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
34typedef	__uint64_t	fenv_t;
35typedef	__uint16_t	fexcept_t;
36
37/* Exception flags */
38#define	FE_INVALID	0x01
39#define	FE_DENORMAL	0x02
40#define	FE_DIVBYZERO	0x04
41#define	FE_OVERFLOW	0x08
42#define	FE_UNDERFLOW	0x10
43#define	FE_INEXACT	0x20
44#define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \
45			 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
46
47/* Rounding modes */
48#define	FE_TONEAREST	0x0000
49#define	FE_DOWNWARD	0x0400
50#define	FE_UPWARD	0x0800
51#define	FE_TOWARDZERO	0x0c00
52#define	_ROUND_MASK	(FE_TONEAREST | FE_DOWNWARD | \
53			 FE_UPWARD | FE_TOWARDZERO)
54
55__BEGIN_DECLS
56
57/* Default floating-point environment */
58extern const fenv_t	__fe_dfl_env;
59#define	FE_DFL_ENV	(&__fe_dfl_env)
60
61#define	_FPUSW_SHIFT	13
62
63#define	__stfpsr(__r)	__asm __volatile("mov %0=ar.fpsr" : "=r" (*(__r)))
64#define	__ldfpsr(__r)	__asm __volatile("mov ar.fpsr=%0;;" : : "r" (__r))
65
66static __inline int
67feclearexcept(int __excepts)
68{
69	fenv_t __fpsr;
70
71	__stfpsr(&__fpsr);
72	__fpsr &= ~((fenv_t)__excepts << _FPUSW_SHIFT);
73	__ldfpsr(__fpsr);
74	return (0);
75}
76
77static __inline int
78fegetexceptflag(fexcept_t *__flagp, int __excepts)
79{
80	fenv_t __fpsr;
81
82	__stfpsr(&__fpsr);
83	*__flagp = (fexcept_t)(__fpsr >> _FPUSW_SHIFT) & __excepts;
84	return (0);
85}
86
87static __inline int
88fesetexceptflag(const fexcept_t *__flagp, int __excepts)
89{
90	fenv_t __fpsr;
91
92	__stfpsr(&__fpsr);
93	__fpsr &= ~((fenv_t)__excepts << _FPUSW_SHIFT);
94	__fpsr |= (fenv_t)(__excepts & *__flagp) << _FPUSW_SHIFT;
95	__ldfpsr(__fpsr);
96	return (0);
97}
98
99/*
100 * It is worthwhile to use the inline version of this function iff it
101 * is called with arguments that are compile-time constants (due to
102 * dead code elimination).  Unfortunately, gcc isn't smart enough to
103 * figure this out automatically, and there's no way to tell it.
104 * We assume that constant arguments will be the common case.
105 */
106static __inline int
107feraiseexcept(int __excepts)
108{
109	volatile double d;
110
111	/*
112	 * With a compiler that supports the FENV_ACCESS pragma
113	 * properly, simple expressions like '0.0 / 0.0' should
114	 * be sufficient to generate traps.  Unfortunately, we
115	 * need to bring a volatile variable into the equation
116	 * to prevent incorrect optimizations.
117	 */
118	if (__excepts & FE_INVALID) {
119		d = 0.0;
120		d = 0.0 / d;
121	}
122	if (__excepts & FE_DIVBYZERO) {
123		d = 0.0;
124		d = 1.0 / d;
125	}
126	if (__excepts & FE_OVERFLOW) {
127		d = 0x1.ffp1023;
128		d *= 2.0;
129	}
130	if (__excepts & FE_UNDERFLOW) {
131		d = 0x1p-1022;
132		d /= 0x1p1023;
133	}
134	if (__excepts & FE_INEXACT) {
135		d = 0x1p-1022;
136		d += 1.0;
137	}
138	return (0);
139}
140
141static __inline int
142fetestexcept(int __excepts)
143{
144	fenv_t __fpsr;
145
146	__stfpsr(&__fpsr);
147	return ((__fpsr >> _FPUSW_SHIFT) & __excepts);
148}
149
150
151static __inline int
152fegetround(void)
153{
154	fenv_t __fpsr;
155
156	__stfpsr(&__fpsr);
157	return (__fpsr & _ROUND_MASK);
158}
159
160static __inline int
161fesetround(int __round)
162{
163	fenv_t __fpsr;
164
165	if (__round & ~_ROUND_MASK)
166		return (-1);
167	__stfpsr(&__fpsr);
168	__fpsr &= ~_ROUND_MASK;
169	__fpsr |= __round;
170	__ldfpsr(__fpsr);
171	return (0);
172}
173
174static __inline int
175fegetenv(fenv_t *__envp)
176{
177
178	__stfpsr(__envp);
179	return (0);
180}
181
182static __inline int
183feholdexcept(fenv_t *__envp)
184{
185	fenv_t __fpsr;
186
187	__stfpsr(&__fpsr);
188	*__envp = __fpsr;
189	__fpsr &= ~((fenv_t)FE_ALL_EXCEPT << _FPUSW_SHIFT);
190	__fpsr |= FE_ALL_EXCEPT;
191	__ldfpsr(__fpsr);
192	return (0);
193}
194
195static __inline int
196fesetenv(const fenv_t *__envp)
197{
198
199	__ldfpsr(*__envp);
200	return (0);
201}
202
203int feupdateenv(const fenv_t *__envp);
204
205#if __BSD_VISIBLE
206
207static __inline int
208feenableexcept(int __mask)
209{
210	fenv_t __newfpsr, __oldfpsr;
211
212	__stfpsr(&__oldfpsr);
213	__newfpsr = __oldfpsr & ~(__mask & FE_ALL_EXCEPT);
214	__ldfpsr(__newfpsr);
215	return (~__oldfpsr & FE_ALL_EXCEPT);
216}
217
218static __inline int
219fedisableexcept(int __mask)
220{
221	fenv_t __newfpsr, __oldfpsr;
222
223	__stfpsr(&__oldfpsr);
224	__newfpsr = __oldfpsr | (__mask & FE_ALL_EXCEPT);
225	__ldfpsr(__newfpsr);
226	return (~__oldfpsr & FE_ALL_EXCEPT);
227}
228
229static __inline int
230fegetexcept(void)
231{
232	fenv_t __fpsr;
233
234	__stfpsr(&__fpsr);
235	return (~__fpsr & FE_ALL_EXCEPT);
236}
237
238#endif /* __BSD_VISIBLE */
239
240__END_DECLS
241
242#endif	/* !_FENV_H_ */
243