PPC: Add DynASM PowerPC module. Standard instructions only.

dynasm/dasm_ppc.lua

@@ -0,0 +1,926 @@
+------------------------------------------------------------------------------
+-- DynASM PPC module.
+--
+-- Copyright (C) 2005-2010 Mike Pall. All rights reserved.
+-- See dynasm.lua for full copyright notice.
+------------------------------------------------------------------------------
+
+-- Module information:
+local _info = {
+  arch =	"ppc",
+  description =	"DynASM PPC module",
+  version =	"1.2.1",
+  vernum =	 10201,
+  release =	"2010-XX-XX",
+  author =	"Mike Pall",
+  license =	"MIT",
+}
+
+-- Exported glue functions for the arch-specific module.
+local _M = { _info = _info }
+
+-- Cache library functions.
+local type, tonumber, pairs, ipairs = type, tonumber, pairs, ipairs
+local assert, setmetatable = assert, setmetatable
+local _s = string
+local sub, format, byte, char = _s.sub, _s.format, _s.byte, _s.char
+local match, gmatch = _s.match, _s.gmatch
+local concat, sort = table.concat, table.sort
+
+-- Inherited tables and callbacks.
+local g_opt, g_arch
+local wline, werror, wfatal, wwarn
+
+-- Action name list.
+-- CHECK: Keep this in sync with the C code!
+local action_names = {
+  "STOP", "SECTION", "ESC", "REL_EXT",
+  "ALIGN", "REL_LG", "LABEL_LG",
+  "REL_PC", "LABEL_PC", "IMM",
+}
+
+-- Maximum number of section buffer positions for dasm_put().
+-- CHECK: Keep this in sync with the C code!
+local maxsecpos = 25 -- Keep this low, to avoid excessively long C lines.
+
+-- Action name -> action number.
+local map_action = {}
+for n,name in ipairs(action_names) do
+  map_action[name] = n-1
+end
+
+-- Action list buffer.
+local actlist = {}
+
+-- Argument list for next dasm_put(). Start with offset 0 into action list.
+local actargs = { 0 }
+
+-- Current number of section buffer positions for dasm_put().
+local secpos = 1
+
+------------------------------------------------------------------------------
+
+-- Return 8 digit hex number.
+local function tohex(x)
+  return sub(format("%08x", x), -8) -- Avoid 64 bit portability problem in Lua.
+end
+
+-- Dump action names and numbers.
+local function dumpactions(out)
+  out:write("DynASM encoding engine action codes:\n")
+  for n,name in ipairs(action_names) do
+    local num = map_action[name]
+    out:write(format("  %-10s %02X  %d\n", name, num, num))
+  end
+  out:write("\n")
+end
+
+-- Write action list buffer as a huge static C array.
+local function writeactions(out, name)
+  local nn = #actlist
+  if nn == 0 then nn = 1; actlist[0] = map_action.STOP end
+  out:write("static const unsigned int ", name, "[", nn, "] = {\n")
+  for i = 1,nn-1 do
+    assert(out:write("0x", tohex(actlist[i]), ",\n"))
+  end
+  assert(out:write("0x", tohex(actlist[nn]), "\n};\n\n"))
+end
+
+------------------------------------------------------------------------------
+
+-- Add word to action list.
+local function wputxw(n)
+  assert(n >= 0 and n <= 0xffffffff and n % 1 == 0, "word out of range")
+  actlist[#actlist+1] = n
+end
+
+-- Add action to list with optional arg. Advance buffer pos, too.
+local function waction(action, val, a, num)
+  local w = assert(map_action[action], "bad action name `"..action.."'")
+  wputxw(w * 0x10000 + (val or 0))
+  if a then actargs[#actargs+1] = a end
+  if a or num then secpos = secpos + (num or 1) end
+end
+
+-- Flush action list (intervening C code or buffer pos overflow).
+local function wflush(term)
+  if #actlist == actargs[1] then return end -- Nothing to flush.
+  if not term then waction("STOP") end -- Terminate action list.
+  wline(format("dasm_put(Dst, %s);", concat(actargs, ", ")), true)
+  actargs = { #actlist } -- Actionlist offset is 1st arg to next dasm_put().
+  secpos = 1 -- The actionlist offset occupies a buffer position, too.
+end
+
+-- Put escaped word.
+local function wputw(n)
+  if n <= 0xffffff then waction("ESC") end
+  wputxw(n)
+end
+
+-- Reserve position for word.
+local function wpos()
+  local pos = #actlist+1
+  actlist[pos] = ""
+  return pos
+end
+
+-- Store word to reserved position.
+local function wputpos(pos, n)
+  assert(n >= 0 and n <= 0xffffffff and n % 1 == 0, "word out of range")
+  actlist[pos] = n
+end
+
+------------------------------------------------------------------------------
+
+-- Global label name -> global label number. With auto assignment on 1st use.
