,
           data->offset);
      else
  to1 = adjust_address (data->to, mode, data->offset);

      if (HAVE_PRE_DECREMENT && data->explicit_inc_to < 0)
  emit_insn (gen_add2_insn (data->to_addr,
          GEN_INT (-(HOST_WIDE_INT) size)));

      cst = (*data->constfun) (data->constfundata, data->offset, mode);
      emit_insn ((*genfun) (to1, cst));

      if (HAVE_POST_INCREMENT && data->explicit_inc_to > 0)
  emit_insn (gen_add2_insn (data->to_addr, GEN_INT (size)));

      if (! data->reverse)
  data->offset += size;

      data->len -= size;
    }
}

/* Write zeros through the storage of OBJECT.  If OBJECT has BLKmode, SIZE is
   its length in bytes.  */

rtx
clear_storage (object, size)
     rtx object;
     rtx size;
{
  rtx retval = 0;
  unsigned int align = (GET_CODE (object) == MEM ? MEM_ALIGN (object)
      : GET_MODE_ALIGNMENT (GET_MODE (object)));

  /* If OBJECT is not BLKmode and SIZE is the same size as its mode,
     just move a zero.  Otherwise, do this a piece at a time.  */
  if (GET_MODE (object) != BLKmode
      && GET_CODE (size) == CONST_INT
      && INTVAL (size) == (HOST_WIDE_INT) GET_MODE_SIZE (GET_MODE (object)))
    emit_move_insn (object, CONST0_RTX (GET_MODE (object)));
  else
    {
      object = protect_from_queue (object, 1);
      size = protect_from_queue (size, 0);

      if (size == const0_rtx)
  ;
      else if (GET_CODE (size) == CONST_INT
    && CLEAR_BY_PIECES_P (INTVAL (size), align))
  clear_by_pieces (object, INTVAL (size), align);
      else if (clear_storage_via_clrstr (object, size, align))
  ;
      else
  retval = clear_storage_via_libcall (object, size);
    }

  return retval;
}

/* A subroutine of clear_storage.  Expand a clrstr pattern;
   return true if successful.  */

static bool
clear_storage_via_clrstr (object, size, align)
     rtx object, size;
     unsigned int align;
{
  /* Try the most limited insn first, because there's no point
     including more than one in the machine description unless
     the more limited one has some advantage.  */

  rtx opalign = GEN_INT (align / BITS_PER_UNIT);
  enum machine_mode mode;

  for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode;
       mode = GET_MODE_WIDER_MODE (mode))
    {
      enum insn_code code = clrstr_optab[(int) mode];
      insn_operand_predicate_fn pred;

      if (code != CODE_FOR_nothing
    /* We don't need MODE to be narrower than
       BITS_PER_HOST_WIDE_INT here because if SIZE is less than
       the mode mask, as it is returned by the macro, it will
       definitely be less than the actual mode mask.  */
    && ((GET_CODE (size) == CONST_INT
         && ((unsigned HOST_WIDE_INT) INTVAL (size)
       <= (GET_MODE_MASK (mode) >> 1)))
        || GET_MODE_BITSIZE (mode) >= BITS_PER_WORD)
    && ((pred = insn_data[(int) code].operand[0].predicate) == 0
        || (*pred) (object, BLKmode))
    && ((pred = insn_data[(int) code].operand[2].predicate) == 0
        || (*pred) (opalign, VOIDmode)))
  {
    rtx op1;
    rtx last = get_last_insn ();
    rtx pat;

    op1 = convert_to_mode (mode, size, 1);
    pred = insn_data[(int) code].operand[1].predicate;
    if (pred != 0 && ! (*pred) (op1, mode))
      op1 = copy_to_mode_reg (mode, op1);

    pat = GEN_FCN ((int) code) (object, op1, opalign);
    if (pat)
      {
        emit_insn (pat);
        return true;
      }
    else
      delete_insns_since (last);
  }
    }

  return false;
}

/* A subroutine of clear_storage.  Expand a call to memset or bzero.
   Return the return value of memset, 0 otherwise.  */

static rtx
clear_storage_via_libcall (object, size)
     rtx object, size;
{
  tree call_expr, arg_list, fn, object_tree, size_tree;
  enum machine_mode size_mode;
  rtx retval;

  /* OBJECT or SIZE may have been passed through protect_from_queue.

     It is unsafe to save the value generated by protect_from_queue
     and reuse it later.  Consider what happens if emit_queue is
     called before the return value from protect_from_queue is used.

     Expansion of the CALL_EXPR below will call emit_queue before
     we are finished emitting RTL for argument setup.  So if we are
     not careful we could get the wrong value for an argument.

     To avoid this problem we go ahead and emit code to copy OBJECT
     and SIZE into new pseudos.  We can then place those new pseudos
     into an RTL_EXPR and use them later, even after a call to
     emit_queue.

     Note this is not strictly needed for library calls since they
     do not call emit_queue before loading their arguments.  However,
     we may need to have library calls call emit_queue in the future
     since failing to do so could cause problems for targets which
     define SMALL_REGISTER_CLASSES and pass arguments in registers.  */

  object = copy_to_mode_reg (Pmode, XEXP (object, 0));

  if (TARGET_MEM_FUNCTIONS)
    size_mode = TYPE_MODE (sizetype);
  else
    size_mode = TYPE_MODE (unsigned_type_node);
  size = convert_to_mode (size_mode, size, 1);
  size = copy_to_mode_reg (size_mode, size);

  /* It is incorrect to use the libcall calling conventions to call
     memset in this context.  This could be a user call to memset and
     the user may wish to examine the return value from memset.  For
     targets where libcalls and normal calls have different conventions
     for returning pointers, we could end up generating incorrect code.

     For convenience, we generate the call to bzero this way as well.  */

  object_tree = make_tree (ptr_type_node, object);
  if (TARGET_MEM_FUNCTIONS)
    size_tree = make_tree (sizetype, size);
  else
    size_tree = make_tree (unsigned_type_node, size);

  fn = clear_storage_libcall_fn (true);
  arg_list = tree_cons (NULL_TREE, size_tree, NULL_TREE);
  if (TARGET_MEM_FUNCTIONS)
    arg_list = tree_cons (NULL_TREE, integer_zero_node, arg_list);
  arg_list = tree_cons (NULL_TREE, object_tree, arg_list);

  /* Now we have to build up the CALL_EXPR itself.  */
  call_expr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (fn)), fn);
  call_expr = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (fn)),
         call_expr, arg_list, NULL_TREE);
  TREE_SIDE_EFFECTS (call_expr) = 1;

  retval = expand_expr (call_expr, NULL_RTX, VOIDmode, 0);

  /* If we are initializing a readonly value, show the above call
     clobbered it.  Otherwise, a load from it may erroneously be
     hoisted from a loop.  */
  if (RTX_UNCHANGING_P (object))
    emit_insn (gen_rtx_CLOBBER (VOIDmode, object));

  return (TARGET_MEM_FUNCTIONS ? retval : NULL_RTX);
}

/* A subroutine of clear_storage_via_libcall.  Create the tree node
   for the function we use for block clears.  The first time FOR_CALL
   is true, we call assemble_external.  */

static GTY(()) tree block_clear_fn;

void
init_block_clear_fn (asmspec)
     const char *asmspec;
{
  if (!block_clear_fn)
    {
      tree fn, args;

      if (TARGET_MEM_FUNCTIONS)
  {
    fn = get_identifier ("memset");
    args = build_function_type_list (ptr_type_node, ptr_type_node,
             integer_type_node, sizetype,
             NULL_TREE);
  }
      else
  {
    fn = get_identifier ("bzero");
    args = build_function_type_list (void_type_node, ptr_type_node,
             unsigned_type_node, NULL_TREE);
  }

      fn = build_decl (FUNCTION_DECL, fn, args);
      DECL_EXTERNAL (fn) = 1;
      TREE_PUBLIC (fn) = 1;
      DECL_ARTIFICIAL (fn) = 1;
      TREE_NOTHROW (fn) = 1;

      block_clear_fn = fn;
    }

  if (asmspec)
    {
      SET_DECL_RTL (block_clear_fn, NULL_RTX);
      SET_DECL_ASSEMBLER_NAME (block_clear_fn, get_identifier (asmspec));
    }
}

static tree
clear_storage_libcall_fn (for_call)
     int for_call;
{
  static bool emitted_extern;

  if (!block_clear_fn)
    init_block_clear_fn (NULL);

  if (for_call && !emitted_extern)
    {
      emitted_extern = true;
      make_decl_rtl (block_clear_fn, NULL);
      assemble_external (block_clear_fn);
    }

  return block_clear_fn;
}

/* Generate code to copy Y into X.
   Both Y and X must have the same mode, except that
   Y can be a constant with VOIDmode.
   This mode cannot be BLKmode; use emit_block_move for that.

   Return the last instruction emitted.  */

rtx
emit_move_insn (x, y)
     rtx x, y;
{
  enum machine_mode mode = GET_MODE (x);
  rtx y_cst = NULL_RTX;
  rtx last_insn;

  x = protect_from_queue (x, 1);
  y = protect_from_queue (y, 0);

#ifndef KEY
  if (mode == BLKmode || (GET_MODE (y) != mode && GET_MODE (y) != VOIDmode))
    abort ();
#endif

  /* Never force constant_p_rtx to memory.  */
  if (GET_CODE (y) == CONSTANT_P_RTX)
    ;
  else if (CONSTANT_P (y))
    {
      if (optimize
    && SCALAR_FLOAT_MODE_P (GET_MODE (x))
    && (last_insn = compress_float_constant (x, y)))
  return last_insn;

      if (!LEGITIMATE_CONSTANT_P (y))
  {
    y_cst = y;
    y = force_const_mem (mode, y);

    /* If the target's cannot_force_const_mem prevented the spill,
       assume that the target's move expanders will also take care
       of the non-legitimate constant.  */
    if (!y)
      y = y_cst;
  }
    }

  /* If X or Y are memory references, verify that their addresses are valid
     for the machine.  */
  if (GET_CODE (x) == MEM
      && ((! memory_address_p (GET_MODE (x), XEXP (x, 0))
     && ! push_operand (x, GET_MODE (x)))
    || (flag_force_addr
        && CONSTANT_ADDRESS_P (XEXP (x, 0)))))
    x = validize_mem (x);

  if (GET_CODE (y) == MEM
      && (! memory_address_p (GET_MODE (y), XEXP (y, 0))
    || (flag_force_addr
        && CONSTANT_ADDRESS_P (XEXP (y, 0)))))
    y = validize_mem (y);

  if (mode == BLKmode)
    abort ();

  last_insn = emit_move_insn_1 (x, y);

  if (y_cst && GET_CODE (x) == REG)
    set_unique_reg_note (last_insn, REG_EQUAL, y_cst);

  return last_insn;
}

/* Low level part of emit_move_insn.
   Called just like emit_move_insn, but assumes X and Y
   are basically valid.  */

rtx
emit_move_insn_1 (x, y)
     rtx x, y;
{
  enum machine_mode mode = GET_MODE (x);
  enum machine_mode submode;
  enum mode_class class = GET_MODE_CLASS (mode);

  if ((unsigned int) mode >= (unsigned int) MAX_MACHINE_MODE)
    abort ();

  if (mov_optab->handlers[(int) mode].insn_code != CODE_FOR_nothing)
    return
      emit_insn (GEN_FCN (mov_optab->handlers[(int) mode].insn_code) (x, y));

  /* Expand complex moves by moving real part and imag part, if possible.  */
  else if ((class == MODE_COMPLEX_FLOAT || class == MODE_COMPLEX_INT)
     && BLKmode != (submode = GET_MODE_INNER (mode))
     && (mov_optab->handlers[(int) submode].insn_code
         != CODE_FOR_nothing))
    {
      /* Don't split destination if it is a stack push.  */
      int stack = push_operand (x, GET_MODE (x));

#ifdef PUSH_ROUNDING
      /* In case we output to the stack, but the size is smaller machine can
   push exactly, we need to use move instructions.  */
      if (stack
    && (PUSH_ROUNDING (GET_MODE_SIZE (submode))
        != GET_MODE_SIZE (submode)))
  {
    rtx temp;
    HOST_WIDE_INT offset1, offset2;

    /* Do not use anti_adjust_stack, since we don't want to update
       stack_pointer_delta.  */
    temp = expand_binop (Pmode,
#ifdef STACK_GROWS_DOWNWARD
             sub_optab,
#else
             add_optab,
#endif
             stack_pointer_rtx,
             GEN_INT
         (PUSH_ROUNDING
          (GET_MODE_SIZE (GET_MODE (x)))),
             stack_pointer_rtx, 0, OPTAB_LIB_WIDEN);

    if (temp != stack_pointer_rtx)
      emit_move_insn (stack_pointer_rtx, temp);

#ifdef STACK_GROWS_DOWNWARD
    offset1 = 0;
    offset2 = GET_MODE_SIZE (submode);
#else
    offset1 = -PUSH_ROUNDING (GET_MODE_SIZE (GET_MODE (x)));
    offset2 = (-PUSH_ROUNDING (GET_MODE_SIZE (GET_MODE (x)))
         + GET_MODE_SIZE (submode));
#endif

    emit_move_insn (change_address (x, submode,
            gen_rtx_PLUS (Pmode,
                    stack_pointer_rtx,
              GEN_INT (offset1))),
        gen_realpart (submode, y));
    emit_move_insn (change_address (x, submode,
            gen_rtx_PLUS (Pmode,
                    stack_pointer_rtx,
              GEN_INT (offset2))),
        gen_imagpart (submode, y));
  }
      else
#endif
      /* If this is a stack, push the highpart first, so it
   will be in the argument order.

   In that case, change_address is used only to convert
   the mode, not to change the address.  */
      if (stack)
  {
    /* Note that the real part always precedes the imag part in memory
       regardless of machine's endianness.  */
#ifdef STACK_GROWS_DOWNWARD
    emit_insn (GEN_FCN (mov_optab->handlers[(int) submode].insn_code)
         (gen_rtx_MEM (submode, XEXP (x, 0)),
          gen_imagpart (submode, y)));
    emit_insn (GEN_FCN (mov_optab->handlers[(int) submode].insn_code)
         (gen_rtx_MEM (submode, XEXP (x, 0)),
          gen_realpart (submode, y)));
#else
    emit_insn (GEN_FCN (mov_optab->handlers[(int) submode].insn_code)
         (gen_rtx_MEM (submode, XEXP (x, 0)),
          gen_realpart (submode, y)));
    emit_insn (GEN_FCN (mov_optab->handlers[(int) submode].insn_code)
         (gen_rtx_MEM (submode, XEXP (x, 0)),
          gen_imagpart (submode, y)));
#endif
  }
      else
  {
    rtx realpart_x, realpart_y;
    rtx imagpart_x, imagpart_y;

    /* If this is a complex value with each part being smaller than a
       word, the usual calling sequence will likely pack the pieces into
       a single register.  Unfortunately, SUBREG of hard registers only
       deals in terms of words, so we have a problem converting input
       arguments to the CONCAT of two registers that is used elsewhere
       for complex values.  If this is before reload, we can copy it into
       memory and reload.  FIXME, we should see about using extract and
       insert on integer registers, but complex short and complex char
       variables should be rarely used.  */
    if (GET_MODE_BITSIZE (mode) < 2 * BITS_PER_WORD
        && (reload_in_progress | reload_completed) == 0)
      {
        int packed_dest_p
    = (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER);
        int packed_src_p
    = (REG_P (y) && REGNO (y) < FIRST_PSEUDO_REGISTER);

        if (packed_dest_p || packed_src_p)
    {
      enum mode_class reg_class = ((class == MODE_COMPLEX_FLOAT)
                 ? MODE_FLOAT : MODE_INT);

      enum machine_mode reg_mode
        = mode_for_size (GET_MODE_BITSIZE (mode), reg_class, 1);

      if (reg_mode != BLKmode)
        {
          rtx mem = assign_stack_temp (reg_mode,
               GET_MODE_SIZE (mode), 0);
          rtx cmem = adjust_address (mem, mode, 0);

          cfun->cannot_inline
      = N_("function using short complex types cannot be inline");

          if (packed_dest_p)
      {
        rtx sreg = gen_rtx_SUBREG (reg_mode, x, 0);

        emit_move_insn_1 (cmem, y);
        return emit_move_insn_1 (sreg, mem);
      }
          else
      {
        rtx sreg = gen_rtx_SUBREG (reg_mode, y, 0);

        emit_move_insn_1 (mem, sreg);
        return emit_move_insn_1 (x, cmem);
      }
        }
    }
      }

    realpart_x = gen_realpart (submode, x);
    realpart_y = gen_realpart (submode, y);
    imagpart_x = gen_imagpart (submode, x);
    imagpart_y = gen_imagpart (submode, y);

    /* Show the output dies here.  This is necessary for SUBREGs
       of pseudos since we cannot track their lifetimes correctly;
       hard regs shouldn't appear here except as return values.
       We never want to emit such a clobber after reload.  */
    if (x != y
        && ! (reload_in_progress || reload_completed)
        && (GET_CODE (realpart_x) == SUBREG
      || GET_CODE (imagpart_x) == SUBREG))
      emit_insn (gen_rtx_CLOBBER (VOIDmode, x));

    emit_insn (GEN_FCN (mov_optab->handlers[(int) submode].insn_code)
         (realpart_x, realpart_y));
    emit_insn (GEN_FCN (mov_optab->handlers[(int) submode].insn_code)
         (imagpart_x, imagpart_y));
  }

      return get_last_insn ();
    }

  /* This will handle any multi-word or full-word mode that lacks a move_insn
     pattern.  However, you will get better code if you define such patterns,
     even if they must turn into multiple assembler instructions.  */
  else if (GET_MODE_SIZE (mode) >= UNITS_PER_WORD)
    {
      rtx last_insn = 0;
      rtx seq, inner;
      int need_clobber;
      int i;

#ifdef PUSH_ROUNDING

      /* If X is a push on the stack, do the push now and replace
   X with a reference to the stack pointer.  */
      if (push_operand (x, GET_MODE (x)))
  {
    rtx temp;
    enum rtx_code code;

    /* Do not use anti_adjust_stack, since we don't want to update
       stack_pointer_delta.  */
    temp = expand_binop (Pmode,
#ifdef STACK_GROWS_DOWNWARD
             sub_optab,
#else
             add_optab,
#endif
             stack_pointer_rtx,
             GEN_INT
         (PUSH_ROUNDING
          (GET_MODE_SIZE (GET_MODE (x)))),
             stack_pointer_rtx, 0, OPTAB_LIB_WIDEN);

    if (temp != stack_pointer_rtx)
      emit_move_insn (stack_pointer_rtx, temp);

    code = GET_CODE (XEXP (x, 0));

    /* Just hope that small offsets off SP are OK.  */
    if (code == POST_INC)
      temp = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
        GEN_INT (-((HOST_WIDE_INT)
             GET_MODE_SIZE (GET_MODE (x)))));
    else if (code == POST_DEC)
      temp = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
        GEN_INT (GET_MODE_SIZE (GET_MODE (x))));
    else
      temp = stack_pointer_rtx;

    x = change_address (x, VOIDmode, temp);
  }
#endif

      /* If we are in reload, see if either operand is a MEM whose address
   is scheduled for replacement.  */
      if (reload_in_progress && GET_CODE (x) == MEM
    && (inner = find_replacement (&XEXP (x, 0))) != XEXP (x, 0))
  x = replace_equiv_address_nv (x, inner);
      if (reload_in_progress && GET_CODE (y) == MEM
    && (inner = find_replacement (&XEXP (y, 0))) != XEXP (y, 0))
  y = replace_equiv_address_nv (y, inner);

      start_sequence ();

      need_clobber = 0;
      for (i = 0;
     i < (GET_MODE_SIZE (mode) + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
     i++)
  {
    rtx xpart = operand_subword (x, i, 1, mode);
    rtx ypart = operand_subword (y, i, 1, mode);

    /* If we can't get a part of Y, put Y into memory if it is a
       constant.  Otherwise, force it into a register.  If we still
       can't get a part of Y, abort.  */
    if (ypart == 0 && CONSTANT_P (y))
      {
        y = force_const_mem (mode, y);
        ypart = operand_subword (y, i, 1, mode);
      }
    else if (ypart == 0)
      ypart = operand_subword_force (y, i, mode);

    if (xpart == 0 || ypart == 0)
      abort ();

    need_clobber |= (GET_CODE (xpart) == SUBREG);

    last_insn = emit_move_insn (xpart, ypart);
  }

      seq = get_insns ();
      end_sequence ();

      /* Show the output dies here.  This is necessary for SUBREGs
   of pseudos since we cannot track their lifetimes correctly;
   hard regs shouldn't appear here except as return values.
   We never want to emit such a clobber after reload.  */
      if (x != y
    && ! (reload_in_progress || reload_completed)
    && need_clobber != 0)
  emit_insn (gen_rtx_CLOBBER (VOIDmode, x));

      emit_insn (seq);

      return last_insn;
    }
  else
    abort ();
}

/* If Y is representable exactly in a narrower mode, and the target can
   perform the extension directly from constant or memory, then emit the
   move as an extension.  */

static rtx
compress_float_constant (x, y)
     rtx x, y;
{
  enum machine_mode dstmode = GET_MODE (x);
  enum machine_mode orig_srcmode = GET_MODE (y);
  enum machine_mode srcmode;
  REAL_VALUE_TYPE r;

  REAL_VALUE_FROM_CONST_DOUBLE (r, y);

  for (srcmode = GET_CLASS_NARROWEST_MODE (GET_MODE_CLASS (orig_srcmode));
       srcmode != orig_srcmode;
       srcmode = GET_MODE_WIDER_MODE (srcmode))
    {
      enum insn_code ic;
      rtx trunc_y, last_insn;

      /* Skip if the target can't extend this way.  */
      ic = can_extend_p (dstmode, srcmode, 0);
      if (ic == CODE_FOR_nothing)
  continue;

      /* Skip if the narrowed value isn't exact.  */
      if (! exact_real_truncate (srcmode, &r))
  continue;

      trunc_y = CONST_DOUBLE_FROM_REAL_VALUE (r, srcmode);

      if (LEGITIMATE_CONSTANT_P (trunc_y))
  {
    /* Skip if the target needs extra instructions to perform
       the extension.  */
    if (! (*insn_data[ic].operand[1].predicate) (trunc_y, srcmode))
      continue;
  }
      else if (float_extend_from_mem[dstmode][srcmode])
  trunc_y = validize_mem (force_const_mem (srcmode, trunc_y));
      else
  continue;

      emit_unop_insn (ic, x, trunc_y, UNKNOWN);
      last_insn = get_last_insn ();

      if (GET_CODE (x) == REG)
  REG_NOTES (last_insn)
    = gen_rtx_EXPR_LIST (REG_EQUAL, y, REG_NOTES (last_insn));

      return last_insn;
    }

  return NULL_RTX;
}

/* Pushing data onto the stack.  */

/* Push a block of length SIZE (perhaps variable)
   and return an rtx to address the beginning of the block.
   Note that it is not possible for the value returned to be a QUEUED.
   The value may be virtual_outgoing_args_rtx.

