diff mbox series

lexicographical_comparison enhancements

Message ID e2cc3c44-ae5a-1a78-e236-b6f0e99de140@gmail.com
State New
Headers show
Series lexicographical_comparison enhancements | expand

Commit Message

François Dumont Sept. 16, 2019, 7:57 p.m. UTC
Hi

This is the next part of:

https://gcc.gnu.org/ml/libstdc++/2019-09/msg00048.html

This time it is to improve behavior of std::lexicographical_compare for 
deque or safe iterators.

To do so I had to make lc internal implementation return int rather than 
bool otherwise it is impossible to have a chunk base approach for the 
deque iterators. I'm surprised that std::lexicographical_compare returns 
a bool by the way, usually comparisons return int.

Tested under Linux x86_64 normal and debug modes.

Ok to commit ?


     * include/bits/stl_algobase.h
     (__lexicographical_compare_impl): Return int.
     (__lexicographical_compare::__lc): Likewise.
     (__lexicographical_compare_aux1(_II1, _II1, _II2, _II2)): New.
     (__lexicographical_compare_aux1(_Deque_iterator<>, _Deque_iterator<>,
     _II2, _II2)): New.
     (__lexicographical_compare_aux1(_II1, _II1,
     _Deque_iterator<>, _Deque_iterator<>)): New.
     (__lexicographical_compare_aux1(_Deque_iterator<>, _Deque_iterator<>,
     _Deque_iterator<>, _Deque_iterator<>)): New.
     (__lexicographical_compare_aux): Adapt, call later.
     (__lexicographical_compare_aux(_Safe_iterator<>, _Safe_iterator<>,
     _II2, _II2)): New.
     (__lexicographical_compare_aux(_II1, _II1,
     _Safe_iterator<>, _Safe_iterator<>)): New.
     (__lexicographical_compare_aux(_Safe_iterator<>, _Safe_iterator<>,
     _Safe_iterator<>, _Safe_iterator<>)): New.
     (std::lexicographical_compare): Adapt, call later.
     * include/bits/stl_deque.h (__lexicographical_compare_aux1): New
     declarations.
     * include/bits/deque.tcc (__lex_cmp_dit): New.
     (__lexicographical_compare_aux1): New definitions.
     * include/debug/safe_iterator.h (__lexicographical_compare_aux): New.
     * testsuite/25_algorithms/lexicographical_compare/1.cc (test6, test7):
     New.
     * testsuite/25_algorithms/lexicographical_compare/deque_iterators/1.cc:
     New.

François
diff mbox series

Patch

diff --git a/libstdc++-v3/include/bits/deque.tcc b/libstdc++-v3/include/bits/deque.tcc
index ab996ca52fa..db8f1b03eec 100644
--- a/libstdc++-v3/include/bits/deque.tcc
+++ b/libstdc++-v3/include/bits/deque.tcc
@@ -1208,6 +1208,98 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
       return true;
     }
 
