Bug fix last peephole

3 files changed, 10 insertions, 8 deletions

diff --git a/chapter05/src/main/java/com/seaofnodes/simple/node/AddNode.java b/chapter05/src/main/java/com/seaofnodes/simple/node/AddNode.java
index 7cb0f822..1e9cc6c9 100644
--- a/chapter05/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/chapter05/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -79,9 +79,9 @@ public class AddNode extends Node {
             // Push constant up through the phi: x + (phi con0+con0 con1+con1...)
             
             // Note that this is the exact reverse of Phi pulling a common op
-            // down to reduce total op-count.  We don't get in a endless push-
+            // down to reduce total op-count.  We don't get in an endless push-
             // up push-down peephole cycle because the constants all fold first.
-            (t2.isConstant() || (rhs instanceof PhiNode && rhs.all_cons()) ) ) {
+            (t2.isConstant() || (rhs instanceof PhiNode && phi.in(0) == rhs.in(0) && rhs.all_cons()) ) ) {
             Node[] ns = new Node[phi.nIns()];
             ns[0] = phi.in(0);
             // Push constant up through the phi: x + (phi con0+con0 con1+con1...)
diff --git a/chapter05/src/main/java/com/seaofnodes/simple/node/PhiNode.java b/chapter05/src/main/java/com/seaofnodes/simple/node/PhiNode.java
index 4334ac10..8e0c9a79 100644
--- a/chapter05/src/main/java/com/seaofnodes/simple/node/PhiNode.java
+++ b/chapter05/src/main/java/com/seaofnodes/simple/node/PhiNode.java
@@ -50,11 +50,6 @@ public class PhiNode extends Node {
             }
             Node phi_lhs = new PhiNode(lhss).peephole();
             Node phi_rhs = new PhiNode(rhss).peephole();
-            //if( phi_lhs instanceof PhiNode && phi_rhs instanceof PhiNode ) {
-            //    phi_lhs.kill();
-            //    phi_rhs.kill();
-            //    return null;    // No progress, no profit
-            //}
             return op.copy(phi_lhs,phi_rhs);
         }
 
diff --git a/chapter05/src/test/java/com/seaofnodes/simple/Chapter05Test.java b/chapter05/src/test/java/com/seaofnodes/simple/Chapter05Test.java
index 7089e000..a4bf89ec 100644
--- a/chapter05/src/test/java/com/seaofnodes/simple/Chapter05Test.java
+++ b/chapter05/src/test/java/com/seaofnodes/simple/Chapter05Test.java
@@ -69,7 +69,14 @@ return c;
         StopNode stop = parser.parse();
         assertEquals("return Phi(Region33,Phi(Region21,2,3),Phi(Region31,4,5));", stop.toString());
     }
-    
+
+    @Test
+    public void testChapter5Merge4() {
+        Parser parser = new Parser("int a=0;int b=0;if(arg)a=1;if(arg==0)b=2;return arg+a+b;#showGraph;", TypeInteger.BOT);
+        StopNode stop = parser.parse();
+        assertEquals("return ((arg+Phi(Region13,1,0))+Phi(Region23,2,0));", stop.toString());
+    }
+
     @Test
     public void testChapter5True() {
       StopNode stop = new Parser("return true;").parse();