optimized SSE2-based group15

benchmark/.gitignore

@@ -0,0 +1,3 @@
+enwik8
+enwik9
+*.exe

benchmark/string.cpp

@@ -3,6 +3,7 @@
 // https://www.boost.org/LICENSE_1_0.txt
 
 #define _SILENCE_CXX17_OLD_ALLOCATOR_MEMBERS_DEPRECATION_WARNING
+#define _SILENCE_CXX20_CISO646_REMOVED_WARNING
 
 #include <boost/unordered_map.hpp>
 #include <boost/unordered/unordered_flat_map.hpp>
@@ -12,11 +13,8 @@
 # include "absl/container/node_hash_map.h"
 # include "absl/container/flat_hash_map.h"
 #endif
-#ifdef HAVE_TSL_HOPSCOTCH
-# include "tsl/hopscotch_map.h"
-#endif
-#ifdef HAVE_TSL_ROBIN
-# include "tsl/robin_map.h"
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+# include "ankerl/unordered_dense.h"
 #endif
 #include <unordered_map>
 #include <vector>
@@ -287,23 +285,10 @@ template<class K, class V> using absl_flat_hash_map =
 
 #endif
 
-#ifdef HAVE_TSL_HOPSCOTCH
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
 
-template<class K, class V> using tsl_hopscotch_map =
-    tsl::hopscotch_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-template<class K, class V> using tsl_hopscotch_pg_map =
-    tsl::hopscotch_pg_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-#endif
-
-#ifdef HAVE_TSL_ROBIN
-
-template<class K, class V> using tsl_robin_map =
-    tsl::robin_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-template<class K, class V> using tsl_robin_pg_map =
-    tsl::robin_pg_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
+template<class K, class V> using ankerl_unordered_dense_map =
+    ankerl::unordered_dense::map<K, V, ankerl::unordered_dense::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
 
 #endif
 
@@ -373,23 +358,10 @@ template<class K, class V> using absl_flat_hash_map_fnv1a =
 
 #endif
 
-#ifdef HAVE_TSL_HOPSCOTCH
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
 
-template<class K, class V> using tsl_hopscotch_map_fnv1a =
-    tsl::hopscotch_map<K, V, fnv1a_hash, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-template<class K, class V> using tsl_hopscotch_pg_map_fnv1a =
-    tsl::hopscotch_pg_map<K, V, fnv1a_hash, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-#endif
-
-#ifdef HAVE_TSL_ROBIN
-
-template<class K, class V> using tsl_robin_map_fnv1a =
-    tsl::robin_map<K, V, fnv1a_hash, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-template<class K, class V> using tsl_robin_pg_map_fnv1a =
-    tsl::robin_pg_map<K, V, fnv1a_hash, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
+template<class K, class V> using ankerl_unordered_dense_map_fnv1a =
+    ankerl::unordered_dense::map<K, V, fnv1a_hash, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
 
 #endif
 
@@ -403,57 +375,41 @@ int main()
     test<boost_unordered_map>( "boost::unordered_map" );
     test<boost_unordered_flat_map>( "boost::unordered_flat_map" );
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+    test<ankerl_unordered_dense_map>( "ankerl::unordered_dense::map" );
+
+#endif
+
 #ifdef HAVE_ABSEIL
 
     test<absl_node_hash_map>( "absl::node_hash_map" );
     test<absl_flat_hash_map>( "absl::flat_hash_map" );
 
-#endif
-
-#ifdef HAVE_TSL_HOPSCOTCH
-
-    test<tsl_hopscotch_map>( "tsl::hopscotch_map" );
-    test<tsl_hopscotch_pg_map>( "tsl::hopscotch_pg_map" );
-
-#endif
-
-#ifdef HAVE_TSL_ROBIN
-
-    test<tsl_robin_map>( "tsl::robin_map" );
-    test<tsl_robin_pg_map>( "tsl::robin_pg_map" );
-
 #endif
 
     test<std_unordered_map_fnv1a>( "std::unordered_map, FNV-1a" );
     test<boost_unordered_map_fnv1a>( "boost::unordered_map, FNV-1a" );
     test<boost_unordered_flat_map_fnv1a>( "boost::unordered_flat_map, FNV-1a" );
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+    test<ankerl_unordered_dense_map_fnv1a>( "ankerl::unordered_dense::map, FNV-1a" );
+
+#endif
+
 #ifdef HAVE_ABSEIL
 
     test<absl_node_hash_map_fnv1a>( "absl::node_hash_map, FNV-1a" );
     test<absl_flat_hash_map_fnv1a>( "absl::flat_hash_map, FNV-1a" );
 
