eigen/cmake/modules/CheckLongDouble.cmake

INCLUDE(CheckCXXSourceCompiles)

MACRO (CHECK_LONG_DOUBLE _RESULT)

SET(_CHECK_LONG_DOUBLE_SOURCE_CODE "

#include <cmath>

int main(int argc, char *argv[])
{
  long double ld = static_cast<long double>(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)