Merge pull request #2672 from kitsunehunter/laundry-keys

[RRG-proxmark3.git] / client / deps / liblua / lvm.c

/*
** $Id: lvm.c $
** Lua virtual machine
** See Copyright Notice in lua.h
*/

#define lvm_c
#define LUA_CORE

#include "lprefix.h"

#include <float.h>
#include <limits.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "lua.h"

#include "ldebug.h"
#include "ldo.h"
#include "lfunc.h"
#include "lgc.h"
#include "lobject.h"
#include "lopcodes.h"
#include "lstate.h"
#include "lstring.h"
#include "ltable.h"
#include "ltm.h"
#include "lvm.h"


/*
** By default, use jump tables in the main interpreter loop on gcc
** and compatible compilers.
*/
#if !defined(LUA_USE_JUMPTABLE)
#if defined(__GNUC__)
#define LUA_USE_JUMPTABLE       1
#else
#define LUA_USE_JUMPTABLE       0
#endif
#endif



/* limit for table tag-method chains (to avoid infinite loops) */
#define MAXTAGLOOP      2000


/*
** 'l_intfitsf' checks whether a given integer is in the range that
** can be converted to a float without rounding. Used in comparisons.
*/

/* number of bits in the mantissa of a float */
#define NBM             (l_floatatt(MANT_DIG))

/*
** Check whether some integers may not fit in a float, testing whether
** (maxinteger >> NBM) > 0. (That implies (1 << NBM) <= maxinteger.)
** (The shifts are done in parts, to avoid shifting by more than the size
** of an integer. In a worst case, NBM == 113 for long double and
** sizeof(long) == 32.)
*/
#if ((((LUA_MAXINTEGER >> (NBM / 4)) >> (NBM / 4)) >> (NBM / 4)) \
        >> (NBM - (3 * (NBM / 4))))  >  0

/* limit for integers that fit in a float */
#define MAXINTFITSF     ((lua_Unsigned)1 << NBM)

/* check whether 'i' is in the interval [-MAXINTFITSF, MAXINTFITSF] */
#define l_intfitsf(i)   ((MAXINTFITSF + l_castS2U(i)) <= (2 * MAXINTFITSF))

#else  /* all integers fit in a float precisely */

#define l_intfitsf(i)   1

#endif


/*
** Try to convert a value from string to a number value.
** If the value is not a string or is a string not representing
** a valid numeral (or if coercions from strings to numbers
** are disabled via macro 'cvt2num'), do not modify 'result'
** and return 0.
*/
static int l_strton(const TValue *obj, TValue *result) {
    lua_assert(obj != result);
    if (!cvt2num(obj))  /* is object not a string? */
        return 0;
    else {
        TString *st = tsvalue(obj);
        return (luaO_str2num(getstr(st), result) == tsslen(st) + 1);
    }
}


/*
** Try to convert a value to a float. The float case is already handled
** by the macro 'tonumber'.
*/
int luaV_tonumber_(const TValue *obj, lua_Number *n) {
    TValue v;
    if (ttisinteger(obj)) {
        *n = cast_num(ivalue(obj));
        return 1;
    } else if (l_strton(obj, &v)) { /* string coercible to number? */
        *n = nvalue(&v);  /* convert result of 'luaO_str2num' to a float */
        return 1;
    } else
        return 0;  /* conversion failed */
}


/*
** try to convert a float to an integer, rounding according to 'mode'.
*/
int luaV_flttointeger(lua_Number n, lua_Integer *p, F2Imod mode) {
    lua_Number f = l_floor(n);
    if (n != f) {  /* not an integral value? */
        if (mode == F2Ieq) return 0;  /* fails if mode demands integral value */
        else if (mode == F2Iceil)  /* needs ceil? */
            f += 1;  /* convert floor to ceil (remember: n != f) */
    }
    return lua_numbertointeger(f, p);
}


/*
** try to convert a value to an integer, rounding according to 'mode',
** without string coercion.
** ("Fast track" handled by macro 'tointegerns'.)
*/
int luaV_tointegerns(const TValue *obj, lua_Integer *p, F2Imod mode) {
    if (ttisfloat(obj))
        return luaV_flttointeger(fltvalue(obj), p, mode);
    else if (ttisinteger(obj)) {
        *p = ivalue(obj);
        return 1;
    } else
        return 0;
}


/*
** try to convert a value to an integer.
*/
int luaV_tointeger(const TValue *obj, lua_Integer *p, F2Imod mode) {
    TValue v;
    if (l_strton(obj, &v))  /* does 'obj' point to a numerical string? */
        obj = &v;  /* change it to point to its corresponding number */
    return luaV_tointegerns(obj, p, mode);
}


/*
** Try to convert a 'for' limit to an integer, preserving the semantics
** of the loop. Return true if the loop must not run; otherwise, '*p'
** gets the integer limit.
** (The following explanation assumes a positive step; it is valid for
** negative steps mutatis mutandis.)
** If the limit is an integer or can be converted to an integer,
** rounding down, that is the limit.
** Otherwise, check whether the limit can be converted to a float. If
** the float is too large, clip it to LUA_MAXINTEGER.  If the float
** is too negative, the loop should not run, because any initial
** integer value is greater than such limit; so, the function returns
** true to signal that. (For this latter case, no integer limit would be
** correct; even a limit of LUA_MININTEGER would run the loop once for
** an initial value equal to LUA_MININTEGER.)
*/
static int forlimit(lua_State *L, lua_Integer init, const TValue *lim,
                    lua_Integer *p, lua_Integer step) {
    if (!luaV_tointeger(lim, p, (step < 0 ? F2Iceil : F2Ifloor))) {
        /* not coercible to in integer */
        lua_Number flim;  /* try to convert to float */
        if (!tonumber(lim, &flim)) /* cannot convert to float? */
            luaG_forerror(L, lim, "limit");
        /* else 'flim' is a float out of integer bounds */
        if (luai_numlt(0, flim)) {  /* if it is positive, it is too large */
            if (step < 0) return 1;  /* initial value must be less than it */
            *p = LUA_MAXINTEGER;  /* truncate */
        } else { /* it is less than min integer */
            if (step > 0) return 1;  /* initial value must be greater than it */
            *p = LUA_MININTEGER;  /* truncate */
        }
    }
    return (step > 0 ? init > *p : init < *p);  /* not to run? */
}


/*
** Prepare a numerical for loop (opcode OP_FORPREP).
** Return true to skip the loop. Otherwise,
** after preparation, stack will be as follows:
**   ra : internal index (safe copy of the control variable)
**   ra + 1 : loop counter (integer loops) or limit (float loops)
**   ra + 2 : step
**   ra + 3 : control variable
*/
static int forprep(lua_State *L, StkId ra) {
    TValue *pinit = s2v(ra);
    TValue *plimit = s2v(ra + 1);
    TValue *pstep = s2v(ra + 2);
    if (ttisinteger(pinit) && ttisinteger(pstep)) { /* integer loop? */
        lua_Integer init = ivalue(pinit);
        lua_Integer step = ivalue(pstep);
        lua_Integer limit;
        if (step == 0)
            luaG_runerror(L, "'for' step is zero");
        setivalue(s2v(ra + 3), init);  /* control variable */
        if (forlimit(L, init, plimit, &limit, step))
            return 1;  /* skip the loop */
        else {  /* prepare loop counter */
            lua_Unsigned count;
            if (step > 0) {  /* ascending loop? */
                count = l_castS2U(limit) - l_castS2U(init);
                if (step != 1)  /* avoid division in the too common case */
                    count /= l_castS2U(step);
            } else { /* step < 0; descending loop */
                count = l_castS2U(init) - l_castS2U(limit);
                /* 'step+1' avoids negating 'mininteger' */
                count /= l_castS2U(-(step + 1)) + 1u;
            }
            /* store the counter in place of the limit (which won't be
               needed anymore) */
            setivalue(plimit, l_castU2S(count));
        }
    } else { /* try making all values floats */
        lua_Number init;
        lua_Number limit;
        lua_Number step;
        if (l_unlikely(!tonumber(plimit, &limit)))
            luaG_forerror(L, plimit, "limit");
        if (l_unlikely(!tonumber(pstep, &step)))
            luaG_forerror(L, pstep, "step");
        if (l_unlikely(!tonumber(pinit, &init)))
            luaG_forerror(L, pinit, "initial value");
        if (step == 0)
            luaG_runerror(L, "'for' step is zero");
        if (luai_numlt(0, step) ? luai_numlt(limit, init)
                : luai_numlt(init, limit))
            return 1;  /* skip the loop */
        else {
            /* make sure internal values are all floats */
            setfltvalue(plimit, limit);
            setfltvalue(pstep, step);
            setfltvalue(s2v(ra), init);  /* internal index */
            setfltvalue(s2v(ra + 3), init);  /* control variable */
        }
    }
    return 0;
}


