(arm_gen_constant, case IOR,XOR): Don't invert a constant if loading

[official-gcc.git] / gcc / config / arm / arm.c

/* Output routines for GCC for ARM/RISCiX.
   Copyright (C) 1991, 1993, 1994, 1995, 1996 Free Software Foundation, Inc.
   Contributed by Pieter `Tiggr' Schoenmakers (rcpieter@win.tue.nl)
              and Martin Simmons (@harleqn.co.uk).
   More major hacks by Richard Earnshaw (rwe11@cl.cam.ac.uk)

This file is part of GNU CC.

GNU CC 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.

GNU CC 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 GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */
    
#include <stdio.h>
#include <string.h>
#include "assert.h"
#include "config.h"
#include "rtl.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "real.h"
#include "insn-config.h"
#include "conditions.h"
#include "insn-flags.h"
#include "output.h"
#include "insn-attr.h"
#include "flags.h"
#include "reload.h"
#include "tree.h"
#include "expr.h"

/* The maximum number of insns skipped which will be conditionalised if
   possible.  */
#define MAX_INSNS_SKIPPED  5

/* Some function declarations.  */
extern FILE *asm_out_file;
extern char *output_multi_immediate ();
extern void arm_increase_location ();

HOST_WIDE_INT int_log2 PROTO ((HOST_WIDE_INT));
static int get_prologue_size PROTO ((void));
static int arm_gen_constant PROTO ((enum rtx_code, enum machine_mode,
                                    HOST_WIDE_INT, rtx, rtx, int, int));

/*  Define the information needed to generate branch insns.  This is
   stored from the compare operation. */

rtx arm_compare_op0, arm_compare_op1;
int arm_compare_fp;

/* What type of cpu are we compiling for? */
enum processor_type arm_cpu;

/* What type of floating point are we compiling for? */
enum floating_point_type arm_fpu;

/* What program mode is the cpu running in? 26-bit mode or 32-bit mode */
enum prog_mode_type arm_prgmode;

char *target_cpu_name = ARM_CPU_NAME;
char *target_fpe_name = NULL;

/* Nonzero if this is an "M" variant of the processor.  */
int arm_fast_multiply = 0;

/* Nonzero if this chip support the ARM Architecture 4 extensions */
int arm_arch4 = 0;

/* In case of a PRE_INC, POST_INC, PRE_DEC, POST_DEC memory reference, we
   must report the mode of the memory reference from PRINT_OPERAND to
   PRINT_OPERAND_ADDRESS.  */
enum machine_mode output_memory_reference_mode;

/* Nonzero if the prologue must setup `fp'.  */
int current_function_anonymous_args;

/* Location counter of .text segment.  */
int arm_text_location = 0;

/* Set to one if we think that lr is only saved because of subroutine calls,
   but all of these can be `put after' return insns */
int lr_save_eliminated;

/* A hash table is used to store text segment labels and their associated
   offset from the start of the text segment.  */
struct label_offset
{
  char *name;
  int offset;
  struct label_offset *cdr;
};

#define LABEL_HASH_SIZE  257

static struct label_offset *offset_table[LABEL_HASH_SIZE];

/* Set to 1 when a return insn is output, this means that the epilogue
   is not needed. */

static int return_used_this_function;

static int arm_constant_limit = 3;

/* For an explanation of these variables, see final_prescan_insn below.  */
int arm_ccfsm_state;
enum arm_cond_code arm_current_cc;
rtx arm_target_insn;
int arm_target_label;

/* The condition codes of the ARM, and the inverse function.  */
char *arm_condition_codes[] =
{
  "eq", "ne", "cs", "cc", "mi", "pl", "vs", "vc",
  "hi", "ls", "ge", "lt", "gt", "le", "al", "nv"
};

static enum arm_cond_code get_arm_condition_code ();

\f
/* Initialization code */

struct arm_cpu_select arm_select[3] =
{
  /* switch     name,           tune    arch */
  { (char *)0,  "--with-cpu=",  1,      1 },
  { (char *)0,  "-mcpu=",       1,      1 },
  { (char *)0,  "-mtune=",      1,      0 },
};

#define FL_CO_PROC    0x01            /* Has external co-processor bus */
#define FL_FAST_MULT  0x02            /* Fast multiply */
#define FL_MODE26     0x04            /* 26-bit mode support */
#define FL_MODE32     0x08            /* 32-bit mode support */
#define FL_ARCH4      0x10            /* Architecture rel 4 */
#define FL_THUMB      0x20            /* Thumb aware */
struct processors
{
  char *name;
  enum processor_type type;
  unsigned int flags;
};

/* Not all of these give usefully different compilation alternatives,
   but there is no simple way of generalizing them.  */
static struct processors all_procs[] =
{
  {"arm2",      PROCESSOR_ARM2, FL_CO_PROC | FL_MODE26},
  {"arm250",    PROCESSOR_ARM2, FL_CO_PROC | FL_MODE26},
  {"arm3",      PROCESSOR_ARM2, FL_CO_PROC | FL_MODE26},
  {"arm6",      PROCESSOR_ARM6, FL_CO_PROC | FL_MODE32 | FL_MODE26},
  {"arm60",     PROCESSOR_ARM6, FL_CO_PROC | FL_MODE32 | FL_MODE26},
  {"arm600",    PROCESSOR_ARM6, FL_CO_PROC | FL_MODE32 | FL_MODE26},
  {"arm610",    PROCESSOR_ARM6, FL_MODE32 | FL_MODE26},
  {"arm620",    PROCESSOR_ARM6, FL_CO_PROC | FL_MODE32 | FL_MODE26},
  {"arm7",      PROCESSOR_ARM7, FL_CO_PROC | FL_MODE32 | FL_MODE26},
  {"arm70",     PROCESSOR_ARM7, FL_CO_PROC | FL_MODE32 | FL_MODE26},
  {"arm7d",     PROCESSOR_ARM7, FL_CO_PROC | FL_MODE32 | FL_MODE26},
  {"arm7di",    PROCESSOR_ARM7, FL_CO_PROC | FL_MODE32 | FL_MODE26},
  {"arm7dm",    PROCESSOR_ARM7, (FL_CO_PROC | FL_FAST_MULT | FL_MODE32
                                 | FL_MODE26)},
  {"arm7dmi",   PROCESSOR_ARM7, (FL_CO_PROC | FL_FAST_MULT | FL_MODE32
                                 | FL_MODE26)},
  {"arm700",    PROCESSOR_ARM7, FL_CO_PROC | FL_MODE32 | FL_MODE26},
  {"arm700i",   PROCESSOR_ARM7, FL_CO_PROC | FL_MODE32 | FL_MODE26},
  {"arm710",    PROCESSOR_ARM7, FL_MODE32 | FL_MODE26},
  {"arm710c",   PROCESSOR_ARM7, FL_MODE32 | FL_MODE26},
  {"arm7100",   PROCESSOR_ARM7, FL_MODE32 | FL_MODE26},
  {"arm7500",   PROCESSOR_ARM7, FL_MODE32 | FL_MODE26},
  {"arm7tdmi",  PROCESSOR_ARM7, (FL_CO_PROC | FL_FAST_MULT | FL_MODE32
                                 | FL_ARCH4 | FL_THUMB)},
  {NULL, 0, 0}
};

/* Fix up any incompatible options that the user has specified.
   This has now turned into a maze.  */
void
arm_override_options ()
{
  int arm_thumb_aware = 0;
  int flags = 0;
  int i;
  struct arm_cpu_select *ptr;

  arm_cpu = PROCESSOR_DEFAULT;
  arm_select[0].string = TARGET_CPU_DEFAULT;

  for (i = 0; i < sizeof (arm_select) / sizeof (arm_select[0]); i++)
    {
      ptr = &arm_select[i];
      if (ptr->string != (char *)0 && ptr->string[0] != '\0')
        {
          struct processors *sel;

          for (sel = all_procs; sel->name != NULL; sel++)
            if (! strcmp (ptr->string, sel->name))
              {
                if (ptr->set_tune_p)
                  arm_cpu = sel->type;

                if (ptr->set_arch_p)
                  flags = sel->flags;
                break;
              }

          if (sel->name == NULL)
            error ("bad value (%s) for %s switch", ptr->string, ptr->name);
        }
    }

  if (write_symbols != NO_DEBUG && flag_omit_frame_pointer)
    warning ("-g with -fomit-frame-pointer may not give sensible debugging");

  if (TARGET_POKE_FUNCTION_NAME)
    target_flags |= ARM_FLAG_APCS_FRAME;

  if (TARGET_6)
    {
      warning ("Option '-m6' deprecated.  Use: '-mapcs-32' or -mcpu=<proc>");
      target_flags |= ARM_FLAG_APCS_32;
      arm_cpu = PROCESSOR_ARM6;
    }

  if (TARGET_3)
    {
      warning ("Option '-m3' deprecated.  Use: '-mapcs-26' or -mcpu=<proc>");
      target_flags &= ~ARM_FLAG_APCS_32;
      arm_cpu = PROCESSOR_ARM2;
    }

  if (TARGET_APCS_REENT && flag_pic)
    fatal ("-fpic and -mapcs-reent are incompatible");

  if (TARGET_APCS_REENT)
    warning ("APCS reentrant code not supported.  Ignored");

  if (flag_pic)
    warning ("Position independent code not supported.  Ignored");

  if (TARGET_APCS_FLOAT)
    warning ("Passing floating point arguments in fp regs not yet supported");

  if (TARGET_APCS_STACK && ! TARGET_APCS)
    {
      warning ("-mapcs-stack-check incompatible with -mno-apcs-frame");
      target_flags |= ARM_FLAG_APCS_FRAME;
    }

  arm_fpu = FP_HARD;

  /* Default value for floating point code... if no co-processor
     bus, then schedule for emulated floating point.  Otherwise,
     assume the user has an FPA, unless overridden with -mfpe-...  */
  if (flags & FL_CO_PROC == 0)
    arm_fpu = FP_SOFT3;
  else
    arm_fpu = FP_HARD;
  arm_fast_multiply = (flags & FL_FAST_MULT) != 0;
  arm_arch4 = (flags & FL_ARCH4) != 0;
  arm_thumb_aware = (flags & FL_THUMB) != 0;

  if (target_fpe_name)
    {
      if (strcmp (target_fpe_name, "2") == 0)
        arm_fpu = FP_SOFT2;
      else if (strcmp (target_fpe_name, "3") == 0)
        arm_fpu = FP_SOFT3;
      else
        fatal ("Invalid floating point emulation option: -mfpe-%s",
               target_fpe_name);
    }

  if (TARGET_THUMB_INTERWORK && ! arm_thumb_aware)
    {
      warning ("This processor variant does not support Thumb interworking");
      target_flags &= ~ARM_FLAG_THUMB;
    }

  if (TARGET_FPE && arm_fpu != FP_HARD)
    arm_fpu = FP_SOFT2;

  /* For arm2/3 there is no need to do any scheduling if there is only
     a floating point emulator, or we are doing software floating-point.  */
  if ((TARGET_SOFT_FLOAT || arm_fpu != FP_HARD) && arm_cpu == PROCESSOR_ARM2)
    flag_schedule_insns = flag_schedule_insns_after_reload = 0;

  arm_prog_mode = TARGET_APCS_32 ? PROG_MODE_PROG32 : PROG_MODE_PROG26;
}
\f
/* Return 1 if it is possible to return using a single instruction */

int
use_return_insn ()
{
  int regno;

  if (!reload_completed ||current_function_pretend_args_size
      || current_function_anonymous_args
      || (get_frame_size () && !(TARGET_APCS || frame_pointer_needed)))
    return 0;

  /* Can't be done if any of the FPU regs are pushed, since this also
     requires an insn */
  for (regno = 20; regno < 24; regno++)
    if (regs_ever_live[regno])
      return 0;

  /* If a function is naked, don't use the "return" insn.  */
  if (arm_naked_function_p (current_function_decl))
    return 0;

  return 1;
}

/* Return TRUE if int I is a valid immediate ARM constant.  */

int
const_ok_for_arm (i)
     HOST_WIDE_INT i;
{
  unsigned HOST_WIDE_INT mask = ~0xFF;

  /* Fast return for 0 and powers of 2 */
  if ((i & (i - 1)) == 0)
    return TRUE;

  do
    {
      if ((i & mask & (unsigned HOST_WIDE_INT) 0xffffffff) == 0)
        return TRUE;
      mask =
          (mask << 2) | ((mask & (unsigned HOST_WIDE_INT) 0xffffffff)
                         >> (32 - 2)) | ~((unsigned HOST_WIDE_INT) 0xffffffff);
    } while (mask != ~0xFF);

  return FALSE;
}

/* Return true if I is a valid constant for the operation CODE. */
int
const_ok_for_op (i, code, mode)
     HOST_WIDE_INT i;
     enum rtx_code code;
     enum machine_mode mode;
{
  if (const_ok_for_arm (i))
    return 1;

  switch (code)
    {
    case PLUS:
      return const_ok_for_arm (ARM_SIGN_EXTEND (-i));

    case MINUS:         /* Should only occur with (MINUS I reg) => rsb */
    case XOR:
    case IOR:
      return 0;

    case AND:
      return const_ok_for_arm (ARM_SIGN_EXTEND (~i));

    default:
      abort ();
    }
}

/* Emit a sequence of insns to handle a large constant.
   CODE is the code of the operation required, it can be any of SET, PLUS,
   IOR, AND, XOR, MINUS;
   MODE is the mode in which the operation is being performed;
   VAL is the integer to operate on;
   SOURCE is the other operand (a register, or a null-pointer for SET);
   SUBTARGETS means it is safe to create scratch registers if that will
   either produce a simpler sequence, or we will want to cse the values.
   Return value is the number of insns emitted.  */

int
arm_split_constant (code, mode, val, target, source, subtargets)
     enum rtx_code code;
     enum machine_mode mode;
     HOST_WIDE_INT val;
     rtx target;
     rtx source;
     int subtargets;
{
  if (subtargets || code == SET
      || (GET_CODE (target) == REG && GET_CODE (source) == REG
          && REGNO (target) != REGNO (source)))
    {
      rtx temp;

      if (arm_gen_constant (code, mode, val, target, source, 1, 0)
          > arm_constant_limit + (code != SET))
        {
          if (code == SET)
            {
              /* Currently SET is the only monadic value for CODE, all
                 the rest are diadic.  */
              emit_insn (gen_rtx (SET, VOIDmode, target, GEN_INT (val)));
              return 1;
            }
          else
            {
              rtx temp = subtargets ? gen_reg_rtx (mode) : target;

              emit_insn (gen_rtx (SET, VOIDmode, temp, GEN_INT (val)));
              /* For MINUS, the value is subtracted from, since we never
                 have subtraction of a constant.  */
              if (code == MINUS)
                emit_insn (gen_rtx (SET, VOIDmode, target,
                                    gen_rtx (code, mode, temp, source)));
              else
                emit_insn (gen_rtx (SET, VOIDmode, target,
                                    gen_rtx (code, mode, source, temp)));
              return 2;
            }
        }
    }

  return arm_gen_constant (code, mode, val, target, source, subtargets, 1);
}

/* As above, but extra parameter GENERATE which, if clear, suppresses
   RTL generation.  */
int
arm_gen_constant (code, mode, val, target, source, subtargets, generate)
     enum rtx_code code;
     enum machine_mode mode;
     HOST_WIDE_INT val;
     rtx target;
     rtx source;
     int subtargets;
     int generate;
{
  int can_add = 0;
  int can_invert = 0;
  int can_negate = 0;
  int can_negate_initial = 0;
  int can_shift = 0;
  int i;
  int num_bits_set = 0;
  int set_sign_bit_copies = 0;
  int clear_sign_bit_copies = 0;
  int clear_zero_bit_copies = 0;
  int set_zero_bit_copies = 0;
  int insns = 0;
  rtx new_src;
  unsigned HOST_WIDE_INT temp1, temp2;
  unsigned HOST_WIDE_INT remainder = val & 0xffffffff;

  /* find out which operations are safe for a given CODE.  Also do a quick
     check for degenerate cases; these can occur when DImode operations
     are split.  */
  switch (code)
    {
    case SET:
      can_invert = 1;
      can_shift = 1;
      can_negate = 1;
      break;

    case PLUS:
      can_negate = 1;
      can_negate_initial = 1;
      break;

    case IOR:
      if (remainder == 0xffffffff)
        {
          if (generate)
            emit_insn (gen_rtx (SET, VOIDmode, target,
                                GEN_INT (ARM_SIGN_EXTEND (val))));
          return 1;
        }
      if (remainder == 0)
        {
          if (reload_completed && rtx_equal_p (target, source))
            return 0;
          if (generate)
            emit_insn (gen_rtx (SET, VOIDmode, target, source));
          return 1;
        }
      break;

    case AND:
      if (remainder == 0)
        {
          if (generate)
            emit_insn (gen_rtx (SET, VOIDmode, target, const0_rtx));
          return 1;
        }
      if (remainder == 0xffffffff)
        {
          if (reload_completed && rtx_equal_p (target, source))
            return 0;
          if (generate)
            emit_insn (gen_rtx (SET, VOIDmode, target, source));
          return 1;
        }
      can_invert = 1;
      break;

    case XOR:
      if (remainder == 0)
        {
          if (reload_completed && rtx_equal_p (target, source))
            return 0;
          if (generate)
            emit_insn (gen_rtx (SET, VOIDmode, target, source));
          return 1;
        }
      if (remainder == 0xffffffff)
        {
          if (generate)
            emit_insn (gen_rtx (SET, VOIDmode, target,
                                gen_rtx (NOT, mode, source)));
          return 1;
        }

      /* We don't know how to handle this yet below.  */
      abort ();

    case MINUS:
      /* We treat MINUS as (val - source), since (source - val) is always
         passed as (source + (-val)).  */
      if (remainder == 0)
        {
          if (generate)
            emit_insn (gen_rtx (SET, VOIDmode, target,
                                gen_rtx (NEG, mode, source)));
          return 1;
        }
      if (const_ok_for_arm (val))
        {
          if (generate)
            emit_insn (gen_rtx (SET, VOIDmode, target, 
                                gen_rtx (MINUS, mode, GEN_INT (val), source)));
          return 1;
        }
      can_negate = 1;

      break;

    default:
      abort ();
    }

  /* If we can do it in one insn get out quickly */
  if (const_ok_for_arm (val)
      || (can_negate_initial && const_ok_for_arm (-val))
      || (can_invert && const_ok_for_arm (~val)))
    {
      if (generate)
        emit_insn (gen_rtx (SET, VOIDmode, target,
                            (source ? gen_rtx (code, mode, source,
                                               GEN_INT (val))
                             : GEN_INT (val))));
      return 1;
    }


  /* Calculate a few attributes that may be useful for specific
     optimizations. */

  for (i = 31; i >= 0; i--)
    {
      if ((remainder & (1 << i)) == 0)
        clear_sign_bit_copies++;
      else
        break;
    }

  for (i = 31; i >= 0; i--)
    {
      if ((remainder & (1 << i)) != 0)
        set_sign_bit_copies++;
      else
        break;
    }

  for (i = 0; i <= 31; i++)
    {
      if ((remainder & (1 << i)) == 0)
        clear_zero_bit_copies++;
      else
        break;
    }

  for (i = 0; i <= 31; i++)
    {
      if ((remainder & (1 << i)) != 0)
        set_zero_bit_copies++;
      else
        break;
    }

  switch (code)
    {
    case SET:
      /* See if we can do this by sign_extending a constant that is known
         to be negative.  This is a good, way of doing it, since the shift
         may well merge into a subsequent insn.  */
      if (set_sign_bit_copies > 1)
        {
          if (const_ok_for_arm
              (temp1 = ARM_SIGN_EXTEND (remainder 
                                        << (set_sign_bit_copies - 1))))
            {
              if (generate)
                {
                  new_src = subtargets ? gen_reg_rtx (mode) : target;
                  emit_insn (gen_rtx (SET, VOIDmode, new_src, 
                                      GEN_INT (temp1)));
                  emit_insn (gen_ashrsi3 (target, new_src, 
                                          GEN_INT (set_sign_bit_copies - 1)));
                }
              return 2;
            }
          /* For an inverted constant, we will need to set the low bits,
             these will be shifted out of harm's way.  */
          temp1 |= (1 << (set_sign_bit_copies - 1)) - 1;
          if (const_ok_for_arm (~temp1))
            {
              if (generate)
                {
                  new_src = subtargets ? gen_reg_rtx (mode) : target;
                  emit_insn (gen_rtx (SET, VOIDmode, new_src,
                                      GEN_INT (temp1)));
                  emit_insn (gen_ashrsi3 (target, new_src, 
                                          GEN_INT (set_sign_bit_copies - 1)));
                }
              return 2;
            }
        }

      /* See if we can generate this by setting the bottom (or the top)
         16 bits, and then shifting these into the other half of the
         word.  We only look for the simplest cases, to do more would cost
         too much.  Be careful, however, not to generate this when the
         alternative would take fewer insns.  */
      if (val & 0xffff0000)
        {
          temp1 = remainder & 0xffff0000;
          temp2 = remainder & 0x0000ffff;

