Use mrb_intern2() instead of mrb_intern(). This is for avoiding overhead by strlen().

10 files changed, 88 insertions, 80 deletions

diff --git a/src/array.c b/src/array.c
index f5d82d326..bfdb1bb97 100644
--- a/src/array.c
+++ b/src/array.c
@@ -301,7 +301,7 @@ mrb_ary_cmp(mrb_state *mrb, mrb_value ary1)
   a1 = RARRAY(ary1); a2 = RARRAY(ary2);
   if (a1->len == a2->len && a1->ptr == a2->ptr) return mrb_fixnum_value(0);
   else {
-    mrb_sym cmp = mrb_intern(mrb, "<=>");
+    mrb_sym cmp = mrb_intern2(mrb, "<=>", 3);
 
     len = RARRAY_LEN(ary1);
     if (len > RARRAY_LEN(ary2)) {
@@ -1069,7 +1069,7 @@ mrb_ary_equal(mrb_state *mrb, mrb_value ary1)
     equal_p = 0;
   }
   else if (!mrb_array_p(ary2)) {
-    if (!mrb_respond_to(mrb, ary2, mrb_intern(mrb, "to_ary"))) {
+    if (!mrb_respond_to(mrb, ary2, mrb_intern2(mrb, "to_ary", 6))) {
         equal_p = 0;
     }
     else {
diff --git a/src/class.c b/src/class.c
index 74bd10415..63b9b39da 100644
--- a/src/class.c
+++ b/src/class.c
@@ -54,7 +54,7 @@ void
 mrb_name_class(mrb_state *mrb, struct RClass *c, mrb_sym name)
 {
   mrb_obj_iv_set(mrb, (struct RObject*)c,
-                 mrb_intern(mrb, "__classid__"), mrb_symbol_value(name));
+                 mrb_intern2(mrb, "__classid__", 11), mrb_symbol_value(name));
 }
 
 #define make_metaclass(mrb, c) prepare_singleton_class((mrb), (struct RBasic*)(c))
@@ -88,7 +88,7 @@ prepare_singleton_class(mrb_state *mrb, struct RBasic *o)
   o->c = sc;
   mrb_field_write_barrier(mrb, (struct RBasic*)o, (struct RBasic*)sc);
   mrb_field_write_barrier(mrb, (struct RBasic*)sc, (struct RBasic*)o);
-  mrb_obj_iv_set(mrb, (struct RObject*)sc, mrb_intern(mrb, "__attached__"), mrb_obj_value(o));
+  mrb_obj_iv_set(mrb, (struct RObject*)sc, mrb_intern2(mrb, "__attached__", 12), mrb_obj_value(o));
 }
 
 struct RClass*
@@ -115,7 +115,7 @@ setup_class(mrb_state *mrb, mrb_value outer, struct RClass *c, mrb_sym id)
   mrb_name_class(mrb, c, id);
   mrb_const_set(mrb, outer, id, mrb_obj_value(c));
   mrb_obj_iv_set(mrb, (struct RObject*)c,
-                 mrb_intern(mrb, "__outer__"), outer);
+                 mrb_intern2(mrb, "__outer__", 9), outer);
 }
 
 struct RClass*
@@ -123,7 +123,7 @@ mrb_class_outer_module(mrb_state *mrb, struct RClass *c)
 {
   mrb_value outer;
 
-  outer = mrb_obj_iv_get(mrb, (struct RObject*)c, mrb_intern(mrb, "__outer__"));
+  outer = mrb_obj_iv_get(mrb, (struct RObject*)c, mrb_intern2(mrb, "__outer__", 9));
   if (mrb_nil_p(outer)) return 0;
   return mrb_class_ptr(outer);
 }
@@ -1138,7 +1138,7 @@ mrb_bob_missing(mrb_state *mrb, mrb_value mod)
     mrb_raise(mrb, E_TYPE_ERROR, "name should be a symbol");
   }
 
-  if (mrb_respond_to(mrb,mod,mrb_intern(mrb,"inspect"))){
+  if (mrb_respond_to(mrb,mod,mrb_intern2(mrb,"inspect",7))){
     inspect = mrb_funcall(mrb, mod, "inspect", 0);
     if (RSTRING_LEN(inspect) > 64) {
       inspect = mrb_any_to_s(mrb, mod);
@@ -1190,8 +1190,9 @@ mrb_class_path(mrb_state *mrb, struct RClass *c)
   mrb_value path;
   const char *name;
   size_t len;
+  mrb_sym classpath = mrb_intern2(mrb, "__classpath__", 13);
 