+local next_global = 20
+local map_global = setmetatable({}, { __index = function(t, name)
+  if not match(name, "^[%a_][%w_]*$") then werror("bad global label") end
+  local n = next_global
+  if n > 2047 then werror("too many global labels") end
+  next_global = n + 1
+  t[name] = n
+  return n
+end})
+
+-- Dump global labels.
+local function dumpglobals(out, lvl)
+  local t = {}
+  for name, n in pairs(map_global) do t[n] = name end
+  out:write("Global labels:\n")
+  for i=20,next_global-1 do
+    out:write(format("  %s\n", t[i]))
+  end
+  out:write("\n")
+end
+
+-- Write global label enum.
+local function writeglobals(out, prefix)
+  local t = {}
+  for name, n in pairs(map_global) do t[n] = name end
+  out:write("enum {\n")
+  for i=20,next_global-1 do
+    out:write("  ", prefix, t[i], ",\n")
+  end
+  out:write("  ", prefix, "_MAX\n};\n")
+end
+
+-- Write global label names.
+local function writeglobalnames(out, name)
+  local t = {}
+  for name, n in pairs(map_global) do t[n] = name end
+  out:write("static const char *const ", name, "[] = {\n")
+  for i=20,next_global-1 do
+    out:write("  \"", t[i], "\",\n")
+  end
+  out:write("  (const char *)0\n};\n")
+end
+
+------------------------------------------------------------------------------
+
+-- Extern label name -> extern label number. With auto assignment on 1st use.
+local next_extern = 0
+local map_extern_ = {}
+local map_extern = setmetatable({}, { __index = function(t, name)
+  -- No restrictions on the name for now.
+  local n = next_extern
+  if n > 2047 then werror("too many extern labels") end
+  next_extern = n + 1
+  t[name] = n
+  map_extern_[n] = name
+  return n
+end})
+
+-- Dump extern labels.
+local function dumpexterns(out, lvl)
+  out:write("Extern labels:\n")
+  for i=0,next_extern-1 do
+    out:write(format("  %s\n", map_extern_[i]))
+  end
+  out:write("\n")
+end
+
+-- Write extern label names.
+local function writeexternnames(out, name)
+  out:write("static const char *const ", name, "[] = {\n")
+  for i=0,next_extern-1 do
+    out:write("  \"", map_extern_[i], "\",\n")
+  end
+  out:write("  (const char *)0\n};\n")
+end
+
+------------------------------------------------------------------------------
+
+-- Arch-specific maps.
+local map_archdef = { sp = "r1" } -- Ext. register name -> int. name.
+
+local map_type = {}		-- Type name -> { ctype, reg }
+local ctypenum = 0		-- Type number (for Dt... macros).
+
+-- Reverse defines for registers.
+function _M.revdef(s)
+  if s == "r1" then return "sp" end
+  return s
+end
+
+local map_cond = {
+  lt = 0, gt = 1, eq = 2, so = 3,
+  ge = 4, le = 5, ne = 6, ns = 7,
+}
+
+------------------------------------------------------------------------------
+
+-- Template strings for PPC instructions.
+local map_op = {
+  tdi_3 =	"08000000ARI",
+  twi_3 =	"0c000000ARI",
+  mulli_3 =	"1c000000RRI",
