opcodes/alpha-dis.c

   1 /* alpha-dis.c -- Disassemble Alpha AXP instructions
   2    Copyright (C) 1996-2014 Free Software Foundation, Inc.
   3    Contributed by Richard Henderson <rth@tamu.edu>,
   4    patterned after the PPC opcode handling written by Ian Lance Taylor.
   5
   6    This file is part of libopcodes.
   7
   8    This library is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3, or (at your option)
  11    any later version.
  12
  13    It is distributed in the hope that it will be useful, but WITHOUT
  14    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  15    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  16    License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this file; see the file COPYING.  If not, write to the Free
  20    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
  21    02110-1301, USA.  */
  22
  23 #include "sysdep.h"
  24 #include <stdio.h>
  25 #include "dis-asm.h"
  26 #include "opcode/alpha.h"
  27
  28 /* OSF register names.  */
  29
  30 static const char * const osf_regnames[64] = {
  31   "v0", "t0", "t1", "t2", "t3", "t4", "t5", "t6",
  32   "t7", "s0", "s1", "s2", "s3", "s4", "s5", "fp",
  33   "a0", "a1", "a2", "a3", "a4", "a5", "t8", "t9",
  34   "t10", "t11", "ra", "t12", "at", "gp", "sp", "zero",
  35   "$f0", "$f1", "$f2", "$f3", "$f4", "$f5", "$f6", "$f7",
  36   "$f8", "$f9", "$f10", "$f11", "$f12", "$f13", "$f14", "$f15",
  37   "$f16", "$f17", "$f18", "$f19", "$f20", "$f21", "$f22", "$f23",
  38   "$f24", "$f25", "$f26", "$f27", "$f28", "$f29", "$f30", "$f31"
  39 };
  40
  41 /* VMS register names.  */
  42
  43 static const char * const vms_regnames[64] = {
  44   "R0", "R1", "R2", "R3", "R4", "R5", "R6", "R7",
  45   "R8", "R9", "R10", "R11", "R12", "R13", "R14", "R15",
  46   "R16", "R17", "R18", "R19", "R20", "R21", "R22", "R23",
  47   "R24", "AI", "RA", "PV", "AT", "FP", "SP", "RZ",
  48   "F0", "F1", "F2", "F3", "F4", "F5", "F6", "F7",
  49   "F8", "F9", "F10", "F11", "F12", "F13", "F14", "F15",
  50   "F16", "F17", "F18", "F19", "F20", "F21", "F22", "F23",
  51   "F24", "F25", "F26", "F27", "F28", "F29", "F30", "FZ"
  52 };
  53
  54 /* Disassemble Alpha instructions.  */
  55
  56 int
  57 print_insn_alpha (memaddr, info)
  58      bfd_vma memaddr;
  59      struct disassemble_info *info;
  60 {
  61   static const struct alpha_opcode *opcode_index[AXP_NOPS+1];
  62   const char * const * regnames;
  63   const struct alpha_opcode *opcode, *opcode_end;
  64   const unsigned char *opindex;
  65   unsigned insn, op, isa_mask;
  66   int need_comma;
  67
  68   /* Initialize the majorop table the first time through */
  69   if (!opcode_index[0])
  70     {
  71       opcode = alpha_opcodes;
  72       opcode_end = opcode + alpha_num_opcodes;
  73
  74       for (op = 0; op < AXP_NOPS; ++op)
  75         {
  76           opcode_index[op] = opcode;
  77           while (opcode < opcode_end && op == AXP_OP (opcode->opcode))
  78             ++opcode;
  79         }
  80       opcode_index[op] = opcode;
  81     }
  82
  83   if (info->flavour == bfd_target_evax_flavour)
  84     regnames = vms_regnames;
  85   else
  86     regnames = osf_regnames;
  87
  88   isa_mask = AXP_OPCODE_NOPAL;
  89   switch (info->mach)
  90     {
  91     case bfd_mach_alpha_ev4:
  92       isa_mask |= AXP_OPCODE_EV4;
  93       break;
  94     case bfd_mach_alpha_ev5:
  95       isa_mask |= AXP_OPCODE_EV5;
  96       break;
  97     case bfd_mach_alpha_ev6:
  98       isa_mask |= AXP_OPCODE_EV6;
  99       break;
 100     }
 101
 102   /* Read the insn into a host word */
 103   {
 104     bfd_byte buffer[4];
 105     int status = (*info->read_memory_func) (memaddr, buffer, 4, info);
 106     if (status != 0)
