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Re: [f-cpu] pointer add & sub


> however, checking ALL results from Xbar in the TLB (just as the "zero
> check" does)
> consumes more resources and power. By only "activating" the TLB when
> needed, this part consumes less power.

Once again : so what ? You don't need another opcode to "activate"
the TLB. You just have to trigger it if the pointer flag is set.
The pointer flag can be calculated very simply, as I've shown.

So :

- you calculate the pointer flag (this can be done in parallel to
the addition)
- at the end of the addition, if the pointer flag is set, you activate
the TLB

That is, instead of having this flag determined by the opcode, you
just calculate it (using a very straightforward formula) at runtime inside
the CPU.

> And this is "only a model", as the implementation can differ (for
> example with some associative memory instead of 1 flag per register).

If implementation can differ, then madd is all the more useless because
its use may be deprecated in next versions of the CPU.

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