xref: /csrg-svn/lib/libc/i386/gen/frexp.c (revision 61221)
147052Sbostic /*-
2*61221Sbostic  * Copyright (c) 1991, 1993
3*61221Sbostic  *	The Regents of the University of California.  All rights reserved.
447052Sbostic  *
547052Sbostic  * %sccs.include.redist.c%
647052Sbostic  */
747052Sbostic 
847052Sbostic #if defined(LIBC_SCCS) && !defined(lint)
9*61221Sbostic static char sccsid[] = "@(#)frexp.c	8.1 (Berkeley) 06/04/93";
1047052Sbostic #endif /* LIBC_SCCS and not lint */
1147052Sbostic 
1247052Sbostic #include <sys/types.h>
1347052Sbostic #include <math.h>
1447052Sbostic 
1547052Sbostic double
frexp(value,eptr)1647052Sbostic frexp(value, eptr)
1747052Sbostic 	double value;
1847052Sbostic 	int *eptr;
1947052Sbostic {
2047052Sbostic 	union {
2147052Sbostic                 double v;
2247052Sbostic                 struct {
2347052Sbostic 			u_int u_mant2 : 32;
2447052Sbostic 			u_int u_mant1 : 20;
2547052Sbostic 			u_int   u_exp : 11;
2647052Sbostic                         u_int  u_sign :  1;
2747052Sbostic                 } s;
2847052Sbostic         } u;
2947052Sbostic 
3047052Sbostic 	if (value) {
3147052Sbostic 		u.v = value;
3247052Sbostic 		*eptr = u.s.u_exp - 1022;
3347052Sbostic 		u.s.u_exp = 1022;
3447052Sbostic 		return(u.v);
3547052Sbostic 	} else {
3647052Sbostic 		*eptr = 0;
3747052Sbostic 		return((double)0);
3847052Sbostic 	}
3947052Sbostic }
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