Any possible way to use llvm to generate *.riscv file for testing ?

[ilo5u]

I've done some works adding several custom RISCV RoCC instructions in llvm. And successfully using clang and riscv-gnu-toolchain to compile *.c source into riscv64-elf executable, now I want to run simulation in chipyard with RocketConfig simulator but haven't found ways to by using llvm. Thanks for any guides !