[PATCH] D38566: [SimplifyCFG] don't sink common insts too soon (PR34603)

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

In https://reviews.llvm.org/D38566#911702, @spatel wrote:

> In https://reviews.llvm.org/D38566#911458, @hfinkel wrote:
>
> > In https://reviews.llvm.org/D38566#910739, @spatel wrote:
> >
> > >
> >
>
>
> I might be overcautious here, but as I wrote in the last comment, I'd like to at least try to manufacture a GVN test case to show that difference. Also, I was hoping to get this diff in independently to reduce the risk of revert from unintended consequences from changing behavior in the later simplifycfg instantiations. If you feel more confident, I can flip the parameter in more places (or invert the default setting) in this patch.


As evidence that my fear is not completely delusional, the preliminary patches for this change were recently reverted:
https://reviews.llvm.org/rL317444
...this even erased the commit that added the innocent bystander test case for this patch (sigh).


https://reviews.llvm.org/D38566