/* * This is the bit32 library (lbitlib.c) from lua 5.2.2, * backported to lua 5.1. * * version 5.2.2 * * Copyright (C) 1994-2013 Lua.org, PUC-Rio. 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. */ #define lbitlib_c #define LUA_LIB #include "lua.h" #include "lauxlib.h" #include "lualib.h" /* ===== begin modifications to lbitlib.c ===== */ /* ----- adapted from lua-5.2.0-alpha luaconf.h: ----- */ /* * @@ LUA_UNSIGNED is the integral type used by lua_pushunsigned/lua_tounsigned. * ** It must have at least 32 bits. * */ #define LUA_UNSIGNED unsigned LUAI_INT32 #if defined(LUA_NUMBER_DOUBLE) && !defined(LUA_ANSI) /* { */ /* On a Microsoft compiler on a Pentium, use assembler to avoid clashes with a DirectX idiosyncrasy */ #if defined(_MSC_VER) && defined(M_IX86) /* { */ # define MS_ASMTRICK #else /* }{ */ /* the next definition uses a trick that should work on any machine using IEEE754 with a 32-bit integer type */ #define LUA_IEEE754TRICK /* @@ LUA_IEEEENDIAN is the endianness of doubles in your machine @@ (0 for little endian, 1 for big endian); if not defined, Lua will @@ check it dynamically. */ /* check for known architectures */ #if defined(__i386__) || defined(__i386) || defined(i386) || \ defined (__x86_64) #define LUA_IEEEENDIAN 0 #elif defined(__POWERPC__) || defined(__ppc__) #define LUA_IEEEENDIAN 1 #endif #endif /* } */ #endif /* } */ /* ----- from lua-5.2.0-alpha lua.h: ----- */ typedef LUA_UNSIGNED lua_Unsigned; /* ----- adapted from lua-5.2.0-alpha llimits.h: ----- */ /* lua_number2unsigned is a macro to convert a lua_Number to a lua_Unsigned. ** lua_unsigned2number is a macro to convert a lua_Unsigned to a lua_Number. */ #if defined(MS_ASMTRICK) /* { */ /* trick with Microsoft assembler for X86 */ #define lua_number2unsigned(i,n) \ {__int64 l; __asm {__asm fld n __asm fistp l} i = (unsigned int)l;} #elif defined(LUA_IEEE754TRICK) /* }{ */ /* the next trick should work on any machine using IEEE754 with a 32-bit integer type */ union luai_Cast2 { double l_d; LUAI_INT32 l_p[2]; }; #if !defined(LUA_IEEEENDIAN) /* { */ #define LUAI_EXTRAIEEE \ static const union luai_Cast2 ieeeendian = {-(33.0 + 6755399441055744.0)}; #define LUA_IEEEENDIAN (ieeeendian.l_p[1] == 33) #else #define LUAI_EXTRAIEEE /* empty */ #endif /* } */ #define lua_number2int32(i,n,t) \ { LUAI_EXTRAIEEE \ volatile union luai_Cast2 u; u.l_d = (n) + 6755399441055744.0; \ (i) = (t)u.l_p[LUA_IEEEENDIAN]; } #define lua_number2unsigned(i,n) lua_number2int32(i, n, lua_Unsigned) #endif /* } */ #if !defined(lua_number2unsigned) /* { */ /* the following definition assures proper modulo behavior */ #if defined(LUA_NUMBER_DOUBLE) #include #define SUPUNSIGNED ((lua_Number)(~(lua_Unsigned)0) + 1) #define lua_number2unsigned(i,n) \ ((i)=(lua_Unsigned)((n) - floor((n)/SUPUNSIGNED)*SUPUNSIGNED)) #else #define lua_number2unsigned(i,n) ((i)=(lua_Unsigned)(n)) #endif #endif /* } */ /* on several machines, coercion from unsigned to double is slow, so it may be worth to avoid */ #define lua_unsigned2number(u) \ (((u) <= (lua_Unsigned)INT_MAX) ? (lua_Number)(int)(u) : (lua_Number)(u)) /* ----- adapted from lua-5.2.0-alpha lapi.c: ----- */ void lua_pushunsigned (lua_State *L, lua_Unsigned u) { lua_Number n; n = lua_unsigned2number(u); lua_pushnumber(L, n); } /* ===== end modifications to lbitlib.c ===== */ /* number of bits to consider in a number */ #if !defined(LUA_NBITS) #define LUA_NBITS 32 #endif #define ALLONES (~(((~(lua_Unsigned)0) << (LUA_NBITS - 1)) << 1)) /* macro to trim extra bits */ #define trim(x) ((x) & ALLONES) /* builds a number with 'n' ones (1 <= n <= LUA_NBITS) */ #define mask(n) (~((ALLONES << 1) << ((n) - 1))) typedef lua_Unsigned b_uint; /* ===== begin modifications to lbitlib.c ===== */ /* ----- adapted from lua-5.2.0-work3 lbitlib.c: ----- */ static lua_Unsigned luaL_checkunsigned (lua_State *L, int narg) { b_uint r; lua_Number x = lua_tonumber(L, narg); if (x == 0) luaL_checktype(L, narg, LUA_TNUMBER); lua_number2unsigned(r, x); return r; } /* ===== end modifications to lbitlib.c ===== */ static b_uint andaux (lua_State *L) { int i, n = lua_gettop(L); b_uint r = ~(b_uint)0; for (i = 1; i <= n; i++) r &= luaL_checkunsigned(L, i); return trim(r); } static int b_and (lua_State *L) { b_uint r = andaux(L); lua_pushunsigned(L, r); return 1; } static int b_test (lua_State *L) { b_uint r = andaux(L); lua_pushboolean(L, r != 0); return 1; } static int b_or (lua_State *L) { int i, n = lua_gettop(L); b_uint r = 0; for (i = 1; i <= n; i++) r |= luaL_checkunsigned(L, i); lua_pushunsigned(L, trim(r)); return 1; } static int b_xor (lua_State *L) { int i, n = lua_gettop(L); b_uint r = 0; for (i = 1; i <= n; i++) r ^= luaL_checkunsigned(L, i); lua_pushunsigned(L, trim(r)); return 1; } static int b_not (lua_State *L) { b_uint r = ~luaL_checkunsigned(L, 1); lua_pushunsigned(L, trim(r)); return 1; } static int b_shift (lua_State *L, b_uint r, int i) { if (i < 0) { /* shift right? */ i = -i; r = trim(r); if (i >= LUA_NBITS) r = 0; else r >>= i; } else { /* shift left */ if (i >= LUA_NBITS) r = 0; else r <<= i; r = trim(r); } lua_pushunsigned(L, r); return 1; } static int b_lshift (lua_State *L) { return b_shift(L, luaL_checkunsigned(L, 1), luaL_checkint(L, 2)); } static int b_rshift (lua_State *L) { return b_shift(L, luaL_checkunsigned(L, 1), -luaL_checkint(L, 2)); } static int b_arshift (lua_State *L) { b_uint r = luaL_checkunsigned(L, 1); int i = luaL_checkint(L, 2); if (i < 0 || !(r & ((b_uint)1 << (LUA_NBITS - 1)))) return b_shift(L, r, -i); else { /* arithmetic shift for 'negative' number */ if (i >= LUA_NBITS) r = ALLONES; else r = trim((r >> i) | ~(~(b_uint)0 >> i)); /* add signal bit */ lua_pushunsigned(L, r); return 1; } } static int b_rot (lua_State *L, int i) { b_uint r = luaL_checkunsigned(L, 1); i &= (LUA_NBITS - 1); /* i = i % NBITS */ r = trim(r); r = (r << i) | (r >> (LUA_NBITS - i)); lua_pushunsigned(L, trim(r)); return 1; } static int b_lrot (lua_State *L) { return b_rot(L, luaL_checkint(L, 2)); } static int b_rrot (lua_State *L) { return b_rot(L, -luaL_checkint(L, 2)); } /* ** get field and width arguments for field-manipulation functions, ** checking whether they are valid. ** ('luaL_error' called without 'return' to avoid later warnings about ** 'width' being used uninitialized.) */ static int fieldargs (lua_State *L, int farg, int *width) { int f = luaL_checkint(L, farg); int w = luaL_optint(L, farg + 1, 1); luaL_argcheck(L, 0 <= f, farg, "field cannot be negative"); luaL_argcheck(L, 0 < w, farg + 1, "width must be positive"); if (f + w > LUA_NBITS) luaL_error(L, "trying to access non-existent bits"); *width = w; return f; } static int b_extract (lua_State *L) { int w; b_uint r = luaL_checkunsigned(L, 1); int f = fieldargs(L, 2, &w); r = (r >> f) & mask(w); lua_pushunsigned(L, r); return 1; } static int b_replace (lua_State *L) { int w; b_uint r = luaL_checkunsigned(L, 1); b_uint v = luaL_checkunsigned(L, 2); int f = fieldargs(L, 3, &w); int m = mask(w); v &= m; /* erase bits outside given width */ r = (r & ~(m << f)) | (v << f); lua_pushunsigned(L, r); return 1; } static const luaL_Reg bitlib[] = { {"arshift", b_arshift}, {"band", b_and}, {"bnot", b_not}, {"bor", b_or}, {"bxor", b_xor}, {"btest", b_test}, {"extract", b_extract}, {"lrotate", b_lrot}, {"lshift", b_lshift}, {"replace", b_replace}, {"rrotate", b_rrot}, {"rshift", b_rshift}, {NULL, NULL} }; int luaopen_bit32 (lua_State *L) { luaL_register(L, "bit32", bitlib); return 1; }