C++程序  |  36行  |  970 B

/* @(#)s_copysign.c 5.1 93/09/24 */
/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */
#include  <LibConfig.h>
#include  <sys/EfiCdefs.h>
#if defined(LIBM_SCCS) && !defined(lint)
__RCSID("$NetBSD: s_copysign.c,v 1.11 2002/05/26 22:01:54 wiz Exp $");
#endif

/*
 * copysign(double x, double y)
 * copysign(x,y) returns a value with the magnitude of x and
 * with the sign bit of y.
 */

#include "math.h"
#include "math_private.h"

double
copysign(double x, double y)
{
  u_int32_t hx,hy;
  GET_HIGH_WORD(hx,x);
  GET_HIGH_WORD(hy,y);
  SET_HIGH_WORD(x,(hx&0x7fffffff)|(hy&0x80000000));
        return x;
}