opcodes/ppc-dis.c

   1 /* ppc-dis.c -- Disassemble PowerPC instructions
   2    Copyright 1994 Free Software Foundation, Inc.
   3    Written by Ian Lance Taylor, Cygnus Support
   4
   5 This file is part of GDB, GAS, and the GNU binutils.
   6
   7 GDB, GAS, and the GNU binutils are free software; you can redistribute
   8 them and/or modify them under the terms of the GNU General Public
   9 License as published by the Free Software Foundation; either version
  10 2, or (at your option) any later version.
  11
  12 GDB, GAS, and the GNU binutils are distributed in the hope that they
  13 will be useful, but WITHOUT ANY WARRANTY; without even the implied
  14 warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  15 the GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this file; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  20
  21 #include <stdio.h>
  22 #include "sysdep.h"
  23 #include "dis-asm.h"
  24 #include "opcode/ppc.h"
  25
  26 /* This file provides several disassembler functions, all of which use
  27    the disassembler interface defined in dis-asm.h.  Several functions
  28    are provided because this file handles disassembly for the PowerPC
  29    in both big and little endian mode and also for the POWER (RS/6000)
  30    chip.  */
  31
  32 static int print_insn_powerpc PARAMS ((bfd_vma, struct disassemble_info *,
  33                                        int bigendian, int dialect));
  34
  35 /* Print a big endian PowerPC instruction.  For convenience, also
  36    disassemble instructions supported by the Motorola PowerPC 601
  37    and the Altivec vector unit.  */
  38
  39 int
  40 print_insn_big_powerpc (memaddr, info)
  41      bfd_vma memaddr;
  42      struct disassemble_info *info;
  43 {
  44   return print_insn_powerpc (memaddr, info, 1,
  45                              PPC_OPCODE_PPC | PPC_OPCODE_601 |
  46                              PPC_OPCODE_ALTIVEC);
  47 }
  48
  49 /* Print a little endian PowerPC instruction.  For convenience, also
  50    disassemble instructions supported by the Motorola PowerPC 601
  51    and the Altivec vector unit.  */
  52
  53 int
  54 print_insn_little_powerpc (memaddr, info)
  55      bfd_vma memaddr;
  56      struct disassemble_info *info;
  57 {
  58   return print_insn_powerpc (memaddr, info, 0,
  59                              PPC_OPCODE_PPC | PPC_OPCODE_601 |
  60                              PPC_OPCODE_ALTIVEC);
  61 }
  62
  63 /* Print a POWER (RS/6000) instruction.  */
  64
  65 int
  66 print_insn_rs6000 (memaddr, info)
  67      bfd_vma memaddr;
  68      struct disassemble_info *info;
  69 {
  70   return print_insn_powerpc (memaddr, info, 1, PPC_OPCODE_POWER);
  71 }
  72
  73 /* Print a PowerPC or POWER instruction.  */
  74
  75 static int
  76 print_insn_powerpc (memaddr, info, bigendian, dialect)
  77      bfd_vma memaddr;
  78      struct disassemble_info *info;
  79      int bigendian;
  80      int dialect;
  81 {
  82   bfd_byte buffer[4];
  83   int status;
  84   unsigned long insn;
  85   const struct powerpc_opcode *opcode;
  86   const struct powerpc_opcode *opcode_end;
  87   unsigned long op;
  88
  89   status = (*info->read_memory_func) (memaddr, buffer, 4, info);
  90   if (status != 0)
  91     {
  92       (*info->memory_error_func) (status, memaddr, info);
  93       return -1;
  94     }
  95
  96   if (bigendian)
  97     insn = bfd_getb32 (buffer);
  98   else
  99     insn = bfd_getl32 (buffer);
 100
 101   /* Get the major opcode of the instruction.  */
 102   op = PPC_OP (insn);
 103
 104   /* Find the first match in the opcode table.  We could speed this up
 105      a bit by doing a binary search on the major opcode.  */
 106   opcode_end = powerpc_opcodes + powerpc_num_opcodes;
 107   for (opcode = powerpc_opcodes; opcode < opcode_end; opcode++)
 108     {
 109       unsigned long table_op;
 110       const unsigned char *opindex;
 111       const struct powerpc_operand *operand;
 112       int invalid;
 113       int need_comma;
 114       int need_paren;
 115
 116       table_op = PPC_OP (opcode->opcode);
 117       if (op < table_op)
 118         break;
 119       if (op > table_op)
 120         continue;
 121
 122       if ((insn & opcode->mask) != opcode->opcode
 123           || (opcode->flags & dialect) == 0)
 124         continue;
 125
 126       /* Make two passes over the operands.  First see if any of them
 127          have extraction functions, and, if they do, make sure the
 128          instruction is valid.  */
 129       invalid = 0;