          /* Overlaps outside this range are best done using other methods. */
          for (i = 9; i < 24; i++)
            {
              if ((((temp2 | (temp2 << i)) & 0xffffffff) == remainder)
                  && ! const_ok_for_arm (temp2))
                {
                  insns = arm_gen_constant (code, mode, temp2,
                                            new_src = (subtargets
                                                       ? gen_reg_rtx (mode)
                                                       : target),
                                            source, subtargets, generate);
                  source = new_src;
                  if (generate)
                    emit_insn (gen_rtx (SET, VOIDmode, target,
                                        gen_rtx (IOR, mode,
                                                 gen_rtx (ASHIFT, mode, source,
                                                          GEN_INT (i)),
                                                 source)));
                  return insns + 1;
                }
            }

          /* Don't duplicate cases already considered. */
          for (i = 17; i < 24; i++)
            {
              if (((temp1 | (temp1 >> i)) == remainder)
                  && ! const_ok_for_arm (temp1))
                {
                  insns = arm_gen_constant (code, mode, temp1,
                                            new_src = (subtargets
                                                       ? gen_reg_rtx (mode)
                                                       : target),
                                            source, subtargets, generate);
                  source = new_src;
                  if (generate)
                    emit_insn (gen_rtx (SET, VOIDmode, target,
                                        gen_rtx (IOR, mode,
                                                 gen_rtx (LSHIFTRT, mode,
                                                          source, GEN_INT (i)),
                                                 source)));
                  return insns + 1;
                }
            }
        }
      break;

    case IOR:
    case XOR:
      /* If we have IOR or XOR, and the constant can be loaded in a
         single instruction, and we can find a temporary to put it in,
         then this can be done in two instructions instead of 3-4.  */
      if (subtargets
          || (reload_completed && ! reg_mentioned_p (target, source)))
        {
          if (const_ok_for_arm (ARM_SIGN_EXTEND (~ val)))
            {
              if (generate)
                {
                  rtx sub = subtargets ? gen_reg_rtx (mode) : target;

                  emit_insn (gen_rtx (SET, VOIDmode, sub, GEN_INT (val)));
                  emit_insn (gen_rtx (SET, VOIDmode, target, 
                                      gen_rtx (code, mode, source, sub)));
                }
              return 2;
            }
        }

      if (code == XOR)
        break;

      if (set_sign_bit_copies > 8
          && (val & (-1 << (32 - set_sign_bit_copies))) == val)
        {
          if (generate)
            {
              rtx sub = subtargets ? gen_reg_rtx (mode) : target;
              rtx shift = GEN_INT (set_sign_bit_copies);

              emit_insn (gen_rtx (SET, VOIDmode, sub,
                                  gen_rtx (NOT, mode, 
                                           gen_rtx (ASHIFT, mode, source, 
                                                    shift))));
              emit_insn (gen_rtx (SET, VOIDmode, target,
                                  gen_rtx (NOT, mode,
                                           gen_rtx (LSHIFTRT, mode, sub,
                                                    shift))));
            }
          return 2;
        }

      if (set_zero_bit_copies > 8
          && (remainder & ((1 << set_zero_bit_copies) - 1)) == remainder)
        {
          if (generate)
            {
              rtx sub = subtargets ? gen_reg_rtx (mode) : target;
              rtx shift = GEN_INT (set_zero_bit_copies);

              emit_insn (gen_rtx (SET, VOIDmode, sub,
                                  gen_rtx (NOT, mode,
                                           gen_rtx (LSHIFTRT, mode, source,
                                                    shift))));
              emit_insn (gen_rtx (SET, VOIDmode, target,
                                  gen_rtx (NOT, mode,
                                           gen_rtx (ASHIFT, mode, sub,
                                                    shift))));
            }
          return 2;
        }

      if (const_ok_for_arm (temp1 = ARM_SIGN_EXTEND (~ val)))
        {
          if (generate)
            {
              rtx sub = subtargets ? gen_reg_rtx (mode) : target;
              emit_insn (gen_rtx (SET, VOIDmode, sub,
                                  gen_rtx (NOT, mode, source)));
              source = sub;
              if (subtargets)
                sub = gen_reg_rtx (mode);
              emit_insn (gen_rtx (SET, VOIDmode, sub,
                                  gen_rtx (AND, mode, source, 
                                           GEN_INT (temp1))));
              emit_insn (gen_rtx (SET, VOIDmode, target,
                                  gen_rtx (NOT, mode, sub)));
            }
          return 3;
        }
      break;

    case AND:
      /* See if two shifts will do 2 or more insn's worth of work.  */
      if (clear_sign_bit_copies >= 16 && clear_sign_bit_copies < 24)
        {
          HOST_WIDE_INT shift_mask = ((0xffffffff 
                                       << (32 - clear_sign_bit_copies))
                                      & 0xffffffff);
          rtx new_source;
          rtx shift;

          if ((remainder | shift_mask) != 0xffffffff)
            {
              if (generate)
                {
                  new_source = subtargets ? gen_reg_rtx (mode) : target;
                  insns = arm_gen_constant (AND, mode, remainder | shift_mask,
                                            new_source, source, subtargets, 1);
                  source = new_source;
                }
              else
                insns = arm_gen_constant (AND, mode, remainder | shift_mask,
                                          new_source, source, subtargets, 0);
            }

          if (generate)
            {
              shift = GEN_INT (clear_sign_bit_copies);
              new_source = subtargets ? gen_reg_rtx (mode) : target;
              emit_insn (gen_ashlsi3 (new_source, source, shift));
              emit_insn (gen_lshrsi3 (target, new_source, shift));
            }

          return insns + 2;
        }

      if (clear_zero_bit_copies >= 16 && clear_zero_bit_copies < 24)
        {
          HOST_WIDE_INT shift_mask = (1 << clear_zero_bit_copies) - 1;
          rtx new_source;
          rtx shift;
          
          if ((remainder | shift_mask) != 0xffffffff)
            {
              if (generate)
                {
                  new_source = subtargets ? gen_reg_rtx (mode) : target;
                  insns = arm_gen_constant (AND, mode, remainder | shift_mask,
                                            new_source, source, subtargets, 1);
                  source = new_source;
                }
              else
                insns = arm_gen_constant (AND, mode, remainder | shift_mask,
                                          new_source, source, subtargets, 0);
            }

          if (generate)
            {
              shift = GEN_INT (clear_zero_bit_copies);
              new_source = subtargets ? gen_reg_rtx (mode) : target;
              emit_insn (gen_lshrsi3 (new_source, source, shift));
              emit_insn (gen_ashlsi3 (target, new_source, shift));
            }

          return insns + 2;
        }

      break;

    default:
      break;
    }

  for (i = 0; i < 32; i++)
    if (remainder & (1 << i))
      num_bits_set++;

  if (code == AND || (can_invert && num_bits_set > 16))
    remainder = (~remainder) & 0xffffffff;
  else if (code == PLUS && num_bits_set > 16)
    remainder = (-remainder) & 0xffffffff;
  else
    {
      can_invert = 0;
      can_negate = 0;
    }

  /* Now try and find a way of doing the job in either two or three
     instructions.
     We start by looking for the largest block of zeros that are aligned on
     a 2-bit boundary, we then fill up the temps, wrapping around to the
     top of the word when we drop off the bottom.
     In the worst case this code should produce no more than four insns. */
  {
    int best_start = 0;
    int best_consecutive_zeros = 0;

    for (i = 0; i < 32; i += 2)
      {
        int consecutive_zeros = 0;

        if (! (remainder & (3 << i)))
          {
            while ((i < 32) && ! (remainder & (3 << i)))
              {
                consecutive_zeros += 2;
                i += 2;
              }
            if (consecutive_zeros > best_consecutive_zeros)
              {
                best_consecutive_zeros = consecutive_zeros;
                best_start = i - consecutive_zeros;
              }
            i -= 2;
          }
      }

    /* Now start emitting the insns, starting with the one with the highest
       bit set: we do this so that the smallest number will be emitted last;
       this is more likely to be combinable with addressing insns. */
    i = best_start;
    do
      {
        int end;

        if (i <= 0)
          i += 32;
        if (remainder & (3 << (i - 2)))
          {
            end = i - 8;
            if (end < 0)
              end += 32;
            temp1 = remainder & ((0x0ff << end)
                                 | ((i < end) ? (0xff >> (32 - end)) : 0));
            remainder &= ~temp1;

            if (code == SET)
              {
                if (generate)
                  emit_insn (gen_rtx (SET, VOIDmode,
                                      new_src = (subtargets
                                                 ? gen_reg_rtx (mode)
                                                 : target),
                                      GEN_INT (can_invert ? ~temp1 : temp1)));
                can_invert = 0;
                code = PLUS;
              }
            else if (code == MINUS)
              {
                if (generate)
                  emit_insn (gen_rtx (SET, VOIDmode,
                                      new_src = (subtargets
                                                 ? gen_reg_rtx (mode)
                                                 : target),
                                      gen_rtx (code, mode, GEN_INT (temp1),
                                               source)));
                code = PLUS;
              }
            else
              {
                if (generate)
                  emit_insn (gen_rtx (SET, VOIDmode,
                                      new_src = (remainder
                                                 ? (subtargets
                                                    ? gen_reg_rtx (mode)
                                                    : target)
                                                 : target),
                                      gen_rtx (code, mode, source,
                                               GEN_INT (can_invert ? ~temp1
                                                        : (can_negate
                                                           ? -temp1
                                                           : temp1)))));
              }

            insns++;
            source = new_src;
            i -= 6;
          }
        i -= 2;
      } while (remainder);
  }
  return insns;
}

/* Canonicalize a comparison so that we are more likely to recognize it.
   This can be done for a few constant compares, where we can make the
   immediate value easier to load.  */
enum rtx_code
arm_canonicalize_comparison (code, op1)
     enum rtx_code code;
     rtx *op1;
{
  HOST_WIDE_INT i = INTVAL (*op1);

  switch (code)
    {
    case EQ:
    case NE:
      return code;

    case GT:
    case LE:
      if (i != (1 << (HOST_BITS_PER_WIDE_INT - 1) - 1)
          && (const_ok_for_arm (i+1) || const_ok_for_arm (- (i+1))))
        {
          *op1 = GEN_INT (i+1);
          return code == GT ? GE : LT;
        }
      break;

    case GE:
    case LT:
      if (i != (1 << (HOST_BITS_PER_WIDE_INT - 1))
          && (const_ok_for_arm (i-1) || const_ok_for_arm (- (i-1))))
        {
          *op1 = GEN_INT (i-1);
          return code == GE ? GT : LE;
        }
      break;

    case GTU:
    case LEU:
      if (i != ~0
          && (const_ok_for_arm (i+1) || const_ok_for_arm (- (i+1))))
        {
          *op1 = GEN_INT (i + 1);
          return code == GTU ? GEU : LTU;
        }
      break;

    case GEU:
    case LTU:
      if (i != 0
          && (const_ok_for_arm (i - 1) || const_ok_for_arm (- (i - 1))))
        {
          *op1 = GEN_INT (i - 1);
          return code == GEU ? GTU : LEU;
        }
      break;

    default:
      abort ();
    }

  return code;
}
        

/* Handle aggregates that are not laid out in a BLKmode element.
   This is a sub-element of RETURN_IN_MEMORY.  */
int
arm_return_in_memory (type)
     tree type;
{
  if (TREE_CODE (type) == RECORD_TYPE)
    {
      tree field;

      /* For a struct, we can return in a register if every element was a
         bit-field.  */
      for (field = TYPE_FIELDS (type); field;  field = TREE_CHAIN (field))
        if (TREE_CODE (field) != FIELD_DECL
            || ! DECL_BIT_FIELD_TYPE (field))
          return 1;

      return 0;
    }
  else if (TREE_CODE (type) == UNION_TYPE)
    {
      tree field;

      /* Unions can be returned in registers if every element is
         integral, or can be returned in an integer register.  */
      for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
        {
          if (TREE_CODE (field) != FIELD_DECL
              || (AGGREGATE_TYPE_P (TREE_TYPE (field))
                  && RETURN_IN_MEMORY (TREE_TYPE (field)))
              || FLOAT_TYPE_P (TREE_TYPE (field)))
            return 1;
        }
      return 0;
    }
  /* XXX Not sure what should be done for other aggregates, so put them in
     memory. */
  return 1;
}

#define REG_OR_SUBREG_REG(X)                                            \
  (GET_CODE (X) == REG                                                  \
   || (GET_CODE (X) == SUBREG && GET_CODE (SUBREG_REG (X)) == REG))

#define REG_OR_SUBREG_RTX(X)                    \
   (GET_CODE (X) == REG ? (X) : SUBREG_REG (X))

#define ARM_FRAME_RTX(X)                                \
  ((X) == frame_pointer_rtx || (X) == stack_pointer_rtx \
   || (X) == arg_pointer_rtx)

int
arm_rtx_costs (x, code, outer_code)
     rtx x;
     enum rtx_code code, outer_code;
{
  enum machine_mode mode = GET_MODE (x);
  enum rtx_code subcode;
  int extra_cost;

  switch (code)
    {
    case MEM:
      /* Memory costs quite a lot for the first word, but subsequent words
         load at the equivalent of a single insn each.  */
      return (10 + 4 * ((GET_MODE_SIZE (mode) - 1) / UNITS_PER_WORD)
              + (CONSTANT_POOL_ADDRESS_P (x) ? 4 : 0));

    case DIV:
    case MOD:
      return 100;

    case ROTATE:
      if (mode == SImode && GET_CODE (XEXP (x, 1)) == REG)
        return 4;
      /* Fall through */
    case ROTATERT:
      if (mode != SImode)
        return 8;
      /* Fall through */
    case ASHIFT: case LSHIFTRT: case ASHIFTRT:
      if (mode == DImode)
        return (8 + (GET_CODE (XEXP (x, 1)) == CONST_INT ? 0 : 8)
                + ((GET_CODE (XEXP (x, 0)) == REG 
                    || (GET_CODE (XEXP (x, 0)) == SUBREG
                        && GET_CODE (SUBREG_REG (XEXP (x, 0))) == REG))
                   ? 0 : 8));
      return (1 + ((GET_CODE (XEXP (x, 0)) == REG
                    || (GET_CODE (XEXP (x, 0)) == SUBREG
                        && GET_CODE (SUBREG_REG (XEXP (x, 0))) == REG))
                   ? 0 : 4)
              + ((GET_CODE (XEXP (x, 1)) == REG
                  || (GET_CODE (XEXP (x, 1)) == SUBREG
                      && GET_CODE (SUBREG_REG (XEXP (x, 1))) == REG)
                  || (GET_CODE (XEXP (x, 1)) == CONST_INT))
                 ? 0 : 4));

    case MINUS:
      if (mode == DImode)
        return (4 + (REG_OR_SUBREG_REG (XEXP (x, 1)) ? 0 : 8)
                + ((REG_OR_SUBREG_REG (XEXP (x, 0))
                    || (GET_CODE (XEXP (x, 0)) == CONST_INT
                       && const_ok_for_arm (INTVAL (XEXP (x, 0)))))
                   ? 0 : 8));

      if (GET_MODE_CLASS (mode) == MODE_FLOAT)
        return (2 + ((REG_OR_SUBREG_REG (XEXP (x, 1))
                      || (GET_CODE (XEXP (x, 1)) == CONST_DOUBLE
                          && const_double_rtx_ok_for_fpu (XEXP (x, 1))))
                     ? 0 : 8)
                + ((REG_OR_SUBREG_REG (XEXP (x, 0))
                    || (GET_CODE (XEXP (x, 0)) == CONST_DOUBLE
                        && const_double_rtx_ok_for_fpu (XEXP (x, 0))))
                   ? 0 : 8));

      if (((GET_CODE (XEXP (x, 0)) == CONST_INT
            && const_ok_for_arm (INTVAL (XEXP (x, 0)))
            && REG_OR_SUBREG_REG (XEXP (x, 1))))
          || (((subcode = GET_CODE (XEXP (x, 1))) == ASHIFT
               || subcode == ASHIFTRT || subcode == LSHIFTRT
               || subcode == ROTATE || subcode == ROTATERT
               || (subcode == MULT
                   && GET_CODE (XEXP (XEXP (x, 1), 1)) == CONST_INT
                   && ((INTVAL (XEXP (XEXP (x, 1), 1)) &
                        (INTVAL (XEXP (XEXP (x, 1), 1)) - 1)) == 0)))
              && REG_OR_SUBREG_REG (XEXP (XEXP (x, 1), 0))
              && (REG_OR_SUBREG_REG (XEXP (XEXP (x, 1), 1))
                  || GET_CODE (XEXP (XEXP (x, 1), 1)) == CONST_INT)
              && REG_OR_SUBREG_REG (XEXP (x, 0))))
        return 1;
      /* Fall through */

    case PLUS: 
      if (GET_MODE_CLASS (mode) == MODE_FLOAT)
        return (2 + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 8)
                + ((REG_OR_SUBREG_REG (XEXP (x, 1))
                    || (GET_CODE (XEXP (x, 1)) == CONST_DOUBLE
                        && const_double_rtx_ok_for_fpu (XEXP (x, 1))))
                   ? 0 : 8));

      /* Fall through */
    case AND: case XOR: case IOR: 
      extra_cost = 0;

      /* Normally the frame registers will be spilt into reg+const during
         reload, so it is a bad idea to combine them with other instructions,
         since then they might not be moved outside of loops.  As a compromise
         we allow integration with ops that have a constant as their second
         operand.  */
      if ((REG_OR_SUBREG_REG (XEXP (x, 0))
           && ARM_FRAME_RTX (REG_OR_SUBREG_RTX (XEXP (x, 0)))
           && GET_CODE (XEXP (x, 1)) != CONST_INT)
          || (REG_OR_SUBREG_REG (XEXP (x, 0))
              && ARM_FRAME_RTX (REG_OR_SUBREG_RTX (XEXP (x, 0)))))
        extra_cost = 4;

      if (mode == DImode)
        return (4 + extra_cost + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 8)
                + ((REG_OR_SUBREG_REG (XEXP (x, 1))
                    || (GET_CODE (XEXP (x, 1)) == CONST_INT
                        && const_ok_for_op (INTVAL (XEXP (x, 1)), code, mode)))
                   ? 0 : 8));

      if (REG_OR_SUBREG_REG (XEXP (x, 0)))
        return (1 + (GET_CODE (XEXP (x, 1)) == CONST_INT ? 0 : extra_cost)
                + ((REG_OR_SUBREG_REG (XEXP (x, 1))
                    || (GET_CODE (XEXP (x, 1)) == CONST_INT
                        && const_ok_for_op (INTVAL (XEXP (x, 1)), code, mode)))
                   ? 0 : 4));

      else if (REG_OR_SUBREG_REG (XEXP (x, 1)))
        return (1 + extra_cost
                + ((((subcode = GET_CODE (XEXP (x, 0))) == ASHIFT
                     || subcode == LSHIFTRT || subcode == ASHIFTRT
                     || subcode == ROTATE || subcode == ROTATERT
                     || (subcode == MULT
                         && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT
                         && ((INTVAL (XEXP (XEXP (x, 0), 1)) &
                              (INTVAL (XEXP (XEXP (x, 0), 1)) - 1)) == 0))
                    && (REG_OR_SUBREG_REG (XEXP (XEXP (x, 0), 0)))
                    && ((REG_OR_SUBREG_REG (XEXP (XEXP (x, 0), 1)))
                        || GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)))
                   ? 0 : 4));

      return 8;

    case MULT:
      if (arm_fast_multiply && mode == DImode
          && (GET_CODE (XEXP (x, 0)) == GET_CODE (XEXP (x, 1)))
          && (GET_CODE (XEXP (x, 0)) == ZERO_EXTEND
              || GET_CODE (XEXP (x, 0)) == SIGN_EXTEND))
        return 8;

      if (GET_MODE_CLASS (mode) == MODE_FLOAT
          || mode == DImode)
        return 30;

      if (GET_CODE (XEXP (x, 1)) == CONST_INT)
        {
          unsigned HOST_WIDE_INT i = (INTVAL (XEXP (x, 1))
                                      & (unsigned HOST_WIDE_INT) 0xffffffff);
          int add_cost = const_ok_for_arm (i) ? 4 : 8;
          int j;
          int booth_unit_size = (arm_fast_multiply ? 8 : 2);

          for (j = 0; i && j < 32; j += booth_unit_size)
            {
              i >>= booth_unit_size;
              add_cost += 2;
            }

          return add_cost;
        }

      return ((arm_fast_multiply ? 8 : 30)
              + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 4)
              + (REG_OR_SUBREG_REG (XEXP (x, 1)) ? 0 : 4));

    case NEG:
      if (GET_MODE_CLASS (mode) == MODE_FLOAT)
        return 4 + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 6);
      /* Fall through */
    case NOT:
      if (mode == DImode)
        return 4 + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 4);

      return 1 + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 4);

    case IF_THEN_ELSE:
      if (GET_CODE (XEXP (x, 1)) == PC || GET_CODE (XEXP (x, 2)) == PC)
        return 14;
      return 2;

    case COMPARE:
      return 1;

    case ABS:
      return 4 + (mode == DImode ? 4 : 0);

    case SIGN_EXTEND:
      if (GET_MODE (XEXP (x, 0)) == QImode)
        return (4 + (mode == DImode ? 4 : 0)
                + (GET_CODE (XEXP (x, 0)) == MEM ? 10 : 0));
      /* Fall through */
    case ZERO_EXTEND:
      switch (GET_MODE (XEXP (x, 0)))
        {
        case QImode:
          return (1 + (mode == DImode ? 4 : 0)
                  + (GET_CODE (XEXP (x, 0)) == MEM ? 10 : 0));

        case HImode:
          return (4 + (mode == DImode ? 4 : 0)
                  + (GET_CODE (XEXP (x, 0)) == MEM ? 10 : 0));

        case SImode:
          return (1 + (GET_CODE (XEXP (x, 0)) == MEM ? 10 : 0));
        }
      abort ();

    default:
      return 99;
    }
}
     
/* This code has been fixed for cross compilation. */

static int fpa_consts_inited = 0;

char *strings_fpa[8] = {
  "0",   "1",   "2",   "3",
  "4",   "5",   "0.5", "10"
};

static REAL_VALUE_TYPE values_fpa[8];

static void
init_fpa_table ()
{
  int i;
  REAL_VALUE_TYPE r;

  for (i = 0; i < 8; i++)
    {
      r = REAL_VALUE_ATOF (strings_fpa[i], DFmode);
      values_fpa[i] = r;
    }

  fpa_consts_inited = 1;
}

/* Return TRUE if rtx X is a valid immediate FPU constant. */

int
const_double_rtx_ok_for_fpu (x)
     rtx x;
{
  REAL_VALUE_TYPE r;
  int i;
  
  if (!fpa_consts_inited)
    init_fpa_table ();
  
  REAL_VALUE_FROM_CONST_DOUBLE (r, x);
  if (REAL_VALUE_MINUS_ZERO (r))
    return 0;

  for (i = 0; i < 8; i++)
    if (REAL_VALUES_EQUAL (r, values_fpa[i]))
      return 1;

  return 0;
}

/* Return TRUE if rtx X is a valid immediate FPU constant. */

int
neg_const_double_rtx_ok_for_fpu (x)
     rtx x;
{
  REAL_VALUE_TYPE r;
  int i;
  
  if (!fpa_consts_inited)
    init_fpa_table ();
  
  REAL_VALUE_FROM_CONST_DOUBLE (r, x);
  r = REAL_VALUE_NEGATE (r);
  if (REAL_VALUE_MINUS_ZERO (r))
    return 0;

  for (i = 0; i < 8; i++)
    if (REAL_VALUES_EQUAL (r, values_fpa[i]))
      return 1;

  return 0;
}
\f
/* Predicates for `match_operand' and `match_operator'.  */

/* s_register_operand is the same as register_operand, but it doesn't accept
   (SUBREG (MEM)...).

