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/*

** $Id: lcode.c,v 2.60 2011/08/30 16:26:41 roberto Exp $

** Code generator for Lua

** See Copyright Notice in lua.h

*/

#include 

#define lcode_c

#define LUA_CORE

#include "lua.h"

#include "lcode.h"

#include "ldebug.h"

#include "ldo.h"

#include "lgc.h"

#include "llex.h"

#include "lmem.h"

#include "lobject.h"

#include "lopcodes.h"

#include "lparser.h"

#include "lstring.h"

#include "ltable.h"

#include "lvm.h"

#define hasjumps(e)	((e)->t != (e)->f)

static int isnumeral(expdesc *e) {

  return (e->k == VKNUM && e->t == NO_JUMP && e->f == NO_JUMP);

}

void luaK_nil (FuncState *fs, int from, int n) {

  Instruction *previous;

  int l = from + n - 1;  /* last register to set nil */

  if (fs->pc > fs->lasttarget) {  /* no jumps to current position? */

    previous = &fs->f->code[fs->pc-1];

    if (GET_OPCODE(*previous) == OP_LOADNIL) {

      int pfrom = GETARG_A(*previous);

      int pl = pfrom + GETARG_B(*previous);

      if ((pfrom <= from && from <= pl + 1) ||

          (from <= pfrom && pfrom <= l + 1)) {  /* can connect both? */

        if (pfrom < from) from = pfrom;  /* from = min(from, pfrom) */

        if (pl > l) l = pl;  /* l = max(l, pl) */

        SETARG_A(*previous, from);

        SETARG_B(*previous, l - from);

        return;

      }

    }  /* else go through */

  }

  luaK_codeABC(fs, OP_LOADNIL, from, n - 1, 0);  /* else no optimization */

}

int luaK_jump (FuncState *fs) {

  int jpc = fs->jpc;  /* save list of jumps to here */

  int j;

  fs->jpc = NO_JUMP;

  j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP);

  luaK_concat(fs, &j, jpc);  /* keep them on hold */

  return j;

}

void luaK_ret (FuncState *fs, int first, int nret) {

  luaK_codeABC(fs, OP_RETURN, first, nret+1, 0);

}

static int condjump (FuncState *fs, OpCode op, int A, int B, int C) {

  luaK_codeABC(fs, op, A, B, C);

  return luaK_jump(fs);

}

static void fixjump (FuncState *fs, int pc, int dest) {

  Instruction *jmp = &fs->f->code[pc];

  int offset = dest-(pc+1);

  lua_assert(dest != NO_JUMP);

  if (abs(offset) > MAXARG_sBx)

    luaX_syntaxerror(fs->ls, "control structure too long");

  SETARG_sBx(*jmp, offset);

}

/*

** returns current `pc' and marks it as a jump target (to avoid wrong

** optimizations with consecutive instructions not in the same basic block).

*/

int luaK_getlabel (FuncState *fs) {

  fs->lasttarget = fs->pc;

  return fs->pc;

}

static int getjump (FuncState *fs, int pc) {

  int offset = GETARG_sBx(fs->f->code[pc]);

  if (offset == NO_JUMP)  /* point to itself represents end of list */

    return NO_JUMP;  /* end of list */

  else

    return (pc+1)+offset;  /* turn offset into absolute position */

}

static Instruction *getjumpcontrol (FuncState *fs, int pc) {

  Instruction *pi = &fs->f->code[pc];

  if (pc >= 1 && testTMode(GET_OPCODE(*(pi-1))))

    return pi-1;

  else

    return pi;

}

/*

** check whether list has any jump that do not produce a value

** (or produce an inverted value)

*/

static int need_value (FuncState *fs, int list) {

  for (; list != NO_JUMP; list = getjump(fs, list)) {

    Instruction i = *getjumpcontrol(fs, list);

    if (GET_OPCODE(i) != OP_TESTSET) return 1;

  }

  return 0;  /* not found */

}

static int patchtestreg (FuncState *fs, int node, int reg) {

  Instruction *i = getjumpcontrol(fs, node);

  if (GET_OPCODE(*i) != OP_TESTSET)

    return 0;  /* cannot patch other instructions */

  if (reg != NO_REG && reg != GETARG_B(*i))

