xref: /illumos-gate/usr/src/lib/libc/i386/fp/ieee.c (revision 5a172a1e0f9068ec8db35fa123baecf7bd540eb5)
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 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include "lint.h"
28 #include "base_conversion.h"
29 
30 /*
31  * Returns IEEE mode/status and
32  * sets up standard environment for base conversion.
33  */
34 void
__get_ieee_flags(__ieee_flags_type * b)35 __get_ieee_flags(__ieee_flags_type *b) {
36 	extern void _getcw(), _getsw(), _putcw();
37 	int cw;
38 
39 	_getcw(&cw);
40 	b->mode = cw;
41 	_getsw(&b->status);
42 	/*
43 	 * set CW to...
44 	 * RC (bits 10:11)	0 == round to nearest even
45 	 * PC (bits 8:9)	2 == round to double
46 	 * EM (bits 0:5)	0x3f == all exception trapping masked off
47 	 */
48 	cw = (cw & ~0xf3f) | 0x23f;
49 	_putcw(cw);
50 }
51 
52 /*
53  * Restores previous IEEE mode/status
54  */
55 void
__set_ieee_flags(__ieee_flags_type * b)56 __set_ieee_flags(__ieee_flags_type *b) {
57 	extern void _putcw(), _putsw();
58 
59 	_putcw(b->mode);
60 	_putsw(b->status);
61 }
62