[Bug tree-optimization/47271] [4.6 Regression] if-conversion removes a test (if), the function generates invalid outputs

[spop at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47271

--- Comment #9 from Sebastian Pop <spop at gcc dot gnu.org> 2011-01-24 18:38:13 
UTC ---
Sorry, (!a and !b) should not modify the value of x.