Re: [ros-users] Question about cmake and SSE optimizations

>     brian.

>>>   set(CMAKE_REQUIRED_FLAGS "-msse2")
>>>   check_cxx_source_runs("
>>>     #include <emmintrin.h>

>>>     int main()
>>>     {
>>>         __m128d a, b;
>>>         double vals[2] = {0};
>>>         a = _mm_loadu_pd(vals);
>>>         b = _mm_add_pd(a,a);
>>>         _mm_storeu_pd(vals,b);
>>>         return 0;
>>>      }"
>>>      HAS_SSE2_EXTENSIONS)

>>>   set(CMAKE_REQUIRED_FLAGS "-msse")
>>>   check_cxx_source_runs("
>>>     #include <xmmintrin.h>
>>>     int main()
>>>     {
>>>         __m128 a, b;
>>>         float vals[4] = {0};
>>>         a = _mm_loadu_ps(vals);
>>>         b = a;
>>>         b = _mm_add_ps(a,b);
>>>         _mm_storeu_ps(vals,b);
>>>         return 0;
>>>     }"
>>>     HAS_SSE_EXTENSIONS)

>>>   if(HAS_SSE2_EXTENSIONS)
>>>     message(STATUS "Using SSE2 extensions")
>>>     set(SSE_FLAGS "-msse2 -mfpmath=sse")
>>>   elseif(HAS_SSE_EXTENSIONS)
>>>     message(STATUS "Using SSE extensions")
>>>     set(SSE_FLAGS "-msse -mfpmath=sse")
>>>   endif()

>>>   add_definitions(${SSE_FLAGS})
>>> elseif(MSVC)
>>>   check_cxx_source_runs("
>>>     #include <emmintrin.h>

>>>     int main()
>>>     {
>>>         __m128d a, b;
>>>         double vals[2] = {0};
>>>         a = _mm_loadu_pd(vals);
>>>         b = _mm_add_pd(a,a);
>>>         _mm_storeu_pd(vals,b);
>>>         return 0;
>>>      }"
>>>      HAS_SSE2_EXTENSIONS)
>>>   if( HAS_SSE2_EXTENSIONS )
>>>     message(STATUS "Using SSE2 extensions")
>>>     add_definitions( "/arch:SSE2 /fp:fast -D__SSE__ -D__SSE2__" )
>>>   endif()
>>> endif()