During vector shuffle lowering, we sometimes commute a vector shuffle to try

to match MOVL (movss, movsd, etc.). Don't forget to commute it back and try
unpck* and shufp* if that doesn't pan out.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31186 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2006-10-25 21:49:50 +00:00
parent 009073d839
commit 9eca5e814d

View File

@ -2954,10 +2954,9 @@ static bool isPSHUFHW_PSHUFLWMask(SDNode *N) {
/// CommuteVectorShuffle - Swap vector_shuffle operandsas well as
/// values in ther permute mask.
static SDOperand CommuteVectorShuffle(SDOperand Op, SelectionDAG &DAG) {
SDOperand V1 = Op.getOperand(0);
SDOperand V2 = Op.getOperand(1);
SDOperand Mask = Op.getOperand(2);
static SDOperand CommuteVectorShuffle(SDOperand Op, SDOperand &V1,
SDOperand &V2, SDOperand &Mask,
SelectionDAG &DAG) {
MVT::ValueType VT = Op.getValueType();
MVT::ValueType MaskVT = Mask.getValueType();
MVT::ValueType EltVT = MVT::getVectorBaseType(MaskVT);
@ -2978,8 +2977,9 @@ static SDOperand CommuteVectorShuffle(SDOperand Op, SelectionDAG &DAG) {
MaskVec.push_back(DAG.getConstant(Val - NumElems, EltVT));
}
std::swap(V1, V2);
Mask = DAG.getNode(ISD::BUILD_VECTOR, MaskVT, &MaskVec[0], MaskVec.size());
return DAG.getNode(ISD::VECTOR_SHUFFLE, VT, V2, V1, Mask);
return DAG.getNode(ISD::VECTOR_SHUFFLE, VT, V1, V2, Mask);
}
/// ShouldXformToMOVHLPS - Return true if the node should be transformed to
@ -3463,25 +3463,21 @@ X86TargetLowering::LowerVECTOR_SHUFFLE(SDOperand Op, SelectionDAG &DAG) {
if (ShouldXformToMOVHLPS(PermMask.Val) ||
ShouldXformToMOVLP(V1.Val, V2.Val, PermMask.Val))
return CommuteVectorShuffle(Op, DAG);
return CommuteVectorShuffle(Op, V1, V2, PermMask, DAG);
bool Commuted = false;
V1IsSplat = isSplatVector(V1.Val);
V2IsSplat = isSplatVector(V2.Val);
if ((V1IsSplat || V1IsUndef) && !(V2IsSplat || V2IsUndef)) {
Op = CommuteVectorShuffle(Op, DAG);
V1 = Op.getOperand(0);
V2 = Op.getOperand(1);
PermMask = Op.getOperand(2);
Op = CommuteVectorShuffle(Op, V1, V2, PermMask, DAG);
std::swap(V1IsSplat, V2IsSplat);
std::swap(V1IsUndef, V2IsUndef);
Commuted = true;
}
if (isCommutedMOVL(PermMask.Val, V2IsSplat, V2IsUndef)) {
if (V2IsUndef) return V1;
Op = CommuteVectorShuffle(Op, DAG);
V1 = Op.getOperand(0);
V2 = Op.getOperand(1);
PermMask = Op.getOperand(2);
Op = CommuteVectorShuffle(Op, V1, V2, PermMask, DAG);
if (V2IsSplat) {
// V2 is a splat, so the mask may be malformed. That is, it may point
// to any V2 element. The instruction selectior won't like this. Get
@ -3515,13 +3511,17 @@ X86TargetLowering::LowerVECTOR_SHUFFLE(SDOperand Op, SelectionDAG &DAG) {
}
// Normalize the node to match x86 shuffle ops if needed
if (V2.getOpcode() != ISD::UNDEF)
if (isCommutedSHUFP(PermMask.Val)) {
Op = CommuteVectorShuffle(Op, DAG);
V1 = Op.getOperand(0);
V2 = Op.getOperand(1);
PermMask = Op.getOperand(2);
}
if (V2.getOpcode() != ISD::UNDEF && isCommutedSHUFP(PermMask.Val))
Op = CommuteVectorShuffle(Op, V1, V2, PermMask, DAG);
if (Commuted) {
// Commute is back and try unpck* again.
Op = CommuteVectorShuffle(Op, V1, V2, PermMask, DAG);
if (X86::isUNPCKL_v_undef_Mask(PermMask.Val) ||
X86::isUNPCKLMask(PermMask.Val) ||
X86::isUNPCKHMask(PermMask.Val))
return Op;
}
// If VT is integer, try PSHUF* first, then SHUFP*.
if (MVT::isInteger(VT)) {