+  subfic_3 =	"20000000RRI",
+  cmplwi_3 =	"28000000XRU",
+  cmplwi_2 =	"28000000-RU",
+  cmpldi_3 =	"28200000XRU",
+  cmpldi_2 =	"28200000-RU",
+  cmpwi_3 =	"2c000000XRI",
+  cmpwi_2 =	"2c000000-RI",
+  cmpdi_3 =	"2c200000XRI",
+  cmpdi_2 =	"2c200000-RI",
+  addic_3 =	"30000000RRI",
+  ["addic._3"] = "34000000RRI",
+  addi_3 =	"38000000RRI",
+  li_2 =	"38000000RI",
+  addis_3 =	"3c000000RRI",
+  lis_2 =	"3c000000RI",
+  lus_2 =	"3c000000RU",
+  la_2 =	"3c000000RD",
+  bc_3 = 	"40000000AAK",
+  bcl_3 = 	"40000001AAK",
+  bdnz_1 =	"42000000K",
+  bdz_1 =	"42400000K",
+  sc_0 =	"44000000",
+  b_1 = 	"48000000J",
+  bl_1 = 	"48000001J",
+  rlwimi_5 =	"50000000RR~AAA.",
+  rlwinm_5 =	"54000000RR~AAA.",
+  rlwnm_5 =	"5c000000RR~RAA.",
+  ori_3 =	"60000000RR~U",
+  nop_0 =	"60000000",
+  oris_3 =	"64000000RR~U",
+  xori_3 =	"68000000RR~U",
+  xoris_3 =	"6c000000RR~U",
+  ["andi._3"] =	"70000000RR~U",
+  ["andis._3"] = "74000000RR~U",
+  lwz_2 =	"80000000RD",
+  lwzu_2 =	"84000000RD",
+  lbz_2 =	"88000000RD",
+  lbzu_2 =	"8c000000RD",
+  stw_2 =	"90000000RD",
+  stwu_2 =	"94000000RD",
+  stb_2 =	"98000000RD",
+  stbu_2 =	"9c000000RD",
+  lhz_2 =	"a0000000RD",
+  lhzu_2 =	"a4000000RD",
+  lha_2 =	"a8000000RD",
+  lhau_2 =	"ac000000RD",
+  sth_2 =	"b0000000RD",
+  sthu_2 =	"b4000000RD",
+  lmw_2 =	"b8000000RD",
+  stmw_2 =	"bc000000RD",
+  lfs_2 =	"c0000000FD",
+  lfsu_2 =	"c4000000FD",
+  lfd_2 =	"c8000000FD",
+  lfdu_2 =	"cc000000FD",
+  stfs_2 =	"d0000000FD",
+  stfsu_2 =	"d4000000FD",
+  stfd_2 =	"d8000000FD",
+  stfdu_2 =	"dc000000FD",
+  ld_2 =	"e8000000RD", -- NYI: displacement must be divisible by 4.
+  ldu_2 =	"e8000001RD",
+  lwa_2 =	"e8000002RD",
+  std_2 =	"f8000000RD",
+  stdu_2 =	"f8000001RD",
+
+  -- Primary opcode 19:
+  mcrf_2 =	"4c000000XX",
+  isync_0 =	"4c00012c",
+  crnor_3 =	"4c000042CCC",
+  crnot_2 =	"4c000042CC=",
+  crandc_3 =	"4c000102CCC",
+  crxor_3 =	"4c000182CCC",
+  crclr_1 =	"4c000182C==",
+  crnand_3 =	"4c0001c2CCC",
+  crand_3 =	"4c000202CCC",
+  creqv_3 =	"4c000242CCC",
+  crset_1 =	"4c000242C==",
+  crorc_3 =	"4c000342CCC",
+  cror_3 =	"4c000382CCC",
+  crmove_2 =	"4c000382CC=",
+  bclr_2 =	"4c000020AA",
+  bclrl_2 =	"4c000021AA",
+  bcctr_2 =	"4c000420AA",
+  bcctrl_2 =	"4c000421AA",
+  blr_0 =	"4e800020",
+  blrl_0 =	"4e800021",
+  bctr_0 =	"4e800420",
+  bctrl_0 =	"4e800421",
+
+  -- Primary opcode 31:
+  cmpw_3 =	"7c000000XRR",
+  cmpw_2 =	"7c000000-RR",
+  cmpd_3 =	"7c200000XRR",
+  cmpd_2 =	"7c200000-RR",
+  tw_3 =	"7c000008ARR",
+  subfc_3 =	"7c000010RRR.",
+  subc_3 =	"7c000010RRR~.",
+  mulhdu_3 =	"7c000012RRR.",
+  addc_3 =	"7c000014RRR.",
+  mulhwu_3 =	"7c000016RRR.",
+  isel_4 =	"7c00001eRRRC",
+  isellt_3 =	"7c00001eRRR",
+  iselgt_3 =	"7c00005eRRR",
+  iseleq_3 =	"7c00009eRRR",
+  mfcr_1 =	"7c000026R",
+  -- NYI: mtcrf, mtocrf, mfocrf
+  lwarx_3 =	"7c000028RRR",
