2023 Summary

Posted on October 28, 2023

Summary

This year marks my first continuous involvement in open-source contributions. I've fixed numerous mis-compilation, added missing optimizations, and included LTO, debugging info, built-in functions, WebAssembly, and even an issue with Apple Silicon.

During this journey, I was fortunate to receive numerous invaluable help, especially from those who reviewed my pull requests. Thank everyone very much. (●´∀｀●)

Highlight:

• Resolving a long-standing issue causing debugging info corruption under LTO.
• Adding the crate for built-in functions to LTO in Rust, addressing another long-standing issue.
• Adopting the English name "Quentin Dian" for better communication.

I've categorized my contributions using these emojis:

• 💢 Mis-compilation
• 🍻 Missing optimization
• ℹ️ Debugging info
• 🦀 Rust-related
• 🐉 LLVM-related
• 🐦 Swift-related
• 🍎 Apple-related
• ⏳ Blocked by other issues

LLVM

Commit history: https://github.com/llvm/llvm-project/commits?author=DianQK&since=2023-01-01&until=2023-12-31.

By the way, my first LLVM commit was [MachineOutliner] Fix the side effect of outlined function when the register is implicit use and implicit-def in the same instruction. D112911.

1. 🍻🦀⏳ [SimplifyCFG] Check if the return instruction causes undefined behavior D144319 Blocked by PR69498
2. 🍻⏳ [SimplifyCFG] Improve the precision of PtrValueMayBeModified D144563 Follows D144319, not blocked by PR69498
3. 💢🦀 [SROA] Remove UB-implying metadata when promoting speculative instruction. D148456 Fixes PR110256
4. 💢🦀 [GlobalOpt] Don't replace the aliasee if it has other references. D145293 Fixes PR108030
5. 🦀🐦ℹ️ [Verifier] definition subprograms cannot be nested within DICompositeType when enabling ODR. D152095
6. 🐦ℹ️ [Coroutine][DebugInfo] Update the linkage name of the declaration of coro-split functions in the debug info. D157184
7. 💢🦀 [TailCallElim] Remove the readonly attribute of byval. D156793
8. 💢🦀 [JumpThreading] Invalidate LVI after combineMetadataForCSE. #65219
9. 🍻🦀 [EarlyCSE] Compare GEP instructions based on offset #65875
10. 🍻🦀 [SimplifyCFG] Hoist common instructions on switch #67077
11. 💢🦀 [MemCpyOpt] Merge alias metadatas when replacing arguments #67539
12. 💢🦀 [LVI][CVP] Treat undef like a full range #68190
13. 💢 [LVI][CVP] Treat undef like a full range on abs(x, false) #68711
14. 💢🦀 [MemCpyOpt] Combine alias metadatas when replacing byval arguments #70580
15. 💢🦀🍎 [AArch64] ORRWrs is copy instruction when there's no implicit def of the X register #75184

Rust

Commit history: https://github.com/rust-lang/rust/commits?author=DianQK&since=2023-01-01&until=2023-12-31.

Apart from simple pull requests like updating test cases, my contributions mainly revolved around built-ins and LTO:

1. Add the no-builtins attribute to functions when no_builtins is applied at the crate level. #113716
2. Restore #![no_builtins] crates participation in LTO. #113923
3. Add thinlto support to codegen, assembly and coverage tests #118036
4. Avoid adding builtin functions to symbols.o #118568

Despite addressing many issues during this process, unfortunately, there are still some known issues that need resolution. I'll submit MCP once these issues are resolved.

Ruslin

I use Joplin for note-taking, but I don't want Joplin's Android client. Hence, I developed a compatible client: ruslin-android. I apologize for the lack of recent updates. I plan to adjust my spare time next year. I'm also considering desktop development.

Other Projects

• ℹ️🍎 [swift][IRGen][DebugInfo] split method declaration and definition. #67077
• ℹ️🍎 [swift][Backtracing][Linux] Support the DW_AT_specification attribute. #67592
• 🦀 [wasm3] Fix the issue of incorrectly freeing the stack address when unwinding local functions. #436
• 🦀 [dioxus] Fix the issue of duplicate unique ID for atoms using newtype. #1112

Personal Details

DianQK is just a casual Chinese pseudonym formed from the pinyin abbreviation of "靛(dian)" and "青(qing)", where "靛青" refers to indigo. It has led to confusion about how to call me. To resolve this, I asked ChatGPT for a name: Quentin Dian. So, you can call me Dian or dianqk.

I switched entirely from Arch Linux to NixOS, a fantastic operating system where I can manage everything with code.

To enhance my efficiency, I also purchased a GPD handheld console. I complete most of the code above using the GPD during my subway commutes. I assembled a machine with a 7950X processor, cutting my local build time in half. I can now complete a full compile in just a few minutes. I also bought a Mac Mini (M2) to test issues on that platform.