src/openpower/decoder/power_decoder.py

   1 """Cascading Power ISA Decoder
   2
   3 License: LGPLv3+
   4
   5 # Copyright (C) 2020 Luke Kenneth Casson Leighton <lkcl@lkcl.net>
   6 # Copyright (C) 2020 Michael Nolan <mtnolan2640@gmail.com>
   7
   8 This module uses CSV tables in a hierarchical/peer cascading fashion,
   9 to create a multi-level instruction decoder by recognising appropriate
  10 patterns.  The output is a wide, flattened (1-level) series of bitfields,
  11 suitable for a simple RISC engine.
  12
  13 This is based on Anton Blanchard's excellent microwatt work:
  14 https://github.com/antonblanchard/microwatt/blob/master/decode1.vhdl
  15
  16 The basic principle is that the python code does the heavy lifting
  17 (reading the CSV files, constructing the hierarchy), creating the HDL
  18 AST with for-loops generating switch-case statements.
  19
  20 Where "normal" HDL would do this, in laborious excruciating detail:
  21
  22     switch (opcode & major_mask_bits):
  23         case opcode_2: decode_opcode_2()
  24         case opcode_19:
  25                 switch (opcode & minor_19_mask_bits)
  26                     case minor_opcode_19_operation_X:
  27                     case minor_opcode_19_operation_y:
  28
  29 we take *full* advantage of the decoupling between python and the
  30 nmigen AST data structure, to do this:
  31
  32     with m.Switch(opcode & self.mask):
  33         for case_bitmask in subcases:
  34             with m.If(opcode & case_bitmask): {do_something}
  35
  36 this includes specifying the information sufficient to perform subdecoding.
  37
  38 create_pdecode()
  39
  40     the full hierarchical tree for decoding POWER9 is specified here
  41     subsetting is possible by specifying col_subset (row_subset TODO)
  42
  43 PowerDecoder
  44
  45     takes a *list* of CSV files with an associated bit-range that it
  46     is requested to match against the "opcode" row of the CSV file.
  47     This pattern can be either an integer, a binary number, *or* a
  48     wildcard nmigen Case pattern of the form "001--1-100".
  49
  50 Subdecoders
  51
  52     these are *additional* cases with further decoding.  The "pattern"
  53     argument is specified as one of the Case statements (a peer of the
  54     opcode row in the CSV file), and thus further fields of the opcode
  55     may be decoded giving increasing levels of detail.
  56
  57 Top Level:
  58
  59     [ (extra.csv: bit-fields entire 32-bit range
  60         opcode                           -> matches
  61         000000---------------01000000000 -> ILLEGAL instruction
  62         01100000000000000000000000000000 -> SIM_CONFIG instruction
  63         ................................ ->
  64       ),
  65       (major.csv: first 6 bits ONLY
  66         opcode                           -> matches
  67         001100                           -> ALU,OP_ADD (add)
  68         001101                           -> ALU,OP_ADD (another type of add)
  69         ......                           -> ...
  70         ......                           -> ...
  71         subdecoders:
  72         001011 this must match *MAJOR*.CSV
  73             [ (minor_19.csv: bits 21 through 30 inclusive:
  74                 opcode                  -> matches
  75                 0b0000000000            -> ALU,OP_MCRF
  76                 ............            -> ....
