--- old/src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp	2019-05-03 12:32:02.352354250 +0200
+++ new/src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp	2019-05-03 12:32:02.158351534 +0200
@@ -1788,6 +1788,8 @@
     }
 #endif //ASSERT
 
+    // Note: checkcast arraycopy is always disjoint. If it were not, then we wouldn't
+    // need to checkcast.
     DecoratorSet decorators = IN_HEAP | IS_ARRAY | ARRAYCOPY_CHECKCAST | ARRAYCOPY_DISJOINT;
     bool is_oop = true;
     if (dest_uninitialized) {
--- old/src/hotspot/cpu/x86/stubGenerator_x86_64.cpp	2019-05-03 12:32:02.863361404 +0200
+++ new/src/hotspot/cpu/x86/stubGenerator_x86_64.cpp	2019-05-03 12:32:02.667358660 +0200
@@ -2343,6 +2343,8 @@
     Address from_element_addr(end_from, count, TIMES_OOP, 0);
     Address   to_element_addr(end_to,   count, TIMES_OOP, 0);
 
+    // Note: checkcast arraycopy is always disjoint. If it were not, then we wouldn't
+    // need to checkcast.
     DecoratorSet decorators = IN_HEAP | IS_ARRAY | ARRAYCOPY_CHECKCAST | ARRAYCOPY_DISJOINT;
     if (dest_uninitialized) {
       decorators |= IS_DEST_UNINITIALIZED;