src/lib_bit.c

   1 /*
   2 ** Bit manipulation library.
   3 ** Copyright (C) 2005-2012 Mike Pall. See Copyright Notice in luajit.h
   4 */
   5
   6 #define lib_bit_c
   7 #define LUA_LIB
   8
   9 #include "lua.h"
  10 #include "lauxlib.h"
  11 #include "lualib.h"
  12
  13 #include "lj_obj.h"
  14 #include "lj_err.h"
  15 #include "lj_str.h"
  16 #include "lj_lib.h"
  17
  18 /* ------------------------------------------------------------------------ */
  19
  20 #define LJLIB_MODULE_bit
  21
  22 LJLIB_ASM(bit_tobit)            LJLIB_REC(bit_unary IR_TOBIT)
  23 {
  24   lj_lib_checknumber(L, 1);
  25   return FFH_RETRY;
  26 }
  27 LJLIB_ASM_(bit_bnot)            LJLIB_REC(bit_unary IR_BNOT)
  28 LJLIB_ASM_(bit_bswap)           LJLIB_REC(bit_unary IR_BSWAP)
  29
  30 LJLIB_ASM(bit_lshift)           LJLIB_REC(bit_shift IR_BSHL)
  31 {
  32   lj_lib_checknumber(L, 1);
  33   lj_lib_checkbit(L, 2);
  34   return FFH_RETRY;
  35 }
  36 LJLIB_ASM_(bit_rshift)          LJLIB_REC(bit_shift IR_BSHR)
  37 LJLIB_ASM_(bit_arshift)         LJLIB_REC(bit_shift IR_BSAR)
  38 LJLIB_ASM_(bit_rol)             LJLIB_REC(bit_shift IR_BROL)
  39 LJLIB_ASM_(bit_ror)             LJLIB_REC(bit_shift IR_BROR)
  40
  41 LJLIB_ASM(bit_band)             LJLIB_REC(bit_nary IR_BAND)
  42 {
  43   int i = 0;
  44   do { lj_lib_checknumber(L, ++i); } while (L->base+i < L->top);
  45   return FFH_RETRY;
  46 }
  47 LJLIB_ASM_(bit_bor)             LJLIB_REC(bit_nary IR_BOR)
  48 LJLIB_ASM_(bit_bxor)            LJLIB_REC(bit_nary IR_BXOR)
  49
  50 /* ------------------------------------------------------------------------ */
  51
  52 LJLIB_CF(bit_tohex)
  53 {
  54   uint32_t b = (uint32_t)lj_lib_checkbit(L, 1);
  55   int32_t i, n = L->base+1 >= L->top ? 8 : lj_lib_checkbit(L, 2);
  56   const char *hexdigits = "0123456789abcdef";
  57   char buf[8];
  58   if (n < 0) { n = -n; hexdigits = "0123456789ABCDEF"; }
  59   if (n > 8) n = 8;
  60   for (i = n; --i >= 0; ) { buf[i] = hexdigits[b & 15]; b >>= 4; }
  61   lua_pushlstring(L, buf, (size_t)n);
  62   return 1;
  63 }
  64
  65 /* ------------------------------------------------------------------------ */
  66
  67 #include "lj_libdef.h"
  68
  69 LUALIB_API int luaopen_bit(lua_State *L)
  70 {
  71   LJ_LIB_REG(L, LUA_BITLIBNAME, bit);
  72   return 1;
  73 }
  74