Changing position of program code

[aerostar]

I want to start some code at a page boundary, I cannot see a command in PBPRO to do this, I am using PB2.43, 16f876a, and there does not seem to be anything after using the search in this and the old list. Perhaps I am not putting in the correct words !.

eg code
org 1000h
code

[mister_e]

It's kinda dangerous but you can use

@ ORG 1000h
your code here

[sayzer]

Why someone would want to start a code at page boundary?

May be I need to learn that.

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[aerostar]

Thanks for the reply, I will try it out tomorrow.

I am trying to debug some code which appears to fall over around the 1000h boundary, so by making some of the code start after the boundary and not cross it I can then perhaps make a more educated guess as to what I have done wrong.

[keithdoxey]

Thanks for the reply, I will try it out tomorrow.

I am trying to debug some code which appears to fall over around the 1000h boundary, so by making some of the code start after the boundary and not cross it I can then perhaps make a more educated guess as to what I have done wrong.

Do you have any BRANCH instructions in there ?

[skimask]

Thanks for the reply, I will try it out tomorrow.

I am trying to debug some code which appears to fall over around the 1000h boundary, so by making some of the code start after the boundary and not cross it I can then perhaps make a more educated guess as to what I have done wrong.

If you're getting the 'cross page boundary' warning, that's all it is... a warning. PBP takes care of business for you.
Nothing to worry about.
JDG

[Archangel]

Why someone would want to start a code at page boundary?

May be I need to learn that.

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I gotta parrot sayzer, why is that important? Are you trying to find out what code to leave off in order to use a pic with less space?
JS.


Curiousity killed the cat
Satisfaction brought him back.

[aerostar]

I know about the compiler warnings. I have now re-arranged some code and removed a subroutine, it is now 4.7k and does not have problems.
Thanks for the comments.

[Acetronics2]

Hi, Aerostar

I've already noted some troubles as you describe ... diseappearing when subs are re-arranged !!!

Generally when subroutines are placed at the end of the program , not so far from boundary limits ... ( If - Then tests not working i.e. )

I wrote a thread about that in those columns ... but no definitive answer !!!

Can't find a satisfying explanation to that ...

Alain

[skimask]

Hi, Aerostar

I've already noted some troubles as you describe ... diseappearing when subs are re-arranged !!!

Generally when subroutines are placed at the end of the program , not so far from boundary limits ... ( If - Then tests not working i.e. )

I wrote a thread about that in those columns ... but no definitive answer !!!

Can't find a satisfying explanation to that ...

Alain

Now that's different...I've always put my sub's at the beginning of the program and jumped over them and haven't had a problem. Huh... even more unsatisfying isn't it?
JDG

[Ioannis]

On older version of PBP there was an issue with the placement of sub's. I think it was prior to 2.32. After that there was no limit as to where one can put his sub's. BUT, I found that rearranging the subs, there was a great improvment on the final code size.

I suppose this is explained considering the boundary limits and the asm commands used by the compiler.

Ioannis

[sayzer]

So in this case, where do we put the subs then?

Based on what criteria do we arrange the subs?


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[Ioannis]

Hi Sayzer. Well, now there is no official directive as to where is better placed a sub. According to old practice, on top. But this does not affect in any way the execution.

I only pointed out that if one has 5 sub's for example, and have different sizes, rearranging the order of them is affecting the final code size. I think is because a bigger sub might fall between two pages while others won't.

After a little experimenting you can find that your code might reduce up to 20% or more! Also if you change your variables to be placed on BANK0 also may help. Especially if there are arrays in the program. I had a program reduced from 7540 bytes to 6200 using the above!

Ioannis

[Acetronics2]

Hi, Sayzer

You meet here The big Basic Programmer's lack of project definition ...

Basic enables you lots of jumps and come back ... But the first thing is to write a neat logical organigram ...

Like It was to be done with "old dinausaurs " programming langages like Fortran ...

So, the thing to do is put the job in a correct order to have the minimum GOTOs and GOSUBs ...

No so easy ... when the project grows more and more !!!

Alain

[Ioannis]

Just a note: what I described at #13 has nothing to do with GOTO's. Just the order of the sub's. If this is going on top of the other has an immediate impact on code size produced.

Ioannis

[Archangel]

Hi Ioannis,acetronics,
I knew aerostar had a reason, now I know why. I learned something again today! Thanks,
JS


edit
FORTRAN ? Now we're talkin OLD I remember studying my dad's fortran manuals in 1968? I think Dr. Peabody used that to program the wayback machine!

[sayzer]

Hi, Sayzer

You meet here The big Basic Programmer's lack of project definition ...

Basic enables you lots of jumps and come back ... But the first thing is to write a neat logical organigram ...

Like It was to be done with "old dinausaurs " programming langages like Fortran ...

So, the thing to do is put the job in a correct order to have the minimum GOTOs and GOSUBs ...

No so easy ... when the project grows more and more !!!

Alain

I always thought that programming structure addresses a programmer who is looking at the code from outside. So that when you write a code, another programmer from outside can understand your coding and logic relatively easier.

If you write a code that is mixed all over, a new comer will not understand the logic flow.

But, despite all, now, I learn that the structure also has a direct effect on the code size.

I just made some tests, moved the subs around in a code.
The code size indeed drops.


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[Ioannis]

I know what I will suggest is not much of a help, but generally the big sub's is better to be placed on top of each memory page. If you cannot find how long a sub may take, then compile it in a new program file, after compilation check the length and move the sub to a better position at the final program.

Then the rest of the page can be filled with a smaller sub.

If anyone has a better suggestion, please, one step forward.

Ioannis