149 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			149 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*-
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 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 *
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 * $FreeBSD: src/lib/msun/amd64/fenv.c,v 1.3 2005/03/16 19:03:45 das Exp $
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 */
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#include <sys/cdefs.h>
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#include <sys/types.h>
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#include <machine/fpu.h>
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#include <fenv.h>
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const fenv_t __fe_dfl_env = {
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	{ 0xffff0000 | __INITIAL_FPUCW__,
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	  0xffff0000,
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	  0xffffffff,
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	  { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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	    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff }
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	},
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	__INITIAL_MXCSR__
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};
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int
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fesetexceptflag(const fexcept_t *flagp, int excepts)
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{
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	fenv_t env;
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	__fnstenv(&env.__x87);
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	env.__x87.__status &= ~excepts;
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	env.__x87.__status |= *flagp & excepts;
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	__fldenv(env.__x87);
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	__stmxcsr(&env.__mxcsr);
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	env.__mxcsr &= ~excepts;
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	env.__mxcsr |= *flagp & excepts;
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	__ldmxcsr(env.__mxcsr);
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	return (0);
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}
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int
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feraiseexcept(int excepts)
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{
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	fexcept_t ex = excepts;
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	fesetexceptflag(&ex, excepts);
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	__fwait();
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	return (0);
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}
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int
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fegetenv(fenv_t *envp)
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{
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	int control;
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	/*
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	 * fnstenv masks all exceptions, so we need to save and
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	 * restore the control word to avoid this side effect.
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	 */
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	__fnstcw(&control);
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	__fnstenv(&envp->__x87);
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	__stmxcsr(&envp->__mxcsr);
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	__fldcw(control);
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	return (0);
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}
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int
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feholdexcept(fenv_t *envp)
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{
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	int mxcsr;
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	__stmxcsr(&mxcsr);
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	__fnstenv(&envp->__x87);
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	__fnclex();
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	envp->__mxcsr = mxcsr;
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	mxcsr &= ~FE_ALL_EXCEPT;
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	mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT;
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	__ldmxcsr(mxcsr);
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	return (0);
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}
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int
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feupdateenv(const fenv_t *envp)
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{
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	int mxcsr, status;
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	__fnstsw(&status);
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	__stmxcsr(&mxcsr);
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	fesetenv(envp);
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	feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT);
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	return (0);
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}
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int
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__feenableexcept(int mask)
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{
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	int mxcsr, control, omask;
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	mask &= FE_ALL_EXCEPT;
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	__fnstcw(&control);
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	__stmxcsr(&mxcsr);
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	omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
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	control &= ~mask;
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	__fldcw(control);
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	mxcsr &= ~(mask << _SSE_EMASK_SHIFT);
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	__ldmxcsr(mxcsr);
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	return (~omask);
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}
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int
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__fedisableexcept(int mask)
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{
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	int mxcsr, control, omask;
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	mask &= FE_ALL_EXCEPT;
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	__fnstcw(&control);
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	__stmxcsr(&mxcsr);
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	omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
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	control |= mask;
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	__fldcw(control);
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	mxcsr |= mask << _SSE_EMASK_SHIFT;
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	__ldmxcsr(mxcsr);
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	return (~omask);
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}
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__weak_reference(__feenableexcept, feenableexcept);
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__weak_reference(__fedisableexcept, fedisableexcept);
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