@Override
	public void setDefaultValue(RegisterValue registerValue, Address start, Address end) {
		if (!registerValue.getRegister().isProcessorContext()) {
			return;
		}
		if (at != null && (start.compareTo(at) > 0 || at.compareTo(end) > 0)) {
			return;
		}
		defctx = defctx.combine(AssemblyPatternBlock.fromRegisterValue(registerValue));
		dbg.println("Combining " + registerValue);
		dbg.println("  " + defctx);
	}
Compute the default value of the context register at the given address

@param addr the addres
@return the value as a pattern block for assembly
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/assembler/sleigh/sem/AssemblyDefaultContext.java