[sanxiyn]

The single most important topic of LLVM compilation time is missing: FastISel. As shown, all time is spent in IR to machine code step. That's because LLVM's default for codegen is optimizing. For debug build, you want to set LLVM's codegen to fast mode.

[BubRoss]

How do you turn that option on? (A Google search actually returns your comment as the first result and some more links to JIT PDFs)