1 /*-
2 * Copyright (c) 2004-2005 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 #define _FENV_H_
31
32 #include <stdint.h>
33 #include <sys/cdefs.h>
34 #include <sys/types.h>
35
36 #ifndef __fenv_static
37 #define __fenv_static static
38 #endif
39
40 typedef uint64_t fenv_t;
41 typedef uint64_t fexcept_t;
42
43 /* Exception flags */
44 #define FE_INVALID 0x00000001
45 #define FE_DIVBYZERO 0x00000002
46 #define FE_OVERFLOW 0x00000004
47 #define FE_UNDERFLOW 0x00000008
48 #define FE_INEXACT 0x00000010
49 #define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | \
50 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
51
52 /*
53 * Rounding modes
54 *
55 * We can't just use the hardware bit values here, because that would
56 * make FE_UPWARD and FE_DOWNWARD negative, which is not allowed.
57 */
58 #define FE_TONEAREST 0x0
59 #define FE_UPWARD 0x1
60 #define FE_DOWNWARD 0x2
61 #define FE_TOWARDZERO 0x3
62 #define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \
63 FE_UPWARD | FE_TOWARDZERO)
64 #define _ROUND_SHIFT 22
65
66 __BEGIN_DECLS
67
68 /* Default floating-point environment */
69 extern const fenv_t __fe_dfl_env;
70 #define FE_DFL_ENV (&__fe_dfl_env)
71
72 /* We need to be able to map status flag positions to mask flag positions */
73 #define _FPUSW_SHIFT 8
74 #define _ENABLE_MASK (FE_ALL_EXCEPT << _FPUSW_SHIFT)
75
76 #define __mrs_fpcr(__r) __asm __volatile("mrs %0, fpcr" : "=r" (__r))
77 #define __msr_fpcr(__r) __asm __volatile("msr fpcr, %0" : : "r" (__r))
78
79 #define __mrs_fpsr(__r) __asm __volatile("mrs %0, fpsr" : "=r" (__r))
80 #define __msr_fpsr(__r) __asm __volatile("msr fpsr, %0" : : "r" (__r))
81
82 __fenv_static __inline int
feclearexcept(int __excepts)83 feclearexcept(int __excepts)
84 {
85 fexcept_t __r;
86
87 __mrs_fpsr(__r);
88 __r &= ~__excepts;
89 __msr_fpsr(__r);
90 return (0);
91 }
92
93 __fenv_static inline int
fegetexceptflag(fexcept_t * __flagp,int __excepts)94 fegetexceptflag(fexcept_t *__flagp, int __excepts)
95 {
96 fexcept_t __r;
97
98 __mrs_fpsr(__r);
99 *__flagp = __r & __excepts;
100 return (0);
101 }
102
103 __fenv_static inline int
fesetexceptflag(const fexcept_t * __flagp,int __excepts)104 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
105 {
106 fexcept_t __r;
107
108 __mrs_fpsr(__r);
109 __r &= ~__excepts;
110 __r |= *__flagp & __excepts;
111 __msr_fpsr(__r);
112 return (0);
113 }
114
115 __fenv_static inline int
feraiseexcept(int __excepts)116 feraiseexcept(int __excepts)
117 {
118 fexcept_t __r;
119
120 __mrs_fpsr(__r);
121 __r |= __excepts;
122 __msr_fpsr(__r);
123 return (0);
124 }
125
126 __fenv_static inline int
fetestexcept(int __excepts)127 fetestexcept(int __excepts)
128 {
129 fexcept_t __r;
130
131 __mrs_fpsr(__r);
132 return (__r & __excepts);
133 }
134
135 __fenv_static inline int
fegetround(void)136 fegetround(void)
137 {
138 fenv_t __r;
139
140 __mrs_fpcr(__r);
141 return ((__r >> _ROUND_SHIFT) & _ROUND_MASK);
142 }
143
144 __fenv_static inline int
fesetround(int __round)145 fesetround(int __round)
146 {
147 fenv_t __r;
148
149 if (__round & ~_ROUND_MASK)
150 return (-1);
151 __mrs_fpcr(__r);
152 __r &= ~(_ROUND_MASK << _ROUND_SHIFT);
153 __r |= __round << _ROUND_SHIFT;
154 __msr_fpcr(__r);
155 return (0);
156 }
157
158 __fenv_static inline int
fegetenv(fenv_t * __envp)159 fegetenv(fenv_t *__envp)
160 {
161 fenv_t __r;
162
163 __mrs_fpcr(__r);
164 *__envp = __r & _ENABLE_MASK;
165
166 __mrs_fpsr(__r);
167 *__envp |= __r & (FE_ALL_EXCEPT | (_ROUND_MASK << _ROUND_SHIFT));
168
169 return (0);
170 }
171
172 __fenv_static inline int
feholdexcept(fenv_t * __envp)173 feholdexcept(fenv_t *__envp)
174 {
175 fenv_t __r;
176
177 __mrs_fpcr(__r);
178 *__envp = __r & _ENABLE_MASK;
179 __r &= ~(_ENABLE_MASK);
180 __msr_fpcr(__r);
181
182 __mrs_fpsr(__r);
183 *__envp |= __r & (FE_ALL_EXCEPT | (_ROUND_MASK << _ROUND_SHIFT));
184 __r &= ~(_ENABLE_MASK);
185 __msr_fpsr(__r);
186 return (0);
187 }
188
189 __fenv_static inline int
fesetenv(const fenv_t * __envp)190 fesetenv(const fenv_t *__envp)
191 {
192
193 __msr_fpcr((*__envp) & _ENABLE_MASK);
194 __msr_fpsr((*__envp) & (FE_ALL_EXCEPT | (_ROUND_MASK << _ROUND_SHIFT)));
195 return (0);
196 }
197
198 __fenv_static inline int
feupdateenv(const fenv_t * __envp)199 feupdateenv(const fenv_t *__envp)
200 {
201 fexcept_t __r;
202
203 __mrs_fpsr(__r);
204 fesetenv(__envp);
205 feraiseexcept(__r & FE_ALL_EXCEPT);
206 return (0);
207 }
208
209 #if __BSD_VISIBLE
210
211 /* We currently provide no external definitions of the functions below. */
212
213 static inline int
feenableexcept(int __mask)214 feenableexcept(int __mask)
215 {
216 fenv_t __old_r, __new_r;
217
218 __mrs_fpcr(__old_r);
219 __new_r = __old_r | ((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT);
220 __msr_fpcr(__new_r);
221 return ((__old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
222 }
223
224 static inline int
fedisableexcept(int __mask)225 fedisableexcept(int __mask)
226 {
227 fenv_t __old_r, __new_r;
228
229 __mrs_fpcr(__old_r);
230 __new_r = __old_r & ~((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT);
231 __msr_fpcr(__new_r);
232 return ((__old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
233 }
234
235 static inline int
fegetexcept(void)236 fegetexcept(void)
237 {
238 fenv_t __r;
239
240 __mrs_fpcr(__r);
241 return ((__r & _ENABLE_MASK) >> _FPUSW_SHIFT);
242 }
243
244 #endif /* __BSD_VISIBLE */
245
246 __END_DECLS
247
248 #endif /* !_FENV_H_ */
249