-#endif
-
-#ifdef HAVE_TSL_HOPSCOTCH
-
-    test<tsl_hopscotch_map_fnv1a>( "tsl::hopscotch_map, FNV-1a" );
-    test<tsl_hopscotch_pg_map_fnv1a>( "tsl::hopscotch_pg_map, FNV-1a" );
-
-#endif
-
-#ifdef HAVE_TSL_ROBIN
-
-    test<tsl_robin_map_fnv1a>( "tsl::robin_map, FNV-1a" );
-    test<tsl_robin_pg_map_fnv1a>( "tsl::robin_pg_map, FNV-1a" );
-
 #endif
 
     std::cout << "---\n\n";
 
     for( auto const& x: times )
     {
-        std::cout << std::setw( 35 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
+        std::cout << std::setw( 38 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
     }
 }
 

benchmark/string_view.cpp

@@ -3,6 +3,7 @@
 // https://www.boost.org/LICENSE_1_0.txt
 
 #define _SILENCE_CXX17_OLD_ALLOCATOR_MEMBERS_DEPRECATION_WARNING
+#define _SILENCE_CXX20_CISO646_REMOVED_WARNING
 
 #include <boost/unordered_map.hpp>
 #include <boost/unordered/unordered_flat_map.hpp>
@@ -12,11 +13,8 @@
 # include "absl/container/node_hash_map.h"
 # include "absl/container/flat_hash_map.h"
 #endif
-#ifdef HAVE_TSL_HOPSCOTCH
-# include "tsl/hopscotch_map.h"
-#endif
-#ifdef HAVE_TSL_ROBIN
-# include "tsl/robin_map.h"
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+# include "ankerl/unordered_dense.h"
 #endif
 #include <unordered_map>
 #include <string_view>
@@ -288,23 +286,10 @@ template<class K, class V> using absl_flat_hash_map =
 
 #endif
 
-#ifdef HAVE_TSL_HOPSCOTCH
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
 
-template<class K, class V> using tsl_hopscotch_map =
-    tsl::hopscotch_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-template<class K, class V> using tsl_hopscotch_pg_map =
-    tsl::hopscotch_pg_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-#endif
-
-#ifdef HAVE_TSL_ROBIN
-
-template<class K, class V> using tsl_robin_map =
-    tsl::robin_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-template<class K, class V> using tsl_robin_pg_map =
-    tsl::robin_pg_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
+template<class K, class V> using ankerl_unordered_dense_map =
+    ankerl::unordered_dense::map<K, V, ankerl::unordered_dense::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
 
 #endif
 
@@ -374,23 +359,10 @@ template<class K, class V> using absl_flat_hash_map_fnv1a =
 
 #endif
 
-#ifdef HAVE_TSL_HOPSCOTCH
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
 
-template<class K, class V> using tsl_hopscotch_map_fnv1a =
-    tsl::hopscotch_map<K, V, fnv1a_hash, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-template<class K, class V> using tsl_hopscotch_pg_map_fnv1a =
-    tsl::hopscotch_pg_map<K, V, fnv1a_hash, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-#endif
-
-#ifdef HAVE_TSL_ROBIN
-
-template<class K, class V> using tsl_robin_map_fnv1a =
-    tsl::robin_map<K, V, fnv1a_hash, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-template<class K, class V> using tsl_robin_pg_map_fnv1a =
-    tsl::robin_pg_map<K, V, fnv1a_hash, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
+template<class K, class V> using ankerl_unordered_dense_map_fnv1a =
+    ankerl::unordered_dense::map<K, V, fnv1a_hash, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
 
