Re: New assembly language instructions to support OO languages?

"bert" <bert.hutchings@btinternet.com> wrote in message
> On 4 Dec, 18:09, "Tony" <t...@my.net> wrote:
>> To me, it seems like "reducing everything to a function" may be a bit
>> dated given that OO languages are the thing nowadays. Can anyone
>> imagine any new potential assembly language instructions that would
>> make implemention of OO languages easier? (Not just necessarily the
>> function thing, but anything).
>
> I don't know about new ones, but how about resurrecting some old ones?
> At least two different computers of the 1960's had an 'indirect' bit
> at the high end of an address word, meaning that it pointed to another
> word containing an address. In its turn, that might have the high bit
> set, etcetera. An instruction to load a datum or an address would
> follow such a chain of indirections until it reached the
> actually-wanted item. I know this was very good for Prolog
> implementations.


OK, good. My mind immediately thought about vptrs after reading that, but I
have a feeling it won't help with what I am trying to do. I am fuzzily
thinking about (from time to time) whether there is a way to avoid vptrs in
objects or some better way of implementing polymorphism (especially or at
least for "interfaces").


(Aside, I'm *starting* to understand assembly language!). :)


> [Indirect addressing was quite common through the 1970s. The PDP-11
> and VAX had it. But I gather that it's a challenge to implement
> efficiently, and if the machine has a lot of registers, it doesn't gain
> you much. -John]


I don't like just pushing complexity to another level in general, but
I'm not sure if I feel that way about it if it gets pushed all the way
to the assembly, machine or hardware level. (?) Probably though.


Tony

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