Re: GCC 4.2.0 Status Report (2007-05-11)

["Richard Guenther" <richard dot guenther at gmail dot com>]

On 5/14/07, Jason Merrill <jason@redhat.com> wrote:
> Mark Mitchell wrote:
>
> > I agree in principle -- much better the bugs we know than the ones we
> > don't.  But, IIUC, the patch we'd be reverting is from March, 2006,
> > which means that there's potentially a lot more that depends on it.  In
> > that sense, I don't even feel confident that reverting the change is a
> > conservative move, likely to lead to less optimal code, but not wrong
> > code.  Are you?  (That's a serious question; not a rhetorical one.)
>
> That's a fair question; I don't know anything about the patch or the bug
> it was intended to fix.  Richard would know better.

It was a patch to enable more optimization.  Reverting it should be as safe
or unsafe as exchanging forwprop and dce passes.  And I have no idea
as how to quantify safeness of either ;)

I'd say we better analyze what goes wrong (as the problem is possibly
latent on the mainline) and fix it properly.  If we paper over it we will not
fix it at all.

Richard.