NAME

       MPI_Comm_compare  -  Compares two communicators.

SYNTAX

C Syntax

       #include <mpi.h>
       int MPI_Comm_compare(MPI_Comm comm1, MPI_Comm comm2, int *result)

Fortran Syntax

       USE MPI
       ! or the older form: INCLUDE 'mpif.h'
       MPI_COMM_COMPARE(COMM1, COMM2, RESULT, IERROR)
            INTEGER   COMM1, COMM2, RESULT, IERROR

Fortran 2008 Syntax

       USE mpi_f08
       MPI_Comm_compare(comm1, comm2, result, ierror)
            TYPE(MPI_Comm), INTENT(IN) :: comm1, comm2
            INTEGER, INTENT(OUT) :: result
            INTEGER, OPTIONAL, INTENT(OUT) :: ierror

C++ Syntax

       #include <mpi.h>
       static int Comm::Compare(const Comm& comm1, const Comm& comm2)

INPUT PARAMETERS

       comm1     Comm1 (handle).

       comm2     Comm2 (handle).

OUTPUT PARAMETERS

       result    Result of comparison (integer).

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       MPI_IDENT  results  if  and only if comm1 and comm2 are handles for the same object (identical groups and
       same contexts). MPI_CONGRUENT results if the underlying groups are identical  in  constituents  and  rank
       order;  these  communicators  differ  only  by  context. MPI_SIMILAR results of the group members of both
       communicators are the same but the rank order differs. MPI_UNEQUAL results otherwise.

ERRORS

       Almost all MPI routines return an error value; C routines as  the  value  of  the  function  and  Fortran
       routines in the last argument. C++ functions do not return errors. If the default error handler is set to
       MPI::ERRORS_THROW_EXCEPTIONS,  then  on  error  the  C++  exception  mechanism  will  be used to throw an
       MPI::Exception object.

       Before the error value is returned, the current MPI error handler  is  called.  By  default,  this  error
       handler  aborts  the  MPI  job,  except  for  I/O  function errors. The error handler may be changed with
       MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values
       to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

4.1.6                                             Sep 30, 2023                               MPI_Comm_compare(3)