   EXTRA is the number of bytes of padding to push in addition to SIZE.
   BELOW nonzero means this padding comes at low addresses;
   otherwise, the padding comes at high addresses.  */

rtx
push_block (size, extra, below)
     rtx size;
     int extra, below;
{
  rtx temp;

  size = convert_modes (Pmode, ptr_mode, size, 1);
  if (CONSTANT_P (size))
    anti_adjust_stack (plus_constant (size, extra));
  else if (GET_CODE (size) == REG && extra == 0)
    anti_adjust_stack (size);
  else
    {
      temp = copy_to_mode_reg (Pmode, size);
      if (extra != 0)
  temp = expand_binop (Pmode, add_optab, temp, GEN_INT (extra),
           temp, 0, OPTAB_LIB_WIDEN);
      anti_adjust_stack (temp);
    }

#ifndef STACK_GROWS_DOWNWARD
  if (0)
#else
  if (1)
#endif
    {
      temp = virtual_outgoing_args_rtx;
      if (extra != 0 && below)
  temp = plus_constant (temp, extra);
    }
  else
    {
      if (GET_CODE (size) == CONST_INT)
  temp = plus_constant (virtual_outgoing_args_rtx,
            -INTVAL (size) - (below ? 0 : extra));
      else if (extra != 0 && !below)
  temp = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
           negate_rtx (Pmode, plus_constant (size, extra)));
      else
  temp = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
           negate_rtx (Pmode, size));
    }

  return memory_address (GET_CLASS_NARROWEST_MODE (MODE_INT), temp);
}

#ifdef PUSH_ROUNDING

/* Emit single push insn.  */

static void
emit_single_push_insn (mode, x, type)
     rtx x;
     enum machine_mode mode;
     tree type;
{
  rtx dest_addr;
  unsigned rounded_size = PUSH_ROUNDING (GET_MODE_SIZE (mode));
  rtx dest;
  enum insn_code icode;
  insn_operand_predicate_fn pred;

  stack_pointer_delta += PUSH_ROUNDING (GET_MODE_SIZE (mode));
  /* If there is push pattern, use it.  Otherwise try old way of throwing
     MEM representing push operation to move expander.  */
  icode = push_optab->handlers[(int) mode].insn_code;
  if (icode != CODE_FOR_nothing)
    {
      if (((pred = insn_data[(int) icode].operand[0].predicate)
     && !((*pred) (x, mode))))
  x = force_reg (mode, x);
      emit_insn (GEN_FCN (icode) (x));
      return;
    }
  if (GET_MODE_SIZE (mode) == rounded_size)
    dest_addr = gen_rtx_fmt_e (STACK_PUSH_CODE, Pmode, stack_pointer_rtx);
  else
    {
#ifdef STACK_GROWS_DOWNWARD
      dest_addr = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
        GEN_INT (-(HOST_WIDE_INT) rounded_size));
#else
      dest_addr = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
        GEN_INT (rounded_size));
#endif
      dest_addr = gen_rtx_PRE_MODIFY (Pmode, stack_pointer_rtx, dest_addr);
    }

  dest = gen_rtx_MEM (mode, dest_addr);

  if (type != 0)
    {
      set_mem_attributes (dest, type, 1);

      if (flag_optimize_sibling_calls)
  /* Function incoming arguments may overlap with sibling call
     outgoing arguments and we cannot allow reordering of reads
     from function arguments with stores to outgoing arguments
     of sibling calls.  */
  set_mem_alias_set (dest, 0);
    }
  emit_move_insn (dest, x);
}
#endif

/* Generate code to push X onto the stack, assuming it has mode MODE and
   type TYPE.
   MODE is redundant except when X is a CONST_INT (since they don't
   carry mode info).
   SIZE is an rtx for the size of data to be copied (in bytes),
   needed only if X is BLKmode.

   ALIGN (in bits) is maximum alignment we can assume.

   If PARTIAL and REG are both nonzero, then copy that many of the first
   words of X into registers starting with REG, and push the rest of X.
   The amount of space pushed is decreased by PARTIAL words,
   rounded *down* to a multiple of PARM_BOUNDARY.
   REG must be a hard register in this case.
   If REG is zero but PARTIAL is not, take any all others actions for an
   argument partially in registers, but do not actually load any
   registers.

   EXTRA is the amount in bytes of extra space to leave next to this arg.
   This is ignored if an argument block has already been allocated.

   On a machine that lacks real push insns, ARGS_ADDR is the address of
   the bottom of the argument block for this call.  We use indexing off there
   to store the arg.  On machines with push insns, ARGS_ADDR is 0 when a
   argument block has not been preallocated.

   ARGS_SO_FAR is the size of args previously pushed for this call.

   REG_PARM_STACK_SPACE is nonzero if functions require stack space
   for arguments passed in registers.  If nonzero, it will be the number
   of bytes required.  */

void
emit_push_insn (x, mode, type, size, align, partial, reg, extra,
    args_addr, args_so_far, reg_parm_stack_space,
    alignment_pad)
     rtx x;
     enum machine_mode mode;
     tree type;
     rtx size;
     unsigned int align;
     int partial;
     rtx reg;
     int extra;
     rtx args_addr;
     rtx args_so_far;
     int reg_parm_stack_space;
     rtx alignment_pad;
{
  rtx xinner;
  enum direction stack_direction
#ifdef STACK_GROWS_DOWNWARD
    = downward;
#else
    = upward;
#endif

  /* Decide where to pad the argument: `downward' for below,
     `upward' for above, or `none' for don't pad it.
     Default is below for small data on big-endian machines; else above.  */
  enum direction where_pad = FUNCTION_ARG_PADDING (mode, type);

  /* Invert direction if stack is post-decrement.
     FIXME: why?  */
  if (STACK_PUSH_CODE == POST_DEC)
    if (where_pad != none)
      where_pad = (where_pad == downward ? upward : downward);

  xinner = x = protect_from_queue (x, 0);

  if (mode == BLKmode)
    {
      /* Copy a block into the stack, entirely or partially.  */

      rtx temp;
      int used = partial * UNITS_PER_WORD;
      int offset = used % (PARM_BOUNDARY / BITS_PER_UNIT);
      int skip;

      if (size == 0)
  abort ();

      used -= offset;

      /* USED is now the # of bytes we need not copy to the stack
   because registers will take care of them.  */

      if (partial != 0)
  xinner = adjust_address (xinner, BLKmode, used);

      /* If the partial register-part of the arg counts in its stack size,
   skip the part of stack space corresponding to the registers.
   Otherwise, start copying to the beginning of the stack space,
   by setting SKIP to 0.  */
      skip = (reg_parm_stack_space == 0) ? 0 : used;

#ifdef PUSH_ROUNDING
      /* Do it with several push insns if that doesn't take lots of insns
   and if there is no difficulty with push insns that skip bytes
   on the stack for alignment purposes.  */
      if (args_addr == 0
    && PUSH_ARGS
    && GET_CODE (size) == CONST_INT
    && skip == 0
    && (MOVE_BY_PIECES_P ((unsigned) INTVAL (size) - used, align))
    /* Here we avoid the case of a structure whose weak alignment
       forces many pushes of a small amount of data,
       and such small pushes do rounding that causes trouble.  */
    && ((! SLOW_UNALIGNED_ACCESS (word_mode, align))
        || align >= BIGGEST_ALIGNMENT
        || (PUSH_ROUNDING (align / BITS_PER_UNIT)
      == (align / BITS_PER_UNIT)))
    && PUSH_ROUNDING (INTVAL (size)) == INTVAL (size))
  {
    /* Push padding now if padding above and stack grows down,
       or if padding below and stack grows up.
       But if space already allocated, this has already been done.  */
    if (extra && args_addr == 0
        && where_pad != none && where_pad != stack_direction)
      anti_adjust_stack (GEN_INT (extra));

    move_by_pieces (NULL, xinner, INTVAL (size) - used, align, 0);
  }
      else
#endif /* PUSH_ROUNDING  */
  {
    rtx target;

    /* Otherwise make space on the stack and copy the data
       to the address of that space.  */

    /* Deduct words put into registers from the size we must copy.  */
    if (partial != 0)
      {
        if (GET_CODE (size) == CONST_INT)
    size = GEN_INT (INTVAL (size) - used);
        else
    size = expand_binop (GET_MODE (size), sub_optab, size,
             GEN_INT (used), NULL_RTX, 0,
             OPTAB_LIB_WIDEN);
      }

    /* Get the address of the stack space.
       In this case, we do not deal with EXTRA separately.
       A single stack adjust will do.  */
    if (! args_addr)
      {
        temp = push_block (size, extra, where_pad == downward);
        extra = 0;
      }
    else if (GET_CODE (args_so_far) == CONST_INT)
      temp = memory_address (BLKmode,
           plus_constant (args_addr,
              skip + INTVAL (args_so_far)));
    else
      temp = memory_address (BLKmode,
           plus_constant (gen_rtx_PLUS (Pmode,
                args_addr,
                args_so_far),
              skip));

    if (!ACCUMULATE_OUTGOING_ARGS)
      {
        /* If the source is referenced relative to the stack pointer,
     copy it to another register to stabilize it.  We do not need
     to do this if we know that we won't be changing sp.  */

        if (reg_mentioned_p (virtual_stack_dynamic_rtx, temp)
      || reg_mentioned_p (virtual_outgoing_args_rtx, temp))
    temp = copy_to_reg (temp);
      }

    target = gen_rtx_MEM (BLKmode, temp);

    if (type != 0)
      {
        set_mem_attributes (target, type, 1);
        /* Function incoming arguments may overlap with sibling call
     outgoing arguments and we cannot allow reordering of reads
     from function arguments with stores to outgoing arguments
     of sibling calls.  */
        set_mem_alias_set (target, 0);
      }

    /* ALIGN may well be better aligned than TYPE, e.g. due to
       PARM_BOUNDARY.  Assume the caller isn't lying.  */
    set_mem_align (target, align);

    emit_block_move (target, xinner, size, BLOCK_OP_CALL_PARM);
  }
    }
  else if (partial > 0)
    {
      /* Scalar partly in registers.  */

      int size = GET_MODE_SIZE (mode) / UNITS_PER_WORD;
      int i;
      int not_stack;
      /* # words of start of argument
   that we must make space for but need not store.  */
      int offset = partial % (PARM_BOUNDARY / BITS_PER_WORD);
      int args_offset = INTVAL (args_so_far);
      int skip;

      /* Push padding now if padding above and stack grows down,
   or if padding below and stack grows up.
   But if space already allocated, this has already been done.  */
      if (extra && args_addr == 0
    && where_pad != none && where_pad != stack_direction)
  anti_adjust_stack (GEN_INT (extra));

      /* If we make space by pushing it, we might as well push
   the real data.  Otherwise, we can leave OFFSET nonzero
   and leave the space uninitialized.  */
      if (args_addr == 0)
  offset = 0;

      /* Now NOT_STACK gets the number of words that we don't need to
   allocate on the stack.  */
      not_stack = partial - offset;

      /* If the partial register-part of the arg counts in its stack size,
   skip the part of stack space corresponding to the registers.
   Otherwise, start copying to the beginning of the stack space,
   by setting SKIP to 0.  */
      skip = (reg_parm_stack_space == 0) ? 0 : not_stack;

      if (CONSTANT_P (x) && ! LEGITIMATE_CONSTANT_P (x))
  x = validize_mem (force_const_mem (mode, x));

      /* If X is a hard register in a non-integer mode, copy it into a pseudo;
   SUBREGs of such registers are not allowed.  */
      if ((GET_CODE (x) == REG && REGNO (x) < FIRST_PSEUDO_REGISTER
     && GET_MODE_CLASS (GET_MODE (x)) != MODE_INT))
  x = copy_to_reg (x);

      /* Loop over all the words allocated on the stack for this arg.  */
      /* We can do it by words, because any scalar bigger than a word
   has a size a multiple of a word.  */
#ifndef PUSH_ARGS_REVERSED
      for (i = not_stack; i < size; i++)
#else
      for (i = size - 1; i >= not_stack; i--)
#endif
  if (i >= not_stack + offset)
    emit_push_insn (operand_subword_force (x, i, mode),
        word_mode, NULL_TREE, NULL_RTX, align, 0, NULL_RTX,
        0, args_addr,
        GEN_INT (args_offset + ((i - not_stack + skip)
              * UNITS_PER_WORD)),
        reg_parm_stack_space, alignment_pad);
    }
  else
    {
      rtx addr;
      rtx target = NULL_RTX;
      rtx dest;

      /* Push padding now if padding above and stack grows down,
   or if padding below and stack grows up.
   But if space already allocated, this has already been done.  */
      if (extra && args_addr == 0
    && where_pad != none && where_pad != stack_direction)
  anti_adjust_stack (GEN_INT (extra));

#ifdef PUSH_ROUNDING
      if (args_addr == 0 && PUSH_ARGS)
  emit_single_push_insn (mode, x, type);
      else
#endif
  {
    if (GET_CODE (args_so_far) == CONST_INT)
      addr
        = memory_address (mode,
        plus_constant (args_addr,
                 INTVAL (args_so_far)));
    else
      addr = memory_address (mode, gen_rtx_PLUS (Pmode, args_addr,
                   args_so_far));
    target = addr;
    dest = gen_rtx_MEM (mode, addr);
    if (type != 0)
      {
        set_mem_attributes (dest, type, 1);
        /* Function incoming arguments may overlap with sibling call
     outgoing arguments and we cannot allow reordering of reads
     from function arguments with stores to outgoing arguments
     of sibling calls.  */
        set_mem_alias_set (dest, 0);
      }

    emit_move_insn (dest, x);
  }
    }

  /* If part should go in registers, copy that part
     into the appropriate registers.  Do this now, at the end,
     since mem-to-mem copies above may do function calls.  */
  if (partial > 0 && reg != 0)
    {
      /* Handle calls that pass values in multiple non-contiguous locations.
   The Irix 6 ABI has examples of this.  */
      if (GET_CODE (reg) == PARALLEL)
  emit_group_load (reg, x, -1);  /* ??? size? */
      else
  move_block_to_reg (REGNO (reg), x, partial, mode);
    }

  if (extra && args_addr == 0 && where_pad == stack_direction)
    anti_adjust_stack (GEN_INT (extra));

  if (alignment_pad && args_addr == 0)
    anti_adjust_stack (alignment_pad);
}

/* Return X if X can be used as a subtarget in a sequence of arithmetic
   operations.  */

static rtx
get_subtarget (x)
     rtx x;
{
  return ((x == 0
     /* Only registers can be subtargets.  */
     || GET_CODE (x) != REG
     /* If the register is readonly, it can't be set more than once.  */
     || RTX_UNCHANGING_P (x)
     /* Don't use hard regs to avoid extending their life.  */
     || REGNO (x) < FIRST_PSEUDO_REGISTER
     /* Avoid subtargets inside loops,
        since they hide some invariant expressions.  */
     || preserve_subexpressions_p ())
    ? 0 : x);
}

/* Expand an assignment that stores the value of FROM into TO.
   If WANT_VALUE is nonzero, return an rtx for the value of TO.
   (This may contain a QUEUED rtx;
   if the value is constant, this rtx is a constant.)
   Otherwise, the returned value is NULL_RTX.

   SUGGEST_REG is no longer actually used.
   It used to mean, copy the value through a register
   and return that register, if that is possible.
   We now use WANT_VALUE to decide whether to do this.  */

rtx
expand_assignment (to, from, want_value, suggest_reg)
     tree to, from;
     int want_value;
     int suggest_reg ATTRIBUTE_UNUSED;
{
  rtx to_rtx = 0;
  rtx result;

  /* Don't crash if the lhs of the assignment was erroneous.  */

  if (TREE_CODE (to) == ERROR_MARK)
    {
      result = expand_expr (from, NULL_RTX, VOIDmode, 0);
      return want_value ? result : NULL_RTX;
    }

  /* Assignment of a structure component needs special treatment
     if the structure component's rtx is not simply a MEM.
     Assignment of an array element at a constant index, and assignment of
     an array element in an unaligned packed structure field, has the same
     problem.  */

  if (TREE_CODE (to) == COMPONENT_REF || TREE_CODE (to) == BIT_FIELD_REF
      || TREE_CODE (to) == ARRAY_REF || TREE_CODE (to) == ARRAY_RANGE_REF
      || TREE_CODE (TREE_TYPE (to)) == ARRAY_TYPE)
    {
      enum machine_mode mode1;
      HOST_WIDE_INT bitsize, bitpos;
      rtx orig_to_rtx;
      tree offset;
      int unsignedp;
      int volatilep = 0;
      tree tem;

      push_temp_slots ();
      tem = get_inner_reference (to, &bitsize, &bitpos, &offset, &mode1,
         &unsignedp, &volatilep);

      /* If we are going to use store_bit_field and extract_bit_field,
   make sure to_rtx will be safe for multiple use.  */

      if (mode1 == VOIDmode && want_value)
  tem = stabilize_reference (tem);

      orig_to_rtx = to_rtx = expand_expr (tem, NULL_RTX, VOIDmode, 0);

      if (offset != 0)
  {
    rtx offset_rtx = expand_expr (offset, NULL_RTX, VOIDmode, EXPAND_SUM);

    if (GET_CODE (to_rtx) != MEM)
      abort ();

#ifdef POINTERS_EXTEND_UNSIGNED
    if (GET_MODE (offset_rtx) != Pmode)
      offset_rtx = convert_to_mode (Pmode, offset_rtx, 0);
#else
    if (GET_MODE (offset_rtx) != ptr_mode)
      offset_rtx = convert_to_mode (ptr_mode, offset_rtx, 0);
#endif

    /* A constant address in TO_RTX can have VOIDmode, we must not try
       to call force_reg for that case.  Avoid that case.  */
    if (GET_CODE (to_rtx) == MEM
        && GET_MODE (to_rtx) == BLKmode
        && GET_MODE (XEXP (to_rtx, 0)) != VOIDmode
        && bitsize > 0
        && (bitpos % bitsize) == 0
        && (bitsize % GET_MODE_ALIGNMENT (mode1)) == 0
        && MEM_ALIGN (to_rtx) == GET_MODE_ALIGNMENT (mode1))
      {
        to_rtx = adjust_address (to_rtx, mode1, bitpos / BITS_PER_UNIT);
        bitpos = 0;
      }

    to_rtx = offset_address (to_rtx, offset_rtx,
           highest_pow2_factor_for_type (TREE_TYPE (to),
                 offset));
  }

      if (GET_CODE (to_rtx) == MEM)
  {
    /* If the field is at offset zero, we could have been given the
       DECL_RTX of the parent struct.  Don't munge it.  */
    to_rtx = shallow_copy_rtx (to_rtx);

    set_mem_attributes_minus_bitpos (to_rtx, to, 0, bitpos);
  }

      /* Deal with volatile and readonly fields.  The former is only done
   for MEM.  Also set MEM_KEEP_ALIAS_SET_P if needed.  */
      if (volatilep && GET_CODE (to_rtx) == MEM)
  {
    if (to_rtx == orig_to_rtx)
      to_rtx = copy_rtx (to_rtx);
    MEM_VOLATILE_P (to_rtx) = 1;
  }

      if (TREE_CODE (to) == COMPONENT_REF
    && TREE_READONLY (TREE_OPERAND (to, 1)))
  {
    if (to_rtx == orig_to_rtx)
      to_rtx = copy_rtx (to_rtx);
    RTX_UNCHANGING_P (to_rtx) = 1;
  }

      if (GET_CODE (to_rtx) == MEM && ! can_address_p (to))
  {
    if (to_rtx == orig_to_rtx)
      to_rtx = copy_rtx (to_rtx);
    MEM_KEEP_ALIAS_SET_P (to_rtx) = 1;
  }

      result = store_field (to_rtx, bitsize, bitpos, mode1, from,
          (want_value
           /* Spurious cast for HPUX compiler.  */
           ? ((enum machine_mode)
        TYPE_MODE (TREE_TYPE (to)))
           : VOIDmode),
          unsignedp, TREE_TYPE (tem), get_alias_set (to));

      preserve_temp_slots (result);
      free_temp_slots ();
      pop_temp_slots ();

      /* If the value is meaningful, convert RESULT to the proper mode.
   Otherwise, return nothing.  */
      return (want_value ? convert_modes (TYPE_MODE (TREE_TYPE (to)),
            TYPE_MODE (TREE_TYPE (from)),
            result,
            TREE_UNSIGNED (TREE_TYPE (to)))
        : NULL_RTX);
    }

  /* If the rhs is a function call and its value is not an aggregate,
     call the function before we start to compute the lhs.
     This is needed for correct code for cases such as
     val = setjmp (buf) on machines where reference to val
     requires loading up part of an address in a separate insn.

