I have downloaded openMP using cygwin which i use as compiler in CLION.
I have included
#include <omp.h>
and used its schemas e.g
#pragma omp paraller
#pragma omp single
however when i use omp_get_max_threads() it throws
undefined reference to `omp_get_max_threads'
error, i tried to add compiler arguments:
But the error remains the same. Is there a way how to fix this? Thanks for help.
I'm not a user of CLION, but are the Program arguments really the arguments for the compiler for your compiled code?
Usually, when compiling an OpenMP source file, the -fopenmp flag need to be added to both the compiler and linker. So, for instance:
gcc -fopenmp -c foo.c -o foo.o
gcc -fopenmp -c bar.c -o bar.o
gcc -fopenmp -o app.exe foo.o bar.o
Or if you comoile and link using just one source file:
gcc -fopenmp -c fooc -o app.exe
PS: There's a typo, it should be #pragma omp parallel instead of #pragma omp paraller.
CLion uses CMake as a build system, OpenMP support was drastically improved in CMake 3.9+. Now, you need to configure your CMakeLists.txt file as follow:
For example, consider the example code below.
#include <iostream>
#include <omp.h>
int main()
{
#pragma omp parallel num_threads(3)
{
int id = omp_get_thread_num();
std::cout << "Greetings from process " << id << std::endl;
}
std::cout << "parallel for ends " << std::endl;
return EXIT_SUCCESS;
}
The CMakeLists.txt file will be like :
cmake_minimum_required(VERSION 3.9)
project(openmp_test) # you can change the project name
find_package(OpenMP)
add_executable(openmp_para_test main.cpp)
if(OpenMP_CXX_FOUND)
target_link_libraries(openmp_para_test PUBLIC OpenMP::OpenMP_CXX)
endif()
If you are not familiar with CMake, Here a quick CMake tutorial to use with CLion.
