XorCompressedBitmap xb = (XorCompressedBitmap) r;
EWAHCompressedBitmap out = xb.bitmap;
for (;;) {
r = xb.xorBitmap.bitmapContainer;
if (r instanceof EWAHCompressedBitmap) {
out = out.xor((EWAHCompressedBitmap) r);
bitmapContainer = out;
return out;
}
xb = (XorCompressedBitmap) r;
out = out.xor(xb.bitmap);