HardenedBSD/lib/msun/amd64/fenv.c
David Schultz 10b01832c3 Replace fegetmask() and fesetmask() with feenableexcept(),
fedisableexcept(), and fegetexcept().  These two sets of routines
provide the same functionality.  I implemented the former as an
undocumented internal interface to make the regression test easier to
write.  However, fe(enable|disable|get)except() is already part of
glibc, and I would like to avoid gratuitous differences.  The only
major flaw in the glibc API is that there's no good way to report
errors on processors that don't support all the unmasked exceptions.
2005-03-16 19:03:46 +00:00

149 lines
3.5 KiB
C

/*-
* 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.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
#include <sys/types.h>
#include <machine/fpu.h>
#include <fenv.h>
const fenv_t __fe_dfl_env = {
{ 0xffff0000 | __INITIAL_FPUCW__,
0xffff0000,
0xffffffff,
{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff }
},
__INITIAL_MXCSR__
};
int
fesetexceptflag(const fexcept_t *flagp, int excepts)
{
fenv_t env;
__fnstenv(&env.__x87);
env.__x87.__status &= ~excepts;
env.__x87.__status |= *flagp & excepts;
__fldenv(env.__x87);
__stmxcsr(&env.__mxcsr);
env.__mxcsr &= ~excepts;
env.__mxcsr |= *flagp & excepts;
__ldmxcsr(env.__mxcsr);
return (0);
}
int
feraiseexcept(int excepts)
{
fexcept_t ex = excepts;
fesetexceptflag(&ex, excepts);
__fwait();
return (0);
}
int
fegetenv(fenv_t *envp)
{
int control;
/*
* fnstenv masks all exceptions, so we need to save and
* restore the control word to avoid this side effect.
*/
__fnstcw(&control);
__fnstenv(&envp->__x87);
__stmxcsr(&envp->__mxcsr);
__fldcw(control);
return (0);
}
int
feholdexcept(fenv_t *envp)
{
int mxcsr;
__stmxcsr(&mxcsr);
__fnstenv(&envp->__x87);
__fnclex();
envp->__mxcsr = 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);
__stmxcsr(&mxcsr);
fesetenv(envp);
feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT);
return (0);
}
int
__feenableexcept(int mask)
{
int mxcsr, control, omask;
mask &= FE_ALL_EXCEPT;
__fnstcw(&control);
__stmxcsr(&mxcsr);
omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
control &= ~mask;
__fldcw(control);
mxcsr &= ~(mask << _SSE_EMASK_SHIFT);
__ldmxcsr(mxcsr);
return (~omask);
}
int
__fedisableexcept(int mask)
{
int mxcsr, control, omask;
mask &= FE_ALL_EXCEPT;
__fnstcw(&control);
__stmxcsr(&mxcsr);
omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
control |= mask;
__fldcw(control);
mxcsr |= mask << _SSE_EMASK_SHIFT;
__ldmxcsr(mxcsr);
return (~omask);
}
__weak_reference(__feenableexcept, feenableexcept);
__weak_reference(__fedisableexcept, fedisableexcept);