(i960_setup_incoming_varargs): Store parameter registers

[gcc.git] / gcc / config / i960 / i960.c

/* Subroutines used for code generation on intel 80960.
   Copyright (C) 1992 Free Software Foundation, Inc.
   Contributed by Steven McGeady, Intel Corp.
   Additional Work by Glenn Colon-Bonet, Jonathan Shapiro, Andy Wilson
   Converted to GCC 2.0 by Jim Wilson and Michael Tiemann, Cygnus Support.

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, 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include <stdio.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 "tree.h"
#include "insn-codes.h"
#include "assert.h"
#include "expr.h"
#include "function.h"
#include "recog.h"
#include <math.h>

/* Save the operands last given to a compare for use when we
   generate a scc or bcc insn.  */

rtx i960_compare_op0, i960_compare_op1;

/* Used to implement #pragma align/noalign.  Initialized by OVERRIDE_OPTIONS
   macro in i960.h.  */

static int i960_maxbitalignment;
static int i960_last_maxbitalignment;

/* Used to implement switching between MEM and ALU insn types, for better
   C series performance.  */

enum insn_types i960_last_insn_type;

/* The leaf-procedure return register.  Set only if this is a leaf routine.  */

static int i960_leaf_ret_reg;

/* True if replacing tail calls with jumps is OK.  */

static int tail_call_ok;

/* A string containing a list of insns to emit in the epilogue so as to
   restore all registers saved by the prologue.  Created by the prologue
   code as it saves registers away.  */

char epilogue_string[1000];

/* A unique number (per function) for return labels.  */

static int ret_label = 0;

#if 0
/* Handle pragmas for compatibility with Intel's compilers.  */

/* ??? This is incomplete, since it does not handle all pragmas that the
   intel compilers understand.  Also, it needs to be rewritten to accept
   a stream instead of a string for GCC 2.  */

void
process_pragma(str)
     char  *str;
{
  int align;
  int i;

  if ((i = sscanf (str, " align %d", &align)) == 1)
    switch (align)
      {
      case 0:                   /* Return to last alignment.  */
        align = i960_last_maxbitalignment / 8;

      case 16:                  /* Byte alignments. */
      case 8:
      case 4:
      case 2:
      case 1:
        i960_last_maxbitalignment = i960_maxbitalignment;
        i960_maxbitalignment = align * 8;
        break;

      default:                  /* Unknown, silently ignore.  */
        break;
      }

  /* NOTE: ic960 R3.0 pragma align definition:

     #pragma align [(size)] | (identifier=size[,...])
     #pragma noalign [(identifier)[,...]]

     (all parens are optional)

     - size is [1,2,4,8,16]
     - noalign means size==1
     - applies only to component elements of a struct (and union?)
     - identifier applies to structure tag (only)
     - missing identifier means next struct

     - alignment rules for bitfields need more investigation  */

  /* Should be pragma 'far' or equivalent for callx/balx here.  */
}
#endif

/* Initialize variables before compiling any files.  */

void
i960_initialize ()
{
  if (TARGET_IC_COMPAT2_0)
    {
      i960_maxbitalignment = 8;
      i960_last_maxbitalignment = 128;
    }
  else
    {
      i960_maxbitalignment = 128;
      i960_last_maxbitalignment = 8;
    }
}
\f
/* Return true if OP can be used as the source of an fp move insn.  */

int
fpmove_src_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (GET_CODE (op) == CONST_DOUBLE || general_operand (op, mode));
}

#if 0
/* Return true if OP is a register or zero.  */

int
reg_or_zero_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return register_operand (op, mode) || op == const0_rtx;
}
#endif

/* Return truth value of whether OP can be used as an operands in a three
   address arithmetic insn (such as add %o1,7,%l2) of mode MODE.  */

int
arith_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (register_operand (op, mode) || literal (op, mode));
}

/* Return true if OP is a register or a valid floating point literal.  */

int
fp_arith_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (register_operand (op, mode) || fp_literal (op, mode));
}

/* Return true is OP is a register or a valid signed integer literal.  */

int
signed_arith_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (register_operand (op, mode) || signed_literal (op, mode));
}

/* Return truth value of whether OP is a integer which fits the
   range constraining immediate operands in three-address insns.  */

int
literal (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return ((GET_CODE (op) == CONST_INT) && INTVAL(op) >= 0 && INTVAL(op) < 32);
}

/* Return true if OP is a float constant of 1.  */

int
fp_literal_one (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (TARGET_NUMERICS && (mode == VOIDmode || mode == GET_MODE (op))
          && (op == CONST1_RTX (mode)));
}

/* Return true if OP is a float constant of 0.  */

int
fp_literal_zero (op, mode)
     rtx op;
     enum machine_mode mode;
{
  return (TARGET_NUMERICS && (mode == VOIDmode || mode == GET_MODE (op))
          && (op == CONST0_RTX (mode)));
}

/* Return true if OP is a valid floating point literal.  */

int
fp_literal(op, mode)
     rtx op;
     enum machine_mode mode;
{
  return fp_literal_zero (op, mode) || fp_literal_one (op, mode);
}

/* Return true if OP is a valid signed immediate constant.  */

int
signed_literal(op, mode)
     rtx op;
     enum machine_mode mode;
{
  return ((GET_CODE (op) == CONST_INT) && INTVAL(op) > -32 && INTVAL(op) < 32);
}

/* Return truth value of statement that OP is a symbolic memory
   operand of mode MODE.  */

int
symbolic_memory_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (GET_CODE (op) == SUBREG)
    op = SUBREG_REG (op);
  if (GET_CODE (op) != MEM)
    return 0;
  op = XEXP (op, 0);
  return (GET_CODE (op) == SYMBOL_REF || GET_CODE (op) == CONST
          || GET_CODE (op) == HIGH || GET_CODE (op) == LABEL_REF);
}

/* Return truth value of whether OP is EQ or NE.  */

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

/* OP is an integer register or a constant.  */

int
arith32_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (register_operand (op, mode))
    return 1;
  return (CONSTANT_P (op));
}

/* Return true if OP is an integer constant which is a power of 2.  */

int
power2_operand (op,mode)
     rtx op;
     enum machine_mode mode;
{
  if (GET_CODE (op) != CONST_INT)
    return 0;

  return exact_log2 (INTVAL (op)) >= 0;
}

/* Return true if OP is an integer constant which is the complement of a
   power of 2.  */

int
cmplpower2_operand (op, mode)
     rtx op;
     enum machine_mode mode;
{
  if (GET_CODE (op) != CONST_INT)
    return 0;

  return exact_log2 (~ INTVAL (op)) >= 0;
}

/* If VAL has only one bit set, return the index of that bit.  Otherwise
   return -1.  */

int
bitpos (val)
     unsigned int val;
{
  register int i;

  for (i = 0; val != 0; i++, val >>= 1)
    {
      if (val & 1)
        {
          if (val != 1)
            return -1;
          return i;
        }
    }
  return -1;
}

/* Return non-zero if OP is a mask, i.e. all one bits are consecutive.
   The return value indicates how many consecutive non-zero bits exist
   if this is a mask.  This is the same as the next function, except that
   it does not indicate what the start and stop bit positions are.  */

int
is_mask (val)
     unsigned int val;
{
  register int start, end, i;

  start = -1;
  for (i = 0; val != 0; val >>= 1, i++)
    {
      if (val & 1)
        {
          if (start < 0)
            start = i;

          end = i;
          continue;
        }
      /* Still looking for the first bit.  */
      if (start < 0)
        continue;

      /* We've seen the start of a bit sequence, and now a zero.  There
         must be more one bits, otherwise we would have exited the loop.
         Therefore, it is not a mask.  */
      if (val)
        return 0;
    }

  /* The bit string has ones from START to END bit positions only.  */
  return end - start + 1;
}

/* If VAL is a mask, then return nonzero, with S set to the starting bit
   position and E set to the ending bit position of the mask.  The return
   value indicates how many consecutive bits exist in the mask.  This is
   the same as the previous function, except that it also indicates the
   start and end bit positions of the mask.  */

int
bitstr (val, s, e)
     unsigned int val;
     int *s, *e;
{
  register int start, end, i;

  start = -1;
  end = -1;
  for (i = 0; val != 0; val >>= 1, i++)
    {
      if (val & 1)
        {
          if (start < 0)
            start = i;

          end = i;
          continue;
        }

      /* Still looking for the first bit.  */
      if (start < 0)
        continue;

