Viewing profile — syg

This kind of elision is implemented.

Yeah this is the bug. My bad, will fix.

Only if your implementation holds doubles without boxing them. V8 boxes doubles, but JSC and SpiderMonkey do not.

Well I'm trying to make it suck less.

To be more precise, aligned to whatever size such that you can guarantee field writes that don't tear. Pointer-aligned is a safe bet. 4-byte aligned should be okay too on 64bit arc…

The ability to do unordered operations on shared memory is important in general to write performant multithreaded code. On x86, which is very close to sequentially consistent by de…

Author here. I hear your feedback about unsafe blocks. Similar sentiment is shared by other delegates of the JS standards committee. The main reason it is there today is to satisfy…

Exactly right. `arr[-1]` means `arr["-1"]` and already does something.

WeakRef and FinalizationRegistry will ship in Chrome 84.

Indeed it's a semantic change. Are you saying you'd like that change to be proposed separately? That can't be done for the text format for the obvious compat reasons. It also has v…

Early error behavior is proposed to be deferred (i.e. made lazy), not skipped. Additionally, it is one of many things that require frontends to look at every character of the sourc…

The gzip point aside (which is not an apples-to-apples comparison as gzipping a big source does not diminish its parse time), I see the response of "JS devs need to stop shipping s…

Please do not disparage an entire committee because you disagree philosophically with one proposal in it.

This is important, as there seems to be a lot of misunderstanding in this thread. What's proposed is structural compression of JS with JS-specific bits to speed things up even more…

The current draft is available at http://tc39.github.io/ecmascript_sharedmem/shmem.html The two strengths provided by the model are sequentially consistent atomics and something be…

Shu here. I'm the person drafting the memory model for the SharedArrayBuffer spec, and as Dave says, it'll be the basis for the wasm story as well. Lars Hansen deserves most of the…

The slowness of functional methods like .map and .forEach for a time was due to their not being self-hosted. Since then, both V8 and SpiderMonkey self-host them, and bz has posted …

I actually don't think we're sharing any code with Gordon. But yes, the name is this obscure transitive-closure reference: (Adobe) Flash -> (Flash) Gordon -> (Gordon) Shumway.

To be more precise, JITs on top of JITs. :) We have both an interpreter for ActionScript bytecode as well as a compiler that compiles that bytecode method-at-a-time to JavaScript u…

There's a CoffeeScript dialect with those features for use optionally. It also emits the typed array-style of JS code, though.