[Bug tree-optimization/33673] New: ICE in verify_flow_info, missing barrier, when multiple tree opts disabled

["janis at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

Benchmark 176.gcc from SPEC CPU2000 fails with an ICE in verify_flow_info and a
message about a missing barrier when compiled on powerpc-linux with "-Os
-fno-forward-propagate -fno-guess-branch-probability -fno-move-loop-invariants
-fno-tree-dominator-opts -fno-tree-loop-optimize".  It's an odd set of options
but the failure probably demonstrates some sort of dependency between the  
optimizations.  All of the options are documented, none as experimental.

A minimized test case (I'll attach it) fails with these options for a cross cc1
  for any of power*-*-*, s390*-linux, cris-elf, frv-elf, or m32c-elf with the
output:

  bug11.c: In function ?find_reg?:
  bug11.c:32: error: missing barrier after block 4
  bug11.c:32: internal compiler error: verify_flow_info failed
  Please submit a full bug report,
  with preprocessed source if appropriate.
  See <http://gcc.gnu.org/bugs.html> for instructions.

The failure starts with this patch:

    http://gcc.gnu.org/viewcvs?view=rev&rev=124786

    r124786 | rakdver | 2007-05-17 08:10:24 +0000 (Thu, 17 May 2007)


-- 
           Summary: ICE in verify_flow_info, missing barrier, when multiple
                    tree opts disabled
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: janis at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33673