Re: gcc/libm floating-point bug?

On Wednesday 21 May 2003 09:10 pm, David O'Brien wrote:
> On Tue, May 20, 2003 at 03:12:27PM -0400, Jon Lido wrote:
> > Yes, this was the problem.  I rebuilt world with -march=pentium3 and that
> > did the trick.
>
> Honest question of you -- I'll assume you're subscribed to
> freebsd-current_at_.  How have you missed all the warnings from myself and
> others not to trust the -march=pentium4 optimizations?  I honestly want
> to know so we can figure out a better way of getting the word out.

I missed it in the volume of email on freebsd-current.  When I started using 
-current almost two weeks ago now, I browsed about a month's worth of the 
mailing list archives.

I searched on gcc and libm in the list archives, but I didn't really connect 
the rambling discussions with the problem I was seeing.  I admit that, in 
hindsight, it should have been pretty obvious.

> > I'm not sure how CPUTYPE gets handled, but perhaps p4 should expand to
> > -march=pentium3, if possible.
>
> I feel some will screem if we take away the ability to use
> -march=pentium4 in places they know for sure will work.  Unix is about
> mechanisms, not policy.

Well, we've got a compiler here with a broken mechanism.  Deciding whether or 
not to act on it sounds like a policy decision to me.  I just hope 5.1 
doesn't get shipped with such an easy way to break stuff.

-Jon