19990502 sourceware importbinu_ss_19990502

1 files changed, 894 insertions, 0 deletions

diff --git a/opcodes/ns32k-dis.c b/opcodes/ns32k-dis.c
new file mode 100644
index 00000000000..050266be849
--- /dev/null
+++ b/opcodes/ns32k-dis.c
@@ -0,0 +1,894 @@
+/* Print National Semiconductor 32000 instructions.
+   Copyright (c) 1986, 88, 91, 92, 94, 95, 1998 Free Software Foundation, Inc.
+
+This file is part of opcodes library.
+
+This program 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 of the License, or
+(at your option) any later version.
+
+This program 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 this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+
+#include "bfd.h"
+#include "sysdep.h"
+#include "dis-asm.h"
+#if !defined(const) && !defined(__STDC__)
+#define const
+#endif
+#include "opcode/ns32k.h"
+#include "opintl.h"
+
+static disassemble_info *dis_info;
+
+/*
+ * Hacks to get it to compile <= READ THESE AS FIXES NEEDED
+ */
+#define INVALID_FLOAT(val, size) invalid_float((char *)val, size)
+
+static int print_insn_arg
+  PARAMS ((int, int, int *, char *, bfd_vma, char *, int));
+static int get_displacement PARAMS ((char *, int *));
+static int invalid_float PARAMS ((char *, int));
+
+static long read_memory_integer(addr, nr)
+     unsigned char *addr;
+     int nr;
+{
+  long val;
+  int i;
+  for (val = 0, i = nr - 1; i >= 0; i--) {
+    val =  (val << 8);
+    val |= (0xff & *(addr + i));
+  }
+  return val;
+}
+
+/* 32000 instructions are never longer than this.  */
+#define MAXLEN 62
+
+
+#include <setjmp.h>
+
+struct private
+{
+  /* Points to first byte not fetched.  */
+  bfd_byte *max_fetched;
+  bfd_byte the_buffer[MAXLEN];
+  bfd_vma insn_start;
+  jmp_buf bailout;
+};
+
+
+/* Make sure that bytes from INFO->PRIVATE_DATA->BUFFER (inclusive)
+   to ADDR (exclusive) are valid.  Returns 1 for success, longjmps
+   on error.  */
+#define FETCH_DATA(info, addr) \
+  ((addr) <= ((struct private *)(info->private_data))->max_fetched \
+   ? 1 : fetch_data ((info), (addr)))
+
+static int
+fetch_data (info, addr)
+     struct disassemble_info *info;
+     bfd_byte *addr;
+{
+  int status;
+  struct private *priv = (struct private *)info->private_data;
+  bfd_vma start = priv->insn_start + (priv->max_fetched - priv->the_buffer);
+
+  status = (*info->read_memory_func) (start,
+				      priv->max_fetched,
+				      addr - priv->max_fetched,
+				      info);
+  if (status != 0)
+    {
+      (*info->memory_error_func) (status, start, info);
+      longjmp (priv->bailout, 1);
+    }
+  else
+    priv->max_fetched = addr;
+  return 1;
+}
+/* Number of elements in the opcode table.  */
+#define NOPCODES (sizeof ns32k_opcodes / sizeof ns32k_opcodes[0])
+
+#define NEXT_IS_ADDR	'|'
+
+
+struct ns32k_option {
+  char *pattern;		/* the option itself */
+  unsigned long value;		/* binary value of the option */
+  unsigned long match;		/* these bits must match */
+};
+
+
+static const struct ns32k_option opt_u[]= /* restore, exit */
+{
+  { "r0",	0x80,	0x80	},
+  { "r1",	0x40,	0x40	},
+  { "r2",	0x20,	0x20	},
+  { "r3",	0x10,	0x10	},
+  { "r4",	0x08,	0x08	},
+  { "r5",	0x04,	0x04	},
+  { "r6",	0x02,	0x02	},
+  { "r7",	0x01,	0x01	},
+  {  0 ,	0x00,	0x00	}
+};
+
+static const struct ns32k_option opt_U[]= /* save, enter */
+{
+  { "r0",	0x01,	0x01	},
+  { "r1",	0x02,	0x02	},
+  { "r2",	0x04,	0x04	},
+  { "r3",	0x08,	0x08	},
+  { "r4",	0x10,	0x10	},
+  { "r5",	0x20,	0x20	},
+  { "r6",	0x40,	0x40	},
+  { "r7",	0x80,	0x80	},
+  {  0 ,	0x00,	0x00	}