 #endif
 
@@ -404,57 +376,41 @@ int main()
     test<boost_unordered_map>( "boost::unordered_map" );
     test<boost_unordered_flat_map>( "boost::unordered_flat_map" );
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+    test<ankerl_unordered_dense_map>( "ankerl::unordered_dense::map" );
+
+#endif
+
 #ifdef HAVE_ABSEIL
 
     test<absl_node_hash_map>( "absl::node_hash_map" );
     test<absl_flat_hash_map>( "absl::flat_hash_map" );
 
-#endif
-
-#ifdef HAVE_TSL_HOPSCOTCH
-
-    test<tsl_hopscotch_map>( "tsl::hopscotch_map" );
-    test<tsl_hopscotch_pg_map>( "tsl::hopscotch_pg_map" );
-
-#endif
-
-#ifdef HAVE_TSL_ROBIN
-
-    test<tsl_robin_map>( "tsl::robin_map" );
-    test<tsl_robin_pg_map>( "tsl::robin_pg_map" );
-
 #endif
 
     test<std_unordered_map_fnv1a>( "std::unordered_map, FNV-1a" );
     test<boost_unordered_map_fnv1a>( "boost::unordered_map, FNV-1a" );
     test<boost_unordered_flat_map_fnv1a>( "boost::unordered_flat_map, FNV-1a" );
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+    test<ankerl_unordered_dense_map_fnv1a>( "ankerl::unordered_dense::map, FNV-1a" );
+
+#endif
+
 #ifdef HAVE_ABSEIL
 
     test<absl_node_hash_map_fnv1a>( "absl::node_hash_map, FNV-1a" );
     test<absl_flat_hash_map_fnv1a>( "absl::flat_hash_map, FNV-1a" );
 
-#endif
-
-#ifdef HAVE_TSL_HOPSCOTCH
-
-    test<tsl_hopscotch_map_fnv1a>( "tsl::hopscotch_map, FNV-1a" );
-    test<tsl_hopscotch_pg_map_fnv1a>( "tsl::hopscotch_pg_map, FNV-1a" );
-
-#endif
-
-#ifdef HAVE_TSL_ROBIN
-
-    test<tsl_robin_map_fnv1a>( "tsl::robin_map, FNV-1a" );
-    test<tsl_robin_pg_map_fnv1a>( "tsl::robin_pg_map, FNV-1a" );
-
 #endif
 
     std::cout << "---\n\n";
 
     for( auto const& x: times )
     {
-        std::cout << std::setw( 35 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
+        std::cout << std::setw( 38 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
     }
 }
 

benchmark/uint32.cpp

@@ -3,6 +3,7 @@
 // https://www.boost.org/LICENSE_1_0.txt
 
 #define _SILENCE_CXX17_OLD_ALLOCATOR_MEMBERS_DEPRECATION_WARNING
+#define _SILENCE_CXX20_CISO646_REMOVED_WARNING
 
 #include <boost/unordered_map.hpp>
 #include <boost/unordered/unordered_flat_map.hpp>
@@ -13,11 +14,8 @@
 # include "absl/container/node_hash_map.h"
 # include "absl/container/flat_hash_map.h"
 #endif
-#ifdef HAVE_TSL_HOPSCOTCH
-# include "tsl/hopscotch_map.h"
-#endif
-#ifdef HAVE_TSL_ROBIN
-# include "tsl/robin_map.h"
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+# include "ankerl/unordered_dense.h"
 #endif
 #include <unordered_map>
 #include <vector>
@@ -304,23 +302,10 @@ template<class K, class V> using absl_flat_hash_map =
 
 #endif
 
-#ifdef HAVE_TSL_HOPSCOTCH
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
 
-template<class K, class V> using tsl_hopscotch_map =
-    tsl::hopscotch_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-template<class K, class V> using tsl_hopscotch_pg_map =
-    tsl::hopscotch_pg_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-#endif
-
-#ifdef HAVE_TSL_ROBIN
-
-template<class K, class V> using tsl_robin_map =
-    tsl::robin_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-template<class K, class V> using tsl_robin_pg_map =
-    tsl::robin_pg_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
+template<class K, class V> using ankerl_unordered_dense_map =
+    ankerl::unordered_dense::map<K, V, ankerl::unordered_dense::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
 
