teach PointerLikeTypeTraits that all pointers to pointers may only be 4-byte aligned.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68147 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 0 deletions

diff --git a/include/llvm/Support/PointerLikeTypeTraits.h b/include/llvm/Support/PointerLikeTypeTraits.h
index c5f79ccb83..226dacf361 100644
--- a/include/llvm/Support/PointerLikeTypeTraits.h
+++ b/include/llvm/Support/PointerLikeTypeTraits.h
@@ -58,6 +58,20 @@ public:
   enum { NumLowBitsAvailable = 3 };
 };
 
+// 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> {