[Boost-users] optimizing use of dynamic_bitset

From: Dave Steffen (dgsteffen_at_[hidden])
Date: 2007-06-14 12:36:18

Hi Folks,

Having gotten a big chunk of code to work, I'm now spending a few days
making it fast.  So far, I've removed enough overhead to drop our
runtime by a factor of 4, and a big part of that was replacing some
other data structures with dynamic_bitset.

Profiling data now indicates that one of the more expensive operations
is spending most of its time calling dynamic_bitset<>::test a
bajillion times.  My question is this: is dynamic_bitset::test
generally thought to be the fastest way to access a specific bit in a
dynamic_bitset?  Are there other ways to determine if bit n is set?  

(I assume that anything using dynamic_bitset::operator[] will be
slower, since it has to set up a proxy, but have not tested this.)

Any thoughts are appreciated.  Thanks!

-- 
Dave Steffen, Ph.D.                Disobey this command!
Software Engineer IV                 - Douglas Hofstadter
Numerica Corporation
dg_at_steffen a_at_t numerica d_at_ot us  (remove @'s to email me)