 #endif
 
@@ -332,32 +317,24 @@ int main()
     test<boost_unordered_map>( "boost::unordered_map" );
     test<boost_unordered_flat_map>( "boost::unordered_flat_map" );
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+    test<ankerl_unordered_dense_map>( "ankerl::unordered_dense::map" );
+
+#endif
+
 #ifdef HAVE_ABSEIL
 
     test<absl_node_hash_map>( "absl::node_hash_map" );
     test<absl_flat_hash_map>( "absl::flat_hash_map" );
 
-#endif
-
-#ifdef HAVE_TSL_HOPSCOTCH
-
-    test<tsl_hopscotch_map>( "tsl::hopscotch_map" );
-    test<tsl_hopscotch_pg_map>( "tsl::hopscotch_pg_map" );
-
-#endif
-
-#ifdef HAVE_TSL_ROBIN
-
-    test<tsl_robin_map>( "tsl::robin_map" );
-    test<tsl_robin_pg_map>( "tsl::robin_pg_map" );
-
 #endif
 
     std::cout << "---\n\n";
 
     for( auto const& x: times )
     {
-        std::cout << std::setw( 27 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
+        std::cout << std::setw( 30 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
     }
 }
 

benchmark/uint64.cpp

@@ -3,6 +3,7 @@
 // https://www.boost.org/LICENSE_1_0.txt
 
 #define _SILENCE_CXX17_OLD_ALLOCATOR_MEMBERS_DEPRECATION_WARNING
+#define _SILENCE_CXX20_CISO646_REMOVED_WARNING
 
 #include <boost/unordered_map.hpp>
 #include <boost/unordered/unordered_flat_map.hpp>
@@ -13,11 +14,8 @@
 # include "absl/container/node_hash_map.h"
 # include "absl/container/flat_hash_map.h"
 #endif
-#ifdef HAVE_TSL_HOPSCOTCH
-# include "tsl/hopscotch_map.h"
-#endif
-#ifdef HAVE_TSL_ROBIN
-# include "tsl/robin_map.h"
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+# include "ankerl/unordered_dense.h"
 #endif
 #include <unordered_map>
 #include <vector>
@@ -304,23 +302,10 @@ template<class K, class V> using absl_flat_hash_map =
 
 #endif
 
-#ifdef HAVE_TSL_HOPSCOTCH
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
 
-template<class K, class V> using tsl_hopscotch_map =
-    tsl::hopscotch_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-template<class K, class V> using tsl_hopscotch_pg_map =
-    tsl::hopscotch_pg_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-#endif
-
-#ifdef HAVE_TSL_ROBIN
-
-template<class K, class V> using tsl_robin_map =
-    tsl::robin_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
-
-template<class K, class V> using tsl_robin_pg_map =
-    tsl::robin_pg_map<K, V, std::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
+template<class K, class V> using ankerl_unordered_dense_map =
+    ankerl::unordered_dense::map<K, V, ankerl::unordered_dense::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
 
 #endif
 
@@ -328,36 +313,38 @@ int main()
 {
     init_indices();
 
+#if defined(BOOST_LIBSTDCXX_VERSION) && __SIZE_WIDTH__ == 32
+
+    // Pathological behavior:
+    // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104945
+
+#else
+
     test<std_unordered_map>( "std::unordered_map" );
+
+#endif
+
     test<boost_unordered_map>( "boost::unordered_map" );
     test<boost_unordered_flat_map>( "boost::unordered_flat_map" );
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+    test<ankerl_unordered_dense_map>( "ankerl::unordered_dense::map" );
+
+#endif
+
 #ifdef HAVE_ABSEIL
 
     test<absl_node_hash_map>( "absl::node_hash_map" );
     test<absl_flat_hash_map>( "absl::flat_hash_map" );
 