  77               ),
  78               (minor_19_00000.csv: bits 21 through 25 inclusive:
  79                 opcode                  -> matches
  80                 0b00010                 -> ALU,add_pcis
  81               )
  82             ]
  83       ),
  84     ]
  85
  86
  87 """
  88
  89 import gc
  90 from collections import namedtuple, OrderedDict
  91 from nmigen import Module, Elaboratable, Signal, Cat, Mux, Const
  92 from nmigen.cli import rtlil, verilog
  93 from openpower.decoder.power_enums import (Function, Form, MicrOp,
  94                                      In1Sel, In2Sel, In3Sel, OutSel,
  95                                      SVEXTRA, SVEtype, SVPtype,  # Simple-V
  96                                      RC, LdstLen, LDSTMode, CryIn,
  97                                      single_bit_flags, CRInSel,
  98                                      CROutSel, get_signal_name,
  99                                      default_values, insns, asmidx,
 100                                      asmlen)
 101 from openpower.decoder.power_fields import DecodeFields
 102 from openpower.decoder.power_fieldsn import SigDecode, SignalBitRange
 103 from openpower.decoder.power_svp64 import SVP64RM
 104
 105 from openpower.util import log
 106
 107 # key data structure in which the POWER decoder is specified,
 108 # in a hierarchical fashion
 109 Subdecoder = namedtuple(  # fix autoformatter
 110     "Subdecoder",
 111     ["pattern",    # the major pattern to search for (e.g. major opcode)
 112      "opcodes",    # a dictionary of minor patterns to find
 113      "opint",      # true => the pattern must not be in "10----11" format
 114      # the bits (as a range) against which "pattern" matches
 115      "bitsel",
 116      "suffix",     # shift the opcode down before decoding
 117      "subdecoders"  # list of further subdecoders for *additional* matches,
 118      # *ONLY* after "pattern" has *ALSO* been matched against.
 119      ])
 120
 121 power_op_types = {'function_unit': Function,
 122                   'internal_op': MicrOp,
 123                   'form': Form,
 124                   'asmcode': asmlen,
 125                   'SV_Etype': SVEtype,
 126                   'SV_Ptype': SVPtype,
 127                   'in1_sel': In1Sel,
 128                   'in2_sel': In2Sel,
 129                   'in3_sel': In3Sel,
 130                   'out_sel': OutSel,
 131                   'cr_in': CRInSel,
 132                   'cr_out': CROutSel,
 133                   'sv_in1': SVEXTRA,
 134                   'sv_in2': SVEXTRA,
 135                   'sv_in3': SVEXTRA,
 136                   'sv_out': SVEXTRA,
 137                   'sv_out2': SVEXTRA,
 138                   'sv_cr_in': SVEXTRA,
 139                   'sv_cr_out': SVEXTRA,
 140                   'ldst_len': LdstLen,
 141                   'upd': LDSTMode,
 142                   'rc_sel': RC,
 143                   'cry_in': CryIn
 144                   }
 145
 146 power_op_csvmap = {'function_unit': 'unit',
 147                    'form': 'form',
 148                    'internal_op': 'internal op',
 149                    'in1_sel': 'in1',
 150                    'in2_sel': 'in2',
 151                    'in3_sel': 'in3',
 152                    'out_sel': 'out',
 153                    'sv_in1': 'sv_in1',
 154                    'sv_in2': 'sv_in2',
 155                    'sv_in3': 'sv_in3',
 156                    'sv_out': 'sv_out',
 157                    'sv_out2': 'sv_out2',
 158                    'sv_cr_in': 'sv_cr_in',
 159                    'sv_cr_out': 'sv_cr_out',
 160                    'SV_Etype': 'SV_Etype',
 161                    'SV_Ptype': 'SV_Ptype',
 162                    'cr_in': 'CR in',
 163                    'cr_out': 'CR out',
 164                    'ldst_len': 'ldst len',
 165                    'upd': 'upd',
 166                    'rc_sel': 'rc',
 167                    'cry_in': 'cry in',
 168                    }
 169
 170
 171 def get_pname(field, pname):
 172     if pname is None:
 173         return field
 174     return "%s_%s" % (pname, field)
 175
 176
 177 class PowerOp:
 178     """PowerOp - a dynamic class that stores (subsets of) CSV rows of data
 179     about a PowerISA instruction.  this is a "micro-code" expanded format
 180     which generates an awful lot of wires, hence the subsetting
 181     """
 182
 183     def __init__(self, incl_asm=True, name=None, subset=None, fields=None):
 184         self.name = name
 185         self.subset = subset
 186         if fields is not None:
 187             for k, v in fields.items():
 188                 setattr(self, k, v)
 189             return
 190         debug_report = set()
 191         fields = set()
 192         for field, ptype in power_op_types.items():
