Subversion Repositories planix.SVN

/*
 * 64-bit IEEE not-a-number routines.
 * This is big/little-endian portable assuming that 
 * the 64-bit doubles and 64-bit integers have the
 * same byte ordering.
 */

#include "nan.h"

typedef unsigned long long uvlong;
typedef unsigned long ulong;

static uvlong uvnan    = 0x7FF0000000000001LL;
static uvlong uvinf    = 0x7FF0000000000000LL;
static uvlong uvneginf = 0xFFF0000000000000LL;

double
__NaN(void)
{
        uvlong *p;

        /* gcc complains about "return *(double*)&uvnan;" */
        p = &uvnan;
        return *(double*)p;
}

int
__isNaN(double d)
{
        uvlong x;
        double *p;

        p = &d;
        x = *(uvlong*)p;
        return (ulong)(x>>32)==0x7FF00000 && !__isInf(d, 0);
}

double
__Inf(int sign)
{
        uvlong *p;

        if(sign < 0)
                p = &uvinf;
        else
                p = &uvneginf;
        return *(double*)p;
}

int
__isInf(double d, int sign)
{
        uvlong x;
        double *p;

        p = &d;
        x = *(uvlong*)p;
        if(sign == 0)
                return x==uvinf || x==uvneginf;
        else if(sign > 0)
                return x==uvinf;
        else
                return x==uvneginf;
}