diff --git a/lcode.c b/lcode.c
index ff65279b..c11005c7 100644
--- a/lcode.c
+++ b/lcode.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lcode.c,v 2.57 2011/07/15 12:50:29 roberto Exp roberto $
+** $Id: lcode.c,v 2.58 2011/07/27 18:07:37 roberto Exp roberto $
 ** Code generator for Lua
 ** See Copyright Notice in lua.h
 */
@@ -304,6 +304,8 @@ static int addk (FuncState *fs, TValue *key, TValue *v) {
   /* constant not found; create a new entry */
   oldsize = f->sizek;
   k = fs->nk;
+  /* numerical value does not need GC barrier;
+     table has no metatable, so it does not need to invalidate cache */
   setnvalue(idx, cast_num(k));
   luaM_growvector(L, f->k, k, f->sizek, TValue, MAXARG_Ax, "constants");
   while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]);
diff --git a/llex.c b/llex.c
index d14ff03e..2cf8d16e 100644
--- a/llex.c
+++ b/llex.c
@@ -1,5 +1,5 @@
 /*
-** $Id: llex.c,v 2.56 2011/08/09 20:58:29 roberto Exp roberto $
+** $Id: llex.c,v 2.57 2011/08/11 17:06:12 roberto Exp roberto $
 ** Lexical Analyzer
 ** See Copyright Notice in lua.h
 */
@@ -128,6 +128,8 @@ TString *luaX_newstring (LexState *ls, const char *str, size_t l) {
   setsvalue2s(L, L->top++, ts);  /* temporarily anchor it in stack */
   o = luaH_set(L, ls->fs->h, L->top - 1);
   if (ttisnil(o)) {  /* not in use yet? (see 'addK') */
+    /* boolean value does not need GC barrier;
+       table has no metatable, so it does not need to invalidate cache */
     setbvalue(o, 1);  /* t[string] = true */
     luaC_checkGC(L);
   }