gdb/tahoe-tdep.c

   1 /* Print instructions for Tahoe target machines, for GDB.
   2    Copyright 1986, 1989, 1991, 1992 Free Software Foundation, Inc.
   3    Contributed by the State University of New York at Buffalo, by the
   4    Distributed Computer Systems Lab, Department of Computer Science, 1991.
   5
   6 This file is part of GDB.
   7
   8 This program 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 2 of the License, or
  11 (at your option) any later version.
  12
  13 This program is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 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 program; if not, write to the Free Software
  20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  21
  22 #include "defs.h"
  23 #include "symtab.h"
  24 #include "opcode/tahoe.h"
  25
  26 /* Tahoe instructions are never longer than this.  */
  27 #define MAXLEN 62
  28
  29 /* Number of elements in the opcode table.  */
  30 #define NOPCODES (sizeof votstrs / sizeof votstrs[0])
  31
  32 static unsigned char *print_insn_arg ();
  33
  34 /* Print the Tahoe instruction at address MEMADDR in debugged memory,
  35    on STREAM.  Returns length of the instruction, in bytes.  */
  36
  37 int
  38 tahoe_print_insn (memaddr, stream)
  39      CORE_ADDR memaddr;
  40      GDB_FILE *stream;
  41 {
  42   unsigned char buffer[MAXLEN];
  43   register int i;
  44   register unsigned char *p;
  45   register char *d;
  46
  47   read_memory (memaddr, buffer, MAXLEN);
  48
  49   for (i = 0; i < NOPCODES; i++)
  50     if (votstrs[i].detail.code == buffer[0]
  51         || votstrs[i].detail.code == *(unsigned short *)buffer)
  52       break;
  53
  54   /* Handle undefined instructions.  */
  55   if (i == NOPCODES)
  56     {
  57       fprintf_unfiltered (stream, "0%o", buffer[0]);
  58       return 1;
  59     }
  60
  61   fprintf_unfiltered (stream, "%s", votstrs[i].name);
  62
  63   /* Point at first byte of argument data,
  64      and at descriptor for first argument.  */
  65   p = buffer + 1 + (votstrs[i].detail.code >= 0x100);
  66   d = votstrs[i].detail.args;
  67
  68   if (*d)
  69     fputc_unfiltered ('\t', stream);
  70
  71   while (*d)
  72     {
  73       p = print_insn_arg (d, p, memaddr + (p - buffer), stream);
  74       d += 2;
  75       if (*d)
  76         fprintf_unfiltered (stream, ",");
  77     }
  78   return p - buffer;
  79 }
  80 /*******************************************************************/
  81 static unsigned char *
  82 print_insn_arg (d, p, addr, stream)
  83      char *d;
  84      register char *p;
  85      CORE_ADDR addr;
  86      GDB_FILE *stream;
  87 {
  88   int temp1 = 0;
  89   register int regnum = *p & 0xf;
  90   float floatlitbuf;
  91
  92   if (*d == 'b')
  93     {
  94       if (d[1] == 'b')
  95         fprintf_unfiltered (stream, "0x%x", addr + *p++ + 1);
  96       else
  97         {
  98
  99           temp1 = *p;
 100           temp1 <<= 8;
 101           temp1 |= *(p + 1);
 102           fprintf_unfiltered (stream, "0x%x", addr + temp1 + 2);
 103           p += 2;
 104         }
 105     }
 106   else
 107     switch ((*p++ >> 4) & 0xf)
 108       {
 109       case 0:
 110       case 1:
 111       case 2:
 112       case 3:                   /* Literal (short immediate byte) mode */
 113         if (d[1] == 'd' || d[1] == 'f' || d[1] == 'g' || d[1] == 'h')
 114           {
 115             *(int *)&floatlitbuf = 0x4000 + ((p[-1] & 0x3f) << 4);
 116             fprintf_unfiltered (stream, "$%f", floatlitbuf);
 117           }
 118         else
 119           fprintf_unfiltered (stream, "$%d", p[-1] & 0x3f);
 120         break;
 121
 122       case 4:                   /* Indexed */
 123         p = (char *) print_insn_arg (d, p, addr + 1, stream);
