Linux manual pages Section 3: Subroutines  

Name

lrint, lrintf, lrintl, llrint, llrintf, llrintl — round to nearest integer

Synopsis

#include <math.h>
long int lrint( double x);
 
long int lrintf( float x);
 
long int lrintl( long double x);
 
long long int llrint( double x);
 
long long int llrintf( float x);
 
long long int llrintl( long double x);
 
[Note] Note
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
All functions shown above:
_XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
or cc -std=c99
[Note] Note

Link with −lm.

DESCRIPTION

These functions round their argument to the nearest integer value, using the current rounding direction (see fesetround(3)).

Note that unlike rint(3), etc., the return type of these functions differs from that of their arguments.

RETURN VALUE

These functions return the rounded integer value.

If x is a NaN or an infinity, or the rounded value is too large to be stored in a long (long long in the case of the ll* functions) then a domain error occurs, and the return value is unspecified.

ERRORS

See math_error(7) for information on how to determine whether an error has occurred when calling these functions.

The following errors can occur:

Domain error: x is a NaN or infinite, or the rounded value is too large

An invalid floating-point exception (FE_INVALID) is raised.

These functions do not set errno.

VERSIONS

These functions first appeared in glibc in version 2.1.

ATTRIBUTES

Multithreading (see pthreads(7))

The lrint(), lrintf(), lrintl(), llrint(), llrintf(), and llrintl() functions are thread-safe.

CONFORMING TO

C99, POSIX.1-2001.

SEE ALSO

ceil(3), floor(3), lround(3), nearbyint(3), rint(3), round(3)

COLOPHON

This page is part of release 3.54 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man−pages/.


  Copyright 2001 Andries Brouwer <aebcwi.nl>.
and Copyright 2008, Linux Foundation, written by Michael Kerrisk
    <mtk.manpagesgmail.com>

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