Fixed a bug in narrowing store operation.
Type MVT::i1 became legal in KNL, but store operation can't be narrowed to this type,
since the size of VT (1 bit) is not equal to its actual store size(8 bits).
Added a test provided by David (dag@cray.com)
llvm-svn: 226805
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 8495088..4a9ae20 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -9497,9 +9497,12 @@
unsigned MSB = BitWidth - Imm.countLeadingZeros() - 1;
unsigned NewBW = NextPowerOf2(MSB - ShAmt);
EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
+ // The narowwing should be profitable, the load/store operation should be
+ // legal (or custom) and the store size should be equal to the NewVT width.
while (NewBW < BitWidth &&
- !(TLI.isOperationLegalOrCustom(Opc, NewVT) &&
- TLI.isNarrowingProfitable(VT, NewVT))) {
+ (NewVT.getStoreSizeInBits() != NewBW ||
+ !TLI.isOperationLegalOrCustom(Opc, NewVT) ||
+ !TLI.isNarrowingProfitable(VT, NewVT))) {
NewBW = NextPowerOf2(NewBW);
NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
}