opcodes/ia64-asmtab.h

   1 /* ia64-asmtab.h -- Header for compacted IA-64 opcode tables.
   2    Copyright 1999, 2000 Free Software Foundation, Inc.
   3    Contributed by Bob Manson of Cygnus Support <manson@cygnus.com>
   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
  19    Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20    02111-1307, USA.  */
  21
  22 #ifndef IA64_ASMTAB_H
  23 #define IA64_ASMTAB_H
  24
  25 #include "opcode/ia64.h"
  26
  27 /* The primary opcode table is made up of the following: */
  28 struct ia64_main_table
  29 {
  30   /* The entry in the string table that corresponds to the name of this
  31      opcode. */
  32   unsigned short name_index;
  33
  34   /* The type of opcode; corresponds to the TYPE field in
  35      struct ia64_opcode. */
  36   unsigned char opcode_type;
  37
  38   /* The number of outputs for this opcode. */
  39   unsigned char num_outputs;
  40
  41   /* The base insn value for this opcode.  It may be modified by completers. */
  42   ia64_insn opcode;
  43
  44   /* The mask of valid bits in OPCODE. Zeros indicate operand fields. */
  45   ia64_insn mask;
  46
  47   /* The operands of this instruction.  Corresponds to the OPERANDS field
  48      in struct ia64_opcode. */
  49   unsigned char operands[5];
  50
  51   /* The flags for this instruction.  Corresponds to the FLAGS field in
  52      struct ia64_opcode. */
  53   short flags;
  54
  55   /* The tree of completers for this instruction; this is an offset into
  56      completer_table. */
  57   short completers;
  58 };
  59
  60 /* Each instruction has a set of possible "completers", or additional
  61    suffixes that can alter the instruction's behavior, and which has
  62    potentially different dependencies.
  63
  64    The completer entries modify certain bits in the instruction opcode.
  65    Which bits are to be modified are marked by the BITS, MASK and
  66    OFFSET fields.  The completer entry may also note dependencies for the
  67    opcode.
  68
  69    These completers are arranged in a DAG; the pointers are indexes
  70    into the completer_table array.  The completer DAG is searched by
  71    find_completer () and ia64_find_matching_opcode ().
  72
  73    Note that each completer needs to be applied in turn, so that if we
  74    have the instruction
  75         cmp.lt.unc
  76    the completer entries for both "lt" and "unc" would need to be applied
  77    to the opcode's value.
  78
  79    Some instructions do not require any completers; these contain an
  80    empty completer entry.  Instructions that require a completer do
  81    not contain an empty entry.
  82
  83    Terminal completers (those completers that validly complete an
  84    instruction) are marked by having the TERMINAL_COMPLETER flag set.
  85
  86    Only dependencies listed in the terminal completer for an opcode are
  87    considered to apply to that opcode instance. */
  88
  89 struct ia64_completer_table
  90 {
  91   /* The bit value that this completer sets. */
  92   unsigned int bits;
  93
  94   /* And its mask. 1s are bits that are to be modified in the
  95      instruction. */
  96   unsigned int mask;
  97
  98   /* The entry in the string table that corresponds to the name of this
  99      completer. */
 100   unsigned short name_index;
 101
 102   /* An alternative completer, or -1 if this is the end of the chain. */
 103   short alternative;
 104
 105   /* A pointer to the DAG of completers that can potentially follow
 106      this one, or -1. */
 107   short subentries;
 108
 109   /* The bit offset in the instruction where BITS and MASK should be
 110      applied. */
 111   unsigned char offset : 7;
 112
 113   unsigned char terminal_completer : 1;
 114
 115   /* Index into the dependency list table */
 116   short dependencies;
 117 };
 118
 119 /* This contains sufficient information for the disassembler to resolve
 120    the complete name of the original instruction.  */
 121 struct ia64_dis_names
 122 {
 123   /* COMPLETER_INDEX represents the tree of completers that make up
 124      the instruction.  The LSB represents the top of the tree for the
 125      specified instruction.
 126
 127      A 0 bit indicates to go to the next alternate completer via the
 128      alternative field; a 1 bit indicates that the current completer
 129      is part of the instruction, and to go down the subentries index.
 130      We know we've reached the final completer when we run out of 1
 131      bits.
 132
 133      There is always at least one 1 bit. */
 134   unsigned int completer_index : 20;
 135
 136   /* The index in the main_table[] array for the instruction. */
 137   unsigned short insn_index : 11;
 138
 139   /* If set, the next entry in this table is an alternate possibility
 140      for this instruction encoding.  Which one to use is determined by
 141      the instruction type and other factors (see opcode_verify ()).  */
 142   unsigned int next_flag : 1;
 143
 144   /* The disassembly priority of this entry among instructions. */
 145   unsigned short priority;
 146 };
 147
 148 #endif