[Bug testsuite/53046] [4.8 Regression] New libstdc++ test failures

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53046

--- Comment #12 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-04-23 11:42:28 UTC ---
(In reply to comment #9)
> Looking at the output of -fdump-tree-all, it looks like the compiler optimises
> the loop which accesses an array out of bounds to:
> 
> while(true);
> 
> Is this expected behaviour? That seems like terrible output for every
> situation...

It's similar to other cases where undefined behavior leads to the GIGO
principle.  Other cases being a simple integer overflow inside a loop
(not even necessarily the loop induction variable itself).