opcodes/cgen-dis.c

   1 /* CGEN generic disassembler support code.
   2
   3 Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   4
   5 This file is part of the GNU Binutils and GDB, the GNU debugger.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License along
  18 with this program; if not, write to the Free Software Foundation, Inc.,
  19 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  20
  21 #include "config.h"
  22 #include <stdio.h>
  23 #ifdef HAVE_STRING_H
  24 #include <string.h>
  25 #endif
  26 #ifdef HAVE_STRINGS_H
  27 #include <strings.h>
  28 #endif
  29 #include "ansidecl.h"
  30 #include "libiberty.h"
  31 #include "bfd.h"
  32 #include "opcode/cgen.h"
  33
  34 /* This is not published as part of the public interface so we don't
  35    declare this in cgen.h.  */
  36 extern CGEN_OPCODE_DATA *cgen_current_opcode_data;
  37
  38 /* Disassembler instruction hash table.  */
  39 static CGEN_INSN_LIST **dis_hash_table;
  40
  41 void
  42 cgen_dis_init ()
  43 {
  44   if (dis_hash_table)
  45     {
  46       free (dis_hash_table);
  47       dis_hash_table = NULL;
  48     }
  49 }
  50
  51 /* Build the disassembler instruction hash table.  */
  52
  53 static void
  54 build_dis_hash_table ()
  55 {
  56   int i;
  57   int big_p = cgen_current_endian == CGEN_ENDIAN_BIG;
  58   unsigned int hash;
  59   char buf[4];
  60   unsigned long value;
  61   int count = cgen_insn_count ();
  62   CGEN_OPCODE_DATA *data = cgen_current_opcode_data;
  63   CGEN_INSN_TABLE *insn_table = data->insn_table;
  64   unsigned int hash_size = insn_table->dis_hash_table_size;
  65   const CGEN_INSN *insn;
  66   CGEN_INSN_LIST *insn_lists,*new_insns;
  67
  68   /* The space allocated for the hash table consists of two parts:
  69      the hash table and the hash lists.  */
  70
  71   dis_hash_table = (CGEN_INSN_LIST **)
  72     xmalloc (hash_size * sizeof (CGEN_INSN_LIST *)
  73              + count * sizeof (CGEN_INSN_LIST));
  74   memset (dis_hash_table, 0,
  75           hash_size * sizeof (CGEN_INSN_LIST *)
  76           + count * sizeof (CGEN_INSN_LIST));
  77   insn_lists = (CGEN_INSN_LIST *) (dis_hash_table + hash_size);
  78
  79   /* Add compiled in insns.
  80      The table is scanned backwards as later additions are inserted in
  81      front of earlier ones and we want earlier ones to be prefered.
  82      We stop at the first one as it is a reserved entry.  */
  83
  84   for (insn = insn_table->init_entries + insn_table->num_init_entries - 1;
  85        insn > insn_table->init_entries;
  86        --insn, ++insn_lists)
  87     {
  88       /* We don't know whether the target uses the buffer or the base insn
  89          to hash on, so set both up.  */
  90       value = insn->syntax.value;
  91       switch (CGEN_INSN_BITSIZE (insn))
  92         {
  93         case 8:
  94           buf[0] = value;
  95           break;
  96         case 16:
  97           if (big_p)
  98             bfd_putb16 ((bfd_vma) value, buf);
  99           else
 100             bfd_putl16 ((bfd_vma) value, buf);
 101           break;
 102         case 32:
 103           if (big_p)
 104             bfd_putb32 ((bfd_vma) value, buf);
 105           else
 106             bfd_putl32 ((bfd_vma) value, buf);
 107           break;
 108         default:
 109           abort ();
 110         }
 111       hash = (*insn_table->dis_hash) (buf, value);
 112       insn_lists->next = dis_hash_table[hash];
 113       insn_lists->insn = insn;
 114       dis_hash_table[hash] = insn_lists;
 115     }
 116
 117   /* Add runtime added insns.
 118      ??? Currently later added insns will be prefered over earlier ones.
 119      Not sure this is a bug or not.  */
 120   for (new_insns = insn_table->new_entries;
 121        new_insns != NULL;
 122        new_insns = new_insns->next, ++insn_lists)
 123     {
 124       /* We don't know whether the target uses the buffer or the base insn
 125          to hash on, so set both up.  */
 126       value = new_insns->insn->syntax.value;
 127       switch (CGEN_INSN_BITSIZE (new_insns->insn))
 128         {
 129         case 8:
 130           buf[0] = value;
 131           break;
 132         case 16:
 133           if (big_p)
 134             bfd_putb16 ((bfd_vma) value, buf);
 135           else
 136             bfd_putl16 ((bfd_vma) value, buf);
 137           break;
 138         case 32:
 139           if (big_p)
 140             bfd_putb32 ((bfd_vma) value, buf);
 141           else
 142             bfd_putl32 ((bfd_vma) value, buf);
 143           break;
 144         default:
 145           abort ();
 146         }
 147       hash = (*insn_table->dis_hash) (buf, value);
 148       insn_lists->next = dis_hash_table[hash];
 149       insn_lists->insn = new_insns->insn;
 150       dis_hash_table[hash] = insn_lists;
 151     }
 152 }
 153
 154 /* Return the first entry in the hash list for INSN.  */
 155
 156 CGEN_INSN_LIST *
 157 cgen_dis_lookup_insn (buf, value)
 158      const char *buf;
 159      unsigned long value;
 160 {
 161   unsigned int hash;
 162
 163   if (dis_hash_table == NULL)
 164     build_dis_hash_table ();
 165
 166   hash = (*cgen_current_opcode_data->insn_table->dis_hash) (buf, value);
 167   return dis_hash_table[hash];
 168 }