Back out previous commit, it isn't safe.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26006 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nate Begeman 2006-02-05 08:23:00 +00:00
parent bab9239d05
commit be71442292

View File

@ -1288,12 +1288,6 @@ SDOperand DAGCombiner::visitSHL(SDNode *N) {
// fold (shl 0, x) -> 0
if (N0C && N0C->isNullValue())
return N0;
// fold (shl c1, (add x, c2)) -> (shl c1 << c2, x)
if (N0C && N1.getOpcode() == ISD::ADD &&
N1.getOperand(1).getOpcode() == ISD::Constant) {
SDOperand LHS = DAG.getNode(ISD::SHL, VT, N0, N1.getOperand(1));
return DAG.getNode(ISD::SHL, VT, LHS, N1.getOperand(0));
}
// fold (shl x, c >= size(x)) -> undef
if (N1C && N1C->getValue() >= OpSizeInBits)
return DAG.getNode(ISD::UNDEF, VT);