There are other resources to learn about the LLVM JIT through online documentation and examples. In the LLVM source tree, <llvm_source>/examples/HowToUseJIT and <llvm_source>/examples/ParallelJIT contain simple source code examples that are useful for learning the JIT basics.

The LLVM kaleidoscope tutorial at http://llvm.org/docs/tutorial contains a specific chapter on how to use JIT http://llvm.org/docs/tutorial/LangImpl4.html.

More information on MCJIT design and implementation can also be found at http://llvm.org/docs/MCJITDesignAndImplementation.html.