Confused Code

[GLS at MIT-MC (Guy L. Steele, Jr.)]

    Date: 18 FEB 1979 0326-EST
    From: RWK at MIT-MC (Robert W. Kerns)
    Sent-by: ___012 at MIT-MC

    IOCERR+13/ HRRZ R,-3(F)
    IOCERR+14/ SKIPL R
    IOCERR+15/ JRST IOCER8

    Is this supposed to make sense?  Since IOCER8 always clobbers R,
    this is identical to a JRST IOCER8.  Maybe the HRRZ is spurious?

Try looking at the source code.  It has some macro-ized stuff
that arranges that a sequence involving a HRROI R, appears for
every IOC handler declared by the code (in much the same manner as an INTPRO).
As it happens, there are presently no such handlers in the code, so it does
indeed produce a silly-looking sequence of instructions.  I suppose it
could suppress the SKIPL if there are no handlers, but I was lazy when
I wrote that code.  (I was even more lazy in not defining a handler or two!)