   This function exists because at the time it was put in it led to better
   code.  SUBREG(MEM) always needs a reload in the places where
   s_register_operand is used, and this seemed to lead to excessive
   reloading.  */

int
s_register_operand (op, mode)
     register rtx op;
     enum machine_mode mode;
{
  if (GET_MODE (op) != mode && mode != VOIDmode)
    return 0;

  if (GET_CODE (op) == SUBREG)
    op = SUBREG_REG (op);

  /* We don't consider registers whose class is NO_REGS
     to be a register operand.  */
  return (GET_CODE (op) == REG
          && (REGNO (op) >= FIRST_PSEUDO_REGISTER
              || REGNO_REG_CLASS (REGNO (op)) != NO_REGS));
}

/* Only accept reg, subreg(reg), const_int.  */

int
reg_or_int_operand (op, mode)
     register rtx op;
     enum machine_mode mode;
{
  if (GET_CODE (op) == CONST_INT)
    return 1;

  if (GET_MODE (op) != mode && mode != VOIDmode)
    return 0;

  if (GET_CODE (op) == SUBREG)
    op = SUBREG_REG (op);

  /* We don't consider registers whose class is NO_REGS
     to be a register operand.  */
  return (GET_CODE (op) == REG
          && (REGNO (op) >= FIRST_PSEUDO_REGISTER
              || REGNO_REG_CLASS (REGNO (op)) != NO_REGS));
}

/* Return 1 if OP is an item in memory, given that we are in reload.  */

int
reload_memory_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  int regno = true_regnum (op);

  return (! CONSTANT_P (op)
          && (regno == -1
              || (GET_CODE (op) == REG
                  && REGNO (op) >= FIRST_PSEUDO_REGISTER)));
}

/* Return TRUE for valid operands for the rhs of an ARM instruction.  */

int
arm_rhs_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (s_register_operand (op, mode)
          || (GET_CODE (op) == CONST_INT && const_ok_for_arm (INTVAL (op))));
}

/* Return TRUE for valid operands for the rhs of an ARM instruction, or a load.
 */

int
arm_rhsm_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (s_register_operand (op, mode)
          || (GET_CODE (op) == CONST_INT && const_ok_for_arm (INTVAL (op)))
          || memory_operand (op, mode));
}

/* Return TRUE for valid operands for the rhs of an ARM instruction, or if a
   constant that is valid when negated.  */

int
arm_add_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (s_register_operand (op, mode)
          || (GET_CODE (op) == CONST_INT
              && (const_ok_for_arm (INTVAL (op))
                  || const_ok_for_arm (-INTVAL (op)))));
}

int
arm_not_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (s_register_operand (op, mode)
          || (GET_CODE (op) == CONST_INT
              && (const_ok_for_arm (INTVAL (op))
                  || const_ok_for_arm (~INTVAL (op)))));
}

/* Return TRUE if the operand is a memory reference which contains an
   offsettable address.  */
int
offsettable_memory_operand (op, mode)
     register rtx op;
     enum machine_mode mode;
{
  if (mode == VOIDmode)
    mode = GET_MODE (op);

  return (mode == GET_MODE (op)
          && GET_CODE (op) == MEM
          && offsettable_address_p (reload_completed | reload_in_progress,
                                    mode, XEXP (op, 0)));
}

/* Return TRUE if the operand is a memory reference which is, or can be
   made word aligned by adjusting the offset.  */
int
alignable_memory_operand (op, mode)
     register rtx op;
     enum machine_mode mode;
{
  rtx reg;

  if (mode == VOIDmode)
    mode = GET_MODE (op);

  if (mode != GET_MODE (op) || GET_CODE (op) != MEM)
    return 0;

  op = XEXP (op, 0);

  return ((GET_CODE (reg = op) == REG
           || (GET_CODE (op) == SUBREG
               && GET_CODE (reg = SUBREG_REG (op)) == REG)
           || (GET_CODE (op) == PLUS
               && GET_CODE (XEXP (op, 1)) == CONST_INT
               && (GET_CODE (reg = XEXP (op, 0)) == REG
                   || (GET_CODE (XEXP (op, 0)) == SUBREG
                       && GET_CODE (reg = SUBREG_REG (XEXP (op, 0))) == REG))))
          && REGNO_POINTER_ALIGN (REGNO (reg)) >= 4);
}

/* Return TRUE for valid operands for the rhs of an FPU instruction.  */

int
fpu_rhs_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (s_register_operand (op, mode))
    return TRUE;
  else if (GET_CODE (op) == CONST_DOUBLE)
    return (const_double_rtx_ok_for_fpu (op));

  return FALSE;
}

int
fpu_add_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (s_register_operand (op, mode))
    return TRUE;
  else if (GET_CODE (op) == CONST_DOUBLE)
    return (const_double_rtx_ok_for_fpu (op) 
            || neg_const_double_rtx_ok_for_fpu (op));

  return FALSE;
}

/* Return nonzero if OP is a constant power of two.  */

int
power_of_two_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (GET_CODE (op) == CONST_INT)
    {
      HOST_WIDE_INT value = INTVAL(op);
      return value != 0  &&  (value & (value - 1)) == 0;
    }
  return FALSE;
}

/* Return TRUE for a valid operand of a DImode operation.
   Either: REG, CONST_DOUBLE or MEM(DImode_address).
   Note that this disallows MEM(REG+REG), but allows
   MEM(PRE/POST_INC/DEC(REG)).  */

int
di_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (s_register_operand (op, mode))
    return TRUE;

  switch (GET_CODE (op))
    {
    case CONST_DOUBLE:
    case CONST_INT:
      return TRUE;

    case MEM:
      return memory_address_p (DImode, XEXP (op, 0));

    default:
      return FALSE;
    }
}

/* Return TRUE for a valid operand of a DFmode operation when -msoft-float.
   Either: REG, CONST_DOUBLE or MEM(DImode_address).
   Note that this disallows MEM(REG+REG), but allows
   MEM(PRE/POST_INC/DEC(REG)).  */

int
soft_df_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (s_register_operand (op, mode))
    return TRUE;

  switch (GET_CODE (op))
    {
    case CONST_DOUBLE:
      return TRUE;

    case MEM:
      return memory_address_p (DFmode, XEXP (op, 0));

    default:
      return FALSE;
    }
}

/* Return TRUE for valid index operands. */

int
index_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (s_register_operand(op, mode)
          || (immediate_operand (op, mode)
              && INTVAL (op) < 4096 && INTVAL (op) > -4096));
}

/* Return TRUE for valid shifts by a constant. This also accepts any
   power of two on the (somewhat overly relaxed) assumption that the
   shift operator in this case was a mult. */

int
const_shift_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (power_of_two_operand (op, mode)
          || (immediate_operand (op, mode)
              && (INTVAL (op) < 32 && INTVAL (op) > 0)));
}

/* Return TRUE for arithmetic operators which can be combined with a multiply
   (shift).  */

int
shiftable_operator (x, mode)
     rtx x;
     enum machine_mode mode;
{
  if (GET_MODE (x) != mode)
    return FALSE;
  else
    {
      enum rtx_code code = GET_CODE (x);

      return (code == PLUS || code == MINUS
              || code == IOR || code == XOR || code == AND);
    }
}

/* Return TRUE for shift operators. */

int
shift_operator (x, mode)
     rtx x;
     enum machine_mode mode;
{
  if (GET_MODE (x) != mode)
    return FALSE;
  else
    {
      enum rtx_code code = GET_CODE (x);

      if (code == MULT)
        return power_of_two_operand (XEXP (x, 1));

      return (code == ASHIFT || code == ASHIFTRT || code == LSHIFTRT
              || code == ROTATERT);
    }
}

int equality_operator (x, mode)
     rtx x;
     enum machine_mode mode;
{
  return GET_CODE (x) == EQ || GET_CODE (x) == NE;
}

/* Return TRUE for SMIN SMAX UMIN UMAX operators. */

int
minmax_operator (x, mode)
     rtx x;
     enum machine_mode mode;
{
  enum rtx_code code = GET_CODE (x);

  if (GET_MODE (x) != mode)
    return FALSE;

  return code == SMIN || code == SMAX || code == UMIN || code == UMAX;
}

/* return TRUE if x is EQ or NE */

/* Return TRUE if this is the condition code register, if we aren't given
   a mode, accept any class CCmode register */

int
cc_register (x, mode)
     rtx x;
     enum machine_mode mode;
{
  if (mode == VOIDmode)
    {
      mode = GET_MODE (x);
      if (GET_MODE_CLASS (mode) != MODE_CC)
        return FALSE;
    }

  if (mode == GET_MODE (x) && GET_CODE (x) == REG && REGNO (x) == 24)
    return TRUE;

  return FALSE;
}

/* Return TRUE if this is the condition code register, if we aren't given
   a mode, accept any class CCmode register which indicates a dominance
   expression.  */

int
dominant_cc_register (x, mode)
     rtx x;
     enum machine_mode mode;
{
  if (mode == VOIDmode)
    {
      mode = GET_MODE (x);
      if (GET_MODE_CLASS (mode) != MODE_CC)
        return FALSE;
    }

  if (mode != CC_DNEmode && mode != CC_DEQmode
      && mode != CC_DLEmode && mode != CC_DLTmode
      && mode != CC_DGEmode && mode != CC_DGTmode
      && mode != CC_DLEUmode && mode != CC_DLTUmode
      && mode != CC_DGEUmode && mode != CC_DGTUmode)
    return FALSE;

  if (mode == GET_MODE (x) && GET_CODE (x) == REG && REGNO (x) == 24)
    return TRUE;

  return FALSE;
}

/* Return TRUE if X references a SYMBOL_REF.  */
int
symbol_mentioned_p (x)
     rtx x;
{
  register char *fmt;
  register int i;

  if (GET_CODE (x) == SYMBOL_REF)
    return 1;

  fmt = GET_RTX_FORMAT (GET_CODE (x));
  for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
    {
      if (fmt[i] == 'E')
        {
          register int j;

          for (j = XVECLEN (x, i) - 1; j >= 0; j--)
            if (symbol_mentioned_p (XVECEXP (x, i, j)))
              return 1;
        }
      else if (fmt[i] == 'e' && symbol_mentioned_p (XEXP (x, i)))
        return 1;
    }

  return 0;
}

/* Return TRUE if X references a LABEL_REF.  */
int
label_mentioned_p (x)
     rtx x;
{
  register char *fmt;
  register int i;

  if (GET_CODE (x) == LABEL_REF)
    return 1;

  fmt = GET_RTX_FORMAT (GET_CODE (x));
  for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
    {
      if (fmt[i] == 'E')
        {
          register int j;

          for (j = XVECLEN (x, i) - 1; j >= 0; j--)
            if (label_mentioned_p (XVECEXP (x, i, j)))
              return 1;
        }
      else if (fmt[i] == 'e' && label_mentioned_p (XEXP (x, i)))
        return 1;
    }

  return 0;
}

enum rtx_code
minmax_code (x)
     rtx x;
{
  enum rtx_code code = GET_CODE (x);

  if (code == SMAX)
    return GE;
  else if (code == SMIN)
    return LE;
  else if (code == UMIN)
    return LEU;
  else if (code == UMAX)
    return GEU;

  abort ();
}

/* Return 1 if memory locations are adjacent */

int
adjacent_mem_locations (a, b)
     rtx a, b;
{
  int val0 = 0, val1 = 0;
  int reg0, reg1;
  
  if ((GET_CODE (XEXP (a, 0)) == REG
       || (GET_CODE (XEXP (a, 0)) == PLUS
           && GET_CODE (XEXP (XEXP (a, 0), 1)) == CONST_INT))
      && (GET_CODE (XEXP (b, 0)) == REG
          || (GET_CODE (XEXP (b, 0)) == PLUS
              && GET_CODE (XEXP (XEXP (b, 0), 1)) == CONST_INT)))
    {
      if (GET_CODE (XEXP (a, 0)) == PLUS)
        {
          reg0 = REGNO (XEXP (XEXP (a, 0), 0));
          val0 = INTVAL (XEXP (XEXP (a, 0), 1));
        }
      else
        reg0 = REGNO (XEXP (a, 0));
      if (GET_CODE (XEXP (b, 0)) == PLUS)
        {
          reg1 = REGNO (XEXP (XEXP (b, 0), 0));
          val1 = INTVAL (XEXP (XEXP (b, 0), 1));
        }
      else
        reg1 = REGNO (XEXP (b, 0));
      return (reg0 == reg1) && ((val1 - val0) == 4 || (val0 - val1) == 4);
    }
  return 0;
}

/* Return 1 if OP is a load multiple operation.  It is known to be
   parallel and the first section will be tested. */

int
load_multiple_operation (op, mode)
     rtx op;
     enum machine_mode mode;
{
  HOST_WIDE_INT count = XVECLEN (op, 0);
  int dest_regno;
  rtx src_addr;
  HOST_WIDE_INT i = 1, base = 0;
  rtx elt;

  if (count <= 1
      || GET_CODE (XVECEXP (op, 0, 0)) != SET)
    return 0;

  /* Check to see if this might be a write-back */
  if (GET_CODE (SET_SRC (elt = XVECEXP (op, 0, 0))) == PLUS)
    {
      i++;
      base = 1;

      /* Now check it more carefully */
      if (GET_CODE (SET_DEST (elt)) != REG
          || GET_CODE (XEXP (SET_SRC (elt), 0)) != REG
          || REGNO (XEXP (SET_SRC (elt), 0)) != REGNO (SET_DEST (elt))
          || GET_CODE (XEXP (SET_SRC (elt), 1)) != CONST_INT
          || INTVAL (XEXP (SET_SRC (elt), 1)) != (count - 2) * 4
          || GET_CODE (XVECEXP (op, 0, count - 1)) != CLOBBER
          || GET_CODE (XEXP (XVECEXP (op, 0, count - 1), 0)) != REG
          || REGNO (XEXP (XVECEXP (op, 0, count - 1), 0))
              != REGNO (SET_DEST (elt)))
        return 0;

      count--;
    }

  /* Perform a quick check so we don't blow up below.  */
  if (count <= i
      || GET_CODE (XVECEXP (op, 0, i - 1)) != SET
      || GET_CODE (SET_DEST (XVECEXP (op, 0, i - 1))) != REG
      || GET_CODE (SET_SRC (XVECEXP (op, 0, i - 1))) != MEM)
    return 0;

  dest_regno = REGNO (SET_DEST (XVECEXP (op, 0, i - 1)));
  src_addr = XEXP (SET_SRC (XVECEXP (op, 0, i - 1)), 0);

  for (; i < count; i++)
    {
      rtx elt = XVECEXP (op, 0, i);

      if (GET_CODE (elt) != SET
          || GET_CODE (SET_DEST (elt)) != REG
          || GET_MODE (SET_DEST (elt)) != SImode
          || REGNO (SET_DEST (elt)) != dest_regno + i - base
          || GET_CODE (SET_SRC (elt)) != MEM
          || GET_MODE (SET_SRC (elt)) != SImode
          || GET_CODE (XEXP (SET_SRC (elt), 0)) != PLUS
          || ! rtx_equal_p (XEXP (XEXP (SET_SRC (elt), 0), 0), src_addr)
          || GET_CODE (XEXP (XEXP (SET_SRC (elt), 0), 1)) != CONST_INT
          || INTVAL (XEXP (XEXP (SET_SRC (elt), 0), 1)) != (i - base) * 4)
        return 0;
    }

  return 1;
}

/* Return 1 if OP is a store multiple operation.  It is known to be
   parallel and the first section will be tested. */

int
store_multiple_operation (op, mode)
     rtx op;
     enum machine_mode mode;
{
  HOST_WIDE_INT count = XVECLEN (op, 0);
  int src_regno;
  rtx dest_addr;
  HOST_WIDE_INT i = 1, base = 0;
  rtx elt;

  if (count <= 1
      || GET_CODE (XVECEXP (op, 0, 0)) != SET)
    return 0;

  /* Check to see if this might be a write-back */
  if (GET_CODE (SET_SRC (elt = XVECEXP (op, 0, 0))) == PLUS)
    {
      i++;
      base = 1;

      /* Now check it more carefully */
      if (GET_CODE (SET_DEST (elt)) != REG
          || GET_CODE (XEXP (SET_SRC (elt), 0)) != REG
          || REGNO (XEXP (SET_SRC (elt), 0)) != REGNO (SET_DEST (elt))
          || GET_CODE (XEXP (SET_SRC (elt), 1)) != CONST_INT
          || INTVAL (XEXP (SET_SRC (elt), 1)) != (count - 2) * 4
          || GET_CODE (XVECEXP (op, 0, count - 1)) != CLOBBER
          || GET_CODE (XEXP (XVECEXP (op, 0, count - 1), 0)) != REG
          || REGNO (XEXP (XVECEXP (op, 0, count - 1), 0))
              != REGNO (SET_DEST (elt)))
        return 0;

      count--;
    }

  /* Perform a quick check so we don't blow up below.  */
  if (count <= i
      || GET_CODE (XVECEXP (op, 0, i - 1)) != SET
      || GET_CODE (SET_DEST (XVECEXP (op, 0, i - 1))) != MEM
      || GET_CODE (SET_SRC (XVECEXP (op, 0, i - 1))) != REG)
    return 0;

  src_regno = REGNO (SET_SRC (XVECEXP (op, 0, i - 1)));
  dest_addr = XEXP (SET_DEST (XVECEXP (op, 0, i - 1)), 0);

  for (; i < count; i++)
    {
      elt = XVECEXP (op, 0, i);

      if (GET_CODE (elt) != SET
          || GET_CODE (SET_SRC (elt)) != REG
          || GET_MODE (SET_SRC (elt)) != SImode
          || REGNO (SET_SRC (elt)) != src_regno + i - base
          || GET_CODE (SET_DEST (elt)) != MEM
          || GET_MODE (SET_DEST (elt)) != SImode
          || GET_CODE (XEXP (SET_DEST (elt), 0)) != PLUS
          || ! rtx_equal_p (XEXP (XEXP (SET_DEST (elt), 0), 0), dest_addr)
          || GET_CODE (XEXP (XEXP (SET_DEST (elt), 0), 1)) != CONST_INT
          || INTVAL (XEXP (XEXP (SET_DEST (elt), 0), 1)) != (i - base) * 4)
        return 0;
    }

  return 1;
}

int
load_multiple_sequence (operands, nops, regs, base, load_offset)
     rtx *operands;
     int nops;
     int *regs;
     int *base;
     HOST_WIDE_INT *load_offset;
{
  int unsorted_regs[4];
  HOST_WIDE_INT unsorted_offsets[4];
  int order[4];
  int base_reg;
  int i;

