| 摘要 |
PROBLEM TO BE SOLVED: To provide an arithmetic system which efficiently achieves processing of obtaining a correction value for a value resulting from addition/subtraction of fixed-precision floating-point numbers.SOLUTION: The arithmetic circuit includes: an arithmetic unit which generates, as a shift amount, a value obtained by subtracting a second exponent and a preceding zero count value of a first mantissa from a first exponent and generates a third exponent obtained by subtracting a preceding zero count value of the first mantissa and a first prescribed value from the first exponent; a shift unit which generates a shifted mantissa obtained by shifting the first mantissa on the basis of the shift amount; an addition unit which generates an addition value obtained by adding the shifted mantissa and a part of a second mantissa and generates a carry due to the addition; a prediction unit which receives the shifted mantissa and the carry to generate flags showing the occurrence of digit overflow and digit cancellation respectively; and a generation unit which generates a correction value mantissa and a correction value exponent on the basis of the addition value, the third exponent, and the flags. |
