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[deliverable/binutils-gdb.git] / gas / config / tc-mn10300.c

/* tc-mn10300.c -- Assembler code for the Matsushita 10300

   Copyright (C) 1996, 1997 Free Software Foundation.

   This file is part of GAS, the GNU Assembler.

   GAS 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.

   GAS 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 GAS; 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 <ctype.h>
#include "as.h"
#include "subsegs.h"     
#include "opcode/mn10300.h"
\f
/* Structure to hold information about predefined registers.  */
struct reg_name
{
  const char *name;
  int value;
};

/* Generic assembler global variables which must be defined by all targets. */

/* Characters which always start a comment. */
const char comment_chars[] = "#";

/* Characters which start a comment at the beginning of a line.  */
const char line_comment_chars[] = ";#";

/* Characters which may be used to separate multiple commands on a 
   single line.  */
const char line_separator_chars[] = ";";

/* Characters which are used to indicate an exponent in a floating 
   point number.  */
const char EXP_CHARS[] = "eE";

/* Characters which mean that a number is a floating point constant, 
   as in 0d1.0.  */
const char FLT_CHARS[] = "dD";
\f

const relax_typeS md_relax_table[] = {
  /* bCC relaxing */
  {0x7f, -0x80, 2, 1},
  {0x7fff, -0x8000, 5, 2},
  {0x7fffffff, -0x80000000, 7, 0},

  /* bCC relaxing (uncommon cases) */
  {0x7f, -0x80, 3, 4},
  {0x7fff, -0x8000, 6, 5},
  {0x7fffffff, -0x80000000, 8, 0},

  /* call relaxing */
  {0x7fff, -0x8000, 5, 7},
  {0x7fffffff, -0x80000000, 7, 0},

  /* calls relaxing */
  {0x7fff, -0x8000, 4, 9},
  {0x7fffffff, -0x80000000, 6, 0},

  /* jmp relaxing */
  {0x7f, -0x80, 2, 11},
  {0x7fff, -0x8000, 3, 12},
  {0x7fffffff, -0x80000000, 5, 0},

};

/* local functions */
static void mn10300_insert_operand PARAMS ((unsigned long *, unsigned long *,
                                            const struct mn10300_operand *,
                                            offsetT, char *, unsigned,
                                            unsigned));
static unsigned long check_operand PARAMS ((unsigned long,
                                            const struct mn10300_operand *,
                                            offsetT));
static int reg_name_search PARAMS ((const struct reg_name *, int, const char *));
static boolean data_register_name PARAMS ((expressionS *expressionP));
static boolean address_register_name PARAMS ((expressionS *expressionP));
static boolean other_register_name PARAMS ((expressionS *expressionP));


/* fixups */
#define MAX_INSN_FIXUPS (5)
struct mn10300_fixup
{
  expressionS exp;
  int opindex;
  bfd_reloc_code_real_type reloc;
};
struct mn10300_fixup fixups[MAX_INSN_FIXUPS];
static int fc;
\f
const char *md_shortopts = "";
struct option md_longopts[] = {
  {NULL, no_argument, NULL, 0}
};
size_t md_longopts_size = sizeof(md_longopts); 

/* The target specific pseudo-ops which we support.  */
const pseudo_typeS md_pseudo_table[] =
{
  { NULL,       NULL,           0 }
};

/* Opcode hash table.  */
static struct hash_control *mn10300_hash;

/* This table is sorted. Suitable for searching by a binary search. */
static const struct reg_name data_registers[] =
{
  { "d0", 0 },
  { "d1", 1 },
  { "d2", 2 },
  { "d3", 3 },
};
#define DATA_REG_NAME_CNT       (sizeof(data_registers) / sizeof(struct reg_name))

static const struct reg_name address_registers[] =
{
  { "a0", 0 },
  { "a1", 1 },
  { "a2", 2 },
  { "a3", 3 },
};
#define ADDRESS_REG_NAME_CNT    (sizeof(address_registers) / sizeof(struct reg_name))

static const struct reg_name other_registers[] =
{
  { "mdr", 0 },
  { "psw", 0 },
  { "sp", 0 },
};
#define OTHER_REG_NAME_CNT      (sizeof(other_registers) / sizeof(struct reg_name))

/* reg_name_search does a binary search of the given register table
   to see if "name" is a valid regiter name.  Returns the register
   number from the array on success, or -1 on failure. */

static int
reg_name_search (regs, regcount, name)
     const struct reg_name *regs;
     int regcount;
     const char *name;
{
  int middle, low, high;
  int cmp;

  low = 0;
  high = regcount - 1;

  do
    {
      middle = (low + high) / 2;
      cmp = strcasecmp (name, regs[middle].name);
      if (cmp < 0)
        high = middle - 1;
      else if (cmp > 0)
        low = middle + 1;
      else 
          return regs[middle].value;
    }
  while (low <= high);
  return -1;
}


/* Summary of register_name().
 *
 * in: Input_line_pointer points to 1st char of operand.
 *
 * out: A expressionS.
 *      The operand may have been a register: in this case, X_op == O_register,
 *      X_add_number is set to the register number, and truth is returned.
 *      Input_line_pointer->(next non-blank) char after operand, or is in
 *      its original state.
 */
static boolean
data_register_name (expressionP)
     expressionS *expressionP;
{
  int reg_number;
  char *name;
  char *start;
  char c;

  /* Find the spelling of the operand */
  start = name = input_line_pointer;

  c = get_symbol_end ();
  reg_number = reg_name_search (data_registers, DATA_REG_NAME_CNT, name);

