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 1.11 2002/05/26 22:01:58 wiz Exp $
13 * $DragonFly: src/lib/libm/src/s_rint.c,v 1.1 2005/07/26 21:15:20 joerg Exp $
18 * Return x rounded to integral value according to the prevailing
21 * Using floating addition.
23 * Inexact flag raised if x not equal to rint(x).
27 #include "math_private.h"
31 4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
32 -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
41 EXTRACT_WORDS(i0,i1,x);
43 j0 = ((i0>>20)&0x7ff)-0x3ff;
46 if(((i0&0x7fffffff)|i1)==0) return x;
49 i0 |= ((i1|-i1)>>12)&0x80000;
54 SET_HIGH_WORD(t,(i0&0x7fffffff)|(sx<<31));
58 if(((i0&i)|i1)==0) return x; /* x is integral */
61 if(j0==19) i1 = 0x40000000; else
62 i0 = (i0&(~i))|((0x20000)>>j0);
66 if(j0==0x400) return x+x; /* inf or NaN */
67 else return x; /* x is integral */
69 i = ((u_int32_t)(0xffffffff))>>(j0-20);
70 if((i1&i)==0) return x; /* x is integral */
72 if((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(j0-20));
74 INSERT_WORDS(x,i0,i1);