6.6.8.10.3 Modifying Exception Status Through Software

Software may simultaneously clear both “most-recent” and “sticky” exception flags using the FAND instruction. Software may also set both “most-recent” and “sticky” exception flags simultaneously using the FIOR instruction, though this operation is of little utility.

Note: Clearing (or setting) a most-recent exception status bit by using the FAND (or FIOR) instruction will not affect any corresponding sticky exception bits.