 193             fields.add(field)
 194             if subset and field not in subset:
 195                 continue
 196             fname = get_pname(field, name)
 197             setattr(self, field, Signal(ptype, reset_less=True, name=fname))
 198             debug_report.add(field)
 199         for bit in single_bit_flags:
 200             field = get_signal_name(bit)
 201             fields.add(field)
 202             if subset and field not in subset:
 203                 continue
 204             debug_report.add(field)
 205             fname = get_pname(field, name)
 206             setattr(self, field, Signal(reset_less=True, name=fname))
 207         self._fields = fields
 208         # comment out, bit too high debug level
 209         #print("PowerOp debug", name, debug_report)
 210         #print("        fields", fields)
 211
 212     @staticmethod
 213     def like(other):
 214         """PowerOp.like: creates a duplicate of a given PowerOp instance
 215         """
 216         fields = {}
 217         for fname in other._fields:
 218             sig = getattr(other, fname, None)
 219             if sig is not None:
 220                 fields[fname] = sig.__class__.like(sig)
 221         return PowerOp(subset=other.subset, fields=fields)
 222
 223     def _eq(self, row=None):
 224         if row is None:
 225             row = default_values
 226         # TODO: this conversion process from a dict to an object
 227         # should really be done using e.g. namedtuple and then
 228         # call eq not _eq
 229         if False:  # debugging
 230             if row['CR in'] == '1':
 231                 import pdb
 232                 pdb.set_trace()
 233                 log(row)
 234             if row['CR out'] == '0':
 235                 import pdb
 236                 pdb.set_trace()
 237                 log(row)
 238             log(row)
 239         ldst_mode = row['upd']
 240         if ldst_mode.isdigit():
 241             row['upd'] = int(ldst_mode)
 242         res = []
 243         for field, ptype in power_op_types.items():
 244             if not hasattr(self, field):
 245                 continue
 246             if field not in power_op_csvmap:
 247                 continue
 248             csvname = power_op_csvmap[field]
 249             # log(field, ptype, csvname, row)
 250             val = row[csvname]
 251             if csvname == 'upd' and isinstance(val, int):  # LDSTMode different
 252                 val = ptype(val)
 253             else:
 254                 val = ptype[val]
 255             res.append(getattr(self, field).eq(val))
 256         if False:
 257             log(row.keys())
 258         asmcode = row['comment']
 259         # process the comment field, strip out "equals" for FP
 260         if "=" in asmcode:
 261             asmcode = asmcode.split("=")[-1]
 262             log ("asmcode stripping =", asmcode,
 263                     asmcode in asmidx, hasattr(self, "asmcode"))
 264         if hasattr(self, "asmcode") and asmcode in asmidx:
 265             res.append(self.asmcode.eq(asmidx[asmcode]))
 266         for bit in single_bit_flags:
 267             field = get_signal_name(bit)
 268             if not hasattr(self, field):
 269                 continue
 270             sig = getattr(self, field)
 271             res.append(sig.eq(int(row.get(bit, 0))))
 272         return res
 273
 274     def _get_eq(self, res, field, otherop):
 275         copyfrom = getattr(otherop, field, None)
 276         copyto = getattr(self, field, None)
 277         if copyfrom is not None and copyto is not None:
 278             res.append(copyto.eq(copyfrom))
 279
 280     def eq(self, otherop):
 281         res = []
 282         for field in power_op_types.keys():
 283             self._get_eq(res, field, otherop)
 284         for bit in single_bit_flags:
 285             self._get_eq(res, get_signal_name(bit), otherop)
 286         return res
 287
 288     def ports(self):
 289         res = []
 290         for field in power_op_types.keys():
 291             if hasattr(self, field):
 292                 res.append(getattr(self, field))
 293         if hasattr(self, "asmcode"):
 294             res.append(self.asmcode)
 295         for field in single_bit_flags:
 296             field = get_signal_name(field)
 297             if hasattr(self, field):
 298                 res.append(getattr(self, field))
 299         return res
 300
 301
 302 class PowerDecoder(Elaboratable):
 303     """PowerDecoder - decodes an incoming opcode into the type of operation
 304
 305     this is a recursive algorithm, creating Switch statements that can
 306     have further match-and-decode on other parts of the opcode field before
 307     finally landing at a "this CSV entry details gets returned" thing.
