xref: /netbsd-src/sys/arch/m68k/include/fenv.h (revision cddc78ea67e20759c213d3f50ea3bd06ade17338)
1 /*	$NetBSD: fenv.h,v 1.10 2024/10/30 15:56:11 riastradh Exp $	*/
2 
3 /*-
4  * Copyright (c) 2015 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Christos Zoulas.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef _M68K_FENV_H_
33 #define _M68K_FENV_H_
34 
35 #include <sys/featuretest.h>
36 #include <sys/stdint.h>
37 
38 #include <m68k/float.h>
39 #include <m68k/fpreg.h>
40 
41 /* Exception bits, from FPSR */
42 #define	FE_INEXACT	FPSR_AINEX
43 #define	FE_DIVBYZERO	FPSR_ADZ
44 #define	FE_UNDERFLOW	FPSR_AUNFL
45 #define	FE_OVERFLOW	FPSR_AOVFL
46 #define	FE_INVALID	FPSR_AIOP
47 
48 #define FE_ALL_EXCEPT \
49     (FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
50 
51 /* Rounding modes, from FPCR */
52 #define FE_TONEAREST	FPCR_NEAR
53 #define	FE_TOWARDZERO	FPCR_ZERO
54 #define	FE_DOWNWARD	FPCR_MINF
55 #define	FE_UPWARD	FPCR_PINF
56 
57 #define _ROUND_MASK	\
58     (FE_TONEAREST | FE_TOWARDZERO | FE_DOWNWARD | FE_UPWARD)
59 
60 #if defined(__HAVE_68881__)
61 
62 #ifndef __fenv_static
63 #define __fenv_static   static
64 #endif
65 
66 typedef uint32_t fexcept_t;
67 
68 /* same layout as fmovem */
69 typedef struct {
70 	uint32_t fpcr;
71 	uint32_t fpsr;
72 	uint32_t fppc;
73 } fenv_t;
74 
75 #define FE_DFL_ENV	((fenv_t *) -1)
76 
77 #define __get_fpcr(__fpcr) \
78     __asm__ __volatile__ ("fmove%.l %!,%0" : "=dm" (__fpcr))
79 #define __set_fpcr(__fpcr) \
80     __asm__ __volatile__ ("fmove%.l %0,%!" : : "dm" (__fpcr))
81 
82 #define __get_fpsr(__fpsr) \
83     __asm__ __volatile__ ("fmove%.l %/fpsr,%0" : "=dm" (__fpsr))
84 #define __set_fpsr(__fpsr) \
85     __asm__ __volatile__ ("fmove%.l %0,%/fpsr" : : "dm" (__fpsr))
86 
87 #define __fmul(__s, __t, __d) \
88     do { \
89 	    __t d = __d; \
90 	    __asm__ __volatile__ ("fmul" __s "; fnop" : "=f" (d) : "0" (d)); \
91     } while (/*CONSTCOND*/0)
92 
93 #define __fdiv(__s, __t, __d) \
94     do { \
95 	    __t d = __d; \
96 	    __asm__ __volatile__ ("fdiv" __s "; fnop" : "=f" (d) : "0" (d)); \
97     } while (/*CONSTCOND*/0)
98 
99 #define __fetox(__s, __t, __d) \
100     do { \
101 	    __t d = __d; \
102 	    __asm__ __volatile__ ("fetox" __s "; fnop" : "=f" (d) : "0" (d)); \
103     } while (/*CONSTCOND*/0)
104 
105 #define __fgetenv(__envp) \
106     __asm__ __volatile__ ("fmovem%.l %/fpcr/%/fpsr/%/fpiar,%0" : "=m" (__envp))
107 
108 #define __fsetenv(__envp) \
109     __asm__ __volatile__ ("fmovem%.l %0,%/fpcr/%/fpsr/%/fpiar" : : "m" (__envp))
110 
111 __BEGIN_DECLS
112 
113 #if __GNUC_PREREQ__(8, 0)
114 #pragma GCC diagnostic push
115 #pragma GCC diagnostic ignored "-Wshadow"
116 #endif
117 
118 __fenv_static inline int
119 feclearexcept(int __excepts)
120 {
121 	fexcept_t __fpsr;
122 
123 	__excepts &= FE_ALL_EXCEPT;
124 
125 	__get_fpsr(__fpsr);
126 	__fpsr &= ~__excepts;
127 	__set_fpsr(__fpsr);
128 
129 	return 0;
130 }
131 
132 __fenv_static inline int
133 fegetexceptflag(fexcept_t *__flagp, int __excepts)
134 {
135 	fexcept_t __fpsr;
136 
137 	__get_fpsr(__fpsr);
138 
139 	*__flagp = __fpsr & __excepts & FE_ALL_EXCEPT;
140 
141 	return 0;
142 }
143 
144 __fenv_static inline int
145 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
146 {
147 	fexcept_t __fpsr;
148 
149 	__get_fpsr(__fpsr);
150 
151 	__fpsr &= ~(__excepts & FE_ALL_EXCEPT);
152 	__fpsr |= *__flagp & __excepts & FE_ALL_EXCEPT;
