xref: /freebsd/lib/msun/powerpc/fenv.h (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
1 /*-
2  * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef	_FENV_H_
30 #define	_FENV_H_
31 
32 #include <sys/_types.h>
33 
34 #ifndef	__fenv_static
35 #define	__fenv_static	static
36 #endif
37 
38 typedef	__uint32_t	fenv_t;
39 typedef	__uint32_t	fexcept_t;
40 
41 /* Exception flags */
42 #define	FE_INEXACT	0x02000000
43 #define	FE_DIVBYZERO	0x04000000
44 #define	FE_UNDERFLOW	0x08000000
45 #define	FE_OVERFLOW	0x10000000
46 #define	FE_INVALID	0x20000000	/* all types of invalid FP ops */
47 
48 /*
49  * The PowerPC architecture has extra invalid flags that indicate the
50  * specific type of invalid operation occurred.  These flags may be
51  * tested, set, and cleared---but not masked---separately.  All of
52  * these bits are cleared when FE_INVALID is cleared, but only
53  * FE_VXSOFT is set when FE_INVALID is explicitly set in software.
54  */
55 #define	FE_VXCVI	0x00000100	/* invalid integer convert */
56 #define	FE_VXSQRT	0x00000200	/* square root of a negative */
57 #define	FE_VXSOFT	0x00000400	/* software-requested exception */
58 #define	FE_VXVC		0x00080000	/* ordered comparison involving NaN */
59 #define	FE_VXIMZ	0x00100000	/* inf * 0 */
60 #define	FE_VXZDZ	0x00200000	/* 0 / 0 */
61 #define	FE_VXIDI	0x00400000	/* inf / inf */
62 #define	FE_VXISI	0x00800000	/* inf - inf */
63 #define	FE_VXSNAN	0x01000000	/* operation on a signalling NaN */
64 #define	FE_ALL_INVALID	(FE_VXCVI | FE_VXSQRT | FE_VXSOFT | FE_VXVC | \
65 			 FE_VXIMZ | FE_VXZDZ | FE_VXIDI | FE_VXISI | \
66 			 FE_VXSNAN | FE_INVALID)
67 #define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
68 			 FE_ALL_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
69 
70 /* Rounding modes */
71 #define	FE_TONEAREST	0x0000
72 #define	FE_TOWARDZERO	0x0001
73 #define	FE_UPWARD	0x0002
74 #define	FE_DOWNWARD	0x0003
75 #define	_ROUND_MASK	(FE_TONEAREST | FE_DOWNWARD | \
76 			 FE_UPWARD | FE_TOWARDZERO)
77 
78 __BEGIN_DECLS
79 
80 /* Default floating-point environment */
81 extern const fenv_t	__fe_dfl_env;
82 #define	FE_DFL_ENV	(&__fe_dfl_env)
83 
84 /* We need to be able to map status flag positions to mask flag positions */
85 #define	_FPUSW_SHIFT	22
86 #define	_ENABLE_MASK	((FE_DIVBYZERO | FE_INEXACT | FE_INVALID | \
87 			 FE_OVERFLOW | FE_UNDERFLOW) >> _FPUSW_SHIFT)
88 
89 #ifndef _SOFT_FLOAT
90 #define	__mffs(__env)	__asm __volatile("mffs %0" : "=f" (*(__env)))
91 #define	__mtfsf(__env)	__asm __volatile("mtfsf 255,%0" : : "f" (__env))
92 #else
93 #define	__mffs(__env)
94 #define	__mtfsf(__env)
95 #endif
96 
97 union __fpscr {
98 	double __d;
99 	struct {
100 		__uint32_t __junk;
101 		fenv_t __reg;
102 	} __bits;
103 };
104 
105 __fenv_static inline int
106 feclearexcept(int __excepts)
107 {
108 	union __fpscr __r;
109 
110 	if (__excepts & FE_INVALID)
111 		__excepts |= FE_ALL_INVALID;
112 	__mffs(&__r.__d);
113 	__r.__bits.__reg &= ~__excepts;
114 	__mtfsf(__r.__d);
115 	return (0);
116 }
117 
118 __fenv_static inline int
119 fegetexceptflag(fexcept_t *__flagp, int __excepts)
120 {
121 	union __fpscr __r;
122 
123 	__mffs(&__r.__d);
124 	*__flagp = __r.__bits.__reg & __excepts;