+};
+
+static const struct ns32k_option opt_O[]= /* setcfg */
+{
+  { "c",	0x8,	0x8	},
+  { "m",	0x4,	0x4	},
+  { "f",	0x2,	0x2	},
+  { "i",	0x1,	0x1	},
+  {  0 ,	0x0,	0x0	}
+};
+
+static const struct ns32k_option opt_C[]= /* cinv */
+{
+  { "a",	0x4,	0x4	},
+  { "i",	0x2,	0x2	},
+  { "d",	0x1,	0x1	},
+  {  0 ,	0x0,	0x0	}
+};
+
+static const struct ns32k_option opt_S[]= /* string inst */
+{
+  { "b",	0x1,	0x1	},
+  { "u",	0x6,	0x6	},
+  { "w",	0x2,	0x2	},
+  {  0 ,	0x0,	0x0	}
+};
+
+static const struct ns32k_option list_P532[]= /* lpr spr */
+{
+  { "us",	0x0,	0xf	},
+  { "dcr",	0x1,	0xf	},
+  { "bpc",	0x2,	0xf	},
+  { "dsr",	0x3,	0xf	},
+  { "car",	0x4,	0xf	},
+  { "fp",	0x8,	0xf	},
+  { "sp",	0x9,	0xf	},
+  { "sb",	0xa,	0xf	},
+  { "usp",	0xb,	0xf	},
+  { "cfg",	0xc,	0xf	},
+  { "psr",	0xd,	0xf	},
+  { "intbase",	0xe,	0xf	},
+  { "mod",	0xf,	0xf	},
+  {  0 ,	0x00,	0xf	}
+};
+
+static const struct ns32k_option list_M532[]= /* lmr smr */
+{
+  { "mcr",	0x9,	0xf	},
+  { "msr",	0xa,	0xf	},
+  { "tear",	0xb,	0xf	},
+  { "ptb0",	0xc,	0xf	},
+  { "ptb1",	0xd,	0xf	},
+  { "ivar0",	0xe,	0xf	},
+  { "ivar1",	0xf,	0xf	},
+  {  0 ,	0x0,	0xf	}
+};
+
+static const struct ns32k_option list_P032[]= /* lpr spr */
+{
+  { "upsr",	0x0,	0xf	},
+  { "fp",	0x8,	0xf	},
+  { "sp",	0x9,	0xf	},
+  { "sb",	0xa,	0xf	},
+  { "psr",	0xb,	0xf	},
+  { "intbase",	0xe,	0xf	},
+  { "mod",	0xf,	0xf	},
+  {  0 ,	0x0,	0xf	}
+};
+
+static const struct ns32k_option list_M032[]= /* lmr smr */
+{
+  { "bpr0",	0x0,	0xf	},
+  { "bpr1",	0x1,	0xf	},
+  { "pf0",	0x4,	0xf	},
+  { "pf1",	0x5,	0xf	},
+  { "sc",	0x8,	0xf	},
+  { "msr",	0xa,	0xf	},
+  { "bcnt",	0xb,	0xf	},
+  { "ptb0",	0xc,	0xf	},
+  { "ptb1",	0xd,	0xf	},
+  { "eia",	0xf,	0xf	},
+  {  0 ,	0x0,	0xf	}
+};
+
+
+/*
+ * figure out which options are present
+ */
+static void
+optlist(options, optionP, result)
+     int options;
+     const struct ns32k_option *optionP;
+     char *result;
+{
+    if (options == 0) {
+	sprintf(result, "[]");
+	return;
+    }
+    sprintf(result, "[");
+
+    for (; (options != 0) && optionP->pattern; optionP++) {
+	if ((options & optionP->match) == optionP->value) {
+	    /* we found a match, update result and options */
+	    strcat(result, optionP->pattern);
+	    options &= ~optionP->value;
+	    if (options != 0)	/* more options to come */
+		strcat(result, ",");
+	}
+    }
+    if (options != 0)
+	strcat(result, "undefined");
+
+    strcat(result, "]");
+}
+
+static void
+list_search (reg_value, optionP, result)
+     int reg_value;
+     const struct ns32k_option *optionP;
+     char *result;
+{
+    for (; optionP->pattern; optionP++) {
+	if ((reg_value & optionP->match) == optionP->value) {
+	    sprintf(result, "%s", optionP->pattern);
+	    return;
+	}
+    }
+    sprintf(result, "undefined");
+}
+
+/*
+ * extract "count" bits starting "offset" bits
+ * into buffer
+ */
+
+static int
+bit_extract (buffer, offset, count)
+     bfd_byte *buffer;
+     int offset;
+     int count;
+{
+  int result;
+  int bit;
+
+  buffer += offset >> 3;
+  offset &= 7;
+  bit = 1;
+  result = 0;
+  while (count--)
+    {
+      FETCH_DATA(dis_info, buffer + 1);
+      if ((*buffer & (1 << offset)))
+	result |= bit;
+      if (++offset == 8)
+	{
+	  offset = 0;
+	  buffer++;
+	}
+      bit <<= 1;
+    }
+  return result;
+}
+
+/* Like bit extract but the buffer is valid and doen't need to be
+ * fetched
+ */
+static int
+bit_extract_simple (buffer, offset, count)
+     bfd_byte *buffer;
+     int offset;
+     int count;
+{