+  template<typename _Tp, typename _Ref, typename _Ptr, typename _II>
+    int
+    __lex_cmp_dit(
+	const _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>& __first1,
+	const _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>& __last1,
+	_II __first2, _II __last2)
+    {
+      typedef _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr> _Iter;
+      typedef typename _Iter::difference_type difference_type;
+
+      if (__first1._M_node != __last1._M_node)
+	{
+	  difference_type __len = __last2 - __first2;
+	  difference_type __flen
+	    = std::min(__len, __first1._M_last - __first1._M_cur);
+	  if (int __ret = std::__lexicographical_compare_aux1(
+	      __first1._M_cur, __first1._M_last, __first2, __first2 + __flen))
+	    return __ret;
+
+	  __first2 += __flen;
+	  __len -= __flen;
+	  __flen = std::min<size_t>(__len, _Iter::_S_buffer_size());
+	  for (typename _Iter::_Map_pointer __node = __first1._M_node + 1;
+	       __node != __last1._M_node;
+	       __first2 += __flen, __len -= __flen,
+	       __flen = std::min<size_t>(__len, _Iter::_S_buffer_size()),
+	       ++__node)
+	    if (int __ret = std::__lexicographical_compare_aux1(
+		  *__node, *__node + _Iter::_S_buffer_size(),
+		  __first2, __first2 + __flen))
+	      return __ret;
+
+	  return std::__lexicographical_compare_aux1(
+	    __last1._M_first, __last1._M_cur, __first2, __last2);
+	}
+
+      return std::__lexicographical_compare_aux1(
+	      __first1._M_cur, __last1._M_cur, __first2, __last2);
+    }
+
+  template<typename _Tp1, typename _Ref1, typename _Ptr1,
+	   typename _II2>
+    typename __gnu_cxx::__enable_if<
+      __is_random_access_iter<_II2>::__value, int>::__type
+    __lexicographical_compare_aux1(
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1> __first1,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1> __last1,
+		_II2 __first2, _II2 __last2)
+    { return std::__lex_cmp_dit(__first1, __last1, __first2, __last2); }
+
+  template<typename _Tp1, typename _Ref1, typename _Ptr1,
+	   typename _Tp2, typename _Ref2, typename _Ptr2>
+    int
+    __lexicographical_compare_aux1(
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1> __first1,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1> __last1,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2> __first2,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2> __last2)
+    { return std::__lex_cmp_dit(__first1, __last1, __first2, __last2); }
+
+  template<typename _II1,
+	   typename _Tp2, typename _Ref2, typename _Ptr2>
+    typename __gnu_cxx::__enable_if<
+      __is_random_access_iter<_II1>::__value, int>::__type
+    __lexicographical_compare_aux1(
+		_II1 __first1, _II1 __last1,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2> __first2,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2> __last2)
+    {
+      typedef _GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2> _Iter;
+      typedef typename _Iter::difference_type difference_type;
+
+      difference_type __len = __last1 - __first1;
+      while (__len > 0)
+	{
+	  const difference_type __flen = __first2._M_node == __last2._M_node
+	    ? __last2._M_cur - __first2._M_cur
+	    : __first2._M_last - __first2._M_cur;
+	  const difference_type __clen = std::min(__len, __flen);
+	  if (int __ret = std::__lexicographical_compare_aux1(
+				__first1, __first1 + __clen,
+				__first2._M_cur, __first2._M_cur + __flen))
+	    return __ret;
+
+	  __first1 += __clen;
+	  __len -= __clen;
+	  __first2 += __clen;
+	}
+
+      return __first1 == __last1 ? (__first2 != __last2 ? -1 : 0) : 1;
+    }
+
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std
 
diff --git a/libstdc++-v3/include/bits/stl_algobase.h b/libstdc++-v3/include/bits/stl_algobase.h
index a165f299a71..4eba053ac75 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -1250,7 +1250,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
 
   template<typename _II1, typename _II2, typename _Compare>
     _GLIBCXX20_CONSTEXPR
-    bool
+    int
     __lexicographical_compare_impl(_II1 __first1, _II1 __last1,
 				   _II2 __first2, _II2 __last2,
 				   _Compare __comp)
@@ -1259,16 +1259,18 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
       typedef typename iterator_traits<_II2>::iterator_category _Category2;
       typedef std::__lc_rai<_Category1, _Category2> __rai_type;
 
-      __last1 = __rai_type::__newlast1(__first1, __last1, __first2, __last2);
-      for (; __first1 != __last1 && __rai_type::__cnd2(__first2, __last2);
+      _II1 __new_last1
+	= __rai_type::__newlast1(__first1, __last1, __first2, __last2);
+      for (; __first1 != __new_last1 && __rai_type::__cnd2(__first2, __last2);
 	   ++__first1, (void)++__first2)
 	{
 	  if (__comp(__first1, __first2))
-	    return true;
+	    return -1;
 	  if (__comp(__first2, __first1))
-	    return false;
+	    return 1;
 	}
-      return __first1 == __last1 && __first2 != __last2;
+
+      return __first1 == __last1 ? (__first2 != __last2 ? -1 : 0) : 1;
     }
 
