[PATCH] D33587: [DAGCombine] Do several rounds of combine.

[Filipe Cabecinhas via Phabricator via llvm-commits]

filcab added a comment.

In https://reviews.llvm.org/D33587#765476, @deadalnix wrote:

> As for performance (I assume you meant compile time performance impact) here are the time I get for a test suite run:
>
> Without this patch:
>
>   real    2m41.665s
>   user    26m33.900s
>   sys     2m44.728s
>   
>
> With this patch:
>
>   real    2m42.729s
>   user    26m45.772s
>   sys     2m42.796s
>   
>
> It doesn't looks like the impact is that significant and it seems worth it to me.


I think for things like this, a run of llc on an LTO'd clang `.bc` would be better to show if there's a problem.

Thank you,
Filipe


https://reviews.llvm.org/D33587