     Don't do this if TO is a VAR_DECL or PARM_DECL whose DECL_RTL is REG
     since it might be a promoted variable where the zero- or sign- extension
     needs to be done.  Handling this in the normal way is safe because no
     computation is done before the call.  */
  if (TREE_CODE (from) == CALL_EXPR && ! aggregate_value_p (from)
      && TREE_CODE (TYPE_SIZE (TREE_TYPE (from))) == INTEGER_CST
      && ! ((TREE_CODE (to) == VAR_DECL || TREE_CODE (to) == PARM_DECL)
      && GET_CODE (DECL_RTL (to)) == REG))
    {
      rtx value;

      push_temp_slots ();
      value = expand_expr (from, NULL_RTX, VOIDmode, 0);
      if (to_rtx == 0)
  to_rtx = expand_expr (to, NULL_RTX, VOIDmode, EXPAND_WRITE);

      /* Handle calls that return values in multiple non-contiguous locations.
   The Irix 6 ABI has examples of this.  */
      if (GET_CODE (to_rtx) == PARALLEL)
  emit_group_load (to_rtx, value, int_size_in_bytes (TREE_TYPE (from)));
      else if (GET_MODE (to_rtx) == BLKmode)
  emit_block_move (to_rtx, value, expr_size (from), BLOCK_OP_NORMAL);
      else
  {
#ifdef POINTERS_EXTEND_UNSIGNED
    if (POINTER_TYPE_P (TREE_TYPE (to))
        && GET_MODE (to_rtx) != GET_MODE (value))
      value = convert_memory_address (GET_MODE (to_rtx), value);
#endif
    emit_move_insn (to_rtx, value);
  }
      preserve_temp_slots (to_rtx);
      free_temp_slots ();
      pop_temp_slots ();
      return want_value ? to_rtx : NULL_RTX;
    }

  /* Ordinary treatment.  Expand TO to get a REG or MEM rtx.
     Don't re-expand if it was expanded already (in COMPONENT_REF case).  */

  if (to_rtx == 0)
    to_rtx = expand_expr (to, NULL_RTX, VOIDmode, EXPAND_WRITE);

  /* Don't move directly into a return register.  */
  if (TREE_CODE (to) == RESULT_DECL
      && (GET_CODE (to_rtx) == REG || GET_CODE (to_rtx) == PARALLEL))
    {
      rtx temp;

      push_temp_slots ();
      temp = expand_expr (from, 0, GET_MODE (to_rtx), 0);

      if (GET_CODE (to_rtx) == PARALLEL)
  emit_group_load (to_rtx, temp, int_size_in_bytes (TREE_TYPE (from)));
      else
  emit_move_insn (to_rtx, temp);

      preserve_temp_slots (to_rtx);
      free_temp_slots ();
      pop_temp_slots ();
      return want_value ? to_rtx : NULL_RTX;
    }

  /* In case we are returning the contents of an object which overlaps
     the place the value is being stored, use a safe function when copying
     a value through a pointer into a structure value return block.  */
  if (TREE_CODE (to) == RESULT_DECL && TREE_CODE (from) == INDIRECT_REF
      && current_function_returns_struct
      && !current_function_returns_pcc_struct)
    {
      rtx from_rtx, size;

      push_temp_slots ();
      size = expr_size (from);
      from_rtx = expand_expr (from, NULL_RTX, VOIDmode, 0);

      if (TARGET_MEM_FUNCTIONS)
  emit_library_call (memmove_libfunc, LCT_NORMAL,
         VOIDmode, 3, XEXP (to_rtx, 0), Pmode,
         XEXP (from_rtx, 0), Pmode,
         convert_to_mode (TYPE_MODE (sizetype),
              size, TREE_UNSIGNED (sizetype)),
         TYPE_MODE (sizetype));
      else
        emit_library_call (bcopy_libfunc, LCT_NORMAL,
         VOIDmode, 3, XEXP (from_rtx, 0), Pmode,
         XEXP (to_rtx, 0), Pmode,
         convert_to_mode (TYPE_MODE (integer_type_node),
              size,
              TREE_UNSIGNED (integer_type_node)),
         TYPE_MODE (integer_type_node));

      preserve_temp_slots (to_rtx);
      free_temp_slots ();
      pop_temp_slots ();
      return want_value ? to_rtx : NULL_RTX;
    }

  /* Compute FROM and store the value in the rtx we got.  */

  push_temp_slots ();
  result = store_expr (from, to_rtx, want_value);
  preserve_temp_slots (result);
  free_temp_slots ();
  pop_temp_slots ();
  return want_value ? result : NULL_RTX;
}

/* Generate code for computing expression EXP,
   and storing the value into TARGET.
   TARGET may contain a QUEUED rtx.

   If WANT_VALUE & 1 is nonzero, return a copy of the value
   not in TARGET, so that we can be sure to use the proper
   value in a containing expression even if TARGET has something
   else stored in it.  If possible, we copy the value through a pseudo
   and return that pseudo.  Or, if the value is constant, we try to
   return the constant.  In some cases, we return a pseudo
   copied *from* TARGET.

   If the mode is BLKmode then we may return TARGET itself.
   It turns out that in BLKmode it doesn't cause a problem.
   because C has no operators that could combine two different
   assignments into the same BLKmode object with different values
   with no sequence point.  Will other languages need this to
   be more thorough?

   If WANT_VALUE & 1 is 0, we return NULL, to make sure
   to catch quickly any cases where the caller uses the value
   and fails to set WANT_VALUE.

   If WANT_VALUE & 2 is set, this is a store into a call param on the
   stack, and block moves may need to be treated specially.  */

rtx
store_expr (exp, target, want_value)
     tree exp;
     rtx target;
     int want_value;
{
  rtx temp;
  int dont_return_target = 0;
  int dont_store_target = 0;

  if (VOID_TYPE_P (TREE_TYPE (exp)))
    {
      /* C++ can generate ?: expressions with a throw expression in one
   branch and an rvalue in the other. Here, we resolve attempts to
   store the throw expression's nonexistant result. */
      if (want_value)
  abort ();
      expand_expr (exp, const0_rtx, VOIDmode, 0);
      return NULL_RTX;
    }
  if (TREE_CODE (exp) == COMPOUND_EXPR)
    {
      /* Perform first part of compound expression, then assign from second
   part.  */
      expand_expr (TREE_OPERAND (exp, 0), const0_rtx, VOIDmode,
       want_value & 2 ? EXPAND_STACK_PARM : EXPAND_NORMAL);
      emit_queue ();
      return store_expr (TREE_OPERAND (exp, 1), target, want_value);
    }
  else if (TREE_CODE (exp) == COND_EXPR && GET_MODE (target) == BLKmode)
    {
      /* For conditional expression, get safe form of the target.  Then
   test the condition, doing the appropriate assignment on either
   side.  This avoids the creation of unnecessary temporaries.
   For non-BLKmode, it is more efficient not to do this.  */

      rtx lab1 = gen_label_rtx (), lab2 = gen_label_rtx ();

      emit_queue ();
      target = protect_from_queue (target, 1);

      do_pending_stack_adjust ();
      NO_DEFER_POP;
      jumpifnot (TREE_OPERAND (exp, 0), lab1);
      start_cleanup_deferral ();
      store_expr (TREE_OPERAND (exp, 1), target, want_value & 2);
      end_cleanup_deferral ();
      emit_queue ();
      emit_jump_insn (gen_jump (lab2));
      emit_barrier ();
      emit_label (lab1);
      start_cleanup_deferral ();
      store_expr (TREE_OPERAND (exp, 2), target, want_value & 2);
      end_cleanup_deferral ();
      emit_queue ();
      emit_label (lab2);
      OK_DEFER_POP;

      return want_value & 1 ? target : NULL_RTX;
    }
  else if (queued_subexp_p (target))
    /* If target contains a postincrement, let's not risk
       using it as the place to generate the rhs.  */
    {
      if (GET_MODE (target) != BLKmode && GET_MODE (target) != VOIDmode)
  {
    /* Expand EXP into a new pseudo.  */
    temp = gen_reg_rtx (GET_MODE (target));
    temp = expand_expr (exp, temp, GET_MODE (target),
            (want_value & 2
             ? EXPAND_STACK_PARM : EXPAND_NORMAL));
  }
      else
  temp = expand_expr (exp, NULL_RTX, GET_MODE (target),
          (want_value & 2
           ? EXPAND_STACK_PARM : EXPAND_NORMAL));

      /* If target is volatile, ANSI requires accessing the value
   *from* the target, if it is accessed.  So make that happen.
   In no case return the target itself.  */
      if (! MEM_VOLATILE_P (target) && (want_value & 1) != 0)
  dont_return_target = 1;
    }
  else if ((want_value & 1) != 0
     && GET_CODE (target) == MEM
     && ! MEM_VOLATILE_P (target)
     && GET_MODE (target) != BLKmode)
    /* If target is in memory and caller wants value in a register instead,
       arrange that.  Pass TARGET as target for expand_expr so that,
       if EXP is another assignment, WANT_VALUE will be nonzero for it.
       We know expand_expr will not use the target in that case.
       Don't do this if TARGET is volatile because we are supposed
       to write it and then read it.  */
    {
      temp = expand_expr (exp, target, GET_MODE (target),
        want_value & 2 ? EXPAND_STACK_PARM : EXPAND_NORMAL);
      if (GET_MODE (temp) != BLKmode && GET_MODE (temp) != VOIDmode)
  {
    /* If TEMP is already in the desired TARGET, only copy it from
       memory and don't store it there again.  */
    if (temp == target
        || (rtx_equal_p (temp, target)
      && ! side_effects_p (temp) && ! side_effects_p (target)))
      dont_store_target = 1;
    temp = copy_to_reg (temp);
  }
      dont_return_target = 1;
    }
  else if (GET_CODE (target) == SUBREG && SUBREG_PROMOTED_VAR_P (target))
    /* If this is a scalar in a register that is stored in a wider mode
       than the declared mode, compute the result into its declared mode
       and then convert to the wider mode.  Our value is the computed
       expression.  */
    {
      rtx inner_target = 0;

      /* If we don't want a value, we can do the conversion inside EXP,
   which will often result in some optimizations.  Do the conversion
   in two steps: first change the signedness, if needed, then
   the extend.  But don't do this if the type of EXP is a subtype
   of something else since then the conversion might involve
   more than just converting modes.  */
      if ((want_value & 1) == 0
    && INTEGRAL_TYPE_P (TREE_TYPE (exp))
    && TREE_TYPE (TREE_TYPE (exp)) == 0)
  {
    if (TREE_UNSIGNED (TREE_TYPE (exp))
        != SUBREG_PROMOTED_UNSIGNED_P (target))
      exp = convert
        ((*lang_hooks.types.signed_or_unsigned_type)
         (SUBREG_PROMOTED_UNSIGNED_P (target), TREE_TYPE (exp)), exp);

    exp = convert ((*lang_hooks.types.type_for_mode)
       (GET_MODE (SUBREG_REG (target)),
        SUBREG_PROMOTED_UNSIGNED_P (target)),
       exp);

    inner_target = SUBREG_REG (target);
  }

      temp = expand_expr (exp, inner_target, VOIDmode,
        want_value & 2 ? EXPAND_STACK_PARM : EXPAND_NORMAL);

      /* If TEMP is a volatile MEM and we want a result value, make
   the access now so it gets done only once.  Likewise if
   it contains TARGET.  */
      if (GET_CODE (temp) == MEM && (want_value & 1) != 0
    && (MEM_VOLATILE_P (temp)
        || reg_mentioned_p (SUBREG_REG (target), XEXP (temp, 0))))
  temp = copy_to_reg (temp);

      /* 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 (TREE_TYPE (exp)),
        temp, SUBREG_PROMOTED_UNSIGNED_P (target));
    temp = convert_modes (GET_MODE (SUBREG_REG (target)),
              GET_MODE (target), temp,
              SUBREG_PROMOTED_UNSIGNED_P (target));
  }

      convert_move (SUBREG_REG (target), temp,
        SUBREG_PROMOTED_UNSIGNED_P (target));

      /* If we promoted a constant, change the mode back down to match
   target.  Otherwise, the caller might get confused by a result whose
   mode is larger than expected.  */

      if ((want_value & 1) != 0 && GET_MODE (temp) != GET_MODE (target))
  {
    if (GET_MODE (temp) != VOIDmode)
      {
        temp = gen_lowpart_SUBREG (GET_MODE (target), temp);
        SUBREG_PROMOTED_VAR_P (temp) = 1;
        SUBREG_PROMOTED_UNSIGNED_SET (temp,
    SUBREG_PROMOTED_UNSIGNED_P (target));
      }
    else
      temp = convert_modes (GET_MODE (target),
          GET_MODE (SUBREG_REG (target)),
          temp, SUBREG_PROMOTED_UNSIGNED_P (target));
  }

      return want_value & 1 ? temp : NULL_RTX;
    }
  else
    {
      temp = expand_expr (exp, target, GET_MODE (target),
        want_value & 2 ? EXPAND_STACK_PARM : EXPAND_NORMAL);
      /* Return TARGET if it's a specified hardware register.
   If TARGET is a volatile mem ref, either return TARGET
   or return a reg copied *from* TARGET; ANSI requires this.

   Otherwise, if TEMP is not TARGET, return TEMP
   if it is constant (for efficiency),
   or if we really want the correct value.  */
      if (!(target && GET_CODE (target) == REG
      && REGNO (target) < FIRST_PSEUDO_REGISTER)
    && !(GET_CODE (target) == MEM && MEM_VOLATILE_P (target))
    && ! rtx_equal_p (temp, target)
    && (CONSTANT_P (temp) || (want_value & 1) != 0))
  dont_return_target = 1;
    }

  /* If TEMP is a VOIDmode constant and the mode of the type of EXP is not
     the same as that of TARGET, adjust the constant.  This is needed, for
     example, in case it is a CONST_DOUBLE and we want only a word-sized
     value.  */
  if (CONSTANT_P (temp) && GET_MODE (temp) == VOIDmode
      && TREE_CODE (exp) != ERROR_MARK
      && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
    temp = convert_modes (GET_MODE (target), TYPE_MODE (TREE_TYPE (exp)),
        temp, TREE_UNSIGNED (TREE_TYPE (exp)));

  /* If value was not generated in the target, store it there.
     Convert the value to TARGET's type first if necessary.
     If TEMP and TARGET compare equal according to rtx_equal_p, but
     one or both of them are volatile memory refs, we have to distinguish
     two cases:
     - expand_expr has used TARGET.  In this case, we must not generate
       another copy.  This can be detected by TARGET being equal according
       to == .
     - expand_expr has not used TARGET - that means that the source just
       happens to have the same RTX form.  Since temp will have been created
       by expand_expr, it will compare unequal according to == .
       We must generate a copy in this case, to reach the correct number
       of volatile memory references.  */

  if ((! rtx_equal_p (temp, target)
       || (temp != target && (side_effects_p (temp)
            || side_effects_p (target))))
      && TREE_CODE (exp) != ERROR_MARK
      && ! dont_store_target
   /* If store_expr stores a DECL whose DECL_RTL(exp) == TARGET,
      but TARGET is not valid memory reference, TEMP will differ
      from TARGET although it is really the same location.  */
      && (TREE_CODE_CLASS (TREE_CODE (exp)) != 'd'
    || target != DECL_RTL_IF_SET (exp))
      /* If there's nothing to copy, don't bother.  Don't call expr_size
   unless necessary, because some front-ends (C++) expr_size-hook
   aborts on objects that are not supposed to be bit-copied or
   bit-initialized.  */
      && expr_size (exp) != const0_rtx)
    {
      target = protect_from_queue (target, 1);
      if (GET_MODE (temp) != GET_MODE (target)
    && GET_MODE (temp) != VOIDmode)
  {
    int unsignedp = TREE_UNSIGNED (TREE_TYPE (exp));
    if (dont_return_target)
      {
        /* In this case, we will return TEMP,
     so make sure it has the proper mode.
     But don't forget to store the value into TARGET.  */
        temp = convert_to_mode (GET_MODE (target), temp, unsignedp);
        emit_move_insn (target, temp);
      }
    else
      convert_move (target, temp, unsignedp);
  }

      else if (GET_MODE (temp) == BLKmode && TREE_CODE (exp) == STRING_CST)
  {
    /* Handle copying a string constant into an array.  The string
       constant may be shorter than the array.  So copy just the string's
       actual length, and clear the rest.  First get the size of the data
       type of the string, which is actually the size of the target.  */
    rtx size = expr_size (exp);

    if (GET_CODE (size) == CONST_INT
        && INTVAL (size) < TREE_STRING_LENGTH (exp))
      emit_block_move (target, temp, size,
           (want_value & 2
            ? BLOCK_OP_CALL_PARM : BLOCK_OP_NORMAL));
    else
      {
        /* Compute the size of the data to copy from the string.  */
        tree copy_size
    = size_binop (MIN_EXPR,
            make_tree (sizetype, size),
            size_int (TREE_STRING_LENGTH (exp)));
        rtx copy_size_rtx
    = expand_expr (copy_size, NULL_RTX, VOIDmode,
             (want_value & 2
        ? EXPAND_STACK_PARM : EXPAND_NORMAL));
        rtx label = 0;

        /* Copy that much.  */
        copy_size_rtx = convert_to_mode (ptr_mode, copy_size_rtx,
                 TREE_UNSIGNED (sizetype));
        emit_block_move (target, temp, copy_size_rtx,
             (want_value & 2
        ? BLOCK_OP_CALL_PARM : BLOCK_OP_NORMAL));

        /* Figure out how much is left in TARGET that we have to clear.
     Do all calculations in ptr_mode.  */
        if (GET_CODE (copy_size_rtx) == CONST_INT)
    {
      size = plus_constant (size, -INTVAL (copy_size_rtx));
      target = adjust_address (target, BLKmode,
             INTVAL (copy_size_rtx));
    }
        else
    {
      size = expand_binop (TYPE_MODE (sizetype), sub_optab, size,
               copy_size_rtx, NULL_RTX, 0,
               OPTAB_LIB_WIDEN);

#ifdef POINTERS_EXTEND_UNSIGNED
      if (GET_MODE (copy_size_rtx) != Pmode)
        copy_size_rtx = convert_to_mode (Pmode, copy_size_rtx,
                 TREE_UNSIGNED (sizetype));
#endif

      target = offset_address (target, copy_size_rtx,
             highest_pow2_factor (copy_size));
      label = gen_label_rtx ();
      emit_cmp_and_jump_insns (size, const0_rtx, LT, NULL_RTX,
             GET_MODE (size), 0, label);
    }

        if (size != const0_rtx)
    clear_storage (target, size);

        if (label)
    emit_label (label);
      }
  }
      /* Handle calls that return values in multiple non-contiguous locations.
   The Irix 6 ABI has examples of this.  */
      else if (GET_CODE (target) == PARALLEL)
  emit_group_load (target, temp, int_size_in_bytes (TREE_TYPE (exp)));
      else if (GET_MODE (temp) == BLKmode)
  emit_block_move (target, temp, expr_size (exp),
       (want_value & 2
        ? BLOCK_OP_CALL_PARM : BLOCK_OP_NORMAL));
      else
  emit_move_insn (target, temp);
    }

  /* If we don't want a value, return NULL_RTX.  */
  if ((want_value & 1) == 0)
    return NULL_RTX;

  /* If we are supposed to return TEMP, do so as long as it isn't a MEM.
     ??? The latter test doesn't seem to make sense.  */
  else if (dont_return_target && GET_CODE (temp) != MEM)
    return temp;

  /* Return TARGET itself if it is a hard register.  */
  else if ((want_value & 1) != 0
     && GET_MODE (target) != BLKmode
     && ! (GET_CODE (target) == REG
     && REGNO (target) < FIRST_PSEUDO_REGISTER))
    return copy_to_reg (target);

  else
    return target;
}

/* Return 1 if EXP just contains zeros.  */

static int
is_zeros_p (exp)
     tree exp;
{
  tree elt;

  switch (TREE_CODE (exp))
    {
    case CONVERT_EXPR:
    case NOP_EXPR:
    case NON_LVALUE_EXPR:
    case VIEW_CONVERT_EXPR:
      return is_zeros_p (TREE_OPERAND (exp, 0));

    case INTEGER_CST:
      return integer_zerop (exp);

    case COMPLEX_CST:
      return
  is_zeros_p (TREE_REALPART (exp)) && is_zeros_p (TREE_IMAGPART (exp));

    case REAL_CST:
      return REAL_VALUES_IDENTICAL (TREE_REAL_CST (exp), dconst0);

    case VECTOR_CST:
      for (elt = TREE_VECTOR_CST_ELTS (exp); elt;
     elt = TREE_CHAIN (elt))
  if (!is_zeros_p (TREE_VALUE (elt)))
    return 0;

      return 1;

    case CONSTRUCTOR:
      if (TREE_TYPE (exp) && TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
  return CONSTRUCTOR_ELTS (exp) == NULL_TREE;
      for (elt = CONSTRUCTOR_ELTS (exp); elt; elt = TREE_CHAIN (elt))
  if (! is_zeros_p (TREE_VALUE (elt)))
    return 0;

      return 1;

    default:
      return 0;
    }
}

/* Return 1 if EXP contains mostly (3/4)  zeros.  */

static int
mostly_zeros_p (exp)
     tree exp;
{
  if (TREE_CODE (exp) == CONSTRUCTOR)
    {
      int elts = 0, zeros = 0;
      tree elt = CONSTRUCTOR_ELTS (exp);
      if (TREE_TYPE (exp) && TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
  {
    /* If there are no ranges of true bits, it is all zero.  */
    return elt == NULL_TREE;
  }
      for (; elt; elt = TREE_CHAIN (elt))
  {
    /* We do not handle the case where the index is a RANGE_EXPR,
       so the statistic will be somewhat inaccurate.
       We do make a more accurate count in store_constructor itself,
       so since this function is only used for nested array elements,
       this should be close enough.  */
    if (mostly_zeros_p (TREE_VALUE (elt)))
      zeros++;
    elts++;
  }

      return 4 * zeros >= 3 * elts;
    }

  return is_zeros_p (exp);
}

/* Helper function for store_constructor.
   TARGET, BITSIZE, BITPOS, MODE, EXP are as for store_field.
   TYPE is the type of the CONSTRUCTOR, not the element type.
   CLEARED is as for store_constructor.
   ALIAS_SET is the alias set to use for any stores.

