[Bug c/49820] Explicit check for integer negative after abs optimized away

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49820

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> 2011-07-23 
17:23:44 UTC ---
(In reply to comment #1)
> Integer overflow is undefined. You have to check before the fact, or compile
> with -fwrapv.

That should say signed integer overflow is undefined.