/*
** Execute a step of a float numerical for loop, returning
** true iff the loop must continue. (The integer case is
** written online with opcode OP_FORLOOP, for performance.)
*/
static int floatforloop(StkId ra) {
    lua_Number step = fltvalue(s2v(ra + 2));
    lua_Number limit = fltvalue(s2v(ra + 1));
    lua_Number idx = fltvalue(s2v(ra));  /* internal index */
    idx = luai_numadd(L, idx, step);  /* increment index */
    if (luai_numlt(0, step) ? luai_numle(idx, limit)
            : luai_numle(limit, idx)) {
        chgfltvalue(s2v(ra), idx);  /* update internal index */
        setfltvalue(s2v(ra + 3), idx);  /* and control variable */
        return 1;  /* jump back */
    } else
        return 0;  /* finish the loop */
}


/*
** Finish the table access 'val = t[key]'.
** if 'slot' is NULL, 't' is not a table; otherwise, 'slot' points to
** t[k] entry (which must be empty).
*/
void luaV_finishget(lua_State *L, const TValue *t, TValue *key, StkId val,
                    const TValue *slot) {
    int loop;  /* counter to avoid infinite loops */
    const TValue *tm;  /* metamethod */
    for (loop = 0; loop < MAXTAGLOOP; loop++) {
        if (slot == NULL) {  /* 't' is not a table? */
            lua_assert(!ttistable(t));
            tm = luaT_gettmbyobj(L, t, TM_INDEX);
            if (l_unlikely(notm(tm)))
                luaG_typeerror(L, t, "index");  /* no metamethod */
            /* else will try the metamethod */
        } else { /* 't' is a table */
            lua_assert(isempty(slot));
            tm = fasttm(L, hvalue(t)->metatable, TM_INDEX);  /* table's metamethod */
            if (tm == NULL) {  /* no metamethod? */
                setnilvalue(s2v(val));  /* result is nil */
                return;
            }
            /* else will try the metamethod */
        }
        if (ttisfunction(tm)) {  /* is metamethod a function? */
            luaT_callTMres(L, tm, t, key, val);  /* call it */
            return;
        }
        t = tm;  /* else try to access 'tm[key]' */
        if (luaV_fastget(L, t, key, slot, luaH_get)) {  /* fast track? */
            setobj2s(L, val, slot);  /* done */
            return;
        }
        /* else repeat (tail call 'luaV_finishget') */
    }
    luaG_runerror(L, "'__index' chain too long; possible loop");
}


/*
** Finish a table assignment 't[key] = val'.
** If 'slot' is NULL, 't' is not a table.  Otherwise, 'slot' points
** to the entry 't[key]', or to a value with an absent key if there
** is no such entry.  (The value at 'slot' must be empty, otherwise
** 'luaV_fastget' would have done the job.)
*/
void luaV_finishset(lua_State *L, const TValue *t, TValue *key,
                    TValue *val, const TValue *slot) {
    int loop;  /* counter to avoid infinite loops */
    for (loop = 0; loop < MAXTAGLOOP; loop++) {
        const TValue *tm;  /* '__newindex' metamethod */
        if (slot != NULL) {  /* is 't' a table? */
            Table *h = hvalue(t);  /* save 't' table */
            lua_assert(isempty(slot));  /* slot must be empty */
            tm = fasttm(L, h->metatable, TM_NEWINDEX);  /* get metamethod */
            if (tm == NULL) {  /* no metamethod? */
                luaH_finishset(L, h, key, slot, val);  /* set new value */
                invalidateTMcache(h);
                luaC_barrierback(L, obj2gco(h), val);
                return;
            }
            /* else will try the metamethod */
        } else { /* not a table; check metamethod */
            tm = luaT_gettmbyobj(L, t, TM_NEWINDEX);
            if (l_unlikely(notm(tm)))
                luaG_typeerror(L, t, "index");
        }
        /* try the metamethod */
        if (ttisfunction(tm)) {
            luaT_callTM(L, tm, t, key, val);
            return;
        }
        t = tm;  /* else repeat assignment over 'tm' */
        if (luaV_fastget(L, t, key, slot, luaH_get)) {
            luaV_finishfastset(L, t, slot, val);
            return;  /* done */
        }
        /* else 'return luaV_finishset(L, t, key, val, slot)' (loop) */
    }
    luaG_runerror(L, "'__newindex' chain too long; possible loop");
}


/*
** Compare two strings 'ts1' x 'ts2', returning an integer less-equal-
** -greater than zero if 'ts1' is less-equal-greater than 'ts2'.
** The code is a little tricky because it allows '\0' in the strings
** and it uses 'strcoll' (to respect locales) for each segment
** of the strings. Note that segments can compare equal but still
** have different lengths.
*/
static int l_strcmp(const TString *ts1, const TString *ts2) {
    const char *s1 = getstr(ts1);
    size_t rl1 = tsslen(ts1);  /* real length */
    const char *s2 = getstr(ts2);
    size_t rl2 = tsslen(ts2);
    for (;;) {  /* for each segment */
        int temp = strcoll(s1, s2);
        if (temp != 0)  /* not equal? */
            return temp;  /* done */
        else {  /* strings are equal up to a '\0' */
            size_t zl1 = strlen(s1);  /* index of first '\0' in 's1' */
            size_t zl2 = strlen(s2);  /* index of first '\0' in 's2' */
            if (zl2 == rl2)  /* 's2' is finished? */
                return (zl1 == rl1) ? 0 : 1;  /* check 's1' */
            else if (zl1 == rl1)  /* 's1' is finished? */
                return -1;  /* 's1' is less than 's2' ('s2' is not finished) */
            /* both strings longer than 'zl'; go on comparing after the '\0' */
            zl1++;
            zl2++;
            s1 += zl1;
            rl1 -= zl1;
            s2 += zl2;
            rl2 -= zl2;
        }
    }
}


/*
** Check whether integer 'i' is less than float 'f'. If 'i' has an
** exact representation as a float ('l_intfitsf'), compare numbers as
** floats. Otherwise, use the equivalence 'i < f <=> i < ceil(f)'.
** If 'ceil(f)' is out of integer range, either 'f' is greater than
** all integers or less than all integers.
** (The test with 'l_intfitsf' is only for performance; the else
** case is correct for all values, but it is slow due to the conversion
** from float to int.)
** When 'f' is NaN, comparisons must result in false.
*/
l_sinline int LTintfloat(lua_Integer i, lua_Number f) {
    if (l_intfitsf(i))
        return luai_numlt(cast_num(i), f);  /* compare them as floats */
    else {  /* i < f <=> i < ceil(f) */
        lua_Integer fi;
        if (luaV_flttointeger(f, &fi, F2Iceil))  /* fi = ceil(f) */
            return i < fi;   /* compare them as integers */
        else  /* 'f' is either greater or less than all integers */
            return f > 0;  /* greater? */
    }
}


/*
** Check whether integer 'i' is less than or equal to float 'f'.
** See comments on previous function.
*/
l_sinline int LEintfloat(lua_Integer i, lua_Number f) {
    if (l_intfitsf(i))
        return luai_numle(cast_num(i), f);  /* compare them as floats */
    else {  /* i <= f <=> i <= floor(f) */
        lua_Integer fi;
        if (luaV_flttointeger(f, &fi, F2Ifloor))  /* fi = floor(f) */
            return i <= fi;   /* compare them as integers */
        else  /* 'f' is either greater or less than all integers */
            return f > 0;  /* greater? */
    }
}


/*
** Check whether float 'f' is less than integer 'i'.
** See comments on previous function.
*/
l_sinline int LTfloatint(lua_Number f, lua_Integer i) {
    if (l_intfitsf(i))
        return luai_numlt(f, cast_num(i));  /* compare them as floats */
    else {  /* f < i <=> floor(f) < i */
        lua_Integer fi;
        if (luaV_flttointeger(f, &fi, F2Ifloor))  /* fi = floor(f) */
            return fi < i;   /* compare them as integers */
        else  /* 'f' is either greater or less than all integers */
            return f < 0;  /* less? */
    }
}


/*
** Check whether float 'f' is less than or equal to integer 'i'.
** See comments on previous function.
*/
l_sinline int LEfloatint(lua_Number f, lua_Integer i) {
    if (l_intfitsf(i))
        return luai_numle(f, cast_num(i));  /* compare them as floats */
    else {  /* f <= i <=> ceil(f) <= i */
        lua_Integer fi;
        if (luaV_flttointeger(f, &fi, F2Iceil))  /* fi = ceil(f) */
            return fi <= i;   /* compare them as integers */
        else  /* 'f' is either greater or less than all integers */
            return f < 0;  /* less? */
    }
}


