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/* i370-dis.c -- Disassemble Instruction 370 (ESA/390) instructions

   Copyright 1994, 2000 Free Software Foundation, Inc.

   PowerPC version written by Ian Lance Taylor, Cygnus Support

   Rewritten for i370 ESA/390 support by Linas Vepstas <linas@linas.org>

This file is part of GDB, GAS, and the GNU binutils.

GDB, GAS, and the GNU binutils are free software; you can redistribute

them and/or modify them 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.

GDB, GAS, and the GNU binutils are distributed in the hope that they

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 file; 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 "sysdep.h"

#include "dis-asm.h"

#include "opcode/i370.h"

/* This file provides several disassembler functions, all of which use

   the disassembler interface defined in dis-asm.h.

*/

int

print_insn_i370 (memaddr, info)

     bfd_vma memaddr;

     struct disassemble_info *info;

{

  bfd_byte buffer[8];

  int status;

  i370_insn_t insn;

  const struct i370_opcode *opcode;

  const struct i370_opcode *opcode_end;

  status = (*info->read_memory_func) (memaddr, buffer, 6, info);

  if (status != 0)

    {

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

      return -1;

    }

  /* Cast the bytes into the insn (in a host-endian indep way) */

  insn.i[0] = (buffer[0] << 24) & 0xff000000;

  insn.i[0] |= (buffer[1] << 16) & 0xff0000;

  insn.i[0] |= (buffer[2] << 8) & 0xff00;

  insn.i[0] |= buffer[3]  & 0xff;

  insn.i[1] = (buffer[4] << 24) & 0xff000000;

  insn.i[1] |= (buffer[5] << 16) & 0xff0000;

  /* Find the first match in the opcode table.  We could speed this up

     a bit by doing a binary search on the major opcode.  */

  opcode_end = i370_opcodes + i370_num_opcodes;

  for (opcode = i370_opcodes; opcode < opcode_end; opcode++)

    {

      const unsigned char *opindex;

      const struct i370_operand *operand;

      i370_insn_t masked;

      int invalid;

      /* Mask off operands, and look for a match ... */

      masked = insn;

      if (2 == opcode->len)

        {

          masked.i[0] >>= 16;

          masked.i[0] &= 0xffff;

        }

      masked.i[0] &= opcode->mask.i[0];

      if (masked.i[0] != opcode->opcode.i[0]) continue;

      if (6 == opcode->len)

        {

          masked.i[1] &= opcode->mask.i[1];

          if (masked.i[1] != opcode->opcode.i[1]) continue;

        }

      /* Found a match.  adjust a tad */

      if (2 == opcode->len)

        {

          insn.i[0] >>= 16;

          insn.i[0] &= 0xffff;

        }

      /* Make two passes over the operands.  First see if any of them

         have extraction functions, and, if they do, make sure the

         instruction is valid.  */

      invalid = 0;

      for (opindex = opcode->operands; *opindex != 0; opindex++)

        {

          operand = i370_operands + *opindex;

          if (operand->extract)

            (*operand->extract) (insn, &invalid);

        }

      if (invalid) continue;

      /* The instruction is valid.  */

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

      if (opcode->operands[0] != 0)

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

      /* Now extract and print the operands.  */

      for (opindex = opcode->operands; *opindex != 0; opindex++)

        {

          long value;

          operand = i370_operands + *opindex;

          /* Extract the value from the instruction.  */

          if (operand->extract)

            value = (*operand->extract) (insn, (int *) NULL);

          else

            {

              value = (insn.i[0] >> operand->shift) & ((1 << operand->bits) - 1);

            }

          /* Print the operand as directed by the flags.  */

          if ((operand->flags & I370_OPERAND_OPTIONAL) != 0)

            {

              if (value)

                (*info->fprintf_func) (info->stream, "(r%ld)", value);

            }

          else if ((operand->flags & I370_OPERAND_SBASE) != 0)

            {

              (*info->fprintf_func) (info->stream, "(r%ld)", value);

            }

          else if ((operand->flags & I370_OPERAND_INDEX) != 0)

            {

              if (value)

                (*info->fprintf_func) (info->stream, "(r%ld,", value);

              else

                (*info->fprintf_func) (info->stream, "(,");

            }

          else if ((operand->flags & I370_OPERAND_LENGTH) != 0)

            {

              (*info->fprintf_func) (info->stream, "(%ld,", value);

            }

          else if ((operand->flags & I370_OPERAND_BASE) != 0)

            (*info->fprintf_func) (info->stream, "r%ld)", value);

          else if ((operand->flags & I370_OPERAND_GPR) != 0)

            (*info->fprintf_func) (info->stream, "r%ld,", value);

          else if ((operand->flags & I370_OPERAND_FPR) != 0)

            (*info->fprintf_func) (info->stream, "f%ld,", value);

          else if ((operand->flags & I370_OPERAND_RELATIVE) != 0)

            (*info->fprintf_func) (info->stream, "%ld", value);

          else

            (*info->fprintf_func) (info->stream, " %ld, ", value);

        }

      return opcode->len;

    }

  /* We could not find a match.  */

  (*info->fprintf_func) (info->stream, ".short 0x%02x%02x", buffer[0], buffer[1]);

  return 2;

}