diff --git a/test/speed_test.cpp b/test/speed_test.cpp
index dcae5a2..c31faa9 100644
--- a/test/speed_test.cpp
+++ b/test/speed_test.cpp
@@ -97,6 +97,34 @@ namespace
     t.report();
   }
 
+  void test_big_int16()
+  {
+    cout << " no +\n ";
+    time<int16_t, big_int16_t>(user::return_x_big_int16);
+    cout << " + int16_t argument\n ";
+    time<int16_t, big_int16_t>(user::return_x_plus_y_big_int16);
+    cout << " + int16_t by value\n ";
+    time<int16_t, big_int16_t>(user::return_x_plus_y_value_big_int16);
+    cout << " + int16_t in place\n ";
+    time<int16_t, big_int16_t>(user::return_x_plus_y_in_place_big_int16);
+    cout << " + big_int16_t\n ";
+    time<int16_t, big_int16_t>(user::return_x_plus_z_big_int16);
+  }
+
+  void test_little_int16()
+  {
+    cout << " no +\n ";
+    time<int16_t, little_int16_t>(user::return_x_little_int16);
+    cout << " + int16_t argument\n ";
+    time<int16_t, little_int16_t>(user::return_x_plus_y_little_int16);
+    cout << " + int16_t by value\n ";
+    time<int16_t, little_int16_t>(user::return_x_plus_y_value_little_int16);
+    cout << " + int16_t in place\n ";
+    time<int16_t, little_int16_t>(user::return_x_plus_y_in_place_little_int16);
+    cout << " + little_int16_t\n ";
+    time<int16_t, little_int16_t>(user::return_x_plus_z_little_int16);
+  }
+
   void test_big_int32()
   {
     cout << " no +\n ";
@@ -125,6 +153,34 @@ namespace
     time<int32_t, little_int32_t>(user::return_x_plus_z_little_int32);
   }
 
+  void test_big_int64()
+  {
+    cout << " no +\n ";
+    time<int64_t, big_int64_t>(user::return_x_big_int64);
+    cout << " + int64_t argument\n ";
+    time<int64_t, big_int64_t>(user::return_x_plus_y_big_int64);
+    cout << " + int64_t by value\n ";
+    time<int64_t, big_int64_t>(user::return_x_plus_y_value_big_int64);
+    cout << " + int64_t in place\n ";
+    time<int64_t, big_int64_t>(user::return_x_plus_y_in_place_big_int64);
+    cout << " + big_int64_t\n ";
+    time<int64_t, big_int64_t>(user::return_x_plus_z_big_int64);
+  }
+
+  void test_little_int64()
+  {
+    cout << " no +\n ";
+    time<int64_t, little_int64_t>(user::return_x_little_int64);
+    cout << " + int64_t argument\n ";
+    time<int64_t, little_int64_t>(user::return_x_plus_y_little_int64);
+    cout << " + int64_t by value\n ";
+    time<int64_t, little_int64_t>(user::return_x_plus_y_value_little_int64);
+    cout << " + int64_t in place\n ";
+    time<int64_t, little_int64_t>(user::return_x_plus_y_in_place_little_int64);
+    cout << " + little_int64_t\n ";
+    time<int64_t, little_int64_t>(user::return_x_plus_z_little_int64);
+  }
+
 }  // unnamed namespace
 
 //--------------------------------------------------------------------------------------//
@@ -137,6 +193,13 @@ int cpp_main(int argc, char* argv[])
 
   cout << endl << "------------------------------------------------------" << endl;
 
+  cout << endl << "big, 16-bit..." << endl;
+  test_big_int16();
+  cout << endl << "little, 16-bit..." << endl;
+  test_little_int16();
+
+  cout << endl << "------------------------------------------------------" << endl;
+
   cout << endl << "big, 32-bit..." << endl;
   test_big_int32();
   cout << endl << "little, 32-bit..." << endl;
@@ -144,6 +207,13 @@ int cpp_main(int argc, char* argv[])
 
   cout << endl << "------------------------------------------------------" << endl;
 
+  cout << endl << "big, 64-bit..." << endl;
+  test_big_int64();
+  cout << endl << "little, 64-bit..." << endl;
+  test_little_int64();
+
+  cout << endl << "------------------------------------------------------" << endl;
+
   //cout << "float" << endl;
   //test<float>(1.2345f);
 
diff --git a/test/speed_test_functions.cpp b/test/speed_test_functions.cpp
index e974aff..873cc0b 100644
--- a/test/speed_test_functions.cpp
+++ b/test/speed_test_functions.cpp
@@ -18,19 +18,37 @@
 namespace user
 {
 
