From owner-sc22wg5@open-std.org Wed Dec 17 16:44:55 2008 Return-Path: X-Original-To: sc22wg5-dom7 Delivered-To: sc22wg5-dom7@www2.open-std.org Received: by www2.open-std.org (Postfix, from userid 521) id 98DEFC178DE; Wed, 17 Dec 2008 16:44:55 +0100 (CET) X-Original-To: sc22wg5@open-std.org Delivered-To: sc22wg5@open-std.org X-Greylist: delayed 2260 seconds by postgrey-1.18 at www2.open-std.org; Wed, 17 Dec 2008 16:44:54 CET Received: from s-utl02-sjpop.stsn.net (s-utl02-sjpop.stsn.net [72.254.0.202]) by www2.open-std.org (Postfix) with SMTP id 3D1C9C178D6 for ; Wed, 17 Dec 2008 16:44:53 +0100 (CET) Received: from s-utl02-sjpop.stsn.net ([127.0.0.1]) by s-utl02-sjpop.stsn.net (SMSSMTP 4.1.2.20) with SMTP id M2008121707070624687 ; Wed, 17 Dec 2008 07:07:06 -0800 X-Spam-Status: No, hits=0.0 required=9.9 tests=ALL_TRUSTED: -2.867,AWL: -1.964,BAYES_00: -1.665, DATE_IN_PAST_12_24: 0.571,HTML_20_30: 0.567,HTML_MESSAGE: 0.001, LOCAL_OBFU_GENERIC: 1.8,MIME_HTML_ONLY: 1.156 X-Spam-Level: Received: from [10.150.155.236] ([10.150.155.236]) by s-utl02-sjpop.stsn.net; Wed, 17 Dec 2008 07:07:05 -0800 X-Uniform-Type-Identifier: com.apple.mail-draft X-Apple-Mail-Signature: SKIP_SIGNATURE From: Craig Rasmussen To: MPI-3 Fortran working group X-Universally-Unique-Identifier: d3385d00-15d1-43d0-aef3-710f55d939ed Subject: Please tell me I'm wrong X-Apple-Mail-Remote-Attachments: YES X-Apple-Windows-Friendly: 1 Message-Id: <71DC5DE2-391C-4057-B808-C5CD6E93E177@lanl.gov> Content-Type: text/html; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Apple Message framework v929.2) X-Apple-Base-Url: x-msg://20/ Date: Tue, 16 Dec 2008 15:42:59 -0700 Cc: WG5 X-Mailer: Apple Mail (2.929.2) Sender: owner-sc22wg5@open-std.org Precedence: bulk Without help from the Fortran = standard, I don't think there is anyway to avoid a combinatorial = explosion of interfaces (made worse by the F2008 with 15 dimensions). = Consider the simple example code = snippet:

---------

subroutine test_recv(message)
= real :: message(:,:)

call MPI_Recv(message, 2, = MPI_INTEGER, 1, 1, MPI_COMM_WORLD, MPI_STATUS_IGNORE)

end = subroutine

---------

For interface = declaration:

subroutine MPI_Recv_wrapper(buf, count, datatype, = source, tag, comm, status, err)
real, dimension(*), = intent(out) :: buf

or:

subroutine = MPI_Recv_wrapper(buf, count, datatype, source, tag, comm, status, = err)
real, dimension(1,1,1,1,1,1,*), intent(out) :: = buf

This give the following error with the Intel = compiler:

fortcom: Error: test_recv_call.f90, line 15: There is = no matching specific subroutine for this generic subroutine call. = [MPI_RECV]
call MPI_Recv(message, 2, MPI_INTEGER, = dest, 1, MPI_COMM_WORLD, MPI_STATUS_IGNORE)
--------^

On the = other hand, if we use the interface:

subroutine = MPI_Recv_wrapper(buf, count, datatype, source, tag, comm, status, = err)
type(C_PTR) :: buf

There is still a problem as = assumed shape arrays are not interoperable. =46rom = gfortran:

call MPI_Recv(C_LOC(message), 2, MPI_INTEGER, = dest, 1, MPI_COMM_WORLD, requ
= &n= bsp; &nbs= p; = 1
Error: Assumed-shape array 'message' = at (1) cannot be an argument to the procedure 'c_loc because it is not C = interoperable

So there doesn't seem to be anyway to currently = do multi-dimensional interfaces for assumed-shape actuals without a = combinatorial explosion of interfaces. This also seems to be the = case for assumed-size actuals as = well.

Comments?

Cheers,
Craig

=