Fixed PR13938: the ARM backend was crashing because it couldn't select a VDUPLANE node with the vector input size different from the output size. This was bacause the BUILD_VECTOR lowering code didn't check that the size of the input vector was correct for using VDUPLANE.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165929 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 21e7e98..6ae44eb 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -4230,9 +4230,26 @@
// If we are VDUPing a value that comes directly from a vector, that will
// cause an unnecessary move to and from a GPR, where instead we could
// just use VDUPLANE.
- if (Value->getOpcode() == ISD::EXTRACT_VECTOR_ELT)
- N = DAG.getNode(ARMISD::VDUPLANE, dl, VT,
+ if (Value->getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
+ // We need to create a new undef vector to use for the VDUPLANE if the
+ // size of the vector from which we get the value is different than the
+ // size of the vector that we need to create. We will insert the element
+ // such that the register coalescer will remove unnecessary copies.
+ if (VT != Value->getOperand(0).getValueType()) {
+ ConstantSDNode *constIndex;
+ constIndex = dyn_cast<ConstantSDNode>(Value->getOperand(1));
+ assert(constIndex && "The index is not a constant!");
+ unsigned index = constIndex->getAPIntValue().getLimitedValue() %
+ VT.getVectorNumElements();
+ N = DAG.getNode(ARMISD::VDUPLANE, dl, VT,
+ DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, DAG.getUNDEF(VT),
+ Value, DAG.getConstant(index, MVT::i32)),
+ DAG.getConstant(index, MVT::i32));
+ } else {
+ N = DAG.getNode(ARMISD::VDUPLANE, dl, VT,
Value->getOperand(0), Value->getOperand(1));
+ }
+ }
else
N = DAG.getNode(ARMISD::VDUP, dl, VT, Value);