Revert "Fix merges of non-zero vector stores"
This reverts commit r239539.
It was causing SDAG assertions while building freetype.
llvm-svn: 239543
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 4ffb409..a71c676 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -387,13 +387,6 @@
unsigned SequenceNum;
};
- /// This is a helper function for MergeStoresOfConstantsOrVecElts. Returns a
- /// constant build_vector of the stored constant values in Stores.
- SDValue getMergedConstantVectorStore(SelectionDAG &DAG,
- SDLoc SL,
- ArrayRef<MemOpLink> Stores,
- EVT Ty) const;
-
/// This is a helper function for MergeConsecutiveStores. When the source
/// elements of the consecutive stores are all constants or all extracted
/// vector elements, try to merge them into one larger store.
@@ -10583,17 +10576,6 @@
};
} // namespace
-SDValue DAGCombiner::getMergedConstantVectorStore(SelectionDAG &DAG,
- SDLoc SL,
- ArrayRef<MemOpLink> Stores,
- EVT Ty) const {
- SmallVector<SDValue, 8> BuildVector;
-
- for (const MemOpLink &Store : Stores)
- BuildVector.push_back(cast<StoreSDNode>(Store.MemNode)->getValue());
- return DAG.getNode(ISD::BUILD_VECTOR, SL, Ty, BuildVector);
-}
-
bool DAGCombiner::MergeStoresOfConstantsOrVecElts(
SmallVectorImpl<MemOpLink> &StoreNodes, EVT MemVT,
unsigned NumElem, bool IsConstantSrc, bool UseVector) {
@@ -10624,7 +10606,12 @@
EVT Ty = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
assert(TLI.isTypeLegal(Ty) && "Illegal vector store");
if (IsConstantSrc) {
- StoredVal = getMergedConstantVectorStore(DAG, DL, StoreNodes, Ty);
+ // A vector store with a constant source implies that the constant is
+ // zero; we only handle merging stores of constant zeros because the zero
+ // can be materialized without a load.
+ // It may be beneficial to loosen this restriction to allow non-zero
+ // store merging.
+ StoredVal = DAG.getConstant(0, DL, Ty);
} else {
SmallVector<SDValue, 8> Ops;
for (unsigned i = 0; i < NumElem ; ++i) {