Re: FW: Build failed in Jenkins: BuildThunderX_native_gcc_upstream #1267

[Jim Wilson <jim dot wilson at linaro dot org>]

On 03/17/2017 03:28 PM, Jeff Law wrote:
> On 03/17/2017 03:31 PM, Andrew Pinski wrote:
> > On Fri, Mar 17, 2017 at 11:47 AM, Bernd Schmidt <bschmidt@redhat.com>
> > wrote:
> > > On 03/17/2017 07:38 PM, Pinski, Andrew wrote:
> > > > One of the following revision caused a bootstrap comparison failure on
> > > > aarch64-linux-gnu:
> > > > r246225
> > > > r246226
> > > > r246227
> > >
> > >
> > > Can you help narrow that down?
> >
> > I can though I don't want to duplicate work since Jeff was going to
> > provision an aarch64 system.  My automated testing is approximately
> > every hour or so; these commits were within an hour window even.
> > I did not look into the revisions when I write the email but I suspect
> > r246227 did NOT cause it since aarch64 does not use reload anymore.
> My the box I got isn't terribly fast, but regardless I'll be walking
> through each commit to see if I can trigger the failure.
>
> 246224 tested OK (as it should).
>
> 246225 is in progress.

I have access to a fast box that isn't otherwise in use at the moment so 
I'm taking a look.  r246225 builds OK.  r246226 does not.  So it is 
Bernd's combine patch.  A little experimenting shows that the compare 
difference is triggered by the use of -gtoggle in stage2, which is not 
used in stage3.  Otherwise stage2 and stage3 generate identical code. 
The bug is apparently due to a problem with handling debug insns in the 
combine patch.

Jim