riscv(misc): add disassmbler support

src/jit/dis_riscv.lua

@@ -0,0 +1,979 @@
+------------------------------------------------------------------------------
+-- LuaJIT RISC-V disassembler module.
+--
+-- Copyright (C) 2005-2025 Mike Pall. All rights reserved.
+-- Released under the MIT license. See Copyright Notice in luajit.h
+--
+-- Contributed by Milos Poletanovic from Syrmia.com.
+-- Contributed by gns from PLCT Lab, ISCAS.
+------------------------------------------------------------------------------
+-- This is a helper module used by the LuaJIT machine code dumper module.
+--
+-- It disassembles most standard RISC-V instructions.
+-- Mode is little-endian
+------------------------------------------------------------------------------
+
+local type = type
+local byte, format = string.byte, string.format
+local match, gmatch = string.match, string.gmatch
+local concat = table.concat
+local bit = require("bit")
+local band, bor, tohex = bit.band, bit.bor, bit.tohex
+local lshift, rshift, arshift = bit.lshift, bit.rshift, bit.arshift
+local jit = require("jit")
+
+local jstat = { jit.status() }
+local function is_opt_enabled(opt)
+  for _, v in ipairs(jstat) do
+    if v == opt then
+      return true
+    end
+  end
+  return false
+end
+local xthead = is_opt_enabled("XThead")
+
+------------------------------------------------------------------------------
+-- Opcode maps
+------------------------------------------------------------------------------
+
+--RVC32 extension
+
+local map_quad0 = {
+  shift = 13, mask = 7,
+  [0] = "c.addi4spnZW", "c.fldNMh", "c.lwZMn", "c.flwNMn",
+  false, "c.fsdNMh", "c.swZMn", "c.fswNMn"
+}
+
+local map_sub2quad1 = {
+  shift = 5, mask = 3,
+  [0] = "c.subMZ", "c.xorMZ", "c.orMZ", "c.andMZ"
+}
+
+local map_sub1quad1 = {
+  shift = 10, mask = 3,
+  [0] = "c.srliM1", "c.sraiM1", "c.andiMx", map_sub2quad1
+}
+
+local map_quad1 = {
+  shift = 13, mask = 7,
+  [0] = {
+    shift = 7, mask = 31,
+    [0] = "c.nop", _ = "c.addiDx"
+  },
+  [1] = "c.jalT", [2] = "c.liDx",
+  [3] = {
+    shift = 7, mask = 31,
+    [0] = "c.luiDK", [1] = "c.luiDK", [2] = "c.addi16spX",
+    _ = "c.luiDK"
+  },
+  [4] = map_sub1quad1, [5] = "c.jT", [6] = "c.beqzMq", [7] = "c.bnezMq"
+}
+
+local map_sub1quad2 = {
+  shift = 12, mask = 1,
+  [0] = {
+    shift = 2, mask = 31,
+    [0] = "c.jrD", _ = "c.mvDE"
+  },
+  [1] = {
+    shift = 2, mask = 31,
+    [0] = {
+      shift = 7, mask = 31,
+      [0] = "c.ebreak", _ = "c.jalrD"
+    },
+   _ = "c.addDE"
+  }
+}
+
+local map_quad2 = {
+  shift = 13, mask = 7,
+  [0] = "c.slliD1", [1] = "c.fldspFQ",[2] = "c.lwspDY", [3] = "c.flwspFY",
+  [4] = map_sub1quad2, [5] = "c.fsdspVt", [6] = "c.swspEu", [7] = "c.fswspVu"
+}
+
+local map_compr = {
+  [0] = map_quad0, map_quad1, map_quad2
+}
+
+--RV32M
+local map_mext = {
+  shift = 12, mask = 7,
+  [0] = "mulDRr", "mulhDRr", "mulhsuDRr", "mulhuDRr",
+  "divDRr", "divuDRr", "remDRr", "remuDRr"
+}
+
+--RV64M
+local map_mext64 = {
+  shift = 12, mask = 7,
+  [0] = "mulwDRr", [4] = "divwDRr", [5] = "divuwDRr", [6] = "remwDRr",
+  [7] = "remuwDRr"
+}
+
+--RV32F, RV64F, RV32D, RV64D
+local map_fload = {
+  shift = 12, mask = 7,
+  [2] = "flwFL", [3] = "fldFL"
+}
+
+local map_fstore = {
+  shift = 12, mask = 7,
+  [2] = "fswSg", [3] = "fsdSg"
+}
+
+local map_fmadd = {