+  int16_t return_x_big_int16(int16_t x, int16_t, big_int16_t) BOOST_NOEXCEPT {return x;}
+  int16_t return_x_little_int16(int16_t x, int16_t, little_int16_t) BOOST_NOEXCEPT {return x;}
+  int16_t return_x_plus_y_big_int16(int16_t x, int16_t y, big_int16_t) BOOST_NOEXCEPT {return x+y;}
+  int16_t return_x_plus_y_little_int16(int16_t x, int16_t y, little_int16_t) BOOST_NOEXCEPT {return x+y;}
+  int16_t return_x_plus_y_value_big_int16(int16_t x, int16_t y, big_int16_t) BOOST_NOEXCEPT {return x+big_endian_value(y);}
+  int16_t return_x_plus_y_value_little_int16(int16_t x, int16_t y, little_int16_t) BOOST_NOEXCEPT {return x+little_endian_value(y);}
+  int16_t return_x_plus_y_in_place_big_int16(int16_t x, int16_t y, big_int16_t) BOOST_NOEXCEPT {big_endian(y);return x+y;}
+  int16_t return_x_plus_y_in_place_little_int16(int16_t x, int16_t y, little_int16_t) BOOST_NOEXCEPT {little_endian(y);return x+y;}
+  int16_t return_x_plus_z_big_int16(int16_t x, int16_t, big_int16_t z) BOOST_NOEXCEPT {return x+z;}
+  int16_t return_x_plus_z_little_int16(int16_t x, int16_t, little_int16_t z) BOOST_NOEXCEPT {return x+z;}
+
   int32_t return_x_big_int32(int32_t x, int32_t, big_int32_t) BOOST_NOEXCEPT {return x;}
   int32_t return_x_little_int32(int32_t x, int32_t, little_int32_t) BOOST_NOEXCEPT {return x;}
-
   int32_t return_x_plus_y_big_int32(int32_t x, int32_t y, big_int32_t) BOOST_NOEXCEPT {return x+y;}
   int32_t return_x_plus_y_little_int32(int32_t x, int32_t y, little_int32_t) BOOST_NOEXCEPT {return x+y;}
-
   int32_t return_x_plus_y_value_big_int32(int32_t x, int32_t y, big_int32_t) BOOST_NOEXCEPT {return x+big_endian_value(y);}
   int32_t return_x_plus_y_value_little_int32(int32_t x, int32_t y, little_int32_t) BOOST_NOEXCEPT {return x+little_endian_value(y);}
-
   int32_t return_x_plus_y_in_place_big_int32(int32_t x, int32_t y, big_int32_t) BOOST_NOEXCEPT {big_endian(y);return x+y;}
   int32_t return_x_plus_y_in_place_little_int32(int32_t x, int32_t y, little_int32_t) BOOST_NOEXCEPT {little_endian(y);return x+y;}
-
   int32_t return_x_plus_z_big_int32(int32_t x, int32_t, big_int32_t z) BOOST_NOEXCEPT {return x+z;}
   int32_t return_x_plus_z_little_int32(int32_t x, int32_t, little_int32_t z) BOOST_NOEXCEPT {return x+z;}
 
+  int64_t return_x_big_int64(int64_t x, int64_t, big_int64_t) BOOST_NOEXCEPT {return x;}
+  int64_t return_x_little_int64(int64_t x, int64_t, little_int64_t) BOOST_NOEXCEPT {return x;}
+  int64_t return_x_plus_y_big_int64(int64_t x, int64_t y, big_int64_t) BOOST_NOEXCEPT {return x+y;}
+  int64_t return_x_plus_y_little_int64(int64_t x, int64_t y, little_int64_t) BOOST_NOEXCEPT {return x+y;}
+  int64_t return_x_plus_y_value_big_int64(int64_t x, int64_t y, big_int64_t) BOOST_NOEXCEPT {return x+big_endian_value(y);}
+  int64_t return_x_plus_y_value_little_int64(int64_t x, int64_t y, little_int64_t) BOOST_NOEXCEPT {return x+little_endian_value(y);}
+  int64_t return_x_plus_y_in_place_big_int64(int64_t x, int64_t y, big_int64_t) BOOST_NOEXCEPT {big_endian(y);return x+y;}
+  int64_t return_x_plus_y_in_place_little_int64(int64_t x, int64_t y, little_int64_t) BOOST_NOEXCEPT {little_endian(y);return x+y;}
+  int64_t return_x_plus_z_big_int64(int64_t x, int64_t, big_int64_t z) BOOST_NOEXCEPT {return x+z;}
+  int64_t return_x_plus_z_little_int64(int64_t x, int64_t, little_int64_t z) BOOST_NOEXCEPT {return x+z;}
+
 }
diff --git a/test/speed_test_functions.hpp b/test/speed_test_functions.hpp
index 9d4b473..a123129 100644
--- a/test/speed_test_functions.hpp
+++ b/test/speed_test_functions.hpp
@@ -24,21 +24,39 @@ namespace user
   using namespace boost;
   using namespace boost::endian;
 
