How to check the version of OpenMP on Linux

user_156458 0
Viewed 73960

I wonder how to check the version of OpenMP on a Linux remote machine?

I don't know where it is installed either.

openmp version gcc linux
7 Answers

You need to check your gcc version using

gcc --version

and then see the (incomplete) table below (whose info is gathered from this Wiki article and from this webpage from the OpenMP official website):

| gcc version | OpenMP version |    Languages    | Offloading |
|-------------|----------------|-----------------|------------|
|    4.2.0    |       2.5      |        C        |            |
|    4.4.0    |       3.0      |        C        |            |
|    4.7.0    |       3.1      |        C        |            |
|    4.9.0    |       4.0      |      C, C++     |            |
|    4.9.1    |       4.0      | C, C++, Fortran |            |
|      5      |                |                 |     Yes    |
|     6.1     |       4.5      |      C, C++     |            |

The blank entries are there because I didn't find the corresponding info.

user_39241180

First set environment variable OMP_DISPLAY_ENV: in bash: 

export  OMP_DISPLAY_ENV="TRUE"

or in csh-like shell:

setenv OMP_DISPLAY_ENV TRUE

Then compile and run your OpenMP program:

./a.out

There will be additional info, like : 

OPENMP DISPLAY ENVIRONMENT BEGIN
  _OPENMP = '201511'
  OMP_DYNAMIC = 'FALSE'
  OMP_NESTED = 'FALSE'
  OMP_NUM_THREADS = '8'
  OMP_SCHEDULE = 'DYNAMIC'
  OMP_PROC_BIND = 'FALSE'
  OMP_PLACES = ''
  OMP_STACKSIZE = '0'
  OMP_WAIT_POLICY = 'PASSIVE'
  OMP_THREAD_LIMIT = '4294967295'
  OMP_MAX_ACTIVE_LEVELS = '2147483647'
  OMP_CANCELLATION = 'FALSE'
  OMP_DEFAULT_DEVICE = '0'
  OMP_MAX_TASK_PRIORITY = '0'
OPENMP DISPLAY ENVIRONMENT END

where _OPENMP have the 8 decimal value yyyymm where yyyy and mm are the year and month designations of the version of the OpenMP API that the implementation supports.

user_22912480

OpenMP documentation improved a lot. You can find more information about supported OpenMP versions corresponding compilers from this link.

Coming to your question, as mentioned above first find the gcc compiler version and then refer the above link to know the corresponding OpenMP version.

Above link also has the supported OpenMP versions in the different compliers.

user_46153520

Actually, I think you can not get the version of openmp directly, but compiler will use a predefined macro _OPENMP to represent the release date of openmp, and you should specify the -fopenmp option to use this macro.

You can get the release date of openmp first using shell command like this

echo _OPENMP | gcc -fopenmp -E -x c - | tail -1

As for my gcc, it is

201511

Then you can check the openmp release history (https://www.openmp.org/news/press-releases/) to get the version. Of 201511, it means Nov 2015, and the version is openmp 4.5 .

The release history is below:

Date        Version
----------------------
Nov 2021    OpenMP 5.2
Nov 2020    OpenMP 5.1
Nov 2018    OpenMP 5.0
Nov 2015    OpenMP 4.5
Jul 2013    OpenMP 4.0
Jul 2011    OpenMP 3.1
May 2008    OpenMP 3.0
May 2005    OpenMP 2.5
Mar 2002    C/C++ 2.0
Nov 2000    Fortran 2.0
Nov 1999    Fortran 1.1
Oct 1998    C/C++ 1.0
Oct 1997    Fortran 1.0
user_187810470

This is a bit safer version of an answer by user2023370 above. Ancient OpenMP versions are omitted for brevity:

#include <map>
#include <fmt/format.h>
using namespace std;
...
fmt::print("OpenMP v{}\n", map<int, string>{{200805, "3.0"},{201107, "3.1"}, {201307, "4.0"}, {201511, "4.5"}, {201811, "5.0"}}[_OPENMP]);

If a new version number or corrupted one is encountered, this statement will not throw exception as opposed to using at() function member.

Version numbers are from https://github.com/jeffhammond/HPCInfo/blob/master/docs/Preprocessor-Macros.md.

user_2191530
Related