[PATCH] D109958: [LoopFlatten] Enable it by default

Fri Sep 17 05:54:40 PDT 2021

SjoerdMeijer added a comment.

In D109958#3006066 <https://reviews.llvm.org/D109958#3006066>, @lebedev.ri wrote:

> Nice! I think this is a good thing.
>
> I have checked this on some code i care about and as far as i can tell
> it pretty much always fails with `Loop::isCanonical()`, e.g. because
> the loops produced by OpenMP lowering are non-canonical by definition.
> This is probably not a blocker, but it does mean that the true impact
> of this change (aka, does it regress cases and require costmodel tuning?)
> will not be apparent until later.

Yeah, by design it is fairly specific in the cases it supports (but still triggers a lot). For example, PR40581 <https://bugs.llvm.org/show_bug.cgi?id=40581> is about a case we don't know yet support. If you have a different case, I would be happy if you can raise a PR, then I can have a look after this lands.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D109958/new/

https://reviews.llvm.org/D109958