Rustc_codegen_cranelift (cg_clif) is an alternative backend for rustc that I have been working on for the past two years. It uses the Cranelift code generator. Unlike LLVM which is optimized for output quality at the cost of compilation speed even when optimizations are disabled, Cranelift is optimized for compilation speed while producing executables that are almost as fast as LLVM with optimizations disabled. This has the potential to reduce the compilation times of rustc in debug mode.
