Open MPI and gfortran require different compiler flags? - openmpi

Question

I have a serial program that uses the ssyevr lapack routine to diagonalize matricies. It runs fine but is a little slow. Recently, I downloaded OpenMPI through MacPorts with the intention of utilizing the dual core processor (with shared memory) to decrease run time.
My program calculates an average of some quantity, so I'd like to run half of my ensemble on one process and the other half on the other process. I require minor communication between each process (mpi_reduce and mpi_barrier to combine the data at the end).
I figured that linking to -llapack would work as with the serial program but found I needed to link -lblas and -latlas when using mpifort to compile my program.
If I don't add flags for blas and atlas I get the following error:
Undefined symbols for architecture x86_64:
"_ATL_cGetNB", referenced from:
_ATL_ilaenv in liblapack.a(ATL_ilaenv.o)
"_ATL_dGetNB", referenced from:
_ATL_ilaenv in liblapack.a(ATL_ilaenv.o)
"_ATL_sGetNB", referenced from:
_ATL_ilaenv in liblapack.a(ATL_ilaenv.o)
"_ATL_zGetNB", referenced from:
_ATL_ilaenv in liblapack.a(ATL_ilaenv.o)
"_cblas_scopy", referenced from:
_ATL_slarfb in liblapack.a(ATL_slarfb.o)
"_cblas_sdot", referenced from:
_ATL_slarftFC.part.0 in liblapack.a(ATL_slarft.o)
_ATL_slarftFR.part.2 in liblapack.a(ATL_slarft.o)
_ATL_slarftBC.part.1 in liblapack.a(ATL_slarft.o)
_ATL_slarftBR.part.3 in liblapack.a(ATL_slarft.o)
_ATL_slarftFC in liblapack.a(ATL_slarft.o)
_ATL_slarftBC in liblapack.a(ATL_slarft.o)
_ATL_slarftFR in liblapack.a(ATL_slarft.o)
...
"_cblas_sgemm", referenced from:
_ATL_slarfb in liblapack.a(ATL_slarfb.o)
_ATL_slarft_blockFC in liblapack.a(ATL_slarft.o)
_ATL_slarft_blockFR in liblapack.a(ATL_slarft.o)
_ATL_slarft_blockBC in liblapack.a(ATL_slarft.o)
_ATL_slarft_blockBR in liblapack.a(ATL_slarft.o)
"_cblas_strmm", referenced from:
_ATL_slarfb in liblapack.a(ATL_slarfb.o)
_ATL_slarft_blockFC in liblapack.a(ATL_slarft.o)
_ATL_slarft_blockFR in liblapack.a(ATL_slarft.o)
_ATL_slarft_blockBC in liblapack.a(ATL_slarft.o)
_ATL_slarft_blockBR in liblapack.a(ATL_slarft.o)
"_isamax_", referenced from:
_sstein_ in liblapack.a(sstein.o)
"_lsame_", referenced from:
_ssyevr_ in liblapack.a(ssyevr.o)
_ilaenv_ in liblapack.a(ilaenv.o)
_slansy_ in liblapack.a(slansy.o)
_sormtr_ in liblapack.a(sormtr.o)
_sstebz_ in liblapack.a(sstebz.o)
_sstemr_ in liblapack.a(sstemr.o)
_ssytrd_ in liblapack.a(ssytrd.o)
...
"_saxpy_", referenced from:
_sstein_ in liblapack.a(sstein.o)
_slatrd_ in liblapack.a(slatrd.o)
_ssytd2_ in liblapack.a(ssytd2.o)
"_scopy_", referenced from:
_ssyevr_ in liblapack.a(ssyevr.o)
_sstein_ in liblapack.a(sstein.o)
_sstemr_ in liblapack.a(sstemr.o)
_slarre_ in liblapack.a(slarre.o)
_slarrv_ in liblapack.a(slarrv.o)
_slarrf_ in liblapack.a(slarrf.o)
"_sdot_", referenced from:
_sstein_ in liblapack.a(sstein.o)
_slatrd_ in liblapack.a(slatrd.o)
_ssytd2_ in liblapack.a(ssytd2.o)
"_sgemv_", referenced from:
_slatrd_ in liblapack.a(slatrd.o)
_slarf_ in liblapack.a(slarf.o)
"_sger_", referenced from:
_slarf_ in liblapack.a(slarf.o)
"_snrm2_", referenced from:
_sstein_ in liblapack.a(sstein.o)
_slarfg_ in liblapack.a(slarfg.o)
"_sscal_", referenced from:
_ssyevr_ in liblapack.a(ssyevr.o)
_sstein_ in liblapack.a(sstein.o)
_sstemr_ in liblapack.a(sstemr.o)
_slarrv_ in liblapack.a(slarrv.o)
_slatrd_ in liblapack.a(slatrd.o)
_slarfg_ in liblapack.a(slarfg.o)
"_sswap_", referenced from:
_ssyevr_ in liblapack.a(ssyevr.o)
_sstemr_ in liblapack.a(sstemr.o)
"_ssymv_", referenced from:
_slatrd_ in liblapack.a(slatrd.o)
_ssytd2_ in liblapack.a(ssytd2.o)
"_ssyr2_", referenced from:
_ssytd2_ in liblapack.a(ssytd2.o)
"_ssyr2k_", referenced from:
_ssytrd_ in liblapack.a(ssytrd.o)
"_xerbla_", referenced from:
_ssyevr_ in liblapack.a(ssyevr.o)
_sormtr_ in liblapack.a(sormtr.o)
_sstebz_ in liblapack.a(sstebz.o)
_sstein_ in liblapack.a(sstein.o)
_sstemr_ in liblapack.a(sstemr.o)
_ssterf_ in liblapack.a(ssterf.o)
_ssytrd_ in liblapack.a(ssytrd.o)
...
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status
I've gotten this error many times before. It happens when you forget to link a library. The error reads as
"_This_routine" was called within the routine:
_That_routine in this_library.a(That_routine.o)
That_routine, was found in the library this_library and it called a routine "This_routine" that could not be found. All of the routines missing are found in either BLAS or ATLAS. So therefore using their compiler flags will solve the issue.
Normally, I'd just be happy and move on but my code does not run successfully despite these changes and I have good reason to believe that the parallelized version is not bugged. I have run it with success on Sharcnet (Which may not be using the same version !!!).
Edit: When I run mpifort --showme I get
/opt/local/bin/gfortran-mp-7 -I/opt/local/include/openmpi-mp -Wl,-flat_namespace -Wl,-commons,use_dylibs -I/opt/local/lib/openmpi-mp -L/opt/local/lib -L/opt/local/lib/openmpi-mp -lmpi_usempif08 -lmpi_usempi_ignore_tkr -lmpi_mpifh -lmpi
I'm not really sure what it tells me.