C	$Id: gsum.F,v 1.2 2006/05/12 22:23:10 ce107 Exp $	
      SUBROUTINE GSUM_R8( ans, phi )

#include "EEPARAMS.h"
#ifdef ALLOW_MPI
#include "mpif.h"
#include "MPI_INFO.h"
#endif

#ifdef USE_MIXED_PRECISION
      REAL*8 ans
      REAL*8 phi
#else
      Real ans
      Real phi
#endif

      INTEGER RC

      ans = phi

#ifdef USE_MPI_GSUM
#ifdef USE_MIXED_PRECISION
      CALL MPI_Allreduce( phi,
     &                    ans,
     &                      1,
     &                    MPI_REAL8,
     &                    MPI_SUM,
     &                    comm_use,
     &                    rc
     &                  )
#else
      CALL MPI_Allreduce( phi,
     &                    ans,
     &                      1,
     &                    _MPI_TYPE_REAL,
     &                    MPI_SUM,
     &                    comm_use,
     &                    rc
     &                  )
#endif
#endif

#ifdef USE_JAM_GSUM
C     JAM global sum
      CALL JAM_barrier_start( phi )
      CALL JAM_barrier_done(  ans )
#endif

C     WRITE(6,*) ' phi = ', phi, ' Sum = ', ans
C     CALL MPI_Finalize( rc )
C     STOP

      RETURN
      END