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 Ops = 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         self.page = {}
  70         for pth in os.listdir(os.path.join(get_isa_dir())):
  71             print (get_isa_dir(), pth)
  72             assert pth.endswith(".mdwn"), "only %s in isa dir" % pth
  73             self.read_file(pth)
  74
  75     def read_file(self, fname):
  76         pagename = fname.split('.')[0]
  77         fname = os.path.join(get_isa_dir(), fname)
  78         with open(fname) as f:
  79             lines = f.readlines()
  80
  81         # set up dict with current page name
  82         d = {'page': pagename}
  83
  84         l = lines.pop(0).rstrip() # get first line
  85         while lines:
  86             print (l)
  87             # expect get heading
  88             assert l.startswith('#'), ("# not found in line %s" % l)
  89             d['desc'] = l[1:].strip()
  90
  91             # whitespace expected
  92             l = lines.pop(0).strip()
  93             print (repr(l))
  94             assert len(l) == 0, ("blank line not found %s" % l)
  95
  96             # Form expected
  97             l = lines.pop(0).strip()
  98             assert l.endswith('-Form'), ("line with -Form expected %s" % l)
  99             d['form'] = l.split('-')[0]
 100
 101             # whitespace expected
 102             l = lines.pop(0).strip()
 103             assert len(l) == 0, ("blank line not found %s" % l)
 104
 105             # get list of opcodes
 106             li = []
 107             while True:
 108                 l = lines.pop(0).strip()
 109                 if len(l) == 0: break
 110                 assert l.startswith('*'), ("* not found in line %s" % l)
 111                 l = l[1:].split(' ') # lose star
 112                 l = filter(lambda x: len(x) != 0, l) # strip blanks
 113                 li.append(list(l))
 114             opcodes = li
 115
 116             # get pseudocode
 117             li = []
 118             while True:
 119                 l = lines.pop(0).rstrip()
 120                 if len(l) == 0: break
 121                 assert l.startswith('    '), ("4spcs not found in line %s" % l)
 122                 l = l[4:] # lose 4 spaces
 123                 li.append(l)
 124             d['pcode'] = li
 125
 126             # "Special Registers Altered" expected
 127             l = lines.pop(0).rstrip()
 128             assert l.startswith("Special"), ("special not found %s" % l)
 129
 130             # whitespace expected
 131             l = lines.pop(0).strip()
 132             assert len(l) == 0, ("blank line not found %s" % l)
 133
 134             # get special regs
 135             li = []
 136             while lines:
 137                 l = lines.pop(0).rstrip()
 138                 if len(l) == 0: break
 139                 assert l.startswith('    '), ("4spcs not found in line %s" % l)
 140                 l = l[4:] # lose 4 spaces
 141                 li.append(l)
 142             d['sregs'] = li
 143
 144             # add in opcode
 145             for o in opcodes:
 146                 self.add_op(o, d)
 147
 148             # expect and drop whitespace
 149             while lines:
 150                 l = lines.pop(0).rstrip()
 151                 if len(l) != 0: break
 152
 153     def add_op(self, o, d):
 154         opcode, regs = o[0], o[1:]
 155         op = copy(d)
 156         op['regs'] = regs
 157         regs[0] = regs[0].split(",")
 158         op['opcode'] = opcode
 159         self.instr[opcode] = Ops(**op)
 160
 161         # create list of instructions by form
 162         form = op['form']
 163         fl = self.forms.get(form, [])
 164         self.forms[form] = fl + [opcode]
 165
 166         # create list of instructions by page
 167         page = op['page']
 168         pl = self.page.get(page, [])
 169         self.page[page] = pl + [opcode]
 170
 171     def pprint_ops(self):
 172         for k, v in self.instr.items():
 173             print ("# %s %s" % (v.opcode, v.desc))
 174             print ("Form: %s Regs: %s" % (v.form, v.regs))
 175             print ('\n'.join(map(lambda x: "    %s" % x, v.pcode)))
 176             print ("Specials")
 177             print ('\n'.join(map(lambda x: "    %s" % x, v.sregs)))
 178             print ()
 179         for k, v in isa.forms.items():
 180             print (k, v)
 181
 182 if __name__ == '__main__':
 183     isa = ISA()
 184     isa.pprint_ops()