Skimming the VxWorks Applications Programmer's Guide shows that pthreads are supported, but no mention of OpenMP. An older thread on the Wind River forum also suggests that the OMP flag is disabled by default in the VxWorks gcc compiler. At this point it seems pretty clear that OpenMP isn't supported, but does anyone know if this has changed in recent years? And are pthreads the only way to implement multithreading in VxWorks?
Upon further review, it seems that VxWorks does not support OpenMP by default, although some finagling will allow you to enable the -libgomp flag after recompiling the gcc compiler (can't guarantee support from Wind River though). The platform I'm using, VxWorks 653, provides pthread (and other POSIX) APIs through vThreads, the multithreading VxWorks partition OS. vThreads itself provides multithreading capabilities and has its own set of libraries. I haven't been able to find any comprehensive API documentation on vThreads unfortunately. This may differ for other VxWorks platforms.
Consider this question answered.