Re-embed when removing Object instance variables

Objects with the same shape must always have the same "embeddedness"
(either embedded or heap allocated) because YJIT assumes so. However,
using remove_instance_variable, it's possible that some objects are
embedded and some are heap allocated because it does not re-embed heap
allocated objects.

This commit changes remove_instance_variable to re-embed Object
instance variables when it becomes small enough.

1 files changed, 6 insertions, 0 deletions

diff --git a/object.c b/object.c
index 2bcfbc4c3c..81d1ed6f6f 100644
--- a/object.c
+++ b/object.c
@@ -92,6 +92,12 @@ static VALUE rb_cFalseClass_to_s;
 
 /*! \endcond */
 
+size_t
+rb_obj_embedded_size(uint32_t numiv)
+{
+    return offsetof(struct RObject, as.ary) + (sizeof(VALUE) * numiv);
+}
+
 VALUE
 rb_obj_hide(VALUE obj)
 {