A question about HalideIR

Hi, I have a small question in cpu code generation case.

I am wondering about the relationship between Halide and TVM.
I understood that TVM uses HalideIR to make AST and convert it to llvm IR. Is it right?

And one more thing, TVM seems to create llvm IR using llvm CodeGen after creating the AST,
is it right that clang(c frontend) is not used in this process? (I think CodeGen-llvm plays the role of clang instead.)
When will clang be used if it is right?

Thank you in advance.

no clang. Just relay LLVM library.