xref: /freebsd/lib/msun/powerpc/fenv.h (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
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 typedef	__uint32_t	fenv_t;
41 typedef	__uint32_t	fexcept_t;
42 
43 /* Exception flags */
44 #define	FE_INEXACT	0x02000000
45 #define	FE_DIVBYZERO	0x04000000
46 #define	FE_UNDERFLOW	0x08000000
47 #define	FE_OVERFLOW	0x10000000
48 #define	FE_INVALID	0x20000000	/* all types of invalid FP ops */
49 
50 /*
51  * The PowerPC architecture has extra invalid flags that indicate the
52  * specific type of invalid operation occurred.  These flags may be
53  * tested, set, and cleared---but not masked---separately.  All of
54  * these bits are cleared when FE_INVALID is cleared, but only
55  * FE_VXSOFT is set when FE_INVALID is explicitly set in software.
56  */
57 #define	FE_VXCVI	0x00000100	/* invalid integer convert */
58 #define	FE_VXSQRT	0x00000200	/* square root of a negative */
59 #define	FE_VXSOFT	0x00000400	/* software-requested exception */
60 #define	FE_VXVC		0x00080000	/* ordered comparison involving NaN */
61 #define	FE_VXIMZ	0x00100000	/* inf * 0 */
62 #define	FE_VXZDZ	0x00200000	/* 0 / 0 */
63 #define	FE_VXIDI	0x00400000	/* inf / inf */
64 #define	FE_VXISI	0x00800000	/* inf - inf */
65 #define	FE_VXSNAN	0x01000000	/* operation on a signalling NaN */
66 #define	FE_ALL_INVALID	(FE_VXCVI | FE_VXSQRT | FE_VXSOFT | FE_VXVC | \
67 			 FE_VXIMZ | FE_VXZDZ | FE_VXIDI | FE_VXISI | \
68 			 FE_VXSNAN | FE_INVALID)
69 #define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
70 			 FE_ALL_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
71 
72 /* Rounding modes */
73 #define	FE_TONEAREST	0x0000
74 #define	FE_TOWARDZERO	0x0001
75 #define	FE_UPWARD	0x0002
76 #define	FE_DOWNWARD	0x0003
77 #define	_ROUND_MASK	(FE_TONEAREST | FE_DOWNWARD | \
78 			 FE_UPWARD | FE_TOWARDZERO)
79 
80 __BEGIN_DECLS
81 
82 /* Default floating-point environment */
83 extern const fenv_t	__fe_dfl_env;
84 #define	FE_DFL_ENV	(&__fe_dfl_env)
85 
86 /* We need to be able to map status flag positions to mask flag positions */
87 #define	_FPUSW_SHIFT	22
88 #define	_ENABLE_MASK	((FE_DIVBYZERO | FE_INEXACT | FE_INVALID | \
89 			 FE_OVERFLOW | FE_UNDERFLOW) >> _FPUSW_SHIFT)
90 
91 #ifndef _SOFT_FLOAT
92 #ifdef __SPE__
93 #define	__mffs(__env)	__asm __volatile("mfspr %0, 512" : "=r" (*(__env)))
94 #define	__mtfsf(__env)	__asm __volatile("mtspr 512,%0" : : "r" (__env))
95 #else
96 #define	__mffs(__env)	__asm __volatile("mffs %0" : "=f" (*(__env)))
97 #define	__mtfsf(__env)	__asm __volatile("mtfsf 255,%0" : : "f" (__env))
98 #endif
99 #else
100 #define	__mffs(__env)
101 #define	__mtfsf(__env)
102 #endif
103 
104 union __fpscr {
105 	double __d;
106 	struct {
107 #if _BYTE_ORDER == _LITTLE_ENDIAN
108 		fenv_t __reg;
109 		__uint32_t __junk;
110 #else
111 		__uint32_t __junk;
112 		fenv_t __reg;
113 #endif
114 	} __bits;
115 };
116 
117 __fenv_static inline int
118 feclearexcept(int __excepts)
119 {
120 	union __fpscr __r;
121 
122 	if (__excepts & FE_INVALID)
123 		__excepts |= FE_ALL_INVALID;
124 	__mffs(&__r.__d);
125 	__r.__bits.__reg &= ~__excepts;
126 	__mtfsf(__r.__d);
127 	return (0);
128 }
129 
130 __fenv_static inline int
131 fegetexceptflag(fexcept_t *__flagp, int __excepts)
132 {
