view src/libm/s_copysign.c @ 3376:106a409ceeef

This is crazy. In order to override the default optimization for GCC, we actually have to include the core autoconf C compiler macro suite.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 11 Oct 2009 06:33:34 +0000 (2009-10-11)
parents dc1eb82ffdaa
children
line wrap: on
line source
/* @(#)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.
 * ====================================================
 */

#if defined(LIBM_SCCS) && !defined(lint)
static const char rcsid[] =
    "$NetBSD: s_copysign.c,v 1.8 1995/05/10 20:46:57 jtc 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"

libm_hidden_proto(copysign)
#ifdef __STDC__
     double copysign(double x, double y)
#else
     double copysign(x, y)
     double x, y;
#endif
{
    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;
}

libm_hidden_def(copysign)