llvm/llvm/include/llvm/CodeGen/GlobalISel/GIMatchTableExecutor.h

//===- llvm/CodeGen/GlobalISel/GIMatchTableExecutor.h -----------*- 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
//
//===----------------------------------------------------------------------===//
//
/// \file This file declares the GIMatchTableExecutor API, the opcodes supported
/// by the match table, and some associated data structures used by the
/// executor's implementation (see `GIMatchTableExecutorImpl.h`).
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_GLOBALISEL_GIMATCHTABLEEXECUTOR_H
#define LLVM_CODEGEN_GLOBALISEL_GIMATCHTABLEEXECUTOR_H

#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/Bitset.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/GlobalISel/Utils.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGenTypes/LowLevelType.h"
#include "llvm/IR/Function.h"
#include <bitset>
#include <cstddef>
#include <cstdint>
#include <functional>
#include <initializer_list>
#include <optional>
#include <vector>

namespace llvm {

class BlockFrequencyInfo;
class CodeGenCoverage;
class MachineBasicBlock;
class ProfileSummaryInfo;
class APInt;
class APFloat;
class GISelKnownBits;
class MachineInstr;
class MachineIRBuilder;
class MachineInstrBuilder;
class MachineFunction;
class MachineOperand;
class MachineRegisterInfo;
class RegisterBankInfo;
class TargetInstrInfo;
class TargetRegisterInfo;

enum { … };

/// The MatchTable is encoded as an array of bytes.
/// Thus, opcodes are expected to be <255.
///
/// Operands can be variable-sized, their size is always after their name
/// in the docs, e.g. "Foo(4)" means that "Foo" takes 4 entries in the table,
/// so 4 bytes. "Foo()"
///
/// As a general rule of thumb:
///   - Instruction & Operand IDs are ULEB128
///   - LLT IDs are 1 byte
///   - Predicates and target opcodes, register and register class IDs are 2
///     bytes.
///   - Indexes into the table are 4 bytes.
///   - Inline constants are 8 bytes
///
/// Design notes:
///   - Inst/Op IDs have to be LEB128 because some targets generate
///     extremely long patterns which need more than 255 temporaries.
///     We could just use 2 bytes everytime, but then some targets like
///     X86/AMDGPU that have no need for it will pay the price all the time.
enum { … };

/// Provides the logic to execute GlobalISel match tables, which are used by the
/// instruction selector and instruction combiners as their engine to match and
/// apply MIR patterns.
class GIMatchTableExecutor { … };

} // end namespace llvm

#endif // LLVM_CODEGEN_GLOBALISEL_GIMATCHTABLEEXECUTOR_H