[Bug tree-optimization/36978] New: ICE in gimple_cond_set_lhs for -O2 -funswitch-loops after tuples merge

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

The following C testcase was reduced from a C++ benchmark:

  unsigned short status;
  void foo (const _Bool flag)
  {
    if (status == 2 || status == 7)
      {
        while (status != 2 && (status != 7 || !flag))
          {
          }
      }
  }

After the merge of the tuples branch into mainline it gets the following ICE on
powerpc-linux with -O3 or with the options shown here:

elm3b149% /home/janis/tools/gcc-trunk-anonsvn/bin/gcc -c -O2 -funswitch-loops
bug.c
bug.c: In function ?foo?:
bug.c:4: internal compiler error: in gimple_cond_set_lhs, at gimple.h:2251
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.


-- 
           Summary: ICE in gimple_cond_set_lhs for -O2 -funswitch-loops
                    after tuples merge
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: janis at gcc dot gnu dot org
GCC target triplet: powerpc-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36978