 124         fprintf_unfiltered (stream, "[%s]", REGISTER_NAME (regnum));
 125         break;
 126
 127       case 5:                   /* Register */
 128         fprintf_unfiltered (stream, REGISTER_NAME (regnum));
 129         break;
 130
 131       case 7:                   /* Autodecrement */
 132         fputc_unfiltered ('-', stream);
 133       case 6:                   /* Register deferred */
 134         fprintf_unfiltered (stream, "(%s)", REGISTER_NAME (regnum));
 135         break;
 136
 137       case 9:                   /* Absolute Address & Autoincrement deferred */
 138         fputc_unfiltered ('*', stream);
 139         if (regnum == PC_REGNUM)
 140           {
 141             temp1 = *p;
 142             temp1 <<= 8;
 143             temp1 |= *(p +1);
 144
 145             fputc_unfiltered ('$', stream);
 146             print_address (temp1, stream);
 147             p += 4;
 148             break;
 149           }
 150       case 8:                   /*Immediate & Autoincrement SP */
 151         if (regnum == 8)         /*88 is Immediate Byte Mode*/
 152           fprintf_unfiltered (stream, "$%d", *p++);
 153
 154         else if (regnum == 9)        /*89 is Immediate Word Mode*/
 155           {
 156             temp1 = *p;
 157             temp1 <<= 8;
 158             temp1 |= *(p +1);
 159             fprintf_unfiltered (stream, "$%d", temp1);
 160             p += 2;
 161           }
 162
 163         else if (regnum == PC_REGNUM)    /*8F is Immediate Long Mode*/
 164           {
 165             temp1 = *p;
 166             temp1 <<=8;
 167             temp1 |= *(p +1);
 168             temp1 <<=8;
 169             temp1 |= *(p +2);
 170             temp1 <<= 8;
 171             temp1 |= *(p +3);
 172             fprintf_unfiltered (stream, "$%d", temp1);
 173             p += 4;
 174           }
 175
 176         else                            /*8E is Autoincrement SP Mode*/
 177               fprintf_unfiltered (stream, "(%s)+", REGISTER_NAME (regnum));
 178         break;
 179
 180       case 11:                  /* Register + Byte Displacement Deferred Mode*/
 181         fputc_unfiltered ('*', stream);
 182       case 10:                  /* Register + Byte Displacement Mode*/
 183         if (regnum == PC_REGNUM)
 184           print_address (addr + *p + 2, stream);
 185         else
 186           fprintf_unfiltered (stream, "%d(%s)", *p, REGISTER_NAME (regnum));
 187         p += 1;
 188         break;
 189
 190       case 13:                  /* Register + Word Displacement Deferred Mode*/
 191         fputc_unfiltered ('*', stream);
 192       case 12:                  /* Register + Word Displacement Mode*/
 193         temp1 = *p;
 194         temp1 <<= 8;
 195         temp1 |= *(p +1);
 196         if (regnum == PC_REGNUM)
 197           print_address (addr + temp1 + 3, stream);
 198         else
 199           fprintf_unfiltered (stream, "%d(%s)", temp1, REGISTER_NAME (regnum));
 200         p += 2;
 201         break;
 202
 203       case 15:                  /* Register + Long Displacement Deferred Mode*/
 204         fputc_unfiltered ('*', stream);
 205       case 14:                  /* Register + Long Displacement Mode*/
 206         temp1 = *p;
 207         temp1 <<= 8;
 208         temp1 |= *(p +1);
 209         temp1 <<= 8;
 210         temp1 |= *(p +2);
 211         temp1 <<= 8;
 212         temp1 |= *(p +3);
 213         if (regnum == PC_REGNUM)
 214           print_address (addr + temp1 + 5, stream);
 215         else
 216           fprintf_unfiltered (stream, "%d(%s)", temp1, REGISTER_NAME (regnum));
 217         p += 4;
 218       }
 219
 220   return (unsigned char *) p;
 221 }
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