Just in Time Compilation

Just in time compilation compiles code into fast machine code at runtime, right when it’s needed

ChatGPT summary:

1. Program starts quickly using bytecode or an interpreter.
2. It watches what code you execute most (“hot” functions/loops).
3. When something becomes hot, it compiles that piece into optimized machine code.
4. Next time you hit that code path, it runs much faster.
5. If the program’s behavior changes, the JIT can re-optimize (or sometimes “de-optimize” if assumptions stop being true).

Trade offs:

• Warm-up time: performance ramps up after the JIT compiles hot code.
• More memory/CPU overhead: compiling while running costs resources.
• Less predictable latency: that first time hitting a hot function might trigger compilation pauses (runtimes try to minimize this).