Re: [hatari-devel] Hatari profiler updates and CPU cycle questions

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

On torstai 31 tammikuu 2013, Laurent Sallafranque wrote:
> When you trace your program (ie, the program is running with the
> registers in the good state), the cycles for this instruction will
> display [04 cycles] if X memory w< $200 or [05 cycles] if X memory is >
> $200

How much cycles can differ for an individual instruction?

I added code for getting min and max values for traced DSP cycles, but for
my simple test programs they always showed min and max values to be
identical (to what's in disassembly).


> > You can't guess the amount of cycles an instruction will consume, except
> when you really run your program and TRACE it.
> 
> When you DISASM the DSP memory, the cycles are given accordingly to the
> value of the registers, which are constant and probably not as they're
> in dynamic running.
> 
> 
> So, when TRACING code, the cycles before the instruction are correct.
> when DISASEMBLING the DSP memory, they can be wrong, but Eero's sum of
> cycles seems good.

I haven't commited the min/max cycles code yet as it makes the output
more verbose and I'm wondering how useful it is.  I guess for 99% of DSP
code, there's no difference between min and max cycles, they always are
executed the same way...?


	- Eero