src/jit/dis_ppc.lua

   1 ----------------------------------------------------------------------------
   2 -- LuaJIT PPC disassembler module.
   3 --
   4 -- Copyright (C) 2005-2014 Mike Pall. All rights reserved.
   5 -- Released under the MIT/X license. See Copyright Notice in luajit.h
   6 ----------------------------------------------------------------------------
   7 -- This is a helper module used by the LuaJIT machine code dumper module.
   8 --
   9 -- It disassembles all common, non-privileged 32/64 bit PowerPC instructions
  10 -- plus the e500 SPE instructions and some Cell/Xenon extensions.
  11 --
  12 -- NYI: VMX, VMX128
  13 ------------------------------------------------------------------------------
  14
  15 local type = type
  16 local sub, byte, format = string.sub, string.byte, string.format
  17 local match, gmatch, gsub = string.match, string.gmatch, string.gsub
  18 local concat = table.concat
  19 local bit = require("bit")
  20 local band, bor, tohex = bit.band, bit.bor, bit.tohex
  21 local lshift, rshift, arshift = bit.lshift, bit.rshift, bit.arshift
  22
  23 ------------------------------------------------------------------------------
  24 -- Primary and extended opcode maps
  25 ------------------------------------------------------------------------------
  26
  27 local map_crops = {
  28   shift = 1, mask = 1023,
  29   [0] = "mcrfXX",
  30   [33] = "crnor|crnotCCC=", [129] = "crandcCCC",
  31   [193] = "crxor|crclrCCC%", [225] = "crnandCCC",
  32   [257] = "crandCCC", [289] = "creqv|crsetCCC%",
  33   [417] = "crorcCCC", [449] = "cror|crmoveCCC=",
  34   [16] = "b_lrKB", [528] = "b_ctrKB",
  35   [150] = "isync",
  36 }
  37
  38 local map_rlwinm = setmetatable({
  39   shift = 0, mask = -1,
  40 },
  41 { __index = function(t, x)
  42     local rot = band(rshift(x, 11), 31)
  43     local mb = band(rshift(x, 6), 31)
  44     local me = band(rshift(x, 1), 31)
  45     if mb == 0 and me == 31-rot then
  46       return "slwiRR~A."
  47     elseif me == 31 and mb == 32-rot then
  48       return "srwiRR~-A."
  49     else
  50       return "rlwinmRR~AAA."
  51     end
  52   end
  53 })
  54
  55 local map_rld = {
  56   shift = 2, mask = 7,
  57   [0] = "rldiclRR~HM.", "rldicrRR~HM.", "rldicRR~HM.", "rldimiRR~HM.",
  58   {
  59     shift = 1, mask = 1,
  60     [0] = "rldclRR~RM.", "rldcrRR~RM.",
  61   },
  62 }
  63
  64 local map_ext = setmetatable({
  65   shift = 1, mask = 1023,
  66
  67   [0] = "cmp_YLRR", [32] = "cmpl_YLRR",
  68   [4] = "twARR", [68] = "tdARR",
  69
  70   [8] = "subfcRRR.", [40] = "subfRRR.",
  71   [104] = "negRR.", [136] = "subfeRRR.",
  72   [200] = "subfzeRR.", [232] = "subfmeRR.",
  73   [520] = "subfcoRRR.", [552] = "subfoRRR.",
