opcodes/i370-dis.c

   1
   2 /* i370-dis.c -- Disassemble Instruction 370 (ESA/390) instructions
   3    Copyright 1994, 2000 Free Software Foundation, Inc.
   4    PowerPC version written by Ian Lance Taylor, Cygnus Support
   5    Rewritten for i370 ESA/390 support by Linas Vepstas <linas@linas.org>
   6
   7 This file is part of GDB, GAS, and the GNU binutils.
   8
   9 GDB, GAS, and the GNU binutils are free software; you can redistribute
  10 them and/or modify them under the terms of the GNU General Public
  11 License as published by the Free Software Foundation; either version
  12 2, or (at your option) any later version.
  13
  14 GDB, GAS, and the GNU binutils are distributed in the hope that they
  15 will be useful, but WITHOUT ANY WARRANTY; without even the implied
  16 warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  17 the GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with this file; see the file COPYING.  If not, write to the Free
  21 Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  22
  23 #include <stdio.h>
  24 #include "ansidecl.h"
  25 #include "sysdep.h"
  26 #include "dis-asm.h"
  27 #include "opcode/i370.h"
  28
  29 /* This file provides several disassembler functions, all of which use
  30    the disassembler interface defined in dis-asm.h.
  31 */
  32
  33 int
  34 print_insn_i370 (memaddr, info)
  35      bfd_vma memaddr;
  36      struct disassemble_info *info;
  37 {
  38   bfd_byte buffer[8];
  39   int status;
  40   i370_insn_t insn;
  41   const struct i370_opcode *opcode;
  42   const struct i370_opcode *opcode_end;
  43
  44   status = (*info->read_memory_func) (memaddr, buffer, 6, info);
  45   if (status != 0)
  46     {
  47       (*info->memory_error_func) (status, memaddr, info);
  48       return -1;
  49     }
  50
  51   /* Cast the bytes into the insn (in a host-endian indep way) */
  52   insn.i[0] = (buffer[0] << 24) & 0xff000000;
  53   insn.i[0] |= (buffer[1] << 16) & 0xff0000;
  54   insn.i[0] |= (buffer[2] << 8) & 0xff00;
  55   insn.i[0] |= buffer[3]  & 0xff;
  56   insn.i[1] = (buffer[4] << 24) & 0xff000000;
  57   insn.i[1] |= (buffer[5] << 16) & 0xff0000;
  58
  59   /* Find the first match in the opcode table.  We could speed this up
  60      a bit by doing a binary search on the major opcode.  */
  61   opcode_end = i370_opcodes + i370_num_opcodes;
  62   for (opcode = i370_opcodes; opcode < opcode_end; opcode++)
  63     {
  64       const unsigned char *opindex;
  65       const struct i370_operand *operand;
  66       i370_insn_t masked;
  67       int invalid;
  68
  69       /* Mask off operands, and look for a match ... */
  70       masked = insn;
  71       if (2 == opcode->len)
  72         {
  73           masked.i[0] >>= 16;
  74           masked.i[0] &= 0xffff;
  75         }
  76       masked.i[0] &= opcode->mask.i[0];
  77       if (masked.i[0] != opcode->opcode.i[0]) continue;
  78
  79       if (6 == opcode->len)
  80         {
  81           masked.i[1] &= opcode->mask.i[1];
  82           if (masked.i[1] != opcode->opcode.i[1]) continue;
  83         }
  84
  85       /* Found a match.  adjust a tad */
  86       if (2 == opcode->len)
  87         {
  88           insn.i[0] >>= 16;
  89           insn.i[0] &= 0xffff;
  90         }
  91
  92       /* Make two passes over the operands.  First see if any of them
  93          have extraction functions, and, if they do, make sure the
  94          instruction is valid.  */
  95       invalid = 0;
  96       for (opindex = opcode->operands; *opindex != 0; opindex++)
  97         {
  98           operand = i370_operands + *opindex;
  99           if (operand->extract)
 100             (*operand->extract) (insn, &invalid);
 101         }
 102       if (invalid) continue;
 103
 104       /* The instruction is valid.  */
 105       (*info->fprintf_func) (info->stream, "%s", opcode->name);
 106       if (opcode->operands[0] != 0)
 107         (*info->fprintf_func) (info->stream, "\t");
 108
 109       /* Now extract and print the operands.  */
 110       for (opindex = opcode->operands; *opindex != 0; opindex++)
 111         {
 112           long value;
 113
 114           operand = i370_operands + *opindex;
 115
 116           /* Extract the value from the instruction.  */
 117           if (operand->extract)
 118             value = (*operand->extract) (insn, (int *) NULL);
 119           else
 120             {
 121               value = (insn.i[0] >> operand->shift) & ((1 << operand->bits) - 1);
 122             }
 123
 124           /* Print the operand as directed by the flags.  */
 125           if ((operand->flags & I370_OPERAND_OPTIONAL) != 0)
 126             {
 127               if (value)
 128                 (*info->fprintf_func) (info->stream, "(r%ld)", value);
 129             }
 130           else if ((operand->flags & I370_OPERAND_SBASE) != 0)
 131             {
 132               (*info->fprintf_func) (info->stream, "(r%ld)", value);
 133             }
 134           else if ((operand->flags & I370_OPERAND_INDEX) != 0)
 135             {
 136               if (value)
 137                 (*info->fprintf_func) (info->stream, "(r%ld,", value);
 138               else
 139                 (*info->fprintf_func) (info->stream, "(,");
 140             }
 141           else if ((operand->flags & I370_OPERAND_LENGTH) != 0)
 142             {
 143               (*info->fprintf_func) (info->stream, "(%ld,", value);
 144             }
 145           else if ((operand->flags & I370_OPERAND_BASE) != 0)
 146             (*info->fprintf_func) (info->stream, "r%ld)", value);
 147           else if ((operand->flags & I370_OPERAND_GPR) != 0)
 148             (*info->fprintf_func) (info->stream, "r%ld,", value);
 149           else if ((operand->flags & I370_OPERAND_FPR) != 0)
 150             (*info->fprintf_func) (info->stream, "f%ld,", value);
 151           else if ((operand->flags & I370_OPERAND_RELATIVE) != 0)
 152             (*info->fprintf_func) (info->stream, "%ld", value);
 153           else
 154             (*info->fprintf_func) (info->stream, " %ld, ", value);
 155
 156         }
 157
 158       return opcode->len;
 159
 160     }
 161
 162
 163   /* We could not find a match.  */
 164   (*info->fprintf_func) (info->stream, ".short 0x%02x%02x", buffer[0], buffer[1]);
 165
 166   return 2;
 167 }