Improved apparatus for representing the size of an element in a compound

Abstract

Improved apparatus for computing locations in compound data items and current lengths in varying-length compound data items when the elements in the compound data items and the varying-length data items have sizes which are powers of 2. The apparatus is used in a digital computer system wherein data items are represented by names associated with name table entry items in memory. The digital computer system's processor includes a name translator for calculating addresses and lengths using the name table entries associated with names. The name table entry associated with a name representing a compound data item or varying-length compound data item having elements whose size is an integer power of 2 includes an element size specifier which has as its value the exponent specifying the power of 2 equal to the size of the elements. When a name table entry for a compound data item includes such an element size specifier, the name translator calculates the displacement of an element in the compound data item or the length of a varying-length data item by shifting an index value specifying one of the elements or a current number of elements value specifying the number of elements currently in the varying-length data item to the left the number of times indicated by the integer value of the element size specifier.