  /* look to see if it's in the register table */
  if (reg_number >= 0) 
    {
      expressionP->X_op = O_register;
      expressionP->X_add_number = reg_number;

      /* make the rest nice */
      expressionP->X_add_symbol = NULL;
      expressionP->X_op_symbol = NULL;
      *input_line_pointer = c;  /* put back the delimiting char */
      return true;
    }
  else
    {
      /* reset the line as if we had not done anything */
      *input_line_pointer = c;   /* put back the delimiting char */
      input_line_pointer = start; /* reset input_line pointer */
      return false;
    }
}

/* Summary of register_name().
 *
 * in: Input_line_pointer points to 1st char of operand.
 *
 * out: A expressionS.
 *      The operand may have been a register: in this case, X_op == O_register,
 *      X_add_number is set to the register number, and truth is returned.
 *      Input_line_pointer->(next non-blank) char after operand, or is in
 *      its original state.
 */
static boolean
address_register_name (expressionP)
     expressionS *expressionP;
{
  int reg_number;
  char *name;
  char *start;
  char c;

  /* Find the spelling of the operand */
  start = name = input_line_pointer;

  c = get_symbol_end ();
  reg_number = reg_name_search (address_registers, ADDRESS_REG_NAME_CNT, name);

  /* look to see if it's in the register table */
  if (reg_number >= 0) 
    {
      expressionP->X_op = O_register;
      expressionP->X_add_number = reg_number;

      /* make the rest nice */
      expressionP->X_add_symbol = NULL;
      expressionP->X_op_symbol = NULL;
      *input_line_pointer = c;  /* put back the delimiting char */
      return true;
    }
  else
    {
      /* reset the line as if we had not done anything */
      *input_line_pointer = c;   /* put back the delimiting char */
      input_line_pointer = start; /* reset input_line pointer */
      return false;
    }
}

/* Summary of register_name().
 *
 * in: Input_line_pointer points to 1st char of operand.
 *
 * out: A expressionS.
 *      The operand may have been a register: in this case, X_op == O_register,
 *      X_add_number is set to the register number, and truth is returned.
 *      Input_line_pointer->(next non-blank) char after operand, or is in
 *      its original state.
 */
static boolean
other_register_name (expressionP)
     expressionS *expressionP;
{
  int reg_number;
  char *name;
  char *start;
  char c;

  /* Find the spelling of the operand */
  start = name = input_line_pointer;

  c = get_symbol_end ();
  reg_number = reg_name_search (other_registers, OTHER_REG_NAME_CNT, name);

  /* look to see if it's in the register table */
  if (reg_number >= 0) 
    {
      expressionP->X_op = O_register;
      expressionP->X_add_number = reg_number;

      /* make the rest nice */
      expressionP->X_add_symbol = NULL;
      expressionP->X_op_symbol = NULL;
      *input_line_pointer = c;  /* put back the delimiting char */
      return true;
    }
  else
    {
      /* reset the line as if we had not done anything */
      *input_line_pointer = c;   /* put back the delimiting char */
      input_line_pointer = start; /* reset input_line pointer */
      return false;
    }
}

void
md_show_usage (stream)
  FILE *stream;
{
  fprintf(stream, "MN10300 options:\n\
none yet\n");
} 

int
md_parse_option (c, arg)
     int c;
     char *arg;
{
  return 0;
}

symbolS *
md_undefined_symbol (name)
  char *name;
{
  return 0;
}

char *
md_atof (type, litp, sizep)
  int type;
  char *litp;
  int *sizep;
{
  int prec;
  LITTLENUM_TYPE words[4];
  char *t;
  int i;

  switch (type)
    {
    case 'f':
      prec = 2;
      break;

    case 'd':
      prec = 4;
      break;

    default:
      *sizep = 0;
      return "bad call to md_atof";
    }
  
  t = atof_ieee (input_line_pointer, type, words);
  if (t)
    input_line_pointer = t;

  *sizep = prec * 2;

  for (i = prec - 1; i >= 0; i--)
    {
      md_number_to_chars (litp, (valueT) words[i], 2);
      litp += 2;
    }

  return NULL;
}


void
md_convert_frag (abfd, sec, fragP)
  bfd *abfd;
  asection *sec;
  fragS *fragP;
{
  static unsigned long label_count = 0;
  char buf[40];

  subseg_change (sec, 0);
  if (fragP->fr_subtype == 0)
    {
      fix_new (fragP, fragP->fr_fix + 1, 1, fragP->fr_symbol,
               fragP->fr_offset + 1, 1, BFD_RELOC_8_PCREL);
      fragP->fr_var = 0;
      fragP->fr_fix += 2;
    }
  else if (fragP->fr_subtype == 1)
    {
      /* Reverse the condition of the first branch.  */
      int offset = fragP->fr_fix;
      int opcode = fragP->fr_literal[offset] & 0xff;

      switch (opcode)
        {
        case 0xc8:
          opcode = 0xc9;
          break;
        case 0xc9:
          opcode = 0xc8;
          break;
        case 0xc0:
          opcode = 0xc2;
          break;
        case 0xc2:
          opcode = 0xc0;
          break;
        case 0xc3:
          opcode = 0xc1;
          break;
        case 0xc1:
          opcode = 0xc3;
          break;
        case 0xc4:
          opcode = 0xc6;
          break;
        case 0xc6:
          opcode = 0xc4;
          break;
        case 0xc7:
          opcode = 0xc5;
          break;
        case 0xc5:
          opcode = 0xc7;
          break;
        default:
          abort ();
        }
      fragP->fr_literal[offset] = opcode;

