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/*-
* 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.c,v 1.2 2005/03/17 22:21:46 das Exp $
*/
#include <sys/cdefs.h>
#include <sys/types.h>
#include <machine/npx.h>
#include "fenv.h"
const fenv_t __fe_dfl_env = {
__INITIAL_NPXCW__,
0x0000,
0x0000,
0x1f80,
0xffffffff,
{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff }
};
enum __sse_support __has_sse =
#ifdef __SSE__
__SSE_YES;
#else
__SSE_UNK;
#endif
#define getfl(x) __asm __volatile("pushfl\n\tpopl %0" : "=mr" (*(x)))
#define setfl(x) __asm __volatile("pushl %0\n\tpopfl" : : "g" (x))
#define cpuid_dx(x) __asm __volatile("pushl %%ebx\n\tmovl $1, %%eax\n\t" \
"cpuid\n\tpopl %%ebx" \
: "=d" (*(x)) : : "eax", "ecx")
/*
* Test for SSE support on this processor. We need to do this because
* we need to use ldmxcsr/stmxcsr to get correct results if any part
* of the program was compiled to use SSE floating-point, but we can't
* use SSE on older processors.
*/
int
__test_sse(void)
{
int flag, nflag;
int dx_features;
/* Am I a 486? */
getfl(&flag);
nflag = flag ^ 0x200000;
setfl(nflag);
getfl(&nflag);
if (flag != nflag) {
/* Not a 486, so CPUID should work. */
cpuid_dx(&dx_features);
if (dx_features & 0x2000000) {
__has_sse = __SSE_YES;
return (1);
}
}
__has_sse = __SSE_NO;
return (0);
}
int
fesetexceptflag(const fexcept_t *flagp, int excepts)
{
fenv_t env;
int mxcsr;
__fnstenv(&env);
env.__status &= ~excepts;
env.__status |= *flagp & excepts;
__fldenv(env);
if (__HAS_SSE()) {
__stmxcsr(&mxcsr);
mxcsr &= ~excepts;
mxcsr |= *flagp & excepts;
__ldmxcsr(mxcsr);
}
return (0);
}
int
feraiseexcept(int excepts)
{
fexcept_t ex = excepts;
fesetexceptflag(&ex, excepts);
__fwait();
return (0);
}
int
fegetenv(fenv_t *envp)
{
int control, mxcsr;
/*
* fnstenv masks all exceptions, so we need to save and
* restore the control word to avoid this side effect.
*/
__fnstcw(&control);
__fnstenv(envp);
if (__HAS_SSE()) {
__stmxcsr(&mxcsr);
__set_mxcsr(*envp, mxcsr);
}
__fldcw(control);
return (0);
}
int
feholdexcept(fenv_t *envp)
{
int mxcsr;
__fnstenv(envp);
__fnclex();
if (__HAS_SSE()) {
__stmxcsr(&mxcsr);
__set_mxcsr(*envp, mxcsr);
mxcsr &= ~FE_ALL_EXCEPT;
mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT;
__ldmxcsr(mxcsr);
}
return (0);
}
int
feupdateenv(const fenv_t *envp)
{
int mxcsr, status;
__fnstsw(&status);
if (__HAS_SSE())
__stmxcsr(&mxcsr);
else
mxcsr = 0;
fesetenv(envp);
feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT);
return (0);
}
int
__feenableexcept(int mask)
{
int mxcsr, control, omask;
mask &= FE_ALL_EXCEPT;
__fnstcw(&control);
if (__HAS_SSE())
__stmxcsr(&mxcsr);
else
mxcsr = 0;
omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
control &= ~mask;
__fldcw(control);
if (__HAS_SSE()) {
mxcsr &= ~(mask << _SSE_EMASK_SHIFT);
__ldmxcsr(mxcsr);
}
return (~omask);
}
int
__fedisableexcept(int mask)
{
int mxcsr, control, omask;
mask &= FE_ALL_EXCEPT;
__fnstcw(&control);
if (__HAS_SSE())
__stmxcsr(&mxcsr);
else
mxcsr = 0;
omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
control |= mask;
__fldcw(control);
if (__HAS_SSE()) {
mxcsr |= mask << _SSE_EMASK_SHIFT;
__ldmxcsr(mxcsr);
}
return (~omask);
}
__weak_reference(__feenableexcept, feenableexcept);
__weak_reference(__fedisableexcept, fedisableexcept);
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