A method in one aspect may include receiving an add instruction. The add instruction may indicate a first source operand, a second source operand, and a third source operand. A sum of the first, second, and third source operands may be stored as a result of the add instruction. The sum may be stored partly in a destination operand indicated by the add instruction and partly a plurality of flags. Other methods are also disclosed, as are apparatus, systems, and instructions on machine-readable medium.