      /* Create a fixup for the reversed conditional branch.  */
      sprintf (buf, "%s_%d", FAKE_LABEL_NAME, label_count++);
      fix_new (fragP, fragP->fr_fix + 1, 1,
               symbol_new (buf, sec, 0, fragP->fr_next),
               fragP->fr_offset + 1, 1, BFD_RELOC_8_PCREL);

      /* Now create the unconditional branch + fixup to the
         final target.  */
      fragP->fr_literal[offset + 2] = 0xcc;
      fix_new (fragP, fragP->fr_fix + 3, 2, fragP->fr_symbol,
               fragP->fr_offset + 1, 1, BFD_RELOC_16_PCREL);
      fragP->fr_var = 0;
      fragP->fr_fix += 5;
    }
  else if (fragP->fr_subtype == 2)
    {
      /* Reverse the condition of the first branch.  */
      int offset = fragP->fr_fix;
      int opcode = fragP->fr_literal[offset] & 0xff;

      switch (opcode)
        {
        case 0xc8:
          opcode = 0xc9;
          break;
        case 0xc9:
          opcode = 0xc8;
          break;
        case 0xc0:
          opcode = 0xc2;
          break;
        case 0xc2:
          opcode = 0xc0;
          break;
        case 0xc3:
          opcode = 0xc1;
          break;
        case 0xc1:
          opcode = 0xc3;
          break;
        case 0xc4:
          opcode = 0xc6;
          break;
        case 0xc6:
          opcode = 0xc4;
          break;
        case 0xc7:
          opcode = 0xc5;
          break;
        case 0xc5:
          opcode = 0xc7;
          break;
        default:
          abort ();
        }
      fragP->fr_literal[offset] = opcode;

      /* Create a fixup for the reversed conditional branch.  */
      sprintf (buf, "%s_%d", FAKE_LABEL_NAME, label_count++);
      fix_new (fragP, fragP->fr_fix + 1, 1,
               symbol_new (buf, sec, 0, fragP->fr_next),
               fragP->fr_offset + 1, 1, BFD_RELOC_8_PCREL);

      /* Now create the unconditional branch + fixup to the
         final target.  */
      fragP->fr_literal[offset + 2] = 0xdc;
      fix_new (fragP, fragP->fr_fix + 3, 4, fragP->fr_symbol,
               fragP->fr_offset + 1, 1, BFD_RELOC_32_PCREL);
      fragP->fr_var = 0;
      fragP->fr_fix += 7;
    }
  else if (fragP->fr_subtype == 3)
    {
      fix_new (fragP, fragP->fr_fix + 2, 1, fragP->fr_symbol,
               fragP->fr_offset + 2, 1, BFD_RELOC_8_PCREL);
      fragP->fr_var = 0;
      fragP->fr_fix += 3;
    }
  else if (fragP->fr_subtype == 4)
    {
      /* Reverse the condition of the first branch.  */
      int offset = fragP->fr_fix;
      int opcode = fragP->fr_literal[offset + 1] & 0xff;

      switch (opcode)
        {
        case 0xe8:
          opcode = 0xe9;
          break;
        case 0xe9:
          opcode = 0xe8;
          break;
        case 0xea:
          opcode = 0xeb;
          break;
        case 0xeb:
          opcode = 0xea;
          break;
        default:
          abort ();
        }
      fragP->fr_literal[offset + 1] = opcode;

      /* Create a fixup for the reversed conditional branch.  */
      sprintf (buf, "%s_%d", FAKE_LABEL_NAME, label_count++);
      fix_new (fragP, fragP->fr_fix + 2, 1,
               symbol_new (buf, sec, 0, fragP->fr_next),
               fragP->fr_offset + 2, 1, BFD_RELOC_8_PCREL);

      /* Now create the unconditional branch + fixup to the
         final target.  */
      fragP->fr_literal[offset + 3] = 0xcc;
      fix_new (fragP, fragP->fr_fix + 4, 2, fragP->fr_symbol,
               fragP->fr_offset + 1, 1, BFD_RELOC_16_PCREL);
      fragP->fr_var = 0;
      fragP->fr_fix += 6;
    }
  else if (fragP->fr_subtype == 5)
    {
      /* Reverse the condition of the first branch.  */
      int offset = fragP->fr_fix;
      int opcode = fragP->fr_literal[offset + 1] & 0xff;

      switch (opcode)
        {
        case 0xe8:
          opcode = 0xe9;
          break;
        case 0xea:
          opcode = 0xeb;
          break;
        case 0xeb:
          opcode = 0xea;
          break;
        default:
          abort ();
        }
      fragP->fr_literal[offset + 1] = opcode;

      /* Create a fixup for the reversed conditional branch.  */
      sprintf (buf, "%s_%d", FAKE_LABEL_NAME, label_count++);
      fix_new (fragP, fragP->fr_fix + 2, 1,
               symbol_new (buf, sec, 0, fragP->fr_next),
               fragP->fr_offset + 2, 1, BFD_RELOC_8_PCREL);

