compile.c (iseq_compile_each): reduce needless rb_str_dup

There is no need to dup the fstring unless we want to set the
debug ivar for it.

[ruby-core:72018] <5668DB6E.8000101@ruby-lang.org>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53021 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 8 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index 577b810064..f8f715ae6b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Dec 10 11:33:34 2015  Eric Wong  <e@80x24.org>
+
+	* compile.c (iseq_compile_each): reduce needless rb_str_dup
+	  [ruby-core:72018] <5668DB6E.8000101@ruby-lang.org>
+
 Thu Dec 10 09:32:51 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/mkmf.rb, lib/shellwords.rb: disable frozen-string-literal.
diff --git a/compile.c b/compile.c
index a8935db0af..44e0d81aec 100644
--- a/compile.c
+++ b/compile.c
@@ -5339,16 +5339,16 @@ iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node, int poped)
 		ADD_INSN1(ret, line, putstring, node->nd_lit);
 	    }
 	    else {
-		VALUE str = rb_str_dup(node->nd_lit);
 		if (ISEQ_COMPILE_DATA(iseq)->option->debug_frozen_string_literal || RTEST(ruby_debug)) {
 		    VALUE debug_info = rb_ary_new_from_args(2, iseq->body->location.path, INT2FIX(line));
+		    VALUE str = rb_str_dup(node->nd_lit);
 		    rb_ivar_set(str, id_debug_created_info, rb_obj_freeze(debug_info));
 		    ADD_INSN1(ret, line, putobject, rb_obj_freeze(str));
+		    iseq_add_mark_object_compile_time(iseq, str);
 		}
 		else {
-		    ADD_INSN1(ret, line, putobject, rb_fstring(str));
+		    ADD_INSN1(ret, line, putobject, node->nd_lit);
 		}
-		iseq_add_mark_object_compile_time(iseq, str);
 	    }
 	}
 	break;