1 files changed, 4 insertions, 4 deletions
diff --git a/chapter04/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter04/src/main/java/com/seaofnodes/simple/node/SubNode.java
index 27e77f90..58d757ea 100644
--- a/chapter04/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/chapter04/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -19,6 +19,10 @@ public class SubNode extends Node {
 
     @Override
     public Type compute() {
+        // Sub of same is 0
+        if( in(1)==in(2) )
+            return TypeInteger.ZERO;
+
         if (in(1)._type instanceof TypeInteger i0 &&
             in(2)._type instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
@@ -30,10 +34,6 @@ public class SubNode extends Node {
 
     @Override
     public Node idealize() {
-        // Sub of same is 0
-        if( in(1)==in(2) )
-            return new ConstantNode(TypeInteger.constant(0));
-
         return null;
     }