    SETARG_A(*i, reg);

  else  /* no register to put value or register already has the value */

    *i = CREATE_ABC(OP_TEST, GETARG_B(*i), 0, GETARG_C(*i));

  return 1;

}

static void removevalues (FuncState *fs, int list) {

  for (; list != NO_JUMP; list = getjump(fs, list))

      patchtestreg(fs, list, NO_REG);

}

static void patchlistaux (FuncState *fs, int list, int vtarget, int reg,

                          int dtarget) {

  while (list != NO_JUMP) {

    int next = getjump(fs, list);

    if (patchtestreg(fs, list, reg))

      fixjump(fs, list, vtarget);

    else

      fixjump(fs, list, dtarget);  /* jump to default target */

    list = next;

  }

}

static void dischargejpc (FuncState *fs) {

  patchlistaux(fs, fs->jpc, fs->pc, NO_REG, fs->pc);

  fs->jpc = NO_JUMP;

}

void luaK_patchlist (FuncState *fs, int list, int target) {

  if (target == fs->pc)

    luaK_patchtohere(fs, list);

  else {

    lua_assert(target < fs->pc);

    patchlistaux(fs, list, target, NO_REG, target);

  }

}

LUAI_FUNC void luaK_patchclose (FuncState *fs, int list, int level) {

  level++;  /* argument is +1 to reserve 0 as non-op */

  while (list != NO_JUMP) {

    int next = getjump(fs, list);

    lua_assert(GET_OPCODE(fs->f->code[list]) == OP_JMP &&

                (GETARG_A(fs->f->code[list]) == 0 ||

                 GETARG_A(fs->f->code[list]) >= level));

    SETARG_A(fs->f->code[list], level);

    list = next;

  }

}

void luaK_patchtohere (FuncState *fs, int list) {

  luaK_getlabel(fs);

  luaK_concat(fs, &fs->jpc, list);

}

void luaK_concat (FuncState *fs, int *l1, int l2) {

  if (l2 == NO_JUMP) return;

  else if (*l1 == NO_JUMP)

    *l1 = l2;

  else {

    int list = *l1;

    int next;

    while ((next = getjump(fs, list)) != NO_JUMP)  /* find last element */

      list = next;

    fixjump(fs, list, l2);

  }

}

static int luaK_code (FuncState *fs, Instruction i) {

  Proto *f = fs->f;

  dischargejpc(fs);  /* `pc' will change */

  /* put new instruction in code array */

  luaM_growvector(fs->ls->L, f->code, fs->pc, f->sizecode, Instruction,

                  MAX_INT, "opcodes");

  f->code[fs->pc] = i;

  /* save corresponding line information */

  luaM_growvector(fs->ls->L, f->lineinfo, fs->pc, f->sizelineinfo, int,

                  MAX_INT, "opcodes");

  f->lineinfo[fs->pc] = fs->ls->lastline;

  return fs->pc++;

}

int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) {

  lua_assert(getOpMode(o) == iABC);

  lua_assert(getBMode(o) != OpArgN || b == 0);

  lua_assert(getCMode(o) != OpArgN || c == 0);

  lua_assert(a <= MAXARG_A && b <= MAXARG_B && c <= MAXARG_C);

  return luaK_code(fs, CREATE_ABC(o, a, b, c));

}

int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) {

  lua_assert(getOpMode(o) == iABx || getOpMode(o) == iAsBx);

  lua_assert(getCMode(o) == OpArgN);

  lua_assert(a <= MAXARG_A && bc <= MAXARG_Bx);

  return luaK_code(fs, CREATE_ABx(o, a, bc));

}

static int codeextraarg (FuncState *fs, int a) {

  lua_assert(a <= MAXARG_Ax);

  return luaK_code(fs, CREATE_Ax(OP_EXTRAARG, a));