 107       {
 108         (*info->memory_error_func) (status, memaddr, info);
 109         return -1;
 110       }
 111     insn = bfd_getl32 (buffer);
 112   }
 113
 114   /* Get the major opcode of the instruction.  */
 115   op = AXP_OP (insn);
 116
 117   /* Find the first match in the opcode table.  */
 118   opcode_end = opcode_index[op + 1];
 119   for (opcode = opcode_index[op]; opcode < opcode_end; ++opcode)
 120     {
 121       if ((insn ^ opcode->opcode) & opcode->mask)
 122         continue;
 123
 124       if (!(opcode->flags & isa_mask))
 125         continue;
 126
 127       /* Make two passes over the operands.  First see if any of them
 128          have extraction functions, and, if they do, make sure the
 129          instruction is valid.  */
 130       {
 131         int invalid = 0;
 132         for (opindex = opcode->operands; *opindex != 0; opindex++)
 133           {
 134             const struct alpha_operand *operand = alpha_operands + *opindex;
 135             if (operand->extract)
 136               (*operand->extract) (insn, &invalid);
 137           }
 138         if (invalid)
 139           continue;
 140       }
 141
 142       /* The instruction is valid.  */
 143       goto found;
 144     }
 145
 146   /* No instruction found */
 147   (*info->fprintf_func) (info->stream, ".long %#08x", insn);
 148
 149   return 4;
 150
 151 found:
 152   (*info->fprintf_func) (info->stream, "%s", opcode->name);
 153   if (opcode->operands[0] != 0)
 154     (*info->fprintf_func) (info->stream, "\t");
 155
 156   /* Now extract and print the operands.  */
 157   need_comma = 0;
 158   for (opindex = opcode->operands; *opindex != 0; opindex++)
 159     {
 160       const struct alpha_operand *operand = alpha_operands + *opindex;
 161       int value;
 162
 163       /* Operands that are marked FAKE are simply ignored.  We
 164          already made sure that the extract function considered
 165          the instruction to be valid.  */
 166       if ((operand->flags & AXP_OPERAND_FAKE) != 0)
 167         continue;
 168
 169       /* Extract the value from the instruction.  */
 170       if (operand->extract)
 171         value = (*operand->extract) (insn, (int *) NULL);
 172       else
 173         {
 174           value = (insn >> operand->shift) & ((1 << operand->bits) - 1);
 175           if (operand->flags & AXP_OPERAND_SIGNED)
 176             {
 177               int signbit = 1 << (operand->bits - 1);
 178               value = (value ^ signbit) - signbit;
 179             }
 180         }
 181
 182       if (need_comma &&
 183           ((operand->flags & (AXP_OPERAND_PARENS | AXP_OPERAND_COMMA))
 184            != AXP_OPERAND_PARENS))
 185         {
 186           (*info->fprintf_func) (info->stream, ",");
 187         }
 188       if (operand->flags & AXP_OPERAND_PARENS)
 189         (*info->fprintf_func) (info->stream, "(");
 190
 191       /* Print the operand as directed by the flags.  */
 192       if (operand->flags & AXP_OPERAND_IR)
 193         (*info->fprintf_func) (info->stream, "%s", regnames[value]);
 194       else if (operand->flags & AXP_OPERAND_FPR)
 195         (*info->fprintf_func) (info->stream, "%s", regnames[value + 32]);
 196       else if (operand->flags & AXP_OPERAND_RELATIVE)
 197         (*info->print_address_func) (memaddr + 4 + value, info);
 198       else if (operand->flags & AXP_OPERAND_SIGNED)
 199         (*info->fprintf_func) (info->stream, "%d", value);
 200       else
 201         (*info->fprintf_func) (info->stream, "%#x", value);
 202
 203       if (operand->flags & AXP_OPERAND_PARENS)
 204         (*info->fprintf_func) (info->stream, ")");
 205       need_comma = 1;
 206     }
 207
 208   return 4;
 209 }