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Eliot, I read what you wrote about a partial read barrier (to own
memory for scans?) to support fast become which allows for
forwarders in the stack execution. Is this right? If so it is a
read barrier into ObjectMemory. And so I think the forwarders access
the CPIC somehow.<br>
<br>
I was under a different conceptualization...that if you had a
read-only mode, where all non-local/temp variables were immutable
(you could set local vars), then more than one OS thread could be in
the image, if only one had the write lock. Perhaps this is a write
barrier.<br>
<br>
The idea being that the lookup could occur separately from the
invocation and could be threaded. Just a thought and I am not sure
where it may fit. Please carry on.<br>
<br>
best,<br>
robert<br>
<br>
<br>
<div class="moz-cite-prefix">On 12/19/2015 04:23 PM, Eliot Miranda
wrote:<br>
</div>
<blockquote
cite="mid:CAC20JE3Oz33G3LFxJqqox3mW+K-FTRpn34TjqFA=FVkeaTPdng@mail.gmail.com"
type="cite">
<pre wrap=""> </pre>
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<div class="gmail_extra"><br>
<div class="gmail_quote">On Fri, Dec 18, 2015 at 11:25 PM,
Robert Withers <span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:robert.w.withers@gmail.com" target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:robert.w.withers@gmail.com">robert.w.withers@gmail.com</a></a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex"> <br>
<div text="#000000" bgcolor="#FFFFFF"> <br>
<br>
<div>On 12/19/2015 02:09 AM, Eliot Miranda wrote:<br>
</div>
<blockquote type="cite">
<pre> </pre>
<br>
<fieldset></fieldset>
<br>
<div>Hi Robert,<br>
<br>
</div>
<div>On Dec 18, 2015, at 9:51 PM, Robert Withers <<a
moz-do-not-send="true"
href="mailto:robert.w.withers@gmail.com"
target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:robert.w.withers@gmail.com">robert.w.withers@gmail.com</a></a>>
wrote:<br>
<br>
</div>
<blockquote type="cite">
<div><span>Eliot, what does Sista do and how is that
accomplished? </span></div>
</blockquote>
<div><br>
</div>
Run-time adaptive optimisation via an SSA-based
image-level bytecode-to-bytecode inlining compiler.
See
<div><br>
<div><a moz-do-not-send="true"
href="http://www.mirandabanda.org/cogblog/on-line-papers-and-presentations/"
target="_blank">http://www.mirandabanda.org/cogblog/on-line-papers-and-presentations/</a></div>
<div><br>
<div><br>
<blockquote type="cite">
<div><span>It sounds like a next level kind of
system. Does it compare to what other JITs
are doing in various VMs?</span><br>
</div>
</blockquote>
<div><br>
</div>
Yes it does. Clément recently attended a
workshop at Google and found that Sista is very
similar in the kinds of optimisations it
performs to V8 and Dart. The key research
funding will be how close the performance of
targeting stack-oriented bytecode that the Cog
JIT converts to register-based code can be made
to JITs that directly target register-based
machine code.</div>
</div>
</div>
</blockquote>
<br>
This sounds like you are saying that Sista performs
better or more naturally with stack-oriented bytecode.
If you wouldn't mind taking the time to explore it with
us, what's the difference between stack-oriented and
register-based code, such that Sista would be different
between them? I'm off to read some.<br>
</div>
</blockquote>
<div><br>
</div>
<div>I'd rather not. That's something there's lots of papers
on, and I'm not sure it's really important that I
explain. Yoiu can inform yourself, and the Sista talks I
pointed to at least mention the topic. I will say that
our thesis is that we can generate efficient
register-based machine code from stack-oriented bytecode,
and that's one of the things we're trying to demonstrate
with Sista.</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF"> <br>
<br>
<blockquote type="cite">
<div>
<div>
<div><span
style="background-color:rgba(255,255,255,0)"><br>
</span></div>
<div><span
style="background-color:rgba(255,255,255,0)">_,,,^..^,,,_
(phone)</span></div>
<div><span
style="background-color:rgba(255,255,255,0)"><br>
</span></div>
<div>
<blockquote type="cite">
<div><span></span><br>
<span>thank you,</span><br>
<span>robert</span><br>
<span></span><br>
<span>. .. ...
