llvm/llvm/lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp

//===- InstCombineAtomicRMW.cpp -------------------------------------------===//
//
// 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 implements the visit functions for atomic rmw instructions.
//
//===----------------------------------------------------------------------===//

#include "InstCombineInternal.h"
#include "llvm/IR/Instructions.h"

usingnamespacellvm;

namespace {
/// Return true if and only if the given instruction does not modify the memory
/// location referenced.  Note that an idemptent atomicrmw may still have
/// ordering effects on nearby instructions, or be volatile.
/// TODO: Common w/ the version in AtomicExpandPass, and change the term used.
/// Idemptotent is confusing in this context.
bool isIdempotentRMW(AtomicRMWInst& RMWI) { … }

/// Return true if the given instruction always produces a value in memory
/// equivalent to its value operand.
bool isSaturating(AtomicRMWInst& RMWI) { … }
} // namespace

Instruction *InstCombinerImpl::visitAtomicRMWInst(AtomicRMWInst &RMWI) { … }