  /* Can only handle 2, 3, or 4 insns at present, though could be easily
     extended if required.  */
  if (nops < 2 || nops > 4)
    abort ();

  /* Loop over the operands and check that the memory references are
     suitable (ie immediate offsets from the same base register).  At
     the same time, extract the target register, and the memory
     offsets.  */
  for (i = 0; i < nops; i++)
    {
      rtx reg;
      rtx offset;

      if (GET_CODE (operands[nops + i]) != MEM)
        abort ();

      /* Don't reorder volatile memory references; it doesn't seem worth
         looking for the case where the order is ok anyway.  */
      if (MEM_VOLATILE_P (operands[nops + i]))
        return 0;

      offset = const0_rtx;

      if ((GET_CODE (reg = XEXP (operands[nops + i], 0)) == REG
           || (GET_CODE (reg) == SUBREG
               && GET_CODE (reg = SUBREG_REG (reg)) == REG))
          || (GET_CODE (XEXP (operands[nops + i], 0)) == PLUS
              && ((GET_CODE (reg = XEXP (XEXP (operands[nops + i], 0), 0))
                   == REG)
                  || (GET_CODE (reg) == SUBREG
                      && GET_CODE (reg = SUBREG_REG (reg)) == REG))
              && (GET_CODE (offset = XEXP (XEXP (operands[nops + i], 0), 1))
                  == CONST_INT)))
        {
          if (i == 0)
            {
              base_reg = REGNO(reg);
              unsorted_regs[0] = (GET_CODE (operands[i]) == REG
                                  ? REGNO (operands[i])
                                  : REGNO (SUBREG_REG (operands[i])));
              order[0] = 0;
            }
          else 
            {
              if (base_reg != REGNO (reg))
                /* Not addressed from the same base register.  */
                return 0;

              unsorted_regs[i] = (GET_CODE (operands[i]) == REG
                                  ? REGNO (operands[i])
                                  : REGNO (SUBREG_REG (operands[i])));
              if (unsorted_regs[i] < unsorted_regs[order[0]])
                order[0] = i;
            }

          /* If it isn't an integer register, or if it overwrites the
             base register but isn't the last insn in the list, then
             we can't do this.  */
          if (unsorted_regs[i] < 0 || unsorted_regs[i] > 14
              || (i != nops - 1 && unsorted_regs[i] == base_reg))
            return 0;

          unsorted_offsets[i] = INTVAL (offset);
        }
      else
        /* Not a suitable memory address.  */
        return 0;
    }

  /* All the useful information has now been extracted from the
     operands into unsorted_regs and unsorted_offsets; additionally,
     order[0] has been set to the lowest numbered register in the
     list.  Sort the registers into order, and check that the memory
     offsets are ascending and adjacent.  */

  for (i = 1; i < nops; i++)
    {
      int j;

      order[i] = order[i - 1];
      for (j = 0; j < nops; j++)
        if (unsorted_regs[j] > unsorted_regs[order[i - 1]]
            && (order[i] == order[i - 1]
                || unsorted_regs[j] < unsorted_regs[order[i]]))
          order[i] = j;

      /* Have we found a suitable register? if not, one must be used more
         than once.  */
      if (order[i] == order[i - 1])
        return 0;

      /* Is the memory address adjacent and ascending? */
      if (unsorted_offsets[order[i]] != unsorted_offsets[order[i - 1]] + 4)
        return 0;
    }

  if (base)
    {
      *base = base_reg;

      for (i = 0; i < nops; i++)
        regs[i] = unsorted_regs[order[i]];

      *load_offset = unsorted_offsets[order[0]];
    }

  if (unsorted_offsets[order[0]] == 0)
    return 1; /* ldmia */

  if (unsorted_offsets[order[0]] == 4)
    return 2; /* ldmib */

  if (unsorted_offsets[order[nops - 1]] == 0)
    return 3; /* ldmda */

  if (unsorted_offsets[order[nops - 1]] == -4)
    return 4; /* ldmdb */

  /* Can't do it without setting up the offset, only do this if it takes
     no more than one insn.  */
  return (const_ok_for_arm (unsorted_offsets[order[0]]) 
          || const_ok_for_arm (-unsorted_offsets[order[0]])) ? 5 : 0;
}

char *
emit_ldm_seq (operands, nops)
     rtx *operands;
     int nops;
{
  int regs[4];
  int base_reg;
  HOST_WIDE_INT offset;
  char buf[100];
  int i;

  switch (load_multiple_sequence (operands, nops, regs, &base_reg, &offset))
    {
    case 1:
      strcpy (buf, "ldm%?ia\t");
      break;

    case 2:
      strcpy (buf, "ldm%?ib\t");
      break;

    case 3:
      strcpy (buf, "ldm%?da\t");
      break;

    case 4:
      strcpy (buf, "ldm%?db\t");
      break;

    case 5:
      if (offset >= 0)
        sprintf (buf, "add%%?\t%s%s, %s%s, #%ld", REGISTER_PREFIX,
                 reg_names[regs[0]], REGISTER_PREFIX, reg_names[base_reg],
                 (long) offset);
      else
        sprintf (buf, "sub%%?\t%s%s, %s%s, #%ld", REGISTER_PREFIX,
                 reg_names[regs[0]], REGISTER_PREFIX, reg_names[base_reg],
                 (long) -offset);
      output_asm_insn (buf, operands);
      base_reg = regs[0];
      strcpy (buf, "ldm%?ia\t");
      break;

    default:
      abort ();
    }

  sprintf (buf + strlen (buf), "%s%s, {%s%s", REGISTER_PREFIX, 
           reg_names[base_reg], REGISTER_PREFIX, reg_names[regs[0]]);

  for (i = 1; i < nops; i++)
    sprintf (buf + strlen (buf), ", %s%s", REGISTER_PREFIX,
             reg_names[regs[i]]);

  strcat (buf, "}\t%@ phole ldm");

  output_asm_insn (buf, operands);
  return "";
}

int
store_multiple_sequence (operands, nops, regs, base, load_offset)
     rtx *operands;
     int nops;
     int *regs;
     int *base;
     HOST_WIDE_INT *load_offset;
{
  int unsorted_regs[4];
  HOST_WIDE_INT unsorted_offsets[4];
  int order[4];
  int base_reg;
  int i;

  /* Can only handle 2, 3, or 4 insns at present, though could be easily
     extended if required.  */
  if (nops < 2 || nops > 4)
    abort ();

  /* Loop over the operands and check that the memory references are
     suitable (ie immediate offsets from the same base register).  At
     the same time, extract the target register, and the memory
     offsets.  */
  for (i = 0; i < nops; i++)
    {
      rtx reg;
      rtx offset;

      if (GET_CODE (operands[nops + i]) != MEM)
        abort ();

      /* Don't reorder volatile memory references; it doesn't seem worth
         looking for the case where the order is ok anyway.  */
      if (MEM_VOLATILE_P (operands[nops + i]))
        return 0;

      offset = const0_rtx;

      if ((GET_CODE (reg = XEXP (operands[nops + i], 0)) == REG
           || (GET_CODE (reg) == SUBREG
               && GET_CODE (reg = SUBREG_REG (reg)) == REG))
          || (GET_CODE (XEXP (operands[nops + i], 0)) == PLUS
              && ((GET_CODE (reg = XEXP (XEXP (operands[nops + i], 0), 0))
                   == REG)
                  || (GET_CODE (reg) == SUBREG
                      && GET_CODE (reg = SUBREG_REG (reg)) == REG))
              && (GET_CODE (offset = XEXP (XEXP (operands[nops + i], 0), 1))
                  == CONST_INT)))
        {
          if (i == 0)
            {
              base_reg = REGNO(reg);
              unsorted_regs[0] = (GET_CODE (operands[i]) == REG
                                  ? REGNO (operands[i])
                                  : REGNO (SUBREG_REG (operands[i])));
              order[0] = 0;
            }
          else 
            {
              if (base_reg != REGNO (reg))
                /* Not addressed from the same base register.  */
                return 0;

              unsorted_regs[i] = (GET_CODE (operands[i]) == REG
                                  ? REGNO (operands[i])
                                  : REGNO (SUBREG_REG (operands[i])));
              if (unsorted_regs[i] < unsorted_regs[order[0]])
                order[0] = i;
            }

          /* If it isn't an integer register, then we can't do this.  */
          if (unsorted_regs[i] < 0 || unsorted_regs[i] > 14)
            return 0;

          unsorted_offsets[i] = INTVAL (offset);
        }
      else
        /* Not a suitable memory address.  */
        return 0;
    }

  /* All the useful information has now been extracted from the
     operands into unsorted_regs and unsorted_offsets; additionally,
     order[0] has been set to the lowest numbered register in the
     list.  Sort the registers into order, and check that the memory
     offsets are ascending and adjacent.  */

  for (i = 1; i < nops; i++)
    {
      int j;

      order[i] = order[i - 1];
      for (j = 0; j < nops; j++)
        if (unsorted_regs[j] > unsorted_regs[order[i - 1]]
            && (order[i] == order[i - 1]
                || unsorted_regs[j] < unsorted_regs[order[i]]))
          order[i] = j;

      /* Have we found a suitable register? if not, one must be used more
         than once.  */
      if (order[i] == order[i - 1])
        return 0;

      /* Is the memory address adjacent and ascending? */
      if (unsorted_offsets[order[i]] != unsorted_offsets[order[i - 1]] + 4)
        return 0;
    }

  if (base)
    {
      *base = base_reg;

      for (i = 0; i < nops; i++)
        regs[i] = unsorted_regs[order[i]];

      *load_offset = unsorted_offsets[order[0]];
    }

  if (unsorted_offsets[order[0]] == 0)
    return 1; /* stmia */

  if (unsorted_offsets[order[0]] == 4)
    return 2; /* stmib */

  if (unsorted_offsets[order[nops - 1]] == 0)
    return 3; /* stmda */

  if (unsorted_offsets[order[nops - 1]] == -4)
    return 4; /* stmdb */

  return 0;
}

char *
emit_stm_seq (operands, nops)
     rtx *operands;
     int nops;
{
  int regs[4];
  int base_reg;
  HOST_WIDE_INT offset;
  char buf[100];
  int i;

  switch (store_multiple_sequence (operands, nops, regs, &base_reg, &offset))
    {
    case 1:
      strcpy (buf, "stm%?ia\t");
      break;

    case 2:
      strcpy (buf, "stm%?ib\t");
      break;

    case 3:
      strcpy (buf, "stm%?da\t");
      break;

    case 4:
      strcpy (buf, "stm%?db\t");
      break;

    default:
      abort ();
    }

  sprintf (buf + strlen (buf), "%s%s, {%s%s", REGISTER_PREFIX, 
           reg_names[base_reg], REGISTER_PREFIX, reg_names[regs[0]]);

  for (i = 1; i < nops; i++)
    sprintf (buf + strlen (buf), ", %s%s", REGISTER_PREFIX,
             reg_names[regs[i]]);

  strcat (buf, "}\t%@ phole stm");

  output_asm_insn (buf, operands);
  return "";
}

int
multi_register_push (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (GET_CODE (op) != PARALLEL
      || (GET_CODE (XVECEXP (op, 0, 0)) != SET)
      || (GET_CODE (SET_SRC (XVECEXP (op, 0, 0))) != UNSPEC)
      || (XINT (SET_SRC (XVECEXP (op, 0, 0)), 1) != 2))
    return 0;

  return 1;
}

\f
/* Routines for use with attributes */

int
const_pool_offset (symbol)
     rtx symbol;
{
  return get_pool_offset (symbol) - get_pool_size () - get_prologue_size ();
}

/* Return nonzero if ATTR is a valid attribute for DECL.
   ATTRIBUTES are any existing attributes and ARGS are the arguments
   supplied with ATTR.

   Supported attributes:

   naked: don't output any prologue or epilogue code, the user is assumed
   to do the right thing.  */

int
arm_valid_machine_decl_attribute (decl, attributes, attr, args)
     tree decl;
     tree attributes;
     tree attr;
     tree args;
{
  if (args != NULL_TREE)
    return 0;

  if (is_attribute_p ("naked", attr))
    return TREE_CODE (decl) == FUNCTION_DECL;
  return 0;
}

/* Return non-zero if FUNC is a naked function.  */

static int
arm_naked_function_p (func)
     tree func;
{
  tree a;

  if (TREE_CODE (func) != FUNCTION_DECL)
    abort ();

  a = lookup_attribute ("naked", DECL_MACHINE_ATTRIBUTES (func));
  return a != NULL_TREE;
}
\f
/* Routines for use in generating RTL */

rtx
arm_gen_load_multiple (base_regno, count, from, up, write_back)
     int base_regno;
     int count;
     rtx from;
     int up;
     int write_back;
{
  int i = 0, j;
  rtx result;
  int sign = up ? 1 : -1;

  result = gen_rtx (PARALLEL, VOIDmode,
                    rtvec_alloc (count + (write_back ? 2 : 0)));
  if (write_back)
    {
      XVECEXP (result, 0, 0)
        = gen_rtx (SET, GET_MODE (from), from,
                   plus_constant (from, count * 4 * sign));
      i = 1;
      count++;
    }

  for (j = 0; i < count; i++, j++)
    {
      XVECEXP (result, 0, i)
        = gen_rtx (SET, VOIDmode, gen_rtx (REG, SImode, base_regno + j),
                   gen_rtx (MEM, SImode,
                            plus_constant (from, j * 4 * sign)));
    }

  if (write_back)
    XVECEXP (result, 0, i) = gen_rtx (CLOBBER, SImode, from);

  return result;
}

rtx
arm_gen_store_multiple (base_regno, count, to, up, write_back)
     int base_regno;
     int count;
     rtx to;
     int up;
     int write_back;
{
  int i = 0, j;
  rtx result;
  int sign = up ? 1 : -1;

  result = gen_rtx (PARALLEL, VOIDmode,
                    rtvec_alloc (count + (write_back ? 2 : 0)));
  if (write_back)
    {
      XVECEXP (result, 0, 0)
        = gen_rtx (SET, GET_MODE (to), to,
                   plus_constant (to, count * 4 * sign));
      i = 1;
      count++;
    }

  for (j = 0; i < count; i++, j++)
    {
      XVECEXP (result, 0, i)
        = gen_rtx (SET, VOIDmode,
                   gen_rtx (MEM, SImode, plus_constant (to, j * 4 * sign)),
                   gen_rtx (REG, SImode, base_regno + j));
    }

  if (write_back)
    XVECEXP (result, 0, i) = gen_rtx (CLOBBER, SImode, to);

  return result;
}

int
arm_gen_movstrqi (operands)
     rtx *operands;
{
  HOST_WIDE_INT in_words_to_go, out_words_to_go, last_bytes;
  int i, r;
  rtx src, dst;
  rtx st_src, st_dst, end_src, end_dst, fin_src, fin_dst;
  rtx part_bytes_reg = NULL;
  extern int optimize;

  if (GET_CODE (operands[2]) != CONST_INT
      || GET_CODE (operands[3]) != CONST_INT
      || INTVAL (operands[2]) > 64
      || INTVAL (operands[3]) & 3)
    return 0;

  st_dst = XEXP (operands[0], 0);
  st_src = XEXP (operands[1], 0);
  fin_dst = dst = copy_to_mode_reg (SImode, st_dst);
  fin_src = src = copy_to_mode_reg (SImode, st_src);

  in_words_to_go = (INTVAL (operands[2]) + 3) / 4;
  out_words_to_go = INTVAL (operands[2]) / 4;
  last_bytes = INTVAL (operands[2]) & 3;

  if (out_words_to_go != in_words_to_go && ((in_words_to_go - 1) & 3) != 0)
    part_bytes_reg = gen_rtx (REG, SImode, (in_words_to_go - 1) & 3);

  for (i = 0; in_words_to_go >= 2; i+=4)
    {
      if (in_words_to_go > 4)
        emit_insn (arm_gen_load_multiple (0, 4, src, TRUE, TRUE));
      else
        emit_insn (arm_gen_load_multiple (0, in_words_to_go, src, TRUE, 
                                          FALSE));

      if (out_words_to_go)
        {
          if (out_words_to_go > 4)
            emit_insn (arm_gen_store_multiple (0, 4, dst, TRUE, TRUE));
          else if (out_words_to_go != 1)
            emit_insn (arm_gen_store_multiple (0, out_words_to_go,
                                               dst, TRUE, 
                                               (last_bytes == 0
                                                ? FALSE : TRUE)));
          else
            {
              emit_move_insn (gen_rtx (MEM, SImode, dst),
                              gen_rtx (REG, SImode, 0));
              if (last_bytes != 0)
                emit_insn (gen_addsi3 (dst, dst, GEN_INT (4)));
            }
        }

      in_words_to_go -= in_words_to_go < 4 ? in_words_to_go : 4;
      out_words_to_go -= out_words_to_go < 4 ? out_words_to_go : 4;
    }

  /* OUT_WORDS_TO_GO will be zero here if there are byte stores to do.  */
  if (out_words_to_go)
  {
    rtx sreg;

    emit_move_insn (sreg = gen_reg_rtx (SImode), gen_rtx (MEM, SImode, src));
    emit_move_insn (fin_src = gen_reg_rtx (SImode), plus_constant (src, 4));
    emit_move_insn (gen_rtx (MEM, SImode, dst), sreg);
    emit_move_insn (fin_dst = gen_reg_rtx (SImode), plus_constant (dst, 4));
    in_words_to_go--;

    if (in_words_to_go) /* Sanity check */
      abort ();
  }

  if (in_words_to_go)
    {
      if (in_words_to_go < 0)
        abort ();

      part_bytes_reg = copy_to_mode_reg (SImode, gen_rtx (MEM, SImode, src));
    }

  if (BYTES_BIG_ENDIAN && last_bytes)
    {
      rtx tmp = gen_reg_rtx (SImode);

      if (part_bytes_reg == NULL)
        abort ();

      /* The bytes we want are in the top end of the word */
      emit_insn (gen_lshrsi3 (tmp, part_bytes_reg,
                              GEN_INT (8 * (4 - last_bytes))));
      part_bytes_reg = tmp;
      
      while (last_bytes)
        {
          emit_move_insn (gen_rtx (MEM, QImode, 
                                   plus_constant (dst, last_bytes - 1)),
                          gen_rtx (SUBREG, QImode, part_bytes_reg, 0));
          if (--last_bytes)
            {
              tmp = gen_reg_rtx (SImode);
              emit_insn (gen_lshrsi3 (tmp, part_bytes_reg, GEN_INT (8)));
              part_bytes_reg = tmp;
            }
        }
          
    }
  else
    {
      while (last_bytes)
        {
          if (part_bytes_reg == NULL)
            abort ();

          emit_move_insn (gen_rtx (MEM, QImode, dst),
                          gen_rtx (SUBREG, QImode, part_bytes_reg, 0));
          if (--last_bytes)
            {
              rtx tmp = gen_reg_rtx (SImode);

              emit_insn (gen_addsi3 (dst, dst, const1_rtx));
              emit_insn (gen_lshrsi3 (tmp, part_bytes_reg, GEN_INT (8)));
              part_bytes_reg = tmp;
            }
        }
    }

  return 1;
}

/* Generate a memory reference for a half word, such that it will be loaded
   into the top 16 bits of the word.  We can assume that the address is
   known to be alignable and of the form reg, or plus (reg, const).  */
rtx
gen_rotated_half_load (memref)
     rtx memref;
{
  HOST_WIDE_INT offset = 0;
  rtx base = XEXP (memref, 0);

  if (GET_CODE (base) == PLUS)
    {
      offset = INTVAL (XEXP (base, 1));
      base = XEXP (base, 0);
    }

  /* If we aren't allowed to generate unalligned addresses, then fail.  */
  if (TARGET_SHORT_BY_BYTES
      && ((BYTES_BIG_ENDIAN ? 1 : 0) ^ ((offset & 2) == 0)))
    return NULL;

  base = gen_rtx (MEM, SImode, plus_constant (base, offset & ~2));

  if ((BYTES_BIG_ENDIAN ? 1 : 0) ^ ((offset & 2) == 2))
    return base;

  return gen_rtx (ROTATE, SImode, base, GEN_INT (16));
}

static enum machine_mode
select_dominance_cc_mode (op, x, y, cond_or)
     enum rtx_code op;
     rtx x;
     rtx y;
     HOST_WIDE_INT cond_or;
{
  enum rtx_code cond1, cond2;
  int swapped = 0;

