WebAssembly
Any plans for wasm64 support?
Are there any plans to support 64-bit builds?
It looks to me like wasm64 (also known as "memory64") uses a LP64 model (int is 32 bits, long, long long, and pointers are 64 bits), which is the same as the memory model on 64-bit Unix-y platforms (not Windows, where long is still 32 bits even on x86_64).
Yes; the main work right now is happening in upstream LLVM (eg. here).
There will also need to be some amount of work to port wasi-libc. All the code in wasi-libc is written with a wasm64 target in mind. We'll need a 64-bit version of the WASI APIs as well, and the code for that is also all written with a wasm64 target in mind. So in theory this should be a straightforward process.
Exciting!
I have a strong vested interest in seeing WASM succeed as a server-side plugin (and write-once, run-anywhere code distribution) platform. There are a few missing pieces:
- 64-bit support
- threads
- sockets
- stack unwinding / exception handling
but it seems that all 4 areas are seeing a lot of active work, which means 2022 will be an exciting year for WASM.
It's been a few years and the clang link seems to have been resolved. Any updates?
I don't see anyone working on this too closely at the moment: are you interested in adding support for wasm64-wasi?
If it isn't a bunch of work. Are there assumptions being made that make this a big effort, or is it a simple change?
I would hope its not too much work. I imagine most things will just work. The biggest change is likely that would we would need to start shipping all of our pre-built libraries in wsam64 variants.
I'd be interested in seeing wasi-sdk support wasm64, if everything is ready for it. Seems that the first thing to do would be to make wasi-libc support wasm64 ; should we open an issue there ?
There's been some work already on that in https://github.com/WebAssembly/wasi-libc/pull/444 but there are concerns about how that is implemented so I think some discussion is needed. @loganek is also interested in making this happen and has added an agenda item to the WASI subgroup meeting to have that discussion: https://github.com/WebAssembly/meetings/pull/1479. Can you join that?
Thanks, I did checked the issues but not the PRs. I just joined the WebAssembly CG and filled the form for the meeting. I'll be there.