Fixed a couple of optimization with EXTRACT_VECTOR_ELT that assumes the result
type is the same as the element type of the vector. EXTRACT_VECTOR_ELT can
be used to extended the width of an integer type. This fixes a bug for
Generic/vector-casts.ll on a ppc750.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94990 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 640bdc0..6729a93 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -5403,12 +5403,19 @@
SDValue InVec = N->getOperand(0);
if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR) {
- // If the operand is wider than the vector element type then it is implicitly
- // truncated. Make that explicit here.
+ // Check if the result type doesn't match the inserted element type. A
+ // SCALAR_TO_VECTOR may truncate the inserted element and the
+ // EXTRACT_VECTOR_ELT may widen the extracted vector.
EVT EltVT = InVec.getValueType().getVectorElementType();
SDValue InOp = InVec.getOperand(0);
- if (InOp.getValueType() != EltVT)
- return DAG.getNode(ISD::TRUNCATE, InVec.getDebugLoc(), EltVT, InOp);
+ EVT NVT = N->getValueType(0);
+ if (InOp.getValueType() != NVT) {
+ assert(InOp.getValueType().isInteger() && NVT.isInteger());
+ if (NVT.getSizeInBits() > InOp.getValueType().getSizeInBits())
+ return DAG.getNode(ISD::SIGN_EXTEND, InVec.getDebugLoc(), NVT, InOp);
+ else
+ return DAG.getNode(ISD::TRUNCATE, InVec.getDebugLoc(), NVT, InOp);
+ }
return InOp;
}