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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.
*
* $FreeBSD$
*/
#ifndef _FENV_H_
#define _FENV_H_
#include <sys/cdefs.h>
#include <sys/_types.h>
typedef struct {
struct {
__uint32_t __control;
__uint32_t __status;
__uint32_t __tag;
char __other[16];
} __x87;
__uint32_t __mxcsr;
} fenv_t;
typedef __uint16_t fexcept_t;
/* Exception flags */
#define FE_INVALID 0x01
#define FE_DENORMAL 0x02
#define FE_DIVBYZERO 0x04
#define FE_OVERFLOW 0x08
#define FE_UNDERFLOW 0x10
#define FE_INEXACT 0x20
#define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \
FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
/* Rounding modes */
#define FE_TONEAREST 0x0000
#define FE_DOWNWARD 0x0400
#define FE_UPWARD 0x0800
#define FE_TOWARDZERO 0x0c00
#define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \
FE_UPWARD | FE_TOWARDZERO)
/*
* As compared to the x87 control word, the SSE unit's control word
* has the rounding control bits offset by 3 and the exception mask
* bits offset by 7.
*/
#define _SSE_ROUND_SHIFT 3
#define _SSE_EMASK_SHIFT 7
__BEGIN_DECLS
/* Default floating-point environment */
extern const fenv_t __fe_dfl_env;
#define FE_DFL_ENV (&__fe_dfl_env)
#define __fldcw(__cw) __asm __volatile("fldcw %0" : : "m" (__cw))
#define __fldenv(__env) __asm __volatile("fldenv %0" : : "m" (__env))
#define __fldenvx(__env) __asm __volatile("fldenv %0" : : "m" (__env) \
: "st", "st(1)", "st(2)", "st(3)", "st(4)", \
"st(5)", "st(6)", "st(7)")
#define __fnclex() __asm __volatile("fnclex")
#define __fnstenv(__env) __asm __volatile("fnstenv %0" : "=m" (*(__env)))
#define __fnstcw(__cw) __asm __volatile("fnstcw %0" : "=m" (*(__cw)))
#define __fnstsw(__sw) __asm __volatile("fnstsw %0" : "=am" (*(__sw)))
#define __fwait() __asm __volatile("fwait")
#define __ldmxcsr(__csr) __asm __volatile("ldmxcsr %0" : : "m" (__csr))
#define __stmxcsr(__csr) __asm __volatile("stmxcsr %0" : "=m" (*(__csr)))
static __inline int
feclearexcept(int __excepts)
{
fenv_t __env;
if (__excepts == FE_ALL_EXCEPT) {
__fnclex();
} else {
__fnstenv(&__env.__x87);
__env.__x87.__status &= ~__excepts;
__fldenv(__env.__x87);
}
__stmxcsr(&__env.__mxcsr);
__env.__mxcsr &= ~__excepts;
__ldmxcsr(__env.__mxcsr);
return (0);
}
static __inline int
fegetexceptflag(fexcept_t *__flagp, int __excepts)
{
__uint32_t __mxcsr;
__uint16_t __status;
__stmxcsr(&__mxcsr);
__fnstsw(&__status);
*__flagp = (__mxcsr | __status) & __excepts;
return (0);
}
int fesetexceptflag(const fexcept_t *__flagp, int __excepts);
int feraiseexcept(int __excepts);
static __inline int
fetestexcept(int __excepts)
{
__uint32_t __mxcsr;
__uint16_t __status;
__stmxcsr(&__mxcsr);
__fnstsw(&__status);
return ((__status | __mxcsr) & __excepts);
}
static __inline int
fegetround(void)
{
__uint16_t __control;
/*
* We assume that the x87 and the SSE unit agree on the
* rounding mode. Reading the control word on the x87 turns
* out to be about 5 times faster than reading it on the SSE
* unit on an Opteron 244.
*/
__fnstcw(&__control);
return (__control & _ROUND_MASK);
}
static __inline int
fesetround(int __round)
{
__uint32_t __mxcsr;
__uint16_t __control;
if (__round & ~_ROUND_MASK)
return (-1);
__fnstcw(&__control);
__control &= ~_ROUND_MASK;
__control |= __round;
__fldcw(__control);
__stmxcsr(&__mxcsr);
__mxcsr &= ~(_ROUND_MASK << _SSE_ROUND_SHIFT);
__mxcsr |= __round << _SSE_ROUND_SHIFT;
__ldmxcsr(__mxcsr);
return (0);
}
int fegetenv(fenv_t *__envp);
int feholdexcept(fenv_t *__envp);
static __inline int
fesetenv(const fenv_t *__envp)
{
/*
* XXX Using fldenvx() instead of fldenv() tells the compiler that this
* instruction clobbers the i387 register stack. This happens because
* we restore the tag word from the saved environment. Normally, this
* would happen anyway and we wouldn't care, because the ABI allows
* function calls to clobber the i387 regs. However, fesetenv() is
* inlined, so we need to be more careful.
*/
__fldenvx(__envp->__x87);
__ldmxcsr(__envp->__mxcsr);
return (0);
}
int feupdateenv(const fenv_t *__envp);
#if __BSD_VISIBLE
int feenableexcept(int __mask);
int fedisableexcept(int __mask);
static __inline int
fegetexcept(void)
{
__uint16_t __control;
/*
* We assume that the masks for the x87 and the SSE unit are
* the same.
*/
__fnstcw(&__control);
return (~__control & FE_ALL_EXCEPT);
}
#endif /* __BSD_VISIBLE */
__END_DECLS
#endif /* !_FENV_H_ */
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