src/openpower/util.py

   1 import os
   2 import random
   3 from openpower.consts import FastRegsEnum, StateRegsEnum
   4 from openpower.decoder.power_enums import SPRfull as SPR, spr_dict
   5
   6
   7 # note that we can get away with using SPRfull here because the values
   8 # (numerical values) are what is used for lookup.
   9 spr_to_fast = {
  10                 SPR.LR: FastRegsEnum.LR,
  11                 SPR.CTR: FastRegsEnum.CTR,
  12                 SPR.SRR0: FastRegsEnum.SRR0,
  13                 SPR.SRR1: FastRegsEnum.SRR1,
  14                 SPR.HSRR0: FastRegsEnum.HSRR0,
  15                 SPR.HSRR1: FastRegsEnum.HSRR1,
  16                 SPR.SPRG0_priv: FastRegsEnum.SPRG0,
  17                 SPR.SPRG1_priv: FastRegsEnum.SPRG1,
  18                 SPR.SPRG2_priv: FastRegsEnum.SPRG2,
  19                 SPR.SPRG3: FastRegsEnum.SPRG3,
  20                 SPR.HSPRG0: FastRegsEnum.HSPRG0,
  21                 SPR.HSPRG1: FastRegsEnum.HSPRG1,
  22                 SPR.XER: FastRegsEnum.XER,
  23                 SPR.TAR: FastRegsEnum.TAR,
  24                 SPR.SVSRR0: FastRegsEnum.SVSRR0,
  25                }
  26
  27 spr_to_state = { SPR.DEC: StateRegsEnum.DEC,
  28                  SPR.TB: StateRegsEnum.TB,
  29                }
  30
  31 sprstr_to_state = {}
  32 state_to_spr = {}
  33 for (k, v) in spr_to_state.items():
  34     sprstr_to_state[k.name] = v
  35     state_to_spr[v] = k
  36
  37 def state_reg_to_spr(spr_num):
  38     return state_to_spr[spr_num].value
  39
  40
  41 def spr_to_state_reg(spr_num):
  42     if not isinstance(spr_num, str):
  43         spr_num = spr_dict[spr_num].SPR
  44     return sprstr_to_state.get(spr_num, None)
  45
  46
  47 sprstr_to_fast = {}
  48 fast_to_spr = {}
  49 for (k, v) in spr_to_fast.items():
  50     sprstr_to_fast[k.name] = v
  51     fast_to_spr[v] = k
  52
  53 def fast_reg_to_spr(spr_num):
  54     return fast_to_spr[spr_num].value
  55
  56
  57 def spr_to_fast_reg(spr_num):
  58     if not isinstance(spr_num, str):
  59         spr_num = spr_dict[spr_num].SPR
  60     return sprstr_to_fast.get(spr_num, None)
  61
  62
  63 def slow_reg_to_spr(slow_reg):
  64     for i, x in enumerate(SPR):
  65         if slow_reg == i:
  66             return x.value
  67
  68
  69 def spr_to_slow_reg(spr_num):
  70     for i, x in enumerate(SPR):
  71         if spr_num == x.value:
  72             return i
  73
  74
  75 # TODO: make this a util routine (somewhere)
  76 def mask_extend(x, nbits, repeat):
  77     res = 0
  78     extended = (1<<repeat)-1
  79     for i in range(nbits):
  80         if x & (1<<i):
  81             res |= extended << (i*repeat)
  82     return res
  83
  84
  85 # makes a logarithmically-skewed random number
  86 def log_rand(n, min_val=1):
  87     logrange = random.randint(1, n)
  88     return random.randint(min_val, (1 << logrange)-1)
  89
  90
  91 def log(*args, **kwargs):
  92     """verbose printing, disabled if an ENV VAR "SILENCELOG" exists.
  93     """
  94     if 'SILENCELOG' in os.environ:
  95         return
  96     print(*args, **kwargs)
  97