Provide a specialization of _Alloc_traits, which allows the G++ runtime to avoid

storing an instance of the allocator in each data structure it uses.  Yaay.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9795 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 26 insertions, 4 deletions

diff --git a/include/Support/MallocAllocator.h b/include/Support/MallocAllocator.h
index e063f31..1ba25b0 100644
--- a/include/Support/MallocAllocator.h
+++ b/include/Support/MallocAllocator.h
@@ -44,11 +44,11 @@ struct MallocAllocator {
   const_pointer address(const_reference x) const { return &x; }
   size_type max_size() const { return ~0 / sizeof(T); }
   
-  pointer allocate(size_t n, void* hint = 0) {
+  static pointer allocate(size_t n, void* hint = 0) {
     return (pointer)malloc(n*sizeof(T));
   }
 
-  void deallocate(pointer p, size_t n) {
+  static void deallocate(pointer p, size_t n) {
     free((void*)p);
   }
 
@@ -69,4 +69,15 @@ inline bool operator!=(const MallocAllocator<T>&, const MallocAllocator<T>&) {
   return false;
 }
 
+namespace std {
+  template<typename Type, typename Type2>
+  struct _Alloc_traits<Type, ::MallocAllocator<Type2> > {
+    static const bool _S_instanceless = true;
+    typedef ::MallocAllocator<Type> base_alloc_type;
+    typedef ::MallocAllocator<Type> _Alloc_type;
+    typedef ::MallocAllocator<Type> allocator_type;
+  };
+}
+
+
 #endif
diff --git a/include/llvm/Support/MallocAllocator.h b/include/llvm/Support/MallocAllocator.h
index e063f31..1ba25b0 100644
--- a/include/llvm/Support/MallocAllocator.h
+++ b/include/llvm/Support/MallocAllocator.h
@@ -44,11 +44,11 @@ struct MallocAllocator {
   const_pointer address(const_reference x) const { return &x; }
   size_type max_size() const { return ~0 / sizeof(T); }
   
-  pointer allocate(size_t n, void* hint = 0) {
+  static pointer allocate(size_t n, void* hint = 0) {
     return (pointer)malloc(n*sizeof(T));
   }
 
-  void deallocate(pointer p, size_t n) {
+  static void deallocate(pointer p, size_t n) {
     free((void*)p);
   }
 
@@ -69,4 +69,15 @@ inline bool operator!=(const MallocAllocator<T>&, const MallocAllocator<T>&) {
   return false;
 }
 
+namespace std {
+  template<typename Type, typename Type2>
+  struct _Alloc_traits<Type, ::MallocAllocator<Type2> > {
+    static const bool _S_instanceless = true;
+    typedef ::MallocAllocator<Type> base_alloc_type;
+    typedef ::MallocAllocator<Type> _Alloc_type;
+    typedef ::MallocAllocator<Type> allocator_type;
+  };
+}
+
+
 #endif