  74   [616] = "negoRR.", [648] = "subfeoRRR.",
  75   [712] = "subfzeoRR.", [744] = "subfmeoRR.",
  76
  77   [9] = "mulhduRRR.", [73] = "mulhdRRR.", [233] = "mulldRRR.",
  78   [457] = "divduRRR.", [489] = "divdRRR.",
  79   [745] = "mulldoRRR.",
  80   [969] = "divduoRRR.", [1001] = "divdoRRR.",
  81
  82   [10] = "addcRRR.", [138] = "addeRRR.",
  83   [202] = "addzeRR.", [234] = "addmeRR.", [266] = "addRRR.",
  84   [522] = "addcoRRR.", [650] = "addeoRRR.",
  85   [714] = "addzeoRR.", [746] = "addmeoRR.", [778] = "addoRRR.",
  86
  87   [11] = "mulhwuRRR.", [75] = "mulhwRRR.", [235] = "mullwRRR.",
  88   [459] = "divwuRRR.", [491] = "divwRRR.",
  89   [747] = "mullwoRRR.",
  90   [971] = "divwouRRR.", [1003] = "divwoRRR.",
  91
  92   [15] = "iselltRRR", [47] = "iselgtRRR", [79] = "iseleqRRR",
  93
  94   [144] = { shift = 20, mask = 1, [0] = "mtcrfRZ~", "mtocrfRZ~", },
  95   [19] = { shift = 20, mask = 1, [0] = "mfcrR", "mfocrfRZ", },
  96   [371] = { shift = 11, mask = 1023, [392] = "mftbR", [424] = "mftbuR", },
  97   [339] = {
  98     shift = 11, mask = 1023,
  99     [32] = "mferR", [256] = "mflrR", [288] = "mfctrR", [16] = "mfspefscrR",
 100   },
 101   [467] = {
 102     shift = 11, mask = 1023,
 103     [32] = "mtxerR", [256] = "mtlrR", [288] = "mtctrR", [16] = "mtspefscrR",
 104   },
 105
 106   [20] = "lwarxRR0R", [84] = "ldarxRR0R",
 107
 108   [21] = "ldxRR0R", [53] = "lduxRRR",
 109   [149] = "stdxRR0R", [181] = "stduxRRR",
 110   [341] = "lwaxRR0R", [373] = "lwauxRRR",
 111
 112   [23] = "lwzxRR0R", [55] = "lwzuxRRR",
 113   [87] = "lbzxRR0R", [119] = "lbzuxRRR",
 114   [151] = "stwxRR0R", [183] = "stwuxRRR",
 115   [215] = "stbxRR0R", [247] = "stbuxRRR",
 116   [279] = "lhzxRR0R", [311] = "lhzuxRRR",
 117   [343] = "lhaxRR0R", [375] = "lhauxRRR",
 118   [407] = "sthxRR0R", [439] = "sthuxRRR",
 119
 120   [54] = "dcbst-R0R", [86] = "dcbf-R0R",
 121   [150] = "stwcxRR0R.", [214] = "stdcxRR0R.",
 122   [246] = "dcbtst-R0R", [278] = "dcbt-R0R",
 123   [310] = "eciwxRR0R", [438] = "ecowxRR0R",
 124   [470] = "dcbi-RR",
 125
 126   [598] = {
 127     shift = 21, mask = 3,
 128     [0] = "sync", "lwsync", "ptesync",
 129   },
 130   [758] = "dcba-RR",
 131   [854] = "eieio", [982] = "icbi-R0R", [1014] = "dcbz-R0R",
 132
 133   [26] = "cntlzwRR~", [58] = "cntlzdRR~",
 134   [122] = "popcntbRR~",
 135   [154] = "prtywRR~", [186] = "prtydRR~",
 136
 137   [28] = "andRR~R.", [60] = "andcRR~R.", [124] = "nor|notRR~R=.",
 138   [284] = "eqvRR~R.", [316] = "xorRR~R.",
 139   [412] = "orcRR~R.", [444] = "or|mrRR~R=.", [476] = "nandRR~R.",
 140   [508] = "cmpbRR~R",
 141
 142   [512] = "mcrxrX",
 143
 144   [532] = "ldbrxRR0R", [660] = "stdbrxRR0R",
 145
