[Patch,optimization]: Optimized changes in the estimate register pressure cost.

[Bin.Cheng]

On Sun, Sep 27, 2015 at 11:13 PM, Ajit Kumar Agarwal
<ajit.kumar.agarwal@xilinx.com> wrote:
>
>
> -----Original Message-----
> From: Segher Boessenkool [mailto:segher@kernel.crashing.org]
> Sent: Sunday, September 27, 2015 7:49 PM
> To: Ajit Kumar Agarwal
> Cc: GCC Patches; Vinod Kathail; Shail Aditya Gupta; Vidhumouli Hunsigida; Nagaraju Mekala
> Subject: Re: [Patch,optimization]: Optimized changes in the estimate register pressure cost.
>
> On Sat, Sep 26, 2015 at 04:51:20AM +0000, Ajit Kumar Agarwal wrote:
>> SPEC CPU 2000 benchmarks are run and there is following impact on the
>> performance and code size.
>>
>> ratio with the optimization vs ratio without optimization for INT
>> benchmarks
>> (3807.632 vs 3804.661)
>>
>> ratio with the optimization vs ratio without optimization for FP
>> benchmarks ( 4668.743 vs 4778.741)
>
>>>Did you swap these?  You're saying FP got significantly worse?
>
> Sorry for the typo error.  Please find the corrected one.
>
> Ratio  with the optimization vs ratio without optimization for FP  benchmarks ( 4668.743 vs 4668.741). With the optimization
> FP is slightly better performance.
Did you mis-type the number again?  Or this must be noise.  Now I
remember why I didn't get perf improvement from this.  Changing
reg_new to reg_new + reg_old doesn't have big impact because it just
increased the starting number for each scenarios.  Maybe it still
makes sense for cases on the verge of exceeding target's available
register number.  I will try to collect benchmark data on ARM, but it
may take some time.

Thanks,
bin
>
> Thanks & Regards
> Ajit
>
> Segher