  /* Currently we will probably get the wrong result if the individual
     comparisons are not simple.  This also ensures that it is safe to
     reverse a comparions if necessary.  */
  if ((arm_select_cc_mode (cond1 = GET_CODE (x), XEXP (x, 0), XEXP (x, 1))
       != CCmode)
      || (arm_select_cc_mode (cond2 = GET_CODE (y), XEXP (y, 0), XEXP (y, 1))
          != CCmode))
    return CCmode;

  if (cond_or)
    cond1 = reverse_condition (cond1);

  /* If the comparisons are not equal, and one doesn't dominate the other,
     then we can't do this.  */
  if (cond1 != cond2 
      && ! comparison_dominates_p (cond1, cond2)
      && (swapped = 1, ! comparison_dominates_p (cond2, cond1)))
    return CCmode;

  if (swapped)
    {
      enum rtx_code temp = cond1;
      cond1 = cond2;
      cond2 = temp;
    }

  switch (cond1)
    {
    case EQ:
      if (cond2 == EQ || ! cond_or)
        return CC_DEQmode;

      switch (cond2)
        {
        case LE: return CC_DLEmode;
        case LEU: return CC_DLEUmode;
        case GE: return CC_DGEmode;
        case GEU: return CC_DGEUmode;
        }

      break;

    case LT:
      if (cond2 == LT || ! cond_or)
        return CC_DLTmode;
      if (cond2 == LE)
        return CC_DLEmode;
      if (cond2 == NE)
        return CC_DNEmode;
      break;

    case GT:
      if (cond2 == GT || ! cond_or)
        return CC_DGTmode;
      if (cond2 == GE)
        return CC_DGEmode;
      if (cond2 == NE)
        return CC_DNEmode;
      break;
      
    case LTU:
      if (cond2 == LTU || ! cond_or)
        return CC_DLTUmode;
      if (cond2 == LEU)
        return CC_DLEUmode;
      if (cond2 == NE)
        return CC_DNEmode;
      break;

    case GTU:
      if (cond2 == GTU || ! cond_or)
        return CC_DGTUmode;
      if (cond2 == GEU)
        return CC_DGEUmode;
      if (cond2 == NE)
        return CC_DNEmode;
      break;

    /* The remaining cases only occur when both comparisons are the
       same.  */
    case NE:
      return CC_DNEmode;

    case LE:
      return CC_DLEmode;

    case GE:
      return CC_DGEmode;

    case LEU:
      return CC_DLEUmode;

    case GEU:
      return CC_DGEUmode;
    }

  abort ();
}

enum machine_mode
arm_select_cc_mode (op, x, y)
     enum rtx_code op;
     rtx x;
     rtx y;
{
  /* All floating point compares return CCFP if it is an equality
     comparison, and CCFPE otherwise.  */
  if (GET_MODE_CLASS (GET_MODE (x)) == MODE_FLOAT)
    return (op == EQ || op == NE) ? CCFPmode : CCFPEmode;
  
  /* A compare with a shifted operand.  Because of canonicalization, the
     comparison will have to be swapped when we emit the assembler.  */
  if (GET_MODE (y) == SImode && GET_CODE (y) == REG
      && (GET_CODE (x) == ASHIFT || GET_CODE (x) == ASHIFTRT
          || GET_CODE (x) == LSHIFTRT || GET_CODE (x) == ROTATE
          || GET_CODE (x) == ROTATERT))
    return CC_SWPmode;

  /* This is a special case, that is used by combine to alow a 
     comarison of a shifted byte load to be split into a zero-extend
     followed by a comparison of the shifted integer (only valid for
     equalities and unsigned inequalites.  */
  if (GET_MODE (x) == SImode
      && GET_CODE (x) == ASHIFT
      && GET_CODE (XEXP (x, 1)) == CONST_INT && INTVAL (XEXP (x, 1)) == 24
      && GET_CODE (XEXP (x, 0)) == SUBREG
      && GET_CODE (SUBREG_REG (XEXP (x, 0))) == MEM
      && GET_MODE (SUBREG_REG (XEXP (x, 0))) == QImode
      && (op == EQ || op == NE
          || op == GEU || op == GTU || op == LTU || op == LEU)
      && GET_CODE (y) == CONST_INT)
    return CC_Zmode;

  /* An operation that sets the condition codes as a side-effect, the
     V flag is not set correctly, so we can only use comparisons where
     this doesn't matter.  (For LT and GE we can use "mi" and "pl"
     instead.  */
  if (GET_MODE (x) == SImode
      && y == const0_rtx
      && (op == EQ || op == NE || op == LT || op == GE)
      && (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
          || GET_CODE (x) == AND || GET_CODE (x) == IOR
          || GET_CODE (x) == XOR || GET_CODE (x) == MULT
          || GET_CODE (x) == NOT || GET_CODE (x) == NEG
          || GET_CODE (x) == LSHIFTRT
          || GET_CODE (x) == ASHIFT || GET_CODE (x) == ASHIFTRT
          || GET_CODE (x) == ROTATERT || GET_CODE (x) == ZERO_EXTRACT))
    return CC_NOOVmode;

  /* A construct for a conditional compare, if the false arm contains
     0, then both conditions must be true, otherwise either condition
     must be true.  Not all conditions are possible, so CCmode is
     returned if it can't be done.  */
  if (GET_CODE (x) == IF_THEN_ELSE
      && (XEXP (x, 2) == const0_rtx
          || XEXP (x, 2) == const1_rtx)
      && GET_RTX_CLASS (GET_CODE (XEXP (x, 0))) == '<'
      && GET_RTX_CLASS (GET_CODE (XEXP (x, 1))) == '<')
    return select_dominance_cc_mode (op, XEXP (x, 0), XEXP (x, 1), 
                                     INTVAL (XEXP (x, 2)));

  if (GET_MODE (x) == QImode && (op == EQ || op == NE))
    return CC_Zmode;

  if (GET_MODE (x) == SImode && (op == LTU || op == GEU)
      && GET_CODE (x) == PLUS
      && (rtx_equal_p (XEXP (x, 0), y) || rtx_equal_p (XEXP (x, 1), y)))
    return CC_Cmode;

  return CCmode;
}

/* X and Y are two things to compare using CODE.  Emit the compare insn and
   return the rtx for register 0 in the proper mode.  FP means this is a
   floating point compare: I don't think that it is needed on the arm.  */

rtx
gen_compare_reg (code, x, y, fp)
     enum rtx_code code;
     rtx x, y;
{
  enum machine_mode mode = SELECT_CC_MODE (code, x, y);
  rtx cc_reg = gen_rtx (REG, mode, 24);

  emit_insn (gen_rtx (SET, VOIDmode, cc_reg,
                      gen_rtx (COMPARE, mode, x, y)));

  return cc_reg;
}

void
arm_reload_in_hi (operands)
     rtx *operands;
{
  rtx base = find_replacement (&XEXP (operands[1], 0));

  emit_insn (gen_zero_extendqisi2 (operands[2], gen_rtx (MEM, QImode, base)));
  emit_insn (gen_zero_extendqisi2 (gen_rtx (SUBREG, SImode, operands[0], 0),
                                   gen_rtx (MEM, QImode, 
                                            plus_constant (base, 1))));
  if (BYTES_BIG_ENDIAN)
    emit_insn (gen_rtx (SET, VOIDmode, gen_rtx (SUBREG, SImode, 
                                                operands[0], 0),
                        gen_rtx (IOR, SImode, 
                                 gen_rtx (ASHIFT, SImode,
                                          gen_rtx (SUBREG, SImode,
                                                   operands[0], 0),
                                          GEN_INT (8)),
                                 operands[2])));
  else
    emit_insn (gen_rtx (SET, VOIDmode, gen_rtx (SUBREG, SImode, 
                                                operands[0], 0),
                        gen_rtx (IOR, SImode, 
                                 gen_rtx (ASHIFT, SImode,
                                          operands[2],
                                          GEN_INT (8)),
                                 gen_rtx (SUBREG, SImode, operands[0], 0))));
}

void
arm_reload_out_hi (operands)
     rtx *operands;
{
  rtx base = find_replacement (&XEXP (operands[0], 0));

  if (BYTES_BIG_ENDIAN)
    {
      emit_insn (gen_movqi (gen_rtx (MEM, QImode, plus_constant (base, 1)),
                            gen_rtx (SUBREG, QImode, operands[1], 0)));
      emit_insn (gen_lshrsi3 (operands[2],
                              gen_rtx (SUBREG, SImode, operands[1], 0),
                              GEN_INT (8)));
      emit_insn (gen_movqi (gen_rtx (MEM, QImode, base),
                            gen_rtx (SUBREG, QImode, operands[2], 0)));
    }
  else
    {
      emit_insn (gen_movqi (gen_rtx (MEM, QImode, base),
                            gen_rtx (SUBREG, QImode, operands[1], 0)));
      emit_insn (gen_lshrsi3 (operands[2],
                              gen_rtx (SUBREG, SImode, operands[1], 0),
                              GEN_INT (8)));
      emit_insn (gen_movqi (gen_rtx (MEM, QImode, plus_constant (base, 1)),
                            gen_rtx (SUBREG, QImode, operands[2], 0)));
    }
}
\f
/* Check to see if a branch is forwards or backwards.  Return TRUE if it
   is backwards.  */

int
arm_backwards_branch (from, to)
     int from, to;
{
  return insn_addresses[to] <= insn_addresses[from];
}

/* Check to see if a branch is within the distance that can be done using
   an arithmetic expression. */
int
short_branch (from, to)
     int from, to;
{
  int delta = insn_addresses[from] + 8 - insn_addresses[to];

  return abs (delta) < 980;     /* A small margin for safety */
}

/* Check to see that the insn isn't the target of the conditionalizing
   code */
int
arm_insn_not_targeted (insn)
     rtx insn;
{
  return insn != arm_target_insn;
}

\f
/* Routines for manipulation of the constant pool.  */
/* This is unashamedly hacked from the version in sh.c, since the problem is
   extremely similar.  */

/* Arm instructions cannot load a large constant into a register,
   constants have to come from a pc relative load.  The reference of a pc
   relative load instruction must be less than 1k infront of the instruction.
   This means that we often have to dump a constant inside a function, and
   generate code to branch around it.

   It is important to minimize this, since the branches will slow things
   down and make things bigger.

   Worst case code looks like:

        ldr     rn, L1
        b       L2
        align
        L1:     .long value
        L2:
        ..

        ldr     rn, L3
        b       L4
        align
        L3:     .long value
        L4:
        ..

   We fix this by performing a scan before scheduling, which notices which
   instructions need to have their operands fetched from the constant table
   and builds the table.


   The algorithm is:

   scan, find an instruction which needs a pcrel move.  Look forward, find th
   last barrier which is within MAX_COUNT bytes of the requirement.
   If there isn't one, make one.  Process all the instructions between
   the find and the barrier.

   In the above example, we can tell that L3 is within 1k of L1, so
   the first move can be shrunk from the 2 insn+constant sequence into
   just 1 insn, and the constant moved to L3 to make:

        ldr     rn, L1
        ..
        ldr     rn, L3
        b       L4
        align
        L1:     .long value
        L3:     .long value
        L4:

   Then the second move becomes the target for the shortening process.

 */

typedef struct
{
  rtx value;                    /* Value in table */
  HOST_WIDE_INT next_offset;
  enum machine_mode mode;       /* Mode of value */
} pool_node;

/* The maximum number of constants that can fit into one pool, since
   the pc relative range is 0...1020 bytes and constants are at least 4
   bytes long */

#define MAX_POOL_SIZE (1020/4)
static pool_node pool_vector[MAX_POOL_SIZE];
static int pool_size;
static rtx pool_vector_label;

/* Add a constant to the pool and return its label.  */
static HOST_WIDE_INT
add_constant (x, mode)
     rtx x;
     enum machine_mode mode;
{
  int i;
  rtx lab;
  HOST_WIDE_INT offset;

  if (mode == SImode && GET_CODE (x) == MEM && CONSTANT_P (XEXP (x, 0))
      && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)))
    x = get_pool_constant (XEXP (x, 0));
#ifndef AOF_ASSEMBLER
  else if (GET_CODE (x) == UNSPEC && XINT (x, 1) == 3)
    x = XVECEXP (x, 0, 0);
#endif

  /* First see if we've already got it */
  for (i = 0; i < pool_size; i++)
    {
      if (GET_CODE (x) == pool_vector[i].value->code
          && mode == pool_vector[i].mode)
        {
          if (GET_CODE (x) == CODE_LABEL)
            {
              if (XINT (x, 3) != XINT (pool_vector[i].value, 3))
                continue;
            }
          if (rtx_equal_p (x, pool_vector[i].value))
            return pool_vector[i].next_offset - GET_MODE_SIZE (mode);
        }
    }

  /* Need a new one */
  pool_vector[pool_size].next_offset = GET_MODE_SIZE (mode);
  offset = 0;
  if (pool_size == 0)
    pool_vector_label = gen_label_rtx ();
  else
    pool_vector[pool_size].next_offset
      += (offset = pool_vector[pool_size - 1].next_offset);

  pool_vector[pool_size].value = x;
  pool_vector[pool_size].mode = mode;
  pool_size++;
  return offset;
}

/* Output the literal table */
static void
dump_table (scan)
     rtx scan;
{
  int i;

  scan = emit_label_after (gen_label_rtx (), scan);
  scan = emit_insn_after (gen_align_4 (), scan);
  scan = emit_label_after (pool_vector_label, scan);

  for (i = 0; i < pool_size; i++)
    {
      pool_node *p = pool_vector + i;

      switch (GET_MODE_SIZE (p->mode))
        {
        case 4:
          scan = emit_insn_after (gen_consttable_4 (p->value), scan);
          break;

        case 8:
          scan = emit_insn_after (gen_consttable_8 (p->value), scan);
          break;

        default:
          abort ();
          break;
        }
    }

  scan = emit_insn_after (gen_consttable_end (), scan);
  scan = emit_barrier_after (scan);
  pool_size = 0;
}

/* Non zero if the src operand needs to be fixed up */
static int
fixit (src, mode, destreg)
     rtx src;
     enum machine_mode mode;
     int destreg;
{
  if (CONSTANT_P (src))
    {
      if (GET_CODE (src) == CONST_INT)
        return (! const_ok_for_arm (INTVAL (src))
                && ! const_ok_for_arm (~INTVAL (src)));
      if (GET_CODE (src) == CONST_DOUBLE)
        return (GET_MODE (src) == VOIDmode
                || destreg < 16
                || (! const_double_rtx_ok_for_fpu (src)
                    && ! neg_const_double_rtx_ok_for_fpu (src)));
      return symbol_mentioned_p (src);
    }
#ifndef AOF_ASSEMBLER
  else if (GET_CODE (src) == UNSPEC && XINT (src, 1) == 3)
    return 1;
#endif
  else
    return (mode == SImode && GET_CODE (src) == MEM
            && GET_CODE (XEXP (src, 0)) == SYMBOL_REF
            && CONSTANT_POOL_ADDRESS_P (XEXP (src, 0)));
}

/* Find the last barrier less than MAX_COUNT bytes from FROM, or create one. */
static rtx
find_barrier (from, max_count)
     rtx from;
     int max_count;
{
  int count = 0;
  rtx found_barrier = 0;

  while (from && count < max_count)
    {
      if (GET_CODE (from) == BARRIER)
        found_barrier = from;

      /* Count the length of this insn */
      if (GET_CODE (from) == INSN
          && GET_CODE (PATTERN (from)) == SET
          && CONSTANT_P (SET_SRC (PATTERN (from)))
          && CONSTANT_POOL_ADDRESS_P (SET_SRC (PATTERN (from))))
        {
          rtx src = SET_SRC (PATTERN (from));
          count += 2;
        }
      else
        count += get_attr_length (from);

      from = NEXT_INSN (from);
    }

  if (!found_barrier)
    {
      /* We didn't find a barrier in time to
         dump our stuff, so we'll make one */
      rtx label = gen_label_rtx ();

      if (from)
        from = PREV_INSN (from);
      else
        from = get_last_insn ();

      /* Walk back to be just before any jump */
      while (GET_CODE (from) == JUMP_INSN
             || GET_CODE (from) == NOTE
             || GET_CODE (from) == CODE_LABEL)
        from = PREV_INSN (from);

      from = emit_jump_insn_after (gen_jump (label), from);
      JUMP_LABEL (from) = label;
      found_barrier = emit_barrier_after (from);
      emit_label_after (label, found_barrier);
      return found_barrier;
    }

  return found_barrier;
}

/* Non zero if the insn is a move instruction which needs to be fixed. */
static int
broken_move (insn)
     rtx insn;
{
  if (!INSN_DELETED_P (insn)
      && GET_CODE (insn) == INSN
      && GET_CODE (PATTERN (insn)) == SET)
    {
      rtx pat = PATTERN (insn);
      rtx src = SET_SRC (pat);
      rtx dst = SET_DEST (pat);
      int destreg;
      enum machine_mode mode = GET_MODE (dst);
      if (dst == pc_rtx)
        return 0;

      if (GET_CODE (dst) == REG)
        destreg = REGNO (dst);
      else if (GET_CODE (dst) == SUBREG && GET_CODE (SUBREG_REG (dst)) == REG)
        destreg = REGNO (SUBREG_REG (dst));

      return fixit (src, mode, destreg);
    }
  return 0;
}

void
arm_reorg (first)
     rtx first;
{
  rtx insn;
  int count_size;
  int regno;

#if 0
  /* The ldr instruction can work with up to a 4k offset, and most constants
     will be loaded with one of these instructions; however, the adr 
     instruction and the ldf instructions only work with a 1k offset.  This
     code needs to be rewritten to use the 4k offset when possible, and to
     adjust when a 1k offset is needed.  For now we just use a 1k offset
     from the start.  */
  count_size = 4000;

  /* Floating point operands can't work further than 1024 bytes from the
     PC, so to make things simple we restrict all loads for such functions.
     */
  if (TARGET_HARD_FLOAT)
    for (regno = 16; regno < 24; regno++)
      if (regs_ever_live[regno])
        {
          count_size = 1000;
          break;
        }
#else
  count_size = 1000;
#endif /* 0 */

  for (insn = first; insn; insn = NEXT_INSN (insn))
    {
      if (broken_move (insn))
        {
          /* This is a broken move instruction, scan ahead looking for
             a barrier to stick the constant table behind */
          rtx scan;
          rtx barrier = find_barrier (insn, count_size);

          /* Now find all the moves between the points and modify them */
          for (scan = insn; scan != barrier; scan = NEXT_INSN (scan))
            {
              if (broken_move (scan))
                {
                  /* This is a broken move instruction, add it to the pool */
                  rtx pat = PATTERN (scan);
                  rtx src = SET_SRC (pat);
                  rtx dst = SET_DEST (pat);
                  enum machine_mode mode = GET_MODE (dst);
                  HOST_WIDE_INT offset;
                  rtx newinsn = scan;
                  rtx newsrc;
                  rtx addr;
                  int scratch;

                  /* If this is an HImode constant load, convert it into
                     an SImode constant load.  Since the register is always
                     32 bits this is safe.  We have to do this, since the
                     load pc-relative instruction only does a 32-bit load. */
                  if (mode == HImode)
                    {
                      mode = SImode;
                      if (GET_CODE (dst) != REG)
                        abort ();
                      PUT_MODE (dst, SImode);
                    }

                  offset = add_constant (src, mode);
                  addr = plus_constant (gen_rtx (LABEL_REF, VOIDmode,
                                                 pool_vector_label),
                                        offset);

                  /* For wide moves to integer regs we need to split the
                     address calculation off into a separate insn, so that
                     the load can then be done with a load-multiple.  This is
                     safe, since we have already noted the length of such
                     insns to be 8, and we are immediately over-writing the
                     scratch we have grabbed with the final result.  */
                  if (GET_MODE_SIZE (mode) > 4
                      && (scratch = REGNO (dst)) < 16)
                    {
                      rtx reg = gen_rtx (REG, SImode, scratch);
                      newinsn = emit_insn_after (gen_movaddr (reg, addr),
                                                 newinsn);
                      addr = reg;
                    }

                  newsrc = gen_rtx (MEM, mode, addr);

                  /* Build a jump insn wrapper around the move instead
                     of an ordinary insn, because we want to have room for
                     the target label rtx in fld[7], which an ordinary
                     insn doesn't have. */
                  newinsn = emit_jump_insn_after (gen_rtx (SET, VOIDmode,
                                                           dst, newsrc),
                                                  newinsn);
                  JUMP_LABEL (newinsn) = pool_vector_label;

                  /* But it's still an ordinary insn */
                  PUT_CODE (newinsn, INSN);

                  /* Kill old insn */
                  delete_insn (scan);
                  scan = newinsn;
                }
            }
          dump_table (barrier);
          insn = scan;
        }
    }
}