}

int luaK_codek (FuncState *fs, int reg, int k) {

  if (k <= MAXARG_Bx)

    return luaK_codeABx(fs, OP_LOADK, reg, k);

  else {

    int p = luaK_codeABx(fs, OP_LOADKX, reg, 0);

    codeextraarg(fs, k);

    return p;

  }

}

void luaK_checkstack (FuncState *fs, int n) {

  int newstack = fs->freereg + n;

  if (newstack > fs->f->maxstacksize) {

    if (newstack >= MAXSTACK)

      luaX_syntaxerror(fs->ls, "function or expression too complex");

    fs->f->maxstacksize = cast_byte(newstack);

  }

}

void luaK_reserveregs (FuncState *fs, int n) {

  luaK_checkstack(fs, n);

  fs->freereg += n;

}

static void freereg (FuncState *fs, int reg) {

  if (!ISK(reg) && reg >= fs->nactvar) {

    fs->freereg--;

    lua_assert(reg == fs->freereg);

  }

}

static void freeexp (FuncState *fs, expdesc *e) {

  if (e->k == VNONRELOC)

    freereg(fs, e->u.info);

}

static int addk (FuncState *fs, TValue *key, TValue *v) {

  lua_State *L = fs->ls->L;

  TValue *idx = luaH_set(L, fs->h, key);

  Proto *f = fs->f;

  int k, oldsize;

  if (ttisnumber(idx)) {

    lua_Number n = nvalue(idx);

    lua_number2int(k, n);

    if (luaV_rawequalobj(&f->k[k], v))

      return k;

    /* else may be a collision (e.g., between 0.0 and "\0\0\0\0\0\0\0\0");

       go through and create a new entry for this value */

  }

  /* constant not found; create a new entry */

  oldsize = f->sizek;

  k = fs->nk;

  /* numerical value does not need GC barrier;

     table has no metatable, so it does not need to invalidate cache */

  setnvalue(idx, cast_num(k));

  luaM_growvector(L, f->k, k, f->sizek, TValue, MAXARG_Ax, "constants");

  while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]);

  setobj(L, &f->k[k], v);

  fs->nk++;

  luaC_barrier(L, f, v);

  return k;

}

int luaK_stringK (FuncState *fs, TString *s) {

  TValue o;

  setsvalue(fs->ls->L, &o, s);

  return addk(fs, &o, &o);

}

int luaK_numberK (FuncState *fs, lua_Number r) {

  int n;

  lua_State *L = fs->ls->L;

  TValue o;

  setnvalue(&o, r);

  if (r == 0 || luai_numisnan(NULL, r)) {  /* handle -0 and NaN */

    /* use raw representation as key to avoid numeric problems */

    setsvalue(L, L->top, luaS_newlstr(L, (char *)&r, sizeof(r)));

     incr_top(L);

     n = addk(fs, L->top - 1, &o);

     L->top--;

  }

  else

    n = addk(fs, &o, &o);  /* regular case */

  return n;

}

static int boolK (FuncState *fs, int b) {

  TValue o;

  setbvalue(&o, b);

  return addk(fs, &o, &o);

}

static int nilK (FuncState *fs) {

  TValue k, v;

  setnilvalue(&v);

  /* cannot use nil as key; instead use table itself to represent nil */

  sethvalue(fs->ls->L, &k, fs->h);

  return addk(fs, &k, &v);

}

void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) {

  if (e->k == VCALL) {  /* expression is an open function call? */

    SETARG_C(getcode(fs, e), nresults+1);

  }

  else if (e->k == VVARARG) {

    SETARG_B(getcode(fs, e), nresults+1);

    SETARG_A(getcode(fs, e), fs->freereg);

    luaK_reserveregs(fs, 1);

  }

}

void luaK_setoneret (FuncState *fs, expdesc *e) {

  if (e->k == VCALL) {  /* expression is an open function call? */

    e->k = VNONRELOC;

    e->u.info = GETARG_A(getcode(fs, e));

  }

  else if (e->k == VVARARG) {

    SETARG_B(getcode(fs, e), 2);

    e->k = VRELOCABLE;  /* can relocate its simple result */

  }

}

void luaK_dischargevars (FuncState *fs, expdesc *e) {

  switch (e->k) {

    case VLOCAL: {

      e->k = VNONRELOC;

      break;

