[PATCH] D40480: MemorySSA backed Dead Store Elimination.

[Bryant Wong via llvm-commits]

Hi Florian,

> I'd also like to lift the post-domination requirement for cases where we
can prove that an overriding store on all paths to the exit/other reads.

Could you provide an example of what this means? It's unclear to me.

Bryant

On Fri, Dec 6, 2019, 5:43 AM Florian Hahn via Phabricator <
reviews at reviews.llvm.org> wrote:

> fhahn added a comment.
> Herald added a subscriber: asbirlea.
> Herald added a project: LLVM.
>
> Hi!
>
> I would be interested giving dead store elimination using MemorySSA
> another push. We've hit plenty DSE limitations especially together with
> `-ftrivial-auto-var-init` and I think modernizing DSE to use MemorySSA will
> help us to improve the situation.
>
> @rnk, @dmgreen are you still interested in pushing for DSE + MSSA?
> Otherwise I would be happy to look into that. I think this patch is a great
> foundation and I think it be possible to break it up into a few distinct
> parts, starting with just replacing completely overwritten stores and
> adding additional cases as follow ups. I also have a few potential
> simplifications in mind I'd like to try. I rebased the patch and I tried to
> build SPEC2006/MultiSource tests, but it does not get very far without
> crashing. Again, my main goal would be to break it up into more manageable
> pieces :)
>
> Looking a bit further ahead, I'd also like to lift the post-domination
> requirement for cases where we can prove that an overriding store on all
> paths to the exit/other reads.
>
> Please let me know what you think!
>
>
> CHANGES SINCE LAST ACTION
>   https://reviews.llvm.org/D40480/new/
>
> https://reviews.llvm.org/D40480
>
>
>
>
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