 308
 309     the complicating factor is the row and col subsetting.  column subsetting
 310     dynamically chooses only the CSV columns requested, whilst row subsetting
 311     allows a function to be called on the row to determine if the Case
 312     statement is to be generated for that row.  this not only generates
 313     completely different Decoders, it also means that some sub-decoders
 314     will turn up blank (empty switch statements).  if that happens we do
 315     not want the parent to include a Mux for an entirely blank switch statement
 316     so we have to store the switch/case statements in a tree, and
 317     post-analyse it.
 318
 319     the reason for the tree is because elaborate can only be called *after*
 320     the constructor is called.  all quite messy.
 321     """
 322
 323     def __init__(self, width, dec, name=None, col_subset=None,
 324                        row_subset=None, conditions=None):
 325         if conditions is None:
 326             # XXX conditions = {}
 327             conditions = {'SVP64BREV': Const(0, 1),
 328                           'SVP64FFT': Const(0, 1),
 329                          }
 330         self.actually_does_something = False
 331         self.pname = name
 332         self.conditions = conditions
 333         self.col_subset = col_subset
 334         self.row_subsetfn = row_subset
 335         if not isinstance(dec, list):
 336             dec = [dec]
 337         self.dec = dec
 338         self.opcode_in = Signal(width, reset_less=True)
 339
 340         self.op = PowerOp(name=name, subset=col_subset)
 341         for d in dec:
 342             if d.suffix is not None and d.suffix >= width:
 343                 d.suffix = None
 344
 345         self.width = width
 346
 347         # create some case statement condition patterns for matching
 348         # a single condition.  "1----" for the first condition,
 349         # "-1----" for the 2nd etc.
 350         # also create a matching ordered list of conditions, for the switch,
 351         # which will Cat() them together
 352         self.ccases = {}
 353         self.ckeys = list(conditions.keys())
 354         self.ckeys.sort()
 355
 356     def find_conditions(self, opcodes):
 357         # look for conditions, create dictionary entries for them
 358         # sorted by opcode
 359         rows = OrderedDict() # start as a dictionary, get as list (after)
 360         for row in opcodes:
 361             condition = row['CONDITIONS']
 362             opcode = row['opcode']
 363             if condition:
 364                 # check it's expected
 365                 assert (condition in self.conditions or
 366                        (condition[0] == '~' and
 367                         condition[1:] in self.conditions)), \
 368                     "condition %s not in %s" % (condition, str(conditions))
 369                 if opcode not in rows:
 370                     rows[opcode] = {}
 371                 rows[opcode][condition] = row
 372             else:
 373                 # check it's unique
 374                 assert opcode not in rows, \
 375                     "opcode %s already in rows for %s" % \
 376                                         (opcode, self.pname)
 377                 rows[opcode] = row
 378         # after checking for conditions, get just the values (ordered)
 379         return list(rows.values())
 380
 381     def suffix_mask(self, d):
 382         return ((1 << d.suffix) - 1)
 383
 384     def divide_opcodes(self, d):
 385         divided = {}
 386         mask = self.suffix_mask(d)
 387         #print("mask", hex(mask))
 388         for row in d.opcodes:
 389             opcode = row['opcode']
 390             if d.opint and '-' not in opcode:
 391                 opcode = int(opcode, 0)
 392             key = opcode & mask
 393             opcode = opcode >> d.suffix
 394             if key not in divided:
 395                 divided[key] = []
 396             r = row.copy()
 397             r['opcode'] = opcode
 398             divided[key].append(r)
 399         return divided
 400
 401     def tree_analyse(self):
 402         self.decs = decs = []
 403         self.submodules = submodules = {}
 404         self.eqs = eqs = []
 405
 406         # go through the list of CSV decoders first
 407         for d in self.dec:
 408             cases = []
 409             opcode_switch = Signal(d.bitsel[1] - d.bitsel[0],
 410                                    reset_less=True)
 411             eq = []
 412             case_does_something = False
 413             look_for = self.opcode_in[d.bitsel[0]:d.bitsel[1]]
 414             eq.append(opcode_switch.eq(look_for))
 415             if d.suffix:
 416                 opcodes = self.divide_opcodes(d)
