diff options
Diffstat (limited to 'src/lib/lua/lbitlib.c')
-rw-r--r-- | src/lib/lua/lbitlib.c | 207 |
1 files changed, 103 insertions, 104 deletions
diff --git a/src/lib/lua/lbitlib.c b/src/lib/lua/lbitlib.c index 31c7b66f129..e963ca6c559 100644 --- a/src/lib/lua/lbitlib.c +++ b/src/lib/lua/lbitlib.c @@ -15,18 +15,18 @@ /* number of bits to consider in a number */ #if !defined(LUA_NBITS) -#define LUA_NBITS 32 +#define LUA_NBITS 32 #endif -#define ALLONES (~(((~(lua_Unsigned)0) << (LUA_NBITS - 1)) << 1)) +#define ALLONES (~(((~(lua_Unsigned)0) << (LUA_NBITS - 1)) << 1)) /* macro to trim extra bits */ -#define trim(x) ((x) & ALLONES) +#define trim(x) ((x) & ALLONES) /* builds a number with 'n' ones (1 <= n <= LUA_NBITS) */ -#define mask(n) (~((ALLONES << 1) << ((n) - 1))) +#define mask(n) (~((ALLONES << 1) << ((n) - 1))) typedef lua_Unsigned b_uint; @@ -34,115 +34,115 @@ 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); + 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; + 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; + 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; + 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; + 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; + 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; + 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)); + 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)); + 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; - } + 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; + 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)); + return b_rot(L, luaL_checkint(L, 2)); } static int b_rrot (lua_State *L) { - return b_rot(L, -luaL_checkint(L, 2)); + return b_rot(L, -luaL_checkint(L, 2)); } @@ -153,60 +153,59 @@ static int b_rrot (lua_State *L) { ** '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; + 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; + 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; + 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} + {"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; + luaL_newlib(L, bitlib); + return 1; } - |