|
| 1 | +/* |
| 2 | +** Lua BitOp -- a bit operations library for Lua 5.1/5.2. |
| 3 | +** http://bitop.luajit.org/ |
| 4 | +** |
| 5 | +** Copyright (C) 2008-2012 Mike Pall. All rights reserved. |
| 6 | +** |
| 7 | +** Permission is hereby granted, free of charge, to any person obtaining |
| 8 | +** a copy of this software and associated documentation files (the |
| 9 | +** "Software"), to deal in the Software without restriction, including |
| 10 | +** without limitation the rights to use, copy, modify, merge, publish, |
| 11 | +** distribute, sublicense, and/or sell copies of the Software, and to |
| 12 | +** permit persons to whom the Software is furnished to do so, subject to |
| 13 | +** the following conditions: |
| 14 | +** |
| 15 | +** The above copyright notice and this permission notice shall be |
| 16 | +** included in all copies or substantial portions of the Software. |
| 17 | +** |
| 18 | +** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 19 | +** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 20 | +** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 21 | +** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| 22 | +** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 23 | +** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 24 | +** SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 25 | +** |
| 26 | +** [ MIT license: http://www.opensource.org/licenses/mit-license.php ] |
| 27 | +*/ |
| 28 | + |
| 29 | +#define LUA_BITOP_VERSION "1.0.3" |
| 30 | + |
| 31 | +#define LUA_LIB |
| 32 | +#include "lua.h" |
| 33 | +#include "lauxlib.h" |
| 34 | + |
| 35 | +#ifdef _MSC_VER |
| 36 | +/* MSVC is stuck in the last century and doesn't have C99's stdint.h. */ |
| 37 | +typedef __int32 int32_t; |
| 38 | +typedef unsigned __int32 uint32_t; |
| 39 | +typedef unsigned __int64 uint64_t; |
| 40 | +#else |
| 41 | +#include <stdint.h> |
| 42 | +#endif |
| 43 | + |
| 44 | +typedef int32_t SBits; |
| 45 | +typedef uint32_t UBits; |
| 46 | + |
| 47 | +typedef union { |
| 48 | + lua_Number n; |
| 49 | +#if defined(LUA_NUMBER_DOUBLE) || defined(LUA_FLOAT_DOUBLE) |
| 50 | + uint64_t b; |
| 51 | +#else |
| 52 | + UBits b; |
| 53 | +#endif |
| 54 | +} BitNum; |
| 55 | + |
| 56 | +/* Convert argument to bit type. */ |
| 57 | +static UBits barg(lua_State *L, int idx) |
| 58 | +{ |
| 59 | + BitNum bn; |
| 60 | + UBits b; |
| 61 | +#if LUA_VERSION_NUM < 502 |
| 62 | + bn.n = lua_tonumber(L, idx); |
| 63 | +#else |
| 64 | + bn.n = luaL_checknumber(L, idx); |
| 65 | +#endif |
| 66 | +#if defined(LUA_NUMBER_DOUBLE) || defined(LUA_FLOAT_DOUBLE) |
| 67 | + bn.n += 6755399441055744.0; /* 2^52+2^51 */ |
| 68 | +#ifdef SWAPPED_DOUBLE |
| 69 | + b = (UBits)(bn.b >> 32); |
| 70 | +#else |
| 71 | + b = (UBits)bn.b; |
| 72 | +#endif |
| 73 | +#elif defined(LUA_NUMBER_INT) || defined(LUA_INT_INT) || \ |
| 74 | + defined(LUA_NUMBER_LONG) || defined(LUA_INT_LONG) || \ |
| 75 | + defined(LUA_NUMBER_LONGLONG) || defined(LUA_INT_LONGLONG) || \ |
| 76 | + defined(LUA_NUMBER_LONG_LONG) || defined(LUA_NUMBER_LLONG) |
| 77 | + if (sizeof(UBits) == sizeof(lua_Number)) |
| 78 | + b = bn.b; |
| 79 | + else |
| 80 | + b = (UBits)(SBits)bn.n; |
| 81 | +#elif defined(LUA_NUMBER_FLOAT) || defined(LUA_FLOAT_FLOAT) |
| 82 | +#error "A 'float' lua_Number type is incompatible with this library" |
| 83 | +#else |
| 84 | +#error "Unknown number type, check LUA_NUMBER_*, LUA_FLOAT_*, LUA_INT_* in luaconf.h" |
| 85 | +#endif |
| 86 | +#if LUA_VERSION_NUM < 502 |
| 87 | + if (b == 0 && !lua_isnumber(L, idx)) { |
| 88 | + luaL_typerror(L, idx, "number"); |
| 89 | + } |
| 90 | +#endif |
| 91 | + return b; |
| 92 | +} |
| 93 | + |
| 94 | +/* Return bit type. */ |
| 95 | +#if LUA_VERSION_NUM < 503 |
| 96 | +#define BRET(b) lua_pushnumber(L, (lua_Number)(SBits)(b)); return 1; |
| 97 | +#else |
