[Bug regression/59320] ftree-vrp breaks simple loops

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59320

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
That is simple, accessing out of bounds element is undefined behavior and the
compiler may optimize based on the fact that undefined behavior does not
happen.
As the upper bound is not constant, no warning is emitted on it, the compiler
just assumes that in a valid program nd must be < 2 before entering the loop.