Comment (by Roland Haas):

Can you provide the value fo the parameter Cactus::presync_mode you are using?

The CCTKi_VarDataPriI function’s “new” thing due to presync is the bit:

  if(!CCTK_HasAccess(GH,vindex))
  {
    return NULL;
  }

and CCTK_HasAccess has a short-circuit:

  static bool presync_only = CCTK_Equals(presync_mode, "presync-only");

  if(!presync_only)
    return true;

which returns early if the static variable indicates that the mode is not presync-early. So if not set then the expense would seem to be the (implicit) mutex to make the static initialization thread safe.
The numbers in you table add up to 169.9% is it possible to see which function calls which other function?

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2512/enable-detection-of-attribute-pure