Fw: GSoC topic: Implement hot cold splitting at GIMPLE IR level

[Aditya K]

As I understand the openmp outliner is also at the tree level. A region based outliner could be reused there. I’m not particular about the outliner being specific to ipa-split. A GSoC project can help us get the coding+testing done.  Any pass that needs a function splitting at tree level can reuse them.

-Aditya
________________________________
From: Jakub Jelinek <jakub@redhat.com>
Sent: Monday, March 16, 2020 5:19:16 PM
To: Aditya K <hiraditya@msn.com>
Cc: Jan Hubicka <hubicka@ucw.cz>; gcc@gcc.gnu.org <gcc@gcc.gnu.org>
Subject: Re: Fw: GSoC topic: Implement hot cold splitting at GIMPLE IR level

On Mon, Mar 16, 2020 at 11:11:14PM +0000, Aditya K via Gcc wrote:
> >
> > 2) ipa-split is very simplistic and only splits when there is no value
> >    computed in header of function used in the tail.  We should support
> >   adding extra parameters for values computed and do more general SESE
> >    outlining
> >  Note that we do SESE outlining for openMP but this code is not
> >  interfaced very generically to be easilly used by ipa-split.
>
> This sounds like a good GSoC project to work on. We could have a SESE/SEME based ipa-split, that
> could help with function splitting as well as openMP.

No, OpenMP region outlining needs to be done where it is done currently,
ipa-split is way too late for that.

        Jakub