   template<bool _BoolType>
@@ -1276,13 +1278,13 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
     {
       template<typename _II1, typename _II2>
 	_GLIBCXX20_CONSTEXPR
-	static bool __lc(_II1, _II1, _II2, _II2);
+	static int __lc(_II1, _II1, _II2, _II2);
     };
 
   template<bool _BoolType>
     template<typename _II1, typename _II2>
       _GLIBCXX20_CONSTEXPR
-      bool
+      int
       __lexicographical_compare<_BoolType>::
       __lc(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2)
       {
@@ -1296,7 +1298,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
     {
       template<typename _Tp, typename _Up>
 	_GLIBCXX20_CONSTEXPR
-	static bool
+	static int
 	__lc(const _Tp* __first1, const _Tp* __last1,
 	     const _Up* __first2, const _Up* __last2)
 	{
@@ -1304,16 +1306,44 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
 	  const size_t __len2 = __last2 - __first2;
 	  if (const size_t __len = std::min(__len1, __len2))
 	    if (int __result = std::__memcmp(__first1, __first2, __len))
-	      return __result < 0;
-	  return __len1 < __len2;
+	      return __result;
+
+	  return __len1 < __len2 ? -1 : (__len2 < __len1 ? 1 : 0);
 	}
     };
 
+  template<typename _Tp1, typename _Ref1, typename _Ptr1,
+	   typename _II2>
+    typename __gnu_cxx::__enable_if<
+      __is_random_access_iter<_II2>::__value, int>::__type
+    __lexicographical_compare_aux1(
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
+		_II2, _II2);
+
+  template<typename _II1,
+	   typename _Tp2, typename _Ref2, typename _Ptr2>
+    typename __gnu_cxx::__enable_if<
+      __is_random_access_iter<_II1>::__value, int>::__type
+    __lexicographical_compare_aux1(
+		_II1, _II1,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
+
+  template<typename _Tp1, typename _Ref1, typename _Ptr1,
+	   typename _Tp2, typename _Ref2, typename _Ptr2>
+    int
+    __lexicographical_compare_aux1(
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
+
   template<typename _II1, typename _II2>
     _GLIBCXX20_CONSTEXPR
-    inline bool
-    __lexicographical_compare_aux(_II1 __first1, _II1 __last1,
-				  _II2 __first2, _II2 __last2)
+    inline int
+    __lexicographical_compare_aux1(_II1 __first1, _II1 __last1,
+				   _II2 __first2, _II2 __last2)
     {
       typedef typename iterator_traits<_II1>::value_type _ValueType1;
       typedef typename iterator_traits<_II2>::value_type _ValueType2;
@@ -1328,6 +1358,43 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
 							    __first2, __last2);
     }
 
+  template<typename _II1, typename _II2>
+    _GLIBCXX20_CONSTEXPR
+    inline int
+    __lexicographical_compare_aux(_II1 __first1, _II1 __last1,
+				  _II2 __first2, _II2 __last2)
+    {
+      return std::__lexicographical_compare_aux1(std::__niter_base(__first1),
+						 std::__niter_base(__last1),
+						 std::__niter_base(__first2),
+						 std::__niter_base(__last2));
+    }
+
+  template<typename _Ite1, typename _Seq1, typename _Cat1,
+	   typename _II2>
+    int
+    __lexicographical_compare_aux(
+		const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>&,
+		const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>&,
+		_II2, _II2);
+
+  template<typename _II1,
+	   typename _Ite2, typename _Seq2, typename _Cat2>
+    int
+    __lexicographical_compare_aux(
+		_II1, _II1,
+		const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>&,
+		const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>&);
+
+  template<typename _Ite1, typename _Seq1, typename _Cat1,
+	   typename _Ite2, typename _Seq2, typename _Cat2>
+    int
+    __lexicographical_compare_aux(
+		const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>&,
+		const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>&,
+		const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>&,
+		const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>&);
+
   template<typename _ForwardIterator, typename _Tp, typename _Compare>
     _GLIBCXX20_CONSTEXPR
     _ForwardIterator
@@ -1627,10 +1694,8 @@  _GLIBCXX_BEGIN_NAMESPACE_ALGO
       __glibcxx_requires_valid_range(__first1, __last1);
       __glibcxx_requires_valid_range(__first2, __last2);
 