      /* Now create the unconditional branch + fixup to the
         final target.  */
      fragP->fr_literal[offset + 3] = 0xdc;
      fix_new (fragP, fragP->fr_fix + 4, 4, fragP->fr_symbol,
               fragP->fr_offset + 1, 1, BFD_RELOC_32_PCREL);
      fragP->fr_var = 0;
      fragP->fr_fix += 8;
    }
  else if (fragP->fr_subtype == 6)
    {
      int offset = fragP->fr_fix;
      fragP->fr_literal[offset] = 0xcd;
      fix_new (fragP, fragP->fr_fix + 1, 2, fragP->fr_symbol,
               fragP->fr_offset + 1, 1, BFD_RELOC_16_PCREL);
      fragP->fr_var = 0;
      fragP->fr_fix += 5;
    }
  else if (fragP->fr_subtype == 7)
    {
      int offset = fragP->fr_fix;
      fragP->fr_literal[offset] = 0xdd;
      fragP->fr_literal[offset + 5] = fragP->fr_literal[offset + 3];
      fragP->fr_literal[offset + 6] = fragP->fr_literal[offset + 4];

      fix_new (fragP, fragP->fr_fix + 2, 4, fragP->fr_symbol,
               fragP->fr_offset + 2, 1, BFD_RELOC_32_PCREL);
      fragP->fr_var = 0;
      fragP->fr_fix += 7;
    }
  else if (fragP->fr_subtype == 8)
    {
      int offset = fragP->fr_fix;
      fragP->fr_literal[offset] = 0xfa;
      fragP->fr_literal[offset + 1] = 0xff;
      fix_new (fragP, fragP->fr_fix + 2, 2, fragP->fr_symbol,
               fragP->fr_offset + 2, 1, BFD_RELOC_16_PCREL);
      fragP->fr_var = 0;
      fragP->fr_fix += 4;
    }
  else if (fragP->fr_subtype == 9)
    {
      int offset = fragP->fr_fix;
      fragP->fr_literal[offset] = 0xfc;
      fragP->fr_literal[offset + 1] = 0xff;

      fix_new (fragP, fragP->fr_fix + 2, 4, fragP->fr_symbol,
               fragP->fr_offset + 2, 1, BFD_RELOC_32_PCREL);
      fragP->fr_var = 0;
      fragP->fr_fix += 6;
    }
  else if (fragP->fr_subtype == 10)
    {
      fragP->fr_literal[fragP->fr_fix] = 0xca;
      fix_new (fragP, fragP->fr_fix + 1, 1, fragP->fr_symbol,
               fragP->fr_offset + 1, 1, BFD_RELOC_8_PCREL);
      fragP->fr_var = 0;
      fragP->fr_fix += 2;
    }
  else if (fragP->fr_subtype == 11)
    {
      int offset = fragP->fr_fix;
      fragP->fr_literal[offset] = 0xcc;

      fix_new (fragP, fragP->fr_fix + 1, 4, fragP->fr_symbol,
               fragP->fr_offset + 1, 1, BFD_RELOC_16_PCREL);
      fragP->fr_var = 0;
      fragP->fr_fix += 3;
    }
  else if (fragP->fr_subtype == 12)
    {
      int offset = fragP->fr_fix;
      fragP->fr_literal[offset] = 0xdc;

      fix_new (fragP, fragP->fr_fix + 1, 4, fragP->fr_symbol,
               fragP->fr_offset + 1, 1, BFD_RELOC_32_PCREL);
      fragP->fr_var = 0;
      fragP->fr_fix += 5;
    }
  else
    abort ();
}

valueT
md_section_align (seg, addr)
     asection *seg;
     valueT addr;
{
  int align = bfd_get_section_alignment (stdoutput, seg);
  return ((addr + (1 << align) - 1) & (-1 << align));
}

void
md_begin ()
{
  char *prev_name = "";
  register const struct mn10300_opcode *op;

  mn10300_hash = hash_new();

  /* Insert unique names into hash table.  The MN10300 instruction set
     has many identical opcode names that have different opcodes based
     on the operands.  This hash table then provides a quick index to
     the first opcode with a particular name in the opcode table.  */

  op = mn10300_opcodes;
  while (op->name)
    {
      if (strcmp (prev_name, op->name)) 
        {
          prev_name = (char *) op->name;
          hash_insert (mn10300_hash, op->name, (char *) op);
        }
      op++;
    }

  /* This is both a simplification (we don't have to write md_apply_fix)
     and support for future optimizations (branch shortening and similar
     stuff in the linker.  */
  linkrelax = 1;
}

void
md_assemble (str) 
     char *str;
{
  char *s;
  struct mn10300_opcode *opcode;
  struct mn10300_opcode *next_opcode;
  const unsigned char *opindex_ptr;
  int next_opindex, relaxable;
  unsigned long insn, extension, size = 0;
  char *f;
  int i;
  int match;

  /* Get the opcode.  */
  for (s = str; *s != '\0' && ! isspace (*s); s++)
    ;
  if (*s != '\0')
    *s++ = '\0';

  /* find the first opcode with the proper name */
  opcode = (struct mn10300_opcode *)hash_find (mn10300_hash, str);
  if (opcode == NULL)
    {
      as_bad ("Unrecognized opcode: `%s'", str);
      return;
    }

  str = s;
  while (isspace (*str))
    ++str;

  input_line_pointer = str;

  for(;;)
    {
      const char *errmsg = NULL;
      int op_idx;
      char *hold;
      int extra_shift = 0;

      relaxable = 0;
      fc = 0;
      match = 0;
      next_opindex = 0;
      insn = opcode->opcode;
      extension = 0;
      for (op_idx = 1, opindex_ptr = opcode->operands;
           *opindex_ptr != 0;
           opindex_ptr++, op_idx++)
        {
          const struct mn10300_operand *operand;
          expressionS ex;

          if (next_opindex == 0)
            {
              operand = &mn10300_operands[*opindex_ptr];
            }
          else
            {
              operand = &mn10300_operands[next_opindex];
              next_opindex = 0;
            }

          errmsg = NULL;

          while (*str == ' ' || *str == ',')
            ++str;

          if (operand->flags & MN10300_OPERAND_RELAX)
            relaxable = 1;

