llvm/llvm/utils/TableGen/X86ModRMFilters.h

//===- X86ModRMFilters.h - Disassembler ModR/M filterss ---------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is part of the X86 Disassembler Emitter.
// It contains ModR/M filters that determine which values of the ModR/M byte
//  are valid for a partiuclar instruction.
// Documentation for the disassembler emitter in general can be found in
//  X86DisassemblerEmitter.h.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_UTILS_TABLEGEN_X86MODRMFILTERS_H
#define LLVM_UTILS_TABLEGEN_X86MODRMFILTERS_H

#include <cstdint>

namespace llvm {

namespace X86Disassembler {

/// ModRMFilter - Abstract base class for clases that recognize patterns in
///   ModR/M bytes.
class ModRMFilter { … };

/// DumbFilter - Accepts any ModR/M byte.  Used for instructions that do not
///   require a ModR/M byte or instructions where the entire ModR/M byte is used
///   for operands.
class DumbFilter : public ModRMFilter { … };

/// ModFilter - Filters based on the mod bits [bits 7-6] of the ModR/M byte.
///   Some instructions are classified based on whether they are 11 or anything
///   else.  This filter performs that classification.
class ModFilter : public ModRMFilter { … };

/// ExtendedFilter - Extended opcodes are classified based on the value of the
///   mod field [bits 7-6] and the value of the nnn field [bits 5-3].
class ExtendedFilter : public ModRMFilter { … };

/// ExtendedRMFilter - Extended opcodes are classified based on the value of the
///   mod field [bits 7-6] and the value of the nnn field [bits 2-0].
class ExtendedRMFilter : public ModRMFilter { … };
/// ExactFilter - The occasional extended opcode (such as VMCALL or MONITOR)
///   requires the ModR/M byte to have a specific value.
class ExactFilter : public ModRMFilter { … };

} // namespace X86Disassembler

} // namespace llvm

#endif