+  int16_t return_x_big_int16(int16_t x, int16_t y, big_int16_t z) BOOST_NOEXCEPT;
+  int16_t return_x_little_int16(int16_t x, int16_t y, little_int16_t z) BOOST_NOEXCEPT;
+  int16_t return_x_plus_y_big_int16(int16_t x, int16_t y, big_int16_t z) BOOST_NOEXCEPT;
+  int16_t return_x_plus_y_little_int16(int16_t x, int16_t y, little_int16_t z) BOOST_NOEXCEPT;
+  int16_t return_x_plus_y_value_big_int16(int16_t x, int16_t y, big_int16_t) BOOST_NOEXCEPT;
+  int16_t return_x_plus_y_value_little_int16(int16_t x, int16_t y, little_int16_t z) BOOST_NOEXCEPT;
+  int16_t return_x_plus_y_in_place_big_int16(int16_t x, int16_t y, big_int16_t z) BOOST_NOEXCEPT;
+  int16_t return_x_plus_y_in_place_little_int16(int16_t x, int16_t y, little_int16_t z) BOOST_NOEXCEPT;
+  int16_t return_x_plus_z_big_int16(int16_t x, int16_t y, big_int16_t z) BOOST_NOEXCEPT;
+  int16_t return_x_plus_z_little_int16(int16_t x, int16_t y, little_int16_t z) BOOST_NOEXCEPT;
+
   int32_t return_x_big_int32(int32_t x, int32_t y, big_int32_t z) BOOST_NOEXCEPT;
   int32_t return_x_little_int32(int32_t x, int32_t y, little_int32_t z) BOOST_NOEXCEPT;
-
   int32_t return_x_plus_y_big_int32(int32_t x, int32_t y, big_int32_t z) BOOST_NOEXCEPT;
   int32_t return_x_plus_y_little_int32(int32_t x, int32_t y, little_int32_t z) BOOST_NOEXCEPT;
-
   int32_t return_x_plus_y_value_big_int32(int32_t x, int32_t y, big_int32_t) BOOST_NOEXCEPT;
   int32_t return_x_plus_y_value_little_int32(int32_t x, int32_t y, little_int32_t z) BOOST_NOEXCEPT;
-
   int32_t return_x_plus_y_in_place_big_int32(int32_t x, int32_t y, big_int32_t z) BOOST_NOEXCEPT;
   int32_t return_x_plus_y_in_place_little_int32(int32_t x, int32_t y, little_int32_t z) BOOST_NOEXCEPT;
-
   int32_t return_x_plus_z_big_int32(int32_t x, int32_t y, big_int32_t z) BOOST_NOEXCEPT;
   int32_t return_x_plus_z_little_int32(int32_t x, int32_t y, little_int32_t z) BOOST_NOEXCEPT;
 
+  int64_t return_x_big_int64(int64_t x, int64_t y, big_int64_t z) BOOST_NOEXCEPT;
+  int64_t return_x_little_int64(int64_t x, int64_t y, little_int64_t z) BOOST_NOEXCEPT;
+  int64_t return_x_plus_y_big_int64(int64_t x, int64_t y, big_int64_t z) BOOST_NOEXCEPT;
+  int64_t return_x_plus_y_little_int64(int64_t x, int64_t y, little_int64_t z) BOOST_NOEXCEPT;
+  int64_t return_x_plus_y_value_big_int64(int64_t x, int64_t y, big_int64_t) BOOST_NOEXCEPT;
+  int64_t return_x_plus_y_value_little_int64(int64_t x, int64_t y, little_int64_t z) BOOST_NOEXCEPT;
+  int64_t return_x_plus_y_in_place_big_int64(int64_t x, int64_t y, big_int64_t z) BOOST_NOEXCEPT;
+  int64_t return_x_plus_y_in_place_little_int64(int64_t x, int64_t y, little_int64_t z) BOOST_NOEXCEPT;
+  int64_t return_x_plus_z_big_int64(int64_t x, int64_t y, big_int64_t z) BOOST_NOEXCEPT;
+  int64_t return_x_plus_z_little_int64(int64_t x, int64_t y, little_int64_t z) BOOST_NOEXCEPT;
+
 }
 
 #endif