/*
** Return 'l < r', for numbers.
*/
l_sinline int LTnum(const TValue *l, const TValue *r) {
    lua_assert(ttisnumber(l) && ttisnumber(r));
    if (ttisinteger(l)) {
        lua_Integer li = ivalue(l);
        if (ttisinteger(r))
            return li < ivalue(r);  /* both are integers */
        else  /* 'l' is int and 'r' is float */
            return LTintfloat(li, fltvalue(r));  /* l < r ? */
    } else {
        lua_Number lf = fltvalue(l);  /* 'l' must be float */
        if (ttisfloat(r))
            return luai_numlt(lf, fltvalue(r));  /* both are float */
        else  /* 'l' is float and 'r' is int */
            return LTfloatint(lf, ivalue(r));
    }
}


/*
** Return 'l <= r', for numbers.
*/
l_sinline int LEnum(const TValue *l, const TValue *r) {
    lua_assert(ttisnumber(l) && ttisnumber(r));
    if (ttisinteger(l)) {
        lua_Integer li = ivalue(l);
        if (ttisinteger(r))
            return li <= ivalue(r);  /* both are integers */
        else  /* 'l' is int and 'r' is float */
            return LEintfloat(li, fltvalue(r));  /* l <= r ? */
    } else {
        lua_Number lf = fltvalue(l);  /* 'l' must be float */
        if (ttisfloat(r))
            return luai_numle(lf, fltvalue(r));  /* both are float */
        else  /* 'l' is float and 'r' is int */
            return LEfloatint(lf, ivalue(r));
    }
}


/*
** return 'l < r' for non-numbers.
*/
static int lessthanothers(lua_State *L, const TValue *l, const TValue *r) {
    lua_assert(!ttisnumber(l) || !ttisnumber(r));
    if (ttisstring(l) && ttisstring(r))  /* both are strings? */
        return l_strcmp(tsvalue(l), tsvalue(r)) < 0;
    else
        return luaT_callorderTM(L, l, r, TM_LT);
}


/*
** Main operation less than; return 'l < r'.
*/
int luaV_lessthan(lua_State *L, const TValue *l, const TValue *r) {
    if (ttisnumber(l) && ttisnumber(r))  /* both operands are numbers? */
        return LTnum(l, r);
    else return lessthanothers(L, l, r);
}


/*
** return 'l <= r' for non-numbers.
*/
static int lessequalothers(lua_State *L, const TValue *l, const TValue *r) {
    lua_assert(!ttisnumber(l) || !ttisnumber(r));
    if (ttisstring(l) && ttisstring(r))  /* both are strings? */
        return l_strcmp(tsvalue(l), tsvalue(r)) <= 0;
    else
        return luaT_callorderTM(L, l, r, TM_LE);
}


/*
** Main operation less than or equal to; return 'l <= r'.
*/
int luaV_lessequal(lua_State *L, const TValue *l, const TValue *r) {
    if (ttisnumber(l) && ttisnumber(r))  /* both operands are numbers? */
        return LEnum(l, r);
    else return lessequalothers(L, l, r);
}


/*
** Main operation for equality of Lua values; return 't1 == t2'.
** L == NULL means raw equality (no metamethods)
*/
int luaV_equalobj(lua_State *L, const TValue *t1, const TValue *t2) {
    const TValue *tm;
    if (ttypetag(t1) != ttypetag(t2)) {  /* not the same variant? */
        if (ttype(t1) != ttype(t2) || ttype(t1) != LUA_TNUMBER)
            return 0;  /* only numbers can be equal with different variants */
        else {  /* two numbers with different variants */
            /* One of them is an integer. If the other does not have an
               integer value, they cannot be equal; otherwise, compare their
               integer values. */
            lua_Integer i1, i2;
            return (luaV_tointegerns(t1, &i1, F2Ieq) &&
                    luaV_tointegerns(t2, &i2, F2Ieq) &&
                    i1 == i2);
        }
    }
    /* values have same type and same variant */
    switch (ttypetag(t1)) {
        case LUA_VNIL:
        case LUA_VFALSE:
        case LUA_VTRUE:
            return 1;
        case LUA_VNUMINT:
            return (ivalue(t1) == ivalue(t2));
        case LUA_VNUMFLT:
            return luai_numeq(fltvalue(t1), fltvalue(t2));
        case LUA_VLIGHTUSERDATA:
            return pvalue(t1) == pvalue(t2);
        case LUA_VLCF:
            return fvalue(t1) == fvalue(t2);
        case LUA_VSHRSTR:
            return eqshrstr(tsvalue(t1), tsvalue(t2));
        case LUA_VLNGSTR:
            return luaS_eqlngstr(tsvalue(t1), tsvalue(t2));
        case LUA_VUSERDATA: {
            if (uvalue(t1) == uvalue(t2)) return 1;
            else if (L == NULL) return 0;
            tm = fasttm(L, uvalue(t1)->metatable, TM_EQ);
            if (tm == NULL)
                tm = fasttm(L, uvalue(t2)->metatable, TM_EQ);
            break;  /* will try TM */
        }
        case LUA_VTABLE: {
            if (hvalue(t1) == hvalue(t2)) return 1;
            else if (L == NULL) return 0;
            tm = fasttm(L, hvalue(t1)->metatable, TM_EQ);
            if (tm == NULL)
                tm = fasttm(L, hvalue(t2)->metatable, TM_EQ);
            break;  /* will try TM */
        }
        default:
            return gcvalue(t1) == gcvalue(t2);
    }
    if (tm == NULL)  /* no TM? */
        return 0;  /* objects are different */
    else {
        luaT_callTMres(L, tm, t1, t2, L->top.p);  /* call TM */
        return !l_isfalse(s2v(L->top.p));
    }
}


/* macro used by 'luaV_concat' to ensure that element at 'o' is a string */
#define tostring(L,o)  \
        (ttisstring(o) || (cvt2str(o) && (luaO_tostring(L, o), 1)))

#define isemptystr(o)   (ttisshrstring(o) && tsvalue(o)->shrlen == 0)

/* copy strings in stack from top - n up to top - 1 to buffer */
static void copy2buff(StkId top, int n, char *buff) {
    size_t tl = 0;  /* size already copied */
    do {
        TString *st = tsvalue(s2v(top - n));
        size_t l = tsslen(st);  /* length of string being copied */
        memcpy(buff + tl, getstr(st), l * sizeof(char));
        tl += l;
    } while (--n > 0);
}


/*
** Main operation for concatenation: concat 'total' values in the stack,
** from 'L->top.p - total' up to 'L->top.p - 1'.
*/
void luaV_concat(lua_State *L, int total) {
    if (total == 1)
        return;  /* "all" values already concatenated */
    do {
        StkId top = L->top.p;
        int n = 2;  /* number of elements handled in this pass (at least 2) */
        if (!(ttisstring(s2v(top - 2)) || cvt2str(s2v(top - 2))) ||
                !tostring(L, s2v(top - 1)))
            luaT_tryconcatTM(L);  /* may invalidate 'top' */
        else if (isemptystr(s2v(top - 1)))  /* second operand is empty? */
            cast_void(tostring(L, s2v(top - 2)));  /* result is first operand */
        else if (isemptystr(s2v(top - 2))) {  /* first operand is empty string? */
            setobjs2s(L, top - 2, top - 1);  /* result is second op. */
        } else {
            /* at least two non-empty string values; get as many as possible */
            size_t tl = tsslen(tsvalue(s2v(top - 1)));
            TString *ts;
            /* collect total length and number of strings */
            for (n = 1; n < total && tostring(L, s2v(top - n - 1)); n++) {
                size_t l = tsslen(tsvalue(s2v(top - n - 1)));
                if (l_unlikely(l >= MAX_SIZE - sizeof(TString) - tl)) {
                    L->top.p = top - total;  /* pop strings to avoid wasting stack */
                    luaG_runerror(L, "string length overflow");
                }
                tl += l;
            }
            if (tl <= LUAI_MAXSHORTLEN) {  /* is result a short string? */
                char buff[LUAI_MAXSHORTLEN];
                copy2buff(top, n, buff);  /* copy strings to buffer */
                ts = luaS_newlstr(L, buff, tl);
            } else { /* long string; copy strings directly to final result */
                ts = luaS_createlngstrobj(L, tl);
                copy2buff(top, n, getlngstr(ts));
            }
            setsvalue2s(L, top - n, ts);  /* create result */
        }
        total -= n - 1;  /* got 'n' strings to create one new */
        L->top.p -= n - 1;  /* popped 'n' strings and pushed one */
    } while (total > 1);  /* repeat until only 1 result left */
}


