xref: /freebsd/lib/msun/arm/fenv.h (revision 8fa0b743820f61c661ba5f3ea0e3be0dc137910e)
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 <sys/_types.h>
33 
34 #ifndef	__fenv_static
35 #define	__fenv_static	static
36 #endif
37 
38 typedef	__uint32_t	fenv_t;
39 typedef	__uint32_t	fexcept_t;
40 
41 /* Exception flags */
42 #define	FE_INVALID	0x0001
43 #define	FE_DIVBYZERO	0x0002
44 #define	FE_OVERFLOW	0x0004
45 #define	FE_UNDERFLOW	0x0008
46 #define	FE_INEXACT	0x0010
47 #define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
48 			 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
49 
50 /* Rounding modes */
51 #define	FE_TONEAREST	0x0000
52 #define	FE_TOWARDZERO	0x0001
53 #define	FE_UPWARD	0x0002
54 #define	FE_DOWNWARD	0x0003
55 #define	_ROUND_MASK	(FE_TONEAREST | FE_DOWNWARD | \
56 			 FE_UPWARD | FE_TOWARDZERO)
57 __BEGIN_DECLS
58 
59 /* Default floating-point environment */
60 extern const fenv_t	__fe_dfl_env;
61 #define	FE_DFL_ENV	(&__fe_dfl_env)
62 
63 /* We need to be able to map status flag positions to mask flag positions */
64 #define _FPUSW_SHIFT	16
65 #define	_ENABLE_MASK	(FE_ALL_EXCEPT << _FPUSW_SHIFT)
66 
67 #ifndef	ARM_HARD_FLOAT
68 
69 int feclearexcept(int __excepts);
70 int fegetexceptflag(fexcept_t *__flagp, int __excepts);
71 int fesetexceptflag(const fexcept_t *__flagp, int __excepts);
72 int feraiseexcept(int __excepts);
73 int fetestexcept(int __excepts);
74 int fegetround(void);
75 int fesetround(int __round);
76 int fegetenv(fenv_t *__envp);
77 int feholdexcept(fenv_t *__envp);
78 int fesetenv(const fenv_t *__envp);
79 int feupdateenv(const fenv_t *__envp);
80 
81 #else	/* ARM_HARD_FLOAT */
82 
83 #define	__rfs(__fpsr)	__asm __volatile("rfs %0" : "=r" (*(__fpsr)))
84 #define	__wfs(__fpsr)	__asm __volatile("wfs %0" : : "r" (__fpsr))
85 
86 __fenv_static inline int
87 feclearexcept(int __excepts)
88 {
89 	fexcept_t __fpsr;
90 
91 	__rfs(&__fpsr);
92 	__fpsr &= ~__excepts;
93 	__wfs(__fpsr);
94 	return (0);
95 }
96 
97 __fenv_static inline int
98 fegetexceptflag(fexcept_t *__flagp, int __excepts)
99 {
100 	fexcept_t __fpsr;
101 
102 	__rfs(&__fpsr);
103 	*__flagp = __fpsr & __excepts;
104 	return (0);
105 }
106 
107 __fenv_static inline int
108 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
109 {
110 	fexcept_t __fpsr;
111 
112 	__rfs(&__fpsr);
113 	__fpsr &= ~__excepts;
114 	__fpsr |= *__flagp & __excepts;
115 	__wfs(__fpsr);
116 	return (0);
117 }
118 
119 __fenv_static inline int
120 feraiseexcept(int __excepts)
121 {
122 	fexcept_t __ex = __excepts;
123 
124 	fesetexceptflag(&__ex, __excepts);	/* XXX */
125 	return (0);
126 }
127 
128 __fenv_static inline int
129 fetestexcept(int __excepts)
130 {
131 	fexcept_t __fpsr;
132 
133 	__rfs(&__fpsr);
134 	return (__fpsr & __excepts);
135 }
136 
137 __fenv_static inline int
138 fegetround(void)
139 {
140 
141 	/*
142 	 * Apparently, the rounding mode is specified as part of the
143 	 * instruction format on ARM, so the dynamic rounding mode is
144 	 * indeterminate.  Some FPUs may differ.
145 	 */
146 	return (-1);
147 }
148 
149 __fenv_static inline int
150 fesetround(int __round)
151 {
152 
153 	return (-1);
154 }
155 
156 __fenv_static inline int
157 fegetenv(fenv_t *__envp)
158 {
159 
160 	__rfs(__envp);
161 	return (0);
162 }
163 
164 __fenv_static inline int
165 feholdexcept(fenv_t *__envp)
166 {
167 	fenv_t __env;
168 
169 	__rfs(&__env);
170 	*__envp = __env;
171 	__env &= ~(FE_ALL_EXCEPT | _ENABLE_MASK);
172 	__wfs(__env);
173 	return (0);
174 }
175 
176 __fenv_static inline int
177 fesetenv(const fenv_t *__envp)
178 {
179 
180 	__wfs(*__envp);
181 	return (0);
182 }
183 
184 __fenv_static inline int
185 feupdateenv(const fenv_t *__envp)
186 {
187 	fexcept_t __fpsr;
188 
189 	__rfs(&__fpsr);
190 	__wfs(*__envp);
191 	feraiseexcept(__fpsr & FE_ALL_EXCEPT);
192 	return (0);
193 }
194 
195 #if __BSD_VISIBLE
196 
197 /* We currently provide no external definitions of the functions below. */
198 
199 static inline int
200 feenableexcept(int __mask)
201 {
202 	fenv_t __old_fpsr, __new_fpsr;
203 
204 	__rfs(&__old_fpsr);
205 	__new_fpsr = __old_fpsr | (__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT;
206 	__wfs(__new_fpsr);
207 	return ((__old_fpsr >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
208 }
209 
210 static inline int
211 fedisableexcept(int __mask)
212 {
213 	fenv_t __old_fpsr, __new_fpsr;
214 
215 	__rfs(&__old_fpsr);
216 	__new_fpsr = __old_fpsr & ~((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT);
217 	__wfs(__new_fpsr);
218 	return ((__old_fpsr >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
219 }
220 
221 static inline int
222 fegetexcept(void)
223 {
224 	fenv_t __fpsr;
225 
226 	__rfs(&__fpsr);
227 	return ((__fpsr & _ENABLE_MASK) >> _FPUSW_SHIFT);
228 }
229 
230 #endif /* __BSD_VISIBLE */
231 
232 #endif	/* ARM_HARD_FLOAT */
233 
234 __END_DECLS
235 
236 #endif	/* !_FENV_H_ */
237