   This provides a recursive shortcut back to store_constructor when it isn't
   necessary to go through store_field.  This is so that we can pass through
   the cleared field to let store_constructor know that we may not have to
   clear a substructure if the outer structure has already been cleared.  */

static void
store_constructor_field (target, bitsize, bitpos, mode, exp, type, cleared,
       alias_set)
     rtx target;
     unsigned HOST_WIDE_INT bitsize;
     HOST_WIDE_INT bitpos;
     enum machine_mode mode;
     tree exp, type;
     int cleared;
     int alias_set;
{
  if (TREE_CODE (exp) == CONSTRUCTOR
      && bitpos % BITS_PER_UNIT == 0
      /* If we have a nonzero bitpos for a register target, then we just
   let store_field do the bitfield handling.  This is unlikely to
   generate unnecessary clear instructions anyways.  */
      && (bitpos == 0 || GET_CODE (target) == MEM))
    {
      if (GET_CODE (target) == MEM)
  target
    = adjust_address (target,
          GET_MODE (target) == BLKmode
          || 0 != (bitpos
             % GET_MODE_ALIGNMENT (GET_MODE (target)))
          ? BLKmode : VOIDmode, bitpos / BITS_PER_UNIT);


      /* Update the alias set, if required.  */
      if (GET_CODE (target) == MEM && ! MEM_KEEP_ALIAS_SET_P (target)
    && MEM_ALIAS_SET (target) != 0)
  {
    target = copy_rtx (target);
    set_mem_alias_set (target, alias_set);
  }

      store_constructor (exp, target, cleared, bitsize / BITS_PER_UNIT);
    }
  else
    store_field (target, bitsize, bitpos, mode, exp, VOIDmode, 0, type,
     alias_set);
}

/* Store the value of constructor EXP into the rtx TARGET.
   TARGET is either a REG or a MEM; we know it cannot conflict, since
   safe_from_p has been called.
   CLEARED is true if TARGET is known to have been zero'd.
   SIZE is the number of bytes of TARGET we are allowed to modify: this
   may not be the same as the size of EXP if we are assigning to a field
   which has been packed to exclude padding bits.  */

static void
store_constructor (exp, target, cleared, size)
     tree exp;
     rtx target;
     int cleared;
     HOST_WIDE_INT size;
{
  tree type = TREE_TYPE (exp);
#ifdef WORD_REGISTER_OPERATIONS
  HOST_WIDE_INT exp_size = int_size_in_bytes (type);
#endif

  if (TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
      || TREE_CODE (type) == QUAL_UNION_TYPE)
    {
      tree elt;

      /* If size is zero or the target is already cleared, do nothing.  */
      if (size == 0 || cleared)
  cleared = 1;
      /* We either clear the aggregate or indicate the value is dead.  */
      else if ((TREE_CODE (type) == UNION_TYPE
    || TREE_CODE (type) == QUAL_UNION_TYPE)
         && ! CONSTRUCTOR_ELTS (exp))
  /* If the constructor is empty, clear the union.  */
  {
    clear_storage (target, expr_size (exp));
    cleared = 1;
  }

      /* If we are building a static constructor into a register,
   set the initial value as zero so we can fold the value into
   a constant.  But if more than one register is involved,
   this probably loses.  */
      else if (GET_CODE (target) == REG && TREE_STATIC (exp)
         && GET_MODE_SIZE (GET_MODE (target)) <= UNITS_PER_WORD)
  {
    emit_move_insn (target, CONST0_RTX (GET_MODE (target)));
    cleared = 1;
  }

      /* If the constructor has fewer fields than the structure
   or if we are initializing the structure to mostly zeros,
   clear the whole structure first.  Don't do this if TARGET is a
   register whose mode size isn't equal to SIZE since clear_storage
   can't handle this case.  */
      else if (((list_length (CONSTRUCTOR_ELTS (exp)) != fields_length (type))
    || mostly_zeros_p (exp))
         && (GET_CODE (target) != REG
       || ((HOST_WIDE_INT) GET_MODE_SIZE (GET_MODE (target))
           == size)))
  {
    clear_storage (target, GEN_INT (size));
    cleared = 1;
  }

      if (! cleared)
  emit_insn (gen_rtx_CLOBBER (VOIDmode, target));

      /* Store each element of the constructor into
   the corresponding field of TARGET.  */

      for (elt = CONSTRUCTOR_ELTS (exp); elt; elt = TREE_CHAIN (elt))
  {
    tree field = TREE_PURPOSE (elt);
    tree value = TREE_VALUE (elt);
    enum machine_mode mode;
    HOST_WIDE_INT bitsize;
    HOST_WIDE_INT bitpos = 0;
    int unsignedp;
    tree offset;
    rtx to_rtx = target;

    /* Just ignore missing fields.
       We cleared the whole structure, above,
       if any fields are missing.  */
    if (field == 0)
      continue;

    if (cleared && is_zeros_p (value))
      continue;

    if (host_integerp (DECL_SIZE (field), 1))
      bitsize = tree_low_cst (DECL_SIZE (field), 1);
    else
      bitsize = -1;

    unsignedp = TREE_UNSIGNED (field);
    mode = DECL_MODE (field);
    if (DECL_BIT_FIELD (field))
      mode = VOIDmode;

    offset = DECL_FIELD_OFFSET (field);
    if (host_integerp (offset, 0)
        && host_integerp (bit_position (field), 0))
      {
        bitpos = int_bit_position (field);
        offset = 0;
      }
    else
      bitpos = tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 0);

    if (offset)
      {
        rtx offset_rtx;

        if (contains_placeholder_p (offset))
    offset = build (WITH_RECORD_EXPR, sizetype,
        offset, make_tree (TREE_TYPE (exp), target));

        offset_rtx = expand_expr (offset, NULL_RTX, VOIDmode, 0);
        if (GET_CODE (to_rtx) != MEM)
    abort ();

#ifdef POINTERS_EXTEND_UNSIGNED
        if (GET_MODE (offset_rtx) != Pmode)
    offset_rtx = convert_to_mode (Pmode, offset_rtx, 0);
#else
        if (GET_MODE (offset_rtx) != ptr_mode)
    offset_rtx = convert_to_mode (ptr_mode, offset_rtx, 0);
#endif

        to_rtx = offset_address (to_rtx, offset_rtx,
               highest_pow2_factor (offset));
      }

    if (TREE_READONLY (field))
      {
        if (GET_CODE (to_rtx) == MEM)
    to_rtx = copy_rtx (to_rtx);

        RTX_UNCHANGING_P (to_rtx) = 1;
      }

#ifdef WORD_REGISTER_OPERATIONS
    /* If this initializes a field that is smaller than a word, at the
       start of a word, try to widen it to a full word.
       This special case allows us to output C++ member function
       initializations in a form that the optimizers can understand.  */
    if (GET_CODE (target) == REG
        && bitsize < BITS_PER_WORD
        && bitpos % BITS_PER_WORD == 0
        && GET_MODE_CLASS (mode) == MODE_INT
        && TREE_CODE (value) == INTEGER_CST
        && exp_size >= 0
        && bitpos + BITS_PER_WORD <= exp_size * BITS_PER_UNIT)
      {
        tree type = TREE_TYPE (value);

        if (TYPE_PRECISION (type) < BITS_PER_WORD)
    {
      type = (*lang_hooks.types.type_for_size)
        (BITS_PER_WORD, TREE_UNSIGNED (type));
      value = convert (type, value);
    }

        if (BYTES_BIG_ENDIAN)
    value
      = fold (build (LSHIFT_EXPR, type, value,
         build_int_2 (BITS_PER_WORD - bitsize, 0)));
        bitsize = BITS_PER_WORD;
        mode = word_mode;
      }
#endif

    if (GET_CODE (to_rtx) == MEM && !MEM_KEEP_ALIAS_SET_P (to_rtx)
        && DECL_NONADDRESSABLE_P (field))
      {
        to_rtx = copy_rtx (to_rtx);
        MEM_KEEP_ALIAS_SET_P (to_rtx) = 1;
      }

    store_constructor_field (to_rtx, bitsize, bitpos, mode,
           value, type, cleared,
           get_alias_set (TREE_TYPE (field)));
  }
    }
  else if (TREE_CODE (type) == ARRAY_TYPE
     || TREE_CODE (type) == VECTOR_TYPE)
    {
      tree elt;
      int i;
      int need_to_clear;
      tree domain = TYPE_DOMAIN (type);
      tree elttype = TREE_TYPE (type);
      int const_bounds_p;
      HOST_WIDE_INT minelt = 0;
      HOST_WIDE_INT maxelt = 0;

      /* Vectors are like arrays, but the domain is stored via an array
   type indirectly.  */
      if (TREE_CODE (type) == VECTOR_TYPE)
  {
    /* Note that although TYPE_DEBUG_REPRESENTATION_TYPE uses
       the same field as TYPE_DOMAIN, we are not guaranteed that
       it always will.  */
    domain = TYPE_DEBUG_REPRESENTATION_TYPE (type);
    domain = TYPE_DOMAIN (TREE_TYPE (TYPE_FIELDS (domain)));
  }

      const_bounds_p = (TYPE_MIN_VALUE (domain)
      && TYPE_MAX_VALUE (domain)
      && host_integerp (TYPE_MIN_VALUE (domain), 0)
      && host_integerp (TYPE_MAX_VALUE (domain), 0));

      /* If we have constant bounds for the range of the type, get them.  */
      if (const_bounds_p)
  {
    minelt = tree_low_cst (TYPE_MIN_VALUE (domain), 0);
    maxelt = tree_low_cst (TYPE_MAX_VALUE (domain), 0);
  }

      /* If the constructor has fewer elements than the array,
         clear the whole array first.  Similarly if this is
         static constructor of a non-BLKmode object.  */
      if (cleared || (GET_CODE (target) == REG && TREE_STATIC (exp)))
  need_to_clear = 1;
      else
  {
    HOST_WIDE_INT count = 0, zero_count = 0;
    need_to_clear = ! const_bounds_p;

    /* This loop is a more accurate version of the loop in
       mostly_zeros_p (it handles RANGE_EXPR in an index).
       It is also needed to check for missing elements.  */
    for (elt = CONSTRUCTOR_ELTS (exp);
         elt != NULL_TREE && ! need_to_clear;
         elt = TREE_CHAIN (elt))
      {
        tree index = TREE_PURPOSE (elt);
        HOST_WIDE_INT this_node_count;

        if (index != NULL_TREE && TREE_CODE (index) == RANGE_EXPR)
    {
      tree lo_index = TREE_OPERAND (index, 0);
      tree hi_index = TREE_OPERAND (index, 1);

      if (! host_integerp (lo_index, 1)
          || ! host_integerp (hi_index, 1))
        {
          need_to_clear = 1;
          break;
        }

      this_node_count = (tree_low_cst (hi_index, 1)
             - tree_low_cst (lo_index, 1) + 1);
    }
        else
    this_node_count = 1;

        count += this_node_count;
        if (mostly_zeros_p (TREE_VALUE (elt)))
    zero_count += this_node_count;
      }

    /* Clear the entire array first if there are any missing elements,
       or if the incidence of zero elements is >= 75%.  */
    if (! need_to_clear
        && (count < maxelt - minelt + 1 || 4 * zero_count >= 3 * count))
      need_to_clear = 1;
  }

      if (need_to_clear && size > 0)
  {
    if (! cleared)
      {
        if (REG_P (target))
    emit_move_insn (target,  CONST0_RTX (GET_MODE (target)));
        else
    clear_storage (target, GEN_INT (size));
      }
    cleared = 1;
  }
      else if (REG_P (target))
  /* Inform later passes that the old value is dead.  */
  emit_insn (gen_rtx_CLOBBER (VOIDmode, target));

      /* Store each element of the constructor into
   the corresponding element of TARGET, determined
   by counting the elements.  */
      for (elt = CONSTRUCTOR_ELTS (exp), i = 0;
     elt;
     elt = TREE_CHAIN (elt), i++)
  {
    enum machine_mode mode;
    HOST_WIDE_INT bitsize;
    HOST_WIDE_INT bitpos;
    int unsignedp;
    tree value = TREE_VALUE (elt);
    tree index = TREE_PURPOSE (elt);
    rtx xtarget = target;

    if (cleared && is_zeros_p (value))
      continue;

    unsignedp = TREE_UNSIGNED (elttype);
    mode = TYPE_MODE (elttype);
    if (mode == BLKmode)
      bitsize = (host_integerp (TYPE_SIZE (elttype), 1)
           ? tree_low_cst (TYPE_SIZE (elttype), 1)
           : -1);
    else
      bitsize = GET_MODE_BITSIZE (mode);

    if (index != NULL_TREE && TREE_CODE (index) == RANGE_EXPR)
      {
        tree lo_index = TREE_OPERAND (index, 0);
        tree hi_index = TREE_OPERAND (index, 1);
        rtx index_r, pos_rtx, hi_r, loop_top, loop_end;
        struct nesting *loop;
        HOST_WIDE_INT lo, hi, count;
        tree position;

        /* If the range is constant and "small", unroll the loop.  */
        if (const_bounds_p
      && host_integerp (lo_index, 0)
      && host_integerp (hi_index, 0)
      && (lo = tree_low_cst (lo_index, 0),
          hi = tree_low_cst (hi_index, 0),
          count = hi - lo + 1,
          (GET_CODE (target) != MEM
           || count <= 2
           || (host_integerp (TYPE_SIZE (elttype), 1)
         && (tree_low_cst (TYPE_SIZE (elttype), 1) * count
             <= 40 * 8)))))
    {
      lo -= minelt;  hi -= minelt;
      for (; lo <= hi; lo++)
        {
          bitpos = lo * tree_low_cst (TYPE_SIZE (elttype), 0);

          if (GET_CODE (target) == MEM
        && !MEM_KEEP_ALIAS_SET_P (target)
        && TREE_CODE (type) == ARRAY_TYPE
        && TYPE_NONALIASED_COMPONENT (type))
      {
        target = copy_rtx (target);
        MEM_KEEP_ALIAS_SET_P (target) = 1;
      }

          store_constructor_field
      (target, bitsize, bitpos, mode, value, type, cleared,
       get_alias_set (elttype));
        }
    }
        else
    {
      hi_r = expand_expr (hi_index, NULL_RTX, VOIDmode, 0);
      loop_top = gen_label_rtx ();
      loop_end = gen_label_rtx ();

      unsignedp = TREE_UNSIGNED (domain);

      index = build_decl (VAR_DECL, NULL_TREE, domain);

      index_r
        = gen_reg_rtx (promote_mode (domain, DECL_MODE (index),
             &unsignedp, 0));
      SET_DECL_RTL (index, index_r);
      if (TREE_CODE (value) == SAVE_EXPR
          && SAVE_EXPR_RTL (value) == 0)
        {
          /* Make sure value gets expanded once before the
                         loop.  */
          expand_expr (value, const0_rtx, VOIDmode, 0);
          emit_queue ();
        }
      store_expr (lo_index, index_r, 0);
      loop = expand_start_loop (0);

      /* Assign value to element index.  */
      position
        = convert (ssizetype,
             fold (build (MINUS_EXPR, TREE_TYPE (index),
              index, TYPE_MIN_VALUE (domain))));
      position = size_binop (MULT_EXPR, position,
           convert (ssizetype,
              TYPE_SIZE_UNIT (elttype)));

      pos_rtx = expand_expr (position, 0, VOIDmode, 0);
      xtarget = offset_address (target, pos_rtx,
              highest_pow2_factor (position));
      xtarget = adjust_address (xtarget, mode, 0);
      if (TREE_CODE (value) == CONSTRUCTOR)
        store_constructor (value, xtarget, cleared,
               bitsize / BITS_PER_UNIT);
      else
        store_expr (value, xtarget, 0);

      expand_exit_loop_if_false (loop,
               build (LT_EXPR, integer_type_node,
                index, hi_index));

      expand_increment (build (PREINCREMENT_EXPR,
             TREE_TYPE (index),
             index, integer_one_node), 0, 0);
      expand_end_loop ();
      emit_label (loop_end);
    }
      }
    else if ((index != 0 && ! host_integerp (index, 0))
       || ! host_integerp (TYPE_SIZE (elttype), 1))
      {
        tree position;

        if (index == 0)
    index = ssize_int (1);

        if (minelt)
    index = convert (ssizetype,
         fold (build (MINUS_EXPR, index,
                TYPE_MIN_VALUE (domain))));

        position = size_binop (MULT_EXPR, index,
             convert (ssizetype,
                TYPE_SIZE_UNIT (elttype)));
        xtarget = offset_address (target,
          expand_expr (position, 0, VOIDmode, 0),
          highest_pow2_factor (position));
        xtarget = adjust_address (xtarget, mode, 0);
        store_expr (value, xtarget, 0);
      }
    else
      {
        if (index != 0)
    bitpos = ((tree_low_cst (index, 0) - minelt)
        * tree_low_cst (TYPE_SIZE (elttype), 1));
        else
    bitpos = (i * tree_low_cst (TYPE_SIZE (elttype), 1));

        if (GET_CODE (target) == MEM && !MEM_KEEP_ALIAS_SET_P (target)
      && TREE_CODE (type) == ARRAY_TYPE
      && TYPE_NONALIASED_COMPONENT (type))
    {
      target = copy_rtx (target);
      MEM_KEEP_ALIAS_SET_P (target) = 1;
    }

        store_constructor_field (target, bitsize, bitpos, mode, value,
               type, cleared, get_alias_set (elttype));

      }
  }
    }

  /* Set constructor assignments.  */
  else if (TREE_CODE (type) == SET_TYPE)
    {
      tree elt = CONSTRUCTOR_ELTS (exp);
      unsigned HOST_WIDE_INT nbytes = int_size_in_bytes (type), nbits;
      tree domain = TYPE_DOMAIN (type);
      tree domain_min, domain_max, bitlength;

      /* The default implementation strategy is to extract the constant
   parts of the constructor, use that to initialize the target,
   and then "or" in whatever non-constant ranges we need in addition.