-      return std::__lexicographical_compare_aux(std::__niter_base(__first1),
-						std::__niter_base(__last1),
-						std::__niter_base(__first2),
-						std::__niter_base(__last2));
+      return std::__lexicographical_compare_aux(__first1, __last1,
+						__first2, __last2) < 0;
     }
 
   /**
@@ -1660,7 +1725,7 @@  _GLIBCXX_BEGIN_NAMESPACE_ALGO
 
       return std::__lexicographical_compare_impl
 	(__first1, __last1, __first2, __last2,
-	 __gnu_cxx::__ops::__iter_comp_iter(__comp));
+	 __gnu_cxx::__ops::__iter_comp_iter(__comp)) < 0;
     }
 
   template<typename _InputIterator1, typename _InputIterator2,
diff --git a/libstdc++-v3/include/bits/stl_deque.h b/libstdc++-v3/include/bits/stl_deque.h
index 62218b1c058..6da19142352 100644
--- a/libstdc++-v3/include/bits/stl_deque.h
+++ b/libstdc++-v3/include/bits/stl_deque.h
@@ -440,6 +440,33 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
     __equal_aux1(_II, _II,
 		_GLIBCXX_STD_C::_Deque_iterator<_Tp, _Ref, _Ptr>);
 
+  template<typename _Tp1, typename _Ref1, typename _Ptr1,
+	   typename _II2>
+    typename __gnu_cxx::__enable_if<
+      __is_random_access_iter<_II2>::__value, int>::__type
+    __lexicographical_compare_aux1(
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
+		_II2, _II2);
+
+  template<typename _II1,
+	   typename _Tp2, typename _Ref2, typename _Ptr2>
+    typename __gnu_cxx::__enable_if<
+      __is_random_access_iter<_II1>::__value, int>::__type
+    __lexicographical_compare_aux1(
+		_II1, _II1,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
+
+  template<typename _Tp1, typename _Ref1, typename _Ptr1,
+	   typename _Tp2, typename _Ref2, typename _Ptr2>
+    int
+    __lexicographical_compare_aux1(
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp1, _Ref1, _Ptr1>,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>,
+		_GLIBCXX_STD_C::_Deque_iterator<_Tp2, _Ref2, _Ptr2>);
+
 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 
   /**
diff --git a/libstdc++-v3/include/debug/safe_iterator.h b/libstdc++-v3/include/debug/safe_iterator.h
index 5f73ee38b6b..1665c95f5df 100644
--- a/libstdc++-v3/include/debug/safe_iterator.h
+++ b/libstdc++-v3/include/debug/safe_iterator.h
@@ -1185,6 +1185,80 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
       return __equal_aux1(__first1, __last1, __first2);
     }
 
