[PATCH] D109296: [LV] Improve inclusivity of vectorization

Mon Sep 20 02:42:57 PDT 2021

ebrevnov added a comment.

In D109296#3002798 <https://reviews.llvm.org/D109296#3002798>, @lebedev.ri wrote:

> Hi @Ayal, @dorit!
> The road forward here isn't mapped, so i would *love* to hear some thoughts
> on the general direction of this patch, and on the steps needed to move this forward.
>
> There is a certain overlap with @ebrevnov's patches; while i'm obviously biased,
> i would say those changes would look more natural building ontop of this change.

I believe, these changes are quite independent. Well there are potential code conflicts (purely technical thing) and may be some cases when one affects the other but logically they are mostly orthogonal. Today cost model underestimates cost of vector version because it doesn't account for cost of RT checks and epilog loop. My patches try to fix that.  It should help stop doing "definitely" unprofitable vectorization. This patch (and original version of D75981 <https://reviews.llvm.org/D75981>) introduces/replaces heuristic which tries to limit potential overhead (btw, should we take probability info into account as well? ) when/if vector version is skipped due to failed runtime checks. At least this is how I see it.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D109296/new/

https://reviews.llvm.org/D109296