   If a large set is all zero or all ones, it is
   probably better to set it using memset (if available) or bzero.
   Also, if a large set has just a single range, it may also be
   better to first clear all the first clear the set (using
   bzero/memset), and set the bits we want.  */

      /* Check for all zeros.  */
      if (elt == NULL_TREE && size > 0)
  {
    if (!cleared)
      clear_storage (target, GEN_INT (size));
    return;
  }

      domain_min = convert (sizetype, TYPE_MIN_VALUE (domain));
      domain_max = convert (sizetype, TYPE_MAX_VALUE (domain));
      bitlength = size_binop (PLUS_EXPR,
            size_diffop (domain_max, domain_min),
            ssize_int (1));

      nbits = tree_low_cst (bitlength, 1);

      /* For "small" sets, or "medium-sized" (up to 32 bytes) sets that
   are "complicated" (more than one range), initialize (the
   constant parts) by copying from a constant.  */
      if (GET_MODE (target) != BLKmode || nbits <= 2 * BITS_PER_WORD
    || (nbytes <= 32 && TREE_CHAIN (elt) != NULL_TREE))
  {
    unsigned int set_word_size = TYPE_ALIGN (TREE_TYPE (exp));
    enum machine_mode mode = mode_for_size (set_word_size, MODE_INT, 1);
    char *bit_buffer = (char *) alloca (nbits);
    HOST_WIDE_INT word = 0;
    unsigned int bit_pos = 0;
    unsigned int ibit = 0;
    unsigned int offset = 0;  /* In bytes from beginning of set.  */

    elt = get_set_constructor_bits (exp, bit_buffer, nbits);
    for (;;)
      {
        if (bit_buffer[ibit])
    {
      if (BYTES_BIG_ENDIAN)
        word |= (1 << (set_word_size - 1 - bit_pos));
      else
        word |= 1 << bit_pos;
    }

        bit_pos++;  ibit++;
        if (bit_pos >= set_word_size || ibit == nbits)
    {
      if (word != 0 || ! cleared)
        {
          rtx datum = GEN_INT (word);
          rtx to_rtx;

          /* The assumption here is that it is safe to use
       XEXP if the set is multi-word, but not if
       it's single-word.  */
          if (GET_CODE (target) == MEM)
      to_rtx = adjust_address (target, mode, offset);
          else if (offset == 0)
      to_rtx = target;
          else
      abort ();
          emit_move_insn (to_rtx, datum);
        }

      if (ibit == nbits)
        break;
      word = 0;
      bit_pos = 0;
      offset += set_word_size / BITS_PER_UNIT;
    }
      }
  }
      else if (!cleared)
  /* Don't bother clearing storage if the set is all ones.  */
  if (TREE_CHAIN (elt) != NULL_TREE
      || (TREE_PURPOSE (elt) == NULL_TREE
    ? nbits != 1
    : ( ! host_integerp (TREE_VALUE (elt), 0)
       || ! host_integerp (TREE_PURPOSE (elt), 0)
       || (tree_low_cst (TREE_VALUE (elt), 0)
           - tree_low_cst (TREE_PURPOSE (elt), 0) + 1
           != (HOST_WIDE_INT) nbits))))
    clear_storage (target, expr_size (exp));

      for (; elt != NULL_TREE; elt = TREE_CHAIN (elt))
  {
    /* Start of range of element or NULL.  */
    tree startbit = TREE_PURPOSE (elt);
    /* End of range of element, or element value.  */
    tree endbit   = TREE_VALUE (elt);
    HOST_WIDE_INT startb, endb;
    rtx bitlength_rtx, startbit_rtx, endbit_rtx, targetx;

    bitlength_rtx = expand_expr (bitlength,
               NULL_RTX, MEM, EXPAND_CONST_ADDRESS);

    /* Handle non-range tuple element like [ expr ].  */
    if (startbit == NULL_TREE)
      {
        startbit = save_expr (endbit);
        endbit = startbit;
      }

    startbit = convert (sizetype, startbit);
    endbit = convert (sizetype, endbit);
    if (! integer_zerop (domain_min))
      {
        startbit = size_binop (MINUS_EXPR, startbit, domain_min);
        endbit = size_binop (MINUS_EXPR, endbit, domain_min);
      }
    startbit_rtx = expand_expr (startbit, NULL_RTX, MEM,
              EXPAND_CONST_ADDRESS);
    endbit_rtx = expand_expr (endbit, NULL_RTX, MEM,
            EXPAND_CONST_ADDRESS);

    if (REG_P (target))
      {
        targetx
    = assign_temp
      ((build_qualified_type ((*lang_hooks.types.type_for_mode)
            (GET_MODE (target), 0),
            TYPE_QUAL_CONST)),
       0, 1, 1);
        emit_move_insn (targetx, target);
      }

    else if (GET_CODE (target) == MEM)
      targetx = target;
    else
      abort ();

    /* Optimization:  If startbit and endbit are constants divisible
       by BITS_PER_UNIT, call memset instead.  */
    if (TARGET_MEM_FUNCTIONS
        && TREE_CODE (startbit) == INTEGER_CST
        && TREE_CODE (endbit) == INTEGER_CST
        && (startb = TREE_INT_CST_LOW (startbit)) % BITS_PER_UNIT == 0
        && (endb = TREE_INT_CST_LOW (endbit) + 1) % BITS_PER_UNIT == 0)
      {
        emit_library_call (memset_libfunc, LCT_NORMAL,
         VOIDmode, 3,
         plus_constant (XEXP (targetx, 0),
            startb / BITS_PER_UNIT),
         Pmode,
         constm1_rtx, TYPE_MODE (integer_type_node),
         GEN_INT ((endb - startb) / BITS_PER_UNIT),
         TYPE_MODE (sizetype));
      }
    else
      emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__setbits"),
             LCT_NORMAL, VOIDmode, 4, XEXP (targetx, 0),
             Pmode, bitlength_rtx, TYPE_MODE (sizetype),
             startbit_rtx, TYPE_MODE (sizetype),
             endbit_rtx, TYPE_MODE (sizetype));

    if (REG_P (target))
      emit_move_insn (target, targetx);
  }
    }

  else
    abort ();
}

/* Store the value of EXP (an expression tree)
   into a subfield of TARGET which has mode MODE and occupies
   BITSIZE bits, starting BITPOS bits from the start of TARGET.
   If MODE is VOIDmode, it means that we are storing into a bit-field.

   If VALUE_MODE is VOIDmode, return nothing in particular.
   UNSIGNEDP is not used in this case.

   Otherwise, return an rtx for the value stored.  This rtx
   has mode VALUE_MODE if that is convenient to do.
   In this case, UNSIGNEDP must be nonzero if the value is an unsigned type.

   TYPE is the type of the underlying object,

   ALIAS_SET is the alias set for the destination.  This value will
   (in general) be different from that for TARGET, since TARGET is a
   reference to the containing structure.  */

static rtx
store_field (target, bitsize, bitpos, mode, exp, value_mode, unsignedp, type,
       alias_set)
     rtx target;
     HOST_WIDE_INT bitsize;
     HOST_WIDE_INT bitpos;
     enum machine_mode mode;
     tree exp;
     enum machine_mode value_mode;
     int unsignedp;
     tree type;
     int alias_set;
{
  HOST_WIDE_INT width_mask = 0;

  if (TREE_CODE (exp) == ERROR_MARK)
    return const0_rtx;

  /* If we have nothing to store, do nothing unless the expression has
     side-effects.  */
  if (bitsize == 0)
    return expand_expr (exp, const0_rtx, VOIDmode, 0);
  else if (bitsize >=0 && bitsize < HOST_BITS_PER_WIDE_INT)
    width_mask = ((HOST_WIDE_INT) 1 << bitsize) - 1;

  /* If we are storing into an unaligned field of an aligned union that is
     in a register, we may have the mode of TARGET being an integer mode but
     MODE == BLKmode.  In that case, get an aligned object whose size and
     alignment are the same as TARGET and store TARGET into it (we can avoid
     the store if the field being stored is the entire width of TARGET).  Then
     call ourselves recursively to store the field into a BLKmode version of
     that object.  Finally, load from the object into TARGET.  This is not
     very efficient in general, but should only be slightly more expensive
     than the otherwise-required unaligned accesses.  Perhaps this can be
     cleaned up later.  */

  if (mode == BLKmode
      && (GET_CODE (target) == REG || GET_CODE (target) == SUBREG))
    {
      rtx object
  = assign_temp
    (build_qualified_type (type, TYPE_QUALS (type) | TYPE_QUAL_CONST),
     0, 1, 1);
      rtx blk_object = adjust_address (object, BLKmode, 0);

      if (bitsize != (HOST_WIDE_INT) GET_MODE_BITSIZE (GET_MODE (target)))
  emit_move_insn (object, target);

      store_field (blk_object, bitsize, bitpos, mode, exp, VOIDmode, 0, type,
       alias_set);

      emit_move_insn (target, object);

      /* We want to return the BLKmode version of the data.  */
      return blk_object;
    }

  if (GET_CODE (target) == CONCAT)
    {
      /* We're storing into a struct containing a single __complex.  */

      if (bitpos != 0)
  abort ();
      return store_expr (exp, target, 0);
    }

  /* If the structure is in a register or if the component
     is a bit field, we cannot use addressing to access it.
     Use bit-field techniques or SUBREG to store in it.  */

  if (mode == VOIDmode
      || (mode != BLKmode && ! direct_store[(int) mode]
    && GET_MODE_CLASS (mode) != MODE_COMPLEX_INT
    && GET_MODE_CLASS (mode) != MODE_COMPLEX_FLOAT)
      || GET_CODE (target) == REG
      || GET_CODE (target) == SUBREG
      /* If the field isn't aligned enough to store as an ordinary memref,
   store it as a bit field.  */
      || (mode != BLKmode && SLOW_UNALIGNED_ACCESS (mode, MEM_ALIGN (target))
    && (MEM_ALIGN (target) < GET_MODE_ALIGNMENT (mode)
        || bitpos % GET_MODE_ALIGNMENT (mode)))
      /* If the RHS and field are a constant size and the size of the
   RHS isn't the same size as the bitfield, we must use bitfield
   operations.  */
      || (bitsize >= 0
    && TREE_CODE (TYPE_SIZE (TREE_TYPE (exp))) == INTEGER_CST
    && compare_tree_int (TYPE_SIZE (TREE_TYPE (exp)), bitsize) != 0))
    {
      rtx temp = expand_expr (exp, NULL_RTX, VOIDmode, 0);

      /* If BITSIZE is narrower than the size of the type of EXP
   we will be narrowing TEMP.  Normally, what's wanted are the
   low-order bits.  However, if EXP's type is a record and this is
   big-endian machine, we want the upper BITSIZE bits.  */
      if (BYTES_BIG_ENDIAN && GET_MODE_CLASS (GET_MODE (temp)) == MODE_INT
    && bitsize < (HOST_WIDE_INT) GET_MODE_BITSIZE (GET_MODE (temp))
    && TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
  temp = expand_shift (RSHIFT_EXPR, GET_MODE (temp), temp,
           size_int (GET_MODE_BITSIZE (GET_MODE (temp))
               - bitsize),
           temp, 1);

      /* Unless MODE is VOIDmode or BLKmode, convert TEMP to
   MODE.  */
      if (mode != VOIDmode && mode != BLKmode
    && mode != TYPE_MODE (TREE_TYPE (exp)))
  temp = convert_modes (mode, TYPE_MODE (TREE_TYPE (exp)), temp, 1);

      /* If the modes of TARGET and TEMP are both BLKmode, both
   must be in memory and BITPOS must be aligned on a byte
   boundary.  If so, we simply do a block copy.  */
      if (GET_MODE (target) == BLKmode && GET_MODE (temp) == BLKmode)
  {
    if (GET_CODE (target) != MEM || GET_CODE (temp) != MEM
        || bitpos % BITS_PER_UNIT != 0)
      abort ();

    target = adjust_address (target, VOIDmode, bitpos / BITS_PER_UNIT);
    emit_block_move (target, temp,
         GEN_INT ((bitsize + BITS_PER_UNIT - 1)
            / BITS_PER_UNIT),
         BLOCK_OP_NORMAL);

    return value_mode == VOIDmode ? const0_rtx : target;
  }

      /* Store the value in the bitfield.  */
      store_bit_field (target, bitsize, bitpos, mode, temp,
           int_size_in_bytes (type));

      if (value_mode != VOIDmode)
  {
    /* The caller wants an rtx for the value.
       If possible, avoid refetching from the bitfield itself.  */
    if (width_mask != 0
        && ! (GET_CODE (target) == MEM && MEM_VOLATILE_P (target)))
      {
        tree count;
        enum machine_mode tmode;

        tmode = GET_MODE (temp);
        if (tmode == VOIDmode)
    tmode = value_mode;

        if (unsignedp)
    return expand_and (tmode, temp,
           gen_int_mode (width_mask, tmode),
           NULL_RTX);

        count = build_int_2 (GET_MODE_BITSIZE (tmode) - bitsize, 0);
        temp = expand_shift (LSHIFT_EXPR, tmode, temp, count, 0, 0);
        return expand_shift (RSHIFT_EXPR, tmode, temp, count, 0, 0);
      }

    return extract_bit_field (target, bitsize, bitpos, unsignedp,
            NULL_RTX, value_mode, VOIDmode,
            int_size_in_bytes (type));
  }
      return const0_rtx;
    }
  else
    {
      rtx addr = XEXP (target, 0);
      rtx to_rtx = target;

      /* If a value is wanted, it must be the lhs;
   so make the address stable for multiple use.  */

      if (value_mode != VOIDmode && GET_CODE (addr) != REG
    && ! CONSTANT_ADDRESS_P (addr)
    /* A frame-pointer reference is already stable.  */
    && ! (GET_CODE (addr) == PLUS
    && GET_CODE (XEXP (addr, 1)) == CONST_INT
    && (XEXP (addr, 0) == virtual_incoming_args_rtx
        || XEXP (addr, 0) == virtual_stack_vars_rtx)))
  to_rtx = replace_equiv_address (to_rtx, copy_to_reg (addr));

      /* Now build a reference to just the desired component.  */

      to_rtx = adjust_address (target, mode, bitpos / BITS_PER_UNIT);

      if (to_rtx == target)
  to_rtx = copy_rtx (to_rtx);

      MEM_SET_IN_STRUCT_P (to_rtx, 1);
      if (!MEM_KEEP_ALIAS_SET_P (to_rtx) && MEM_ALIAS_SET (to_rtx) != 0)
  set_mem_alias_set (to_rtx, alias_set);

      return store_expr (exp, to_rtx, value_mode != VOIDmode);
    }
}

/* Given an expression EXP that may be a COMPONENT_REF, a BIT_FIELD_REF,
   an ARRAY_REF, or an ARRAY_RANGE_REF, look for nested operations of these
   codes and find the ultimate containing object, which we return.

   We set *PBITSIZE to the size in bits that we want, *PBITPOS to the
   bit position, and *PUNSIGNEDP to the signedness of the field.
   If the position of the field is variable, we store a tree
   giving the variable offset (in units) in *POFFSET.
   This offset is in addition to the bit position.
   If the position is not variable, we store 0 in *POFFSET.

   If any of the extraction expressions is volatile,
   we store 1 in *PVOLATILEP.  Otherwise we don't change that.

   If the field is a bit-field, *PMODE is set to VOIDmode.  Otherwise, it
   is a mode that can be used to access the field.  In that case, *PBITSIZE
   is redundant.

   If the field describes a variable-sized object, *PMODE is set to
   VOIDmode and *PBITSIZE is set to -1.  An access cannot be made in
   this case, but the address of the object can be found.  */

tree
get_inner_reference (exp, pbitsize, pbitpos, poffset, pmode,
         punsignedp, pvolatilep)
     tree exp;
     HOST_WIDE_INT *pbitsize;
     HOST_WIDE_INT *pbitpos;
     tree *poffset;
     enum machine_mode *pmode;
     int *punsignedp;
     int *pvolatilep;
{
  tree size_tree = 0;
  enum machine_mode mode = VOIDmode;
  tree offset = size_zero_node;
  tree bit_offset = bitsize_zero_node;
  tree placeholder_ptr = 0;
  tree tem;

  /* First get the mode, signedness, and size.  We do this from just the
     outermost expression.  */
  if (TREE_CODE (exp) == COMPONENT_REF)
    {
      size_tree = DECL_SIZE (TREE_OPERAND (exp, 1));
      if (! DECL_BIT_FIELD (TREE_OPERAND (exp, 1)))
  mode = DECL_MODE (TREE_OPERAND (exp, 1));

      *punsignedp = TREE_UNSIGNED (TREE_OPERAND (exp, 1));
    }
  else if (TREE_CODE (exp) == BIT_FIELD_REF)
    {
      size_tree = TREE_OPERAND (exp, 1);
      *punsignedp = TREE_UNSIGNED (exp);
    }
  else
    {
      mode = TYPE_MODE (TREE_TYPE (exp));
      *punsignedp = TREE_UNSIGNED (TREE_TYPE (exp));

      if (mode == BLKmode)
  size_tree = TYPE_SIZE (TREE_TYPE (exp));
      else
  *pbitsize = GET_MODE_BITSIZE (mode);
    }

  if (size_tree != 0)
    {
      if (! host_integerp (size_tree, 1))
  mode = BLKmode, *pbitsize = -1;
      else
  *pbitsize = tree_low_cst (size_tree, 1);
    }

  /* Compute cumulative bit-offset for nested component-refs and array-refs,
     and find the ultimate containing object.  */
  while (1)
    {
      if (TREE_CODE (exp) == BIT_FIELD_REF)
  bit_offset = size_binop (PLUS_EXPR, bit_offset, TREE_OPERAND (exp, 2));
      else if (TREE_CODE (exp) == COMPONENT_REF)
  {
    tree field = TREE_OPERAND (exp, 1);
    tree this_offset = DECL_FIELD_OFFSET (field);

    /* If this field hasn't been filled in yet, don't go
       past it.  This should only happen when folding expressions
       made during type construction.  */
    if (this_offset == 0)
      break;
    else if (! TREE_CONSTANT (this_offset)
       && contains_placeholder_p (this_offset))
      this_offset = build (WITH_RECORD_EXPR, sizetype, this_offset, exp);

    offset = size_binop (PLUS_EXPR, offset, this_offset);
    bit_offset = size_binop (PLUS_EXPR, bit_offset,
           DECL_FIELD_BIT_OFFSET (field));

    /* ??? Right now we don't do anything with DECL_OFFSET_ALIGN.  */
  }

      else if (TREE_CODE (exp) == ARRAY_REF
         || TREE_CODE (exp) == ARRAY_RANGE_REF)
  {
    tree index = TREE_OPERAND (exp, 1);
    tree array = TREE_OPERAND (exp, 0);
    tree domain = TYPE_DOMAIN (TREE_TYPE (array));
    tree low_bound = (domain ? TYPE_MIN_VALUE (domain) : 0);
    tree unit_size = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (array)));

    /* We assume all arrays have sizes that are a multiple of a byte.
       First subtract the lower bound, if any, in the type of the
       index, then convert to sizetype and multiply by the size of the
       array element.  */
    if (low_bound != 0 && ! integer_zerop (low_bound))
      index = fold (build (MINUS_EXPR, TREE_TYPE (index),
         index, low_bound));

    /* If the index has a self-referential type, pass it to a
       WITH_RECORD_EXPR; if the component size is, pass our
       component to one.  */
    if (! TREE_CONSTANT (index)
        && contains_placeholder_p (index))
      index = build (WITH_RECORD_EXPR, TREE_TYPE (index), index, exp);
    if (! TREE_CONSTANT (unit_size)
        && contains_placeholder_p (unit_size))
      unit_size = build (WITH_RECORD_EXPR, sizetype, unit_size, array);

    offset = size_binop (PLUS_EXPR, offset,
             size_binop (MULT_EXPR,
             convert (sizetype, index),
             unit_size));
  }

      else if (TREE_CODE (exp) == PLACEHOLDER_EXPR)
  {
    tree new = find_placeholder (exp, &placeholder_ptr);

    /* If we couldn't find the replacement, return the PLACEHOLDER_EXPR.
       We might have been called from tree optimization where we
       haven't set up an object yet.  */
    if (new == 0)
      break;
    else
      exp = new;

    continue;
  }
      else if (TREE_CODE (exp) != NON_LVALUE_EXPR
         && TREE_CODE (exp) != VIEW_CONVERT_EXPR
         && ! ((TREE_CODE (exp) == NOP_EXPR
          || TREE_CODE (exp) == CONVERT_EXPR)
         && (TYPE_MODE (TREE_TYPE (exp))
       == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0))))))
  break;

      /* If any reference in the chain is volatile, the effect is volatile.  */
      if (TREE_THIS_VOLATILE (exp))
  *pvolatilep = 1;

      exp = TREE_OPERAND (exp, 0);
    }

  /* If OFFSET is constant, see if we can return the whole thing as a
     constant bit position.  Otherwise, split it up.  */
  if (host_integerp (offset, 0)
      && 0 != (tem = size_binop (MULT_EXPR, convert (bitsizetype, offset),
         bitsize_unit_node))
      && 0 != (tem = size_binop (PLUS_EXPR, tem, bit_offset))
      && host_integerp (tem, 0))
    *pbitpos = tree_low_cst (tem, 0), *poffset = 0;
  else
    *pbitpos = tree_low_cst (bit_offset, 0), *poffset = offset;

  *pmode = mode;
  return exp;
}

/* Return 1 if T is an expression that get_inner_reference handles.  */

int
handled_component_p (t)
     tree t;
{
  switch (TREE_CODE (t))
    {
    case BIT_FIELD_REF:
    case COMPONENT_REF:
    case ARRAY_REF:
    case ARRAY_RANGE_REF:
    case NON_LVALUE_EXPR:
    case VIEW_CONVERT_EXPR:
      return 1;

    case NOP_EXPR:
    case CONVERT_EXPR:
      return (TYPE_MODE (TREE_TYPE (t))
        == TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 0))));

    default:
      return 0;
    }
}

/* Given an rtx VALUE that may contain additions and multiplications, return
   an equivalent value that just refers to a register, memory, or constant.
   This is done by generating instructions to perform the arithmetic and
   returning a pseudo-register containing the value.

