[MUD-Dev] Naming and Directories?
Nathan F Yospe
yospe at hawaii.edu
Mon Mar 15 13:29:44 New Zealand Daylight Time 1999
On Mon, 15 Mar 1999, Ola Fosheim [iso-8859-1] Gr=F8stad wrote:
:Nathan F Yospe wrote:
:> of looking up words. My implementation was similar, except that I had an
:> extra level of switching when the wordbag got small... a bag that was at
:> least seven links full had the 26 branches, but the smaller ones had the
:> optimization of holding no empty links, and rapid-checking the links. In
:> testing, I'd found this became faster than the array-indexing at smaller
:> sizes, for some reason. I still haven't a clue as to why this would come
:> to be...
:You didn't happen to test this with a tight loop? If you did, then it
:most likely was caused by the the non-array implementation being held in
:the primary cache which is usually small (8K on a Pentium). Caches are
:very sensitive to non-continuous hits. This does of course not matter at
:all if the cache was wiped by some intermediate code anyway. Something I
:would expect to be the case for real life user-name lookups.
This was, IIRC, on a 1st generation PPC 601, no L2 cache, 16k primary, I
think. The test was a tight loop, and you may be entirely correct. There
should be better performance with the array indexing, and I was a little
puzzled by the results. I think I said elsewhere in the original that it
was probably a primary cache issue.
Nathan F. Yospe - Born in the year of the tiger, riding it forever after
University of Hawaii at Manoa, Dept of Physics, second year senior (joy)
(On Call) Associate Algorithm Developer, Textron Systems Corp, Maui Ops.
yospe#hawaii.edu http://www2.hawaii.edu/~yospe Non commercial email only
MUD-Dev maillist - MUD-Dev at kanga.nu
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