[Llvm-bgq-discuss] Details behind MPI wrapper for bgclang++

[Hal Finkel]

----- Original Message -----
> From: "Jack Poulson" <jack.poulson at gmail.com>
> To: "Hal Finkel" <hfinkel at anl.gov>
> Cc: "Jeff Hammond" <jhammond at alcf.anl.gov>, llvm-bgq-discuss at lists.alcf.anl.gov
> Sent: Thursday, February 28, 2013 6:12:21 PM
> Subject: Re: [Llvm-bgq-discuss] Details behind MPI wrapper for bgclang++
> 
> Hi Hal,
> 
> 
> As far as I can tell, there are only two distinct wrappers in the
> /home/projects/llvm/mpi/clang/bin folder, mpicc and mpicxx, and all
> of the others are simply symlinks to them. Is it possible that I am
> misunderstanding?

You're correct, but the wrapper scripts alter their behavior slightly depending on the invoking name. Specifically, if you use mpic++ then you get the GNU C++03 mode by default with libstdc++ as the primary C++ STL implementation (and you still get libstdc++ in C++11 mode if you specify -std=c++11, etc.). If you use the mpic++11 wrapper, then you get libc++ as the primary C++ STL implementation (and the GNU C++11 mode by default). The libc++ implementation, being much more recent than the system libstdc++, provides significantly better C++11 support.

Can you give me access to the directory with the core files so that I can take a look?

Thanks again,
Hal

> 
> 
> I am using the mpicxx wrapper.
> 
> 
> Jack
> 
> 
> On Thu, Feb 28, 2013 at 4:08 PM, Hal Finkel < hfinkel at anl.gov >
> wrote:
> 
> 
> Jack,
> 
> What Jeff said is correct. Jeff, I did not specifically update the
> wrapper scripts after the V1R2 transition. Is there anything that I
> need to do for that?
> 
> Also, Jack, are you using the mpic++ (with -std=c++11) wrapper or the
> mpic++11 wrapper?
> 
> -Hal
> 
> 
> 
> ----- Original Message -----
> > From: "Jeff Hammond" < jhammond at alcf.anl.gov >
> > To: "Jack Poulson" < jack.poulson at gmail.com >
> > Cc: llvm-bgq-discuss at lists.alcf.anl.gov
> > Sent: Thursday, February 28, 2013 5:59:08 PM
> > Subject: Re: [Llvm-bgq-discuss] Details behind MPI wrapper for
> > bgclang++
> > 
> > IBM does not provide MPI builds as part of the driver because they
> > do
> > not - and are not required to - provide LLVM builds of MPI.
> > 
> > ALCF can provide /home/projects/pami/llvm/mpi.... if you want an
> > MPI
> > build using LLVM. I will do this next week during MiraCon as part
> > of
> > building MPICH2 1.5 + IBM patches from source.
> > 
> > Best,
> > 
> > Jeff
> > 
> > On Thu, Feb 28, 2013 at 6:56 PM, Jack Poulson
> > < jack.poulson at gmail.com > wrote:
> > > Hello All,
> > > 
> > > I am trying to run a C++11 code on BGQ and have been running into
> > > strange
> > > sporadic segfaults with non-helpful stack traces. I started
> > > looking
> > > through
> > > the details of the driver
> > > /home/projects/llvm/mpi/clang/bin/mpicxx and was
> > > surprised by the 31st line:
> > > prefix=/bgsys/drivers/ppcfloor/comm/gcc
> > > When I look in the /bgsys/drivers/ppcfloor/comm folder, I notice
> > > that there
> > > are directories for gcc and xl, but none for Clang. Is there some
> > > clear
> > > explanation for this?
> > > 
> > > Thanks!
> > > Jack
> > > 
> > > _______________________________________________
> > > llvm-bgq-discuss mailing list
> > > llvm-bgq-discuss at lists.alcf.anl.gov
> > > https://lists.alcf.anl.gov/mailman/listinfo/llvm-bgq-discuss
> > > 
> > 
> > 
> > 
> > --
> > Jeff Hammond
> > Argonne Leadership Computing Facility
> > University of Chicago Computation Institute
> > jhammond at alcf.anl.gov / (630) 252-5381
> > http://www.linkedin.com/in/jeffhammond
> > https://wiki.alcf.anl.gov/parts/index.php/User:Jhammond
> > _______________________________________________
> > llvm-bgq-discuss mailing list
> > llvm-bgq-discuss at lists.alcf.anl.gov
> > https://lists.alcf.anl.gov/mailman/listinfo/llvm-bgq-discuss
> > 
> 
>