   The returned value may be a REG, SUBREG, MEM or constant.  */

rtx
force_operand (value, target)
     rtx value, target;
{
  rtx op1, op2;
  /* Use subtarget as the target for operand 0 of a binary operation.  */
  rtx subtarget = get_subtarget (target);
  enum rtx_code code = GET_CODE (value);

  /* Check for a PIC address load.  */
  if ((code == PLUS || code == MINUS)
      && XEXP (value, 0) == pic_offset_table_rtx
      && (GET_CODE (XEXP (value, 1)) == SYMBOL_REF
    || GET_CODE (XEXP (value, 1)) == LABEL_REF
    || GET_CODE (XEXP (value, 1)) == CONST))
    {
      if (!subtarget)
  subtarget = gen_reg_rtx (GET_MODE (value));
      emit_move_insn (subtarget, value);
      return subtarget;
    }

  if (code == ZERO_EXTEND || code == SIGN_EXTEND)
    {
      if (!target)
  target = gen_reg_rtx (GET_MODE (value));
      convert_move (target, force_operand (XEXP (value, 0), NULL),
        code == ZERO_EXTEND);
      return target;
    }

  if (GET_RTX_CLASS (code) == '2' || GET_RTX_CLASS (code) == 'c')
    {
      op2 = XEXP (value, 1);
      if (!CONSTANT_P (op2) && !(GET_CODE (op2) == REG && op2 != subtarget))
  subtarget = 0;
      if (code == MINUS && GET_CODE (op2) == CONST_INT)
  {
    code = PLUS;
    op2 = negate_rtx (GET_MODE (value), op2);
  }

      /* Check for an addition with OP2 a constant integer and our first
         operand a PLUS of a virtual register and something else.  In that
         case, we want to emit the sum of the virtual register and the
         constant first and then add the other value.  This allows virtual
         register instantiation to simply modify the constant rather than
         creating another one around this addition.  */
      if (code == PLUS && GET_CODE (op2) == CONST_INT
    && GET_CODE (XEXP (value, 0)) == PLUS
    && GET_CODE (XEXP (XEXP (value, 0), 0)) == REG
    && REGNO (XEXP (XEXP (value, 0), 0)) >= FIRST_VIRTUAL_REGISTER
    && REGNO (XEXP (XEXP (value, 0), 0)) <= LAST_VIRTUAL_REGISTER)
  {
    rtx temp = expand_simple_binop (GET_MODE (value), code,
            XEXP (XEXP (value, 0), 0), op2,
            subtarget, 0, OPTAB_LIB_WIDEN);
    return expand_simple_binop (GET_MODE (value), code, temp,
              force_operand (XEXP (XEXP (value,
                 0), 1), 0),
              target, 0, OPTAB_LIB_WIDEN);
  }

      op1 = force_operand (XEXP (value, 0), subtarget);
      op2 = force_operand (op2, NULL_RTX);
      switch (code)
  {
  case MULT:
    return expand_mult (GET_MODE (value), op1, op2, target, 1);
  case DIV:
    if (!INTEGRAL_MODE_P (GET_MODE (value)))
      return expand_simple_binop (GET_MODE (value), code, op1, op2,
          target, 1, OPTAB_LIB_WIDEN);
    else
      return expand_divmod (0,
          FLOAT_MODE_P (GET_MODE (value))
          ? RDIV_EXPR : TRUNC_DIV_EXPR,
          GET_MODE (value), op1, op2, target, 0);
    break;
  case MOD:
    return expand_divmod (1, TRUNC_MOD_EXPR, GET_MODE (value), op1, op2,
        target, 0);
    break;
  case UDIV:
    return expand_divmod (0, TRUNC_DIV_EXPR, GET_MODE (value), op1, op2,
        target, 1);
    break;
  case UMOD:
    return expand_divmod (1, TRUNC_MOD_EXPR, GET_MODE (value), op1, op2,
        target, 1);
    break;
  case ASHIFTRT:
    return expand_simple_binop (GET_MODE (value), code, op1, op2,
              target, 0, OPTAB_LIB_WIDEN);
    break;
  default:
    return expand_simple_binop (GET_MODE (value), code, op1, op2,
              target, 1, OPTAB_LIB_WIDEN);
  }
    }
  if (GET_RTX_CLASS (code) == '1')
    {
      op1 = force_operand (XEXP (value, 0), NULL_RTX);
      return expand_simple_unop (GET_MODE (value), code, op1, target, 0);
    }

#ifdef INSN_SCHEDULING
  /* On machines that have insn scheduling, we want all memory reference to be
     explicit, so we need to deal with such paradoxical SUBREGs.  */
  if (GET_CODE (value) == SUBREG && GET_CODE (SUBREG_REG (value)) == MEM
      && (GET_MODE_SIZE (GET_MODE (value))
    > GET_MODE_SIZE (GET_MODE (SUBREG_REG (value)))))
    value
      = simplify_gen_subreg (GET_MODE (value),
           force_reg (GET_MODE (SUBREG_REG (value)),
          force_operand (SUBREG_REG (value),
                   NULL_RTX)),
           GET_MODE (SUBREG_REG (value)),
           SUBREG_BYTE (value));
#endif

  return value;
}

/* Subroutine of expand_expr: return nonzero iff there is no way that
   EXP can reference X, which is being modified.  TOP_P is nonzero if this
   call is going to be used to determine whether we need a temporary
   for EXP, as opposed to a recursive call to this function.

   It is always safe for this routine to return zero since it merely
   searches for optimization opportunities.  */

int
safe_from_p (x, exp, top_p)
     rtx x;
     tree exp;
     int top_p;
{
  rtx exp_rtl = 0;
  int i, nops;
  static tree save_expr_list;

  if (x == 0
      /* If EXP has varying size, we MUST use a target since we currently
   have no way of allocating temporaries of variable size
   (except for arrays that have TYPE_ARRAY_MAX_SIZE set).
   So we assume here that something at a higher level has prevented a
   clash.  This is somewhat bogus, but the best we can do.  Only
   do this when X is BLKmode and when we are at the top level.  */
      || (top_p && TREE_TYPE (exp) != 0 && COMPLETE_TYPE_P (TREE_TYPE (exp))
    && TREE_CODE (TYPE_SIZE (TREE_TYPE (exp))) != INTEGER_CST
    && (TREE_CODE (TREE_TYPE (exp)) != ARRAY_TYPE
        || TYPE_ARRAY_MAX_SIZE (TREE_TYPE (exp)) == NULL_TREE
        || TREE_CODE (TYPE_ARRAY_MAX_SIZE (TREE_TYPE (exp)))
        != INTEGER_CST)
    && GET_MODE (x) == BLKmode)
      /* If X is in the outgoing argument area, it is always safe.  */
      || (GET_CODE (x) == MEM
    && (XEXP (x, 0) == virtual_outgoing_args_rtx
        || (GET_CODE (XEXP (x, 0)) == PLUS
      && XEXP (XEXP (x, 0), 0) == virtual_outgoing_args_rtx))))
    return 1;

  /* If this is a subreg of a hard register, declare it unsafe, otherwise,
     find the underlying pseudo.  */
  if (GET_CODE (x) == SUBREG)
    {
      x = SUBREG_REG (x);
      if (GET_CODE (x) == REG && REGNO (x) < FIRST_PSEUDO_REGISTER)
  return 0;
    }

  /* A SAVE_EXPR might appear many times in the expression passed to the
     top-level safe_from_p call, and if it has a complex subexpression,
     examining it multiple times could result in a combinatorial explosion.
     E.g. on an Alpha running at least 200MHz, a Fortran test case compiled
     with optimization took about 28 minutes to compile -- even though it was
     only a few lines long.  So we mark each SAVE_EXPR we see with TREE_PRIVATE
     and turn that off when we are done.  We keep a list of the SAVE_EXPRs
     we have processed.  Note that the only test of top_p was above.  */

  if (top_p)
    {
      int rtn;
      tree t;

      save_expr_list = 0;

      rtn = safe_from_p (x, exp, 0);

      for (t = save_expr_list; t != 0; t = TREE_CHAIN (t))
  TREE_PRIVATE (TREE_PURPOSE (t)) = 0;

      return rtn;
    }

  /* Now look at our tree code and possibly recurse.  */
  switch (TREE_CODE_CLASS (TREE_CODE (exp)))
    {
    case 'd':
      exp_rtl = DECL_RTL_IF_SET (exp);
      break;

    case 'c':
      return 1;

    case 'x':
      if (TREE_CODE (exp) == TREE_LIST)
  {
    while (1)
      {
        if (TREE_VALUE (exp) && !safe_from_p (x, TREE_VALUE (exp), 0))
    return 0;
        exp = TREE_CHAIN (exp);
        if (!exp)
    return 1;
        if (TREE_CODE (exp) != TREE_LIST)
    return safe_from_p (x, exp, 0);
      }
  }
      else if (TREE_CODE (exp) == ERROR_MARK)
  return 1; /* An already-visited SAVE_EXPR? */
      else
  return 0;

    case '2':
    case '<':
      if (!safe_from_p (x, TREE_OPERAND (exp, 1), 0))
  return 0;
      /* FALLTHRU */

    case '1':
      return safe_from_p (x, TREE_OPERAND (exp, 0), 0);

    case 'e':
    case 'r':
      /* Now do code-specific tests.  EXP_RTL is set to any rtx we find in
   the expression.  If it is set, we conflict iff we are that rtx or
   both are in memory.  Otherwise, we check all operands of the
   expression recursively.  */

      switch (TREE_CODE (exp))
  {
  case ADDR_EXPR:
    /* If the operand is static or we are static, we can't conflict.
       Likewise if we don't conflict with the operand at all.  */
    if (staticp (TREE_OPERAND (exp, 0))
        || TREE_STATIC (exp)
        || safe_from_p (x, TREE_OPERAND (exp, 0), 0))
      return 1;

    /* Otherwise, the only way this can conflict is if we are taking
       the address of a DECL a that address if part of X, which is
       very rare.  */
    exp = TREE_OPERAND (exp, 0);
    if (DECL_P (exp))
      {
        if (!DECL_RTL_SET_P (exp)
      || GET_CODE (DECL_RTL (exp)) != MEM)
    return 0;
        else
    exp_rtl = XEXP (DECL_RTL (exp), 0);
      }
    break;

  case INDIRECT_REF:
    if (GET_CODE (x) == MEM
        && alias_sets_conflict_p (MEM_ALIAS_SET (x),
          get_alias_set (exp)))
      return 0;
    break;

  case CALL_EXPR:
    /* Assume that the call will clobber all hard registers and
       all of memory.  */
    if ((GET_CODE (x) == REG && REGNO (x) < FIRST_PSEUDO_REGISTER)
        || GET_CODE (x) == MEM)
      return 0;
    break;

  case RTL_EXPR:
    /* If a sequence exists, we would have to scan every instruction
       in the sequence to see if it was safe.  This is probably not
       worthwhile.  */
    if (RTL_EXPR_SEQUENCE (exp))
      return 0;

    exp_rtl = RTL_EXPR_RTL (exp);
    break;

  case WITH_CLEANUP_EXPR:
    exp_rtl = WITH_CLEANUP_EXPR_RTL (exp);
    break;

  case CLEANUP_POINT_EXPR:
    return safe_from_p (x, TREE_OPERAND (exp, 0), 0);

  case SAVE_EXPR:
    exp_rtl = SAVE_EXPR_RTL (exp);
    if (exp_rtl)
      break;

    /* If we've already scanned this, don't do it again.  Otherwise,
       show we've scanned it and record for clearing the flag if we're
       going on.  */
    if (TREE_PRIVATE (exp))
      return 1;

    TREE_PRIVATE (exp) = 1;
    if (! safe_from_p (x, TREE_OPERAND (exp, 0), 0))
      {
        TREE_PRIVATE (exp) = 0;
        return 0;
      }

    save_expr_list = tree_cons (exp, NULL_TREE, save_expr_list);
    return 1;

  case BIND_EXPR:
    /* The only operand we look at is operand 1.  The rest aren't
       part of the expression.  */
    return safe_from_p (x, TREE_OPERAND (exp, 1), 0);

  case METHOD_CALL_EXPR:
    /* This takes an rtx argument, but shouldn't appear here.  */
    abort ();

  default:
    break;
  }

      /* If we have an rtx, we do not need to scan our operands.  */
      if (exp_rtl)
  break;

      nops = first_rtl_op (TREE_CODE (exp));
      for (i = 0; i < nops; i++)
  if (TREE_OPERAND (exp, i) != 0
      && ! safe_from_p (x, TREE_OPERAND (exp, i), 0))
    return 0;

      /* If this is a language-specific tree code, it may require
   special handling.  */
      if ((unsigned int) TREE_CODE (exp)
    >= (unsigned int) LAST_AND_UNUSED_TREE_CODE
    && !(*lang_hooks.safe_from_p) (x, exp))
  return 0;
    }

  /* If we have an rtl, find any enclosed object.  Then see if we conflict
     with it.  */
  if (exp_rtl)
    {
      if (GET_CODE (exp_rtl) == SUBREG)
  {
    exp_rtl = SUBREG_REG (exp_rtl);
    if (GET_CODE (exp_rtl) == REG
        && REGNO (exp_rtl) < FIRST_PSEUDO_REGISTER)
      return 0;
  }

      /* If the rtl is X, then it is not safe.  Otherwise, it is unless both
   are memory and they conflict.  */
      return ! (rtx_equal_p (x, exp_rtl)
    || (GET_CODE (x) == MEM && GET_CODE (exp_rtl) == MEM
        && true_dependence (exp_rtl, VOIDmode, x,
          rtx_addr_varies_p)));
    }

  /* If we reach here, it is safe.  */
  return 1;
}

/* Subroutine of expand_expr: return rtx if EXP is a
   variable or parameter; else return 0.  */

static rtx
var_rtx (exp)
     tree exp;
{
  STRIP_NOPS (exp);
  switch (TREE_CODE (exp))
    {
    case PARM_DECL:
    case VAR_DECL:
      return DECL_RTL (exp);
    default:
      return 0;
    }
}

#ifdef MAX_INTEGER_COMPUTATION_MODE

void
check_max_integer_computation_mode (exp)
     tree exp;
{
  enum tree_code code;
  enum machine_mode mode;

  /* Strip any NOPs that don't change the mode.  */
  STRIP_NOPS (exp);
  code = TREE_CODE (exp);

  /* We must allow conversions of constants to MAX_INTEGER_COMPUTATION_MODE.  */
  if (code == NOP_EXPR
      && TREE_CODE (TREE_OPERAND (exp, 0)) == INTEGER_CST)
    return;

  /* First check the type of the overall operation.   We need only look at
     unary, binary and relational operations.  */
  if (TREE_CODE_CLASS (code) == '1'
      || TREE_CODE_CLASS (code) == '2'
      || TREE_CODE_CLASS (code) == '<')
    {
      mode = TYPE_MODE (TREE_TYPE (exp));
      if (GET_MODE_CLASS (mode) == MODE_INT
    && mode > MAX_INTEGER_COMPUTATION_MODE)
  internal_error ("unsupported wide integer operation");
    }

  /* Check operand of a unary op.  */
  if (TREE_CODE_CLASS (code) == '1')
    {
      mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
      if (GET_MODE_CLASS (mode) == MODE_INT
    && mode > MAX_INTEGER_COMPUTATION_MODE)
  internal_error ("unsupported wide integer operation");
    }

  /* Check operands of a binary/comparison op.  */
  if (TREE_CODE_CLASS (code) == '2' || TREE_CODE_CLASS (code) == '<')
    {
      mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
      if (GET_MODE_CLASS (mode) == MODE_INT
    && mode > MAX_INTEGER_COMPUTATION_MODE)
  internal_error ("unsupported wide integer operation");

      mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 1)));
      if (GET_MODE_CLASS (mode) == MODE_INT
    && mode > MAX_INTEGER_COMPUTATION_MODE)
  internal_error ("unsupported wide integer operation");
    }
}
#endif

/* Return the highest power of two that EXP is known to be a multiple of.
   This is used in updating alignment of MEMs in array references.  */

static HOST_WIDE_INT
highest_pow2_factor (exp)
     tree exp;
{
  HOST_WIDE_INT c0, c1;

  switch (TREE_CODE (exp))
    {
    case INTEGER_CST:
      /* We can find the lowest bit that's a one.  If the low
   HOST_BITS_PER_WIDE_INT bits are zero, return BIGGEST_ALIGNMENT.
   We need to handle this case since we can find it in a COND_EXPR,
   a MIN_EXPR, or a MAX_EXPR.  If the constant overlows, we have an
   erroneous program, so return BIGGEST_ALIGNMENT to avoid any
   later ICE.  */
      if (TREE_CONSTANT_OVERFLOW (exp))
  return BIGGEST_ALIGNMENT;
      else
  {
    /* Note: tree_low_cst is intentionally not used here,
       we don't care about the upper bits.  */
    c0 = TREE_INT_CST_LOW (exp);
    c0 &= -c0;
    return c0 ? c0 : BIGGEST_ALIGNMENT;
  }
      break;

    case PLUS_EXPR:  case MINUS_EXPR:  case MIN_EXPR:  case MAX_EXPR:
      c0 = highest_pow2_factor (TREE_OPERAND (exp, 0));
      c1 = highest_pow2_factor (TREE_OPERAND (exp, 1));
      return MIN (c0, c1);

    case MULT_EXPR:
      c0 = highest_pow2_factor (TREE_OPERAND (exp, 0));
      c1 = highest_pow2_factor (TREE_OPERAND (exp, 1));
      return c0 * c1;

    case ROUND_DIV_EXPR:  case TRUNC_DIV_EXPR:  case FLOOR_DIV_EXPR:
    case CEIL_DIV_EXPR:
      if (integer_pow2p (TREE_OPERAND (exp, 1))
    && host_integerp (TREE_OPERAND (exp, 1), 1))
  {
    c0 = highest_pow2_factor (TREE_OPERAND (exp, 0));
    c1 = tree_low_cst (TREE_OPERAND (exp, 1), 1);
    return MAX (1, c0 / c1);
  }
      break;

    case NON_LVALUE_EXPR:  case NOP_EXPR:  case CONVERT_EXPR:
    case SAVE_EXPR: case WITH_RECORD_EXPR:
      return highest_pow2_factor (TREE_OPERAND (exp, 0));

    case COMPOUND_EXPR:
      return highest_pow2_factor (TREE_OPERAND (exp, 1));

    case COND_EXPR:
      c0 = highest_pow2_factor (TREE_OPERAND (exp, 1));
      c1 = highest_pow2_factor (TREE_OPERAND (exp, 2));
      return MIN (c0, c1);

    default:
      break;
    }

  return 1;
}

/* Similar, except that it is known that the expression must be a multiple
   of the alignment of TYPE.  */

static HOST_WIDE_INT
highest_pow2_factor_for_type (type, exp)
     tree type;
     tree exp;
{
  HOST_WIDE_INT type_align, factor;

  factor = highest_pow2_factor (exp);
  type_align = TYPE_ALIGN (type) / BITS_PER_UNIT;
  return MAX (factor, type_align);
}

/* Return an object on the placeholder list that matches EXP, a
   PLACEHOLDER_EXPR.  An object "matches" if it is of the type of the
   PLACEHOLDER_EXPR or a pointer type to it.  For further information, see
   tree.def.  If no such object is found, return 0.  If PLIST is nonzero, it
   is a location which initially points to a starting location in the
   placeholder list (zero means start of the list) and where a pointer into
   the placeholder list at which the object is found is placed.  */

tree
find_placeholder (exp, plist)
     tree exp;
     tree *plist;
{
  tree type = TREE_TYPE (exp);
  tree placeholder_expr;

  for (placeholder_expr
       = plist && *plist ? TREE_CHAIN (*plist) : placeholder_list;
       placeholder_expr != 0;
       placeholder_expr = TREE_CHAIN (placeholder_expr))
    {
      tree need_type = TYPE_MAIN_VARIANT (type);
      tree elt;

      /* Find the outermost reference that is of the type we want.  If none,
   see if any object has a type that is a pointer to the type we
   want.  */
      for (elt = TREE_PURPOSE (placeholder_expr); elt != 0;
     elt = ((TREE_CODE (elt) == COMPOUND_EXPR
       || TREE_CODE (elt) == COND_EXPR)
      ? TREE_OPERAND (elt, 1)
      : (TREE_CODE_CLASS (TREE_CODE (elt)) == 'r'
         || TREE_CODE_CLASS (TREE_CODE (elt)) == '1'
         || TREE_CODE_CLASS (TREE_CODE (elt)) == '2'
         || TREE_CODE_CLASS (TREE_CODE (elt)) == 'e')
      ? TREE_OPERAND (elt, 0) : 0))
  if (TYPE_MAIN_VARIANT (TREE_TYPE (elt)) == need_type)
    {
      if (plist)
        *plist = placeholder_expr;
      return elt;
    }

      for (elt = TREE_PURPOSE (placeholder_expr); elt != 0;
     elt
     = ((TREE_CODE (elt) == COMPOUND_EXPR
         || TREE_CODE (elt) == COND_EXPR)
        ? TREE_OPERAND (elt, 1)
        : (TREE_CODE_CLASS (TREE_CODE (elt)) == 'r'
     || TREE_CODE_CLASS (TREE_CODE (elt)) == '1'
     || TREE_CODE_CLASS (TREE_CODE (elt)) == '2'
     || TREE_CODE_CLASS (TREE_CODE (elt)) == 'e')
        ? TREE_OPERAND (elt, 0) : 0))
  if (POINTER_TYPE_P (TREE_TYPE (elt))
      && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (elt)))
    == need_type))
    {
      if (plist)
        *plist = placeholder_expr;
      return build1 (INDIRECT_REF, need_type, elt);
    }
    }

  return 0;
}

/* expand_expr: generate code for computing expression EXP.
   An rtx for the computed value is returned.  The value is never null.
   In the case of a void EXP, const0_rtx is returned.

