From 684c23f1c5257886a219d540ac4ec0e574b7e49b Mon Sep 17 00:00:00 2001
From: Cliff Click <cliffc@acm.org>
Date: Tue, 29 Sep 2026 16:16:13 -0700
Subject: Bring forward the lazy mem alias

Integrate with ch15 NewNode creating aliases
---
 .../java/com/seaofnodes/simple/Chapter04Test.java  |   5 +-
 .../java/com/seaofnodes/simple/Chapter05Test.java  |  14 +--
 .../java/com/seaofnodes/simple/Chapter06Test.java  |  12 +-
 .../java/com/seaofnodes/simple/Chapter07Test.java  |  26 ++--
 .../java/com/seaofnodes/simple/Chapter08Test.java  |  16 +--
 .../java/com/seaofnodes/simple/Chapter09Test.java  |  10 +-
 .../java/com/seaofnodes/simple/Chapter10Test.java  | 135 +++++++++++++++++++--
 .../java/com/seaofnodes/simple/Chapter10bTest.java |  64 ++++++++++
 .../java/com/seaofnodes/simple/Chapter11Test.java  |   8 +-
 .../java/com/seaofnodes/simple/Chapter12Test.java  |   2 +-
 .../com/seaofnodes/simple/evaluator/Evaluator.java |   7 +-
 .../com/seaofnodes/simple/evaluator/Scheduler.java |  11 +-
 12 files changed, 253 insertions(+), 57 deletions(-)
 create mode 100644 chapter12/src/test/java/com/seaofnodes/simple/Chapter10bTest.java

(limited to 'chapter12/src/test/java/com/seaofnodes')

diff --git a/chapter12/src/test/java/com/seaofnodes/simple/Chapter04Test.java b/chapter12/src/test/java/com/seaofnodes/simple/Chapter04Test.java
index a3109ff7..14d31245 100644
--- a/chapter12/src/test/java/com/seaofnodes/simple/Chapter04Test.java
+++ b/chapter12/src/test/java/com/seaofnodes/simple/Chapter04Test.java
@@ -84,7 +84,10 @@ public class Chapter04Test {
         StopNode stop = parser.parse();
         ReturnNode ret = stop.ret();
         assertTrue(ret.in(0) instanceof CProjNode);
-        assertTrue(ret.in(1) instanceof  ProjNode);
+        assertTrue(ret.in(1) instanceof ProjNode);
+        assertEquals(1, ((ProjNode)ret.in(1))._idx);
+        assertTrue(ret.in(2) instanceof ProjNode);
+        assertEquals(2, ((ProjNode)ret.in(2))._idx);
     }
 
     @Test
diff --git a/chapter12/src/test/java/com/seaofnodes/simple/Chapter05Test.java b/chapter12/src/test/java/com/seaofnodes/simple/Chapter05Test.java
index 8d15493f..91efc3d6 100644
--- a/chapter12/src/test/java/com/seaofnodes/simple/Chapter05Test.java
+++ b/chapter12/src/test/java/com/seaofnodes/simple/Chapter05Test.java
@@ -22,7 +22,7 @@ else {
 
 return a;""");
         StopNode ret = parser.parse().iterate();
-        assertEquals("return Phi(Region20,(arg+2),(arg-3));", ret.toString());
+        assertEquals("return Phi(Region21,(arg+2),(arg-3));", ret.toString());
     }
 
     @Test
@@ -37,7 +37,7 @@ if (arg == 1) {
 }
 return c;""", TypeInteger.BOT);
         StopNode ret = parser.parse().iterate();
-        assertEquals("return Phi(Region18,4,3);", ret.toString());
+        assertEquals("return Phi(Region19,4,3);", ret.toString());
     }
 
     @Test
@@ -65,7 +65,7 @@ else
     b=a+1;
 return a+b;""");
         StopNode ret = parser.parse().iterate();
-        assertEquals("return ((arg*2)+Phi(Region23,2,3));", ret.toString());
+        assertEquals("return ((arg*2)+Phi(Region24,2,3));", ret.toString());
     }
 
     @Test
@@ -80,7 +80,7 @@ else
     a=b+1;
 return a+b;""");
         StopNode ret = parser.parse().iterate();
-        assertEquals("return ((Phi(Region34,(arg*2),arg)+arg)+Phi(Region,4,5));", ret.toString());
+        assertEquals("return ((Phi(Region35,(arg*2),arg)+arg)+Phi(Region,4,5));", ret.toString());
     }
 
