x-x==0

Move x-x==0 to compute.
Add x/1 ==> x
All chapters

2 files changed, 10 insertions, 5 deletions

diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/DivNode.java
index 0d169cda..da9571db 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -35,7 +35,12 @@ public class DivNode extends Node {
     }
 
     @Override
-    public Node idealize() { return null; }
+    public Node idealize() {
+        // Div of 1.
+        if( in(2)._type.isConstant() && in(2)._type instanceof TypeInteger i && i.value()==1 )
+            return in(1);
+        return null;
+    }
 
     @Override Node copy(Node lhs, Node rhs) { return new DivNode(lhs,rhs); }
     @Override Node copyF() { return new DivFNode(null,null); }
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/SubNode.java
index 89e7227e..009fb30e 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -30,15 +30,15 @@ public class SubNode extends Node {
             if (i1.isConstant() && i2.isConstant())
                 return TypeInteger.constant(i1.value()-i2.value());
         }
+        // Sub of same is 0
+        if( in(1)==in(2) )
+            return TypeInteger.ZERO;
+
         return TypeInteger.BOT;
     }
 
     @Override
     public Node idealize() {
-        // Sub of same is 0
-        if( in(1)==in(2) )
-            return Parser.ZERO;
-
         // x - (-y) is x+y
         if( in(2) instanceof MinusNode minus )
             return new AddNode(in(1),minus.in(1));