+  shift = 25, mask = 3,
+  [0] = "fmadd.sFGgHo", "fmadd.dFGgHo"
+}
+
+local map_fmsub = {
+  shift = 25, mask = 3,
+  [0] = "fmsub.sFGgHo", "fmsub.dFGgHo"
+}
+
+local map_fnmsub = {
+  shift = 25, mask = 3,
+  [0] = "fnmsub.sFGgHo", "fnmsub.dFGgHo"
+}
+
+local map_fnmadd = {
+  shift = 25, mask = 3,
+  [0] = "fnmadd.sFGgHo", "fnmadd.dFGgHo"
+}
+
+local map_fsgnjs = {
+  shift = 12, mask = 7,
+  [0] = "fsgnj.s|fmv.sFGg6", "fsgnjn.s|fneg.sFGg6", "fsgnjx.s|fabs.sFGg6"
+}
+
+local map_fsgnjd = {
+  shift = 12, mask = 7,
+  [0] = "fsgnj.d|fmv.dFGg6", "fsgnjn.d|fneg.dFGg6", "fsgnjx.d|fabs.dFGg6"
+}
+
+local map_fms = {
+  shift = 12, mask = 7,
+  [0] = "fmin.sFGg", "fmax.sFGg", "fminm.sFGg", "fmaxm.sFGg"
+}
+
+local map_fmd = {
+  shift = 12, mask = 7,
+  [0] = "fmin.dFGg", "fmax.dFGg", "fminm.dFGg", "fmaxm.dFGg"
+}
+
+local map_fcomps = {
+  shift = 12, mask = 7,
+  [0] = "fle.sDGg", "flt.sDGg", "feq.sDGg",
+  [4] = "fleq.sDGg", "fltq.sDGg"
+}
+
+local map_fcompd = {
+  shift = 12, mask = 7,
+  [0] = "fle.dDGg", "flt.dDGg", "feq.dDGg",
+  [4] = "fleq.dDGg", "fltq.dDGg"
+}
+
+local map_fcvtwls = {
+  shift = 20, mask = 31,
+  [0] = "fcvt.w.sDGo", "fcvt.wu.sDGo", "fcvt.l.sDGo", "fcvt.lu.sDGo"
+}
+
+local map_fcvtwld = {
+  shift = 20, mask = 31,
+  [0] = "fcvt.w.dDGo", "fcvt.wu.dDGo", "fcvt.l.dDGo", "fcvt.lu.dDGo",
+  [8] = {
+    shift = 12, mask = 7,
+    [1] = "fcvtmodw.dDG"
+  }
+}
+
+local map_fcvts = {
+  shift = 20, mask = 31,
+  [0] = "fcvt.s.wFRo", "fcvt.s.wuFRo", "fcvt.s.lFRo", "fcvt.s.luFRo"
+}
+
+local map_fcvtd = {
+  shift = 20, mask = 31,
+  [0] = "fcvt.d.wFRo", "fcvt.d.wuFRo", "fcvt.d.lFRo", "fcvt.d.luFRo"
+}
+
+local map_fcvtsd = {
+  shift = 20, mask = 31,
+  [0] = "fcvt.s.dFGo",
+  [4] = "fround.sFGo", [5] = "froundnx.sFGo"
+}
+
+local map_fcvtds = {
+  shift = 20, mask = 31,
+  [0] = "fcvt.d.sFGo",
+  [4] = "fround.dFGo", [5] = "froundnx.dFGo"
+}
+
+local map_fmvwx = {
+  shift = 20, mask = 31,
+  [0] = "fmv.w.xFR", [1] = "fli.sFy"
+}
+
+local map_fmvdx = {
+  shift = 20, mask = 31,
+  [0] = "fmv.d.xFR", [1] = "fli.dFy"
+}
+
+local map_fext = {
+  shift = 25, mask = 127,
+  [0] = "fadd.sFGgo", [1] = "fadd.dFGgo", [4] = "fsub.sFGgo", [5] = "fsub.dFGgo",
+  [8] = "fmul.sFGgo", [9] = "fmul.dFGgo", [12] = "fdiv.sFGgo", [13] = "fdiv.dFGgo",
+  [16] = map_fsgnjs, [17] = map_fsgnjd, [20] = map_fms, [21] = map_fmd,
+  [32] = map_fcvtsd, [33] = map_fcvtds,[44] = "fsqrt.sFGo", [45] = "fsqrt.dFGo",
+  [80] = map_fcomps, [81] = map_fcompd, [96] = map_fcvtwls, [97] = map_fcvtwld,
+  [104] = map_fcvts, [105] = map_fcvtd,
+  [112] = {
+    shift = 12, mask = 7,
+    [0] = "fmv.x.wDG", "fclass.sDG"
+  },
+  [113] = {
+  shift = 12, mask = 7,
+    [0] = "fmv.x.dDG", "fclass.dDG"
+  },
+  [120] = map_fmvwx, [121] = map_fmvdx
+}
+
+--RV32A, RV64A
+local map_aext = {
+  shift = 27, mask = 31,
+  [0] = {
+    shift = 12, mask = 7,
+    [2] = "amoadd.wDrO", [3] = "amoadd.dDrO"
+  },
+  {
+    shift = 12, mask = 7,
+    [2] = "amoswap.wDrO", [3] = "amoswap.dDrO"
+  },
+  {
+    shift = 12, mask = 7,
+    [2] = "lr.wDO", [3] = "lr.dDO"
+  },
+  {
+    shift = 12, mask = 7,
+    [2] = "sc.wDrO", [3] = "sc.dDrO"
+  },
+  {
+    shift = 12, mask = 7,
+    [2] = "amoxor.wDrO", [3] = "amoxor.dDrO"
+  },
+  [8] = {
+    shift = 12, mask = 7,
+    [2] = "amoor.wDrO", [3] = "amoor.dDrO"
