Making calls to WebAssembly fast and implementing anyref

#1

Post by ag_dubs » Wed, Jul 04, 2018, 5:36 PM UTC

Making calls to WebAssembly fast and implementing anyref
blog.benj.me

Re: Making calls to WebAssembly fast and implementing anyref

#2

Post by Game_Ender » Thu, Jul 05, 2018, 2:13 AM UTC

I am curious to know if this also makes calls from WASM into JS faster. One of the issues with WASM is that you need the JS DOM API, it is essentially your OS abstraction layer, so faster that is, the better WASM will be.

Re: Making calls to WebAssembly fast and implementing anyref

#3

Post by msoad » Thu, Jul 05, 2018, 3:15 AM UTC

Game_Ender wrote: post #2

I am curious to know if this also makes calls from WASM into JS faster. One of the issues with WASM is that you need the JS DOM API, it is essentially your OS abstraction layer, so faster that is, the better WASM will be.

JS DOM API is a bridge to a native implementation. I wish we could use DOM directly in WS. Problem is DOM calls are blocking but removing the JS layer can help.

Re: Making calls to WebAssembly fast and implementing anyref

#4

Post by devwastaken » Thu, Jul 05, 2018, 4:54 AM UTC

This is great. I've been tracking down performance issues in libraries porting to wasm due to what appears to be Emscripten having to do JS calls every time a function pointer is used for the equivalent wasm dynamic call.

On that issue i've spent the last month having to also go through and remake tooling for wasm because Emscripten is still stuck in the asm.js ages and isn't at all flexibly modifiable.

Re: Making calls to WebAssembly fast and implementing anyref

#5

Post by btown » Thu, Jul 05, 2018, 5:47 AM UTC

Is there documentation on what Chrome/v8 currently does here? Could a similar optimization be ported over?

Re: Making calls to WebAssembly fast and implementing anyref

#6

Post by bnjbvr » Thu, Jul 05, 2018, 9:53 AM UTC

Game_Ender wrote: post #2

I am curious to know if this also makes calls from WASM into JS faster. One of the issues with WASM is that you need the JS DOM API, it is essentially your OS abstraction layer, so faster that is, the better WASM will be.

We've had optimizations to make wasm -> JS calls fast for a long time, and they became even slightly faster (around 10 or 15%) last year. There is a proposal to add DOM integration within wasm, so one could import DOM functions in wasm and call them directly (from wasm to C++, without a "trampoline" in JS).

Re: Making calls to WebAssembly fast and implementing anyref

#7

Post by ThJ » Fri, Jul 06, 2018, 9:02 AM UTC

Still waiting for direct DOM/HTML5 API access. Then you could use any language that compiles to WASM as a front-end language. Until then, WASM is of limited interest to me.

EDIT: I mean, why wouldn't that be one of the first items on the agenda of WASM? I was surprised when I found out that this seemingly isn't high on the list of priorities. If WASM is meant exclusively for high performance sections of code, it makes more sense, but that's a bit dull if you ask me. The ability to use any compiled language as a front-end language is far more interesting.