      /* We've seen the start of a bit sequence, and now a zero.  There
         must be more one bits, otherwise we would have exited the loop.
         Therefor, it is not a mask.  */
      if (val)
        {
          start = -1;
          end = -1;
          break;
        }
    }

  /* The bit string has ones from START to END bit positions only.  */
  *s = start;
  *e = end;
  return ((start < 0) ? 0 : end - start + 1);
}
\f
/* Return the machine mode to use for a comparison.  */

enum machine_mode
select_cc_mode (op, x)
     RTX_CODE op;
     rtx x;
{
  if (op == GTU || op == LTU || op == GEU || op == LEU)
    return CC_UNSmode;
  return CCmode;
}

/* X and Y are two things to compare using CODE.  Emit the compare insn and
   return the rtx for register 36 in the proper mode.  */

rtx
gen_compare_reg (code, x, y)
     enum rtx_code code;
     rtx x, y;
{
  rtx cc_reg;
  enum machine_mode ccmode = SELECT_CC_MODE (code, x, y);
  enum machine_mode mode
    = GET_MODE (x) == VOIDmode ? GET_MODE (y) : GET_MODE (x);

  if (mode == SImode)
    {
      if (! arith_operand (x, mode))
        x = force_reg (SImode, x);
      if (! arith_operand (y, mode))
        y = force_reg (SImode, y);
    }

  cc_reg = gen_rtx (REG, ccmode, 36);
  emit_insn (gen_rtx (SET, VOIDmode, cc_reg,
                      gen_rtx (COMPARE, ccmode, x, y)));

  return cc_reg;
}

/* For the i960, REG is cost 1, REG+immed CONST is cost 2, REG+REG is cost 2,
   REG+nonimmed CONST is cost 4.  REG+SYMBOL_REF, SYMBOL_REF, and similar
   are 4.  Indexed addresses are cost 6.  */

/* ??? Try using just RTX_COST, i.e. not defining ADDRESS_COST.  */

int
i960_address_cost (x)
     rtx x;
{
#if 0
  /* Handled before calling here.  */
  if (GET_CODE (x) == REG)
    return 1;
#endif
  if (GET_CODE (x) == PLUS)
    {
      rtx base = XEXP (x, 0);
      rtx offset = XEXP (x, 1);

      if (GET_CODE (base) == SUBREG)
        base = SUBREG_REG (base);
      if (GET_CODE (offset) == SUBREG)
        offset = SUBREG_REG (offset);

      if (GET_CODE (base) == REG)
        {
          if (GET_CODE (offset) == REG)
            return 2;
          if (GET_CODE (offset) == CONST_INT)
            {
              if ((unsigned)INTVAL (offset) < 2047)
                return 2;
              return 4;
            }
          if (CONSTANT_P (offset))
            return 4;
        }
      if (GET_CODE (base) == PLUS || GET_CODE (base) == MULT)
        return 6;

      /* This is an invalid address.  The return value doesn't matter, but
         for convenience we make this more expensive than anything else.  */
      return 12;
    }
  if (GET_CODE (x) == MULT)
    return 6;

  /* Symbol_refs and other unrecognized addresses are cost 4.  */
  return 4;
}
\f
/* Emit insns to move operands[1] into operands[0].

   Return 1 if we have written out everything that needs to be done to
   do the move.  Otherwise, return 0 and the caller will emit the move
   normally.  */

int
emit_move_sequence (operands, mode)
     rtx *operands;
     enum machine_mode mode;
{
  register rtx operand0 = operands[0];
  register rtx operand1 = operands[1];

  /* We can only store registers to memory.  */

  if (GET_CODE (operand0) == MEM && GET_CODE (operand1) != REG)
    operands[1] = force_reg (mode, operand1);

  return 0;
}
\f
/* Emit insns to load a constant.  Uses several strategies to try to use
   as few insns as possible.  */

char *
i960_output_ldconst (dst, src)
     register rtx dst, src;
{
  register int rsrc1;
  register unsigned rsrc2;
  enum machine_mode mode = GET_MODE (dst);
  rtx operands[4];
  union { long l[2]; double d; } x;

  operands[0] = operands[2] = dst;
  operands[1] = operands[3] = src;

  /* Anything that isn't a compile time constant, such as a SYMBOL_REF,
     must be a ldconst insn.  */

  if (GET_CODE (src) != CONST_INT && GET_CODE (src) != CONST_DOUBLE)
    {
      output_asm_insn ("ldconst %1,%0", operands);
      return "";
    }
  else if (mode == DFmode)
    {
      rtx first, second;

      if (fp_literal_zero (src, VOIDmode))
        {
          if (FP_REG_P (dst))
            return "movrl       %1,%0";
          else
            return "movl        0,%0";
        }

#if HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT
      split_double (src, &first, &second);

      output_asm_insn ("# ldconst       %1,%0",operands);

      operands[0] = gen_rtx (REG, SImode, REGNO (dst));
      operands[1] = first;
      output_asm_insn (i960_output_ldconst (operands[0], operands[1]),
                      operands);
      operands[0] = gen_rtx (REG, SImode, REGNO (dst) + 1);
      operands[1] = second;
      output_asm_insn (i960_output_ldconst (operands[0], operands[1]),
                      operands);
      return "";
#else
      if (fp_literal_one (src, VOIDmode))
        return "movrl   0f1.0,%0";
      fatal ("inline double constants not supported on this host");
#endif
    }
  else if (mode == TImode)
    {
      /* ??? This is currently not handled at all.  */
      abort ();

      /* Note: lowest order word goes in lowest numbered reg.  */
      rsrc1 = INTVAL (src);
      if (rsrc1 >= 0 && rsrc1 < 32)
        return "movq    %1,%0";
      else
        output_asm_insn ("movq\t0,%0\t# ldconstq %1,%0",operands);
      /* Go pick up the low-order word.  */
    }
  else if (mode == DImode)
    {
      rtx upperhalf, lowerhalf, xoperands[2];
      char *string;

      if (GET_CODE (src) == CONST_DOUBLE)
        {
          upperhalf = gen_rtx (CONST_INT, VOIDmode, CONST_DOUBLE_HIGH (src));
          lowerhalf = gen_rtx (CONST_INT, VOIDmode, CONST_DOUBLE_LOW (src));
        }
      else if (GET_CODE (src) == CONST_INT)
        {
          lowerhalf = src;
          upperhalf = INTVAL (src) < 0 ? constm1_rtx : const0_rtx;
        }
      else
        abort ();

      /* Note: lowest order word goes in lowest numbered reg.  */
      /* Numbers from 0 to 31 can be handled with a single insn.  */
      rsrc1 = INTVAL (lowerhalf);
      if (upperhalf == const0_rtx && rsrc1 >= 0 && rsrc1 < 32)
        return "movl    %1,%0";

      /* Output the upper half with a recursive call.  */
      xoperands[0] = gen_rtx (REG, SImode, REGNO (dst) + 1);
      xoperands[1] = upperhalf;
      output_asm_insn (i960_output_ldconst (xoperands[0], xoperands[1]),
                       xoperands);
      /* The lower word is emitted as normally.  */
    }
  else if (mode == SFmode)
    {
#if HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT
      REAL_VALUE_TYPE d;
      long value;

      REAL_VALUE_FROM_CONST_DOUBLE (d, src);
      REAL_VALUE_TO_TARGET_SINGLE (d, value);

      output_asm_insn ("# ldconst       %1,%0",operands);
      operands[0] = gen_rtx (REG, SImode, REGNO (dst));
      operands[1] = gen_rtx (CONST_INT, VOIDmode, value);
      output_asm_insn (i960_output_ldconst (operands[0], operands[1]),
                      operands);
#else
      if (fp_literal_zero (src, VOIDmode))
        return "movr    0f0.0,%0";
      if (fp_literal_one (src, VOIDmode))
        return "movr    0f1.0,%0";
      fatal ("inline float constants not supported on this host");
#endif
      return "";
    }
  else
    {
      rsrc1 = INTVAL (src);
      if (mode == QImode)
        {
          if (rsrc1 > 0xff)
            rsrc1 &= 0xff;
        }
      else if (mode == HImode)
        {
          if (rsrc1 > 0xffff)
            rsrc1 &= 0xffff;
        }
    }

  if (rsrc1 >= 0)
    {
      /* ldconst        0..31,X         ->      mov     0..31,X  */
      if (rsrc1 < 32)
        {
          if (i960_last_insn_type == I_TYPE_REG && TARGET_C_SERIES)
            return "lda %1,%0";
          return "mov   %1,%0";
        }

