How to configure OpenCL for a custom core

Hello, I am a beginner in llvm. I am also a beginner at OpenCL. I want to use OpenCL to compile code for a RISC-V core(rv32gcv let’s say). The processor is in a many-core structure so it is better to use OpenCL advantages. I have some questions.
How to compile openCL for RISC-V? For example, there are many example codes on the web like simple vector addition. Also, I have both clang and RISC-V gnu toolchain separately but I don’t have the OpenCL libraries for my core. I don’t know which libraries I can use for my processor because it has a possibly different number of processing elements, W-G size… compared to the example target on the web. Should I write my own libraries matching my processor structure?