xref: /illumos-gate/usr/src/lib/libm/i386/src/remquo.S (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
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 "remquo.s"
30
31#include "libm.h"
32LIBM_ANSI_PRAGMA_WEAK(remquo,function)
33#include "libm_protos.h"
34
35	ENTRY(remquo)
36	fldl	12(%esp)		/ load arg y
37	fldl	4(%esp)			/ load arg x
38.Lrem_loop:
39	fprem1				/ partial remainder
40	fstsw	%ax			/ store status word
41	andw	$0x400,%ax		/ check whether reduction complete
42	jne	.Lrem_loop		/ while reduction incomplete, do fprem1
43	fstsw	%ax
44	fwait
45	fstp	%st(1)
46	movw	%ax,%dx
47	andw	$0x4000,%dx		/ get C3
48	sarw	$13,%dx
49	movw	%ax,%cx
50	andw	$0x100,%cx		/ get C0
51	sarw	$6,%cx
52	addw	%cx,%dx
53	andw	$0x200,%ax		/ get C1
54	sarw	$9,%ax
55	addw	%dx,%ax
56	cwtl
57	movl	8(%esp),%edx		/ sign and bexp of x
58	movl	16(%esp),%ecx		/ sign and bexp of y
59	andl	$0x80000000,%edx	/ edx <- sign(x)
60	andl	$0x80000000,%ecx	/ ecx <- sign(y)
61	cmpl	%edx,%ecx
62	je	.pos
63	negl	%eax			/ negative n
64.pos:
65	movl	20(%esp),%ecx
66	movl	%eax,0(%ecx)		/ last 3 significant bits of quotient
67	ret
68	.align	4
69	SET_SIZE(remquo)
70