This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
RE: [RFC] Add middle end hook for stack red zone size
- From: "Jiangning Liu" <jiangning dot liu at arm dot com>
- To: "'Jakub Jelinek'" <jakub at redhat dot com>
- Cc: "'Joern Rennecke'" <amylaar at spamcop dot net>, <gcc at gcc dot gnu dot org>, <gcc-patches at gcc dot gnu dot org>, <vmakarov at redhat dot com>, <dje dot gcc at gmail dot com>, "Richard Henderson" <rth at redhat dot com>, "Ramana Radhakrishnan" <Ramana dot Radhakrishnan at arm dot com>, "'Ramana Radhakrishnan'" <ramana dot radhakrishnan at linaro dot org>
- Date: Mon, 1 Aug 2011 18:14:27 +0800
- Subject: RE: [RFC] Add middle end hook for stack red zone size
- References: <4e255312.0a852b0a.528d.6933SMTPIN_ADDED@mx.google.com> <CACUk7=WsaUN+TUw7rb8-o1EukoaCMrAh8bFJM6832LtRmfkofg@mail.gmail.com> <001e01cc4b33$6d3818f0$47a84ad0$@liu@arm.com> <20110725223319.petrcv01csccs44s-nzlynne@webmail.spamcop.net> <000001cc4ffd$48680ac0$d9382040$@liu@arm.com> <20110801091151.GD27949@sunsite.ms.mff.cuni.cz>
The answer is ARM can. However, if you look into the bugs PR30282 and
PR38644, PR44199, you may find in history, there are several different cases
in different ports reporting the similar failures, covering x86, PowerPC and
ARM. You are right, they were all fixed in back-ends in the past, but we
should
fix the bug in a general way to make GCC infrastructure stronger, rather
than fixing the problem target-by-target and case-by-case! If you further
look into the back-end fixes in x86 and PowerPC, you may find they looks
quite similar in back-ends.
Thanks,
-Jiangning
> -----Original Message-----
> From: gcc-patches-owner@gcc.gnu.org [mailto:gcc-patches-owner@gcc.gnu.org]
> On Behalf Of Jakub Jelinek
> Sent: Monday, August 01, 2011 5:12 PM
> To: Jiangning Liu
> Cc: 'Joern Rennecke'; gcc@gcc.gnu.org; gcc-patches@gcc.gnu.org;
> vmakarov@redhat.com; dje.gcc@gmail.com; Richard Henderson; Ramana
> Radhakrishnan; 'Ramana Radhakrishnan'
> Subject: Re: [RFC] Add middle end hook for stack red zone size
>
> On Mon, Aug 01, 2011 at 11:44:04AM +0800, Jiangning Liu wrote:
> > It's quite necessary to solve the general problem in middle-end rather
than in
> back-end.
>
> That's what we disagree on. All back-ends but ARM are able to handle it
> right, why can't ARM too? The ABI rules for stack handling in the
epilogues
> are simply too diverse and complex to be handled easily in the scheduler.
>
> Jakub