Guidence regarding RISCV target

In the directory : llvm/lib/Target/RISCV/ several files for V extension are present. Can someone please explain what is the purpose of the following files:

1. RISCVInstrInfoVPseudos.td
2. RISCVInstrInfoVSDPatterns.td
3. RISCVInstrInfoVVLPatterns.td

Thanks in anticipation :slightly_smiling_face:

P.S : I am trying to understand how intrinsics are lowered to assembly instructions in llvm. If you know about any useful resource, kindly share.