[fpc-devel] FPC ARM7 problems

[Jonas Maebe]

On 07/08/14 15:45, Sergio Flores wrote:
> I see guys, lots of useful info!
> I did not know that optimizations where switchable per unit, that is
> quite interesting and I can probably use it to better isolate the problem.
> I will also try disabling peephole optimisations then, it can probably
> work as a temporary fix to let me use all other optimizations.
>
> Any clue how I could work around for that assembler problem in 2.7.1.
> Could breaking the source file into smaller units help?

No, but breaking down a procedure into smaller ones might help. However, 
it needs to be fixed. The only way it can be fixed is by providing us 
with a source code fragment that we can compile to reproduce the problem.

> I don't have the knowledge of how the internals work, so I don't know
> how a function can actually modify the value of "self". I guess some
> stack corruption is happening somehow?

A broken optimisation can do anything with any possible random side effect.

> This is what I've discovered, not sure if it helps, maybe I could
> provide the asm code of that specific method with and without optimizations?

That may help, but it might also be any of the called procedures that 
causes the problem.

> PS: I have no clue in the ammount of work necessary to add
> dwarf/lineinfo support to those platforms, but in case it is something
> doable without too much work, and can benefit both OSX and iOS, I'm
> willing to donate some money to have have such support implemented.

At least I don't have time for it right now.


Jonas