src/openpower/util.py

   1 from openpower.consts import FastRegsEnum
   2 from openpower.decoder.power_enums import SPRfull as SPR, spr_dict
   3
   4 # note that we can get away with using SPRfull here because the values
   5 # (numerical values) are what is used for lookup.
   6 spr_to_fast = { SPR.CTR: FastRegsEnum.CTR,
   7                 SPR.LR: FastRegsEnum.LR,
   8                 SPR.TAR: FastRegsEnum.TAR,
   9                 SPR.SRR0: FastRegsEnum.SRR0,
  10                 SPR.SRR1: FastRegsEnum.SRR1,
  11                 SPR.XER: FastRegsEnum.XER,
  12                 SPR.DEC: FastRegsEnum.DEC,
  13                 SPR.TB: FastRegsEnum.TB,
  14                }
  15
  16 sprstr_to_fast = {}
  17 fast_to_spr = {}
  18 for (k, v) in spr_to_fast.items():
  19     sprstr_to_fast[k.name] = v
  20     fast_to_spr[v] = k
  21
  22 def fast_reg_to_spr(spr_num):
  23     return fast_to_spr[spr_num].value
  24
  25
  26 def spr_to_fast_reg(spr_num):
  27     if not isinstance(spr_num, str):
  28         spr_num = spr_dict[spr_num].SPR
  29     return sprstr_to_fast.get(spr_num, None)
  30
  31
  32 def slow_reg_to_spr(slow_reg):
  33     for i, x in enumerate(SPR):
  34         if slow_reg == i:
  35             return x.value
  36
  37
  38 def spr_to_slow_reg(spr_num):
  39     for i, x in enumerate(SPR):
  40         if spr_num == x.value:
  41             return i
  42
  43
  44 # TODO: make this a util routine (somewhere)
  45 def mask_extend(x, nbits, repeat):
  46     res = 0
  47     extended = (1<<repeat)-1
  48     for i in range(nbits):
  49         if x & (1<<i):
  50             res |= extended << (i*repeat)
  51     return res
  52
  53