1 files changed, 6 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 0aeb3c14aa3..9952d4d9ac9 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -6888,7 +6888,10 @@ void SelectionDAGBuilder::visitConstrainedFPIntrinsic(
   ComputeValueVTs(TLI, DAG.getDataLayout(), FPI.getType(), ValueVTs);
   ValueVTs.push_back(MVT::Other); // Out chain
 
-  SDValue Chain = getRoot();
+  // We do not need to serialize constrained FP intrinsics against
+  // each other or against (nonvolatile) loads, so they can be
+  // chained like loads.
+  SDValue Chain = DAG.getRoot();
   SmallVector<SDValue, 4> Opers;
   Opers.push_back(Chain);
   if (FPI.isUnaryOp()) {
@@ -6926,8 +6929,9 @@ void SelectionDAGBuilder::visitConstrainedFPIntrinsic(
   }
 
   assert(Result.getNode()->getNumValues() == 2);
+  // See above -- chain is handled like for loads here.
   SDValue OutChain = Result.getValue(1);
-  DAG.setRoot(OutChain);
+  PendingLoads.push_back(OutChain);
   SDValue FPResult = Result.getValue(0);
   setValue(&FPI, FPResult);
 }