[DAGCombiner] Add a shuffle mask commutation helper function. NFCI.
We have an increasing number of cases where we are creating commuted shuffle masks - all implementing nearly the same code.
This patch adds a static helper function - ShuffleVectorSDNode::commuteMask() and replaces a number of cases to use it.
Differential Revision: http://reviews.llvm.org/D8139
llvm-svn: 231581
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 232c592..ac719f6 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -1446,13 +1446,7 @@
// N2 to point at N1.
static void commuteShuffle(SDValue &N1, SDValue &N2, SmallVectorImpl<int> &M) {
std::swap(N1, N2);
- int NElts = M.size();
- for (int i = 0; i != NElts; ++i) {
- if (M[i] >= NElts)
- M[i] -= NElts;
- else if (M[i] >= 0)
- M[i] += NElts;
- }
+ ShuffleVectorSDNode::commuteMask(M);
}
SDValue SelectionDAG::getVectorShuffle(EVT VT, SDLoc dl, SDValue N1,
@@ -1625,19 +1619,8 @@
SDValue SelectionDAG::getCommutedVectorShuffle(const ShuffleVectorSDNode &SV) {
MVT VT = SV.getSimpleValueType(0);
- unsigned NumElems = VT.getVectorNumElements();
- SmallVector<int, 8> MaskVec;
-
- for (unsigned i = 0; i != NumElems; ++i) {
- int Idx = SV.getMaskElt(i);
- if (Idx >= 0) {
- if (Idx < (int)NumElems)
- Idx += NumElems;
- else
- Idx -= NumElems;
- }
- MaskVec.push_back(Idx);
- }
+ SmallVector<int, 8> MaskVec(SV.getMask().begin(), SV.getMask().end());
+ ShuffleVectorSDNode::commuteMask(MaskVec);
SDValue Op0 = SV.getOperand(0);
SDValue Op1 = SV.getOperand(1);