     @Test
@@ -100,7 +100,7 @@ else
 return a;
 """, TypeInteger.BOT);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region38,Phi(Region24,2,3),Phi(Region36,4,5));", stop.toString());
+        assertEquals("return Phi(Region39,Phi(Region25,2,3),Phi(Region37,4,5));", stop.toString());
     }
 
     @Test
@@ -116,7 +116,7 @@ if( arg==0 )
 return arg+a+b;
 """, TypeInteger.BOT);
         StopNode stop = parser.parse();
-        assertEquals("return ((arg+Phi(Region15,1,0))+Phi(Region30,2,0));", stop.toString());
+        assertEquals("return ((arg+Phi(Region16,1,0))+Phi(Region31,2,0));", stop.toString());
     }
 
     @Test
@@ -130,7 +130,7 @@ if( arg==1 )
 }
 return a;""");
         StopNode ret = parser.parse().iterate();
-        assertEquals("return (arg==Phi(Region18,3,2));", ret.toString());
+        assertEquals("return (arg==Phi(Region19,3,2));", ret.toString());
     }
 
     @Test
diff --git a/chapter12/src/test/java/com/seaofnodes/simple/Chapter06Test.java b/chapter12/src/test/java/com/seaofnodes/simple/Chapter06Test.java
index 7b11bc35..df0f2848 100644
--- a/chapter12/src/test/java/com/seaofnodes/simple/Chapter06Test.java
+++ b/chapter12/src/test/java/com/seaofnodes/simple/Chapter06Test.java
@@ -30,7 +30,7 @@ if (arg)
 return (arg < a) < 3;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return ((arg<Phi(Region14,2,1))<3);", stop.toString());
+        assertEquals("return ((arg<Phi(Region15,2,1))<3);", stop.toString());
     }
 
     @Test
@@ -65,7 +65,7 @@ else
     b=5;
 return b;""", TypeInteger.BOT);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region39,42,5);", stop.toString());
+        assertEquals("return Phi(Region40,42,5);", stop.toString());
     }
 
     @Test
@@ -84,7 +84,7 @@ else
     b=5;
 return b;""", TypeInteger.BOT);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region32,2,5);", stop.toString());
+        assertEquals("return Phi(Region33,2,5);", stop.toString());
     }
 
     @Test
@@ -144,7 +144,7 @@ else
 return a;
 """, TypeInteger.BOT);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region43,3,Phi(Region41,4,5));", stop.toString());
+        assertEquals("return Phi(Region44,3,Phi(Region42,4,5));", stop.toString());
     }
 
     @Test
@@ -200,7 +200,7 @@ if( arg ) {
 return a+b;
 """);
         StopNode ret = parser.parse().iterate();
-        assertEquals("return Phi(Region26,4,1);", ret.toString());
+        assertEquals("return Phi(Region27,4,1);", ret.toString());
     }
 
 
@@ -251,7 +251,7 @@ if( arg ) {
 return a+b+c;
 """);
         StopNode ret = parser.parse().iterate();
-        assertEquals("return (Phi(Region38,Phi(Region25,2,3),0)+Phi(Region,3,1));", ret.toString());
+        assertEquals("return (Phi(Region39,Phi(Region26,2,3),0)+Phi(Region,3,1));", ret.toString());
     }
 
 
diff --git a/chapter12/src/test/java/com/seaofnodes/simple/Chapter07Test.java b/chapter12/src/test/java/com/seaofnodes/simple/Chapter07Test.java
index 177b54d1..222982e7 100644
--- a/chapter12/src/test/java/com/seaofnodes/simple/Chapter07Test.java
+++ b/chapter12/src/test/java/com/seaofnodes/simple/Chapter07Test.java
@@ -18,7 +18,7 @@ public class Chapter07Test {
                 return arg;
                 """);
         StopNode stop = parser.parse();
-        assertEquals("return Phi(Loop8,arg,(Phi_arg+1));", stop.toString());
+        assertEquals("return Phi(Loop9,arg,(Phi_arg+1));", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
@@ -35,7 +35,7 @@ if(arg){}else{
 return a;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region26,1,Phi(Loop15,1,(Phi_a+1)));", stop.toString());
+        assertEquals("return Phi(Region27,1,Phi(Loop16,1,(Phi_a+1)));", stop.toString());
     }
 
