/* @(#)s_rint.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. * ==================================================== *//* * rint(x) * Return x rounded to integral value according to the prevailing * rounding mode. * Method: *	Using floating addition. * Exception: *	Inexact flag raised if x not equal to rint(x). */#include "fdlibm.h"#ifndef _DOUBLE_IS_32BITS#ifdef __STDC__static const double#elsestatic double #endifTWO52[2]={  4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */ -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */};#ifdef __STDC__	double rint(double x)#else	double rint(x)	double x;#endif{	__int32_t i0,j0,sx;	__uint32_t i,i1;	double w,t;	EXTRACT_WORDS(i0,i1,x);	sx = (i0>>31)&1;	j0 = ((i0>>20)&0x7ff)-0x3ff;	if(j0<20) {	    if(j0<0) { 			if(((i0&0x7fffffff)|i1)==0) return x;		i1 |= (i0&0x0fffff);		i0 &= 0xfffe0000;		i0 |= ((i1|-i1)>>12)&0x80000;		SET_HIGH_WORD(x,i0);	        w = TWO52[sx]+x;	        t =  w-TWO52[sx];		GET_HIGH_WORD(i0,t);		SET_HIGH_WORD(t,(i0&0x7fffffff)|(sx<<31));	        return t;	    } else {		i = (0x000fffff)>>j0;		if(((i0&i)|i1)==0) return x; /* x is integral */		i>>=1;		if(((i0&i)|i1)!=0) {		    if(j0==19) i1 = 0x40000000; else		    i0 = (i0&(~i))|((0x20000)>>j0);		}	    }	} else if (j0>51) {	    if(j0==0x400) return x+x;	/* inf or NaN */	    else return x;		/* x is integral */	} else {	    i = ((__uint32_t)(0xffffffff))>>(j0-20);	    if((i1&i)==0) return x;	/* x is integral */	    i>>=1;	    if((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(j0-20));	}	INSERT_WORDS(x,i0,i1);	w = TWO52[sx]+x;	return w-TWO52[sx];}#endif /* _DOUBLE_IS_32BITS */