If a shuffle is unary, i.e. one of the vector argument is not needed, turn the

operand into a undef and adjust mask accordingly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29232 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2006-07-20 22:44:41 +00:00
parent 514e258994
commit e7bec0dbb5

View File

@ -2597,10 +2597,33 @@ SDOperand DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
} }
} }
if (isIdentity) return N->getOperand(1); if (isIdentity) return N->getOperand(1);
// If the LHS and the RHS are the same node, turn the RHS into an undef. // Check if the shuffle is a unary shuffle, i.e. one of the vectors is not
if (N->getOperand(0) == N->getOperand(1)) { // needed at all.
if (N->getOperand(0).getOpcode() == ISD::UNDEF) bool isUnary = true;
int VecNum = -1;
for (unsigned i = 0; i != NumElts; ++i)
if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF) {
unsigned Idx = cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue();
int V = (Idx < NumElts) ? 0 : 1;
if (VecNum == -1)
VecNum = V;
else if (VecNum != V) {
isUnary = false;
break;
}
}
SDOperand N0 = N->getOperand(0);
SDOperand N1 = N->getOperand(1);
// Normalize unary shuffle so the RHS is undef.
if (isUnary && VecNum == 1)
std::swap(N0, N1);
// If it is a unary or the LHS and the RHS are the same node, turn the RHS
// into an undef.
if (isUnary || N0 == N1) {
if (N0.getOpcode() == ISD::UNDEF)
return DAG.getNode(ISD::UNDEF, N->getValueType(0)); return DAG.getNode(ISD::UNDEF, N->getValueType(0));
// Check the SHUFFLE mask, mapping any inputs from the 2nd operand into the // Check the SHUFFLE mask, mapping any inputs from the 2nd operand into the
// first operand. // first operand.
@ -2619,7 +2642,7 @@ SDOperand DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
MappedOps); MappedOps);
AddToWorkList(ShufMask.Val); AddToWorkList(ShufMask.Val);
return DAG.getNode(ISD::VECTOR_SHUFFLE, N->getValueType(0), return DAG.getNode(ISD::VECTOR_SHUFFLE, N->getValueType(0),
N->getOperand(0), N0,
DAG.getNode(ISD::UNDEF, N->getValueType(0)), DAG.getNode(ISD::UNDEF, N->getValueType(0)),
ShufMask); ShufMask);
} }
@ -2653,8 +2676,31 @@ SDOperand DAGCombiner::visitVVECTOR_SHUFFLE(SDNode *N) {
} }
if (isIdentity) return N->getOperand(1); if (isIdentity) return N->getOperand(1);
// If the LHS and the RHS are the same node, turn the RHS into an undef. // Check if the shuffle is a unary shuffle, i.e. one of the vectors is not
if (N->getOperand(0) == N->getOperand(1)) { // needed at all.
bool isUnary = true;
int VecNum = -1;
for (unsigned i = 0; i != NumElts; ++i)
if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF) {
unsigned Idx = cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue();
int V = (Idx < NumElts) ? 0 : 1;
if (VecNum == -1)
VecNum = V;
else if (VecNum != V) {
isUnary = false;
break;
}
}
SDOperand N0 = N->getOperand(0);
SDOperand N1 = N->getOperand(1);
// Normalize unary shuffle so the RHS is undef.
if (isUnary && VecNum == 1)
std::swap(N0, N1);
// If it is a unary or the LHS and the RHS are the same node, turn the RHS
// into an undef.
if (isUnary || N0 == N1) {
// Check the SHUFFLE mask, mapping any inputs from the 2nd operand into the // Check the SHUFFLE mask, mapping any inputs from the 2nd operand into the
// first operand. // first operand.
std::vector<SDOperand> MappedOps; std::vector<SDOperand> MappedOps;
@ -2680,12 +2726,12 @@ SDOperand DAGCombiner::visitVVECTOR_SHUFFLE(SDNode *N) {
SDOperand UDVal = DAG.getNode(ISD::UNDEF, MappedOps[0].getValueType()); SDOperand UDVal = DAG.getNode(ISD::UNDEF, MappedOps[0].getValueType());
for (unsigned i = 0; i != NumElts; ++i) for (unsigned i = 0; i != NumElts; ++i)
MappedOps[i] = UDVal; MappedOps[i] = UDVal;
MappedOps[NumElts ] = *(N->getOperand(0).Val->op_end()-2); MappedOps[NumElts ] = *(N0.Val->op_end()-2);
MappedOps[NumElts+1] = *(N->getOperand(0).Val->op_end()-1); MappedOps[NumElts+1] = *(N0.Val->op_end()-1);
UDVal = DAG.getNode(ISD::VBUILD_VECTOR, MVT::Vector, MappedOps); UDVal = DAG.getNode(ISD::VBUILD_VECTOR, MVT::Vector, MappedOps);
return DAG.getNode(ISD::VVECTOR_SHUFFLE, MVT::Vector, return DAG.getNode(ISD::VVECTOR_SHUFFLE, MVT::Vector,
N->getOperand(0), UDVal, ShufMask, N0, UDVal, ShufMask,
MappedOps[NumElts], MappedOps[NumElts+1]); MappedOps[NumElts], MappedOps[NumElts+1]);
} }