/*
* There is no need to worry about double rounding in directed
* rounding modes.
+ * TODO: underflow is not raised correctly, example in downward rounding:
+ * fmal(0x1.0000000001p-16000L, 0x1.0000000001p-400L, -0x1p-16440L)
*/
fesetround(oround);
adj = r.lo + xy.lo;