On Fri, 14 May 2010, christophe.jalady@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.)

Levente

Christophe.