--- old/src/share/vm/gc/g1/g1CollectedHeap.inline.hpp	2016-05-23 12:17:53.259404608 +0200
+++ new/src/share/vm/gc/g1/g1CollectedHeap.inline.hpp	2016-05-23 12:17:53.187404611 +0200
@@ -109,7 +109,7 @@
   _old_set.remove(hr);
 }
 
-// It dirties the cards that cover the block so that so that the post
+// It dirties the cards that cover the block so that the post
 // write barrier never queues anything when updating objects on this
 // block. It is assumed (and in fact we assert) that the block
 // belongs to a young region.
--- old/src/share/vm/gc/shared/collectedHeap.cpp	2016-05-23 12:17:53.495404597 +0200
+++ new/src/share/vm/gc/shared/collectedHeap.cpp	2016-05-23 12:17:53.427404600 +0200
@@ -386,7 +386,7 @@
 //     initialized by this point, a fact that we assert when doing the
 //     card-mark.)
 // (c) G1CollectedHeap(G1) uses two kinds of write barriers. When a
-//     G1 concurrent marking is in progress an SATB (pre-write-)barrier is
+//     G1 concurrent marking is in progress an SATB (pre-write-)barrier
 //     is used to remember the pre-value of any store. Initializing
 //     stores will not need this barrier, so we need not worry about
 //     compensating for the missing pre-barrier here. Turning now
--- old/src/share/vm/opto/arraycopynode.cpp	2016-05-23 12:17:53.739404585 +0200
+++ new/src/share/vm/opto/arraycopynode.cpp	2016-05-23 12:17:53.671404589 +0200
@@ -222,6 +222,7 @@
   Node* dest = in(ArrayCopyNode::Dest);
   const Type* src_type = phase->type(src);
   const TypeAryPtr* ary_src = src_type->isa_aryptr();
+  assert(ary_src != NULL, "should be an array copy/clone");
 
   if (is_arraycopy() || is_copyofrange() || is_copyof()) {
     const Type* dest_type = phase->type(dest);
@@ -523,6 +524,12 @@
     return mem;
   }
 
+  if (phase->type(in(ArrayCopyNode::Src))->isa_aryptr() == NULL) {
+    // Non-array Object.clone() with card marks is not handled by 'try_clone_instance'.
+    assert(!GraphKit::use_ReduceInitialCardMarks(), "can only happen with card marking");
+    return NULL;
+  }
+
   Node* adr_src = NULL;
   Node* base_src = NULL;
   Node* adr_dest = NULL;
--- old/src/share/vm/opto/graphKit.cpp	2016-05-23 12:17:53.995404573 +0200
+++ new/src/share/vm/opto/graphKit.cpp	2016-05-23 12:17:53.919404577 +0200
@@ -4198,8 +4198,16 @@
                                      Node* val,
                                      BasicType bt,
                                      bool use_precise) {
-  // If we are writing a NULL then we need no post barrier
+  if (val == NULL) {
+    // The Object.clone() intrinsic uses this path if !ReduceInitialCardMarks.
+    // We don't need a barrier here because the destination is a newly allocated object
+    // in Eden. Otherwise, GC verification breaks because we assume that cards in Eden
+    // are set to 'g1_young_gen' (see G1SATBCardTableModRefBS::verify_g1_young_region()).
+    assert(!use_ReduceInitialCardMarks(), "can only happen with card marking");
+    return;
+  }
 
+  // If we are writing a NULL then we need no post barrier
   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
     // Must be NULL
     const Type* t = val->bottom_type();
@@ -4274,41 +4282,34 @@
 
   // If we know the value being stored does it cross regions?
 
-  if (val != NULL) {
-    // Does the store cause us to cross regions?
-
-    // Should be able to do an unsigned compare of region_size instead of
-    // and extra shift. Do we have an unsigned compare??
-    // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
-    Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
-
-    // if (xor_res == 0) same region so skip
-    __ if_then(xor_res, BoolTest::ne, zeroX); {
-
-      // No barrier if we are storing a NULL
-      __ if_then(val, BoolTest::ne, null(), unlikely); {
-
-        // Ok must mark the card if not already dirty
-
-        // load the original value of the card
-        Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
-
-        __ if_then(card_val, BoolTest::ne, young_card); {
-          sync_kit(ideal);
-          insert_store_load_for_barrier();
-          __ sync_kit(this);
-
-          Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
-          __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
-            g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
-          } __ end_if();
+  // Should be able to do an unsigned compare of region_size instead of
+  // and extra shift. Do we have an unsigned compare??
+  // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
+  Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
+
+  // if (xor_res == 0) same region so skip
+  __ if_then(xor_res, BoolTest::ne, zeroX); {
+
+    // No barrier if we are storing a NULL
+    __ if_then(val, BoolTest::ne, null(), unlikely); {
+
+      // Ok must mark the card if not already dirty
+
+      // load the original value of the card
+      Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
+
+      __ if_then(card_val, BoolTest::ne, young_card); {
+        sync_kit(ideal);
+        insert_store_load_for_barrier();
+        __ sync_kit(this);
+
+        Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
+        __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
+          g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
         } __ end_if();
       } __ end_if();
     } __ end_if();
-  } else {
-    // Object.clone() instrinsic uses this path.
-    g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
-  }
+  } __ end_if();
 
   // Final sync IdealKit and GraphKit.
   final_sync(ideal);
--- old/test/compiler/arraycopy/TestInstanceCloneAsLoadsStores.java	2016-05-23 12:17:54.283404560 +0200
+++ new/test/compiler/arraycopy/TestInstanceCloneAsLoadsStores.java	2016-05-23 12:17:54.211404563 +0200
@@ -23,12 +23,12 @@
 
 /*
  * @test
- * @bug 6700100
+ * @bug 6700100 8156760
  * @summary small instance clone as loads/stores
  * @compile TestInstanceCloneAsLoadsStores.java TestInstanceCloneUtils.java
  * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:CompileCommand=dontinline,TestInstanceCloneAsLoadsStores::m* TestInstanceCloneAsLoadsStores
  * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:CompileCommand=dontinline,TestInstanceCloneAsLoadsStores::m* -XX:+IgnoreUnrecognizedVMOptions -XX:+StressArrayCopyMacroNode TestInstanceCloneAsLoadsStores
- *
+ * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:CompileCommand=dontinline,TestInstanceCloneAsLoadsStores::m* -XX:+IgnoreUnrecognizedVMOptions -XX:-ReduceInitialCardMarks TestInstanceCloneAsLoadsStores
  */
 
 public class TestInstanceCloneAsLoadsStores extends TestInstanceCloneUtils {