Implement Objects on VWA

This commit implements Objects on Variable Width Allocation. This allows
Objects with more ivars to be embedded (i.e. contents directly follow the
object header) which improves performance through better cache locality.

1 files changed, 6 insertions, 27 deletions

diff --git a/object.c b/object.c
index 6a7b2cbf23..4baf7ffc56 100644
--- a/object.c
+++ b/object.c
@@ -267,34 +267,13 @@ rb_obj_singleton_class(VALUE obj)
 MJIT_FUNC_EXPORTED void
 rb_obj_copy_ivar(VALUE dest, VALUE obj)
 {
-    VALUE *dst_buf = 0;
-    VALUE *src_buf = 0;
-    uint32_t len = ROBJECT_EMBED_LEN_MAX;
+    VALUE *dest_buf = ROBJECT_IVPTR(dest);
+    VALUE *src_buf = ROBJECT_IVPTR(obj);
+    uint32_t dest_len = ROBJECT_NUMIV(dest);
+    uint32_t src_len = ROBJECT_NUMIV(obj);
+    uint32_t len = dest_len < src_len ? dest_len : src_len;
 
-    if (RBASIC(obj)->flags & ROBJECT_EMBED) {
-        src_buf = ROBJECT(obj)->as.ary;
-
-        // embedded -> embedded
-        if (RBASIC(dest)->flags & ROBJECT_EMBED) {
-            dst_buf = ROBJECT(dest)->as.ary;
-        }
-        // embedded -> extended
-        else {
-            dst_buf = ROBJECT(dest)->as.heap.ivptr;
-        }
-    }
-    // extended -> extended
-    else {
-        RUBY_ASSERT(!(RBASIC(dest)->flags & ROBJECT_EMBED));
-        uint32_t src_len = ROBJECT(obj)->as.heap.numiv;
-        uint32_t dst_len = ROBJECT(dest)->as.heap.numiv;
-
-        len = src_len < dst_len ? src_len : dst_len;
-        dst_buf = ROBJECT(dest)->as.heap.ivptr;
-        src_buf = ROBJECT(obj)->as.heap.ivptr;
-    }
-
-    MEMCPY(dst_buf, src_buf, VALUE, len);
+    MEMCPY(dest_buf, src_buf, VALUE, len);
 }
 
 static void