Handle splats of undefs properly. This includes the testcase for PR5364 as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85767 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 88649ab..41a597a 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -2735,6 +2735,9 @@
if (ShuffleVectorSDNode::isSplatMask(&ShuffleMask[0], VT)) {
int Lane = SVN->getSplatIndex();
+ // If this is undef splat, generate it via "just" vdup, if possible.
+ if (Lane == -1) Lane = 0;
+
if (Lane == 0 && V1.getOpcode() == ISD::SCALAR_TO_VECTOR) {
return DAG.getNode(ARMISD::VDUP, dl, VT, V1.getOperand(0));
}