You can't compare LLVM to native code, since these are different things. LLVM IR can be compiled to efficient native code if that's what you want. In fact, this

You can't compare LLVM to native code, since these are different things. LLVM IR can be compiled to efficient native code if that's what you want. In fact, this is what happens when you use clang+llvm to compile code into native executables. LLVM is much more than that, however. You might want to use it as a JITting interpreter of the IR instead of as a native compiler with all the benefits that may result from this. You may also use it as a sophisticated optimization framework (including cross-object, link-time optimization) taking IR and giving (optimized) IR back.