opcodes/alpha-dis.c

   1 /* alpha-dis.c -- Disassemble Alpha AXP instructions
   2    Copyright 1996, 1998, 1999, 2000, 2001, 2002, 2007
   3    Free Software Foundation, Inc.
   4    Contributed by Richard Henderson <rth@tamu.edu>,
   5    patterned after the PPC opcode handling written by Ian Lance Taylor.
   6
   7    This file is part of libopcodes.
   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, MA
  22    02110-1301, USA.  */
  23
  24 #include <stdio.h>
  25 #include "sysdep.h"
  26 #include "dis-asm.h"
  27 #include "opcode/alpha.h"
  28
  29 /* OSF register names.  */
  30
  31 static const char * const osf_regnames[64] = {
  32   "v0", "t0", "t1", "t2", "t3", "t4", "t5", "t6",
  33   "t7", "s0", "s1", "s2", "s3", "s4", "s5", "fp",
  34   "a0", "a1", "a2", "a3", "a4", "a5", "t8", "t9",
  35   "t10", "t11", "ra", "t12", "at", "gp", "sp", "zero",
  36   "$f0", "$f1", "$f2", "$f3", "$f4", "$f5", "$f6", "$f7",
  37   "$f8", "$f9", "$f10", "$f11", "$f12", "$f13", "$f14", "$f15",
  38   "$f16", "$f17", "$f18", "$f19", "$f20", "$f21", "$f22", "$f23",
  39   "$f24", "$f25", "$f26", "$f27", "$f28", "$f29", "$f30", "$f31"
  40 };
  41
  42 /* VMS register names.  */
  43
  44 static const char * const vms_regnames[64] = {
  45   "R0", "R1", "R2", "R3", "R4", "R5", "R6", "R7",
  46   "R8", "R9", "R10", "R11", "R12", "R13", "R14", "R15",
  47   "R16", "R17", "R18", "R19", "R20", "R21", "R22", "R23",
  48   "R24", "AI", "RA", "PV", "AT", "FP", "SP", "RZ",
  49   "F0", "F1", "F2", "F3", "F4", "F5", "F6", "F7",
  50   "F8", "F9", "F10", "F11", "F12", "F13", "F14", "F15",
  51   "F16", "F17", "F18", "F19", "F20", "F21", "F22", "F23",
  52   "F24", "F25", "F26", "F27", "F28", "F29", "F30", "FZ"
  53 };
  54
  55 /* Disassemble Alpha instructions.  */
  56
  57 int
  58 print_insn_alpha (memaddr, info)
  59      bfd_vma memaddr;
  60      struct disassemble_info *info;
  61 {
  62   static const struct alpha_opcode *opcode_index[AXP_NOPS+1];
  63   const char * const * regnames;
  64   const struct alpha_opcode *opcode, *opcode_end;
  65   const unsigned char *opindex;
  66   unsigned insn, op, isa_mask;
  67   int need_comma;
  68
  69   /* Initialize the majorop table the first time through */
  70   if (!opcode_index[0])
  71     {
  72       opcode = alpha_opcodes;
  73       opcode_end = opcode + alpha_num_opcodes;
  74
  75       for (op = 0; op < AXP_NOPS; ++op)
  76         {
  77           opcode_index[op] = opcode;
  78           while (opcode < opcode_end && op == AXP_OP (opcode->opcode))
  79             ++opcode;
  80         }
  81       opcode_index[op] = opcode;
  82     }
  83
  84   if (info->flavour == bfd_target_evax_flavour)
  85     regnames = vms_regnames;
  86   else
  87     regnames = osf_regnames;
  88
  89   isa_mask = AXP_OPCODE_NOPAL;
  90   switch (info->mach)
  91     {
  92     case bfd_mach_alpha_ev4:
  93       isa_mask |= AXP_OPCODE_EV4;
  94       break;
  95     case bfd_mach_alpha_ev5:
  96       isa_mask |= AXP_OPCODE_EV5;
  97       break;
  98     case bfd_mach_alpha_ev6:
  99       isa_mask |= AXP_OPCODE_EV6;
 100       break;
 101     }
 102
 103   /* Read the insn into a host word */
 104   {
 105     bfd_byte buffer[4];
 106     int status = (*info->read_memory_func) (memaddr, buffer, 4, info);
 107     if (status != 0)
 108       {
 109         (*info->memory_error_func) (status, memaddr, info);
 110         return -1;
 111       }
 112     insn = bfd_getl32 (buffer);
 113   }
 114
 115   /* Get the major opcode of the instruction.  */
