Tracking Issue for merging to upstream (LLVM-57)

[polarathene]

I understand it will take quite some time for this backend to be merged upstream into LLVM.

This issue is for notifying anyone that subscribes to it when the merge to upstream has completed closing this issue.

[DarkWiiPlayer]

Is there a rough ETA or roadmap for this?

[igrr]

The patches are in review (see links in https://esp32.com/viewtopic.php?t=11412#p46446) and further timeline will depend on the review process. We will keep updating the patch set to address the feedback!

[breckwagner]

The patches are in review (see links in https://esp32.com/viewtopic.php?t=11412#p46446) and further timeline will depend on the review process. We will keep updating the patch set to address the feedback!

From Espressif Forum post Re: Status of LLVM support?

• D64826: [Xtensa 1/10] Recognize Xtensa in triple parsing code.
• D64827: [Xtensa 2/10] Add Xtensa ELF definitions.
• D64829: [Xtensa 3/10] Add initial version of the Xtensa backend.
• D64830: [Xtensa 4/10] Add basic *td files with Xtensa architecture description.
• D64831: [Xtensa 5/10] Add Xtensa MCTargetDescr initial functionality.
• D64832: [Xtensa 6/10] Add Xtensa basic assembler parser.
• D64833: [Xtensa 7/10] Add Xtensa instruction printer.
• D64834: [Xtensa 8/10] Add support of the Xtensa shift/load/store/move and processor control instructions.
• D64835: [Xtensa 9/10] Add basic support of Xtensa disassembler.
• D64836: [Xtensa 10/10] Add relaxations and fixups. Add rest part of Xtensa Core Instructions.

Status as of 2019-12-24
[x] = Accepted [ ] = Needs Review

[igrr]

We are moving this and other issues to https://github.com/espressif/llvm-project, which will host the Xtensa patches for LLVM based on the new monorepo layout. This new repository will be updated with Xtensa patches based on LLVM 9 soon.

[andreisfr]

@polarathene, @DarkWiiPlayer , @breckwagner, we updated current patches (1-10), which are in LLVM review, according to changes in upstream version and reviewers requests for changes.

[lexxvir]

Hi @andreisfr,

Is there any plan/way to merge this fork into the upstream?

I've skimmed some pull requests on the reviews.llvm.org, it seems the process is stalled.

[andreisfr]

Hi @lexxvir,

Yes, we plan to continue integration process of the Xtensa backend to the upstream.

[windoze]

Is there any progress for this?
I'm dying to see it merging into upstream, it's really a PITA to build the whole LLVM/Clang project from the scratch in a CI pipeline.

[shymega]

Hey, hope you don't mind me chasing this up 😄 I've been getting ready to start work on Rust code for an ESP32, but without official LLVM and Rust support, I fear I'll have to use C. It does take ages to compile as well. I might be able to influence a different chip, but I think the ESP32 is a solid choice.

Thanks.

[torpak]

It seems nobody at LLVM is even answering since may. Does anyone know a reason for this?

[clouds56]

@torpak according to this https://reviews.llvm.org/D64830#2615149 comment, I think they are waiting the author to rewrite a RFC since things changed a lot.
Correct me if wrong.

[Hao123br]

@clouds56 the author already sent another RFC but had no response. https://lists.llvm.org/pipermail/llvm-dev/2021-March/149090.html

[clouds56]

@Hao123br thanks for the link, shall we also provide the link in the thread and ping aykevl & tstellar, maybe they are too busy and missing the RFC?