1 /* $NetBSD: fenv.c,v 1.3 2017/12/30 17:59:24 martin Exp $ */
2
3 /*-
4 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD: src/lib/msun/alpha/fenv.c,v 1.2 2005/03/16 19:03:44 das Exp $
29 */
30 #include <sys/cdefs.h>
31 __RCSID("$NetBSD: fenv.c,v 1.3 2017/12/30 17:59:24 martin Exp $");
32
33 #include "namespace.h"
34
35 #include <machine/sysarch.h>
36 #include <fenv.h>
37
38 #ifdef __weak_alias
39 __weak_alias(fegetenv,_fegetenv)
40 __weak_alias(feholdexcept,_feholdexcept)
41 __weak_alias(fesetenv,_fesetenv)
42 __weak_alias(feupdateenv,_feupdateenv)
43 __weak_alias(feenableexcept,_feenableexcept)
44 __weak_alias(fedisableexcept,_fedisableexcept)
45 __weak_alias(fegetexcept,_fegetexcept)
46 #endif
47
48 const fenv_t __fe_dfl_env = 0x680e000000000000ULL;
49
50 /*
51 * The lower 49 bits of the FPCR are unused by the hardware, so we use
52 * the lower order bits to store the kernel's idea of the FP mask as
53 * described in the Alpha Architecture Manual.
54 */
55 int
fegetenv(fenv_t * envp)56 fegetenv(fenv_t *envp)
57 {
58 struct alpha_fp_except_args p;
59 union __fpcr r;
60
61 /*
62 * The syscall acts as an implicit exception barrier, so we
63 * only need to issue an excb after the mf_fpcr to ensure that
64 * the read is executed before any subsequent FP ops.
65 */
66 p.mask = sysarch(ALPHA_FPGETMASK, 0);
67 __mf_fpcr(&r.__d);
68 *envp = r.__bits | p.mask;
69 __excb();
70 return 0;
71 }
72
73 int
feholdexcept(fenv_t * envp)74 feholdexcept(fenv_t *envp)
75 {
76 struct alpha_fp_except_args p;
77 union __fpcr r;
78
79 p.mask = sysarch(ALPHA_FPGETMASK, 0);
80 __mf_fpcr(&r.__d);
81 *envp = r.__bits | p.mask;
82 r.__bits &= ~((fenv_t)FE_ALL_EXCEPT << _FPUSW_SHIFT);
83 __mt_fpcr(r.__d);
84 if (p.mask & FE_ALL_EXCEPT) {
85 p.mask = 0;
86 sysarch(ALPHA_FPSETMASK, &p);
87 }
88 __excb();
89 return 0;
90 }
91
92 int
fesetenv(const fenv_t * envp)93 fesetenv(const fenv_t *envp)
94 {
95 struct alpha_fp_except_args p;
96 union __fpcr r;
97
98 p.mask = *envp & FE_ALL_EXCEPT;
99 sysarch(ALPHA_FPSETMASK, &p);
100 r.__bits = *envp & ~FE_ALL_EXCEPT;
101 __mt_fpcr(r.__d);
102 __excb();
103 return 0;
104 }
105
106 int
feupdateenv(const fenv_t * envp)107 feupdateenv(const fenv_t *envp)
108 {
109 struct alpha_fp_except_args p;
110 union __fpcr oldr, newr;
111
112 p.mask = *envp & FE_ALL_EXCEPT;
113 sysarch(ALPHA_FPSETMASK, &p);
114 __mf_fpcr(&oldr.__d);
115 newr.__bits = *envp & ~FE_ALL_EXCEPT;
116 __excb();
117 __mt_fpcr(newr.__d);
118 feraiseexcept((oldr.__bits >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
119 return 0;
120 }
121
122 int
feenableexcept(int mask)123 feenableexcept(int mask)
124 {
125 struct alpha_fp_except_args p;
126
127 p.mask = sysarch(ALPHA_FPGETMASK, 0);
128 p.mask |= (mask & FE_ALL_EXCEPT);
129 sysarch(ALPHA_FPSETMASK, &p);
130 return p.mask;
131 }
132
133 int
fedisableexcept(int mask)134 fedisableexcept(int mask)
135 {
136 struct alpha_fp_except_args p;
137
138 p.mask = sysarch(ALPHA_FPGETMASK, 0);
139 p.mask &= ~(mask & FE_ALL_EXCEPT);
140 sysarch(ALPHA_FPSETMASK, &p);
141 return p.mask;
142 }
143
144 int
fegetexcept(void)145 fegetexcept(void)
146 {
147
148 return sysarch(ALPHA_FPGETMASK, 0);
149 }
150