On Fri, 14 May 2010, Eliot Miranda wrote:

> On Fri, May 14, 2010 at 10:28 AM, Levente Uzonyi <leves at elte.hu> wrote:
>
>> On Fri, 14 May 2010, christophe.jalady at free.fr wrote:
>>
>>  Just print this two scripts:
>>>
>>> |s|
>>> s := WideString with: (Character value: 16r55E4).
>>> [100000 timesRepeat: [s hash]] timeToRun.
>>>
>>> |s|
>>> s := ByteString with: (Character value: 16rE4) with: (Character value:
>>> 16rE4)
>>> with: (Character value: 16rE4) with: (Character value: 16rE4).
>>> [100000 timesRepeat: [s hash]] timeToRun.
>>>
>>> I've seen that "ByteString>>stringHash:initialHash" use a primitive. Could
>>> we
>>> have such optimisation for WideString ?
>>>
>>
>> Sure. There are (at least) four ways to do it:
>> 1) Update the implementation of the primitive to support wordarrays. Then
>> build a vm with it and finally change the image side code. This would be the
>> best IMHO. Is there a reason why the primitive is not implemented this way?
>> 2) Use NativeBoost to write a primitive for this method. This is much
>> easier than building a vm/plugin, though you have to write the code in X86
>> assembly. This would be a cool demo for NativeBoost's primitive writing
>> capabilities. (Much better than the Fibonacci-number calculator. :))
>> 3) Use Exupery, I think it can optimize methods like this.
>> 4) Use the Cog VM. ;) (I wonder how fast this method is with Cog.)
>>
>
> 2.66GHz Intel Core i7 MacBook Pro (my new tool!!!!).  Current Cog, my 3.8
> derived work image:
>
> |s|
> s := WideString with: (Character value: 16r55E4).
> [100000 timesRepeat: [s hash]] timeToRun. 16
>
> |s|
> s := ByteString with: (Character value: 16rE4) with: (Character value:
> 16rE4)
> with: (Character value: 16rE4) with: (Character value: 16rE4).
> [100000 timesRepeat: [s hash]] timeToRun. 10
>
> |s|
> s := WideString with: (Character value: 16r55E4).
> [100000000 timesRepeat: [s hash]] timeToRun. 15725
>
> |s|
> s := ByteString with: (Character value: 16rE4) with: (Character value:
> 16rE4)
> with: (Character value: 16rE4) with: (Character value: 16rE4).
> [100000000 timesRepeat: [s hash]] timeToRun. 11078
>
>
> Current 4.1/Squeak 4.1.1beta2U.app:
> |s|
> s := WideString with: (Character value: 16r55E4).
> [100000 timesRepeat: [s hash]] timeToRun. 98
>
> |s|
> s := ByteString with: (Character value: 16rE4) with: (Character value:
> 16rE4)
> with: (Character value: 16rE4) with: (Character value: 16rE4).
> [100000 timesRepeat: [s hash]] timeToRun. 31
>
> |s|
> s := WideString with: (Character value: 16r55E4).
> [100000000 timesRepeat: [s hash]] timeToRun. 100660
>
> |s|
> s := ByteString with: (Character value: 16rE4) with: (Character value:
> 16rE4)
> with: (Character value: 16rE4) with: (Character value: 16rE4).
> [100000000 timesRepeat: [s hash]] timeToRun. 29476
>
> Current 4.1/current Cog
> |s|
> s := WideString with: (Character value: 16r55E4).
> [100000 timesRepeat: [s hash]] timeToRun. 14
>
> |s|
> s := ByteString with: (Character value: 16rE4) with: (Character value:
> 16rE4)
> with: (Character value: 16rE4) with: (Character value: 16rE4).
> [100000 timesRepeat: [s hash]] timeToRun. 10
>
> |s|
> s := WideString with: (Character value: 16r55E4).
> [100000000 timesRepeat: [s hash]] timeToRun. 14946
>
> |s|
> s := ByteString with: (Character value: 16rE4) with: (Character value:
> 16rE4)
> with: (Character value: 16rE4) with: (Character value: 16rE4).
> [100000000 timesRepeat: [s hash]] timeToRun. 10171
>
> So quite a bit faster :)

Thanks, it looks really nice. I wonder why are the results with 4.1 better 
than with your 3.8 derived image.


Levente

>
> best
> Eliot
>
>
>>
>> Levente
>>
>>
>>> Christophe.
>>>
>>>
>>>
>>
>