--- a/hotspot/src/cpu/sparc/vm/c1_LIRGenerator_sparc.cpp	Tue Jun 09 16:19:10 2009 -0700
+++ b/hotspot/src/cpu/sparc/vm/c1_LIRGenerator_sparc.cpp	Wed Jun 10 12:19:48 2009 -0700
@@ -371,7 +371,7 @@
   }
   __ move(value.result(), array_addr, null_check_info);
   if (obj_store) {
-    // Is this precise?
+    // Precise card mark
     post_barrier(LIR_OprFact::address(array_addr), value.result());
   }
 }
@@ -685,11 +685,8 @@
   LIR_Opr result = rlock_result(x);
   __ cmove(lir_cond_equal, LIR_OprFact::intConst(1), LIR_OprFact::intConst(0), result);
   if (type == objectType) {  // Write-barrier needed for Object fields.
-#ifdef PRECISE_CARDMARK
+    // Precise card mark since could either be object or array
     post_barrier(addr, val.result());
-#else
-    post_barrier(obj.result(), val.result());
-#endif // PRECISE_CARDMARK
   }
 }
 

--- a/hotspot/src/share/vm/c1/c1_LIRGenerator.cpp	Tue Jun 09 16:19:10 2009 -0700
+++ b/hotspot/src/share/vm/c1/c1_LIRGenerator.cpp	Wed Jun 10 12:19:48 2009 -0700
@@ -1534,12 +1534,8 @@
   }
 
   if (is_oop) {
-#ifdef PRECISE_CARDMARK
-    // Precise cardmarks don't work
-    post_barrier(LIR_OprFact::address(address), value.result());
-#else
+    // Store to object so mark the card of the header
     post_barrier(object.result(), value.result());
-#endif // PRECISE_CARDMARK
   }
 
   if (is_volatile && os::is_MP()) {

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/6849574/Test.java	Wed Jun 10 12:19:48 2009 -0700
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+/**
+ * @test
+ * @bug 6849574
+ * @summary VM crash using NonBlockingHashMap (high_scale_lib)
+ *
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+VerifyBeforeGC Test
+ */
+
+import java.util.concurrent.atomic.*;
+
+public class Test extends Thread {
+
+    public static void main(String[] args) {
+        AtomicReferenceArray a = new AtomicReferenceArray(10000);
+        for (int i = 0; i < 100000; i++) {
+            a.getAndSet(9999, new Object());
+            if (i > 99990) System.gc();
+        }
+    }
+}