LLVM Social #22 - Writing a custom IR transformation pass

Happy new year everyone! For our first gathering in 2023, we have Yoshitomo Nakanishi talking about writing your custom LLVM-IR transformation pass.

Abstract:
The IR transformation plays an important role in machine-independent optimizations. One of the prominent features of LLVM is its beautiful design which allows us to write our custom IR transformation passes with minimum effort. Ok, let's dive into the attractive transformation world!

In the first half of the meetup, we'll see
1. Basic data structures essential for data flow analysis
2. LLVM architecture to write your custom transformation passes
3. The usage of the "FileCheck" testing utility to verify the transformation

In the last half, we'll learn a real-world optimization pass and tips through a custom "Mem2Reg" implementation.

As discussions fade into casual conversation, we may go for drinks to c-base or one of the surrounding bars. There is always space for other topics and discussions, so please bring your questions. Looking forward to meeting everyone in 2023!