xref: /onnv-gate/usr/src/lib/libbc/libc/gen/common/sparc/isinf.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 1986 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate /*
30*0Sstevel@tonic-gate  * Recognize an infinity or a NaN when one is presented.
31*0Sstevel@tonic-gate  * This is for keeping various IO routines out of trouble
32*0Sstevel@tonic-gate  */
33*0Sstevel@tonic-gate 
34*0Sstevel@tonic-gate 
35*0Sstevel@tonic-gate int
isinf(d0,d1)36*0Sstevel@tonic-gate isinf( d0, d1 )
37*0Sstevel@tonic-gate     unsigned d0,d1;
38*0Sstevel@tonic-gate     /* a lie -- actually its a ``double'' */
39*0Sstevel@tonic-gate {
40*0Sstevel@tonic-gate     if (d1 != 0 ) return 0; /* nope -- low-order must be all zeros */
41*0Sstevel@tonic-gate     if (d0 != 0x7ff00000 && d0 != 0xfff00000) return 0; /* nope */
42*0Sstevel@tonic-gate     return 1;
43*0Sstevel@tonic-gate }
44*0Sstevel@tonic-gate 
45*0Sstevel@tonic-gate int
isnan(d0,d1)46*0Sstevel@tonic-gate isnan( d0,d1 )
47*0Sstevel@tonic-gate     unsigned d0,d1;
48*0Sstevel@tonic-gate     /* a lie -- actually its a ``double'' */
49*0Sstevel@tonic-gate {
50*0Sstevel@tonic-gate #define EXPONENT 0x7ff00000
51*0Sstevel@tonic-gate #define SIGN     0x80000000
52*0Sstevel@tonic-gate     if ((d0 & EXPONENT) != EXPONENT ) return 0; /* exponent wrong */
53*0Sstevel@tonic-gate     if ((d0 & ~(EXPONENT|SIGN)) == 0 && d1 == 0 ) return 0; /* must have bits */
54*0Sstevel@tonic-gate     return 1;
55*0Sstevel@tonic-gate }
56