 417                 # TODO opcodes = self.find_conditions(opcodes)
 418                 opc_in = Signal(d.suffix, reset_less=True)
 419                 eq.append(opc_in.eq(opcode_switch[:d.suffix]))
 420                 # begin the dynamic Switch statement here
 421                 switch_case = {}
 422                 cases.append([opc_in, switch_case])
 423                 sub_eqs = []
 424                 for key, row in opcodes.items():
 425                     bitsel = (d.suffix+d.bitsel[0], d.bitsel[1])
 426                     sd = Subdecoder(pattern=None, opcodes=row,
 427                                     bitsel=bitsel, suffix=None,
 428                                     opint=False, subdecoders=[])
 429                     mname = get_pname("dec_sub%d" % key, self.pname)
 430                     subdecoder = PowerDecoder(width=32, dec=sd,
 431                                               name=mname,
 432                                               col_subset=self.col_subset,
 433                                               row_subset=self.row_subsetfn,
 434                                               conditions=self.conditions)
 435                     if not subdecoder.tree_analyse():
 436                         del subdecoder
 437                         continue
 438                     submodules[mname] = subdecoder
 439                     sub_eqs.append(subdecoder.opcode_in.eq(self.opcode_in))
 440                     # add in the dynamic Case statement here
 441                     switch_case[key] = self.op.eq(subdecoder.op)
 442                     self.actually_does_something = True
 443                     case_does_something = True
 444                 if case_does_something:
 445                     eq += sub_eqs
 446             else:
 447                 # TODO: arguments, here (all of them) need to be a list.
 448                 # a for-loop around the *list* of decoder args.
 449                 switch_case = {}
 450                 cases.append([opcode_switch, switch_case])
 451                 seqs = self.handle_subdecoders(switch_case, submodules, d)
 452                 if seqs:
 453                     case_does_something = True
 454                 eq += seqs
 455                 opcodes = self.find_conditions(d.opcodes)
 456                 for row in opcodes:
 457                     # urrr this is an awful hack. if "conditions" are active
 458                     # get the FIRST item (will be the same opcode), and it
 459                     # had BETTER have the same unit and also pass other
 460                     # row subset conditions.
 461                     if 'opcode' not in row: # must be a "CONDITIONS" dict...
 462                         is_conditions = True
 463                         _row = row[list(row.keys())[0]]
 464                     else:
 465                         is_conditions = False
 466                         _row = row
 467                     opcode = _row['opcode']
 468                     if d.opint and '-' not in opcode:
 469                         opcode = int(opcode, 0)
 470                     if not _row['unit']:
 471                         continue
 472                     if self.row_subsetfn:
 473                         if not self.row_subsetfn(opcode, _row):
 474                             continue
 475                     # add in the dynamic Case statement here
 476                     if is_conditions:
 477                         switch_case[opcode] = {}
 478                         for k, crow in row.items():
 479                             # log("ordered", k, crow)
 480                             switch_case[opcode][k] = self.op._eq(crow)
 481                     else:
 482                         switch_case[opcode] = self.op._eq(row)
 483                     self.actually_does_something = True
 484                     case_does_something = True
 485
 486             if cases:
 487                 decs.append(cases)
 488             if case_does_something:
 489                 eqs += eq
 490                 #print("submodule eqs", self.pname, eq)
 491
 492         #print("submodules", self.pname, submodules)
 493
 494         gc.collect()
 495         return self.actually_does_something
 496
 497     def handle_subdecoders(self, switch_case, submodules, d):
 498         eqs = []
 499         for dlist in d.subdecoders:
 500             if not isinstance(dlist, list):  # XXX HACK: take first pattern
 501                 dlist = [dlist]
 502             for dec in dlist:
 503                 #print("subdec", dec.pattern, self.pname)
 504                 mname = get_pname("dec%d" % dec.pattern, self.pname)
 505                 if mname in submodules:
 506                     # sigh, HACK...
