[Bug tree-optimization/123330] Optimization fails with standard branchless idiom with power of 2s

[tobi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123330

--- Comment #2 from Tobias Schlüter <tobi at gcc dot gnu.org> ---
Sure, I meant "undefined on the hardware level."  I hope you're not saying that
the optimizers go crazy when using __builtin_clz(0) even when using -mlzcnt?