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/* Disassembler for the i860.

   Copyright 2000 Free Software Foundation, Inc.

   Contributed by Jason Eckhardt <jle@cygnus.com>.

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 "dis-asm.h"

#include "opcode/i860.h"

/* Later we should probably choose the prefix based on which OS flavor.  */

#define I860_REG_PREFIX "%"

/* Integer register names (encoded as 0..31 in the instruction).  */

static const char *const grnames[] =

 {"r0",  "r1",  "sp",  "fp",  "r4",  "r5",  "r6",  "r7",

  "r8",  "r9",  "r10", "r11", "r12", "r13", "r14", "r15",

  "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",

  "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31"};

/* FP register names (encoded as 0..31 in the instruction).  */

static const char *const frnames[] =

 {"f0",  "f1",  "f2",  "f3",  "f4",  "f5",  "f6",  "f7",

  "f8",  "f9",  "f10", "f11", "f12", "f13", "f14", "f15",

  "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",

  "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31"};

/* Control/status register names (encoded as 0..5 in the instruction).  */

static const char *const crnames[] =

 {"fir", "psr", "dirbase", "db", "fsr", "epsr", "", ""};

/* Prototypes.  */

static int sign_ext             PARAMS((unsigned int, int));

static void print_br_address    PARAMS((disassemble_info *, bfd_vma, long));

/* True if opcode is xor, xorh, and, andh, or, orh, andnot, andnoth.  */

#define BITWISE_OP(op)  ((op) == 0x30 || (op) == 0x31           \

                         || (op) == 0x34 || (op) == 0x35        \

                         || (op) == 0x38 || (op) == 0x39        \

                         || (op) == 0x3c || (op) == 0x3d        \

                         || (op) == 0x33 || (op) == 0x37        \

                         || (op) == 0x3b || (op) == 0x3f)

/* Sign extend N-bit number.  */

static int

sign_ext (x, n)

     unsigned int x;

     int n;

{

  int t;

  t = x >> (n - 1);

  t = ((-t) << n) | x;

  return t;

}

/* Print a PC-relative branch offset.  VAL is the sign extended value

   from the branch instruction.  */

static void

print_br_address (info, memaddr, val)

     disassemble_info *info;

     bfd_vma memaddr;

     long val;

{

  long adj = (long)memaddr + 4 + (val << 2);

  (*info->fprintf_func) (info->stream, "0x%08x", adj);

  /* Attempt to obtain a symbol for the target address.  */

  if (info->print_address_func && adj != 0)

    {

      (*info->fprintf_func) (info->stream, "\t// ");

      (*info->print_address_func) (adj, info);

    }

}

/* Print one instruction.  */

int

print_insn_i860 (memaddr, info)

     bfd_vma memaddr;

     disassemble_info *info;

{

  bfd_byte buff[4];

  unsigned int insn, i;

  int status;

  const struct i860_opcode *opcode = 0;

  status = (*info->read_memory_func) (memaddr, buff, sizeof (buff), info);

  if (status != 0)

    {

      (*info->memory_error_func) (status, memaddr, info);

      return -1;

    }

  /* Note that i860 instructions are always accessed as little endian

     data, regardless of the endian mode of the i860.  */

  insn = bfd_getl32 (buff);

  status = 0;

  i = 0;

  while (i860_opcodes[i].name != NULL)

    {

      opcode = &i860_opcodes[i];

      if ((insn & opcode->match) == opcode->match

          && (insn & opcode->lose) == 0)

        {

          status = 1;

          break;

        }

      ++i;

    }

  if (status == 0)

    {

      /* Instruction not in opcode table.  */

      (*info->fprintf_func) (info->stream, ".long %#08x", insn);

    }

  else

    {

      const char *s;

      int val;

      /* If this a flop and its dual bit is set, prefix with 'd.'.  */

      if ((insn & 0xfc000000) == 0x48000000 && (insn & 0x200))

        (*info->fprintf_func) (info->stream, "d.%s\t", opcode->name);

      else

        (*info->fprintf_func) (info->stream, "%s\t", opcode->name);

      for (s = opcode->args; *s; s++)

        {

          switch (*s)

            {

            /* Integer register (src1).  */

            case '1':

              (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,

                                     grnames[(insn >> 11) & 0x1f]);

              break;