+  ldx_3 =	"7c00002aRRR",
+  lwzx_3 =	"7c00002eRRR",
+  slw_3 =	"7c000030RR~R.",
+  cntlzw_2 =	"7c000034RR~",
+  sld_3 =	"7c000036RR~R.",
+  and_3 =	"7c000038RR~R.",
+  cmplw_3 =	"7c000040XRR",
+  cmplw_2 =	"7c000040-RR",
+  cmpld_3 =	"7c200040XRR",
+  cmpld_2 =	"7c200040-RR",
+  subf_3 =	"7c000050RRR.",
+  sub_3 =	"7c000050RRR~.",
+  ldux_3 =	"7c00006aRRR",
+  dcbst_2 =	"7c00006c-RR",
+  lwzux_3 =	"7c00006eRRR",
+  cntlzd_2 =	"7c000074RR~",
+  andc_3 =	"7c000078RR~R.",
+  td_3 =	"7c000088ARR",
+  mulhd_3 =	"7c000092RRR.",
+  mulhw_3 =	"7c000096RRR.",
+  ldarx_3 =	"7c0000a8RRR",
+  dcbf_2 =	"7c0000ac-RR",
+  lbzx_3 =	"7c0000aeRRR",
+  neg_2 =	"7c0000d0RR.",
+  lbzux_3 =	"7c0000eeRRR",
+  popcntb_2 =	"7c0000f4RR~",
+  not_2 =	"7c0000f8RR~%.",
+  nor_3 =	"7c0000f8RR~R.",
+  subfe_3 =	"7c000110RRR.",
+  adde_3 =	"7c000114RRR.",
+  stdx_3 =	"7c00012aRRR",
+  stwcx_3 =	"7c00012cRRR.",
+  stwx_3 =	"7c00012eRRR",
+  prtyw_2 =	"7c000134RR~",
+  stdux_3 =	"7c00016aRRR",
+  stwux_3 =	"7c00016eRRR",
+  prtyd_2 =	"7c000174RR~",
+  subfze_2 =	"7c000190RR.",
+  addze_2 =	"7c000194RR.",
+  stdcx_3 =	"7c0001acRRR.",
+  stbx_3 =	"7c0001aeRRR",
+  subfme_2 =	"7c0001d0RR.",
+  mulld_3 =	"7c0001d2RRR.",
+  addme_2 =	"7c0001d4RR.",
+  mullw_3 =	"7c0001d6RRR.",
+  dcbtst_2 =	"7c0001ec-RR",
+  stbux_3 =	"7c0001eeRRR",
+  add_3 =	"7c000214RRR.",
+  dcbt_2 =	"7c00022c-RR",
+  lhzx_3 =	"7c00022eRRR",
+  eqv_3 =	"7c000238RR~R.",
+  eciwx_3 =	"7c00026cRRR",
+  lhzux_3 =	"7c00026eRRR",
+  xor_3 =	"7c000278RR~R.",
+  mfspefscr_1 =	"7c0082a6R",
+  mfxer_1 =	"7c0102a6R",
+  mflr_1 =	"7c0802a6R",
+  mfctr_1 =	"7c0902a6R",
+  lwax_3 =	"7c0002aaRRR",
+  lhax_3 =	"7c0002aeRRR",
+  mftb_1 =	"7c0c42e6R",
+  mftbu_1 =	"7c0d42e6R",
+  lwaux_3 =	"7c0002eaRRR",
+  lhaux_3 =	"7c0002eeRRR",
+  sthx_3 =	"7c00032eRRR",
+  orc_3 =	"7c000338RR~R.",
+  ecowx_3 =	"7c00036cRRR",
+  sthux_3 =	"7c00036eRRR",
+  or_3 =	"7c000378RR~R.",
+  mr_2 =	"7c000378RR~%.",
+  divdu_3 =	"7c000392RRR.",
+  divwu_3 =	"7c000396RRR.",
+  mtspefscr_1 =	"7c0083a6R",
+  mtxer_1 =	"7c0103a6R",
+  mtlr_1 =	"7c0803a6R",
+  mtctr_1 =	"7c0903a6R",
+  dcbi_2 =	"7c0003ac-RR",
+  nand_3 =	"7c0003b8RR~R.",
+  divd_3 =	"7c0003d2RRR.",
+  divw_3 =	"7c0003d6RRR.",
+  cmpb_3 =	"7c0003f8RR~R.",
+  mcrxr_1 =	"7c000400X",
+  subfco_3 =	"7c000410RRR.",
+  addco_3 =	"7c000414RRR.",
+  ldbrx_3 =	"7c000428RRR",
+  lswx_3 =	"7c00042aRRR",
+  lwbrx_3 =	"7c00042cRRR",
+  lfsx_3 =	"7c00042eFRR",
+  srw_3 =	"7c000430RR~R.",
+  srd_3 =	"7c000436RR~R.",
+  subfo_3 =	"7c000450RRR.",
+  lfsux_3 =	"7c00046eFRR",
+  lswi_3 =	"7c0004aaRRA",
+  sync_0 =	"7c0004ac",
+  lwsync_0 =	"7c2004ac",
+  ptesync_0 =	"7c4004ac",
+  lfdx_3 =	"7c0004aeFRR",
+  nego_2 =	"7c0004d0RR.",
+  lfdux_3 =	"7c0004eeFRR",
+  subfeo_3 =	"7c000510RRR.",
+  addeo_3 =	"7c000514RRR.",
+  stdbrx_3 =	"7c000528RRR",
+  stswx_3 =	"7c00052aRRR",
