if (Op0Const && Op1Const)
return ConstantFoldShuffleVectorInstruction(Op0Const, Op1Const, Mask);
+ SmallVector<int, 32> Indices;
+ ShuffleVectorInst::getShuffleMask(Mask, Indices);
+ assert(MaskNumElts == Indices.size() &&
+ "Size of Indices not same as number of mask elements?");
+
// If only one of the operands is constant, constant fold the shuffle if the
// mask does not select elements from the variable operand.
bool MaskSelects0 = false, MaskSelects1 = false;
for (unsigned i = 0; i != MaskNumElts; ++i) {
- int Idx = ShuffleVectorInst::getMaskValue(Mask, i);
- if (Idx == -1)
+ if (Indices[i] == -1)
continue;
- if ((unsigned)Idx < InVecNumElts)
+ if ((unsigned)Indices[i] < InVecNumElts)
MaskSelects0 = true;
else
MaskSelects1 = true;
// Don't fold a shuffle with undef mask elements. This may get folded in a
// better way using demanded bits or other analysis.
// TODO: Should we allow this?
- for (unsigned i = 0; i != MaskNumElts; ++i)
- if (ShuffleVectorInst::getMaskValue(Mask, i) == -1)
- return nullptr;
+ if (find(Indices, -1) != Indices.end())
+ return nullptr;
// Check if every element of this shuffle can be mapped back to the
// corresponding element of a single root vector. If so, we don't need this