            /* Integer register (src2).  */

            case '2':

              (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,

                                     grnames[(insn >> 21) & 0x1f]);

              break;

            /* Integer destination register.  */

            case 'd':

              (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,

                                     grnames[(insn >> 16) & 0x1f]);

              break;

            /* Floating-point register (src1).  */

            case 'e':

              (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,

                                     frnames[(insn >> 11) & 0x1f]);

              break;

            /* Floating-point register (src2).  */

            case 'f':

              (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,

                                     frnames[(insn >> 21) & 0x1f]);

              break;

            /* Floating-point destination register.  */

            case 'g':

              (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,

                                     frnames[(insn >> 16) & 0x1f]);

              break;

            /* Control register.  */

            case 'c':

              (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,

                                     crnames[(insn >> 21) & 0x7]);

              break;

            /* 16-bit immediate (sign extend, except for bitwise ops).  */

            case 'i':

              if (BITWISE_OP ((insn & 0xfc000000) >> 26))

                (*info->fprintf_func) (info->stream, "0x%04x",

                                       (unsigned int) (insn & 0xffff));

              else

                (*info->fprintf_func) (info->stream, "%d",

                                       sign_ext ((insn & 0xffff), 16));

              break;

            /* 16-bit immediate, aligned (2^0, ld.b).  */

            case 'I':

              (*info->fprintf_func) (info->stream, "%d",

                                     sign_ext ((insn & 0xffff), 16));

              break;

            /* 16-bit immediate, aligned (2^1, ld.s).  */

            case 'J':

              (*info->fprintf_func) (info->stream, "%d",

                                     sign_ext ((insn & 0xfffe), 16));

              break;

            /* 16-bit immediate, aligned (2^2, ld.l, {p}fld.l, fst.l).  */

            case 'K':

              (*info->fprintf_func) (info->stream, "%d",

                                     sign_ext ((insn & 0xfffc), 16));

              break;

            /* 16-bit immediate, aligned (2^3, {p}fld.d, fst.d).  */

            case 'L':

              (*info->fprintf_func) (info->stream, "%d",

                                     sign_ext ((insn & 0xfff8), 16));

              break;

            /* 16-bit immediate, aligned (2^4, {p}fld.q, fst.q).  */

            case 'M':

              (*info->fprintf_func) (info->stream, "%d",

                                     sign_ext ((insn & 0xfff0), 16));

              break;

            /* 5-bit immediate (zero extend).  */

            case '5':

              (*info->fprintf_func) (info->stream, "%d",

                                     ((insn >> 11) & 0x1f));

              break;

            /* Split 16 bit immediate (20..16:10..0).  */

            case 's':

              val = ((insn >> 5) & 0xf800) | (insn & 0x07ff);

              (*info->fprintf_func) (info->stream, "%d",

                                     sign_ext (val, 16));

              break;

            /* Split 16 bit immediate, aligned. (2^0, st.b).  */

            case 'S':

              val = ((insn >> 5) & 0xf800) | (insn & 0x07ff);

              (*info->fprintf_func) (info->stream, "%d",

                                     sign_ext (val, 16));

              break;

            /* Split 16 bit immediate, aligned. (2^1, st.s).  */

            case 'T':

              val = ((insn >> 5) & 0xf800) | (insn & 0x07fe);

              (*info->fprintf_func) (info->stream, "%d",

                                     sign_ext (val, 16));

              break;

            /* Split 16 bit immediate, aligned. (2^2, st.l).  */

            case 'U':

              val = ((insn >> 5) & 0xf800) | (insn & 0x07fc);

              (*info->fprintf_func) (info->stream, "%d",

                                     sign_ext (val, 16));

              break;

            /* 26-bit PC relative immediate (lbroff).  */

            case 'l':

              val = sign_ext ((insn & 0x03ffffff), 26);

              print_br_address (info, memaddr, val);

              break;

            /* 16-bit PC relative immediate (sbroff).  */

            case 'r':

              val = sign_ext ((((insn >> 5) & 0xf800) | (insn & 0x07ff)), 16);

              print_br_address (info, memaddr, val);

              break;

            default:

              (*info->fprintf_func) (info->stream, "%c", *s);

              break;

            }

        }

    }

  return sizeof (insn);

}