          /* Gather the operand. */
          hold = input_line_pointer;
          input_line_pointer = str;

          if (operand->flags & MN10300_OPERAND_PAREN)
            {
              if (*input_line_pointer != ')' && *input_line_pointer != '(')
                {
                  input_line_pointer = hold;
                  str = hold;
                  goto error;
                }
              input_line_pointer++;
              goto keep_going;
            }
          /* See if we can match the operands.  */
          else if (operand->flags & MN10300_OPERAND_DREG)
            {
              if (!data_register_name (&ex))
                {
                  input_line_pointer = hold;
                  str = hold;
                  goto error;
                }
            }
          else if (operand->flags & MN10300_OPERAND_AREG)
            {
              if (!address_register_name (&ex))
                {
                  input_line_pointer = hold;
                  str = hold;
                  goto error;
                }
            }
          else if (operand->flags & MN10300_OPERAND_SP)
            {
              char *start = input_line_pointer;
              char c = get_symbol_end ();

              if (strcmp (start, "sp") != 0)
                {
                  *input_line_pointer = c;
                  input_line_pointer = hold;
                  str = hold;
                  goto error;
                }
              *input_line_pointer = c;
              goto keep_going;
            }
          else if (operand->flags & MN10300_OPERAND_PSW)
            {
              char *start = input_line_pointer;
              char c = get_symbol_end ();

              if (strcmp (start, "psw") != 0)
                {
                  *input_line_pointer = c;
                  input_line_pointer = hold;
                  str = hold;
                  goto error;
                }
              *input_line_pointer = c;
              goto keep_going;
            }
          else if (operand->flags & MN10300_OPERAND_MDR)
            {
              char *start = input_line_pointer;
              char c = get_symbol_end ();

              if (strcmp (start, "mdr") != 0)
                {
                  *input_line_pointer = c;
                  input_line_pointer = hold;
                  str = hold;
                  goto error;
                }
              *input_line_pointer = c;
              goto keep_going;
            }
          else if (operand->flags & MN10300_OPERAND_REG_LIST)
            {
              unsigned int value = 0;
              if (*input_line_pointer != '[')
                {
                  input_line_pointer = hold;
                  str = hold;
                  goto error;
                }

              /* Eat the '['.  */
              input_line_pointer++;
             
              /* A null register list can not be specified.  */
              if (*input_line_pointer == ']')
                {
                  input_line_pointer = hold;
                  str = hold;
                  goto error;
                }

              while (*input_line_pointer != ']')
                {
                  char *start;
                  char c;

                  if (*input_line_pointer == ',')
                    input_line_pointer++;

                  start = input_line_pointer;
                  c = get_symbol_end ();

                  if (strcmp (start, "d2") == 0)
                    {
                      value |= 0x80;
                      *input_line_pointer = c;
                    }
                  else if (strcmp (start, "d3") == 0)
                    {
                      value |= 0x40;
                      *input_line_pointer = c;
                    }
                  else if (strcmp (start, "a2") == 0)
                    {
                      value |= 0x20;
                      *input_line_pointer = c;
                    }
                  else if (strcmp (start, "a3") == 0)
                    {
                      value |= 0x10;
                      *input_line_pointer = c;
                    }
                  else if (strcmp (start, "other") == 0)
                    {
                      value |= 0x08;
                      *input_line_pointer = c;
                    }
                  else
                    {
                      input_line_pointer = hold;
                      str = hold;
                      goto error;
                    }
                }
              input_line_pointer++;
              mn10300_insert_operand (&insn, &extension, operand,
                                      value, (char *) NULL, 0, 0);
              goto keep_going;

            }
          else if (data_register_name (&ex))
            {
              input_line_pointer = hold;
              str = hold;
              goto error;
            }
          else if (address_register_name (&ex))
            {
              input_line_pointer = hold;
              str = hold;
              goto error;
            }
          else if (other_register_name (&ex))
            {
              input_line_pointer = hold;
              str = hold;
              goto error;
            }
          else if (*str == ')' || *str == '(')
            {
              input_line_pointer = hold;
              str = hold;
              goto error;
            }
          else
            {
              expression (&ex);
            }

          switch (ex.X_op) 
            {
            case O_illegal:
              errmsg = "illegal operand";
              goto error;
            case O_absent:
              errmsg = "missing operand";
              goto error;
            case O_register:
              if ((operand->flags
                   & (MN10300_OPERAND_DREG | MN10300_OPERAND_AREG)) == 0)
                {
                  input_line_pointer = hold;
                  str = hold;
                  goto error;
                }
                
              if (opcode->format == FMT_D1 || opcode->format == FMT_S1)
                extra_shift = 8;
              else if (opcode->format == FMT_D2 || opcode->format == FMT_D4
                       || opcode->format == FMT_S2 || opcode->format == FMT_S4
                       || opcode->format == FMT_S6 || opcode->format == FMT_D5)
                extra_shift = 16;
              else
                extra_shift = 0;
              
              mn10300_insert_operand (&insn, &extension, operand,
                                      ex.X_add_number, (char *) NULL,
                                      0, extra_shift);

              break;

            case O_constant:
              /* If this operand can be promoted, and it doesn't
                 fit into the allocated bitfield for this insn,
                 then promote it (ie this opcode does not match).  */
              if (operand->flags
                  & (MN10300_OPERAND_PROMOTE | MN10300_OPERAND_RELAX)
                  && ! check_operand (insn, operand, ex.X_add_number))
                {
                  input_line_pointer = hold;
                  str = hold;
                  goto error;
                }

              mn10300_insert_operand (&insn, &extension, operand,
                                      ex.X_add_number, (char *) NULL,
                                      0, 0);
              break;

            default:
              /* If this operand can be promoted, then this opcode didn't
                 match since we can't know if it needed promotion!  */
              if (operand->flags & MN10300_OPERAND_PROMOTE)
                {
                  input_line_pointer = hold;
                  str = hold;
                  goto error;
                }

