jank's custom IR is completely separate and unrelated to LLVM IR, aside from both of them being SSA-based IRs. We go from jank's AST into jank's IR into C++, which we then give to Clang compile into the LLVM JIT runtime. So LLVM IR is used in the pipeline, but we don't touch it directly. More info on that, and a diagram, is here: https://book.jank-lang.org/dev/ir.html (which I linked in the post)