Taints the non-acquire RMW's store address with the load part

[oota-llvm.git] / include / llvm / Support / PointerLikeTypeTraits.h

diff --git a/include/llvm/Support/PointerLikeTypeTraits.h b/include/llvm/Support/PointerLikeTypeTraits.h
index 226dacf36118bf69b0ce185e1a2be9c902eee3b6..c12d237b2796a015633305d789240850c95ebf51 100644 (file)
--- a/include/llvm/Support/PointerLikeTypeTraits.h
+++ b/include/llvm/Support/PointerLikeTypeTraits.h
@@ -15,69 +15,70 @@
 #ifndef LLVM_SUPPORT_POINTERLIKETYPETRAITS_H
 #define LLVM_SUPPORT_POINTERLIKETYPETRAITS_H
 
+#include "llvm/Support/AlignOf.h"
 #include "llvm/Support/DataTypes.h"
 
 namespace llvm {
-  
-/// PointerLikeTypeTraits - This is a traits object that is used to handle
-/// pointer types and things that are just wrappers for pointers as a uniform
-/// entity.
-template <typename T>
-class PointerLikeTypeTraits {
+
+/// A traits type that is used to handle pointer types and things that are just
+/// wrappers for pointers as a uniform entity.
+template <typename T> class PointerLikeTypeTraits {
   // getAsVoidPointer
   // getFromVoidPointer
   // getNumLowBitsAvailable
 };
 
+namespace detail {
+/// A tiny meta function to compute the log2 of a compile time constant.
+template <size_t N>
+struct ConstantLog2
+    : std::integral_constant<size_t, ConstantLog2<N / 2>::value + 1> {};
+template <> struct ConstantLog2<1> : std::integral_constant<size_t, 0> {};
+}
+
 // Provide PointerLikeTypeTraits for non-cvr pointers.
-template<typename T>
-class PointerLikeTypeTraits<T*> {
-public:
-  static inline void *getAsVoidPointer(T* P) { return P; }
-  static inline T *getFromVoidPointer(void *P) {
-    return static_cast<T*>(P);
-  }
-  
-  /// Note, we assume here that malloc returns objects at least 8-byte aligned.
-  /// However, this may be wrong, or pointers may be from something other than
-  /// malloc.  In this case, you should specialize this template to reduce this.
+template <typename T> struct PointerLikeTypeTraits<T *> {
+  static inline void *getAsVoidPointer(T *P) { return P; }
+  static inline T *getFromVoidPointer(void *P) { return static_cast<T *>(P); }
+
+  enum {
+    NumLowBitsAvailable = detail::ConstantLog2<AlignOf<T>::Alignment>::value
+  };
+};
+
+template <> struct PointerLikeTypeTraits<void *> {
+  static inline void *getAsVoidPointer(void *P) { return P; }
+  static inline void *getFromVoidPointer(void *P) { return P; }
+
+  /// Note, we assume here that void* is related to raw malloc'ed memory and
+  /// that malloc returns objects at least 4-byte aligned. However, this may be
+  /// wrong, or pointers may be from something other than malloc. In this case,
+  /// you should specify a real typed pointer or avoid this template.
   ///
   /// All clients should use assertions to do a run-time check to ensure that
   /// this is actually true.
-  enum { NumLowBitsAvailable = 3 };
+  enum { NumLowBitsAvailable = 2 };
 };
-  
+
 // Provide PointerLikeTypeTraits for const pointers.
-template<typename T>
-class PointerLikeTypeTraits<const T*> {
+template <typename T> class PointerLikeTypeTraits<const T *> {
+  typedef PointerLikeTypeTraits<T *> NonConst;
+
 public:
-  static inline const void *getAsVoidPointer(const T* P) { return P; }
+  static inline const void *getAsVoidPointer(const T *P) {
+    return NonConst::getAsVoidPointer(const_cast<T *>(P));
+  }
   static inline const T *getFromVoidPointer(const void *P) {
-    return static_cast<const T*>(P);
+    return NonConst::getFromVoidPointer(const_cast<void *>(P));
   }
-  enum { NumLowBitsAvailable = 3 };
+  enum { NumLowBitsAvailable = NonConst::NumLowBitsAvailable };
 };
 
-// Pointers to pointers are only 4-byte aligned on 32-bit systems.
-template<typename T>
-class PointerLikeTypeTraits<T**> {
-public:
-  static inline void *getAsVoidPointer(T** P) { return P; }
-  static inline T **getFromVoidPointer(void *P) {
-    return static_cast<T**>(P);
-  }
-  enum { NumLowBitsAvailable = 2 };
-};
-  
-  
-  
-  
 // Provide PointerLikeTypeTraits for uintptr_t.
-template<>
-class PointerLikeTypeTraits<uintptr_t> {
+template <> class PointerLikeTypeTraits<uintptr_t> {
 public:
   static inline void *getAsVoidPointer(uintptr_t P) {
-    return reinterpret_cast<void*>(P);
+    return reinterpret_cast<void *>(P);
   }
   static inline uintptr_t getFromVoidPointer(void *P) {
     return reinterpret_cast<uintptr_t>(P);
@@ -85,7 +86,7 @@ public:
   // No bits are available!
   enum { NumLowBitsAvailable = 0 };
 };
-  
+
 } // end namespace llvm
 
 #endif