arch/ppc/xmon/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 "nonstdio.h"
  22 #include "ansidecl.h"
  23 #include "ppc.h"
  24
  25 static int print_insn_powerpc PARAMS ((FILE *, unsigned long insn,
  26                                        unsigned memaddr, int dialect));
  27
  28 extern void print_address PARAMS((unsigned memaddr));
  29
  30 /* Print a big endian PowerPC instruction.  For convenience, also
  31    disassemble instructions supported by the Motorola PowerPC 601.  */
  32
  33 int
  34 print_insn_big_powerpc (FILE *out, unsigned long insn, unsigned memaddr)
  35 {
  36   return print_insn_powerpc (out, insn, memaddr,
  37                              PPC_OPCODE_PPC | PPC_OPCODE_601);
  38 }
  39
  40 /* Print a PowerPC or POWER instruction.  */
  41
  42 static int
  43 print_insn_powerpc (FILE *out, unsigned long insn, unsigned memaddr,
  44                     int dialect)
  45 {
  46   const struct powerpc_opcode *opcode;
  47   const struct powerpc_opcode *opcode_end;
  48   unsigned long op;
  49
  50   /* Get the major opcode of the instruction.  */
  51   op = PPC_OP (insn);
  52
  53   /* Find the first match in the opcode table.  We could speed this up
  54      a bit by doing a binary search on the major opcode.  */
  55   opcode_end = powerpc_opcodes + powerpc_num_opcodes;
  56   for (opcode = powerpc_opcodes; opcode < opcode_end; opcode++)
  57     {
  58       unsigned long table_op;
  59       const unsigned char *opindex;
  60       const struct powerpc_operand *operand;
  61       int invalid;
  62       int need_comma;
  63       int need_paren;
  64
  65       table_op = PPC_OP (opcode->opcode);
  66       if (op < table_op)
  67                 break;
  68       if (op > table_op)
  69                 continue;
  70
  71       if ((insn & opcode->mask) != opcode->opcode
  72           || (opcode->flags & dialect) == 0)
  73                 continue;
  74
  75       /* Make two passes over the operands.  First see if any of them
  76                  have extraction functions, and, if they do, make sure the
  77                  instruction is valid.  */
  78       invalid = 0;
  79       for (opindex = opcode->operands; *opindex != 0; opindex++)
  80                 {
  81                   operand = powerpc_operands + *opindex;
  82                   if (operand->extract)
  83                     (*operand->extract) (insn, &invalid);
  84                 }
  85       if (invalid)
  86                 continue;
  87
  88       /* The instruction is valid.  */
  89       fprintf(out, "%s", opcode->name);
  90       if (opcode->operands[0] != 0)
  91                 fprintf(out, "\t");
  92
  93       /* Now extract and print the operands.  */
  94       need_comma = 0;
  95       need_paren = 0;
  96       for (opindex = opcode->operands; *opindex != 0; opindex++)
  97                 {
  98                   long value;
  99
 100                   operand = powerpc_operands + *opindex;
 101
 102                   /* Operands that are marked FAKE are simply ignored.  We
 103                      already made sure that the extract function considered
 104                      the instruction to be valid.  */
 105                   if ((operand->flags & PPC_OPERAND_FAKE) != 0)
 106                     continue;
 107
 108                   /* Extract the value from the instruction.  */
 109                   if (operand->extract)
 110                     value = (*operand->extract) (insn, (int *) 0);
 111                   else
 112                     {
 113                       value = (insn >> operand->shift) & ((1 << operand->bits) - 1);
 114                       if ((operand->flags & PPC_OPERAND_SIGNED) != 0
 115                           && (value & (1 << (operand->bits - 1))) != 0)
 116                         value -= 1 << operand->bits;
 117                     }
 118
 119                   /* If the operand is optional, and the value is zero, don't
 120                      print anything.  */
 121                   if ((operand->flags & PPC_OPERAND_OPTIONAL) != 0
 122                       && (operand->flags & PPC_OPERAND_NEXT) == 0
 123                       && value == 0)
 124                     continue;
 125
 126                   if (need_comma)
 127                     {
 128                       fprintf(out, ",");
 129                       need_comma = 0;
 130                     }
 131
 132                   /* Print the operand as directed by the flags.  */
 133                   if ((operand->flags & PPC_OPERAND_GPR) != 0)
 134                     fprintf(out, "r%ld", value);
 135                   else if ((operand->flags & PPC_OPERAND_FPR) != 0)
 136                     fprintf(out, "f%ld", value);
 137                   else if ((operand->flags & PPC_OPERAND_RELATIVE) != 0)
 138                     print_address (memaddr + value);
 139                   else if ((operand->flags & PPC_OPERAND_ABSOLUTE) != 0)
 140                     print_address (value & 0xffffffff);
 141                   else if ((operand->flags & PPC_OPERAND_CR) == 0
 142                            || (dialect & PPC_OPCODE_PPC) == 0)
 143                     fprintf(out, "%ld", value);
 144                   else
 145                     {
 146                       if (operand->bits == 3)
 147                                 fprintf(out, "cr%d", value);
 148                       else
 149                         {
 150                           static const char *cbnames[4] = { "lt", "gt", "eq", "so" };
 151                           int cr;
 152                           int cc;
 153
 154                           cr = value >> 2;
 155                           if (cr != 0)
 156                             fprintf(out, "4*cr%d", cr);
 157                           cc = value & 3;
 158                           if (cc != 0)
 159                             {
 160                               if (cr != 0)
 161                                         fprintf(out, "+");
 162                               fprintf(out, "%s", cbnames[cc]);
 163                             }
 164                         }
 165             }
 166
 167           if (need_paren)
 168             {
 169               fprintf(out, ")");
 170               need_paren = 0;
 171             }
 172
 173           if ((operand->flags & PPC_OPERAND_PARENS) == 0)
 174             need_comma = 1;
 175           else
 176             {
 177               fprintf(out, "(");
 178               need_paren = 1;
 179             }
 180         }
 181
 182       /* We have found and printed an instruction; return.  */
 183       return 4;
 184     }
 185
 186   /* We could not find a match.  */
 187   fprintf(out, ".long 0x%lx", insn);
 188
 189   return 4;
 190 }