Index: lib/Target/MSP430/MSP430ISelLowering.cpp =================================================================== --- lib/Target/MSP430/MSP430ISelLowering.cpp +++ lib/Target/MSP430/MSP430ISelLowering.cpp @@ -952,15 +952,26 @@ // Expand the stuff into sequence of shifts. SDValue Victim = N->getOperand(0); - if ((Opc == ISD::SRA || Opc == ISD::SRL) && ShiftAmount >= 8) { - // foo >> (8 + N) => sxt(swpb(foo)) >> N + if (ShiftAmount >= 8) { assert(VT == MVT::i16 && "Can not shift i8 by 8 and more"); - Victim = DAG.getNode(ISD::BSWAP, dl, VT, Victim); - if (Opc == ISD::SRA) - Victim = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, VT, Victim, - DAG.getValueType(MVT::i8)); - else + switch(Opc) { + default: + llvm_unreachable("Unknown shift"); + case ISD::SHL: + // foo << (8 + N) => swpb(zext(foo)) << N Victim = DAG.getZeroExtendInReg(Victim, dl, MVT::i8); + Victim = DAG.getNode(ISD::BSWAP, dl, VT, Victim); + break; + case ISD::SRA: + case ISD::SRL: + // foo >> (8 + N) => sxt(swpb(foo)) >> N + Victim = DAG.getNode(ISD::BSWAP, dl, VT, Victim); + Victim = (Opc == ISD::SRA) + ? DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, VT, Victim, + DAG.getValueType(MVT::i8)) + : DAG.getZeroExtendInReg(Victim, dl, MVT::i8); + break; + } ShiftAmount -= 8; } Index: test/CodeGen/MSP430/shifts.ll =================================================================== --- test/CodeGen/MSP430/shifts.ll +++ test/CodeGen/MSP430/shifts.ll @@ -74,3 +74,14 @@ %shr = lshr i16 %a, 10 ret i16 %shr } + +define i16 @lshl10_i16(i16 %a) #0 { +entry: +; CHECK-LABEL: lshl10_i16: +; CHECK: mov.b r12, r12 +; CHECK-NEXT: swpb r12 +; CHECK-NEXT: add r12, r12 +; CHECK-NEXT: add r12, r12 + %shl = shl i16 %a, 10 + ret i16 %shl +}