Changed internal representation of booleans

Instead of an explicit value (field 'b'), true and false use different
tag variants. This avoids reading an extra field and results in more
direct code. (Most code that uses booleans needs to distinguish between
true and false anyway.)

1 files changed, 10 insertions, 7 deletions

diff --git a/lobject.h b/lobject.h
index 7d30b46f..a529ceba 100644
--- a/lobject.h
+++ b/lobject.h
@@ -44,7 +44,6 @@
 typedef union Value {
   struct GCObject *gc;    /* collectable objects */
   void *p;         /* light userdata */
-  int b;           /* booleans */
   lua_CFunction f; /* light C functions */
   lua_Integer i;   /* integer numbers */
   lua_Number n;    /* float numbers */
@@ -210,16 +209,20 @@ typedef StackValue *StkId;
 ** ===================================================================
 */
 
-#define ttisboolean(o)          checktag((o), LUA_TBOOLEAN)
 
-#define bvalue(o)       check_exp(ttisboolean(o), val_(o).b)
+#define LUA_TFALSE      (LUA_TBOOLEAN | (1 << 4))
+#define LUA_TTRUE       (LUA_TBOOLEAN | (2 << 4))
 
-#define bvalueraw(v)    ((v).b)
+#define ttisboolean(o)          checktype((o), LUA_TBOOLEAN)
+#define ttisfalse(o)            checktag((o), LUA_TFALSE)
+#define ttistrue(o)             checktag((o), LUA_TTRUE)
 
-#define l_isfalse(o)    (ttisboolean(o) ? bvalue(o) == 0 : ttisnil(o))
 
-#define setbvalue(obj,x) \
-  { TValue *io=(obj); val_(io).b=(x); settt_(io, LUA_TBOOLEAN); }
+#define l_isfalse(o)    (ttisfalse(o) || ttisnil(o))
+
+
+#define setbfvalue(obj)         settt_(obj, LUA_TFALSE)
+#define setbtvalue(obj)         settt_(obj, LUA_TTRUE)
 
 /* }================================================================== */