Wrong types checked at DAGCombiner::visitSRA(SDNode *N)

[akiva-pripas]

The following check is performed at DAGCombiner::visitSRA(SDNode *N)

if ((ShiftAmt > 0) &&
          TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, **TruncVT**) &&
          TLI.isOperationLegalOrCustom(ISD::TRUNCATE, **VT**) &&
          TLI.isTruncateFree(VT, TruncVT)) {
        SDValue Amt = DAG.getShiftAmountConstant(ShiftAmt, VT, DL);
        SDValue Shift = DAG.getNode(ISD::SRL, DL, VT,
                                    N0.getOperand(0), Amt);
        SDValue Trunc = DAG.getNode(ISD::TRUNCATE, DL, TruncVT,
                                    Shift);
        return DAG.getNode(ISD::SIGN_EXTEND, DL,
                           N->getValueType(0), Trunc);
      }

but it should be

if ((ShiftAmt > 0) &&
          TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, **VT**) &&
          TLI.isOperationLegalOrCustom(ISD::TRUNCATE, **TruncVT**) &&
          TLI.isTruncateFree(VT, TruncVT)) {
        SDValue Amt = DAG.getShiftAmountConstant(ShiftAmt, VT, DL);
        SDValue Shift = DAG.getNode(ISD::SRL, DL, VT,
                                    N0.getOperand(0), Amt);
        SDValue Trunc = DAG.getNode(ISD::TRUNCATE, DL, TruncVT,
                                    Shift);
        return DAG.getNode(ISD::SIGN_EXTEND, DL,
                           N->getValueType(0), Trunc);
      }

this mistake can cause operation marked with expand to reach selection

[llvmbot]

Hi!

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[llvmbot]

@llvm/issue-subscribers-good-first-issue

Author: None (akiva-pripas)

The following check is performed at DAGCombiner::visitSRA(SDNode *N) ```c if ((ShiftAmt > 0) && TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, **TruncVT**) && TLI.isOperationLegalOrCustom(ISD::TRUNCATE, **VT**) && TLI.isTruncateFree(VT, TruncVT)) { SDValue Amt = DAG.getShiftAmountConstant(ShiftAmt, VT, DL); SDValue Shift = DAG.getNode(ISD::SRL, DL, VT, N0.getOperand(0), Amt); SDValue Trunc = DAG.getNode(ISD::TRUNCATE, DL, TruncVT, Shift); return DAG.getNode(ISD::SIGN_EXTEND, DL, N->getValueType(0), Trunc); } ``` but it should be ```c if ((ShiftAmt > 0) && TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, **VT**) && TLI.isOperationLegalOrCustom(ISD::TRUNCATE, **TruncVT**) && TLI.isTruncateFree(VT, TruncVT)) { SDValue Amt = DAG.getShiftAmountConstant(ShiftAmt, VT, DL); SDValue Shift = DAG.getNode(ISD::SRL, DL, VT, N0.getOperand(0), Amt); SDValue Trunc = DAG.getNode(ISD::TRUNCATE, DL, TruncVT, Shift); return DAG.getNode(ISD::SIGN_EXTEND, DL, N->getValueType(0), Trunc); } ``` this mistake can cause operation marked with expand to reach selection

[woruyu]

I would like to work for this issue!