/*
** Main operation 'ra = #rb'.
*/
void luaV_objlen(lua_State *L, StkId ra, const TValue *rb) {
    const TValue *tm;
    switch (ttypetag(rb)) {
        case LUA_VTABLE: {
            Table *h = hvalue(rb);
            tm = fasttm(L, h->metatable, TM_LEN);
            if (tm) break;  /* metamethod? break switch to call it */
            setivalue(s2v(ra), luaH_getn(h));  /* else primitive len */
            return;
        }
        case LUA_VSHRSTR: {
            setivalue(s2v(ra), tsvalue(rb)->shrlen);
            return;
        }
        case LUA_VLNGSTR: {
            setivalue(s2v(ra), tsvalue(rb)->u.lnglen);
            return;
        }
        default: {  /* try metamethod */
            tm = luaT_gettmbyobj(L, rb, TM_LEN);
            if (l_unlikely(notm(tm)))  /* no metamethod? */
                luaG_typeerror(L, rb, "get length of");
            break;
        }
    }
    luaT_callTMres(L, tm, rb, rb, ra);
}


/*
** Integer division; return 'm // n', that is, floor(m/n).
** C division truncates its result (rounds towards zero).
** 'floor(q) == trunc(q)' when 'q >= 0' or when 'q' is integer,
** otherwise 'floor(q) == trunc(q) - 1'.
*/
lua_Integer luaV_idiv(lua_State *L, lua_Integer m, lua_Integer n) {
    if (l_unlikely(l_castS2U(n) + 1u <= 1u)) {  /* special cases: -1 or 0 */
        if (n == 0)
            luaG_runerror(L, "attempt to divide by zero");
        return intop(-, 0, m);   /* n==-1; avoid overflow with 0x80000...//-1 */
    } else {
        lua_Integer q = m / n;  /* perform C division */
        if ((m ^ n) < 0 && m % n != 0)  /* 'm/n' would be negative non-integer? */
            q -= 1;  /* correct result for different rounding */
        return q;
    }
}


/*
** Integer modulus; return 'm % n'. (Assume that C '%' with
** negative operands follows C99 behavior. See previous comment
** about luaV_idiv.)
*/
lua_Integer luaV_mod(lua_State *L, lua_Integer m, lua_Integer n) {
    if (l_unlikely(l_castS2U(n) + 1u <= 1u)) {  /* special cases: -1 or 0 */
        if (n == 0)
            luaG_runerror(L, "attempt to perform 'n%%0'");
        return 0;   /* m % -1 == 0; avoid overflow with 0x80000...%-1 */
    } else {
        lua_Integer r = m % n;
        if (r != 0 && (r ^ n) < 0)  /* 'm/n' would be non-integer negative? */
            r += n;  /* correct result for different rounding */
        return r;
    }
}


/*
** Float modulus
*/
lua_Number luaV_modf(lua_State *L, lua_Number m, lua_Number n) {
    lua_Number r;
    luai_nummod(L, m, n, r);
    return r;
}


/* number of bits in an integer */
#define NBITS   cast_int(sizeof(lua_Integer) * CHAR_BIT)


/*
** Shift left operation. (Shift right just negates 'y'.)
*/
lua_Integer luaV_shiftl(lua_Integer x, lua_Integer y) {
    if (y < 0) {  /* shift right? */
        if (y <= -NBITS) return 0;
        else return intop( >>, x, -y);
    } else { /* shift left */
        if (y >= NBITS) return 0;
        else return intop( <<, x, y);
    }
}


/*
** create a new Lua closure, push it in the stack, and initialize
** its upvalues.
*/
static void pushclosure(lua_State *L, Proto *p, UpVal **encup, StkId base,
                        StkId ra) {
    int nup = p->sizeupvalues;
    Upvaldesc *uv = p->upvalues;
    int i;
    LClosure *ncl = luaF_newLclosure(L, nup);
    ncl->p = p;
    setclLvalue2s(L, ra, ncl);  /* anchor new closure in stack */
    for (i = 0; i < nup; i++) {  /* fill in its upvalues */
        if (uv[i].instack)  /* upvalue refers to local variable? */
            ncl->upvals[i] = luaF_findupval(L, base + uv[i].idx);
        else  /* get upvalue from enclosing function */
            ncl->upvals[i] = encup[uv[i].idx];
        luaC_objbarrier(L, ncl, ncl->upvals[i]);
    }
}


/*
** finish execution of an opcode interrupted by a yield
*/
void luaV_finishOp(lua_State *L) {
    CallInfo *ci = L->ci;
    StkId base = ci->func.p + 1;
    Instruction inst = *(ci->u.l.savedpc - 1);  /* interrupted instruction */
    OpCode op = GET_OPCODE(inst);
    switch (op) {  /* finish its execution */
        case OP_MMBIN:
        case OP_MMBINI:
        case OP_MMBINK: {
            setobjs2s(L, base + GETARG_A(*(ci->u.l.savedpc - 2)), --L->top.p);
            break;
        }
        case OP_UNM:
        case OP_BNOT:
        case OP_LEN:
        case OP_GETTABUP:
        case OP_GETTABLE:
        case OP_GETI:
        case OP_GETFIELD:
        case OP_SELF: {
            setobjs2s(L, base + GETARG_A(inst), --L->top.p);
            break;
        }
        case OP_LT:
        case OP_LE:
        case OP_LTI:
        case OP_LEI:
        case OP_GTI:
        case OP_GEI:
        case OP_EQ: {  /* note that 'OP_EQI'/'OP_EQK' cannot yield */
            int res = !l_isfalse(s2v(L->top.p - 1));
            L->top.p--;
#if defined(LUA_COMPAT_LT_LE)
            if (ci->callstatus & CIST_LEQ) {  /* "<=" using "<" instead? */
                ci->callstatus ^= CIST_LEQ;  /* clear mark */
                res = !res;  /* negate result */
            }
#endif
            lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_JMP);
            if (res != GETARG_k(inst))  /* condition failed? */
                ci->u.l.savedpc++;  /* skip jump instruction */
            break;
        }
        case OP_CONCAT: {
            StkId top = L->top.p - 1;  /* top when 'luaT_tryconcatTM' was called */
            int a = GETARG_A(inst);      /* first element to concatenate */
            int total = cast_int(top - 1 - (base + a));  /* yet to concatenate */
            setobjs2s(L, top - 2, top);  /* put TM result in proper position */
            L->top.p = top - 1;  /* top is one after last element (at top-2) */
            luaV_concat(L, total);  /* concat them (may yield again) */
            break;
        }
        case OP_CLOSE: {  /* yielded closing variables */
            ci->u.l.savedpc--;  /* repeat instruction to close other vars. */
            break;
        }
        case OP_RETURN: {  /* yielded closing variables */
            StkId ra = base + GETARG_A(inst);
            /* adjust top to signal correct number of returns, in case the
               return is "up to top" ('isIT') */
            L->top.p = ra + ci->u2.nres;
            /* repeat instruction to close other vars. and complete the return */
            ci->u.l.savedpc--;
            break;
        }
        default: {
            /* only these other opcodes can yield */
            lua_assert(op == OP_TFORCALL || op == OP_CALL ||
                       op == OP_TAILCALL || op == OP_SETTABUP || op == OP_SETTABLE ||
                       op == OP_SETI || op == OP_SETFIELD);
            break;
        }
    }
}




/*
** {==================================================================
** Macros for arithmetic/bitwise/comparison opcodes in 'luaV_execute'
** ===================================================================
*/

#define l_addi(L,a,b)   intop(+, a, b)
#define l_subi(L,a,b)   intop(-, a, b)
#define l_muli(L,a,b)   intop(*, a, b)
#define l_band(a,b)     intop(&, a, b)
#define l_bor(a,b)      intop(|, a, b)
#define l_bxor(a,b)     intop(^, a, b)

#define l_lti(a,b)      (a < b)
#define l_lei(a,b)      (a <= b)
#define l_gti(a,b)      (a > b)
#define l_gei(a,b)      (a >= b)


/*
** Arithmetic operations with immediate operands. 'iop' is the integer
** operation, 'fop' is the float operation.
*/
#define op_arithI(L,iop,fop) {  \
  StkId ra = RA(i); \
  TValue *v1 = vRB(i);  \
  int imm = GETARG_sC(i);  \
  if (ttisinteger(v1)) {  \
    lua_Integer iv1 = ivalue(v1);  \
    pc++; setivalue(s2v(ra), iop(L, iv1, imm));  \
  }  \
  else if (ttisfloat(v1)) {  \
    lua_Number nb = fltvalue(v1);  \
    lua_Number fimm = cast_num(imm);  \
    pc++; setfltvalue(s2v(ra), fop(L, nb, fimm)); \
  }}


/*
** Auxiliary function for arithmetic operations over floats and others
** with two register operands.
*/
#define op_arithf_aux(L,v1,v2,fop) {  \
  lua_Number n1; lua_Number n2;  \
  if (tonumberns(v1, n1) && tonumberns(v2, n2)) {  \
    pc++; setfltvalue(s2v(ra), fop(L, n1, n2));  \
  }}


