1 /* $NetBSD: fenv.h,v 1.4 2024/10/30 15:56:10 riastradh 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.h,v 1.3 2005/03/16 19:03:44 das Exp $
29 */
30
31 #ifndef _ALPHA_FENV_H_
32 #define _ALPHA_FENV_H_
33
34 #include <sys/featuretest.h>
35 #include <sys/stdint.h>
36
37 typedef __uint64_t fenv_t;
38 typedef __uint16_t fexcept_t;
39
40 /* Exception flags */
41 #define FE_INVALID 0x01
42 #define FE_DIVBYZERO 0x02
43 #define FE_OVERFLOW 0x04
44 #define FE_UNDERFLOW 0x08
45 #define FE_INEXACT 0x10
46 #define FE_INTOVF 0x20 /* not maskable */
47 #define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INTOVF | \
48 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
49
50 /* Rounding modes */
51 #define FE_TOWARDZERO 0x00
52 #define FE_DOWNWARD 0x01
53 #define FE_TONEAREST 0x02
54 #define FE_UPWARD 0x03
55 #define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \
56 FE_UPWARD | FE_TOWARDZERO)
57 #define _ROUND_SHIFT 58
58
59 #define _FPUSW_SHIFT 52
60
61 #define __excb() __asm __volatile("excb")
62 #define __mf_fpcr(__cw) __asm __volatile("mf_fpcr %0" : "=f" (*(__cw)))
63 #define __mt_fpcr(__cw) __asm __volatile("mt_fpcr %0" : : "f" (__cw))
64
65 union __fpcr {
66 double __d;
67 fenv_t __bits;
68 };
69
70 __BEGIN_DECLS
71
72 /* Default floating-point environment */
73 extern const fenv_t __fe_dfl_env;
74 #define FE_DFL_ENV (&__fe_dfl_env)
75
76 #if __GNUC_PREREQ__(8, 0)
77 #pragma GCC diagnostic push
78 #pragma GCC diagnostic ignored "-Wshadow"
79 #endif
80
81 static __inline int
feclearexcept(int __excepts)82 feclearexcept(int __excepts)
83 {
84 union __fpcr __r;
85
86 __excb();
87 __mf_fpcr(&__r.__d);
88 __r.__bits &= ~((fenv_t)__excepts << _FPUSW_SHIFT);
89 __mt_fpcr(__r.__d);
90 __excb();
91 return 0;
92 }
93
94 static __inline int
fegetexceptflag(fexcept_t * __flagp,int __excepts)95 fegetexceptflag(fexcept_t *__flagp, int __excepts)
96 {
97 union __fpcr __r;
98
99 __excb();
100 __mf_fpcr(&__r.__d);
101 __excb();
102 *__flagp = (__r.__bits >> _FPUSW_SHIFT) & __excepts;
103 return 0;
104 }
105
106 static __inline int
fesetexceptflag(const fexcept_t * __flagp,int __excepts)107 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
108 {
109 union __fpcr __r;
110 fenv_t __xflag, __xexcepts;
111
112 __xflag = (fenv_t)*__flagp << _FPUSW_SHIFT;
113 __xexcepts = (fenv_t)__excepts << _FPUSW_SHIFT;
114 __excb();
115 __mf_fpcr(&__r.__d);
116 __r.__bits &= ~__xexcepts;
117 __r.__bits |= __xflag & __xexcepts;
118 __mt_fpcr(__r.__d);
119 __excb();
120 return 0;
121 }
122
123 static __inline int
feraiseexcept(int __excepts)124 feraiseexcept(int __excepts)
125 {
126
127 /*
128 * XXX Generating exceptions this way does not actually invoke
129 * a userland trap handler when enabled, but neither do
130 * arithmetic operations as far as I can tell. Perhaps there
131 * are more bugs in the kernel trap handler.
132 */
133 fexcept_t __ex = __excepts;
134 fesetexceptflag(&__ex, __excepts);
135 return 0;
136 }
137
138 static __inline int
fetestexcept(int __excepts)139 fetestexcept(int __excepts)
140 {
141 union __fpcr __r;
142
143 __excb();
144 __mf_fpcr(&__r.__d);
145 __excb();
146 return (__r.__bits >> _FPUSW_SHIFT) & __excepts;
147 }
148
149 static __inline int
fegetround(void)150 fegetround(void)
151 {
152 union __fpcr __r;
153
154 /*
155 * No exception barriers should be required here if we assume
156 * that only fesetround() can change the rounding mode.
157 */
158 __mf_fpcr(&__r.__d);
159 return (int)(__r.__bits >> _ROUND_SHIFT) & _ROUND_MASK;
160 }
161
162 static __inline int
fesetround(int __round)163 fesetround(int __round)
164 {
165 union __fpcr __r;
166
167 if (__round & ~_ROUND_MASK)
168 return (-1);
169 __excb();
170 __mf_fpcr(&__r.__d);
171 __r.__bits &= ~((fenv_t)_ROUND_MASK << _ROUND_SHIFT);
172 __r.__bits |= (fenv_t)__round << _ROUND_SHIFT;
173 __mt_fpcr(__r.__d);
174 __excb();
175 return 0;
176 }
177
178 #if __GNUC_PREREQ__(8, 0)
179 #pragma GCC diagnostic pop
180 #endif
181
182 int fegetenv(fenv_t *);
183 int feholdexcept(fenv_t *);
184 int fesetenv(const fenv_t *);
185 int feupdateenv(const fenv_t *);
186
187 #if defined(_NETBSD_SOURCE) || defined(_GNU_SOURCE)
188 int feenableexcept(int);
189 int fedisableexcept(int);
190 int fegetexcept(void);
191 #endif /* _NETBSD_SOURCE || _GNU_SOURCE */
192
193
194 __END_DECLS
195
196 #endif /* !_ALPHA_FENV_H_ */
197