Aucbvax.2641
fa.unix-wizards
utzoo!decvax!ucbvax!unix-wizards
Tue Aug 11 21:37:10 1981
Needed: quick way to do a 16-bit ROR
>From JNC Tue Aug 11 21:33:03 1981
       This isn't really a UNIX question, but there are a lot of
PDP-11 people out there, so here goes: I need a quick way to do a
16 bit ROR. (The ROR instruction itself uses the C bit, for an
effective 17 bits). A 16 bit ROL can be performed by the following
code:
       CLC
       ROL     RX
       ADC     RX

but I can't think of an equivalent hack for ROR that's any better than

       CLC
       ROR     RX
       BCC     1$
       BIS     #100000, RX
1$:

Any ideas? (Improvements to the former are welcome as well!)

               Noel


PS Please reply to me, not the whole list! If there is general
interest, I will forward the best reply.
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