final int v = Unsafe.getInt(ptr);
final int v = Unsafe.getByte(ptr) & 0xFF;
	private static final boolean isInUse(long blockNr) {		// 32-bits per int, so shift=5, mask=31		final long offset = blockNr >>> 5;		final int mask = (1 << (int) (blockNr & 31));		final Address ptr = Unsafe.add(bitmapPtr, Unsafe.longToAddress(offset));		final int v = Unsafe.getInt(ptr);		return ((v & mask) == mask);	}