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source: vbox/trunk/include/iprt/nocrt/amd64/fenv.h@ 53402

Last change on this file since 53402 was 44528, checked in by vboxsync, 12 years ago

header (C) fixes

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Line 
1/** @file
2 * IPRT / No-CRT - fenv.h, AMD64.
3 */
4
5/*
6 * Copyright (C) 2006-2010 Oracle Corporation
7 *
8 * This file is part of VirtualBox Open Source Edition (OSE), as
9 * available from http://www.virtualbox.org. This file is free software;
10 * you can redistribute it and/or modify it under the terms of the GNU
11 * General Public License (GPL) as published by the Free Software
12 * Foundation, in version 2 as it comes in the "COPYING" file of the
13 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
14 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
15 *
16 * The contents of this file may alternatively be used under the terms
17 * of the Common Development and Distribution License Version 1.0
18 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
19 * VirtualBox OSE distribution, in which case the provisions of the
20 * CDDL are applicable instead of those of the GPL.
21 *
22 * You may elect to license modified versions of this file under the
23 * terms and conditions of either the GPL or the CDDL or both.
24 * --------------------------------------------------------------------
25 *
26 * This code is based on:
27 *
28 * Copyright (c) 2004-2005 David Schultz <[email protected]>
29 * All rights reserved.
30 *
31 * Redistribution and use in source and binary forms, with or without
32 * modification, are permitted provided that the following conditions
33 * are met:
34 * 1. Redistributions of source code must retain the above copyright
35 * notice, this list of conditions and the following disclaimer.
36 * 2. Redistributions in binary form must reproduce the above copyright
37 * notice, this list of conditions and the following disclaimer in the
38 * documentation and/or other materials provided with the distribution.
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 */
52
53#ifndef ___iprt_nocrt_amd64_fenv_h
54#define ___iprt_nocrt_amd64_fenv_h
55
56#include <iprt/types.h>
57
58typedef struct {
59 struct {
60 uint32_t __control;
61 uint32_t __status;
62 uint32_t __tag;
63 char __other[16];
64 } __x87;
65 uint32_t __mxcsr;
66} fenv_t;
67
68typedef uint16_t fexcept_t;
69
70/* Exception flags */
71#define FE_INVALID 0x01
72#define FE_DENORMAL 0x02
73#define FE_DIVBYZERO 0x04
74#define FE_OVERFLOW 0x08
75#define FE_UNDERFLOW 0x10
76#define FE_INEXACT 0x20
77#define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \
78 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
79
80/* Rounding modes */
81#define FE_TONEAREST 0x0000
82#define FE_DOWNWARD 0x0400
83#define FE_UPWARD 0x0800
84#define FE_TOWARDZERO 0x0c00
85#define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \
86 FE_UPWARD | FE_TOWARDZERO)
87
88/*
89 * As compared to the x87 control word, the SSE unit's control word
90 * has the rounding control bits offset by 3 and the exception mask
91 * bits offset by 7.
92 */
93#define _SSE_ROUND_SHIFT 3
94#define _SSE_EMASK_SHIFT 7
95
96RT_C_DECLS_BEGIN
97
98/* Default floating-point environment */
99extern const fenv_t RT_NOCRT(__fe_dfl_env);
100#define FE_DFL_ENV (&__fe_dfl_env)
101
102#define __fldcw(__cw) __asm __volatile("fldcw %0" : : "m" (__cw))