-  path = mrb_obj_iv_get(mrb, (struct RObject*)c, mrb_intern(mrb, "__classpath__"));
+  path = mrb_obj_iv_get(mrb, (struct RObject*)c, classpath);
   if (mrb_nil_p(path)) {
     struct RClass *outer = mrb_class_outer_module(mrb, c);
     mrb_sym sym = mrb_class_sym(mrb, c, outer);
@@ -1208,7 +1209,7 @@ mrb_class_path(mrb_state *mrb, struct RClass *c)
       name = mrb_sym2name_len(mrb, sym, &len);
       path = mrb_str_new(mrb, name, len);
     }
-    mrb_obj_iv_set(mrb, (struct RObject*)c, mrb_intern(mrb, "__classpath__"), path);
+    mrb_obj_iv_set(mrb, (struct RObject*)c, classpath, path);
   }
   return path;
 }
@@ -1351,7 +1352,7 @@ mrb_mod_to_s(mrb_state *mrb, mrb_value klass)
 {
   if (mrb_type(klass) == MRB_TT_SCLASS) {
     mrb_value s = mrb_str_new(mrb, "#<", 2);
-    mrb_value v = mrb_iv_get(mrb, klass, mrb_intern(mrb, "__attached__"));
+    mrb_value v = mrb_iv_get(mrb, klass, mrb_intern2(mrb, "__attached__", 12));
 
     mrb_str_cat2(mrb, s, "Class:");
     switch (mrb_type(v)) {
diff --git a/src/codegen.c b/src/codegen.c
index 7a91d597d..e9a667049 100644
--- a/src/codegen.c
+++ b/src/codegen.c
@@ -560,7 +560,7 @@ for_body(codegen_scope *s, node *tree)
   s = prev;
   genop(s, MKOP_Abc(OP_LAMBDA, cursp(), idx - base, OP_L_BLOCK));
   pop();
-  idx = new_msym(s, mrb_intern(s->mrb, "each"));
+  idx = new_msym(s, mrb_intern2(s->mrb, "each", 4));
   genop(s, MKOP_ABC(OP_SENDB, cursp(), idx, 0));
 }
 
@@ -959,7 +959,7 @@ static void
 gen_send_intern(codegen_scope *s)
 {
   pop();
-  genop(s, MKOP_ABC(OP_SEND, cursp(), new_msym(s, mrb_intern(s->mrb, "intern")), 0));
+  genop(s, MKOP_ABC(OP_SEND, cursp(), new_msym(s, mrb_intern2(s->mrb, "intern", 6)), 0));
   push();
 }
 static void
@@ -1151,12 +1151,12 @@ codegen(codegen_scope *s, node *tree, int val)
               codegen(s, n4->car, VAL);
             }
             else {
-              genop(s, MKOP_ABx(OP_GETCONST, cursp(), new_msym(s, mrb_intern(s->mrb, "StandardError"))));
+              genop(s, MKOP_ABx(OP_GETCONST, cursp(), new_msym(s, mrb_intern2(s->mrb, "StandardError", 13))));
               push();
             }
             genop(s, MKOP_AB(OP_MOVE, cursp(), exc));
             pop();
-            genop(s, MKOP_ABC(OP_SEND, cursp(), new_msym(s, mrb_intern(s->mrb, "===")), 1));
+            genop(s, MKOP_ABC(OP_SEND, cursp(), new_msym(s, mrb_intern2(s->mrb, "===", 3)), 1));
             tmp = new_label(s);
             genop(s, MKOP_AsBx(OP_JMPIF, cursp(), pos2));
             pos2 = tmp;
@@ -1360,7 +1360,7 @@ codegen(codegen_scope *s, node *tree, int val)
           if (head) {
             genop(s, MKOP_AB(OP_MOVE, cursp(), head));
             pop();
-            genop(s, MKOP_ABC(OP_SEND, cursp(), new_msym(s, mrb_intern(s->mrb, "===")), 1));
+            genop(s, MKOP_ABC(OP_SEND, cursp(), new_msym(s, mrb_intern2(s->mrb, "===", 3)), 1));
           }
           else {
             pop();
@@ -1701,7 +1701,7 @@ codegen(codegen_scope *s, node *tree, int val)
       }
       pop_n(n+1);
       if (sendv) n = CALL_MAXARGS;
-      genop(s, MKOP_ABC(OP_SEND, cursp(), new_msym(s, mrb_intern(s->mrb, "call")), n));
+      genop(s, MKOP_ABC(OP_SEND, cursp(), new_msym(s, mrb_intern2(s->mrb, "call", 4)), n));
       if (val) push();
     }
     break;
@@ -1968,7 +1968,7 @@ codegen(codegen_scope *s, node *tree, int val)
 
