There was a recent article on code optimization technique in Safari involving on-the-fly javascript -> LLVM compilation. So the entire chain now will look as C++ -> LLVM -> javascript (asm.js) -> LLVM
Things are getting curiouser by the day...
The LLVM phase is really an alternative to the existing DFG JIT, and more precisely to the final phase thereof: the front of the DFG JIT is still used up to CPS optimisations, then it branches right before codegen: DFG generates its code directly while FTL converts DFG to SSA, applies SSA optimisations, converts to LLVM IR and passes the IR to LLVM for codegen.