String compare performance

[Jonathan M Davis]

On Saturday 27 November 2010 22:13:39 Austin Hastings wrote:
> On 11/27/2010 11:53 AM, bearophile wrote:
> > While translating a common Python script to D, I have found something
> > interesting, so I have reduced it to a little benchmark.
> > 
> > Below there is the reduced Python2 code (it uses Psyco), and a little
> > program to generate some test data. The timing of the first D2 version
> > is not good compared to the Python-Psyco program (the generation of the
> > *300 array is a quick thing), so I have created two more D2 versions to
> > show myself that D2 wasn't broken :-)
> > 
> > The reduced code looks like a syntetic benchmark, but it has about the
> > same performance profile of a 60 lines long Python script (the original
> > code was using xrange(0,len(...)-3,3)  instead of xrange(len(...)-3),
> > but the situation doesn't change much).
> 
> It's not clear to me if the point of your post is "how do I make this go
> faster?" or "Waa! D underperforms Python by default".


What I think is pretty clear from this is that at some point, some work needs to 
be done to optimize array comparisons when memcmp can be used instead of having 
to call the individual opEquals() of each element. It's not the sort of thing 
that's likely to be a priority, but it really should be done at some point.

- Jonathan M Davis