[llvm-dev] AMDGPU workgroup size as metadata

[Frank Winter via llvm-dev]

 From LLVM IR, how can you get the 'workgroup size' value?
It seems to be set by the AMDGPU backend as metadata since in 
AMDGPUMetadata.h there are things defined like

constexpr char ReqdWorkGroupSize[] = "ReqdWorkGroupSize";

and

struct Metadata final {
   /// 'reqd_work_group_size' attribute. Optional.
   std::vector<uint32_t> mReqdWorkGroupSize = std::vector<uint32_t>();
   ...
}

Is this metadata set to the kernel function or to the module?

What IR instructions would give access to the value of, say, the 
workgroup size in dimension x?


Frank