       default:
         {
-          int sym = new_msym(s, mrb_intern(s->mrb, "-"));
+          int sym = new_msym(s, mrb_intern2(s->mrb, "-", 1));
 
           genop(s, MKOP_ABx(OP_LOADI, cursp(), 0));
           push();
@@ -2052,7 +2052,7 @@ codegen(codegen_scope *s, node *tree, int val)
         pop();
       }
       pop();
-      sym = new_sym(s, mrb_intern(s->mrb, "compile"));
+      sym = new_sym(s, mrb_intern2(s->mrb, "compile", 7));
       genop(s, MKOP_ABC(OP_SEND, cursp(), sym, argc));
       mrb_gc_arena_restore(s->mrb, ai);
       push();
@@ -2100,7 +2100,7 @@ codegen(codegen_scope *s, node *tree, int val)
         pop();
       }
       pop();
-      sym = new_sym(s, mrb_intern(s->mrb, "compile"));
+      sym = new_sym(s, mrb_intern2(s->mrb, "compile", 7));
       genop(s, MKOP_ABC(OP_SEND, cursp(), sym, argc));
       mrb_gc_arena_restore(s->mrb, ai);
       push();
@@ -2165,7 +2165,7 @@ codegen(codegen_scope *s, node *tree, int val)
     {
       int a = new_msym(s, sym(tree->car));
       int b = new_msym(s, sym(tree->cdr));
-      int c = new_msym(s, mrb_intern(s->mrb, "alias_method"));
+      int c = new_msym(s, mrb_intern2(s->mrb, "alias_method", 12));
 
       genop(s, MKOP_A(OP_TCLASS, cursp()));
       push();
@@ -2184,7 +2184,7 @@ codegen(codegen_scope *s, node *tree, int val)
 
   case NODE_UNDEF:
     {
-      int undef = new_msym(s, mrb_intern(s->mrb, "undef_method"));
+      int undef = new_msym(s, mrb_intern2(s->mrb, "undef_method", 12));
       int num = 0;
       node *t = tree;
 
diff --git a/src/error.c b/src/error.c
index b65ff2183..7cb6b53ef 100644
--- a/src/error.c
+++ b/src/error.c
@@ -44,7 +44,7 @@ exc_initialize(mrb_state *mrb, mrb_value exc)
   mrb_value mesg;
 
   if (mrb_get_args(mrb, "|o", &mesg) == 1) {
-    mrb_iv_set(mrb, exc, mrb_intern(mrb, "mesg"), mesg);
+    mrb_iv_set(mrb, exc, mrb_intern2(mrb, "mesg", 4), mesg);
   }
   return exc;
 }
@@ -73,7 +73,7 @@ exc_exception(mrb_state *mrb, mrb_value self)
   if (argc == 0) return self;
   if (mrb_obj_equal(mrb, self, a)) return self;
   exc = mrb_obj_clone(mrb, self);
-  mrb_iv_set(mrb, exc, mrb_intern(mrb, "mesg"), a);
+  mrb_iv_set(mrb, exc, mrb_intern2(mrb, "mesg", 4), a);
 
   return exc;
 }
@@ -89,7 +89,7 @@ exc_exception(mrb_state *mrb, mrb_value self)
 static mrb_value
 exc_to_s(mrb_state *mrb, mrb_value exc)
 {
-  mrb_value mesg = mrb_attr_get(mrb, exc, mrb_intern(mrb, "mesg"));
+  mrb_value mesg = mrb_attr_get(mrb, exc, mrb_intern2(mrb, "mesg", 4));
 
   if (mrb_nil_p(mesg)) return mrb_str_new_cstr(mrb, mrb_obj_classname(mrb, exc));
   return mesg;
@@ -123,9 +123,9 @@ exc_inspect(mrb_state *mrb, mrb_value exc)
 {
   mrb_value str, mesg, file, line;
 
