xref: /freebsd/lib/msun/powerpc/fenv.h (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
29 #ifndef	_FENV_H_
30 #define	_FENV_H_
31 
32 #include <sys/_types.h>
33 #include <machine/endian.h>
34 
35 #ifndef	__fenv_static
36 #define	__fenv_static	static
37 #endif
38 
39 typedef	__uint32_t	fenv_t;
40 typedef	__uint32_t	fexcept_t;
41 
42 /* Exception flags */
43 #ifdef __SPE__
44 #define FE_OVERFLOW	0x00000100
45 #define FE_UNDERFLOW	0x00000200
46 #define FE_DIVBYZERO	0x00000400
47 #define FE_INVALID	0x00000800
48 #define FE_INEXACT	0x00001000
49 
50 #define	FE_ALL_INVALID	FE_INVALID
51 
52 #define	_FPUSW_SHIFT	6
53 #else
54 #define	FE_INEXACT	0x02000000
55 #define	FE_DIVBYZERO	0x04000000
56 #define	FE_UNDERFLOW	0x08000000
57 #define	FE_OVERFLOW	0x10000000
58 #define	FE_INVALID	0x20000000	/* all types of invalid FP ops */
59 
60 /*
61  * The PowerPC architecture has extra invalid flags that indicate the
62  * specific type of invalid operation occurred.  These flags may be
63  * tested, set, and cleared---but not masked---separately.  All of
64  * these bits are cleared when FE_INVALID is cleared, but only
65  * FE_VXSOFT is set when FE_INVALID is explicitly set in software.
66  */
67 #define	FE_VXCVI	0x00000100	/* invalid integer convert */
68 #define	FE_VXSQRT	0x00000200	/* square root of a negative */
69 #define	FE_VXSOFT	0x00000400	/* software-requested exception */
70 #define	FE_VXVC		0x00080000	/* ordered comparison involving NaN */
71 #define	FE_VXIMZ	0x00100000	/* inf * 0 */
72 #define	FE_VXZDZ	0x00200000	/* 0 / 0 */
73 #define	FE_VXIDI	0x00400000	/* inf / inf */
74 #define	FE_VXISI	0x00800000	/* inf - inf */
75 #define	FE_VXSNAN	0x01000000	/* operation on a signalling NaN */
76 #define	FE_ALL_INVALID	(FE_VXCVI | FE_VXSQRT | FE_VXSOFT | FE_VXVC | \
77 			 FE_VXIMZ | FE_VXZDZ | FE_VXIDI | FE_VXISI | \
78 			 FE_VXSNAN | FE_INVALID)
79 
80 #define	_FPUSW_SHIFT	22
81 #endif
82 #define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
83 			 FE_ALL_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
84 
85 /* Rounding modes */
86 #define	FE_TONEAREST	0x0000
87 #define	FE_TOWARDZERO	0x0001
88 #define	FE_UPWARD	0x0002
89 #define	FE_DOWNWARD	0x0003
90 #define	_ROUND_MASK	(FE_TONEAREST | FE_DOWNWARD | \
91 			 FE_UPWARD | FE_TOWARDZERO)
92 
93 __BEGIN_DECLS
94 
95 /* Default floating-point environment */
96 extern const fenv_t	__fe_dfl_env;
97 #define	FE_DFL_ENV	(&__fe_dfl_env)
98 
99 /* We need to be able to map status flag positions to mask flag positions */
100 #define	_ENABLE_MASK	((FE_DIVBYZERO | FE_INEXACT | FE_INVALID | \
101 			 FE_OVERFLOW | FE_UNDERFLOW) >> _FPUSW_SHIFT)
102 
103 #ifndef _SOFT_FLOAT
104 #ifdef __SPE__
105 #define	__mffs(__env) \
106 	__asm __volatile("mfspr %0, 512" : "=r" ((__env)->__bits.__reg))
107 #define	__mtfsf(__env) \
108 	__asm __volatile("mtspr 512,%0;isync" :: "r" ((__env).__bits.__reg))
109 #else
110 #define	__mffs(__env) \
111 	__asm __volatile("mffs %0" : "=f" ((__env)->__d))
112 #define	__mtfsf(__env) \
113 	__asm __volatile("mtfsf 255,%0" :: "f" ((__env).__d))
114 #endif
115 #else
116 #define	__mffs(__env)
117 #define	__mtfsf(__env)
118 #endif
119 
120 union __fpscr {
121 	double __d;
122 	struct {
123 #if _BYTE_ORDER == _LITTLE_ENDIAN
124 		fenv_t __reg;
125 		__uint32_t __junk;
126 #else
127 		__uint32_t __junk;
128 		fenv_t __reg;
129 #endif
130 	} __bits;
131 };
132 
133 __fenv_static inline int
134 feclearexcept(int __excepts)
135 {
136 	union __fpscr __r;
137 
138 	if (__excepts & FE_INVALID)