 507                     mname += "_1"
 508                     assert mname not in submodules
 509                 subdecoder = PowerDecoder(self.width, dec,
 510                                           name=mname,
 511                                           col_subset=self.col_subset,
 512                                           row_subset=self.row_subsetfn,
 513                                           conditions=self.conditions)
 514                 log ("subdecoder", mname, subdecoder)
 515                 if not subdecoder.tree_analyse():  # doesn't do anything
 516                     log ("analysed, DELETING", mname)
 517                     del subdecoder
 518                     continue                      # skip
 519                 submodules[mname] = subdecoder
 520                 eqs.append(subdecoder.opcode_in.eq(self.opcode_in))
 521                 switch_case[dec.pattern] = self.op.eq(subdecoder.op)
 522                 self.actually_does_something = True
 523
 524         return eqs
 525
 526     def elaborate(self, platform):
 527         #print("decoder elaborate", self.pname, self.submodules)
 528         m = Module()
 529         comb = m.d.comb
 530
 531         comb += self.eqs
 532
 533         for mname, subdecoder in self.submodules.items():
 534             setattr(m.submodules, mname, subdecoder)
 535
 536         for switch_case in self.decs:
 537             for (switch, cases) in switch_case:
 538                 with m.Switch(switch):
 539                     for key, eqs in cases.items():
 540                         with m.Case(key):
 541                             # "conditions" are a further switch statement
 542                             if isinstance(eqs, dict):
 543                                 self.condition_switch(m, eqs)
 544                             else:
 545                                 comb += eqs
 546         return m
 547
 548     def condition_switch(self, m, cases):
 549         """against the global list of "conditions", having matched against
 550         bits of the opcode, we FINALLY now have to match against some
 551         additional "conditions".  this is because there can be **MULTIPLE**
 552         entries for a given opcode match. here we discern them.
 553         """
 554         comb = m.d.comb
 555         cswitch = []
 556         ccases = []
 557         for casekey, eqs in cases.items():
 558             if casekey.startswith('~'):
 559                 with m.If(~self.conditions[casekey[1:]]):
 560                     comb += eqs
 561             else:
 562                 with m.If(self.conditions[casekey]):
 563                     comb += eqs
 564
 565     def ports(self):
 566         return [self.opcode_in] + self.op.ports()
 567
 568
 569 class TopPowerDecoder(PowerDecoder):
 570     """TopPowerDecoder
 571
 572     top-level hierarchical decoder for POWER ISA
 573     bigendian dynamically switches between big and little endian decoding
 574     (reverses byte order).  See V3.0B p44 1.11.2
 575     """
 576
 577     def __init__(self, width, dec, name=None, col_subset=None,
 578                                    row_subset=None, conditions=None):
 579         PowerDecoder.__init__(self, width, dec, name,
 580                               col_subset, row_subset, conditions)
 581         self.fields = df = DecodeFields(SignalBitRange, [self.opcode_in])
 582         self.fields.create_specs()
 583         self.raw_opcode_in = Signal.like(self.opcode_in, reset_less=True)
 584         self.bigendian = Signal(reset_less=True)
 585
 586         for fname, value in self.fields.common_fields.items():
 587             signame = get_pname(fname, name)
 588             sig = Signal(value[0:-1].shape(), reset_less=True, name=signame)
 589             setattr(self, fname, sig)
 590
 591         # create signals for all field forms
 592         forms = self.form_names
 593         self.sigforms = {}
 594         for form in forms:
 595             fields = self.fields.instrs[form]
 596             fk = fields.keys()
 597             Fields = namedtuple("Fields", fk)
 598             sf = {}
 599             for k, value in fields.items():
 600                 fname = "%s_%s" % (form, k)
 601                 sig = Signal(value[0:-1].shape(), reset_less=True, name=fname)
 602                 sf[k] = sig
 603             instr = Fields(**sf)
 604             setattr(self, "Form%s" % form, instr)
 605             self.sigforms[form] = instr
 606
 607         self.tree_analyse()
 608
 609     @property
 610     def form_names(self):
 611         return self.fields.instrs.keys()
 612
 613     def elaborate(self, platform):
 614         m = PowerDecoder.elaborate(self, platform)