 146   [533] = "lswxRR0R", [597] = "lswiRR0A",
 147   [661] = "stswxRR0R", [725] = "stswiRR0A",
 148
 149   [534] = "lwbrxRR0R", [662] = "stwbrxRR0R",
 150   [790] = "lhbrxRR0R", [918] = "sthbrxRR0R",
 151
 152   [535] = "lfsxFR0R", [567] = "lfsuxFRR",
 153   [599] = "lfdxFR0R", [631] = "lfduxFRR",
 154   [663] = "stfsxFR0R", [695] = "stfsuxFRR",
 155   [727] = "stfdxFR0R", [759] = "stfduxFR0R",
 156   [855] = "lfiwaxFR0R",
 157   [983] = "stfiwxFR0R",
 158
 159   [24] = "slwRR~R.",
 160
 161   [27] = "sldRR~R.", [536] = "srwRR~R.",
 162   [792] = "srawRR~R.", [824] = "srawiRR~A.",
 163
 164   [794] = "sradRR~R.", [826] = "sradiRR~H.", [827] = "sradiRR~H.",
 165   [922] = "extshRR~.", [954] = "extsbRR~.", [986] = "extswRR~.",
 166
 167   [539] = "srdRR~R.",
 168 },
 169 { __index = function(t, x)
 170     if band(x, 31) == 15 then return "iselRRRC" end
 171   end
 172 })
 173
 174 local map_ld = {
 175   shift = 0, mask = 3,
 176   [0] = "ldRRE", "lduRRE", "lwaRRE",
 177 }
 178
 179 local map_std = {
 180   shift = 0, mask = 3,
 181   [0] = "stdRRE", "stduRRE",
 182 }
 183
 184 local map_fps = {
 185   shift = 5, mask = 1,
 186   {
 187     shift = 1, mask = 15,
 188     [0] = false, false, "fdivsFFF.", false,
 189     "fsubsFFF.", "faddsFFF.", "fsqrtsF-F.", false,
 190     "fresF-F.", "fmulsFF-F.", "frsqrtesF-F.", false,
 191     "fmsubsFFFF~.", "fmaddsFFFF~.", "fnmsubsFFFF~.", "fnmaddsFFFF~.",
 192   }
 193 }
 194
 195 local map_fpd = {
 196   shift = 5, mask = 1,
 197   [0] = {
 198     shift = 1, mask = 1023,
 199     [0] = "fcmpuXFF", [32] = "fcmpoXFF", [64] = "mcrfsXX",
 200     [38] = "mtfsb1A.", [70] = "mtfsb0A.", [134] = "mtfsfiA>>-A>",
 201     [8] = "fcpsgnFFF.", [40] = "fnegF-F.", [72] = "fmrF-F.",
 202     [136] = "fnabsF-F.", [264] = "fabsF-F.",
 203     [12] = "frspF-F.",
 204     [14] = "fctiwF-F.", [15] = "fctiwzF-F.",
 205     [583] = "mffsF.", [711] = "mtfsfZF.",
 206     [392] = "frinF-F.", [424] = "frizF-F.",
 207     [456] = "fripF-F.", [488] = "frimF-F.",
 208     [814] = "fctidF-F.", [815] = "fctidzF-F.", [846] = "fcfidF-F.",
 209   },
 210   {
 211     shift = 1, mask = 15,
 212     [0] = false, false, "fdivFFF.", false,
 213     "fsubFFF.", "faddFFF.", "fsqrtF-F.", "fselFFFF~.",
 214     "freF-F.", "fmulFF-F.", "frsqrteF-F.", false,
 215     "fmsubFFFF~.", "fmaddFFFF~.", "fnmsubFFFF~.", "fnmaddFFFF~.",
 216   }
 217 }
 218
 219 local map_spe = {
 220   shift = 0, mask = 2047,
 221
 222   [512] = "evaddwRRR", [514] = "evaddiwRAR~",
 223   [516] = "evsubwRRR~", [518] = "evsubiwRAR~",
 224   [520] = "evabsRR", [521] = "evnegRR",
 225   [522] = "evextsbRR", [523] = "evextshRR", [524] = "evrndwRR",
 226   [525] = "evcntlzwRR", [526] = "evcntlswRR",
 227
 228   [527] = "brincRRR",