^,^</span><br>
<span></span><br>
<span></span><br>
<span></span><br>
<span>On 12/18/2015 11:11 PM, Eliot Miranda
wrote:</span><br>
<blockquote type="cite"><span> Further,
please keep the original Smalltalk
non-primitive implementation around do
that when we deliver Sista we can see
how well we stack up against C.</span><br>
</blockquote>
<blockquote type="cite"><span></span><br>
</blockquote>
<blockquote type="cite"><span>_,,,^..^,,,_
(phone)</span><br>
</blockquote>
<blockquote type="cite"><span></span><br>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span>On Dec 18,
2015, at 5:59 PM, David T. Lewis <<a
moz-do-not-send="true"
href="mailto:lewis@mail.msen.com"
target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:lewis@mail.msen.com">lewis@mail.msen.com</a></a>>
wrote:</span><br>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span></span><br>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span></span><br>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>On Fri,
Dec 18, 2015 at 08:13:00PM -0500,
Robert Withers wrote:</span><br>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span></span><br>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>On
12/18/2015 08:07 PM, David T.
Lewis wrote:</span><br>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span></span><br>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>If you
are implementing your algorithm
from scratch, then it would be</span><br>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>nice if
it could be done in Smalltalk,
because that means we can all</span><br>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>read it,
play with it in the image, and
write unit tests to validate and</span><br>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>document
its behavior. We can figure out
the translation to C afterwords,</span><br>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>once you
have a good implementation in
Smalltalk (and yes I will help</span><br>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>with
that).</span><br>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>I have a
smalltalk implmentation that came
from Google Java code and is</span><br>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>fully
implemented in squeak/pharo. I am
intermittently fixing byte</span><br>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>mutations
in the payload, so it is working to
a degree. Check out the</span><br>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>classes
GenericGF, GenericGFPoly and
GaloisField to see the insides.</span><br>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>FECEncoder
and FECDecoder are calling the
galoisField which builds a</span><br>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>ReedSolomon
Decoder. That last is where the
error detection occurs.</span><br>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span></span><br>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite">
<blockquote type="cite"><span>Thank you
all very much for looking out!</span><br>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span>I guess my
suggestion would be that once you have
a fairly good working</span><br>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span>implementation
that you are comfortable with from a
functional point of</span><br>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span>view, then
let's look at which methods in that
implementation would benefit</span><br>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span>from being
translated to primitives in C. It
would be especially good if</span><br>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span>you can run
a profiler on your Smalltalk
implementation and see where the</span><br>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span>time is
being spent. Those would be the things
we would want to turn into</span><br>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span>primitives.
But first things first, let's get it
working 100% (not "to a</span><br>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span>degree") and
then we can do the translation to
primitives.</span><br>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span></span><br>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span>Dave</span><br>
</blockquote>
</blockquote>
<blockquote type="cite">
<blockquote type="cite"><span></span><br>
</blockquote>
</blockquote>
<span></span><br>
<span>-- </span><br>
<span>. .. .. ^,^ robert</span><br>
</div>
</blockquote>
</div>
</div>
</div>
</blockquote>
<br>
<div>-- <br>
<div align="left">. .. .. ^,^ robert </div>
</div>
</div>
<br>
</blockquote>
</div>
<br>
<br clear="all">
<div><br>
</div>
-- <br>
<div class="gmail_signature">
<div dir="ltr">
<div><span
style="font-size:small;border-collapse:separate">
<div>_,,,^..^,,,_<br>
</div>
<div>best, Eliot</div>
</span></div>
</div>
</div>
</div>
</div>
</blockquote>
<br>
<div class="moz-signature">-- <br>
<div align="left">. .. .. ^,^ robert
</div>
</div>
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