rocWMMA, Question about MaxVWSelector.

[DoubleRedX]

Hi, I'm learning rocWMMA source code.
I want to know why MaxVWSelector's TestWidth calculated by "4u * DWORD_SIZE_BYTES / sizeof(DataT)"? Because of some hardwares' features?

template <typename MatrixT,
                  uint32_t BlockDim,
                  uint32_t BlockK,
                  typename DataT,
                  typename DataLayoutT,
                  uint32_t WaveCount = 1u,
                  uint32_t TestWidth
                  = 4u * Constants::AMDGCN_DWORD_SIZE_BYTES / (uint32_t)sizeof(DataT)> 

https://github.com/ROCm/rocm-libraries/blob/abfa88d222215ca4f83765c1ef26c1e2e5059447/projects/rocwmma/library/include/rocwmma/internal/io_layout.hpp#L48