xref: /illumos-gate/usr/src/lib/libm/i386/src/isnanl.S (revision 5d9d9091)
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
23 */
24/*
25 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
26 * Use is subject to license terms.
27 */
28
29        .file "isnanl.s"
30
31#include "libm.h"
32LIBM_ANSI_PRAGMA_WEAK(isnanl,function)
33
34	ENTRY(isnanl)
35	movl    12(%esp),%eax		/ ax <-- sign bit and exp
36	andl    $0x00007fff,%eax
37	jz	.not_nan		/ jump if exp is all 0
38	xorl    $0x00007fff,%eax
39	jz	.nan_or_inf		/ jump if exp is all 1
40	testl   $0x80000000,8(%esp)
41	jz	.got_nan		/ jump if leading bit is 0
42	movl	$0,%eax
43.not_nan:
44	ret
45.nan_or_inf:				/ note that %eax = 0 from before
46	cmpl    $0x80000000,8(%esp)     / what is first half of significand?
47	jnz	.got_nan		/ jump if not equal to 0x80000000
48	testl	$0xffffffff,4(%esp)	/ is second half of significand 0?
49	jnz	.got_nan		/ jump if not equal to 0
50	ret
51.got_nan:
52	movl	$1,%eax
53	ret
54	.align	4
55	SET_SIZE(isnanl)
56