     @Test
@@ -55,7 +55,7 @@ while(i < arg) {
 return sum;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop10,0,Phi(Loop22,Phi_sum,(Phi_sum+Phi(Loop,0,(Phi_j+1)))));", stop.toString());
+        assertEquals("return Phi(Loop11,0,Phi(Loop23,Phi_sum,(Phi_sum+Phi(Loop,0,(Phi_j+1)))));", stop.toString());
     }
 
     @Test
@@ -71,7 +71,7 @@ while(a < 10) {
 return b;
 """);
         StopNode stop = parser.parse();
-        assertEquals("return Phi(Loop10,2,Phi(Region29,Phi_b,4));", stop.toString());
+        assertEquals("return Phi(Loop11,2,Phi(Region30,Phi_b,4));", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
@@ -90,7 +90,7 @@ while(a < 10) {
 return b;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop10,2,(Phi(Region29,Phi_b,4)+1));", stop.toString());
+        assertEquals("return Phi(Loop11,2,(Phi(Region30,Phi_b,4)+1));", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
@@ -107,7 +107,7 @@ while(a < 10) {
 return a;
 """);
         StopNode stop = parser.parse();
-        assertEquals("return Phi(Loop9,1,(Phi_a+3));", stop.toString());
+        assertEquals("return Phi(Loop10,1,(Phi_a+3));", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
@@ -123,7 +123,7 @@ while(a < 10) {
 return a;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop9,1,(Phi_a+3));", stop.toString());
+        assertEquals("return Phi(Loop10,1,(Phi_a+3));", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
@@ -136,7 +136,7 @@ while(arg) a = 2;
 return a;
 """);
         StopNode stop = parser.parse();
-        assertEquals("return Phi(Loop9,1,2);", stop.toString());
+        assertEquals("return Phi(Loop10,1,2);", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
@@ -149,7 +149,7 @@ while(arg) a = 2;
 return a;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop9,1,2);", stop.toString());
+        assertEquals("return Phi(Loop10,1,2);", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
@@ -165,7 +165,7 @@ while(a < 10) {
 return a;
 """);
         StopNode stop = parser.parse();
-        assertEquals("return Phi(Loop9,1,(Phi_a+3));", stop.toString());
+        assertEquals("return Phi(Loop10,1,(Phi_a+3));", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
@@ -181,7 +181,7 @@ while(a < 10) {
 return a;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop9,1,(Phi_a+3));", stop.toString());
+        assertEquals("return Phi(Loop10,1,(Phi_a+3));", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
@@ -198,7 +198,7 @@ while(a < 10) {
 return a;
 """);
         StopNode stop = parser.parse();
-        assertEquals("return Phi(Loop10,1,(Phi_a+3));", stop.toString());
+        assertEquals("return Phi(Loop11,1,(Phi_a+3));", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
@@ -215,7 +215,7 @@ while(a < 10) {
 return a;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop10,1,(Phi_a+3));", stop.toString());
+        assertEquals("return Phi(Loop11,1,(Phi_a+3));", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
diff --git a/chapter12/src/test/java/com/seaofnodes/simple/Chapter08Test.java b/chapter12/src/test/java/com/seaofnodes/simple/Chapter08Test.java
index 6aa74125..8c644977 100644
--- a/chapter12/src/test/java/com/seaofnodes/simple/Chapter08Test.java
+++ b/chapter12/src/test/java/com/seaofnodes/simple/Chapter08Test.java
@@ -23,7 +23,7 @@ while(arg < 10) {
 return arg;
                 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region36,Phi(Region26,Phi(Loop8,arg,(Phi_arg+1)),Add),Add);", stop.toString());
+        assertEquals("return Phi(Region37,Phi(Region27,Phi(Loop9,arg,(Phi_arg+1)),Add),Add);", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof RegionNode);
         Assert.assertEquals(5L, Evaluator.evaluate(stop, 1));
         Assert.assertEquals(10L, Evaluator.evaluate(stop, 6));
@@ -46,7 +46,7 @@ while(arg < 10) {
 return a;
                 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop9,1,Phi(Region41,Phi_a,(Phi_a+1)));", stop.toString());
+        assertEquals("return Phi(Loop10,1,Phi(Region42,Phi_a,(Phi_a+1)));", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
@@ -65,7 +65,7 @@ while(arg < 10) {
 return arg;
                 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region34,Phi(Loop8,arg,(Phi_arg+1)),Add);", stop.toString());
+        assertEquals("return Phi(Region35,Phi(Loop9,arg,(Phi_arg+1)),Add);", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof RegionNode);
     }
 
