gcc-2.9x & gcc-3.3x peacfully coinciding?

[Kurt Wall]

Quoth Net Llama!:
> On Mon, 7 Jul 2003, Kurt Wall wrote:
> > Quoth Net Llama!:
> > > On Mon, 7 Jul 2003, Kurt Wall wrote:
> > > > > Is there any reason to keep the old version of gcc around, other than for
> > > > > the random stuff that still won't buld right on gcc-3.x?
> > > >
> > > > I'd keep it around until you're sure the new one works.
> > >
> > > Do you know of a list of stuff that is known not to build with gcc-3.x?
> >
> > The kernel doesn't usually build with 3.3. I'm not aware of anything
> > else, but I just started playing with it.
> 
> Does the kernel build with 3.2?  Is there anything that runs much
> faster/better when built with gcc-3.x?

I have build a grundle of kernels with 3.2.3 with no problem. I've
also grabbed a couple of choice patches from LKML that let the 
kernel take advantage of some of the new features. I haven't done
any benchmarking to compare kernels built with old and new versions
of GCC.

In general, the 3.2 compiler series was a almost strictly a a bug fix
series. An ABI change from 3.1.x forced the bump to 3.2, so the developers
made the decision to buckle down and retire a bunch of bugs (something like
350 bugs) and to spend time fixing noticeable slowdowns in the compiler
itself. 3.3, though, adds some new optimization techniques, beter C99
conformance, yadda yadda. It's too long to go into here and pretty darn
technical, which is one of the reasons the book exists.

Kurt
-- 
Loose bits sink chips.