+  stwbrx_3 =	"7c00052cRRR",
+  stfsx_3 =	"7c00052eFRR",
+  stfsux_3 =	"7c00056eFRR",
+  subfzeo_2 =	"7c000590RR.",
+  addzeo_2 =	"7c000594RR.",
+  stswi_3 =	"7c0005aaRRA",
+  stfdx_3 =	"7c0005aeFRR",
+  subfmeo_2 =	"7c0005d0RR.",
+  mulldo_3 =	"7c0005d2RRR.",
+  addmeo_2 =	"7c0005d4RR.",
+  mullwo_3 =	"7c0005d6RRR.",
+  dcba_2 =	"7c0005ec-RR",
+  stfdux_3 =	"7c0005eeFRR",
+  addo_3 =	"7c000614RRR.",
+  lhbrx_3 =	"7c00062cRRR",
+  sraw_3 =	"7c000630RR~R.",
+  srad_3 =	"7c000634RR~R.",
+  srawi_3 =	"7c000670RR~A.",
+  eieio_0 =	"7c0006ac",
+  lfiwax_3 =	"7c0006aeFRR",
+  sthbrx_3 =	"7c00072cRRR",
+  extsh_2 =	"7c000734RR~.",
+  extsb_2 =	"7c000774RR~.",
+  divduo_3 =	"7c000792RRR.",
+  divwou_3 =	"7c000796RRR.",
+  icbi_2 =	"7c0007ac-RR",
+  stfiwx_3 =	"7c0007aeFRR",
+  extsw_2 =	"7c0007b4RR~.",
+  divdo_3 =	"7c0007d2RRR.",
+  divwo_3 =	"7c0007d6RRR.",
+  dcbz_2 =	"7c0007ec-RR",
+
+  -- Primary opcode 59:
+  fdivs_3 =	"ec000024FFF.",
+  fsubs_3 =	"ec000028FFF.",
+  fadds_3 =	"ec00002aFFF.",
+  fsqrts_2 =	"ec00002cF-F.",
+  fres_2 =	"ec000030F-F.",
+  fmuls_3 =	"ec000032FF-F.",
+  frsqrtes_2 =	"ec000034F-F.",
+  fmsubs_4 =	"ec000038FFFF~.",
+  fmadds_4 =	"ec00003aFFFF~.",
+  fnmsubs_4 =	"ec00003cFFFF~.",
+  fnmadds_4 =	"ec00003eFFFF~.",
+
+  -- Primary opcode 63:
+  fdiv_3 =	"fc000024FFF.",
+  fsub_3 =	"fc000028FFF.",
+  fadd_3 =	"fc00002aFFF.",
+  fsqrt_2 =	"fc00002cF-F.",
+  fsel_4 =	"fc00002eFFFF~.",
+  fre_2 =	"fc000030F-F.",
+  fmul_3 =	"fc000032FF-F.",
+  frsqrte_2 =	"fc000034F-F.",
+  fmsub_4 =	"fc000038FFFF~.",
+  fmadd_4 =	"fc00003aFFFF~.",
+  fnmsub_4 =	"fc00003cFFFF~.",
+  fnmadd_4 =	"fc00003eFFFF~.",
+  fcmpu_3 =	"fc000000XFF",
+  fcpsgn_3 =	"fc000010FFF.",
+  fcmpo_3 =	"fc000040XFF",
+  mtfsb1_1 =	"fc00004cA",
+  fneg_2 =	"fc000050F-F.",
+  mcrfs_2 =	"fc000080XX",
+  mtfsb0_1 =	"fc00008cA",
+  fmr_2 =	"fc000090F-F.",
+  frsp_2 =	"fc000018F-F.",
+  fctiw_2 =	"fc00001cF-F.",
+  fctiwz_2 =	"fc00001eF-F.",
+  mtfsfi_2 =	"fc00010cAA", -- NYI: upshift.
+  fnabs_2 =	"fc000110F-F.",
+  fabs_2 =	"fc000210F-F.",
+  frin_2 =	"fc000310F-F.",
+  friz_2 =	"fc000350F-F.",
+  frip_2 =	"fc000390F-F.",
+  frim_2 =	"fc0003d0F-F.",
+  mffs_1 =	"fc00048eF.",
+  mtfsf_1 =	"fc00058eF.",
+  fctid_2 =	"fc00065cF-F.",
+  fctidz_2 =	"fc00065eF-F.",
+  fcfid_2 =	"fc00069cF-F.",
+
+  -- NYI: some 64 bit PowerPC and Book E instructions:
+  --   rldicl, rldicr, rldic, rldimi, rldcl, rldcr, sradi, 64 bit ext. add/sub,
+  --   extended addressing branches, cache management, loads and stores
+}
+
+-- Add mnemonics for "." variants.
+do
+  local t = {}
+  for k,v in pairs(map_op) do
+    if sub(v, -1) == "." then
+      local v2 = sub(v, 1, 7)..char(byte(v, 8)+1)..sub(v, 9, -2)
+      t[sub(k, 1, -3).."."..sub(k, -2)] = v2
+    end
+  end
+  for k,v in pairs(t) do
+    map_op[k] = v
+  end
+end
+
+-- Add more branch mnemonics.
