xref: /freebsd/lib/msun/aarch64/fenv.h (revision 4543ef516683042d46f3bd3bb8a4f3f746e00499)
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 
27 #ifdef __arm__
28 #include <arm/fenv.h>
29 #else /* __arm__ */
30 
31 #ifndef	_FENV_H_
32 #define	_FENV_H_
33 
34 #include <sys/_types.h>
35 
36 #ifndef	__fenv_static
37 #define	__fenv_static	static
38 #endif
39 
40 /* The high 32 bits contain fpcr, low 32 contain fpsr. */
41 typedef	__uint64_t	fenv_t;
42 typedef	__uint64_t	fexcept_t;
43 
44 /* Exception flags */
45 #define	FE_INVALID	0x00000001
46 #define	FE_DIVBYZERO	0x00000002
47 #define	FE_OVERFLOW	0x00000004
48 #define	FE_UNDERFLOW	0x00000008
49 #define	FE_INEXACT	0x00000010
50 #define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
51 			 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
52 
53 /*
54  * Rounding modes
55  *
56  * We can't just use the hardware bit values here, because that would
57  * make FE_UPWARD and FE_DOWNWARD negative, which is not allowed.
58  */
59 #define	FE_TONEAREST	0x0
60 #define	FE_UPWARD	0x1
61 #define	FE_DOWNWARD	0x2
62 #define	FE_TOWARDZERO	0x3
63 #define	_ROUND_MASK	(FE_TONEAREST | FE_DOWNWARD | \
64 			 FE_UPWARD | FE_TOWARDZERO)
65 #define	_ROUND_SHIFT	22
66 
67 __BEGIN_DECLS
68 
69 /* Default floating-point environment */
70 extern const fenv_t	__fe_dfl_env;
71 #define	FE_DFL_ENV	(&__fe_dfl_env)
72 
73 /* We need to be able to map status flag positions to mask flag positions */
74 #define _FPUSW_SHIFT	8
75 #define	_ENABLE_MASK	(FE_ALL_EXCEPT << _FPUSW_SHIFT)
76 
77 #define	__mrs_fpcr(__r)	__asm __volatile("mrs %0, fpcr" : "=r" (__r))
78 #define	__msr_fpcr(__r)	__asm __volatile("msr fpcr, %0" : : "r" (__r))
79 
80 #define	__mrs_fpsr(__r)	__asm __volatile("mrs %0, fpsr" : "=r" (__r))
81 #define	__msr_fpsr(__r)	__asm __volatile("msr fpsr, %0" : : "r" (__r))
82 
83 __fenv_static __inline int
84 feclearexcept(int __excepts)
85 {
86 	fexcept_t __r;
87 
88 	__mrs_fpsr(__r);
89 	__r &= ~__excepts;
90 	__msr_fpsr(__r);
91 	return (0);
92 }
93 
94 __fenv_static inline int
95 fegetexceptflag(fexcept_t *__flagp, int __excepts)
96 {
97 	fexcept_t __r;
98 
99 	__mrs_fpsr(__r);
100 	*__flagp = __r & __excepts;
101 	return (0);
102 }
103 
104 __fenv_static inline int
105 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
106 {
107 	fexcept_t __r;
108 
109 	__mrs_fpsr(__r);
110 	__r &= ~__excepts;
111 	__r |= *__flagp & __excepts;
112 	__msr_fpsr(__r);
113 	return (0);
114 }
115 
116 __fenv_static inline int
117 feraiseexcept(int __excepts)
118 {
119 	fexcept_t __r;
120 
121 	__mrs_fpsr(__r);
122 	__r |= __excepts;
123 	__msr_fpsr(__r);
124 	return (0);
125 }
126 
127 __fenv_static inline int
128 fetestexcept(int __excepts)
129 {
130 	fexcept_t __r;
131 
132 	__mrs_fpsr(__r);
133 	return (__r & __excepts);
134 }
135 
136 __fenv_static inline int
137 fegetround(void)
138 {
139 	fenv_t __r;
140 
141 	__mrs_fpcr(__r);
142 	return ((__r >> _ROUND_SHIFT) & _ROUND_MASK);
143 }
144 
145 __fenv_static inline int
146 fesetround(int __round)
147 {
148 	fenv_t __r;
149 
150 	if (__round & ~_ROUND_MASK)
151 		return (-1);
152 	__mrs_fpcr(__r);
153 	__r &= ~(_ROUND_MASK << _ROUND_SHIFT);
154 	__r |= __round << _ROUND_SHIFT;
155 	__msr_fpcr(__r);
156 	return (0);
157 }
158 
159 __fenv_static inline int
160 fegetenv(fenv_t *__envp)
161 {
162 	__uint64_t fpcr;
163 	__uint64_t fpsr;
164 
165 	__mrs_fpcr(fpcr);
166 	__mrs_fpsr(fpsr);
167 	*__envp = fpsr | (fpcr << 32);
168 
169 	return (0);
170 }
171 
172 __fenv_static inline int
173 feholdexcept(fenv_t *__envp)
174 {
175 	fenv_t __r;
176 
177 	__mrs_fpcr(__r);
178 	*__envp = __r << 32;
179 	__r &= ~(_ENABLE_MASK);
180 	__msr_fpcr(__r);
181 
182 	__mrs_fpsr(__r);
183 	*__envp |= (__uint32_t)__r;
184 	__r &= ~(_ENABLE_MASK);
185 	__msr_fpsr(__r);
186 	return (0);
187 }
188 
189 __fenv_static inline int
190 fesetenv(const fenv_t *__envp)
191 {
192 
193 	__msr_fpcr((*__envp) >> 32);
194 	__msr_fpsr((fenv_t)(__uint32_t)*__envp);
195 	return (0);
196 }
197 
198 __fenv_static inline int
199 feupdateenv(const fenv_t *__envp)
200 {
201 	fexcept_t __r;
202 
203 	__mrs_fpsr(__r);
204 	fesetenv(__envp);
205 	feraiseexcept(__r & FE_ALL_EXCEPT);
206 	return (0);
207 }
208 
209 #if __BSD_VISIBLE
210 
211 /* We currently provide no external definitions of the functions below. */
212 
213 static inline int
214 feenableexcept(int __mask)
215 {
216 	fenv_t __old_r, __new_r;
217 
218 	__mrs_fpcr(__old_r);
219 	__new_r = __old_r | ((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT);
220 	__msr_fpcr(__new_r);
221 	return ((__old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
222 }
223 
224 static inline int
225 fedisableexcept(int __mask)
226 {
227 	fenv_t __old_r, __new_r;
228 
229 	__mrs_fpcr(__old_r);
230 	__new_r = __old_r & ~((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT);
231 	__msr_fpcr(__new_r);
232 	return ((__old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
233 }
234 
235 static inline int
236 fegetexcept(void)
237 {
238 	fenv_t __r;
239 
240 	__mrs_fpcr(__r);
241 	return ((__r & _ENABLE_MASK) >> _FPUSW_SHIFT);
242 }
243 
244 #endif /* __BSD_VISIBLE */
245 
246 __END_DECLS
247 
248 #endif	/* !_FENV_H_ */
249 
250 #endif /* __arm__ */
251