INCLUDE(CheckCXXSourceCompiles) MACRO (CHECK_LONG_DOUBLE _RESULT) SET(_CHECK_LONG_DOUBLE_SOURCE_CODE " #include int main(int argc, char *argv[]) { long double ld = static_cast(1); sqrt(ld); cos(ld); sin(ld); exp(ld); log(ld); fabs(ld); return 0; } ") CHECK_CXX_SOURCE_COMPILES("${_CHECK_LONG_DOUBLE_SOURCE_CODE}" ${_RESULT}) ENDMACRO (CHECK_LONG_DOUBLE)