[Vm-dev] Re: [squeak-dev] re: compiled squeakjs
Yoshiki.Ohshima at acm.org
Mon Jan 19 18:33:01 UTC 2015
On Mon, Jan 19, 2015 at 6:21 AM, Craig Latta <craig at netjam.org> wrote:
>> As I understand it, running under NaCl requires reworking the JIT and
>> has real problems doing the self-modifying code involved in inline
>> caches, etc.
> Yep, you rebuild your app to use the NaCl instruction set, and it
> translates to physical instructions on demand. The "safety" constraints
> it places on the code you generate are substantial. If you were even
> allowed to run the code you want, the performance goal would be demolished.
"Demolished" is probably a too strong word; The Mono JIT they ported
to NaCl only slowed down something like 7%. (Not going through the
PNaCl layer but just x86 nacl code.) So that is not that bad...
> But worse, you've also demolished the "run anywhere" goal from the
> outset, by limiting yourself to browsers that support NaCl. And I don't
> see how to meet this goal with any browser-plugin approach. There just
> isn't a widely-supported mechanism anymore, after the death of the
> Netscape-style plugin.
Yes, this is a real issue. In that regard, asm.js has a better
it may not give us the real Cog performance.
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