FE_DIVBYZERO, FE_INEXACT, FE_INVALID, FE_OVERFLOW, FE_UNDERFLOW, FE_ALL_EXCEPT

 

C

Language

headers

Type support

Dynamic memory management

Error handling

Program utilities

Variadic function support

Date and time utilities

Strings library

Algorithms

Numerics

Input/output support

Localization support

Thread support (C11)

Atomic operations (C11)

Technical Specifications

 

Numerics

Common mathematical functions

Floating-point environment

Complex number arithmetics

Random number generation

Type-generic math

 

Floating point environment

Functions

feclearexcept (C99)

fetestexcept (C99)

feraiseexcept (C99)

fegetexceptflagfesetexceptflag (C99)(C99)

fegetroundfesetround (C99)(C99)

fegetenvfesetenv (C99)

feholdexcept (C99)

feupdateenv (C99)

Macro constants

FE_ALL_EXCEPTFE_DIVBYZEROFE_INEXACTFE_INVALIDFE_OVERFLOWFE_UNDERFLOW (C99)

FE_DOWNWARDFE_TONEARESTFE_TOWARDZEROFE_UPWARD (C99)

FE_DFL_ENV (C99)

 

Defined in header <fenv.h>
#define FE_DIVBYZERO    /*implementation defined power of 2*/		(since C99)
#define FE_INEXACT      /*implementation defined power of 2*/		(since C99)
#define FE_INVALID      /*implementation defined power of 2*/		(since C99)
#define FE_OVERFLOW     /*implementation defined power of 2*/		(since C99)
#define FE_UNDERFLOW    /*implementation defined power of 2*/		(since C99)
#define FE_ALL_EXCEPT  FE_DIVBYZERO | FE_INEXACT | \                        FE_INVALID | FE_OVERFLOW |  \                        FE_UNDERFLOW		(since C99)

All these macro constants (except FE_ALL_EXCEPT) expand to integer constant expressions that are distinct powers of 2, which uniquely identify all supported floating-point exceptions. Each macro is only defined if it is supported.

The macro constant FE_ALL_EXCEPT, which expands to the bitwise OR of all other FE_*, is always defined and is zero if floating-point exceptions are not supported by the implementation.

Constant	Explanation
FE_DIVBYZERO	pole error occurred in an earlier floating-point operation
FE_INEXACT	inexact result: rounding was necessary to store the result of an earlier floating-point operation
FE_INVALID	domain error occurred in an earlier floating-point operation
FE_OVERFLOW	the result of an earlier floating-point operation was too large to be representable
FE_UNDERFLOW	the result of an earlier floating-point operation was subnormal with a loss of precision
FE_ALL_EXCEPT	bitwise OR of all supported floating-point exceptions

The implementation may define additional macro constants in <fenv.h> to identify additional floating-point exceptions. All such constants begin with FE_ followed by at least one uppercase letter.

See math_errhandling for further details.