Make every initial size pool shape a root shape

This commit makes every initial size pool shape a root shape and assigns
it a capacity of 0.

8 files changed, 7 insertions, 29 deletions

diff --git a/ext/objspace/objspace_dump.c b/ext/objspace/objspace_dump.c
index bcee5312fc..c80c38eba4 100644
--- a/ext/objspace/objspace_dump.c
+++ b/ext/objspace/objspace_dump.c
@@ -776,11 +776,6 @@ shape_i(rb_shape_t *shape, void *data)
         dump_append(dc, ", \"capacity\":");
         dump_append_sizet(dc, shape->capacity);
         break;
-      case SHAPE_INITIAL_CAPACITY:
-        dump_append(dc, "\"INITIAL_CAPACITY\"");
-        dump_append(dc, ", \"capacity\":");
-        dump_append_sizet(dc, shape->capacity);
-        break;
       case SHAPE_T_OBJECT:
         dump_append(dc, "\"T_OBJECT\"");
         break;
diff --git a/gc.c b/gc.c
index 6f13ff9284..efbb254168 100644
--- a/gc.c
+++ b/gc.c
@@ -2980,8 +2980,7 @@ rb_class_instance_allocate_internal(VALUE klass, VALUE flags, bool wb_protected)
     }
 
     VALUE obj = newobj_of(GET_RACTOR(), klass, flags, 0, 0, 0, wb_protected, size);
-    RUBY_ASSERT(rb_shape_get_shape(obj)->type == SHAPE_ROOT ||
-            rb_shape_get_shape(obj)->type == SHAPE_INITIAL_CAPACITY);
+    RUBY_ASSERT(rb_shape_get_shape(obj)->type == SHAPE_ROOT);
 
     // Set the shape to the specific T_OBJECT shape which is always
     // SIZE_POOL_COUNT away from the root shape.
diff --git a/rjit_c.rb b/rjit_c.rb
index 949040e10e..cde9109b16 100644
--- a/rjit_c.rb
+++ b/rjit_c.rb
@@ -416,7 +416,6 @@ module RubyVM::RJIT # :nodoc: all
   C::SHAPE_FLAG_SHIFT = Primitive.cexpr! %q{ SIZET2NUM(SHAPE_FLAG_SHIFT) }
   C::SHAPE_FROZEN = Primitive.cexpr! %q{ SIZET2NUM(SHAPE_FROZEN) }
   C::SHAPE_ID_NUM_BITS = Primitive.cexpr! %q{ SIZET2NUM(SHAPE_ID_NUM_BITS) }
-  C::SHAPE_INITIAL_CAPACITY = Primitive.cexpr! %q{ SIZET2NUM(SHAPE_INITIAL_CAPACITY) }
   C::SHAPE_IVAR = Primitive.cexpr! %q{ SIZET2NUM(SHAPE_IVAR) }
   C::SHAPE_MASK = Primitive.cexpr! %q{ SIZET2NUM(SHAPE_MASK) }
   C::SHAPE_ROOT = Primitive.cexpr! %q{ SIZET2NUM(SHAPE_ROOT) }
diff --git a/shape.c b/shape.c
index 4510c618d4..bc0951082f 100644
--- a/shape.c
+++ b/shape.c
@@ -442,7 +442,6 @@ rb_shape_alloc_new_child(ID id, rb_shape_t * shape, enum shape_type shape_type)
         new_shape->next_iv_index = shape->next_iv_index;
         break;
       case SHAPE_OBJ_TOO_COMPLEX:
-      case SHAPE_INITIAL_CAPACITY:
       case SHAPE_ROOT:
         rb_bug("Unreachable");
         break;
@@ -756,7 +755,6 @@ rb_shape_get_iv_index(rb_shape_t * shape, ID id, attr_index_t *value)
                     return true;
                   case SHAPE_CAPACITY_CHANGE:
                   case SHAPE_ROOT:
-                  case SHAPE_INITIAL_CAPACITY:
                   case SHAPE_T_OBJECT:
                     return false;
                   case SHAPE_OBJ_TOO_COMPLEX:
@@ -823,7 +821,6 @@ rb_shape_traverse_from_new_root(rb_shape_t *initial_shape, rb_shape_t *dest_shap
         break;
       case SHAPE_ROOT:
       case SHAPE_CAPACITY_CHANGE:
-      case SHAPE_INITIAL_CAPACITY:
       case SHAPE_T_OBJECT:
         break;
       case SHAPE_OBJ_TOO_COMPLEX:
@@ -868,7 +865,6 @@ rb_shape_rebuild_shape(rb_shape_t * initial_shape, rb_shape_t * dest_shape)
       case SHAPE_ROOT:
       case SHAPE_FROZEN:
       case SHAPE_CAPACITY_CHANGE:
-      case SHAPE_INITIAL_CAPACITY:
       case SHAPE_T_OBJECT:
         break;
       case SHAPE_OBJ_TOO_COMPLEX:
@@ -1149,8 +1145,8 @@ Init_default_shapes(void)
     }
 