+  },
+  [12] = {
+    shift = 12, mask = 7,
+    [2] = "amoand.wDrO", [3] = "amoand.dDrO"
+  },
+  [16] = {
+    shift = 12, mask = 7,
+    [2] = "amomin.wDrO", [3] = "amomin.dDrO"
+  },
+  [20] = {
+    shift = 12, mask = 7,
+    [2] = "amomax.wDrO", [3] = "amomax.dDrO"
+  },
+  [24] = {
+    shift = 12, mask = 7,
+    [2] = "amominu.wDrO", [3] = "amominu.dDrO"
+  },
+  [28] = {
+   shift = 12, mask = 7,
+   [2] = "amomaxu.wDrO", [3] = "amomaxu.dDrO"
+  },
+}
+
+-- RV32I, RV64I
+local map_load = {
+  shift = 12, mask = 7,
+  [0] = "lbDL", "lhDL", "lwDL", "ldDL",
+  "lbuDL", "lhuDL", "lwuDL"
+}
+
+local map_opimm = {
+  shift = 12, mask = 7,
+  [0] = {
+    shift = 7, mask = 0x1ffffff,
+    [0] = "nop", _ = "addi|li|mvDR0I2"
+  },
+  {
+    shift = 25, mask = 127,
+    [48] = {
+      shift = 20, mask = 31,
+      [4] = "sext.bDR", [5] = "sext.hDR"
+    },
+    _ = "slliDRi",
+  }, "sltiDRI", "sltiu|seqzDRI5",
+  "xori|notDRI4",
+  {
+    shift = 26, mask = 63,
+    [0] = "srliDRi", [16] = "sraiDRi", [24] = "roriDRi",
+    [26] = {
+      shift = 20, mask = 63,
+      [56] = "rev8DR"
+    }
+  },
+  "oriDRI", "andiDRI"
+}
+
+local map_branch = {
+  shift = 12, mask = 7,
+  [0] = "beq|beqzRr0B", "bne|bnezRr0B" , false, false,
+  "blt|bgtz|bltzR0r2B", "bge|blez|bgezR0r2B", "bltuRrB", "bgeuRrB"
+}
+
+local map_store = {
+  shift = 12, mask = 7,
+  [0] = "sbSr", "shSr", "swSr", "sdSr"
+}
+
+local map_op = {
+  shift = 25, mask = 127,
+  [0] = {
+    shift = 12, mask = 7,
+    [0] = "addDRr", "sllDRr", "slt|sgtz|sltzDR0r2", "sltu|snezDR0r",
+    "xorDRr", "srlDRr", "orDRr", "andDRr"
+  },
+  [1] = map_mext,
+  [4] = {
+
+  },
+  [5] = { -- Zbb
+    shift = 12, mask = 7,
+    [4] = "minDRr", [5] = "minuDRr", [6] = "maxDRr", [7] = "maxuDRr"
+  },
+  [7] = { -- Zicond
+    shift = 12, mask = 7,
+    [5] = "czero.eqzDRr", [7] = "czero.nezDRr"
+  },
+  [16] = { -- Zba
+    shift = 12, mask = 7,
+    [2] = "sh1addDRr", [4] = "sh2addDRr", [6] = "sh3addDRr"
+  },
+  [32] = { -- Zbb
+    shift = 12, mask = 7,
+    [0] = "sub|negDR0r", [4] = "xnorDRr", [5] = "sraDRr", [6] = "ornDRr", [7] = "andnDRr"
+  },
+  [48] = { -- Zbb
+    shift = 12, mask = 7,
+    [1] = "rolDRr", [5] = "rorDRr"
+  }
+}
+
+--- 64I
+local map_opimm32 = {
+  shift = 12, mask = 7,
+  [0] = "addiw|sext.wDRI0", "slliwDRi",
+  [2] = { -- Zba
+    shift = 25, mask = 127,
+    [1] = "slli.uwDRi"
+  },
+  [5] = { -- 64I
+    shift = 25, mask = 127,
+    [0] = "srliwDRi", [32] = "sraiwDRi", [48] = "roriwDRi"
+  },
+  [48] = { -- Zbb
+    shift = 25, mask = 127,
+    [5] = "roriwDRi"
+  }
+}
+
+local map_op32 = {
+  shift = 25, mask = 127,
+  [0] = { -- 64I
+    shift = 12, mask = 7,
+    [0] = "addwDRr", [1] = "sllwDRr", [5] = "srlwDRr"
+  },
+  [1] = map_mext64,
+  [4] = { -- Zba & Zbb
+    shift = 12, mask = 7,
+    [0] = "add.uw|zext.w|DRr0", [4] = "zext.hDRr"
+  },
+  [16] = { -- Zba
+    shift = 12, mask = 7,
+    [2] = "sh1add.uw", [4] = "sh2add.uw", [6] = "sh3add.uw"
+  },
+  [32] = { -- 64I
+    shift = 12, mask = 7,
+    [0] = "subw|negwDR0r", [5] = "srawDRr"
+  },
+  [48] = { -- Zbb
+    shift = 12, mask = 7,
+    [1] = "rolwDRr", [5] = "rorwDRr"
+  }
+}
+
+local map_ecabre = {
+  shift = 12, mask = 7,
+  [0] = {
+   shift = 20, mask = 4095,
+   [0] = "ecall", "ebreak"
+  }
+}