              /* We need to generate a fixup for this expression.  */
              if (fc >= MAX_INSN_FIXUPS)
                as_fatal ("too many fixups");
              fixups[fc].exp = ex;
              fixups[fc].opindex = *opindex_ptr;
              fixups[fc].reloc = BFD_RELOC_UNUSED;
              ++fc;
              break;
            }

keep_going:
          str = input_line_pointer;
          input_line_pointer = hold;

          while (*str == ' ' || *str == ',')
            ++str;

        }

      /* Make sure we used all the operands!  */
      if (*str != ',')
        match = 1;

    error:
      if (match == 0)
        {
          next_opcode = opcode + 1;
          if (!strcmp(next_opcode->name, opcode->name))
            {
              opcode = next_opcode;
              continue;
            }
          
          as_bad ("%s", errmsg);
          return;
        }
      break;
    }
      
  while (isspace (*str))
    ++str;

  if (*str != '\0')
    as_bad ("junk at end of line: `%s'", str);

  input_line_pointer = str;

  /* Determine the size of the instruction.  */
  if (opcode->format == FMT_S0)
    size = 1;

  if (opcode->format == FMT_S1 || opcode->format == FMT_D0)
    size = 2;

  if (opcode->format == FMT_S2 || opcode->format == FMT_D1)
    size = 3;

  if (opcode->format == FMT_S4)
    size = 5;

  if (opcode->format == FMT_S6 || opcode->format == FMT_D5)
    size = 7;

  if (opcode->format == FMT_D2)
    size = 4;

  if (opcode->format == FMT_D4)
    size = 6;

  if (relaxable && fc > 0)
    {
      int type;

      /* bCC */
      if (size == 2)
        type = 0;
      /* call */
      else if (size == 5)
        type = 6;
      /* calls */
      else if (size == 4)
        type = 8;
      /* jmp */
      else if (size == 3 && opcode->opcode == 0xcc0000)
        type = 10;
      /* bCC (uncommon cases) */
      else
        type = 3;

      f = frag_var (rs_machine_dependent, 8, 8 - size, type,
                    fixups[0].exp.X_add_symbol,
                    fixups[0].exp.X_add_number,
                    (char *)fixups[0].opindex);
      
      /* This is pretty hokey.  We basically just care about the
         opcode, so we have to write out the first word big endian.

         The exception is "call", which has two operands that we
         care about.

         The first operand (the register list) happens to be in the
         first instruction word, and will be in the right place if
         we output the first word in big endian mode.

         The second operand (stack size) is in the extension word,
         and we want it to appear as the first character in the extension
         word (as it appears in memory).  Luckily, writing the extension
         word in big endian format will do what we want.  */
      number_to_chars_bigendian (f, insn, size > 4 ? 4 : size);
      if (size > 8)
        {
          number_to_chars_bigendian (f + 4, extension, 4);
          number_to_chars_bigendian (f + 8, 0, size - 8);
        }
      else if (size > 4)
        number_to_chars_bigendian (f + 4, extension, size - 4);
    }
  else
    {
      /* Allocate space for the instruction.  */
      f = frag_more (size);

      /* Fill in bytes for the instruction.  Note that opcode fields
         are written big-endian, 16 & 32bit immediates are written
         little endian.  Egad.  */
      if (opcode->format == FMT_S0
          || opcode->format == FMT_S1
          || opcode->format == FMT_D0
          || opcode->format == FMT_D1)
        {
          number_to_chars_bigendian (f, insn, size);
        }
      else if (opcode->format == FMT_S2
               && opcode->opcode != 0xdf0000
               && opcode->opcode != 0xde0000)
        {
          /* A format S2 instruction that is _not_ "ret" and "retf".  */
          number_to_chars_bigendian (f, (insn >> 16) & 0xff, 1);
          number_to_chars_littleendian (f + 1, insn & 0xffff, 2);
        }
      else if (opcode->format == FMT_S2)
        {
          /* This must be a ret or retf, which is written entirely in
             big-endian format.  */
          number_to_chars_bigendian (f, insn, 3);
        }
      else if (opcode->format == FMT_S4
               && opcode->opcode != 0xdc000000)
        {
          /* This must be a format S4 "call" instruction.  What a pain.  */
          unsigned long temp = (insn >> 8) & 0xffff;
          number_to_chars_bigendian (f, (insn >> 24) & 0xff, 1);
          number_to_chars_littleendian (f + 1, temp, 2);
          number_to_chars_bigendian (f + 3, insn & 0xff, 1);
          number_to_chars_bigendian (f + 4, extension & 0xff, 1);
        }
      else if (opcode->format == FMT_S4)
        {
          /* This must be a format S4 "jmp" instruction.  */
          unsigned long temp = ((insn & 0xffffff) << 8) | (extension & 0xff);
          number_to_chars_bigendian (f, (insn >> 24) & 0xff, 1);
          number_to_chars_littleendian (f + 1, temp, 4);
        }
      else if (opcode->format == FMT_S6)
        {
          unsigned long temp = ((insn & 0xffffff) << 8)
            | ((extension >> 16) & 0xff);
          number_to_chars_bigendian (f, (insn >> 24) & 0xff, 1);
          number_to_chars_littleendian (f + 1, temp, 4);
          number_to_chars_bigendian (f + 5, (extension >> 8) & 0xff, 1);
          number_to_chars_bigendian (f + 6, extension & 0xff, 1);
        }
      else if (opcode->format == FMT_D2
               && opcode->opcode != 0xfaf80000
               && opcode->opcode != 0xfaf00000
               && opcode->opcode != 0xfaf40000)
        {
          /* A format D2 instruction where the 16bit immediate is
             really a single 16bit value, not two 8bit values.  */
          number_to_chars_bigendian (f, (insn >> 16) & 0xffff, 2);
          number_to_chars_littleendian (f + 2, insn & 0xffff, 2);
        }
      else if (opcode->format == FMT_D2)
        {
          /* A format D2 instruction where the 16bit immediate
             is really two 8bit immediates.  */
          number_to_chars_bigendian (f, insn, 4);
        }
      else if (opcode->format == FMT_D4)
        {
          unsigned long temp = ((insn & 0xffff) << 16) | (extension & 0xffff);
          number_to_chars_bigendian (f, (insn >> 16) & 0xffff, 2);
          number_to_chars_littleendian (f + 2, temp, 4);
        }
      else if (opcode->format == FMT_D5)
        {
          unsigned long temp = ((insn & 0xffff) << 16)
                                | ((extension >> 8) & 0xffff);
          number_to_chars_bigendian (f, (insn >> 16) & 0xffff, 2);
          number_to_chars_littleendian (f + 2, temp, 4);
          number_to_chars_bigendian (f + 6, extension & 0xff, 1);
        }

