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x64: Optimize internal/external tag conversion in lua_type().

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Mike Pall 2010-10-11 17:26:07 +02:00
parent 5dcf630c54
commit 5140b40b44
1 changed files with 4 additions and 0 deletions
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4
src/lj_api.c
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@ -196,7 +196,11 @@ LUA_API int lua_type(lua_State *L, int idx)
return LUA_TNONE;
} else { /* Magic internal/external tag conversion. ORDER LJ_T */
uint32_t t = ~itype(o);
#if LJ_64
int tt = (int)((U64x(7506,98042110) >> 4*t) & 15u);
#else
int tt = (int)(((t < 8 ? 0x98042110 : 0x7506) >> 4*(t&7)) & 15u);
#endif
lua_assert(tt != LUA_TNIL || tvisnil(o));
return tt;
}