\f
/* Routines to output assembly language.  */

/* If the rtx is the correct value then return the string of the number.
   In this way we can ensure that valid double constants are generated even
   when cross compiling. */
char *
fp_immediate_constant (x)
     rtx x;
{
  REAL_VALUE_TYPE r;
  int i;
  
  if (!fpa_consts_inited)
    init_fpa_table ();
  
  REAL_VALUE_FROM_CONST_DOUBLE (r, x);
  for (i = 0; i < 8; i++)
    if (REAL_VALUES_EQUAL (r, values_fpa[i]))
      return strings_fpa[i];

  abort ();
}

/* As for fp_immediate_constant, but value is passed directly, not in rtx.  */
static char *
fp_const_from_val (r)
     REAL_VALUE_TYPE *r;
{
  int i;

  if (! fpa_consts_inited)
    init_fpa_table ();

  for (i = 0; i < 8; i++)
    if (REAL_VALUES_EQUAL (*r, values_fpa[i]))
      return strings_fpa[i];

  abort ();
}

/* Output the operands of a LDM/STM instruction to STREAM.
   MASK is the ARM register set mask of which only bits 0-15 are important.
   INSTR is the possibly suffixed base register.  HAT unequals zero if a hat
   must follow the register list.  */

void
print_multi_reg (stream, instr, mask, hat)
     FILE *stream;
     char *instr;
     int mask, hat;
{
  int i;
  int not_first = FALSE;

  fputc ('\t', stream);
  fprintf (stream, instr, REGISTER_PREFIX);
  fputs (", {", stream);
  for (i = 0; i < 16; i++)
    if (mask & (1 << i))
      {
        if (not_first)
          fprintf (stream, ", ");
        fprintf (stream, "%s%s", REGISTER_PREFIX, reg_names[i]);
        not_first = TRUE;
      }

  fprintf (stream, "}%s\n", hat ? "^" : "");
}

/* Output a 'call' insn. */

char *
output_call (operands)
     rtx *operands;
{
  /* Handle calls to lr using ip (which may be clobbered in subr anyway). */

  if (REGNO (operands[0]) == 14)
    {
      operands[0] = gen_rtx (REG, SImode, 12);
      output_asm_insn ("mov%?\t%0, %|lr", operands);
    }
  output_asm_insn ("mov%?\t%|lr, %|pc", operands);
  output_asm_insn ("mov%?\t%|pc, %0", operands);
  return "";
}

static int
eliminate_lr2ip (x)
     rtx *x;
{
  int something_changed = 0;
  rtx x0 = *x;
  int code = GET_CODE (x0);
  register int i, j;
  register char *fmt;
  
  switch (code)
    {
    case REG:
      if (REGNO (x0) == 14)
        {
          *x = gen_rtx (REG, SImode, 12);
          return 1;
        }
      return 0;
    default:
      /* Scan through the sub-elements and change any references there */
      fmt = GET_RTX_FORMAT (code);
      for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
        if (fmt[i] == 'e')
          something_changed |= eliminate_lr2ip (&XEXP (x0, i));
        else if (fmt[i] == 'E')
          for (j = 0; j < XVECLEN (x0, i); j++)
            something_changed |= eliminate_lr2ip (&XVECEXP (x0, i, j));
      return something_changed;
    }
}
  
/* Output a 'call' insn that is a reference in memory. */

char *
output_call_mem (operands)
     rtx *operands;
{
  operands[0] = copy_rtx (operands[0]); /* Be ultra careful */
  /* Handle calls using lr by using ip (which may be clobbered in subr anyway).
   */
  if (eliminate_lr2ip (&operands[0]))
    output_asm_insn ("mov%?\t%|ip, %|lr", operands);

  output_asm_insn ("mov%?\t%|lr, %|pc", operands);
  output_asm_insn ("ldr%?\t%|pc, %0", operands);
  return "";
}


/* Output a move from arm registers to an fpu registers.
   OPERANDS[0] is an fpu register.
   OPERANDS[1] is the first registers of an arm register pair.  */

char *
output_mov_long_double_fpu_from_arm (operands)
     rtx *operands;
{
  int arm_reg0 = REGNO (operands[1]);
  rtx ops[3];

  if (arm_reg0 == 12)
    abort();

  ops[0] = gen_rtx (REG, SImode, arm_reg0);
  ops[1] = gen_rtx (REG, SImode, 1 + arm_reg0);
  ops[2] = gen_rtx (REG, SImode, 2 + arm_reg0);
  
  output_asm_insn ("stm%?fd\t%|sp!, {%0, %1, %2}", ops);
  output_asm_insn ("ldf%?e\t%0, [%|sp], #12", operands);
  return "";
}

/* Output a move from an fpu register to arm registers.
   OPERANDS[0] is the first registers of an arm register pair.
   OPERANDS[1] is an fpu register.  */

char *
output_mov_long_double_arm_from_fpu (operands)
     rtx *operands;
{
  int arm_reg0 = REGNO (operands[0]);
  rtx ops[3];

  if (arm_reg0 == 12)
    abort();

  ops[0] = gen_rtx (REG, SImode, arm_reg0);
  ops[1] = gen_rtx (REG, SImode, 1 + arm_reg0);
  ops[2] = gen_rtx (REG, SImode, 2 + arm_reg0);

  output_asm_insn ("stf%?e\t%1, [%|sp, #-12]!", operands);
  output_asm_insn ("ldm%?fd\t%|sp!, {%0, %1, %2}", ops);
  return "";
}

/* Output a move from arm registers to arm registers of a long double
   OPERANDS[0] is the destination.
   OPERANDS[1] is the source.  */
char *
output_mov_long_double_arm_from_arm (operands)
     rtx *operands;
{
  /* We have to be careful here because the two might overlap */
  int dest_start = REGNO (operands[0]);
  int src_start = REGNO (operands[1]);
  rtx ops[2];
  int i;

  if (dest_start < src_start)
    {
      for (i = 0; i < 3; i++)
        {
          ops[0] = gen_rtx (REG, SImode, dest_start + i);
          ops[1] = gen_rtx (REG, SImode, src_start + i);
          output_asm_insn ("mov%?\t%0, %1", ops);
        }
    }
  else
    {
      for (i = 2; i >= 0; i--)
        {
          ops[0] = gen_rtx (REG, SImode, dest_start + i);
          ops[1] = gen_rtx (REG, SImode, src_start + i);
          output_asm_insn ("mov%?\t%0, %1", ops);
        }
    }

  return "";
}


/* Output a move from arm registers to an fpu registers.
   OPERANDS[0] is an fpu register.
   OPERANDS[1] is the first registers of an arm register pair.  */

char *
output_mov_double_fpu_from_arm (operands)
     rtx *operands;
{
  int arm_reg0 = REGNO (operands[1]);
  rtx ops[2];

  if (arm_reg0 == 12)
    abort();
  ops[0] = gen_rtx (REG, SImode, arm_reg0);
  ops[1] = gen_rtx (REG, SImode, 1 + arm_reg0);
  output_asm_insn ("stm%?fd\t%|sp!, {%0, %1}", ops);
  output_asm_insn ("ldf%?d\t%0, [%|sp], #8", operands);
  return "";
}

/* Output a move from an fpu register to arm registers.
   OPERANDS[0] is the first registers of an arm register pair.
   OPERANDS[1] is an fpu register.  */

char *
output_mov_double_arm_from_fpu (operands)
     rtx *operands;
{
  int arm_reg0 = REGNO (operands[0]);
  rtx ops[2];

  if (arm_reg0 == 12)
    abort();

  ops[0] = gen_rtx (REG, SImode, arm_reg0);
  ops[1] = gen_rtx (REG, SImode, 1 + arm_reg0);
  output_asm_insn ("stf%?d\t%1, [%|sp, #-8]!", operands);
  output_asm_insn ("ldm%?fd\t%|sp!, {%0, %1}", ops);
  return "";
}

/* Output a move between double words.
   It must be REG<-REG, REG<-CONST_DOUBLE, REG<-CONST_INT, REG<-MEM
   or MEM<-REG and all MEMs must be offsettable addresses.  */

char *
output_move_double (operands)
     rtx *operands;
{
  enum rtx_code code0 = GET_CODE (operands[0]);
  enum rtx_code code1 = GET_CODE (operands[1]);
  rtx otherops[2];

  if (code0 == REG)
    {
      int reg0 = REGNO (operands[0]);

      otherops[0] = gen_rtx (REG, SImode, 1 + reg0);
      if (code1 == REG)
        {
          int reg1 = REGNO (operands[1]);
          if (reg1 == 12)
            abort();

          /* Ensure the second source is not overwritten */
          if (reg1 == reg0 + (WORDS_BIG_ENDIAN ? -1 : 1))
            output_asm_insn("mov%?\t%Q0, %Q1\n\tmov%?\t%R0, %R1", operands);
          else
            output_asm_insn("mov%?\t%R0, %R1\n\tmov%?\t%Q0, %Q1", operands);
        }
      else if (code1 == CONST_DOUBLE)
        {
          if (GET_MODE (operands[1]) == DFmode)
            {
              long l[2];
              union real_extract u;

              bcopy ((char *) &CONST_DOUBLE_LOW (operands[1]), (char *) &u,
                     sizeof (u));
              REAL_VALUE_TO_TARGET_DOUBLE (u.d, l);
              otherops[1] = GEN_INT(l[1]);
              operands[1] = GEN_INT(l[0]);
            }
          else if (GET_MODE (operands[1]) != VOIDmode)
            abort ();
          else if (WORDS_BIG_ENDIAN)
            {
              
              otherops[1] = GEN_INT (CONST_DOUBLE_LOW (operands[1]));
              operands[1] = GEN_INT (CONST_DOUBLE_HIGH (operands[1]));
            }
          else
            {
              
              otherops[1] = GEN_INT (CONST_DOUBLE_HIGH (operands[1]));
              operands[1] = GEN_INT (CONST_DOUBLE_LOW (operands[1]));
            }
          output_mov_immediate (operands);
          output_mov_immediate (otherops);
        }
      else if (code1 == CONST_INT)
        {
          /* sign extend the intval into the high-order word */
          if (WORDS_BIG_ENDIAN)
            {
              otherops[1] = operands[1];
              operands[1] = (INTVAL (operands[1]) < 0
                             ? constm1_rtx : const0_rtx);
            }
          else
            otherops[1] = INTVAL (operands[1]) < 0 ? constm1_rtx : const0_rtx;
          output_mov_immediate (otherops);
          output_mov_immediate (operands);
        }
      else if (code1 == MEM)
        {
          switch (GET_CODE (XEXP (operands[1], 0)))
            {
            case REG:
              output_asm_insn ("ldm%?ia\t%m1, %M0", operands);
              break;

            case PRE_INC:
              abort (); /* Should never happen now */
              break;

            case PRE_DEC:
              output_asm_insn ("ldm%?db\t%m1!, %M0", operands);
              break;

            case POST_INC:
              output_asm_insn ("ldm%?ia\t%m1!, %M0", operands);
              break;

            case POST_DEC:
              abort (); /* Should never happen now */
              break;

            case LABEL_REF:
            case CONST:
              output_asm_insn ("adr%?\t%0, %1", operands);
              output_asm_insn ("ldm%?ia\t%0, %M0", operands);
              break;

            default:
              if (arm_add_operand (XEXP (XEXP (operands[1], 0), 1)))
                {
                  otherops[0] = operands[0];
                  otherops[1] = XEXP (XEXP (operands[1], 0), 0);
                  otherops[2] = XEXP (XEXP (operands[1], 0), 1);
                  if (GET_CODE (XEXP (operands[1], 0)) == PLUS)
                    {
                      if (GET_CODE (otherops[2]) == CONST_INT)
                        {
                          switch (INTVAL (otherops[2]))
                            {
                            case -8:
                              output_asm_insn ("ldm%?db\t%1, %M0", otherops);
                              return "";
                            case -4:
                              output_asm_insn ("ldm%?da\t%1, %M0", otherops);
                              return "";
                            case 4:
                              output_asm_insn ("ldm%?ib\t%1, %M0", otherops);
                              return "";
                            }
                          if (!(const_ok_for_arm (INTVAL (otherops[2]))))
                            output_asm_insn ("sub%?\t%0, %1, #%n2", otherops);
                          else
                            output_asm_insn ("add%?\t%0, %1, %2", otherops);
                        }
                      else
                        output_asm_insn ("add%?\t%0, %1, %2", otherops);
                    }
                  else
                    output_asm_insn ("sub%?\t%0, %1, %2", otherops);
                  return "ldm%?ia\t%0, %M0";
                }
              else
                {
                  otherops[1] = adj_offsettable_operand (operands[1], 4);
                  /* Take care of overlapping base/data reg.  */
                  if (reg_mentioned_p (operands[0], operands[1]))
                    {
                      output_asm_insn ("ldr%?\t%0, %1", otherops);
                      output_asm_insn ("ldr%?\t%0, %1", operands);
                    }
                  else
                    {
                      output_asm_insn ("ldr%?\t%0, %1", operands);
                      output_asm_insn ("ldr%?\t%0, %1", otherops);
                    }
                }
            }
        }
      else
        abort();  /* Constraints should prevent this */
    }
  else if (code0 == MEM && code1 == REG)
    {
      if (REGNO (operands[1]) == 12)
        abort();

      switch (GET_CODE (XEXP (operands[0], 0)))
        {
        case REG:
          output_asm_insn ("stm%?ia\t%m0, %M1", operands);
          break;

        case PRE_INC:
          abort (); /* Should never happen now */
          break;

        case PRE_DEC:
          output_asm_insn ("stm%?db\t%m0!, %M1", operands);
          break;

        case POST_INC:
          output_asm_insn ("stm%?ia\t%m0!, %M1", operands);
          break;

        case POST_DEC:
          abort (); /* Should never happen now */
          break;

        case PLUS:
          if (GET_CODE (XEXP (XEXP (operands[0], 0), 1)) == CONST_INT)
            {
              switch (INTVAL (XEXP (XEXP (operands[0], 0), 1)))
                {
                case -8:
                  output_asm_insn ("stm%?db\t%m0, %M1", operands);
                  return "";

                case -4:
                  output_asm_insn ("stm%?da\t%m0, %M1", operands);
                  return "";

                case 4:
                  output_asm_insn ("stm%?ib\t%m0, %M1", operands);
                  return "";
                }
            }
          /* Fall through */

        default:
          otherops[0] = adj_offsettable_operand (operands[0], 4);
          otherops[1] = gen_rtx (REG, SImode, 1 + REGNO (operands[1]));
          output_asm_insn ("str%?\t%1, %0", operands);
          output_asm_insn ("str%?\t%1, %0", otherops);
        }
    }
  else
    abort();  /* Constraints should prevent this */

  return "";
}


/* Output an arbitrary MOV reg, #n.
   OPERANDS[0] is a register.  OPERANDS[1] is a const_int.  */

char *
output_mov_immediate (operands)
     rtx *operands;
{
  HOST_WIDE_INT n = INTVAL (operands[1]);
  int n_ones = 0;
  int i;

  /* Try to use one MOV */
  if (const_ok_for_arm (n))
    {
      output_asm_insn ("mov%?\t%0, %1", operands);
      return "";
    }

  /* Try to use one MVN */
  if (const_ok_for_arm (~n))
    {
      operands[1] = GEN_INT (~n);
      output_asm_insn ("mvn%?\t%0, %1", operands);
      return "";
    }

  /* If all else fails, make it out of ORRs or BICs as appropriate. */

  for (i=0; i < 32; i++)
    if (n & 1 << i)
      n_ones++;

  if (n_ones > 16)  /* Shorter to use MVN with BIC in this case. */
    output_multi_immediate(operands, "mvn%?\t%0, %1", "bic%?\t%0, %0, %1", 1,
                           ~n);
  else
    output_multi_immediate(operands, "mov%?\t%0, %1", "orr%?\t%0, %0, %1", 1,
                           n);

  return "";
}


/* Output an ADD r, s, #n where n may be too big for one instruction.  If
   adding zero to one register, output nothing.  */

char *
output_add_immediate (operands)
     rtx *operands;
{
  HOST_WIDE_INT n = INTVAL (operands[2]);

  if (n != 0 || REGNO (operands[0]) != REGNO (operands[1]))
    {
      if (n < 0)
        output_multi_immediate (operands,
                                "sub%?\t%0, %1, %2", "sub%?\t%0, %0, %2", 2,
                                -n);
      else
        output_multi_immediate (operands,
                                "add%?\t%0, %1, %2", "add%?\t%0, %0, %2", 2,
                                n);
    }

  return "";
}

/* Output a multiple immediate operation.
   OPERANDS is the vector of operands referred to in the output patterns.
   INSTR1 is the output pattern to use for the first constant.
   INSTR2 is the output pattern to use for subsequent constants.
   IMMED_OP is the index of the constant slot in OPERANDS.
   N is the constant value.  */

char *
output_multi_immediate (operands, instr1, instr2, immed_op, n)
     rtx *operands;
     char *instr1, *instr2;
     int immed_op;
     HOST_WIDE_INT n;
{
#if HOST_BITS_PER_WIDE_INT > 32
  n &= 0xffffffff;
#endif

  if (n == 0)
    {
      operands[immed_op] = const0_rtx;
      output_asm_insn (instr1, operands); /* Quick and easy output */
    }
  else
    {
      int i;
      char *instr = instr1;

      /* Note that n is never zero here (which would give no output) */
      for (i = 0; i < 32; i += 2)
        {
          if (n & (3 << i))
            {
              operands[immed_op] = GEN_INT (n & (255 << i));
              output_asm_insn (instr, operands);
              instr = instr2;
              i += 6;
            }
        }
    }
  return "";
}


/* Return the appropriate ARM instruction for the operation code.
   The returned result should not be overwritten.  OP is the rtx of the
   operation.  SHIFT_FIRST_ARG is TRUE if the first argument of the operator
   was shifted.  */

char *
arithmetic_instr (op, shift_first_arg)
     rtx op;
     int shift_first_arg;
{
  switch (GET_CODE (op))
    {
    case PLUS:
      return "add";

    case MINUS:
      return shift_first_arg ? "rsb" : "sub";

    case IOR:
      return "orr";

    case XOR:
      return "eor";

    case AND:
      return "and";

    default:
      abort ();
    }
}


/* Ensure valid constant shifts and return the appropriate shift mnemonic
   for the operation code.  The returned result should not be overwritten.
   OP is the rtx code of the shift.
   On exit, *AMOUNTP will be -1 if the shift is by a register, or a constant
   shift. */

static char *
shift_op (op, amountp)
     rtx op;
     HOST_WIDE_INT *amountp;
{
  char *mnem;
  enum rtx_code code = GET_CODE (op);

  if (GET_CODE (XEXP (op, 1)) == REG || GET_CODE (XEXP (op, 1)) == SUBREG)
    *amountp = -1;
  else if (GET_CODE (XEXP (op, 1)) == CONST_INT)
    *amountp = INTVAL (XEXP (op, 1));
  else
    abort ();

  switch (code)
    {
    case ASHIFT:
      mnem = "asl";
      break;

    case ASHIFTRT:
      mnem = "asr";
      break;

    case LSHIFTRT:
      mnem = "lsr";
      break;

    case ROTATERT:
      mnem = "ror";
      break;

    case MULT:
      /* We never have to worry about the amount being other than a
         power of 2, since this case can never be reloaded from a reg.  */
      if (*amountp != -1)
        *amountp = int_log2 (*amountp);
      else
        abort ();
      return "asl";

    default:
      abort ();
    }

  if (*amountp != -1)
    {
      /* This is not 100% correct, but follows from the desire to merge
         multiplication by a power of 2 with the recognizer for a
         shift.  >=32 is not a valid shift for "asl", so we must try and
         output a shift that produces the correct arithmetical result.
         Using lsr #32 is identical except for the fact that the carry bit
         is not set correctly if we set the flags; but we never use the 
         carry bit from such an operation, so we can ignore that.  */
      if (code == ROTATERT)
        *amountp &= 31;         /* Rotate is just modulo 32 */
      else if (*amountp != (*amountp & 31))
        {
          if (code == ASHIFT)
            mnem = "lsr";
          *amountp = 32;
        }