133 	union __fpscr __r;
134 
135 	__mffs(&__r.__d);
136 	*__flagp = __r.__bits.__reg & __excepts;
137 	return (0);
138 }
139 
140 __fenv_static inline int
141 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
142 {
143 	union __fpscr __r;
144 
145 	if (__excepts & FE_INVALID)
146 		__excepts |= FE_ALL_EXCEPT;
147 	__mffs(&__r.__d);
148 	__r.__bits.__reg &= ~__excepts;
149 	__r.__bits.__reg |= *__flagp & __excepts;
150 	__mtfsf(__r.__d);
151 	return (0);
152 }
153 
154 __fenv_static inline int
155 feraiseexcept(int __excepts)
156 {
157 	union __fpscr __r;
158 
159 	if (__excepts & FE_INVALID)
160 		__excepts |= FE_VXSOFT;
161 	__mffs(&__r.__d);
162 	__r.__bits.__reg |= __excepts;
163 	__mtfsf(__r.__d);
164 	return (0);
165 }
166 
167 __fenv_static inline int
168 fetestexcept(int __excepts)
169 {
170 	union __fpscr __r;
171 
172 	__mffs(&__r.__d);
173 	return (__r.__bits.__reg & __excepts);
174 }
175 
176 __fenv_static inline int
177 fegetround(void)
178 {
179 	union __fpscr __r;
180 
181 	__mffs(&__r.__d);
182 	return (__r.__bits.__reg & _ROUND_MASK);
183 }
184 
185 __fenv_static inline int
186 fesetround(int __round)
187 {
188 	union __fpscr __r;
189 
190 	if (__round & ~_ROUND_MASK)
191 		return (-1);
192 	__mffs(&__r.__d);
193 	__r.__bits.__reg &= ~_ROUND_MASK;
194 	__r.__bits.__reg |= __round;
195 	__mtfsf(__r.__d);
196 	return (0);
197 }
198 
199 __fenv_static inline int
200 fegetenv(fenv_t *__envp)
201 {
202 	union __fpscr __r;
203 
204 	__mffs(&__r.__d);
205 	*__envp = __r.__bits.__reg;
206 	return (0);
207 }
208 
209 __fenv_static inline int
210 feholdexcept(fenv_t *__envp)
211 {
212 	union __fpscr __r;
213 
214 	__mffs(&__r.__d);
215 	*__envp = __r.__d;
216 	__r.__bits.__reg &= ~(FE_ALL_EXCEPT | _ENABLE_MASK);
217 	__mtfsf(__r.__d);
218 	return (0);
219 }
220 
221 __fenv_static inline int
222 fesetenv(const fenv_t *__envp)
223 {
224 	union __fpscr __r;
225 
226 	__r.__bits.__reg = *__envp;
227 	__mtfsf(__r.__d);
228 	return (0);
229 }
230 
231 __fenv_static inline int
232 feupdateenv(const fenv_t *__envp)
233 {
234 	union __fpscr __r;
235 
236 	__mffs(&__r.__d);
237 	__r.__bits.__reg &= FE_ALL_EXCEPT;
238 	__r.__bits.__reg |= *__envp;
239 	__mtfsf(__r.__d);
240 	return (0);
241 }
242 
243 #if __BSD_VISIBLE
244 
245 /* We currently provide no external definitions of the functions below. */
246 
247 static inline int
248 feenableexcept(int __mask)
249 {
250 	union __fpscr __r;
251 	fenv_t __oldmask;
252 
253 	__mffs(&__r.__d);
254 	__oldmask = __r.__bits.__reg;
255 	__r.__bits.__reg |= (__mask & FE_ALL_EXCEPT) >> _FPUSW_SHIFT;
256 	__mtfsf(__r.__d);
257 	return ((__oldmask & _ENABLE_MASK) << _FPUSW_SHIFT);
258 }
259 
260 static inline int
261 fedisableexcept(int __mask)
262 {
263 	union __fpscr __r;
264 	fenv_t __oldmask;
265 
266 	__mffs(&__r.__d);
267 	__oldmask = __r.__bits.__reg;
268 	__r.__bits.__reg &= ~((__mask & FE_ALL_EXCEPT) >> _FPUSW_SHIFT);
269 	__mtfsf(__r.__d);
270 	return ((__oldmask & _ENABLE_MASK) << _FPUSW_SHIFT);
271 }
272 
273 static inline int
274 fegetexcept(void)
275 {
276 	union __fpscr __r;
277 
278 	__mffs(&__r.__d);
279 	return ((__r.__bits.__reg & _ENABLE_MASK) << _FPUSW_SHIFT);
280 }
281 
282 #endif /* __BSD_VISIBLE */
283 
284 __END_DECLS
285 
286 #endif	/* !_FENV_H_ */
287