MiniOMP runtime library

Minimal implementation of the OpenMP runtime library, lightweight replacement of libgomp for Mingw-w64.
Good to use in libraries and small applications.

The original project page is here.

Advantages

• Small size with static linking
  It's ~150k less without linking with libpthread and libgomp in Mingw-w64.

• Supports Windows XP
  The latest version of Mingw-w64 is not, because of libpthread dependency, which needs GetTickCount64.

• Portable
  Although written to work with Mingw-w64, it also works on Linux using pthreads. Can be ported to different platforms.

• CLANG support
  You can link object files from GCC and CLANG together with the same library.

OpenMP features

Supported

• GCC compiler (GOMP_* interface)
• CLANG compiler (__kmpc_* interface)
• parallel
• for
• num_threads
• schedule(static) for CLANG
• schedule(dynamic)
• chunk-size
• loop with index decrement
• 32/64-bit loop index
• critical (unnamed only)
• barrier
• single
• sections for GCC
• reduction for CLANG (stub)
• master for CLANG
• features implemented by the compiler (inlined in object code)
  • atomic
  • schedule(static) with GCC
  • sections with CLANG
  • reduction with GCC
  • master with GCC

Unsupported

• for nowait
• for ordered
• schedule(runtime)
• named critical
• omp_lock_t, omp_init_lock(), omp_set_lock(), omp_unset_lock()
• OpenMP environment variables

And other rarely used features.

Limitations

• guided work same as dynamic

• the maximum number of threads is limited at compile time
  (MAX_THREADS define)

• always monotonic

• limited overflow checking for the loop indexes
  Can overflow with extreme chunk-size and increment values.

• you can run only one parallel block at a time
  Use locks if this situation can occur. This implementation uses static resources that are shared by all threads in the process. But for static linking, it is independent from other static linkages and different OpenMP runtime implementations.