1
2 /* @(#)s_copysign.c 5.1 93/09/24 */
3 /*
4 * ====================================================
5 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6 *
7 * Developed at SunPro, a Sun Microsystems, Inc. business.
8 * Permission to use, copy, modify, and distribute this
9 * software is freely granted, provided that this notice
10 * is preserved.
11 * ====================================================
12 */
13
14 /*
15 FUNCTION
16 <<copysign>>, <<copysignf>>---sign of <[y]>, magnitude of <[x]>
17
18 INDEX
19 copysign
20 INDEX
21 copysignf
22
23 SYNOPSIS
24 #include <math.h>
25 double copysign (double <[x]>, double <[y]>);
26 float copysignf (float <[x]>, float <[y]>);
27
28 DESCRIPTION
29 <<copysign>> constructs a number with the magnitude (absolute value)
30 of its first argument, <[x]>, and the sign of its second argument,
31 <[y]>.
32
33 <<copysignf>> does the same thing; the two functions differ only in
34 the type of their arguments and result.
35
36 RETURNS
37 <<copysign>> returns a <<double>> with the magnitude of
38 <[x]> and the sign of <[y]>.
39 <<copysignf>> returns a <<float>> with the magnitude of
40 <[x]> and the sign of <[y]>.
41
42 PORTABILITY
43 <<copysign>> is not required by either ANSI C or the System V Interface
44 Definition (Issue 2).
45
46 */
47
48 /*
49 * copysignl(long double x, long double y)
50 * copysignl(x,y) returns a value with the magnitude of x and
51 * with the sign bit of y.
52 */
53
54 long double
copysignl(long double x,long double y)55 copysignl(long double x, long double y)
56 {
57 int64_t hx, hy;
58 GET_LDOUBLE_MSW64(hx, x);
59 GET_LDOUBLE_MSW64(hy, y);
60 SET_LDOUBLE_MSW64(x, (hx & 0x7fffffffffffffffLL)|(hy & 0x8000000000000000LL));
61 return x;
62 }
63
