The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 31, 1994
Filed:
Sep. 23, 1992
Miki Urano, Osaka, JP;
Takashi Taniguchi, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
At a format conversion of a floating point number from double-precision to single-precision, a temporary exponent e.sub.1 is obtained by subtracting a double-precision bias B.sub.d from an exponent E of an operand and by adding a single-precision bias B.sub.s thereto. A mantissa M of the operand is shifted to right by a number obtained by adding 1 to an absolute value of the exponent e.sub.1 when e.sub.1 .ltoreq.0. When e.sub.1 >0, the mantissa M is not shifted. the result is rounded to a 23-bit length. When no carry is caused, the rounded value and 0 (when e.sub.1 .ltoreq.0) or e.sub.1 (when e.sub.1 >0) are respectively a mantissa and an exponent to be obtained. The rounded value and e.sub.1 +1 are regarded as a conversion result when e.sub.1 =0 and a carry is caused. A value obtained by shifting the rounded value to right by 1 bit and e.sub.1 +1 are selected when e.sub.1 >0 and a carry is caused. Accordingly, denormalization is executed with a high speed without interrupting a procedure being executed, and conversion results can be always obtained with a minimum number of procedures.