This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: RFA: patch for PR37397


On Wed, Nov 12, 2008 at 9:17 AM, Jeff Law <law@redhat.com> wrote:
> Vladimir Makarov wrote:
>>
>> This patch improves SPEC benchmarks.  I saw stable improvements on
>> x86/x86_64 and ppc.  This patch implements a small trick mentioned in one
>> classical article by Chaitin etc (Register allocation and spilling via graph
>> coloring).  There is no sense to spill pseudo in whose live range nothing is
>> dying because the spill will not make other allocnos colorable and
>> additional reloads for the corresponding pseudo will be generated in reload
>> pass for each insn it occurs.
>>
>> Is it ok to commit?
>
> OK.  Good find.
>

Hi Vladimir,

This caused 30% slowdown on 454.calculix in SPEC CPU 2006
with -O2 -ffast-math on Linux/Intel64.


-- 
H.J.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]