src/common/frexp.c

#ifndef lint
static const char       RCSid[] = "$Id: frexp.c,v 1.3 2003/02/25 02:47:21 greg Exp $";
#endif

double
frexp(x, ip)            /* call it paranoia, I've seen the lib version */
double  x;
int  *ip;
{
        int  neg;
        register int  i;

        if (neg = (x < 0.0))
                x = -x;
        else if (x == 0.0) {
                *ip = 0;
                return(0.0);
        }
        if (x < 0.5)
                for (i = 0; x < 0.5; i--)
                        x *= 2.0;
        else
                for (i = 0; x >= 1.0; i++)
                        x *= 0.5;
        *ip = i;
        return (neg ? -x : x);
}
Revision:	1.4
Committed:	Wed Nov 12 18:06:54 2003 UTC (21 years, 11 months ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad3R6P1, rad3R6
Changes since 1.3:	+5 -8 lines
Log Message:	Update to library replacement function frexp()
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	1.4	static const char RCSid[] = "$Id: frexp.c,v 1.3 2003/02/25 02:47:21 greg Exp $";
3	greg	1.1	#endif
4
5	greg	1.4	double
6	greg	1.1	frexp(x, ip) /* call it paranoia, I've seen the lib version */
7	greg	1.4	double x;
8	greg	1.1	int *ip;
9			{
10			int neg;
11			register int i;
12
13			if (neg = (x < 0.0))
14			x = -x;
15			else if (x == 0.0) {
16			*ip = 0;
17			return(0.0);
18			}
19			if (x < 0.5)
20			for (i = 0; x < 0.5; i--)
21			x *= 2.0;
22			else
23			for (i = 0; x >= 1.0; i++)
24	greg	1.4	x *= 0.5;
25	greg	1.1	*ip = i;
26	greg	1.4	return (neg ? -x : x);
27	greg	1.1	}