+
+local map_fence = {
+  shift = 12, mask = 1,
+  [0] = "fence", --"fence.i" ZIFENCEI EXTENSION
+}
+
+local map_jalr = {
+  shift = 7, mask = 0x1ffffff,
+  _ = "jalr|jrDRI7", [256] = "ret"
+}
+
+local map_xthead_custom0 = {
+  shift = 12, mask = 7,
+  [1] = { -- Arithmetic
+    shift = 27, mask = 31,
+    [0] = "th.addslDRrv",
+    [2] = {
+      shift = 26, mask = 63,
+      [4] = "th.srriDRi",
+      [5] = {
+        shift = 25, mask = 127,
+        [10] = "th.srriwDRi"
+      }
+    },
+    [4] = { -- XTheadMac
+      shift = 25, mask = 3,
+      [0] = "th.mulaDRr", "th.mulsDRr", "th.mulawDRr", "th.mulswDRr"
+    },
+    [5] = { -- XTheadMac
+      shift = 25, mask = 3,
+      [0] = "th.mulahDRr", "th.mulshDRr"
+    },
+    [8] = { -- XTheadCondMov
+      shift = 25, mask = 3,
+      [0] = "th.mveqzDRr", "th.mvnezDRr"
+    },
+    [16] = { -- XTheadBb
+      shift = 20, mask = 31,
+      [0] = {
+        shift = 25, mask = 3,
+        [0] = "th.tstnbzDRi", "th.revDR", "th.ff0DR", "th.ff1DR"
+      }
+    },
+    [17] = { -- XTheadBb
+      shift = 26, mask = 1,
+      [0] = "th.tstDRi"
+    },
+    [18] = { -- XTheadBb
+      shift = 20, mask = 31,
+      [0] = {
+        shift = 25, mask = 3,
+        [0] = "th.revwDR"
+      }
+    }
+  },
+  [2] = "th.extDRji", [3] = "th.extuDRji",
+  { -- MemLoad
+    shift = 29, mask = 7,
+    [7] = { -- XTheadMemPair
+      shift = 25, mask = 3,
+      [0] = "th.lwdDrP", [2] = "th.lwudDrP", "th.lddDrP"
+    }
+  },
+  { -- MemStore
+    shift = 29, mask = 7,
+    [7] = { -- XTheadMemPair
+      shift = 25, mask = 3,
+      [0] = "th.swdDrP", [3] = "th.sddDrP"
+    }
+  }
+}
+
+local map_custom0 = xthead and map_xthead_custom0 or nil
+
+local map_pri = {
+  [3] = map_load, [7] = map_fload, [11] = map_custom0, [15] = map_fence, [19] = map_opimm,
+  [23] = "auipcDA", [27] = map_opimm32,
+  [35] = map_store, [39] = map_fstore, [47] = map_aext, [51] = map_op,
+  [55] = "luiDU", [59] = map_op32, [67] = map_fmadd, [71] = map_fmsub,
+  [75] = map_fnmsub, [99] = map_branch, [79] = map_fnmadd, [83] = map_fext,
+  [103] = map_jalr, [111] = "jal|j|D0J", [115] = map_ecabre
+}
+
+------------------------------------------------------------------------------
+
+local map_gpr = {
+  [0] = "zero", "ra", "sp", "gp", "tp", "x5", "x6", "x7",
+  "x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
+  "x16", "x17", "x18", "x19", "x20", "x21", "x22", "x23",
+  "x24", "x25", "x26", "x27", "x28", "x29", "x30", "x31",
+}
+
+local map_fgpr = {
+  [0] = "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
+  "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",
+  "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",
+  "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31",
+}
+
+local map_rm = {
+  [0] = "rne", "rtz", "rdn", "rup", "rmm", [7] = "dyn"
+}
+
+local map_fli = {
+  [0] = "-1.0",
+  "min",
+  "0x1p-16", "0x1p-15", "0x1p-8", "0x1p-7",
+  "0.0625", "0.125",
+  "0.25", "0.3125", "0.375", "0.4375",
+  "0.5", "0.625", "0.75", "0.875",
+  "1.0", "1.25", "1.5", "1.75",
+  "2.0", "2.5", "3.0",
+  "4.0", "8.0", "16.0", "128.0", "256.0",
+  "32768.0", "65536.0", "inf", "nan"
+}
+
+------------------------------------------------------------------------------
+
+-- Output a nicely formatted line with an opcode and operands.
