I am beginning to have a suspicion that some readers at least do not
know how branch tables. C switch statements, and the like work.  Here,
given a state-code of, say, 'NY', its two-byte code point, in EBCDIC
x' d5e8', is used as  an offset to address a unique byte in that
table, one of bytes 0,1, 2,...,65635.  A single properly framed TRTO
instruction yields the value of that target byte.  There is no faster
way to do this, and this is the case even on, say, a RISC machine ,
where it must be programmed [trivially].

John McKown's suggestion that a three way branch should perhaps be
implemented as if-then-else-if-then-else-if-then-else<error sink> is
entirely correct but not interesting here.  COBOL EVALUATE and its
analogues in other languages are for many-way branches.

John Gilmore, Ashland, MA 01721 - USA

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