[Coco] Optimizing 6809 Assembly Code: Part 2 – Speedup Storing Data – Unrolling Loops

[Joel Rees]

erk.

2017/09/17 2:21 "Joel Rees" <joel.rees at gmail.com>:
>
> A few comments and words of caution.
>
> [...]
> Converting the fig-Forth model interpreter from the 6800 model I had
> to 6809 taught me a lot of this kond of thing, but I'd have learned a bit
> more converting the 6502 model, instead. And Forth itself makes some
> assumptions that are not valid in compiled code, or when using careful
> memory management to protect the system from certain kinds of attacks.

And I've just shown an example of an error called false generalization.

Some Forth systems -- most of the modern ones -- are not built using the
assumptions I refer to above. Forth can be constructed to handle memory
protection properly, but many of the early interpreters did not.

Many implementations of both interpreted and compiled languages had
(and some still have) such problems. OSses also. CPUs, too.

Any run-time architecture that mixes parameters on the call stack is not
properly separating user space from system space, but a properly split
stack doesn't solve all problems.

And I've wandered way beyond what you guys are having fun with.

Enjoy.

> [...]

> --
> Joel Rees
>
> http://reiisi.blogspot.com