#include <u.h>#include <libc.h> #define	NANEXP	(2047<<20)#define	NANMASK	(2047<<20)#define	NANSIGN	(1<<31) doubleNaN(void){	union	{		double	d;		long	x[2];	} a; 	a.x[0] = NANEXP;	a.x[1] = 1;	return a.d;} intisNaN(double d){	union	{		double	d;		long	x[2];	} a; 	a.d = d;	if((a.x[0] & NANMASK) != NANEXP)		return 0;	return !isInf(d, 0);} doubleInf(int sign){	union	{		double	d;		long	x[2];	} a; 	a.x[0] = NANEXP;	a.x[1] = 0;	if(sign < 0)		a.x[0] |= NANSIGN;	return a.d;} intisInf(double d, int sign){	union	{		double	d;		long	x[2];	} a; 	a.d = d;	if(a.x[1] != 0)		return 0;	if(a.x[0] == NANEXP)		return sign >= 0;	if(a.x[0] == (NANEXP|NANSIGN))		return sign <= 0;	return 0;}