Don't crash on X^X if X is a vector. Instead, produce a vector of zeros.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27229 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2006-03-28 19:11:05 +00:00
parent f35b29765b
commit 4fbdd59f4f

View File

@ -1396,8 +1396,16 @@ SDOperand DAGCombiner::visitXOR(SDNode *N) {
DAG.getConstant(N1C->getValue()^N01C->getValue(), VT));
}
// fold (xor x, x) -> 0
if (N0 == N1)
return DAG.getConstant(0, VT);
if (N0 == N1) {
if (!MVT::isVector(VT)) {
return DAG.getConstant(0, VT);
} else if (!AfterLegalize || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)) {
// Produce a vector of zeros.
SDOperand El = DAG.getConstant(0, MVT::getVectorBaseType(VT));
std::vector<SDOperand> Ops(MVT::getVectorNumElements(VT), El);
return DAG.getNode(ISD::BUILD_VECTOR, VT, Ops);
}
}
// fold (xor (zext x), (zext y)) -> (zext (xor x, y))
if (N0.getOpcode() == ISD::ZERO_EXTEND &&
N1.getOpcode() == ISD::ZERO_EXTEND &&