+  int result;
+  int mask;
+  int bit;
+
+  buffer += offset >> 3;
+  offset &= 7;
+  bit = 1;
+  result = 0;
+  while (count--)
+    {
+      if ((*buffer & (1 << offset)))
+	result |= bit;
+      if (++offset == 8)
+	{
+	  offset = 0;
+	  buffer++;
+	}
+      bit <<= 1;
+    }
+  return result;
+}
+
+static void
+bit_copy (buffer, offset, count, to)
+     char *buffer;
+     int offset;
+     int count;
+     char *to;
+{
+  for(; count > 8; count -= 8, to++, offset += 8)
+    *to = bit_extract (buffer, offset, 8);
+  *to = bit_extract (buffer, offset, count);
+}
+
+
+static int
+sign_extend (value, bits)
+     int value, bits;
+{
+  value = value & ((1 << bits) - 1);
+  return (value & (1 << (bits-1))
+	  ? value | (~((1 << bits) - 1))
+	  : value);
+}
+
+static void
+flip_bytes (ptr, count)
+     char *ptr;
+     int count;
+{
+  char tmp;
+
+  while (count > 0)
+    {
+      tmp = ptr[0];
+      ptr[0] = ptr[count-1];
+      ptr[count-1] = tmp;
+      ptr++;
+      count -= 2;
+    }
+}
+
+/* Given a character C, does it represent a general addressing mode?  */
+#define Is_gen(c) \
+  ((c) == 'F' || (c) == 'L' || (c) == 'B' \
+   || (c) == 'W' || (c) == 'D' || (c) == 'A' || (c) == 'I' || (c) == 'Z')
+
+/* Adressing modes.  */
+#define Adrmod_index_byte 0x1c
+#define Adrmod_index_word 0x1d
+#define Adrmod_index_doubleword 0x1e
+#define Adrmod_index_quadword 0x1f
+
+/* Is MODE an indexed addressing mode?  */
+#define Adrmod_is_index(mode) \
+  (mode == Adrmod_index_byte \
+   || mode == Adrmod_index_word \
+   || mode == Adrmod_index_doubleword \
+   || mode == Adrmod_index_quadword)
+
+
+/* Print the 32000 instruction at address MEMADDR in debugged memory,
+   on STREAM.  Returns length of the instruction, in bytes.  */
+
+int
+print_insn_ns32k (memaddr, info)
+     bfd_vma memaddr;
+     disassemble_info *info;
+{
+  register unsigned int i;
+  register char *d;
+  unsigned short first_word;
+  int ioffset;		/* bits into instruction */
+  int aoffset;		/* bits into arguments */
+  char arg_bufs[MAX_ARGS+1][ARG_LEN];
+  int argnum;
+  int maxarg;
+  struct private priv;
+  bfd_byte *buffer = priv.the_buffer;
+  dis_info = info;
+
+  info->private_data = (PTR) &priv;
+  priv.max_fetched = priv.the_buffer;
+  priv.insn_start = memaddr;
+  if (setjmp (priv.bailout) != 0)
+    /* Error return.  */
+    return -1;
+
+  /* Look for 8bit opcodes first. Other wise, fetching two bytes could take
+   * us over the end of accessible data unnecessarilly
+   */
+  FETCH_DATA(info, buffer + 1);
+  for (i = 0; i < NOPCODES; i++)
+    if (ns32k_opcodes[i].opcode_id_size <= 8
+	&& ((buffer[0]
+	     & (((unsigned long) 1 << ns32k_opcodes[i].opcode_id_size) - 1))
+	    == ns32k_opcodes[i].opcode_seed))
+      break;
+  if (i == NOPCODES) {
+    /* Maybe it is 9 to 16 bits big */
+    FETCH_DATA(info, buffer + 2);
+    first_word = read_memory_integer(buffer, 2);
+
+    for (i = 0; i < NOPCODES; i++)
+      if ((first_word
+	   & (((unsigned long) 1 << ns32k_opcodes[i].opcode_id_size) - 1))
+	  == ns32k_opcodes[i].opcode_seed)
+	break;
+
+    /* Handle undefined instructions.  */
+    if (i == NOPCODES)
+      {
+	(*dis_info->fprintf_func)(dis_info->stream, "0%o", buffer[0]);
+	return 1;
+      }
+  }
+
+  (*dis_info->fprintf_func)(dis_info->stream, "%s", ns32k_opcodes[i].name);
+
+  ioffset = ns32k_opcodes[i].opcode_size;
+  aoffset = ns32k_opcodes[i].opcode_size;
+  d = ns32k_opcodes[i].operands;
+
+  if (*d)
+    {
+      /* Offset in bits of the first thing beyond each index byte.
