Number of VGPRs and SGPRs vs. hipDeviceProp_t::regsPerBlock

[maartenarnst]

I have a question about the member variable regsPerBlock of the struct hipDeviceProp_t. The documentation indicates that this variable provides the "number of registers per block". My question is how to relate this number to the VGPRs and SGPRs? Is there a way to deduce these numbers separately? Thank you very much in advance.

[yxsamliu]

These are number of VGPR's per CU.

It is eventually from:

https://github.com/ROCm-Developer-Tools/clr/blob/1338ff37e89b4d1fb36d23d48ccdf55998e15df5/rocclr/device/rocm/rocdevice.cpp#L1706

https://github.com/ROCm-Developer-Tools/clr/blob/1338ff37e89b4d1fb36d23d48ccdf55998e15df5/rocclr/device/rocm/rocdevice.cpp#L1702

https://github.com/RadeonOpenCompute/ROCm-CompilerSupport/blob/8276083301409001ec7643e68f5ad58b057c21fd/lib/comgr/src/comgr-isa-metadata.def#L49

[maartenarnst]

Hi @yxsamliu. Thanks a lot for your help! That's indeed exactly what I was looking for.

In my code, I'm now retrieving the number of VGPRs and SGPRs from the comgr, by proceeding similarly as in the code in rocdevice.cpp that you had referred me to.

I found that most of the functions used in rocdevice.cpp are available from the api in amd_comgr/amd_comgr.h. However, the function getValueFromIsaMeta is in rocdevice.cpp but it appears it's not in amd_comgr/amd_comgr.h. So it might be a suggestion to try to include this function in amd_comgr/amd_comgr.h. I'd be happy to post it as a suggestion on a GitHub repository, but it seems RadeonOpenCompute/llvm-project/tree/amd-stg-open/amd/comgr doesn't accept issues.

[yxsamliu]

comgr was migrated from https://github.com/RadeonOpenCompute/ROCm-CompilerSupport

You may open an issue there

[kjayapra-amd]

Closing the issue, since this is not related to HIP.
Please open a ticket https://github.com/RadeonOpenCompute/ROCm-CompilerSupport here as @yxsamliu suggested.