DAG: Add nuw when splitting loads and stores

The object can't straddle the address space
wrap around, so I think it's OK to assume any
offsets added to the base object pointer can't
overflow. Similar logic already appears to be
applied in SelectionDAGBuilder when lowering
aggregate returns.

llvm-svn: 319272

1 files changed, 2 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
index 793a935aa08..928db8280bb 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
@@ -554,7 +554,6 @@ SDValue VectorLegalizer::ExpandLoad(SDValue Op) {
     unsigned Offset = 0;
     unsigned RemainingBytes = SrcVT.getStoreSize();
     SmallVector<SDValue, 8> LoadVals;
-
     while (RemainingBytes > 0) {
       SDValue ScalarLoad;
       unsigned LoadBytes = WideBytes;
@@ -580,9 +579,8 @@ SDValue VectorLegalizer::ExpandLoad(SDValue Op) {
 
       RemainingBytes -= LoadBytes;
       Offset += LoadBytes;
-      BasePTR = DAG.getNode(ISD::ADD, dl, BasePTR.getValueType(), BasePTR,
-                            DAG.getConstant(LoadBytes, dl,
-                                            BasePTR.getValueType()));
+
+      BasePTR = DAG.getObjectPtrOffset(dl, BasePTR, LoadBytes);
 
       LoadVals.push_back(ScalarLoad.getValue(0));
       LoadChains.push_back(ScalarLoad.getValue(1));