Index: libcxx/include/memory
===================================================================
--- libcxx/include/memory
+++ libcxx/include/memory
@@ -3908,6 +3908,52 @@
 
     template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
     template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
+
+    template<class _Yp, class _Deleter = default_delete<_Yp>,
+                        class _Alloc = typename __shared_ptr_default_allocator<_Yp>::type>
+    static __shared_weak_count*
+    __allocate_shared(_Yp* __p, _Deleter __d = _Deleter(), _Alloc __a = _Alloc())
+    {
+        try {
+            typedef __shared_ptr_pointer<_Yp*, _Deleter, _Alloc> _CT;
+            typedef typename __allocator_traits_rebind<_Alloc, _CT>::type _A2;
+            typedef __allocator_destructor<_A2> _D2;
+
+            _A2 __a2(__a);
+            unique_ptr<_CT, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
+
+            ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
+                _CT(__p, __d, __a);
+
+            return _VSTD::addressof(*__hold2.release());
+        } catch (...) {
+            __d(__p);
+            throw;
+        }
+    }
+
+    template<class _Deleter = default_delete<_Tp>,
+             class _Alloc = typename __shared_ptr_default_allocator<_Tp>::type>
+    static __shared_weak_count*
+    __allocate_shared(nullptr_t __p, _Deleter __d = _Deleter(), _Alloc __a = _Alloc())
+    {
+        try {
+            typedef __shared_ptr_pointer<_Tp*, _Deleter, _Alloc> _CT;
+            typedef typename __allocator_traits_rebind<_Alloc, _CT>::type _A2;
+            typedef __allocator_destructor<_A2> _D2;
+
+            _A2 __a2(__a);
+            unique_ptr<_CT, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
+
+            ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
+                _CT(__p, __d, __a);
+
+            return _VSTD::addressof(*__hold2.release());
+        } catch (...) {
+            __d(__p);
+            throw;
+        }
+    }
 };
 
 
@@ -3916,30 +3962,22 @@
 _LIBCPP_CONSTEXPR
 shared_ptr<_Tp>::shared_ptr() _NOEXCEPT
     : __ptr_(0),
-      __cntrl_(0)
-{
-}
+      __cntrl_(0) {}
 
 template<class _Tp>
 inline
 _LIBCPP_CONSTEXPR
 shared_ptr<_Tp>::shared_ptr(nullptr_t) _NOEXCEPT
     : __ptr_(0),
-      __cntrl_(0)
-{
-}
+      __cntrl_(0) {}
 
 template<class _Tp>
 template<class _Yp>
 shared_ptr<_Tp>::shared_ptr(_Yp* __p,
                             typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
-    : __ptr_(__p)
+    : __ptr_(__p),
+      __cntrl_(__allocate_shared(__p))
 {
-    unique_ptr<_Yp> __hold(__p);
-    typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
-    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, _AllocT > _CntrlBlk;
-    __cntrl_ = new _CntrlBlk(__p, default_delete<_Yp>(), _AllocT());
-    __hold.release();
     __enable_weak_this(__p, __p);
 }
 
@@ -3947,103 +3985,33 @@
 template<class _Yp, class _Dp>
 shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d,
                             typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
-    : __ptr_(__p)
+    : __ptr_(__p),
+      __cntrl_(__allocate_shared(__p, __d))
 {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
-        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
-        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
-        __enable_weak_this(__p, __p);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __d(__p);
-        throw;
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
+    __enable_weak_this(__p, __p);
 }
 
 template<class _Tp>
 template<class _Dp>
 shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d)
-    : __ptr_(0)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT;
-        typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT > _CntrlBlk;
-        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __d(__p);
-        throw;
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
+    : __ptr_(0),
+      __cntrl_(__allocate_shared(__p, __d)) {}
 
 template<class _Tp>
 template<class _Yp, class _Dp, class _Alloc>
 shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
                             typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
-    : __ptr_(__p)
+    : __ptr_(__p),
+      __cntrl_(__allocate_shared(__p, __d, __a))
 {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
-        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
-        typedef __allocator_destructor<_A2> _D2;
-        _A2 __a2(__a);
-        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
-        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
-            _CntrlBlk(__p, __d, __a);
-        __cntrl_ = _VSTD::addressof(*__hold2.release());
-        __enable_weak_this(__p, __p);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __d(__p);
-        throw;
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
+    __enable_weak_this(__p, __p);
 }
 
 template<class _Tp>
 template<class _Dp, class _Alloc>
 shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a)
-    : __ptr_(0)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
-        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
-        typedef __allocator_destructor<_A2> _D2;
-        _A2 __a2(__a);
-        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
-        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
-            _CntrlBlk(__p, __d, __a);
-        __cntrl_ = _VSTD::addressof(*__hold2.release());
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __d(__p);
-        throw;
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
+    : __ptr_(0),
+      __cntrl_(__allocate_shared(__p, __d, __a)) {}
 
 template<class _Tp>
 template<class _Yp>