+	 Element 0 is for operand A and element 1 is for operand B.
+	 The rest are irrelevant, but we put them here so we don't
+	 index outside the array.  */
+      int index_offset[MAX_ARGS];
+
+      /* 0 for operand A, 1 for operand B, greater for other args.  */
+      int whicharg = 0;
+      
+      (*dis_info->fprintf_func)(dis_info->stream, "\t");
+
+      maxarg = 0;
+
+      /* First we have to find and keep track of the index bytes,
+	 if we are using scaled indexed addressing mode, since the index
+	 bytes occur right after the basic instruction, not as part
+	 of the addressing extension.  */
+      if (Is_gen(d[1]))
+	{
+	  int addr_mode = bit_extract (buffer, ioffset - 5, 5);
+
+	  if (Adrmod_is_index (addr_mode))
+	    {
+	      aoffset += 8;
+	      index_offset[0] = aoffset;
+	    }
+	}
+      if (d[2] && Is_gen(d[3]))
+	{
+	  int addr_mode = bit_extract (buffer, ioffset - 10, 5);
+
+	  if (Adrmod_is_index (addr_mode))
+	    {
+	      aoffset += 8;
+	      index_offset[1] = aoffset;
+	    }
+	}
+
+      while (*d)
+	{
+	  argnum = *d - '1';
+	  d++;
+	  if (argnum > maxarg && argnum < MAX_ARGS)
+	    maxarg = argnum;
+	  ioffset = print_insn_arg (*d, ioffset, &aoffset, buffer,
+				    memaddr, arg_bufs[argnum],
+				    index_offset[whicharg]);
+	  d++;
+	  whicharg++;
+	}
+      for (argnum = 0; argnum <= maxarg; argnum++)
+	{
+	  bfd_vma addr;
+	  char *ch;
+	  for (ch = arg_bufs[argnum]; *ch;)
+	    {
+	      if (*ch == NEXT_IS_ADDR)
+		{
+		  ++ch;
+		  addr = bfd_scan_vma (ch, NULL, 16);
+		  (*dis_info->print_address_func) (addr, dis_info);
+		  while (*ch && *ch != NEXT_IS_ADDR)
+		    ++ch;
+		  if (*ch)
+		    ++ch;
+		}
+	      else
+		(*dis_info->fprintf_func)(dis_info->stream, "%c", *ch++);
+	    }
+	  if (argnum < maxarg)
+	    (*dis_info->fprintf_func)(dis_info->stream, ", ");
+	}
+    }
+  return aoffset / 8;
+}
+
+/* Print an instruction operand of category given by d.  IOFFSET is
+   the bit position below which small (<1 byte) parts of the operand can
+   be found (usually in the basic instruction, but for indexed
+   addressing it can be in the index byte).  AOFFSETP is a pointer to the
+   bit position of the addressing extension.  BUFFER contains the
+   instruction.  ADDR is where BUFFER was read from.  Put the disassembled
+   version of the operand in RESULT.  INDEX_OFFSET is the bit position
+   of the index byte (it contains garbage if this operand is not a
+   general operand using scaled indexed addressing mode).  */
+
+static int
+print_insn_arg (d, ioffset, aoffsetp, buffer, addr, result, index_offset)
+     int d;
+     int ioffset, *aoffsetp;
+     char *buffer;
+     bfd_vma addr;
+     char *result;
+     int index_offset;
+{
+  int addr_mode;
+  float Fvalue;
+  double Lvalue;
