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[NVPTX] Use correct mul.wide operand type when matching on shl in combineMulWide #168986

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[NVPTX] Use correct mul.wide operand type when matching on shl in combineMulWide #168986

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[NVPTX] Fix `mul.wide` operand type when matching on `shl` in `combin…
justinfargnoli Nov 21, 2025
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Merge branch 'main' into fix-mul-wide-shl
justinfargnoli Nov 21, 2025
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4 changes: 2 additions & 2 deletions llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
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Expand Up @@ -5695,8 +5695,8 @@ static SDValue combineMulWide(SDNode *N, TargetLowering::DAGCombinerInfo &DCI,
SDValue RHS = Op.getOperand(1);
if (Op.getOpcode() == ISD::SHL) {
const auto ShiftAmt = Op.getConstantOperandVal(1);
const auto MulVal = APInt(ToVT.getSizeInBits(), 1) << ShiftAmt;
RHS = DCI.DAG.getConstant(MulVal, DL, ToVT);
const auto MulVal = APInt(FromVT.getSizeInBits(), 1) << ShiftAmt;
RHS = DCI.DAG.getConstant(MulVal, DL, FromVT);
Comment on lines +5698 to +5699
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@Artem-B Artem-B Nov 21, 2025

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It would be great to add a test that would catch such a mismatch.

}
return DCI.DAG.getNode(Opcode, DL, ToVT, Op.getOperand(0), RHS);
}
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