src/soc/sv/trans/svp64.py

   1 # SPDX-License-Identifier: LGPLv3+
   2 # Copyright (C) 2021 Luke Kenneth Casson Leighton <lkcl@lkcl.net>
   3 # Funded by NLnet http://nlnet.nl
   4
   5 """SVP64 OpenPOWER v3.0B assembly translator
   6
   7 This class takes raw svp64 assembly mnemonics (aliases excluded) and
   8 creates an EXT001-encoded "svp64 prefix" followed by a v3.0B opcode.
   9 It is very simple
  10 """
  11
  12 from soc.decoder.pseudo.pagereader import ISA
  13
  14
  15 def is_CR_3bit(regname):
  16     return regname in ['BF', 'BFA']
  17
  18 def is_CR_5bit(regname):
  19     return regname in ['BA', 'BB', 'BC', 'BI', 'BT']
  20
  21 def is_GPR(regname):
  22     return regname in ['RA', 'RB', 'RC', 'RS', 'RT']
  23
  24
  25 class SVP64:
  26     def __init__(self, lst):
  27         self.lst = lst
  28         self.trans = self.translate(lst)
  29
  30     def __iter__(self):
  31         for insn in self.trans:
  32             yield insn
  33
  34     def translate(self, lst):
  35         isa = ISA() # reads the v3.0B pseudo-code markdown files
  36         res = []
  37         for insn in lst:
  38             # find first space, to get opcode
  39             ls = insn.split(' ')
  40             opcode = ls[0]
  41             # now find opcode fields
  42             fields = ''.join(ls[1:]).split(',')
  43             fields = list(map(str.strip, fields))
  44             print (opcode, fields)
  45
  46             # identify if is a svp64 mnemonic
  47             if not opcode.startswith('sv.'):
  48                 res.append(insn) # unaltered
  49                 continue
  50
  51             # start working on decoding the svp64 op: sv.baseop.vec2.mode
  52             opmodes = opcode.split(".")[1:] # strip leading "sv."
  53             v30b_op = opmodes.pop(0)        # first is the v3.0B
  54             if v30b_op not in isa.instr:
  55                 raise Exception("opcode %s of '%s' not supported" % \
  56                                 (v30b_op, insn))
  57
  58         return res
  59
  60 if __name__ == '__main__':
  61     isa = SVP64(['slw 3, 1, 4',
  62                  'extsw 5, 3'])
  63