      /* ldconst        32..63,X        ->      add     31,nn,X  */
      if (rsrc1 < 63)
        {
          if (i960_last_insn_type == I_TYPE_REG && TARGET_C_SERIES)
            return "lda %1,%0";
          operands[1] = gen_rtx (CONST_INT, VOIDmode, rsrc1 - 31);
          output_asm_insn ("addo\t31,%1,%0\t# ldconst %3,%0", operands);
          return "";
        }
    }
  else if (rsrc1 < 0)
    {
      /* ldconst        -1..-31         ->      sub     0,0..31,X  */
      if (rsrc1 >= -31)
        {
          /* return 'sub -(%1),0,%0' */
          operands[1] = gen_rtx (CONST_INT, VOIDmode, - rsrc1);
          output_asm_insn ("subo\t%1,0,%0\t# ldconst %3,%0", operands);
          return "";
        }
      
      /* ldconst        -32             ->      not     31,X  */
      if (rsrc1 == -32)
        {
          operands[1] = gen_rtx (CONST_INT, VOIDmode, ~rsrc1);
          output_asm_insn ("not\t%1,%0  # ldconst %3,%0", operands);
          return "";
        }
    }

  /* If const is a single bit.  */
  if (bitpos (rsrc1) >= 0)
    {
      operands[1] = gen_rtx (CONST_INT, VOIDmode, bitpos (rsrc1));
      output_asm_insn ("setbit\t%1,0,%0\t# ldconst %3,%0", operands);
      return "";
    }

  /* If const is a bit string of less than 6 bits (1..31 shifted).  */
  if (is_mask (rsrc1))
    {
      int s, e;

      if (bitstr (rsrc1, &s, &e) < 6)
        {
          rsrc2 = ((unsigned int) rsrc1) >> s;
          operands[1] = gen_rtx (CONST_INT, VOIDmode, rsrc2);
          operands[2] = gen_rtx (CONST_INT, VOIDmode, s);
          output_asm_insn ("shlo\t%2,%1,%0\t# ldconst %3,%0", operands);
          return "";
        }
    }

  /* Unimplemented cases:
     const is in range 0..31 but rotated around end of word:
     ror        31,3,g0 -> ldconst 0xe0000003,g0
   
     and any 2 instruction cases that might be worthwhile  */
  
  output_asm_insn ("ldconst     %1,%0", operands);
  return "";
}

/* Determine if there is an opportunity for a bypass optimization.
   Bypass succeeds on the 960K* if the destination of the previous
   instruction is the second operand of the current instruction.
   Bypass always succeeds on the C*.
 
   Return 1 if the pattern should interchange the operands.

   CMPBR_FLAG is true if this is for a compare-and-branch insn.
   OP1 and OP2 are the two source operands of a 3 operand insn.  */

int
i960_bypass (insn, op1, op2, cmpbr_flag)
     register rtx insn, op1, op2;
     int cmpbr_flag;
{
  register rtx prev_insn, prev_dest;

  if (TARGET_C_SERIES)
    return 0;

  /* Can't do this if op1 isn't a register.  */
  if (! REG_P (op1))
    return 0;

  /* Can't do this for a compare-and-branch if both ops aren't regs.  */
  if (cmpbr_flag && ! REG_P (op2))
    return 0;

  prev_insn = prev_real_insn (insn);

  if (prev_insn && GET_CODE (prev_insn) == INSN
      && GET_CODE (PATTERN (prev_insn)) == SET)
    {
      prev_dest = SET_DEST (PATTERN (prev_insn));
      if ((GET_CODE (prev_dest) == REG && REGNO (prev_dest) == REGNO (op1))
          || (GET_CODE (prev_dest) == SUBREG
              && GET_CODE (SUBREG_REG (prev_dest)) == REG
              && REGNO (SUBREG_REG (prev_dest)) == REGNO (op1)))
        return 1;
    }
  return 0;
}
\f
/* Output the code which declares the function name.  This also handles
   leaf routines, which have special requirements, and initializes some
   global variables.  */

void
i960_function_name_declare (file, name, fndecl)
     FILE *file;
     char *name;
     tree fndecl;
{
  register int i, j;
  int leaf_proc_ok;
  rtx insn;

  /* Increment global return label.  */

  ret_label++;

  /* Compute whether tail calls and leaf routine optimizations can be performed
     for this function.  */

  if (TARGET_TAILCALL)
    tail_call_ok = 1;
  else
    tail_call_ok = 0;

  if (TARGET_LEAFPROC)
    leaf_proc_ok = 1;
  else
    leaf_proc_ok = 0;

  /* Even if nobody uses extra parms, can't have leafroc or tail calls if
     argblock, because argblock uses g14 implicitly.  */

  if (current_function_args_size != 0)
    {
      tail_call_ok = 0;
      leaf_proc_ok = 0;
    }
      
  /* See if caller passes in an address to return value. */

  if (aggregate_value_p (DECL_RESULT (fndecl)))
    {
      tail_call_ok = 0;
      leaf_proc_ok = 0;
    }

  /* Can not use tail calls or make this a leaf routine if there is a non
     zero frame size.  */

  if (get_frame_size () != 0)
    leaf_proc_ok = 0;

  /* I don't understand this condition, and do not think that it is correct.
     Apparently this is just checking whether the frame pointer is used, and
     we can't trust regs_ever_live[fp] since it is (almost?) always set.  */

  if (tail_call_ok)
    for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
      if (GET_CODE (insn) == INSN
          && reg_mentioned_p (frame_pointer_rtx, insn))
        {
          tail_call_ok = 0;
          break;
        }

  /* Check for CALL insns.  Can not be a leaf routine if there are any.  */

  if (leaf_proc_ok)
    for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
      if (GET_CODE (insn) == CALL_INSN)
        {
          leaf_proc_ok = 0;
          break;
        }

  /* Can not be a leaf routine if any non-call clobbered registers are
     used in this function.  */

  if (leaf_proc_ok)
    for (i = 0, j = 0; i < FIRST_PSEUDO_REGISTER; i++)
      if (regs_ever_live[i]
          && ((! call_used_regs[i]) || (i > 7 && i < 12)))
        {
          /* Global registers.  */
          if (i < 16 && i > 7 && i != 13)
            leaf_proc_ok = 0;
          /* Local registers.  */
          else if (i < 32)
            leaf_proc_ok = 0;
        }

  /* Now choose a leaf return register, if we can find one, and if it is
     OK for this to be a leaf routine.  */

  i960_leaf_ret_reg = -1;

  if (optimize && leaf_proc_ok)
    {
      for (i960_leaf_ret_reg = -1, i = 0; i < 8; i++)
        if (regs_ever_live[i] == 0)
          {
            i960_leaf_ret_reg = i;
            regs_ever_live[i] = 1;
            break;
          }
    }

  /* Do this after choosing the leaf return register, so it will be listed
     if one was chosen.  */

  fprintf (file, "\t#  Function '%s'\n", (name[0] == '*' ? &name[1] : name));
  fprintf (file, "\t#  Registers used: ");

  for (i = 0, j = 0; i < FIRST_PSEUDO_REGISTER; i++)
    {
      if (regs_ever_live[i])
        {
          fprintf (file, "%s%s ", reg_names[i], call_used_regs[i] ? "" : "*");

          if (i > 15 && j == 0)
            {
              fprintf (file,"\n\t#\t\t   ");
              j++;
            }
        }
    }

  fprintf (file, "\n");

  if (i960_leaf_ret_reg >= 0)
    {
      /* Make it a leaf procedure.  */

      if (TREE_PUBLIC (fndecl))
        fprintf (file,"\t.globl\t%s.lf\n", (name[0] == '*' ? &name[1] : name));

      fprintf (file, "\t.leafproc\t");
      assemble_name (file, name);
      fprintf (file, ",%s.lf\n", (name[0] == '*' ? &name[1] : name));
      ASM_OUTPUT_LABEL (file, name);
      fprintf (file, "\tlda    LR%d,g14\n", ret_label);
      fprintf (file, "%s.lf:\n", (name[0] == '*' ? &name[1] : name));
      fprintf (file, "\tmov    g14,g%d\n", i960_leaf_ret_reg);

      if (TARGET_C_SERIES)
        {
          fprintf (file, "\tlda    0,g14\n");
          i960_last_insn_type = I_TYPE_MEM;
        }
      else
        {
          fprintf (file, "\tmov    0,g14\n");
          i960_last_insn_type = I_TYPE_REG;
        }
    }
  else
    {
      ASM_OUTPUT_LABEL (file, name);
      i960_last_insn_type = I_TYPE_CTRL; 
    }
}
\f
/* Compute and return the frame size.  */

int
compute_frame_size (size)
     int size;
{
  int actual_fsize;
  int outgoing_args_size
    = current_function_outgoing_args_size + current_function_pretend_args_size;

