hash.c: revert r43870 and add alternative parser patch for literal keys

* hash.c (hash_aset_str): revert r43870 due to performance issue
  [Bug #9188] [ruby-core:58730]
* parse.y (assoc): convert literal string hash keys to fstrings
* test/ruby/test_hash.rb (class TestHash): expand test

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44058 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,10 @@
+Sun Dec  8 10:45:05 2013  Aman Gupta <ruby@tmm1.net>
+
+	* hash.c (hash_aset_str): revert r43870 due to performance issue
+	  [Bug #9188] [ruby-core:58730]
+	* parse.y (assoc): convert literal string hash keys to fstrings
+	* test/ruby/test_hash.rb (class TestHash): expand test
+
 Sun Dec  8 10:22:38 2013  Aman Gupta <ruby@tmm1.net>
 
 	* parse.y (register_symid_str): use fstrings in symbol table

hash.c

@@ -1288,9 +1288,7 @@ static int
 hash_aset_str(st_data_t *key, st_data_t *val, struct update_arg *arg, int existing)
 {
     if (!existing) {
-	VALUE str = (VALUE)*key;
-	if (!OBJ_FROZEN(str))
-	    *key = rb_fstring(str);
+	*key = rb_str_new_frozen(*key);
     }
     return hash_aset(key, val, arg, existing);
 }

parse.y

@@ -4912,6 +4912,10 @@ assocs		: assoc
 assoc		: arg_value tASSOC arg_value
 		    {
 		    /*%%%*/
+			if (nd_type($1) == NODE_STR) {
+			    nd_set_type($1, NODE_LIT);
+			    $1->nd_lit = rb_fstring($1->nd_lit);
+			}
 			$$ = list_append(NEW_LIST($1), $3);
 		    /*%
 			$$ = dispatch2(assoc_new, $1, $3);

test/ruby/test_hash.rb

@@ -209,10 +209,11 @@ class TestHash < Test::Unit::TestCase
     assert_equal(256,     h[z])
   end
 
-  def test_ASET_string
+  def test_NEWHASH_fstring_key
     a = {"ABC" => :t}
     b = {"ABC" => :t}
     assert_same a.keys[0], b.keys[0]
+    assert_same "ABC".freeze, a.keys[0]
   end
 
   def test_EQUAL # '=='