/*
* There is no need to worry about double rounding in directed
* rounding modes.
+ * TODO: underflow is not raised properly, example in downward rounding:
+ * fma(0x1.000000001p-1000, 0x1.000000001p-30, -0x1p-1066)
*/
fesetround(oround);
adj = r.lo + xy.lo;