llvm/llvm/include/llvm/IR/MemoryModelRelaxationAnnotations.h

//===- MemoryModelRelaxationAnnotations.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 provides utility for Memory Model Relaxation Annotations (MMRAs).
/// Those annotations are represented using Metadata. The MMRATagSet class
/// offers a simple API to parse the metadata and perform common operations on
/// it. The MMRAMetadata class is a simple tuple of MDNode that provides easy
/// access to all MMRA annotations on an instruction.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_IR_MEMORYMODELRELAXATIONANNOTATIONS_H
#define LLVM_IR_MEMORYMODELRELAXATIONANNOTATIONS_H

#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/StringRef.h"
#include <tuple> // for std::pair

namespace llvm {

template <typename T> class ArrayRef;

class MDNode;
class MDTuple;
class Metadata;
class raw_ostream;
class LLVMContext;
class Instruction;

/// Helper class to manipulate `!mmra` metadata nodes.
///
/// This can be visualized as a set of "tags", with each tag
/// representing a particular property of an instruction, as
/// explained in the MemoryModelRelaxationAnnotations docs.
///
/// This class (and the optimizer in general) does not reason
/// about the exact nature of the tags and the properties they
/// imply. It just sees the metadata as a collection of tags, which
/// are a prefix/suffix pair of strings.
class MMRAMetadata { … };

/// \returns true if \p I can have !mmra metadata.
bool canInstructionHaveMMRAs(const Instruction &I);

} // namespace llvm

#endif