 130       for (opindex = opcode->operands; *opindex != 0; opindex++)
 131         {
 132           operand = powerpc_operands + *opindex;
 133           if (operand->extract)
 134             (*operand->extract) (insn, &invalid);
 135         }
 136       if (invalid)
 137         continue;
 138
 139       /* The instruction is valid.  */
 140       (*info->fprintf_func) (info->stream, "%s", opcode->name);
 141       if (opcode->operands[0] != 0)
 142         (*info->fprintf_func) (info->stream, "\t");
 143
 144       /* Now extract and print the operands.  */
 145       need_comma = 0;
 146       need_paren = 0;
 147       for (opindex = opcode->operands; *opindex != 0; opindex++)
 148         {
 149           long value;
 150
 151           operand = powerpc_operands + *opindex;
 152
 153           /* Operands that are marked FAKE are simply ignored.  We
 154              already made sure that the extract function considered
 155              the instruction to be valid.  */
 156           if ((operand->flags & PPC_OPERAND_FAKE) != 0)
 157             continue;
 158
 159           /* Extract the value from the instruction.  */
 160           if (operand->extract)
 161             value = (*operand->extract) (insn, (int *) NULL);
 162           else
 163             {
 164               value = (insn >> operand->shift) & ((1 << operand->bits) - 1);
 165               if ((operand->flags & PPC_OPERAND_SIGNED) != 0
 166                   && (value & (1 << (operand->bits - 1))) != 0)
 167                 value -= 1 << operand->bits;
 168             }
 169
 170           /* If the operand is optional, and the value is zero, don't
 171              print anything.  */
 172           if ((operand->flags & PPC_OPERAND_OPTIONAL) != 0
 173               && (operand->flags & PPC_OPERAND_NEXT) == 0
 174               && value == 0)
 175             continue;
 176
 177           if (need_comma)
 178             {
 179               (*info->fprintf_func) (info->stream, ",");
 180               need_comma = 0;
 181             }
 182
 183           /* Print the operand as directed by the flags.  */
 184           if ((operand->flags & PPC_OPERAND_GPR) != 0)
 185             (*info->fprintf_func) (info->stream, "r%ld", value);
 186           else if ((operand->flags & PPC_OPERAND_FPR) != 0)
 187             (*info->fprintf_func) (info->stream, "f%ld", value);
 188           else if ((operand->flags & PPC_OPERAND_VR) != 0)
 189             (*info->fprintf_func) (info->stream, "v%ld", value);
 190           else if ((operand->flags & PPC_OPERAND_RELATIVE) != 0)
 191             (*info->print_address_func) (memaddr + value, info);
 192           else if ((operand->flags & PPC_OPERAND_ABSOLUTE) != 0)
 193             (*info->print_address_func) ((bfd_vma) value & 0xffffffff, info);
 194           else if ((operand->flags & PPC_OPERAND_CR) == 0
 195                    || (dialect & PPC_OPCODE_PPC) == 0)
 196             (*info->fprintf_func) (info->stream, "%ld", value);
 197           else
 198             {
 199               if (operand->bits == 3)
 200                 (*info->fprintf_func) (info->stream, "cr%d", value);
 201               else
 202                 {
 203                   static const char *cbnames[4] = { "lt", "gt", "eq", "so" };
 204                   int cr;
 205                   int cc;
 206
 207                   cr = value >> 2;
 208                   if (cr != 0)
 209                     (*info->fprintf_func) (info->stream, "4*cr%d", cr);
 210                   cc = value & 3;
 211                   if (cc != 0)
 212                     {
 213                       if (cr != 0)
 214                         (*info->fprintf_func) (info->stream, "+");
 215                       (*info->fprintf_func) (info->stream, "%s", cbnames[cc]);
 216                     }
 217                 }
 218             }
 219
 220           if (need_paren)
 221             {
 222               (*info->fprintf_func) (info->stream, ")");
 223               need_paren = 0;
 224             }
 225
 226           if ((operand->flags & PPC_OPERAND_PARENS) == 0)
 227             need_comma = 1;
 228           else
 229             {
 230               (*info->fprintf_func) (info->stream, "(");
 231               need_paren = 1;
 232             }
 233         }
 234
 235       /* We have found and printed an instruction; return.  */
 236       return 4;
 237     }
 238
 239   /* We could not find a match.  */
 240   (*info->fprintf_func) (info->stream, ".long 0x%lx", insn);
 241
 242   return 4;
 243 }