   The value may be stored in TARGET if TARGET is nonzero.
   TARGET is just a suggestion; callers must assume that
   the rtx returned may not be the same as TARGET.

   If TARGET is CONST0_RTX, it means that the value will be ignored.

   If TMODE is not VOIDmode, it suggests generating the
   result in mode TMODE.  But this is done only when convenient.
   Otherwise, TMODE is ignored and the value generated in its natural mode.
   TMODE is just a suggestion; callers must assume that
   the rtx returned may not have mode TMODE.

   Note that TARGET may have neither TMODE nor MODE.  In that case, it
   probably will not be used.

   If MODIFIER is EXPAND_SUM then when EXP is an addition
   we can return an rtx of the form (MULT (REG ...) (CONST_INT ...))
   or a nest of (PLUS ...) and (MINUS ...) where the terms are
   products as above, or REG or MEM, or constant.
   Ordinarily in such cases we would output mul or add instructions
   and then return a pseudo reg containing the sum.

   EXPAND_INITIALIZER is much like EXPAND_SUM except that
   it also marks a label as absolutely required (it can't be dead).
   It also makes a ZERO_EXTEND or SIGN_EXTEND instead of emitting extend insns.
   This is used for outputting expressions used in initializers.

   EXPAND_CONST_ADDRESS says that it is okay to return a MEM
   with a constant address even if that address is not normally legitimate.
   EXPAND_INITIALIZER and EXPAND_SUM also have this effect.

   EXPAND_STACK_PARM is used when expanding to a TARGET on the stack for
   a call parameter.  Such targets require special care as we haven't yet
   marked TARGET so that it's safe from being trashed by libcalls.  We
   don't want to use TARGET for anything but the final result;
   Intermediate values must go elsewhere.   Additionally, calls to
   emit_block_move will be flagged with BLOCK_OP_CALL_PARM.  */

rtx
expand_expr (exp, target, tmode, modifier)
     tree exp;
     rtx target;
     enum machine_mode tmode;
     enum expand_modifier modifier;
{
  rtx op0, op1, temp;
  tree type = TREE_TYPE (exp);
  int unsignedp = TREE_UNSIGNED (type);
  enum machine_mode mode;
  enum tree_code code = TREE_CODE (exp);
  optab this_optab;
  rtx subtarget, original_target;
  int ignore;
  tree context;

  /* Handle ERROR_MARK before anybody tries to access its type.  */
  if (TREE_CODE (exp) == ERROR_MARK || TREE_CODE (type) == ERROR_MARK)
    {
      op0 = CONST0_RTX (tmode);
      if (op0 != 0)
  return op0;
      return const0_rtx;
    }

  mode = TYPE_MODE (type);
  /* Use subtarget as the target for operand 0 of a binary operation.  */
  subtarget = get_subtarget (target);
  original_target = target;
  ignore = (target == const0_rtx
      || ((code == NON_LVALUE_EXPR || code == NOP_EXPR
     || code == CONVERT_EXPR || code == REFERENCE_EXPR
     || code == COND_EXPR || code == VIEW_CONVERT_EXPR)
    && TREE_CODE (type) == VOID_TYPE));

  /* If we are going to ignore this result, we need only do something
     if there is a side-effect somewhere in the expression.  If there
     is, short-circuit the most common cases here.  Note that we must
     not call expand_expr with anything but const0_rtx in case this
     is an initial expansion of a size that contains a PLACEHOLDER_EXPR.  */

  if (ignore)
    {
      if (! TREE_SIDE_EFFECTS (exp))
  return const0_rtx;

      /* Ensure we reference a volatile object even if value is ignored, but
   don't do this if all we are doing is taking its address.  */
      if (TREE_THIS_VOLATILE (exp)
    && TREE_CODE (exp) != FUNCTION_DECL
    && mode != VOIDmode && mode != BLKmode
    && modifier != EXPAND_CONST_ADDRESS)
  {
    temp = expand_expr (exp, NULL_RTX, VOIDmode, modifier);
    if (GET_CODE (temp) == MEM)
      temp = copy_to_reg (temp);
    return const0_rtx;
  }

      if (TREE_CODE_CLASS (code) == '1' || code == COMPONENT_REF
    || code == INDIRECT_REF || code == BUFFER_REF)
  return expand_expr (TREE_OPERAND (exp, 0), const0_rtx, VOIDmode,
          modifier);

      else if (TREE_CODE_CLASS (code) == '2' || TREE_CODE_CLASS (code) == '<'
         || code == ARRAY_REF || code == ARRAY_RANGE_REF)
  {
    expand_expr (TREE_OPERAND (exp, 0), const0_rtx, VOIDmode, modifier);
    expand_expr (TREE_OPERAND (exp, 1), const0_rtx, VOIDmode, modifier);
    return const0_rtx;
  }
      else if ((code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
         && ! TREE_SIDE_EFFECTS (TREE_OPERAND (exp, 1)))
  /* If the second operand has no side effects, just evaluate
     the first.  */
  return expand_expr (TREE_OPERAND (exp, 0), const0_rtx, VOIDmode,
          modifier);
      else if (code == BIT_FIELD_REF)
  {
    expand_expr (TREE_OPERAND (exp, 0), const0_rtx, VOIDmode, modifier);
    expand_expr (TREE_OPERAND (exp, 1), const0_rtx, VOIDmode, modifier);
    expand_expr (TREE_OPERAND (exp, 2), const0_rtx, VOIDmode, modifier);
    return const0_rtx;
  }

      target = 0;
    }

#ifdef MAX_INTEGER_COMPUTATION_MODE
  /* Only check stuff here if the mode we want is different from the mode
     of the expression; if it's the same, check_max_integer_computiation_mode
     will handle it.  Do we really need to check this stuff at all?  */

  if (target
      && GET_MODE (target) != mode
      && TREE_CODE (exp) != INTEGER_CST
      && TREE_CODE (exp) != PARM_DECL
      && TREE_CODE (exp) != ARRAY_REF
      && TREE_CODE (exp) != ARRAY_RANGE_REF
      && TREE_CODE (exp) != COMPONENT_REF
      && TREE_CODE (exp) != BIT_FIELD_REF
      && TREE_CODE (exp) != INDIRECT_REF
      && TREE_CODE (exp) != CALL_EXPR
      && TREE_CODE (exp) != VAR_DECL
      && TREE_CODE (exp) != RTL_EXPR)
    {
      enum machine_mode mode = GET_MODE (target);

      if (GET_MODE_CLASS (mode) == MODE_INT
    && mode > MAX_INTEGER_COMPUTATION_MODE)
  internal_error ("unsupported wide integer operation");
    }

  if (tmode != mode
      && TREE_CODE (exp) != INTEGER_CST
      && TREE_CODE (exp) != PARM_DECL
      && TREE_CODE (exp) != ARRAY_REF
      && TREE_CODE (exp) != ARRAY_RANGE_REF
      && TREE_CODE (exp) != COMPONENT_REF
      && TREE_CODE (exp) != BIT_FIELD_REF
      && TREE_CODE (exp) != INDIRECT_REF
      && TREE_CODE (exp) != VAR_DECL
      && TREE_CODE (exp) != CALL_EXPR
      && TREE_CODE (exp) != RTL_EXPR
      && GET_MODE_CLASS (tmode) == MODE_INT
      && tmode > MAX_INTEGER_COMPUTATION_MODE)
    internal_error ("unsupported wide integer operation");

  check_max_integer_computation_mode (exp);
#endif

  /* If will do cse, generate all results into pseudo registers
     since 1) that allows cse to find more things
     and 2) otherwise cse could produce an insn the machine
     cannot support.  And exception is a CONSTRUCTOR into a multi-word
     MEM: that's much more likely to be most efficient into the MEM.  */

  if (! cse_not_expected && mode != BLKmode && target
      && (GET_CODE (target) != REG || REGNO (target) < FIRST_PSEUDO_REGISTER)
      && ! (code == CONSTRUCTOR && GET_MODE_SIZE (mode) > UNITS_PER_WORD))
    target = 0;

  switch (code)
    {
    case LABEL_DECL:
      {
  tree function = decl_function_context (exp);
  /* Handle using a label in a containing function.  */
  if (function != current_function_decl
      && function != inline_function_decl && function != 0)
    {
      struct function *p = find_function_data (function);
      p->expr->x_forced_labels
        = gen_rtx_EXPR_LIST (VOIDmode, label_rtx (exp),
           p->expr->x_forced_labels);
    }
  else
    {
      if (modifier == EXPAND_INITIALIZER)
        forced_labels = gen_rtx_EXPR_LIST (VOIDmode,
             label_rtx (exp),
             forced_labels);
    }

  temp = gen_rtx_MEM (FUNCTION_MODE,
          gen_rtx_LABEL_REF (Pmode, label_rtx (exp)));
  if (function != current_function_decl
      && function != inline_function_decl && function != 0)
    LABEL_REF_NONLOCAL_P (XEXP (temp, 0)) = 1;
  return temp;
      }

    case PARM_DECL:
      if (!DECL_RTL_SET_P (exp))
  {
    error_with_decl (exp, "prior parameter's size depends on `%s'");
    return CONST0_RTX (mode);
  }

      /* ... fall through ...  */

    case VAR_DECL:
      /* If a static var's type was incomplete when the decl was written,
   but the type is complete now, lay out the decl now.  */
      if (DECL_SIZE (exp) == 0
    && COMPLETE_OR_UNBOUND_ARRAY_TYPE_P (TREE_TYPE (exp))
    && (TREE_STATIC (exp) || DECL_EXTERNAL (exp)))
  layout_decl (exp, 0);

      /* ... fall through ...  */

    case FUNCTION_DECL:
    case RESULT_DECL:
      if (DECL_RTL (exp) == 0)
  abort ();

      /* Ensure variable marked as used even if it doesn't go through
   a parser.  If it hasn't be used yet, write out an external
   definition.  */
      if (! TREE_USED (exp))
  {
    assemble_external (exp);
    TREE_USED (exp) = 1;
  }

      /* Show we haven't gotten RTL for this yet.  */
      temp = 0;

      /* Handle variables inherited from containing functions.  */
      context = decl_function_context (exp);

      /* We treat inline_function_decl as an alias for the current function
   because that is the inline function whose vars, types, etc.
   are being merged into the current function.
   See expand_inline_function.  */

      if (context != 0 && context != current_function_decl
    && context != inline_function_decl
    /* If var is static, we don't need a static chain to access it.  */
    && ! (GET_CODE (DECL_RTL (exp)) == MEM
    && CONSTANT_P (XEXP (DECL_RTL (exp), 0))))
  {
    rtx addr;

    /* Mark as non-local and addressable.  */
    DECL_NONLOCAL (exp) = 1;
    if (DECL_NO_STATIC_CHAIN (current_function_decl))
      abort ();
    (*lang_hooks.mark_addressable) (exp);
    if (GET_CODE (DECL_RTL (exp)) != MEM)
      abort ();
    addr = XEXP (DECL_RTL (exp), 0);
    if (GET_CODE (addr) == MEM)
      addr
        = replace_equiv_address (addr,
               fix_lexical_addr (XEXP (addr, 0), exp));
    else
      addr = fix_lexical_addr (addr, exp);

    temp = replace_equiv_address (DECL_RTL (exp), addr);
  }

      /* This is the case of an array whose size is to be determined
   from its initializer, while the initializer is still being parsed.
   See expand_decl.  */

      else if (GET_CODE (DECL_RTL (exp)) == MEM
         && GET_CODE (XEXP (DECL_RTL (exp), 0)) == REG)
  temp = validize_mem (DECL_RTL (exp));

      /* If DECL_RTL is memory, we are in the normal case and either
   the address is not valid or it is not a register and -fforce-addr
   is specified, get the address into a register.  */

      else if (GET_CODE (DECL_RTL (exp)) == MEM
         && modifier != EXPAND_CONST_ADDRESS
         && modifier != EXPAND_SUM
         && modifier != EXPAND_INITIALIZER
         && (! memory_address_p (DECL_MODE (exp),
               XEXP (DECL_RTL (exp), 0))
       || (flag_force_addr
           && GET_CODE (XEXP (DECL_RTL (exp), 0)) != REG)))
  temp = replace_equiv_address (DECL_RTL (exp),
              copy_rtx (XEXP (DECL_RTL (exp), 0)));

      /* If we got something, return it.  But first, set the alignment
   if the address is a register.  */
      if (temp != 0)
  {
    if (GET_CODE (temp) == MEM && GET_CODE (XEXP (temp, 0)) == REG)
      mark_reg_pointer (XEXP (temp, 0), DECL_ALIGN (exp));

    return temp;
  }

      /* If the mode of DECL_RTL does not match that of the decl, it
   must be a promoted value.  We return a SUBREG of the wanted mode,
   but mark it so that we know that it was already extended.  */

      if (GET_CODE (DECL_RTL (exp)) == REG
    && GET_MODE (DECL_RTL (exp)) != DECL_MODE (exp))
  {
    /* Get the signedness used for this variable.  Ensure we get the
       same mode we got when the variable was declared.  */
    if (GET_MODE (DECL_RTL (exp))
        != promote_mode (type, DECL_MODE (exp), &unsignedp,
             (TREE_CODE (exp) == RESULT_DECL ? 1 : 0)))
      abort ();

    temp = gen_lowpart_SUBREG (mode, DECL_RTL (exp));
    SUBREG_PROMOTED_VAR_P (temp) = 1;
    SUBREG_PROMOTED_UNSIGNED_SET (temp, unsignedp);
    return temp;
  }

      return DECL_RTL (exp);

    case INTEGER_CST:
      temp = immed_double_const (TREE_INT_CST_LOW (exp),
         TREE_INT_CST_HIGH (exp), mode);

      /* ??? If overflow is set, fold will have done an incomplete job,
   which can result in (plus xx (const_int 0)), which can get
   simplified by validate_replace_rtx during virtual register
   instantiation, which can result in unrecognizable insns.
   Avoid this by forcing all overflows into registers.  */
      if (TREE_CONSTANT_OVERFLOW (exp)
    && modifier != EXPAND_INITIALIZER)
  temp = force_reg (mode, temp);

      return temp;

    case VECTOR_CST:
      return const_vector_from_tree (exp);

    case CONST_DECL:
      return expand_expr (DECL_INITIAL (exp), target, VOIDmode, modifier);

    case REAL_CST:
      /* If optimized, generate immediate CONST_DOUBLE
   which will be turned into memory by reload if necessary.

   We used to force a register so that loop.c could see it.  But
   this does not allow gen_* patterns to perform optimizations with
   the constants.  It also produces two insns in cases like "x = 1.0;".
   On most machines, floating-point constants are not permitted in
   many insns, so we'd end up copying it to a register in any case.

   Now, we do the copying in expand_binop, if appropriate.  */
      return CONST_DOUBLE_FROM_REAL_VALUE (TREE_REAL_CST (exp),
             TYPE_MODE (TREE_TYPE (exp)));

    case COMPLEX_CST:
    case STRING_CST:
      if (! TREE_CST_RTL (exp))
  output_constant_def (exp, 1);

      /* TREE_CST_RTL probably contains a constant address.
   On RISC machines where a constant address isn't valid,
   make some insns to get that address into a register.  */
      if (GET_CODE (TREE_CST_RTL (exp)) == MEM
    && modifier != EXPAND_CONST_ADDRESS
    && modifier != EXPAND_INITIALIZER
    && modifier != EXPAND_SUM
    && (! memory_address_p (mode, XEXP (TREE_CST_RTL (exp), 0))
        || (flag_force_addr
      && GET_CODE (XEXP (TREE_CST_RTL (exp), 0)) != REG)))
  return replace_equiv_address (TREE_CST_RTL (exp),
              copy_rtx (XEXP (TREE_CST_RTL (exp), 0)));
      return TREE_CST_RTL (exp);

    case EXPR_WITH_FILE_LOCATION:
      {
  rtx to_return;
  const char *saved_input_filename = input_filename;
  int saved_lineno = lineno;
  input_filename = EXPR_WFL_FILENAME (exp);
  lineno = EXPR_WFL_LINENO (exp);
  if (EXPR_WFL_EMIT_LINE_NOTE (exp))
    emit_line_note (input_filename, lineno);
  /* Possibly avoid switching back and forth here.  */
  to_return = expand_expr (EXPR_WFL_NODE (exp), target, tmode, modifier);
  input_filename = saved_input_filename;
  lineno = saved_lineno;
  return to_return;
      }

    case SAVE_EXPR:
      context = decl_function_context (exp);

      /* If this SAVE_EXPR was at global context, assume we are an
   initialization function and move it into our context.  */
      if (context == 0)
  SAVE_EXPR_CONTEXT (exp) = current_function_decl;

      /* We treat inline_function_decl as an alias for the current function
   because that is the inline function whose vars, types, etc.
   are being merged into the current function.
   See expand_inline_function.  */
      if (context == current_function_decl || context == inline_function_decl)
  context = 0;

      /* If this is non-local, handle it.  */
      if (context)
  {
    /* The following call just exists to abort if the context is
       not of a containing function.  */
    find_function_data (context);

    temp = SAVE_EXPR_RTL (exp);
    if (temp && GET_CODE (temp) == REG)
      {
        put_var_into_stack (exp, /*rescan=*/true);
        temp = SAVE_EXPR_RTL (exp);
      }
    if (temp == 0 || GET_CODE (temp) != MEM)
      abort ();
    return
      replace_equiv_address (temp,
           fix_lexical_addr (XEXP (temp, 0), exp));
  }
      if (SAVE_EXPR_RTL (exp) == 0)
  {
    if (mode == VOIDmode)
      temp = const0_rtx;
    else
      temp = assign_temp (build_qualified_type (type,
                  (TYPE_QUALS (type)
                   | TYPE_QUAL_CONST)),
        3, 0, 0);

    SAVE_EXPR_RTL (exp) = temp;
    if (!optimize && GET_CODE (temp) == REG)
      save_expr_regs = gen_rtx_EXPR_LIST (VOIDmode, temp,
            save_expr_regs);

    /* If the mode of TEMP does not match that of the expression, it
       must be a promoted value.  We pass store_expr a SUBREG of the
       wanted mode but mark it so that we know that it was already
       extended.  */

    if (GET_CODE (temp) == REG && GET_MODE (temp) != mode)
      {
        temp = gen_lowpart_SUBREG (mode, SAVE_EXPR_RTL (exp));
        promote_mode (type, mode, &unsignedp, 0);
        SUBREG_PROMOTED_VAR_P (temp) = 1;
        SUBREG_PROMOTED_UNSIGNED_SET (temp, unsignedp);
      }

    if (temp == const0_rtx)
      expand_expr (TREE_OPERAND (exp, 0), const0_rtx, VOIDmode, 0);
    else
      store_expr (TREE_OPERAND (exp, 0), temp,
      modifier == EXPAND_STACK_PARM ? 2 : 0);

