ruby.h: swap iv_index_tbl and super for struct RClass

* include/ruby/ruby.h (struct RClass): add super, remove iv_index_tbl.
  since RCLASS_SUPER() is commonly used inside while loops, we move it
  back inside struct RClass to improve cache hits. this provides a
  small improvement (1%) in hotspots like rb_obj_is_kind_of()
* internal.h (struct rb_classext_struct): remove super, add
  iv_index_table
* internal.h (RCLASS_SUPER): update for new location
* internal.h (RCLASS_SET_SUPER): ditto
* internal.h (RCLASS_IV_INDEX_TBL): ditto
* object.c (rb_class_get_superclass): ditto
* include/ruby/backward/classext.h (RCLASS_SUPER): ditto

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44294 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

5 files changed, 21 insertions, 7 deletions

diff --git a/ChangeLog b/ChangeLog
index 4927f015db..9b8e187366 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+Fri Dec 20 14:00:01 2013  Aman Gupta <ruby@tmm1.net>
+
+	* include/ruby/ruby.h (struct RClass): add super, remove iv_index_tbl.
+	  since RCLASS_SUPER() is commonly used inside while loops, we move it
+	  back inside struct RClass to improve cache hits. this provides a
+	  small improvement (1%) in hotspots like rb_obj_is_kind_of()
+	* internal.h (struct rb_classext_struct): remove super, add
+	  iv_index_table
+	* internal.h (RCLASS_SUPER): update for new location
+	* internal.h (RCLASS_SET_SUPER): ditto
+	* internal.h (RCLASS_IV_INDEX_TBL): ditto
+	* object.c (rb_class_get_superclass): ditto
+	* include/ruby/backward/classext.h (RCLASS_SUPER): ditto
+
 Fri Dec 20 07:07:35 2013  Eric Hodel  <drbrain@segment7.net>
 
 	* lib/rubygems:  Update to RubyGems master 03d6ae7.  Changes include:
diff --git a/include/ruby/backward/classext.h b/include/ruby/backward/classext.h
index 615e6f6858..33f3b014b8 100644
--- a/include/ruby/backward/classext.h
+++ b/include/ruby/backward/classext.h
@@ -13,6 +13,6 @@ typedef struct rb_deprecated_classext_struct {
 
 #undef RCLASS_SUPER(c)
 #define RCLASS_EXT(c) ((rb_deprecated_classext_t *)RCLASS(c)->ptr)
-#define RCLASS_SUPER(c) (RCLASS_EXT(c)->super)
+#define RCLASS_SUPER(c) (RCLASS(c)->super)
 
 #endif	/* RUBY_BACKWARD_CLASSEXT_H */
diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index 9af062ec94..03b9bd0d1a 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -789,9 +789,9 @@ typedef struct rb_classext_struct rb_classext_t;
 
 struct RClass {
     struct RBasic basic;
+    VALUE super;
     rb_classext_t *ptr;
     struct method_table_wrapper *m_tbl_wrapper;
-    struct st_table *iv_index_tbl;
 };
 #define RCLASS_SUPER(c) rb_class_get_superclass(c)
 #define RMODULE_IV_TBL(m) RCLASS_IV_TBL(m)
diff --git a/internal.h b/internal.h
index d01f6cf6ec..338929ba8b 100644
--- a/internal.h
+++ b/internal.h
@@ -262,7 +262,7 @@ typedef unsigned long rb_serial_t;
 #endif
 
 struct rb_classext_struct {
-    VALUE super;
+    struct st_table *iv_index_tbl;
     struct st_table *iv_tbl;
     struct st_table *const_tbl;
     rb_subclass_entry_t *subclasses;
@@ -293,7 +293,7 @@ void rb_class_remove_from_super_subclasses(VALUE);
 #define RCLASS_CONST_TBL(c) (RCLASS_EXT(c)->const_tbl)
 #define RCLASS_M_TBL_WRAPPER(c) (RCLASS(c)->m_tbl_wrapper)
 #define RCLASS_M_TBL(c) (RCLASS_M_TBL_WRAPPER(c) ? RCLASS_M_TBL_WRAPPER(c)->tbl : 0)
-#define RCLASS_IV_INDEX_TBL(c) (RCLASS(c)->iv_index_tbl)
+#define RCLASS_IV_INDEX_TBL(c) (RCLASS_EXT(c)->iv_index_tbl)
 #define RCLASS_ORIGIN(c) (RCLASS_EXT(c)->origin)
 #define RCLASS_REFINED_CLASS(c) (RCLASS_EXT(c)->refined_class)
 #define RCLASS_SERIAL(c) (RCLASS_EXT(c)->class_serial)
@@ -312,7 +312,7 @@ RCLASS_M_TBL_INIT(VALUE c)
 static inline VALUE
 RCLASS_SUPER(VALUE klass)
 {
-    return RCLASS_EXT(klass)->super;
+    return RCLASS(klass)->super;
 }
 
 static inline VALUE
@@ -322,7 +322,7 @@ RCLASS_SET_SUPER(VALUE klass, VALUE super)
 	rb_class_remove_from_super_subclasses(klass);
 	rb_class_subclass_add(super, klass);
     }
-    OBJ_WRITE(klass, &RCLASS_EXT(klass)->super, super);
+    OBJ_WRITE(klass, &RCLASS(klass)->super, super);
     return super;
 }
 
diff --git a/object.c b/object.c
index 81c5c5643f..466ec75492 100644
--- a/object.c
+++ b/object.c
@@ -1884,7 +1884,7 @@ rb_class_superclass(VALUE klass)
 VALUE
 rb_class_get_superclass(VALUE klass)
 {
-    return RCLASS_EXT(klass)->super;
+    return RCLASS(klass)->super;
 }
 
 #define id_for_setter(name, type, message) \