JIT performance of LLVM

Question

Can anybody provide some data showing the performance of code output by llvm's JIT, say compared to static compilation with -O3? It is better that such performance is illustrated by spec benchmark. People say code output by JIT is slow. I am just curious how slow it is.

Answer 1

Give this presentation a read, it covers benchmarks of the JIT generated code (for a JVM & .Net though, unfortunately, most benchmarks will for existing languages with a new JIT backend, such as Rubinius). There are also a few interesting graphs here.

As an added bonus, here is a presentation on building an efficient JIT with LLVM and Clang that covers memory usage and speed benchmarks of the JITing process, which can affect the speed and quality of generated code, if you do decide to create your own benchmarks.

However, you might find this question interesting as well.