A modern Music Player Daemon based on Rockbox open source high quality audio player
tsiry-sandratraina.com
libadwaita
audio
rust
zig
deno
mpris
rockbox
mpd
1/* Bitwise operations library */
2/* (c) Reuben Thomas 2000-2008 */
3/* bitlib is copyright Reuben Thomas 2000-2008, and is released under the MIT
4 license, like Lua (see http://www.lua.org/copyright.html; it's
5 basically the same as the BSD license). There is no warranty. */
6
7#include "config.h"
8
9#include "lua.h"
10#include "lauxlib.h"
11#include "lualib.h"
12#include <limits.h>
13
14
15/* FIXME: Assume lua_Integer is ptrdiff_t */
16#define LUA_INTEGER_MAX INTPTR_MAX
17#define LUA_INTEGER_MIN INTPTR_MIN
18
19/* FIXME: Assume size_t is an unsigned lua_Integer */
20typedef size_t lua_UInteger;
21#define LUA_UINTEGER_MAX UINT_MAX
22
23
24/* Bit type size and limits */
25
26#define BIT_BITS (CHAR_BIT * sizeof(lua_Integer))
27
28/* This code may give warnings if BITLIB_FLOAT_* are too big to fit in
29 long, but that doesn't matter since in that case they won't be
30 used. */
31#define BIT_MAX (LUA_INTEGER_MAX)
32
33#define BIT_MIN (LUA_INTEGER_MIN)
34
35#define BIT_UMAX (LUA_UINTEGER_MAX)
36
37
38/* Define TOBIT to get a bit value */
39#ifdef BUILTIN_CAST
40#define
41#define TOBIT(L, n, res) \
42 ((void)(res), luaL_checkinteger((L), (n)))
43#else
44
45#define TOBIT(L, n, res) \
46 ((lua_Integer)(((res) = luaL_checknumber(L, (n)) % BIT_UMAX), \
47 (res) > BIT_MAX ? ((res) -= BIT_UMAX, (res) -= 1) : \
48 ((res) < BIT_MIN ? ((res) += BIT_UMAX, (res) += 1) : (res))))
49#endif
50
51
52#define BIT_TRUNCATE(i) \
53 ((i) & BIT_UMAX)
54
55
56/* Operations
57
58 The macros MONADIC and VARIADIC only deal with bitwise operations.
59
60 LOGICAL_SHIFT truncates its left-hand operand before shifting so
61 that any extra bits at the most-significant end are not shifted
62 into the result.
63
64 ARITHMETIC_SHIFT does not truncate its left-hand operand, so that
65 the sign bits are not removed and right shift work properly.
66 */
67
68#define MONADIC(name, op) \
69 static int bit_ ## name(lua_State *L) { \
70 lua_Number f; \
71 lua_pushinteger(L, BIT_TRUNCATE(op TOBIT(L, 1, f))); \
72 return 1; \
73 }
74
75#define VARIADIC(name, op) \
76 static int bit_ ## name(lua_State *L) { \
77 lua_Number f; \
78 int n = lua_gettop(L), i; \
79 lua_Integer w = TOBIT(L, 1, f); \
80 for (i = 2; i <= n; i++) \
81 w op TOBIT(L, i, f); \
82 lua_pushinteger(L, BIT_TRUNCATE(w)); \
83 return 1; \
84 }
85
86#define LOGICAL_SHIFT(name, op) \
87 static int bit_ ## name(lua_State *L) { \
88 lua_Number f; \
89 lua_pushinteger(L, BIT_TRUNCATE(BIT_TRUNCATE((lua_UInteger)TOBIT(L, 1, f)) op \
90 (unsigned)luaL_checknumber(L, 2))); \
91 return 1; \
92 }
93
94#define ARITHMETIC_SHIFT(name, op) \
95 static int bit_ ## name(lua_State *L) { \
96 lua_Number f; \
97 lua_pushinteger(L, BIT_TRUNCATE((lua_Integer)TOBIT(L, 1, f) op \
98 (unsigned)luaL_checknumber(L, 2))); \
99 return 1; \
100 }
101
102MONADIC(bnot, ~)
103VARIADIC(band, &=)
104VARIADIC(bor, |=)
105VARIADIC(bxor, ^=)
106ARITHMETIC_SHIFT(lshift, <<)
107LOGICAL_SHIFT(rshift, >>)
108ARITHMETIC_SHIFT(arshift, >>)
109
110static const struct luaL_reg bitlib[] = {
111 {"bnot", bit_bnot},
112 {"band", bit_band},
113 {"bor", bit_bor},
114 {"bxor", bit_bxor},
115 {"lshift", bit_lshift},
116 {"rshift", bit_rshift},
117 {"arshift", bit_arshift},
118 {NULL, NULL}
119};
120
121LUALIB_API int luaopen_bit (lua_State *L) {
122 luaL_register(L, "bit", bitlib);
123 lua_pushnumber(L, BIT_BITS);
124 lua_setfield(L, -2, "bits");
125 return 1;
126}