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Re: PDD 2, vtables

From:
Tim Bunce
Date:
February 12, 2001 05:01
Subject:
Re: PDD 2, vtables
Message ID:
20010212111624.H25707@ig.co.uk
On Fri, Feb 09, 2001 at 04:15:42PM -0500, Dan Sugalski wrote:
> 
> >On the other side, for a string that is matched against regexps, it doesn't
> >matter much if it has variable character length, since regexps normally read
> >all the string anyway, and indexing characters isn't much of a concern.
> 
> You underestimate the impact of variable-length data, I think. Regexes 
> should go rather faster on fixed-length than variable length data. How much 
> so depends on your processor. (I can guarantee that Alphas will run a 
> darned sight faster on UTF-32 than UTF-8...)

Umm, don't cpu data cache size issues complicate that? What if the ~4x
bigger UTF-32 string doesn't fit in the cache but the UTF-8 one does?
(I'm obviously simplifying somewhere here, but you get the idea.)

Tim.

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