1 /*-
2 * Copyright (c) 2004-2011 David Schultz <das@FreeBSD.ORG>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29 #ifndef _FENV_H_
30 #error "This file is meant to be included only by <fenv.h>."
31 #endif
32
33 /*
34 * This file implements the functionality of <fenv.h> on platforms that
35 * lack an FPU and use softfloat in libc for floating point. To use it,
36 * you must write an <fenv.h> that provides the following:
37 *
38 * - a typedef for fenv_t, which may be an integer or struct type
39 * - a typedef for fexcept_t (XXX This file assumes fexcept_t is a
40 * simple integer type containing the exception mask.)
41 * - definitions of FE_* constants for the five exceptions and four
42 * rounding modes in IEEE 754, as described in fenv(3)
43 * - a definition, and the corresponding external symbol, for FE_DFL_ENV
44 * - a macro __set_env(env, flags, mask, rnd), which sets the given fenv_t
45 * from the exception flags, mask, and rounding mode
46 * - macros __env_flags(env), __env_mask(env), and __env_round(env), which
47 * extract fields from an fenv_t
48 * - a definition of __fenv_static
49 *
50 * If the architecture supports an optional FPU, it's recommended that you
51 * define fenv_t and fexcept_t to match the hardware ABI. Otherwise, it
52 * doesn't matter how you define them.
53 */
54
55 extern int __softfloat_float_exception_flags;
56 extern int __softfloat_float_exception_mask;
57 extern int __softfloat_float_rounding_mode;
58 void __softfloat_float_raise(int);
59
60 __fenv_static inline int
feclearexcept(int __excepts)61 feclearexcept(int __excepts)
62 {
63
64 __softfloat_float_exception_flags &= ~__excepts;
65 return (0);
66 }
67
68 __fenv_static inline int
fegetexceptflag(fexcept_t * __flagp,int __excepts)69 fegetexceptflag(fexcept_t *__flagp, int __excepts)
70 {
71
72 *__flagp = __softfloat_float_exception_flags & __excepts;
73 return (0);
74 }
75
76 __fenv_static inline int
fesetexceptflag(const fexcept_t * __flagp,int __excepts)77 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
78 {
79
80 __softfloat_float_exception_flags &= ~__excepts;
81 __softfloat_float_exception_flags |= *__flagp & __excepts;
82 return (0);
83 }
84
85 __fenv_static inline int
feraiseexcept(int __excepts)86 feraiseexcept(int __excepts)
87 {
88
89 __softfloat_float_raise(__excepts);
90 return (0);
91 }
92
93 __fenv_static inline int
fetestexcept(int __excepts)94 fetestexcept(int __excepts)
95 {
96
97 return (__softfloat_float_exception_flags & __excepts);
98 }
99
100 __fenv_static inline int
fegetround(void)101 fegetround(void)
102 {
103
104 return (__softfloat_float_rounding_mode);
105 }
106
107 __fenv_static inline int
fesetround(int __round)108 fesetround(int __round)
109 {
110
111 __softfloat_float_rounding_mode = __round;
112 return (0);
113 }
114
115 __fenv_static inline int
fegetenv(fenv_t * __envp)116 fegetenv(fenv_t *__envp)
117 {
118
119 __set_env(*__envp, __softfloat_float_exception_flags,
120 __softfloat_float_exception_mask, __softfloat_float_rounding_mode);
121 return (0);
122 }
123
124 __fenv_static inline int
feholdexcept(fenv_t * __envp)125 feholdexcept(fenv_t *__envp)
126 {
127 fenv_t __env;
128
129 fegetenv(__envp);
130 __softfloat_float_exception_flags = 0;
131 __softfloat_float_exception_mask = 0;
132 return (0);
133 }
134
135 __fenv_static inline int
fesetenv(const fenv_t * __envp)136 fesetenv(const fenv_t *__envp)
137 {
138
139 __softfloat_float_exception_flags = __env_flags(*__envp);
140 __softfloat_float_exception_mask = __env_mask(*__envp);
141 __softfloat_float_rounding_mode = __env_round(*__envp);
142 return (0);
143 }
144
145 __fenv_static inline int
feupdateenv(const fenv_t * __envp)146 feupdateenv(const fenv_t *__envp)
147 {
148 int __oflags = __softfloat_float_exception_flags;
149
150 fesetenv(__envp);
151 feraiseexcept(__oflags);
152 return (0);
153 }
154
155 #if __BSD_VISIBLE
156
157 /* We currently provide no external definitions of the functions below. */
158
159 static inline int
feenableexcept(int __mask)160 feenableexcept(int __mask)
161 {
162 int __omask = __softfloat_float_exception_mask;
163
164 __softfloat_float_exception_mask |= __mask;
165 return (__omask);
166 }
167
168 static inline int
fedisableexcept(int __mask)169 fedisableexcept(int __mask)
170 {
171 int __omask = __softfloat_float_exception_mask;
172
173 __softfloat_float_exception_mask &= ~__mask;
174 return (__omask);
175 }
176
177 static inline int
fegetexcept(void)178 fegetexcept(void)
179 {
180
181 return (__softfloat_float_exception_mask);
182 }
183
184 #endif /* __BSD_VISIBLE */
185