/*
** Arithmetic operations over floats and others with register operands.
*/
#define op_arithf(L,fop) {  \
  StkId ra = RA(i); \
  TValue *v1 = vRB(i);  \
  TValue *v2 = vRC(i);  \
  op_arithf_aux(L, v1, v2, fop); }


/*
** Arithmetic operations with K operands for floats.
*/
#define op_arithfK(L,fop) {  \
  StkId ra = RA(i); \
  TValue *v1 = vRB(i);  \
  TValue *v2 = KC(i); lua_assert(ttisnumber(v2));  \
  op_arithf_aux(L, v1, v2, fop); }


/*
** Arithmetic operations over integers and floats.
*/
#define op_arith_aux(L,v1,v2,iop,fop) {  \
  StkId ra = RA(i); \
  if (ttisinteger(v1) && ttisinteger(v2)) {  \
    lua_Integer i1 = ivalue(v1); lua_Integer i2 = ivalue(v2);  \
    pc++; setivalue(s2v(ra), iop(L, i1, i2));  \
  }  \
  else op_arithf_aux(L, v1, v2, fop); }


/*
** Arithmetic operations with register operands.
*/
#define op_arith(L,iop,fop) {  \
  TValue *v1 = vRB(i);  \
  TValue *v2 = vRC(i);  \
  op_arith_aux(L, v1, v2, iop, fop); }


/*
** Arithmetic operations with K operands.
*/
#define op_arithK(L,iop,fop) {  \
  TValue *v1 = vRB(i);  \
  TValue *v2 = KC(i); lua_assert(ttisnumber(v2));  \
  op_arith_aux(L, v1, v2, iop, fop); }


/*
** Bitwise operations with constant operand.
*/
#define op_bitwiseK(L,op) {  \
  StkId ra = RA(i); \
  TValue *v1 = vRB(i);  \
  TValue *v2 = KC(i);  \
  lua_Integer i1;  \
  lua_Integer i2 = ivalue(v2);  \
  if (tointegerns(v1, &i1)) {  \
    pc++; setivalue(s2v(ra), op(i1, i2));  \
  }}


/*
** Bitwise operations with register operands.
*/
#define op_bitwise(L,op) {  \
  StkId ra = RA(i); \
  TValue *v1 = vRB(i);  \
  TValue *v2 = vRC(i);  \
  lua_Integer i1; lua_Integer i2;  \
  if (tointegerns(v1, &i1) && tointegerns(v2, &i2)) {  \
    pc++; setivalue(s2v(ra), op(i1, i2));  \
  }}


/*
** Order operations with register operands. 'opn' actually works
** for all numbers, but the fast track improves performance for
** integers.
*/
#define op_order(L,opi,opn,other) {  \
  StkId ra = RA(i); \
  int cond;  \
  TValue *rb = vRB(i);  \
  if (ttisinteger(s2v(ra)) && ttisinteger(rb)) {  \
    lua_Integer ia = ivalue(s2v(ra));  \
    lua_Integer ib = ivalue(rb);  \
    cond = opi(ia, ib);  \
  }  \
  else if (ttisnumber(s2v(ra)) && ttisnumber(rb))  \
    cond = opn(s2v(ra), rb);  \
  else  \
    Protect(cond = other(L, s2v(ra), rb));  \
  docondjump(); }


/*
** Order operations with immediate operand. (Immediate operand is
** always small enough to have an exact representation as a float.)
*/
#define op_orderI(L,opi,opf,inv,tm) {  \
  StkId ra = RA(i); \
  int cond;  \
  int im = GETARG_sB(i);  \
  if (ttisinteger(s2v(ra)))  \
    cond = opi(ivalue(s2v(ra)), im);  \
  else if (ttisfloat(s2v(ra))) {  \
    lua_Number fa = fltvalue(s2v(ra));  \
    lua_Number fim = cast_num(im);  \
    cond = opf(fa, fim);  \
  }  \
  else {  \
    int isf = GETARG_C(i);  \
    Protect(cond = luaT_callorderiTM(L, s2v(ra), im, inv, isf, tm));  \
  }  \
  docondjump(); }

/* }================================================================== */


/*
** {==================================================================
** Function 'luaV_execute': main interpreter loop
** ===================================================================
*/

/*
** some macros for common tasks in 'luaV_execute'
*/


#define RA(i)   (base+GETARG_A(i))
#define RB(i)   (base+GETARG_B(i))
#define vRB(i)  s2v(RB(i))
#define KB(i)   (k+GETARG_B(i))
#define RC(i)   (base+GETARG_C(i))
#define vRC(i)  s2v(RC(i))
#define KC(i)   (k+GETARG_C(i))
#define RKC(i)  ((TESTARG_k(i)) ? k + GETARG_C(i) : s2v(base + GETARG_C(i)))



#define updatetrap(ci)  (trap = ci->u.l.trap)

#define updatebase(ci)  (base = ci->func.p + 1)


#define updatestack(ci)  \
        { if (l_unlikely(trap)) { updatebase(ci); ra = RA(i); } }


/*
** Execute a jump instruction. The 'updatetrap' allows signals to stop
** tight loops. (Without it, the local copy of 'trap' could never change.)
*/
#define dojump(ci,i,e)  { pc += GETARG_sJ(i) + e; updatetrap(ci); }


/* for test instructions, execute the jump instruction that follows it */
#define donextjump(ci)  { Instruction ni = *pc; dojump(ci, ni, 1); }

/*
** do a conditional jump: skip next instruction if 'cond' is not what
** was expected (parameter 'k'), else do next instruction, which must
** be a jump.
*/
#define docondjump()    if (cond != GETARG_k(i)) pc++; else donextjump(ci);


/*
** Correct global 'pc'.
*/
#define savepc(L)       (ci->u.l.savedpc = pc)


/*
** Whenever code can raise errors, the global 'pc' and the global
** 'top' must be correct to report occasional errors.
*/
#define savestate(L,ci)         (savepc(L), L->top.p = ci->top.p)


/*
** Protect code that, in general, can raise errors, reallocate the
** stack, and change the hooks.
*/
#define Protect(exp)  (savestate(L,ci), (exp), updatetrap(ci))

/* special version that does not change the top */
#define ProtectNT(exp)  (savepc(L), (exp), updatetrap(ci))

/*
** Protect code that can only raise errors. (That is, it cannot change
** the stack or hooks.)
*/
#define halfProtect(exp)  (savestate(L,ci), (exp))

/* 'c' is the limit of live values in the stack */
#define checkGC(L,c)  \
        { luaC_condGC(L, (savepc(L), L->top.p = (c)), \
                         updatetrap(ci)); \
           luai_threadyield(L); }


/* fetch an instruction and prepare its execution */
#define vmfetch()       { \
  if (l_unlikely(trap)) {  /* stack reallocation or hooks? */ \
    trap = luaG_traceexec(L, pc);  /* handle hooks */ \
    updatebase(ci);  /* correct stack */ \
  } \
  i = *(pc++); \
}

#define vmdispatch(o)   switch(o)
#define vmcase(l)       case l:
#define vmbreak         break


