[Bug tree-optimization/39870] VRP can't see through cast to unsigned

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39870

--- Comment #15 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-09 
14:58:53 UTC ---
VRP optimizes the testcase form comment #12, it doesn't optimize the original
one because there we deal with symbolic ranges.