--- old/src/cpu/x86/vm/vmreg_x86.inline.hpp	2014-04-24 15:53:06.000000000 -1000
+++ new/src/cpu/x86/vm/vmreg_x86.inline.hpp	2014-04-24 15:53:06.000000000 -1000
@@ -25,8 +25,10 @@
 #ifndef CPU_X86_VM_VMREG_X86_INLINE_HPP
 #define CPU_X86_VM_VMREG_X86_INLINE_HPP
 
-inline VMReg RegisterImpl::as_VMReg() {
-  if( this==noreg ) return VMRegImpl::Bad();
+inline VMReg Register::as_VMReg() const {
+  if (encoding() == noreg.encoding()) {
+    return VMRegImpl::Bad();
+  }
 #ifdef AMD64
   return VMRegImpl::as_VMReg(encoding() << 1 );
 #else
@@ -34,11 +36,11 @@
 #endif // AMD64
 }
 
-inline VMReg FloatRegisterImpl::as_VMReg() {
+inline VMReg FloatRegister::as_VMReg() const {
   return VMRegImpl::as_VMReg((encoding() << 1) + ConcreteRegisterImpl::max_gpr);
 }
 
-inline VMReg XMMRegisterImpl::as_VMReg() {
+inline VMReg XMMRegister::as_VMReg() const {
   return VMRegImpl::as_VMReg((encoding() << 3) + ConcreteRegisterImpl::max_fpr);
 }