Fix a couple of logic bugs in TargetLowering::SimplifyDemandedBits. PR11514.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146219 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 8956651..ee329dc 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1483,9 +1483,8 @@
if (InOp.getNode()->getOpcode() == ISD::ANY_EXTEND) {
SDValue InnerOp = InOp.getNode()->getOperand(0);
EVT InnerVT = InnerOp.getValueType();
- if ((APInt::getHighBitsSet(BitWidth,
- BitWidth - InnerVT.getSizeInBits()) &
- DemandedMask) == 0 &&
+ unsigned InnerBits = InnerVT.getSizeInBits();
+ if (ShAmt < InnerBits && NewMask.lshr(InnerBits) == 0 &&
isTypeDesirableForOp(ISD::SHL, InnerVT)) {
EVT ShTy = getShiftAmountTy(InnerVT);
if (!APInt(BitWidth, ShAmt).isIntN(ShTy.getSizeInBits()))
@@ -1555,7 +1554,7 @@
// always convert this into a logical shr, even if the shift amount is
// variable. The low bit of the shift cannot be an input sign bit unless
// the shift amount is >= the size of the datatype, which is undefined.
- if (DemandedMask == 1)
+ if (NewMask == 1)
return TLO.CombineTo(Op,
TLO.DAG.getNode(ISD::SRL, dl, Op.getValueType(),
Op.getOperand(0), Op.getOperand(1)));