    }

    case VUPVAL: {

      e->u.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.info, 0);

      e->k = VRELOCABLE;

      break;

    }

    case VINDEXED: {

      OpCode op = OP_GETTABUP;  /* assume 't' is in an upvalue */

      freereg(fs, e->u.ind.idx);

      if (e->u.ind.vt == VLOCAL) {  /* 't' is in a register? */

        freereg(fs, e->u.ind.t);

        op = OP_GETTABLE;

      }

      e->u.info = luaK_codeABC(fs, op, 0, e->u.ind.t, e->u.ind.idx);

      e->k = VRELOCABLE;

      break;

    }

    case VVARARG:

    case VCALL: {

      luaK_setoneret(fs, e);

      break;

    }

    default: break;  /* there is one value available (somewhere) */

  }

}

static int code_label (FuncState *fs, int A, int b, int jump) {

  luaK_getlabel(fs);  /* those instructions may be jump targets */

  return luaK_codeABC(fs, OP_LOADBOOL, A, b, jump);

}

static void discharge2reg (FuncState *fs, expdesc *e, int reg) {

  luaK_dischargevars(fs, e);

  switch (e->k) {

    case VNIL: {

      luaK_nil(fs, reg, 1);

      break;

    }

    case VFALSE:  case VTRUE: {

      luaK_codeABC(fs, OP_LOADBOOL, reg, e->k == VTRUE, 0);

      break;

    }

    case VK: {

      luaK_codek(fs, reg, e->u.info);

      break;

    }

    case VKNUM: {

      luaK_codek(fs, reg, luaK_numberK(fs, e->u.nval));

      break;

    }

    case VRELOCABLE: {

      Instruction *pc = &getcode(fs, e);

      SETARG_A(*pc, reg);

      break;

    }

    case VNONRELOC: {

      if (reg != e->u.info)

        luaK_codeABC(fs, OP_MOVE, reg, e->u.info, 0);

      break;

    }

    default: {

      lua_assert(e->k == VVOID || e->k == VJMP);

      return;  /* nothing to do... */

    }

  }

  e->u.info = reg;

  e->k = VNONRELOC;

}

static void discharge2anyreg (FuncState *fs, expdesc *e) {

  if (e->k != VNONRELOC) {

    luaK_reserveregs(fs, 1);

    discharge2reg(fs, e, fs->freereg-1);

  }

}

static void exp2reg (FuncState *fs, expdesc *e, int reg) {

  discharge2reg(fs, e, reg);

  if (e->k == VJMP)

    luaK_concat(fs, &e->t, e->u.info);  /* put this jump in `t' list */

  if (hasjumps(e)) {

    int final;  /* position after whole expression */

    int p_f = NO_JUMP;  /* position of an eventual LOAD false */

    int p_t = NO_JUMP;  /* position of an eventual LOAD true */

    if (need_value(fs, e->t) || need_value(fs, e->f)) {

      int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs);

      p_f = code_label(fs, reg, 0, 1);

      p_t = code_label(fs, reg, 1, 0);

      luaK_patchtohere(fs, fj);

    }

    final = luaK_getlabel(fs);

    patchlistaux(fs, e->f, final, reg, p_f);

    patchlistaux(fs, e->t, final, reg, p_t);

  }

  e->f = e->t = NO_JUMP;

  e->u.info = reg;

  e->k = VNONRELOC;

}

void luaK_exp2nextreg (FuncState *fs, expdesc *e) {

  luaK_dischargevars(fs, e);

  freeexp(fs, e);

  luaK_reserveregs(fs, 1);

  exp2reg(fs, e, fs->freereg - 1);

}

int luaK_exp2anyreg (FuncState *fs, expdesc *e) {

  luaK_dischargevars(fs, e);

  if (e->k == VNONRELOC) {

    if (!hasjumps(e)) return e->u.info;  /* exp is already in a register */

    if (e->u.info >= fs->nactvar) {  /* reg. is not a local? */

      exp2reg(fs, e, e->u.info);  /* put value on it */

      return e->u.info;

