llvm/llvm/include/llvm/CodeGen/ByteProvider.h

//===-- include/llvm/CodeGen/ByteProvider.h - Map bytes ---------*- 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 implements ByteProvider. The purpose of ByteProvider is to provide
// a map between a target node's byte (byte position is DestOffset) and the
// source (and byte position) that provides it (in Src and SrcOffset
// respectively) See CodeGen/SelectionDAG/DAGCombiner.cpp MatchLoadCombine
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_BYTEPROVIDER_H
#define LLVM_CODEGEN_BYTEPROVIDER_H

#include <optional>
#include <type_traits>

namespace llvm {

/// Represents known origin of an individual byte in combine pattern. The
/// value of the byte is either constant zero, or comes from memory /
/// some other productive instruction (e.g. arithmetic instructions).
/// Bit manipulation instructions like shifts are not ByteProviders, rather
/// are used to extract Bytes.
template <typename ISelOp> class ByteProvider { … };
} // end namespace llvm

#endif // LLVM_CODEGEN_BYTEPROVIDER_H