This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: continuing egcs-1.1 problems
- To: Elgin Lee <ehl at funghi dot com>
- Subject: Re: continuing egcs-1.1 problems
- From: Fred Bacon <bacon at mediaone dot net>
- Date: Tue, 10 Nov 1998 18:55:01 +0000
- CC: David Edelsohn <dje at watson dot ibm dot com>, Fred Bacon <bacon at aerodyne dot com>, Jeffrey A Law <law at cygnus dot com>, Franz Sirl <Franz dot Sirl-kernel at lauterbach dot com>, Amal Phadke <phadke at kewalo dot eng dot hawaii dot edu>, egcs at cygnus dot com
- References: <199811102145.NAA05873@porcini.funghi.com>
- Reply-To: bacon at mediaone dot net
Elgin Lee wrote:
>
> >>>>> In <9811101610.AA27716@marc.watson.ibm.com>
> >>>>> David Edelsohn <dje@watson.ibm.com> wrote:
>
> David> I am certain that removing the alignment part of the patch and
> David> only reversing the trampoline test ordering will solve the symptom. I
> David> thought that someone already did that. The question is whether the
> David> trampoline test ordering truly is the source of the problem.
> David>
> David> I thought that we previously received a confirmation a couple of
> David> months ago that the alignment part of the patch violated the SVR4 PPC ABI
> David> and was incorrect.
> David>
> David> David
> David>
>
<...snip...>
>
> SECOND PATCH (trampoline size tweaking)
> =======================================
>
> I don't have an opinion on this, as I don't know the SVR4 ABI for PPC.
> (Is it online somewhere?)
>
> As it turns out, I never applied to second patch to my egcs 1.1b
> build-- only the first one. That seemed to work fine on some small
> test programs that invoked the glibc functions that used nested
> functions, but I haven't tried it on anything substantial.
>
When I got home this evening, I dug out my copy of the SysV ABI PowerPC
Processor Supplement (July 25, 1994). According to this document, page
3-15:
"The following requirements apply to the stack frame:
* The stack pointer shall maintain a 16-byte alignment.
* The stack pointer shall point to the first word..."
Well, the rest is immaterial. So a 40 byte stack frame would be
incorrect, but if another portion of egcs is rounding the stack frame
size to the next largest 16-byte multiple, then I see no problem with
omitting the second patch. But only if the proper alignment is being
maintained elsewhere.
--
Fred Bacon
==========================================================================
Aerodyne Research, Inc. Phone: (978) 663-9500 ext.
273
45 Manning Rd. FAX: (978) 663-4918
Billerica, MA 01821-3976 http://www.aerodyne.com
==========================================================================
Life is a tragedy for those who feel and a comedy for those who
think.