[PATCH] D29092: PR31729: [GVNHoist] Don't hoist unsafe scalars at -Oz

[Hans Wennborg via Phabricator via llvm-commits]

hans added a comment.

In https://reviews.llvm.org/D29092#688923, @hiraditya wrote:

> In https://reviews.llvm.org/D29092#688816, @majnemer wrote:
>
> > In https://reviews.llvm.org/D29092#687515, @hans wrote:
> >
> > > Looks good to me.
> > >
> > > David, what do you think?
> >
> >
> > I think we should also remove the OptForMinSize check in hostExpressions.
>
>
> If you can explain why then I may be able to show why it is safe to do so.
>  Thanks,


I hadn't seen that check before, but I agree with David that it looks scary.

What is the check doing anyway? It sounds like we don't think it's safe to hoist this kind of instruction; why is it safe to hoist past it, and what has OptForMinSize got to do with it?


https://reviews.llvm.org/D29092