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 <stdint.h>
33#include <sys/cdefs.h>
34#include <sys/types.h>
35
36typedef	uint32_t	fenv_t;
37typedef	uint32_t	fexcept_t;
38
39/* Exception flags */
40#define	FE_INVALID	0x0001
41#define	FE_DIVBYZERO	0x0002
42#define	FE_OVERFLOW	0x0004
43#define	FE_UNDERFLOW	0x0008
44#define	FE_INEXACT	0x0010
45#define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
46			 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
47
48/* Rounding modes */
49#define	FE_TONEAREST	0x0000
50#define	FE_TOWARDZERO	0x0001
51#define	FE_UPWARD	0x0002
52#define	FE_DOWNWARD	0x0003
53#define	_ROUND_MASK	(FE_TONEAREST | FE_DOWNWARD | \
54			 FE_UPWARD | FE_TOWARDZERO)
55__BEGIN_DECLS
56
57/* Default floating-point environment */
58extern const fenv_t	__fe_dfl_env;
59#define	FE_DFL_ENV	(&__fe_dfl_env)
60
61/* We need to be able to map status flag positions to mask flag positions */
62#define _FPUSW_SHIFT	16
63#define	_ENABLE_MASK	(FE_ALL_EXCEPT << _FPUSW_SHIFT)
64
65#ifdef	ARM_HARD_FLOAT
66#define	__rfs(__fpsr)	__asm __volatile("rfs %0" : "=r" (*(__fpsr)))
67#define	__wfs(__fpsr)	__asm __volatile("wfs %0" : : "r" (__fpsr))
68#else
69#define __rfs(__fpsr)
70#define __wfs(__fpsr)
71#endif
72
73static __inline int
74feclearexcept(int __excepts)
75{
76	fexcept_t __fpsr;
77
78	__rfs(&__fpsr);
79	__fpsr &= ~__excepts;
80	__wfs(__fpsr);
81	return (0);
82}
83
84static __inline int
85fegetexceptflag(fexcept_t *__flagp, int __excepts)
86{
87	fexcept_t __fpsr;
88
89	__rfs(&__fpsr);
90	*__flagp = __fpsr & __excepts;
91	return (0);
92}
93
94static __inline int
95fesetexceptflag(const fexcept_t *__flagp, int __excepts)
96{
97	fexcept_t __fpsr;
98
99	__rfs(&__fpsr);
100	__fpsr &= ~__excepts;
101	__fpsr |= *__flagp & __excepts;
102	__wfs(__fpsr);
103	return (0);
104}
105
106static __inline int
107feraiseexcept(int __excepts)
108{
109	fexcept_t __ex = __excepts;
110
111	fesetexceptflag(&__ex, __excepts);	/* XXX */
112	return (0);
113}
114
115static __inline int
116fetestexcept(int __excepts)
117{
118	fexcept_t __fpsr;
119
120	__rfs(&__fpsr);
121	return (__fpsr & __excepts);
122}
123
124static __inline int
125fegetround(void)
126{
127
128	/*
129	 * Apparently, the rounding mode is specified as part of the
130	 * instruction format on ARM, so the dynamic rounding mode is
131	 * indeterminate.  Some FPUs may differ.
132	 */
133	return (-1);
134}
135
136static __inline int
137fesetround(int __round)
138{
139
140	return (-1);
141}
142
143static __inline int
144fegetenv(fenv_t *__envp)
145{
146
147	__rfs(__envp);
148	return (0);
149}
150
151static __inline int
152feholdexcept(fenv_t *__envp)
153{
154	fenv_t __env;
155
156	__rfs(&__env);
157	*__envp = __env;
158	__env &= ~(FE_ALL_EXCEPT | _ENABLE_MASK);
159	__wfs(__env);
160	return (0);
161}
162
163static __inline int
164fesetenv(const fenv_t *__envp)
165{
166
167	__wfs(*__envp);
168	return (0);
169}
170
171static __inline int
172feupdateenv(const fenv_t *__envp)
173{
174	fexcept_t __fpsr;
175
176	__rfs(&__fpsr);
177	__wfs(*__envp);
178	feraiseexcept(__fpsr & FE_ALL_EXCEPT);
179	return (0);
180}
181
182#if __BSD_VISIBLE
183
184static __inline int
185feenableexcept(int __mask)
186{
187	fenv_t __old_fpsr, __new_fpsr;
188
189	__rfs(&__old_fpsr);
190	__new_fpsr = __old_fpsr | (__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT;
191	__wfs(__new_fpsr);
192	return ((__old_fpsr >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
193}
194
195static __inline int
196fedisableexcept(int __mask)
197{
198	fenv_t __old_fpsr, __new_fpsr;
199
200	__rfs(&__old_fpsr);
201	__new_fpsr = __old_fpsr & ~((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT);
202	__wfs(__new_fpsr);
203	return ((__old_fpsr >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
204}
205
206static __inline int
207fegetexcept(void)
208{
209	fenv_t __fpsr;
210
211	__rfs(&__fpsr);
212	return ((__fpsr & _ENABLE_MASK) >> _FPUSW_SHIFT);
213}
214
215#endif /* __BSD_VISIBLE */
216
217__END_DECLS
218
219#endif	/* !_FENV_H_ */
220