Re: Ada updates frozen

[Mark Mitchell <mark at codesourcery dot com>]

On Sun, 2003-11-02 at 11:40, Zack Weinberg wrote:
> Geert Bosch <bosch@gnat.com> writes:
> 
> > On Nov 2, 2003, at 9:11 AM, Roger Sayle wrote:
> >> I think you are well within your rights to invoke the "patch reversion"
> >> rule and start the 48-hour clock ticking.  If x86/IA-64 bootstrap can't
> >> be restored on mainline by Tuesday the patches should be pulled, or the
> >> problematic aspects temporarily disabled.
> >
> > Given the significant problems this patch introduces, I would
> > appreciate it if Jan would revert this patch, until the regressions
> > are resolved.
> >
> > Richard Kenner already implemented the required changes for gigi
> > (the Ada front end/back end interface), but these are on hold now.
> > It will be a few days before the remaining front end work is
> > finished.
> 
> I am presently testing a patch which reverts GET_MODE_BITSIZE to its
> original meaning (i.e. GET_MODE_SIZE * BITS_PER_UNIT) and introduces
> a new macro GET_MODE_PRECISION which is used in a very few places
> (notably mode_for_size).  I think this should be an adequate bandage
> to restore Ada bootstrap so that work can go forward on the complete
> solution.  However, there are still some issues with the patch, so I
> cannot provide it just yet, but I intend to have them worked out by
> the end of the day.

I'm too far behind on email to understand what the reference to Jan's
patch is.  I do know about Zack's patch.  So, this email refers to
Zack's patch, but not Jan's patch.

I think that Zack's XFmode/TFmode patch is (a) the right thing, in
principle, and (b) has demonstrable benefit.

With respect to (a), the patch eliminates the weird design bug in GCC
that prevented the simultaneous use of 80-bit and 128-bit floating-point
modes.  With respect to (b), this change allowed us to support all of
the floating-point types on IA64 HP-UX, and also allowed us to improve
the code generated on IA64 HP-UX by, for example, inlining division. 
(That previously was allowed only on IA64 GNU/Linux, due to the problems
with floating-point modes.)

I do think that Zack (and, for that matter) CodeSourcery have an
obligation to solve the problems introduced by the patch.  I know that
Zack is working hard on that, and that is one of his present duties as a
CodeSourcery employee.

In general, as long as someone is continuing to work on fixing the
problems and as long as overall sentiment is that the patch is in
general a good thing, we've not reverted patches.  

I think that this problem will be solved relatively soon.

-- 
Mark Mitchell <mark@codesourcery.com>
CodeSourcery, LLC