[Trilinos-Users] [EXTERNAL] llvm-gcc / clang

Perschbacher, Brent M bmpersc at sandia.gov
Thu Apr 12 15:16:16 MDT 2012


Holger,
  actually the compiler I was using to do the llvm port was clang 3.0, so
yes clang will be supported with this. All of the issues that had to be
fixed were actually from differences in the internals of the compiler
compared to gcc, so it should be that any llvm based compiler set should
work with Trilinos once these fixes are out.

Not all of Trilinos had issues with the llvm compilers, I think it was half
a dozen packages had to have fixes applied to them is all. So depending on
what you doing there is a decent chance that you aren't using any of the
packages that had problems. If you were building Trilinos with gcc and then
linking a clang build code to it then depending on how you built Trilinos
you could avoid all of the compile errors that way.

Between 10.6 and 10.10 there were also efforts to port to other compilers
which I'm sure had some impact on working with llvm as we tend to move
closer to the standard and rely less on gnu extensions with every new
compiler we support.

Brent


On 4/12/12 1:22 PM, "Holger Brandsmeier"
<holger.brandsmeier at sam.math.ethz.ch> wrote:

> Brent,
> 
> will Trilinos also work with clang (also part of llvm and mostly
> compatible to gcc) or only llvm-gcc? I actually never used llvm-gcc,
> does it produces as nice error messages as clang?
> 
> Do those errors occur if I use clang to compile trilinos itself, or
> also if I build trilinos with gcc and use clang to build a library
> which links against trilinos? I never experienced such problems in the
> second variant and I already do that for a year now. Including the use
> of fortran based lapack / blas implementations.
> 
> As for clang, I ocasionaly got crashes of the compiler itself, which
> disappeared once I started to use very recent versions of clang (3.1).
> I noticed that I didn't have to change any header files for Trilinos
> 10.10 any more, which I still had to fix quite a few headers for 10.6.
> Thanks for that.
> 
> -Holger
> 
> 
> 
> On Thu, Apr 12, 2012 at 01:15, Perschbacher, Brent M <bmpersc at sandia.gov>
> wrote:
>> Chris,
>>  I have a couple suggestions that may help you. First I highly recommend
>> using the cmake build of clapack instead of the provided Makefiles. The
>> biggest reason is that by default the provided Makefiles mangle the blas and
>> lapack library names differently which makes it difficult to link against
>> them. The cmake build by default does not do that. Given that the cmake
>> build for clapack was actually done for the Trilinos project it is generally
>> more likely to work effortlessly with Trilinos.
>> 
>> We also know of several issues with the llvm compiler that could be causing
>> you problems. I've actually recently fixed most of the build errors llvm,
>> however we haven't provided a bug release with those changes yet. There is
>> one coming, but in the  mean time I would highly recommend using a gcc that
>> does not use llvm as the back end, we currently test against 4.3, 4.4, 4.5
>> and 4.6 so any of those should be pretty safe to use.
>> 
>> I hope this helps,
>> 
>> Brent
>> 
>> 
>> On 4/11/12 3:24 PM, "Christian Staudt" <christian.staudt at ira.uka.de> wrote:
>> 
>>> Thanks, I'll describe the situation:
>>> 
>>> I am running Mac OS X 10.6 on x86, gcc is: i686-apple-darwin10-llvm-gcc-4.2,
>>> gfortran is i686-apple-darwin10-gfortran-4.2.1
>>> 
>>> Basically, I am trying to follow the instructions from [1], therefore I have
>>> 
>>> - built CLAPACK, using the example make.inc file and running "make",
>>> producing
>>> lapack_OSX.a and blas_OSX.a - no error messages
>>> - run my custom do-configure script [4] in which I have given the location
>>> of
>>> BLAS and LAPACK (correctly?), producing the following output: [3]
>>> - run "make" in the Trilinos target directory, which fails with following
>>> output: [2]
>>> 
>>> I see that several tests from the do-configure script have "Failed".
>>> However,
>>> I do not know how to proceed from here.
>>> 
>>> Chris
>>> 
>>> 
>>> [1] https://code.google.com/p/trilinos/wiki/TrilinosHandsOnTutorial
>>> 
>>> [2] http://pastebin.com/SaRxYEaE
>>> 
>>> [3] http://pastebin.com/XpXuVX3p
>>> 
>>> [4] http://pastebin.com/aunLq554
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> Am 11.04.2012 um 22:05 schrieb Heroux, Michael A:
>>> 
>>>> Chris,
>>>> 
>>>> What kind of computer system are you running on?  Give us a few details
>>>> about your situation.
>>>> 
>>>> Thanks.
>>>> 
>>>> Mike
>>>> 
>>>> On 4/11/12 2:35 PM, "Christian Staudt" <christian.staudt at ira.uka.de> wrote:
>>>> 
>>>>> Hello Trilinos users,
>>>>> 
>>>>> I'm working on a multigrid scheme for solving linear systems where the
>>>>> system matrix is a graph Laplacian. The project will be based on either
>>>>> PETSc or Trilinos - I am new to both. From what I have read, I gravitate
>>>>> towards Trilinos.
>>>>> 
>>>>> However, I have had no success building Trilinos so far. The error I run
>>>>> into during the "make" step is related to CLAPACK. Before I go into more
>>>>> details: Are installation troubleshooting questions/discussions
>>>>> appropriate on this list?
>>>>> 
>>>>> Regards
>>>>> Chris
>>>>> 
>>>>> _______________________________________________
>>>>> Trilinos-Users mailing list
>>>>> Trilinos-Users at software.sandia.gov
>>>>> http://software.sandia.gov/mailman/listinfo/trilinos-users
>>>> 
>>>> 
>>> 
>>> 
>>> 
>>> _______________________________________________
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>>> Trilinos-Users at software.sandia.gov
>>> http://software.sandia.gov/mailman/listinfo/trilinos-users
>> 
>> 
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> 
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