+  template<typename _Ite1, typename _Seq1, typename _Cat1,
+	   typename _II2>
+    int
+    __lexicographical_compare_aux(
+	const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>& __first1,
+	const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>& __last1,
+	_II2 __first2, _II2 __last2)
+    {
+      typename ::__gnu_debug::_Distance_traits<_Ite1>::__type __dist1;
+      __glibcxx_check_valid_range2(__first1, __last1, __dist1);
+      __glibcxx_check_valid_range(__first2, __last2);
+
+      if (__dist1.second > ::__gnu_debug::__dp_equality)
+	return std::__lexicographical_compare_aux(__first1.base(),
+						  __last1.base(),
+						  __first2, __last2);
+      return std::__lexicographical_compare_aux1(__first1, __last1,
+						 __first2, __last2);
+    }
+
+  template<typename _II1,
+	   typename _Ite2, typename _Seq2, typename _Cat2>
+    int
+    __lexicographical_compare_aux(
+	_II1 __first1, _II1 __last1,
+	const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>& __first2,
+	const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>& __last2)
+    {
+      __glibcxx_check_valid_range(__first1, __last1);
+      typename ::__gnu_debug::_Distance_traits<_II1>::__type __dist2;
+      __glibcxx_check_valid_range2(__first2, __last2, __dist2);
+
+      if (__dist2.second > ::__gnu_debug::__dp_equality)
+	return std::__lexicographical_compare_aux(__first1, __last1,
+						  __first2.base(),
+						  __last2.base());
+      return std::__lexicographical_compare_aux1(__first1, __last1,
+						 __first2, __last2);
+    }
+
+  template<typename _Ite1, typename _Seq1, typename _Cat1,
+	   typename _Ite2, typename _Seq2, typename _Cat2>
+    int
+    __lexicographical_compare_aux(
+	const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>& __first1,
+	const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>& __last1,
+	const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>& __first2,
+	const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>& __last2)
+    {
+      typename ::__gnu_debug::_Distance_traits<_Ite1>::__type __dist1;
+      __glibcxx_check_valid_range2(__first1, __last1, __dist1);
+      typename ::__gnu_debug::_Distance_traits<_Ite2>::__type __dist2;
+      __glibcxx_check_valid_range2(__first2, __last2, __dist2);
+
+      if (__dist1.second > ::__gnu_debug::__dp_equality)
+	{
+	  if (__dist2.second > ::__gnu_debug::__dp_equality)
+	    return std::__lexicographical_compare_aux(__first1.base(),
+						      __last1.base(),
+						      __first2.base(),
+						      __last2.base());
+	  return std::__lexicographical_compare_aux(__first1.base(),
+						    __last1.base(),
+						    __first2, __last2);
+	}
+
+      if (__dist2.second > ::__gnu_debug::__dp_equality)
+	return std::__lexicographical_compare_aux(__first1, __last1,
+						  __first2.base(),
+						  __last2.base());
+      return std::__lexicographical_compare_aux1(__first1, __last1,
+						__first2, __last2);
+    }
+
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std
 
diff --git a/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/1.cc b/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/1.cc
index a7645a40ac3..d745fec052d 100644
--- a/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/1.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/1.cc
@@ -23,11 +23,12 @@ 
 
 using __gnu_test::test_container;
 using __gnu_test::input_iterator_wrapper;
+using __gnu_test::random_access_iterator_wrapper;
 
 typedef test_container<int, input_iterator_wrapper> Container;
-int array1[] = {0, 1};
-int array2[] = {1, 0};
-int array3[] = {1, 0, 1};
+int array1[] = { 0, 1 };
+int array2[] = { 1, 0 };
+int array3[] = { 1, 0, 1 };
 
