lib/libm/src/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 #include <sys/cdefs.h>
  14 #if defined(LIBM_SCCS) && !defined(lint)
  15 __RCSID("$NetBSD: s_copysign.c,v 1.13 2015/05/14 19:26:12 joerg Exp $");
  16 #endif
  17
  18 /*
  19  * copysign(double x, double y)
  20  * copysign(x,y) returns a value with the magnitude of x and
  21  * with the sign bit of y.
  22  */
  23
  24 #include "math.h"
  25 #include "math_private.h"
  26
  27 #if !defined(__HAVE_LONG_DOUBLE) && !defined(__HAVE_IBM_LONGDOUBLE)
  28 __strong_alias(_copysignl, copysign)
  29 __weak_alias(copysignl, copysign)
  30 #endif
  31
  32 double
  33 copysign(double x, double y)
  34 {
  35         u_int32_t hx,hy;
  36         GET_HIGH_WORD(hx,x);
  37         GET_HIGH_WORD(hy,y);
  38         SET_HIGH_WORD(x,(hx&0x7fffffff)|(hy&0x80000000));
  39         return x;
  40 }