__fp_type_select
__fp_type_select(x, __fpclassifyf, __fpclassifyd, __fpclassifyl)
#define isfinite(x) __fp_type_select(x, __isfinitef, __isfinite, __isfinitel)
#define isinf(x) __fp_type_select(x, __isinff, __isinf, __isinfl)
__fp_type_select(x, __inline_isnanf, __inline_isnan, __inline_isnanl)
#define isnormal(x) __fp_type_select(x, __isnormalf, __isnormal, __isnormall)
#define signbit(x) __fp_type_select(x, __signbitf, __signbit, __signbitl)