static void DumpNumber(lua_Number x, DumpState* D)
{
/*
http://stackoverflow.com/questions/14954088/how-do-i-handle-byte-order-differences-when-reading-writing-floating-point-types/14955046#14955046
10-byte little-endian serialized format for double:
- normalized mantissa stored as 64-bit (8-byte) signed integer:
negative range: (-2^53, -2^52]
zero: 0
positive range: [+2^52, +2^53)
- 16-bit (2-byte) signed exponent:
range: [-0x7FFE, +0x7FFE]
Represented value = mantissa * 2^(exponent - 53)
Special cases:
- +infinity: mantissa = 0x7FFFFFFFFFFFFFFF, exp = 0x7FFF
- -infinity: mantissa = 0x8000000000000000, exp = 0x7FFF
- NaN: mantissa = 0x0000000000000000, exp = 0x7FFF
- +/-0: only one zero supported
*/
double y=(double)x,m;
unsigned char z[8];
long long im;
int ie;
if (luai_numisnan(NULL,x)) { DumpChar(0,D); /* NaN */ return; }
else if (x == LUA_INFINITY) { DumpChar(1,D); /* +inf */ return; }
else if (x == -LUA_INFINITY) { DumpChar(2,D); /* -inf */ return; }
else if (x == 0) { DumpChar(3,D); /* 0 */ return; }
/* Split double into normalized mantissa (range: (-1, -0.5], 0, [+0.5, +1)) and base-2 exponent */
m = frexp(y, &ie); /* y = m * 2^ie exactly for FLT_RADIX=2, frexp() can't fail */
/* Extract most significant 53 bits of mantissa as integer */
m = ldexp(m, 53); /* can't overflow because DBL_MAX_10_EXP >= 37 equivalent to DBL_MAX_2_EXP >= 122 */
im = (long long)trunc(m); /* exact unless DBL_MANT_DIG > 53 */
/* If the exponent is too small or too big, reduce the number to 0 or +/- infinity */
if (ie>0x7FFE)
{
if (im<0) DumpChar(2,D); /* -inf */ else DumpChar(1,D); /* +inf */
return;
}
else if (ie<-0x7FFE) { DumpChar(3,D); /* 0 */ return; }
DumpChar(4,D); /* encoded */
/* Store im as signed 64-bit little-endian integer */
z[0]=(unsigned char)(im&0xFF);
z[1]=(unsigned char)((im>>8)&0xFF);
z[2]=(unsigned char)((im>>16)&0xFF);
z[3]=(unsigned char)((im>>24)&0xFF);
z[4]=(unsigned char)((im>>32)&0xFF);
z[5]=(unsigned char)((im>>40)&0xFF);
z[6]=(unsigned char)((im>>48)&0xFF);
z[7]=(unsigned char)((im>>56)&0xFF);
DumpMem(z,1,8,D);
/* Store ie as signed 16-bit little-endian integer */
z[0]=(unsigned char)(ie&0xFF);
z[1]=(unsigned char)((ie>>8)&0xFF);
DumpMem(z,1,2,D);
}
static int l_hashfloat (lua_Number n) {
int i;
lua_Integer ni;
n = l_mathop(frexp)(n, &i) * -cast_num(INT_MIN);
if (!lua_numbertointeger(n, &ni)) { /* is 'n' inf/-inf/NaN? */
lua_assert(luai_numisnan(n) || l_mathop(fabs)(n) == cast_num(HUGE_VAL));
return 0;
}
else { /* normal case */
unsigned int u = cast_uint(i) + cast_uint(ni);
return cast_int(u <= cast_uint(INT_MAX) ? u : ~u);
}
}
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)));
n = addk(fs, L->top - 1, &o);
L->top--;
}
else
n = addk(fs, &o, &o); /* regular case */
return n;