+  int Ivalue;
+  int disp1, disp2;
+  int index;
+  int size;
+
+  switch (d)
+    {
+    case 'f':
+      /* a "gen" operand but 5 bits from the end of instruction */
+      ioffset -= 5;
+    case 'Z':
+    case 'F':
+    case 'L':
+    case 'I':
+    case 'B':
+    case 'W':
+    case 'D':
+    case 'A':
+      addr_mode = bit_extract (buffer, ioffset-5, 5);
+      ioffset -= 5;
+      switch (addr_mode)
+	{
+	case 0x0: case 0x1: case 0x2: case 0x3:
+	case 0x4: case 0x5: case 0x6: case 0x7:
+	  /* register mode R0 -- R7 */
+	  switch (d)
+	    {
+	    case 'F':
+	    case 'L':
+	    case 'Z':
+	      sprintf (result, "f%d", addr_mode);
+	      break;
+	    default:
+	      sprintf (result, "r%d", addr_mode);
+	    }
+	  break;
+	case 0x8: case 0x9: case 0xa: case 0xb:
+	case 0xc: case 0xd: case 0xe: case 0xf:
+	  /* Register relative disp(R0 -- R7) */
+	  disp1 = get_displacement (buffer, aoffsetp);
+	  sprintf (result, "%d(r%d)", disp1, addr_mode & 7);
+	  break;
+	case 0x10:
+	case 0x11:
+	case 0x12:
+	  /* Memory relative disp2(disp1(FP, SP, SB)) */
+	  disp1 = get_displacement (buffer, aoffsetp);
+	  disp2 = get_displacement (buffer, aoffsetp);
+	  sprintf (result, "%d(%d(%s))", disp2, disp1,
+		   addr_mode==0x10?"fp":addr_mode==0x11?"sp":"sb");
+	  break;
+	case 0x13:
+	  /* reserved */
+	  sprintf (result, "reserved");
+	  break;
+	case 0x14:
+	  /* Immediate */
+	  switch (d)
+	    {
+	    case 'I': case 'Z': case 'A':
+	      /* I and Z are output operands and can`t be immediate
+	       * A is an address and we can`t have the address of
+	       * an immediate either. We don't know how much to increase
+	       * aoffsetp by since whatever generated this is broken
+	       * anyway!
+	       */
+	      sprintf (result, _("$<undefined>"));
+	      break;
+	    case 'B':
+	      Ivalue = bit_extract (buffer, *aoffsetp, 8);
+	      Ivalue = sign_extend (Ivalue, 8);
+	      *aoffsetp += 8;
+	      sprintf (result, "$%d", Ivalue);
+	      break;
+	    case 'W':
+	      Ivalue = bit_extract (buffer, *aoffsetp, 16);
+	      flip_bytes (&Ivalue, 2);
+	      *aoffsetp += 16;
+	      Ivalue = sign_extend (Ivalue, 16);
+	      sprintf (result, "$%d", Ivalue);
+	      break;
+	    case 'D':
+	      Ivalue = bit_extract (buffer, *aoffsetp, 32);
+	      flip_bytes (&Ivalue, 4);
+	      *aoffsetp += 32;
+	      sprintf (result, "$%d", Ivalue);
+	      break;
+	    case 'F':
+	      bit_copy (buffer, *aoffsetp, 32, (char *) &Fvalue);
+	      flip_bytes (&Fvalue, 4);
+	      *aoffsetp += 32;
+	      if (INVALID_FLOAT (&Fvalue, 4))
+		sprintf (result, "<<invalid float 0x%.8x>>", *(int *) &Fvalue);
+	      else /* assume host has ieee float */
+		sprintf (result, "$%g", Fvalue);
+	      break;
+	    case 'L':
