fenv.h File Reference

#include <corecrt.h>
#include <float.h>

Go to the source code of this file.

Classes
struct	fenv_t

Macros
#define	_FENV
#define	FE_TONEAREST   _RC_NEAR
#define	FE_UPWARD   _RC_UP
#define	FE_DOWNWARD   _RC_DOWN
#define	FE_TOWARDZERO   _RC_CHOP
#define	FE_ROUND_MASK   _MCW_RC
#define	FE_INEXACT   _SW_INEXACT
#define	FE_UNDERFLOW   _SW_UNDERFLOW
#define	FE_OVERFLOW   _SW_OVERFLOW
#define	FE_DIVBYZERO   _SW_ZERODIVIDE
#define	FE_INVALID   _SW_INVALID
#define	FE_ALL_EXCEPT   (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
#define	FE_DFL_ENV   (&_Fenv1)
#define	_BEGIN_PRAGMA_OPTIMIZE_DISABLE(flags, bug, reason)   __pragma(optimize(flags, off))
#define	_BEGIN_PRAGMA_OPTIMIZE_ENABLE(flags, bug, reason)   __pragma(optimize(flags, on))
#define	_END_PRAGMA_OPTIMIZE()   __pragma(optimize("", on))

Typedefs
typedef unsigned long	fexcept_t
typedef struct fenv_t	fenv_t

Functions
_ACRTIMP int __cdecl	fegetround (void)
_ACRTIMP int __cdecl	fesetround (_In_ int _Round)
_ACRTIMP int __cdecl	fegetenv (_Out_ fenv_t *_Env)
_ACRTIMP int __cdecl	fesetenv (_In_ fenv_t const *_Env)
_ACRTIMP int __cdecl	feclearexcept (_In_ int _Flags)
_ACRTIMP	_Success_ (return==0) int __cdecl feholdexcept(_Out_ fenv_t *_Env)
_ACRTIMP int __cdecl	fetestexcept (_In_ int _Flags)
_ACRTIMP int __cdecl	fegetexceptflag (_Out_ fexcept_t *_Except, _In_ int _TestFlags)
_ACRTIMP int __cdecl	fesetexceptflag (_In_ fexcept_t const *_Except, _In_ int _SetFlags)
	__declspec (selectany) extern const fenv_t _Fenv1
__inline int __CRTDECL	feraiseexcept (_In_ int _Except)
__inline int __CRTDECL	feupdateenv (_In_ const fenv_t *_Penv)

Macro Definition Documentation

#define _BEGIN_PRAGMA_OPTIMIZE_DISABLE	(		flags,
			bug,
			reason
	)		__pragma(optimize(flags, off))

#define _BEGIN_PRAGMA_OPTIMIZE_ENABLE	(		flags,
			bug,
			reason
	)		__pragma(optimize(flags, on))

#define _END_PRAGMA_OPTIMIZE

(

)

__pragma(optimize("", on))

#define _FENV

#define FE_ALL_EXCEPT   (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)

#define FE_DFL_ENV   (&_Fenv1)

#define FE_DIVBYZERO   _SW_ZERODIVIDE

#define FE_DOWNWARD   _RC_DOWN

#define FE_INEXACT   _SW_INEXACT

#define FE_INVALID   _SW_INVALID

#define FE_OVERFLOW   _SW_OVERFLOW

#define FE_ROUND_MASK   _MCW_RC

#define FE_TONEAREST   _RC_NEAR

#define FE_TOWARDZERO   _RC_CHOP

#define FE_UNDERFLOW   _SW_UNDERFLOW

#define FE_UPWARD   _RC_UP

Typedef Documentation

typedef struct fenv_t fenv_t

typedef unsigned long fexcept_t

Function Documentation

__declspec

(

selectany

)

const

_ACRTIMP _Success_

(

return

= =0

)

_ACRTIMP int __cdecl feclearexcept

(

_In_ int

_Flags

)

_ACRTIMP int __cdecl fegetenv

(

_Out_ fenv_t *

_Env

)

_ACRTIMP int __cdecl fegetexceptflag	(	_Out_ fexcept_t *	_Except,
		_In_ int	_TestFlags
	)

_ACRTIMP int __cdecl fegetround

(

void

)

__inline int __CRTDECL feraiseexcept

(

_In_ int

_Except

)

        {
            static struct
            {
                int    _Except_Val;
                double _Num;
                double _Denom;
            } const _Table[] =
            {  // Raise exception by evaluating num / denom:
                {FE_INVALID,   0.0,    0.0    },
                {FE_DIVBYZERO, 1.0,    0.0    },
                {FE_OVERFLOW,  1e+300, 1e-300 },
                {FE_UNDERFLOW, 1e-300, 1e+300 },
                {FE_INEXACT,   2.0,    3.0    }
            };

            double _Ans = 0.0;
            int _N;

            if ((_Except &= FE_ALL_EXCEPT) == 0)
            {
                return 0;
            }

            // Raise the exceptions not masked:
            for (_N = 0; _N < sizeof(_Table) / sizeof(_Table[0]); ++_N)
            {
                if ((_Except & _Table[_N]._Except_Val) != 0)
                {
                    _Ans = _Table[_N]._Num / _Table[_N]._Denom;

                    // x87 exceptions are raised immediately before execution of the
                    // next floating point instruction.  If we're using /arch:IA32,
                    // force the exception to be raised immediately:
                    #if defined _M_IX86 && _M_IX86_FP == 0
                    __asm fwait;
                    #endif
                }
            }

            return 0;
        }

_ACRTIMP int __cdecl fesetenv

(

_In_ fenv_t const *

_Env

)

_ACRTIMP int __cdecl fesetexceptflag	(	_In_ fexcept_t const *	_Except,
		_In_ int	_SetFlags
	)

_ACRTIMP int __cdecl fesetround

(

_In_ int

_Round

)

_ACRTIMP int __cdecl fetestexcept

(

_In_ int

_Flags

)

__inline int __CRTDECL feupdateenv

(

_In_ const fenv_t *

_Penv

)

        {
            int _Except = fetestexcept(FE_ALL_EXCEPT);

            if (fesetenv(_Penv) != 0 || feraiseexcept(_Except) != 0)
            {
                return 1;
            }

            return 0;
        }