[python-win32] Still looking for a method to get CPUID info ...

[Dave Angel]

Gertjan Klein wrote:
> Tim Roberts wrote:
>
>   
>> However, I'll bet I know what it is.  CPUID trashes ebx, and in the x86
>> calling sequence, that's supposed to be saved and restored.
>>     
>
> That's it! Now, both Python 2.5 and 2.6 (and 3.1, if I change the print
> statement) run this code successfully. Does that mean there is a
> difference in calling sequence between Python 2.5 and 2.6? Or do they
> have different expectations of which registers are left untouched?
>
> Thanks for sticking with this. I often save little bits of code from
> this newsgroup that I might want to use later, and now I have a little
> project that shows me how to create a DLL from assembly code and call it
> from Python.
>
> Gertjan.
>
>
>   
On general principle, I'd use
    push ebx
...
    pop ebx

pairs around the cpuid instruction, if trashing ebx is a problem.  Seems 
to me it's safer than making any assumptions about implicit 
saves/restores.  I haven't looked at the cpuid instruction for years, 
but I'd push/pop any register (other than EAX) it modifies, and in 
between them do the cpuid and an appropriate move of whichever register.

DaveA