139 		__excepts |= FE_ALL_INVALID;
140 	__mffs(&__r);
141 	__r.__bits.__reg &= ~__excepts;
142 	__mtfsf(__r);
143 	return (0);
144 }
145 
146 __fenv_static inline int
147 fegetexceptflag(fexcept_t *__flagp, int __excepts)
148 {
149 	union __fpscr __r;
150 
151 	__mffs(&__r);
152 	*__flagp = __r.__bits.__reg & __excepts;
153 	return (0);
154 }
155 
156 __fenv_static inline int
157 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
158 {
159 	union __fpscr __r;
160 
161 	if (__excepts & FE_INVALID)
162 		__excepts |= FE_ALL_INVALID;
163 	__mffs(&__r);
164 	__r.__bits.__reg &= ~__excepts;
165 	__r.__bits.__reg |= *__flagp & __excepts;
166 	__mtfsf(__r);
167 	return (0);
168 }
169 
170 #ifdef __SPE__
171 extern int	feraiseexcept(int __excepts);
172 #else
173 __fenv_static inline int
174 feraiseexcept(int __excepts)
175 {
176 	union __fpscr __r;
177 
178 	if (__excepts & FE_INVALID)
179 		__excepts |= FE_VXSOFT;
180 	__mffs(&__r);
181 	__r.__bits.__reg |= __excepts;
182 	__mtfsf(__r);
183 	return (0);
184 }
185 #endif
186 
187 __fenv_static inline int
188 fetestexcept(int __excepts)
189 {
190 	union __fpscr __r;
191 
192 	__mffs(&__r);
193 	return (__r.__bits.__reg & __excepts);
194 }
195 
196 __fenv_static inline int
197 fegetround(void)
198 {
199 	union __fpscr __r;
200 
201 	__mffs(&__r);
202 	return (__r.__bits.__reg & _ROUND_MASK);
203 }
204 
205 __fenv_static inline int
206 fesetround(int __round)
207 {
208 	union __fpscr __r;
209 
210 	if (__round & ~_ROUND_MASK)
211 		return (-1);
212 	__mffs(&__r);
213 	__r.__bits.__reg &= ~_ROUND_MASK;
214 	__r.__bits.__reg |= __round;
215 	__mtfsf(__r);
216 	return (0);
217 }
218 
219 __fenv_static inline int
220 fegetenv(fenv_t *__envp)
221 {
222 	union __fpscr __r;
223 
224 	__mffs(&__r);
225 	*__envp = __r.__bits.__reg;
226 	return (0);
227 }
228 
229 __fenv_static inline int
230 feholdexcept(fenv_t *__envp)
231 {
232 	union __fpscr __r;
233 
234 	__mffs(&__r);
235 	*__envp = __r.__bits.__reg;
236 	__r.__bits.__reg &= ~(FE_ALL_EXCEPT | _ENABLE_MASK);
237 	__mtfsf(__r);
238 	return (0);
239 }
240 
241 __fenv_static inline int
242 fesetenv(const fenv_t *__envp)
243 {
244 	union __fpscr __r;
245 
246 	__r.__bits.__reg = *__envp;
247 	__mtfsf(__r);
248 	return (0);
249 }
250 
251 __fenv_static inline int
252 feupdateenv(const fenv_t *__envp)
253 {
254 	union __fpscr __r;
255 
256 	__mffs(&__r);
257 	__r.__bits.__reg &= FE_ALL_EXCEPT;
258 	__r.__bits.__reg |= *__envp;
259 	__mtfsf(__r);
260 	return (0);
261 }
262 
263 #if __BSD_VISIBLE
264 
265 __fenv_static inline int
266 feenableexcept(int __mask)
267 {
268 	union __fpscr __r;
269 	fenv_t __oldmask;
270 
271 	__mffs(&__r);
272 	__oldmask = __r.__bits.__reg;
273 	__r.__bits.__reg |= (__mask & FE_ALL_EXCEPT) >> _FPUSW_SHIFT;
274 	__mtfsf(__r);
275 	return ((__oldmask & _ENABLE_MASK) << _FPUSW_SHIFT);
276 }
277 
278 __fenv_static inline int
279 fedisableexcept(int __mask)
280 {
281 	union __fpscr __r;
282 	fenv_t __oldmask;
283 
284 	__mffs(&__r);
285 	__oldmask = __r.__bits.__reg;
286 	__r.__bits.__reg &= ~((__mask & FE_ALL_EXCEPT) >> _FPUSW_SHIFT);
287 	__mtfsf(__r);
288 	return ((__oldmask & _ENABLE_MASK) << _FPUSW_SHIFT);
289 }
290 
291 /* We currently provide no external definition of fegetexcept(). */
292 static inline int
293 fegetexcept(void)
294 {
295 	union __fpscr __r;
296 
297 	__mffs(&__r);
298 	return ((__r.__bits.__reg & _ENABLE_MASK) << _FPUSW_SHIFT);
299 }
300 
301 #endif /* __BSD_VISIBLE */
302 
303 __END_DECLS
304 
305 #endif	/* !_FENV_H_ */
306