[DotGNU]Problems with Pnet certain GCC 3.4.1 optimization settings

[Marcus]

In the GCC 3.4.0 release, pnet would not build unless some patches from nb 
were applied. These patches slowed down executed significantly.

With the GCC 3.4.1 release, pnet compiles fine with conservative optimization 
settings. I've tried -O2 -march=athlon-tbird, and that works. However, 
tonight I experimented with more aggressive settings: -O3 -march=athlon-tbird 
-fomit-frame-pointer -mpreferred-stack-boundary=2. The -O3 and 
-fomit-frame-pointer optimizations are fairly common, although there is 
disagreement about their effect on performance. The 
-mpreferred-stack-boundary=2 was an experiment because in theory, Athlons 
might do better with a 2^2 stack boundary (keeping more code in the cache). 
(Interestingly, with GCJ, on one benchmark, that flag increased performance 
by a factor of 3.)

Anyway, the result was that pnet built, but when compiling pnetlib, cscc 
consistently consumed all available memory and effectively locked up my 
system.

I just wanted to mention that in case other users were using aggressive 
compiler optimizations.