BLIS is a framework to instantiate (among other things) a BLAS. The exciting bit is that they distilled it down to a couple compute kernels. You provide stuff like the inner loops for a matrix multiplication, it turns it into a numerical library.
AMD did use it to create their BLAS library though.
Also, side note, when I’ve heard “reference BLAS,” it has been used in the opposite way. Netlib BLAS is the reference BLAS, it has basically bad performance but it defines the functionality. AMD used BLIS to create a tuned vendor BLAS.
BLIS is a different library from BLAS, with a better API. For example when you pass an array, you can pass independent strides for all axes, and you can give independent transpose/conjugate flags. It does have a BLAS compatibility interface.
The interface isn't perfect though. For example they didn't commit to supporting zero strides. That used to work anyway, but it's broken now for some archs.
