platform_bionic/libm/alpha/fenv.c
2009-03-03 19:28:35 -08:00

144 lines
3.6 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: src/lib/msun/alpha/fenv.c,v 1.2 2005/03/16 19:03:44 das Exp $
*/
#include <sys/cdefs.h>
#include <machine/sysarch.h>
#include <fenv.h>
const fenv_t __fe_dfl_env = 0x680e000000000000ULL;
struct mask_args {
fenv_t mask;
};
/*
* The lower 49 bits of the FPCR are unused by the hardware, so we use
* the lower order bits to store the kernel's idea of the FP mask as
* described in the Alpha Architecture Manual.
*/
int
fegetenv(fenv_t *envp)
{
struct mask_args p;
union __fpcr r;
/*
* The syscall acts as an implicit exception barrier, so we
* only need to issue an excb after the mf_fpcr to ensure that
* the read is executed before any subsequent FP ops.
*/
sysarch(ALPHA_GET_FPMASK, (char *)&p);
__mf_fpcr(&r.__d);
*envp = r.__bits | p.mask;
__excb();
return (0);
}
int
feholdexcept(fenv_t *envp)
{
struct mask_args p;
union __fpcr r;
sysarch(ALPHA_GET_FPMASK, (char *)&p);
__mf_fpcr(&r.__d);
*envp = r.__bits | p.mask;
r.__bits &= ~((fenv_t)FE_ALL_EXCEPT << _FPUSW_SHIFT);
__mt_fpcr(r.__d);
if (p.mask & FE_ALL_EXCEPT) {
p.mask = 0;
sysarch(ALPHA_SET_FPMASK, &p);
}
__excb();
return (0);
}
int
fesetenv(const fenv_t *envp)
{
struct mask_args p;
union __fpcr r;
p.mask = *envp & FE_ALL_EXCEPT;
sysarch(ALPHA_SET_FPMASK, &p);
r.__bits = *envp & ~FE_ALL_EXCEPT;
__mt_fpcr(r.__d);
__excb();
return (0);
}
int
feupdateenv(const fenv_t *envp)
{
struct mask_args p;
union __fpcr oldr, newr;
p.mask = *envp & FE_ALL_EXCEPT;
sysarch(ALPHA_SET_FPMASK, &p);
__mf_fpcr(&oldr.__d);
newr.__bits = *envp & ~FE_ALL_EXCEPT;
__excb();
__mt_fpcr(newr.__d);
feraiseexcept((oldr.__bits >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
return (0);
}
int
__feenableexcept(int mask)
{
struct mask_args p;
sysarch(ALPHA_GET_FPMASK, &p);
p.mask |= (mask & FE_ALL_EXCEPT);
sysarch(ALPHA_SET_FPMASK, &p);
return (p.mask);
}
int
__fedisableexcept(int mask)
{
struct mask_args p;
sysarch(ALPHA_GET_FPMASK, &p);
p.mask &= ~(mask & FE_ALL_EXCEPT);
sysarch(ALPHA_SET_FPMASK, &p);
return (p.mask);
}
int
__fegetexcept(void)
{
struct mask_args p;
sysarch(ALPHA_GET_FPMASK, &p);
return (p.mask);
}
__weak_reference(__feenableexcept, feenableexcept);
__weak_reference(__fedisableexcept, fedisableexcept);
__weak_reference(__fegetexcept, fegetexcept);