 615         comb = m.d.comb
 616         # sigh duplicated in SVP64PowerDecoder
 617         # raw opcode in assumed to be in LE order: byte-reverse it to get BE
 618         raw_le = self.raw_opcode_in
 619         l = []
 620         for i in range(0, self.width, 8):
 621             l.append(raw_le[i:i+8])
 622         l.reverse()
 623         raw_be = Cat(*l)
 624         comb += self.opcode_in.eq(Mux(self.bigendian, raw_be, raw_le))
 625
 626         # add all signal from commonly-used fields
 627         for fname, value in self.fields.common_fields.items():
 628             sig = getattr(self, fname)
 629             comb += sig.eq(value[0:-1])
 630
 631         # link signals for all field forms
 632         forms = self.form_names
 633         for form in forms:
 634             sf = self.sigforms[form]
 635             fields = self.fields.instrs[form]
 636             for k, value in fields.items():
 637                 sig = getattr(sf, k)
 638                 comb += sig.eq(value[0:-1])
 639
 640         return m
 641
 642     def ports(self):
 643         res = [self.raw_opcode_in, self.bigendian] + PowerDecoder.ports(self)
 644         for condition in self.conditions.values():
 645             res.append(condition)
 646         return res
 647
 648
 649 #############################################################
 650 # PRIMARY FUNCTION SPECIFYING ALTERNATIVE SVP64 POWER DECODER
 651
 652 def create_pdecode_svp64_ldst(name=None, col_subset=None, row_subset=None,
 653                    include_fp=False):
 654     """create_pdecode - creates a cascading hierarchical POWER ISA decoder
 655
 656     subsetting of the PowerOp decoding is possible by setting col_subset
 657     """
 658     log ("create_pdecode_svp64_ldst", name, col_subset, row_subset, include_fp)
 659
 660     # some alteration to the CSV files is required for SV so we use
 661     # a class to do it
 662     isa = SVP64RM()
 663     get_csv = isa.get_svp64_csv
 664
 665     # minor opcodes.
 666     pminor = [
 667         Subdecoder(pattern=58, opcodes=get_csv("svldst_minor_58.csv"),
 668                    opint=True, bitsel=(0, 2), suffix=None, subdecoders=[]),
 669         # nope - needs 4-in regs
 670         #Subdecoder(pattern=62, opcodes=get_csv("svldst_minor_62.csv"),
 671         #           opint=True, bitsel=(0, 2), suffix=None, subdecoders=[]),
 672     ]
 673
 674     # FP 63L/H decoders. TODO: move mffsfamily to separate subdecoder
 675     if False and include_fp:
 676         pminor.append(
 677             Subdecoder(pattern=63, opcodes=get_csv("minor_63.csv"),
 678                                  opint=False, bitsel=(1, 11), suffix=None,
 679                                  subdecoders=[]),
 680             )
 681         pminor.append(
 682             Subdecoder(pattern=59, opcodes=get_csv("minor_59.csv"),
 683                                  opint=False, bitsel=(1, 11), suffix=None,
 684                                  subdecoders=[]),
 685             )
 686
 687     # top level: extra merged with major
 688     dec = []
 689     opcodes = get_csv("svldst_major.csv")
 690     dec.append(Subdecoder(pattern=None, opint=True, opcodes=opcodes,
 691                           bitsel=(26, 32), suffix=None, subdecoders=pminor))
 692
 693     return TopPowerDecoder(32, dec, name=name, col_subset=col_subset,
 694                            row_subset=row_subset)
 695
 696
 697 ####################################################
 698 # PRIMARY FUNCTION SPECIFYING THE FULL POWER DECODER
 699
 700 def create_pdecode(name=None, col_subset=None, row_subset=None,
 701                    include_fp=False, conditions=None):
 702     """create_pdecode - creates a cascading hierarchical POWER ISA decoder
 703
 704     subsetting of the PowerOp decoding is possible by setting col_subset
 705     """
 706     log ("create_pdecode", name, col_subset, row_subset, include_fp)
 707
 708     # some alteration to the CSV files is required for SV so we use
 709     # a class to do it
 710     isa = SVP64RM()
 711     get_csv = isa.get_svp64_csv
 712
 713     # minor 19 has extra patterns
 714     m19 = []
 715     m19.append(Subdecoder(pattern=19, opcodes=get_csv("minor_19.csv"),
 716                           opint=True, bitsel=(1, 11), suffix=None,
 717                           subdecoders=[]))
 718     # XXX problem with sub-decoders (can only handle one),
 719     # sort this another time
 720     #m19.append(Subdecoder(pattern=19, opcodes=get_csv("minor_19_00000.csv"),
 721     #                      opint=True, bitsel=(1, 6), suffix=None,
 722     #                      subdecoders=[]))
 723
 724     # minor opcodes.