+local function putop(ctx, text, operands)
+  local pos = ctx.pos
+	local extra = ""
+  if ctx.rel then
+    local sym = ctx.symtab[ctx.rel]
+    if sym then extra = "\t->"..sym end
+  end
+  if ctx.hexdump > 0 then
+    ctx.out:write((format("%08x  %s  %-7s %s%s\n",
+    ctx.addr+pos, tohex(ctx.op), text, concat(operands, ","), extra)))
+  else
+    ctx.out(format("%08x  %-7s %s%s\n",
+    ctx.addr+pos, text, concat(operands, ", "), extra))
+  end
+  local pos = ctx.pos
+  local first_byte = byte(ctx.code, ctx.pos+1)
+  --Examine if the next instruction is 16-bits or 32-bits
+  if(band(first_byte, 3) < 3) then
+    ctx.pos = pos + 2
+  else
+    ctx.pos = pos + 4
+  end
+end
+
+-- Fallback for unknown opcodes.
+local function unknown(ctx)
+  return putop(ctx, ".long", { "0x"..tohex(ctx.op) })
+end
+
+local function get_le(ctx)
+  local pos = ctx.pos
+  --Examine if the next instruction is 16-bits or 32-bits
+  local first_byte = byte(ctx.code, pos+1)
+  if(band(first_byte, 3) < 3) then --checking first two bits of opcode
+    local b0, b1 = byte(ctx.code, pos+1, pos+2)
+    return bor(lshift(b1, 8), b0)
+  else
+    local b0, b1, b2, b3 = byte(ctx.code, pos+1, pos+4)
+    return bor(lshift(b3, 24), lshift(b2, 16), lshift(b1, 8), b0)
+  end
+end
+
+local function parse_W(opcode)
+  local part1 = band(rshift(opcode, 7), 15) --9:6
+  local part2 = band(rshift(opcode, 11), 3) --5:4
+  local part3 = band(rshift(opcode, 5), 1)--3
+  local part4 = band(rshift(opcode, 6), 1)--2
+  return bor(lshift(0, 31), lshift(part1, 6) , lshift(part2, 4),
+             lshift(part3, 3), lshift(part4, 2))
+end
+
+local function parse_x(opcode)
+  local part1 = band(rshift(opcode, 12), 1) --5
+  local part2 = band(rshift(opcode, 2), 31) --4:0
+  if(part1 == 1) then
+    return bor(lshift(1, 31), lshift(0x1ffffff, 6), lshift(part1, 5), part2)
+  else
+    return bor(lshift(0, 31), lshift(part1, 5), part2)
+  end
+end
+
+local function parse_X(opcode)
+  local part1 = band(rshift(opcode, 12), 1) --12
+  local part2 = band(rshift(opcode, 3), 3) --8:7
+  local part3 = band(rshift(opcode, 5), 1) --6
+  local part4 = band(rshift(opcode, 2), 1) --5
+  local part5 = band(rshift(opcode, 6), 1) --4
+  if(part1 == 1) then
+    return bor(lshift(1, 31), lshift(0x3fffff, 9), lshift(part2, 7),
+               lshift(part3, 6), lshift(part4, 5), lshift(part5, 4))
+  else
+    return bor(lshift(0, 31), lshift(part2, 7), lshift(part3, 6),
+               lshift(part4, 5), lshift(part5, 4))
+  end
+end
+
+local function parse_S(opcode)
+  local part1 = band(rshift(opcode, 25), 127) --11:5
+  local sign = band(rshift(part1, 6), 1)
+  local part2 = band(rshift(opcode, 7), 31) --4:0
+  if (sign == 1) then
+    return bor(lshift(1, 31), lshift(0x7ffff, 12), lshift(part1, 5), part2)
+  else
+    return bor(lshift(0, 31), lshift(part1, 5), part2)
+  end
+end
+
+local function parse_B(opcode)
+  local part1 = band(rshift(opcode, 7), 1) --11
+  local part2 = band(rshift(opcode, 25), 63) --10:5
+  local part3 = band(rshift(opcode, 8), 15) -- 4 : 1
+  if (part1 == 1) then
+    return bor(lshift(1, 31), lshift(0x7ffff, 12), lshift(part1, 11),
+               lshift(part2, 5), lshift(part3, 1), 0)
+  else
+    return bor(lshift(0, 31), lshift(part1, 11), lshift(part2, 5),
+               lshift(part3, 1), 0)
+  end
+end
+
+local function parse_q(opcode)
+  local part1 = band(rshift(opcode, 12), 1) --8
+  local part2 = band(rshift(opcode, 5), 3) --7:6
+  local part3 = band(rshift(opcode, 2), 1) --5
+  local part4 = band(rshift(opcode, 10), 3) --4:3
+  local part5 = band(rshift(opcode, 3), 3) --2:1
+  if(part1 == 1) then
+    return bor(lshift(1, 31), lshift(0x7fffff, 8), lshift(part2, 6),
+               lshift(part3, 5), lshift(part4, 3), lshift(part5, 1))
+  else
+    return bor(lshift(0, 31), lshift(part2, 6), lshift(part3, 5),
+               lshift(part4, 3), lshift(part5, 1))
+  end
+end
+
+local function parse_J(opcode)
+  local part1 = band(rshift(opcode, 31), 1) --20
+  local part2 = band(rshift(opcode, 12), 255) -- 19:12
+  local part3 = band(rshift(opcode, 20), 1) --11
