3 files changed, 9 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index aadfa264203..a3dd36e2880 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -2955,8 +2955,10 @@ void SelectionDAGLegalize::ExpandNode(SDNode *Node,
     Results.push_back(DAG.getConstant(0, MVT::i32));
     Results.push_back(Node->getOperand(0));
     break;
+  case ISD::ATOMIC_FENCE:
   case ISD::MEMBARRIER: {
     // If the target didn't lower this, lower it to '__sync_synchronize()' call
+    // FIXME: handle "fence singlethread" more efficiently.
     TargetLowering::ArgListTy Args;
     std::pair<SDValue, SDValue> CallResult =
       TLI.LowerCallTo(Node->getOperand(0), Type::getVoidTy(*DAG.getContext()),
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 68db87d8790..9785b4c7809 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -5769,6 +5769,7 @@ std::string SDNode::getOperationName(const SelectionDAG *G) const {
 #endif
   case ISD::PREFETCH:      return "Prefetch";
   case ISD::MEMBARRIER:    return "MemBarrier";
+  case ISD::ATOMIC_FENCE:    return "AtomicFence";
   case ISD::ATOMIC_CMP_SWAP:    return "AtomicCmpSwap";
   case ISD::ATOMIC_SWAP:        return "AtomicSwap";
   case ISD::ATOMIC_LOAD_ADD:    return "AtomicLoadAdd";
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index bdddca3514e..67707c6425e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -3221,7 +3221,12 @@ void SelectionDAGBuilder::visitStore(const StoreInst &I) {
 }
 
 void SelectionDAGBuilder::visitFence(const FenceInst &I) {
-  llvm_unreachable("Not implemented yet");
+  DebugLoc dl = getCurDebugLoc();
+  SDValue Ops[3];
+  Ops[0] = getRoot();
+  Ops[1] = DAG.getConstant(I.getOrdering(), TLI.getPointerTy());
+  Ops[2] = DAG.getConstant(I.getSynchScope(), TLI.getPointerTy());
+  DAG.setRoot(DAG.getNode(ISD::ATOMIC_FENCE, dl, MVT::Other, Ops, 3));
 }
 
 /// visitTargetIntrinsic - Lower a call of a target intrinsic to an INTRINSIC