2019-03-17 09:24:24 +03:00
|
|
|
# Using experimental WebAssembly features
|
|
|
|
|
|
2020-04-24 19:00:46 +03:00
|
|
|
By default, Asterius only emits code that uses WebAssembly MVP features. There
|
2019-08-11 17:45:33 +03:00
|
|
|
are [flags](ahc-link.md) to make use of WebAssembly experimental features:
|
2019-03-17 09:24:24 +03:00
|
|
|
|
2019-08-11 17:45:33 +03:00
|
|
|
* `--tail-calls`: Emits tail call opcodes for Cmm function calls; overrides the
|
|
|
|
|
default trampoline approach. Only supported by the `wasm-toolkit` backend at
|
|
|
|
|
the moment.
|
|
|
|
|
* `--debug`: Uses i64 BigInt integration for passing i64 values between js/wasm.
|
2019-03-17 09:24:24 +03:00
|
|
|
|
2019-08-11 17:45:33 +03:00
|
|
|
The above features require specific flags to switch on in V8. They are known to
|
|
|
|
|
work in latest Node.js 12.x versions, and we test them on CI.
|
|
|
|
|
|
|
|
|
|
The V8 team maintains a Node.js 13.x build which integrates V8 trunk, described
|
|
|
|
|
[here](https://v8.dev/docs/node-next-generation). It's possible to use that
|
|
|
|
|
build to evaluate experimental WebAssembly features; we provide a
|
|
|
|
|
[script](https://github.com/tweag/asterius/blob/master/utils/v8-node.py) which
|
|
|
|
|
unzips the latest test-passing build to the current directory, so it's possible
|
2020-04-24 19:00:46 +03:00
|
|
|
to use the `node` binary for testing bleeding-edge Wasm features in V8.
|
2019-08-11 17:45:33 +03:00
|
|
|
|
|
|
|
|
We are keeping an eye on the development of experimental WebAssembly features.
|
|
|
|
|
Here is a list of V8 tracking issues of the features we are interested in. Some
|
|
|
|
|
are already available in recent Node.js or Chromium releases.
|
2019-03-17 09:24:24 +03:00
|
|
|
|
|
|
|
|
* [WebAssembly SIMD](https://bugs.chromium.org/p/v8/issues/detail?id=6020)
|
|
|
|
|
* [WebAssembly Multi-value](https://bugs.chromium.org/p/v8/issues/detail?id=6672)
|
|
|
|
|
* [WebAssembly nontrapping float-to-int conversions](https://bugs.chromium.org/p/v8/issues/detail?id=7226)
|
|
|
|
|
* [Tail call opcodes](https://bugs.chromium.org/p/v8/issues/detail?id=7431)
|
|
|
|
|
* [Reference types](https://bugs.chromium.org/p/v8/issues/detail?id=7581)
|
|
|
|
|
* [WebAssembly i64 BigInt integration](https://bugs.chromium.org/p/v8/issues/detail?id=7741)
|
|
|
|
|
* [WebAssembly JS Reflection API](https://bugs.chromium.org/p/v8/issues/detail?id=7742)
|
|
|
|
|
* [WebAssembly Bulk Memory](https://bugs.chromium.org/p/v8/issues/detail?id=7747)
|
2019-08-11 17:45:33 +03:00
|
|
|
* [Garbage Collection](https://bugs.chromium.org/p/v8/issues/detail?id=7748)
|
|
|
|
|
* [Exception handling](https://bugs.chromium.org/p/v8/issues/detail?id=8091)
|
