opcodes/alpha-dis.c

   1 /* alpha-dis.c -- Disassemble Alpha AXP instructions
   2    Copyright 1996, 1998, 1999, 2000, 2001 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 GDB, GAS, and the GNU binutils.
   7
   8 GDB, GAS, and the GNU binutils are free software; you can redistribute
   9 them and/or modify them under the terms of the GNU General Public
  10 License as published by the Free Software Foundation; either version
  11 2, or (at your option) any later version.
  12
  13 GDB, GAS, and the GNU binutils are distributed in the hope that they
  14 will be useful, but WITHOUT ANY WARRANTY; without even the implied
  15 warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  16 the GNU General Public 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, 59 Temple Place - Suite 330, Boston, MA
  21 02111-1307, USA.  */
  22
  23 #include <stdio.h>
  24 #include "sysdep.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 }