125 	return (0);
126 }
127 
128 __fenv_static inline int
129 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
130 {
131 	union __fpscr __r;
132 
133 	if (__excepts & FE_INVALID)
134 		__excepts |= FE_ALL_EXCEPT;
135 	__mffs(&__r.__d);
136 	__r.__bits.__reg &= ~__excepts;
137 	__r.__bits.__reg |= *__flagp & __excepts;
138 	__mtfsf(__r.__d);
139 	return (0);
140 }
141 
142 __fenv_static inline int
143 feraiseexcept(int __excepts)
144 {
145 	union __fpscr __r;
146 
147 	if (__excepts & FE_INVALID)
148 		__excepts |= FE_VXSOFT;
149 	__mffs(&__r.__d);
150 	__r.__bits.__reg |= __excepts;
151 	__mtfsf(__r.__d);
152 	return (0);
153 }
154 
155 __fenv_static inline int
156 fetestexcept(int __excepts)
157 {
158 	union __fpscr __r;
159 
160 	__mffs(&__r.__d);
161 	return (__r.__bits.__reg & __excepts);
162 }
163 
164 __fenv_static inline int
165 fegetround(void)
166 {
167 	union __fpscr __r;
168 
169 	__mffs(&__r.__d);
170 	return (__r.__bits.__reg & _ROUND_MASK);
171 }
172 
173 __fenv_static inline int
174 fesetround(int __round)
175 {
176 	union __fpscr __r;
177 
178 	if (__round & ~_ROUND_MASK)
179 		return (-1);
180 	__mffs(&__r.__d);
181 	__r.__bits.__reg &= ~_ROUND_MASK;
182 	__r.__bits.__reg |= __round;
183 	__mtfsf(__r.__d);
184 	return (0);
185 }
186 
187 __fenv_static inline int
188 fegetenv(fenv_t *__envp)
189 {
190 	union __fpscr __r;
191 
192 	__mffs(&__r.__d);
193 	*__envp = __r.__bits.__reg;
194 	return (0);
195 }
196 
197 __fenv_static inline int
198 feholdexcept(fenv_t *__envp)
199 {
200 	union __fpscr __r;
201 
202 	__mffs(&__r.__d);
203 	*__envp = __r.__d;
204 	__r.__bits.__reg &= ~(FE_ALL_EXCEPT | _ENABLE_MASK);
205 	__mtfsf(__r.__d);
206 	return (0);
207 }
208 
209 __fenv_static inline int
210 fesetenv(const fenv_t *__envp)
211 {
212 	union __fpscr __r;
213 
214 	__r.__bits.__reg = *__envp;
215 	__mtfsf(__r.__d);
216 	return (0);
217 }
218 
219 __fenv_static inline int
220 feupdateenv(const fenv_t *__envp)
221 {
222 	union __fpscr __r;
223 
224 	__mffs(&__r.__d);
225 	__r.__bits.__reg &= FE_ALL_EXCEPT;
226 	__r.__bits.__reg |= *__envp;
227 	__mtfsf(__r.__d);
228 	return (0);
229 }
230 
231 #if __BSD_VISIBLE
232 
233 /* We currently provide no external definitions of the functions below. */
234 
235 static inline int
236 feenableexcept(int __mask)
237 {
238 	union __fpscr __r;
239 	fenv_t __oldmask;
240 
241 	__mffs(&__r.__d);
242 	__oldmask = __r.__bits.__reg;
243 	__r.__bits.__reg |= (__mask & FE_ALL_EXCEPT) >> _FPUSW_SHIFT;
244 	__mtfsf(__r.__d);
245 	return ((__oldmask & _ENABLE_MASK) << _FPUSW_SHIFT);
246 }
247 
248 static inline int
249 fedisableexcept(int __mask)
250 {
251 	union __fpscr __r;
252 	fenv_t __oldmask;
253 
254 	__mffs(&__r.__d);
255 	__oldmask = __r.__bits.__reg;
256 	__r.__bits.__reg &= ~((__mask & FE_ALL_EXCEPT) >> _FPUSW_SHIFT);
257 	__mtfsf(__r.__d);
258 	return ((__oldmask & _ENABLE_MASK) << _FPUSW_SHIFT);
259 }
260 
261 static inline int
262 fegetexcept(void)
263 {
264 	union __fpscr __r;
265 
266 	__mffs(&__r.__d);
267 	return ((__r.__bits.__reg & _ENABLE_MASK) << _FPUSW_SHIFT);
268 }
269 
270 #endif /* __BSD_VISIBLE */
271 
272 __END_DECLS
273 
274 #endif	/* !_FENV_H_ */
275