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| -rw-r--r-- | include/iprt/nocrt/x86/fenv.h | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/include/iprt/nocrt/x86/fenv.h b/include/iprt/nocrt/x86/fenv.h new file mode 100644 index 00000000..19af59db --- /dev/null +++ b/include/iprt/nocrt/x86/fenv.h @@ -0,0 +1,286 @@ +/** @file + * IPRT / No-CRT - fenv.h, X86. + */ + +/* + * Copyright (C) 2006-2019 Oracle Corporation + * + * This file is part of VirtualBox Open Source Edition (OSE), as + * available from http://www.virtualbox.org. This file is free software; + * you can redistribute it and/or modify it under the terms of the GNU + * General Public License (GPL) as published by the Free Software + * Foundation, in version 2 as it comes in the "COPYING" file of the + * VirtualBox OSE distribution. VirtualBox OSE is distributed in the + * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL) only, as it comes in the "COPYING.CDDL" file of the + * VirtualBox OSE distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + * -------------------------------------------------------------------- + * + * This code is based on: + * + * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD: src/lib/msun/i387/fenv.h,v 1.4 2005/03/17 22:21:46 das Exp $ + */ + +#ifndef IPRT_INCLUDED_nocrt_x86_fenv_h +#define IPRT_INCLUDED_nocrt_x86_fenv_h +#ifndef RT_WITHOUT_PRAGMA_ONCE +# pragma once +#endif + +#include <iprt/types.h> + +/* + * To preserve binary compatibility with FreeBSD 5.3, we pack the + * mxcsr into some reserved fields, rather than changing sizeof(fenv_t). + */ +typedef struct { + uint16_t __control; + uint16_t __mxcsr_hi; + uint16_t __status; + uint16_t __mxcsr_lo; + uint32_t __tag; + char __other[16]; +} fenv_t; + +#define __get_mxcsr(env) (((env).__mxcsr_hi << 16) | \ + ((env).__mxcsr_lo)) +#define __set_mxcsr(env, x) do { \ + (env).__mxcsr_hi = (uint32_t)(x) >> 16; \ + (env).__mxcsr_lo = (uint16_t)(x); \ +} while (0) + +typedef uint16_t fexcept_t; + +/* Exception flags */ +#define FE_INVALID 0x01 +#define FE_DENORMAL 0x02 +#define FE_DIVBYZERO 0x04 +#define FE_OVERFLOW 0x08 +#define FE_UNDERFLOW 0x10 +#define FE_INEXACT 0x20 +#define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \ + FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW) + +/* Rounding modes */ +#define FE_TONEAREST 0x0000 +#define FE_DOWNWARD 0x0400 +#define FE_UPWARD 0x0800 +#define FE_TOWARDZERO 0x0c00 +#define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \ + FE_UPWARD | FE_TOWARDZERO) + +/* + * As compared to the x87 control word, the SSE unit's control word + * has the rounding control bits offset by 3 and the exception mask + * bits offset by 7. + */ +#define _SSE_ROUND_SHIFT 3 +#define _SSE_EMASK_SHIFT 7 + +/* After testing for SSE support once, we cache the result in __has_sse. */ +enum __sse_support { __SSE_YES, __SSE_NO, __SSE_UNK }; +extern enum __sse_support RT_NOCRT(__has_sse); +int RT_NOCRT(__test_sse)(void); +#ifdef __SSE__ +#define __HAS_SSE() 1 +#else +#define __HAS_SSE() (RT_NOCRT(__has_sse) == __SSE_YES || \ + (RT_NOCRT(__has_sse) == __SSE_UNK && RT_NOCRT(__test_sse)())) +#endif + +RT_C_DECLS_BEGIN + +/* Default floating-point environment */ +extern const fenv_t __fe_dfl_env; +#define FE_DFL_ENV (&__fe_dfl_env) + +#define __fldcw(__cw) __asm __volatile("fldcw %0" : : "m" (__cw)) +#define __fldenv(__env) __asm __volatile("fldenv %0" : : "m" (__env)) +#define __fnclex() __asm __volatile("fnclex") +#define __fnstenv(__env) __asm __volatile("fnstenv %0" : "=m" (*(__env))) +#define __fnstcw(__cw) __asm __volatile("fnstcw %0" : "=m" (*(__cw))) +#define __fnstsw(__sw) __asm __volatile("fnstsw %0" : "=am" (*(__sw))) +#define __fwait() __asm __volatile("fwait") +#define __ldmxcsr(__csr) __asm __volatile("ldmxcsr %0" : : "m" (__csr)) +#define __stmxcsr(__csr) __asm __volatile("stmxcsr %0" : "=m" (*(__csr))) + +#if RT_GNUC_PREREQ(4, 6) +# pragma GCC diagnostic push +# pragma GCC diagnostic ignored "-Wshadow" +#endif + +DECLINLINE(int) +feclearexcept(int __excepts) +{ + fenv_t __env; + int __mxcsr; + + if (__excepts == FE_ALL_EXCEPT) { + __fnclex(); + } else { + __fnstenv(&__env); + __env.__status &= ~__excepts; + __fldenv(__env); + } + if (__HAS_SSE()) { + __stmxcsr(&__mxcsr); + __mxcsr &= ~__excepts; + __ldmxcsr(__mxcsr); + } + return (0); +} + +DECLINLINE(int) +fegetexceptflag(fexcept_t *__flagp, int __excepts) +{ + int __mxcsr, __status; + + __fnstsw(&__status); + if (__HAS_SSE()) + __stmxcsr(&__mxcsr); + else + __mxcsr = 0; + *__flagp = (__mxcsr | __status) & __excepts; + return (0); +} + +int RT_NOCRT(fesetexceptflag)(const fexcept_t *__flagp, int __excepts); +int RT_NOCRT(feraiseexcept)(int __excepts); + +DECLINLINE(int) +fetestexcept(int __excepts) +{ + int __mxcsr, __status; + + __fnstsw(&__status); + if (__HAS_SSE()) + __stmxcsr(&__mxcsr); + else + __mxcsr = 0; + return ((__status | __mxcsr) & __excepts); +} + +DECLINLINE(int) +fegetround(void) +{ + int __control; + + /* + * We assume that the x87 and the SSE unit agree on the + * rounding mode. Reading the control word on the x87 turns + * out to be about 5 times faster than reading it on the SSE + * unit on an Opteron 244. + */ + __fnstcw(&__control); + return (__control & _ROUND_MASK); +} + +DECLINLINE(int) +fesetround(int __round) +{ + int __mxcsr, __control; + + if (__round & ~_ROUND_MASK) + return (-1); + + __fnstcw(&__control); + __control &= ~_ROUND_MASK; + __control |= __round; + __fldcw(__control); + + if (__HAS_SSE()) { + __stmxcsr(&__mxcsr); + __mxcsr &= ~(_ROUND_MASK << _SSE_ROUND_SHIFT); + __mxcsr |= __round << _SSE_ROUND_SHIFT; + __ldmxcsr(__mxcsr); + } + + return (0); +} + +int RT_NOCRT(fegetenv)(fenv_t *__envp); +int RT_NOCRT(feholdexcept)(fenv_t *__envp); + +DECLINLINE(int) +fesetenv(const fenv_t *__envp) +{ + fenv_t __env = *__envp; + int __mxcsr; + + __mxcsr = __get_mxcsr(__env); + __set_mxcsr(__env, 0xffffffff); + __fldenv(__env); + if (__HAS_SSE()) + __ldmxcsr(__mxcsr); + return (0); +} + +int RT_NOCRT(feupdateenv)(const fenv_t *__envp); +int RT_NOCRT(feenableexcept)(int __mask); +int RT_NOCRT(fedisableexcept)(int __mask); + +DECLINLINE(int) +fegetexcept(void) +{ + int __control; + + /* + * We assume that the masks for the x87 and the SSE unit are + * the same. + */ + __fnstcw(&__control); + return (~__control & FE_ALL_EXCEPT); +} + +#if RT_GNUC_PREREQ(4, 6) +# pragma GCC diagnostic pop +#endif + +RT_C_DECLS_END + +#ifndef RT_WIHTOUT_NOCRT_WRAPPERS +# define __has_sse RT_NOCRT(__has_sse) +# define __test_sse RT_NOCRT(__test_sse) +# define __test_sse RT_NOCRT(__test_sse) +# define fesetexceptflag RT_NOCRT(fesetexceptflag) +# define feraiseexcept RT_NOCRT(feraiseexcept) +# define fegetenv RT_NOCRT(fegetenv) +# define feholdexcept RT_NOCRT(feholdexcept) +# define feupdateenv RT_NOCRT(feupdateenv) +# define feenableexcept RT_NOCRT(feenableexcept) +# define fedisableexcept RT_NOCRT(fedisableexcept) +#endif + +#endif /* !IPRT_INCLUDED_nocrt_x86_fenv_h */ + |