code: purgatorio

ref: 21947578303cdb0fcb4b0cdfe80aa9dab5f6b447
dir: /emu/Nt/fp.c/

typedef	unsigned long	ulong;
typedef	unsigned int	uint;
typedef	unsigned short	ushort;
typedef	unsigned char	uchar;
typedef	signed char	schar;

#include <float.h>
#include "mathi.h"

#define	NANEXP	(2047<<20)
#define	NANMASK	(2047<<20)
#define	NANSIGN	(1<<31)

int	isInf(double, int);

double
NaN(void)
{
	union
	{
		double	d;
		long	x[2];
	} a;

	a.x[1] = NANEXP;
	a.x[0] = 1;
	return a.d;
}

int
isNaN(double d)
{
	union
	{
		double	d;
		long	x[2];
	} a;

	a.d = d;
	if((a.x[1] & NANMASK) != NANEXP)
		return 0;
	return !isInf(d, 0);
}

double
Inf(int sign)
{
	union
	{
		double	d;
		long	x[2];
	} a;

	a.x[1] = NANEXP;
	a.x[0] = 0;
	if(sign < 0)
		a.x[1] |= NANSIGN;
	return a.d;
}

int
isInf(double d, int sign)
{
	union
	{
		double	d;
		long	x[2];
	} a;

	a.d = d;
	if(a.x[0] != 0)
		return 0;
	if(a.x[1] == NANEXP)
		return sign >= 0;
	if(a.x[1] == (NANEXP|NANSIGN))
		return sign <= 0;
	return 0;
}

ulong
getfcr(void)
{
	return getFPcontrol();
}

void
setfcr(ulong m)
{
	FPcontrol(m, ~0);
}

ulong
getfsr(void)
{
	return getFPstatus();
}

void
setfsr(ulong m)
{
	FPstatus(m, ~0);
}