Index: include/polly/TempScopInfo.h
===================================================================
--- include/polly/TempScopInfo.h
+++ include/polly/TempScopInfo.h
@@ -42,7 +42,8 @@
   // The type of the scev affine function
   enum TypeKind {
     READ = 0x1,
-    WRITE = 0x2,
+    MUST_WRITE = 0x2,
+    MAY_WRITE = 0x3,
   };
 
 private:
@@ -72,7 +73,9 @@
 
   bool isRead() const { return Type == READ; }
 
-  bool isWrite() const { return Type == WRITE; }
+  bool isWrite() const { return Type == MUST_WRITE; }
+
+  bool isMayWrite() const { return Type == MAY_WRITE; }
 
   bool isScalar() const { return Subscripts.size() == 0; }
 
Index: lib/Analysis/ScopInfo.cpp
===================================================================
--- lib/Analysis/ScopInfo.cpp
+++ lib/Analysis/ScopInfo.cpp
@@ -330,6 +330,18 @@
   isl_map_free(newAccessRelation);
 }
 
+static MemoryAccess::AccessType getMemoryAccessType(const IRAccess &Access) {
+  switch (Access.getType()) {
+  case IRAccess::READ:
+    return MemoryAccess::READ;
+  case IRAccess::MUST_WRITE:
+    return MemoryAccess::MUST_WRITE;
+  case IRAccess::MAY_WRITE:
+    return MemoryAccess::MAY_WRITE;
+  }
+  llvm_unreachable("Unknown IRAccess type!");
+}
+
 isl_id *MemoryAccess::getArrayId() const {
   return isl_map_get_tuple_id(AccessRelation, isl_dim_out);
 }
@@ -416,7 +428,8 @@
 
 MemoryAccess::MemoryAccess(const IRAccess &Access, Instruction *AccInst,
                            ScopStmt *Statement)
-    : Statement(Statement), Inst(AccInst), newAccessRelation(nullptr) {
+    : Type(getMemoryAccessType(Access)), Statement(Statement), Inst(AccInst),
+      newAccessRelation(nullptr) {
 
   isl_ctx *Ctx = Statement->getIslCtx();
   BaseAddr = Access.getBase();
@@ -431,12 +444,9 @@
     AccessRelation = isl_map_from_basic_map(createBasicAccessMap(Statement));
     AccessRelation =
         isl_map_set_tuple_id(AccessRelation, isl_dim_out, BaseAddrId);
-    Type = Access.isRead() ? READ : MAY_WRITE;
     return;
   }
 
-  Type = Access.isRead() ? READ : MUST_WRITE;
-
   isl_space *Space = isl_space_alloc(Ctx, 0, Statement->getNumIterators(), 0);
   AccessRelation = isl_map_universe(Space);
 
Index: lib/Analysis/TempScopInfo.cpp
===================================================================
--- lib/Analysis/TempScopInfo.cpp
+++ lib/Analysis/TempScopInfo.cpp
@@ -41,9 +41,11 @@
 void IRAccess::print(raw_ostream &OS) const {
   if (isRead())
     OS << "Read ";
-  else
+  else {
+    if (isMayWrite())
+      OS << "May";
     OS << "Write ";
-
+  }
   OS << BaseAddress->getName() << '[' << *Offset << "]\n";
 }
 
@@ -160,7 +162,7 @@
     StoreInst *Store = cast<StoreInst>(Inst);
     SizeType = Store->getValueOperand()->getType();
     Size = TD->getTypeStoreSize(SizeType);
-    Type = IRAccess::WRITE;
+    Type = IRAccess::MUST_WRITE;
   }
 
   const SCEV *AccessFunction = SE->getSCEVAtScope(getPointerOperand(*Inst), L);
@@ -178,6 +180,9 @@
 
   bool IsAffine = isAffineExpr(R, AccessFunction, *SE, BasePointer->getValue());
   Subscripts.push_back(AccessFunction);
+  if (!IsAffine && Type == IRAccess::MUST_WRITE)
+    Type = IRAccess::MAY_WRITE;
+
   Sizes.push_back(SE->getConstant(ZeroOffset->getType(), Size));
   return IRAccess(Type, BasePointer->getValue(), AccessFunction, Size, IsAffine,
                   Subscripts, Sizes);
@@ -196,7 +201,7 @@
       // If the Instruction is used outside the statement, we need to build the
       // write access.
       SmallVector<const SCEV *, 4> Subscripts, Sizes;
-      IRAccess ScalarAccess(IRAccess::WRITE, Inst, ZeroOffset, 1, true,
+      IRAccess ScalarAccess(IRAccess::MUST_WRITE, Inst, ZeroOffset, 1, true,
                             Subscripts, Sizes);
       Functions.push_back(std::make_pair(ScalarAccess, Inst));
     }