Unsigned versus signed

That was an impressive one. I did not expect gcc to use *val* for the loop condition.

I think this is yet one more point in favor of a personal rule of "always use unsigned unless you have a good reason to use signed" (that is, use "unsigned" by default when programming). If you followed that rule, all three "int" on this function would become "unsigned int", since there is no good reason to use signed here.