Stream: t-compiler

Topic: Closing issues related to llvm_asm!


Amanieu (May 20 2020 at 22:23, on Zulip):

We have a lot of open issues about the various bugs in llvm_asm!. At the moment there is no plan to fix these, we are instead encouraging people to migrate to the new asm! instead. Should we go ahead and close most of these issues if they do not apply to the new asm!?

Amanieu (May 20 2020 at 22:27, on Zulip):

https://github.com/rust-lang/rust/labels/A-inline-assembly

Amanieu (May 20 2020 at 22:30, on Zulip):

I figure we can close about 40 issues.

Gary Guo (May 20 2020 at 23:08, on Zulip):

Wouldn't it make more sense to wait until the new asm! lands on nightly? Until then users of llvm_asm! couldn't migrate and check if their issue is still relevant with the new asm! syntax.

Jonas Schievink (May 20 2020 at 23:11, on Zulip):

It has landed

Gary Guo (May 20 2020 at 23:17, on Zulip):

It's on master now but I don't a nightly with it is released yet.

Gary Guo (May 20 2020 at 23:18, on Zulip):

Anyway probably it's better to wait a little to allow ppl to try the new asm first

Jonas Schievink (May 20 2020 at 23:19, on Zulip):

Most issues are LLVM crashes and rustc ICEs, so they can probably all be closed as wontfix immediately (unless asm! has the same bug)

Vadim Petrochenkov (May 21 2020 at 06:20, on Zulip):

Yeah, it would be nice to translate all the issues into the new asm! (if possible) and verify that they don't reproduce.
Perhaps some of them are LLVM issues independent from our asm flavor.

simulacrum (May 21 2020 at 13:12, on Zulip):

I would support that policy -- translate and check. If there's an easy to use guide for how to do so (we should definitely have one!) then I imagine we could largely get the community to provide the translations, too.

I do think we should have a policy going forward of closing llvm_asm! issues that get filed, and asking filer(s) to try with asm! and file new issues as needed.

nikomatsakis (May 22 2020 at 18:44, on Zulip):

I definitely think that trying to enlist community to do that translation would be better than having @Amanieu try to do it all by themselves...

nikomatsakis (May 22 2020 at 18:45, on Zulip):

...I also think a plausible strategy might to leave a comment on each issue, encouraging the OP or others to port it to the new asm!, and after some amoutn of time, close the rest

nikomatsakis (May 22 2020 at 18:45, on Zulip):

that + publish a list somewhere of the issues and try to get eyeballs

nikomatsakis (May 22 2020 at 18:45, on Zulip):

Actually @Amanieu I think an Inside Rust! blog post about the new asm! syntax would be a nice thing to do

Amanieu (May 22 2020 at 18:45, on Zulip):

It's not such a big deal, most of the issues are caused by passing invalid types to asm!. These are all rejected by the new asm! type checking.

nikomatsakis (May 22 2020 at 18:45, on Zulip):

and at the end there could be a

Next steps

that encourages people to try it out, give feedback, and/or do any kind of rote work we want

nikomatsakis (May 22 2020 at 18:46, on Zulip):

ok, regardless I think it'd be great to have a blog post touting the new feature :)

nikomatsakis (May 22 2020 at 18:46, on Zulip):

or maybe @Josh Triplett wants to do it

nikomatsakis (May 22 2020 at 18:46, on Zulip):

I'd probably just crib from the RFC

nikomatsakis (May 22 2020 at 18:46, on Zulip):

i.e., include a few examples and things

nikomatsakis (May 22 2020 at 18:46, on Zulip):

the text was already pretty darn readable

Josh Triplett (May 22 2020 at 18:46, on Zulip):

I would be quite happy to write such a blog post.

Amanieu (May 22 2020 at 18:59, on Zulip):

I can help review the blog post if you like.

Josh Triplett (May 22 2020 at 19:42, on Zulip):

Currently drafting.

Josh Triplett (May 22 2020 at 19:43, on Zulip):

I plan to include a simple hello world example, but if you have an example of using asm for acceleration, that might help as well.

Josh Triplett (May 25 2020 at 08:53, on Zulip):

https://github.com/rust-lang/blog.rust-lang.org/pull/600

Last update: Jun 04 2020 at 17:50UTC