    }

  }

  luaK_exp2nextreg(fs, e);  /* default */

  return e->u.info;

}

void luaK_exp2anyregup (FuncState *fs, expdesc *e) {

  if (e->k != VUPVAL || hasjumps(e))

    luaK_exp2anyreg(fs, e);

}

void luaK_exp2val (FuncState *fs, expdesc *e) {

  if (hasjumps(e))

    luaK_exp2anyreg(fs, e);

  else

    luaK_dischargevars(fs, e);

}

int luaK_exp2RK (FuncState *fs, expdesc *e) {

  luaK_exp2val(fs, e);

  switch (e->k) {

    case VTRUE:

    case VFALSE:

    case VNIL: {

      if (fs->nk <= MAXINDEXRK) {  /* constant fits in RK operand? */

        e->u.info = (e->k == VNIL) ? nilK(fs) : boolK(fs, (e->k == VTRUE));

        e->k = VK;

        return RKASK(e->u.info);

      }

      else break;

    }

    case VKNUM: {

      e->u.info = luaK_numberK(fs, e->u.nval);

      e->k = VK;

      /* go through */

    }

    case VK: {

      if (e->u.info <= MAXINDEXRK)  /* constant fits in argC? */

        return RKASK(e->u.info);

      else break;

    }

    default: break;

  }

  /* not a constant in the right range: put it in a register */

  return luaK_exp2anyreg(fs, e);

}

void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) {

  switch (var->k) {

    case VLOCAL: {

      freeexp(fs, ex);

      exp2reg(fs, ex, var->u.info);

      return;

    }

    case VUPVAL: {

      int e = luaK_exp2anyreg(fs, ex);

      luaK_codeABC(fs, OP_SETUPVAL, e, var->u.info, 0);

      break;

    }

    case VINDEXED: {

      OpCode op = (var->u.ind.vt == VLOCAL) ? OP_SETTABLE : OP_SETTABUP;

      int e = luaK_exp2RK(fs, ex);

      luaK_codeABC(fs, op, var->u.ind.t, var->u.ind.idx, e);

      break;

    }

    default: {

      lua_assert(0);  /* invalid var kind to store */

      break;

    }

  }

  freeexp(fs, ex);

}

void luaK_self (FuncState *fs, expdesc *e, expdesc *key) {

  int ereg;

  luaK_exp2anyreg(fs, e);

  ereg = e->u.info;  /* register where 'e' was placed */

  freeexp(fs, e);

  e->u.info = fs->freereg;  /* base register for op_self */

  e->k = VNONRELOC;

  luaK_reserveregs(fs, 2);  /* function and 'self' produced by op_self */

  luaK_codeABC(fs, OP_SELF, e->u.info, ereg, luaK_exp2RK(fs, key));

  freeexp(fs, key);

}

static void invertjump (FuncState *fs, expdesc *e) {

  Instruction *pc = getjumpcontrol(fs, e->u.info);

  lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET &&

                                           GET_OPCODE(*pc) != OP_TEST);

  SETARG_A(*pc, !(GETARG_A(*pc)));

}

static int jumponcond (FuncState *fs, expdesc *e, int cond) {

  if (e->k == VRELOCABLE) {

    Instruction ie = getcode(fs, e);

    if (GET_OPCODE(ie) == OP_NOT) {

      fs->pc--;  /* remove previous OP_NOT */

      return condjump(fs, OP_TEST, GETARG_B(ie), 0, !cond);

    }

    /* else go through */

  }

  discharge2anyreg(fs, e);

  freeexp(fs, e);

  return condjump(fs, OP_TESTSET, NO_REG, e->u.info, cond);

}

void luaK_goiftrue (FuncState *fs, expdesc *e) {

  int pc;  /* pc of last jump */

  luaK_dischargevars(fs, e);

  switch (e->k) {

    case VJMP: {

      invertjump(fs, e);

      pc = e->u.info;

      break;

    }

    case VK: case VKNUM: case VTRUE: {

      pc = NO_JUMP;  /* always true; do nothing */

      break;

