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[RISCV] Use significant bits helpers in narrowing of build vectors [nfc] #104511

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Merged
merged 1 commit into from
Aug 15, 2024
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[RISCV] Use significant bits helpers in narrowing of build vectors [nfc] #104511

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18 changes: 8 additions & 10 deletions llvm/lib/Target/RISCV/RISCVISelLowering.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3813,16 +3813,14 @@ static SDValue lowerBuildVectorOfConstants(SDValue Op, SelectionDAG &DAG,
// TODO: We really should be costing the smaller vector. There are
// profitable cases this misses.
if (EltBitSize > 8 && VT.isInteger() &&
(NumElts <= 4 || VT.getSizeInBits() > Subtarget.getRealMinVLen())) {
unsigned SignBits = DAG.ComputeNumSignBits(Op);
if (EltBitSize - SignBits < 8) {
SDValue Source = DAG.getBuildVector(VT.changeVectorElementType(MVT::i8),
DL, Op->ops());
Source = convertToScalableVector(ContainerVT.changeVectorElementType(MVT::i8),
Source, DAG, Subtarget);
SDValue Res = DAG.getNode(RISCVISD::VSEXT_VL, DL, ContainerVT, Source, Mask, VL);
return convertFromScalableVector(VT, Res, DAG, Subtarget);
}
(NumElts <= 4 || VT.getSizeInBits() > Subtarget.getRealMinVLen()) &&
DAG.ComputeMaxSignificantBits(Op) <= 8) {
SDValue Source = DAG.getBuildVector(VT.changeVectorElementType(MVT::i8),
DL, Op->ops());
Source = convertToScalableVector(ContainerVT.changeVectorElementType(MVT::i8),
Source, DAG, Subtarget);
SDValue Res = DAG.getNode(RISCVISD::VSEXT_VL, DL, ContainerVT, Source, Mask, VL);
return convertFromScalableVector(VT, Res, DAG, Subtarget);
}

if (SDValue Res = lowerBuildVectorViaDominantValues(Op, DAG, Subtarget))
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