Setting the Rounding Precision (cont'd) We may keep it double precision (supposing the store-reload applies). [Q] If the precision is kept double, the result of an operation is rounded twice. to double prec. (53 bits) when stored in a register to single prec. (24 bits) when stored in memory Can the double-rounded result be differentiated from the true result ? [A] No problem. The double-rounded result cannot be different from the true result. Results of single-precision addition and subtraction reaches only 25 bits at most. The product reaches 48 bits at most. The quotient cannot take the form which suffers double rounding.