Re: Sparse MatrixVector Multiply (again) and BitVector Compression
Nick Knight
Hi Dawei, Unfortunately the Vextension does not currently feature blockmatrix multiplication instructions, including the bitmasked versions that you're describing. Some of these operations are intended to be addressed by a future (sub) extension (perhaps EDIV). Presently, you can apply your scheme directly to the restricted class of BCSR matrices with 1dimensional blocks. You can imagine various (nonzerostructuredependent) tradeoffs between using rby1 and 1byc blocks. More generally you can recursively compose (singly or doubly compressed) blockCS{R,C} formats, encoding indices using bitvectors or lists at any level of the recursion. Best, Nick Hi， 
