Struct-path aware TBAA: uniformize scalar tag and path tag.
For struct-path aware TBAA, we used to use scalar type node as the scalar tag,
which has an incompatible format with the struct path tag. We now use the same
format: base type, access type and offset.
We also uniformize the scalar type node and the struct type node: name, a list
of pairs (offset + pointer to MDNode). For scalar type, we have a single pair.
These are to make implementaiton of aliasing rules easier.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179335 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CodeGenTBAA.h b/lib/CodeGen/CodeGenTBAA.h
index 9ddc3aa..f0c9e06 100644
--- a/lib/CodeGen/CodeGenTBAA.h
+++ b/lib/CodeGen/CodeGenTBAA.h
@@ -61,6 +61,8 @@
llvm::DenseMap<const Type *, llvm::MDNode *> StructTypeMetadataCache;
/// This maps TBAAPathTags to a tag node.
llvm::DenseMap<TBAAPathTag, llvm::MDNode *> StructTagMetadataCache;
+ /// This maps a scalar type to a scalar tag node.
+ llvm::DenseMap<const llvm::MDNode *, llvm::MDNode *> ScalarTagMetadataCache;
/// StructMetadataCache - This maps clang::Types to llvm::MDNodes describing
/// them for struct assignments.
@@ -84,6 +86,11 @@
SmallVectorImpl<llvm::MDBuilder::TBAAStructField> &Fields,
bool MayAlias);
+ /// A wrapper function to create a scalar type. For struct-path aware TBAA,
+ /// the scalar type has the same format as the struct type: name, offset,
+ /// pointer to another node in the type DAG.
+ llvm::MDNode *createTBAAScalarType(StringRef Name, llvm::MDNode *Parent);
+
public:
CodeGenTBAA(ASTContext &Ctx, llvm::LLVMContext &VMContext,
const CodeGenOptions &CGO,
@@ -105,10 +112,13 @@
/// Get the MDNode in the type DAG for given struct type QType.
llvm::MDNode *getTBAAStructTypeInfo(QualType QType);
- /// Get the tag MDNode for a given base type, the actual sclar access MDNode
+ /// Get the tag MDNode for a given base type, the actual scalar access MDNode
/// and offset into the base type.
llvm::MDNode *getTBAAStructTagInfo(QualType BaseQType,
llvm::MDNode *AccessNode, uint64_t Offset);
+
+ /// Get the sclar tag MDNode for a given scalar type.
+ llvm::MDNode *getTBAAScalarTagInfo(llvm::MDNode *AccessNode);
};
} // end namespace CodeGen