Re: [PATCH] Enhance reload_cse_move2add

[Jie Zhang <jie at codesourcery dot com>]

On 07/13/2010 12:37 AM, Jeff Law wrote:
> On 06/30/10 01:45, Jie Zhang wrote:
> > Currently reload_cse_move2add can transform
> >
> > (set (REGX) (CONST_INT A))
> > ...
> > (set (REGX) (CONST_INT B))
> >
> > to
> >
> > (set (REGX) (CONST_INT A))
> > ...
> > (set (REGX) (plus (REGX) (CONST_INT B-A)))
> >
> > This patch enhances it to be able to transform
> >
> > (set (REGX) (CONST (PLUS (SYMBOL_REF) (CONST_INT A))))
> > ...
> > (set (REGY) (CONST (PLUS (SYMBOL_REF) (CONST_INT B))))
> >
> > to
> >
> > (set (REGX) (CONST (PLUS (SYMBOL_REF) (CONST_INT A))))
> > ...
> > (set (REGY) (CONST (PLUS (REGX) (CONST_INT B-A))))
> >
> >
> > Benchmarking using EEMBC on ARM Cortex-A8 shows performance
> > improvement on one test:
> >
> > idctrn01: 6%
> >
> > No meaningful changes on other tests.
> >
> > Benchmarking using SPEC2000 on AMD Athlon64 X2 3800+ shows 0.4%
> > regression on CINT2000 and 0.1% improvement on CFP2000.
> >
> > Bootstrapped and regression tested on x86_64.
> >
> > Is it OK?
> Thanks for your patience, particularly when my requests for additional
> data. I think we're OK with the benchmarking #s, particularly looking at
> the amount of noise in the runs we're seeing for x86_64.
>
> Appoved,
Jeff,

Thanks! I learned a lot during the procedure.

On 07/10/2010 08:06 AM, Bernd Schmidt wrote:
> So what kinds of changes are there that would explain a 1.48% drop on
> 179.art?  If you can verify that the code is in fact identical, and the
> performance change is noise, the patch is ok.
>
Bernd,

I didn't realize it was a conditional approval until I asked you 
privately. Thanks!


I have committed it on trunk.


Regards,
--
Jie Zhang
CodeSourcery