[Bug sanitizer/64996] UBsan check optimized out by -O

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64996

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |mpolacek at gcc dot gnu.org
         Resolution|---                         |INVALID

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Since the variable is unused, we get rid of it, and then DCE removes the ubsan
check.  I don't think it is a bug.  Adding asm ("" : "+g" (i)); after the
decrement makes the runtime error appear again.