diff options
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelLowering.cpp | 77 |
1 files changed, 40 insertions, 37 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index b50376bea53..7f1432c8128 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -23122,6 +23122,40 @@ static SDValue LowerScalarImmediateShift(SDValue Op, SelectionDAG &DAG, return SDValue(); } +// Determine if V is a splat value, and return the scalar. +// TODO: Add support for SUB(SPLAT_CST, SPLAT) cases to support rotate patterns. +static SDValue IsSplatValue(SDValue V, const SDLoc &dl, SelectionDAG &DAG) { + // Check if this is a splat build_vector node. + if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(V)) { + SDValue SplatAmt = BV->getSplatValue(); + if (SplatAmt && SplatAmt.isUndef()) + return SDValue(); + return SplatAmt; + } + + // Check if this is a shuffle node doing a splat. + ShuffleVectorSDNode *SVN = dyn_cast<ShuffleVectorSDNode>(V); + if (!SVN || !SVN->isSplat()) + return SDValue(); + + unsigned SplatIdx = (unsigned)SVN->getSplatIndex(); + SDValue InVec = V.getOperand(0); + if (InVec.getOpcode() == ISD::BUILD_VECTOR) { + assert((SplatIdx < InVec.getSimpleValueType().getVectorNumElements()) && + "Unexpected shuffle index found!"); + return InVec.getOperand(SplatIdx); + } else if (InVec.getOpcode() == ISD::INSERT_VECTOR_ELT) { + if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(InVec.getOperand(2))) + if (C->getZExtValue() == SplatIdx) + return InVec.getOperand(1); + } + + // Avoid introducing an extract element from a shuffle. + return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, + V.getValueType().getVectorElementType(), InVec, + DAG.getIntPtrConstant(SplatIdx, dl)); +} + static SDValue LowerScalarVariableShift(SDValue Op, SelectionDAG &DAG, const X86Subtarget &Subtarget) { MVT VT = Op.getSimpleValueType(); @@ -23135,44 +23169,13 @@ static SDValue LowerScalarVariableShift(SDValue Op, SelectionDAG &DAG, unsigned X86OpcV = (Op.getOpcode() == ISD::SHL) ? X86ISD::VSHL : (Op.getOpcode() == ISD::SRL) ? X86ISD::VSRL : X86ISD::VSRA; - if (SupportedVectorShiftWithBaseAmnt(VT, Subtarget, Op.getOpcode())) { - SDValue BaseShAmt; - MVT EltVT = VT.getVectorElementType(); - - if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(Amt)) { - // Check if this build_vector node is doing a splat. - // If so, then set BaseShAmt equal to the splat value. - BaseShAmt = BV->getSplatValue(); - if (BaseShAmt && BaseShAmt.isUndef()) - BaseShAmt = SDValue(); - } else { - if (Amt.getOpcode() == ISD::EXTRACT_SUBVECTOR) - Amt = Amt.getOperand(0); - - ShuffleVectorSDNode *SVN = dyn_cast<ShuffleVectorSDNode>(Amt); - if (SVN && SVN->isSplat()) { - unsigned SplatIdx = (unsigned)SVN->getSplatIndex(); - SDValue InVec = Amt.getOperand(0); - if (InVec.getOpcode() == ISD::BUILD_VECTOR) { - assert((SplatIdx < InVec.getSimpleValueType().getVectorNumElements()) && - "Unexpected shuffle index found!"); - BaseShAmt = InVec.getOperand(SplatIdx); - } else if (InVec.getOpcode() == ISD::INSERT_VECTOR_ELT) { - if (ConstantSDNode *C = - dyn_cast<ConstantSDNode>(InVec.getOperand(2))) { - if (C->getZExtValue() == SplatIdx) - BaseShAmt = InVec.getOperand(1); - } - } - - if (!BaseShAmt) - // Avoid introducing an extract element from a shuffle. - BaseShAmt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, InVec, - DAG.getIntPtrConstant(SplatIdx, dl)); - } - } + // Peek through any EXTRACT_SUBVECTORs. + while (Amt.getOpcode() == ISD::EXTRACT_SUBVECTOR) + Amt = Amt.getOperand(0); - if (BaseShAmt.getNode()) { + if (SupportedVectorShiftWithBaseAmnt(VT, Subtarget, Op.getOpcode())) { + if (SDValue BaseShAmt = IsSplatValue(Amt, dl, DAG)) { + MVT EltVT = VT.getVectorElementType(); assert(EltVT.bitsLE(MVT::i64) && "Unexpected element type!"); if (EltVT != MVT::i64 && EltVT.bitsGT(MVT::i32)) BaseShAmt = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i64, BaseShAmt); |