+for cond,c in pairs(map_cond) do
+  local b1 = "b"..cond
+  local c1 = (c%4)*0x00010000 + (c < 4 and 0x01000000 or 0)
+  -- bX
+  map_op[b1.."_1"] = tohex(0x40800000 + c1).."K"
+  map_op[b1.."_2"] = tohex(0x40800000 + c1).."-XK"
+  -- bXlr[l]
+  map_op[b1.."lr".."_0"] = tohex(0x4c800020 + c1)
+  map_op[b1.."lrl".."_0"] = tohex(0x4c800021 + c1)
+  map_op[b1.."ctr".."_0"] = tohex(0x4c800420 + c1)
+  map_op[b1.."ctrl".."_0"] = tohex(0x4c800421 + c1)
+  -- bXctr[l]
+  map_op[b1.."lr".."_1"] = tohex(0x4c800020 + c1).."-X"
+  map_op[b1.."lrl".."_1"] = tohex(0x4c800021 + c1).."-X"
+  map_op[b1.."ctr".."_1"] = tohex(0x4c800420 + c1).."-X"
+  map_op[b1.."ctrl".."_1"] = tohex(0x4c800421 + c1).."-X"
+end
+
+------------------------------------------------------------------------------
+
+local function parse_gpr(expr)
+  local tname, ovreg = match(expr, "^([%w_]+):(r[0-9][0-9]?)$")
+  local tp = map_type[tname or expr]
+  if tp then
+    local reg = ovreg or tp.reg
+    if not reg then
+      werror("type `"..(tname or expr).."' needs a register override")
+    end
+    expr = reg
+  end
+  local r = match(expr, "^r([1-3]?[0-9])$")
+  if r then
+    r = tonumber(r)
+    if r <= 31 then return r, tp end
+  end
+  werror("bad register name `"..expr.."'")
+end
+
+local function parse_fpr(expr)
+  local r = match(expr, "^f([1-3]?[0-9])$")
+  if r then
+    r = tonumber(r)
+    if r <= 31 then return r end
+  end
+  werror("bad register name `"..expr.."'")
+end
+
+local function parse_cr(expr)
+  local r = match(expr, "^cr([0-7])$")
+  if r then return tonumber(r) end
+  werror("bad condition register name `"..expr.."'")
+end
+
+local function parse_cond(expr)
+  local r, cond = match(expr, "^4%*cr([0-7])%+(%w%w)$")
+  if r then
+    r = tonumber(r)
+    local c = map_cond[cond]
+    if c and c < 4 then return r*4+c end
+  end
+  werror("bad condition bit name `"..expr.."'")
+end
+
+local function parse_imm(imm, bits, shift, scale, signed)
+  local n = tonumber(imm)
+  if n then
+    if n % 2^scale == 0 then
+      n = n / 2^scale
+      if signed then
+	if n >= 0 then
+	  if n < 2^(bits-1) then return n*2^shift end
+	else
+	  if n >= -(2^(bits-1))-1 then return (n+2^bits)*2^shift end
+	end
+      else
+	if n >= 0 and n <= 2^bits-1 then return n*2^shift end
+      end
+    end
+    werror("out of range immediate `"..imm.."'")
+  else
+    waction("IMM", (signed and 32768 or 0)+scale*1024+bits*32+shift, imm)
+    return 0
+  end
+end
+
+local function parse_disp(disp)
+  local imm, reg = match(disp, "^(.*)%(([%w_:]+)%)$")
+  if imm then
+    local r = parse_gpr(reg)
+    if r == 0 then werror("cannot use r0 in displacement") end
+    return r*65536 + parse_imm(imm, 16, 0, 0, true)
+  end
+  local reg, tailr = match(disp, "^([%w_:]+)%s*(.*)$")
+  if reg and tailr ~= "" then
+    local r, tp = parse_gpr(reg)
+    if r == 0 then werror("cannot use r0 in displacement") end
+    if tp then
+      waction("IMM", 32768+16*32, format(tp.ctypefmt, tailr))
+      return r*65536
+    end
+  end
+  werror("bad displacement `"..disp.."'")
+end
+
+local function parse_u5disp(disp, scale)
+  local imm, reg = match(disp, "^(.*)%(([%w_:]+)%)$")
+  if imm then
+    local r = parse_gpr(reg)
+    if r == 0 then werror("cannot use r0 in displacement") end
+    return r*65536 + parse_imm(imm, 5, 11, scale, false)
+  end
+  local reg, tailr = match(disp, "^([%w_:]+)%s*(.*)$")
+  if reg and tailr ~= "" then
+    local r, tp = parse_gpr(reg)
+    if r == 0 then werror("cannot use r0 in displacement") end
+    if tp then
+      waction("IMM", scale*1024+5*32+11, format(tp.ctypefmt, tailr))
+      return r*65536
+    end
+  end
+  werror("bad displacement `"..disp.."'")
