xref: /freebsd/lib/msun/arm/fenv.h (revision f0adf7f5cdd241db2f2c817683191a6ef64a4e95)
1 /*-
2  * Copyright (c) 2004 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 typedef	__uint32_t	fenv_t;
35 typedef	__uint32_t	fexcept_t;
36 
37 /* Exception flags */
38 #define	FE_INVALID	0x0001
39 #define	FE_DIVBYZERO	0x0002
40 #define	FE_OVERFLOW	0x0004
41 #define	FE_UNDERFLOW	0x0008
42 #define	FE_INEXACT	0x0010
43 #define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
44 			 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
45 
46 __BEGIN_DECLS
47 
48 /* Default floating-point environment */
49 extern const fenv_t	__fe_dfl_env;
50 #define	FE_DFL_ENV	(&__fe_dfl_env)
51 
52 /* We need to be able to map status flag positions to mask flag positions */
53 #define _FPUSW_SHIFT	16
54 #define	_ENABLE_MASK	(FE_ALL_EXCEPT << _FPUSW_SHIFT)
55 
56 #define	__rfs(__fpsr)	__asm("rfs %0" : "=m" (*(__fpsr)))
57 #define	__wfs(__fpsr)	__asm __volatile("wfs %0" : : "m" (__fpsr))
58 
59 static __inline int
60 feclearexcept(int __excepts)
61 {
62 	fexcept_t __fpsr;
63 
64 	__rfs(&__fpsr);
65 	__fpsr &= ~__excepts;
66 	__wfs(__fpsr);
67 	return (0);
68 }
69 
70 static __inline int
71 fegetexceptflag(fexcept_t *__flagp, int __excepts)
72 {
73 	fexcept_t __fpsr;
74 
75 	__rfs(&__fpsr);
76 	*__flagp = __fpsr & __excepts;
77 	return (0);
78 }
79 
80 static __inline int
81 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
82 {
83 	fexcept_t __fpsr;
84 
85 	__rfs(&__fpsr);
86 	__fpsr &= ~__excepts;
87 	__fpsr |= *__flagp & __excepts;
88 	__wfs(__fpsr);
89 	return (0);
90 }
91 
92 static __inline int
93 feraiseexcept(int __excepts)
94 {
95 	fexcept_t __ex = __excepts;
96 
97 	fesetexceptflag(&__ex, __excepts);	/* XXX */
98 	return (0);
99 }
100 
101 static __inline int
102 fetestexcept(int __excepts)
103 {
104 	fexcept_t __fpsr;
105 
106 	__rfs(&__fpsr);
107 	return (__fpsr & __excepts);
108 }
109 
110 static __inline int
111 fegetround(void)
112 {
113 
114 	/*
115 	 * Apparently, the rounding mode is specified as part of the
116 	 * instruction format on ARM, so the dynamic rounding mode is
117 	 * indeterminate.  Some FPUs may differ.
118 	 */
119 	return (-1);
120 }
121 
122 static __inline int
123 fesetround(int __round)
124 {
125 
126 	return (-1);
127 }
128 
129 static __inline int
130 fegetenv(fenv_t *__envp)
131 {
132 
133 	__rfs(__envp);
134 	return (0);
135 }
136 
137 static __inline int
138 feholdexcept(fenv_t *__envp)
139 {
140 	fenv_t __env;
141 
142 	__rfs(&__env);
143 	*__envp = __env;
144 	__env &= ~(FE_ALL_EXCEPT | _ENABLE_MASK);
145 	__wfs(__env);
146 	return (0);
147 }
148 
149 static __inline int
150 fesetenv(const fenv_t *__envp)
151 {
152 
153 	__wfs(*__envp);
154 	return (0);
155 }
156 
157 static __inline int
158 feupdateenv(const fenv_t *__envp)
159 {
160 	fexcept_t __fpsr;
161 
162 	__rfs(&__fpsr);
163 	__wfs(*__envp);
164 	feraiseexcept(__fpsr & FE_ALL_EXCEPT);
165 	return (0);
166 }
167 
168 #if __BSD_VISIBLE
169 
170 static __inline int
171 fesetmask(int __mask)
172 {
173 	fenv_t __fpsr;
174 
175 	__rfs(&__fpsr);
176 	__fpsr &= ~_ENABLE_MASK;
177 	__fpsr |= __mask << _FPUSW_SHIFT;
178 	__wfs(__fpsr);
179 	return (0);
180 }
181 
182 static __inline int
183 fegetmask(void)
184 {
185 	fenv_t __fpsr;
186 
187 	__rfs(&__fpsr);
188 	return ((__fpsr & _ENABLE_MASK) >> _FPUSW_SHIFT);
189 }
190 
191 #endif /* __BSD_VISIBLE */
192 
193 __END_DECLS
194 
195 #endif	/* !_FENV_H_ */
196