      /* Create any fixups.  */
      for (i = 0; i < fc; i++)
        {
          const struct mn10300_operand *operand;

          operand = &mn10300_operands[fixups[i].opindex];
          if (fixups[i].reloc != BFD_RELOC_UNUSED)
            {
              reloc_howto_type *reloc_howto;
              int size;
              int offset;
              fixS *fixP;

              reloc_howto = bfd_reloc_type_lookup (stdoutput, fixups[i].reloc);

              if (!reloc_howto)
                abort();
          
              size = bfd_get_reloc_size (reloc_howto);

              if (size < 1 || size > 4)
                abort();

              offset = 4 - size;
              fixP = fix_new_exp (frag_now, f - frag_now->fr_literal + offset,
                                  size, &fixups[i].exp,
                                  reloc_howto->pc_relative,
                                  fixups[i].reloc);
            }
          else
            {
              int reloc, pcrel, reloc_size, offset;
              fixS *fixP;

              reloc = BFD_RELOC_NONE;
              /* How big is the reloc?  Remember SPLIT relocs are
                 implicitly 32bits.  */
              if ((operand->flags & MN10300_OPERAND_SPLIT) != 0)
                reloc_size = 32;
              else
                reloc_size = operand->bits;

              /* Is the reloc pc-relative?  */
              pcrel = (operand->flags & MN10300_OPERAND_PCREL) != 0;

              /* Gross.  This disgusting hack is to make sure we
                 get the right offset for the 16/32 bit reloc in 
                 "call" instructions.  Basically they're a pain
                 because the reloc isn't at the end of the instruction.  */
              if ((size == 5 || size == 7)
                  && (((insn >> 24) & 0xff) == 0xcd
                      || ((insn >> 24) & 0xff) == 0xdd))
                size -= 2;

              /* Similarly for certain bit instructions which don't
                 hav their 32bit reloc at the tail of the instruction.  */
              if (size == 7
                  && (((insn >> 16) & 0xffff) == 0xfe00
                      || ((insn >> 16) & 0xffff) == 0xfe01
                      || ((insn >> 16) & 0xffff) == 0xfe02))
                size -= 1;
        
              offset = size - reloc_size / 8;

              /* Choose a proper BFD relocation type.  */
              if (pcrel)
                {
                  if (reloc_size == 32)
                    reloc = BFD_RELOC_32_PCREL;
                  else if (reloc_size == 16)
                    reloc = BFD_RELOC_16_PCREL;
                  else if (reloc_size == 8)
                    reloc = BFD_RELOC_8_PCREL;
                  else
                    abort ();
                }
              else
                {
                  if (reloc_size == 32)
                    reloc = BFD_RELOC_32;
                  else if (reloc_size == 16)
                    reloc = BFD_RELOC_16;
                  else if (reloc_size == 8)
                    reloc = BFD_RELOC_8;
                  else
                    abort ();
                }

              /* Convert the size of the reloc into what fix_new_exp wants.  */
              reloc_size = reloc_size / 8;
              if (reloc_size == 8)
                reloc_size = 0;
              else if (reloc_size == 16)
                reloc_size = 1;
              else if (reloc_size == 32)
                reloc_size = 2;

              fixP = fix_new_exp (frag_now, f - frag_now->fr_literal + offset,
                                  reloc_size, &fixups[i].exp, pcrel,
                                  ((bfd_reloc_code_real_type) reloc));

              if (pcrel)
                fixP->fx_offset += offset;
            }
        }
    }
}