153 
154 	__set_fpsr(__fpsr);
155 
156 	return 0;
157 }
158 
159 __fenv_static inline int
160 feraiseexcept(int __excepts)
161 {
162 	if (__excepts & FE_INVALID)	/* Inf * 0 */
163 		__fmul("%.s %#0r0,%0", double, __builtin_huge_val());
164 
165 	if (__excepts & FE_DIVBYZERO)	/* 1.0 / 0 */
166 		__fdiv("%.s %#0r0,%0", double, 1.0);
167 
168 	if (__excepts & FE_OVERFLOW)	/* MAX * MAX */
169 		__fmul("%.x %0,%0", long double, LDBL_MAX);
170 
171 	if (__excepts & FE_UNDERFLOW)	/* e ^ -MAX */
172 		__fetox("%.x %0", long double, -LDBL_MAX);
173 
174 	if (__excepts & FE_INEXACT)	/* 1 / 3 */
175 		__fdiv("%.s %#0r3,%0", long double, 1.0);
176 
177 	return 0;
178 }
179 
180 __fenv_static inline int
181 fetestexcept(int __excepts)
182 {
183 	fexcept_t __fpsr;
184 
185 	__get_fpsr(__fpsr);
186 
187 	return __fpsr & __excepts & FE_ALL_EXCEPT;
188 }
189 
190 __fenv_static inline int
191 fegetround(void)
192 {
193 	fexcept_t __fpcr;
194 
195 	__get_fpcr(__fpcr);
196 	return __fpcr & _ROUND_MASK;
197 }
198 
199 __fenv_static inline int
200 fesetround(int __round)
201 {
202 	fexcept_t __fpcr;
203 
204 	if (__round & ~_ROUND_MASK)
205 		return -1;
206 
207 	__get_fpcr(__fpcr);
208 
209 	__fpcr &= ~_ROUND_MASK;
210 	__fpcr |= __round;
211 
212 	__set_fpcr(__fpcr);
213 
214 	return 0;
215 }
216 
217 __fenv_static inline int
218 fegetenv(fenv_t *__envp)
219 {
220 	__fgetenv(*__envp);
221 
222 	return 0;
223 }
224 
225 __fenv_static inline int
226 feholdexcept(fenv_t *__envp)
227 {
228 	fexcept_t __fpcr, __fpsr;
229 
230 	__fgetenv(*__envp);
231 	__fpsr = __envp->fpsr & ~FE_ALL_EXCEPT;
232 	__set_fpsr(__fpsr);	/* clear all */
233 	__fpcr = __envp->fpcr & ~(FE_ALL_EXCEPT << 6);
234 	__set_fpcr(__fpcr);	/* set non/stop */
235 
236 	return 0;
237 }
238 
239 __fenv_static inline int
240 fesetenv(const fenv_t *__envp)
241 {
242 	fenv_t __tenv;
243 
244 	__fgetenv(__tenv);
245 
246 	if (__envp == FE_DFL_ENV) {
247 		__tenv.fpcr |=
248 		    __envp->fpcr & ((FE_ALL_EXCEPT << 6) | FE_UPWARD);
249 		__tenv.fpsr |= __envp->fpsr & FE_ALL_EXCEPT;
250 	}
251 
252 	__fsetenv(__tenv);
253 
254 	return 0;
255 }
256 
257 __fenv_static inline int
258 feupdateenv(const fenv_t *__envp)
259 {
260 	fexcept_t __fpsr;
261 
262 	__get_fpsr(__fpsr);
263 	__fpsr &= FE_ALL_EXCEPT;
264 	fesetenv(__envp);
265 	feraiseexcept((int)__fpsr);
266 	return 0;
267 }
268 
269 #if __GNUC_PREREQ__(8, 0)
270 #pragma GCC diagnostic pop
271 #endif
272 
273 #if defined(_NETBSD_SOURCE) || defined(_GNU_SOURCE)
274 
275 __fenv_static inline int
276 feenableexcept(int __mask)
277 {
278 	fexcept_t __fpcr, __oldmask;
279 
280 	__get_fpcr(__fpcr);
281 	__oldmask = (__fpcr >> 6) & FE_ALL_EXCEPT;
282 	__fpcr |= (__mask & FE_ALL_EXCEPT) << 6;
283 	__set_fpcr(__fpcr);
284 
285 	return __oldmask;
286 }
287 
288 __fenv_static inline int
289 fedisableexcept(int __mask)
290 {
291 	fexcept_t __fpcr, __oldmask;
292 
293 	__get_fpcr(__fpcr);
294 	__oldmask = (__fpcr >> 6) & FE_ALL_EXCEPT;
295 	__fpcr &= ~((__mask & FE_ALL_EXCEPT) << 6);
296 	__set_fpcr(__fpcr);
297 
298 	return __oldmask;
299 }
300 
301 __fenv_static inline int
302 fegetexcept(void)
303 {
304 	fexcept_t __fpcr;
305 
306 	__get_fpcr(__fpcr);
307 
308 	return (__fpcr >> 6) & FE_ALL_EXCEPT;
309 }
310 
311 #endif /* _NETBSD_SOURCE || _GNU_SOURCE */
312 
313 __END_DECLS
314 
315 #endif /* __HAVE_68881__ */
316 
317 #endif /* _M68K_FENV_H_ */
318