-  mesg = mrb_attr_get(mrb, exc, mrb_intern(mrb, "mesg"));
-  file = mrb_attr_get(mrb, exc, mrb_intern(mrb, "file"));
-  line = mrb_attr_get(mrb, exc, mrb_intern(mrb, "line"));
+  mesg = mrb_attr_get(mrb, exc, mrb_intern2(mrb, "mesg", 4));
+  file = mrb_attr_get(mrb, exc, mrb_intern2(mrb, "file", 4));
+  line = mrb_attr_get(mrb, exc, mrb_intern2(mrb, "line", 4));
 
   if (!mrb_nil_p(file) && !mrb_nil_p(line)) {
     str = file;
@@ -161,7 +161,7 @@ exc_equal(mrb_state *mrb, mrb_value exc)
   mrb_value obj;
   mrb_value mesg;
   mrb_bool equal_p;
-  mrb_sym id_mesg = mrb_intern(mrb, "mesg");
+  mrb_sym id_mesg = mrb_intern2(mrb, "mesg", 4);
 
   mrb_get_args(mrb, "o", &obj);
   if (mrb_obj_equal(mrb, exc, obj)) {
@@ -169,7 +169,7 @@ exc_equal(mrb_state *mrb, mrb_value exc)
   }
   else {
     if (mrb_obj_class(mrb, exc) != mrb_obj_class(mrb, obj)) {
-      if (mrb_respond_to(mrb, obj, mrb_intern(mrb, "message"))) {
+      if (mrb_respond_to(mrb, obj, mrb_intern2(mrb, "message", 7))) {
         mesg = mrb_funcall(mrb, obj, "message", 0);
       }
       else
@@ -191,15 +191,15 @@ exc_debug_info(mrb_state *mrb, struct RObject *exc)
   mrb_callinfo *ci = mrb->ci;
   mrb_code *pc = ci->pc;
 
-  mrb_obj_iv_set(mrb, exc, mrb_intern(mrb, "ciidx"), mrb_fixnum_value(ci - mrb->cibase));
+  mrb_obj_iv_set(mrb, exc, mrb_intern2(mrb, "ciidx", 5), mrb_fixnum_value(ci - mrb->cibase));
   ci--;
   while (ci >= mrb->cibase) {
     if (ci->proc && !MRB_PROC_CFUNC_P(ci->proc)) {
       mrb_irep *irep = ci->proc->body.irep;
 
       if (irep->filename && irep->lines && irep->iseq <= pc && pc < irep->iseq + irep->ilen) {
-        mrb_obj_iv_set(mrb, exc, mrb_intern(mrb, "file"), mrb_str_new_cstr(mrb, irep->filename));
-        mrb_obj_iv_set(mrb, exc, mrb_intern(mrb, "line"), mrb_fixnum_value(irep->lines[pc - irep->iseq - 1]));
+        mrb_obj_iv_set(mrb, exc, mrb_intern2(mrb, "file", 4), mrb_str_new_cstr(mrb, irep->filename));
+        mrb_obj_iv_set(mrb, exc, mrb_intern2(mrb, "line", 4), mrb_fixnum_value(irep->lines[pc - irep->iseq - 1]));
         return;
       }
     }
@@ -335,7 +335,7 @@ mrb_bug_errno(const char *mesg, int errno_arg)
 int
 sysexit_status(mrb_state *mrb, mrb_value err)
 {
-  mrb_value st = mrb_iv_get(mrb, err, mrb_intern(mrb, "status"));
+  mrb_value st = mrb_iv_get(mrb, err, mrb_intern2(mrb, "status", 6));
   return mrb_fixnum(st);
 }
 
@@ -373,7 +373,7 @@ make_exception(mrb_state *mrb, int argc, mrb_value *argv, int isstr)
       n = 1;
 exception_call:
       {
-        mrb_sym exc = mrb_intern(mrb, "exception");
+        mrb_sym exc = mrb_intern2(mrb, "exception", 9);
         if (mrb_respond_to(mrb, argv[0], exc)) {
           mesg = mrb_funcall_argv(mrb, argv[0], exc, n, argv+1);
         }
diff --git a/src/hash.c b/src/hash.c
index dc00c0db5..74474df95 100644
--- a/src/hash.c
+++ b/src/hash.c
@@ -262,7 +262,7 @@ mrb_hash_init_core(mrb_state *mrb, mrb_value hash)
     RHASH(hash)->flags |= MRB_HASH_PROC_DEFAULT;
     ifnone = block;
   }
-  mrb_iv_set(mrb, hash, mrb_intern(mrb, "ifnone"), ifnone);
+  mrb_iv_set(mrb, hash, mrb_intern2(mrb, "ifnone", 6), ifnone);
   return hash;
 }
 
