Tribblix: manual page: llround.3m

LLROUND(3M) Mathematical Library Functions LLROUND(3M)

NAME

llround, llroundf, llroundl - round to nearest integer value

SYNOPSIS

c99 [ flag... ] file... -lm [ library... ]
#include <math.h>

long long llround(double x);

long long llroundf(float x);

long long llroundl(long double x);

DESCRIPTION

These functions rounds their argument to the nearest integer value,
rounding halfway cases away from 0 regardless of the current rounding
direction.

RETURN VALUES

Upon successful completion, these functions return the rounded
integer value.

If x is NaN, a domain error occurs and an unspecified value is
returned.

If x is +Inf, a domain error occurs and an unspecified value is
returned.

If x is -Inf, a domain error occurs and an unspecified value is
returned.

If the correct value is positive and too large to represent as a long
long, a domain error occurs and an unspecified value is returned.

If the correct value is negative and too large to represent as a
long long, a domain error occurs and an unspecified value is
returned.

ERRORS

These functions will fail if:

Domain Error
The x argument is NaN or +-Inf, or the correct value
is not representable as an integer.

If the integer expression (math_errhandling &
MATH_ERREXCEPT) is non-zero, then the invalid
floating-point exception will be raised.

USAGE

An application wanting to check for exceptions should call
feclearexcept(FE_ALL_EXCEPT) before calling these functions. On
return, if fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW |
FE_UNDERFLOW) is non-zero, an exception has been raised. An
application should either examine the return value or check the
floating point exception flags to detect exceptions.

These functions differ from the llrint(3M) functions in that the
default rounding direction for the llround() functions round halfway
cases away from 0 and need not raise the inexact floating-point
exception for non-integer arguments that round to within the range of
the return type.

ATTRIBUTES