Introduction

OpenMP (Open Multi-Processing) is an API (Application Programming Interface) that makes it easier to write programs that can run on multiple processors or cores. It's designed for shared-memory parallel programming, meaning all the processors can access the same memory. OpenMP is supported for C, C++, and Fortran.

Install on CodeBlocks

1. Download and install Codeblocks and choose the default GNU GCC compiler.
2. Open "Compiler and debugger settings", put -fopenmp in "other options", and -lgomp -pthread in "Other linker options".
3. Add C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\bin to "Compiler and debugger settings" -> "Toolchain Executables" -> Additional Paths ->Add.

Verify

Copy this simple code snippet and compile to see the OpenMP version.

#include <stdio.h>
#include <omp.h>

int main() {
    // Check whether OpenMP is installed and get the OpenMP version
    printf("OpenMP version: %d\n", _OPENMP);
    return 0;
}

Versions are as follows.

• OpenMP 2.0: _OPENMP is defined as 200203
• OpenMP 2.5: _OPENMP is defined as 200505
• OpenMP 3.0: _OPENMP is defined as 200805
• OpenMP 4.0: _OPENMP is defined as 201307
• OpenMP 4.5: _OPENMP is defined as 201511
• OpenMP 5.0: _OPENMP is defined as 201811
• OpenMP 5.1: _OPENMP is defined as 202011