 void 
 test1()
@@ -74,6 +75,28 @@  test5()
 					con2.begin(), con2.end()) );
 }
 
+void
+test6()
+{
+  VERIFY( std::lexicographical_compare(array2, array2 + 2,
+				       array3, array3 + 3) );
+  VERIFY( !std::lexicographical_compare(array3, array3 + 3,
+					array2, array2 + 2) );
+}
+
+typedef test_container<int, random_access_iterator_wrapper> RaiContainer;
+
+void
+test7()
+{
+  RaiContainer con2(array2, array2 + 2);
+  RaiContainer con3(array3, array3 + 3);
+  VERIFY( std::lexicographical_compare(con2.begin(), con2.end(),
+				       con3.begin(), con3.end()) );
+  VERIFY( !std::lexicographical_compare(con3.begin(), con3.end(),
+					con2.begin(), con2.end()) );
+}
+
 int 
 main()
 {
@@ -82,4 +105,6 @@  main()
   test3();
   test4();
   test5();
+  test6();
+  test7();
 }
diff --git a/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/deque_iterators/1.cc b/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/deque_iterators/1.cc
new file mode 100644
index 00000000000..4b7275a1522
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/lexicographical_compare/deque_iterators/1.cc
@@ -0,0 +1,134 @@ 
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <algorithm>
+#include <vector>
+#include <deque>
+
+#include <ext/new_allocator.h>
+#include <ext/malloc_allocator.h>
+
+#include <testsuite_hooks.h>
+
+void test01()
+{
+  using namespace std;
+
+  deque<int> d;
+  for (int i = 0; i != _GLIBCXX_STD_C::__deque_buf_size(sizeof(int)); ++i)
+    d.push_back(i);
+
+  const deque<int>& cd = d;
+
+  VERIFY( !lexicographical_compare(cd.begin(), cd.end(), cd.begin(), cd.end()) );
+  VERIFY( !lexicographical_compare(cd.begin(), cd.end(), d.begin(), d.end()) );
+  VERIFY( !lexicographical_compare(d.begin(), d.end(), d.begin(), d.end()) );
+  VERIFY( !lexicographical_compare(d.begin(), d.end(), cd.begin(), cd.end()) );
+}
+
+void test02()
+{
+  using namespace std;
+
+  deque<int> d;
+  for (int i = 0; i != 1000; ++i)
+    d.push_back(i % 10);
+
+  VERIFY( !lexicographical_compare(d.begin(), d.begin() + 10,
+				   d.begin() + 20, d.begin() + 30) );
+  VERIFY( lexicographical_compare(d.begin(), d.begin() + 10,
+				  d.begin() + 20, d.begin() + 31) );
+  VERIFY( !lexicographical_compare(d.begin() + 10, d.end() - 10,
+				   d.begin(), d.end() - 20) );
+
+  const deque<int>& cd = d;
+
+  VERIFY( !lexicographical_compare(cd.begin(), cd.begin() + 10,
+				   cd.begin() + 20, cd.begin() + 30) );
+  VERIFY( !lexicographical_compare(cd.begin() + 10, cd.end() - 10,
+				   d.begin(), d.end() - 20) );
+  VERIFY( !lexicographical_compare(d.begin() + 10, d.end() - 10,
+				   cd.begin(), cd.end() - 20) );
+}
+
+void test03()
+{
+  using namespace std;
+
+  deque<int> d1;
+  for (int i = 0; i != 1000; ++i)
+    d1.push_back(i % 10);
+
+  deque<int> d2(d1);
+  for (int i = 0; i != 10; ++i)
+    d2.pop_front();
+
+  VERIFY( !lexicographical_compare(d1.begin(), d1.begin() + 10,
+				   d2.begin(), d2.begin() + 10) );
+  VERIFY( !lexicographical_compare(d1.begin() + 10, d1.end() - 10,
+				   d2.begin(), d2.end() - 10) );
+
+  const deque<int>& cd1 = d1;
+  const deque<int>& cd2 = d2;
+
+  VERIFY( !lexicographical_compare(cd1.begin(), cd1.begin() + 10,
+				   cd2.begin() + 20, cd2.begin() + 30) );
+  VERIFY( !lexicographical_compare(cd1.begin() + 10, cd1.end() - 10,
+				   d2.begin(), d2.end() - 10) );
+  VERIFY( lexicographical_compare(cd2.begin() + 10, cd2.end() - 10,
+				  cd1.begin(), cd1.end() - 20) );
+}
+
+void test04()
+{
+  using namespace std;
+
+  deque<int> d;
+  for (int i = 0; i != 1024; ++i)
+    d.push_back(i);
+
+  vector<int> v(d.begin(), d.end());
+
+  VERIFY( lexicographical_compare(d.begin() + 5, d.end() - 1, v.begin() + 5, v.end()) );
+  VERIFY( !lexicographical_compare(v.begin(), v.end(), d.begin(), d.end()) );
+
+  const deque<int>& cd = d;
+
+  VERIFY( !lexicographical_compare(cd.begin(), cd.end(), v.begin(), v.end()) );
+  VERIFY( !lexicographical_compare(v.begin(), v.end(), cd.begin(), cd.end()) );
+}
+
+void test05()
+{
+  using namespace std;
+
+  int a[] { 0, 1, 2, 3, 4 };
+  deque<int, __gnu_cxx::new_allocator<int> > d1(a, a + 5);
+  deque<int, __gnu_cxx::malloc_allocator<int> > d2(a, a + 5);
+
+  VERIFY( !lexicographical_compare(d1.begin(), d1.end(), d2.begin(), d2.end()) );
+}
+
+int main()
+{
+  test01();
+  test02();
+  test03();
+  test04();
+  test05();
+  return 0;
+}