[Bug target/57796] AVX2 gather vectorization: code bloat and reduction of performance

[ysrumyan at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57796

--- Comment #4 from Yuri Rumyantsev <ysrumyan at gmail dot com> ---
(In reply to Jakub Jelinek from comment #3)
> By tuning I've meant the vectorizer cost model.  If the desirability of
> gathers vs. no vectorization at all doesn't depend only on the insns in the
> loop, but also on how many iterations the loop has, then perhaps we'd need
> to runtime version it or something.

Jakub,

We have runtime versioning but for original bench vectorized version of loop is
 selected to execute, but if we change lower bound to 0 (as I did) scalar
version of loop is run.