/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

union ieee754_double
  {
    double d;

    /* This is the IEEE 754 double-precision format.  */
    struct
      {
	unsigned int negative:1;
	unsigned int exponent:11;
	/* Together these comprise the mantissa.  */
	unsigned int mantissa0:20;
	unsigned int mantissa1:32;
      } ieee;
  };

/* Return X with its signed changed to Y's.  */
double copysign (double x, double y)
{
  union ieee754_double ux, uy;

  ux.d = x;
  uy.d = y;

  ux.ieee.negative = uy.ieee.negative;

  return ux.d;
}