[CodeGen] emitOMPArraySectionBase() to generate TBAA info along with LValue base info

[kosarev]

Summary

Prepared on top of D38733.

[rjmccall]

LGTM.

cfe/trunk/lib/CodeGen/CGExpr.cpp

if (getLangOpts().ObjC1 &&
     LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
     setObjCGCLValueClass(getContext(), E, LV);
   }
   return LV;
 }
 
 static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
                                        LValueBaseInfo &BaseInfo,
+                                       TBAAAccessInfo &TBAAInfo,
                                        QualType BaseTy, QualType ElTy,
                                        bool IsLowerBound) {
+  TBAAInfo = CGF.CGM.getTBAAAccessInfo(ElTy);
+
   LValue BaseLVal;
   if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
     BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
     if (BaseTy->isArrayType()) {
       Address Addr = BaseLVal.getAddress();
       BaseInfo = BaseLVal.getBaseInfo();
 
       // If the array type was an incomplete type, we need to make sure
if (Length) {
         Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
       }
     }
   }
   assert(Idx);
 
   Address EltPtr = Address::invalid();
   LValueBaseInfo BaseInfo;
+  TBAAAccessInfo TBAAInfo;
   if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
     // The base must be a pointer, which is not an aggregate.  Emit
     // it.  It needs to be emitted first in case it's what captures
     // the VLA bounds.
     Address Base =
-        emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, BaseTy,
-                                VLA->getElementType(), IsLowerBound);
+        emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
+                                BaseTy, VLA->getElementType(), IsLowerBound);
     // The element count here is the total number of non-VLA elements.
     llvm::Value *NumElements = getVLASize(VLA).first;
 
     // Effectively, the multiply by the VLA size is part of the GEP.
     // GEP indexes are signed, and scaling an index isn't permitted to
     // signed-overflow, so we use the same semantics for our explicit
     // multiply.  We suppress this if overflow is not undefined behavior.
     if (getLangOpts().isSignedOverflowDefined())
else
       ArrayLV = EmitLValue(Array);
 
     // Propagate the alignment from the array itself to the result.
     EltPtr = emitArraySubscriptGEP(
         *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
         ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
         /*SignedIndices=*/false, E->getExprLoc());
     BaseInfo = ArrayLV.getBaseInfo();
+    TBAAInfo = CGM.getTBAAAccessInfo(ResultExprTy);
   } else {
     Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
-                                           BaseTy, ResultExprTy, IsLowerBound);
+                                           TBAAInfo, BaseTy, ResultExprTy,
+                                           IsLowerBound);
     EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
                                    !getLangOpts().isSignedOverflowDefined(),
                                    /*SignedIndices=*/false, E->getExprLoc());
   }
 
-  return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo,
-                        CGM.getTBAAAccessInfo(ResultExprTy));
+  return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
 }
 
 LValue CodeGenFunction::
 EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
   // Emit the base vector as an l-value.
   LValue Base;
 
   // ExtVectorElementExpr's base can either be a vector or pointer to vector.