xref: /freebsd/lib/msun/arm/fenv.h (revision 9a14aa017b21c292740c00ee098195cd46642730)
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 #ifdef	ARM_HARD_FLOAT
68 #define	__rfs(__fpsr)	__asm __volatile("rfs %0" : "=r" (*(__fpsr)))
69 #define	__wfs(__fpsr)	__asm __volatile("wfs %0" : : "r" (__fpsr))
70 #else
71 #define __rfs(__fpsr)
72 #define __wfs(__fpsr)
73 #endif
74 
75 __fenv_static inline int
76 feclearexcept(int __excepts)
77 {
78 	fexcept_t __fpsr;
79 
80 	__rfs(&__fpsr);
81 	__fpsr &= ~__excepts;
82 	__wfs(__fpsr);
83 	return (0);
84 }
85 
86 __fenv_static inline int
87 fegetexceptflag(fexcept_t *__flagp, int __excepts)
88 {
89 	fexcept_t __fpsr;
90 
91 	__rfs(&__fpsr);
92 	*__flagp = __fpsr & __excepts;
93 	return (0);
94 }
95 
96 __fenv_static inline int
97 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
98 {
99 	fexcept_t __fpsr;
100 
101 	__rfs(&__fpsr);
102 	__fpsr &= ~__excepts;
103 	__fpsr |= *__flagp & __excepts;
104 	__wfs(__fpsr);
105 	return (0);
106 }
107 
108 __fenv_static inline int
109 feraiseexcept(int __excepts)
110 {
111 	fexcept_t __ex = __excepts;
112 
113 	fesetexceptflag(&__ex, __excepts);	/* XXX */
114 	return (0);
115 }
116 
117 __fenv_static inline int
118 fetestexcept(int __excepts)
119 {
120 	fexcept_t __fpsr;
121 
122 	__rfs(&__fpsr);
123 	return (__fpsr & __excepts);
124 }
125 
126 __fenv_static inline int
127 fegetround(void)
128 {
129 
130 	/*
131 	 * Apparently, the rounding mode is specified as part of the
132 	 * instruction format on ARM, so the dynamic rounding mode is
133 	 * indeterminate.  Some FPUs may differ.
134 	 */
135 	return (-1);
136 }
137 
138 __fenv_static inline int
139 fesetround(int __round)
140 {
141 
142 	return (-1);
143 }
144 
145 __fenv_static inline int
146 fegetenv(fenv_t *__envp)
147 {
148 
149 	__rfs(__envp);
150 	return (0);
151 }
152 
153 __fenv_static inline int
154 feholdexcept(fenv_t *__envp)
155 {
156 	fenv_t __env;
157 
158 	__rfs(&__env);
159 	*__envp = __env;
160 	__env &= ~(FE_ALL_EXCEPT | _ENABLE_MASK);
161 	__wfs(__env);
162 	return (0);
163 }
164 
165 __fenv_static inline int
166 fesetenv(const fenv_t *__envp)
167 {
168 
169 	__wfs(*__envp);
170 	return (0);
171 }
172 
173 __fenv_static inline int
174 feupdateenv(const fenv_t *__envp)
175 {
176 	fexcept_t __fpsr;
177 
178 	__rfs(&__fpsr);
179 	__wfs(*__envp);
180 	feraiseexcept(__fpsr & FE_ALL_EXCEPT);
181 	return (0);
182 }
183 
184 #if __BSD_VISIBLE
185 
186 /* We currently provide no external definitions of the functions below. */
187 
188 static inline int
189 feenableexcept(int __mask)
190 {
191 	fenv_t __old_fpsr, __new_fpsr;
192 
193 	__rfs(&__old_fpsr);
194 	__new_fpsr = __old_fpsr | (__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT;
195 	__wfs(__new_fpsr);
196 	return ((__old_fpsr >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
197 }
198 
199 static inline int
200 fedisableexcept(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 fegetexcept(void)
212 {
213 	fenv_t __fpsr;
214 
215 	__rfs(&__fpsr);
216 	return ((__fpsr & _ENABLE_MASK) >> _FPUSW_SHIFT);
217 }
218 
219 #endif /* __BSD_VISIBLE */
220 
221 __END_DECLS
222 
223 #endif	/* !_FENV_H_ */
224