On: Knuth–Morris–Pratt algorithm

[rimantas]

It's the same when m=n.

[waps → rimantas]

Of course in string search it never is. In m=n case KMP would simply compare the first character, and if it doesn't match declare nothing was found.

Yes there'd be much more different instructions involved but I think KMP would start beating naive pretty quickly in the m=n case.