[Bug tree-optimization/23471] a*a (for signed ints with -fno-wrapv) is always postive

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=23471

--- Comment #9 from Drea Pinski <pinskia at gcc dot gnu.org> ---
`a*a*a*a*a*a` is still not handled.

But now VRP/ranger is handling `a*a` and so is fold/match.