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/*
* 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;
}
static int nixio_bit_swap(lua_State *L) {
uint64_t op = luaL_checknumber(L, 1);
op = (op >> 24) | ((op >> 8) & 0xff00) | ((op & 0xff00) << 8) | (op << 24);
lua_pushnumber(L, op);
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},
{"tobit", nixio_bit_cast},
{"bswap", nixio_bit_swap},
{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");
}
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