[Bug tree-optimization/48702] [4.6/4.7 Regression] optimization regression with gcc-4.6 on x86_64-unknown-linux-gnu

[xinliangli at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48702

--- Comment #12 from davidxl <xinliangli at gmail dot com> 2011-04-21 16:22:03 
UTC ---
(In reply to comment #3)
> I have a patch that makes it fail on trunk as well.  IVOPTs generates
> 
>   for (p = &a; p != &a - 3; --p)
>     *(p + 3) = ...
> 
> and alias analysis doesn't like this invalid pointer.


I wonder why ivopt does not select the iv candidate whose base is &a+3.