Directly emit LLVM IR?

Hello! I'm interested in using LLVM as a target for a compiler I've
written in common lisp (SBCL). While I looked at perhaps wrapping the
LLVM C++ interface, wrapping C++ in, well, anything not C++ is a pain.
Someone on IRC mentioned that they didn't think I'd miss out on any
functionality by directly emitting IR, but suggested I query the list.

Do I miss out on any optimizations or other neat trickery by using the
IR directly? Does anyone know of any other platforms which directly
target LLVM via emitting IR?

      ...Eric Jonas