[gmx-users] Build fails with AVX2_256 on Intel Xeon CPU E5-2680 v3

[Koji Tanaka]

Hello Gromacs Community,

I'm trying to build Gromacs with SIMD=AVX2_256 support, but it fails.
Instead, if I pick AVX_256, the build will finish okay.

However, according to the documentation(
http://www.gromacs.org/Documentation/Installation_Instructions_5.0),
AVX2_256 is the right option for the Intel Xeon CPU E5-2680 v3 (Haswell).
Does anyone have the same problem?

My environment is;
- CentOS 6.7
- Gromacs 5.1.1
- OpenMPI 1.10.1

The error message is;
-------------------------------------------------------------------
CMake Error at cmake/gmxManageSimd.cmake:271 (message):
  Cannot find AVX2 compiler flag.  Use a newer compiler, or choose AVX SIMD
  (slower).
Call Stack (most recent call first):
  CMakeLists.txt:645 (gmx_manage_simd)


Also, I found the following error in build/CMakeFiles/CMakeError.log
-------------------------------------------------------------------
Run Build Command:/usr/bin/gmake "cmTryCompileExec1019102511/fast"
/usr/bin/gmake -f CMakeFiles/cmTryCompileExec1019102511.dir/build.make
CMakeFiles/cmTryCompileExec1019102511.dir/build
gmake[1]: Entering directory `/tmp/gromacs-5.1.1/build/CMakeFiles/CMakeTmp'
/usr/bin/cmake -E cmake_progress_report
/tmp/gromacs-5.1.1/build/CMakeFiles/CMakeTmp/CMakeFiles 1
Building C object CMakeFiles/cmTryCompileExec1019102511.dir/src.c.o
/opt/openmpi/1.10.1/bin/mpicc   -Wundef -Wextra
-Wno-missing-field-initializers -Wno-sign-compare -Wpointer-arith -Wall
-Wno-unused -Wunused-value -Wunused-p
arameter  -D_callconv___regcall   -o
CMakeFiles/cmTryCompileExec1019102511.dir/src.c.o   -c
/tmp/gromacs-5.1.1/build/CMakeFiles/CMakeTmp/src.c
/tmp/gromacs-5.1.1/build/CMakeFiles/CMakeTmp/src.c:1: error: expected ‘=’,
‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘f’
/tmp/gromacs-5.1.1/build/CMakeFiles/CMakeTmp/src.c: In function ‘main’:
/tmp/gromacs-5.1.1/build/CMakeFiles/CMakeTmp/src.c:1: warning: implicit
declaration of function ‘f’
gmake[1]: *** [CMakeFiles/cmTryCompileExec1019102511.dir/src.c.o] Error 1
gmake[1]: Leaving directory `/tmp/gromacs-5.1.1/build/CMakeFiles/CMakeTmp'
gmake: *** [cmTryCompileExec1019102511/fast] Error 2


Any comment/suggestion would be appreciated!

Thanks a lot,
Koji