xref: /netbsd-src/sys/arch/powerpc/include/fenv.h (revision cddc78ea67e20759c213d3f50ea3bd06ade17338)
1 /*	$NetBSD: fenv.h,v 1.8 2024/10/30 15:56:11 riastradh Exp $	*/
2 
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: head/lib/msun/powerpc/fenv.h 226218 2011-10-10 15:43:09Z das $
29  */
30 
31 #ifndef	_POWERPC_FENV_H_
32 #define	_POWERPC_FENV_H_
33 
34 #include <sys/featuretest.h>
35 #include <sys/stdint.h>
36 
37 /* Exception flags */
38 #define	FE_INEXACT	0x02000000
39 #define	FE_DIVBYZERO	0x04000000
40 #define	FE_UNDERFLOW	0x08000000
41 #define	FE_OVERFLOW	0x10000000
42 #define	FE_INVALID	0x20000000	/* all types of invalid FP ops */
43 
44 /*
45  * The PowerPC architecture has extra invalid flags that indicate the
46  * specific type of invalid operation occurred.  These flags may be
47  * tested, set, and cleared---but not masked---separately.  All of
48  * these bits are cleared when FE_INVALID is cleared, but only
49  * FE_VXSOFT is set when FE_INVALID is explicitly set in software.
50  */
51 #define	FE_VXCVI	0x00000100	/* invalid integer convert */
52 #define	FE_VXSQRT	0x00000200	/* square root of a negative */
53 #define	FE_VXSOFT	0x00000400	/* software-requested exception */
54 #define	FE_VXVC		0x00080000	/* ordered comparison involving NaN */
55 #define	FE_VXIMZ	0x00100000	/* inf * 0 */
56 #define	FE_VXZDZ	0x00200000	/* 0 / 0 */
57 #define	FE_VXIDI	0x00400000	/* inf / inf */
58 #define	FE_VXISI	0x00800000	/* inf - inf */
59 #define	FE_VXSNAN	0x01000000	/* operation on a signalling NaN */
60 #define	FE_ALL_INVALID	(FE_VXCVI | FE_VXSQRT | FE_VXSOFT | FE_VXVC | \
61 			 FE_VXIMZ | FE_VXZDZ | FE_VXIDI | FE_VXISI | \
62 			 FE_VXSNAN | FE_INVALID)
63 #define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
64 			 FE_ALL_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
65 
66 /* Rounding modes */
67 #define	FE_TONEAREST	0x0000
68 #define	FE_TOWARDZERO	0x0001
69 #define	FE_UPWARD	0x0002
70 #define	FE_DOWNWARD	0x0003
71 #define	_ROUND_MASK	(FE_TONEAREST | FE_DOWNWARD | \
72 			 FE_UPWARD | FE_TOWARDZERO)
73 
74 #ifndef _SOFT_FLOAT
75 
76 #ifndef	__fenv_static
77 #define	__fenv_static	static
78 #endif
79 
80 typedef	uint32_t	fenv_t;
81 typedef	uint32_t	fexcept_t;
82 
83 #ifndef _KERNEL
84 __BEGIN_DECLS
85 
86 /* Default floating-point environment */
87 extern const fenv_t	__fe_dfl_env;
88 #define	FE_DFL_ENV	(&__fe_dfl_env)
89 
90 /* We need to be able to map status flag positions to mask flag positions */
91 #define	_FPUSW_SHIFT	22
92 #define	_ENABLE_MASK	((FE_DIVBYZERO | FE_INEXACT | FE_INVALID | \
93 			 FE_OVERFLOW | FE_UNDERFLOW) >> _FPUSW_SHIFT)
94 
95 #ifndef _SOFT_FLOAT
96 #define	__mffs(__env)	__asm __volatile("mffs %0" : "=f" (*(__env)))
97 #define	__mtfsf(__env)	__asm __volatile("mtfsf 255,%0" : : "f" (__env))
98 
99 static __inline uint32_t
100 __mfmsr(void)
101 {
102 	uint32_t __msr;
103 
104 	__asm volatile ("mfmsr %0" : "=r"(__msr));
105 	return __msr;
106 }
107 
108 static __inline void
109 __mtmsr(uint32_t __msr)
110 {
111 
112 	__asm volatile ("mtmsr %0" : : "r"(__msr));
113 }
114 
115 #define __MSR_FE_MASK	(0x00000800 | 0x00000100)
116 #define __MSR_FE_DIS	(0)
117 #define __MSR_FE_PREC	(0x00000800 | 0x00000100)
118 
119 static __inline void
120 __updatemsr(uint32_t __reg)
121 {
122 	uint32_t __msr;
123 
124 	__msr = __mfmsr() & ~__MSR_FE_MASK;
125 	if (__reg != 0) {
126 		__msr |= __MSR_FE_PREC;
127 	} else {
128 		__msr |= __MSR_FE_DIS;
129 	}
130 	__mtmsr(__msr);
131 }
132 
133 #else
134 #define	__mffs(__env)
135 #define	__mtfsf(__env)
136 #define __updatemsr(__reg)
137 #endif
138 
139 union __fpscr {
140 	double __d;
141 	struct {
142 		uint32_t __junk;
143 		fenv_t __reg;
144 	} __bits;
145 };
146 
147 #if __GNUC_PREREQ__(8, 0)
148 #pragma GCC diagnostic push
149 #pragma GCC diagnostic ignored "-Wshadow"
150 #endif
151 
152 __fenv_static __inline int
153 feclearexcept(int __excepts)
154 {