  /* The STARTING_FRAME_OFFSET is totally hidden to us as far
     as size is concerned.  */
  actual_fsize = (size + 15) & -16;
  actual_fsize += (outgoing_args_size + 15) & -16;

  return actual_fsize;
}

/* Output code for the function prologue.  */

void
i960_function_prologue (file, size)
     FILE *file;
     unsigned int size;
{
  register int i, j, nr;
  int n_iregs = 0;
  int rsize = 0;
  int actual_fsize, offset;
  char tmpstr[1000];
  /* -1 if reg must be saved on proc entry, 0 if available, 1 if saved
     somewhere.  */
  int regs[FIRST_PSEUDO_REGISTER];

  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
    if (regs_ever_live[i]
        && ((! call_used_regs[i]) || (i > 7 && i < 12)))
      {
        regs[i] = -1;
        /* Count global registers that need saving.  */
        if (i < 16)
          n_iregs++;
      }
    else
      regs[i] = 0;

  epilogue_string[0] = '\0';

  if (profile_flag || profile_block_flag)
    {
      /* When profiling, we may use registers 20 to 27 to save arguments, so
         they can't be used here for saving globals.  J is the number of
         argument registers the mcount call will save.  */
      for (j = 7; j >= 0 && ! regs_ever_live[j]; j--)
        ;

      for (i = 20; i <= j + 20; i++)
        regs[i] = -1;
    }

  /* First look for local registers to save globals in.  */
  for (i = 0; i < 16; i++)
    {
      if (regs[i] == 0)
        continue;

      /* Start at r4, not r3.  */
      for (j = 20; j < 32; j++)
        {
          if (regs[j] != 0)
            continue;

          regs[i] = 1;
          regs[j] = -1;
          regs_ever_live[j] = 1;
          nr = 1;
          if (i <= 14 && i % 2 == 0 && j <= 30 && j % 2 == 0
              && regs[i+1] != 0 && regs[j+1] == 0)
            {
              nr = 2;
              regs[i+1] = 1;
              regs[j+1] = -1;
              regs_ever_live[j+1] = 1;
            }
          if (nr == 2 && i <= 12 && i % 4 == 0 && j <= 28 && j % 4 == 0
              && regs[i+2] != 0 && regs[j+2] == 0)
            {
              nr = 3;
              regs[i+2] = 1;
              regs[j+2] = -1;
              regs_ever_live[j+2] = 1;
            }
          if (nr == 3 && regs[i+3] != 0 && regs[j+3] == 0)
            {
              nr = 4;
              regs[i+3] = 1;
              regs[j+3] = -1;
              regs_ever_live[j+3] = 1;
            }

          fprintf (file, "\tmov%s       %s,%s\n",
                   ((nr == 4) ? "q" :
                    (nr == 3) ? "t" :
                    (nr == 2) ? "l" : ""),
                   reg_names[i], reg_names[j]);
          sprintf (tmpstr, "\tmov%s     %s,%s\n",
                   ((nr == 4) ? "q" :
                    (nr == 3) ? "t" :
                    (nr == 2) ? "l" : ""),
                   reg_names[j], reg_names[i]);
          strcat (epilogue_string, tmpstr);

          n_iregs -= nr;
          i += nr-1;
          break;
        }
    }

  /* N_iregs is now the number of global registers that haven't been saved
     yet.  */

  rsize = (n_iregs * 4);
  actual_fsize = compute_frame_size (size) + rsize;
#if 0
  /* ??? The 1.2.1 compiler does this also.  This is meant to round the frame
     size up to the nearest multiple of 16.  I don't know whether this is
     necessary, or even desirable.

     The frame pointer must be aligned, but the call instruction takes care of
     that.  If we leave the stack pointer unaligned, we may save a little on
     dynamic stack allocation.  And we don't lose, at least according to the
     i960CA manual.  */
  actual_fsize = (actual_fsize + 15) & ~0xF;
#endif

  /* Allocate space for register save and locals.  */
  if (actual_fsize > 0)
    {
      if (actual_fsize < 32)
        fprintf (file, "\taddo  %d,sp,sp\n", actual_fsize);
      else
        fprintf (file, "\tlda\t%d(sp),sp\n", actual_fsize);
    }

  /* Take hardware register save area created by the call instruction
     into account, but store them before the argument block area.  */
  offset = 64 + actual_fsize - compute_frame_size (0) - rsize;
  /* Save registers on stack if needed.  */
  for (i = 0, j = n_iregs; j > 0 && i < 16; i++)
    {
      if (regs[i] != -1)
        continue;

      nr = 1;

      if (i <= 14 && i % 2 == 0 && regs[i+1] == -1 && offset % 2 == 0)
        nr = 2;

      if (nr == 2 && i <= 12 && i % 4 == 0 && regs[i+2] == -1
          && offset % 4 == 0)
        nr = 3;

      if (nr == 3 && regs[i+3] == -1)
        nr = 4;

      fprintf (file,"\tst%s     %s,%d(fp)\n",
               ((nr == 4) ? "q" :
                (nr == 3) ? "t" :
                (nr == 2) ? "l" : ""),
               reg_names[i], offset);
      sprintf (tmpstr,"\tld%s   %d(fp),%s\n",
               ((nr == 4) ? "q" :
                (nr == 3) ? "t" :
                (nr == 2) ? "l" : ""),
               offset, reg_names[i]);
      strcat (epilogue_string, tmpstr);
      i += nr-1;
      j -= nr;
      offset += nr * 4;
    }

  if (actual_fsize == 0 && size == 0 && rsize == 0)
    return;

  fprintf (file, "\t#Prologue stats:\n");
  fprintf (file, "\t#  Total Frame Size: %d bytes\n", actual_fsize);

  if (size)
    fprintf (file, "\t#  Local Variable Size: %d bytes\n", size);
  if (rsize)
    fprintf (file, "\t#  Register Save Size: %d regs, %d bytes\n",
             n_iregs, rsize);
  fprintf (file, "\t#End Prologue#\n");
}

/* Output code for the function profiler.  */

void
output_function_profiler (file, labelno)
     FILE *file;
     int labelno;
{
  /* The last used parameter register.  */
  int last_parm_reg;
  int i, j, increment;

  /* Figure out the last used parameter register.  The proper thing to do
     is to walk incoming args of the function.  A function might have live
     parameter registers even if it has no incoming args.  Note that we
     don't have to save parameter registers g8 to g11 because they are
     call preserved.  */

  /* See also output_function_prologue, which tries to use local registers
     for preserved call-saved global registers.  */

  for (last_parm_reg = 7;
       last_parm_reg >= 0 && ! regs_ever_live[last_parm_reg];
       last_parm_reg--)
    ;

  /* Save parameter registers in regs r4 (20) to r11 (27).  */

  for (i = 0, j = 4; i <= last_parm_reg; i += increment, j += increment)
    {
      if (i % 4 == 0 && (last_parm_reg - i) >= 3)
        increment = 4;
      else if (i % 4 == 0 && (last_parm_reg - i) >= 2)
        increment = 3;
      else if (i % 2 == 0 && (last_parm_reg - i) >= 1)
        increment = 2;
      else
        increment = 1;

      fprintf (file, "\tmov%s   g%d,r%d\n",
               (increment == 4 ? "q" : increment == 3 ? "t"
                : increment == 2 ? "l": ""), i, j);
      }

  /* If this function uses the arg pointer, then save it in r3 and then
     set it to zero.  */

  if (current_function_args_size != 0)
    fprintf (file, "\tmov       g14,r3\n\tmov   0,g14\n");

  /* Load location address into g0 and call mcount.  */

  fprintf (file, "\tlda\tLP%d,g0\n\tcallx\tmcount\n", labelno);

  /* If this function uses the arg pointer, restore it.  */

  if (current_function_args_size != 0)
    fprintf (file, "\tmov       r3,g14\n");