 229
 230   [529] = "evandRRR", [530] = "evandcRRR", [534] = "evxorRRR",
 231   [535] = "evor|evmrRRR=", [536] = "evnor|evnotRRR=",
 232   [537] = "eveqvRRR", [539] = "evorcRRR", [542] = "evnandRRR",
 233
 234   [544] = "evsrwuRRR", [545] = "evsrwsRRR",
 235   [546] = "evsrwiuRRA", [547] = "evsrwisRRA",
 236   [548] = "evslwRRR", [550] = "evslwiRRA",
 237   [552] = "evrlwRRR", [553] = "evsplatiRS",
 238   [554] = "evrlwiRRA", [555] = "evsplatfiRS",
 239   [556] = "evmergehiRRR", [557] = "evmergeloRRR",
 240   [558] = "evmergehiloRRR", [559] = "evmergelohiRRR",
 241
 242   [560] = "evcmpgtuYRR", [561] = "evcmpgtsYRR",
 243   [562] = "evcmpltuYRR", [563] = "evcmpltsYRR",
 244   [564] = "evcmpeqYRR",
 245
 246   [632] = "evselRRR", [633] = "evselRRRW",
 247   [634] = "evselRRRW", [635] = "evselRRRW",
 248   [636] = "evselRRRW", [637] = "evselRRRW",
 249   [638] = "evselRRRW", [639] = "evselRRRW",
 250
 251   [640] = "evfsaddRRR", [641] = "evfssubRRR",
 252   [644] = "evfsabsRR", [645] = "evfsnabsRR", [646] = "evfsnegRR",
 253   [648] = "evfsmulRRR", [649] = "evfsdivRRR",
 254   [652] = "evfscmpgtYRR", [653] = "evfscmpltYRR", [654] = "evfscmpeqYRR",
 255   [656] = "evfscfuiR-R", [657] = "evfscfsiR-R",
 256   [658] = "evfscfufR-R", [659] = "evfscfsfR-R",
 257   [660] = "evfsctuiR-R", [661] = "evfsctsiR-R",
 258   [662] = "evfsctufR-R", [663] = "evfsctsfR-R",
 259   [664] = "evfsctuizR-R", [666] = "evfsctsizR-R",
 260   [668] = "evfststgtYRR", [669] = "evfststltYRR", [670] = "evfststeqYRR",
 261
 262   [704] = "efsaddRRR", [705] = "efssubRRR",
 263   [708] = "efsabsRR", [709] = "efsnabsRR", [710] = "efsnegRR",
 264   [712] = "efsmulRRR", [713] = "efsdivRRR",
 265   [716] = "efscmpgtYRR", [717] = "efscmpltYRR", [718] = "efscmpeqYRR",
 266   [719] = "efscfdR-R",
 267   [720] = "efscfuiR-R", [721] = "efscfsiR-R",
 268   [722] = "efscfufR-R", [723] = "efscfsfR-R",
 269   [724] = "efsctuiR-R", [725] = "efsctsiR-R",
 270   [726] = "efsctufR-R", [727] = "efsctsfR-R",
 271   [728] = "efsctuizR-R", [730] = "efsctsizR-R",
 272   [732] = "efststgtYRR", [733] = "efststltYRR", [734] = "efststeqYRR",
 273
 274   [736] = "efdaddRRR", [737] = "efdsubRRR",
 275   [738] = "efdcfuidR-R", [739] = "efdcfsidR-R",
 276   [740] = "efdabsRR", [741] = "efdnabsRR", [742] = "efdnegRR",
 277   [744] = "efdmulRRR", [745] = "efddivRRR",
 278   [746] = "efdctuidzR-R", [747] = "efdctsidzR-R",
 279   [748] = "efdcmpgtYRR", [749] = "efdcmpltYRR", [750] = "efdcmpeqYRR",
 280   [751] = "efdcfsR-R",
 281   [752] = "efdcfuiR-R", [753] = "efdcfsiR-R",
 282   [754] = "efdcfufR-R", [755] = "efdcfsfR-R",
 283   [756] = "efdctuiR-R", [757] = "efdctsiR-R",
 284   [758] = "efdctufR-R", [759] = "efdctsfR-R",
 285   [760] = "efdctuizR-R", [762] = "efdctsizR-R",
