gnu/dist/gdb6/opcodes/i860-dis.c

   1 /* Disassembler for the i860.
   2    Copyright 2000, 2003 Free Software Foundation, Inc.
   3
   4    Contributed by Jason Eckhardt <jle@cygnus.com>.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
  19
  20 #include "dis-asm.h"
  21 #include "opcode/i860.h"
  22
  23 /* Later we should probably choose the prefix based on which OS flavor.  */
  24 #define I860_REG_PREFIX "%"
  25
  26 /* Integer register names (encoded as 0..31 in the instruction).  */
  27 static const char *const grnames[] =
  28  {"r0",  "r1",  "sp",  "fp",  "r4",  "r5",  "r6",  "r7",
  29   "r8",  "r9",  "r10", "r11", "r12", "r13", "r14", "r15",
  30   "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
  31   "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31"};
  32
  33 /* FP register names (encoded as 0..31 in the instruction).  */
  34 static const char *const frnames[] =
  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 /* Control/status register names (encoded as 0..11 in the instruction).
  41    Registers bear, ccr, p0, p1, p2 and p3 are XP only.  */
  42 static const char *const crnames[] =
  43  {"fir", "psr", "dirbase", "db", "fsr", "epsr", "bear", "ccr",
  44   "p0", "p1", "p2", "p3", "--", "--", "--", "--" };
  45
  46
  47
  48 /* True if opcode is xor, xorh, and, andh, or, orh, andnot, andnoth.  */
  49 #define BITWISE_OP(op)  ((op) == 0x30 || (op) == 0x31           \
  50                          || (op) == 0x34 || (op) == 0x35        \
  51                          || (op) == 0x38 || (op) == 0x39        \
  52                          || (op) == 0x3c || (op) == 0x3d        \
  53                          || (op) == 0x33 || (op) == 0x37        \
  54                          || (op) == 0x3b || (op) == 0x3f)
  55
  56
  57 /* Sign extend N-bit number.  */
  58 static int
  59 sign_ext (unsigned int x, int n)
  60 {
  61   int t;
  62   t = x >> (n - 1);
  63   t = ((-t) << n) | x;
  64   return t;
  65 }
  66
  67
  68 /* Print a PC-relative branch offset.  VAL is the sign extended value
  69    from the branch instruction.  */
  70 static void
  71 print_br_address (disassemble_info *info, bfd_vma memaddr, long val)
  72 {
  73
  74   long adj = (long)memaddr + 4 + (val << 2);
  75
  76   (*info->fprintf_func) (info->stream, "0x%08lx", adj);
  77
  78   /* Attempt to obtain a symbol for the target address.  */
  79
  80   if (info->print_address_func && adj != 0)
  81     {
  82       (*info->fprintf_func) (info->stream, "\t// ");
  83       (*info->print_address_func) (adj, info);
  84     }
  85 }
  86
  87
  88 /* Print one instruction.  */
  89 int
  90 print_insn_i860 (bfd_vma memaddr, disassemble_info *info)
  91 {
  92   bfd_byte buff[4];
  93   unsigned int insn, i;
  94   int status;
  95   const struct i860_opcode *opcode = 0;
  96
  97   status = (*info->read_memory_func) (memaddr, buff, sizeof (buff), info);
  98   if (status != 0)
  99     {
 100       (*info->memory_error_func) (status, memaddr, info);
 101       return -1;
 102     }
 103
 104   /* Note that i860 instructions are always accessed as little endian
 105      data, regardless of the endian mode of the i860.  */
 106   insn = bfd_getl32 (buff);
 107
 108   status = 0;
 109   i = 0;
 110   while (i860_opcodes[i].name != NULL)
 111     {
 112       opcode = &i860_opcodes[i];
 113       if ((insn & opcode->match) == opcode->match
 114           && (insn & opcode->lose) == 0)
 115         {
 116           status = 1;
 117           break;
 118         }
 119       ++i;
 120     }
 121
 122   if (status == 0)
 123     {
 124       /* Instruction not in opcode table.  */
 125       (*info->fprintf_func) (info->stream, ".long %#08x", insn);
 126     }
 127   else
 128     {
 129       const char *s;
 130       int val;
 131
 132       /* If this a flop (or a shrd) and its dual bit is set,
 133          prefix with 'd.'.  */
 134       if (((insn & 0xfc000000) == 0x48000000
 135            || (insn & 0xfc000000) == 0xb0000000)
 136           && (insn & 0x200))
 137         (*info->fprintf_func) (info->stream, "d.%s\t", opcode->name);
 138       else
 139         (*info->fprintf_func) (info->stream, "%s\t", opcode->name);
 140
 141       for (s = opcode->args; *s; s++)
 142         {
 143           switch (*s)
 144             {
 145             /* Integer register (src1).  */
 146             case '1':
 147               (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,
 148                                      grnames[(insn >> 11) & 0x1f]);
 149               break;
 150
 151             /* Integer register (src2).  */
 152             case '2':
 153               (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,
 154                                      grnames[(insn >> 21) & 0x1f]);
 155               break;
 156
 157             /* Integer destination register.  */
 158             case 'd':
 159               (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,
 160                                      grnames[(insn >> 16) & 0x1f]);
 161               break;
 162
