1 /* @(#)s_rint.c 5.1 93/09/24 */
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
10 * ====================================================
12 * $NetBSD: s_rint.c,v 1.12 2008/04/25 22:21:53 christos Exp $
17 * Return x rounded to integral value according to the prevailing
20 * Using floating addition.
22 * Inexact flag raised if x not equal to rint(x).
26 #include "math_private.h"
30 4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
31 -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
40 EXTRACT_WORDS(i0,i1,x);
42 jj0 = ((i0>>20)&0x7ff)-0x3ff;
45 if(((i0&0x7fffffff)|i1)==0) return x;
48 i0 |= ((i1|-i1)>>12)&0x80000;
53 SET_HIGH_WORD(t,(i0&0x7fffffff)|(sx<<31));
56 i = (0x000fffff)>>jj0;
57 if(((i0&i)|i1)==0) return x; /* x is integral */
60 if(jj0==19) i1 = 0x40000000; else
61 i0 = (i0&(~i))|((0x20000)>>jj0);
65 if(jj0==0x400) return x+x; /* inf or NaN */
66 else return x; /* x is integral */
68 i = ((u_int32_t)(0xffffffff))>>(jj0-20);
69 if((i1&i)==0) return x; /* x is integral */
71 if((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(jj0-20));
73 INSERT_WORDS(x,i0,i1);