Data conversion when packing

I think we need a feature in which data conversion is done while packing. This way all architectures could get lower resolution kernels to work by converting either A or B or BOTH to a desired format and then using a kernel that uses that format.

It would be useful for SBGEMM and SHGEMM in some situations in which there is no fast hardware instructions with MADD in these formats.

Flow -

Current:

pack -> convert -> kernel

Proposed new feature:

pack_convert -> kernel

Yes, it would increase memory requirements. But for hardware that has slower conversions we are wasting NxKxM converts that could be done as NxK and MxK - which is a much smaller number.

Plus we could save the repetitive conversions that is done sometimes.