[Bug rtl-optimization/46238] New: s390x bootstrap problem: wrong code generated due to crossjumping

[Bug rtl-optimization/46238] New: s390x bootstrap problem: wrong code generated due to crossjumping

[krebbel at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46238

           Summary: s390x bootstrap problem: wrong code generated due to
                    crossjumping
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: critical
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: krebbel@gcc.gnu.org


collect2 gets miscompiled due to a bug in cfgcleanup.

try_head_merge_bb moves an insn setting r2 over an insn clobbering that
register. DCE removes the set afterwards. try_head_merge_bb doesn't notice due
to wrong live info in the 'live_union' variable.

Proposed fix:
http://gcc.gnu.org/ml/gcc-patches/2010-10/msg02569.html

[Bug rtl-optimization/46238] s390x bootstrap problem: wrong code generated due to crossjumping

[krebbel at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46238

Andreas Krebbel <krebbel at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |s390x-ibm-linux
           Priority|P3                          |P2
                 CC|                            |bernds at codesourcery dot
                   |                            |com
               Host|                            |s390x-ibm-linux
              Build|                            |s390x-ibm-linux

[Bug rtl-optimization/46238] s390x bootstrap problem: wrong code generated in cfgcleanup/crossjumping

[krebbel at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46238

Andreas Krebbel <krebbel at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P2                          |P1
           Severity|critical                    |blocker

--- Comment #1 from Andreas Krebbel <krebbel at gcc dot gnu.org> 2010-11-03 12:36:56 UTC ---
I've raised the prio and severity. This problem currently prevents our GCC
daily build system from doing proper testing. That way we will not get aware of
other potential problems introduced in the meantime.

[Bug rtl-optimization/46238] s390x bootstrap problem: wrong code generated in cfgcleanup/crossjumping

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46238

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING
   Last reconfirmed|                            |2010.11.03 17:10:33
   Target Milestone|---                         |4.6.0
     Ever Confirmed|0                           |1

--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> 2010-11-03 17:10:33 UTC ---
Please try revision 166259.

[Bug rtl-optimization/46238] [4.6 Regression] s390x bootstrap problem: wrong code generated in cfgcleanup/crossjumping

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46238

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
            Summary|s390x bootstrap problem:    |[4.6 Regression] s390x
                   |wrong code generated in     |bootstrap problem: wrong
                   |cfgcleanup/crossjumping     |code generated in
                   |                            |cfgcleanup/crossjumping

[Bug rtl-optimization/46238] [4.6 Regression] s390x bootstrap problem: wrong code generated in cfgcleanup/crossjumping

[krebbel at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46238

--- Comment #3 from Andreas Krebbel <krebbel at gcc dot gnu.org> 2010-11-04 08:47:26 UTC ---
(In reply to comment #2)
> Please try revision 166259.

Ok. I've started bootstrap. I'm quite sure that reverting the will fix the
problem. Perhaps I missed that on the list but when was it decided to revert
the patch?

Have you tried my patch? It definitely fixes on of the problems for me.

[Bug rtl-optimization/46238] [4.6 Regression] s390x bootstrap problem: wrong code generated in cfgcleanup/crossjumping

[krebbel at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46238

--- Comment #4 from Andreas Krebbel <krebbel at gcc dot gnu.org> 2010-11-04 16:05:52 UTC ---
(In reply to comment #2)
> Please try revision 166259.

As expected reverting the patch fixes bootstrap on s390x.

[Bug rtl-optimization/46238] [4.6 Regression] s390x bootstrap problem: wrong code generated in cfgcleanup/crossjumping

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46238

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |jakub at gcc dot gnu.org
         Resolution|                            |FIXED

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-11-05 12:30:19 UTC ---
Fixed then.