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/*
** Lua BitOp -- a bit operations library for Lua 5.1/5.2.
** http://bitop.luajit.org/
**
** Copyright (C) 2008-2012 Mike Pall. All rights reserved.
**
** Permission is hereby granted, free of charge, to any person obtaining
** a copy of this software and associated documentation files (the
** "Software"), to deal in the Software without restriction, including
** without limitation the rights to use, copy, modify, merge, publish,
** distribute, sublicense, and/or sell copies of the Software, and to
** permit persons to whom the Software is furnished to do so, subject to
** the following conditions:
**
** The above copyright notice and this permission notice shall be
** included in all copies or substantial portions of the Software.
**
** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
** SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
**
** [ MIT license: http://www.opensource.org/licenses/mit-license.php ]
*/
#include "bit.h"
#define LUA_BITOP_VERSION "1.0.2"
#define LUA_LIB
#include "lauxlib.h"
#ifdef _MSC_VER
/* MSVC is stuck in the last century and doesn't have C99's stdint.h. */
typedef __int32 int32_t;
typedef unsigned __int32 uint32_t;
typedef unsigned __int64 uint64_t;
#else
#include <stdint.h>
#endif
typedef int32_t SBits;
typedef uint32_t UBits;
typedef union {
lua_Number n;
#ifdef LUA_NUMBER_DOUBLE
uint64_t b;
#else
UBits b;
#endif
} BitNum;
/* Convert argument to bit type. */
static UBits barg(lua_State *L, int idx)
{
BitNum bn;
UBits b;
#if LUA_VERSION_NUM < 502
bn.n = lua_tonumber(L, idx);
#else
bn.n = luaL_checknumber(L, idx);
#endif
#if defined(LUA_NUMBER_DOUBLE)
bn.n += 6755399441055744.0; /* 2^52+2^51 */
#ifdef SWAPPED_DOUBLE
b = (UBits)(bn.b >> 32);
#else
b = (UBits)bn.b;
#endif
#elif defined(LUA_NUMBER_INT) || defined(LUA_NUMBER_LONG) || \
defined(LUA_NUMBER_LONGLONG) || defined(LUA_NUMBER_LONG_LONG) || \
defined(LUA_NUMBER_LLONG)
if (sizeof(UBits) == sizeof(lua_Number))
b = bn.b;
else
b = (UBits)(SBits)bn.n;
#elif defined(LUA_NUMBER_FLOAT)
#error "A 'float' lua_Number type is incompatible with this library"
#else
#error "Unknown number type, check LUA_NUMBER_* in luaconf.h"
#endif
#if LUA_VERSION_NUM < 502
if (b == 0 && !lua_isnumber(L, idx)) {
luaL_typerror(L, idx, "number");
}
#endif
return b;
}
/* Return bit type. */
#define BRET(b) lua_pushnumber(L, (lua_Number)(SBits)(b)); return 1;
static int bit_tobit(lua_State *L) { BRET(barg(L, 1)) }
static int bit_bnot(lua_State *L) { BRET(~barg(L, 1)) }
#define BIT_OP(func, opr) \
static int func(lua_State *L) { int i; UBits b = barg(L, 1); \
for (i = lua_gettop(L); i > 1; i--) b opr barg(L, i); BRET(b) }
BIT_OP(bit_band, &=)
BIT_OP(bit_bor, |=)
BIT_OP(bit_bxor, ^=)
#define bshl(b, n) (b << n)
#define bshr(b, n) (b >> n)
#define bsar(b, n) ((SBits)b >> n)
#define brol(b, n) ((b << n) | (b >> (32-n)))
#define bror(b, n) ((b << (32-n)) | (b >> n))
#define BIT_SH(func, fn) \
static int func(lua_State *L) { \
UBits b = barg(L, 1); UBits n = barg(L, 2) & 31; BRET(fn(b, n)) }
BIT_SH(bit_lshift, bshl)
BIT_SH(bit_rshift, bshr)
BIT_SH(bit_arshift, bsar)
BIT_SH(bit_rol, brol)
BIT_SH(bit_ror, bror)
static int bit_bswap(lua_State *L)
{
UBits b = barg(L, 1);
b = (b >> 24) | ((b >> 8) & 0xff00) | ((b & 0xff00) << 8) | (b << 24);
BRET(b)
}
static int bit_tohex(lua_State *L)
{
UBits b = barg(L, 1);
SBits n = lua_isnone(L, 2) ? 8 : (SBits)barg(L, 2);
const char *hexdigits = "0123456789abcdef";
char buf[8];
int i;
if (n < 0) { n = -n; hexdigits = "0123456789ABCDEF"; }
if (n > 8) n = 8;
for (i = (int)n; --i >= 0; ) { buf[i] = hexdigits[b & 15]; b >>= 4; }
lua_pushlstring(L, buf, (size_t)n);
return 1;
}
static const struct luaL_Reg bit_funcs[] = {
{ "tobit", bit_tobit },
{ "bnot", bit_bnot },
{ "band", bit_band },
{ "bor", bit_bor },
{ "bxor", bit_bxor },
{ "lshift", bit_lshift },
{ "rshift", bit_rshift },
{ "arshift", bit_arshift },
{ "rol", bit_rol },
{ "ror", bit_ror },
{ "bswap", bit_bswap },
{ "tohex", bit_tohex },
{ NULL, NULL }
};
/* Signed right-shifts are implementation-defined per C89/C99.
** But the de facto standard are arithmetic right-shifts on two's
** complement CPUs. This behaviour is required here, so test for it.
*/
#define BAD_SAR (bsar(-8, 2) != (SBits)-2)
LUALIB_API int luaopen_bit(lua_State *L)
{
UBits b;
lua_pushnumber(L, (lua_Number)1437217655L);
b = barg(L, -1);
if (b != (UBits)1437217655L || BAD_SAR) { /* Perform a simple self-test. */
const char *msg = "compiled with incompatible luaconf.h";
#ifdef LUA_NUMBER_DOUBLE
#ifdef _WIN32
if (b == (UBits)1610612736L)
msg = "use D3DCREATE_FPU_PRESERVE with DirectX";
#endif
if (b == (UBits)1127743488L)
msg = "not compiled with SWAPPED_DOUBLE";
#endif
if (BAD_SAR)
msg = "arithmetic right-shift broken";
luaL_error(L, "bit library self-test failed (%s)", msg);
}
#if LUA_VERSION_NUM < 502
luaL_register(L, "bit", bit_funcs);
#else
luaL_newlib(L, bit_funcs);
#endif
return 1;
}
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