diff options
author | Steven Barth <steven@midlink.org> | 2009-04-21 16:26:45 +0000 |
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committer | Steven Barth <steven@midlink.org> | 2009-04-21 16:26:45 +0000 |
commit | a2b916ab736802050b19562b7c163e3f3bb1566f (patch) | |
tree | d35b68f7bcac43f66f4cdb915ef327b76856594b /libs/nixio/src/bit.c | |
parent | 085a0a9ec040fc3ea5ee537d2cee724aa775747b (diff) |
Merge nixio 0.2
Diffstat (limited to 'libs/nixio/src/bit.c')
-rw-r--r-- | libs/nixio/src/bit.c | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/libs/nixio/src/bit.c b/libs/nixio/src/bit.c new file mode 100644 index 000000000..14fdecab1 --- /dev/null +++ b/libs/nixio/src/bit.c @@ -0,0 +1,125 @@ +/* + * nixio - Linux I/O library for lua + * + * Copyright (C) 2009 Steven Barth <steven@midlink.org> + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "nixio.h" +#include <stdint.h> +#include <stdlib.h> + +/* 52 bit maximum precision */ +#define NIXIO_BIT_BMAX 52 +#define NIXIO_BIT_NMAX 0xfffffffffffff + +#define NIXIO_BIT_XOP(BIT_XOP) \ + uint64_t oper = luaL_checknumber(L, 1); \ + const int args = lua_gettop(L); \ + \ + for (int i = 2; i <= args; i++) { \ + uint64_t oper2 = luaL_checknumber(L, i); \ + oper BIT_XOP oper2; \ + } \ + \ + lua_pushnumber(L, oper); \ + return 1; \ + + +static int nixio_bit_or(lua_State *L) { + NIXIO_BIT_XOP(|=); +} + +static int nixio_bit_and(lua_State *L) { + NIXIO_BIT_XOP(&=); +} + +static int nixio_bit_xor(lua_State *L) { + NIXIO_BIT_XOP(^=); +} + +static int nixio_bit_unset(lua_State *L) { + NIXIO_BIT_XOP(&= ~); +} + +static int nixio_bit_not(lua_State *L) { + lua_pushnumber(L, (~((uint64_t)luaL_checknumber(L, 1))) & NIXIO_BIT_NMAX); + return 1; +} + +static int nixio_bit_shl(lua_State *L) { + uint64_t oper = luaL_checknumber(L, 1); + oper <<= luaL_checkinteger(L, 2); + if (oper > NIXIO_BIT_NMAX) { + return luaL_error(L, "arithmetic overflow"); + } else { + lua_pushnumber(L, oper); + return 1; + } +} + +static int nixio_bit_ashr(lua_State *L) { + int64_t oper = luaL_checknumber(L, 1); + lua_pushnumber(L, oper >> luaL_checkinteger(L, 2)); + return 1; +} + +static int nixio_bit_shr(lua_State *L) { + uint64_t oper = luaL_checknumber(L, 1); + lua_pushnumber(L, oper >> luaL_checkinteger(L, 2)); + return 1; +} + +static int nixio_bit_div(lua_State *L) { + NIXIO_BIT_XOP(/=); +} + +static int nixio_bit_check(lua_State *L) { + uint64_t oper = luaL_checknumber(L, 1); + uint64_t oper2 = luaL_checknumber(L, 2); + lua_pushboolean(L, (oper & oper2) == oper2); + return 1; +} + +static int nixio_bit_cast(lua_State *L) { + lua_pushnumber(L, ((uint64_t)luaL_checknumber(L, 1)) & NIXIO_BIT_NMAX); + return 1; +} + +/* module table */ +static const luaL_reg R[] = { + {"bor", nixio_bit_or}, + {"set", nixio_bit_or}, + {"band", nixio_bit_and}, + {"bxor", nixio_bit_xor}, + {"unset", nixio_bit_unset}, + {"bnot", nixio_bit_not}, + {"rshift", nixio_bit_shr}, + {"arshift", nixio_bit_ashr}, + {"lshift", nixio_bit_shl}, + {"div", nixio_bit_div}, + {"check", nixio_bit_check}, + {"cast", nixio_bit_cast}, + {NULL, NULL} +}; + +void nixio_open_bit(lua_State *L) { + lua_newtable(L); + luaL_register(L, NULL, R); + lua_pushnumber(L, NIXIO_BIT_BMAX); + lua_setfield(L, -2, "bits"); + lua_pushnumber(L, NIXIO_BIT_NMAX); + lua_setfield(L, -2, "max"); + lua_setfield(L, -2, "bit"); +} |