musl/src/math/__fpclassifyl.c

#include "libm.h"

#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024

#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
int __fpclassifyl(long double x)
{
	union ldshape u = {x};
	int e = u.i.se & 0x7fff;
	int msb = u.i.m>>63;
	if (!e && !msb)
		return u.i.m ? FP_SUBNORMAL : FP_ZERO;
	if (!msb)
		return FP_NAN;
	if (e == 0x7fff)
		return u.i.m << 1 ? FP_NAN : FP_INFINITE;
	return FP_NORMAL;
}
#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
int __fpclassifyl(long double x)
{
	union ldshape u = {x};
	int e = u.i.se & 0x7fff;
	if (!e)
		return u.i2.lo | u.i2.hi ? FP_SUBNORMAL : FP_ZERO;
	if (e == 0x7fff) {
		u.i.se = 0;
		return u.i2.lo | u.i2.hi ? FP_NAN : FP_INFINITE;
	}
	return FP_NORMAL;
}
#endif