Re: [mkgmap-dev] Rounding bug in splitter?

On Mon, Aug 10, 2009 at 09:37:44PM +0000, Chris Miller wrote:

Assuming my understanding above is correct, here's how I think the rounding methods should be implemented to give the correct rounding in all situations:

private int roundDown(int val) { return val >> SHIFT << SHIFT; }

I would write this as return val & ~(1 << SHIFT);

private int roundUp(int val) { return (val + (1 << SHIFT) - 1) >> SHIFT << SHIFT; }

And this one as return (val + ((1 << SHIFT) - 1))) & ~(1 << SHIFT); It's probably not a big deal, but if SHIFT is a compile-time constant and the compiler performs constant folding, the run-time code should be shorter and faster. Marko