xref: /titanic_41/usr/src/lib/libc/amd64/fp/ieee.c (revision bb6fd8f9750a0c1d46a75c5bcc91952d3709334b)
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 #include <sys/isa_defs.h>
30 
31 #define	CSR_DEFAULT 0x1f80
32 
33 /*
34  * Returns IEEE mode/status and
35  * sets up standard environment for base conversion.
36  */
37 void
38 __get_ieee_flags(__ieee_flags_type *b) {
39 	extern void _getmxcsr(), _putmxcsr();
40 
41 	_getmxcsr(&b->status);
42 
43 	/* round-to-nearest, all exceptions masked, gradual underflow */
44 	_putmxcsr(CSR_DEFAULT);
45 }
46 
47 /*
48  * Restores previous IEEE mode/status
49  */
50 void
51 __set_ieee_flags(__ieee_flags_type *b) {
52 	extern void _putmxcsr();
53 
54 	_putmxcsr(b->status);
55 }
56