    }

    default: {

      pc = jumponcond(fs, e, 0);

      break;

    }

  }

  luaK_concat(fs, &e->f, pc);  /* insert last jump in `f' list */

  luaK_patchtohere(fs, e->t);

  e->t = NO_JUMP;

}

void luaK_goiffalse (FuncState *fs, expdesc *e) {

  int pc;  /* pc of last jump */

  luaK_dischargevars(fs, e);

  switch (e->k) {

    case VJMP: {

      pc = e->u.info;

      break;

    }

    case VNIL: case VFALSE: {

      pc = NO_JUMP;  /* always false; do nothing */

      break;

    }

    default: {

      pc = jumponcond(fs, e, 1);

      break;

    }

  }

  luaK_concat(fs, &e->t, pc);  /* insert last jump in `t' list */

  luaK_patchtohere(fs, e->f);

  e->f = NO_JUMP;

}

static void codenot (FuncState *fs, expdesc *e) {

  luaK_dischargevars(fs, e);

  switch (e->k) {

    case VNIL: case VFALSE: {

      e->k = VTRUE;

      break;

    }

    case VK: case VKNUM: case VTRUE: {

      e->k = VFALSE;

      break;

    }

    case VJMP: {

      invertjump(fs, e);

      break;

    }

    case VRELOCABLE:

    case VNONRELOC: {

      discharge2anyreg(fs, e);

      freeexp(fs, e);

      e->u.info = luaK_codeABC(fs, OP_NOT, 0, e->u.info, 0);

      e->k = VRELOCABLE;

      break;

    }

    default: {

      lua_assert(0);  /* cannot happen */

      break;

    }

  }

  /* interchange true and false lists */

  { int temp = e->f; e->f = e->t; e->t = temp; }

  removevalues(fs, e->f);

  removevalues(fs, e->t);

}

void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) {

  lua_assert(!hasjumps(t));

  t->u.ind.t = t->u.info;

  t->u.ind.idx = luaK_exp2RK(fs, k);

  t->u.ind.vt = (t->k == VUPVAL) ? VUPVAL

                                 : check_exp(vkisinreg(t->k), VLOCAL);

  t->k = VINDEXED;

}

static int constfolding (OpCode op, expdesc *e1, expdesc *e2) {

  lua_Number r;

  if (!isnumeral(e1) || !isnumeral(e2)) return 0;

  if ((op == OP_DIV || op == OP_MOD) && e2->u.nval == 0)

    return 0;  /* do not attempt to divide by 0 */

  r = luaO_arith(op - OP_ADD + LUA_OPADD, e1->u.nval, e2->u.nval);

  e1->u.nval = r;

  return 1;

}

static void codearith (FuncState *fs, OpCode op,

                       expdesc *e1, expdesc *e2, int line) {

  if (constfolding(op, e1, e2))

    return;

  else {

    int o2 = (op != OP_UNM && op != OP_LEN) ? luaK_exp2RK(fs, e2) : 0;

    int o1 = luaK_exp2RK(fs, e1);

    if (o1 > o2) {

      freeexp(fs, e1);

      freeexp(fs, e2);

    }

    else {

      freeexp(fs, e2);

      freeexp(fs, e1);

    }

    e1->u.info = luaK_codeABC(fs, op, 0, o1, o2);

    e1->k = VRELOCABLE;

    luaK_fixline(fs, line);

  }

}

static void codecomp (FuncState *fs, OpCode op, int cond, expdesc *e1,

                                                          expdesc *e2) {

  int o1 = luaK_exp2RK(fs, e1);

  int o2 = luaK_exp2RK(fs, e2);

  freeexp(fs, e2);

  freeexp(fs, e1);

  if (cond == 0 && op != OP_EQ) {

    int temp;  /* exchange args to replace by `<' or `<=' */

    temp = o1; o1 = o2; o2 = temp;  /* o1 <==> o2 */

    cond = 1;

  }

  e1->u.info = condjump(fs, op, cond, o1, o2);

  e1->k = VJMP;

