private void checkRegisterAccess(Instruction instr) {

		if (instr.getNumOperands() == 0) {
			return;
		}
		else if ("MOVLB".equals(instr.getMnemonicString())) {
			handleBSRModification(instr);
		}
		else {
			Object[] objs = instr.getOpObjects(0);
			if (objs.length == 0) {
				return;
			}
			if (bsrReg.equals(objs[0]) || bsrReg.getAddress().equals(objs[0])) {
				handleBSRModification(instr);
			}
		}
	}
Attempt to markup FReg access instruction with register reference.

@param instr
@return register name if identified, else null
Ghidra/Processors/PIC/src/main/java/ghidra/app/plugin/core/analysis/Pic18Analyzer.java