--- old/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot.amd64/src/org/graalvm/compiler/hotspot/amd64/AMD64HotSpotBackend.java	2019-05-14 01:06:01.872381907 +0200
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot.amd64/src/org/graalvm/compiler/hotspot/amd64/AMD64HotSpotBackend.java	2019-05-14 01:06:01.472378988 +0200
@@ -263,14 +263,19 @@
 
             if (config.useCompressedClassPointers) {
                 Register register = r10;
-                AMD64HotSpotMove.decodeKlassPointer(crb, asm, register, providers.getRegisters().getHeapBaseRegister(), src, config);
+                Register heapBase = providers.getRegisters().getHeapBaseRegister();
+                AMD64HotSpotMove.decodeKlassPointer(crb, asm, register, heapBase, src, config);
                 if (GeneratePIC.getValue(crb.getOptions())) {
-                    asm.movq(providers.getRegisters().getHeapBaseRegister(), asm.getPlaceholder(-1));
+                    asm.movq(heapBase, asm.getPlaceholder(-1));
                     crb.recordMark(config.MARKID_NARROW_OOP_BASE_ADDRESS);
                 } else {
                     if (config.narrowKlassBase != 0) {
                         // The heap base register was destroyed above, so restore it
-                        asm.movq(providers.getRegisters().getHeapBaseRegister(), config.narrowOopBase);
+                        if (config.narrowOopBase == 0L) {
+                            asm.xorq(heapBase, heapBase);
+                        } else {
+                            asm.movq(heapBase, config.narrowOopBase);
+                        }
                     }
                 }
                 asm.cmpq(inlineCacheKlass, register);