xref: /titanic_51/usr/src/lib/libm/i386/src/finitel.s (revision b59c4a48daf5a1863ecac763711b497b2f8321e4)
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 "finitel.s"
30
31#include "libm.h"
32LIBM_ANSI_PRAGMA_WEAK(finitel,function)
33#include "libm_synonyms.h"
34
35	ENTRY(finitel)
36	movl    12(%esp),%eax		/ %ax <-- sign&bexp(x)
37	testl	$0x80000000,8(%esp)	/ ZF = 1 iff hi_32(sgnfcnd(x))'s msb = 0
38	jz	.chk_denormal_or_0
39	notl	%eax			/ not(bexp) = 0 iff bexp = all 1's
40	andl    $0x00007fff,%eax	/ ZF <-- 1      iff not(bexp) = 0
41	jz	.done			/ no jump if arg. is finite
42	movl	$1,%eax			/ ansi needs %eax = 1
43.done:
44	ret
45
46.chk_denormal_or_0:
47	andl	$0x00007fff,%eax	/ ZF <-- 1 iff bexp = 0 iff denormal or 0
48	jnz	.unsupported		/ jump if arg has unsupported format
49	movl	$1,%eax			/ ansi needs %eax = 1
50	ret
51
52.unsupported:
53	movl	$0,%eax			/ unsupported format does not represent
54	ret				/ a finite number
55	.align	4
56	SET_SIZE(finitel)
57