155 	union __fpscr __r;
156 
157 	if (__excepts & FE_INVALID)
158 		__excepts |= FE_ALL_INVALID;
159 	__mffs(&__r.__d);
160 	__r.__bits.__reg &= ~__excepts;
161 	__mtfsf(__r.__d);
162 	return (0);
163 }
164 
165 __fenv_static __inline int
166 fegetexceptflag(fexcept_t *__flagp, int __excepts)
167 {
168 	union __fpscr __r;
169 
170 	__mffs(&__r.__d);
171 	*__flagp = __r.__bits.__reg & __excepts;
172 	return (0);
173 }
174 
175 __fenv_static __inline int
176 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
177 {
178 	union __fpscr __r;
179 
180 	if (__excepts & FE_INVALID)
181 		__excepts |= FE_ALL_INVALID;
182 	__mffs(&__r.__d);
183 	__r.__bits.__reg &= ~__excepts;
184 	__r.__bits.__reg |= *__flagp & __excepts;
185 	__mtfsf(__r.__d);
186 	return (0);
187 }
188 
189 __fenv_static __inline int
190 feraiseexcept(int __excepts)
191 {
192 	union __fpscr __r;
193 
194 	if (__excepts & FE_INVALID)
195 		__excepts |= FE_VXSOFT;
196 	__mffs(&__r.__d);
197 	__r.__bits.__reg |= __excepts;
198 	__mtfsf(__r.__d);
199 	return (0);
200 }
201 
202 __fenv_static __inline int
203 fetestexcept(int __excepts)
204 {
205 	union __fpscr __r;
206 
207 	__mffs(&__r.__d);
208 	return (__r.__bits.__reg & __excepts);
209 }
210 
211 __fenv_static __inline int
212 fegetround(void)
213 {
214 	union __fpscr __r;
215 
216 	__mffs(&__r.__d);
217 	return (__r.__bits.__reg & _ROUND_MASK);
218 }
219 
220 __fenv_static __inline int
221 fesetround(int __round)
222 {
223 	union __fpscr __r;
224 
225 	if (__round & ~_ROUND_MASK)
226 		return (-1);
227 	__mffs(&__r.__d);
228 	__r.__bits.__reg &= ~_ROUND_MASK;
229 	__r.__bits.__reg |= __round;
230 	__mtfsf(__r.__d);
231 	return (0);
232 }
233 
234 __fenv_static __inline int
235 fegetenv(fenv_t *__envp)
236 {
237 	union __fpscr __r;
238 
239 	__mffs(&__r.__d);
240 	*__envp = __r.__bits.__reg;
241 	return (0);
242 }
243 
244 __fenv_static __inline int
245 feholdexcept(fenv_t *__envp)
246 {
247 	union __fpscr __r;
248 	uint32_t msr;
249 
250 	__mffs(&__r.__d);
251 	*__envp = __r.__bits.__reg;
252 	__r.__bits.__reg &= ~(FE_ALL_EXCEPT | _ENABLE_MASK);
253 	__mtfsf(__r.__d);
254 	__updatemsr(__r.__bits.__reg);
255 	return (0);
256 }
257 
258 __fenv_static __inline int
259 fesetenv(const fenv_t *__envp)
260 {
261 	union __fpscr __r;
262 
263 	__r.__bits.__reg = *__envp;
264 	__mtfsf(__r.__d);
265 	__updatemsr(__r.__bits.__reg);
266 	return (0);
267 }
268 
269 __fenv_static __inline int
270 feupdateenv(const fenv_t *__envp)
271 {
272 	union __fpscr __r;
273 
274 	__mffs(&__r.__d);
275 	__r.__bits.__reg &= FE_ALL_EXCEPT;
276 	__r.__bits.__reg |= *__envp;
277 	__mtfsf(__r.__d);
278 	__updatemsr(__r.__bits.__reg);
279 	return (0);
280 }
281 
282 #if __GNUC_PREREQ__(8, 0)
283 #pragma GCC diagnostic pop
284 #endif
285 
286 #if defined(_NETBSD_SOURCE) || defined(_GNU_SOURCE)
287 
288 __fenv_static __inline int
289 feenableexcept(int __mask)
290 {
291 	union __fpscr __r;
292 	fenv_t __oldmask;
293 
294 	__mffs(&__r.__d);
295 	__oldmask = __r.__bits.__reg;
296 	__r.__bits.__reg |= (__mask & FE_ALL_EXCEPT) >> _FPUSW_SHIFT;
297 	__mtfsf(__r.__d);
298 	__updatemsr(__r.__bits.__reg);
299 	return ((__oldmask & _ENABLE_MASK) << _FPUSW_SHIFT);
300 }
301 
302 __fenv_static __inline int
303 fedisableexcept(int __mask)
304 {
305 	union __fpscr __r;
306 	fenv_t __oldmask;
307 
308 	__mffs(&__r.__d);
309 	__oldmask = __r.__bits.__reg;
310 	__r.__bits.__reg &= ~((__mask & FE_ALL_EXCEPT) >> _FPUSW_SHIFT);
311 	__mtfsf(__r.__d);
312 	__updatemsr(__r.__bits.__reg);
313 	return ((__oldmask & _ENABLE_MASK) << _FPUSW_SHIFT);
314 }
315 
316 __fenv_static __inline int
317 fegetexcept(void)
318 {
319 	union __fpscr __r;
320 
321 	__mffs(&__r.__d);
322 	return ((__r.__bits.__reg & _ENABLE_MASK) << _FPUSW_SHIFT);
323 }
324 
325 #endif /* _NETBSD_SOURCE || _GNU_SOURCE */
326 
327 __END_DECLS
328 
329 #endif
330 #endif	/* _SOFT_FLOAT */
331 
332 #endif	/* !_POWERPC_FENV_H_ */
333