[Vm-dev] [Pharo-dev] shallowCopy problem on 64 bit Pharo ?

[Ciprian Teodorov]

Thanks guys I'll will try with the latest version and I'll come back with
updates.


On Sun, Feb 5, 2017 at 8:25 PM, tim Rowledge <tim at rowledge.org> wrote:

>
>
> > On 05-02-2017, at 5:08 AM, Clément Bera <bera.clement at gmail.com> wrote:
> >
> > I remember there was a discussion about that somewhere but I can't find
> it. I cc vm-dev they may have a clue.
> >
> > When copying a pointer object in 64 bits instead of 32 bits, you need to
> copy twice many data, so it is going to be slower in any case.
>
> Err, not really. Probably. Assuming you have a 64 bit cpu etc, of course.
> And dependent on details of the memory architecture outside the cpu too -
> after all many systems do not need the memory chip organisation to match
> the cpu word size, having multiple lanes, burst read cache loading, even
> heterogenous regions (I suspect mostly in embedded systems for that, but
> y’never know).
>
> Yes, you’re moving twice as much stuff but it will still be a single read
> & write per word. After that you’re at the mercy of cache lines, write
> buffers, chip specs and not to mention the Hamsters.
>
> tim
> --
> tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
> We can rescue a hostage or bankrupt a system. Now, what would you like us
> to do?
>
>
>


-- 
Dr. Ciprian TEODOROV
Enseignant-chercheur
ENSTA Bretagne

tél : 06 08 54 73 48
mail : ciprian.teodorov at gmail.com
www.teodorov.ro
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