diff options
Diffstat (limited to 'module/lua/lbitlib.c')
-rw-r--r-- | module/lua/lbitlib.c | 213 |
1 files changed, 0 insertions, 213 deletions
diff --git a/module/lua/lbitlib.c b/module/lua/lbitlib.c deleted file mode 100644 index 1294e45fc..000000000 --- a/module/lua/lbitlib.c +++ /dev/null @@ -1,213 +0,0 @@ -/* BEGIN CSTYLED */ -/* -** $Id: lbitlib.c,v 1.18.1.2 2013/07/09 18:01:41 roberto Exp $ -** Standard library for bitwise operations -** See Copyright Notice in lua.h -*/ - -#define lbitlib_c -#define LUA_LIB - -#include <sys/lua/lua.h> - -#include <sys/lua/lauxlib.h> -#include <sys/lua/lualib.h> - - -/* 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; - - - -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); - if (i != 0) /* avoid undefined shift of LUA_NBITS when i == 0 */ - 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} -}; - - - -LUAMOD_API int luaopen_bit32 (lua_State *L) { - luaL_newlib(L, bitlib); - return 1; -} -/* END CSTYLED */ |