diff --git a/libstdc++-v3/include/bits/stl_algo.h b/libstdc++-v3/include/bits/stl_algo.h
index d8488a7..bf5b25f 100644
--- a/libstdc++-v3/include/bits/stl_algo.h
+++ b/libstdc++-v3/include/bits/stl_algo.h
@@ -1577,15 +1577,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	}
 
       _ForwardIterator __middle = __first;
-      std::advance(__middle, __len / 2);
+      std::advance(__middle, __buffer_size);
       _ForwardIterator __left_split =
-	std::__stable_partition_adaptive(__first, __middle, __pred,
-					 __len / 2, __buffer,
-					 __buffer_size);
+	std::__stable_partition_adaptive(__first, __middle,
+					 __pred, __buffer_size,
+					 __buffer, __buffer_size);
 
       // Advance past true-predicate values to satisfy this
       // function's preconditions.
-      _Distance __right_len = __len - __len / 2;
+      _Distance __right_len = __len - __buffer_size;
       _ForwardIterator __right_split =
 	std::__find_if_not_n(__middle, __right_len, __pred);
 
@@ -2432,9 +2432,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	  _BidirectionalIterator __second_cut = __middle;
 	  _Distance __len11 = 0;
 	  _Distance __len22 = 0;
-	  if (__len1 > __len2)
+	  if (__len1 < __len2)
 	    {
-	      __len11 = __len1 / 2;
+	      __len11 = __buffer_size;
 	      std::advance(__first_cut, __len11);
 	      __second_cut
 		= std::__lower_bound(__middle, __last, *__first_cut,
@@ -2443,7 +2443,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	    }
 	  else
 	    {
-	      __len22 = __len2 / 2;
+	      __len22 = __buffer_size;
 	      std::advance(__second_cut, __len22);
 	      __first_cut
 		= std::__upper_bound(__first, __middle, *__second_cut,
@@ -2453,14 +2453,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 	  _BidirectionalIterator __new_middle
 	    = std::__rotate_adaptive(__first_cut, __middle, __second_cut,
-				     __len1 - __len11, __len22, __buffer,
-				     __buffer_size);
-	  std::__merge_adaptive(__first, __first_cut, __new_middle, __len11,
-				__len22, __buffer, __buffer_size, __comp);
+				     __len1 - __len11, __len22,
+				     __buffer, __buffer_size);
+	  std::__merge_adaptive(__first, __first_cut, __new_middle,
+				__len11, __len22,
+				__buffer, __buffer_size, __comp);
 	  std::__merge_adaptive(__new_middle, __second_cut, __last,
-				__len1 - __len11,
-				__len2 - __len22, __buffer,
-				__buffer_size, __comp);
+				__len1 - __len11, __len2 - __len22,
+				__buffer, __buffer_size, __comp);
 	}
     }
 
@@ -2535,7 +2535,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       const _DistanceType __len2 = std::distance(__middle, __last);
 
       typedef _Temporary_buffer<_BidirectionalIterator, _ValueType> _TmpBuf;
-      _TmpBuf __buf(__first, __len1 + __len2);
+      _TmpBuf __buf(__first, std::min(__len1, __len2));
 
       if (__buf.begin() == 0)
 	std::__merge_without_buffer
@@ -2730,9 +2730,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 			   _Compare __comp)
     {
       const _Distance __len = (__last - __first + 1) / 2;
-      const _RandomAccessIterator __middle = __first + __len;
+      _RandomAccessIterator __middle;
       if (__len > __buffer_size)
 	{
+	  __middle = __first + __buffer_size + __buffer_size;
 	  std::__stable_sort_adaptive(__first, __middle, __buffer,
 				      __buffer_size, __comp);
 	  std::__stable_sort_adaptive(__middle, __last, __buffer,
@@ -2740,9 +2741,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	}
       else
 	{
+	  __middle = __first + __len;
 	  std::__merge_sort_with_buffer(__first, __middle, __buffer, __comp);
 	  std::__merge_sort_with_buffer(__middle, __last, __buffer, __comp);
 	}
+
       std::__merge_adaptive(__first, __middle, __last,
 			    _Distance(__middle - __first),
 			    _Distance(__last - __middle),
@@ -4992,8 +4995,11 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
       typedef typename iterator_traits<_RandomAccessIterator>::difference_type
 	_DistanceType;
 
+      if (__first == __last)
+	return;
+
       typedef _Temporary_buffer<_RandomAccessIterator, _ValueType> _TmpBuf;
-      _TmpBuf __buf(__first, std::distance(__first, __last));
+      _TmpBuf __buf(__first, (__last - __first + 1) / 2);
 
       if (__buf.begin() == 0)
 	std::__inplace_stable_sort(__first, __last, __comp);
diff --git a/libstdc++-v3/include/bits/stl_tempbuf.h b/libstdc++-v3/include/bits/stl_tempbuf.h
index 159ee27..7fb97d0 100644
--- a/libstdc++-v3/include/bits/stl_tempbuf.h
+++ b/libstdc++-v3/include/bits/stl_tempbuf.h
@@ -95,7 +95,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 							std::nothrow));
 	  if (__tmp != 0)
 	    return std::pair<_Tp*, ptrdiff_t>(__tmp, __len);
-	  __len /= 2;
+	  __len = __len == 1 ? 0 : ((__len + 1) / 2);
 	}
       return std::pair<_Tp*, ptrdiff_t>(static_cast<_Tp*>(0), 0);
     }