[Bug tree-optimization/17955] Perform associative optimization when it is safe

[dberlin at gcc dot gnu dot org]

-- 
Bug 17955 depends on bug 21445, which changed state.

Bug 21445 Summary: [meta-bug] we need a reassociate pass
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21445

           What    |Old Value                   |New Value
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17955