🚀 go-pugleaf

You might consider instructions of the form "Execute Register" or
"Execute Memory", where the primary instruction specified where a
(single) second instruction was to be fetched from, a form of
self-modifying code.

Certainly, these caused the same difficulties for the pipeline.

I have seen "Execute Register" used to synthesize dynamic shift
instructions, where the shift amount is not known at compile time
(dynamic shifts are much less frequent than static shifts in most
instruction mixes), and to produce the indirect syscall() system call.
"Execute Register" was also used to produce a relatively fast
instruction level simulator for a similar, but not identical,
instruction set processor.

--
Andy "Krazy" Glew,  Motorola MCD,    	    	    aglew@urbana.mcd.mot.com
1101 E. University, Urbana, IL 61801, USA.          {uunet!,}uiucuxc!udc!aglew
   
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