 163             /* Floating-point register (src1).  */
 164             case 'e':
 165               (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,
 166                                      frnames[(insn >> 11) & 0x1f]);
 167               break;
 168
 169             /* Floating-point register (src2).  */
 170             case 'f':
 171               (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,
 172                                      frnames[(insn >> 21) & 0x1f]);
 173               break;
 174
 175             /* Floating-point destination register.  */
 176             case 'g':
 177               (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,
 178                                      frnames[(insn >> 16) & 0x1f]);
 179               break;
 180
 181             /* Control register.  */
 182             case 'c':
 183               (*info->fprintf_func) (info->stream, "%s%s", I860_REG_PREFIX,
 184                                      crnames[(insn >> 21) & 0xf]);
 185               break;
 186
 187             /* 16-bit immediate (sign extend, except for bitwise ops).  */
 188             case 'i':
 189               if (BITWISE_OP ((insn & 0xfc000000) >> 26))
 190                 (*info->fprintf_func) (info->stream, "0x%04x",
 191                                        (unsigned int) (insn & 0xffff));
 192               else
 193                 (*info->fprintf_func) (info->stream, "%d",
 194                                        sign_ext ((insn & 0xffff), 16));
 195               break;
 196
 197             /* 16-bit immediate, aligned (2^0, ld.b).  */
 198             case 'I':
 199               (*info->fprintf_func) (info->stream, "%d",
 200                                      sign_ext ((insn & 0xffff), 16));
 201               break;
 202
 203             /* 16-bit immediate, aligned (2^1, ld.s).  */
 204             case 'J':
 205               (*info->fprintf_func) (info->stream, "%d",
 206                                      sign_ext ((insn & 0xfffe), 16));
 207               break;
 208
 209             /* 16-bit immediate, aligned (2^2, ld.l, {p}fld.l, fst.l).  */
 210             case 'K':
 211               (*info->fprintf_func) (info->stream, "%d",
 212                                      sign_ext ((insn & 0xfffc), 16));
 213               break;
 214
 215             /* 16-bit immediate, aligned (2^3, {p}fld.d, fst.d).  */
 216             case 'L':
 217               (*info->fprintf_func) (info->stream, "%d",
 218                                      sign_ext ((insn & 0xfff8), 16));
 219               break;
 220
 221             /* 16-bit immediate, aligned (2^4, {p}fld.q, fst.q).  */
 222             case 'M':
 223               (*info->fprintf_func) (info->stream, "%d",
 224                                      sign_ext ((insn & 0xfff0), 16));
 225               break;
 226
 227             /* 5-bit immediate (zero extend).  */
 228             case '5':
 229               (*info->fprintf_func) (info->stream, "%d",
 230                                      ((insn >> 11) & 0x1f));
 231               break;
 232
 233             /* Split 16 bit immediate (20..16:10..0).  */
 234             case 's':
 235               val = ((insn >> 5) & 0xf800) | (insn & 0x07ff);
 236               (*info->fprintf_func) (info->stream, "%d",
 237                                      sign_ext (val, 16));
 238               break;
 239
 240             /* Split 16 bit immediate, aligned. (2^0, st.b).  */
 241             case 'S':
 242               val = ((insn >> 5) & 0xf800) | (insn & 0x07ff);
 243               (*info->fprintf_func) (info->stream, "%d",
 244                                      sign_ext (val, 16));
 245               break;
 246
 247             /* Split 16 bit immediate, aligned. (2^1, st.s).  */
 248             case 'T':
 249               val = ((insn >> 5) & 0xf800) | (insn & 0x07fe);
 250               (*info->fprintf_func) (info->stream, "%d",
 251                                      sign_ext (val, 16));
 252               break;
 253
 254             /* Split 16 bit immediate, aligned. (2^2, st.l).  */
 255             case 'U':
 256               val = ((insn >> 5) & 0xf800) | (insn & 0x07fc);
 257               (*info->fprintf_func) (info->stream, "%d",
 258                                      sign_ext (val, 16));
 259               break;
 260
 261             /* 26-bit PC relative immediate (lbroff).  */
 262             case 'l':
 263               val = sign_ext ((insn & 0x03ffffff), 26);
 264               print_br_address (info, memaddr, val);
 265               break;
 266
 267             /* 16-bit PC relative immediate (sbroff).  */
 268             case 'r':
 269               val = sign_ext ((((insn >> 5) & 0xf800) | (insn & 0x07ff)), 16);
 270               print_br_address (info, memaddr, val);
 271               break;
 272
 273             default:
 274               (*info->fprintf_func) (info->stream, "%c", *s);
 275               break;
 276             }
 277         }
 278     }
 279
 280   return sizeof (insn);
 281 }
 282