topic Re: Does libmkl_rt.so use avx2 instructions? in Intel® oneAPI Math Kernel Library

Does libmkl_rt.so use avx2 instructions?

User1578037094245524 — Tue, 30 Jun 2020 09:26:58 GMT

Hi,

I installed mkl_2020.1 on centos7 and linked my cpp file with libmkl_rt.so. The application runs as well.

My question is that does my application use avx2 to speed up? It seems that libmkl_avx2.so was not called because it runs as well even I delete file libmkl_avx2.so. I confirmed my cpu is support avx2 instruction.

Thanks!

Re: Does libmkl_rt.so use avx2 instructions?

Gennady_F_Intel — Tue, 30 Jun 2020 10:11:32 GMT

It has to work. Which routines are you calling?

Re: Does libmkl_rt.so use avx2 instructions?

User1578037094245524 — Mon, 06 Jul 2020 02:33:03 GMT

Thanks for your reply. I just write a simple code to test. You mean libmkl_rt.so only can works and needn't libmkl_avx2.so?

Re: Does libmkl_rt.so use avx2 instructions?

Gennady_F_Intel — Mon, 06 Jul 2020 03:11:09 GMT

Yes, linking with lmkl_rt would be enough to run your code on avx2 based system w/o explicit linking with lmkl_avx2. You may easier to check which code path has been called by setting MKL_VERBOSE env. variable and if your code calls BLAS, LAPACK, or FFT routines. All another part of MKL still doesn't support the verbose mode so far.

Re: Does libmkl_rt.so use avx2 instructions?

Gennady_F_Intel — Mon, 06 Jul 2020 03:21:28 GMT

You may take into account that using mkl singly dynamic library has some restrictions by using Intel LP64 and Intel threading only. You may find out more details into MKL User's Guide

Re: Does libmkl_rt.so use avx2 instructions?

User1578037094245524 — Mon, 06 Jul 2020 05:44:48 GMT

Thank you very much! It's clear to me now.