      /* Shifts of 0 are no-ops.  */
      if (*amountp == 0)
        return NULL;
    }     

  return mnem;
}


/* Obtain the shift from the POWER of two. */

HOST_WIDE_INT
int_log2 (power)
     HOST_WIDE_INT power;
{
  HOST_WIDE_INT shift = 0;

  while (((((HOST_WIDE_INT) 1) << shift) & power) == 0)
    {
      if (shift > 31)
        abort ();
      shift++;
    }

  return shift;
}

/* Output a .ascii pseudo-op, keeping track of lengths.  This is because
   /bin/as is horribly restrictive.  */

void
output_ascii_pseudo_op (stream, p, len)
     FILE *stream;
     unsigned char *p;
     int len;
{
  int i;
  int len_so_far = 1000;
  int chars_so_far = 0;

  for (i = 0; i < len; i++)
    {
      register int c = p[i];

      if (len_so_far > 50)
        {
          if (chars_so_far)
            fputs ("\"\n", stream);
          fputs ("\t.ascii\t\"", stream);
          len_so_far = 0;
          arm_increase_location (chars_so_far);
          chars_so_far = 0;
        }

      if (c == '\"' || c == '\\')
        {
          putc('\\', stream);
          len_so_far++;
        }

      if (c >= ' ' && c < 0177)
        {
          putc (c, stream);
          len_so_far++;
        }
      else
        {
          fprintf (stream, "\\%03o", c);
          len_so_far +=4;
        }

      chars_so_far++;
    }

  fputs ("\"\n", stream);
  arm_increase_location (chars_so_far);
}
\f

/* Try to determine whether a pattern really clobbers the link register.
   This information is useful when peepholing, so that lr need not be pushed
   if we combine a call followed by a return.
   NOTE: This code does not check for side-effect expressions in a SET_SRC:
   such a check should not be needed because these only update an existing
   value within a register; the register must still be set elsewhere within
   the function. */

static int
pattern_really_clobbers_lr (x)
     rtx x;
{
  int i;
  
  switch (GET_CODE (x))
    {
    case SET:
      switch (GET_CODE (SET_DEST (x)))
        {
        case REG:
          return REGNO (SET_DEST (x)) == 14;

        case SUBREG:
          if (GET_CODE (XEXP (SET_DEST (x), 0)) == REG)
            return REGNO (XEXP (SET_DEST (x), 0)) == 14;

          if (GET_CODE (XEXP (SET_DEST (x), 0)) == MEM)
            return 0;
          abort ();

        default:
          return 0;
        }

    case PARALLEL:
      for (i = 0; i < XVECLEN (x, 0); i++)
        if (pattern_really_clobbers_lr (XVECEXP (x, 0, i)))
          return 1;
      return 0;

    case CLOBBER:
      switch (GET_CODE (XEXP (x, 0)))
        {
        case REG:
          return REGNO (XEXP (x, 0)) == 14;

        case SUBREG:
          if (GET_CODE (XEXP (XEXP (x, 0), 0)) == REG)
            return REGNO (XEXP (XEXP (x, 0), 0)) == 14;
          abort ();

        default:
          return 0;
        }

    case UNSPEC:
      return 1;

    default:
      return 0;
    }
}

static int
function_really_clobbers_lr (first)
     rtx first;
{
  rtx insn, next;
  
  for (insn = first; insn; insn = next_nonnote_insn (insn))
    {
      switch (GET_CODE (insn))
        {
        case BARRIER:
        case NOTE:
        case CODE_LABEL:
        case JUMP_INSN:         /* Jump insns only change the PC (and conds) */
        case INLINE_HEADER:
          break;

        case INSN:
          if (pattern_really_clobbers_lr (PATTERN (insn)))
            return 1;
          break;

        case CALL_INSN:
          /* Don't yet know how to handle those calls that are not to a 
             SYMBOL_REF */
          if (GET_CODE (PATTERN (insn)) != PARALLEL)
            abort ();

          switch (GET_CODE (XVECEXP (PATTERN (insn), 0, 0)))
            {
            case CALL:
              if (GET_CODE (XEXP (XEXP (XVECEXP (PATTERN (insn), 0, 0), 0), 0))
                  != SYMBOL_REF)
                return 1;
              break;

            case SET:
              if (GET_CODE (XEXP (XEXP (SET_SRC (XVECEXP (PATTERN (insn),
                                                          0, 0)), 0), 0))
                  != SYMBOL_REF)
                return 1;
              break;

            default:    /* Don't recognize it, be safe */
              return 1;
            }

          /* A call can be made (by peepholing) not to clobber lr iff it is
             followed by a return.  There may, however, be a use insn iff
             we are returning the result of the call. 
             If we run off the end of the insn chain, then that means the
             call was at the end of the function.  Unfortunately we don't
             have a return insn for the peephole to recognize, so we
             must reject this.  (Can this be fixed by adding our own insn?) */
          if ((next = next_nonnote_insn (insn)) == NULL)
            return 1;

          if (GET_CODE (next) == INSN && GET_CODE (PATTERN (next)) == USE
              && (GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
              && (REGNO (SET_DEST (XVECEXP (PATTERN (insn), 0, 0)))
                  == REGNO (XEXP (PATTERN (next), 0))))
            if ((next = next_nonnote_insn (next)) == NULL)
              return 1;

          if (GET_CODE (next) == JUMP_INSN
              && GET_CODE (PATTERN (next)) == RETURN)
            break;
          return 1;

        default:
          abort ();
        }
    }

  /* We have reached the end of the chain so lr was _not_ clobbered */
  return 0;
}

char *
output_return_instruction (operand, really_return, reverse)
     rtx operand;
     int really_return;
     int reverse;
{
  char instr[100];
  int reg, live_regs = 0;
  int volatile_func = (optimize > 0 
                       && TREE_THIS_VOLATILE (current_function_decl));

  return_used_this_function = 1;

  if (volatile_func)
    {
      rtx ops[2];
      /* If this function was declared non-returning, and we have found a tail 
         call, then we have to trust that the called function won't return. */
      if (! really_return)
        return "";

      /* Otherwise, trap an attempted return by aborting. */
      ops[0] = operand;
      ops[1] = gen_rtx (SYMBOL_REF, Pmode, "abort");
      assemble_external_libcall (ops[1]);
      output_asm_insn (reverse ? "bl%D0\t%a1" : "bl%d0\t%a1", ops);
      return "";
    }
      
  if (current_function_calls_alloca && ! really_return)
    abort();
    
  for (reg = 0; reg <= 10; reg++)
    if (regs_ever_live[reg] && ! call_used_regs[reg])
      live_regs++;

  if (live_regs || (regs_ever_live[14] && ! lr_save_eliminated))
    live_regs++;

  if (frame_pointer_needed)
    live_regs += 4;

  if (live_regs)
    {
      if (lr_save_eliminated || ! regs_ever_live[14])
        live_regs++;

      if (frame_pointer_needed)
        strcpy (instr,
                reverse ? "ldm%?%D0ea\t%|fp, {" : "ldm%?%d0ea\t%|fp, {");
      else
        strcpy (instr, 
                reverse ? "ldm%?%D0fd\t%|sp!, {" : "ldm%?%d0fd\t%|sp!, {");

      for (reg = 0; reg <= 10; reg++)
        if (regs_ever_live[reg] && ! call_used_regs[reg])
          {
            strcat (instr, "%|");
            strcat (instr, reg_names[reg]);
            if (--live_regs)
              strcat (instr, ", ");
          }

      if (frame_pointer_needed)
        {
          strcat (instr, "%|");
          strcat (instr, reg_names[11]);
          strcat (instr, ", ");
          strcat (instr, "%|");
          strcat (instr, reg_names[13]);
          strcat (instr, ", ");
          strcat (instr, "%|");
          strcat (instr, really_return ? reg_names[15] : reg_names[14]);
        }
      else
        {
          strcat (instr, "%|");
          strcat (instr, really_return ? reg_names[15] : reg_names[14]);
        }
      strcat (instr, (TARGET_APCS_32 || !really_return) ? "}" : "}^");
      output_asm_insn (instr, &operand);
    }
  else if (really_return)
    {
      sprintf (instr, "mov%%?%%%s0%s\t%%|pc, %%|lr",
               reverse ? "D" : "d", TARGET_APCS_32 ? "" : "s");
      output_asm_insn (instr, &operand);
    }

  return "";
}

/* Return nonzero if optimizing and the current function is volatile.
   Such functions never return, and many memory cycles can be saved
   by not storing register values that will never be needed again.
   This optimization was added to speed up context switching in a
   kernel application. */

int
arm_volatile_func ()
{
  return (optimize > 0 && TREE_THIS_VOLATILE (current_function_decl));
}

/* Return the size of the prologue.  It's not too bad if we slightly 
   over-estimate.  */

static int
get_prologue_size ()
{
  return profile_flag ? 12 : 0;
}

/* The amount of stack adjustment that happens here, in output_return and in
   output_epilogue must be exactly the same as was calculated during reload,
   or things will point to the wrong place.  The only time we can safely
   ignore this constraint is when a function has no arguments on the stack,
   no stack frame requirement and no live registers execpt for `lr'.  If we
   can guarantee that by making all function calls into tail calls and that
   lr is not clobbered in any other way, then there is no need to push lr
   onto the stack. */
   
void
output_func_prologue (f, frame_size)
     FILE *f;
     int frame_size;
{
  int reg, live_regs_mask = 0;
  rtx operands[3];
  int volatile_func = (optimize > 0
                       && TREE_THIS_VOLATILE (current_function_decl));

  /* Nonzero if we must stuff some register arguments onto the stack as if
     they were passed there.  */
  int store_arg_regs = 0;

  if (arm_ccfsm_state || arm_target_insn)
    abort ();                                   /* Sanity check */

  if (arm_naked_function_p (current_function_decl))
    return;

  return_used_this_function = 0;
  lr_save_eliminated = 0;
  
  fprintf (f, "\t%s args = %d, pretend = %d, frame = %d\n",
           ASM_COMMENT_START, current_function_args_size,
           current_function_pretend_args_size, frame_size);
  fprintf (f, "\t%s frame_needed = %d, current_function_anonymous_args = %d\n",
           ASM_COMMENT_START, frame_pointer_needed,
           current_function_anonymous_args);

  if (volatile_func)
    fprintf (f, "\t%s Volatile function.\n", ASM_COMMENT_START);

  if (current_function_anonymous_args && current_function_pretend_args_size)
    store_arg_regs = 1;

  for (reg = 0; reg <= 10; reg++)
    if (regs_ever_live[reg] && ! call_used_regs[reg])
      live_regs_mask |= (1 << reg);

  if (frame_pointer_needed)
    live_regs_mask |= 0xD800;
  else if (regs_ever_live[14])
    {
      if (! current_function_args_size
          && ! function_really_clobbers_lr (get_insns ()))
        lr_save_eliminated = 1;
      else
        live_regs_mask |= 0x4000;
    }

  if (live_regs_mask)
    {
      /* if a di mode load/store multiple is used, and the base register
         is r3, then r4 can become an ever live register without lr
         doing so,  in this case we need to push lr as well, or we
         will fail to get a proper return. */

      live_regs_mask |= 0x4000;
      lr_save_eliminated = 0;

    }

  if (lr_save_eliminated)
    fprintf (f,"\t%s I don't think this function clobbers lr\n",
             ASM_COMMENT_START);
}


void
output_func_epilogue (f, frame_size)
     FILE *f;
     int frame_size;
{
  int reg, live_regs_mask = 0, code_size = 0;
  /* If we need this then it will always be at lesat this much */
  int floats_offset = 24;
  rtx operands[3];
  int volatile_func = (optimize > 0
                       && TREE_THIS_VOLATILE (current_function_decl));

  if (use_return_insn() && return_used_this_function)
    {
      if (frame_size && !(frame_pointer_needed || TARGET_APCS))
        {
          abort ();
        }
      goto epilogue_done;
    }

  /* Naked functions don't have epilogues.  */
  if (arm_naked_function_p (current_function_decl))
    goto epilogue_done;

  /* A volatile function should never return.  Call abort.  */
  if (volatile_func)
    {
      rtx op = gen_rtx (SYMBOL_REF, Pmode, "abort");
      assemble_external_libcall (op);
      output_asm_insn ("bl\t%a0", &op);
      code_size = 4;
      goto epilogue_done;
    }

  for (reg = 0; reg <= 10; reg++)
    if (regs_ever_live[reg] && ! call_used_regs[reg])
      {
        live_regs_mask |= (1 << reg);
        floats_offset += 4;
      }

  if (frame_pointer_needed)
    {
      for (reg = 23; reg > 15; reg--)
        if (regs_ever_live[reg] && ! call_used_regs[reg])
          {
            fprintf (f, "\tldfe\t%s%s, [%sfp, #-%d]\n", REGISTER_PREFIX,
                     reg_names[reg], REGISTER_PREFIX, floats_offset);
            floats_offset += 12;
            code_size += 4;
          }

      live_regs_mask |= 0xA800;
      print_multi_reg (f, "ldmea\t%sfp", live_regs_mask,
                       TARGET_APCS_32 ? FALSE : TRUE);
      code_size += 4;
    }
  else
    {
      /* Restore stack pointer if necessary.  */
      if (frame_size)
        {
          operands[0] = operands[1] = stack_pointer_rtx;
          operands[2] = gen_rtx (CONST_INT, VOIDmode, frame_size);
          output_add_immediate (operands);
        }

      for (reg = 16; reg < 24; reg++)
        if (regs_ever_live[reg] && ! call_used_regs[reg])
          {
            fprintf (f, "\tldfe\t%s%s, [%ssp], #12\n", REGISTER_PREFIX,
                     reg_names[reg], REGISTER_PREFIX);
            code_size += 4;
          }
      if (current_function_pretend_args_size == 0 && regs_ever_live[14])
        {
          print_multi_reg (f, "ldmfd\t%ssp!", live_regs_mask | 0x8000,
                           TARGET_APCS_32 ? FALSE : TRUE);
          code_size += 4;
        }
      else
        {
          if (live_regs_mask || regs_ever_live[14])
            {
              live_regs_mask |= 0x4000;
              print_multi_reg (f, "ldmfd\t%ssp!", live_regs_mask, FALSE);
              code_size += 4;
            }
          if (current_function_pretend_args_size)
            {
              operands[0] = operands[1] = stack_pointer_rtx;
              operands[2] = gen_rtx (CONST_INT, VOIDmode,
                                     current_function_pretend_args_size);
              output_add_immediate (operands);
            }
          fprintf (f, (TARGET_APCS_32 ? "\tmov\t%spc, %slr\n"
                       : "\tmovs\t%spc, %slr\n"),
                   REGISTER_PREFIX, REGISTER_PREFIX, f);
          code_size += 4;
        }
    }

 epilogue_done:

  /* insn_addresses isn't allocated when not optimizing */
  /* ??? The previous comment is incorrect.  Clarify.  */

  if (optimize > 0)
    arm_increase_location (code_size
                           + insn_addresses[INSN_UID (get_last_insn ())]
                           + get_prologue_size ());

  current_function_anonymous_args = 0;
}

static void
emit_multi_reg_push (mask)
     int mask;
{
  int num_regs = 0;
  int i, j;
  rtx par;

  for (i = 0; i < 16; i++)
    if (mask & (1 << i))
      num_regs++;

  if (num_regs == 0 || num_regs > 16)
    abort ();

  par = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num_regs));

  for (i = 0; i < 16; i++)
    {
      if (mask & (1 << i))
        {
          XVECEXP (par, 0, 0)
            = gen_rtx (SET, VOIDmode, gen_rtx (MEM, BLKmode,
                                               gen_rtx (PRE_DEC, BLKmode,
                                                        stack_pointer_rtx)),
                       gen_rtx (UNSPEC, BLKmode,
                                gen_rtvec (1, gen_rtx (REG, SImode, i)),
                                2));
          break;
        }
    }

  for (j = 1, i++; j < num_regs; i++)
    {
      if (mask & (1 << i))
        {
          XVECEXP (par, 0, j)
            = gen_rtx (USE, VOIDmode, gen_rtx (REG, SImode, i));
          j++;
        }
    }
  emit_insn (par);
}

void
arm_expand_prologue ()
{
  int reg;
  rtx amount = GEN_INT (- get_frame_size ());
  rtx push_insn;
  int num_regs;
  int live_regs_mask = 0;
  int store_arg_regs = 0;
  int volatile_func = (optimize > 0
                       && TREE_THIS_VOLATILE (current_function_decl));

  /* Naked functions don't have prologues.  */
  if (arm_naked_function_p (current_function_decl))
    return;

  if (current_function_anonymous_args && current_function_pretend_args_size)
    store_arg_regs = 1;

  if (! volatile_func)
    for (reg = 0; reg <= 10; reg++)
      if (regs_ever_live[reg] && ! call_used_regs[reg])
        live_regs_mask |= 1 << reg;

  if (! volatile_func && regs_ever_live[14])
    live_regs_mask |= 0x4000;

  if (frame_pointer_needed)
    {
      live_regs_mask |= 0xD800;
      emit_insn (gen_movsi (gen_rtx (REG, SImode, 12),
                            stack_pointer_rtx));
    }

  if (current_function_pretend_args_size)
    {
      if (store_arg_regs)
        emit_multi_reg_push ((0xf0 >> (current_function_pretend_args_size / 4))
                             & 0xf);
      else
        emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx, 
                               GEN_INT (-current_function_pretend_args_size)));
    }

  if (live_regs_mask)
    {
      /* If we have to push any regs, then we must push lr as well, or
         we won't get a proper return.  */
      live_regs_mask |= 0x4000;
      emit_multi_reg_push (live_regs_mask);
    }
      
  /* For now the integer regs are still pushed in output_func_epilogue ().  */

  if (! volatile_func)
    for (reg = 23; reg > 15; reg--)
      if (regs_ever_live[reg] && ! call_used_regs[reg])
        emit_insn (gen_rtx (SET, VOIDmode, 
                            gen_rtx (MEM, XFmode, 
                                     gen_rtx (PRE_DEC, XFmode,
                                              stack_pointer_rtx)),
                            gen_rtx (REG, XFmode, reg)));

  if (frame_pointer_needed)
    emit_insn (gen_addsi3 (hard_frame_pointer_rtx, gen_rtx (REG, SImode, 12),
                           (GEN_INT
                            (-(4 + current_function_pretend_args_size)))));

  if (amount != const0_rtx)
    {
      emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx, amount));
      emit_insn (gen_rtx (CLOBBER, VOIDmode, 
                          gen_rtx (MEM, BLKmode, stack_pointer_rtx)));
    }

  /* If we are profiling, make sure no instructions are scheduled before
     the call to mcount.  */
  if (profile_flag || profile_block_flag)
    emit_insn (gen_blockage ());
}
  
\f
/* If CODE is 'd', then the X is a condition operand and the instruction
   should only be executed if the condition is true.
   if CODE is 'D', then the X is a condition operand and the instruction
   should only be executed if the condition is false: however, if the mode
   of the comparison is CCFPEmode, then always execute the instruction -- we
   do this because in these circumstances !GE does not necessarily imply LT;
   in these cases the instruction pattern will take care to make sure that
   an instruction containing %d will follow, thereby undoing the effects of
   doing this instruction unconditionally.
   If CODE is 'N' then X is a floating point operand that must be negated
   before output.
   If CODE is 'B' then output a bitwise inverted value of X (a const int).
   If X is a REG and CODE is `M', output a ldm/stm style multi-reg.  */

void
arm_print_operand (stream, x, code)
     FILE *stream;
     rtx x;
     int code;
{
  switch (code)
    {
    case '@':
      fputs (ASM_COMMENT_START, stream);
      return;

    case '|':
      fputs (REGISTER_PREFIX, stream);
      return;

    case '?':
      if (arm_ccfsm_state == 3 || arm_ccfsm_state == 4)
        fputs (arm_condition_codes[arm_current_cc], stream);
      return;

    case 'N':
      {
        REAL_VALUE_TYPE r;
        REAL_VALUE_FROM_CONST_DOUBLE (r, x);
        r = REAL_VALUE_NEGATE (r);
        fprintf (stream, "%s", fp_const_from_val (&r));
      }
      return;

    case 'B':
      if (GET_CODE (x) == CONST_INT)
        fprintf (stream,
#if HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_INT
                 "%d",
#else
                 "%ld",
#endif
                 ARM_SIGN_EXTEND (~ INTVAL (x)));
      else
        {
          putc ('~', stream);
          output_addr_const (stream, x);
        }
      return;

    case 'i':
      fprintf (stream, "%s", arithmetic_instr (x, 1));
      return;

    case 'I':
      fprintf (stream, "%s", arithmetic_instr (x, 0));
      return;

    case 'S':
      {
        HOST_WIDE_INT val;
        char *shift = shift_op (x, &val);

        if (shift)
          {
            fprintf (stream, ", %s ", shift_op (x, &val));
            if (val == -1)
              arm_print_operand (stream, XEXP (x, 1), 0);
            else
              fprintf (stream,
#if HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_INT
                       "#%d",
#else
                       "#%ld",
#endif
                       val);
          }
      }
      return;

    case 'Q':
      if (REGNO (x) > 15)
        abort ();
      fputs (REGISTER_PREFIX, stream);
      fputs (reg_names[REGNO (x) + (WORDS_BIG_ENDIAN ? 1 : 0)], stream);
      return;

    case 'R':
      if (REGNO (x) > 15)
        abort ();
      fputs (REGISTER_PREFIX, stream);
      fputs (reg_names[REGNO (x) + (WORDS_BIG_ENDIAN ? 0 : 1)], stream);
      return;

    case 'm':
      fputs (REGISTER_PREFIX, stream);
      if (GET_CODE (XEXP (x, 0)) == REG)
        fputs (reg_names[REGNO (XEXP (x, 0))], stream);
      else
        fputs (reg_names[REGNO (XEXP (XEXP (x, 0), 0))], stream);
      return;

    case 'M':
      fprintf (stream, "{%s%s-%s%s}", REGISTER_PREFIX, reg_names[REGNO (x)],
               REGISTER_PREFIX, reg_names[REGNO (x) - 1
                                         + ((GET_MODE_SIZE (GET_MODE (x))
                                             + GET_MODE_SIZE (SImode) - 1)
                                            / GET_MODE_SIZE (SImode))]);
      return;

    case 'd':
      if (x)
        fputs (arm_condition_codes[get_arm_condition_code (x)],
               stream);
      return;

    case 'D':
      if (x)
        fputs (arm_condition_codes[ARM_INVERSE_CONDITION_CODE
                                   (get_arm_condition_code (x))],
               stream);
      return;

    default:
      if (x == 0)
        abort ();

      if (GET_CODE (x) == REG)
        {
          fputs (REGISTER_PREFIX, stream);
          fputs (reg_names[REGNO (x)], stream);
        }
      else if (GET_CODE (x) == MEM)
        {
          output_memory_reference_mode = GET_MODE (x);
          output_address (XEXP (x, 0));
        }
      else if (GET_CODE (x) == CONST_DOUBLE)
        fprintf (stream, "#%s", fp_immediate_constant (x));
      else if (GET_CODE (x) == NEG)
        abort (); /* This should never happen now. */
      else
        {
          fputc ('#', stream);
          output_addr_const (stream, x);
        }
    }
}

/* Increase the `arm_text_location' by AMOUNT if we're in the text
   segment.  */

void
arm_increase_location (amount)
     int amount;
{
  if (in_text_section ())
    arm_text_location += amount;
}


/* Output a label definition.  If this label is within the .text segment, it
   is stored in OFFSET_TABLE, to be used when building `llc' instructions.
   Maybe GCC remembers names not starting with a `*' for a long time, but this
   is a minority anyway, so we just make a copy.  Do not store the leading `*'
   if the name starts with one.  */

void
arm_asm_output_label (stream, name)
     FILE *stream;
     char *name;
{
  char *real_name, *s;
  struct label_offset *cur;
  int hash = 0;

  ARM_OUTPUT_LABEL (stream, name);
  if (! in_text_section ())
    return;

  if (name[0] == '*')
    {
      real_name = xmalloc (1 + strlen (&name[1]));
      strcpy (real_name, &name[1]);
    }
  else
    {
      real_name = xmalloc (2 + strlen (name));
      strcpy (real_name, USER_LABEL_PREFIX);
      strcat (real_name, name);
    }
  for (s = real_name; *s; s++)
    hash += *s;

  hash = hash % LABEL_HASH_SIZE;
  cur = (struct label_offset *) xmalloc (sizeof (struct label_offset));
  cur->name = real_name;
  cur->offset = arm_text_location;
  cur->cdr = offset_table[hash];
  offset_table[hash] = cur;
}

/* Output code resembling an .lcomm directive.  /bin/as doesn't have this
   directive hence this hack, which works by reserving some `.space' in the
   bss segment directly.

