sf_copysign.c

标准c库代码,可以应用于各个系统提供了大量的基本函数

/* sf_copysign.c -- float version of s_copysign.c.
 * Conversion to float by Ian Lance Taylor, Cygnus Support, [e-mail].
 */

/*
 * ====================================================
 * 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.
 * ====================================================
 */

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

#include "fdlibm.h"

#ifdef __STDC__
	float copysignf(float x, float y)
#else
	float copysignf(x,y)
	float x,y;
#endif
{
	__uint32_t ix,iy;
	GET_FLOAT_WORD(ix,x);
	GET_FLOAT_WORD(iy,y);
	SET_FLOAT_WORD(x,(ix&0x7fffffff)|(iy&0x80000000));
        return x;
}