@@ -81,7 +81,7 @@ while(arg < 10) {
 return arg;
                 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region26,Phi(Loop8,arg,(Phi_arg+1)),Add);", stop.toString());
+        assertEquals("return Phi(Region27,Phi(Loop9,arg,(Phi_arg+1)),Add);", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof RegionNode);
     }
 
@@ -100,7 +100,7 @@ while(arg < 10) {
 return arg;
                 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop8,arg,(Phi_arg+1));", stop.toString());
+        assertEquals("return Phi(Loop9,arg,(Phi_arg+1));", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
@@ -117,7 +117,7 @@ while(arg < 10) {
 return arg;
                 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop8,arg,(Phi_arg+1));", stop.toString());
+        assertEquals("return Phi(Loop9,arg,(Phi_arg+1));", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode);
     }
 
@@ -185,7 +185,7 @@ while(arg < 10) {
 return a;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region29,Phi(Loop9,1,(Phi_a+1)),Add);", stop.toString());
+        assertEquals("return Phi(Region30,Phi(Loop10,1,(Phi_a+1)),Add);", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof RegionNode);
     }
 
@@ -201,7 +201,7 @@ while(1) {
 return a;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return (Phi(Loop9,1,Add)+1);", stop.toString());
+        assertEquals("return (Phi(Loop10,1,Add)+1);", stop.toString());
         assertTrue(stop.ret().ctrl() instanceof CProjNode prj && prj._idx==1 );
     }
 
diff --git a/chapter12/src/test/java/com/seaofnodes/simple/Chapter09Test.java b/chapter12/src/test/java/com/seaofnodes/simple/Chapter09Test.java
index 64bbf245..49ee75a2 100644
--- a/chapter12/src/test/java/com/seaofnodes/simple/Chapter09Test.java
+++ b/chapter12/src/test/java/com/seaofnodes/simple/Chapter09Test.java
@@ -69,7 +69,7 @@ while (arg < 10) {
 return arg;
                 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop9,arg,(Phi_arg+2));", stop.toString());
+        assertEquals("return Phi(Loop10,arg,(Phi_arg+2));", stop.toString());
         Assert.assertEquals(11L, Evaluator.evaluate(stop, 1));
     }
 
@@ -86,7 +86,7 @@ while (arg < 10) {
 return arg;
                 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop10,arg,(Phi_arg+4));", stop.toString());
+        assertEquals("return Phi(Loop11,arg,(Phi_arg+4));", stop.toString());
         Assert.assertEquals(13L, Evaluator.evaluate(stop, 1));
     }
 
@@ -115,7 +115,7 @@ while (arg) {
 return arg;
                 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop16,arg,(Phi_arg+1));", stop.toString());
+        assertEquals("return Phi(Loop17,arg,(Phi_arg+1));", stop.toString());
     }
 
     @Test
@@ -185,7 +185,7 @@ while(arg) {
 return a;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop11,0,(-(Phi_a+3)));", stop.toString());
+        assertEquals("return Phi(Loop12,0,(-(Phi_a+3)));", stop.toString());
     }
 
     @Test
@@ -283,7 +283,7 @@ return v1+v0;
     public void testFuzz8() {
         Parser parser = new Parser("while(arg) arg = arg - 1;  return arg;");
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop8,arg,(Phi_arg-1));", stop.toString());
+        assertEquals("return Phi(Loop9,arg,(Phi_arg-1));", stop.toString());
     }
 
     @Test
diff --git a/chapter12/src/test/java/com/seaofnodes/simple/Chapter10Test.java b/chapter12/src/test/java/com/seaofnodes/simple/Chapter10Test.java
index 9ac1f1e6..38aceb84 100644
--- a/chapter12/src/test/java/com/seaofnodes/simple/Chapter10Test.java
+++ b/chapter12/src/test/java/com/seaofnodes/simple/Chapter10Test.java
@@ -3,6 +3,10 @@ package com.seaofnodes.simple;
 import com.seaofnodes.simple.node.Node;
 import com.seaofnodes.simple.node.StopNode;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.node.LoadNode;
+import com.seaofnodes.simple.node.StoreNode;
+import com.seaofnodes.simple.evaluator.Evaluator;
+import java.util.BitSet;
 import org.junit.Test;
 
 import java.util.Arrays;
@@ -165,7 +169,7 @@ while (arg) {
 return bar.a;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop11,0,(Phi_a+2));", stop.toString());
+        assertEquals("return Phi(Loop12,0,(Phi_a+2));", stop.toString());
     }
 