-#endif
-
-#ifdef HAVE_TSL_HOPSCOTCH
-
-    test<tsl_hopscotch_map>( "tsl::hopscotch_map" );
-    test<tsl_hopscotch_pg_map>( "tsl::hopscotch_pg_map" );
-
-#endif
-
-#ifdef HAVE_TSL_ROBIN
-
-    test<tsl_robin_map>( "tsl::robin_map" );
-    test<tsl_robin_pg_map>( "tsl::robin_pg_map" );
-
 #endif
 
     std::cout << "---\n\n";
 
     for( auto const& x: times )
     {
-        std::cout << std::setw( 27 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
+        std::cout << std::setw( 30 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
     }
 }
 

benchmark/uuid.cpp

@@ -3,6 +3,7 @@
 // https://www.boost.org/LICENSE_1_0.txt
 
 #define _SILENCE_CXX17_OLD_ALLOCATOR_MEMBERS_DEPRECATION_WARNING
+#define _SILENCE_CXX20_CISO646_REMOVED_WARNING
 
 #include <boost/unordered_map.hpp>
 #include <boost/unordered/unordered_flat_map.hpp>
@@ -14,6 +15,9 @@
 # include "absl/container/node_hash_map.h"
 # include "absl/container/flat_hash_map.h"
 #endif
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+# include "ankerl/unordered_dense.h"
+#endif
 #include <unordered_map>
 #include <vector>
 #include <memory>
@@ -349,6 +353,13 @@ template<class K, class V> using absl_flat_hash_map =
 
 #endif
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+template<class K, class V> using ankerl_unordered_dense_map =
+    ankerl::unordered_dense::map<K, V, ankerl::unordered_dense::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
+
+#endif
+
 int main()
 {
     init_indices();
@@ -357,6 +368,12 @@ int main()
     test<boost_unordered_map>( "boost::unordered_map" );
     test<boost_unordered_flat_map>( "boost::unordered_flat_map" );
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+    test<ankerl_unordered_dense_map>( "ankerl::unordered_dense::map" );
+
+#endif
+
 #ifdef HAVE_ABSEIL
 
     test<absl_node_hash_map>( "absl::node_hash_map" );
@@ -368,7 +385,7 @@ int main()
 
     for( auto const& x: times )
     {
-        std::cout << std::setw( 27 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
+        std::cout << std::setw( 30 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
     }
 }
 

benchmark/word_count.cpp

@@ -12,6 +12,9 @@
 # include "absl/container/node_hash_map.h"
 # include "absl/container/flat_hash_map.h"
 #endif
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+# include "ankerl/unordered_dense.h"
+#endif
 #include <unordered_map>
 #include <vector>
 #include <memory>
@@ -38,8 +41,16 @@ static std::vector<std::string> words;
 
 static void init_words()
 {
+#if SIZE_MAX > UINT32_MAX
+
     char const* fn = "enwik9"; // http://mattmahoney.net/dc/textdata
 
+#else
+
+    char const* fn = "enwik8"; // ditto
+
+#endif
+
     auto t1 = std::chrono::steady_clock::now();
 
     std::ifstream is( fn );
@@ -229,6 +240,13 @@ template<class K, class V> using absl_flat_hash_map =
 
 #endif
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+template<class K, class V> using ankerl_unordered_dense_map =
+    ankerl::unordered_dense::map<K, V, ankerl::unordered_dense::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
+
+#endif
+
 // fnv1a_hash
 
 template<int Bits> struct fnv1a_hash_impl;
@@ -295,6 +313,13 @@ template<class K, class V> using absl_flat_hash_map_fnv1a =
 
 #endif
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+template<class K, class V> using ankerl_unordered_dense_map_fnv1a =
+    ankerl::unordered_dense::map<K, V, fnv1a_hash, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
+
+#endif
+
 //
 
 int main()
@@ -305,6 +330,12 @@ int main()
     test<boost_unordered_map>( "boost::unordered_map" );
     test<boost_unordered_flat_map>( "boost::unordered_flat_map" );
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+    test<ankerl_unordered_dense_map>( "ankerl::unordered_dense::map" );
+
+#endif
+
 #ifdef HAVE_ABSEIL
 
