-O2 compiler bug on amd64? (Re: new TCL vs. current-6)

[Jeremy Messenger]

On Tue, 14 Dec 2004 14:24:53 +0100, Anthony Ginepro  
<anthony.ginepro at laposte.net> wrote:

> Le Mardi 14 décembre 2004 à 13:39 +0100, Alexander Leidinger a écrit :
>> Zitat von Kris Kennaway <kris at obsecurity.org>:
>>
>> > > Peter speculated a problem when the world is built with -O2 (with or
>> > > without -fno-strict-aliasing).  I haven't been able to confirm this  
>> by
>> > > testing with a world built with -O, because I only have one working
>> > > amd64 package builder.
>> >
>> > Looks like building the port against an -O world has fixed the
>> > problems.  This suggests a compiler bug with -O2 on amd64.
>>
>> I "hope" this is the case, not only on amd64. Background: I see  
>> coredumps
>> of gst-register on my system (x86). I've recompiled all ports, with and
>> without -Os, with and without -fno-strict-aliasing, but it still
>> segfaults. I also recompiled world with "-Os -fno-strict-aliasing"  
>> instead
>> of my usual "-Os". I haven't tested plain "-O" for the world yet, but I
>> think the problem is somewhere in the system libs...
>>
>> Bye,
>> Alexander.
>
> Some more information :
> gst-register coredumps if gstreamer-plugins is compiled with CPUTYPE=p4.
> eclipse also coredumps if gtk2 is compiled with CPUTYPE=p4.
> Both ports don't depend on optimization level (-O2 or -O).

gstreamer-plugins is weird.

Crash:
=======================
CPUTYPE?=athlon-xp
CFLAGS= -O -pipe
=======================

No crash:
=======================
#CPUTYPE?=athlon-xp
CFLAGS= -O -pipe
=======================

No crash:
=======================
CPUTYPE?=athlon-xp
CFLAGS= -O2 -pipe
=======================

No crash:
=======================
Add '-fgcse' in gstreamer-plugins and it will fix everything for  
athlon-xp, but not p4. The '-fgcse' is automatic add in when you use -O2,  
so it's why it doesn't crash with -O2.
=======================

I personal have no idea if it's bug in FreeBSD or gstreamer-plugins, but  
there is no issue if it's in Linux.

On another note, there has different thread in freebsd-threads about 'SSE  
vs. stack alignment vs. pthread'. It included a libc patch that fix for an  
app for SSE and 16-byte aligned stuff on p4.

Cheers,
Mezz

> Anthony.


-- 
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FreeBSD GNOME Team
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