diff options
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp index d7427f48e4f..ce166058d35 100644 --- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp @@ -569,9 +569,18 @@ bool TargetLowering::SimplifyDemandedBits(SDValue Op, const APInt &DemandedBits, SDValue TargetLowering::SimplifyMultipleUseDemandedBits( SDValue Op, const APInt &DemandedBits, const APInt &DemandedElts, SelectionDAG &DAG, unsigned Depth) const { - if (Depth >= 6) // Limit search depth. + // Limit search depth. + if (Depth >= 6) + return SDValue(); + + // Ignore UNDEFs. + if (Op.isUndef()) return SDValue(); + // Not demanding any bits/elts from Op. + if (DemandedBits == 0 || DemandedElts == 0) + return DAG.getUNDEF(Op.getValueType()); + unsigned NumElts = DemandedElts.getBitWidth(); KnownBits LHSKnown, RHSKnown; switch (Op.getOpcode()) { |
