llvm/utils/TableGen/X86DisassemblerShared.h

   1 //===- X86DisassemblerShared.h - Emitter shared header ----------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_UTILS_TABLEGEN_X86DISASSEMBLERSHARED_H
  10 #define LLVM_UTILS_TABLEGEN_X86DISASSEMBLERSHARED_H
  11
  12 #include <cstring>
  13 #include <string>
  14
  15 #include "llvm/Support/X86DisassemblerDecoderCommon.h"
  16
  17 struct InstructionSpecifier {
  18   llvm::X86Disassembler::OperandSpecifier
  19       operands[llvm::X86Disassembler::X86_MAX_OPERANDS];
  20   llvm::X86Disassembler::InstructionContext insnContext;
  21   std::string name;
  22
  23   InstructionSpecifier() {
  24     insnContext = llvm::X86Disassembler::IC;
  25     name = "";
  26     memset(operands, 0, sizeof(operands));
  27   }
  28 };
  29
  30 /// Specifies whether a ModR/M byte is needed and (if so) which
  31 /// instruction each possible value of the ModR/M byte corresponds to. Once
  32 /// this information is known, we have narrowed down to a single instruction.
  33 struct ModRMDecision {
  34   uint8_t modrm_type;
  35   llvm::X86Disassembler::InstrUID instructionIDs[256];
  36 };
  37
  38 /// Specifies which set of ModR/M->instruction tables to look at
  39 /// given a particular opcode.
  40 struct OpcodeDecision {
  41   ModRMDecision modRMDecisions[256];
  42 };
  43
  44 /// Specifies which opcode->instruction tables to look at given
  45 /// a particular context (set of attributes).  Since there are many possible
  46 /// contexts, the decoder first uses CONTEXTS_SYM to determine which context
  47 /// applies given a specific set of attributes.  Hence there are only IC_max
  48 /// entries in this table, rather than 2^(ATTR_max).
  49 struct ContextDecision {
  50   OpcodeDecision opcodeDecisions[llvm::X86Disassembler::IC_max];
  51
  52   ContextDecision() { memset(opcodeDecisions, 0, sizeof(opcodeDecisions)); }
  53 };
  54
  55 #endif