[deliverable/binutils-gdb.git] / gas / config / tc-mn10200.c

/* tc-mn10200.c -- Assembler code for the Matsushita 10200

   Copyright (C) 1996 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/mn10200.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

/* local functions */
static void mn10200_insert_operand PARAMS ((unsigned long *, unsigned long *,
					    const struct mn10200_operand *,
					    offsetT, char *, unsigned,
					    unsigned));
static unsigned long check_operand PARAMS ((unsigned long,
					    const struct mn10200_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 mn10200_fixup
{
  expressionS exp;
  int opindex;
  bfd_reloc_code_real_type reloc;
};
struct mn10200_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 *mn10200_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 },
};
#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, "MN10200 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;
{
  /* printf ("call to md_convert_frag \n"); */
  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 mn10200_opcode *op;

  mn10200_hash = hash_new();

  /* Insert unique names into hash table.  The MN10200 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 = mn10200_opcodes;
  while (op->name)
    {
      if (strcmp (prev_name, op->name)) 
	{
	  prev_name = (char *) op->name;
	  hash_insert (mn10200_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 mn10200_opcode *opcode;
  struct mn10200_opcode *next_opcode;
  const unsigned char *opindex_ptr;
  int next_opindex;
  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 mn10200_opcode *)hash_find (mn10200_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;

      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 mn10200_operand *operand;
	  expressionS ex;

	  if (next_opindex == 0)
	    {
	      operand = &mn10200_operands[*opindex_ptr];
	    }
	  else
	    {
	      operand = &mn10200_operands[next_opindex];
	      next_opindex = 0;
	    }

	  errmsg = NULL;

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

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

	  if (operand->flags & MN10200_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 & MN10200_OPERAND_DREG)
	    {
	      if (!data_register_name (&ex))
		{
		  input_line_pointer = hold;
		  str = hold;
		  goto error;
		}
	    }
	  else if (operand->flags & MN10200_OPERAND_AREG)
	    {
	      if (!address_register_name (&ex))
		{
		  input_line_pointer = hold;
		  str = hold;
		  goto error;
		}
	    }
	  else if (operand->flags & MN10200_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 & MN10200_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 (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
                   & (MN10200_OPERAND_DREG | MN10200_OPERAND_AREG)) == 0)
		{
		  input_line_pointer = hold;
		  str = hold;
		  goto error;
		}
		
	      if (opcode->format == FMT_2 || opcode->format == FMT_5)
		extra_shift = 8;
	      else if (opcode->format == FMT_3 || opcode->format == FMT_6
		       || opcode->format == FMT_7)
		extra_shift = 16;
	      else
		extra_shift = 0;
	      
	      mn10200_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 & MN10200_OPERAND_PROMOTE
		  && ! check_operand (insn, operand, ex.X_add_number))
		{
		  input_line_pointer = hold;
		  str = hold;
		  goto error;
		}

	      mn10200_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 & MN10200_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;

  if (opcode->format == FMT_1)
    size = 1;
  else if (opcode->format == FMT_2 || opcode->format == FMT_4)
    size = 2;
  else if (opcode->format == FMT_3 || opcode->format == FMT_5)
    size = 3;
  else if (opcode->format == FMT_6)
    size = 4;
  else if (opcode->format == FMT_7)
    size = 5;
  else
    abort ();
         
  /* Write out the instruction.  */

  f = frag_more (size);

  /* Oh, what a mess.  The instruction is in big endian format, but
     16 and 24bit immediates are little endian!  */
  if (opcode->format == FMT_3)
    {
      number_to_chars_bigendian (f, (insn >> 16) & 0xff, 1);
      number_to_chars_littleendian (f + 1, insn & 0xffff, 2);
    }
  else if (opcode->format == FMT_6)
    {
      number_to_chars_bigendian (f, (insn >> 16) & 0xffff, 2);
      number_to_chars_littleendian (f + 2, insn & 0xffff, 2);
    }
  else if (opcode->format == FMT_7)
    {
      number_to_chars_bigendian (f, (insn >> 16) & 0xffff, 2);
      number_to_chars_littleendian (f + 2, insn & 0xffff, 2);
      number_to_chars_littleendian (f + 4, extension & 0xff, 1);
    }
  else
    {
      number_to_chars_bigendian (f, insn, size > 4 ? 4 : size);
    }

#if 0
  /* Create any fixups.  */
  for (i = 0; i < fc; i++)
    {
      const struct mn10200_operand *operand;

      operand = &mn10200_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;

	  reloc = BFD_RELOC_NONE;
	  /* How big is the reloc?  Remember SPLIT relocs are
	     implicitly 32bits.  */
	  reloc_size = operand->bits;

	  /* Is the reloc pc-relative?  */
	  pcrel = (operand->flags & MN10200_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 (size == 6)
		reloc = BFD_RELOC_MN10200_32_PCREL;
	      else if (size == 4)
		reloc = BFD_RELOC_MN10200_16_PCREL;
	      else 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_MN10200_32B;
	      else if (reloc_size == 16)
		reloc = BFD_RELOC_MN10200_16B;
	      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;

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


/* 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 *) bfd_alloc_by_size_t (stdoutput, sizeof (arelent));
  reloc->sym_ptr_ptr = &fixp->fx_addsy->bsym;
  reloc->address = fixp->fx_frag->fr_address + fixp->fx_where;
  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->addend = fixp->fx_offset;
  /*  printf("tc_gen_reloc: addr=%x  addend=%x\n", reloc->address, reloc->addend); */
  return reloc;
}

int
md_estimate_size_before_relax (fragp, seg)
     fragS *fragp;
     asection *seg;
{
  return 0;
} 

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
mn10200_insert_operand (insnp, extensionp, operand, val, file, line, shift)
     unsigned long *insnp;
     unsigned long *extensionp;
     const struct mn10200_operand *operand;
     offsetT val;
     char *file;
     unsigned int line;
     unsigned int shift;
{
  /* No need to check 24 or 32bit operands for a bit.  */
  if (operand->bits < 24)
    {
      long min, max;
      offsetT test;

      if ((operand->flags & MN10200_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 & MN10200_OPERAND_EXTENDED) == 0)
    {
      *insnp |= (((long) val & ((1 << operand->bits) - 1))
		 << (operand->shift + shift));

      if ((operand->flags & MN10200_OPERAND_REPEATED) != 0)
	*insnp |= (((long) val & ((1 << operand->bits) - 1))
		   << (operand->shift + shift + 2));
    }
  else
    {
      *extensionp |= (val >> 16) & 0xff;
      *insnp |= val & 0xffff;
    }
}

static unsigned long
check_operand (insn, operand, val)
     unsigned long insn;
     const struct mn10200_operand *operand;
     offsetT val;
{
  /* No need to check 24bit or 32bit operands for a bit.  */
  if (operand->bits < 24)
    {
      long min, max;
      offsetT test;

      if ((operand->flags & MN10200_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;
}