@@ -427,7 +427,7 @@ mrb_hash_set_default(mrb_state *mrb, mrb_value hash)
 
   mrb_get_args(mrb, "o", &ifnone);
   mrb_hash_modify(mrb, hash);
-  mrb_iv_set(mrb, hash, mrb_intern(mrb, "ifnone"), ifnone);
+  mrb_iv_set(mrb, hash, mrb_intern2(mrb, "ifnone", 6), ifnone);
   RHASH(hash)->flags &= ~(MRB_HASH_PROC_DEFAULT);
 
   return ifnone;
@@ -478,7 +478,7 @@ mrb_hash_set_default_proc(mrb_state *mrb, mrb_value hash)
 
   mrb_get_args(mrb, "o", &ifnone);
   mrb_hash_modify(mrb, hash);
-  mrb_iv_set(mrb, hash, mrb_intern(mrb, "ifnone"), ifnone);
+  mrb_iv_set(mrb, hash, mrb_intern2(mrb, "ifnone", 6), ifnone);
   RHASH(hash)->flags |= MRB_HASH_PROC_DEFAULT;
 
   return ifnone;
@@ -759,7 +759,7 @@ mrb_hash_replace(mrb_state *mrb, mrb_value hash)
   else {
     ifnone = RHASH_IFNONE(hash2);
   }
-  mrb_iv_set(mrb, hash, mrb_intern(mrb, "ifnone"), ifnone);
+  mrb_iv_set(mrb, hash, mrb_intern2(mrb, "ifnone", 6), ifnone);
 
   return hash;
 }
@@ -1104,7 +1104,7 @@ hash_equal(mrb_state *mrb, mrb_value hash1, mrb_value hash2, int eql)
 
   if (mrb_obj_equal(mrb, hash1, hash2)) return mrb_true_value();
   if (!mrb_hash_p(hash2)) {
-      if (!mrb_respond_to(mrb, hash2, mrb_intern(mrb, "to_hash"))) {
+      if (!mrb_respond_to(mrb, hash2, mrb_intern2(mrb, "to_hash", 7))) {
           return mrb_false_value();
       }
       if (eql)
diff --git a/src/kernel.c b/src/kernel.c
index 66bd7b233..0c746d987 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -29,7 +29,7 @@ typedef enum {
 int
 mrb_obj_basic_to_s_p(mrb_state *mrb, mrb_value obj)
 {
-    struct RProc *me = mrb_method_search(mrb, mrb_class(mrb, obj), mrb_intern(mrb, "to_s"));
+    struct RProc *me = mrb_method_search(mrb, mrb_class(mrb, obj), mrb_intern2(mrb, "to_s", 4));
     if (me && MRB_PROC_CFUNC_P(me) && (me->body.func == mrb_any_to_s))
       return TRUE;
     return FALSE;
@@ -283,7 +283,7 @@ mrb_singleton_class_clone(mrb_state *mrb, mrb_value obj)
     clone->super = klass->super;
     if (klass->iv) {
       mrb_iv_copy(mrb, mrb_obj_value(clone), mrb_obj_value(klass));
-      mrb_obj_iv_set(mrb, (struct RObject*)clone, mrb_intern(mrb, "__attached__"), obj);
+      mrb_obj_iv_set(mrb, (struct RObject*)clone, mrb_intern2(mrb, "__attached__", 12), obj);
     }
     if (klass->mt) {
       clone->mt = kh_copy(mt, mrb, klass->mt);
@@ -928,7 +928,7 @@ mrb_f_raise(mrb_state *mrb, mrb_value self)
     /* fall through */
   default:
     exc = mrb_make_exception(mrb, argc, a);
-    mrb_obj_iv_set(mrb, mrb_obj_ptr(exc), mrb_intern(mrb, "lastpc"), mrb_voidp_value(mrb->ci->pc));
+    mrb_obj_iv_set(mrb, mrb_obj_ptr(exc), mrb_intern2(mrb, "lastpc", 6), mrb_voidp_value(mrb->ci->pc));
     mrb_exc_raise(mrb, exc);
     break;
   }
diff --git a/src/parse.y b/src/parse.y
index 8f1241d33..f59f2e364 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -68,6 +68,13 @@ intern_gen(parser_state *p, const char *s)
 }
 #define intern(s) intern_gen(p,(s))
 
