fesetround

fesetround

Set the floating point rounding mode

Portability: C99

SYNOPSIS
DESCRIPTION
RETURN VALUE
CAUTIONS
RELATED FUNCTIONS
SEE ALSO

SYNOPSIS

   #include <fenv.h>

   int fesetround(int mode);

DESCRIPTION

fesetround is used to change the rounding mode in the current floating-point environment. The mode argument must be one of the values FE_TONEAREST, FE_TOWARDZERO, FE_UPWARD or FE_DOWNWARD, defined in fenv.h.

RETURN VALUE

fesetround returns zero if the request was successful, or a non-zero value if the request could not be honored.

CAUTIONS

fesetround returns -1 when called from a function whose default floating-point format is hexadecimal, that is, one compiled without the bfp option.

A program which calls fesetround must use the standard FENV_ACCESS pragma in an enclosing scope, or the effects are unpredictable. The pragma must also be present in any code with runs with a rounding mode other than the default, FE_TONEAREST.

RELATED FUNCTIONS

fegetround

SEE ALSO

"Mathematical Functions" in Chapter 2, "Function Categories"

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