private boolean extractSign(long x) {
		x >>>= signbit_pos;
		return ((x & 1) != 0);
	}
Get the minimum finite subnormal {@link BigFloat} value for this format

@return minimum finite subnormal {@link BigFloat} value
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/pcode/floatformat/FloatFormat.java