freebsd-dev/lib/msun/alpha/fenv.h
David Schultz f365db00e5 Mark all inline asms that read the floating-point control or status
registers as volatile.  Instructions that *wrote* to FP state were
already marked volatile, but apparently gcc has license to move
non-volatile asms past volatile asms.  This broke amd64's feupdateenv
at -O2 due to a WAR conflict between fnstsw and fldenv there.
2005-01-14 07:09:23 +00:00

185 lines
4.5 KiB
C

/*-
* Copyright (c) 2004 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.
*
* $FreeBSD$
*/
#ifndef _FENV_H_
#define _FENV_H_
#include <sys/_types.h>
typedef __uint64_t fenv_t;
typedef __uint16_t fexcept_t;
/* Exception flags */
#define FE_INVALID 0x02
#define FE_DIVBYZERO 0x04
#define FE_OVERFLOW 0x08
#define FE_UNDERFLOW 0x10
#define FE_INEXACT 0x20
#define FE_INTOVF 0x40 /* not maskable */
#define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INTOVF | \
FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
/* Rounding modes */
#define FE_TOWARDZERO 0x00
#define FE_DOWNWARD 0x01
#define FE_TONEAREST 0x02
#define FE_UPWARD 0x03
#define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \
FE_UPWARD | FE_TOWARDZERO)
#define _ROUND_SHIFT 58
#define _FPUSW_SHIFT 51
#define __excb() __asm __volatile("excb")
#define __mf_fpcr(__cw) __asm __volatile("mf_fpcr %0" : "=f" (*(__cw)))
#define __mt_fpcr(__cw) __asm __volatile("mt_fpcr %0" : : "f" (__cw))
union __fpcr {
double __d;
fenv_t __bits;
};
__BEGIN_DECLS
/* Default floating-point environment */
extern const fenv_t __fe_dfl_env;
#define FE_DFL_ENV (&__fe_dfl_env)
static __inline int
feclearexcept(int __excepts)
{
union __fpcr __r;
__excb();
__mf_fpcr(&__r.__d);
__r.__bits &= ~((fenv_t)__excepts << _FPUSW_SHIFT);
__mt_fpcr(__r.__d);
__excb();
return (0);
}
static __inline int
fegetexceptflag(fexcept_t *__flagp, int __excepts)
{
union __fpcr __r;
__excb();
__mf_fpcr(&__r.__d);
__excb();
*__flagp = (__r.__bits >> _FPUSW_SHIFT) & __excepts;
return (0);
}
static __inline int
fesetexceptflag(const fexcept_t *__flagp, int __excepts)
{
union __fpcr __r;
fenv_t __xflag, __xexcepts;
__xflag = (fenv_t)*__flagp << _FPUSW_SHIFT;
__xexcepts = (fenv_t)__excepts << _FPUSW_SHIFT;
__excb();
__mf_fpcr(&__r.__d);
__r.__bits &= ~__xexcepts;
__r.__bits |= __xflag & __xexcepts;
__mt_fpcr(__r.__d);
__excb();
return (0);
}
static __inline int
feraiseexcept(int __excepts)
{
/*
* XXX Generating exceptions this way does not actually invoke
* a userland trap handler when enabled, but neither do
* arithmetic operations as far as I can tell. Perhaps there
* are more bugs in the kernel trap handler.
*/
fexcept_t __ex = __excepts;
fesetexceptflag(&__ex, __excepts);
return (0);
}
static __inline int
fetestexcept(int __excepts)
{
union __fpcr __r;
__excb();
__mf_fpcr(&__r.__d);
__excb();
return ((__r.__bits >> _FPUSW_SHIFT) & __excepts);
}
static __inline int
fegetround(void)
{
union __fpcr __r;
/*
* No exception barriers should be required here if we assume
* that only fesetround() can change the rounding mode.
*/
__mf_fpcr(&__r.__d);
return ((int)(__r.__bits >> _ROUND_SHIFT) & _ROUND_MASK);
}
static __inline int
fesetround(int __round)
{
union __fpcr __r;
if (__round & ~_ROUND_MASK)
return (-1);
__excb();
__mf_fpcr(&__r.__d);
__r.__bits &= ~((fenv_t)_ROUND_MASK << _ROUND_SHIFT);
__r.__bits |= (fenv_t)__round << _ROUND_SHIFT;
__mt_fpcr(__r.__d);
__excb();
return (0);
}
int fegetenv(fenv_t *__envp);
int feholdexcept(fenv_t *__envp);
int fesetenv(const fenv_t *__envp);
int feupdateenv(const fenv_t *__envp);
#if __BSD_VISIBLE
int fesetmask(int __mask);
int fegetmask(void);
#endif /* __BSD_VISIBLE */
__END_DECLS
#endif /* !_FENV_H_ */