Bug#198172: [arm] gcc-3.3 miscompile pari with -O3

[Bill Allombert <allomber@math.u-bordeaux.fr>]

On Wed, Jun 25, 2003 at 09:27:33AM +0100, Philip Blundell wrote:
> On Thu, 2003-06-19 at 16:26, Bill Allombert wrote:
> > Package: gcc-3.3
> > Version: 1:3.3-3
> > Severity: normal
> > 
> > Dear GCC maintainers,
> > 
> > gcc 3.3 (1:3.3ds9-3) miscompile pari (2.1.5) on arm with -O3, whereas
> > gcc 3.2 (3.2.3 20030331) worked fine.
> > 
> > With -O2 gcc 3.3 works fine also
> > 
> > The preprocessed miscompiled file is available at
> > http://people.debian.org/~ballombe/misc/init.i.gz
> 
> Thanks for your report.  Can you give any details of the miscompilation?

Dear Philip, I perfectly understand that this bug report is not very
useful (outside the fact that you can grab PARI source and try to
build for yourself), but that let you know gcc has arm specific issue.
I also agree that using -O3 is asking for trouble.

I believe there are two problems:

1) The file init.c is miscompiled to the point of making gp just crash
at start up. It crash so hard that gdb does not provide useful
backtrace, so I gave up trying to find why.

2) Other files are miscompiled with -O3 according to 'make bench'.
This can be easier to attack.

If you want I can try to investigate that, but no promise.

Cheers,
-- 
Bill. <ballombe@debian.org>

Imagine a large red swirl here.