cvs commit: src/share/examples/etc make.conf

[David O'Brien]

On Sat, Jul 03, 2004 at 10:16:07PM -0700, Kris Kennaway wrote:
> On Sat, Jul 03, 2004 at 08:21:39PM -0700, David Schultz wrote:
> > FWIW, I've been compiling most things with -O2 for a while (to
> > find -O2 bugs, not for speed) and haven't noticed many problems.
> > The only significant one I know of is that -O2 breaks
> > floating-point exceptions in libm because gcc doesn't support the
> > FENV_ACCESS pragma.  I think for some routines like rint(3), it
> > may even give the wrong answer due to incorrect optimizations, but
> > I'd have to check that again.
> > 
> > AFAIK, the necessary functionality to make gcc's optimizer treat
> > floating-point code in a sane manner isn't on the horizon, so
> > maybe -O2 should be automatically turned off while compiling libm
> > (and perhaps libalias as well).  That would make it more
> > easily justifiable to make -O2 the default at some future point.
> 
> I don't think we can ever make it the default since there's likely to
> be a lot of software in ports that would be broken too.

99% of the ports that "may break" build with -O2 on Linux (as -O2 is
their default).  What is different about us vs. Linux for these ports?

-- 
-- David  (obrien at FreeBSD.org)