}

void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e, int line) {

  expdesc e2;

  e2.t = e2.f = NO_JUMP; e2.k = VKNUM; e2.u.nval = 0;

  switch (op) {

    case OPR_MINUS: {

      if (isnumeral(e))  /* minus constant? */

        e->u.nval = luai_numunm(NULL, e->u.nval);  /* fold it */

      else {

        luaK_exp2anyreg(fs, e);

        codearith(fs, OP_UNM, e, &e2, line);

      }

      break;

    }

    case OPR_NOT: codenot(fs, e); break;

    case OPR_LEN: {

      luaK_exp2anyreg(fs, e);  /* cannot operate on constants */

      codearith(fs, OP_LEN, e, &e2, line);

      break;

    }

    default: lua_assert(0);

  }

}

void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {

  switch (op) {

    case OPR_AND: {

      luaK_goiftrue(fs, v);

      break;

    }

    case OPR_OR: {

      luaK_goiffalse(fs, v);

      break;

    }

    case OPR_CONCAT: {

      luaK_exp2nextreg(fs, v);  /* operand must be on the `stack' */

      break;

    }

    case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV:

    case OPR_MOD: case OPR_POW: {

      if (!isnumeral(v)) luaK_exp2RK(fs, v);

      break;

    }

    default: {

      luaK_exp2RK(fs, v);

      break;

    }

  }

}

void luaK_posfix (FuncState *fs, BinOpr op,

                  expdesc *e1, expdesc *e2, int line) {

  switch (op) {

    case OPR_AND: {

      lua_assert(e1->t == NO_JUMP);  /* list must be closed */

      luaK_dischargevars(fs, e2);

      luaK_concat(fs, &e2->f, e1->f);

      *e1 = *e2;

      break;

    }

    case OPR_OR: {

      lua_assert(e1->f == NO_JUMP);  /* list must be closed */

      luaK_dischargevars(fs, e2);

      luaK_concat(fs, &e2->t, e1->t);

      *e1 = *e2;

      break;

    }

    case OPR_CONCAT: {

      luaK_exp2val(fs, e2);

      if (e2->k == VRELOCABLE && GET_OPCODE(getcode(fs, e2)) == OP_CONCAT) {

        lua_assert(e1->u.info == GETARG_B(getcode(fs, e2))-1);

        freeexp(fs, e1);

        SETARG_B(getcode(fs, e2), e1->u.info);

        e1->k = VRELOCABLE; e1->u.info = e2->u.info;

      }

      else {

        luaK_exp2nextreg(fs, e2);  /* operand must be on the 'stack' */

        codearith(fs, OP_CONCAT, e1, e2, line);

      }

      break;

    }

    case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV:

    case OPR_MOD: case OPR_POW: {

      codearith(fs, cast(OpCode, op - OPR_ADD + OP_ADD), e1, e2, line);

      break;

    }

    case OPR_EQ: case OPR_LT: case OPR_LE: {

      codecomp(fs, cast(OpCode, op - OPR_EQ + OP_EQ), 1, e1, e2);

      break;

    }

    case OPR_NE: case OPR_GT: case OPR_GE: {

      codecomp(fs, cast(OpCode, op - OPR_NE + OP_EQ), 0, e1, e2);

      break;

    }

    default: lua_assert(0);

  }

}

void luaK_fixline (FuncState *fs, int line) {

  fs->f->lineinfo[fs->pc - 1] = line;

}

void luaK_setlist (FuncState *fs, int base, int nelems, int tostore) {

  int c =  (nelems - 1)/LFIELDS_PER_FLUSH + 1;

  int b = (tostore == LUA_MULTRET) ? 0 : tostore;

  lua_assert(tostore != 0);

  if (c <= MAXARG_C)

    luaK_codeABC(fs, OP_SETLIST, base, b, c);

  else if (c <= MAXARG_Ax) {

    luaK_codeABC(fs, OP_SETLIST, base, b, 0);

    codeextraarg(fs, c);

  }

  else

    luaX_syntaxerror(fs->ls, "constructor too long");

  fs->freereg = base + 1;  /* free registers with list values */

}