xref: /freebsd/lib/msun/riscv/fenv.h (revision 9ff086544d5f85b58349e28ed36a9811b8fe5cf9)
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  * $FreeBSD$
36  */
37 
38 #ifndef	_FENV_H_
39 #define	_FENV_H_
40 
41 #include <sys/_types.h>
42 
43 #ifndef	__fenv_static
44 #define	__fenv_static	static
45 #endif
46 
47 typedef	__uint64_t	fenv_t;
48 typedef	__uint64_t	fexcept_t;
49 
50 /* Exception flags */
51 #define	FE_INVALID	0x0010
52 #define	FE_DIVBYZERO	0x0008
53 #define	FE_OVERFLOW	0x0004
54 #define	FE_UNDERFLOW	0x0002
55 #define	FE_INEXACT	0x0001
56 #define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
57 			 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
58 
59 /*
60  * RISC-V Rounding modes
61  */
62 #define	_ROUND_SHIFT	5
63 #define	FE_TONEAREST	(0x00 << _ROUND_SHIFT)
64 #define	FE_TOWARDZERO	(0x01 << _ROUND_SHIFT)
65 #define	FE_DOWNWARD	(0x02 << _ROUND_SHIFT)
66 #define	FE_UPWARD	(0x03 << _ROUND_SHIFT)
67 #define	_ROUND_MASK	(FE_TONEAREST | FE_DOWNWARD | \
68 			 FE_UPWARD | FE_TOWARDZERO)
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 #ifndef SOFTFLOAT
77 #define	__rfs(__fcsr)	__asm __volatile("csrr %0, fcsr" : "=r" (__fcsr))
78 #define	__wfs(__fcsr)	__asm __volatile("csrw fcsr, %0" :: "r" (__fcsr))
79 #endif
80 
81 #ifdef SOFTFLOAT
82 int feclearexcept(int __excepts);
83 int fegetexceptflag(fexcept_t *__flagp, int __excepts);
84 int fesetexceptflag(const fexcept_t *__flagp, int __excepts);
85 int feraiseexcept(int __excepts);
86 int fetestexcept(int __excepts);
87 int fegetround(void);
88 int fesetround(int __round);
89 int fegetenv(fenv_t *__envp);
90 int feholdexcept(fenv_t *__envp);
91 int fesetenv(const fenv_t *__envp);
92 int feupdateenv(const fenv_t *__envp);
93 #else
94 __fenv_static inline int
95 feclearexcept(int __excepts)
96 {
97 
98 	__asm __volatile("csrc fflags, %0" :: "r"(__excepts));
99 
100 	return (0);
101 }
102 
103 __fenv_static inline int
104 fegetexceptflag(fexcept_t *__flagp, int __excepts)
105 {
106 	fexcept_t __fcsr;
107 
108 	__rfs(__fcsr);
109 	*__flagp = __fcsr & __excepts;
110 
111 	return (0);
112 }
113 
114 __fenv_static inline int
115 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
116 {
117 	fexcept_t __fcsr;
118 
119 	__fcsr = *__flagp;
120 	__asm __volatile("csrc fflags, %0" :: "r"(__excepts));
121 	__asm __volatile("csrs fflags, %0" :: "r"(__fcsr & __excepts));
122 
123 	return (0);
124 }
125 
126 __fenv_static inline int
127 feraiseexcept(int __excepts)
128 {
129 
130 	__asm __volatile("csrs fflags, %0" :: "r"(__excepts));
131 
132 	return (0);
133 }
134 
135 __fenv_static inline int
136 fetestexcept(int __excepts)
137 {
138 	fexcept_t __fcsr;
139 
140 	__rfs(__fcsr);
141 
142 	return (__fcsr & __excepts);
143 }
144 
145 __fenv_static inline int
146 fegetround(void)
147 {
148 	fexcept_t __fcsr;
149 
150 	__rfs(__fcsr);
151 
152 	return (__fcsr & _ROUND_MASK);
153 }
154 
155 __fenv_static inline int
156 fesetround(int __round)
157 {
158 	fexcept_t __fcsr;
159 
160 	if (__round & ~_ROUND_MASK)
161 		return (-1);
162 
163 	__rfs(__fcsr);
164 	__fcsr &= ~_ROUND_MASK;
165 	__fcsr |= __round;
166 	__wfs(__fcsr);
167 
168 	return (0);
169 }
170 
171 __fenv_static inline int
172 fegetenv(fenv_t *__envp)
173 {
174 
175 	__rfs(*__envp);
176 
177 	return (0);
178 }
179 
180 __fenv_static inline int
181 feholdexcept(fenv_t *__envp)
182 {
183 
184 	/* No exception traps. */
185 
186 	return (-1);
187 }
188 
189 __fenv_static inline int
190 fesetenv(const fenv_t *__envp)
191 {
192 
193 	__wfs(*__envp);
194 
195 	return (0);
196 }
197 
198 __fenv_static inline int
199 feupdateenv(const fenv_t *__envp)
200 {
201 	fexcept_t __fcsr;
202 
203 	__rfs(__fcsr);
204 	__wfs(*__envp);
205 	feraiseexcept(__fcsr & FE_ALL_EXCEPT);
206 
207 	return (0);
208 }
209 #endif /* !SOFTFLOAT */
210 
211 #if __BSD_VISIBLE
212 
213 /* We currently provide no external definitions of the functions below. */
214 
215 #ifdef SOFTFLOAT
216 int feenableexcept(int __mask);
217 int fedisableexcept(int __mask);
218 int fegetexcept(void);
219 #else
220 static inline int
221 feenableexcept(int __mask)
222 {
223 
224 	/* No exception traps. */
225 
226 	return (-1);
227 }
228 
229 static inline int
230 fedisableexcept(int __mask)
231 {
232 
233 	/* No exception traps. */
234 
235 	return (0);
236 }
237 
238 static inline int
239 fegetexcept(void)
240 {
241 
242 	/* No exception traps. */
243 
244 	return (0);
245 }
246 #endif /* !SOFTFLOAT */
247 
248 #endif /* __BSD_VISIBLE */
249 
250 __END_DECLS
251 
252 #endif	/* !_FENV_H_ */
253