Tables

Indexed tables

Statement: Accessing data items in indexed tables

Options: OPT(2)

Conditions: In all cases

V6 behavior: An efficient sequence is used to access indexed table elements by caching the offset to the start of the table in a globally available register versus having to reload this each time

1  TAB.
   5 TABENTS OCCURS 40 TIMES INDEXED BY TABIDX.
      10 TABENT1    PIC X(4) VALUE SPACES.
      10 TABENT2    PIC X(4) VALUE SPACES.

IF TABENT1 (TABIDX) NOT = TABENT2 (TABIDX)
    statements
END-IF

Performance: V6 is 17% faster than V4