sysdeps/ieee754/dbl-64/s_copysign.c

   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 <math.h>
  24 #include <math_private.h>
  25
  26 double
  27 __copysign (double x, double y)
  28 {
  29   u_int32_t hx, hy;
  30   GET_HIGH_WORD (hx, x);
  31   GET_HIGH_WORD (hy, y);
  32   SET_HIGH_WORD (x, (hx & 0x7fffffff) | (hy & 0x80000000));
  33   return x;
  34 }
  35 weak_alias (__copysign, copysign)
  36 #ifdef NO_LONG_DOUBLE
  37 strong_alias (__copysign, __copysignl)
  38 weak_alias (__copysign, copysignl)
  39 #endif