+static inline mrb_sym
+intern_gen2(parser_state *p, const char *s, size_t len)
+{
+  return mrb_intern2(p->mrb, s, len);
+}
+#define intern2(s,len) intern_gen2(p,(s),(len))
+
 static void
 cons_free_gen(parser_state *p, node *cons)
 {
@@ -1214,7 +1221,7 @@ stmt		: keyword_alias fsym {p->lstate = EXPR_FNAME;} fsym
 		    }
 		| primary_value '[' opt_call_args rbracket tOP_ASGN command_call
 		    {
-		      $$ = new_op_asgn(p, new_call(p, $1, intern("[]"), $3), $5, $6);
+		      $$ = new_op_asgn(p, new_call(p, $1, intern2("[]",2), $3), $5, $6);
 		    }
 		| primary_value '.' tIDENTIFIER tOP_ASGN command_call
 		    {
@@ -1453,7 +1460,7 @@ mlhs_node	: variable
 		    }
 		| primary_value '[' opt_call_args rbracket
 		    {
-		      $$ = new_call(p, $1, intern("[]"), $3);
+		      $$ = new_call(p, $1, intern2("[]",2), $3);
 		    }
 		| primary_value '.' tIDENTIFIER
 		    {
@@ -1492,7 +1499,7 @@ lhs		: variable
 		    }
 		| primary_value '[' opt_call_args rbracket
 		    {
-		      $$ = new_call(p, $1, intern("[]"), $3);
+		      $$ = new_call(p, $1, intern2("[]",2), $3);
 		    }
 		| primary_value '.' tIDENTIFIER
 		    {
@@ -1578,31 +1585,31 @@ undef_list	: fsym
 op		: '|'		{ $$ = intern("|"); }
 		| '^'		{ $$ = intern("^"); }
 		| '&'		{ $$ = intern("&"); }
-		| tCMP		{ $$ = intern("<=>"); }
-		| tEQ		{ $$ = intern("=="); }
-		| tEQQ		{ $$ = intern("==="); }
-		| tMATCH	{ $$ = intern("=~"); }
-		| tNMATCH	{ $$ = intern("!~"); }
+		| tCMP		{ $$ = intern2("<=>",3); }
+		| tEQ		{ $$ = intern2("==",2); }
+		| tEQQ		{ $$ = intern2("===",3); }
+		| tMATCH	{ $$ = intern2("=~",2); }
+		| tNMATCH	{ $$ = intern2("!~",2); }
 		| '>'		{ $$ = intern(">"); }
-		| tGEQ		{ $$ = intern(">="); }
+		| tGEQ		{ $$ = intern2(">=",2); }
 		| '<'		{ $$ = intern("<"); }
-		| tLEQ		{ $$ = intern("<="); }
-		| tNEQ		{ $$ = intern("!="); }
-		| tLSHFT	{ $$ = intern("<<"); }
-		| tRSHFT	{ $$ = intern(">>"); }
+		| tLEQ		{ $$ = intern2("<=",2); }
+		| tNEQ		{ $$ = intern2("!=",2); }
+		| tLSHFT	{ $$ = intern2("<<",2); }
+		| tRSHFT	{ $$ = intern2(">>",2); }
 		| '+'		{ $$ = intern("+"); }
 		| '-'		{ $$ = intern("-"); }
 		| '*'		{ $$ = intern("*"); }
 		| tSTAR		{ $$ = intern("*"); }
 		| '/'		{ $$ = intern("/"); }
 		| '%'		{ $$ = intern("%"); }
-		| tPOW		{ $$ = intern("**"); }
+		| tPOW		{ $$ = intern2("**",2); }
 		| '!'		{ $$ = intern("!"); }
 		| '~'		{ $$ = intern("~"); }
-		| tUPLUS	{ $$ = intern("+@"); }
-		| tUMINUS	{ $$ = intern("-@"); }
-		| tAREF		{ $$ = intern("[]"); }
-		| tASET		{ $$ = intern("[]="); }
+		| tUPLUS	{ $$ = intern2("+@",2); }
+		| tUMINUS	{ $$ = intern2("-@",2); }
+		| tAREF		{ $$ = intern2("[]",2); }
+		| tASET		{ $$ = intern2("[]=",3); }
 		;
 
