1/*	$NetBSD: fenv.h,v 1.9 2023/09/26 12:46:30 tsutsui 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/stdint.h>
36#include <m68k/float.h>
37#include <m68k/fpreg.h>
38
39/* Exception bits, from FPSR */
40#define	FE_INEXACT	FPSR_AINEX
41#define	FE_DIVBYZERO	FPSR_ADZ
42#define	FE_UNDERFLOW	FPSR_AUNFL
43#define	FE_OVERFLOW	FPSR_AOVFL
44#define	FE_INVALID	FPSR_AIOP
45
46#define FE_ALL_EXCEPT \
47    (FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
48
49/* Rounding modes, from FPCR */
50#define FE_TONEAREST	FPCR_NEAR
51#define	FE_TOWARDZERO	FPCR_ZERO
52#define	FE_DOWNWARD	FPCR_MINF
53#define	FE_UPWARD	FPCR_PINF
54
55#define _ROUND_MASK	\
56    (FE_TONEAREST | FE_TOWARDZERO | FE_DOWNWARD | FE_UPWARD)
57
58#if defined(__HAVE_68881__)
59
60#ifndef __fenv_static
61#define __fenv_static   static
62#endif
63
64typedef uint32_t fexcept_t;
65
66/* same layout as fmovem */
67typedef struct {
68	uint32_t fpcr;
69	uint32_t fpsr;
70	uint32_t fppc;
71} fenv_t;
72
73#define FE_DFL_ENV	((fenv_t *) -1)
74
75#define __get_fpcr(__fpcr) \
76    __asm__ __volatile__ ("fmove%.l %!,%0" : "=dm" (__fpcr))
77#define __set_fpcr(__fpcr) \
78    __asm__ __volatile__ ("fmove%.l %0,%!" : : "dm" (__fpcr))
79
80#define __get_fpsr(__fpsr) \
81    __asm__ __volatile__ ("fmove%.l %/fpsr,%0" : "=dm" (__fpsr))
82#define __set_fpsr(__fpsr) \
83    __asm__ __volatile__ ("fmove%.l %0,%/fpsr" : : "dm" (__fpsr))
84
85#define __fmul(__s, __t, __d) \
86    do { \
87	    __t d = __d; \
88	    __asm__ __volatile__ ("fmul" __s "; fnop" : "=f" (d) : "0" (d)); \
89    } while (/*CONSTCOND*/0)
90
91#define __fdiv(__s, __t, __d) \
92    do { \
93	    __t d = __d; \
94	    __asm__ __volatile__ ("fdiv" __s "; fnop" : "=f" (d) : "0" (d)); \
95    } while (/*CONSTCOND*/0)
96
97#define __fetox(__s, __t, __d) \
98    do { \
99	    __t d = __d; \
100	    __asm__ __volatile__ ("fetox" __s "; fnop" : "=f" (d) : "0" (d)); \
101    } while (/*CONSTCOND*/0)
102
103#define __fgetenv(__envp) \
104    __asm__ __volatile__ ("fmovem%.l %/fpcr/%/fpsr/%/fpiar,%0" : "=m" (__envp))
105
106#define __fsetenv(__envp) \
107    __asm__ __volatile__ ("fmovem%.l %0,%/fpcr/%/fpsr/%/fpiar" : : "m" (__envp))
108
109__BEGIN_DECLS
110
111#if __GNUC_PREREQ__(8, 0)
112#pragma GCC diagnostic push
113#pragma GCC diagnostic ignored "-Wshadow"
114#endif
115
116__fenv_static inline int
117feclearexcept(int __excepts)
118{
119	fexcept_t __fpsr;
120
121	__excepts &= FE_ALL_EXCEPT;
122
123	__get_fpsr(__fpsr);
124	__fpsr &= ~__excepts;
125	__set_fpsr(__fpsr);
126
127	return 0;
128}
129
130__fenv_static inline int
131fegetexceptflag(fexcept_t *__flagp, int __excepts)
132{
133	fexcept_t __fpsr;
134
135	__get_fpsr(__fpsr);
136
137	*__flagp = __fpsr & __excepts & FE_ALL_EXCEPT;
138
139	return 0;
140}
141
142__fenv_static inline int
143fesetexceptflag(const fexcept_t *__flagp, int __excepts)
144{
145	fexcept_t __fpsr;
146
147	__get_fpsr(__fpsr);
148
149	__fpsr &= ~(__excepts & FE_ALL_EXCEPT);
150	__fpsr |= *__flagp & __excepts & FE_ALL_EXCEPT;
151
152	__set_fpsr(__fpsr);
153
154	return 0;
155}
156
157__fenv_static inline int
158feraiseexcept(int __excepts)
