check_cxx_source_runs("
      #include <immintrin.h>
      int main()
      {
        __m256 a, b;
        float vals[8] = {1, 2, 3, 4, 5, 6, 7, 8};
        const int mask = 123;
        a = _mm256_loadu_ps(vals);
        b = a;
        b = _mm256_dp_ps (a, a, 3);
        _mm256_storeu_ps(vals,b);
        return 0;
      }"
      HAVE_AVX_EXTENSIONS)

elseif(HAVE_AVX_EXTENSIONS)

elseif(HAVE_AVX_EXTENSIONS AND APSI_USE_AVX)

check_cxx_source_runs("
            #include <immintrin.h>
            int main()
            {
              __m256 a, b, c;
              const float src[8] = { 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f };
              float dst[8];
              a = _mm256_loadu_ps( src );
              b = _mm256_loadu_ps( src );
              c = _mm256_add_ps( a, b );
              _mm256_storeu_ps( dst, c );
              for( int i = 0; i < 8; i++ ){
                if( ( src[i] + src[i] ) != dst[i] ){
                  return -1;
                }
              }
              return 0;
            }"
            HAVE_AVX_EXTENSIONS)

elseif(HAVE_AVX_EXTENSIONS AND MSVC_VERSION GREATER_EQUAL 1600)

elseif(HAVE_AVX_EXTENSIONS)