}
/*
** Return 'l <= r', for numbers.
*/
static int LEnum (const TValue *l, const TValue *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 if (luai_numisnan(lf)) /* 'r' is int and 'l' is float */
return 0; /* NaN <= i is always false */
else /* without NaN, (l <= r) <--> not(r < l) */
return !LTintfloat(ivalue(r), lf); /* not (r < l) ? */
}
}
/*
** Try to "constant-fold" an operation; return 1 iff successful
*/
static int constfolding (FuncState *fs, int op, expdesc *e1, expdesc *e2) {
TValue v1, v2, res;
if (!tonumeral(e1, &v1) || !tonumeral(e2, &v2) || !validop(op, &v1, &v2))
return 0; /* non-numeric operands or not safe to fold */
luaO_arith(fs->ls->L, op, &v1, &v2, &res);
if (ttisinteger(&res)) {
e1->k = VKINT;
e1->u.ival = ivalue(&res);
}
else {
lua_Number n = fltvalue(&res);
if (luai_numisnan(n) || isminuszero(n))
return 0; /* folds neither NaN nor -0 */
e1->k = VKFLT;
e1->u.nval = n;
}
return 1;
}
static int load_table(lua_State * L, lbs_LoadState * ls)
{
int array_size = 0;
int hash_size = 0;
unsigned int total_size = 0;
int result = lbsLS_readbytes(ls, (unsigned char *)&array_size, LUABINS_LINT);
if (result == LUABINS_ESUCCESS)
{
result = lbsLS_readbytes(ls, (unsigned char *)&hash_size, LUABINS_LINT);
}
if (result == LUABINS_ESUCCESS)
{
total_size = array_size + hash_size;
/*
SPAM((
"LT SIZE CHECK\n"
"* array_size %d limit 0 .. %d\n"
"* hash_size %d limit >0\n"
"* hash_size bytes %d, limit %d\n"
"* unread %u limit >min_size %u (total_size %u)\n",
array_size, MAXASIZE,
hash_size,
ceillog2((unsigned int)hash_size), MAXBITS,
(unsigned int)lbsLS_unread(ls),
(unsigned int)luabins_min_table_data_size(total_size),
(unsigned int)total_size
));
*/
if (
array_size < 0 || array_size > MAXASIZE ||
hash_size < 0 ||
(hash_size > 0 && ceillog2((unsigned int)hash_size) > MAXBITS) ||
lbsLS_unread(ls) < luabins_min_table_data_size(total_size)
)
{
result = LUABINS_EBADSIZE;
}
}
if (result == LUABINS_ESUCCESS)
{
unsigned int i = 0;
XSPAM((
"* load: creating table a:%d + h:%d = %d\n",
array_size, hash_size, total_size
));
lua_createtable(L, array_size, hash_size);
for (i = 0; i < total_size; ++i)
{
int key_type = LUA_TNONE;
result = load_value(L, ls); /* Load key. */
if (result != LUABINS_ESUCCESS)
{
break;
}
/* Table key can't be nil or NaN */
key_type = lua_type(L, -1);
if (key_type == LUA_TNIL)
{
/* Corrupt data? */
SPAM(("load: nil as key detected\n"));
result = LUABINS_EBADDATA;
break;
}
if (key_type == LUA_TNUMBER)
{
lua_Number key = lua_tonumber(L, -1);
if (luai_numisnan(key))
{
/* Corrupt data? */
SPAM(("load: NaN as key detected\n"));
result = LUABINS_EBADDATA;
break;
}
}
result = load_value(L, ls); /* Load value. */
if (result != LUABINS_ESUCCESS)
{
break;
}
lua_rawset(L, -3);
}
}
return result;
}
/*
** Both NaN and -0.0 should not go to the constant table, as they have
** problems with the hashing. (NaN is not a valid key, -0.0 collides
** with +0.0.)
*/
static int luaK_numberK (FuncState *fs, lua_Number r) {
TValue o;
lua_assert(!luai_numisnan(r) && !isminuszero(r));
setfltvalue(&o, r);
return addk(fs, &o, &o);
}
