Details:
- This commit adds a new BLIS sandbox that (1) provides implementations
based on low-precision gemm kernels, and (2) extends the BLIS typed
API for those new implementations. Currently, these new kernels can
only be used for the POWER10 microarchitecture; however, they may
provide a template for developing similar kernels for other
microarchitectures (even those beyond POWER), as changes would likely
be limited to select places in the microkernel and possibly the
packing routines. The new low-precision operations that are now
supported include: shgemm, sbgemm, i16gemm, i8gemm, i4gemm. For more
information, refer to the POWER10.md document that is included in
'sandbox/power10'.