+  local part4 = band(rshift(opcode, 21), 1023) --10:1
+  if(part1 == 1) then
+    return bor(lshift(1, 31), lshift(0x7ff, 20), lshift(part2, 12),
+               lshift(part3, 11), lshift(part4, 1))
+  else
+    return bor(lshift(0, 31), lshift(0, 20), lshift(part2, 12),
+               lshift(part3, 11), lshift(part4, 1))
+  end
+end
+
+local function parse_T(opcode)
+  local part1 = band(rshift(opcode, 12), 1) --11
+  local part2 = band(rshift(opcode, 8), 1) --10
+  local part3 = band(rshift(opcode, 9), 3)--9:8
+  local part4 = band(rshift(opcode, 6), 1) --7
+  local part5 = band(rshift(opcode, 7), 1) -- 6
+  local part6 = band(rshift(opcode, 2), 1) --5
+  local part7 = band(rshift(opcode, 11), 1) --4
+  local part8 = band(rshift(opcode, 3), 7) --3:1
+  if(part1 == 1) then
+    return bor(lshift(1, 31), lshift(0x7ffff, 12), lshift(part1, 11),
+               lshift(part2, 10), lshift(part3, 8), lshift(part4, 7),
+               lshift(part5, 6), lshift(part6, 5), lshift(part7, 4),
+               lshift(part8, 1))
+  else
+    return bor(lshift(0, 31), lshift(part1, 11), lshift(part2, 10),
+               lshift(part3, 8), lshift(part4, 7), lshift(part5, 6),
+               lshift(part6, 5), lshift(part7, 4), lshift(part8, 1))
+  end
+end
+
+local function parse_K(opcode)
+  local part1 = band(rshift(opcode, 12), 1) --5 17
+  local part2 = band(rshift(opcode, 2), 31) --4:0  16:12
+  if(part1 == 1) then
+    return bor(lshift(0, 31), lshift(0x7fff, 5), part2)
+  else
+    return bor(lshift(0, 31), lshift(part1, 5), part2)
+  end
+end
+
+-- Disassemble a single instruction.
+local function disass_ins(ctx)
+  local op = ctx:get()
+  local operands = {}
+  local last = nil
+  ctx.op = op
+  ctx.rel =nil
+
+  local opat = 0
+  --for compressed instructions
+  if(band(op, 3) < 3) then
+    opat = ctx.map_compr[band(op, 3)]
+    while type(opat) ~= "string" do
+      if not opat then return unknown(ctx) end
+      local test = band(rshift(op, opat.shift), opat.mask)
+      opat = opat[band(rshift(op, opat.shift), opat.mask)] or opat._
+    end
+  else
+    opat = ctx.map_pri[band(op,127)]
+    while type(opat) ~= "string" do
+      if not opat then return unknown(ctx) end
+      opat = opat[band(rshift(op, opat.shift), opat.mask)] or opat._
+    end
+  end
+  local name, pat = match(opat, "^([a-z0-9_.]*)(.*)")
+  local altname, pat2 = match(pat, "|([a-z0-9_.|]*)(.*)")
+  local a1, a2 = 0
+  if altname then
+   pat = pat2
+  end
+
+  local alias_done = false --variable for the case of 2 pseudoinstructions, if both parameters are x0, 0
+
+  for p in gmatch(pat, ".") do
+    local x = nil
+    if p == "D" then
+      x = map_gpr[band(rshift(op, 7), 31)]
+    elseif p == "F" then
+      x = map_fgpr[band(rshift(op, 7), 31)]
+    elseif p == "R" then
+      x = map_gpr[band(rshift(op, 15), 31)]
+    elseif p == "G" then
+      x = map_fgpr[band(rshift(op, 15), 31)]
+    elseif p == "r" then
+      x = map_gpr[band(rshift(op, 20), 31)]
+      if(name == "sb" or name == "sh" or name == "sw" or name == "sd") then
+        local temp = last --because of the diffrent order of the characters
+        operands[#operands] = x
+        x = temp
+      end
+    elseif p == "g" then
+      x = map_fgpr[band(rshift(op, 20), 31)]
+     if(name == "fsw" or name == "fsd") then
+        local temp = last
+        operands[#operands] = x
+        x = temp
+     end
+    elseif p == "Z" then
+      x = map_gpr[8 + band(rshift(op, 2), 7)]
+    elseif p == "N" then
+      x = map_fgpr[8 + band(rshift(op, 2), 7)]
+    elseif p == "M" then
+      x = map_gpr[8 + band(rshift(op, 7), 7)]
+    elseif p == "E" then
+      x = map_gpr[band(rshift(op, 2), 31)]
+    elseif p == "W" then
+      local uimm = parse_W(op)
+      x = format("%s,%d", "sp", uimm)
+    elseif p == "x" then
+      x = parse_x(op)
+    elseif p == "h" then
+      local part1 = band(rshift(op, 5), 3) --7:6
+      local part2 = band(rshift(op, 10), 7) --5:3
+      local uimm = bor(lshift(0, 31), lshift(part1, 6) , lshift(part2, 3))
+      operands[#operands] = format("%d(%s)", uimm, last)
+    elseif p == "X" then