+end
+
+local function parse_label(label, def)
+  local prefix = sub(label, 1, 2)
+  -- =>label (pc label reference)
+  if prefix == "=>" then
+    return "PC", 0, sub(label, 3)
+  end
+  -- ->name (global label reference)
+  if prefix == "->" then
+    return "LG", map_global[sub(label, 3)]
+  end
+  if def then
+    -- [1-9] (local label definition)
+    if match(label, "^[1-9]$") then
+      return "LG", 10+tonumber(label)
+    end
+  else
+    -- [<>][1-9] (local label reference)
+    local dir, lnum = match(label, "^([<>])([1-9])$")
+    if dir then -- Fwd: 1-9, Bkwd: 11-19.
+      return "LG", lnum + (dir == ">" and 0 or 10)
+    end
+    -- extern label (extern label reference)
+    local extname = match(label, "^extern%s+(%S+)$")
+    if extname then
+      return "EXT", map_extern[extname]
+    end
+  end
+  werror("bad label `"..label.."'")
+end
+
+------------------------------------------------------------------------------
+
+-- Handle opcodes defined with template strings.
+map_op[".template__"] = function(params, template, nparams)
+  if not params then return sub(template, 9) end
+  local op = tonumber(sub(template, 1, 8), 16)
+  local n, rs = 1, 26
+
+  -- Limit number of section buffer positions used by a single dasm_put().
+  -- A single opcode needs a maximum of 3 positions (rlwinm).
+  if secpos+3 > maxsecpos then wflush() end
+  local pos = wpos()
+
+  -- Process each character.
+  for p in gmatch(sub(template, 9), ".") do
+    if p == "R" then
+      rs = rs - 5; op = op + parse_gpr(params[n]) * 2^rs; n = n + 1
+    elseif p == "F" then
+      rs = rs - 5; op = op + parse_fpr(params[n]) * 2^rs; n = n + 1
+    elseif p == "A" then
+      rs = rs - 5; op = op + parse_imm(params[n], 5, rs, 0, false); n = n + 1
+    elseif p == "I" then
+      op = op + parse_imm(params[n], 16, 0, 0, true); n = n + 1
+    elseif p == "U" then
+      op = op + parse_imm(params[n], 16, 0, 0, false); n = n + 1
+    elseif p == "D" then
+      op = op + parse_disp(params[n]); n = n + 1
+    elseif p == "C" then
+      rs = rs - 5; op = op + parse_cond(params[n]) * 2^rs; n = n + 1
+    elseif p == "X" then
+      rs = rs - 5; op = op + parse_cr(params[n]) * 2^(rs+2); n = n + 1
+    elseif p == "J" or p == "K" then
+      local mode, n, s = parse_label(params[n], false)
+      if p == "K" then n = n + 2048 end
+      waction("REL_"..mode, n, s, 1)
+      n = n + 1
+    elseif p == "=" or p == "%" then
+      local mm = 2^(rs + (p == "%" and 5 or 0))
+      local t = ((op - op % mm) / mm) % 32
+      rs = rs - 5
+      op = op + t * 2^rs
+    elseif p == "~" then
+      local mm = 2^rs
+      local t1l = op % mm
+      local t1h = (op - t1l) / mm
+      local t2l = t1h % 32
+      local t2h = (t1h - t2l) / 32
+      local t3l = t2h % 32
+      op = ((t2h - t3l + t2l)*32 + t3l)*mm + t1l
+    elseif p == "-" then
+      rs = rs - 5
+    elseif p == "." then
+      -- Ignored.
+    else
+      assert(false)
+    end
+  end
+  wputpos(pos, op)
+end
+
+------------------------------------------------------------------------------
+
+-- Pseudo-opcode to mark the position where the action list is to be emitted.
+map_op[".actionlist_1"] = function(params)
+  if not params then return "cvar" end
+  local name = params[1] -- No syntax check. You get to keep the pieces.
+  wline(function(out) writeactions(out, name) end)
+end
+
+-- Pseudo-opcode to mark the position where the global enum is to be emitted.
+map_op[".globals_1"] = function(params)
+  if not params then return "prefix" end
+  local prefix = params[1] -- No syntax check. You get to keep the pieces.
+  wline(function(out) writeglobals(out, prefix) end)
+end
+
+-- Pseudo-opcode to mark the position where the global names are to be emitted.
+map_op[".globalnames_1"] = function(params)
+  if not params then return "cvar" end
+  local name = params[1] -- No syntax check. You get to keep the pieces.