 725     pminor = [
 726         m19,
 727         Subdecoder(pattern=30, opcodes=get_csv("minor_30.csv"),
 728                    opint=True, bitsel=(1, 5), suffix=None, subdecoders=[]),
 729         Subdecoder(pattern=31, opcodes=get_csv("minor_31.csv"),
 730                    opint=True, bitsel=(1, 11), suffix=0b00101, subdecoders=[]),
 731         Subdecoder(pattern=58, opcodes=get_csv("minor_58.csv"),
 732                    opint=True, bitsel=(0, 2), suffix=None, subdecoders=[]),
 733         Subdecoder(pattern=62, opcodes=get_csv("minor_62.csv"),
 734                    opint=True, bitsel=(0, 2), suffix=None, subdecoders=[]),
 735         Subdecoder(pattern=22, opcodes=get_csv("minor_22.csv"),
 736                    opint=True, bitsel=(1, 5), suffix=None, subdecoders=[]),
 737     ]
 738
 739     # FP 63L/H decoders. TODO: move mffsfamily to separate subdecoder
 740     if include_fp:
 741         pminor.append(
 742             Subdecoder(pattern=63, opcodes=get_csv("minor_63.csv"),
 743                                  opint=False, bitsel=(1, 11), suffix=None,
 744                                  subdecoders=[]),
 745             )
 746         pminor.append(
 747             Subdecoder(pattern=59, opcodes=get_csv("minor_59.csv"),
 748                                  opint=False, bitsel=(1, 11), suffix=None,
 749                                  subdecoders=[]),
 750             )
 751
 752     # top level: extra merged with major
 753     dec = []
 754     opcodes = get_csv("major.csv")
 755     dec.append(Subdecoder(pattern=None, opint=True, opcodes=opcodes,
 756                           bitsel=(26, 32), suffix=None, subdecoders=pminor))
 757     opcodes = get_csv("extra.csv")
 758     dec.append(Subdecoder(pattern=None, opint=False, opcodes=opcodes,
 759                           bitsel=(0, 32), suffix=None, subdecoders=[]))
 760
 761     return TopPowerDecoder(32, dec, name=name, col_subset=col_subset,
 762                            row_subset=row_subset,
 763                            conditions=conditions)
 764
 765
 766 if __name__ == '__main__':
 767
 768     if True:
 769         # row subset
 770
 771         def rowsubsetfn(opcode, row):
 772             log("row_subset", opcode, row)
 773             return row['unit'] in ['LDST', 'FPU']
 774
 775         conditions = {'SVP64BREV': Signal(name="svp64brev", reset_less=True),
 776                       'SVP64FFT': Signal(name="svp64fft", reset_less=True),
 777                      }
 778         pdecode = create_pdecode(name="rowsub",
 779                                  col_subset={'opcode', 'function_unit',
 780                                               'asmcode',
 781                                              'in2_sel', 'in3_sel'},
 782                                  row_subset=rowsubsetfn,
 783                                  include_fp=True,
 784                                  conditions=conditions)
 785         vl = rtlil.convert(pdecode, ports=pdecode.ports())
 786         with open("row_subset_decoder.il", "w") as f:
 787             f.write(vl)
 788
 789         vl = verilog.convert(pdecode, ports=pdecode.ports())
 790         with open("row_subset_decoder.v", "w") as f:
 791             f.write(vl)
 792
 793         exit(0)
 794
 795         # col subset
 796
 797         pdecode = create_pdecode(name="fusubset", col_subset={'function_unit'})
 798         vl = rtlil.convert(pdecode, ports=pdecode.ports())
 799         with open("col_subset_decoder.il", "w") as f:
 800             f.write(vl)
 801
 802     # full decoder
 803     pdecode = create_pdecode(include_fp=True)
 804     vl = rtlil.convert(pdecode, ports=pdecode.ports())
 805     with open("decoder.il", "w") as f:
 806         f.write(vl)
 807
 808     # full SVP64 decoder
 809     pdecode = create_pdecode_svp64_ldst(include_fp=True)
 810     vl = rtlil.convert(pdecode, ports=pdecode.ports())
 811     with open("decoder_svp64.il", "w") as f:
 812         f.write(vl)