src/soc/fu/regspec.py

   1 # see https://libre-soc.org/3d_gpu/architecture/regfile/ section on regspecs
   2
   3 def get_regspec_bitwidth(regspec, srcdest, idx):
   4     bitspec = regspec[srcdest][idx]
   5     wid = 0
   6     print (bitspec)
   7     for ranges in bitspec[2].split(","):
   8         ranges = ranges.split(":")
   9         print (ranges)
  10         if len(ranges) == 1: # only one bit
  11             wid += 1
  12         else:
  13             start, end = map(int, ranges)
  14             wid += (end-start)+1
  15     return wid
  16
  17
  18 class RegSpec:
  19     def __init__(self, rwid, n_src=None, n_dst=None, name=None):
  20         self._rwid = rwid
  21         if isinstance(rwid, int):
  22             # rwid: integer (covers all registers)
  23             self._n_src, self._n_dst = n_src, n_dst
  24         else:
  25             # rwid: a regspec.
  26             self._n_src, self._n_dst = len(rwid[0]), len(rwid[1])
  27
  28     def _get_dstwid(self, i):
  29         if isinstance(self._rwid, int):
  30             return self._rwid
  31         return get_regspec_bitwidth(self._rwid, 1, i)
  32
  33     def _get_srcwid(self, i):
  34         if isinstance(self._rwid, int):
  35             return self._rwid
  36         return get_regspec_bitwidth(self._rwid, 0, i)
  37
  38
  39 class RegSpecALUAPI:
  40     def __init__(self, rwid, alu):
  41         """RegSpecAPI
  42
  43         * :rwid:       regspec
  44         * :alu:        ALU covered by this regspec
  45         """
  46         self.rwid = rwid
  47         self.alu = alu # actual ALU - set as a "submodule" of the CU
  48
  49     def get_out(self, i):
  50         if isinstance(self.rwid, int): # old - testing - API (rwid is int)
  51             return self.alu.out[i]
  52         # regspec-based API: look up variable through regspec according to row number
  53         return getattr(self.alu.n.data_o, self.rwid[1][i][1])
  54
  55     def get_in(self, i):
  56         if isinstance(self.rwid, int): # old - testing - API (rwid is int)
  57             return self.alu.i[i]
  58         # regspec-based API: look up variable through regspec according to row number
  59         return getattr(self.alu.p.data_i, self.rwid[0][i][1])
  60
  61     def get_op(self):
  62         if isinstance(self.rwid, int): # old - testing - API (rwid is int)
  63             return self.alu.op
  64         return self.alu.p.data_i.ctx.op