     test<absl_node_hash_map>( "absl::node_hash_map" );
@@ -316,6 +347,12 @@ int main()
     test<boost_unordered_map_fnv1a>( "boost::unordered_map, FNV-1a" );
     test<boost_unordered_flat_map_fnv1a>( "boost::unordered_flat_map, FNV-1a" );
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+    test<ankerl_unordered_dense_map_fnv1a>( "ankerl::unordered_dense::map, FNV-1a" );
+
+#endif
+
 #ifdef HAVE_ABSEIL
 
     test<absl_node_hash_map_fnv1a>( "absl::node_hash_map, FNV-1a" );
@@ -327,7 +364,7 @@ int main()
 
     for( auto const& x: times )
     {
-        std::cout << std::setw( 35 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
+        std::cout << std::setw( 38 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
     }
 }
 

benchmark/word_size.cpp

@@ -3,6 +3,7 @@
 // https://www.boost.org/LICENSE_1_0.txt
 
 #define _SILENCE_CXX17_OLD_ALLOCATOR_MEMBERS_DEPRECATION_WARNING
+#define _SILENCE_CXX20_CISO646_REMOVED_WARNING
 
 #include <boost/unordered_map.hpp>
 #include <boost/unordered/unordered_flat_map.hpp>
@@ -11,6 +12,9 @@
 # include "absl/container/node_hash_map.h"
 # include "absl/container/flat_hash_map.h"
 #endif
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+# include "ankerl/unordered_dense.h"
+#endif
 #include <unordered_map>
 #include <vector>
 #include <memory>
@@ -35,8 +39,16 @@ static std::vector<std::string> words;
 
 static void init_words()
 {
+#if SIZE_MAX > UINT32_MAX
+
     char const* fn = "enwik9"; // http://mattmahoney.net/dc/textdata
 
+#else
+
+    char const* fn = "enwik8"; // ditto
+
+#endif
+
     auto t1 = std::chrono::steady_clock::now();
 
     std::ifstream is( fn );
@@ -182,6 +194,13 @@ template<class K, class V> using absl_flat_hash_map =
 
 #endif
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+template<class K, class V> using ankerl_unordered_dense_map =
+    ankerl::unordered_dense::map<K, V, ankerl::unordered_dense::hash<K>, std::equal_to<K>, ::allocator< std::pair<K, V> >>;
+
+#endif
+
 int main()
 {
     init_words();
@@ -190,6 +209,12 @@ int main()
     test<boost_unordered_map>( "boost::unordered_map" );
     test<boost_unordered_flat_map>( "boost::unordered_flat_map" );
 
+#ifdef HAVE_ANKERL_UNORDERED_DENSE
+
+    test<ankerl_unordered_dense_map>( "ankerl::unordered_dense::map" );
+
+#endif
+
 #ifdef HAVE_ABSEIL
 
     test<absl_node_hash_map>( "absl::node_hash_map" );
@@ -201,7 +226,7 @@ int main()
 
     for( auto const& x: times )
     {
-        std::cout << std::setw( 27 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
+        std::cout << std::setw( 30 ) << ( x.label_ + ": " ) << std::setw( 5 ) << x.time_ << " ms, " << std::setw( 9 ) << x.bytes_ << " bytes in " << x.count_ << " allocations\n";
     }
 }
 

include/boost/unordered/detail/foa.hpp

@@ -135,6 +135,7 @@ static const std::size_t default_bucket_count = 0;
 
 #if defined(BOOST_UNORDERED_SSE2)
 
+#if 0
 struct group15
 {
   static constexpr int N=15;
@@ -299,6 +300,157 @@ private:
 