     // Root shape
-    rb_shape_t * root = rb_shape_alloc_with_parent_id(0, INVALID_SHAPE_ID);
-    root->capacity = (uint32_t)((rb_size_pool_slot_size(0) - offsetof(struct RObject, as.ary)) / sizeof(VALUE));
+    rb_shape_t *root = rb_shape_alloc_with_parent_id(0, INVALID_SHAPE_ID);
+    root->capacity = 0;
     root->type = SHAPE_ROOT;
     root->size_pool_index = 0;
     GET_SHAPE_TREE()->root_shape = root;
@@ -1158,9 +1154,8 @@ Init_default_shapes(void)
 
     // Shapes by size pool
     for (int i = 1; i < SIZE_POOL_COUNT; i++) {
-        size_t capa = ((rb_size_pool_slot_size(i) - offsetof(struct RObject, as.ary)) / sizeof(VALUE));
-        rb_shape_t * new_shape = rb_shape_transition_shape_capa_create(root, capa);
-        new_shape->type = SHAPE_INITIAL_CAPACITY;
+        rb_shape_t *new_shape = rb_shape_alloc_with_parent_id(0, INVALID_SHAPE_ID);
+        new_shape->type = SHAPE_ROOT;
         new_shape->size_pool_index = i;
         new_shape->ancestor_index = LEAF;
         RUBY_ASSERT(rb_shape_id(new_shape) == (shape_id_t)i);
@@ -1172,6 +1167,7 @@ Init_default_shapes(void)
         bool dont_care;
         rb_shape_t * t_object_shape =
             get_next_shape_internal(shape, id_t_object, SHAPE_T_OBJECT, &dont_care, true);
+        t_object_shape->capacity = (uint32_t)((rb_size_pool_slot_size(i) - offsetof(struct RObject, as.ary)) / sizeof(VALUE));
         t_object_shape->edges = rb_id_table_create(0);
         t_object_shape->ancestor_index = LEAF;
         RUBY_ASSERT(rb_shape_id(t_object_shape) == (shape_id_t)(i + SIZE_POOL_COUNT));
diff --git a/shape.h b/shape.h
index 00d90e6161..bcfd94b964 100644
--- a/shape.h
+++ b/shape.h
@@ -65,7 +65,6 @@ enum shape_type {
     SHAPE_IVAR,
     SHAPE_FROZEN,
     SHAPE_CAPACITY_CHANGE,
-    SHAPE_INITIAL_CAPACITY,
     SHAPE_T_OBJECT,
     SHAPE_OBJ_TOO_COMPLEX,
 };
diff --git a/test/ruby/test_shapes.rb b/test/ruby/test_shapes.rb
index b627b58281..09a99c4855 100644
--- a/test/ruby/test_shapes.rb
+++ b/test/ruby/test_shapes.rb
@@ -691,14 +691,6 @@ class TestShapes < Test::Unit::TestCase
     assert_shape_equal(RubyVM::Shape.root_shape, RubyVM::Shape.of([]))
   end
 
-  def test_hash_has_correct_pool_shape
-    omit "SHAPE_IN_BASIC_FLAGS == 0" unless RbConfig::SIZEOF["uint64_t"] <= RbConfig::SIZEOF["void*"]
-
-    # All hashes are now allocated their own ar_table, so start in a
-    # larger pool, and have already transitioned once.
-    assert_shape_equal(RubyVM::Shape.root_shape, RubyVM::Shape.of({}).parent)
-  end
-
   def test_true_has_special_const_shape_id
     assert_equal(RubyVM::Shape::SPECIAL_CONST_SHAPE_ID, RubyVM::Shape.of(true).id)
   end
diff --git a/tool/rjit/bindgen.rb b/tool/rjit/bindgen.rb
index deb989dcfd..ebb58d8281 100755
--- a/tool/rjit/bindgen.rb
+++ b/tool/rjit/bindgen.rb
@@ -439,7 +439,6 @@ generator = BindingGenerator.new(
       SHAPE_FLAG_SHIFT
       SHAPE_FROZEN
       SHAPE_ID_NUM_BITS
-      SHAPE_INITIAL_CAPACITY
       SHAPE_IVAR
       SHAPE_MASK
       SHAPE_ROOT
diff --git a/variable.c b/variable.c
index 496e70589f..48ca1452df 100644
--- a/variable.c
+++ b/variable.c
@@ -1870,7 +1870,6 @@ iterate_over_shapes_with_callback(rb_shape_t *shape, rb_ivar_foreach_callback_fu
             }
         }
         return false;
-      case SHAPE_INITIAL_CAPACITY:
       case SHAPE_CAPACITY_CHANGE:
       case SHAPE_FROZEN:
       case SHAPE_T_OBJECT:
@@ -4210,7 +4209,7 @@ rb_iv_tbl_copy(VALUE dst, VALUE src)
     RUBY_ASSERT(rb_type(dst) == rb_type(src));
     RUBY_ASSERT(RB_TYPE_P(dst, T_CLASS) || RB_TYPE_P(dst, T_MODULE));
 
-    RUBY_ASSERT(RCLASS_SHAPE_ID(dst) == ROOT_SHAPE_ID || rb_shape_get_shape_by_id(RCLASS_SHAPE_ID(dst))->type == SHAPE_INITIAL_CAPACITY);
+    RUBY_ASSERT(rb_shape_get_shape(dst)->type == SHAPE_ROOT);
     RUBY_ASSERT(!RCLASS_IVPTR(dst));
 
     rb_ivar_foreach(src, tbl_copy_i, dst);