Re: [Tiny-cobol-users] (no subject)

[Rildo P. <rpr...@ac...>]

Hi Jim,

On Mon, 13 Dec 1999, Noeth, Jim wrote:

> I have been working on the run time routines to facilitate the cobol move
> verb, and have them very close to being finished. My concern, though, is
> that these routines have considerable overhead (especially when moving
> numeric fields) to figure out what type of move is involved, how much to
> pad, how much to truncate, etc.. I'm afraid that our move routines are going
> to be very innefficient. What I would like to do is to modify the 'gen_move'
> routine to generate the code directly, all of the information to do these
> 'overhead' calculations is available at compile time, and we could generate
> code that is very specific to each move statement.

We can do a simple 2-way classification. If the fields are both binaries,
we generate a simple move at compile-time. If not, we call your routine.
What you think?

There are some optimizations I have already introduced, but I can try to
do more. (or you can too, if you want. Look for the functions gen_move,
gen_loadvar, gen_loadloc at the file htcobgen.c)
I really think we are more concerned with having something usable fast.
Then we make gradual performance improvements.

> I realize that this will make the compiler less portable (and a little more
> difficult to debug), I believe that I can write the code generation routines
> such that they can be easily modified for different platforms. Let me know
> what you think.

We can leeave the more efficient code generation for the next version of
the compiler.  We need a beta version soon, to have more contributors
helping us. We only will have a really portable compiler when we output C
language code (or some intermediary language), perhaps with a multi-pass
compiler.

regards,
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