  /* Restore parameter registers.  */

  for (i = 0, j = 4; i <= last_parm_reg; i += increment, j += increment)
    {
      if (i % 4 == 0 && (last_parm_reg - i) >= 3)
        increment = 4;
      else if (i % 4 == 0 && (last_parm_reg - i) >= 2)
        increment = 3;
      else if (i % 2 == 0 && (last_parm_reg - i) >= 1)
        increment = 2;
      else
        increment = 1;

      fprintf (file, "\tmov%s   r%d,g%d\n",
               (increment == 4 ? "q" : increment == 3 ? "t"
                : increment == 2 ? "l": ""), j, i);
    }
}

/* Output code for the function epilogue.  */

void
i960_function_epilogue (file, size)
     FILE *file;
     unsigned int size;
{
  if (i960_leaf_ret_reg >= 0)
    {
      fprintf (file, "LR%d:     ret\n", ret_label);
      return;
    }

  if (*epilogue_string == 0)
    {
      register rtx tmp;
        
      /* Emit a return insn, but only if control can fall through to here.  */

      tmp = get_last_insn ();
      while (tmp)
        {
          if (GET_CODE (tmp) == BARRIER)
            return;
          if (GET_CODE (tmp) == CODE_LABEL)
            break;
          if (GET_CODE (tmp) == JUMP_INSN)
            {
              if (GET_CODE (PATTERN (tmp)) == RETURN)
                return;
              break;
            }
          if (GET_CODE (tmp) == NOTE)
            {
              tmp = PREV_INSN (tmp);
              continue;
            }
          break;
        }
      fprintf (file, "LR%d:     ret\n", ret_label);
      return;
    }

  fprintf (file, "LR%d:\n", ret_label);

  fprintf (file, "\t#EPILOGUE#\n");

  /* Output the string created by the prologue which will restore all
     registers saved by the prologue.  */

  if (epilogue_string[0] != '\0')
    fprintf (file, "%s", epilogue_string);

  /* Must clear g14 on return.  */

  if (current_function_args_size != 0)
    fprintf (file, "\tmov       0,g14\n");

  fprintf (file, "\tret\n");
  fprintf (file, "\t#End Epilogue#\n");
}

/* Output code for a call insn.  */

char *
i960_output_call_insn (target, argsize_rtx, arg_pointer, insn)
     register rtx target, argsize_rtx, arg_pointer, insn;
{
  int argsize = INTVAL (argsize_rtx);
  rtx nexti = next_real_insn (insn);
  rtx operands[2];

  operands[0] = target;
  operands[1] = arg_pointer;

  if (current_function_args_size != 0)
    output_asm_insn ("mov       g14,r3", operands);

  if (argsize > 48)
    output_asm_insn ("lda       %a1,g14", operands);
  else if (current_function_args_size != 0)
    output_asm_insn ("mov       0,g14", operands);

  /* The code used to assume that calls to SYMBOL_REFs could not be more
     than 24 bits away (b vs bx, callj vs callx).  This is not true.  This
     feature is now implemented by relaxing in the GNU linker.  It can convert
     bx to b if in range, and callx to calls/call/balx/bal as appropriate.  */

  /* Nexti could be zero if the called routine is volatile.  */
  if (optimize && (*epilogue_string == 0) && argsize == 0 && tail_call_ok 
      && (nexti == 0 || GET_CODE (PATTERN (nexti)) == RETURN))
    {
      /* Delete following return insn.  */
      if (nexti && no_labels_between_p (insn, nexti))
        delete_insn (nexti);
      output_asm_insn ("bx      %0", operands);
      return "# notreached";
    }

  output_asm_insn ("callx       %0", operands);

  if (current_function_args_size != 0)
    output_asm_insn ("mov       r3,g14", operands);

  return "";
}

/* Output code for a return insn.  */

char *
i960_output_ret_insn (insn)
     register rtx insn;
{
  static char lbuf[20];
  
  if (*epilogue_string != 0)
    {
      if (! TARGET_CODE_ALIGN && next_real_insn (insn) == 0)
        return "";

      sprintf (lbuf, "b LR%d", ret_label);
      return lbuf;
    }

  if (current_function_args_size != 0)
    output_asm_insn ("mov       0,g14", 0);

  if (i960_leaf_ret_reg >= 0)
    {
      sprintf (lbuf, "bx        (%s)", reg_names[i960_leaf_ret_reg]);
      return lbuf;
    }
  return "ret";
}
\f
#if 0
/* Return a character string representing the branch prediction
   opcode to be tacked on an instruction.  This must at least
   return a null string.  */

char *
i960_br_predict_opcode (lab_ref, insn)
     rtx lab_ref, insn;
{
  if (TARGET_BRANCH_PREDICT)
    {
      unsigned long label_uid;
      
      if (GET_CODE (lab_ref) == CODE_LABEL)
        label_uid = INSN_UID (lab_ref);
      else if (GET_CODE (lab_ref) == LABEL_REF)
        label_uid = INSN_UID (XEXP (lab_ref, 0));
      else
        return ".f";

      /* If not optimizing, then the insn_addresses array will not be
         valid.  In this case, always return ".t" since most branches
         are taken.  If optimizing, return .t for backward branches
         and .f for forward branches.  */
      if (! optimize
          || insn_addresses[label_uid] < insn_addresses[INSN_UID (insn)])
        return ".t";
      return ".f";
    }
    
  return "";
}
#endif

/* Print the operand represented by rtx X formatted by code CODE.  */

void
i960_print_operand (file, x, code)
     FILE *file;
     rtx x;
     char code;
{
  enum rtx_code rtxcode = GET_CODE (x);

  if (rtxcode == REG)
    {
      switch (code)
        {
        case 'D':
          /* Second reg of a double.  */
          fprintf (file, "%s", reg_names[REGNO (x)+1]);
          break;

        case 0:
          fprintf (file, "%s", reg_names[REGNO (x)]);
          break;

        default:
          abort ();
        }
      return;
    }
  else if (rtxcode == MEM)
    {
      output_address (XEXP (x, 0));
      return;
    }
  else if (rtxcode == CONST_INT)
    {
      if (INTVAL (x) > 9999 || INTVAL (x) < -999)
        fprintf (file, "0x%x", INTVAL (x));
      else
        fprintf (file, "%d", INTVAL (x));
      return;
    }
  else if (rtxcode == CONST_DOUBLE)
    {
      double d;

      if (x == CONST0_RTX (DFmode) || x == CONST0_RTX (SFmode))
        {
          fprintf (file, "0f0.0");
          return;
        }
      else if (x == CONST1_RTX (DFmode) || x == CONST1_RTX (SFmode))
        {
          fprintf (file, "0f1.0");
          return;
        }

      /* This better be a comment.  */
      REAL_VALUE_FROM_CONST_DOUBLE (d, x);
      fprintf (file, "%#g", d);
      return;
    }

  switch(code)
    {
    case 'B':
      /* Branch or jump, depending on assembler.  */
      if (TARGET_ASM_COMPAT)
        fputs ("j", file);
      else
        fputs ("b", file);
      break;

    case 'S':
      /* Sign of condition.  */
      if ((rtxcode == EQ) || (rtxcode == NE) || (rtxcode == GTU)
          || (rtxcode == LTU) || (rtxcode == GEU) || (rtxcode == LEU))
        fputs ("o", file);
      else if ((rtxcode == GT) || (rtxcode == LT)
          || (rtxcode == GE) || (rtxcode == LE))
        fputs ("i", file);
      else
        abort();
      break;

    case 'I':
      /* Inverted condition.  */
      rtxcode = reverse_condition (rtxcode);
      goto normal;

    case 'X':
      /* Inverted condition w/ reversed operands.  */
      rtxcode = reverse_condition (rtxcode);
      /* Fallthrough.  */

    case 'R':
      /* Reversed operand condition.  */
      rtxcode = swap_condition (rtxcode);
      /* Fallthrough.  */

    case 'C':
      /* Normal condition.  */
    normal:
      if (rtxcode == EQ)  { fputs ("e", file); return; }
      else if (rtxcode == NE)  { fputs ("ne", file); return; }
      else if (rtxcode == GT)  { fputs ("g", file); return; }
      else if (rtxcode == GTU) { fputs ("g", file); return; }
      else if (rtxcode == LT)  { fputs ("l", file); return; }
      else if (rtxcode == LTU) { fputs ("l", file); return; }
      else if (rtxcode == GE)  { fputs ("ge", file); return; }
      else if (rtxcode == GEU) { fputs ("ge", file); return; }
      else if (rtxcode == LE)  { fputs ("le", file); return; }
      else if (rtxcode == LEU) { fputs ("le", file); return; }
      else abort ();
      break;

    case 0:
      output_addr_const (file, x);
      break;

    default:
      abort ();
    }

  return;
}
\f
/* Print a memory address as an operand to reference that memory location.

