s_copysign.c

来自「linux下建立JAVA虚拟机的源码KAFFE」· C语言 代码 · 共 38 行

/* @(#)s_copysign.c 1.3 95/01/18 */
/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunSoft, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice 
 * is preserved.
 * ====================================================
 */

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

#include "fdlibm.h"

#ifndef _DOUBLE_IS_32BITS

#ifdef __STDC__
	double copysign(double x, double y)
#else
	double copysign(x,y)
	double x,y;
#endif
{
        uint32_t hx, hy;
	GET_HIGH_WORD(hx, x);
	GET_HIGH_WORD(hy, y);
	SET_HIGH_WORD(x, (hx&0x7fffffff)|(hy&0x80000000));
        return x;
}
#endif /* _DOUBLE_IS_32BITS */