diff options
Diffstat (limited to 'lib/CodeGen/SelectionDAG')
-rw-r--r-- | lib/CodeGen/SelectionDAG/TargetLowering.cpp | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp index 2f5ee0c56c..f98f0dd292 100644 --- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp +++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp @@ -848,6 +848,31 @@ bool TargetLowering::SimplifyDemandedBits(SDValue Op, } break; } + case ISD::BUILD_PAIR: { + EVT HalfVT = Op.getOperand(0).getValueType(); + unsigned HalfBitWidth = HalfVT.getScalarSizeInBits(); + + APInt MaskLo = NewMask.getLoBits(HalfBitWidth).trunc(HalfBitWidth); + APInt MaskHi = NewMask.getHiBits(HalfBitWidth).trunc(HalfBitWidth); + + APInt KnownZeroLo, KnownOneLo; + APInt KnownZeroHi, KnownOneHi; + + if (SimplifyDemandedBits(Op.getOperand(0), MaskLo, KnownZeroLo, + KnownOneLo, TLO, Depth + 1)) + return true; + + if (SimplifyDemandedBits(Op.getOperand(1), MaskHi, KnownZeroHi, + KnownOneHi, TLO, Depth + 1)) + return true; + + KnownZero = KnownZeroLo.zext(BitWidth) | + KnownZeroHi.zext(BitWidth).shl(HalfBitWidth); + + KnownOne = KnownOneLo.zext(BitWidth) | + KnownOneHi.zext(BitWidth).shl(HalfBitWidth); + break; + } case ISD::ZERO_EXTEND: { unsigned OperandBitWidth = Op.getOperand(0).getValueType().getScalarType().getSizeInBits(); |