[PATCH] D90554: [CostModel] remove cost-kind predicate for intrinsics in basic TTI implementation

[Eric Christopher via llvm-commits]

On Fri, Nov 20, 2020 at 1:44 PM Mehdi AMINI via Phabricator <
reviews at reviews.llvm.org> wrote:

> mehdi_amini added a comment.
>
> In D90554#2408163 <https://reviews.llvm.org/D90554#2408163>, @spatel
> wrote:
>
> > So to clarify policy, we reverted patches when (1) a test based on an
> experimental intrinsic was crashing and (2) that crash is easily
> reproducible independent of this patch as shown here:
> > 7ae346434 <
> https://reviews.llvm.org/rG7ae346434a5f51b81ebaeeb50bd5d97666ee288b>
> >
> > I understand that we revert first and ask questions later, but should
> that be the rule for experimental code?
>
> In that case it seems like there was user-visible impact for some clang
> user according to @brooksmoses comment above? It isn't like an arbitrary
> Fuzzer was plugged to the system. IMO a revert is "low cost" and easy to
> re-land with a fix here, little downside to do this?
>

Appreciated for sure. I'm not sure how "experimental" we want to consider
the rounding math intrinsics at this point. It's an interesting question
and probably should be raised on llvm-dev. If it were something not user
visible or really experimental I probably wouldn't have reverted, but given
it's a fairly common use case for developers to use the option it seemed on
the "not really as experimental as it sounds" area. I think the intrinsics
themselves might be experimental in the "we could change these radically"
rather than "we don't really expect these to work".

-eric
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20201120/08baa4d1/attachment.html>