   This is exactly the same as legitimate_address_p, except that it the prints
   addresses instead of recognizing them.  */

void
i960_print_operand_addr (file, addr)
     FILE *file;
     register rtx addr;
{
  rtx breg, ireg;
  rtx scale, offset;

  ireg = 0;
  breg = 0;
  offset = 0;
  scale = const1_rtx;

  if (GET_CODE (addr) == REG)
    breg = addr;
  else if (CONSTANT_P (addr))
    offset = addr;
  else if (GET_CODE (addr) == PLUS)
    {
      rtx op0, op1;

      op0 = XEXP (addr, 0);
      op1 = XEXP (addr, 1);

      if (GET_CODE (op0) == REG)
        {
          breg = op0;
          if (GET_CODE (op1) == REG)
            ireg = op1;
          else if (CONSTANT_P (op1))
            offset = op1;
          else
            abort ();
        }
      else if (GET_CODE (op0) == PLUS)
        {
          if (GET_CODE (XEXP (op0, 0)) == MULT)
            {
              ireg = XEXP (XEXP (op0, 0), 0);
              scale = XEXP (XEXP (op0, 0), 1);
              if (GET_CODE (XEXP (op0, 1)) == REG)
                {
                  breg = XEXP (op0, 1);
                  offset = op1;
                }
              else
                abort ();
            }
          else if (GET_CODE (XEXP (op0, 0)) == REG)
            {
              breg = XEXP (op0, 0);
              if (GET_CODE (XEXP (op0, 1)) == REG)
                {
                  ireg = XEXP (op0, 1);
                  offset = op1;
                }
              else
                abort ();
            }
          else
            abort ();
        }
      else if (GET_CODE (op0) == MULT)
        {
          ireg = XEXP (op0, 0);
          scale = XEXP (op0, 1);
          if (GET_CODE (op1) == REG)
            breg = op1;
          else if (CONSTANT_P (op1))
            offset = op1;
          else
            abort ();
        }
      else
        abort ();
    }
  else if (GET_CODE (addr) == MULT)
    {
      ireg = XEXP (addr, 0);
      scale = XEXP (addr, 1);
    }
  else
    abort ();

  if (offset)
    output_addr_const (file, offset);
  if (breg)
    fprintf (file, "(%s)", reg_names[REGNO (breg)]);
  if (ireg)
    fprintf (file, "[%s*%d]", reg_names[REGNO (ireg)], INTVAL (scale));
}
\f
/* GO_IF_LEGITIMATE_ADDRESS recognizes an RTL expression
   that is a valid memory address for an instruction.
   The MODE argument is the machine mode for the MEM expression
   that wants to use this address.

        On 80960, legitimate addresses are:
                base                            ld      (g0),r0
                disp    (12 or 32 bit)          ld      foo,r0
                base + index                    ld      (g0)[g1*1],r0
                base + displ                    ld      0xf00(g0),r0
                base + index*scale + displ      ld      0xf00(g0)[g1*4],r0
                index*scale + base              ld      (g0)[g1*4],r0
                index*scale + displ             ld      0xf00[g1*4],r0
                index*scale                     ld      [g1*4],r0
                index + base + displ            ld      0xf00(g0)[g1*1],r0

        In each case, scale can be 1, 2, 4, 8, or 16.  */

/* This is exactly the same as i960_print_operand_addr, except that
   it recognizes addresses instead of printing them.

   It only recognizes address in canonical form.  LEGITIMIZE_ADDRESS should
   convert common non-canonical forms to canonical form so that they will
   be recognized.  */

/* These two macros allow us to accept either a REG or a SUBREG anyplace
   where a register is valid.  */

#define RTX_OK_FOR_BASE_P(X, STRICT)                                    \
  ((GET_CODE (X) == REG                                                 \
    && (STRICT ? REG_OK_FOR_BASE_P_STRICT (X) : REG_OK_FOR_BASE_P (X))) \
   || (GET_CODE (X) == SUBREG                                           \
       && GET_CODE (SUBREG_REG (X)) == REG                              \
       && (STRICT ? REG_OK_FOR_BASE_P_STRICT (SUBREG_REG (X))           \
           : REG_OK_FOR_BASE_P (SUBREG_REG (X)))))

#define RTX_OK_FOR_INDEX_P(X, STRICT)                                   \
  ((GET_CODE (X) == REG                                                 \
    && (STRICT ? REG_OK_FOR_INDEX_P_STRICT (X) : REG_OK_FOR_INDEX_P (X)))\
   || (GET_CODE (X) == SUBREG                                           \
       && GET_CODE (SUBREG_REG (X)) == REG                              \
       && (STRICT ? REG_OK_FOR_INDEX_P_STRICT (SUBREG_REG (X))          \
           : REG_OK_FOR_INDEX_P (SUBREG_REG (X)))))

int
legitimate_address_p (mode, addr, strict)
     enum machine_mode mode;
     register rtx addr;
     int strict;
{
  if (RTX_OK_FOR_BASE_P (addr, strict))
    return 1;
  else if (CONSTANT_P (addr))
    return 1;
  else if (GET_CODE (addr) == PLUS)
    {
      rtx op0, op1;

      if (! TARGET_COMPLEX_ADDR && ! reload_completed)
        return 0;

      op0 = XEXP (addr, 0);
      op1 = XEXP (addr, 1);

      if (RTX_OK_FOR_BASE_P (op0, strict))
        {
          if (RTX_OK_FOR_INDEX_P (op1, strict))
            return 1;
          else if (CONSTANT_P (op1))
            return 1;
          else
            return 0;
        }
      else if (GET_CODE (op0) == PLUS)
        {
          if (GET_CODE (XEXP (op0, 0)) == MULT)
            {
              if (! (RTX_OK_FOR_INDEX_P (XEXP (XEXP (op0, 0), 0), strict)
                     && SCALE_TERM_P (XEXP (XEXP (op0, 0), 1))))
                return 0;

              if (RTX_OK_FOR_BASE_P (XEXP (op0, 1), strict)
                  && CONSTANT_P (op1))
                return 1;
              else
                return 0;
            }
          else if (RTX_OK_FOR_BASE_P (XEXP (op0, 0), strict))
            {
              if (RTX_OK_FOR_INDEX_P (XEXP (op0, 1), strict)
                  && CONSTANT_P (op1))
                return 1;
              else
                return 0;
            }
          else
            return 0;
        }
      else if (GET_CODE (op0) == MULT)
        {
          if (! (RTX_OK_FOR_INDEX_P (XEXP (op0, 0), strict)
                 && SCALE_TERM_P (XEXP (op0, 1))))
            return 0;

          if (RTX_OK_FOR_BASE_P (op1, strict))
            return 1;
          else if (CONSTANT_P (op1))
            return 1;
          else
            return 0;
        }
      else
        return 0;
    }
  else if (GET_CODE (addr) == MULT)
    {
      if (! TARGET_COMPLEX_ADDR && ! reload_completed)
        return 0;

      return (RTX_OK_FOR_INDEX_P (XEXP (addr, 0), strict)
              && SCALE_TERM_P (XEXP (addr, 1)));
    }
  else
    return 0;
}

/* Try machine-dependent ways of modifying an illegitimate address
   to be legitimate.  If we find one, return the new, valid address.
   This macro is used in only one place: `memory_address' in explow.c.