 286   [764] = "efdtstgtYRR", [765] = "efdtstltYRR", [766] = "efdtsteqYRR",
 287
 288   [768] = "evlddxRR0R", [769] = "evlddRR8",
 289   [770] = "evldwxRR0R", [771] = "evldwRR8",
 290   [772] = "evldhxRR0R", [773] = "evldhRR8",
 291   [776] = "evlhhesplatxRR0R", [777] = "evlhhesplatRR2",
 292   [780] = "evlhhousplatxRR0R", [781] = "evlhhousplatRR2",
 293   [782] = "evlhhossplatxRR0R", [783] = "evlhhossplatRR2",
 294   [784] = "evlwhexRR0R", [785] = "evlwheRR4",
 295   [788] = "evlwhouxRR0R", [789] = "evlwhouRR4",
 296   [790] = "evlwhosxRR0R", [791] = "evlwhosRR4",
 297   [792] = "evlwwsplatxRR0R", [793] = "evlwwsplatRR4",
 298   [796] = "evlwhsplatxRR0R", [797] = "evlwhsplatRR4",
 299
 300   [800] = "evstddxRR0R", [801] = "evstddRR8",
 301   [802] = "evstdwxRR0R", [803] = "evstdwRR8",
 302   [804] = "evstdhxRR0R", [805] = "evstdhRR8",
 303   [816] = "evstwhexRR0R", [817] = "evstwheRR4",
 304   [820] = "evstwhoxRR0R", [821] = "evstwhoRR4",
 305   [824] = "evstwwexRR0R", [825] = "evstwweRR4",
 306   [828] = "evstwwoxRR0R", [829] = "evstwwoRR4",
 307
 308   [1027] = "evmhessfRRR", [1031] = "evmhossfRRR", [1032] = "evmheumiRRR",
 309   [1033] = "evmhesmiRRR", [1035] = "evmhesmfRRR", [1036] = "evmhoumiRRR",
 310   [1037] = "evmhosmiRRR", [1039] = "evmhosmfRRR", [1059] = "evmhessfaRRR",
 311   [1063] = "evmhossfaRRR", [1064] = "evmheumiaRRR", [1065] = "evmhesmiaRRR",
 312   [1067] = "evmhesmfaRRR", [1068] = "evmhoumiaRRR", [1069] = "evmhosmiaRRR",
 313   [1071] = "evmhosmfaRRR", [1095] = "evmwhssfRRR", [1096] = "evmwlumiRRR",
 314   [1100] = "evmwhumiRRR", [1101] = "evmwhsmiRRR", [1103] = "evmwhsmfRRR",
 315   [1107] = "evmwssfRRR", [1112] = "evmwumiRRR", [1113] = "evmwsmiRRR",
 316   [1115] = "evmwsmfRRR", [1127] = "evmwhssfaRRR", [1128] = "evmwlumiaRRR",
 317   [1132] = "evmwhumiaRRR", [1133] = "evmwhsmiaRRR", [1135] = "evmwhsmfaRRR",
 318   [1139] = "evmwssfaRRR", [1144] = "evmwumiaRRR", [1145] = "evmwsmiaRRR",
 319   [1147] = "evmwsmfaRRR",
 320
 321   [1216] = "evaddusiaawRR", [1217] = "evaddssiaawRR",
 322   [1218] = "evsubfusiaawRR", [1219] = "evsubfssiaawRR",
 323   [1220] = "evmraRR",
 324   [1222] = "evdivwsRRR", [1223] = "evdivwuRRR",
 325   [1224] = "evaddumiaawRR", [1225] = "evaddsmiaawRR",
 326   [1226] = "evsubfumiaawRR", [1227] = "evsubfsmiaawRR",
 327
 328   [1280] = "evmheusiaawRRR", [1281] = "evmhessiaawRRR",
 329   [1283] = "evmhessfaawRRR", [1284] = "evmhousiaawRRR",
 330   [1285] = "evmhossiaawRRR", [1287] = "evmhossfaawRRR",
 331   [1288] = "evmheumiaawRRR", [1289] = "evmhesmiaawRRR",
 332   [1291] = "evmhesmfaawRRR", [1292] = "evmhoumiaawRRR",
 333   [1293] = "evmhosmiaawRRR", [1295] = "evmhosmfaawRRR",
 334   [1320] = "evmhegumiaaRRR", [1321] = "evmhegsmiaaRRR",
