mainline boostrap comparison failure on i686-pc-linux-gnu with gcc 3.2.3 20030502 (Red Hat Linux 3.2.3-49)

[H. J. Lu]

On Thu, May 12, 2005 at 06:11:46AM -0700, H. J. Lu wrote:
> On Thu, May 12, 2005 at 01:42:26PM +0100, Joern RENNECKE wrote:
> > Andrew Pinski wrote:
> > 
> > >>	
> > >>   
> > >>
> > >Actually it is easy to peak at any of them and you will see that the
> > >tree optimizators (lim to be in fact) has changed something somewhere.
> > > 
> > >
> > The trouble is that I'm running the tests on Red hat Enterprise Linux, 
> > and even
> > with the address randomization allegedly turned off, most addresses 
> > still end
> > up being random.  So I've looked at differences of dump file sizes 
> > instead, and the
> > first was in the greg dumps.  Still, experimentation with 3.4.3 supports 
> > your
> > statement that the mainline code is to blame: I also get bootstrap 
> > comparison
> > failures with 3.4.3 as the bootstrap compiler, in fact two different sets
> > using two different mainline snapshots:
> > 
> > Bootstrap comparison failure!
> > ./expmed.o differs
> > build/genattrtab.o differs
> > build/gengtype-lex.o differs
> > make[1]: *** [gnucompare] Error 1
> > 
> > and
> > 
> > Bootstrap comparison failure!
> > ./emit-rtl.o differs
> > ./expmed.o differs
> > build/genattrtab.o differs
> > make[1]: *** [gnucompare] Error 1
> 
> FWIW, I saw the same problem on RHEL 4.
> 

I have verified that this patch

http://gcc.gnu.org/ml/gcc-patches/2005-05/msg00955.html

caused the comparsion failure on RHEL 4/ia32. RHEL 4/ia64 and
RHEL 4/EM64T are OK. The difference is I have

kernel.exec-shield-randomize = 0

in /etc/sysctl.conf on RHEL 4/ia32. I am rerunning it on RHEL 4/ia32
with

kernel.exec-shield-randomize = 1

now.


H.J.