 116   op = AXP_OP (insn);
 117
 118   /* Find the first match in the opcode table.  */
 119   opcode_end = opcode_index[op + 1];
 120   for (opcode = opcode_index[op]; opcode < opcode_end; ++opcode)
 121     {
 122       if ((insn ^ opcode->opcode) & opcode->mask)
 123         continue;
 124
 125       if (!(opcode->flags & isa_mask))
 126         continue;
 127
 128       /* Make two passes over the operands.  First see if any of them
 129          have extraction functions, and, if they do, make sure the
 130          instruction is valid.  */
 131       {
 132         int invalid = 0;
 133         for (opindex = opcode->operands; *opindex != 0; opindex++)
 134           {
 135             const struct alpha_operand *operand = alpha_operands + *opindex;
 136             if (operand->extract)
 137               (*operand->extract) (insn, &invalid);
 138           }
 139         if (invalid)
 140           continue;
 141       }
 142
 143       /* The instruction is valid.  */
 144       goto found;
 145     }
 146
 147   /* No instruction found */
 148   (*info->fprintf_func) (info->stream, ".long %#08x", insn);
 149
 150   return 4;
 151
 152 found:
 153   (*info->fprintf_func) (info->stream, "%s", opcode->name);
 154   if (opcode->operands[0] != 0)
 155     (*info->fprintf_func) (info->stream, "\t");
 156
 157   /* Now extract and print the operands.  */
 158   need_comma = 0;
 159   for (opindex = opcode->operands; *opindex != 0; opindex++)
 160     {
 161       const struct alpha_operand *operand = alpha_operands + *opindex;
 162       int value;
 163
 164       /* Operands that are marked FAKE are simply ignored.  We
 165          already made sure that the extract function considered
 166          the instruction to be valid.  */
 167       if ((operand->flags & AXP_OPERAND_FAKE) != 0)
 168         continue;
 169
 170       /* Extract the value from the instruction.  */
 171       if (operand->extract)
 172         value = (*operand->extract) (insn, (int *) NULL);
 173       else
 174         {
 175           value = (insn >> operand->shift) & ((1 << operand->bits) - 1);
 176           if (operand->flags & AXP_OPERAND_SIGNED)
 177             {
 178               int signbit = 1 << (operand->bits - 1);
 179               value = (value ^ signbit) - signbit;
 180             }
 181         }
 182
 183       if (need_comma &&
 184           ((operand->flags & (AXP_OPERAND_PARENS | AXP_OPERAND_COMMA))
 185            != AXP_OPERAND_PARENS))
 186         {
 187           (*info->fprintf_func) (info->stream, ",");
 188         }
 189       if (operand->flags & AXP_OPERAND_PARENS)
 190         (*info->fprintf_func) (info->stream, "(");
 191
 192       /* Print the operand as directed by the flags.  */
 193       if (operand->flags & AXP_OPERAND_IR)
 194         (*info->fprintf_func) (info->stream, "%s", regnames[value]);
 195       else if (operand->flags & AXP_OPERAND_FPR)
 196         (*info->fprintf_func) (info->stream, "%s", regnames[value + 32]);
 197       else if (operand->flags & AXP_OPERAND_RELATIVE)
 198         (*info->print_address_func) (memaddr + 4 + value, info);
 199       else if (operand->flags & AXP_OPERAND_SIGNED)
 200         (*info->fprintf_func) (info->stream, "%d", value);
 201       else
 202         (*info->fprintf_func) (info->stream, "%#x", value);
 203
 204       if (operand->flags & AXP_OPERAND_PARENS)
 205         (*info->fprintf_func) (info->stream, ")");
 206       need_comma = 1;
 207     }
 208
 209   return 4;
 210 }