src/soc/decoder/pseudo/pagereader.py

   1 # Reads OpenPOWER ISA pages from http://libre-riscv.org/openpower/isa
   2 """OpenPOWER ISA page parser
   3
   4 returns an OrderedDict of namedtuple "Ops" containing details of all
   5 instructions listed in markdown files.
   6
   7 format must be strictly as follows (no optional sections) including whitespace:
   8
   9 # Compare Logical
  10
  11 X-Form
  12
  13 * cmpl BF,L,RA,RB
  14
  15     if L = 0 then a <- [0]*32 || (RA)[32:63]
  16                   b <- [0]*32 || (RB)[32:63]
  17              else a <-  (RA)
  18                   b <-  (RB)
  19     if      a <u b then c <- 0b100
  20     else if a >u b then c <- 0b010
  21     else                c <-  0b001
  22     CR[4*BF+32:4*BF+35] <- c || XER[SO]
  23
  24 Special Registers Altered:
  25
  26     CR field BF
  27     Another field
  28
  29 this translates to:
  30
  31     # heading
  32     blank
  33     Some-Form
  34     blank
  35     * instruction registerlist
  36     * instruction registerlist
  37     blank
  38     4-space-indented pseudo-code
  39     4-space-indented pseudo-code
  40     blank
  41     Special Registers Altered:
  42     4-space-indented register description
  43     blank
  44     blank (optional)
  45
  46 """
  47
  48 from collections import namedtuple, OrderedDict
  49 from copy import copy
  50 import os
  51
  52 op = namedtuple("Ops", ("desc", "form", "opcode", "regs", "pcode", "sregs"))
  53
  54 def get_isa_dir():
  55     fdir = os.path.abspath(os.path.dirname(__file__))
  56     fdir = os.path.split(fdir)[0]
  57     fdir = os.path.split(fdir)[0]
  58     fdir = os.path.split(fdir)[0]
  59     fdir = os.path.split(fdir)[0]
  60     return os.path.join(fdir, "libreriscv", "openpower", "isa")
  61
  62 class ISA:
  63
  64     def __init__(self):
  65         self.instr = OrderedDict()
  66
  67     def read_file(self, fname):
  68         fname = os.path.join(get_isa_dir(), fname)
  69         with open(fname) as f:
  70             lines = f.readlines()
  71
  72         d = {}
  73         l = lines.pop(0).rstrip() # get first line
  74         while lines:
  75             print (l)
  76             # expect get heading
  77             assert l.startswith('#'), ("# not found in line %s" % l)
  78             d['desc'] = l[1:].strip()
  79
  80             # whitespace expected
  81             l = lines.pop(0).strip()
  82             print (repr(l))
  83             assert len(l) == 0, ("blank line not found %s" % l)
  84
  85             # Form expected
  86             l = lines.pop(0).strip()
  87             assert l.endswith('-Form'), ("line with -Form expected %s" % l)
  88             d['form'] = l.split('-')[0]
  89
  90             # whitespace expected
  91             l = lines.pop(0).strip()
  92             assert len(l) == 0, ("blank line not found %s" % l)
  93
  94             # get list of opcodes
  95             li = []
  96             while True:
  97                 l = lines.pop(0).strip()
  98                 if len(l) == 0: break
  99                 assert l.startswith('*'), ("* not found in line %s" % l)
 100                 l = l[1:].split(' ') # lose star
 101                 l = filter(lambda x: len(x) != 0, l) # strip blanks
 102                 li.append(list(l))
 103             opcodes = li
 104
 105             # get pseudocode
 106             li = []
 107             while True:
 108                 l = lines.pop(0).rstrip()
 109                 if len(l) == 0: break
 110                 assert l.startswith('    '), ("4spcs not found in line %s" % l)
 111                 l = l[4:] # lose 4 spaces
 112                 li.append(l)
 113             d['pcode'] = li
 114
 115             # "Special Registers Altered" expected
 116             l = lines.pop(0).rstrip()
 117             assert l.startswith("Special"), ("special not found %s" % l)
 118
 119             # whitespace expected
 120             l = lines.pop(0).strip()
 121             assert len(l) == 0, ("blank line not found %s" % l)
 122
 123             # get special regs
 124             li = []
 125             while lines:
 126                 l = lines.pop(0).rstrip()
 127                 if len(l) == 0: break
 128                 assert l.startswith('    '), ("4spcs not found in line %s" % l)
 129                 l = l[4:] # lose 4 spaces
 130                 li.append(l)
 131             d['sregs'] = li
 132
 133             # add in opcode
 134             for o in opcodes:
 135                 opcode, regs = o[0], o[1:]
 136                 op = copy(d)
 137                 op['regs'] = regs
 138                 op['opcode'] = opcode
 139                 self.instr[opcode] = op
 140
 141             # expect and drop whitespace
 142             while lines:
 143                 l = lines.pop(0).rstrip()
 144                 if len(l) != 0: break
 145
 146     def pprint_ops(self):
 147         for k, v in self.instr.items():
 148             print ("# %s %s" % (v['opcode'], v['desc']))
 149             print ("Form: %s Regs: %s" % (v['form'], v['regs']))
 150             print ('\n'.join(map(lambda x: "    %s" % x, v['pcode'])))
 151             print ("Specials")
 152             print ('\n'.join(map(lambda x: "    %s" % x, v['sregs'])))
 153             print ()
 154
 155 if __name__ == '__main__':
 156     isa = ISA()
 157     for pth in os.listdir(os.path.join(get_isa_dir())):
 158         print (get_isa_dir(), pth)
 159         assert pth.endswith(".mdwn"), "only %s in isa dir" % pth
 160         isa.read_file(pth)
 161
 162     isa.pprint_ops()