void luaV_execute(lua_State *L, CallInfo *ci) {
    LClosure *cl;
    TValue *k;
    StkId base;
    const Instruction *pc;
    int trap;
#if LUA_USE_JUMPTABLE
#include "ljumptab.h"
#endif
startfunc:
    trap = L->hookmask;
returning:  /* trap already set */
    cl = ci_func(ci);
    k = cl->p->k;
    pc = ci->u.l.savedpc;
    if (l_unlikely(trap))
        trap = luaG_tracecall(L);
    base = ci->func.p + 1;
    /* main loop of interpreter */
    for (;;) {
        Instruction i;  /* instruction being executed */
        vmfetch();
#if 0
        /* low-level line tracing for debugging Lua */
        printf("line: %d\n", luaG_getfuncline(cl->p, pcRel(pc, cl->p)));
#endif
        lua_assert(base == ci->func.p + 1);
        lua_assert(base <= L->top.p && L->top.p <= L->stack_last.p);
        /* invalidate top for instructions not expecting it */
        lua_assert(isIT(i) || (cast_void(L->top.p = base), 1));
        vmdispatch(GET_OPCODE(i)) {
            vmcase(OP_MOVE) {
                StkId ra = RA(i);
                setobjs2s(L, ra, RB(i));
                vmbreak;
            }
            vmcase(OP_LOADI) {
                StkId ra = RA(i);
                lua_Integer b = GETARG_sBx(i);
                setivalue(s2v(ra), b);
                vmbreak;
            }
            vmcase(OP_LOADF) {
                StkId ra = RA(i);
                int b = GETARG_sBx(i);
                setfltvalue(s2v(ra), cast_num(b));
                vmbreak;
            }
            vmcase(OP_LOADK) {
                StkId ra = RA(i);
                TValue *rb = k + GETARG_Bx(i);
                setobj2s(L, ra, rb);
                vmbreak;
            }
            vmcase(OP_LOADKX) {
                StkId ra = RA(i);
                TValue *rb;
                rb = k + GETARG_Ax(*pc);
                pc++;
                setobj2s(L, ra, rb);
                vmbreak;
            }
            vmcase(OP_LOADFALSE) {
                StkId ra = RA(i);
                setbfvalue(s2v(ra));
                vmbreak;
            }
            vmcase(OP_LFALSESKIP) {
                StkId ra = RA(i);
                setbfvalue(s2v(ra));
                pc++;  /* skip next instruction */
                vmbreak;
            }
            vmcase(OP_LOADTRUE) {
                StkId ra = RA(i);
                setbtvalue(s2v(ra));
                vmbreak;
            }
            vmcase(OP_LOADNIL) {
                StkId ra = RA(i);
                int b = GETARG_B(i);
                do {
                    setnilvalue(s2v(ra++));
                } while (b--);
                vmbreak;
            }
            vmcase(OP_GETUPVAL) {
                StkId ra = RA(i);
                int b = GETARG_B(i);
                setobj2s(L, ra, cl->upvals[b]->v.p);
                vmbreak;
            }
            vmcase(OP_SETUPVAL) {
                StkId ra = RA(i);
                UpVal *uv = cl->upvals[GETARG_B(i)];
                setobj(L, uv->v.p, s2v(ra));
                luaC_barrier(L, uv, s2v(ra));
                vmbreak;
            }
            vmcase(OP_GETTABUP) {
                StkId ra = RA(i);
                const TValue *slot;
                TValue *upval = cl->upvals[GETARG_B(i)]->v.p;
                TValue *rc = KC(i);
                TString *key = tsvalue(rc);  /* key must be a short string */
                if (luaV_fastget(L, upval, key, slot, luaH_getshortstr)) {
                    setobj2s(L, ra, slot);
                } else
                    Protect(luaV_finishget(L, upval, rc, ra, slot));
                vmbreak;
            }
            vmcase(OP_GETTABLE) {
                StkId ra = RA(i);
                const TValue *slot;
                TValue *rb = vRB(i);
                TValue *rc = vRC(i);
                lua_Unsigned n;
                if (ttisinteger(rc)  /* fast track for integers? */
                        ? (cast_void(n = ivalue(rc)), luaV_fastgeti(L, rb, n, slot))
                        : luaV_fastget(L, rb, rc, slot, luaH_get)) {
                    setobj2s(L, ra, slot);
                } else
                    Protect(luaV_finishget(L, rb, rc, ra, slot));
                vmbreak;
            }
            vmcase(OP_GETI) {
                StkId ra = RA(i);
                const TValue *slot;
                TValue *rb = vRB(i);
                int c = GETARG_C(i);
                if (luaV_fastgeti(L, rb, c, slot)) {
                    setobj2s(L, ra, slot);
                } else {
                    TValue key;
                    setivalue(&key, c);
                    Protect(luaV_finishget(L, rb, &key, ra, slot));
                }
                vmbreak;
            }
            vmcase(OP_GETFIELD) {
                StkId ra = RA(i);
                const TValue *slot;
                TValue *rb = vRB(i);
                TValue *rc = KC(i);
                TString *key = tsvalue(rc);  /* key must be a short string */
                if (luaV_fastget(L, rb, key, slot, luaH_getshortstr)) {
                    setobj2s(L, ra, slot);
                } else
                    Protect(luaV_finishget(L, rb, rc, ra, slot));
                vmbreak;
            }
            vmcase(OP_SETTABUP) {
                const TValue *slot;
                TValue *upval = cl->upvals[GETARG_A(i)]->v.p;
                TValue *rb = KB(i);
                TValue *rc = RKC(i);
                TString *key = tsvalue(rb);  /* key must be a short string */
                if (luaV_fastget(L, upval, key, slot, luaH_getshortstr)) {
                    luaV_finishfastset(L, upval, slot, rc);
                } else
                    Protect(luaV_finishset(L, upval, rb, rc, slot));
                vmbreak;
            }
            vmcase(OP_SETTABLE) {
                StkId ra = RA(i);
                const TValue *slot;
                TValue *rb = vRB(i);  /* key (table is in 'ra') */
                TValue *rc = RKC(i);  /* value */
                lua_Unsigned n;
                if (ttisinteger(rb)  /* fast track for integers? */
                        ? (cast_void(n = ivalue(rb)), luaV_fastgeti(L, s2v(ra), n, slot))
                        : luaV_fastget(L, s2v(ra), rb, slot, luaH_get)) {
                    luaV_finishfastset(L, s2v(ra), slot, rc);
                } else
                    Protect(luaV_finishset(L, s2v(ra), rb, rc, slot));
                vmbreak;
            }
            vmcase(OP_SETI) {
                StkId ra = RA(i);
                const TValue *slot;
                int c = GETARG_B(i);
                TValue *rc = RKC(i);
                if (luaV_fastgeti(L, s2v(ra), c, slot)) {
                    luaV_finishfastset(L, s2v(ra), slot, rc);
                } else {
                    TValue key;
                    setivalue(&key, c);
                    Protect(luaV_finishset(L, s2v(ra), &key, rc, slot));
                }
                vmbreak;
            }
            vmcase(OP_SETFIELD) {
                StkId ra = RA(i);
                const TValue *slot;
                TValue *rb = KB(i);
                TValue *rc = RKC(i);
                TString *key = tsvalue(rb);  /* key must be a short string */
                if (luaV_fastget(L, s2v(ra), key, slot, luaH_getshortstr)) {
                    luaV_finishfastset(L, s2v(ra), slot, rc);
                } else
                    Protect(luaV_finishset(L, s2v(ra), rb, rc, slot));
                vmbreak;
            }
            vmcase(OP_NEWTABLE) {
                StkId ra = RA(i);
                int b = GETARG_B(i);  /* log2(hash size) + 1 */
                int c = GETARG_C(i);  /* array size */
                Table *t;
                if (b > 0)
                    b = 1 << (b - 1);  /* size is 2^(b - 1) */
                lua_assert((!TESTARG_k(i)) == (GETARG_Ax(*pc) == 0));
                if (TESTARG_k(i))  /* non-zero extra argument? */
                    c += GETARG_Ax(*pc) * (MAXARG_C + 1);  /* add it to size */
                pc++;  /* skip extra argument */
                L->top.p = ra + 1;  /* correct top in case of emergency GC */
                t = luaH_new(L);  /* memory allocation */
                sethvalue2s(L, ra, t);
                if (b != 0 || c != 0)
                    luaH_resize(L, t, c, b);  /* idem */
                checkGC(L, ra + 1);
                vmbreak;
            }
            vmcase(OP_SELF) {
                StkId ra = RA(i);
                const TValue *slot;
                TValue *rb = vRB(i);
                TValue *rc = RKC(i);
                TString *key = tsvalue(rc);  /* key must be a string */
                setobj2s(L, ra + 1, rb);
                if (luaV_fastget(L, rb, key, slot, luaH_getstr)) {
                    setobj2s(L, ra, slot);
                } else
                    Protect(luaV_finishget(L, rb, rc, ra, slot));
                vmbreak;
            }
            vmcase(OP_ADDI) {
                op_arithI(L, l_addi, luai_numadd);
                vmbreak;
            }
            vmcase(OP_ADDK) {
                op_arithK(L, l_addi, luai_numadd);
                vmbreak;
            }
            vmcase(OP_SUBK) {
                op_arithK(L, l_subi, luai_numsub);
                vmbreak;
            }
            vmcase(OP_MULK) {
                op_arithK(L, l_muli, luai_nummul);
                vmbreak;
            }
            vmcase(OP_MODK) {
                savestate(L, ci);  /* in case of division by 0 */
                op_arithK(L, luaV_mod, luaV_modf);
                vmbreak;
            }
            vmcase(OP_POWK) {