+      local imm = parse_X(op)
+      x = format("%s,%d", "sp", imm)
+    elseif p == "O" then
+      x = format("(%s)", map_gpr[band(rshift(op, 15), 31)])
+    elseif p == "H" then
+      x = map_fgpr[band(rshift(op, 27), 31)]
+    elseif p == "L" then
+      local register = map_gpr[band(rshift(op, 15), 31)]
+      local disp = arshift(op, 20)
+      x = format("%d(%s)", disp, register)
+    elseif p == "P" then -- XTheadMemPair
+      local register = map_gpr[band(rshift(op, 15), 31)]
+      local disp = band(arshift(op, 25), 3)
+      local isword = bxor(band(arshift(op, 26), 1), 1)
+      x = format("(%s), %d, %d", register, disp, isword and 3 or 4)
+    elseif p == "I" then
+      x = arshift(op, 20)
+      --different for jalr
+      if(name == "jalr") then
+        local reg = map_gpr[band(rshift(op, 15), 31)]
+        if(ctx.reltab[reg] == nil) then
+          operands[#operands] = format("%d(%s)", x, last)
+        else
+          local target = ctx.reltab[reg] + x
+          operands[#operands] = format("%d(%s) #0x%08x", x, last, target)
+          ctx.rel = target
+          ctx.reltab[reg] = nil --assume no reuses of the register
+        end
+        x = nil --not to add additional operand
+      end
+    elseif p == "i" then
+      --both for RV32I AND RV64I
+      local value = band(arshift(op, 20), 63)
+      x = string.format("%d", value)
+    elseif p == "j" then -- XThead imm1[31..26]
+      local value = band(rshift(op, 26), 63)
+      x = string.format("%d", value)
+    elseif p == "v" then --XThead imm[2][26..25]
+      local value = band(rshift(op, 25), 3)
+      x = string.format("%d", value)
+    elseif p == "S" then
+      local register = map_gpr[band(rshift(op, 15), 31)] --register
+      local imm = parse_S(op)
+      x = format("%d(%s)", imm, register)
+    elseif p == "n" then
+      local part1 = band(rshift(op, 5), 1) --6
+      local part2 = band(rshift(op, 10), 7) --5:3
+      local part3 = band(rshift(op, 6), 1) --2
+      local uimm = bor(lshift(0, 31), lshift(part1, 6), lshift(part2, 3),
+                       lshift(part3, 2))
+      operands[#operands] = format("%d(%s)", uimm, last)
+    elseif p == "A" then
+      local value, dest = band(rshift(op, 12), 0xfffff), map_gpr[band(rshift(op, 7), 31)]
+      ctx.reltab[dest] = ctx.addr + ctx.pos + lshift(value, 12)
+      x = format("0x%x", value)
+    elseif p == "B" then
+      x = ctx.addr + ctx.pos + parse_B(op)
+      ctx.rel = x
+      x = format("0x%08x", x)
+    elseif p == "U" then
+      local value = band(rshift(op, 12), 0xfffff)
+      x = string.format("0x%x", value)
+    elseif p == "Q" then
+      local part1 = band(rshift(op, 2), 7) --8:6
+      local part2 = band(rshift(op, 12), 1) --5
+      local part3 = band(rshift(op, 5), 3) --4:3
+      local uimm = bor(lshift(0, 31), lshift(part1, 6), lshift(part2, 5),
+                       lshift(part3, 3))
+      x = format("%d(%s)", uimm, "sp")
+   elseif p == "q" then
+      x = ctx.addr + ctx.pos + parse_q(op)
+      ctx.rel = x
+      x = format("0x%08x", x)
+    elseif p == "J" then
+      x = ctx.addr + ctx.pos + parse_J(op)
+      ctx.rel = x
+      x = format("0x%08x", x)
+    elseif p == "K" then
+      local value = parse_K(op)
+      x = string.format("0x%x", value)
+    elseif p == "Y" then
+      local part1 = band(rshift(op, 2), 3) --7:6
+      local part2 = band(rshift(op, 12), 1) --5
+      local part3 = band(rshift(op, 4), 7) --4:2
+      local uimm = bor(lshift(0, 31), lshift(part1, 6), lshift(part2, 5),
+                       lshift(part3, 2))
+      x = format("%d(%s)", uimm, "sp")
+    elseif p == "o" then -- rounding mode
+      x = map_rm[band(rshift(op, 12), 7)]
+    elseif p == "y" then -- fli lut
+      x = map_fli[band(rshift(op, 15), 31)]
+    elseif p == "1" then
+      local part1 = band(rshift(op, 12), 1) --5
+      local part2 = band(rshift(op, 2), 31) --4:0
+      local uimm = bor(lshift(0, 31), lshift(part1, 5), part2)
+      x = string.format("0x%x", uimm)
+    elseif p == "T" then
+      x = ctx.addr + ctx.pos + parse_T(op)
+      ctx.rel = x
