xref: /illumos-gate/usr/src/lib/libm/common/m9x/feround.c (revision 2c5ec7a875dcd76853e6618614e990f1e8cdd56d)
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 2011 Nexenta Systems, Inc.  All rights reserved.
24  */
25 /*
26  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #pragma weak __fegetround = fegetround
31 #pragma weak __fesetround = fesetround
32 
33 #pragma weak fegetround96 = __fegetround
34 
35 #include <fenv.h>
36 #include <ucontext.h>
37 #include <thread.h>
38 #include "fex_handler.h"
39 #include "fenv_inlines.h"
40 
41 #if defined(__i386) && !defined(__amd64)
42 #include <float.h>
43 #endif
44 
45 int fegetround(void)
46 {
47 	unsigned long	fsr;
48 
49 	__fenv_getfsr(&fsr);
50 	return (int)__fenv_get_rd(fsr);
51 }
52 
53 int fesetround(int r)
54 {
55 	unsigned long	fsr;
56 
57 	if (r & ~3)
58 		return -1;
59 	__fenv_getfsr(&fsr);
60 	__fenv_set_rd(fsr, r);
61 	__fenv_setfsr(&fsr);
62 #if defined(__i386) && !defined(__amd64)
63 	FLT_ROUNDS = (0x2D >> (r << 1)) & 3;	/* 0->1, 1->3, 2->2, 3->0 */
64 #endif
65 	return 0;
66 }
67 
68 int fesetround96(int r)
69 {
70 	unsigned long	fsr;
71 
72 	if (r & ~3)
73 		return 0;
74 	__fenv_getfsr(&fsr);
75 	__fenv_set_rd(fsr, r);
76 	__fenv_setfsr(&fsr);
77 #if defined(__i386) && !defined(__amd64)
78 	FLT_ROUNDS = (0x2D >> (r << 1)) & 3;	/* 0->1, 1->3, 2->2, 3->0 */
79 #endif
80 	return 1;
81 }
82