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(s) (optional for convenience at end-of-page)
  45 """
  46
  47 from collections import namedtuple, OrderedDict
  48 from copy import copy
  49 import os
  50
  51 opfields = ("desc", "form", "opcode", "regs", "pcode", "sregs", "page")
  52 op = namedtuple("Ops", opfields)
  53
  54
  55 def get_isa_dir():
  56     fdir = os.path.abspath(os.path.dirname(__file__))
  57     fdir = os.path.split(fdir)[0]
  58     fdir = os.path.split(fdir)[0]
  59     fdir = os.path.split(fdir)[0]
  60     fdir = os.path.split(fdir)[0]
  61     return os.path.join(fdir, "libreriscv", "openpower", "isa")
  62
  63
  64 class ISA:
  65
  66     def __init__(self):
  67         self.instr = OrderedDict()
  68         self.forms = {}
  69         for pth in os.listdir(os.path.join(get_isa_dir())):
  70             print (get_isa_dir(), pth)
  71             assert pth.endswith(".mdwn"), "only %s in isa dir" % pth
  72             self.read_file(pth)
  73
  74     def read_file(self, fname):
  75         pagename = fname.split('.')[0]
  76         fname = os.path.join(get_isa_dir(), fname)
  77         with open(fname) as f:
  78             lines = f.readlines()
  79
  80         # set up dict with current page name
  81         d = {'pagename': pagename}
  82
  83         l = lines.pop(0).rstrip() # get first line
  84         while lines:
  85             print (l)
  86             # expect get heading
  87             assert l.startswith('#'), ("# not found in line %s" % l)
  88             d['desc'] = l[1:].strip()
  89
  90             # whitespace expected
  91             l = lines.pop(0).strip()
  92             print (repr(l))
  93             assert len(l) == 0, ("blank line not found %s" % l)
  94
  95             # Form expected
  96             l = lines.pop(0).strip()
  97             assert l.endswith('-Form'), ("line with -Form expected %s" % l)
  98             d['form'] = l.split('-')[0]
  99
 100             # whitespace expected
 101             l = lines.pop(0).strip()
 102             assert len(l) == 0, ("blank line not found %s" % l)
 103
 104             # get list of opcodes
 105             li = []
 106             while True:
 107                 l = lines.pop(0).strip()
 108                 if len(l) == 0: break
 109                 assert l.startswith('*'), ("* not found in line %s" % l)
 110                 l = l[1:].split(' ') # lose star
 111                 l = filter(lambda x: len(x) != 0, l) # strip blanks
 112                 li.append(list(l))
 113             opcodes = li
 114
 115             # get pseudocode
 116             li = []
 117             while True:
 118                 l = lines.pop(0).rstrip()
 119                 if len(l) == 0: break
 120                 assert l.startswith('    '), ("4spcs not found in line %s" % l)
 121                 l = l[4:] # lose 4 spaces
 122                 li.append(l)
 123             d['pcode'] = li
 124
 125             # "Special Registers Altered" expected
 126             l = lines.pop(0).rstrip()
 127             assert l.startswith("Special"), ("special not found %s" % l)
 128
 129             # whitespace expected
 130             l = lines.pop(0).strip()
 131             assert len(l) == 0, ("blank line not found %s" % l)
 132
 133             # get special regs
 134             li = []
 135             while lines:
 136                 l = lines.pop(0).rstrip()
 137                 if len(l) == 0: break
 138                 assert l.startswith('    '), ("4spcs not found in line %s" % l)
 139                 l = l[4:] # lose 4 spaces
 140                 li.append(l)
 141             d['sregs'] = li
 142
 143             # add in opcode
 144             for o in opcodes:
 145                 self.add_op(o, d)
 146
 147             # expect and drop whitespace
 148             while lines:
 149                 l = lines.pop(0).rstrip()
 150                 if len(l) != 0: break
 151
 152     def add_op(self, o, d):
 153         opcode, regs = o[0], o[1:]
 154         op = copy(d)
 155         op['regs'] = regs
 156         op['opcode'] = opcode
 157         self.instr[opcode] = op
 158
 159         # create list of instructions by form
 160         form = op['form']
 161         fl = self.forms.get(form, [])
 162         self.forms[form] = fl + [opcode]
 163
 164     def pprint_ops(self):
 165         for k, v in self.instr.items():
 166             print ("# %s %s" % (v['opcode'], v['desc']))
 167             print ("Form: %s Regs: %s" % (v['form'], v['regs']))
 168             print ('\n'.join(map(lambda x: "    %s" % x, v['pcode'])))
 169             print ("Specials")
 170             print ('\n'.join(map(lambda x: "    %s" % x, v['sregs'])))
 171             print ()
 172         for k, v in isa.forms.items():
 173             print (k, v)
 174
 175 if __name__ == '__main__':
 176     isa = ISA()
 177     isa.pprint_ops()