                op_arithfK(L, luai_numpow);
                vmbreak;
            }
            vmcase(OP_DIVK) {
                op_arithfK(L, luai_numdiv);
                vmbreak;
            }
            vmcase(OP_IDIVK) {
                savestate(L, ci);  /* in case of division by 0 */
                op_arithK(L, luaV_idiv, luai_numidiv);
                vmbreak;
            }
            vmcase(OP_BANDK) {
                op_bitwiseK(L, l_band);
                vmbreak;
            }
            vmcase(OP_BORK) {
                op_bitwiseK(L, l_bor);
                vmbreak;
            }
            vmcase(OP_BXORK) {
                op_bitwiseK(L, l_bxor);
                vmbreak;
            }
            vmcase(OP_SHRI) {
                StkId ra = RA(i);
                TValue *rb = vRB(i);
                int ic = GETARG_sC(i);
                lua_Integer ib;
                if (tointegerns(rb, &ib)) {
                    pc++;
                    setivalue(s2v(ra), luaV_shiftl(ib, -ic));
                }
                vmbreak;
            }
            vmcase(OP_SHLI) {
                StkId ra = RA(i);
                TValue *rb = vRB(i);
                int ic = GETARG_sC(i);
                lua_Integer ib;
                if (tointegerns(rb, &ib)) {
                    pc++;
                    setivalue(s2v(ra), luaV_shiftl(ic, ib));
                }
                vmbreak;
            }
            vmcase(OP_ADD) {
                op_arith(L, l_addi, luai_numadd);
                vmbreak;
            }
            vmcase(OP_SUB) {
                op_arith(L, l_subi, luai_numsub);
                vmbreak;
            }
            vmcase(OP_MUL) {
                op_arith(L, l_muli, luai_nummul);
                vmbreak;
            }
            vmcase(OP_MOD) {
                savestate(L, ci);  /* in case of division by 0 */
                op_arith(L, luaV_mod, luaV_modf);
                vmbreak;
            }
            vmcase(OP_POW) {
                op_arithf(L, luai_numpow);
                vmbreak;
            }
            vmcase(OP_DIV) {  /* float division (always with floats) */
                op_arithf(L, luai_numdiv);
                vmbreak;
            }
            vmcase(OP_IDIV) {  /* floor division */
                savestate(L, ci);  /* in case of division by 0 */
                op_arith(L, luaV_idiv, luai_numidiv);
                vmbreak;
            }
            vmcase(OP_BAND) {
                op_bitwise(L, l_band);
                vmbreak;
            }
            vmcase(OP_BOR) {
                op_bitwise(L, l_bor);
                vmbreak;
            }
            vmcase(OP_BXOR) {
                op_bitwise(L, l_bxor);
                vmbreak;
            }
            vmcase(OP_SHR) {
                op_bitwise(L, luaV_shiftr);
                vmbreak;
            }
            vmcase(OP_SHL) {
                op_bitwise(L, luaV_shiftl);
                vmbreak;
            }
            vmcase(OP_MMBIN) {
                StkId ra = RA(i);
                Instruction pi = *(pc - 2);  /* original arith. expression */
                TValue *rb = vRB(i);
                TMS tm = (TMS)GETARG_C(i);
                StkId result = RA(pi);
                lua_assert(OP_ADD <= GET_OPCODE(pi) && GET_OPCODE(pi) <= OP_SHR);
                Protect(luaT_trybinTM(L, s2v(ra), rb, result, tm));
                vmbreak;
            }
            vmcase(OP_MMBINI) {
                StkId ra = RA(i);
                Instruction pi = *(pc - 2);  /* original arith. expression */
                int imm = GETARG_sB(i);
                TMS tm = (TMS)GETARG_C(i);
                int flip = GETARG_k(i);
                StkId result = RA(pi);
                Protect(luaT_trybiniTM(L, s2v(ra), imm, flip, result, tm));
                vmbreak;
            }
            vmcase(OP_MMBINK) {
                StkId ra = RA(i);
                Instruction pi = *(pc - 2);  /* original arith. expression */
                TValue *imm = KB(i);
                TMS tm = (TMS)GETARG_C(i);
                int flip = GETARG_k(i);
                StkId result = RA(pi);
                Protect(luaT_trybinassocTM(L, s2v(ra), imm, flip, result, tm));
                vmbreak;
            }
            vmcase(OP_UNM) {
                StkId ra = RA(i);
                TValue *rb = vRB(i);
                lua_Number nb;
                if (ttisinteger(rb)) {
                    lua_Integer ib = ivalue(rb);
                    setivalue(s2v(ra), intop(-, 0, ib));
                } else if (tonumberns(rb, nb)) {
                    setfltvalue(s2v(ra), luai_numunm(L, nb));
                } else
                    Protect(luaT_trybinTM(L, rb, rb, ra, TM_UNM));
                vmbreak;
            }
            vmcase(OP_BNOT) {
                StkId ra = RA(i);
                TValue *rb = vRB(i);
                lua_Integer ib;
                if (tointegerns(rb, &ib)) {
                    setivalue(s2v(ra), intop(^, ~l_castS2U(0), ib));
                } else
                    Protect(luaT_trybinTM(L, rb, rb, ra, TM_BNOT));
                vmbreak;
            }
            vmcase(OP_NOT) {
                StkId ra = RA(i);
                TValue *rb = vRB(i);
                if (l_isfalse(rb))
                    setbtvalue(s2v(ra));
                else
                    setbfvalue(s2v(ra));
                vmbreak;
            }
            vmcase(OP_LEN) {
                StkId ra = RA(i);
                Protect(luaV_objlen(L, ra, vRB(i)));
                vmbreak;
            }
            vmcase(OP_CONCAT) {
                StkId ra = RA(i);
                int n = GETARG_B(i);  /* number of elements to concatenate */
                L->top.p = ra + n;  /* mark the end of concat operands */
                ProtectNT(luaV_concat(L, n));
                checkGC(L, L->top.p); /* 'luaV_concat' ensures correct top */
                vmbreak;
            }
            vmcase(OP_CLOSE) {
                StkId ra = RA(i);
                Protect(luaF_close(L, ra, LUA_OK, 1));
                vmbreak;
            }
            vmcase(OP_TBC) {
                StkId ra = RA(i);
                /* create new to-be-closed upvalue */
                halfProtect(luaF_newtbcupval(L, ra));
                vmbreak;
            }
            vmcase(OP_JMP) {
                dojump(ci, i, 0);
                vmbreak;
            }
            vmcase(OP_EQ) {
                StkId ra = RA(i);
                int cond;
                TValue *rb = vRB(i);
                Protect(cond = luaV_equalobj(L, s2v(ra), rb));
                docondjump();
                vmbreak;
            }
            vmcase(OP_LT) {
                op_order(L, l_lti, LTnum, lessthanothers);
                vmbreak;
            }
            vmcase(OP_LE) {
                op_order(L, l_lei, LEnum, lessequalothers);
                vmbreak;
            }
            vmcase(OP_EQK) {
                StkId ra = RA(i);
                TValue *rb = KB(i);
                /* basic types do not use '__eq'; we can use raw equality */
                int cond = luaV_rawequalobj(s2v(ra), rb);
                docondjump();
                vmbreak;
            }
            vmcase(OP_EQI) {
                StkId ra = RA(i);
                int cond;
                int im = GETARG_sB(i);
                if (ttisinteger(s2v(ra)))
                    cond = (ivalue(s2v(ra)) == im);
                else if (ttisfloat(s2v(ra)))
                    cond = luai_numeq(fltvalue(s2v(ra)), cast_num(im));
                else
                    cond = 0;  /* other types cannot be equal to a number */
                docondjump();
                vmbreak;
            }
            vmcase(OP_LTI) {
                op_orderI(L, l_lti, luai_numlt, 0, TM_LT);
                vmbreak;
            }
            vmcase(OP_LEI) {
                op_orderI(L, l_lei, luai_numle, 0, TM_LE);
                vmbreak;
            }
            vmcase(OP_GTI) {
                op_orderI(L, l_gti, luai_numgt, 1, TM_LT);
                vmbreak;
            }
            vmcase(OP_GEI) {
                op_orderI(L, l_gei, luai_numge, 1, TM_LE);
                vmbreak;
            }
            vmcase(OP_TEST) {
                StkId ra = RA(i);
                int cond = !l_isfalse(s2v(ra));
                docondjump();
                vmbreak;
            }
            vmcase(OP_TESTSET) {
                StkId ra = RA(i);
                TValue *rb = vRB(i);
                if (l_isfalse(rb) == GETARG_k(i))
                    pc++;
                else {
                    setobj2s(L, ra, rb);
                    donextjump(ci);
                }
                vmbreak;
            }
            vmcase(OP_CALL) {
                StkId ra = RA(i);
                CallInfo *newci;
                int b = GETARG_B(i);
                int nresults = GETARG_C(i) - 1;
                if (b != 0)  /* fixed number of arguments? */
                    L->top.p = ra + b;  /* top signals number of arguments */
                /* else previous instruction set top */
                savepc(L);  /* in case of errors */
                if ((newci = luaD_precall(L, ra, nresults)) == NULL)
                    updatetrap(ci);  /* C call; nothing else to be done */
                else {  /* Lua call: run function in this same C frame */
                    ci = newci;
                    goto startfunc;
                }
                vmbreak;
            }
