Re: [Boost-users] performance of dijkstra_shortest_paths

Subject: Re: [Boost-users] performance of dijkstra_shortest_paths
From: Thomas Klimpel (Thomas.Klimpel_at_[hidden])
Date: 2009-05-01 14:34:50

Bhaskara Marthi wrote:
> > Try building in release mode? The debugging instrumentation in the BGL can
> > kill performance.
>
> I'm compiling my source files with -O3 using gcc on ubuntu.
> That should be sufficient, right?

For release mode, NDEBUG must be defined. However, a superficial glance at the sources doesn't reveal any debugging instrumentation depending on NDEBUG. Andrew, is there any?

Another question for Andrew: Why was the relaxed heap replaced with a 4-ary heap? In my experience, a normal array based binary heap is a nightmare for the cache, and I wonder whether the 4-ary heap will be much better in this respect. However, I don't know whether the cache behavior of a relaxed heap is much better.

Regards,
Thomas