    TREE_USED (exp) = 1;
  }

      /* If the mode of SAVE_EXPR_RTL does not match that of the expression, it
   must be a promoted value.  We return a SUBREG of the wanted mode,
   but mark it so that we know that it was already extended.  */

      if (GET_CODE (SAVE_EXPR_RTL (exp)) == REG
    && GET_MODE (SAVE_EXPR_RTL (exp)) != mode)
  {
    /* Compute the signedness and make the proper SUBREG.  */
    promote_mode (type, mode, &unsignedp, 0);
    temp = gen_lowpart_SUBREG (mode, SAVE_EXPR_RTL (exp));
    SUBREG_PROMOTED_VAR_P (temp) = 1;
    SUBREG_PROMOTED_UNSIGNED_SET (temp, unsignedp);
    return temp;
  }

      return SAVE_EXPR_RTL (exp);

    case UNSAVE_EXPR:
      {
  rtx temp;
  temp = expand_expr (TREE_OPERAND (exp, 0), target, tmode, modifier);
  TREE_OPERAND (exp, 0)
    = (*lang_hooks.unsave_expr_now) (TREE_OPERAND (exp, 0));
  return temp;
      }

    case PLACEHOLDER_EXPR:
      {
  tree old_list = placeholder_list;
  tree placeholder_expr = 0;

  exp = find_placeholder (exp, &placeholder_expr);
  if (exp == 0)
    abort ();

  placeholder_list = TREE_CHAIN (placeholder_expr);
  temp = expand_expr (exp, original_target, tmode, modifier);
  placeholder_list = old_list;
  return temp;
      }

    case WITH_RECORD_EXPR:
      /* Put the object on the placeholder list, expand our first operand,
   and pop the list.  */
      placeholder_list = tree_cons (TREE_OPERAND (exp, 1), NULL_TREE,
            placeholder_list);
      target = expand_expr (TREE_OPERAND (exp, 0), original_target, tmode,
          modifier);
      placeholder_list = TREE_CHAIN (placeholder_list);
      return target;

    case GOTO_EXPR:
      if (TREE_CODE (TREE_OPERAND (exp, 0)) == LABEL_DECL)
  expand_goto (TREE_OPERAND (exp, 0));
      else
  expand_computed_goto (TREE_OPERAND (exp, 0));
      return const0_rtx;

    case EXIT_EXPR:
      expand_exit_loop_if_false (NULL,
         invert_truthvalue (TREE_OPERAND (exp, 0)));
      return const0_rtx;

    case LABELED_BLOCK_EXPR:
      if (LABELED_BLOCK_BODY (exp))
  expand_expr_stmt_value (LABELED_BLOCK_BODY (exp), 0, 1);
      /* Should perhaps use expand_label, but this is simpler and safer.  */
      do_pending_stack_adjust ();
      emit_label (label_rtx (LABELED_BLOCK_LABEL (exp)));
      return const0_rtx;

    case EXIT_BLOCK_EXPR:
      if (EXIT_BLOCK_RETURN (exp))
  sorry ("returned value in block_exit_expr");
      expand_goto (LABELED_BLOCK_LABEL (EXIT_BLOCK_LABELED_BLOCK (exp)));
      return const0_rtx;

    case LOOP_EXPR:
      push_temp_slots ();
      expand_start_loop (1);
      expand_expr_stmt_value (TREE_OPERAND (exp, 0), 0, 1);
      expand_end_loop ();
      pop_temp_slots ();

      return const0_rtx;

    case BIND_EXPR:
      {
  tree vars = TREE_OPERAND (exp, 0);
  int vars_need_expansion = 0;

  /* Need to open a binding contour here because
     if there are any cleanups they must be contained here.  */
  expand_start_bindings (2);

  /* Mark the corresponding BLOCK for output in its proper place.  */
  if (TREE_OPERAND (exp, 2) != 0
      && ! TREE_USED (TREE_OPERAND (exp, 2)))
    (*lang_hooks.decls.insert_block) (TREE_OPERAND (exp, 2));

  /* If VARS have not yet been expanded, expand them now.  */
  while (vars)
    {
      if (!DECL_RTL_SET_P (vars))
        {
    vars_need_expansion = 1;
    expand_decl (vars);
        }
      expand_decl_init (vars);
      vars = TREE_CHAIN (vars);
    }

  temp = expand_expr (TREE_OPERAND (exp, 1), target, tmode, modifier);

  expand_end_bindings (TREE_OPERAND (exp, 0), 0, 0);

  return temp;
      }

    case RTL_EXPR:
      if (RTL_EXPR_SEQUENCE (exp))
  {
    if (RTL_EXPR_SEQUENCE (exp) == const0_rtx)
      abort ();
    emit_insn (RTL_EXPR_SEQUENCE (exp));
    RTL_EXPR_SEQUENCE (exp) = const0_rtx;
  }
      preserve_rtl_expr_result (RTL_EXPR_RTL (exp));
      free_temps_for_rtl_expr (exp);
      return RTL_EXPR_RTL (exp);

    case CONSTRUCTOR:
      /* If we don't need the result, just ensure we evaluate any
   subexpressions.  */
      if (ignore)
  {
    tree elt;

    for (elt = CONSTRUCTOR_ELTS (exp); elt; elt = TREE_CHAIN (elt))
      expand_expr (TREE_VALUE (elt), const0_rtx, VOIDmode, 0);

    return const0_rtx;
  }

      /* All elts simple constants => refer to a constant in memory.  But
   if this is a non-BLKmode mode, let it store a field at a time
   since that should make a CONST_INT or CONST_DOUBLE when we
   fold.  Likewise, if we have a target we can use, it is best to
   store directly into the target unless the type is large enough
   that memcpy will be used.  If we are making an initializer and
   all operands are constant, put it in memory as well.

  FIXME: Avoid trying to fill vector constructors piece-meal.
  Output them with output_constant_def below unless we're sure
  they're zeros.  This should go away when vector initializers
  are treated like VECTOR_CST instead of arrays.
      */
      else if ((TREE_STATIC (exp)
    && ((mode == BLKmode
         && ! (target != 0 && safe_from_p (target, exp, 1)))
        || TREE_ADDRESSABLE (exp)
        || (host_integerp (TYPE_SIZE_UNIT (type), 1)
      && (! MOVE_BY_PIECES_P
          (tree_low_cst (TYPE_SIZE_UNIT (type), 1),
           TYPE_ALIGN (type)))
      && ((TREE_CODE (type) == VECTOR_TYPE
           && !is_zeros_p (exp))
          || ! mostly_zeros_p (exp)))))
         || (modifier == EXPAND_INITIALIZER && TREE_CONSTANT (exp)))
  {
    rtx constructor = output_constant_def (exp, 1);

    if (modifier != EXPAND_CONST_ADDRESS
        && modifier != EXPAND_INITIALIZER
        && modifier != EXPAND_SUM)
      constructor = validize_mem (constructor);

    return constructor;
  }
      else
  {
    /* Handle calls that pass values in multiple non-contiguous
       locations.  The Irix 6 ABI has examples of this.  */
    if (target == 0 || ! safe_from_p (target, exp, 1)
        || GET_CODE (target) == PARALLEL
        || modifier == EXPAND_STACK_PARM)
      target
        = assign_temp (build_qualified_type (type,
               (TYPE_QUALS (type)
                | (TREE_READONLY (exp)
                   * TYPE_QUAL_CONST))),
           0, TREE_ADDRESSABLE (exp), 1);

    store_constructor (exp, target, 0, int_expr_size (exp));
    return target;
  }

    case INDIRECT_REF:
      {
  tree exp1 = TREE_OPERAND (exp, 0);
  tree index;
  tree string = string_constant (exp1, &index);

  /* Try to optimize reads from const strings.  */
  if (string
      && TREE_CODE (string) == STRING_CST
      && TREE_CODE (index) == INTEGER_CST
      && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
      && GET_MODE_CLASS (mode) == MODE_INT
      && GET_MODE_SIZE (mode) == 1
      && modifier != EXPAND_WRITE)
    return gen_int_mode (TREE_STRING_POINTER (string)
             [TREE_INT_CST_LOW (index)], mode);

  op0 = expand_expr (exp1, NULL_RTX, VOIDmode, EXPAND_SUM);
  op0 = memory_address (mode, op0);
  temp = gen_rtx_MEM (mode, op0);
  set_mem_attributes (temp, exp, 0);

  /* If we are writing to this object and its type is a record with
     readonly fields, we must mark it as readonly so it will
     conflict with readonly references to those fields.  */
  if (modifier == EXPAND_WRITE && readonly_fields_p (type))
    RTX_UNCHANGING_P (temp) = 1;

  return temp;
      }

    case ARRAY_REF:
      if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) != ARRAY_TYPE)
  abort ();

      {
  tree array = TREE_OPERAND (exp, 0);
  tree domain = TYPE_DOMAIN (TREE_TYPE (array));
  tree low_bound = domain ? TYPE_MIN_VALUE (domain) : integer_zero_node;
  tree index = convert (sizetype, TREE_OPERAND (exp, 1));
  HOST_WIDE_INT i;

  /* Optimize the special-case of a zero lower bound.

     We convert the low_bound to sizetype to avoid some problems
     with constant folding.  (E.g. suppose the lower bound is 1,
     and its mode is QI.  Without the conversion,  (ARRAY
     +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
     +INDEX), which becomes (ARRAY+255+INDEX).  Oops!)  */

  if (! integer_zerop (low_bound))
    index = size_diffop (index, convert (sizetype, low_bound));

  /* Fold an expression like: "foo"[2].
     This is not done in fold so it won't happen inside &.
     Don't fold if this is for wide characters since it's too
     difficult to do correctly and this is a very rare case.  */

  if (modifier != EXPAND_CONST_ADDRESS
      && modifier != EXPAND_INITIALIZER
      && modifier != EXPAND_MEMORY
      && TREE_CODE (array) == STRING_CST
      && TREE_CODE (index) == INTEGER_CST
      && compare_tree_int (index, TREE_STRING_LENGTH (array)) < 0
      && GET_MODE_CLASS (mode) == MODE_INT
      && GET_MODE_SIZE (mode) == 1)
    return gen_int_mode (TREE_STRING_POINTER (array)
             [TREE_INT_CST_LOW (index)], mode);

  /* If this is a constant index into a constant array,
     just get the value from the array.  Handle both the cases when
     we have an explicit constructor and when our operand is a variable
     that was declared const.  */

  if (modifier != EXPAND_CONST_ADDRESS
      && modifier != EXPAND_INITIALIZER
      && modifier != EXPAND_MEMORY
      && TREE_CODE (array) == CONSTRUCTOR
      && ! TREE_SIDE_EFFECTS (array)
      && TREE_CODE (index) == INTEGER_CST
      && 0 > compare_tree_int (index,
             list_length (CONSTRUCTOR_ELTS
              (TREE_OPERAND (exp, 0)))))
    {
      tree elem;

      for (elem = CONSTRUCTOR_ELTS (TREE_OPERAND (exp, 0)),
     i = TREE_INT_CST_LOW (index);
     elem != 0 && i != 0; i--, elem = TREE_CHAIN (elem))
        ;

      if (elem)
        return expand_expr (fold (TREE_VALUE (elem)), target, tmode,
          modifier);
    }

  else if (optimize >= 1
     && modifier != EXPAND_CONST_ADDRESS
     && modifier != EXPAND_INITIALIZER
     && modifier != EXPAND_MEMORY
     && TREE_READONLY (array) && ! TREE_SIDE_EFFECTS (array)
     && TREE_CODE (array) == VAR_DECL && DECL_INITIAL (array)
     && TREE_CODE (DECL_INITIAL (array)) != ERROR_MARK)
    {
      if (TREE_CODE (index) == INTEGER_CST)
        {
    tree init = DECL_INITIAL (array);

    if (TREE_CODE (init) == CONSTRUCTOR)
      {
        tree elem;

        for (elem = CONSTRUCTOR_ELTS (init);
       (elem
        && !tree_int_cst_equal (TREE_PURPOSE (elem), index));
       elem = TREE_CHAIN (elem))
          ;

        if (elem && !TREE_SIDE_EFFECTS (TREE_VALUE (elem)))
          return expand_expr (fold (TREE_VALUE (elem)), target,
            tmode, modifier);
      }
    else if (TREE_CODE (init) == STRING_CST
       && 0 > compare_tree_int (index,
              TREE_STRING_LENGTH (init)))
      {
        tree type = TREE_TYPE (TREE_TYPE (init));
        enum machine_mode mode = TYPE_MODE (type);

        if (GET_MODE_CLASS (mode) == MODE_INT
      && GET_MODE_SIZE (mode) == 1)
          return gen_int_mode (TREE_STRING_POINTER (init)
             [TREE_INT_CST_LOW (index)], mode);
      }
        }
    }
      }
      /* Fall through.  */

    case COMPONENT_REF:
    case BIT_FIELD_REF:
    case ARRAY_RANGE_REF:
      /* If the operand is a CONSTRUCTOR, we can just extract the
   appropriate field if it is present.  Don't do this if we have
   already written the data since we want to refer to that copy
   and varasm.c assumes that's what we'll do.  */
      if (code == COMPONENT_REF
    && TREE_CODE (TREE_OPERAND (exp, 0)) == CONSTRUCTOR
    && TREE_CST_RTL (TREE_OPERAND (exp, 0)) == 0)
  {
    tree elt;

    for (elt = CONSTRUCTOR_ELTS (TREE_OPERAND (exp, 0)); elt;
         elt = TREE_CHAIN (elt))
      if (TREE_PURPOSE (elt) == TREE_OPERAND (exp, 1)
    /* We can normally use the value of the field in the
       CONSTRUCTOR.  However, if this is a bitfield in
       an integral mode that we can fit in a HOST_WIDE_INT,
       we must mask only the number of bits in the bitfield,
       since this is done implicitly by the constructor.  If
       the bitfield does not meet either of those conditions,
       we can't do this optimization.  */
    && (! DECL_BIT_FIELD (TREE_PURPOSE (elt))
        || ((GET_MODE_CLASS (DECL_MODE (TREE_PURPOSE (elt)))
       == MODE_INT)
      && (GET_MODE_BITSIZE (DECL_MODE (TREE_PURPOSE (elt)))
          <= HOST_BITS_PER_WIDE_INT))))
        {
    if (DECL_BIT_FIELD (TREE_PURPOSE (elt))
        && modifier == EXPAND_STACK_PARM)
      target = 0;
    op0 = expand_expr (TREE_VALUE (elt), target, tmode, modifier);
    if (DECL_BIT_FIELD (TREE_PURPOSE (elt)))
      {
        HOST_WIDE_INT bitsize
          = TREE_INT_CST_LOW (DECL_SIZE (TREE_PURPOSE (elt)));
        enum machine_mode imode
          = TYPE_MODE (TREE_TYPE (TREE_PURPOSE (elt)));

        if (TREE_UNSIGNED (TREE_TYPE (TREE_PURPOSE (elt))))
          {
      op1 = GEN_INT (((HOST_WIDE_INT) 1 << bitsize) - 1);
      op0 = expand_and (imode, op0, op1, target);
          }
        else
          {
      tree count
        = build_int_2 (GET_MODE_BITSIZE (imode) - bitsize,
           0);

      op0 = expand_shift (LSHIFT_EXPR, imode, op0, count,
              target, 0);
      op0 = expand_shift (RSHIFT_EXPR, imode, op0, count,
              target, 0);
          }
      }

    return op0;
        }
  }

      {
  enum machine_mode mode1;
  HOST_WIDE_INT bitsize, bitpos;
  tree offset;
  int volatilep = 0;
  tree tem = get_inner_reference (exp, &bitsize, &bitpos, &offset,
          &mode1, &unsignedp, &volatilep);
  rtx orig_op0;

  /* If we got back the original object, something is wrong.  Perhaps
     we are evaluating an expression too early.  In any event, don't
     infinitely recurse.  */
  if (tem == exp)
    abort ();

  /* If TEM's type is a union of variable size, pass TARGET to the inner
     computation, since it will need a temporary and TARGET is known
     to have to do.  This occurs in unchecked conversion in Ada.  */

  orig_op0 = op0
    = expand_expr (tem,
       (TREE_CODE (TREE_TYPE (tem)) == UNION_TYPE
        && (TREE_CODE (TYPE_SIZE (TREE_TYPE (tem)))
            != INTEGER_CST)
        && modifier != EXPAND_STACK_PARM
        ? target : NULL_RTX),
       VOIDmode,
       (modifier == EXPAND_INITIALIZER
        || modifier == EXPAND_CONST_ADDRESS
        || modifier == EXPAND_STACK_PARM)
       ? modifier : EXPAND_NORMAL);

  /* If this is a constant, put it into a register if it is a
     legitimate constant and OFFSET is 0 and memory if it isn't.  */
  if (CONSTANT_P (op0))
    {
      enum machine_mode mode = TYPE_MODE (TREE_TYPE (tem));
      if (mode != BLKmode && LEGITIMATE_CONSTANT_P (op0)
    && offset == 0)
        op0 = force_reg (mode, op0);
      else
        op0 = validize_mem (force_const_mem (mode, op0));
    }

  if (offset != 0)
    {
      rtx offset_rtx = expand_expr (offset, NULL_RTX, VOIDmode,
            EXPAND_SUM);

      /* If this object is in a register, put it into memory.
         This case can't occur in C, but can in Ada if we have
         unchecked conversion of an expression from a scalar type to
         an array or record type.  */
      if (GET_CODE (op0) == REG || GET_CODE (op0) == SUBREG
    || GET_CODE (op0) == CONCAT || GET_CODE (op0) == ADDRESSOF)
        {
    /* If the operand is a SAVE_EXPR, we can deal with this by
       forcing the SAVE_EXPR into memory.  */
    if (TREE_CODE (TREE_OPERAND (exp, 0)) == SAVE_EXPR)
      {
        put_var_into_stack (TREE_OPERAND (exp, 0), 
          /*rescan=*/true);
        op0 = SAVE_EXPR_RTL (TREE_OPERAND (exp, 0));
      }
    else
      {
        tree nt
          = build_qualified_type (TREE_TYPE (tem),
                (TYPE_QUALS (TREE_TYPE (tem))
                 | TYPE_QUAL_CONST));
        rtx memloc = assign_temp (nt, 1, 1, 1);

        emit_move_insn (memloc, op0);
        op0 = memloc;
      }
        }

      if (GET_CODE (op0) != MEM)
        abort ();

#ifdef POINTERS_EXTEND_UNSIGNED
      if (GET_MODE (offset_rtx) != Pmode)
        offset_rtx = convert_to_mode (Pmode, offset_rtx, 0);
#else
      if (GET_MODE (offset_rtx) != ptr_mode)
        offset_rtx = convert_to_mode (ptr_mode, offset_rtx, 0);
#endif

      /* A constant address in OP0 can have VOIDmode, we must not try
         to call force_reg for that case.  Avoid that case.  */
      if (GET_CODE (op0) == MEM
    && GET_MODE (op0) == BLKmode
    && GET_MODE (XEXP (op0, 0)) != VOIDmode
    && bitsize != 0
    && (bitpos % bitsize) == 0
    && (bitsize % GET_MODE_ALIGNMENT (mode1)) == 0
    && MEM_ALIGN (op0) == GET_MODE_ALIGNMENT (mode1))
        {
    op0 = adjust_address (op0, mode1, bitpos / BITS_PER_UNIT);
    bitpos = 0;
        }

      op0 = offset_address (op0, offset_rtx,
          highest_pow2_factor (offset));
    }

  /* If OFFSET is making OP0 more aligned than BIGGEST_ALIGNMENT,
     record its alignment as BIGGEST_ALIGNMENT.  */
  if (GET_CODE (op0) == MEM && bitpos == 0 && offset != 0
      && is_aligning_offset (offset, tem))
    set_mem_align (op0, BIGGEST_ALIGNMENT);

  /* Don't forget about volatility even if this is a bitfield.  */
  if (GET_CODE (op0) == MEM && volatilep && ! MEM_VOLATILE_P (op0))
    {
      if (op0 == orig_op0)
        op0 = copy_rtx (op0);

      MEM_VOLATILE_P (op0) = 1;
    }

  /* The following code doesn't handle CONCAT.
     Assume only bitpos == 0 can be used for CONCAT, due to
     one element arrays having the same mode as its element.  */
  if (GET_CODE (op0) == CONCAT)
    {
      if (bitpos != 0 || bitsize != GET_MODE_BITSIZE (GET_MODE (op0)))
        abort ();
      return op0;
    }

  /* In cases where an aligned union has an unaligned object
     as a field, we might be extracting a BLKmode value from
     an integer-mode (e.g., SImode) object.  Handle this case
     by doing the extract into an object as wide as the field
     (which we know to be the width of a basic mode), then
     storing into memory, and changing the mode to BLKmode.  */
  if (mode1 == VOIDmode
      || GET_CODE (op0) == REG || GET_CODE (op0) == SUBREG
      || (mode1 != BLKmode && ! direct_load[(int) mode1]
    && GET_MODE_CLASS (mode) != MODE_COMPLEX_INT
    && GET_MODE_CLASS (mode) != MODE_COMPLEX_FLOAT
    && modifier != EXPAND_CONST_ADDRESS
    && modifier != EXPAND_INITIALIZER)
      /* If the field isn't aligned enough to fetch as a memref,
         fetch it as a bit field.  */
      || (mode1 != BLKmode
    && SLOW_UNALIGNED_ACCESS (mode1, MEM_ALIGN (op0))
    && ((TYPE_ALIGN (TREE_TYPE (tem))
         < GET_MODE_ALIGNMENT (mode))
        || (bitpos % GET_MODE_ALIGNMENT (mode) != 0)))
      /* If the type and the field are a constant size and the
         size of the type isn't the same size as the bitfield,
<