1. Getting Started with LLVM Core Libraries It's a bit dated (covers DAGISel rather than GlobalISel) but it gives a thorough introduction. 2. LLVM Developer M

1. Getting Started with LLVM Core Libraries It's a bit dated (covers DAGISel rather than GlobalISel) but it gives a thorough introduction. 2. LLVM Developer Meeting tutorials These are really good although you'll have to put them in order yourself. They will be out of date, a little. LLVM is a moving target. Also, you don't have to go through every tutorial. For example, MLIR is not for me. 3. LLVM documentation I spent less time reading this than going through the Developer Meeting tutorials. I generally use it as a reference. 4. Discord, LLVM email list, git blame, LLVM Weekly ... because you will have questions. 5. MyFirstTypoFix (in the docs) ... when it comes time to submit a patch. 6. Mips backend If you're doing a backend, you will need a place to start. The LLVM documentation points you to the horribly out of date SPARC backend. Don't even touch that. AArch64 and x86 are very full featured and thus very complex (100 kloc+). Don't use those either. RISC-V is ok but concerns itself mostly with supporting new RISC-V features rather than keeping up to date with LLVM compiler services. Don't use that either although definitely work through Alex Bradbury's RISC-V backend tutorials. Read the Mips backend. It is actively maintained. It has good GlobalISel support almost on par with the flagship AArch64 and x86 backends. BTW, Chris Lattner is a super nice guy.