     @Test
@@ -217,7 +221,7 @@ if( bar ) bar.a = 1;
 return bar;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region16,null,new Bar);", stop.toString());
+        assertEquals("return Phi(Region17,null,new Bar);", stop.toString());
     }
 
     @Test
@@ -233,7 +237,7 @@ else bar.a = 1;
 return rez;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region33,4,3);", stop.toString());
+        assertEquals("return Phi(Region35,4,3);", stop.toString());
     }
 
     @Test
@@ -287,7 +291,7 @@ while( i.x < i.len ) {
 return sum;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop15,0,(Phi(Loop,0,(Phi_x+1))+Phi_sum));", stop.toString());
+        assertEquals("return Phi(Loop17,0,(Phi(Loop,0,(Phi_x+1))+Phi_sum));", stop.toString());
     }
 
 
@@ -308,7 +312,7 @@ while(arg) {
 return ret;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop11,new s0,Phi(Region31,new s0,Phi_ret));", stop.toString());
+        assertEquals("return Phi(Loop12,new s0,Phi(Region34,new s0,Phi_ret));", stop.toString());
     }
 
     @Test
@@ -325,7 +329,7 @@ while(arg) {
 return ret;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop13,new s0,Phi(Region32,new s0,Phi_ret));", stop.toString());
+        assertEquals("return Phi(Loop15,new s0,Phi(Region35,new s0,Phi_ret));", stop.toString());
     }
 
 
@@ -342,7 +346,7 @@ while(arg < 10) {
 return ret;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop11,new s0,Phi(Region30,new s0,Phi_ret));", stop.toString());
+        assertEquals("return Phi(Loop12,new s0,Phi(Region32,new s0,Phi_ret));", stop.toString());
     }
 
     @Test
@@ -460,4 +464,121 @@ return 0;
         assertEquals("return 0;", stop.toString());
     }
 
