LLRINT(3P) POSIX Programmer's Manual LLRINT(3P)PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the corresponding
Linux manual page for details of Linux behavior), or the interface may
not be implemented on Linux.
NAME
llrint, llrintf, llrintl - round to the nearest integer value using
current rounding direction
SYNOPSIS
#include <math.h>
long long llrint(double x);
long long llrintf(float x);
long long llrintl(long double x);
DESCRIPTION
These functions shall round their argument to the nearest integer
value, rounding according to the current rounding direction.
An application wishing to check for error situations should set errno
to zero and call feclearexcept(FE_ALL_EXCEPT) before calling these
functions. On return, if errno is non-zero or fetestexcept(FE_INVALID
| FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error has
occurred.
RETURN VALUE
Upon successful completion, these functions shall return the rounded
integer value.
If x is NaN, a domain error shall occur, and an unspecified value is
returned.
If x is +Inf, a domain error shall occur and an unspecified value is
returned.
If x is -Inf, a domain error shall occur and an unspecified value is
returned.
If the correct value is positive and too large to represent as a long
long, a domain error shall occur and an unspecified value is returned.
If the correct value is negative and too large to represent as a long
long, a domain error shall occur and an unspecified value is returned.
ERRORS
These functions shall fail if:
Domain Error
The x argument is NaN or ±Inf, or the correct value is not rep‐
resentable as an integer.
If the integer expression (math_errhandling & MATH_ERRNO) is non-zero,
then errno shall be set to [EDOM]. If the integer expression
(math_errhandling & MATH_ERREXCEPT) is non-zero, then the invalid
floating-point exception shall be raised.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
On error, the expressions (math_errhandling & MATH_ERRNO) and
(math_errhandling & MATH_ERREXCEPT) are independent of each other, but
at least one of them must be non-zero.
RATIONALE
These functions provide floating-to-integer conversions. They round
according to the current rounding direction. If the rounded value is
outside the range of the return type, the numeric result is unspecified
and the invalid floating-point exception is raised. When they raise no
other floating-point exception and the result differs from the argu‐
ment, they raise the inexact floating-point exception.
FUTURE DIRECTIONS
None.
SEE ALSOfeclearexcept(), fetestexcept(), lrint(), the Base Definitions volume
of IEEE Std 1003.1-2001, Section 4.18, Treatment of Error Conditions
for Mathematical Functions, <math.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 LLRINT(3P)