   XXX This is a severe hack, which is guaranteed NOT to work since it doesn't
   define STATIC COMMON space but merely STATIC BSS space.  */

void
output_lcomm_directive (stream, name, size, align)
     FILE *stream;
     char *name;
     int size, align;
{
  bss_section ();
  ASM_OUTPUT_ALIGN (stream, floor_log2 (align / BITS_PER_UNIT));
  ARM_OUTPUT_LABEL (stream, name);
  fprintf (stream, "\t.space\t%d\n", size);
}
\f
/* A finite state machine takes care of noticing whether or not instructions
   can be conditionally executed, and thus decrease execution time and code
   size by deleting branch instructions.  The fsm is controlled by
   final_prescan_insn, and controls the actions of ASM_OUTPUT_OPCODE.  */

/* The state of the fsm controlling condition codes are:
   0: normal, do nothing special
   1: make ASM_OUTPUT_OPCODE not output this instruction
   2: make ASM_OUTPUT_OPCODE not output this instruction
   3: make instructions conditional
   4: make instructions conditional

   State transitions (state->state by whom under condition):
   0 -> 1 final_prescan_insn if the `target' is a label
   0 -> 2 final_prescan_insn if the `target' is an unconditional branch
   1 -> 3 ASM_OUTPUT_OPCODE after not having output the conditional branch
   2 -> 4 ASM_OUTPUT_OPCODE after not having output the conditional branch
   3 -> 0 ASM_OUTPUT_INTERNAL_LABEL if the `target' label is reached
          (the target label has CODE_LABEL_NUMBER equal to arm_target_label).
   4 -> 0 final_prescan_insn if the `target' unconditional branch is reached
          (the target insn is arm_target_insn).

   If the jump clobbers the conditions then we use states 2 and 4.

   A similar thing can be done with conditional return insns.

   XXX In case the `target' is an unconditional branch, this conditionalising
   of the instructions always reduces code size, but not always execution
   time.  But then, I want to reduce the code size to somewhere near what
   /bin/cc produces.  */

/* Returns the index of the ARM condition code string in
   `arm_condition_codes'.  COMPARISON should be an rtx like
   `(eq (...) (...))'.  */

static enum arm_cond_code
get_arm_condition_code (comparison)
     rtx comparison;
{
  enum machine_mode mode = GET_MODE (XEXP (comparison, 0));
  register int code;
  register enum rtx_code comp_code = GET_CODE (comparison);

  if (GET_MODE_CLASS (mode) != MODE_CC)
    mode = SELECT_CC_MODE (comp_code, XEXP (comparison, 0),
                           XEXP (comparison, 1));

  switch (mode)
    {
    case CC_DNEmode: code = ARM_NE; goto dominance;
    case CC_DEQmode: code = ARM_EQ; goto dominance;
    case CC_DGEmode: code = ARM_GE; goto dominance;
    case CC_DGTmode: code = ARM_GT; goto dominance;
    case CC_DLEmode: code = ARM_LE; goto dominance;
    case CC_DLTmode: code = ARM_LT; goto dominance;
    case CC_DGEUmode: code = ARM_CS; goto dominance;
    case CC_DGTUmode: code = ARM_HI; goto dominance;
    case CC_DLEUmode: code = ARM_LS; goto dominance;
    case CC_DLTUmode: code = ARM_CC;

    dominance:
      if (comp_code != EQ && comp_code != NE)
        abort ();

      if (comp_code == EQ)
        return ARM_INVERSE_CONDITION_CODE (code);
      return code;

    case CC_NOOVmode:
      switch (comp_code)
        {
        case NE: return ARM_NE;
        case EQ: return ARM_EQ;
        case GE: return ARM_PL;
        case LT: return ARM_MI;
        default: abort ();
        }

    case CC_Zmode:
    case CCFPmode:
      switch (comp_code)
        {
        case NE: return ARM_NE;
        case EQ: return ARM_EQ;
        default: abort ();
        }

    case CCFPEmode:
      switch (comp_code)
        {
        case GE: return ARM_GE;
        case GT: return ARM_GT;
        case LE: return ARM_LS;
        case LT: return ARM_MI;
        default: abort ();
        }

    case CC_SWPmode:
      switch (comp_code)
        {
        case NE: return ARM_NE;
        case EQ: return ARM_EQ;
        case GE: return ARM_LE;
        case GT: return ARM_LT;
        case LE: return ARM_GE;
        case LT: return ARM_GT;
        case GEU: return ARM_LS;
        case GTU: return ARM_CC;
        case LEU: return ARM_CS;
        case LTU: return ARM_HI;
        default: abort ();
        }

    case CC_Cmode:
      switch (comp_code)
      {
      case LTU: return ARM_CS;
      case GEU: return ARM_CC;
      default: abort ();
      }
      
    case CCmode:
      switch (comp_code)
        {
        case NE: return ARM_NE;
        case EQ: return ARM_EQ;
        case GE: return ARM_GE;
        case GT: return ARM_GT;
        case LE: return ARM_LE;
        case LT: return ARM_LT;
        case GEU: return ARM_CS;
        case GTU: return ARM_HI;
        case LEU: return ARM_LS;
        case LTU: return ARM_CC;
        default: abort ();
        }

    default: abort ();
    }

  abort ();
}


void
final_prescan_insn (insn, opvec, noperands)
     rtx insn;
     rtx *opvec;
     int noperands;
{
  /* BODY will hold the body of INSN.  */
  register rtx body = PATTERN (insn);

  /* This will be 1 if trying to repeat the trick, and things need to be
     reversed if it appears to fail.  */
  int reverse = 0;

  /* JUMP_CLOBBERS will be one implies that the conditions if a branch is
     taken are clobbered, even if the rtl suggests otherwise.  It also
     means that we have to grub around within the jump expression to find
     out what the conditions are when the jump isn't taken.  */
  int jump_clobbers = 0;
  
  /* If we start with a return insn, we only succeed if we find another one. */
  int seeking_return = 0;
  
  /* START_INSN will hold the insn from where we start looking.  This is the
     first insn after the following code_label if REVERSE is true.  */
  rtx start_insn = insn;

  /* If in state 4, check if the target branch is reached, in order to
     change back to state 0.  */
  if (arm_ccfsm_state == 4)
    {
      if (insn == arm_target_insn)
      {
        arm_target_insn = NULL;
        arm_ccfsm_state = 0;
      }
      return;
    }

  /* If in state 3, it is possible to repeat the trick, if this insn is an
     unconditional branch to a label, and immediately following this branch
     is the previous target label which is only used once, and the label this
     branch jumps to is not too far off.  */
  if (arm_ccfsm_state == 3)
    {
      if (simplejump_p (insn))
        {
          start_insn = next_nonnote_insn (start_insn);
          if (GET_CODE (start_insn) == BARRIER)
            {
              /* XXX Isn't this always a barrier?  */
              start_insn = next_nonnote_insn (start_insn);
            }
          if (GET_CODE (start_insn) == CODE_LABEL
              && CODE_LABEL_NUMBER (start_insn) == arm_target_label
              && LABEL_NUSES (start_insn) == 1)
            reverse = TRUE;
          else
            return;
        }
      else if (GET_CODE (body) == RETURN)
        {
          start_insn = next_nonnote_insn (start_insn);
          if (GET_CODE (start_insn) == BARRIER)
            start_insn = next_nonnote_insn (start_insn);
          if (GET_CODE (start_insn) == CODE_LABEL
              && CODE_LABEL_NUMBER (start_insn) == arm_target_label
              && LABEL_NUSES (start_insn) == 1)
            {
              reverse = TRUE;
              seeking_return = 1;
            }
          else
            return;
        }
      else
        return;
    }

  if (arm_ccfsm_state != 0 && !reverse)
    abort ();
  if (GET_CODE (insn) != JUMP_INSN)
    return;

  /* This jump might be paralleled with a clobber of the condition codes 
     the jump should always come first */
  if (GET_CODE (body) == PARALLEL && XVECLEN (body, 0) > 0)
    body = XVECEXP (body, 0, 0);

#if 0  
  /* If this is a conditional return then we don't want to know */
  if (GET_CODE (body) == SET && GET_CODE (SET_DEST (body)) == PC
      && GET_CODE (SET_SRC (body)) == IF_THEN_ELSE
      && (GET_CODE (XEXP (SET_SRC (body), 1)) == RETURN
          || GET_CODE (XEXP (SET_SRC (body), 2)) == RETURN))
    return;
#endif

  if (reverse
      || (GET_CODE (body) == SET && GET_CODE (SET_DEST (body)) == PC
          && GET_CODE (SET_SRC (body)) == IF_THEN_ELSE))
    {
      int insns_skipped;
      int fail = FALSE, succeed = FALSE;
      /* Flag which part of the IF_THEN_ELSE is the LABEL_REF.  */
      int then_not_else = TRUE;
      rtx this_insn = start_insn, label = 0;

      if (get_attr_conds (insn) == CONDS_JUMP_CLOB)
        {
          /* The code below is wrong for these, and I haven't time to
             fix it now.  So we just do the safe thing and return.  This
             whole function needs re-writing anyway.  */
          jump_clobbers = 1;
          return;
        }
      
      /* Register the insn jumped to.  */
      if (reverse)
        {
          if (!seeking_return)
            label = XEXP (SET_SRC (body), 0);
        }
      else if (GET_CODE (XEXP (SET_SRC (body), 1)) == LABEL_REF)
        label = XEXP (XEXP (SET_SRC (body), 1), 0);
      else if (GET_CODE (XEXP (SET_SRC (body), 2)) == LABEL_REF)
        {
          label = XEXP (XEXP (SET_SRC (body), 2), 0);
          then_not_else = FALSE;
        }
      else if (GET_CODE (XEXP (SET_SRC (body), 1)) == RETURN)
        seeking_return = 1;
      else if (GET_CODE (XEXP (SET_SRC (body), 2)) == RETURN)
        {
          seeking_return = 1;
          then_not_else = FALSE;
        }
      else
        abort ();

      /* See how many insns this branch skips, and what kind of insns.  If all
         insns are okay, and the label or unconditional branch to the same
         label is not too far away, succeed.  */
      for (insns_skipped = 0;
           !fail && !succeed && insns_skipped++ < MAX_INSNS_SKIPPED;)
        {
          rtx scanbody;

          this_insn = next_nonnote_insn (this_insn);
          if (!this_insn)
            break;

          scanbody = PATTERN (this_insn);

          switch (GET_CODE (this_insn))
            {
            case CODE_LABEL:
              /* Succeed if it is the target label, otherwise fail since
                 control falls in from somewhere else.  */
              if (this_insn == label)
                {
                  if (jump_clobbers)
                    {
                      arm_ccfsm_state = 2;
                      this_insn = next_nonnote_insn (this_insn);
                    }
                  else
                    arm_ccfsm_state = 1;
                  succeed = TRUE;
                }
              else
                fail = TRUE;
              break;

            case BARRIER:
              /* Succeed if the following insn is the target label.
                 Otherwise fail.  
                 If return insns are used then the last insn in a function 
                 will be a barrier. */
              this_insn = next_nonnote_insn (this_insn);
              if (this_insn && this_insn == label)
                {
                  if (jump_clobbers)
                    {
                      arm_ccfsm_state = 2;
                      this_insn = next_nonnote_insn (this_insn);
                    }
                  else
                    arm_ccfsm_state = 1;
                  succeed = TRUE;
                }
              else
                fail = TRUE;
              break;

            case CALL_INSN:
              /* If using 32-bit addresses the cc is not preserved over
                 calls */
              if (TARGET_APCS_32)
                {
                  /* Succeed if the following insn is the target label,
                     or if the following two insns are a barrier and
                     the target label.  */
                  this_insn = next_nonnote_insn (this_insn);
                  if (this_insn && GET_CODE (this_insn) == BARRIER)
                    this_insn = next_nonnote_insn (this_insn);

                  if (this_insn && this_insn == label
                      && insns_skipped < MAX_INSNS_SKIPPED)
                    {
                      if (jump_clobbers)
                        {
                          arm_ccfsm_state = 2;
                          this_insn = next_nonnote_insn (this_insn);
                        }
                      else
                        arm_ccfsm_state = 1;
                      succeed = TRUE;
                    }
                  else
                    fail = TRUE;
                }
              break;

            case JUMP_INSN:
              /* If this is an unconditional branch to the same label, succeed.
                 If it is to another label, do nothing.  If it is conditional,
                 fail.  */
              /* XXX Probably, the test for the SET and the PC are unnecessary. */

              if (GET_CODE (scanbody) == SET
                  && GET_CODE (SET_DEST (scanbody)) == PC)
                {
                  if (GET_CODE (SET_SRC (scanbody)) == LABEL_REF
                      && XEXP (SET_SRC (scanbody), 0) == label && !reverse)
                    {
                      arm_ccfsm_state = 2;
                      succeed = TRUE;
                    }
                  else if (GET_CODE (SET_SRC (scanbody)) == IF_THEN_ELSE)
                    fail = TRUE;
                }
              else if (GET_CODE (scanbody) == RETURN
                       && seeking_return)
                {
                  arm_ccfsm_state = 2;
                  succeed = TRUE;
                }
              else if (GET_CODE (scanbody) == PARALLEL)
                {
                  switch (get_attr_conds (this_insn))
                    {
                    case CONDS_NOCOND:
                      break;
                    default:
                      fail = TRUE;
                      break;
                    }
                }
              break;

            case INSN:
              /* Instructions using or affecting the condition codes make it
                 fail.  */
              if ((GET_CODE (scanbody) == SET
                   || GET_CODE (scanbody) == PARALLEL)
                  && get_attr_conds (this_insn) != CONDS_NOCOND)
                fail = TRUE;
              break;

            default:
              break;
            }
        }
      if (succeed)
        {
          if ((!seeking_return) && (arm_ccfsm_state == 1 || reverse))
            arm_target_label = CODE_LABEL_NUMBER (label);
          else if (seeking_return || arm_ccfsm_state == 2)
            {
              while (this_insn && GET_CODE (PATTERN (this_insn)) == USE)
                {
                  this_insn = next_nonnote_insn (this_insn);
                  if (this_insn && (GET_CODE (this_insn) == BARRIER
                                    || GET_CODE (this_insn) == CODE_LABEL))
                    abort ();
                }
              if (!this_insn)
                {
                  /* Oh, dear! we ran off the end.. give up */
                  recog (PATTERN (insn), insn, NULL_PTR);
                  arm_ccfsm_state = 0;
                  arm_target_insn = NULL;
                  return;
                }
              arm_target_insn = this_insn;
            }
          else
            abort ();
          if (jump_clobbers)
            {
              if (reverse)
                abort ();
              arm_current_cc = 
                  get_arm_condition_code (XEXP (XEXP (XEXP (SET_SRC (body),
                                                            0), 0), 1));
              if (GET_CODE (XEXP (XEXP (SET_SRC (body), 0), 0)) == AND)
                arm_current_cc = ARM_INVERSE_CONDITION_CODE (arm_current_cc);
              if (GET_CODE (XEXP (SET_SRC (body), 0)) == NE)
                arm_current_cc = ARM_INVERSE_CONDITION_CODE (arm_current_cc);
            }
          else
            {
              /* If REVERSE is true, ARM_CURRENT_CC needs to be inverted from
                 what it was.  */
              if (!reverse)
                arm_current_cc = get_arm_condition_code (XEXP (SET_SRC (body),
                                                               0));
            }

          if (reverse || then_not_else)
            arm_current_cc = ARM_INVERSE_CONDITION_CODE (arm_current_cc);
        }
      /* restore recog_operand (getting the attributes of other insns can
         destroy this array, but final.c assumes that it remains intact
         across this call; since the insn has been recognized already we
         call recog direct). */
      recog (PATTERN (insn), insn, NULL_PTR);
    }
}

#ifdef AOF_ASSEMBLER
/* Special functions only needed when producing AOF syntax assembler. */

int arm_text_section_count = 1;

char *
aof_text_section ()
{
  static char buf[100];
  sprintf (buf, "\tAREA |C$$code%d|, CODE, READONLY",
           arm_text_section_count++);
  if (flag_pic)
    strcat (buf, ", PIC, REENTRANT");
  return buf;
}

static int arm_data_section_count = 1;

char *
aof_data_section ()
{
  static char buf[100];
  sprintf (buf, "\tAREA |C$$data%d|, DATA", arm_data_section_count++);
  return buf;
}

/* The AOF assembler is religiously strict about declarations of
   imported and exported symbols, so that it is impossible to declare
   a function as imported near the begining of the file, and then to
   export it later on.  It is, however, possible to delay the decision
   until all the functions in the file have been compiled.  To get
   around this, we maintain a list of the imports and exports, and
   delete from it any that are subsequently defined.  At the end of
   compilation we spit the remainder of the list out before the END
   directive.  */

struct import
{
  struct import *next;
  char *name;
};

static struct import *imports_list = NULL;

void
aof_add_import (name)
     char *name;
{
  struct import *new;

  for (new = imports_list; new; new = new->next)
    if (new->name == name)
      return;

  new = (struct import *) xmalloc (sizeof (struct import));
  new->next = imports_list;
  imports_list = new;
  new->name = name;
}

void
aof_delete_import (name)
     char *name;
{
  struct import **old;

  for (old = &imports_list; *old; old = & (*old)->next)
    {
      if ((*old)->name == name)
        {
          *old = (*old)->next;
          return;
        }
    }
}

int arm_main_function = 0;

void
aof_dump_imports (f)
     FILE *f;
{
  /* The AOF assembler needs this to cause the startup code to be extracted
     from the library.  Brining in __main causes the whole thing to work
     automagically.  */
  if (arm_main_function)
    {
      text_section ();
      fputs ("\tIMPORT __main\n", f);
      fputs ("\tDCD __main\n", f);
    }

  /* Now dump the remaining imports.  */
  while (imports_list)
    {
      fprintf (f, "\tIMPORT\t");
      assemble_name (f, imports_list->name);
      fputc ('\n', f);
      imports_list = imports_list->next;
    }
}
#endif /* AOF_ASSEMBLER */