159{
160	if (__excepts & FE_INVALID)	/* Inf * 0 */
161		__fmul("%.s %#0r0,%0", double, __builtin_huge_val());
162
163	if (__excepts & FE_DIVBYZERO)	/* 1.0 / 0 */
164		__fdiv("%.s %#0r0,%0", double, 1.0);
165
166	if (__excepts & FE_OVERFLOW)	/* MAX * MAX */
167		__fmul("%.x %0,%0", long double, LDBL_MAX);
168
169	if (__excepts & FE_UNDERFLOW)	/* e ^ -MAX */
170		__fetox("%.x %0", long double, -LDBL_MAX);
171
172	if (__excepts & FE_INEXACT)	/* 1 / 3 */
173		__fdiv("%.s %#0r3,%0", long double, 1.0);
174
175	return 0;
176}
177
178__fenv_static inline int
179fetestexcept(int __excepts)
180{
181	fexcept_t __fpsr;
182
183	__get_fpsr(__fpsr);
184
185	return __fpsr & __excepts & FE_ALL_EXCEPT;
186}
187
188__fenv_static inline int
189fegetround(void)
190{
191	fexcept_t __fpcr;
192
193	__get_fpcr(__fpcr);
194	return __fpcr & _ROUND_MASK;
195}
196
197__fenv_static inline int
198fesetround(int __round)
199{
200	fexcept_t __fpcr;
201
202	if (__round & ~_ROUND_MASK)
203		return -1;
204
205	__get_fpcr(__fpcr);
206
207	__fpcr &= ~_ROUND_MASK;
208	__fpcr |= __round;
209
210	__set_fpcr(__fpcr);
211
212	return 0;
213}
214
215__fenv_static inline int
216fegetenv(fenv_t *__envp)
217{
218	__fgetenv(*__envp);
219
220	return 0;
221}
222
223__fenv_static inline int
224feholdexcept(fenv_t *__envp)
225{
226	fexcept_t __fpcr, __fpsr;
227
228	__fgetenv(*__envp);
229	__fpsr = __envp->fpsr & ~FE_ALL_EXCEPT;
230	__set_fpsr(__fpsr);	/* clear all */
231	__fpcr = __envp->fpcr & ~(FE_ALL_EXCEPT << 6);
232	__set_fpcr(__fpcr);	/* set non/stop */
233
234	return 0;
235}
236
237__fenv_static inline int
238fesetenv(const fenv_t *__envp)
239{
240	fenv_t __tenv;
241
242	__fgetenv(__tenv);
243
244	if (__envp == FE_DFL_ENV) {
245		__tenv.fpcr |=
246		    __envp->fpcr & ((FE_ALL_EXCEPT << 6) | FE_UPWARD);
247		__tenv.fpsr |= __envp->fpsr & FE_ALL_EXCEPT;
248	}
249
250	__fsetenv(__tenv);
251
252	return 0;
253}
254
255__fenv_static inline int
256feupdateenv(const fenv_t *__envp)
257{
258	fexcept_t __fpsr;
259
260	__get_fpsr(__fpsr);
261	__fpsr &= FE_ALL_EXCEPT;
262	fesetenv(__envp);
263	feraiseexcept((int)__fpsr);
264	return 0;
265}
266
267#if __GNUC_PREREQ__(8, 0)
268#pragma GCC diagnostic pop
269#endif
270
271#if defined(_NETBSD_SOURCE) || defined(_GNU_SOURCE)
272
273__fenv_static inline int
274feenableexcept(int __mask)
275{
276	fexcept_t __fpcr, __oldmask;
277
278	__get_fpcr(__fpcr);
279	__oldmask = (__fpcr >> 6) & FE_ALL_EXCEPT;
280	__fpcr |= (__mask & FE_ALL_EXCEPT) << 6;
281	__set_fpcr(__fpcr);
282
283	return __oldmask;
284}
285
286__fenv_static inline int
287fedisableexcept(int __mask)
288{
289	fexcept_t __fpcr, __oldmask;
290
291	__get_fpcr(__fpcr);
292	__oldmask = (__fpcr >> 6) & FE_ALL_EXCEPT;
293	__fpcr &= ~((__mask & FE_ALL_EXCEPT) << 6);
294	__set_fpcr(__fpcr);
295
296	return __oldmask;
297}
298
299__fenv_static inline int
300fegetexcept(void)
301{
302	fexcept_t __fpcr;
303
304	__get_fpcr(__fpcr);
305
306	return (__fpcr >> 6) & FE_ALL_EXCEPT;
307}
308
309#endif /* _NETBSD_SOURCE || _GNU_SOURCE */
310
311__END_DECLS
312
313#endif /* __HAVE_68881__ */
314
315#endif /* _M68K_FENV_H_ */
316