xref: /freebsd/lib/msun/riscv/fenv.h (revision 15c433351f54e7cd5bec8d36c8e89e6a7fa55b26)
1 /*-
2  * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
3  * Copyright (c) 2015 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	FE_TONEAREST	(0x00 << 5)
63 #define	FE_TOWARDZERO	(0x01 << 5)
64 #define	FE_DOWNWARD	(0x02 << 5)
65 #define	FE_UPWARD	(0x03 << 5)
66 #define	_ROUND_SHIFT	5
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 /* We need to be able to map status flag positions to mask flag positions */
77 #define	_FPUSW_SHIFT	0
78 #define	_ENABLE_MASK	(FE_ALL_EXCEPT << _FPUSW_SHIFT)
79 
80 #define	__rfs(__fpsr)	__asm __volatile("csrr %0, fcsr" : "=r" (*(__fpsr)))
81 #define	__wfs(__fpsr)	__asm __volatile("csrw fcsr, %0" :: "r" (__fpsr))
82 
83 __fenv_static inline int
84 feclearexcept(int __excepts)
85 {
86 	fexcept_t __fpsr;
87 
88 	__rfs(&__fpsr);
89 	__fpsr &= ~__excepts;
90 	__wfs(__fpsr);
91 	return (0);
92 }
93 
94 __fenv_static inline int
95 fegetexceptflag(fexcept_t *__flagp, int __excepts)
96 {
97 	fexcept_t __fpsr;
98 
99 	__rfs(&__fpsr);
100 	*__flagp = __fpsr & __excepts;
101 	return (0);
102 }
103 
104 __fenv_static inline int
105 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
106 {
107 	fexcept_t __fpsr;
108 
109 	__rfs(&__fpsr);
110 	__fpsr &= ~__excepts;
111 	__fpsr |= *__flagp & __excepts;
112 	__wfs(__fpsr);
113 	return (0);
114 }
115 
116 __fenv_static inline int
117 feraiseexcept(int __excepts)
118 {
119 	fexcept_t __ex = __excepts;
120 
121 	fesetexceptflag(&__ex, __excepts);	/* XXX */
122 	return (0);
123 }
124 
125 __fenv_static inline int
126 fetestexcept(int __excepts)
127 {
128 	fexcept_t __fpsr;
129 
130 	__rfs(&__fpsr);
131 	return (__fpsr & __excepts);
132 }
133 
134 __fenv_static inline int
135 fegetround(void)
136 {
137 
138 	return (-1);
139 }
140 
141 __fenv_static inline int
142 fesetround(int __round)
143 {
144 
145 	return (-1);
146 }
147 
148 __fenv_static inline int
149 fegetenv(fenv_t *__envp)
150 {
151 
152 	__rfs(__envp);
153 	return (0);
154 }
155 
156 __fenv_static inline int
157 feholdexcept(fenv_t *__envp)
158 {
159 	fenv_t __env;
160 
161 	__rfs(&__env);
162 	*__envp = __env;
163 	__env &= ~(FE_ALL_EXCEPT | _ENABLE_MASK);
164 	__wfs(__env);
165 	return (0);
166 }
167 
168 __fenv_static inline int
169 fesetenv(const fenv_t *__envp)
170 {
171 
172 	__wfs(*__envp);
173 	return (0);
174 }
175 
176 __fenv_static inline int
177 feupdateenv(const fenv_t *__envp)
178 {
179 	fexcept_t __fpsr;
180 
181 	__rfs(&__fpsr);
182 	__wfs(*__envp);
183 	feraiseexcept(__fpsr & FE_ALL_EXCEPT);
184 	return (0);
185 }
186 
187 #if __BSD_VISIBLE
188 
189 /* We currently provide no external definitions of the functions below. */
190 
191 static inline int
192 feenableexcept(int __mask)
193 {
194 	fenv_t __old_fpsr;
195 	fenv_t __new_fpsr;
196 
197 	__rfs(&__old_fpsr);
198 	__new_fpsr = __old_fpsr | (__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT;
199 	__wfs(__new_fpsr);
200 	return ((__old_fpsr >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
201 }
202 
203 static inline int
204 fedisableexcept(int __mask)
205 {
206 	fenv_t __old_fpsr;
207 	fenv_t __new_fpsr;
208 
209 	__rfs(&__old_fpsr);
210 	__new_fpsr = __old_fpsr & ~((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT);
211 	__wfs(__new_fpsr);
212 	return ((__old_fpsr >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
213 }
214 
215 static inline int
216 fegetexcept(void)
217 {
218 	fenv_t __fpsr;
219 
220 	__rfs(&__fpsr);
221 	return ((__fpsr & _ENABLE_MASK) >> _FPUSW_SHIFT);
222 }
223 
224 #endif /* __BSD_VISIBLE */
225 
226 __END_DECLS
227 
228 #endif	/* !_FENV_H_ */
229