+static void createCmpXchgInstFun(IRBuilder<> &Builder, Value *Addr,
+ Value *Loaded, Value *NewVal,
+ AtomicOrdering MemOpOrder,
+ Value *&Success, Value *&NewLoaded) {
+ Value* Pair = Builder.CreateAtomicCmpXchg(
+ Addr, Loaded, NewVal, MemOpOrder,
+ AtomicCmpXchgInst::getStrongestFailureOrdering(MemOpOrder));
+ Success = Builder.CreateExtractValue(Pair, 1, "success");
+ NewLoaded = Builder.CreateExtractValue(Pair, 0, "newloaded");
+}
+
+/// Emit IR to implement the given atomicrmw operation on values in registers,
+/// returning the new value.
+static Value *performAtomicOp(AtomicRMWInst::BinOp Op, IRBuilder<> &Builder,
+ Value *Loaded, Value *Inc) {
+ Value *NewVal;
+ switch (Op) {
+ case AtomicRMWInst::Xchg:
+ return Inc;
+ case AtomicRMWInst::Add:
+ return Builder.CreateAdd(Loaded, Inc, "new");
+ case AtomicRMWInst::Sub:
+ return Builder.CreateSub(Loaded, Inc, "new");
+ case AtomicRMWInst::And:
+ return Builder.CreateAnd(Loaded, Inc, "new");
+ case AtomicRMWInst::Nand:
+ return Builder.CreateNot(Builder.CreateAnd(Loaded, Inc), "new");
+ case AtomicRMWInst::Or:
+ return Builder.CreateOr(Loaded, Inc, "new");
+ case AtomicRMWInst::Xor:
+ return Builder.CreateXor(Loaded, Inc, "new");
+ case AtomicRMWInst::Max:
+ NewVal = Builder.CreateICmpSGT(Loaded, Inc);
+ return Builder.CreateSelect(NewVal, Loaded, Inc, "new");
+ case AtomicRMWInst::Min:
+ NewVal = Builder.CreateICmpSLE(Loaded, Inc);
+ return Builder.CreateSelect(NewVal, Loaded, Inc, "new");
+ case AtomicRMWInst::UMax:
+ NewVal = Builder.CreateICmpUGT(Loaded, Inc);
+ return Builder.CreateSelect(NewVal, Loaded, Inc, "new");
+ case AtomicRMWInst::UMin:
+ NewVal = Builder.CreateICmpULE(Loaded, Inc);
+ return Builder.CreateSelect(NewVal, Loaded, Inc, "new");
+ default:
+ llvm_unreachable("Unknown atomic op");
+ }
+}
+
+bool AtomicExpand::tryExpandAtomicRMW(AtomicRMWInst *AI) {
+ switch (TLI->shouldExpandAtomicRMWInIR(AI)) {
+ case TargetLoweringBase::AtomicExpansionKind::None:
+ return false;
+ case TargetLoweringBase::AtomicExpansionKind::LLSC:
+ return expandAtomicOpToLLSC(AI, AI->getPointerOperand(), AI->getOrdering(),
+ [&](IRBuilder<> &Builder, Value *Loaded) {
+ return performAtomicOp(AI->getOperation(),
+ Builder, Loaded,
+ AI->getValOperand());
+ });
+ case TargetLoweringBase::AtomicExpansionKind::CmpXChg:
+ return expandAtomicRMWToCmpXchg(AI, createCmpXchgInstFun);
+ default:
+ llvm_unreachable("Unhandled case in tryExpandAtomicRMW");
+ }
+}
+
+bool AtomicExpand::expandAtomicOpToLLSC(
+ Instruction *I, Value *Addr, AtomicOrdering MemOpOrder,
+ std::function<Value *(IRBuilder<> &, Value *)> PerformOp) {
+ BasicBlock *BB = I->getParent();