   alignas(16) __m128i m;
 };
+#else
+struct group15
+{
+  static constexpr int N=15;
+
+  struct dummy_group_type
+  {
+    alignas(16) unsigned char storage[N+1]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0};
+  };
+
+  inline void initialize(){m=_mm_setzero_si128();}
+
+  inline void set(std::size_t pos,std::size_t hash)
+  {
+    BOOST_ASSERT(pos<N);
+    at(pos)=reduced_hash(hash+pos);
+  }
+
+  inline void set_sentinel()
+  {
+    at(N-1)=sentinel_;
+  }
+
+  inline bool is_sentinel(std::size_t pos)const
+  {
+    BOOST_ASSERT(pos<N);
+    return at(pos)==sentinel_;
+  }
+
+  inline void reset(std::size_t pos)
+  {
+    BOOST_ASSERT(pos<N);
+    at(pos)=available_;
+  }
+
+  static inline void reset(unsigned char* pc)
+  {
+    *pc=available_;
+  }
+
+  inline int match(std::size_t hash)const
+  {
+    return _mm_movemask_epi8(_mm_cmpeq_epi8(m,match_word(hash)))&0x7FFF;
+  }
+
+  inline bool is_not_overflowed(std::size_t hash)const
+  {
+    static constexpr unsigned char shift[]={1,2,4,8,16,32,64,128};
+
+    return !(overflow()&shift[hash%8]);
+  }
+
+  inline void mark_overflow(std::size_t hash)
+  {
+#if BOOST_WORKAROUND(BOOST_GCC, >= 50000 && BOOST_GCC < 60000)
+    overflow() = static_cast<unsigned char>( overflow() | static_cast<unsigned char>(1<<(hash%8)) );
+#else
+    overflow()|=static_cast<unsigned char>(1<<(hash%8));
+#endif
+  }
+
+  static inline bool maybe_caused_overflow(unsigned char* pc)
+  {
+    std::size_t pos=reinterpret_cast<uintptr_t>(pc)%sizeof(group15);
+    group15    *pg=reinterpret_cast<group15*>(pc-pos);
+    return !pg->is_not_overflowed(*pc-pos);
+  };
+
+  inline int match_available()const
+  {
+    return _mm_movemask_epi8(
+      _mm_cmpeq_epi8(m,_mm_setzero_si128()))&0x7FFF;
+  }
+
+  inline int match_occupied()const
+  {
+    return (~match_available())&0x7FFF;
+  }
+
+  inline int match_really_occupied()const /* excluding sentinel */
+  {
+    return at(N-1)==sentinel_?match_occupied()&0x3FFF:match_occupied();
+  }
+
+private:
+  static constexpr unsigned char available_=0,
+                                 sentinel_=1;
+
+  static constexpr unsigned char reduced_hash_table[]={
+    8,9,2,3,4,5,6,7,8,9,10,11,12,13,14,15,
+    16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,
+    32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,
+    48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,
+    64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,
+    80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,
+    96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,
+    112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,
+    128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
+    144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,
+    160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,
+    176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,
+    192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,
+    208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,
+    224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,
+    240,241,242,243,244,245,246,247,248,249,250,251,252,253,254,255,
+    8,9,2,3,4,5,6,7,8,9,10,11,12,13,14,
+  };
+
+  inline static __m128i match_word(std::size_t hash)
+  {
+#if defined(__MSVC_RUNTIME_CHECKS)
+    return _mm_loadu_si128(reinterpret_cast<const __m128i*>(
+      reduced_hash_table+(hash&0xffu)));
+#else
+    return _mm_loadu_si128(reinterpret_cast<const __m128i*>(
+      reduced_hash_table+(unsigned char)(hash)));
+#endif
+  }
+
+  inline static unsigned char reduced_hash(std::size_t hash)
+  {
+#if defined(__MSVC_RUNTIME_CHECKS)
+    return reduced_hash_table[hash&0xffu];
+#else
+    return reduced_hash_table[(unsigned char)hash];
+#endif
+  }
+
+  inline unsigned char& at(std::size_t pos)
+  {
+    return reinterpret_cast<unsigned char*>(&m)[pos];
+  }
+
+  inline unsigned char at(std::size_t pos)const
+  {
+    return reinterpret_cast<const unsigned char*>(&m)[pos];
+  }
+
+  inline unsigned char& overflow()
+  {
+    return at(N);
+  }
+
+  inline unsigned char overflow()const
+  {
+    return at(N);
+  }
+
+  alignas(16) __m128i m;
+};
+#endif
 
 #elif defined(BOOST_UNORDERED_LITTLE_ENDIAN_NEON)