llvm/llvm/lib/Target/RISCV/RISCVZacasABIFix.cpp

//===----- RISCVZacasABIFix.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 pass implements a fence insertion for an atomic cmpxchg in a case that
// isn't easy to do with the current AtomicExpandPass hooks API.
//
//===----------------------------------------------------------------------===//

#include "RISCV.h"
#include "RISCVTargetMachine.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/CodeGen/TargetPassConfig.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InstVisitor.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/IntrinsicsRISCV.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"

usingnamespacellvm;

#define DEBUG_TYPE …
#define PASS_NAME …

namespace {

class RISCVZacasABIFix : public FunctionPass,
                         public InstVisitor<RISCVZacasABIFix, bool> { … };

} // end anonymous namespace

// Insert a leading fence (needed for broadest atomics ABI compatibility)
// only if the Zacas extension is enabled and the AtomicCmpXchgInst has a
// SequentiallyConsistent failure ordering.
bool RISCVZacasABIFix::visitAtomicCmpXchgInst(AtomicCmpXchgInst &I) { … }

bool RISCVZacasABIFix::runOnFunction(Function &F) { … }

INITIALIZE_PASS_BEGIN(RISCVZacasABIFix, DEBUG_TYPE, PASS_NAME, false, false)
INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
INITIALIZE_PASS_END(RISCVZacasABIFix, DEBUG_TYPE, PASS_NAME, false, false)

char RISCVZacasABIFix::ID = …;

FunctionPass *llvm::createRISCVZacasABIFixPass() { … }