103#define __fldenv(__env) __asm __volatile("fldenv %0" : : "m" (__env))
104#define __fnclex() __asm __volatile("fnclex")
105#define __fnstenv(__env) __asm __volatile("fnstenv %0" : "=m" (*(__env)))
106#define __fnstcw(__cw) __asm __volatile("fnstcw %0" : "=m" (*(__cw)))
107#define __fnstsw(__sw) __asm __volatile("fnstsw %0" : "=am" (*(__sw)))
108#define __fwait() __asm __volatile("fwait")
109#define __ldmxcsr(__csr) __asm __volatile("ldmxcsr %0" : : "m" (__csr))
110#define __stmxcsr(__csr) __asm __volatile("stmxcsr %0" : "=m" (*(__csr)))
111
112DECLINLINE(int)
113feclearexcept(int __excepts)
114{
115 fenv_t __env;
116
117 if (__excepts == FE_ALL_EXCEPT) {
118 __fnclex();
119 } else {
120 __fnstenv(&__env.__x87);
121 __env.__x87.__status &= ~__excepts;
122 __fldenv(__env.__x87);
123 }
124 __stmxcsr(&__env.__mxcsr);
125 __env.__mxcsr &= ~__excepts;
126 __ldmxcsr(__env.__mxcsr);
127 return (0);
128}
129
130DECLINLINE(int)
131fegetexceptflag(fexcept_t *__flagp, int __excepts)
132{
133 int __mxcsr, __status;
134
135 __stmxcsr(&__mxcsr);
136 __fnstsw(&__status);
137 *__flagp = (__mxcsr | __status) & __excepts;
138 return (0);
139}
140
141int RT_NOCRT(fesetexceptflag)(const fexcept_t *__flagp, int __excepts);
142int RT_NOCRT(feraiseexcept)(int __excepts);
143
144DECLINLINE(int)
145fetestexcept(int __excepts)
146{
147 int __mxcsr, __status;
148
149 __stmxcsr(&__mxcsr);
150 __fnstsw(&__status);
151 return ((__status | __mxcsr) & __excepts);
152}
153
154DECLINLINE(int)
155fegetround(void)
156{
157 int __control;
158
159 /*
160 * We assume that the x87 and the SSE unit agree on the
161 * rounding mode. Reading the control word on the x87 turns
162 * out to be about 5 times faster than reading it on the SSE
163 * unit on an Opteron 244.
164 */
165 __fnstcw(&__control);
166 return (__control & _ROUND_MASK);
167}
168
169DECLINLINE(int)
170fesetround(int __round)
171{
172 int __mxcsr, __control;
173
174 if (__round & ~_ROUND_MASK)
175 return (-1);
176
177 __fnstcw(&__control);
178 __control &= ~_ROUND_MASK;
179 __control |= __round;
180 __fldcw(__control);
181
182 __stmxcsr(&__mxcsr);
183 __mxcsr &= ~(_ROUND_MASK << _SSE_ROUND_SHIFT);
184 __mxcsr |= __round << _SSE_ROUND_SHIFT;
185 __ldmxcsr(__mxcsr);
186
187 return (0);
188}
189
190int RT_NOCRT(fegetenv)(fenv_t *__envp);
191int RT_NOCRT(feholdexcept)(fenv_t *__envp);
192
193DECLINLINE(int)
194fesetenv(const fenv_t *__envp)
195{
196
197 __fldenv(__envp->__x87);
198 __ldmxcsr(__envp->__mxcsr);
199 return (0);
200}
201
202int RT_NOCRT(feupdateenv)(const fenv_t *__envp);
203int RT_NOCRT(feenableexcept)(int __mask);
204int RT_NOCRT(fedisableexcept)(int __mask);
205
206DECLINLINE(int)
207fegetexcept(void)
208{
209 int __control;
210
211 /*
212 * We assume that the masks for the x87 and the SSE unit are
213 * the same.
214 */
215 __fnstcw(&__control);
216 return (~__control & FE_ALL_EXCEPT);
217}
218
219RT_C_DECLS_END
220
221#ifndef RT_WITHOUT_NOCRT_WRAPPERS
222# define fesetexceptflag RT_NOCRT(fesetexceptflag)
223# define feraiseexcept RT_NOCRT(feraiseexcept)
224# define fegetenv RT_NOCRT(fegetenv)
225# define feholdexcept RT_NOCRT(feholdexcept)
226# define feupdateenv RT_NOCRT(feupdateenv)
227# define feenableexcept RT_NOCRT(feenableexcept)
228# define fedisableexcept RT_NOCRT(fedisableexcept)
229# define __fe_dfl_env RT_NOCRT(__fe_dfl_env)
230#endif
231
232#endif /* !__iprt_nocrt_amd64_fenv_h__ */
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