   This converts some non-canonical addresses to canonical form so they
   can be recognized.  */

rtx
legitimize_address (x, oldx, mode)
     register rtx x;
     register rtx oldx;
     enum machine_mode mode;
{ 
  if (GET_CODE (x) == SYMBOL_REF)
    {
      abort ();
      x = copy_to_reg (x);
    }

  if (! TARGET_COMPLEX_ADDR && ! reload_completed)
    return x;

  /* Canonicalize (plus (mult (reg) (const)) (plus (reg) (const)))
     into (plus (plus (mult (reg) (const)) (reg)) (const)).  This can be
     created by virtual register instantiation, register elimination, and
     similar optimizations.  */
  if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 0)) == MULT
      && GET_CODE (XEXP (x, 1)) == PLUS)
    x = gen_rtx (PLUS, Pmode,
                 gen_rtx (PLUS, Pmode, XEXP (x, 0), XEXP (XEXP (x, 1), 0)),
                 XEXP (XEXP (x, 1), 1));

  /* Canonicalize (plus (plus (mult (reg) (const)) (plus (reg) (const))) const)
     into (plus (plus (mult (reg) (const)) (reg)) (const)).  */
  else if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 0)) == PLUS
           && GET_CODE (XEXP (XEXP (x, 0), 0)) == MULT
           && GET_CODE (XEXP (XEXP (x, 0), 1)) == PLUS
           && CONSTANT_P (XEXP (x, 1)))
    {
      rtx constant, other;

      if (GET_CODE (XEXP (x, 1)) == CONST_INT)
        {
          constant = XEXP (x, 1);
          other = XEXP (XEXP (XEXP (x, 0), 1), 1);
        }
      else if (GET_CODE (XEXP (XEXP (XEXP (x, 0), 1), 1)) == CONST_INT)
        {
          constant = XEXP (XEXP (XEXP (x, 0), 1), 1);
          other = XEXP (x, 1);
        }
      else
        constant = 0;

      if (constant)
        x = gen_rtx (PLUS, Pmode,
                     gen_rtx (PLUS, Pmode, XEXP (XEXP (x, 0), 0),
                              XEXP (XEXP (XEXP (x, 0), 1), 0)),
                     plus_constant (other, INTVAL (constant)));
    }

  return x;
}
\f
#if 0
/* Return the most stringent alignment that we are willing to consider
   objects of size SIZE and known alignment ALIGN as having. */
   
int
i960_alignment (size, align)
     int size;
     int align;
{
  int i;

  if (! TARGET_STRICT_ALIGN)
    if (TARGET_IC_COMPAT2_0 || align >= 4)
      {
        i = i960_object_bytes_bitalign (size) / BITS_PER_UNIT;
        if (i > align)
          align = i;
      }

  return align;
}
#endif
\f
/* Modes for condition codes.  */
#define C_MODES         \
  ((1 << (int) CCmode) | (1 << (int) CC_UNSmode) | (1<< (int) CC_CHKmode))

/* Modes for single-word (and smaller) quantities.  */
#define S_MODES                                         \
 (~C_MODES                                              \
  & ~ ((1 << (int) DImode) | (1 << (int) TImode)        \
       | (1 << (int) DFmode) | (1 << (int) TFmode)))

/* Modes for double-word (and smaller) quantities.  */
#define D_MODES                                 \
  (~C_MODES                                     \
   & ~ ((1 << (int) TImode) | (1 << (int) TFmode)))

/* Modes for quad-word quantities.  */
#define T_MODES (~C_MODES)

/* Modes for single-float quantities.  */
#define SF_MODES ((1 << (int) SFmode))

/* Modes for double-float quantities.  */
#define DF_MODES (SF_MODES | (1 << (int) DFmode) | (1 << (int) SCmode))

/* Modes for quad-float quantities.  */
#define TF_MODES (DF_MODES | (1 << (int) TFmode) | (1 << (int) DCmode))

unsigned int hard_regno_mode_ok[FIRST_PSEUDO_REGISTER] = {
  T_MODES, S_MODES, D_MODES, S_MODES, T_MODES, S_MODES, D_MODES, S_MODES,
  T_MODES, S_MODES, D_MODES, S_MODES, T_MODES, S_MODES, D_MODES, S_MODES,
  T_MODES, S_MODES, D_MODES, S_MODES, T_MODES, S_MODES, D_MODES, S_MODES,
  T_MODES, S_MODES, D_MODES, S_MODES, T_MODES, S_MODES, D_MODES, S_MODES,

  TF_MODES, TF_MODES, TF_MODES, TF_MODES, C_MODES};

\f
/* Return the minimum alignment of an expression rtx X in bytes.  This takes
   advantage of machine specific facts, such as knowing that the frame pointer
   is always 16 byte aligned.  */

int
i960_expr_alignment (x, size)
     rtx x;
     int size;
{
  int align = 1;

  if (x == 0)
    return 1;

  switch (GET_CODE(x))
    {
    case CONST_INT:
      align = INTVAL(x);

      if ((align & 0xf) == 0)
        align = 16;
      else if ((align & 0x7) == 0)
        align = 8;
      else if ((align & 0x3) == 0)
        align = 4;
      else if ((align & 0x1) == 0)
        align = 2;
      else
        align = 1;
      break;

    case PLUS:
      align = MIN (i960_expr_alignment (XEXP (x, 0), size),
                   i960_expr_alignment (XEXP (x, 1), size));
      break;

    case SYMBOL_REF:
      /* If this is a valid program, objects are guaranteed to be
         correctly aligned for whatever size the reference actually is. */
      align = i960_object_bytes_bitalign (size) / BITS_PER_UNIT;
      break;

    case REG:
      if (REGNO (x) == FRAME_POINTER_REGNUM)
        align = 16;
      break;

    case ASHIFT:
      align = i960_expr_alignment (XEXP (x, 0));

      if (GET_CODE (XEXP (x, 1)) == CONST_INT)
        {
          align = align << INTVAL (XEXP (x, 1));
          align = MIN (align, 16);
        }
      break;

    case MULT:
      align = (i960_expr_alignment (XEXP (x, 0), size) *
               i960_expr_alignment (XEXP (x, 1), size));

      align = MIN (align, 16);
      break;
    }

  return align;
}

/* Return true if it is possible to reference both BASE and OFFSET, which
   have alignment at least as great as 4 byte, as if they had alignment valid
   for an object of size SIZE.  */

int
i960_improve_align (base, offset, size)
     rtx base;
     rtx offset;
     int size;
{
  int i, j;

  /* We have at least a word reference to the object, so we know it has to
     be aligned at least to 4 bytes.  */

  i = MIN (i960_expr_alignment (base, 4),
           i960_expr_alignment (offset, 4));

  i = MAX (i, 4);

  /* We know the size of the request.  If strict align is not enabled, we
     can guess that the alignment is OK for the requested size.  */

  if (! TARGET_STRICT_ALIGN)
    if ((j = (i960_object_bytes_bitalign (size) / BITS_PER_UNIT)) > i)
      i = j;

  return (i >= size);
}

/* Return true if it is possible to access BASE and OFFSET, which have 4 byte
   (SImode) alignment as if they had 16 byte (TImode) alignment.  */

int
i960_si_ti (base, offset)
     rtx base;
     rtx offset;
{
  return i960_improve_align (base, offset, 16);
}

/* Return true if it is possible to access BASE and OFFSET, which have 4 byte
   (SImode) alignment as if they had 8 byte (DImode) alignment.  */

int
i960_si_di (base, offset)
     rtx base;
     rtx offset;
{
  return i960_improve_align (base, offset, 8);
}
\f
/* Return raw values of size and alignment (in words) for the data
   type being accessed.  These values will be rounded by the caller.  */

static void 
i960_arg_size_and_align (mode, type, size_out, align_out)
     enum machine_mode mode;
     tree type;
     int *size_out;
     int *align_out;
{
  int size, align;

  /* Use formal alignment requirements of type being passed, except make
     it at least a word.  If we don't have a type, this is a library call,
     and the parm has to be of scalar type.  In this case, consider its
     formal alignment requirement to be its size in words.  */

  if (mode == BLKmode)
    size = (int_size_in_bytes (type) + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
  else if (mode == VOIDmode)
    {
      /* End of parm list.  */
      assert (type != 0 && TYPE_MODE (type) == VOIDmode);
      size = 1;
    }
  else
    size = (GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD;

  if (type == 0)
    align = size;
  else if (TYPE_ALIGN (type) >= BITS_PER_WORD)
    align = TYPE_ALIGN (type) / BITS_PER_WORD;
  else
    align = 1;

  *size_out  = size;
  *align_out = align;
}

/* On the 80960 the first 12 args are in registers and the rest are pushed.
   Any arg that is bigger than 4 words is placed on the stack and all
   subsequent arguments are placed on the stack.

