The SPR regfile on the other hand is *binary*-encoded, and, furthermore,
has to be "remapped" to internal SPR Enum indices (see SPRMap in PowerDecode2)
-see https://libre-so:.org/3d_gpu/architecture/regfile/ section on regspecs
+see https://libre-soc.org/3d_gpu/architecture/regfile/ section on regspecs
"""
from nmigen import Const, Signal
from openpower.consts import XERRegsEnum, FastRegsEnum, StateRegsEnum