+    @Test public void testReadBeforeStores() {
+        var stop = new Parser("""
+            struct S { int x; int y; }
+            S a = new S; S b = new S;
+            a.x = 11; b.x = 22;
+            S p = a; if (arg) p = b;
+            int before = p.x;
+            a.y = 55; b.y = 66;
+            a.x = 33; b.x = 44;
+            return before*100 + p.x;
+            """).parse().iterate();
+        assertEquals(1133L, com.seaofnodes.simple.evaluator.Evaluator.evaluate(stop,0));
+        assertEquals(2244L, com.seaofnodes.simple.evaluator.Evaluator.evaluate(stop,1));
+    }
+
+    static final String NESTED_MEMORY = """
+            struct S { int x; int y; int z; }
+            S s = new S;
+            s.x = 5; s.y = 7; s.z = 11;
+            while (arg > 0) {
+                s.x = s.x + 1;
+                int j = 3;
+                while (j > 0) {
+                    j = j - 1;
+                    if (j == 1) continue;
+                    s.y = s.y + arg;
+                    if (arg == 2) break;
+                    s.z = s.z + 1;
+                }
+                arg = arg - 1;
+            }
+            return s;
+            """;
+
+    @Test public void testMemoryAcrossNestedLoops() {
+        var stop = new Parser(NESTED_MEMORY).parse().iterate();
+        for (int arg=0; arg<7; arg++) {
+            var obj = (com.seaofnodes.simple.evaluator.Evaluator.Obj)
+                com.seaofnodes.simple.evaluator.Evaluator.evaluate(stop,arg);
+            org.junit.Assert.assertArrayEquals(new Object[] {
+                5L+arg, 7L+arg*(arg+1)-(arg>=2 ? 2 : 0), 11L+2*arg-(arg>=2 ? 2 : 0)
+            }, obj.fields());
+        }
+    }
+
+    @Test public void testMemoryAtEarlyReturns() {
+        var stop = new Parser("""
+            struct S { int x; int y; int z; }
+            S s = new S;
+            s.x = 3; s.y = 5; s.z = 7;
+            if (arg) { s.x = 11; s.z = 13; return s; }
+            s.y = 17;
+            return s;
+            """).parse().iterate();
+        for (int arg=0; arg<2; arg++) {
+            var obj = (com.seaofnodes.simple.evaluator.Evaluator.Obj)
+                com.seaofnodes.simple.evaluator.Evaluator.evaluate(stop,arg);
+            org.junit.Assert.assertArrayEquals(arg==0 ? new Object[]{3L,17L,7L} : new Object[]{11L,5L,13L}, obj.fields());
+        }
+    }
+
+    @Test public void testKeepLoadsAtMerge() {
+        StopNode stop = new Parser("""
+            struct S { int x; }
+            S a = new S; S b = new S;
+            a.x = arg; b.x = arg+1;
+            S p = a; S q = b;
+            if (arg<0) { p=b; q=a; }
+            int v;
+            if (arg>1) v=p.x; else v=q.x;
+            return v;
+            """).parse().iterate();
+        // The one-step safety check stops at the memory aggregate.
+        assertEquals(2,countMemoryNodes(stop,LoadNode.class,new BitSet()));
+        assertEquals(-1L,Evaluator.evaluate(stop,-1));
+        assertEquals(1L,Evaluator.evaluate(stop,0));
+        assertEquals(3L,Evaluator.evaluate(stop,3));
+    }
+
+    @Test public void testDropStores() {
+        StopNode stop = new Parser("""
+            struct S { int x; }
+            S s = new S;
+            if (arg) s.x=arg+1; else s.x=arg+2;
+            return s;
+            """).parse().iterate();
+        // These chapters still bind struct Stores to branch control.
+        assertEquals(3,countMemoryNodes(stop,StoreNode.class,new BitSet()));
+        assertEquals(2L,((Evaluator.Obj)Evaluator.evaluate(stop,0)).fields()[0]);
+        assertEquals(4L,((Evaluator.Obj)Evaluator.evaluate(stop,3)).fields()[0]);
+    }
+
+    @Test public void testKeepReadsBeforeWrites() {
+        StopNode stop = new Parser("""
+            struct S { int x; int y; }
+            S a = new S; S b = new S;
+            a.x=arg; b.x=arg+1;
+            S p=a; S q=b;
+            if (arg<0) { p=b; q=a; }
+            int v;
+            if (arg>1) { v=p.x; p.x=41; p.y=5; }
+            else       { v=q.x; q.x=42; }
+            return v;
+            """).parse().iterate();
+        assertEquals(2,countMemoryNodes(stop,LoadNode.class,new BitSet()));
+        assertEquals(-1L,Evaluator.evaluate(stop,-1));
+        assertEquals(1L,Evaluator.evaluate(stop,0));
+        assertEquals(3L,Evaluator.evaluate(stop,3));
+    }
+