+	      bit_copy (buffer, *aoffsetp, 64, (char *) &Lvalue);
+	      flip_bytes (&Lvalue, 8);
+	      *aoffsetp += 64;
+	      if (INVALID_FLOAT (&Lvalue, 8))
+		sprintf (result, "<<invalid long 0x%.8x%.8x>>",
+			 *(((int *) &Lvalue) + 1), *(int *) &Lvalue);
+	      else /* assume host has ieee float */
+		sprintf (result, "$%g", Lvalue);
+	      break;
+	    }
+	  break;
+	case 0x15:
+	  /* Absolute @disp */
+	  disp1 = get_displacement (buffer, aoffsetp);
+	  sprintf (result, "@|%d|", disp1);
+	  break;
+	case 0x16:
+	  /* External EXT(disp1) + disp2 (Mod table stuff) */
+	  disp1 = get_displacement (buffer, aoffsetp);
+	  disp2 = get_displacement (buffer, aoffsetp);
+	  sprintf (result, "EXT(%d) + %d", disp1, disp2);
+	  break;
+	case 0x17:
+	  /* Top of stack tos */
+	  sprintf (result, "tos");
+	  break;
+	case 0x18:
+	  /* Memory space disp(FP) */
+	  disp1 = get_displacement (buffer, aoffsetp);
+	  sprintf (result, "%d(fp)", disp1);
+	  break;
+	case 0x19:
+	  /* Memory space disp(SP) */
+	  disp1 = get_displacement (buffer, aoffsetp);
+	  sprintf (result, "%d(sp)", disp1);
+	  break;
+	case 0x1a:
+	  /* Memory space disp(SB) */
+	  disp1 = get_displacement (buffer, aoffsetp);
+	  sprintf (result, "%d(sb)", disp1);
+	  break;
+	case 0x1b:
+	  /* Memory space disp(PC) */
+	  disp1 = get_displacement (buffer, aoffsetp);
+	  *result++ = NEXT_IS_ADDR;
+	  sprintf_vma (result, addr + disp1);
+	  result += strlen (result);
+	  *result++ = NEXT_IS_ADDR;
+	  *result = '\0';
+	  break;
+	case 0x1c:
+	case 0x1d:
+	case 0x1e:
+	case 0x1f:
+	  /* Scaled index basemode[R0 -- R7:B,W,D,Q] */
+	  index = bit_extract (buffer, index_offset - 8, 3);
+	  print_insn_arg (d, index_offset, aoffsetp, buffer, addr,
+			  result, 0);
+	  {
+	    static const char *ind = "bwdq";
+	    char *off;
+
+	    off = result + strlen (result);
+	    sprintf (off, "[r%d:%c]", index,
+		     ind[addr_mode & 3]);
+	  }
+	  break;
+	}
+      break;
+    case 'H':
+    case 'q':
+      Ivalue = bit_extract (buffer, ioffset-4, 4);
+      Ivalue = sign_extend (Ivalue, 4);
+      sprintf (result, "%d", Ivalue);
+      ioffset -= 4;
+      break;
+    case 'r':
+      Ivalue = bit_extract (buffer, ioffset-3, 3);
+      sprintf (result, "r%d", Ivalue&7);
+      ioffset -= 3;
+      break;
+    case 'd':
+      sprintf (result, "%d", get_displacement (buffer, aoffsetp));
+      break;
+    case 'b':
+      Ivalue = get_displacement (buffer, aoffsetp);
+      /*
+       * Warning!!  HACK ALERT!
+       * Operand type 'b' is only used by the cmp{b,w,d} and
+       * movm{b,w,d} instructions; we need to know whether
+       * it's a `b' or `w' or `d' instruction; and for both
+       * cmpm and movm it's stored at the same place so we
+       * just grab two bits of the opcode and look at it...
