--- old/src/os_cpu/linux_x86/vm/os_linux_x86.cpp	2012-02-23 16:37:29.701923727 +0100
+++ new/src/os_cpu/linux_x86/vm/os_linux_x86.cpp	2012-02-23 16:37:29.522428472 +0100
@@ -862,3 +862,11 @@
                       : "r" (fpu_cntrl) : "memory");
 #endif // !AMD64
 }
+
+#ifndef PRODUCT
+void os::verify_stack_alignment() {
+#ifdef AMD64
+  assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
+#endif
+}
+#endif