| 98 | +#define BRET(b) lua_pushinteger(L, (lua_Integer)(SBits)(b)); return 1; |
| 99 | +#endif |
| 100 | + |
| 101 | +static int bit_tobit(lua_State *L) { BRET(barg(L, 1)) } |
| 102 | +static int bit_bnot(lua_State *L) { BRET(~barg(L, 1)) } |
| 103 | + |
| 104 | +#define BIT_OP(func, opr) \ |
| 105 | + static int func(lua_State *L) { int i; UBits b = barg(L, 1); \ |
| 106 | + for (i = lua_gettop(L); i > 1; i--) b opr barg(L, i); BRET(b) } |
| 107 | +BIT_OP(bit_band, &=) |
| 108 | +BIT_OP(bit_bor, |=) |
| 109 | +BIT_OP(bit_bxor, ^=) |
| 110 | + |
| 111 | +#define bshl(b, n) (b << n) |
| 112 | +#define bshr(b, n) (b >> n) |
| 113 | +#define bsar(b, n) ((SBits)b >> n) |
| 114 | +#define brol(b, n) ((b << n) | (b >> (32-n))) |
| 115 | +#define bror(b, n) ((b << (32-n)) | (b >> n)) |
| 116 | +#define BIT_SH(func, fn) \ |
| 117 | + static int func(lua_State *L) { \ |
| 118 | + UBits b = barg(L, 1); UBits n = barg(L, 2) & 31; BRET(fn(b, n)) } |
| 119 | +BIT_SH(bit_lshift, bshl) |
| 120 | +BIT_SH(bit_rshift, bshr) |
| 121 | +BIT_SH(bit_arshift, bsar) |
| 122 | +BIT_SH(bit_rol, brol) |
| 123 | +BIT_SH(bit_ror, bror) |
| 124 | + |
| 125 | +static int bit_bswap(lua_State *L) |
| 126 | +{ |
| 127 | + UBits b = barg(L, 1); |
| 128 | + b = (b >> 24) | ((b >> 8) & 0xff00) | ((b & 0xff00) << 8) | (b << 24); |
| 129 | + BRET(b) |
| 130 | +} |
| 131 | + |
| 132 | +static int bit_tohex(lua_State *L) |
| 133 | +{ |
| 134 | + UBits b = barg(L, 1); |
| 135 | + SBits n = lua_isnone(L, 2) ? 8 : (SBits)barg(L, 2); |
| 136 | + const char *hexdigits = "0123456789abcdef"; |
| 137 | + char buf[8]; |
| 138 | + int i; |
| 139 | + if (n < 0) { n = -n; hexdigits = "0123456789ABCDEF"; } |
| 140 | + if (n > 8) n = 8; |
| 141 | + for (i = (int)n; --i >= 0; ) { buf[i] = hexdigits[b & 15]; b >>= 4; } |
| 142 | + lua_pushlstring(L, buf, (size_t)n); |
| 143 | + return 1; |
| 144 | +} |
| 145 | + |
| 146 | +static const struct luaL_Reg bit_funcs[] = { |
| 147 | + { "tobit", bit_tobit }, |
| 148 | + { "bnot", bit_bnot }, |
| 149 | + { "band", bit_band }, |
| 150 | + { "bor", bit_bor }, |
| 151 | + { "bxor", bit_bxor }, |
| 152 | + { "lshift", bit_lshift }, |
| 153 | + { "rshift", bit_rshift }, |
| 154 | + { "arshift", bit_arshift }, |
| 155 | + { "rol", bit_rol }, |
| 156 | + { "ror", bit_ror }, |
| 157 | + { "bswap", bit_bswap }, |
| 158 | + { "tohex", bit_tohex }, |
| 159 | + { NULL, NULL } |
| 160 | +}; |
| 161 | + |
| 162 | +/* Signed right-shifts are implementation-defined per C89/C99. |
| 163 | +** But the de facto standard are arithmetic right-shifts on two's |
| 164 | +** complement CPUs. This behaviour is required here, so test for it. |
| 165 | +*/ |
| 166 | +#define BAD_SAR (bsar(-8, 2) != (SBits)-2) |
| 167 | + |
| 168 | +LUALIB_API int luaopen_bit(lua_State *L) |
| 169 | +{ |
| 170 | + UBits b; |
| 171 | +#if LUA_VERSION_NUM < 503 |
| 172 | + lua_pushnumber(L, (lua_Number)1437217655L); |
| 173 | +#else |
| 174 | + lua_pushinteger(L, (lua_Integer)1437217655L); |
| 175 | +#endif |
| 176 | + b = barg(L, -1); |
| 177 | + if (b != (UBits)1437217655L || BAD_SAR) { /* Perform a simple self-test. */ |
| 178 | + const char *msg = "compiled with incompatible luaconf.h"; |
| 179 | +#if defined(LUA_NUMBER_DOUBLE) || defined(LUA_FLOAT_DOUBLE) |
| 180 | +#ifdef _WIN32 |
| 181 | + if (b == (UBits)1610612736L) |
| 182 | + msg = "use D3DCREATE_FPU_PRESERVE with DirectX"; |
| 183 | +#endif |
| 184 | + if (b == (UBits)1127743488L) |
| 185 | + msg = "not compiled with SWAPPED_DOUBLE"; |
| 186 | +#endif |
| 187 | + if (BAD_SAR) |
| 188 | + msg = "arithmetic right-shift broken"; |
| 189 | + luaL_error(L, "bit library self-test failed (%s)", msg); |
| 190 | + } |
| 191 | + |
| 192 | + luaL_newlib(L, bit_funcs); |
| 193 | + lua_setglobal(L, "bit"); |
| 194 | + |
| 195 | + return 1; |
| 196 | +} |
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