 reswords	: keyword__LINE__ | keyword__FILE__ | keyword__ENCODING__
@@ -1637,7 +1644,7 @@ arg		: lhs '=' arg
 		    }
 		| primary_value '[' opt_call_args rbracket tOP_ASGN arg
 		    {
-		      $$ = new_op_asgn(p, new_call(p, $1, intern("[]"), $3), $5, $6);
+		      $$ = new_op_asgn(p, new_call(p, $1, intern2("[]",2), $3), $5, $6);
 		    }
 		| primary_value '.' tIDENTIFIER tOP_ASGN arg
 		    {
@@ -2445,11 +2452,11 @@ method_call	: operation paren_args
 		    }
 		| primary_value '.' paren_args
 		    {
-		      $$ = new_call(p, $1, intern("call"), $3);
+		      $$ = new_call(p, $1, intern2("call",4), $3);
 		    }
 		| primary_value tCOLON2 paren_args
 		    {
-		      $$ = new_call(p, $1, intern("call"), $3);
+		      $$ = new_call(p, $1, intern2("call",4), $3);
 		    }
 		| keyword_super paren_args
 		    {
@@ -2461,7 +2468,7 @@ method_call	: operation paren_args
 		    }
 		| primary_value '[' opt_call_args rbracket
 		    {
-		      $$ = new_call(p, $1, intern("[]"), $3);
+		      $$ = new_call(p, $1, intern2("[]",2), $3);
 		    }
 		;
 
@@ -3840,7 +3847,7 @@ parser_yylex(parser_state *p)
   case '*':
     if ((c = nextc(p)) == '*') {
       if ((c = nextc(p)) == '=') {
-	yylval.id = intern("**");
+	yylval.id = intern2("**",2);
 	p->lstate = EXPR_BEG;
 	return tOP_ASGN;
       }
@@ -3949,7 +3956,7 @@ parser_yylex(parser_state *p)
     }
     if (c == '<') {
       if ((c = nextc(p)) == '=') {
-	yylval.id = intern("<<");
+	yylval.id = intern2("<<",2);
 	p->lstate = EXPR_BEG;
 	return tOP_ASGN;
       }
@@ -3970,7 +3977,7 @@ parser_yylex(parser_state *p)
     }
     if (c == '>') {
       if ((c = nextc(p)) == '=') {
-	yylval.id = intern(">>");
+	yylval.id = intern2(">>",2);
 	p->lstate = EXPR_BEG;
 	return tOP_ASGN;
       }
@@ -4069,7 +4076,7 @@ parser_yylex(parser_state *p)
     if ((c = nextc(p)) == '&') {
       p->lstate = EXPR_BEG;
       if ((c = nextc(p)) == '=') {
-	yylval.id = intern("&&");
+	yylval.id = intern2("&&",2);
 	p->lstate = EXPR_BEG;
 	return tOP_ASGN;
       }
@@ -4103,7 +4110,7 @@ parser_yylex(parser_state *p)
     if ((c = nextc(p)) == '|') {
       p->lstate = EXPR_BEG;
       if ((c = nextc(p)) == '=') {
-	yylval.id = intern("||");
+	yylval.id = intern2("||",2);
 	p->lstate = EXPR_BEG;
 	return tOP_ASGN;
       }
diff --git a/src/string.c b/src/string.c
index 8f16a4ef0..97d53cd6c 100644
--- a/src/string.c
+++ b/src/string.c
@@ -532,10 +532,10 @@ mrb_str_cmp_m(mrb_state *mrb, mrb_value str1)
 
   mrb_get_args(mrb, "o", &str2);
   if (!mrb_string_p(str2)) {
-    if (!mrb_respond_to(mrb, str2, mrb_intern(mrb, "to_s"))) {
+    if (!mrb_respond_to(mrb, str2, mrb_intern2(mrb, "to_s", 4))) {
       return mrb_nil_value();
     }
-    else if (!mrb_respond_to(mrb, str2, mrb_intern(mrb, "<=>"))) {
+    else if (!mrb_respond_to(mrb, str2, mrb_intern2(mrb, "<=>", 3))) {
       return mrb_nil_value();
     }
     else {
@@ -572,7 +572,7 @@ mrb_str_equal(mrb_state *mrb, mrb_value str1, mrb_value str2)
   if (mrb_obj_equal(mrb, str1, str2)) return TRUE;
   if (!mrb_string_p(str2)) {
     if (mrb_nil_p(str2)) return FALSE;
-    if (!mrb_respond_to(mrb, str2, mrb_intern(mrb, "to_str"))) {
+    if (!mrb_respond_to(mrb, str2, mrb_intern2(mrb, "to_str", 6))) {
       return FALSE;
     }
     str2 = mrb_funcall(mrb, str2, "to_str", 0);
diff --git a/src/variable.c b/src/variable.c
index 850999042..4345f49a7 100644
--- a/src/variable.c
+++ b/src/variable.c
@@ -832,7 +832,7 @@ L_RETRY:
     goto L_RETRY;
   }
   c = base;
-  cm = mrb_intern(mrb, "const_missing");
+  cm = mrb_intern2(mrb, "const_missing", 13);
   while (c) {
     if (mrb_respond_to(mrb, mrb_obj_value(c), cm)) {
       mrb_value name = mrb_symbol_value(sym);
@@ -1047,7 +1047,7 @@ mrb_class_sym(mrb_state *mrb, struct RClass *c, struct RClass *outer)
 {
   mrb_value name;
 
