      real             tol, bb_t
      parameter(tol=5e-13, bb_t=0.01)
      integer          ltots
      parameter(ltots=4*lx1*ly1*lz1*lelt) ! max source mesh size

      integer                fldh_gfldr,inth_gfldr
      common /gfldr_handles/ fldh_gfldr,inth_gfldr

      logical ifbswp
      common /gfldr_log/     ifbswp

      integer*8              noff0_b,ntots_b,rankoff_b,nSizeFld_b
      common /gfldr_byte/    noff0_b,ntots_b,rankoff_b,nSizeFld_b

      integer                nelgs,nels,nxyzs
      common /gfldr_meshs/   nelgs,nels,nxyzs

      real             buffld(ltots)  ! one source field
      common /scruz/   buffld

      real             xm1s  (ltots)  ! source x coord
      common /scrmg/   xm1s

      real             ym1s  (ltots)  ! source y coord
      common /ctmp1/   ym1s

      real             zm1s  (ltots)  ! source z coord
      common /scrsf/   zm1s

      real*4           bufr  (2*ldim*ltots) ! read buffer
      common /vrthov/  bufr 

      ! interpolation working arrays 
      real             grst   (  ldim*ltots)  
      common /ctmp0/   grst   ! use ctmp0 as no other big CBs are left

      real             gdist  (       ltots)
      common /scrvh/   gdist 

      integer          grcode (ltots)
      integer          gelid  (ltots)
      integer          gproc  (ltots)
      common /scrns/   grcode,gelid,gproc
