[Insight-developers] vxl update

[Hans Johnson]

First:  I am willing to loose this argument.  I just think it is important
that we think about the cons of supporting a wide range of compilers.

The default download of mingw is version 4.5 of the gcc compiler.  After
several minute of looking, I could not find the mingw 3 series.

===

I am concerned that the gcc3 compiler has several work a rounds that have
been propagated with the ITKv3 being mainly tuned for gcc3 compiler.

This still needs testing, but there is some anecdotal evidence form Brad
Lowekamp that the TEMPLATE_META_PROGRAMMING_LOOP_UNROLLING improves
performance on gcc3, but gcc4 (and any vectorizing compilers)  are
significantly better with the for loops.

===  What follows are my options
To me, the scariest part of making ITKv4 live for the next 10 years on it's
own without significant funding support, is the maintenance of the software.
Any way that we can minimize the maintenance support structure of ITKv4 now
will pay back dividends later (yes this is a developer concern, not an
end-user concern).  If we drive away developers because of the difficulty in
supporting too many compilers, we have shot ourselves in the foot.  I can
tell you that we have items that we would have contributed to ITKv3, but the
pain in getting it to work with the Borland compiler means that it is still
in our won private svn repository.