Keep TBAA info when rewriting SelectionDAG loads and stores

Most SelectionDAG code drops the TBAA info when creating a new form of a
load and store (e.g. during legalization, or when converting a plain
load to an extending one).  This patch tries to catch all cases where
the TBAA information can legitimately be carried over.

The patch adds alternative forms of getLoad() and getExtLoad() that take
a MachineMemOperand instead of individual fields.  (The corresponding
getTruncStore() already exists.)  The idea is to use the MachineMemOperand
forms when all fields are carried over (size, pointer info, isVolatile,
isNonTemporal, alignment and TBAA info).  If some adjustment is being
made, e.g. to narrow the load, then we still pass the individual fields
but also pass the TBAA info.

llvm-svn: 193517

1 files changed, 7 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
index 81c8dac307b..2c3cdccb56e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
@@ -418,7 +418,8 @@ SDValue VectorLegalizer::ExpandLoad(SDValue Op) {
         ScalarLoad = DAG.getLoad(WideVT, dl, Chain, BasePTR,
                                  LD->getPointerInfo().getWithOffset(Offset),
                                  LD->isVolatile(), LD->isNonTemporal(),
-                                 LD->isInvariant(), LD->getAlignment());
+                                 LD->isInvariant(), LD->getAlignment(),
+                                 LD->getTBAAInfo());
       } else {
         EVT LoadVT = WideVT;
         while (RemainingBytes < LoadBytes) {
@@ -428,7 +429,8 @@ SDValue VectorLegalizer::ExpandLoad(SDValue Op) {
         ScalarLoad = DAG.getExtLoad(ISD::EXTLOAD, dl, WideVT, Chain, BasePTR,
                                     LD->getPointerInfo().getWithOffset(Offset),
                                     LoadVT, LD->isVolatile(),
-                                    LD->isNonTemporal(), LD->getAlignment());
+                                    LD->isNonTemporal(), LD->getAlignment(),
+                                    LD->getTBAAInfo());
       }
 
       RemainingBytes -= LoadBytes;
@@ -499,7 +501,7 @@ SDValue VectorLegalizer::ExpandLoad(SDValue Op) {
                 Chain, BasePTR, LD->getPointerInfo().getWithOffset(Idx * Stride),
                 SrcVT.getScalarType(),
                 LD->isVolatile(), LD->isNonTemporal(),
-                LD->getAlignment());
+                LD->getAlignment(), LD->getTBAAInfo());
 
       BasePTR = DAG.getNode(ISD::ADD, dl, BasePTR.getValueType(), BasePTR,
                          DAG.getConstant(Stride, BasePTR.getValueType()));
@@ -531,6 +533,7 @@ SDValue VectorLegalizer::ExpandStore(SDValue Op) {
   unsigned Alignment = ST->getAlignment();
   bool isVolatile = ST->isVolatile();
   bool isNonTemporal = ST->isNonTemporal();
+  const MDNode *TBAAInfo = ST->getTBAAInfo();
 
   unsigned NumElem = StVT.getVectorNumElements();
   // The type of the data we want to save
@@ -558,7 +561,7 @@ SDValue VectorLegalizer::ExpandStore(SDValue Op) {
     // This scalar TruncStore may be illegal, but we legalize it later.
     SDValue Store = DAG.getTruncStore(Chain, dl, Ex, BasePTR,
                ST->getPointerInfo().getWithOffset(Idx*Stride), MemSclVT,
-               isVolatile, isNonTemporal, Alignment);
+               isVolatile, isNonTemporal, Alignment, TBAAInfo);
 
     BasePTR = DAG.getNode(ISD::ADD, dl, BasePTR.getValueType(), BasePTR,
                                DAG.getConstant(Stride, BasePTR.getValueType()));