/* derived from /netlib/fdlibm */ /* @(#)s_modf.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. * ==================================================== */ /* * modf(double x, double *iptr)  * return fraction part of x, and return x's integral part in *iptr. * Method: *	Bit twiddling. * * Exception: *	No exception. */ #include "fdlibm.h" static const double one = 1.0; 	double modf(double x, double *iptr){	int i0,i1,j0;	unsigned i;	i0 =  __HI(x);		/* high x */	i1 =  __LO(x);		/* low  x */	j0 = ((i0>>20)&0x7ff)-0x3ff;	/* exponent of x */	if(j0<20) {			/* integer part in high x */	    if(j0<0) {			/* |x|<1 */		__HIp(iptr) = i0&0x80000000;		__LOp(iptr) = 0;		/* *iptr = +-0 */		return x;	    } else {		i = (0x000fffff)>>j0;		if(((i0&i)|i1)==0) {		/* x is integral */		    *iptr = x;		    __HI(x) &= 0x80000000;		    __LO(x)  = 0;	/* return +-0 */		    return x;		} else {		    __HIp(iptr) = i0&(~i);		    __LOp(iptr) = 0;		    return x - *iptr;		}	    }	} else if (j0>51) {		/* no fraction part */	    *iptr = x*one;	    __HI(x) &= 0x80000000;	    __LO(x)  = 0;	/* return +-0 */	    return x;	} else {			/* fraction part in low x */	    i = ((unsigned)(0xffffffff))>>(j0-20);	    if((i1&i)==0) { 		/* x is integral */		*iptr = x;		__HI(x) &= 0x80000000;		__LO(x)  = 0;	/* return +-0 */		return x;	    } else {		__HIp(iptr) = i0;		__LOp(iptr) = i1&(~i);		return x - *iptr;	    }	}}