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Re: Make ipa-ref somewhat less stupid
- From: Jan Hubicka <hubicka at ucw dot cz>
- To: Martin Liška <mliska at suse dot cz>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Mon, 16 Jun 2014 10:01:47 +0200
- Subject: Re: Make ipa-ref somewhat less stupid
- Authentication-results: sourceware.org; auth=none
- References: <20140610063448 dot GA13424 at kam dot mff dot cuni dot cz> <539AF2A4 dot 7010006 at suse dot cz>
> On 06/10/2014 08:34 AM, Jan Hubicka wrote:
> >Hi,
> >ipa-reference is somewhat stupid and builds its data sets for all variables including
> >addressable and public one just to prune them out after all bitmaps are constructed.
> >This used to make sense when the profile generation happened at compile time, but
> >since ipa_ref datastructure was intrdocued this is a nonsense.
> >
> >Martin: It may be interesting to check if this solves the memory use issues with
> >chrome. We also may be able to re-enable ipa-ref with profile-generate as
> >I think all the datastructures are considered to have address taken.
>
> Hi,
> there is a link to chromium stats: https://drive.google.com/file/d/0B0pisUJ80pO1VmNHeklCRWVkOUU/edit?usp=sharing
>
> Both compilation were run with '-flto=6', where the upper graph adds '-fprofile-generate'. Memory footprint is IMHO acceptable, but compilation process takes twice longer with profile generation. Yeah, chromium contains a really big code base :)
Yep, I wonder why WPA takes so much longer. Do you think you can build lto1
with --enable-gather-detailed-mem-stats and relink with -fpre-ipa-mem-report
-fpost-ipa-mem-report -fmem-report -Q and send me the output? It would be nice
to push Chromium under 4GB of WPA :)
Thanks a lot!
Honza