[llvm] [bolt][aarch64] Add R_AARCH64_P32_ABS16/32 relocations (PR #143773)

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whubeibei wrote:

> > I'd say it's more that this PR is still unfinished :)
> > 
> > * [[BOLT][AArch64] Add jump table support using .llvm_jump_table_info #132114](https://github.com/llvm/llvm-project/pull/132114)
> > 
> > Mystery solved then. Τhanks for being keen and trying it out! Would you mind if I go ahead and close #143709 ?
> > BTW, @aaupov is the diff rendering properly here?
> > 
> > * https://github.com/llvm/llvm-project/pull/132114/files
> > 
> > When I pull that PR locally I see changes on 17 files, including JumpTable.cpp, but online I only see 7 changed files.
> 
> I agree with closing about #143709

thanks for your earlier comment!

based on the jump table support introduced in PR #132114.

As we noted, BOLT attempts to generate relocations for jump table entries, but currently there is no suitable relocation type for these entries on AArch64.

Since I’m still not very familiar with BOLT internals and ARM architecture specifics, I would like to seek more detailed guidance on how to properly improve or extend the implementation to handle this case.

Specifically:
- Should we define a new AArch64 relocation type within BOLT for jump table entries?
- Or is there an alternative approach recommended for jump tables using `.byte` offset entries without relocations?
- Or are there any other best practices or existing mechanisms in BOLT that I might have overlooked?

I’m eager to learn and contribute to the fix once I better understand the recommended path forward.

Thank you very much for your advice and help!

  

https://github.com/llvm/llvm-project/pull/143773