ASM in Lazarus

[Namenloser]

You’re calling push right in the middle of your high level code – this is almost bound to cause problems because the asm code generated by the compiler from your source code most likely uses the stack, too. You were just lucky that it didn’t break before.

[plusplus]

Zitat von NamenLozer:

You’re calling push right in the middle of your high level code – this is almost bound to cause problems because the asm code generated by the compiler from your source code most likely uses the stack, too. You were just lucky that it didn’t break before.

Never had a problem from Delphi 3 on and upwards to Delphi XE, I haven't tested in XE2 but I am sure this code works there too.

I am trying to find a way to do the same in Lazarus. I also tried to make a simple call without any params
(so a simple asm call proc; end; )
and does not work either. I think this is a FPC bug.

[Namenloser]

Zitat von plusplus:

Never had a problem from Delphi 3 on and upwards to Delphi XE, I haven't tested in XE2 but I am sure this code works there too.

Maybe the Delphi compiler generates more optimized code that keeps everything in registers and avoids the stack for performance reasons?

Zitat von plusplus:

I am trying to find a way to do the same in Lazarus. I also tried to make a simple call without any params
(so a simple asm call proc; end; )
and does not work either. I think this is a FPC bug.

That’s strange. What kind of procedure are you calling and how is it declared? (calling convention?)

Also: Have you checked what instructions the FPC compiler actually generates? I don’t know if FPC/Lazarus comes with a debugger like the one included in Delphi where you can set a breakpoint somewhere in the source code and then switch to the cpu pane to see the generated asm code... that would be the easiest way. If there isn’t such a thing, you could always put an asm int 3; end; (which acts as a breakpoint) at the beginning of the routine and run it through an ordinary debugger (though it will be more difficult to figure out which opcodes correspond to which instruction in the source code that way). If it really is a bug in FPC, you may spot something here.

[jaenicke]

Zitat von plusplus:

Never had a problem from Delphi 3 on and upwards to Delphi XE, I haven't tested in XE2 but I am sure this code works there too.

Using 32-bit as target I think so too, but you won't be able to compile this for 64-Bit. Just because you can't put a few pieces assembler code in a procedure. You have to make the whole procedure use assembler in 64-Bit in XE2.