calc: faster sums ...
michael.meeks at collabora.com
Thu Oct 29 07:21:19 PDT 2015
I'd love some input (if you have a minute) on the attached. The
punch-line is, that if we want to do really fast arithmetic, we start to
need to do some odd things; while I suspect that this piece of unrolling
can be done with the iterator - the next step I'm poking at (SSE3
assembler ;-) is not going to like that.
The win from this on a sum heavy sheet calculation is from 14.4s
seconds to recalculate to 9s (actually testing using the
'puncture_mdds_encap' approach ;-) - a 35%+ speedup.
I guess, what I'd most like is a:
'const double *getDoubles(size_t nAtOffset);
Or somesuch =) or, failing that - a chunked double iterator that would
give a pointer and size (reflecting the underlying chunks but giving
some freedom there).
Thoughts much appreciated =)
michael.meeks at collabora.com <><, Pseudo Engineer, itinerant idiot
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 4226 bytes
Desc: not available
More information about the LibreOffice