+  wline(function(out) writeglobalnames(out, name) end)
+end
+
+-- Pseudo-opcode to mark the position where the extern names are to be emitted.
+map_op[".externnames_1"] = function(params)
+  if not params then return "cvar" end
+  local name = params[1] -- No syntax check. You get to keep the pieces.
+  wline(function(out) writeexternnames(out, name) end)
+end
+
+------------------------------------------------------------------------------
+
+-- Label pseudo-opcode (converted from trailing colon form).
+map_op[".label_1"] = function(params)
+  if not params then return "[1-9] | ->global | =>pcexpr" end
+  if secpos+1 > maxsecpos then wflush() end
+  local mode, n, s = parse_label(params[1], true)
+  if mode == "EXT" then werror("bad label definition") end
+  waction("LABEL_"..mode, n, s, 1)
+end
+
+------------------------------------------------------------------------------
+
+-- Pseudo-opcodes for data storage.
+map_op[".long_*"] = function(params)
+  if not params then return "imm..." end
+  for _,p in ipairs(params) do
+    local n = tonumber(p)
+    if not n then werror("bad immediate `"..p.."'") end
+    if n < 0 then n = n + 2^32 end
+    wputw(n)
+    if secpos+2 > maxsecpos then wflush() end
+  end
+end
+
+-- Alignment pseudo-opcode.
+map_op[".align_1"] = function(params)
+  if not params then return "numpow2" end
+  if secpos+1 > maxsecpos then wflush() end
+  local align = tonumber(params[1])
+  if align then
+    local x = align
+    -- Must be a power of 2 in the range (2 ... 256).
+    for i=1,8 do
+      x = x / 2
+      if x == 1 then
+	waction("ALIGN", align-1, nil, 1) -- Action byte is 2**n-1.
+	return
+      end
+    end
+  end
+  werror("bad alignment")
+end
+
+------------------------------------------------------------------------------
+
+-- Pseudo-opcode for (primitive) type definitions (map to C types).
+map_op[".type_3"] = function(params, nparams)
+  if not params then
+    return nparams == 2 and "name, ctype" or "name, ctype, reg"
+  end
+  local name, ctype, reg = params[1], params[2], params[3]
+  if not match(name, "^[%a_][%w_]*$") then
+    werror("bad type name `"..name.."'")
+  end
+  local tp = map_type[name]
+  if tp then
+    werror("duplicate type `"..name.."'")
+  end
+  -- Add #type to defines. A bit unclean to put it in map_archdef.
+  map_archdef["#"..name] = "sizeof("..ctype..")"
+  -- Add new type and emit shortcut define.
+  local num = ctypenum + 1
+  map_type[name] = {
+    ctype = ctype,
+    ctypefmt = format("Dt%X(%%s)", num),
+    reg = reg,
+  }
+  wline(format("#define Dt%X(_V) (int)(ptrdiff_t)&(((%s *)0)_V)", num, ctype))
+  ctypenum = num
+end
+map_op[".type_2"] = map_op[".type_3"]
+
+-- Dump type definitions.
+local function dumptypes(out, lvl)
+  local t = {}
+  for name in pairs(map_type) do t[#t+1] = name end
+  sort(t)
+  out:write("Type definitions:\n")
+  for _,name in ipairs(t) do
+    local tp = map_type[name]
+    local reg = tp.reg or ""
+    out:write(format("  %-20s %-20s %s\n", name, tp.ctype, reg))
+  end
+  out:write("\n")
+end
+
+------------------------------------------------------------------------------
+
+-- Set the current section.
+function _M.section(num)
+  waction("SECTION", num)
+  wflush(true) -- SECTION is a terminal action.
+end
+
+------------------------------------------------------------------------------
+
+-- Dump architecture description.
+function _M.dumparch(out)
+  out:write(format("DynASM %s version %s, released %s\n\n",
+    _info.arch, _info.version, _info.release))
+  dumpactions(out)
+end
+
+-- Dump all user defined elements.
+function _M.dumpdef(out, lvl)
+  dumptypes(out, lvl)
+  dumpglobals(out, lvl)
+  dumpexterns(out, lvl)
+end
+
+------------------------------------------------------------------------------
+
+-- Pass callbacks from/to the DynASM core.
+function _M.passcb(wl, we, wf, ww)
+  wline, werror, wfatal, wwarn = wl, we, wf, ww
+  return wflush
+end
+
+-- Setup the arch-specific module.
+function _M.setup(arch, opt)
+  g_arch, g_opt = arch, opt
+end
+
+-- Merge the core maps and the arch-specific maps.
+function _M.mergemaps(map_coreop, map_def)
+  setmetatable(map_op, { __index = map_coreop })
+  setmetatable(map_def, { __index = map_archdef })
+  return map_op, map_def
+end
+
+return _M
+
+------------------------------------------------------------------------------
+