JIT Compilation

Purpose

Guide agents through just-in-time compilation: LLVM ORC JIT v2 (ExecutionSession, IRLayer, ObjectLayer), LLJIT for simpler use cases, Cranelift JIT, inline caches for dynamic dispatch, trampolines for lazy compilation, security considerations (W^X, code signing), and Rust dynasm for x86 codegen.

When to Use

• Building an interpreter with a JIT hot-path
• Implementing lazy function compilation on first call
• Embedding dynamic code generation in a REPL or game engine
• Prototyping codegen without writing a full linker
• Creating inline caches for polymorphic call sites
• Generating x86 machine code from Rust with dynasm

Workflow

1. JIT architecture overview