To: WG5 and J3 08-185 From: Craig Rasmussen Subject: Request for new features from MPI Forum Date: 2008 May 14 The MPI Forum has been restarted in order to update the Message Passing Interface (MPI) standard. As part of this standarization effort, a new Fortran binding will be created for version 3.0 of the MPI standard. The MPI Forum has requested that J3 consider modifying the Fortran standard to accomplish the following: 1. A mechanism to suppress copyin/copyout semantics for MPI asynchronous operations. 2. Suppress argument checking for MPI choice buffers (C void * formal parameter). A series of straw votes were taken to determine how to address the request from the MPI Forum. The results were: 1. The VOLATILE attribute should be given to both the actual and dummy arguments to suppress copyin/copyout. 2. The J3 committee voted to consider three different candidates for suppressing argument checking of C void * formal parameters. WG5 is asked to consider this as a work item for the C Interop TR. The candidates for the mapping of dummy argments to void * parameters are: a. Create a new derived type, TYPE(C_VOID), in the ISO_C_BINDING intrinsic module. b. Add an IGNORE(TKR) attribute for dummy arguments. This attribute can optionally ignore any combination of type, kind, and rank. c. Create new syntax, TYPE(*), to allow any type actual parameter. When combined with DIMENSION(*), this is effectively equivalent syntax for IGNORE(TKR).