diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp index 3918dd21bc09d..0ad829ab09de6 100644 --- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp +++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp @@ -16184,10 +16184,12 @@ static SDValue expandMul(SDNode *N, SelectionDAG &DAG, // 2^N - 3/5/9 --> (sub (shl X, C1), (shXadd X, x)) for (uint64_t Offset : {3, 5, 9}) { if (isPowerOf2_64(MulAmt + Offset)) { + unsigned ShAmt = Log2_64(MulAmt + Offset); + if (ShAmt >= VT.getSizeInBits()) + continue; SDLoc DL(N); SDValue Shift1 = - DAG.getNode(ISD::SHL, DL, VT, X, - DAG.getConstant(Log2_64(MulAmt + Offset), DL, VT)); + DAG.getNode(ISD::SHL, DL, VT, X, DAG.getConstant(ShAmt, DL, VT)); SDValue Mul359 = DAG.getNode(RISCVISD::SHL_ADD, DL, VT, X, DAG.getConstant(Log2_64(Offset - 1), DL, VT), X);