PPC: Improve code generation for mixed-precision reciprocal sqrt
The DAGCombine logic that recognized a/sqrt(b) and transformed it into
a multiplication by the reciprocal sqrt did not handle cases where the
sqrt and the division were separated by an fpext or fptrunc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178801 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index e33d2cc..8195f5e 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -6849,6 +6849,33 @@
return DAG.getNode(ISD::FMUL, dl, N->getValueType(0),
N->getOperand(0), RV);
}
+ } else if (N->getOperand(1).getOpcode() == ISD::FP_EXTEND &&
+ N->getOperand(1).getOperand(0).getOpcode() == ISD::FSQRT) {
+ SDValue RV =
+ DAGCombineFastRecipFSQRT(N->getOperand(1).getOperand(0).getOperand(0),
+ DCI);
+ if (RV.getNode() != 0) {
+ DCI.AddToWorklist(RV.getNode());
+ RV = DAG.getNode(ISD::FP_EXTEND, N->getOperand(1).getDebugLoc(),
+ N->getValueType(0), RV);
+ DCI.AddToWorklist(RV.getNode());
+ return DAG.getNode(ISD::FMUL, dl, N->getValueType(0),
+ N->getOperand(0), RV);
+ }
+ } else if (N->getOperand(1).getOpcode() == ISD::FP_ROUND &&
+ N->getOperand(1).getOperand(0).getOpcode() == ISD::FSQRT) {
+ SDValue RV =
+ DAGCombineFastRecipFSQRT(N->getOperand(1).getOperand(0).getOperand(0),
+ DCI);
+ if (RV.getNode() != 0) {
+ DCI.AddToWorklist(RV.getNode());
+ RV = DAG.getNode(ISD::FP_ROUND, N->getOperand(1).getDebugLoc(),
+ N->getValueType(0), RV,
+ N->getOperand(1).getOperand(1));
+ DCI.AddToWorklist(RV.getNode());
+ return DAG.getNode(ISD::FMUL, dl, N->getValueType(0),
+ N->getOperand(0), RV);
+ }
}
SDValue RV = DAGCombineFastRecip(N->getOperand(1), DCI);