Is there any generic cpu model support for RVV？Or how to add a cpu model for RISCV?

[dinyy]

While I‘m tryring OpenCL(PoCL) on RISC-V，it call llvm to generate it's kernel. I want to use -march=rv64gcv, but it occurs that I need -mcpu when I use opt. I need a cpu model which support RVV.
Now I change the code in llvm-project/llvm/lib/Target/RISCV/RISCVProcessors.td that :

but I don't find other place to change,I saw that page,but code has been changed so much.

[dinyy]

I saw a PR here.But it occured some conflicts.

[llvmbot]

@llvm/issue-subscribers-backend-risc-v

Author: None (dinyy)

While I‘m tryring OpenCL(PoCL) on RISC-V，it call llvm to generate it's kernel. I want to use `-march=rv64gcv`, but it occurs that I need `-mcpu` when I use opt. I need a cpu model which support RVV. Now I change the code in `llvm-project/llvm/lib/Target/RISCV/RISCVProcessors.td` that :  but I don't find other place to change,I saw that [page](https://discourse.llvm.org/t/custom-risc-v-processor-can-be-selected-via-mcpu-in-llc-but-not-in-clang/5849),but code has been changed so much.

[topperc]

When https://discourse.llvm.org/t/custom-risc-v-processor-can-be-selected-via-mcpu-in-llc-but-not-in-clang/5849 was written, there were two files that contained the list of CPUs. One for the backend and one for the frontend.

Since early 2023, RISCVProcessors.td is used by both the frontend and the backend.

[michaelmaitland]

I saw a PR #84877 it occured some conflicts.

Have you seen #76357?

I think -march=rva23s64 and -march=rva23u64 profile has V extension. I did search for +v on this commit. You can see more about what extensions are part of which profiles here.

[topperc]

I think -march=rva23s64 and -march=rva23u64 profile has V extension. I did search for +v on this commit. You can see more about what extensions are part of which profiles here.

-march is a clang option. The description mentions the opt tool which does not support -march

[dinyy]

I think -march=rva23s64 and -march=rva23u64 profile has V extension. I did search for +v on this commit. You can see more about what extensions are part of which profiles here.

-march is a clang option. The description mentions the opt tool which does not support -march

So I must add a cpu model, do you mean I could add a cpu model just by changing llvm-project/llvm/lib/Target/RISCV/RISCVProcessors.td?
But I added as above picture, and failed.

[michaelmaitland]

63f742c might help you see what is needed to add a new mcpu. It looks like you were on the right path in your original screen shot.

[dinyy]

63f742c might help you see what is needed to add a new mcpu. It looks like you were on the right path in your original screen shot.

Thank you very much, I will try again.

[wangpc-pp]

I saw a PR here.But it occured some conflicts.

I can fix these conflicts and thanks for raising this problem! I think this can be a good use case to push #84877 forward. cc @asb @preames