[Octave-bug-tracker] [bug #58926] Octave gives wrong results with intel-mkl when diagonalizing large matrices

[anonymous]

Follow-up Comment #23, bug #58926 (project octave):

@John: Latest doc version attached incorporating your feedback.

I dug deeper into the question of how other programs achieve the correct
results with MKL. I cannot speak specifically for Scilab, but one way to get
correct results with MKL is apparently to use IOMP instead of GOMP throughout.
There was some discussion elsewhere [1] that using Clang/LLVM instead of GCC
can be used to make it link against IOMP instead of GOMP if that is what the
user wants. The consensus was that using GCC with "-fopenmp" automatically
goes to GOMP, and that using Clang to link it overrides the GOMP calls with
IOMP. Presumably someone who compiles Octave with Clang and uses IOMP instead
of GOMP throughout will get fully functional MKL, but there doesn't seem to be
any actual evidence yet one way or another. Since it was unproven, I left it
out of the Known Bugs section as a possible workaround. In any case it won't
help OP who is using a pre-compiled Octave 5.2.0 binary from the Ubuntu
repository.

[1]:
https://stackoverflow.com/questions/25986091/telling-gcc-to-not-link-libgomp-so-it-links-libiomp5-instead

(file #49654)
    _______________________________________________________

Additional Item Attachment:

File name: bugs.txi.diff                  Size:1 KB
    <https://file.savannah.gnu.org/file/bugs.txi.diff?file_id=49654>



    _______________________________________________________

Reply to this item at:

  <https://savannah.gnu.org/bugs/?58926>

_______________________________________________
  Message sent via Savannah
  https://savannah.gnu.org/