7.1) OpenMP

OpenMP is the standard for shared memory programming, and is supported by the compilers installed on ARC2. It provides a standard set of directives, run time library routines and environment variables to enable parallelising code under a shared memory model.

There are a number of advantages to using OpenMP:

• Can parallelise existing code incrementally
• Provide a relatively simple set of directives
• Works on shared data, so do not need to manage communications

There are also some disadvantages, such as:

• Requires and is restricted to shared memory machines
• Programmer needs to specify what data is shared between different processes and what should be private to each process
• Shared data, means can get contention for data