xref: /freebsd/lib/msun/riscv/fenv.h (revision 1603881667360c015f6685131f2f25474fa67a72)
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 #if !defined(__riscv_float_abi_soft) && !defined(__riscv_float_abi_double)
77 #if defined(__riscv_float_abi_single)
78 #error single precision floating point ABI not supported
79 #else
80 #error compiler did not set soft/hard float macros
81 #endif
82 #endif
83 
84 #ifndef __riscv_float_abi_soft
85 #define	__rfs(__fcsr)	__asm __volatile("csrr %0, fcsr" : "=r" (__fcsr))
86 #define	__wfs(__fcsr)	__asm __volatile("csrw fcsr, %0" :: "r" (__fcsr))
87 #endif
88 
89 #ifdef __riscv_float_abi_soft
90 int feclearexcept(int __excepts);
91 int fegetexceptflag(fexcept_t *__flagp, int __excepts);
92 int fesetexceptflag(const fexcept_t *__flagp, int __excepts);
93 int feraiseexcept(int __excepts);
94 int fetestexcept(int __excepts);
95 int fegetround(void);
96 int fesetround(int __round);
97 int fegetenv(fenv_t *__envp);
98 int feholdexcept(fenv_t *__envp);
99 int fesetenv(const fenv_t *__envp);
100 int feupdateenv(const fenv_t *__envp);
101 #else
102 __fenv_static inline int
103 feclearexcept(int __excepts)
104 {
105 
106 	__asm __volatile("csrc fflags, %0" :: "r"(__excepts));
107 
108 	return (0);
109 }
110 
111 __fenv_static inline int
112 fegetexceptflag(fexcept_t *__flagp, int __excepts)
113 {
114 	fexcept_t __fcsr;
115 
116 	__rfs(__fcsr);
117 	*__flagp = __fcsr & __excepts;
118 
119 	return (0);
120 }
121 
122 __fenv_static inline int
123 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
124 {
125 	fexcept_t __fcsr;
126 
127 	__fcsr = *__flagp;
128 	__asm __volatile("csrc fflags, %0" :: "r"(__excepts));
129 	__asm __volatile("csrs fflags, %0" :: "r"(__fcsr & __excepts));
130 
131 	return (0);
132 }
133 
134 __fenv_static inline int
135 feraiseexcept(int __excepts)
136 {
137 
138 	__asm __volatile("csrs fflags, %0" :: "r"(__excepts));
139 
140 	return (0);
141 }
142 
143 __fenv_static inline int
144 fetestexcept(int __excepts)
145 {
146 	fexcept_t __fcsr;
147 
148 	__rfs(__fcsr);
149 
150 	return (__fcsr & __excepts);
151 }
152 
153 __fenv_static inline int
154 fegetround(void)
155 {
156 	fexcept_t __fcsr;
157 
158 	__rfs(__fcsr);
159 
160 	return (__fcsr & _ROUND_MASK);
161 }
162 
163 __fenv_static inline int
164 fesetround(int __round)
165 {
166 	fexcept_t __fcsr;
167 
168 	if (__round & ~_ROUND_MASK)
169 		return (-1);
170 
171 	__rfs(__fcsr);
172 	__fcsr &= ~_ROUND_MASK;
173 	__fcsr |= __round;
174 	__wfs(__fcsr);
175 
176 	return (0);
177 }
178 
179 __fenv_static inline int
180 fegetenv(fenv_t *__envp)
181 {
182 
183 	__rfs(*__envp);
184 
185 	return (0);
186 }
187 
188 __fenv_static inline int
189 feholdexcept(fenv_t *__envp __unused)
190 {
191 
192 	/* No exception traps. */
193 
194 	return (-1);
195 }
196 
197 __fenv_static inline int
198 fesetenv(const fenv_t *__envp)
199 {
200 
201 	__wfs(*__envp);
202 
203 	return (0);
204 }
205 
206 __fenv_static inline int
207 feupdateenv(const fenv_t *__envp)
208 {
209 	fexcept_t __fcsr;
210 
211 	__rfs(__fcsr);
212 	__wfs(*__envp);
213 	feraiseexcept(__fcsr & FE_ALL_EXCEPT);
214 
215 	return (0);
216 }
217 #endif /* !__riscv_float_abi_soft */
218 
219 #if __BSD_VISIBLE
220 
221 /* We currently provide no external definitions of the functions below. */
222 
223 #ifdef __riscv_float_abi_soft
224 int feenableexcept(int __mask);
225 int fedisableexcept(int __mask);
226 int fegetexcept(void);
227 #else
228 static inline int
229 feenableexcept(int __mask __unused)
230 {
231 
232 	/* No exception traps. */
233 
234 	return (0);
235 }
236 
237 static inline int
238 fedisableexcept(int __mask __unused)
239 {
240 
241 	/* No exception traps. */
242 
243 	return (0);
244 }
245 
246 static inline int
247 fegetexcept(void)
248 {
249 
250 	/* No exception traps. */
251 
252 	return (0);
253 }
254 #endif /* !__riscv_float_abi_soft */
255 
256 #endif /* __BSD_VISIBLE */
257 
258 __END_DECLS
259 
260 #endif	/* !_FENV_H_ */
261