openpower/sv/bmask.py

   1 def bmask(mode, RA, RB=None, zero=False):
   2     RT = RA if RB is not None and not zero else 0
   3     mask = RB if RB is not None else 0xffffffffffffffff
   4     RA = RA & mask
   5     a1 = RA if mode&1 else ~RA
   6     mode2 = (mode >> 1) & 0b11
   7     if mode2 == 0:
   8         a2 = -RA
   9     if mode2 == 1:
  10         a2 = RA-1
  11     if mode2 == 2:
  12         a2 = RA+1
  13     if mode2 == 3:
  14         a2 = ~(RA+1)
  15     a1 = a1 & mask
  16     a2 = a2 & mask
  17     mode3 = (mode >> 3) & 0b11
  18     if mode3 == 0:
  19          RT = a1 | a2
  20     if mode3 == 1:
  21          RT = a1 & a2
  22     if mode3 == 2:
  23          RT = a1 ^ a2
  24     return RT & mask
  25
  26 SBF = 0b01010
  27 SOF = 0b01001
  28 SIF = 0b10000 # 10011 also works no idea why yet
  29
  30 if __name__ == '__main__':
  31    for SBF in range(32):
  32      print("mode", bin(SBF))
  33      m  = 0b11000011
  34      v3 = 0b10010100 # vmsbf.m v2, v3
  35      v2 = 0b01000011 # v2
  36      RT = bmask(SBF, v3, m, zero=True)
  37      print(bin(v3), bin(v2), bin(RT))
  38      v3 = 0b10010100 # vmsbf.m v2, v3
  39      v2 = 0b00000011 # v2 contents
  40      RT = bmask(SBF, v3)
  41      print(bin(v3), bin(v2), bin(RT))
  42      v3 = 0b10010101 # vmsbf.m v2, v3
  43      v2 = 0b00000000 # v2
  44      RT = bmask(SBF, v3)
  45      print(bin(v3), bin(v2), bin(RT))
  46      v3 = 0b00000000 # vmsbf.m v2, v3
  47      v2 = 0b11111111 # v2
  48      RT = bmask(SBF, v3)
  49      print(bin(v3), bin(v2), bin(RT))
  50      print()