remove duplicated code

Author: poor-circle

libcxx/include/__memory/align.h

@@ -19,13 +19,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#ifdef _LIBCPP_ALIGN_DEFINE_LEGACY_INLINE_FUNCTIONS
-
-_LIBCPP_EXPORTED_FROM_ABI void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
-
-#else
-
-inline _LIBCPP_HIDE_FROM_ABI void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space) {
+__attribute__((always_inline)) inline void* __align_impl(size_t __align, size_t __sz, void*& __ptr, size_t& __space) {
   void* __r = nullptr;
   if (__sz <= __space) {
     char* __p1 = static_cast<char*>(__ptr);
@@ -40,6 +34,16 @@ inline _LIBCPP_HIDE_FROM_ABI void* align(size_t __align, size_t __sz, void*& __p
   return __r;
 }
 
+#ifdef _LIBCPP_ALIGN_DEFINE_LEGACY_INLINE_FUNCTIONS
+
+_LIBCPP_EXPORTED_FROM_ABI void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
+
+#else
+
+inline _LIBCPP_HIDE_FROM_ABI void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space) {
+  return __align_impl(__align, __sz, __ptr, __space);
+}
+
 #endif // _LIBCPP_ALIGN_DEFINE_LEGACY_INLINE_FUNCTIONS
 
 _LIBCPP_END_NAMESPACE_STD

libcxx/src/memory.cpp

@@ -136,18 +136,7 @@ __sp_mut& __get_sp_mut(const void* p) {
 #if defined(_LIBCPP_ALIGN_DEFINE_LEGACY_INLINE_FUNCTIONS)
 
 void* align(size_t alignment, size_t size, void*& ptr, size_t& space) {
-  void* r = nullptr;
-  if (size <= space) {
-    char* p1 = static_cast<char*>(ptr);
-    char* p2 = reinterpret_cast<char*>(reinterpret_cast<uintptr_t>(p1 + (alignment - 1)) & -alignment);
-    size_t d = static_cast<size_t>(p2 - p1);
-    if (d <= space - size) {
-      r   = p2;
-      ptr = r;
-      space -= d;
-    }
-  }
-  return r;
+  return __align_impl(alignment, size, ptr, space);
 }
 #endif // _LIBCPP_ALIGN_DEFINE_LEGACY_INLINE_FUNCTIONS