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LRINT(3P)                  POSIX Programmer's Manual                 LRINT(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
       lrint, lrintf, lrintl - round to nearest integer  value  using  current
       rounding direction
SYNOPSIS
       #include <math.h>
       long lrint(double x);
       long lrintf(float x);
       long lrintl(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,
       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,
       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 ALSO
       feclearexcept(),  fetestexcept(), llrint(), 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                            LRINT(3P)