On Thu, Oct 09, 1997 at 06:14:27PM +0100, Jorge Ferreira wrote:

>         Its a long way from PDP-11 to a PIC, don't you think.

Nope, all processors have their little subtleties. That's just a nice
example that I trot out from time to time. I should probably come up
with one for the PIC, I guess.

>         So fire me ;-). I've doing such things since I can remenber, its a
> matter of exploring the darkest aspects of your hardware (by the way

The point is that using such tricks in hand-coded assembler greatly increases
the chances that later on you will change something that breaks your
clever optimization. A compiler on the other other hand rewrites the
assember code each time it compiles the source, so it can check
the validity of such clever tricks each time - you have to remember
to do it.

> By the way compilers are made by programmers, aren't they, so I think
> all this discussion as no point at all, because the code a compiler

Exactly my point; the limiting case of both hand-written and automatically
generated code is the same. It's just a matter of how much time you have
to spend to get there, and how much time you have to spend later
maintaining it. On a small project (say < 1K of code) it's not hard
to make a case for using assembler. As the project gets larger it gets
harder and harder to make that case. At some point the growing complexity
of the project makes it impossible to write in assembler (the time required
to write code grows exponentially with the size of the project).

It is true that a good compiler can routinely out-code an average assembler
programmer. The difference between an average programmer and a hot one is
an order of magnitude or so. Of course no-one on this list is merely average :-)

Cheers.

--
Clyde Smith-Stubbs               |            HI-TECH Software
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