--- old/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.aarch64/src/org/graalvm/compiler/core/aarch64/AArch64ArithmeticLIRGenerator.java	2019-03-28 07:36:41.208439058 +0100
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.aarch64/src/org/graalvm/compiler/core/aarch64/AArch64ArithmeticLIRGenerator.java	2019-03-28 07:36:40.820436463 +0100
@@ -62,11 +62,26 @@
 
 public class AArch64ArithmeticLIRGenerator extends ArithmeticLIRGenerator implements AArch64ArithmeticLIRGeneratorTool {
 
+    public AArch64ArithmeticLIRGenerator(AllocatableValue nullRegisterValue) {
+        this.nullRegisterValue = nullRegisterValue;
+    }
+
+    private final AllocatableValue nullRegisterValue;
+
     @Override
     public AArch64LIRGenerator getLIRGen() {
         return (AArch64LIRGenerator) super.getLIRGen();
     }
 
+    public boolean mustReplaceNullWithNullRegister(JavaConstant nullConstant) {
+        /* Uncompressed null pointers only */
+        return nullRegisterValue != null && JavaConstant.NULL_POINTER.equals(nullConstant);
+    }
+
+    public AllocatableValue getNullRegisterValue() {
+        return nullRegisterValue;
+    }
+
     @Override
     protected boolean isNumericInteger(PlatformKind kind) {
         return ((AArch64Kind) kind).isInteger();
@@ -485,11 +500,6 @@
     }
 
     @Override
-    public void emitCompareOp(AArch64Kind cmpKind, Variable left, Value right) {
-        throw GraalError.unimplemented();
-    }
-
-    @Override
     public Value emitRound(Value value, RoundingMode mode) {
         AArch64ArithmeticOp op;
         switch (mode) {