fenv.h revision 1.1 
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: releng/10.1/lib/msun/ia64/fenv.h 226218 2011-10-10 15:43:09Z das $
27 */
28
29#ifndef	_IA64_FENV_H_
30#define	_IA64_FENV_H_
31
32#include <sys/stdint.h>
33
34#ifndef	__fenv_static
35#define	__fenv_static	static
36#endif
37
38typedef	__uint64_t	fenv_t;
39typedef	__uint16_t	fexcept_t;
40
41/* Exception flags */
42#define	FE_INVALID	0x01
43#define	FE_DENORMAL	0x02
44#define	FE_DIVBYZERO	0x04
45#define	FE_OVERFLOW	0x08
46#define	FE_UNDERFLOW	0x10
47#define	FE_INEXACT	0x20
48#define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \
49			 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
50
51/* Rounding modes */
52#define	FE_TONEAREST	0x0000
53#define	FE_DOWNWARD	0x0400
54#define	FE_UPWARD	0x0800
55#define	FE_TOWARDZERO	0x0c00
56#define	_ROUND_MASK	(FE_TONEAREST | FE_DOWNWARD | \
57			 FE_UPWARD | FE_TOWARDZERO)
58
59__BEGIN_DECLS
60
61/* Default floating-point environment */
62extern const fenv_t	__fe_dfl_env;
63#define	FE_DFL_ENV	(&__fe_dfl_env)
64
65#define	_FPUSW_SHIFT	13
66
67#define	__stfpsr(__r)	__asm __volatile("mov %0=ar.fpsr" : "=r" (*(__r)))
68#define	__ldfpsr(__r)	__asm __volatile("mov ar.fpsr=%0;;" : : "r" (__r))
69
70__fenv_static inline int
71feclearexcept(int __excepts)
72{
73	fenv_t __fpsr;
74
75	__stfpsr(&__fpsr);
76	__fpsr &= ~((fenv_t)__excepts << _FPUSW_SHIFT);
77	__ldfpsr(__fpsr);
78	return (0);
79}
80
81__fenv_static inline int
82fegetexceptflag(fexcept_t *__flagp, int __excepts)
83{
84	fenv_t __fpsr;
85
86	__stfpsr(&__fpsr);
87	*__flagp = (fexcept_t)(__fpsr >> _FPUSW_SHIFT) & __excepts;
88	return (0);
89}
90
91__fenv_static inline int
92fesetexceptflag(const fexcept_t *__flagp, int __excepts)
93{
94	fenv_t __fpsr;
95
96	__stfpsr(&__fpsr);
97	__fpsr &= ~((fenv_t)__excepts << _FPUSW_SHIFT);
98	__fpsr |= (fenv_t)(__excepts & *__flagp) << _FPUSW_SHIFT;
99	__ldfpsr(__fpsr);
100	return (0);
101}
102
103/*
104 * It is worthwhile to use the inline version of this function iff it
105 * is called with arguments that are compile-time constants (due to
106 * dead code elimination).  Unfortunately, gcc isn't smart enough to
107 * figure this out automatically, and there's no way to tell it.
108 * We assume that constant arguments will be the common case.
109 */
110__fenv_static inline int
111feraiseexcept(int __excepts)
112{
113	volatile double d;
114
115	/*
116	 * With a compiler that supports the FENV_ACCESS pragma
117	 * properly, simple expressions like '0.0 / 0.0' should
118	 * be sufficient to generate traps.  Unfortunately, we
119	 * need to bring a volatile variable into the equation
120	 * to prevent incorrect optimizations.
121	 */
122	if (__excepts & FE_INVALID) {
123		d = 0.0;
124		d = 0.0 / d;
125	}
126	if (__excepts & FE_DIVBYZERO) {
127		d = 0.0;
128		d = 1.0 / d;
129	}
130	if (__excepts & FE_OVERFLOW) {
131		d = 0x1.ffp1023;
132		d *= 2.0;
133	}
134	if (__excepts & FE_UNDERFLOW) {
135		d = 0x1p-1022;
136		d /= 0x1p1023;
137	}
138	if (__excepts & FE_INEXACT) {
139		d = 0x1p-1022;
140		d += 1.0;
141	}
142	return (0);
143}
144
145__fenv_static inline int
146fetestexcept(int __excepts)
147{
148	fenv_t __fpsr;
149
150	__stfpsr(&__fpsr);
151	return ((__fpsr >> _FPUSW_SHIFT) & __excepts);
152}
153
154
155__fenv_static inline int
156fegetround(void)
157{
158	fenv_t __fpsr;
159
160	__stfpsr(&__fpsr);
161	return (__fpsr & _ROUND_MASK);
162}
163
164__fenv_static inline int
165fesetround(int __round)
166{
167	fenv_t __fpsr;
168
169	if (__round & ~_ROUND_MASK)
170		return (-1);
171	__stfpsr(&__fpsr);
172	__fpsr &= ~_ROUND_MASK;
173	__fpsr |= __round;
174	__ldfpsr(__fpsr);
175	return (0);
176}
177
178__fenv_static inline int
179fegetenv(fenv_t *__envp)
180{
181
182	__stfpsr(__envp);
183	return (0);
184}
185
186__fenv_static inline int
187feholdexcept(fenv_t *__envp)
188{
189	fenv_t __fpsr;
190
191	__stfpsr(&__fpsr);
192	*__envp = __fpsr;
193	__fpsr &= ~((fenv_t)FE_ALL_EXCEPT << _FPUSW_SHIFT);
194	__fpsr |= FE_ALL_EXCEPT;
195	__ldfpsr(__fpsr);
196	return (0);
197}
198
199__fenv_static inline int
200fesetenv(const fenv_t *__envp)
201{
202
203	__ldfpsr(*__envp);
204	return (0);
205}
206
207int feupdateenv(const fenv_t *__envp);
208
209#if defined(_NETBSD_SOURCE) || defined(_GNU_SOURCE)
210
211/* We currently provide no external definitions of the functions below. */
212
213static inline int
214feenableexcept(int __mask)
215{
216	fenv_t __newfpsr, __oldfpsr;
217
218	__stfpsr(&__oldfpsr);
219	__newfpsr = __oldfpsr & ~(__mask & FE_ALL_EXCEPT);
220	__ldfpsr(__newfpsr);
221	return (~__oldfpsr & FE_ALL_EXCEPT);
222}
223
224static inline int
225fedisableexcept(int __mask)
226{
227	fenv_t __newfpsr, __oldfpsr;
228
229	__stfpsr(&__oldfpsr);
230	__newfpsr = __oldfpsr | (__mask & FE_ALL_EXCEPT);
231	__ldfpsr(__newfpsr);
232	return (~__oldfpsr & FE_ALL_EXCEPT);
233}
234
235static inline int
236fegetexcept(void)
237{
238	fenv_t __fpsr;
239
240	__stfpsr(&__fpsr);
241	return (~__fpsr & FE_ALL_EXCEPT);
242}
243
244#endif /* _NETBSD_SOURCE || _GNU_SOURCE */
245
246__END_DECLS
247
248#endif	/* !_IA64_FENV_H_ */
249