[Bug libgomp/96837] A false if clause in "omp parallel" seriously affects the performance

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96837

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
The standard describes in detail what parallel if (false) creates, and what the
various APIs should return for that.  It does create a parallel region, albeit
an inactive one.  So, e.g. for the question whether threadprivate needs to be
preserved between parallel regions with the same number of threads etc. if they
are nested in an explicit inactive parallel, the answer is no.