   Additionally, parameters with an alignment requirement stronger than
   a word must be be aligned appropriately.  */

/* Update CUM to advance past an argument described by MODE and TYPE.  */

void
i960_function_arg_advance (cum, mode, type, named)
     CUMULATIVE_ARGS *cum;
     enum machine_mode mode;
     tree type;
     int named;
{
  int size, align;

  i960_arg_size_and_align (mode, type, &size, &align);

  if (named == 0 || size > 4 || cum->ca_nstackparms != 0
      || (size + ROUND_PARM (cum->ca_nregparms, align)) > NPARM_REGS
      || MUST_PASS_IN_STACK (mode, type))
    cum->ca_nstackparms = ROUND_PARM (cum->ca_nstackparms, align) + size;
  else
    cum->ca_nregparms = ROUND_PARM (cum->ca_nregparms, align) + size;
}

/* Return the register that the argument described by MODE and TYPE is
   passed in, or else return 0 if it is passed on the stack.  */

rtx
i960_function_arg (cum, mode, type, named)
     CUMULATIVE_ARGS *cum;
     enum machine_mode mode;
     tree type;
     int named;
{
  rtx ret;
  int size, align;

  i960_arg_size_and_align (mode, type, &size, &align);

  if (named == 0 || size > 4 || cum->ca_nstackparms != 0
      || (size + ROUND_PARM (cum->ca_nregparms, align)) > NPARM_REGS
      || MUST_PASS_IN_STACK (mode, type))
    {
      cum->ca_nstackparms = ROUND_PARM (cum->ca_nstackparms, align);
      ret = 0;
    }
  else
    {
      cum->ca_nregparms = ROUND_PARM (cum->ca_nregparms, align);
      ret = gen_rtx (REG, mode, cum->ca_nregparms);
    }

  return ret;
}
\f
/* Floating-point support.  */

void
i960_output_double (file, value)
     FILE *file;
     double value;
{
  if (REAL_VALUE_ISINF (value))
    {
      fprintf (file, "\t.word   0\n");
      fprintf (file, "\t.word   0x7ff00000      # Infinity\n");
    }
  else
    fprintf (file, "\t.double 0d%.17e\n", (value));
}

void
i960_output_float (file, value)
     FILE *file;
     double value;
{
  if (REAL_VALUE_ISINF (value))
    fprintf (file, "\t.word     0x7f800000      # Infinity\n");
  else
    fprintf (file, "\t.float 0f%.12e\n", (value));
}
\f
/* Return the number of bits that an object of size N bytes is aligned to.  */

int
i960_object_bytes_bitalign (n)
     int n;
{
  if (n > 8)      n = 128;
  else if (n > 4) n = 64;
  else if (n > 2) n = 32;
  else if (n > 1) n = 16;
  else            n = 8;

  return n;
}

/* Compute the size of an aggregate type TSIZE.  */

tree
i960_round_size (tsize)
     tree tsize;
{
  int size, byte_size, align;

  if (TREE_CODE (tsize) != INTEGER_CST)
    return tsize;

  size = TREE_INT_CST_LOW (tsize);
  byte_size = (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
  align = i960_object_bytes_bitalign (byte_size);

  /* Handle #pragma align.  */
  if (align > i960_maxbitalignment)
    align = i960_maxbitalignment;

  if (size % align)
    size = ((size / align) + 1) * align;

  return size_int (size);
}

/* Compute the alignment for an aggregate type TSIZE.  */

int
i960_round_align (align, tsize)
     int align;
     tree tsize;
{
  int byte_size;

  if (TREE_CODE (tsize) != INTEGER_CST)
    return align;

  byte_size = (TREE_INT_CST_LOW (tsize) + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
  align = i960_object_bytes_bitalign (byte_size);
  return align;
}
\f
/* Do any needed setup for a varargs function.  For the i960, we must
   create a register parameter block if one doesn't exist, and then copy
   all register parameters to memory.  */

void
i960_setup_incoming_varargs (cum, mode, type, pretend_size, no_rtl)
     CUMULATIVE_ARGS *cum;
     enum machine_mode mode;
     tree type;
     int *pretend_size;
     int no_rtl;
{
  if (cum->ca_nregparms < NPARM_REGS)
    {
      int first_reg_offset = cum->ca_nregparms;

      if (first_reg_offset > NPARM_REGS)
        first_reg_offset = NPARM_REGS;

      if (! (no_rtl) && first_reg_offset != NPARM_REGS)
        {
          rtx label = gen_label_rtx ();
          rtx regblock;

          emit_insn (gen_cmpsi (arg_pointer_rtx, const0_rtx));
          emit_jump_insn (gen_bne (label));
          emit_insn (gen_rtx (SET, VOIDmode, arg_pointer_rtx,
                              stack_pointer_rtx));
          emit_insn (gen_rtx (SET, VOIDmode, stack_pointer_rtx,
                              memory_address (SImode,
                                              plus_constant (stack_pointer_rtx,
                                                             48))));
          emit_label (label);

          regblock = gen_rtx (MEM, BLKmode,
                              plus_constant (arg_pointer_rtx,
                                             first_reg_offset * 4));
          move_block_from_reg (first_reg_offset, regblock,
                               NPARM_REGS - first_reg_offset,
                               ((NPARM_REGS - first_reg_offset)
                                * UNITS_PER_WORD));
        }
      *pretend_size = (NPARM_REGS - first_reg_offset) * UNITS_PER_WORD;
    }
}

/* Calculate the final size of the reg parm stack space for the current
   function, based on how many bytes would be allocated on the stack.  */

int
i960_final_reg_parm_stack_space (const_size, var_size)
     int const_size;
     tree var_size;
{
  if (var_size || const_size > 48)
    return 48;
  else
    return 0;
}

/* Calculate the size of the reg parm stack space.  This is a bit complicated
   on the i960.  */

int
i960_reg_parm_stack_space (fndecl)
     tree fndecl;
{
  /* In this case, we are called from emit_library_call, and we don't need
     to pretend we have more space for parameters than what's apparent.  */
  if (fndecl == 0)
    return 0;

  /* In this case, we are called from locate_and_pad_parms when we're
     not IN_REGS, so we have an arg block.  */
  if (fndecl != current_function_decl)
    return 48;

  /* Otherwise, we have an arg block if the current function has more than
     48 bytes of parameters.  */
  if (current_function_args_size != 0)
    return 48;
  else
    return 0;
}
\f
/* Return the register class of a scratch register needed to copy IN into
   or out of a register in CLASS in MODE.  If it can be done directly,
   NO_REGS is returned.  */

enum reg_class
secondary_reload_class (class, mode, in)
     enum reg_class class;
     enum machine_mode mode;
     rtx in;
{
  int regno = -1;

  if (GET_CODE (in) == REG || GET_CODE (in) == SUBREG)
    regno = true_regnum (in);

  /* We can place anything into LOCAL_OR_GLOBAL_REGS and can put
     LOCAL_OR_GLOBAL_REGS into anything.  */
  if (class == LOCAL_OR_GLOBAL_REGS || class == LOCAL_REGS
      || class == GLOBAL_REGS || (regno >= 0 && regno < 32))
    return NO_REGS;

  /* We can place any hard register, 0.0, and 1.0 into FP_REGS.  */
  if (class == FP_REGS
      && ((regno >= 0 && regno < FIRST_PSEUDO_REGISTER)
          || in == CONST0_RTX (mode) || in == CONST1_RTX (mode)))
    return NO_REGS;

  return LOCAL_OR_GLOBAL_REGS;
}
\f
/* Look at the opcode P, and set i96_last_insn_type to indicate which
   function unit it executed on.  */

/* ??? This would make more sense as an attribute.  */

void
i960_scan_opcode (p)
     char *p;
{
  switch (*p)
    {
    case 'a':
    case 'd':
    case 'e':
    case 'm':
    case 'n':
    case 'o':
    case 'r':
      /* Ret is not actually of type REG, but it won't matter, because no
         insn will ever follow it.  */
    case 'u':
    case 'x':
      i960_last_insn_type = I_TYPE_REG;
      break;

    case 'b':
      if (p[1] == 'x' || p[3] == 'x')
        i960_last_insn_type = I_TYPE_MEM;
      i960_last_insn_type = I_TYPE_CTRL;
      break;

    case 'f':
    case 't':
      i960_last_insn_type = I_TYPE_CTRL;
      break;

    case 'c':
      if (p[1] == 'a')
        {
          if (p[4] == 'x')
            i960_last_insn_type = I_TYPE_MEM;
          else
            i960_last_insn_type = I_TYPE_CTRL;
        }
      else if (p[1] == 'm')
        {
          if (p[3] == 'd')
            i960_last_insn_type = I_TYPE_REG;
          else if (p[4] == 'b' || p[4] == 'j')
            i960_last_insn_type = I_TYPE_CTRL;
          else
            i960_last_insn_type = I_TYPE_REG;
        }
      else
        i960_last_insn_type = I_TYPE_REG;
      break;

    case 'l':
      i960_last_insn_type = I_TYPE_MEM;
      break;

    case 's':
      if (p[1] == 't')
        i960_last_insn_type = I_TYPE_MEM;
      else
        i960_last_insn_type = I_TYPE_REG;
      break;
    }
}