Fixed a few problems with vector shifts

- when transforming a vector shift of a non-immediate scalar shift amount, zero
    extend the i32 shift amount to i64 since the vector shift reads 64 bits
  - when transforming i16 vectors to use a vector shift, zero extend i16 shift amount
  - improve the code quality in some cases when transforming vectors to use a vector shift



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80935 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Mon P Wang 2009-09-03 19:56:25 +00:00
parent 2f67df794a
commit efa422023f

View File

@ -6359,9 +6359,23 @@ X86TargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) {
break;
}
}
// The vector shift intrinsics with scalars uses 32b shift amounts but
// the sse2/mmx shift instructions reads 64 bits. Set the upper 32 bits
// to be zero.
SDValue ShOps[4];
ShOps[0] = ShAmt;
ShOps[1] = DAG.getConstant(0, MVT::i32);
if (ShAmtVT == MVT::v4i32) {
ShOps[2] = DAG.getUNDEF(MVT::i32);
ShOps[3] = DAG.getUNDEF(MVT::i32);
ShAmt = DAG.getNode(ISD::BUILD_VECTOR, dl, ShAmtVT, &ShOps[0], 4);
} else {
ShAmt = DAG.getNode(ISD::BUILD_VECTOR, dl, ShAmtVT, &ShOps[0], 2);
}
EVT VT = Op.getValueType();
ShAmt = DAG.getNode(ISD::BIT_CONVERT, dl, VT,
DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, ShAmtVT, ShAmt));
ShAmt = DAG.getNode(ISD::BIT_CONVERT, dl, VT, ShAmt);
return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT,
DAG.getConstant(NewIntNo, MVT::i32),
Op.getOperand(1), ShAmt);
@ -8554,7 +8568,7 @@ static SDValue PerformShiftCombine(SDNode* N, SelectionDAG &DAG,
SDValue ShAmtOp = N->getOperand(1);
EVT EltVT = VT.getVectorElementType();
DebugLoc DL = N->getDebugLoc();
SDValue BaseShAmt;
SDValue BaseShAmt = SDValue();
if (ShAmtOp.getOpcode() == ISD::BUILD_VECTOR) {
unsigned NumElts = VT.getVectorNumElements();
unsigned i = 0;
@ -8573,15 +8587,34 @@ static SDValue PerformShiftCombine(SDNode* N, SelectionDAG &DAG,
}
} else if (ShAmtOp.getOpcode() == ISD::VECTOR_SHUFFLE &&
cast<ShuffleVectorSDNode>(ShAmtOp)->isSplat()) {
BaseShAmt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, EltVT, ShAmtOp,
DAG.getIntPtrConstant(0));
SDValue InVec = ShAmtOp.getOperand(0);
if (InVec.getOpcode() == ISD::BUILD_VECTOR) {
unsigned NumElts = InVec.getValueType().getVectorNumElements();
unsigned i = 0;
for (; i != NumElts; ++i) {
SDValue Arg = InVec.getOperand(i);
if (Arg.getOpcode() == ISD::UNDEF) continue;
BaseShAmt = Arg;
break;
}
} else if (InVec.getOpcode() == ISD::INSERT_VECTOR_ELT) {
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(InVec.getOperand(2))) {
unsigned SplatIdx = cast<ShuffleVectorSDNode>(ShAmtOp)->getSplatIndex();
if (C->getZExtValue() == SplatIdx)
BaseShAmt = InVec.getOperand(1);
}
}
if (BaseShAmt.getNode() == 0)
BaseShAmt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, EltVT, ShAmtOp,
DAG.getIntPtrConstant(0));
} else
return SDValue();
// The shift amount is an i32.
if (EltVT.bitsGT(MVT::i32))
BaseShAmt = DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, BaseShAmt);
else if (EltVT.bitsLT(MVT::i32))
BaseShAmt = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i32, BaseShAmt);
BaseShAmt = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, BaseShAmt);
// The shift amount is identical so we can do a vector shift.
SDValue ValOp = N->getOperand(0);