Instead of passing 2 different 4-bit precision values via the SGPR, pass
the quant mode enum + log_samples as 3 bits, and 2-bit log_samples
separately. This saves 3 bits in the SGPR, which we'll need for culling
states.
This completely changes how the small prim precision is computed from
the state bits.
Reviewed-by: Timur Kristóf <timur.kristof@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31865>
Marek Olšák
73abbf1175