This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: RFC: MIPS: Workaround the "daddi" and "daddiu" errata
- From: Eric Christopher <echristo at redhat dot com>
- To: "Maciej W. Rozycki" <macro at ds2 dot pg dot gda dot pl>
- Cc: Richard Sandiford <rsandifo at redhat dot com>, gcc-patches at gcc dot gnu dot org
- Date: Mon, 31 May 2004 12:19:31 -0700
- Subject: Re: RFC: MIPS: Workaround the "daddi" and "daddiu" errata
- References: <Pine.LNX.4.55.0403031531360.3561@jurand.ds.pg.gda.pl> <877jxyz19w.fsf@redhat.com> <Pine.LNX.4.55.0403180100020.14525@jurand.ds.pg.gda.pl> <871xnqvckt.fsf@redhat.com> <Pine.LNX.4.55.0405261524580.1025@jurand.ds.pg.gda.pl>
> > But this for me is the main example of why this goal seems wrong.
> > We know full well that stack pointer allocations can safely be done
> > with daddiu. Why double the number of instructions needed just so
> > that a simple grep will yield no matches?
>
> To make a user sure code will behave as specified in any circumstances.
> The subtlety of the errata makes one try to avoid hitting them as they may
> lead to data corruption that may long survive unnoticed.
> What do you think?
I'm still not a big fan of this patch either. It's a workaround for
hardware that hasn't been produced in years, is only available in
vintage machines, and the patch itself touches huge amounts of code.
What did SGI do for this? Do you know?
-eric
--
Eric Christopher <echristo@redhat.com>