# AOCL (not MKL) acceleration on AMD Ryzen CPU's

**URL:** https://discourse.julialang.org/t/aocl-not-mkl-acceleration-on-amd-ryzen-cpus/112890
**Category:** Performance
**Tags:** blas, linearalgebra, lapack, svd
**Created:** [April 12, 2024, 9:50pm UTC](https://discourse.julialang.org/t/aocl-not-mkl-acceleration-on-amd-ryzen-cpus/112890 "2024-04-12T21:50:51Z")
**Posts on this page:** 1
**Showing post:** 5

<div class="post-metadata">

### Author: ![aasdelat](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/aasdelat/32/45268_2.png) [@aasdelat](https://discourse.julialang.org/u/aasdelat)
#### Post date: [April 13, 2024, 4:23pm UTC](https://discourse.julialang.org/t/aocl-not-mkl-acceleration-on-amd-ryzen-cpus/112890/5 "2024-04-13T16:23:45Z")

</div>

Thank you, @Elrod .  
First of all, an internet search on `dnrm2`, leads to some pages where `dnrm2` is described as:

```julia
 *> DNRM2 returns the euclidean norm of a vector via the function
   27 *> name, so that
   28 *>
   29 *> DNRM2 := sqrt( x'*x )

```

And it is [part of the LAPACK, but in the BLAS library.](https://netlib.org/lapack/explore-html-3.6.1/da/d7f/dnrm2_8f_source.html)

Inspecting the `libflame.so` as suggested:

```julia
$ nm -D libflame.so | grep dnrm2
00000000002a73f0 T bl1_dnrm2
                 U dnrm2_

```

According to the [`nm` doumentation](https://linux.die.net/man/1/nm), `U` means “The symbol is undefined”, what, in turn, I think, means that the code for that function is not in `libflame.so`. This is what I expected, if dnrm2 is in BLAS. So, I inspected the `libblis.so` (single thread) and `libblis-mt.so` (multi threaded) libraries, and got:

```julia
$ nm -D libblis.so | grep dnrm2_
0000000000930100 T dnrm2_
0000000000930090 T dnrm2_blis_impl

```

and

```julia
$ nm -D libblis-mt.so | grep dnrm2
000000000094a7d0 T cblas_dnrm2
00000000009a9fb0 T dnrm2
000000000092dd70 T dnrm2_
000000000092dd00 T dnrm2_blis_impl
00000000009ab780 T dnrm2sub
0000000000944aa0 T dnrm2sub_
0000000000944a90 T dnrm2sub_blis_impl

```

respectively. According to the [`nm` doumentation](https://linux.die.net/man/1/nm), “T” or “t” means: “The symbol is in the text (code) section.”

So it exists, but not in `libflame.so`, but in `libblis.so` and `libblis-mt.so`. So, I have to link to any of these libraries (well I am interested int he multi threaded one).

As suggested in the [suggested thread](https://discourse.julialang.org/t/calling-code-from-a-library-so-works-on-one-system-fails-on-another/904/3), I have tested my `LD_LIBRARY_PATH`, getting:

```julia
/opt/AMD/aocl/aocl-linux-aocc-4.2.0/aocc/lib:/opt/AMD/aocc-compiler-4.2.0/ompd:/opt/AMD/aocc-compiler-4.2.0/lib:/opt/AMD/aocc-compiler-4.2.0/lib32:/usr/lib/x86_64-linux-gnu:/usr/lib64:/usr/lib32:/usr/lib

