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Re: [RFC] Cse reducing performance of register allocation with -O2
- From: Jeff Law <law at redhat dot com>
- To: Vladimir Makarov <vmakarov at redhat dot com>, gcc at gcc dot gnu dot org, Dominik Vogt <vogt at linux dot vnet dot ibm dot com>
- Date: Thu, 22 Oct 2015 09:27:48 -0600
- Subject: Re: [RFC] Cse reducing performance of register allocation with -O2
- Authentication-results: sourceware.org; auth=none
- References: <20151013131230 dot GA30317 at linux dot vnet dot ibm dot com> <561D3A28 dot 9090407 at redhat dot com> <561D71A8 dot 5010300 at redhat dot com> <20151022100528 dot GA22729 at linux dot vnet dot ibm dot com> <5628FBD1 dot 7090801 at redhat dot com>
On 10/22/2015 09:08 AM, Vladimir Makarov wrote:
On 10/22/2015 06:05 AM, Dominik Vogt wrote:
On Tue, Oct 13, 2015 at 05:03:36PM -0400, Vladimir Makarov wrote:
I checked my article
and GVN gave mostly 0.2% on eon only. The current environment is
quite different (IRA, LRA) so the results might be different too.
Also as I remember I implemented GVN only for pseudos.
LRA also checks values too but again only for reload and original
Do you still have the branches you've tested back then? I'd
really like to try how this patch affects other targets (big
endian?). Gcc seems to do a better job optimising code for x86 in
some complicated situations, so the extra logic might pay off more
on other targets.
No, sorry. I can not find the code after 12 years since it was done. As
I remember that time we even used cvs and there was no branch for the
code. That time the the development practice was different. Even these
days results of most modern research articles in CS can not be
reproduced. If I did such research today, I'd definitely put these code
somewhere on github with detail instructions how to reproduce the results.
I don't even recall that work being on the Red Hat/Cygnus internal CVS repo.
But even if I found the code, I guess it would be easier to write it
from the scratch than make it working in the current environment.
Completely agree here.