diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 1e05d583e83..1d6d40eb9a9 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -2102,6 +2102,18 @@ SDOperand DAGCombiner::visitFP_ROUND(SDNode *N) { // fold (fp_round c1fp) -> c1fp if (N0CFP) return DAG.getNode(ISD::FP_ROUND, VT, N0); + + // fold (fp_round (fp_extend x)) -> x + if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType()) + return N0.getOperand(0); + + // fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y) + if (N0.getOpcode() == ISD::FCOPYSIGN && N0.Val->hasOneUse()) { + SDOperand Tmp = DAG.getNode(ISD::FP_ROUND, VT, N0.getOperand(0)); + AddToWorkList(Tmp.Val); + return DAG.getNode(ISD::FCOPYSIGN, VT, Tmp, N0.getOperand(1)); + } + return SDOperand(); }