1/*-
2 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
3 * Copyright (c) 2015-2016 Ruslan Bukin <br@bsdpad.com>
4 * All rights reserved.
5 *
6 * Portions of this software were developed by SRI International and the
7 * University of Cambridge Computer Laboratory under DARPA/AFRL contract
8 * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
9 *
10 * Portions of this software were developed by the University of Cambridge
11 * Computer Laboratory as part of the CTSRD Project, with support from the
12 * UK Higher Education Innovation Fund (HEIF).
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#ifndef _FENV_H_
37#define _FENV_H_
38
39#include <sys/cdefs.h>
40#include <sys/_types.h>
41
42#ifndef __fenv_static
43#define __fenv_static static
44#endif
45
46typedef __uint64_t fenv_t;
47typedef __uint64_t fexcept_t;
48
49/* Exception flags */
50#define FE_INVALID 0x0010
51#define FE_DIVBYZERO 0x0008
52#define FE_OVERFLOW 0x0004
53#define FE_UNDERFLOW 0x0002
54#define FE_INEXACT 0x0001
55#define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | \
56 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
57
58/*
59 * RISC-V Rounding modes
60 */
61#define _ROUND_SHIFT 5
62#define FE_TONEAREST (0x00 << _ROUND_SHIFT)
63#define FE_TOWARDZERO (0x01 << _ROUND_SHIFT)
64#define FE_DOWNWARD (0x02 << _ROUND_SHIFT)
65#define FE_UPWARD (0x03 << _ROUND_SHIFT)
66#define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \
67 FE_UPWARD | FE_TOWARDZERO)
68
69__BEGIN_DECLS
70
71/* Default floating-point environment */
72extern const fenv_t __fe_dfl_env;
73#define FE_DFL_ENV (&__fe_dfl_env)
74
75#ifndef __riscv_float_abi_double
76#error only double hard float ABI supported
77#endif
78
79#define __rfs(__fcsr) __asm __volatile("csrr %0, fcsr" : "=r" (__fcsr))
80#define __wfs(__fcsr) __asm __volatile("csrw fcsr, %0" :: "r" (__fcsr))
81
82__fenv_static inline int
83feclearexcept(int __excepts)
84{
85
86 __asm __volatile("csrc fflags, %0" :: "r"(__excepts));
87
88 return (0);
89}
90
91__fenv_static inline int
92fegetexceptflag(fexcept_t *__flagp, int __excepts)
93{
94 fexcept_t __fcsr;
95
96 __rfs(__fcsr);
97 *__flagp = __fcsr & __excepts;
98
99 return (0);
100}
101
102__fenv_static inline int
103fesetexceptflag(const fexcept_t *__flagp, int __excepts)
104{
105 fexcept_t __fcsr;
106
107 __fcsr = *__flagp;
108 __asm __volatile("csrc fflags, %0" :: "r"(__excepts));
109 __asm __volatile("csrs fflags, %0" :: "r"(__fcsr & __excepts));
110
111 return (0);
112}
113
114__fenv_static inline int
115feraiseexcept(int __excepts)
116{
117
118 __asm __volatile("csrs fflags, %0" :: "r"(__excepts));
119
120 return (0);
121}
122
123__fenv_static inline int
124fetestexcept(int __excepts)
125{
126 fexcept_t __fcsr;
127
128 __rfs(__fcsr);
129
130 return (__fcsr & __excepts);
131}
132
133__fenv_static inline int
134fegetround(void)
135{
136 fexcept_t __fcsr;
137
138 __rfs(__fcsr);
139
140 return (__fcsr & _ROUND_MASK);
141}
142
143__fenv_static inline int
144fesetround(int __round)
145{
146 fexcept_t __fcsr;
147
148 if (__round & ~_ROUND_MASK)
149 return (-1);
150
151 __rfs(__fcsr);
152 __fcsr &= ~_ROUND_MASK;
153 __fcsr |= __round;
154 __wfs(__fcsr);
155
156 return (0);
157}
158
159__fenv_static inline int
160fegetenv(fenv_t *__envp)
161{
162
163 __rfs(*__envp);
164
165 return (0);
166}
167
168__fenv_static inline int
169feholdexcept(fenv_t *__envp __unused)
170{
171
172 /* No exception traps. */
173
174 return (-1);
175}
176
177__fenv_static inline int
178fesetenv(const fenv_t *__envp)
179{
180
181 __wfs(*__envp);
182
183 return (0);
184}
185
186__fenv_static inline int
187feupdateenv(const fenv_t *__envp)
188{
189 fexcept_t __fcsr;
190
191 __rfs(__fcsr);
192 __wfs(*__envp);
193 feraiseexcept(__fcsr & FE_ALL_EXCEPT);
194
195 return (0);
196}
197
198#if __BSD_VISIBLE
199
200__fenv_static inline int
201feenableexcept(int __mask __unused)
202{
203
204 /* No exception traps. */
205
206 return (0);
207}
208
209__fenv_static inline int
210fedisableexcept(int __mask __unused)
211{
212
213 /* No exception traps. */
214
215 return (0);
216}
217
218/* We currently provide no external definition of fegetexcept(). */
219static inline int
220fegetexcept(void)
221{
222
223 /* No exception traps. */
224
225 return (0);
226}
227
228#endif /* __BSD_VISIBLE */
229
230__END_DECLS
231
232#endif /* !_FENV_H_ */