+    private static int countMemoryNodes(Node n, Class<?> kind, BitSet seen) {
+        if (n==null || seen.get(n._nid)) return 0;
+        seen.set(n._nid);
+        int cnt=kind.isInstance(n) ? 1 : 0;
+        for (Node def : n._inputs) cnt+=countMemoryNodes(def,kind,seen);
+        return cnt;
+    }
 }
diff --git a/chapter12/src/test/java/com/seaofnodes/simple/Chapter10bTest.java b/chapter12/src/test/java/com/seaofnodes/simple/Chapter10bTest.java
new file mode 100644
index 00000000..6f094cfb
--- /dev/null
+++ b/chapter12/src/test/java/com/seaofnodes/simple/Chapter10bTest.java
@@ -0,0 +1,64 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.evaluator.Evaluator;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class Chapter10bTest {
+    @Test public void testIndependentField() {
+        var stop = new Parser("""
+            struct S { int x; int y; }
+            S s = new S;
+            s.x = 42;
+            while (arg > 0) { s.y = s.y + arg; arg = arg - 1; }
+            return s.x;
+            """).parse().iterate();
+        assertEquals("return 42;",stop.toString());
+        assertEquals(42L,Evaluator.evaluate(stop,5));
+        assertNull(stop.walk(n -> n instanceof LoadNode ? n : null));
+    }
+
+    @Test public void testParallelMemoryPhis() {
+        var stop = new Parser("""
+            struct S { int x; int y; int z; }
+            S a = new S; S b = new S;
+            S p = a; if (arg) p = b;
+            while (arg > 0) {
+                a.x = p.x + arg;
+                a.y = p.y + 2;
+                a.z = p.z + 3;
+                arg = arg - 1;
+            }
+            return a;
+            """).parse().iterate();
+        int[] phis = {0};
+        stop.walk(n -> {
+            if (n instanceof MemPhiNode) phis[0]++;
+            if (n instanceof MemMergeNode m && m.in(1) instanceof BulkMemPhiNode b)
+                for(int a=b._aliases.nextSetBit(0); a>=0; a=b._aliases.nextSetBit(a+1))
+                    assertTrue(a<m.nIns() && m.in(a)!=null);
+            assertFalse(n instanceof PhiNode && n.isMem() &&
+                !(n instanceof MemPhiNode) && !(n instanceof BulkMemPhiNode));
+            return null;
+        });
+        assertTrue(phis[0]>=3);
+        assertArrayEquals(new Object[]{1L,2L,3L},((Evaluator.Obj)Evaluator.evaluate(stop,4)).fields());
+    }
+
+    @Test public void testLateSliceWorklist() throws ReflectiveOperationException {
+        // Seed 97 exposed a store selecting a bulk predecessor without queuing
+        // it. Keep both the worklist assertion and the final heap check.
+        for (int seed : new int[]{0,97,123,456}) {
+            var parser = new Parser(Chapter10Test.NESTED_MEMORY);
+            var field = IterPeeps.class.getDeclaredField("WORK");
+            field.setAccessible(true);
+            Object work = field.get(null);
+            field = work.getClass().getDeclaredField("_R");
+            field.setAccessible(true);
+            ((java.util.Random)field.get(work)).setSeed(seed);
+            var stop = parser.parse().iterate();
+            assertArrayEquals(new Object[]{9L,25L,17L},((Evaluator.Obj)Evaluator.evaluate(stop,4)).fields());
+        }
+    }
+}
diff --git a/chapter12/src/test/java/com/seaofnodes/simple/Chapter11Test.java b/chapter12/src/test/java/com/seaofnodes/simple/Chapter11Test.java
index 5a60c8b4..0e492591 100644
--- a/chapter12/src/test/java/com/seaofnodes/simple/Chapter11Test.java
+++ b/chapter12/src/test/java/com/seaofnodes/simple/Chapter11Test.java
@@ -325,7 +325,7 @@ while( prime <= arg ) {
 return primeCount;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("Stop[ return 0; return Phi(Loop19,1,Phi(Region81,Phi_primeCount,Phi(Region76,(Phi_primeCount+1),Phi_primeCount))); ]", stop.toString());
+        assertEquals("Stop[ return 0; return Phi(Loop20,1,Phi(Region82,Phi_primeCount,Phi(Region77,(Phi_primeCount+1),Phi_primeCount))); ]", stop.toString());
         assertEquals(0L, Evaluator.evaluate(stop,  1)); // No primes 1 or below
         assertEquals(1L, Evaluator.evaluate(stop,  2)); // 2
         assertEquals(2L, Evaluator.evaluate(stop,  3)); // 2, 3
@@ -367,7 +367,7 @@ if (arg) {
 return i;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region31,.f,0);", stop.toString());
+        assertEquals("return Phi(Region34,.f,0);", stop.toString());
     }
 
