public static long getSignedOffset(Varnode v) {
		int size = v.getSize();
		if (size == 0 || size >= 8) {
			return v.getOffset();
		}
		long offset = v.getOffset();
		if (offset > 0 && (offset & SIGN_BIT[size]) != 0) {
			offset |= ~VALUE_MASK[size];
		}
		return offset;
	}
@return Varnode that represents the stack pointer register
Ghidra/Features/Base/src/main/java/ghidra/util/state/ResultsState.java