Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>

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

double
NaN(void)
{
        FPdbleword a;

        a.hi = NANEXP;
        a.lo = 1;
        return a.x;
}

int
isNaN(double d)
{
        FPdbleword a;

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

double
Inf(int sign)
{
        FPdbleword a;

        a.hi = NANEXP;
        a.lo = 0;
        if(sign < 0)
                a.hi |= NANSIGN;
        return a.x;
}

int
isInf(double d, int sign)
{
        FPdbleword a;

        a.x = d;
        if(a.lo != 0)
                return 0;
        if(a.hi == NANEXP)
                return sign >= 0;
        if(a.hi == (NANEXP|NANSIGN))
                return sign <= 0;
        return 0;
}