linking to MKL

[cantele]

Hi,

it's the third time I'm trying to post a message but when I go back to the forum I cannot find my message, I'm making some mistake but I cannot understand which.......could you please reply to this just to be sure that you were able to read it????

Well, I think that the "specific" names of the libraries should not be so important because they do depend on the library you ar using. I set:

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BLACS_LIBS="$MKL_PATH/libmkl_solver_lp64_sequential.a $MKL_PATH/libmkl_intel_lp64.a $MKL_PATH/libmkl_sequential.a $MKL_PATH/libmkl_core.a $MKL_PATH/libmkl_blacs_openmpi_lp64.a -lpthread"

and

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SCALAPACK_LIBS="$MKL_PATH/libmkl_scalapack_lp64.a"

because this is enough for MKL. In this case, as you can see, you must also call other libraries, that have nothing to do with blacs and scalapack, just to prevent from unresolved link to MKL calls!

Currently, the options for blas and lapack just do the same job, because they require the specification of the library and do not look for any specific name. For example, I successfully compiled the code using:

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--with-blas="-L$MKL_PATH -lmkl_intel_lp64 -lmkl_sequential -lmkl_core -lpthread"                                                                 \
--with-lapack="-L$MKL_PATH -lmkl_intel_lp64 -lmkl_sequential -lmkl_core -lpthread"  

Another strategy would be to use LIBS and LDFLAGS variables also, that means that I can specify LDFLAGS or LIBS="$MKL_PATH/libmkl_scalapack_lp64.a MKL_PATH/libmkl_solver_lp64_sequential.a $MKL_PATH/libmkl_intel_lp64.a $MKL_PATH/libmkl_sequential.a $MKL_PATH/libmkl_core.a $MKL_PATH/libmkl_blacs_openmpi_lp64.a -lpthread". If the options --with-blacs and/or --with-scalapack are not set, the configure might try to compile a dummy program containing a call to a routine of a given library like (this is an example for lapack)

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      program main
      call dgemm
      end

and then decide if that library is available or not depending on whether the link procedure found or not unresolved calls.

Giovanni

[myrta gruning]

Hallo Giovanni

your message is posted

m

[cantele]

maybe I never replied to this request (just browsing across my posts I found it!).

What I presently do also with the last 3.2.3-rev11 version is to modify by hand configure adding

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BLACS_LIBS="$MKL_PATH/libmkl_solver_lp64_sequential.a $MKL_PATH/libmkl_intel_lp64.a $MKL_PATH/libmkl_sequential.a $MKL_PATH/libmkl_core.a $MKL_PATH/libmkl_blacs_openmpi_lp64.a -lpthread"

immediately after

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# { $as_echo "$as_me:$LINENO: checking the BLACS library" >&5
$as_echo_n "checking the BLACS library... " >&6; }
 cinit_lib=`find $with_blacs -name '*blacsCinit*.a'`
 blacs_lib=`find $with_blacs -name '*blacs.a'`
 if ! test "$cinit_lib" = "" && ! test "$blacs_lib" = "" ; then
   BLACS_LIBS="$cinit_lib $blacs_lib"
   { $as_echo "$as_me:$LINENO: result: yes" >&5
$as_echo "yes" >&6; }
 else
   { $as_echo "$as_me:$LINENO: result: no" >&5
$as_echo "no" >&6; }
 fi

and

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SCALAPACK_LIBS="$MKL_PATH/libmkl_scalapack_lp64.a"

just after

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#
# then SLPK if BLACS has been found
#
  { $as_echo "$as_me:$LINENO: checking the SCALAPACK library" >&5
$as_echo_n "checking the SCALAPACK library... " >&6; }
  SCALAPACK_LIBS=`find $with_scalapack -name '*scalapack.a'`
  if ! test "$SCALAPACK_LIBS" = "" ; then
   enable_scalapack="yes"
   { $as_echo "$as_me:$LINENO: result: yes" >&5
$as_echo "yes" >&6; }
  else
   BLACS_LIBS=""
   enable_scalapack="no"
   { $as_echo "$as_me:$LINENO: result: no" >&5
$as_echo "no" >&6; }
  fi
 fi
fi

As you may see, the present configure just searches for SPECIFIC library names, just preventing from accepting libraries with non-standard names.

What should be done, in my opinion, is that the --with-blacs and --with-scalapack configure options should be set (if specified) to the set of needed libraries
(e.g. --with-blacs="BLACS_LIBS="$MKL_PATH/libmkl_solver_lp64_sequential.a $MKL_PATH/libmkl_intel_lp64.a $MKL_PATH/libmkl_sequential.a $MKL_PATH/libmkl_core.a $MKL_PATH/libmkl_blacs_openmpi_lp64.a -lpthread") instead of (as it is at the moment) to the path of the library directory. The configure should then enable BLACS/SCALAPACK provided the --with-blacs/--with-scalapack options are given in input (so just set BLACS_LIBS="$with_blacs" if $with_blacs is not empty). A more complete code would try to compile a dummy code containing a call to BLACS using BLACS_LIBS to link.

[myrta gruning]

Thanks Giovanni,

I hope to have the time to look into that.

m

[cantele]

Thanks Giovanni,

I hope to have the time to look into that.

m

No problem! I just (re)posted to share my experience with the latest version I compiled few weeks ago!

Thanks,

Giovanni