[petsc-dev] Configure fails on macOS with MKL

[Pierre Jolivet]

On Wed, 21 Dec 2016 09:17:33 -0600, Satish Balay wrote:
> I've added $MKLROOT/lib/ to search path for MKL. Thanks for the 
> report.
>
> 
> https://bitbucket.org/petsc/petsc/commits/7fe016461159234c29eaa106eb46d0bf81683f36

Thanks.

> Wrt libiomp5.dylib - its an intel compiler library - so its found 
> when
> using icc,icpc [as you describe below].
>
> I guess it doesn't work when building with clang?
>
> Intel MKL advisor is the authoritative tool for such checks..

Yet another bug'd Intel "software"...

> 
> https://software.intel.com/en-us/articles/intel-mkl-link-line-advisor/
>
> it says:
>
>  -L${MKLROOT}/lib -Wl,-rpath,${MKLROOT}/lib -lmkl_intel_lp64
> -lmkl_intel_thread -lmkl_core -lmkl_blacs_mpich_lp64 -liomp5 
> -lpthread
> -lm -ldl
>
> So it suggests using -liomp5 - but doesn't say - its not a clang
> library. Not sure how to deal with this automatically.
> Your current approach of using LDFLAGS is appropriate [workarround].

It should be reachable by the linker in most cases in one of the 
following folder: 
${MKLROOT}/../compiler/[os.path.join('lib','64'),os.path.join('lib','ia64'),os.path.join('lib','em64t'),os.path.join('lib','intel64'),'lib','64','ia64','em64t','intel64',os.path.join('lib','32'),os.path.join('lib','ia32'),'32','ia32','']

But there might be a more appropriate (or less ugly) way to go.
Thanks.

> Satish
>
> On Wed, 21 Dec 2016, Pierre Jolivet wrote:
>
>> Hello,
>> There are some issues when using (most recent versions of) the MKL 
>> on macOS:
>> 1) the correct path to libmkl_*.dylib is now $MKLROOT/lib/, but this 
>> is not taken into account by the build system
>>
>> diff --git a/config/BuildSystem/config/packages/BlasLapack.py 
>> b/config/BuildSystem/config/packages/BlasLapack.py
>> index 43597e2..017ed12 100644
>> --- a/config/BuildSystem/config/packages/BlasLapack.py
>> +++ b/config/BuildSystem/config/packages/BlasLapack.py
>> @@ -217,7 +217,7 @@ class Configure(config.package.Package):
>>          mkl_blacs_32=[]
>>        if useCPardiso or usePardiso:
>>          self.logPrintBox('BLASLAPACK: Looking for Multithreaded MKL 
>> for C/Pardiso')
>> -        for libdir in 
>> [os.path.join('lib','64'),os.path.join('lib','ia64'),os.path.join('lib','em64t'),os.path.join('lib','intel64'),'64','ia64','em64t','intel64',
>> +        for libdir in 
>> [os.path.join('lib','64'),os.path.join('lib','ia64'),os.path.join('lib','em64t'),os.path.join('lib','intel64'),'64','ia64','em64t','lib','intel64',
>>                         
>> os.path.join('lib','32'),os.path.join('lib','ia32'),'32','ia32','']:
>>            if not os.path.exists(os.path.join(dir,libdir)):
>>              self.logPrint('MKL Path not found.. skipping: 
>> '+os.path.join(dir,libdir))
>>
>> 2) Once this is fixed, it is assumed that libiomp5.dylib is in the 
>> same folder as libmkl_intel_thread.dylib (which is wrong), or at least 
>> visible to the linker. Thus, the configure will fail because it can’t 
>> find libiomp5.dylib, unless explicitly using —CXX=icpc and —CC=icc, or 
>> —LDFLAGS=-L${PATH_TO_LIBIOMP5}
>>
>> I don’t know if you care enough to fix this (I’m guessing there 
>> aren’t that many macOS users compiling PETSc with MKL support but 
>> without the Intel compilers), but just in case…
>> Thanks,
>> Pierre