xref: /openbsd-src/lib/libm/src/s_copysign.c (revision 2b0358df1d88d06ef4139321dd05bd5e05d91eaf)
1 /* @(#)s_copysign.c 5.1 93/09/24 */
2 /*
3  * ====================================================
4  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5  *
6  * Developed at SunPro, a Sun Microsystems, Inc. business.
7  * Permission to use, copy, modify, and distribute this
8  * software is freely granted, provided that this notice
9  * is preserved.
10  * ====================================================
11  */
12 
13 #if defined(LIBM_SCCS) && !defined(lint)
14 static char rcsid[] = "$NetBSD: s_copysign.c,v 1.8 1995/05/10 20:46:57 jtc Exp $";
15 #endif
16 
17 /*
18  * copysign(double x, double y)
19  * copysign(x,y) returns a value with the magnitude of x and
20  * with the sign bit of y.
21  */
22 
23 #include <sys/cdefs.h>
24 #include <float.h>
25 #include <math.h>
26 
27 #include "math_private.h"
28 
29 double
30 copysign(double x, double y)
31 {
32 	u_int32_t hx,hy;
33 	GET_HIGH_WORD(hx,x);
34 	GET_HIGH_WORD(hy,y);
35 	SET_HIGH_WORD(x,(hx&0x7fffffff)|(hy&0x80000000));
36         return x;
37 }
38 
39 #if LDBL_MANT_DIG == 53
40 #ifdef __weak_alias
41 __weak_alias(copysignl, copysign);
42 #endif /* __weak_alias */
43 #endif /* LDBL_MANT_DIG == 53 */
44