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

[Ciprian Teodorov]

It is strange, to me it seems like the <primitive: 148> fails back to the
smalltalk implementation (http://bit.ly/2kjYdHv).
However when trying to copy a small array like #(1 2 3 4) copy I cannot
step-into the #shallowCopy
nor when I try to copy a big array like   (1 to: 100000) asArray copy

However, when I do cmd+. while running my bench the debugger stops in the
shallowCopy

is this a debugger thing ?
or the primitive really fails ? -- which can explain the > 2.6 slowdown

best regards,
cip

On Mon, Feb 6, 2017 at 7:36 PM, Ciprian Teodorov <ciprian.teodorov at gmail.com
> wrote:

> 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
>



-- 
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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