1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2004-2011 David Schultz <[email protected]>
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 * $FreeBSD$
29 */
30
31 #ifndef _FENV_H_
32 #error "This file is meant to be included only by <fenv.h>."
33 #endif
34
35 /*
36 * This file implements the functionality of <fenv.h> on platforms that
37 * lack an FPU and use softfloat in libc for floating point. To use it,
38 * you must write an <fenv.h> that provides the following:
39 *
40 * - a typedef for fenv_t, which may be an integer or struct type
41 * - a typedef for fexcept_t (XXX This file assumes fexcept_t is a
42 * simple integer type containing the exception mask.)
43 * - definitions of FE_* constants for the five exceptions and four
44 * rounding modes in IEEE 754, as described in fenv(3)
45 * - a definition, and the corresponding external symbol, for FE_DFL_ENV
46 * - a macro __set_env(env, flags, mask, rnd), which sets the given fenv_t
47 * from the exception flags, mask, and rounding mode
48 * - macros __env_flags(env), __env_mask(env), and __env_round(env), which
49 * extract fields from an fenv_t
50 * - a definition of __fenv_static
51 *
52 * If the architecture supports an optional FPU, it's recommended that you
53 * define fenv_t and fexcept_t to match the hardware ABI. Otherwise, it
54 * doesn't matter how you define them.
55 */
56
57 extern int __softfloat_float_exception_flags;
58 extern int __softfloat_float_exception_mask;
59 extern int __softfloat_float_rounding_mode;
60 void __softfloat_float_raise(int);
61
62 __fenv_static inline int
feclearexcept(int __excepts)63 feclearexcept(int __excepts)
64 {
65
66 __softfloat_float_exception_flags &= ~__excepts;
67 return (0);
68 }
69
70 __fenv_static inline int
fegetexceptflag(fexcept_t * __flagp,int __excepts)71 fegetexceptflag(fexcept_t *__flagp, int __excepts)
72 {
73
74 *__flagp = __softfloat_float_exception_flags & __excepts;
75 return (0);
76 }
77
78 __fenv_static inline int
fesetexceptflag(const fexcept_t * __flagp,int __excepts)79 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
80 {
81
82 __softfloat_float_exception_flags &= ~__excepts;
83 __softfloat_float_exception_flags |= *__flagp & __excepts;
84 return (0);
85 }
86
87 __fenv_static inline int
feraiseexcept(int __excepts)88 feraiseexcept(int __excepts)
89 {
90
91 __softfloat_float_raise(__excepts);
92 return (0);
93 }
94
95 __fenv_static inline int
fetestexcept(int __excepts)96 fetestexcept(int __excepts)
97 {
98
99 return (__softfloat_float_exception_flags & __excepts);
100 }
101
102 __fenv_static inline int
fegetround(void)103 fegetround(void)
104 {
105
106 return (__softfloat_float_rounding_mode);
107 }
108
109 __fenv_static inline int
fesetround(int __round)110 fesetround(int __round)
111 {
112
113 __softfloat_float_rounding_mode = __round;
114 return (0);
115 }
116
117 __fenv_static inline int
fegetenv(fenv_t * __envp)118 fegetenv(fenv_t *__envp)
119 {
120
121 __set_env(*__envp, __softfloat_float_exception_flags,
122 __softfloat_float_exception_mask, __softfloat_float_rounding_mode);
123 return (0);
124 }
125
126 __fenv_static inline int
feholdexcept(fenv_t * __envp)127 feholdexcept(fenv_t *__envp)
128 {
129 fenv_t __env;
130
131 fegetenv(__envp);
132 __softfloat_float_exception_flags = 0;
133 __softfloat_float_exception_mask = 0;
134 return (0);
135 }
136
137 __fenv_static inline int
fesetenv(const fenv_t * __envp)138 fesetenv(const fenv_t *__envp)
139 {
140
141 __softfloat_float_exception_flags = __env_flags(*__envp);
142 __softfloat_float_exception_mask = __env_mask(*__envp);
143 __softfloat_float_rounding_mode = __env_round(*__envp);
144 return (0);
145 }
146
147 __fenv_static inline int
feupdateenv(const fenv_t * __envp)148 feupdateenv(const fenv_t *__envp)
149 {
150 int __oflags = __softfloat_float_exception_flags;
151
152 fesetenv(__envp);
153 feraiseexcept(__oflags);
154 return (0);
155 }
156
157 #if __BSD_VISIBLE
158
159 /* We currently provide no external definitions of the functions below. */
160
161 __fenv_static inline int
feenableexcept(int __mask)162 feenableexcept(int __mask)
163 {
164 int __omask = __softfloat_float_exception_mask;
165
166 __softfloat_float_exception_mask |= __mask;
167 return (__omask);
168 }
169
170 __fenv_static inline int
fedisableexcept(int __mask)171 fedisableexcept(int __mask)
172 {
173 int __omask = __softfloat_float_exception_mask;
174
175 __softfloat_float_exception_mask &= ~__mask;
176 return (__omask);
177 }
178
179 __fenv_static inline int
fegetexcept(void)180 fegetexcept(void)
181 {
182
183 return (__softfloat_float_exception_mask);
184 }
185
186 #endif /* __BSD_VISIBLE */
187