            vmcase(OP_TAILCALL) {
                StkId ra = RA(i);
                int b = GETARG_B(i);  /* number of arguments + 1 (function) */
                int n;  /* number of results when calling a C function */
                int nparams1 = GETARG_C(i);
                /* delta is virtual 'func' - real 'func' (vararg functions) */
                int delta = (nparams1) ? ci->u.l.nextraargs + nparams1 : 0;
                if (b != 0)
                    L->top.p = ra + b;
                else  /* previous instruction set top */
                    b = cast_int(L->top.p - ra);
                savepc(ci);  /* several calls here can raise errors */
                if (TESTARG_k(i)) {
                    luaF_closeupval(L, base);  /* close upvalues from current call */
                    lua_assert(L->tbclist.p < base);  /* no pending tbc variables */
                    lua_assert(base == ci->func.p + 1);
                }
                if ((n = luaD_pretailcall(L, ci, ra, b, delta)) < 0)  /* Lua function? */
                    goto startfunc;  /* execute the callee */
                else {  /* C function? */
                    ci->func.p -= delta;  /* restore 'func' (if vararg) */
                    luaD_poscall(L, ci, n);  /* finish caller */
                    updatetrap(ci);  /* 'luaD_poscall' can change hooks */
                    goto ret;  /* caller returns after the tail call */
                }
            }
            vmcase(OP_RETURN) {
                StkId ra = RA(i);
                int n = GETARG_B(i) - 1;  /* number of results */
                int nparams1 = GETARG_C(i);
                if (n < 0)  /* not fixed? */
                    n = cast_int(L->top.p - ra);  /* get what is available */
                savepc(ci);
                if (TESTARG_k(i)) {  /* may there be open upvalues? */
                    ci->u2.nres = n;  /* save number of returns */
                    if (L->top.p < ci->top.p)
                        L->top.p = ci->top.p;
                    luaF_close(L, base, CLOSEKTOP, 1);
                    updatetrap(ci);
                    updatestack(ci);
                }
                if (nparams1)  /* vararg function? */
                    ci->func.p -= ci->u.l.nextraargs + nparams1;
                L->top.p = ra + n;  /* set call for 'luaD_poscall' */
                luaD_poscall(L, ci, n);
                updatetrap(ci);  /* 'luaD_poscall' can change hooks */
                goto ret;
            }
            vmcase(OP_RETURN0) {
                if (l_unlikely(L->hookmask)) {
                    StkId ra = RA(i);
                    L->top.p = ra;
                    savepc(ci);
                    luaD_poscall(L, ci, 0);  /* no hurry... */
                    trap = 1;
                } else { /* do the 'poscall' here */
                    int nres;
                    L->ci = ci->previous;  /* back to caller */
                    L->top.p = base - 1;
                    for (nres = ci->nresults; l_unlikely(nres > 0); nres--)
                        setnilvalue(s2v(L->top.p++));  /* all results are nil */
                }
                goto ret;
            }
            vmcase(OP_RETURN1) {
                if (l_unlikely(L->hookmask)) {
                    StkId ra = RA(i);
                    L->top.p = ra + 1;
                    savepc(ci);
                    luaD_poscall(L, ci, 1);  /* no hurry... */
                    trap = 1;
                } else { /* do the 'poscall' here */
                    int nres = ci->nresults;
                    L->ci = ci->previous;  /* back to caller */
                    if (nres == 0)
                        L->top.p = base - 1;  /* asked for no results */
                    else {
                        StkId ra = RA(i);
                        setobjs2s(L, base - 1, ra);  /* at least this result */
                        L->top.p = base;
                        for (; l_unlikely(nres > 1); nres--)
                            setnilvalue(s2v(L->top.p++));  /* complete missing results */
                    }
                }
ret:  /* return from a Lua function */
                if (ci->callstatus & CIST_FRESH)
                    return;  /* end this frame */
                else {
                    ci = ci->previous;
                    goto returning;  /* continue running caller in this frame */
                }
            }
            vmcase(OP_FORLOOP) {
                StkId ra = RA(i);
                if (ttisinteger(s2v(ra + 2))) {  /* integer loop? */
                    lua_Unsigned count = l_castS2U(ivalue(s2v(ra + 1)));
                    if (count > 0) {  /* still more iterations? */
                        lua_Integer step = ivalue(s2v(ra + 2));
                        lua_Integer idx = ivalue(s2v(ra));  /* internal index */
                        chgivalue(s2v(ra + 1), count - 1);  /* update counter */
                        idx = intop(+, idx, step);  /* add step to index */
                        chgivalue(s2v(ra), idx);  /* update internal index */
                        setivalue(s2v(ra + 3), idx);  /* and control variable */
                        pc -= GETARG_Bx(i);  /* jump back */
                    }
                } else if (floatforloop(ra)) /* float loop */
                    pc -= GETARG_Bx(i);  /* jump back */
                updatetrap(ci);  /* allows a signal to break the loop */
                vmbreak;
            }
            vmcase(OP_FORPREP) {
                StkId ra = RA(i);
                savestate(L, ci);  /* in case of errors */
                if (forprep(L, ra))
                    pc += GETARG_Bx(i) + 1;  /* skip the loop */
                vmbreak;
            }
            vmcase(OP_TFORPREP) {
                StkId ra = RA(i);
                /* create to-be-closed upvalue (if needed) */
                halfProtect(luaF_newtbcupval(L, ra + 3));
                pc += GETARG_Bx(i);
                i = *(pc++);  /* go to next instruction */
                lua_assert(GET_OPCODE(i) == OP_TFORCALL && ra == RA(i));
                goto l_tforcall;
            }
            vmcase(OP_TFORCALL) {
l_tforcall: {
                    StkId ra = RA(i);
                    /* 'ra' has the iterator function, 'ra + 1' has the state,
                       'ra + 2' has the control variable, and 'ra + 3' has the
                       to-be-closed variable. The call will use the stack after
                       these values (starting at 'ra + 4')
                    */
                    /* push function, state, and control variable */
                    memcpy(ra + 4, ra, 3 * sizeof(*ra));
                    L->top.p = ra + 4 + 3;
                    ProtectNT(luaD_call(L, ra + 4, GETARG_C(i)));  /* do the call */
                    updatestack(ci);  /* stack may have changed */
                    i = *(pc++);  /* go to next instruction */
                    lua_assert(GET_OPCODE(i) == OP_TFORLOOP && ra == RA(i));
                    goto l_tforloop;
                }
            }
            vmcase(OP_TFORLOOP) {
l_tforloop: {
                    StkId ra = RA(i);
                    if (!ttisnil(s2v(ra + 4))) {  /* continue loop? */
                        setobjs2s(L, ra + 2, ra + 4);  /* save control variable */
                        pc -= GETARG_Bx(i);  /* jump back */
                    }
                    vmbreak;
                }
            }
            vmcase(OP_SETLIST) {
                StkId ra = RA(i);
                int n = GETARG_B(i);
                unsigned int last = GETARG_C(i);
                Table *h = hvalue(s2v(ra));
                if (n == 0)
                    n = cast_int(L->top.p - ra) - 1;  /* get up to the top */
                else
                    L->top.p = ci->top.p;  /* correct top in case of emergency GC */
                last += n;
                if (TESTARG_k(i)) {
                    last += GETARG_Ax(*pc) * (MAXARG_C + 1);
                    pc++;
                }
                if (last > luaH_realasize(h))  /* needs more space? */
                    luaH_resizearray(L, h, last);  /* preallocate it at once */
                for (; n > 0; n--) {
                    TValue *val = s2v(ra + n);
                    setobj2t(L, &h->array[last - 1], val);
                    last--;
                    luaC_barrierback(L, obj2gco(h), val);
                }
                vmbreak;
            }
            vmcase(OP_CLOSURE) {
                StkId ra = RA(i);
                Proto *p = cl->p->p[GETARG_Bx(i)];
                halfProtect(pushclosure(L, p, cl->upvals, base, ra));
                checkGC(L, ra + 1);
                vmbreak;
            }
            vmcase(OP_VARARG) {
                StkId ra = RA(i);
                int n = GETARG_C(i) - 1;  /* required results */
                Protect(luaT_getvarargs(L, ci, ra, n));
                vmbreak;
            }
            vmcase(OP_VARARGPREP) {
                ProtectNT(luaT_adjustvarargs(L, GETARG_A(i), ci, cl->p));
                if (l_unlikely(trap)) {  /* previous "Protect" updated trap */
                    luaD_hookcall(L, ci);
                    L->oldpc = 1;  /* next opcode will be seen as a "new" line */
                }
                updatebase(ci);  /* function has new base after adjustment */
                vmbreak;
            }
            vmcase(OP_EXTRAARG) {
                lua_assert(0);
                vmbreak;
            }
        }
    }
}

/* }================================================================== */