Paul Gilmartin noted:
>I would be careful not to create confusion by inviting undue attention
>to the notion of "sequential position".
COMPARE AND SWAP
CS R1,R3,D2(B2) [RS-a]
If you wrote
CS 0,4,X
the assembler says operand 1 is 0, operand 2 is 4, and operand 3 is X,
while the PoP swaps the latter two.
Assembler programmers must deal with the confusion caused by multiple uses
of the word "operand". The PoP sense (and numbering) is different from the
assembler's sense. Sadly, the assembler's notation is just as old as that
of the PoP, and generations of assembler programmers have had to cope with
the differences..
