[Bug tree-optimization/55329] New: [4.8 Regression] ICE: internal compiler error: in operator[], at vec.h:487 with -O -fno-guess-branch-probability -fnon-call-exceptions --param=early-inlining-insns=111

[Bug tree-optimization/55329] New: [4.8 Regression] ICE: internal compiler error: in operator[], at vec.h:487 with -O -fno-guess-branch-probability -fnon-call-exceptions --param=early-inlining-insns=111

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55329

             Bug #: 55329
           Summary: [4.8 Regression] ICE: internal compiler error: in
                    operator[], at vec.h:487 with -O
                    -fno-guess-branch-probability -fnon-call-exceptions
                    --param=early-inlining-insns=111
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz


Created attachment 28689
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28689
preprocessed source; can't be significantly reduced

Compiler output:
$ gcc -O -fno-guess-branch-probability -fnon-call-exceptions
--param=early-inlining-insns=111
/mnt/svn/gcc-trunk/gcc/testsuite/g++.dg/torture/pr48271.C -save-temps
/mnt/svn/gcc-trunk/gcc/testsuite/g++.dg/torture/pr48271.C: In function 'void
stCheckReverseTrain()':                                                 
/mnt/svn/gcc-trunk/gcc/testsuite/g++.dg/torture/pr48271.C:116:6: internal
compiler error: in operator[], at vec.h:487                                
 void stCheckReverseTrain ()                                                    
      ^                                                                         
0xc8fecb vec_t<basic_block_def*>::operator[](unsigned int)                      
        /mnt/svn/gcc-trunk/gcc/vec.h:487                                        
0xc8fecb tree_ssa_dominator_optimize
        /mnt/svn/gcc-trunk/gcc/tree-ssa-dom.c:807
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.

Tested revisions:
r193495 - crash
4.7 r191640 - OK

[Bug tree-optimization/55329] [4.8 Regression] ICE: internal compiler error: in operator[], at vec.h:487 with -O -fno-guess-branch-probability -fnon-call-exceptions --param=early-inlining-insns=111

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55329

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-11-14
     Ever Confirmed|0                           |1

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2012-11-14 21:22:02 UTC ---
Confirmed: 
revision 192891 (2012-10-28) is OK;
revision 193261 (2012-11-06) gives the ICE.

[Bug tree-optimization/55329] [4.8 Regression] ICE: internal compiler error: in operator[], at vec.h:487 with -O -fno-guess-branch-probability -fnon-call-exceptions --param=early-inlining-insns=111

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55329

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org
   Target Milestone|---                         |4.8.0

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-15 11:26:25 UTC ---
Started with http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=193157 but looks
unrelated to the ICE, so probably it has been just latent before.

[Bug tree-optimization/55329] [4.8 Regression] ICE: internal compiler error: in operator[], at vec.h:487 with -O -fno-guess-branch-probability -fnon-call-exceptions --param=early-inlining-insns=111

[hubicka at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55329

Jan Hubicka <hubicka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hubicka at gcc dot gnu.org

--- Comment #3 from Jan Hubicka <hubicka at gcc dot gnu.org> 2012-11-15 11:29:24 UTC ---
Yep, it does not seem inliner related bug...

[Bug tree-optimization/55329] [4.8 Regression] ICE: internal compiler error: in operator[], at vec.h:487 with -O -fno-guess-branch-probability -fnon-call-exceptions --param=early-inlining-insns=111

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55329

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |jakub at gcc dot gnu.org
                   |gnu.org                     |

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-15 16:31:10 UTC ---
Created attachment 28701
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28701
gcc48-pr55329.patch

Untested fix.  The problem is that clearing bits in a bitmap while it is being
iterated using EXECUTE_IF_SET_IN_BITMAP is dangerous and can't work reliably,
in this case the bitmap contained just a single bit, that got cleared and
replaced by a smaller bit (the clearing removed the only bitmap_element,
setting reused it with different index (smaller) with higher bits set in it).
In gimple_purge_all_dead_eh_edges it is just a few extra instructions to
process
the forwarder blocks (it quickly finds out that they don't have any EDGE_EH
edges and does nothing for them), so IMHO it doesn't matter much if we don't
clear those bits.  On the other side, if there could be multiple forwarder
blocks, we might risk we don't handle them correctly, as they could have bb's
with lower indexes as successors.

[Bug tree-optimization/55329] [4.8 Regression] ICE: internal compiler error: in operator[], at vec.h:487 with -O -fno-guess-branch-probability -fnon-call-exceptions --param=early-inlining-insns=111

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55329

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-16 22:05:36 UTC ---
Author: jakub
Date: Fri Nov 16 22:05:32 2012
New Revision: 193577

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=193577
Log:
    PR tree-optimization/55329
    * tree-ssa-dom.c (tree_ssa_dominator_optimize): Never clear
    bits in needed_eh_cleanup while iterating over the bitmap.
    Look through all forwarder blocks at once.

    * g++.dg/opt/pr55329.C: New test.

Added:
    trunk/gcc/testsuite/g++.dg/opt/pr55329.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-dom.c

[Bug tree-optimization/55329] [4.8 Regression] ICE: internal compiler error: in operator[], at vec.h:487 with -O -fno-guess-branch-probability -fnon-call-exceptions --param=early-inlining-insns=111

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55329

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-19 09:45:49 UTC ---
Fixed.