Attached testcase fails with gcc trunk when compiled with -O2 it works ok with
-O1. This works fine with gcc 4.4/-O2


-- 
           Summary:  unimplemented: inlining failed in call to ‘pskb_trim’:
                    recursive inlining
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: regression
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: raj dot khem at gmail dot com
 GCC build triplet: i686-linux
  GCC host triplet: i686-linux
GCC target triplet: i686-oe-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42632