public boolean isContextMatch(ParserWalker walker) {
		if (nonzerosize <= 0) {
			return (nonzerosize == 0);
		}
		int off = offset;
		for (int i = 0; i < maskvec.length; ++i) {
			int data = walker.getContextBytes(off, 4);
			if ((maskvec[i] & data) != valvec[i]) {
				return false;
			}
			off += 4;
		}
		return true;
	}
A mask/value pair viewed as two bitstreams
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/processors/sleigh/pattern/PatternBlock.java