[Bug tree-optimization/21532] New: ICE caused by PRE dead instruction removal

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

The attached unreduced testcase from glibc generates an ICE using today's CVS. 
The only necessary option is -O2.

regcomp.c: In function 'build_equiv_class':
regcomp.c:3462: error: Missing definition
for SSA_NAME: pretmp.2916_545 in statement:
D.26795_433 = (<unnamed type>) pretmp.2916_545;
regcomp.c:3462: internal compiler error: verify_ssa failed.

-- 
           Summary: ICE caused by PRE dead instruction removal
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: drow at gcc dot gnu dot org
                CC: dberlin at gcc dot gnu dot org,gcc-bugs at gcc dot gnu
                    dot org,pinskia at gcc dot gnu dot org,stevenb at suse
                    dot de
GCC target triplet: arm-none-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21532