spec VS .NET Runtime

You can parse many things from this file, what are you trying to extract?

https://github.com/WebAssembly/spec/blob/main/document/core/...

Still strikes me as super sad JS never got SIMD support. It seemed like there were some strong candidate specs. On Node there are some add-on npm libraries that implement.

My understanding was the main protest was that we would get wasm & some certain implementers said they wanted to focus their energy on wasm.

That was well over half a decade ago & wasm is still in incredible infancy, with basically only statically linked capabilities in the spec.

Wasm SIMD proposal itself only merged into wasm in November 2021. https://github.com/WebAssembly/spec/pull/1391

It seems really unfortunate to have decided to keep JS the slow inferior language.

Blazor and WASM itself (outside of dotnet) are relatively new tools and they already show impressive results. They will keep getting better with every release. E.g. this proposal https://github.com/WebAssembly/spec/blob/main/proposals/simd/SIMD.md which should bring WASM closer to "near native speed". Blazor already started working on it true.

Big fan of this author's work.

They have a Gameboy emulator written in C, which can be compiled to WASM and run in the browser.

https://github.com/binji/binjgb

I learned a lot from the code.

Also I love this project with a bunch of demos in hand-written WebAssembly Text (WAT) format, which is like low-level Lisp that works only with raw memory, numbers, and minimal syntax.

https://github.com/binji/raw-wasm

Then I discovered the same author is quite active in the WebAssembly ecosystem, including specs and tooling. Fascinating stuff!

https://github.com/WebAssembly/spec

https://github.com/WebAssembly/wabt

[The WebAssembly specification (https://webassembly.github.io/spec/) maintains that the standards apply to more than just the browser host, but also to any other compliant host runtime (what the specification refers to as an embedder).

Heya,

(1) Thank you for implementing this in JSC!! I hope they take it, it makes it into Safari, and the tail-call proposal advances.

(2) I don't think you are exactly right about the call stack being observable via thrown exceptions. There's no formal spec for the v3 exceptions proposal yet, but in the documents and tests, there's nothing that would change in WebAssembly core to make the call stack observable. It's true that the proposal amends the JS API (but only the JS API) to describe a traceStack=true option; from Wasm's perspective I understand that's just an ordinary exception that happens to include an externref value (just like any other value) to which Wasm itself attaches no special significance. The engine can attach a stack trace if it wants, but there's no requirement (here) about what that stack trace contains or whether some frames might have been optimized out.

(3) I think the real reason that a Wasm engine can't implicitly make tail calls proper is that the spec tests forbid it, basically because they didn't want the implementation base to split by having some engines perform an optimization that changes the space complexity of a program, which some programs would have started to depend on (the spec tests say: "Implementations are required to have every call consume some abstract resource towards exhausting some abstract finite limit, such that infinitely recursive test cases reliably trap in finite time. This is because otherwise applications could come to depend on it on those implementations and be incompatible with implementations that don't do it (or don't do it under the same circumstances.)" More discussion here: https://github.com/WebAssembly/spec/issues/150

The WASM paper discusses that in the final section: https://github.com/WebAssembly/spec/blob/master/papers/pldi2017.pdf

WebAssembly has a formal specification that includes both operational semantics and natural language-based descriptions of everything in the language. The official repository also has a lot of tests. Besides tests, you should be able to find lots of examples by searching.

It's an interesting "time is a circle" problem given that a century only has 100 years and then we loop around again. 2-digit years is convenient for people in many situations but they are very lossy, and horrible for machines.

It reminds me of this breaking change to .Net from last year.[1][2] Maybe AA just needs to update .Net which would pad them out until the 2050's when someone born in the 1950s would be having...exactly the same problem in the article. (It is configurable now so you could just keep pushing it each decade, until it wraps again).

Or they could use 4-digit years.

[1] https://github.com/dotnet/runtime/issues/75148

These can also be passed as arguments to `dotnet publish` if necessary.

Reference:

- https://learn.microsoft.com/en-us/dotnet/core/deploying/nati...

