Programming in Cilk

OpenCilk makes it easy to parallelize an existing serial C or C++ program.

1. Modify the source file to include the cilk/cilk.h header file.

2. Expose logical parallelism within the program using Cilk’s three keywords: cilk_spawn, cilk_sync and cilk_for.

3. Compile the program using the OpenCilk compiler by passing the extra compiler flag -fopencilk.

4. Run the resulting binary.

We also recommend the following best practices for Cilk programming.

1. Use Cilksan to check that your Cilk program is free from unintended races.

2. Use Cilkscale to measure your program’s parallel scalability and zero-in on scalability bottlenecks.