[Bug tree-optimization/70729] Loop marked with omp simd pragma is not vectorized

[ienkovich at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70729

--- Comment #14 from Ilya Enkovich <ienkovich at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #13)
> (In reply to Yuri Rumyantsev from comment #12)
> > Created attachment 38367 [details]
> > modified patch
> 
> The loop->aux flagging looks redundant to me.  Why is ->safelen only valid
> before vectorization?  I suppose we're lucky that no pass before
> vectorization
> applies any unrolling (like predictive commoning for example) as such pass
> must adjust ->safelen accordingly.  But as LIM only cares for safelen > 0
> _this_ property shouldn't change, not even by vectorization, no?
> 

SIMD lane access is not invariant before vectorization but is invariant after
vectorization.  This means when GOMP_SIMD_LANE calls are removed we can't use
safelen for invariant moves anymore.