 335   [1323] = "evmhegsmfaaRRR", [1324] = "evmhogumiaaRRR",
 336   [1325] = "evmhogsmiaaRRR", [1327] = "evmhogsmfaaRRR",
 337   [1344] = "evmwlusiaawRRR", [1345] = "evmwlssiaawRRR",
 338   [1352] = "evmwlumiaawRRR", [1353] = "evmwlsmiaawRRR",
 339   [1363] = "evmwssfaaRRR", [1368] = "evmwumiaaRRR",
 340   [1369] = "evmwsmiaaRRR", [1371] = "evmwsmfaaRRR",
 341   [1408] = "evmheusianwRRR", [1409] = "evmhessianwRRR",
 342   [1411] = "evmhessfanwRRR", [1412] = "evmhousianwRRR",
 343   [1413] = "evmhossianwRRR", [1415] = "evmhossfanwRRR",
 344   [1416] = "evmheumianwRRR", [1417] = "evmhesmianwRRR",
 345   [1419] = "evmhesmfanwRRR", [1420] = "evmhoumianwRRR",
 346   [1421] = "evmhosmianwRRR", [1423] = "evmhosmfanwRRR",
 347   [1448] = "evmhegumianRRR", [1449] = "evmhegsmianRRR",
 348   [1451] = "evmhegsmfanRRR", [1452] = "evmhogumianRRR",
 349   [1453] = "evmhogsmianRRR", [1455] = "evmhogsmfanRRR",
 350   [1472] = "evmwlusianwRRR", [1473] = "evmwlssianwRRR",
 351   [1480] = "evmwlumianwRRR", [1481] = "evmwlsmianwRRR",
 352   [1491] = "evmwssfanRRR", [1496] = "evmwumianRRR",
 353   [1497] = "evmwsmianRRR", [1499] = "evmwsmfanRRR",
 354 }
 355
 356 local map_pri = {
 357   [0] = false,  false,          "tdiARI",       "twiARI",
 358   map_spe,      false,          false,          "mulliRRI",
 359   "subficRRI",  false,          "cmpl_iYLRU",   "cmp_iYLRI",
 360   "addicRRI",   "addic.RRI",    "addi|liRR0I",  "addis|lisRR0I",
 361   "b_KBJ",      "sc",            "bKJ",         map_crops,
 362   "rlwimiRR~AAA.", map_rlwinm,  false,          "rlwnmRR~RAA.",
 363   "oriNRR~U",   "orisRR~U",     "xoriRR~U",     "xorisRR~U",
 364   "andi.RR~U",  "andis.RR~U",   map_rld,        map_ext,
 365   "lwzRRD",     "lwzuRRD",      "lbzRRD",       "lbzuRRD",
 366   "stwRRD",     "stwuRRD",      "stbRRD",       "stbuRRD",
 367   "lhzRRD",     "lhzuRRD",      "lhaRRD",       "lhauRRD",
 368   "sthRRD",     "sthuRRD",      "lmwRRD",       "stmwRRD",
 369   "lfsFRD",     "lfsuFRD",      "lfdFRD",       "lfduFRD",
 370   "stfsFRD",    "stfsuFRD",     "stfdFRD",      "stfduFRD",
 371   false,        false,          map_ld,         map_fps,
 372   false,        false,          map_std,        map_fpd,
 373 }
 374
 375 ------------------------------------------------------------------------------
 376
 377 local map_gpr = {
 378   [0] = "r0", "sp", "r2", "r3", "r4", "r5", "r6", "r7",
 379   "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
 380   "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
 381   "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",
 382 }
 383
 384 local map_cond = { [0] = "lt", "gt", "eq", "so", "ge", "le", "ne", "ns", }
 385
 386 -- Format a condition bit.
