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added the tohex and rotate functions from http://bitop.luajit.org/

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Thomas Hornschuh 2017-08-03 17:13:23 +02:00
parent 7a45fcde7a
commit 90e86c6e7b
1 changed files with 44 additions and 0 deletions
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44
src/modules/bit.c
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@ -4,6 +4,15 @@
// Modified by BogdanM for eLua
// TH: Fixed various places to do all conversions to/from lua numbers as unsigned
// This is also consitent with other parts of eLua e.g. the cpu module
// If have also considered using signed integers like in http://bitop.luajit.org/
// This would have the advantage that the behaviour for lua "long" would be
// identical to lua "double". But it also a lot of drawbacks, and would be inconsistent
// with e.g. the cpu.r/w operations, because they expect unsigned numbers.
//
// In addtion I added the tohex and rotate functions from http://bitop.luajit.org/
#include <limits.h>
@ -71,6 +80,17 @@ void bit_pushuinteger(lua_State *L, lua_UInteger n)
(unsigned)luaL_checknumber(L, 2)); \
return 1; \
}
// Added TH
#define BIT_SH(name, fn) \
static int bit_ ## name(lua_State *L) { \
bit_pushuinteger(L, fn((lua_UInteger)TOBIT(L, 1), \
(unsigned)luaL_checknumber(L, 2))); \
return 1; \
}
#define brol(b, n) ((b << n) | (b >> (32-n)))
#define bror(b, n) ((b << (32-n)) | (b >> n))
MONADIC(bnot, ~)
VARIADIC(band, &=)
@ -80,6 +100,11 @@ ARITHMETIC_SHIFT(lshift, <<)
LOGICAL_SHIFT(rshift, >>)
ARITHMETIC_SHIFT(arshift, >>)
BIT_SH(rol, brol) // TH
BIT_SH(ror, bror) // TH
// Lua: res = bit( position )
static int bit_bit( lua_State* L )
{
@ -131,6 +156,21 @@ static int bit_clear( lua_State* L )
return 1;
}
//TH: "Borrowed" from luaBitop
static int bit_tohex(lua_State *L)
{
lua_UInteger b = ( lua_UInteger )TOBIT( L, 1 );
int n = lua_isnone(L, 2) ? 8 : luaL_checkinteger(L, 2);
const char *hexdigits = "0123456789abcdef";
char buf[8];
int i;
if (n < 0) { n = -n; hexdigits = "0123456789ABCDEF"; }
if (n > 8) n = 8;
for (i = (int)n; --i >= 0; ) { buf[i] = hexdigits[b & 15]; b >>= 4; }
lua_pushlstring(L, buf, (size_t)n);
return 1;
}
#define MIN_OPT_LEVEL 2
#include "lrodefs.h"
const LUA_REG_TYPE bit_map[] = {
@ -146,9 +186,13 @@ const LUA_REG_TYPE bit_map[] = {
{ LSTRKEY( "clear" ), LFUNCVAL( bit_clear ) },
{ LSTRKEY( "isset" ), LFUNCVAL( bit_isset ) },
{ LSTRKEY( "isclear" ), LFUNCVAL( bit_isclear ) },
{ LSTRKEY( "tohex" ), LFUNCVAL( bit_tohex ) }, // TH
{ LSTRKEY("rol"), LFUNCVAL(bit_rol) }, // TH
{ LSTRKEY("ror"), LFUNCVAL(bit_ror) }, // TH
{ LNILKEY, LNILVAL}
};
LUALIB_API int luaopen_bit (lua_State *L) {
LREGISTER( L, "bit", bit_map );
}