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
);