Greetings,

I think some more math libraries would be great for JALLIB.

My two cents worth opinion follows:

Perhaps it would be advisable to consider testability first --
ideally an automated self-test for 16F and 18F would be run often,
especially when a new compiler comes out or a new release of the
JALLIB itself.

With a good test suite, I don't see where it matters if the
implementation is in pure JAL, assembly, or a mix of both.

I noticed on the JALV2 page that JALV2 has 'built-in' multiply and
divide, but I have not really done much with it -- if we can do, say
24 or 32 bit signed and unsigned multiply, divide, addition and
subtraction, already in pure JAL, that would see a great start towards
a fixed point library.

A practical application might be converting K-type thermocouple A/D
readings to degrees C or F.

William


On Oct 22, 10:39 am, vasile surducan <[email protected]> wrote:
> Hi all,
>
> I've played a little with this (and other) math collection on the old jal.
> In my opinion at least the floating math will be much faster if code is kept
> as much as possible in assembler. However, with this new jal I can't be sure
> will be the same. Math is quite difficuld for debugging anyway.
>
> best wishes,
> Vasile
>
> On 10/22/09, Rob Hamerling <[email protected]> wrote:
>
>
>
>
>
> > Joep, and others who replied,
>
> > I'll make a start with a math lib with only a few relatively simple
> > functions.  Then we can gradually expand it with more functionality.
>
> > Joep Suijs wrote:
>
> > > - I suggest we don't code in assembler for now. Get it working with JAL.
> > > It's easly enough to concider porting to asm if someone runs into
> > > perfomance problems.
>
> > OK (will translate existing functions in ASM to JAL).
>
> > > - iirc we have multiply, divide, add, subract with any size of integer.
> > > I wonder however how often it is used, besides 8,16 and 32 bits.
>
> > I have not checked it, but will put it in a test set anyway.
>
> > > - You define functions like goniometric functions (sin, cos, tg, etc),
> > > square root and other 'power' functions, logarithm (natural?). These are
> > > all candidates imho.
>
> > I was afraid of that! ;-)
> > It has been a long time since I had to work with these!
>
> > > - You also mention integer, fixed point and floating point. This would
> > > suggest 3 versions of each function mentioned above (and for fixed point
> > > and float, also for multiply, divide, add, subtract).
>
> > I thought of starting with integer arithmetic. We'll see if the others
> > are really worth the effort if we cannot find examples of it.
>
> > > I think I have a partially funcitonal fixed point sine laying around
> > > somewhere and recently created a integer-based quare root funtion (not
> > > too accurate, but like the sine, optimised for my problem....)
>
> > Welcome! I've seen the PicList has a collection, mostly in ASM, but with
> > explanations (Scott Dattalo seems to be guru). I'll collect and make a
> > comparison to see what can be implemented quickly and reliably.
>
> > Regards, Rob.
>
> > --
> > Rob Hamerling, Vianen, NL (http://www.robh.nl/)
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