```

Going to the first listed directory:

```julia
$ ls
cmake libblis-mt.so libfftw3l_mpi.la libfftw3q_omp.so.3
libalcp.a libblis-mt.so.4 libfftw3l_mpi.so libfftw3q_omp.so.3.6.10
libalcp.so libblis-mt.so.4.2.0 libfftw3l_mpi.so.3 libfftw3q.so
libalm.a libblis.so libfftw3l_mpi.so.3.6.10 libfftw3q.so.3
libalmfast.a libblis.so.4 libfftw3l_omp.a libfftw3q.so.3.6.10
libalmfast.so libblis.so.4.2.0 libfftw3l_omp.la libfftw3.so
libalm.so libbz2.so libfftw3l_omp.so libfftw3.so.3
libamdlibm.a libfftw3.a libfftw3l_omp.so.3 libfftw3.so.3.6.10
libamdlibmfast.a libfftw3f.a libfftw3l_omp.so.3.6.10 libflame.a
libamdlibmfast.so libfftw3f.la libfftw3l.so libflame.so
libamdlibm.so libfftw3f_mpi.a libfftw3l.so.3 libipp-compat.so
libamdsecrng.a libfftw3f_mpi.la libfftw3l.so.3.6.10 liblz4.so
libamdsecrng.so libfftw3f_mpi.so libfftw3_mpi.a liblzma.so
libamdsecrng.so.4.2 libfftw3f_mpi.so.3 libfftw3_mpi.la libopenssl-compat.so
libamdsecrng.so.4.2.0 libfftw3f_mpi.so.3.6.10 libfftw3_mpi.so librng_amd.a
libaocl_compression.a libfftw3f_omp.a libfftw3_mpi.so.3 librng_amd.so
libaocl_compression.so libfftw3f_omp.la libfftw3_mpi.so.3.6.10 librng_amd.so.4.2
libaocl-libmem.a libfftw3f_omp.so libfftw3_omp.a librng_amd.so.4.2.0
libaocl-libmem.so libfftw3f_omp.so.3 libfftw3_omp.la libscalapack.a
libaocl-libmem.so.4.2.0 libfftw3f_omp.so.3.6.10 libfftw3_omp.so libscalapack.so
libaoclsparse.a libfftw3f.so libfftw3_omp.so.3 libsnappy.so
libaoclsparse.so libfftw3f.so.3 libfftw3_omp.so.3.6.10 libz.so
libaoclsparse.so.4.2.0.0 libfftw3f.so.3.6.10 libfftw3q.a libzstd.so
libaoclutils.a libfftw3.la libfftw3q.la pkgconfig
libaoclutils.so libfftw3l.a libfftw3q_omp.a
libblis.a libfftw3l.la libfftw3q_omp.la
libblis-mt.a libfftw3l_mpi.a libfftw3q_omp.so

```

We can see `libblis.so` and `libblis-mt.so`, so the `LD_LIBRARY_PATH` is correct.

I addition, lets see if `libflame.so` knows where libblis is:

```julia
$ ldd libflame.so 
	linux-vdso.so.1 (0x00007ffd9d4eb000)
	libaoclutils.so => /opt/AMD/aocl/aocl-linux-aocc-4.2.0/aocc/lib/libaoclutils.so (0x0000737c0e67c000)
	libomp.so => /opt/AMD/aocc-compiler-4.2.0/lib/libomp.so (0x0000737c0d200000)
	libpthread.so.0 => /usr/lib/x86_64-linux-gnu/libpthread.so.0 (0x0000737c0e677000)
	libc.so.6 => /usr/lib/x86_64-linux-gnu/libc.so.6 (0x0000737c0ce00000)
	/lib64/ld-linux-x86-64.so.2 (0x0000737c0e688000)
	libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x0000737c0ca00000)
	libm.so.6 => /usr/lib/x86_64-linux-gnu/libm.so.6 (0x0000737c0d519000)
	libgcc_s.so.1 => /usr/lib/x86_64-linux-gnu/libgcc_s.so.1 (0x0000737c0e655000)
	librt.so.1 => /usr/lib/x86_64-linux-gnu/librt.so.1 (0x0000737c0e650000)
	libdl.so.2 => /usr/lib/x86_64-linux-gnu/libdl.so.2 (0x0000737c0e64b000)

```

There are not unresolved directions, but it does not show any dependency on `libblis.so` or `libblis-mt.so` (well, my understanding on ldd is not precisely expert, but I think this is the interpretation).

So, the last option, I think, is to explicitly link the `libblis-mt.so`. According to the [AOCL documentation](https://www.amd.com/content/dam/amd/en/documents/developer/version-4-2-documents/aocl/aocl-4-2-user-guide.pdf):

> To use AOCL-LAPACK in your application, link with AOCL-LAPACK, AOCL-BLAS, and AOCL-Utils libraries while building the application.
> 
> AOCL-Utils library has libstdc++ library dependency. As AOCL-LAPACK is dependent on AOCL-Utils, applications must link with libstdc++(-lstdc++) as well.

But, How do I link to several shared libraries in Julia? Is there a way to do this with `ccall` or do I have to make weird compilation or pre-compilation things?

---

_[View the full topic](https://discourse.julialang.org/t/aocl-not-mkl-acceleration-on-amd-ryzen-cpus/112890)._