[fpc-devel] Exception handling differences with Delphi

[Tomas Hajny]

On Fri, November 25, 2011 13:57, Sergei Gorelkin wrote:
> 24.11.2011 21:48, Florian Klämpfl пишет:
>> Am 24.11.2011 14:59, schrieb Sergei Gorelkin:
 .
 .
>>> 5) What is the 'Athlon prefetch bug' we're trying to handle? Should be
>>> an old thing, since it originates from svn revision 1; googling for
>>> 'Athlon prefetch bug' does not give relevant information, and my
>>> general
>>> knowledge tells that such code should normally reside in OS kernel, not
>>> in RTL. Anyway, does it apply to x86_64 target?
>>
>> Some old athlons, might include x86_64 ones, had a bug that sometimes
>> prefetch (0^) causes a sig fault while it shouldn't, prefetch(0^)
>> happens in the typical use case of prefetch:
>>
>> while assigned(p) do
>>    begin
>>      prefetch(p^.next^);
>>      ...
>>      ...
>>      p:=p^.next;
>>    end;
>
> This means no program using prefetch instructions could execute on such
> CPU without similar
> exception handling. Consequently, either Microsoft fixed it in next
> service pack, or every complier
> vendor would have to fix it independently (in which case it should become
> much better known over the
> Internet). We also don't have similar code in i386-linux RTL.
> Maybe it is targeted to support some old Windows?

Isn't the fact that it's missing in i386-linux RTL more an omission of the
respective platform maintainer rather than a hint that it might be
specific to Windows (and specifically to old Windows)?

Tomas