dnl Determine COPYSIGNL_LIBM.
gl_MATHFUNC([copysignl], [long double], [(long double, long double)])
if test $gl_cv_func_copysignl_no_libm = no \
dnl Determine COPYSIGNL_LIBM.
gl_MATHFUNC([copysignl], [long double], [(long double, long double)])
if test $gl_cv_func_copysignl_no_libm = no \