finish "step6":exercise 1

Author: YuZhen-Yang

Step6/CMakePresets.json

@@ -7,6 +7,9 @@
       "description": "Preset to use with the tutorial",
       "binaryDir": "${sourceDir}/build",
       "cacheVariables": {
+        "CMAKE_CXX_COMPILER":"g++-13",
+        "CMAKE_EXPORT_COMPILE_COMMANDS":"ON",
+
         "TUTORIAL_USE_STD_SQRT": "OFF"
       }
     }

Step6/MathFunctions/CMakeLists.txt

@@ -28,10 +28,15 @@ endif()
 
 # TODO1: Include the CheckIncludeFiles module and use it to check for
 #        the emmintrin.h header.
+include(CheckIncludeFiles)
+CHECK_INCLUDE_FILES(emmintrin.h HAS_EMMINTRIN LANGUAGE CXX)
 
 # TODO2: If emmintrin.h is available, add a compile definition to MathFunctions
 #        named TUTORIAL_USE_SSE2. This will only be needed by the MathFunctions
 #        implementation file.
+if(HAS_EMMINTRIN)
+  target_compile_definitions(MathFunctions PRIVATE TUTORIAL_USE_SSE2)
+endif()
 
 # TODO4: Include the CheckSourceCompiles module and use it to check if the
 #        following program compiles:

Step6/MathFunctions/MathFunctions.cxx

@@ -5,6 +5,9 @@
 
 // TODO3: If the TUTORIAL_USE_SSE2 definition is set, include
 //        the <emmintrin.h> header
+#ifdef  TUTORIAL_USE_SSE2
+#include "emmintrin.h"
+#endif 
 
 namespace {