opcodes/i370-dis.c

   1 /* i370-dis.c -- Disassemble Instruction 370 (ESA/390) instructions
   2    Copyright 1994, 2000, 2003, 2005, 2007, 2012
   3    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 the GNU opcodes library.
   8
   9    This library is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3, or (at your option)
  12    any later version.
  13
  14    It is distributed in the hope that it will be useful, but WITHOUT
  15    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  16    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  17    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, 51 Franklin Street - Fifth Floor, Boston,
  22    MA 02110-1301, USA.  */
  23
  24 #include "sysdep.h"
  25 #include <stdio.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 int
  33 print_insn_i370 (bfd_vma memaddr, struct disassemble_info *info)
  34 {
  35   bfd_byte buffer[8];
  36   int status;
  37   i370_insn_t insn;
  38   const struct i370_opcode *opcode;
  39   const struct i370_opcode *opcode_end;
  40
  41   status = (*info->read_memory_func) (memaddr, buffer, 6, info);
  42   if (status != 0)
  43     {
  44       (*info->memory_error_func) (status, memaddr, info);
  45       return -1;
  46     }
  47
  48   /* Cast the bytes into the insn (in a host-endian indep way).  */
  49   insn.i[0] = (buffer[0] << 24) & 0xff000000;
  50   insn.i[0] |= (buffer[1] << 16) & 0xff0000;
  51   insn.i[0] |= (buffer[2] << 8) & 0xff00;
  52   insn.i[0] |= buffer[3]  & 0xff;
  53   insn.i[1] = (buffer[4] << 24) & 0xff000000;
  54   insn.i[1] |= (buffer[5] << 16) & 0xff0000;
  55
  56   /* Find the first match in the opcode table.  We could speed this up
  57      a bit by doing a binary search on the major opcode.  */
  58   opcode_end = i370_opcodes + i370_num_opcodes;
  59   for (opcode = i370_opcodes; opcode < opcode_end; opcode++)
  60     {
  61       const unsigned char *opindex;
  62       const struct i370_operand *operand;
  63       i370_insn_t masked;
  64       int invalid;
  65
  66       /* Mask off operands, and look for a match ... */
  67       masked = insn;
  68       if (2 == opcode->len)
  69         {
  70           masked.i[0] >>= 16;
  71           masked.i[0] &= 0xffff;
  72         }
  73       masked.i[0] &= opcode->mask.i[0];
  74       if (masked.i[0] != opcode->opcode.i[0])
  75         continue;
  76
  77       if (6 == opcode->len)
  78         {
  79           masked.i[1] &= opcode->mask.i[1];
  80           if (masked.i[1] != opcode->opcode.i[1])
  81             continue;
  82         }
  83
  84       /* Found a match.  adjust a tad.  */
  85       if (2 == opcode->len)
  86         {
  87           insn.i[0] >>= 16;
  88           insn.i[0] &= 0xffff;
  89         }
  90
  91       /* Make two passes over the operands.  First see if any of them
  92          have extraction functions, and, if they do, make sure the
  93          instruction is valid.  */
  94       invalid = 0;
  95       for (opindex = opcode->operands; *opindex != 0; opindex++)
  96         {
  97           operand = i370_operands + *opindex;
  98           if (operand->extract)
  99             (*operand->extract) (insn, &invalid);
 100         }
 101       if (invalid)
 102         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             value = (insn.i[0] >> operand->shift) & ((1 << operand->bits) - 1);
 121
 122           /* Print the operand as directed by the flags.  */
 123           if ((operand->flags & I370_OPERAND_OPTIONAL) != 0)
 124             {
 125               if (value)
 126                 (*info->fprintf_func) (info->stream, "(r%ld)", value);
 127             }
 128           else if ((operand->flags & I370_OPERAND_SBASE) != 0)
 129             {
 130               (*info->fprintf_func) (info->stream, "(r%ld)", value);
 131             }
 132           else if ((operand->flags & I370_OPERAND_INDEX) != 0)
 133             {
 134               if (value)
 135                 (*info->fprintf_func) (info->stream, "(r%ld,", value);
 136               else
 137                 (*info->fprintf_func) (info->stream, "(,");
 138             }
 139           else if ((operand->flags & I370_OPERAND_LENGTH) != 0)
 140             {
 141               (*info->fprintf_func) (info->stream, "(%ld,", value);
 142             }
 143           else if ((operand->flags & I370_OPERAND_BASE) != 0)
 144             (*info->fprintf_func) (info->stream, "r%ld)", value);
 145           else if ((operand->flags & I370_OPERAND_GPR) != 0)
 146             (*info->fprintf_func) (info->stream, "r%ld,", value);
 147           else if ((operand->flags & I370_OPERAND_FPR) != 0)
 148             (*info->fprintf_func) (info->stream, "f%ld,", value);
 149           else if ((operand->flags & I370_OPERAND_RELATIVE) != 0)
 150             (*info->fprintf_func) (info->stream, "%ld", value);
 151           else
 152             (*info->fprintf_func) (info->stream, " %ld, ", value);
 153         }
 154
 155       return opcode->len;
 156     }
 157
 158   /* We could not find a match.  */
 159   (*info->fprintf_func) (info->stream, ".short 0x%02x%02x", buffer[0], buffer[1]);
 160
 161   return 2;
 162 }