 387 local function condfmt(cond)
 388   if cond <= 3 then
 389     return map_cond[band(cond, 3)]
 390   else
 391     return format("4*cr%d+%s", rshift(cond, 2), map_cond[band(cond, 3)])
 392   end
 393 end
 394
 395 ------------------------------------------------------------------------------
 396
 397 -- Output a nicely formatted line with an opcode and operands.
 398 local function putop(ctx, text, operands)
 399   local pos = ctx.pos
 400   local extra = ""
 401   if ctx.rel then
 402     local sym = ctx.symtab[ctx.rel]
 403     if sym then extra = "\t->"..sym end
 404   end
 405   if ctx.hexdump > 0 then
 406     ctx.out(format("%08x  %s  %-7s %s%s\n",
 407             ctx.addr+pos, tohex(ctx.op), text, concat(operands, ", "), extra))
 408   else
 409     ctx.out(format("%08x  %-7s %s%s\n",
 410             ctx.addr+pos, text, concat(operands, ", "), extra))
 411   end
 412   ctx.pos = pos + 4
 413 end
 414
 415 -- Fallback for unknown opcodes.
 416 local function unknown(ctx)
 417   return putop(ctx, ".long", { "0x"..tohex(ctx.op) })
 418 end
 419
 420 -- Disassemble a single instruction.
 421 local function disass_ins(ctx)
 422   local pos = ctx.pos
 423   local b0, b1, b2, b3 = byte(ctx.code, pos+1, pos+4)
 424   local op = bor(lshift(b0, 24), lshift(b1, 16), lshift(b2, 8), b3)
 425   local operands = {}
 426   local last = nil
 427   local rs = 21
 428   ctx.op = op
 429   ctx.rel = nil
 430
 431   local opat = map_pri[rshift(b0, 2)]
 432   while type(opat) ~= "string" do
 433     if not opat then return unknown(ctx) end
 434     opat = opat[band(rshift(op, opat.shift), opat.mask)]
 435   end
 436   local name, pat = match(opat, "^([a-z0-9_.]*)(.*)")
 437   local altname, pat2 = match(pat, "|([a-z0-9_.]*)(.*)")
 438   if altname then pat = pat2 end
 439
 440   for p in gmatch(pat, ".") do
 441     local x = nil
 442     if p == "R" then
 443       x = map_gpr[band(rshift(op, rs), 31)]
 444       rs = rs - 5
 445     elseif p == "F" then
 446       x = "f"..band(rshift(op, rs), 31)
 447       rs = rs - 5
 448     elseif p == "A" then
 449       x = band(rshift(op, rs), 31)
 450       rs = rs - 5
 451     elseif p == "S" then
 452       x = arshift(lshift(op, 27-rs), 27)
 453       rs = rs - 5
 454     elseif p == "I" then
 455       x = arshift(lshift(op, 16), 16)
 456     elseif p == "U" then
 457       x = band(op, 0xffff)
 458     elseif p == "D" or p == "E" then
 459       local disp = arshift(lshift(op, 16), 16)
 460       if p == "E" then disp = band(disp, -4) end
 461       if last == "r0" then last = "0" end
 462       operands[#operands] = format("%d(%s)", disp, last)
 463     elseif p >= "2" and p <= "8" then
 464       local disp = band(rshift(op, rs), 31) * p
 465       if last == "r0" then last = "0" end
 466       operands[#operands] = format("%d(%s)", disp, last)
 467     elseif p == "H" then
 468       x = band(rshift(op, rs), 31) + lshift(band(op, 2), 4)
 469       rs = rs - 5
 470     elseif p == "M" then
 471       x = band(rshift(op, rs), 31) + band(op, 0x20)
 472     elseif p == "C" then
 473       x = condfmt(band(rshift(op, rs), 31))
 474       rs = rs - 5
 475     elseif p == "B" then
 476       local bo = rshift(op, 21)
 477       local cond = band(rshift(op, 16), 31)
 478       local cn = ""
 479       rs = rs - 10
 480       if band(bo, 4) == 0 then
 481         cn = band(bo, 2) == 0 and "dnz" or "dz"
 482         if band(bo, 0x10) == 0 then
 483           cn = cn..(band(bo, 8) == 0 and "f" or "t")
 484         end
 485         if band(bo, 0x10) == 0 then x = condfmt(cond) end