     @Test
@@ -473,7 +473,7 @@ while(arg) {
 return arg;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop13,arg,Phi(Region35,.f,0));", stop.toString());
+        assertEquals("return Phi(Loop15,arg,Phi(Region39,.f,0));", stop.toString());
     }
 
     @Test
@@ -524,7 +524,7 @@ else if (arg == 1) s.f = 1;
 return s.f;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Region35,1,Phi(Region33,1,0));", stop.toString());
+        assertEquals("return Phi(Region41,1,Phi(Region36,1,0));", stop.toString());
         assertEquals(1L, Evaluator.evaluate(stop,  0));
         assertEquals(1L, Evaluator.evaluate(stop,  1));
         assertEquals(0L, Evaluator.evaluate(stop,  2));
diff --git a/chapter12/src/test/java/com/seaofnodes/simple/Chapter12Test.java b/chapter12/src/test/java/com/seaofnodes/simple/Chapter12Test.java
index 9da4a4b8..e577c8c3 100644
--- a/chapter12/src/test/java/com/seaofnodes/simple/Chapter12Test.java
+++ b/chapter12/src/test/java/com/seaofnodes/simple/Chapter12Test.java
@@ -65,7 +65,7 @@ while( 1 ) {
 return guess;
 """);
         StopNode stop = parser.parse().iterate();
-        assertEquals("return Phi(Loop9,(flt)arg,(((ToFloat/Phi_guess)+Phi_guess)/2.0));", stop.toString());
+        assertEquals("return Phi(Loop10,(flt)arg,(((ToFloat/Phi_guess)+Phi_guess)/2.0));", stop.toString());
         assertEquals(3.0, Evaluator.evaluate(stop,  9));
         assertEquals(1.414213562373095, Evaluator.evaluate(stop,  2));
     }
diff --git a/chapter12/src/test/java/com/seaofnodes/simple/evaluator/Evaluator.java b/chapter12/src/test/java/com/seaofnodes/simple/evaluator/Evaluator.java
index 3512d2e9..40a2f78d 100644
--- a/chapter12/src/test/java/com/seaofnodes/simple/evaluator/Evaluator.java
+++ b/chapter12/src/test/java/com/seaofnodes/simple/evaluator/Evaluator.java
@@ -154,6 +154,7 @@ public class Evaluator {
             case ToFloatNode  cast  -> (double)vall(cast.in(1));
             case LoadNode     load  -> load(load);
             case StoreNode    store -> store(store);
+            case MemMergeNode merge -> MEMORY;
             case NewNode      alloc -> alloc(alloc);
             case CProjNode    cproj -> ((Object[])val(cproj.ctrl()))[cproj._idx];
             case ProjNode     proj  -> ((Object[])val( proj.in(0) ))[ proj._idx];
@@ -167,8 +168,8 @@ public class Evaluator {
     public Object evaluate(long parameter, int loops) {
         if (start == null) return Status.TIMEOUT;
         var s = new Object[start.compute()._types.length];
-        s[1] = parameter;
-        for(int i=2;i<s.length;i++) s[i] = MEMORY;
+        s[1] = MEMORY;
+        s[2] = parameter;
         values[start._nid] = s;
         int i=0;
         Scheduler.Block block = this.startBlock;
@@ -179,7 +180,7 @@ public class Evaluator {
                 case null:
                     return Status.FALLTHROUGH;
                 case ReturnNode ret:
-                    return val(ret.in(1));
+                    return val(ret.expr());
                 case IfNode ifn:
                     block = block.next()[isTrue(val(ifn.in(1))) ? 0 : 1];
                     if (block == null) return Status.FALLTHROUGH;
diff --git a/chapter12/src/test/java/com/seaofnodes/simple/evaluator/Scheduler.java b/chapter12/src/test/java/com/seaofnodes/simple/evaluator/Scheduler.java
index 8b86d67a..d16f4300 100644
--- a/chapter12/src/test/java/com/seaofnodes/simple/evaluator/Scheduler.java
+++ b/chapter12/src/test/java/com/seaofnodes/simple/evaluator/Scheduler.java
@@ -250,6 +250,12 @@ public class Scheduler {
                 // so do that now.
                 var mem = l.in(1);
                 for(var out : mem._outputs) {
+                    // Aggregates describe partitions; they do not overwrite
+                    // memory. Only users of this alias constrain the load.
+                    if (out instanceof MemMergeNode || out instanceof ReturnNode) continue;
+                    if (out instanceof StoreNode s && s._alias != l._alias) continue;
+                    if (out instanceof MemPhiNode p && p._alias != l._alias) continue;
+                    if (out instanceof BulkMemPhiNode p && p.isSplit(l._alias)) continue;
                     if (out instanceof PhiNode p) {
                         var r = p.in(0);
                         for (int i = 1; i < p.nIns(); i++) {
@@ -271,7 +277,7 @@ public class Scheduler {
                 // Store nodes have anti-deps to load nodes.
                 // So decrease the uses of these loads when the store is placed.
                 for (var out: s.in(1)._outputs) {
-                    if (out instanceof LoadNode) od(out).ifPresent(this::decUsers);
+                    if (out instanceof LoadNode l && l._alias==s._alias) od(out).ifPresent(this::decUsers);
                 }
             }
         }
@@ -469,7 +475,8 @@ public class Scheduler {
             var data = mem.pop();
             node = data.node;
             for(var out:node.in(1)._outputs) {
-                if (out instanceof LoadNode) od(out).ifPresent(d->d.users++);
+                if (out instanceof LoadNode l && l._alias==((StoreNode)node)._alias)
+                    od(out).ifPresent(d->d.users++);
             }
         }
     }
-- 
cgit v1.2.3