diff -r c6c141c46516 src/cpu/x86/vm/stubGenerator_x86_64.cpp
--- a/src/cpu/x86/vm/stubGenerator_x86_64.cpp	Mon Feb 29 13:02:10 2016 +0100
+++ b/src/cpu/x86/vm/stubGenerator_x86_64.cpp	Mon Feb 29 22:09:53 2016 +0300
@@ -2147,6 +2147,22 @@
     __ lea(end_from, Address(from, qword_count, Address::times_8, -8));
     __ lea(end_to,   Address(to,   qword_count, Address::times_8, -8));
     __ negptr(qword_count);
+
+    // Pre-loop to align destination
+    if (UseNewCode) {
+      Label L_preloop;
+      __ BIND(L_preloop);
+      __ movq(rax, Address(end_from, qword_count, Address::times_8, 8));
+      __ movq(Address(end_to, qword_count, Address::times_8, 8), rax);
+
+      __ lea(rax, Address(end_to, qword_count, Address::times_8, 8));
+      __ testptr(rax, 63);
+      __ jcc(Assembler::zero, L_copy_bytes);
+
+      __ increment(qword_count);
+      __ jcc(Assembler::lessEqual, L_preloop);
+    }
+
     __ jmp(L_copy_bytes);
 
     // Copy trailing qwords