Blocked-Ellpack format convertor

[neoblizz]

Need help understanding Blocked-ELLpack format. Or how to go from dense to sparse (said format).

• https://developer.nvidia.com/blog/accelerating-matrix-multiplication-with-block-sparse-format-and-nvidia-tensor-cores/
• https://docs.nvidia.com/cuda/cusparse/index.html#cusparse-generic-function-dense2sparse
• https://github.com/NVIDIA/CUDALibrarySamples/blob/master/cuSPARSE/spmm_blockedell/spmm_blockedell_example.cpp#L91-L93

[neoblizz]

cusparseStatus_t
cusparseCreateBlockedEll(cusparseSpMatDescr_t* spMatDescr,
                         int64_t               rows,
                         int64_t               cols,
                         int64_t               ellBlockSize,
                         int64_t               ellCols,
                         void*                 ellColInd,
                         void*                 ellValue,
                         cusparseIndexType_t   ellIdxType,
                         cusparseIndexBase_t   idxBase,
                         cudaDataType          valueType)

This function initializes the sparse matrix descriptor spMatDescr for the Blocked-Ellpack (ELL) format.

Param.	Memory	In/out	Meaning
spMatDescr	HOST	OUT	Sparse matrix descriptor
rows	HOST	IN	Number of rows of the sparse matrix
cols	HOST	IN	Number of columns of the sparse matrix
ellBlockSize	HOST	IN	Size of the ELL-Block
ellCols	HOST	IN	Actual number of columns of the Blocked-Ellpack format
ellColInd	DEVICE	IN	Blocked-ELL Column indices. Array of size [ellCols / ellBlockSize][rows / ellBlockSize]
ellValue	DEVICE	IN	Values of the sparse martix. Array of size rows * ellCols
ellIdxType	HOST	IN	Data type of ellColInd
idxBase	HOST	IN	Base index of ellColInd
valueType	HOST	IN	Datatype of ellValue