From e62307421053f527e2837e7a4d1d3c246b39303f Mon Sep 17 00:00:00 2001
From: Marshall Clow <mclow.lists@gmail.com>
Date: Tue, 2 Jun 2015 13:04:18 +0000
Subject: [PATCH] In the case where we are copying/moving zero elements, do
 less work

llvm-svn: 238828
---
 libcxx/include/memory | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/libcxx/include/memory b/libcxx/include/memory
index 6f3fdd5..4e3a6f8 100644
--- a/libcxx/include/memory
+++ b/libcxx/include/memory
@@ -1522,8 +1522,10 @@ struct _LIBCPP_TYPE_VIS_ONLY allocator_traits
         {
             ptrdiff_t _Np = __end1 - __begin1;
             if (_Np > 0)
+            {
                 _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
-            __begin2 += _Np;
+                __begin2 += _Np;
+            }
         }
 
     template <class _Iter, class _Ptr>
@@ -1551,8 +1553,10 @@ struct _LIBCPP_TYPE_VIS_ONLY allocator_traits
             typedef typename remove_const<_Tp>::type _Vp;
             ptrdiff_t _Np = __end1 - __begin1;
             if (_Np > 0)
+            {
                 _VSTD::memcpy(const_cast<_Vp*>(__begin2), __begin1, _Np * sizeof(_Tp));
-            __begin2 += _Np;
+                __begin2 += _Np;
+            }
         }
 
     template <class _Ptr>
-- 
2.7.4