+       * 
+       */
+      size = bit_extract(buffer, ioffset-6, 2);
+      if (size == 0)		/* 00 => b */
+	size = 1;
+      else if (size == 1)	/* 01 => w */
+	size = 2;
+      else
+	size = 4;		/* 11 => d */
+
+      sprintf (result, "%d", (Ivalue / size) + 1);
+      break;
+    case 'p':
+      *result++ = NEXT_IS_ADDR;
+      sprintf_vma (result, addr + get_displacement (buffer, aoffsetp));
+      result += strlen (result);
+      *result++ = NEXT_IS_ADDR;
+      *result = '\0';
+      break;
+    case 'i':
+      Ivalue = bit_extract (buffer, *aoffsetp, 8);
+      *aoffsetp += 8;
+      sprintf (result, "0x%x", Ivalue);
+      break;
+    case 'u':
+      Ivalue = bit_extract (buffer, *aoffsetp, 8);
+      optlist(Ivalue, opt_u, result);
+      *aoffsetp += 8;
+      break;
+    case 'U':
+      Ivalue = bit_extract(buffer, *aoffsetp, 8);
+      optlist(Ivalue, opt_U, result);
+      *aoffsetp += 8;
+      break;
+    case 'O':
+      Ivalue = bit_extract(buffer, ioffset-9, 9);
+      optlist(Ivalue, opt_O, result);
+      ioffset -= 9;
+      break;
+    case 'C':
+      Ivalue = bit_extract(buffer, ioffset-4, 4);
+      optlist(Ivalue, opt_C, result);
+      ioffset -= 4;
+      break;
+    case 'S':
+      Ivalue = bit_extract(buffer, ioffset - 8, 8);
+      optlist(Ivalue, opt_S, result);
+      ioffset -= 8;
+      break;
+    case 'M':
+      Ivalue = bit_extract(buffer, ioffset-4, 4);
+      list_search(Ivalue, 0 ? list_M032 : list_M532, result);
+      ioffset -= 4;
+      break;
+    case 'P':
+      Ivalue = bit_extract(buffer, ioffset-4, 4);
+      list_search(Ivalue, 0 ? list_P032 : list_P532, result);
+      ioffset -= 4;
+      break;
+    case 'g':
+      Ivalue = bit_extract(buffer, *aoffsetp, 3);
+      sprintf(result, "%d", Ivalue);
+      *aoffsetp += 3;
+      break;
+    case 'G':
+      Ivalue = bit_extract(buffer, *aoffsetp, 5);
+      sprintf(result, "%d", Ivalue + 1);
+      *aoffsetp += 5;
+      break;
+    }
+  return ioffset;
+}
+
+static int
+get_displacement (buffer, aoffsetp)
+     char *buffer;
+     int *aoffsetp;
+{
+  int Ivalue;
+  short Ivalue2;
+
+  Ivalue = bit_extract (buffer, *aoffsetp, 8);
+  switch (Ivalue & 0xc0)
+    {
+    case 0x00:
+    case 0x40:
+      Ivalue = sign_extend (Ivalue, 7);
+      *aoffsetp += 8;
+      break;
+    case 0x80:
+      Ivalue2 = bit_extract (buffer, *aoffsetp, 16);
+      flip_bytes (&Ivalue2, 2);
+      Ivalue = sign_extend (Ivalue2, 14);
+      *aoffsetp += 16;
+      break;
+    case 0xc0:
+      Ivalue = bit_extract (buffer, *aoffsetp, 32);
+      flip_bytes (&Ivalue, 4);
+      Ivalue = sign_extend (Ivalue, 30);
+      *aoffsetp += 32;
+      break;
+    }
+  return Ivalue;
+}
+
+
+#if 1 /* a version that should work on ns32k f's&d's on any machine */
+static int
+invalid_float (p, len)
+     register char *p;
+     register int len;
+{
+  register int val;
+
+  if ( len == 4 )
+    val = (bit_extract_simple(p, 23, 8)/*exponent*/ == 0xff
+	   || (bit_extract_simple(p, 23, 8)/*exponent*/ == 0 &&
+	       bit_extract_simple(p, 0, 23)/*mantisa*/ != 0));
+  else if ( len == 8 )
+    val = (bit_extract_simple(p, 52, 11)/*exponent*/ == 0x7ff
+	   || (bit_extract_simple(p, 52, 11)/*exponent*/ == 0
+	       && (bit_extract_simple(p, 0, 32)/*low mantisa*/ != 0
+		   || bit_extract_simple(p, 32, 20)/*high mantisa*/ != 0)));
+  else
+    val = 1;
+  return (val);
+}
+#else
+
+/* assumes the bytes have been swapped to local order */
+typedef union { double d;
+		float f;
+		struct { unsigned m:23, e:8, :1;} sf;
+		struct { unsigned lm; unsigned m:20, e:11, :1;} sd;
+	      } float_type_u;
+
+static int
+invalid_float (p, len)
+     register float_type_u *p;
+     register int len;
+{
+  register int val;
+  if ( len == sizeof (float) )
+    val = (p->sf.e == 0xff
+	   || (p->sf.e == 0 && p->sf.m != 0));
+  else if ( len == sizeof (double) )
+    val = (p->sd.e == 0x7ff
+	   || (p->sd.e == 0 && (p->sd.m != 0 || p->sd.lm != 0)));
+  else
+    val = 1;
+  return (val);
+}
+#endif