-  name = mrb_obj_iv_get(mrb, (struct RObject*)c, mrb_intern(mrb, "__classid__"));
+  name = mrb_obj_iv_get(mrb, (struct RObject*)c, mrb_intern2(mrb, "__classid__", 11));
   if (mrb_nil_p(name)) {
 
     if (!outer) return 0;
diff --git a/src/vm.c b/src/vm.c
index 881acf4fc..393ce3e0d 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -349,7 +349,7 @@ mrb_funcall_with_block(mrb_state *mrb, mrb_value self, mrb_sym mid, int argc, mr
     p = mrb_method_search_vm(mrb, &c, mid);
     if (!p) {
       undef = mid;
-      mid = mrb_intern(mrb, "method_missing");
+      mid = mrb_intern2(mrb, "method_missing", 14);
       p = mrb_method_search_vm(mrb, &c, mid);
       n++; argc++;
     }
@@ -869,7 +869,7 @@ mrb_run(mrb_state *mrb, struct RProc *proc, mrb_value self)
       if (!m) {
         mrb_value sym = mrb_symbol_value(mid);
 
-        mid = mrb_intern(mrb, "method_missing");
+        mid = mrb_intern2(mrb, "method_missing", 14);
         m = mrb_method_search_vm(mrb, &c, mid);
         if (n == CALL_MAXARGS) {
           mrb_ary_unshift(mrb, regs[a+1], sym);
@@ -1011,7 +1011,7 @@ mrb_run(mrb_state *mrb, struct RProc *proc, mrb_value self)
       c = mrb->ci->target_class->super;
       m = mrb_method_search_vm(mrb, &c, mid);
       if (!m) {
-        mid = mrb_intern(mrb, "method_missing");
+        mid = mrb_intern2(mrb, "method_missing", 14);
         m = mrb_method_search_vm(mrb, &c, mid);
         if (n == CALL_MAXARGS) {
           mrb_ary_unshift(mrb, regs[a+1], mrb_symbol_value(ci->mid));
@@ -1216,8 +1216,8 @@ mrb_run(mrb_state *mrb, struct RProc *proc, mrb_value self)
 
       L_RAISE:
         ci = mrb->ci;
-        mrb_obj_iv_ifnone(mrb, mrb->exc, mrb_intern(mrb, "lastpc"), mrb_voidp_value(pc));
-        mrb_obj_iv_ifnone(mrb, mrb->exc, mrb_intern(mrb, "ciidx"), mrb_fixnum_value(ci - mrb->cibase));
+        mrb_obj_iv_ifnone(mrb, mrb->exc, mrb_intern2(mrb, "lastpc", 6), mrb_voidp_value(pc));
+        mrb_obj_iv_ifnone(mrb, mrb->exc, mrb_intern2(mrb, "ciidx", 5), mrb_fixnum_value(ci - mrb->cibase));
         eidx = ci->eidx;
         if (ci == mrb->cibase) {
           if (ci->ridx == 0) goto L_STOP;
@@ -1333,7 +1333,7 @@ mrb_run(mrb_state *mrb, struct RProc *proc, mrb_value self)
       if (!m) {
         mrb_value sym = mrb_symbol_value(mid);
 
-        mid = mrb_intern(mrb, "method_missing");
+        mid = mrb_intern2(mrb, "method_missing", 14);
         m = mrb_method_search_vm(mrb, &c, mid);
         if (n == CALL_MAXARGS) {
           mrb_ary_unshift(mrb, regs[a+1], sym);