public static BigFloat sub(BigFloat a, BigFloat b) {
		BigFloat c = b.copy();
		c.sign *= -1;
		c.add(a);
		if (c.isZero()) {
			c.sign = (a.sign < 0 && b.sign > 0) ? -1 : 1;
		}
		return c;
	}
@param a a BigFloat
@param b a BigFloat
@return {@code a-b}
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/pcode/floatformat/BigFloat.java