/* if while processing a fixup, a reloc really needs to be created */
/* then it is done here */
                 
arelent *
tc_gen_reloc (seg, fixp)
     asection *seg;
     fixS *fixp;
{
  arelent *reloc;
  reloc = (arelent *) xmalloc (sizeof (arelent));

  reloc->howto = bfd_reloc_type_lookup (stdoutput, fixp->fx_r_type);
  if (reloc->howto == (reloc_howto_type *) NULL)
    {
      as_bad_where (fixp->fx_file, fixp->fx_line,
                    "reloc %d not supported by object file format",
                    (int)fixp->fx_r_type);
      return NULL;
    }
  reloc->address = fixp->fx_frag->fr_address + fixp->fx_where;

  if (fixp->fx_addsy && fixp->fx_subsy)
    {
      reloc->sym_ptr_ptr = &bfd_abs_symbol;
      reloc->addend = (S_GET_VALUE (fixp->fx_addsy)
                       - S_GET_VALUE (fixp->fx_subsy) + fixp->fx_offset);
    }
  else 
    {
      reloc->sym_ptr_ptr = &fixp->fx_addsy->bsym;
      reloc->addend = fixp->fx_offset;
    }
  return reloc;
}

int
md_estimate_size_before_relax (fragp, seg)
     fragS *fragp;
     asection *seg;
{
  if (fragp->fr_subtype == 0)
    return 2;
  if (fragp->fr_subtype == 3)
    return 3;
  if (fragp->fr_subtype == 6)
    {
      if (!S_IS_DEFINED (fragp->fr_symbol)
          || seg != S_GET_SEGMENT (fragp->fr_symbol))
        {
          fragp->fr_subtype = 7;
          return 7;
        }
      else
        return 5;
    }
  if (fragp->fr_subtype == 8)
    {
      if (!S_IS_DEFINED (fragp->fr_symbol)
          || seg != S_GET_SEGMENT (fragp->fr_symbol))
        {
          fragp->fr_subtype = 9;
          return 6;
        }
      else
        return 4;
    }
  if (fragp->fr_subtype == 10)
    {
      if (!S_IS_DEFINED (fragp->fr_symbol)
          || seg != S_GET_SEGMENT (fragp->fr_symbol))
        {
          fragp->fr_subtype = 12;
          return 5;
        }
      else
        return 2;
    }
} 

long
md_pcrel_from (fixp)
     fixS *fixp;
{
  return fixp->fx_frag->fr_address;
#if 0
  if (fixp->fx_addsy != (symbolS *) NULL && ! S_IS_DEFINED (fixp->fx_addsy))
    {
      /* The symbol is undefined.  Let the linker figure it out.  */
      return 0;
    }
  return fixp->fx_frag->fr_address + fixp->fx_where;
#endif
}

int
md_apply_fix3 (fixp, valuep, seg)
     fixS *fixp;
     valueT *valuep;
     segT seg;
{
  /* We shouldn't ever get here because linkrelax is nonzero.  */
  abort ();
  fixp->fx_done = 1;
  return 0;
}

/* Insert an operand value into an instruction.  */

static void
mn10300_insert_operand (insnp, extensionp, operand, val, file, line, shift)
     unsigned long *insnp;
     unsigned long *extensionp;
     const struct mn10300_operand *operand;
     offsetT val;
     char *file;
     unsigned int line;
     unsigned int shift;
{
  /* No need to check 32bit operands for a bit.  Note that
     MN10300_OPERAND_SPLIT is an implicit 32bit operand.  */
  if (operand->bits != 32
      && (operand->flags & MN10300_OPERAND_SPLIT) == 0)
    {
      long min, max;
      offsetT test;

      if ((operand->flags & MN10300_OPERAND_SIGNED) != 0)
        {
          max = (1 << (operand->bits - 1)) - 1;
          min = - (1 << (operand->bits - 1));
        }
      else
        {
          max = (1 << operand->bits) - 1;
          min = 0;
        }

      test = val;


      if (test < (offsetT) min || test > (offsetT) max)
        {
          const char *err =
            "operand out of range (%s not between %ld and %ld)";
          char buf[100];

          sprint_value (buf, test);
          if (file == (char *) NULL)
            as_warn (err, buf, min, max);
          else
            as_warn_where (file, line, err, buf, min, max);
        }
    }

  if ((operand->flags & MN10300_OPERAND_SPLIT) != 0)
    {
      *insnp |= (val >> (32 - operand->bits)) & ((1 << operand->bits) - 1);
      *extensionp |= ((val & ((1 << (32 - operand->bits)) - 1))
                      << operand->shift);
    }
  else if ((operand->flags & MN10300_OPERAND_EXTENDED) == 0)
    {
      *insnp |= (((long) val & ((1 << operand->bits) - 1))
                 << (operand->shift + shift));

      if ((operand->flags & MN10300_OPERAND_REPEATED) != 0)
        *insnp |= (((long) val & ((1 << operand->bits) - 1))
                   << (operand->shift + shift + 2));
    }
  else
    {
      *extensionp |= (((long) val & ((1 << operand->bits) - 1))
                      << (operand->shift + shift));

      if ((operand->flags & MN10300_OPERAND_REPEATED) != 0)
        *extensionp |= (((long) val & ((1 << operand->bits) - 1))
                        << (operand->shift + shift + 2));
    }
}

static unsigned long
check_operand (insn, operand, val)
     unsigned long insn;
     const struct mn10300_operand *operand;
     offsetT val;
{
  /* No need to check 32bit operands for a bit.  Note that
     MN10300_OPERAND_SPLIT is an implicit 32bit operand.  */
  if (operand->bits != 32
      && (operand->flags & MN10300_OPERAND_SPLIT) == 0)
    {
      long min, max;
      offsetT test;

      if ((operand->flags & MN10300_OPERAND_SIGNED) != 0)
        {
          max = (1 << (operand->bits - 1)) - 1;
          min = - (1 << (operand->bits - 1));
        }
      else
        {
          max = (1 << operand->bits) - 1;
          min = 0;
        }

      test = val;


      if (test < (offsetT) min || test > (offsetT) max)
        return 0;
      else
        return 1;
    }
  return 1;
}