 486         name = name..(band(bo, 1) == band(rshift(op, 15), 1) and "-" or "+")
 487       elseif band(bo, 0x10) == 0 then
 488         cn = map_cond[band(cond, 3) + (band(bo, 8) == 0 and 4 or 0)]
 489         if cond > 3 then x = "cr"..rshift(cond, 2) end
 490         name = name..(band(bo, 1) == band(rshift(op, 15), 1) and "-" or "+")
 491       end
 492       name = gsub(name, "_", cn)
 493     elseif p == "J" then
 494       x = arshift(lshift(op, 27-rs), 29-rs)*4
 495       if band(op, 2) == 0 then x = ctx.addr + pos + x end
 496       ctx.rel = x
 497       x = "0x"..tohex(x)
 498     elseif p == "K" then
 499       if band(op, 1) ~= 0 then name = name.."l" end
 500       if band(op, 2) ~= 0 then name = name.."a" end
 501     elseif p == "X" or p == "Y" then
 502       x = band(rshift(op, rs+2), 7)
 503       if x == 0 and p == "Y" then x = nil else x = "cr"..x end
 504       rs = rs - 5
 505     elseif p == "W" then
 506       x = "cr"..band(op, 7)
 507     elseif p == "Z" then
 508       x = band(rshift(op, rs-4), 255)
 509       rs = rs - 10
 510     elseif p == ">" then
 511       operands[#operands] = rshift(operands[#operands], 1)
 512     elseif p == "0" then
 513       if last == "r0" then
 514         operands[#operands] = nil
 515         if altname then name = altname end
 516       end
 517     elseif p == "L" then
 518       name = gsub(name, "_", band(op, 0x00200000) ~= 0 and "d" or "w")
 519     elseif p == "." then
 520       if band(op, 1) == 1 then name = name.."." end
 521     elseif p == "N" then
 522       if op == 0x60000000 then name = "nop"; break end
 523     elseif p == "~" then
 524       local n = #operands
 525       operands[n-1],  operands[n] = operands[n], operands[n-1]
 526     elseif p == "=" then
 527       local n = #operands
 528       if last == operands[n-1] then
 529         operands[n] = nil
 530         name = altname
 531       end
 532     elseif p == "%" then
 533       local n = #operands
 534       if last == operands[n-1] and last == operands[n-2] then
 535         operands[n] = nil
 536         operands[n-1] = nil
 537         name = altname
 538       end
 539     elseif p == "-" then
 540       rs = rs - 5
 541     else
 542       assert(false)
 543     end
 544     if x then operands[#operands+1] = x; last = x end
 545   end
 546
 547   return putop(ctx, name, operands)
 548 end
 549
 550 ------------------------------------------------------------------------------
 551
 552 -- Disassemble a block of code.
 553 local function disass_block(ctx, ofs, len)
 554   if not ofs then ofs = 0 end
 555   local stop = len and ofs+len or #ctx.code
 556   stop = stop - stop % 4
 557   ctx.pos = ofs - ofs % 4
 558   ctx.rel = nil
 559   while ctx.pos < stop do disass_ins(ctx) end
 560 end
 561
 562 -- Extended API: create a disassembler context. Then call ctx:disass(ofs, len).
 563 local function create(code, addr, out)
 564   local ctx = {}
 565   ctx.code = code
 566   ctx.addr = addr or 0
 567   ctx.out = out or io.write
 568   ctx.symtab = {}
 569   ctx.disass = disass_block
 570   ctx.hexdump = 8
 571   return ctx
 572 end
 573
 574 -- Simple API: disassemble code (a string) at address and output via out.
 575 local function disass(code, addr, out)
 576   create(code, addr, out):disass()
 577 end
 578
 579 -- Return register name for RID.
 580 local function regname(r)
 581   if r < 32 then return map_gpr[r] end
 582   return "f"..(r-32)
 583 end
 584
 585 -- Public module functions.
 586 return {
 587   create = create,
 588   disass = disass,
 589   regname = regname
 590 }
 591