OpenMP: Introduction to OpenMP (Part 3)

How to Run OpenMP Programs on Different Operating Systems

macOS:

• The default compiler on macOS is Clang, which supports OpenMP since version 3.8.
• To compile an OpenMP program on macOS, you can use the following command in the Terminal:

  clang -Xpreprocessor -fopenmp -lomp your_program.c -o your_program

  Replace your_program.c with the filename of your OpenMP program and your_program with the desired output executable name.
• Here's an example of a simple OpenMP program that calculates the sum of elements in an array:

  
  #include <stdio.h>
  #include <omp.h>
  
  int main() {
    int sum = 0;
    int array[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
  
    #pragma omp parallel for reduction(+:sum)
    for (int i = 0; i < 10; i++) {
      sum += array[i];
    }
  
    printf("Sum: %d\n", sum);
  
    return 0;
  }
        

  Save the above code in a file named sum_parallel.c.
• To compile the program using Clang on macOS, run the following command in the Terminal:

  clang -Xpreprocessor -fopenmp -lomp sum_parallel.c -o sum_parallel

  This will generate an executable named sum_parallel.
• Run the compiled program:

  ./sum_parallel

Windows:

• On Windows, you can use compilers such as MinGW-w64 (with GCC) or Microsoft Visual C++ (MSVC) to compile OpenMP programs.
• With MinGW-w64 (GCC), you can use the following command to compile an OpenMP program:

  gcc -fopenmp your_program.c -o your_program

• With MSVC, you can use the /openmp flag to enable OpenMP support:

  cl /openmp your_program.c

• Replace your_program.c with the filename of your OpenMP program and your_program with the desired output executable name.

Linux:

• On Linux, you can use GCC or Clang as the compiler to run OpenMP programs.
• With GCC, use the following command to compile an OpenMP program:

  gcc -fopenmp your_program.c -o your_program

• With Clang, use the following command to compile an OpenMP program:

  clang -fopenmp your_program.c -o your_program

• Replace your_program.c with the filename of your OpenMP program and your_program with the desired output executable name.

By using the appropriate compiler and specifying the OpenMP flag, you can successfully compile and run OpenMP programs on different operating systems.

References:

• Clang - OpenMP Support: https://clang.llvm.org/docs/OpenMPSupport.html
• OpenMP API - macOS: https://www.openmp.org/resources/openmp-compilers-tools/openmp-compilers-tools-macos/