[gmx-users] avx2 with gcc 4.8.3

Harry Mark Greenblatt harry.greenblatt at weizmann.ac.il
Mon Dec 15 14:47:58 CET 2014


Dear All,

  While trying to run cmake under Centos 6.6 on a Haswell cpu for Gromacs 5.0.3 using gcc 4.8.3, cmake fails claiming the compiler doesn't support AVX2, but as far as I know it should...

Cannot find AVX2 compiler flag.  Use a newer compiler, or choose AVX SIMD

Some tests for AVX2 *do* succeed:

-- Try C compiler AVX2 flag = [-mavx2]
-- Performing Test C_FLAG_mavx2
-- Performing Test C_FLAG_mavx2 - Success
-- Try C++ compiler AVX2 flag = [-mavx2]
-- Performing Test CXX_FLAG_mavx2
-- Performing Test CXX_FLAG_mavx2 - Success

Using  -DGMX_SIMD=AVX_256 does solve the problem, but then I lose AVX2 acceleration.

I am using CUDA 6.5-19 (which was compiled with gcc 4.4.7, but that doesn't seem to be the issue).

Any advice?



Harry M. Greenblatt
Associate Staff Scientist
Dept of Structural Biology           harry.greenblatt at weizmann.ac.il<mailto:harry.greenblatt at weizmann.ac.il>
Weizmann Institute of Science        Phone:  972-8-934-3625
234 Herzl St.                        Facsimile:   972-8-934-4159
Rehovot, 76100

More information about the gromacs.org_gmx-users mailing list