+      x = format("0x%08x", x)
+    elseif p == "t" then
+      local part1 = band(rshift(op, 7), 7) --8:6
+      local part2 = band(rshift(op, 10), 7) --5:3
+      local uimm = bor(lshift(0, 31), lshift(part1, 6), lshift(part2, 3))
+      x = format("%d(%s)", uimm, "sp")
+    elseif p == "u" then
+      local part1 = band(rshift(op, 7), 3) --7:6
+      local part2 = band(rshift(op, 9), 15) --5:2
+      local uimm = bor(lshift(0, 31), lshift(part1, 6), lshift(part2, 2))
+      x = format("%d(%s)", uimm, "sp")
+    elseif p == "V" then
+      x = map_fgpr[band(rshift(op, 2), 31)]
+    elseif p == "0" then --PSEUDOINSTRUCTIONS
+      if (last == "zero" or last == 0) then
+        local n = #operands
+        operands[n] = nil
+        last = operands[n-1]
+        local a1, a2 = match(altname, "([^|]*)|(.*)")
+        if a1 then name, altname = a1, a2
+        else name = altname end
+        alias_done = true
+      end
+    elseif (p == "4") then
+      if(last == -1) then
+        name = altname
+        operands[#operands] = nil
+      end
+    elseif (p == "5") then
+      if(last == 1) then
+        name = altname
+        operands[#operands] = nil
+      end
+    elseif (p == "6") then
+      if(last == operands[#operands - 1]) then
+        name = altname
+        operands[#operands] = nil
+      end
+    elseif (p == "7") then --jalr rs
+      local value = string.sub(operands[#operands], 1, 1)
+      local reg = string.sub(operands[#operands], 3, #(operands[#operands]) - 1)
+      if(value == "0" and
+         (operands[#operands - 1] == "ra" or operands[#operands - 1] == "zero")) then
+        if(operands[#operands - 1] == "zero") then
+          name = altname
+        end
+        operands[#operands] = nil
+        operands[#operands] = reg
+      end
+    elseif (p == "2" and alias_done == false) then
+      if (last == "zero" or last == 0) then
+        local a1, a2 = match(altname, "([^|]*)|(.*)")
+        name = a2
+        operands[#operands] = nil
+      end
+    end
+    if x then operands[#operands+1] = x; last = x end
+  end
+  return putop(ctx, name, operands)
+end
+
+------------------------------------------------------------------------------
+
+-- Disassemble a block of code.
+local function disass_block(ctx, ofs, len)
+  if not ofs then
+    ofs = 0
+  end
+  local stop = len and ofs+len or #ctx.code
+  --instructions can be both 32 and 16 bits
+  stop = stop - stop % 2
+  ctx.pos = ofs - ofs % 2
+  ctx.rel = nil
+  while ctx.pos < stop do disass_ins(ctx) end
+end
+
+-- Extended API: create a disassembler context. Then call ctx:disass(ofs, len).
+local function create(code, addr, out)
+  local ctx = {}
+  ctx.code = code
+  ctx.addr = addr or 0
+  ctx.out = out or io.write
+  ctx.symtab = {}
+  ctx.disass = disass_block
+  ctx.hexdump = 8
+  ctx.get = get_le
+  ctx.map_pri = map_pri
+  ctx.map_compr = map_compr
+  ctx.reltab = {}
+  return ctx
+end
+
+-- Simple API: disassemble code (a string) at address and output via out.
+local function disass(code, addr, out)
+  create(code, addr, out):disass(addr)
+end
+
+-- Return register name for RID.
+local function regname(r)
+  if r < 32 then return map_gpr[r] end
+  return "f"..(r-32)
+end
+
+-- Public module functions.
+return {
+  create = create,
+  disass = disass,
+  regname = regname
+}

src/jit/dis_riscv64.lua

@@ -0,0 +1,16 @@
+----------------------------------------------------------------------------
+-- LuaJIT RISC-V 64 disassembler wrapper module.
+--
+-- Copyright (C) 2005-2025 Mike Pall. All rights reserved.
+-- Released under the MIT license. See Copyright Notice in luajit.h
+----------------------------------------------------------------------------
+-- This module just exports the default riscv little-endian functions from the
+-- RISC-V disassembler module. All the interesting stuff is there.
+------------------------------------------------------------------------------
+
+local dis_riscv = require((string.match(..., ".*%.") or "").."dis_riscv")
+return {
+  create = dis_riscv.create,
+  disass = dis_riscv.disass,
+  regname = dis_riscv.regname
+}