- https://github.com/dotnet/runtime/blob/main/src/coreclr/nati...

- https://github.com/dotnet/runtime/blob/5b4e770daa190ce69f402... (full list of recognized keys for IlcInstructionSet)

Yes, that is true. I'm not sure about JVM implementation details but the reason the comment says "virtual and interface" calls is to outline the difference. Virtual calls in .NET are sufficiently close[0] to virtual calls in C++. Interface calls, however, are coded differently[1].

Also you are correct - virtual calls are not terribly expensive, but they encroach on ever limited* CPU resources like indirect jump and load predictors and, as noted in parent comments, block inlining, which is highly undesirable for small and frequently called methods, particularly when they are in a loop.

* through great effort of our industry to take back whatever performance wins each generation brings with even more abstractions that fail to improve our productivity

[0] https://github.com/dotnet/coreclr/blob/4895a06c/src/vm/amd64...

[1] https://github.com/dotnet/runtime/blob/main/docs/design/core... (mind you, the text was initially written 18 ago, wow)

If you care about portable SIMD and performance, you may want to save yourself trouble and skip to C# instead, it also has an extensive guide to using it: https://github.com/dotnet/runtime/blob/69110bfdcf5590db1d32c...

CoreLib and many new libraries are using it heavily to match performance of manually intensified C++ code.

DEBUG: packageFiles with updates (repository=local) "config": { "nuget": [ { "deps": [ { "datasource": "nuget", "depType": "nuget", "depName": "Microsoft.Extensions.Hosting", "currentValue": "7.0.0", "updates": [ { "bucket": "non-major", "newVersion": "7.0.1", "newValue": "7.0.1", "releaseTimestamp": "2023-02-14T13:21:52.713Z", "newMajor": 7, "newMinor": 0, "updateType": "patch", "branchName": "renovate/dotnet-monorepo" }, { "bucket": "major", "newVersion": "8.0.0", "newValue": "8.0.0", "releaseTimestamp": "2023-11-14T13:23:17.653Z", "newMajor": 8, "newMinor": 0, "updateType": "major", "branchName": "renovate/major-dotnet-monorepo" } ], "packageName": "Microsoft.Extensions.Hosting", "versioning": "nuget", "warnings": [], "sourceUrl": "https://github.com/dotnet/runtime", "registryUrl": "https://api.nuget.org/v3/index.json", "homepage": "https://dot.net/", "currentVersion": "7.0.0", "isSingleVersion": true, "fixedVersion": "7.0.0" } ], "packageFile": "RenovateDemo.csproj" } ] }

https://github.com/dotnet/runtime/issues/59591

Support zstd Content-Encoding:

We might not be that far away already. There is this issue[1] on Github, where Microsoft and the community discuss some significant changes.

There is still a lot of questions unanswered, but initial tests look promising.

Ref: https://github.com/dotnet/runtime/issues/94620

https://github.com/dotnet/dotnet exists for source build that stitches together SDK, Roslyn, runtime and other dependencies. A lot of them can be built and used individually, which is what contributors usually do. For example, you can clone and build https://github.com/dotnet/runtime and use the produced artifacts to execute .NET assemblies or build .NET binaries.

Yeah, it kind of is. There are quite a few of experiments that are conducted to see if they show promise in the prototype form and then are taken further for proper integration if they do.

Unfortunately, object stack allocation was not one of them even though DOTNET_JitObjectStackAllocation configuration knob exists today, enabling it makes zero impact as it almost never kicks in. By the end of the experiment[0], it was concluded that before investing effort in this kind of feature becomes profitable given how a lot of C# code is written, there are many other lower hanging fruits.

To contrast this, in continuation to green threads experiment, a runtime handled tasks experiment[1] which moves async state machine handling from IL emitted by Roslyn to special-cased methods and then handling purely in runtime code has been a massive success and is now being worked on to be integrated in one of the future version of .NET (hopefully 10?)

[0] https://github.com/dotnet/runtime/issues/11192

[1] https://github.com/dotnet/runtimelab/blob/feature/async2-exp...